John Bertram

APOL1 Risk Alleles Are Associated With More Severe Arteriosclerosis in Renal Resistance Vessels With Aging and Hypertension

Publisher: Elsevier BV

Date: 05-2016

DOI: 10.1016/J.EKIR.2016.03.002

Influence of tissue composition on the final volume of rat liver blocks prepared for electron microscopy

Publisher: Wiley

Date: 1986

DOI: 10.1002/JEMT.1060040306

Membership

Publisher: Elsevier BV

Date: 10-2005

DOI: 10.1111/J.1523-1755.2005.90684.X

Nephron Endowment and Renal Filtration Surface Area in Young Spontaneously Hypertensive Rats

Publisher: S. Karger AG

Date: 2002

DOI: 10.1159/000049431

Abstract: i Background/Aims: /i A reduction in nephron endowment leading to reduced renal filtration surface area has been implicated in the development of hypertension. The aim of this study was to compare glomerular (and thereby nephron) number and renal filtration surface area in young Wistar-Kyoto rats (WKY) with young spontaneously hypertensive rats (SHR), prior to the development of hypertension in this model. i Methods: /i Using unbiased stereological methods the number and size of glomeruli, as well as total renal filtration surface area were determined in perfusion-fixed kidneys of 4-week-old WKY and SHR. i Results: /i At 4 weeks of age, in weight-matched animals, there was no significant difference in the number of glomeruli in the kidneys of SHR compared to WKY (28,620 ± 1,643 and 25,670 ± 1,263 glomeruli/kidney, respectively). Similarly, there was no difference in mean glomerular volume (SHR: 4.70 ± 0.31 × 10 sup –4 /sup mm sup /sup WKY: 4.28 ± 0.20 × 10 sup –4 /sup mm sup /sup ). Surprisingly, total renal filtration surface area was significantly greater in SHR than WKY (3,867 ± 116 and 3,176 ± 83 mm sup /sup , respectively). i Conclusion: /i The renal abnormality underlying the development of hypertension in the SHR is not due to inborn deficits in nephron endowment and/or filtration surface area.

Nephron endowment in glial cell line-derived neurotrophic factor (GDNF) heterozygous mice

Publisher: Elsevier BV

Date: 07-2001

DOI: 10.1046/J.1523-1755.2001.00767.X

Abstract: The exact molecular mechanisms that regulate ureteric branching morphogenesis in the developing metanephros have not been fully elucidated. However, in vivo and in vitro evidence indicates that glial cell line-derived neurotrophic factor (GDNF) is a key regulator of the initiation of ureteric branching. GDNF knockout mice show renal agenesis or severe dysgenesis and die 24 hours after birth from renal failure. Inhibition of GDNF activity in metanephric organ culture inhibits ureteric branching. Since nephron initiation only occurs at the tips of ureteric branches, the aim of the present study was to determine whether nephron number in GDNF heterozygous mice is reduced. Male GDNF heterozygous mice of hybrid 129/Sv and C57/BL genetic background were mated with C57BL/6 females. Offspring were genotyped at postnatal day 30 (PN30) by polymerase chain reaction. Left kidneys were used for estimating kidney volume and total nephron number. We also estimated absolute and relative volumes of ureteric duct epithelium. Unbiased stereological methods were used throughout (Cavalieri method, physical disector/fractionator combination). GDNF wild-type and heterozygous mice had similar body weights at PN30. However, heterozygous kidneys were 25% smaller than wild-type kidneys (wild-type, 114.75 +/- 16.46 mm3 heterozygous, 87.11 +/- 21.84 mm3, P < 0.001) and contained approximately 30% fewer nephrons (wild-type, 11886 +/- 1277 heterozygous, 8573 +/- 2240, P < 0.01). In addition, the absolute ureteric duct volume was significantly reduced in heterozygous mice (P < 0.001). : These results indicate that the loss of one GDNF allele results in reduced nephron endowment in the adult kidney, presumably as the result of reduced branching morphogenesis of the ureteric bud.

Quartz crystal microbalance‐based measurements of shear‐induced senescence in human embryonic kidney cells

Publisher: Wiley

Date: 14-10-2004

DOI: 10.1002/BIT.20253

Abstract: Fluid shear and other mechanical forces play an important role in the normal biophysical, biochemical, and gene regulatory responses of vertebrate tissue that are reflected in the expression of normal cell differentiation, growth, and function. Despite some promising work reported on the application of the quartz crystal microbalance (QCM) to both prokaryote and eukaryote cells over the last decade, QCM has yet to be successfully applied to cells in culture under conditions of flow-induced shear. In this study, high sensitivity QCM in conjunction with fluid modelling was used to monitor the onset of senescence in immortalised human embryonic kidney cells under laminar shear stresses of between 0.04 and 335 dyne/cm(2). The feasibility of this approach as a means of quantification and characterisation of cell physiological response and adhesion are explored and discussed.

Advances in renal development

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 05-2000

DOI: 10.1097/00041552-200005000-00007

Abstract: Branching morphogenesis, mesenchymal cell condensation and mesenchymal-to-epithelial conversion are key steps in kidney development and morphogenesis of several other organs. Review articles describing our current knowledge of the genetic and molecular regulation of these processes have been published. Therefore, this review focuses on the important question of cell lineage specification during kidney development. We describe how new insights are being made into the specification of kidney cells in the intermediate mesoderm, as well as specification of cells that will form the renal mesenchyme, ureteric duct, nephron tubule epithelium and renal vasculature.

Exogenous BMP-4 amplifies asymmetric ureteric branching in the developing mouse kidney in vitro

Publisher: Elsevier BV

Date: 02-2005

DOI: 10.1111/J.1523-1755.2005.67098.X

Abstract: Exogenous bone morphogenetic protein 4 (BMP-4) has been reported to inhibit ureteric branching morphogenesis and regulate the anterior-posterior axis of the developing kidney in vitro. We examined the role of BMP-4 on ureteric branching in vitro using three-dimensional image analysis software and statistical models. Additionally, in vivo ureteric branching was analyzed and the effect of reduced levels of BMP-4 in vivo on nephron number was examined. Embryonic day 12.5 (E12.5) Balb/c mouse metanephroi cultured for 48 hours with or without 260 ng/mL recombinant human BMP-4 (rhBMP-4) were immunostained to identify the ureteric epithelium which was quantified in three dimensions. In vivo ureteric branching morphogenesis in Hoxb7/GFP mice was also analyzed. The effect of reduced in vivo levels of BMP-4 on nephron number was examined in BMP-4(+/-) and wild-type mice using an unbiased stereologic method. Qualitative and quantitative studies identified a decrease in total ureteric length and branch number in wild-type mouse metanephroi cultured in the presence of BMP-4. A marked anterior-posterior asymmetry in both ureteric length and branch number was observed in BMP-4-treated metanephroi. A similar asymmetry was revealed in control metanephroi, both in vitro and in vivo. This asymmetry is the result of reduced ureteric branching morphogenesis in the posterior region of the kidney and appears to be due to slower growth rather than the adoption of an alternate branching pattern. Reduction of endogenous BMP-4 in BMP-4(+/-) mice resulted in no change in total nephron number in macroscopically normal kidneys. These results suggest that BMP-4 plays an important role in the regulation of ureteric branching morphogenesis, and that excess BMP-4 in vitro can lify the existing asymmetry of the normal mouse kidney.

In vitro differentiation of murine embryonic stem cells toward a renal lineage

Publisher: Elsevier BV

Date: 06-2007

DOI: 10.1111/J.1432-0436.2006.00149.X

Abstract: Embryonic stem (ES) cells have the capacity to differentiate into all cells of the developing embryo and may provide a renewable resource for future cell replacement therapies. The addition of bone morphogenetic protein 4 (BMP4) to serum-free ES cell culture has previously been shown to induce transcription factors, signaling molecules, and cell adhesion proteins expressed during mesoderm specification of the embryo. Here, we show the dynamics of primitive streak mesoderm differentiation in ES cells is comparable between serum and serum-free embryoid body (EB) cultures, supplemented with BMP4. Furthermore, we show a delayed wave of expression of a cohort of genes (Pax2, WT1, podocalyxin, pod-1, and nephrin), which play important roles during embryonic kidney development. The paired box transcription factor, Pax2, is one of the earliest genes expressed during kidney organogenesis and is required for normal urogenital development. ES cell lines containing either a modified Pax2 promoter-lacZ or bacterial artificial chromosome-green fluorescent protein (GFP) transgene were generated, which enabled the quantitative analysis of kidney rather than neuronal Pax2 expression within EBs. Both beta-galactosidase activity and GFP expression were detected by immunohistochemical and flow cytometric analysis following 16 days of EB culture, which correlated with an increase in Pax2 transcript levels. Together, these results suggest a spontaneous kidney gene expression program develops in mature EBs grown in both serum and serum-free conditions, when supplemented with BMP4. Further, the recombinant growth factors BMP2, BMP4, and BMP7 strongly influence gene expression within mesoderm induced EBs. BMP4 promotes ventral (blood) and intermediate (kidney) mesoderm gene expression, whereas BMP2 and BMP7 promote kidney outcomes at the expense of hematopoietic commitment. This induction assay and these unique ES cell lines will be useful for the generation of mesoderm-derived cell populations with implications for future cell therapeutic/integration assays.

Repeated ethanol exposure during late gestation decreases nephron endowment in fetal sheep

Publisher: American Physiological Society

Date: 08-2008

DOI: 10.1152/AJPREGU.90316.2008

Abstract: Maternal alcohol consumption during pregnancy can affect fetal development, but little is known about the effects on the developing kidney. Our objectives were to determine the effects of repeated ethanol exposure during the latter half of gestation on glomerular (nephron) number and expression of key genes involved in renal development or function in the ovine fetal kidney. Pregnant ewes received daily intravenous infusion of ethanol (0.75 g/kg, n = 5) or saline (control, n = 5) over 1 h from 95 to 133 days of gestational age (DGA term is ∼147 DGA). Maternal and fetal arterial blood s les were taken before and after the start of the daily ethanol infusions for determination of blood ethanol concentration (BEC). Necropsy was performed at 134 DGA, and fetal kidneys were collected for determination of total glomerular number using the physical disector/fractionator technique at this gestational age nephrogenesis is completed in sheep. Maximal maternal and fetal BECs of 0.12 ± 0.01 g/dl (mean ± SE) and 0.11 ± 0.01 g/dl, respectively, were reached 1 h after starting maternal ethanol infusions. Ethanol exposure had no effect on fetal body weight, kidney weight, or the gene expression of members of the renin-angiotensin system, insulin-like growth factors, and sodium channels. However, fetal glomerular number was lower after ethanol exposure (377,585 ± 8,325) than in controls (423,177 ± 17,178, P 0.001). The data demonstrate that our regimen of fetal ethanol exposure during the latter half of gestation results in an 11% reduction in nephron endowment without affecting the overall growth of the kidney or fetus or the expression of key genes involved in renal development or function. A reduced nephron endowment of this magnitude could have important implications for the cardiovascular health of offspring during postnatal life.

Expression of transforming growth factor‐β type II receptor mRNA in embryonic and adult rat kidney

Publisher: Wiley

Date: 10-1995

DOI: 10.1111/J.1440-1797.1995.TB00054.X

Counting cells with the new stereology

Publisher: Elsevier BV

Date: 06-1992

DOI: 10.1016/0962-8924(92)90038-O

Cardiovascular hypertrophy in one-kidney, one-clip renal hypertension is resistant to heparin

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 04-2004

DOI: 10.1097/00004872-200404000-00020

Abstract: Heparin inhibits vascular hypertrophy in angiotensin-induced hypertension, in addition to its well-known role in inhibiting injury-induced vascular smooth muscle proliferation. We tested whether hypertension and vascular hypertrophy could be reduced by heparin independently from the renin-angiotensin system. Rats were made hypertensive with a one-kidney, one-clip (1K1C) procedure and received heparin from osmotic minipumps (0.3 mg/h per kg i.v.) or saline vehicle for 2 weeks. Blood pressure was measured by the tail-cuff method and vessel cross-sectional area was measured by morphometry in the aorta and mesenteric arteries. Proliferation was assessed with bromodeoxyuridine labelling. Blood pressure elevation and cardiovascular hypertrophy were evident in 1K1C rats. The media of mesenteric arteries was increased by 25%, and the media : lumen ratio by 35%, in hypertensive rats. DNA synthesis by smooth muscle cells in the mesenteric arteries was increased sevenfold in renal hypertension. Heparin treatment did not influence either the increase in blood pressure, the cardiovascular hypertrophy response or hypertension-mediated proliferation of arterial smooth muscle cells. These data suggest that the vascular hypertrophy mechanisms operating in 1K1C renal hypertension are not inhibited by heparin and thus are different from those in angiotensin-mediated hypertension. Identifying such mechanisms in the future will be important for devising appropriate intervention strategies in angiotensin-independent forms of vascular hypertrophy.

Reactive oxygen species in puromycin aminonucleoside nephrosis: In vitro studies

Publisher: Elsevier BV

Date: 04-1994

DOI: 10.1038/KI.1994.142

Abstract: We examined the role of reactive oxygen species (ROS) in puromycin aminonucleoside (PAN)-induced changes to glomerular epithelial cells (GECs) in vitro. Levels of superoxide anion (O2.-), hydrogen peroxide (H2O2) and hydroxyl radical (HO.) were measured in rat kidney-slice cultures containing PAN with or without antioxidants (allopurinol, probucol and alpha-tocopherol/ascorbic acid). GEC morphology was assessed after three days of culture using transmission (TEM) and scanning (SEM) electron microscopy. The effects of hypoxanthine on GEC ultrastructure was also assessed. O2.-, H2O2 and HO. were generated when PAN was added to kidney-slice cultures in Medium 199. TEM morphometry revealed that incubation with PAN (100 micrograms/ml) significantly (P < 0.05 at least) retarded the loss of GEC foot processes normally seen in vitro. When the hydrophobic antioxidants probucol or alpha-tocopherol/ascorbic acid, which scavenged/inhibited generation of O2.-, H2O2 and HO., were added to cultures containing PAN, the effect of PAN on foot processes was abolished. The TEM appearance of GECs now resembled that seen in control cultures. On the other hand, SEM revealed that probucol and alpha-tocopherol/ascorbic acid provided no protection against the changes induced by PAN in GEC cell bodies or major processes. Allopurinol provided no protection against the changes induced by PAN in GEC cell bodies, major processes or foot processes. The addition of hypoxanthine to kidney-slice cultures did not result in the generation of O2.-, H2O2 or HO., or alter GEC ultrastructure. These findings indicate that ROS play a role in PAN-induced alterations to GEC foot process architecture in vitro. However, the xanthine oxidase pathway does not appear to play a major role in generating ROS from PAN in vitro.

Fast glomerular quantification of whole ex vivo mouse kidneys using Magnetic Resonance Imaging at 9.4 Tesla

Publisher: Elsevier BV

Date: 03-2016

DOI: 10.1016/J.ZEMEDI.2015.12.008

Abstract: A method to measure total glomerular number (Nglom) in whole mouse kidneys using MRI is presented. The method relies on efficient acquisition times. A 9.4 T preclinical MRI system with a surface cryogenic coil and a 3D gradient echo sequence were used to image nine whole ex vivo BALB/c mouse kidneys labelled with cationized-ferritin (CF). A novel method to segment the glomeruli was developed. The quantification of glomeruli was achieved by identifying and fitting the probability distribution of glomeruli thus reducing variations due to noise. For validation, Nglom of the same kidneys were also obtained using the gold standard: design-based stereology. Excellent agreement was found between the MRI and stereological measurements of Nglom, with values differing by less than 4%: (mean ± SD) MRI = 15 606±1 178 stereology = 16 273±1 523. Using a robust segmentation method and a reliable quantification method, it was possible to acquire Nglom with a scanning time of 33minutes and 20seconds. This was more than 8 times faster than previously presented MRI-based methods. Thus, an efficient approach to measure Nglom ex vivo in health and disease is provided.

Associations between age, body size and nephron number with individual glomerular volumes in urban West African males

Publisher: Oxford University Press (OUP)

Date: 21-11-2009

DOI: 10.1093/NDT/GFN636

Urine-concentrating defects exacerbate with age in male offspring with a low-nephron endowment

Publisher: American Physiological Society

Date: 12-2011

DOI: 10.1152/AJPRENAL.00463.2011

Abstract: Fetal uninephrectomy (uni-x) in male sheep at 100 days of gestation (term = 150 days) reduces overall nephron endowment without affecting birth weight. Offspring have a lower glomerular filtration rate (GFR) and elevated mean arterial pressure (MAP) at 6 mo of age. This study investigated whether this reduction in renal function was associated with impaired urine-concentrating ability at 6 mo of age and exacerbated with ageing (4 yr) and examined response to 1) nonpressor dose of exogenous arginine vasopressin (AVP 0.2 μg·kg −1 ·h −1 iv) and 2) 30 h of water deprivation. Basal MAP was higher in uni-x animals at both ages, and became further elevated with age compared with the sham group (elevation in MAP with age sham: ∼4 mmHg, uni-x: 9 mmHg, P group × age 0.01). GFR declined with ageing in both groups with the decrease being greater with age in the uni-x group (further 26%, P group × age 0.001). In response to AVP infusion, urine osmolality increased in both treatment groups this response was significantly lower in the uni-x animals and became further reduced with ageing. Uni-x animals had reduced renal expression of vasopressin-2 receptor and aquaporin-2 at both ages ( P 0.01). The increase in plasma AVP levels in response to dehydration was similar between the treatment groups, suggesting the urine-concentrating defect was associated with these renal gene changes rather than defects in AVP secretion. Renal insufficiency due to a low-nephron endowment increases the risk of hypertension and chronic renal disease and may incur greater vulnerability to physiological challenges such as water deprivation as observed in the uni-x animals.

Riboregulators in kidney development and function

Publisher: Elsevier BV

Date: 03-2010

DOI: 10.1016/J.BIOCHI.2009.12.008

Abstract: The discovery of microRNAs has brought in another level of intricacy in gene regulation. These microRNAs are small non-coding RNAs that have dual ability to act as repressors or inducers of gene activity. MicroRNAs have been implicated in a wide spectrum of biological processes and their expressions have been found to be dysregulated in several diseases. Recently, microRNAs have emerged as a new area of interest in renal development and pathology. MicroRNA profilings have revealed a number of microRNAs that are specific to the kidney or restricted to certain regions of the organ suggesting possible exclusive roles therein. Recently, knockout studies have shown that these riboregulators are critical for normal renal growth and functional renal system. In idual microRNAs have also been identified in renal disease models including kidney cancers, diabetic nephropathy and polycystic kidney disease. Several mechanisms of modulating microRNA activity have also been introduced in recent years. Further progress in the understanding of microRNA activity, identification of microRNA signatures in different states as well as advancement of microRNA manipulation techniques will be valuable for kidney research.

Blockade of Endothelial-Mesenchymal Transition by a Smad3 Inhibitor Delays the Early Development of Streptozotocin-Induced Diabetic Nephropathy

Publisher: American Diabetes Association

Date: 03-08-2010

DOI: 10.2337/DB09-1631

Abstract: A multicenter, controlled trial showed that early blockade of the renin-angiotensin system in patients with type 1 diabetes and normoalbuminuria did not retard the progression of nephropathy, suggesting that other mechanism(s) are involved in the pathogenesis of early diabetic nephropathy (diabetic nephropathy). We have previously demonstrated that endothelial-mesenchymal-transition (EndoMT) contributes to the early development of renal interstitial fibrosis independently of microalbuminuria in mice with streptozotocin (STZ)-induced diabetes. In the present study, we hypothesized that blocking EndoMT reduces the early development of diabetic nephropathy. EndoMT was induced in a mouse pancreatic microvascular endothelial cell line (MMEC) in the presence of advanced glycation end products (AGEs) and in the endothelial lineage–traceble mouse line Tie2-Cre Loxp-EGFP by administration of AGEs, with nonglycated mouse albumin serving as a control. Phosphorylated Smad3 was detected by immunoprecipitation/Western blotting and confocal microscopy. Blocking studies using receptor for AGE siRNA and a specific inhibitor of Smad3 (SIS3) were performed in MMECs and in STZ-induced diabetic nephropathy in Tie2-Cre Loxp-EGFP mice. Confocal microscopy and real-time PCR demonstrated that AGEs induced EndoMT in MMECs and in Tie2-Cre Loxp-EGFP mice. Immunoprecipitation/Western blotting showed that Smad3 was activated by AGEs but was inhibited by SIS3 in MMECs and in STZ-induced diabetic nephropathy. Confocal microscopy and real-time PCR further demonstrated that SIS3 abrogated EndoMT, reduced renal fibrosis, and retarded progression of nephropathy. EndoMT is a novel pathway leading to early development of diabetic nephropathy. Blockade of EndoMT by SIS3 may provide a new strategy to retard the progression of diabetic nephropathy and other diabetes complications.

Is there an association between level of adult blood pressure and nephron number or renal filtration surface area?

Publisher: Elsevier BV

Date: 02-2004

DOI: 10.1111/J.1523-1755.2004.00406.X

MRI-based glomerular morphology and pathology in whole human kidneys

Publisher: American Physiological Society

Date: 06-2014

DOI: 10.1152/AJPRENAL.00092.2014

Abstract: Nephron number ( N glom ) and size (V glom ) are correlated with risk for chronic cardiovascular and kidney disease and may be predictive of renal allograft viability. Unfortunately, there are no techniques to assess N glom and V glom in intact kidneys. This work demonstrates the use of cationized ferritin (CF) as a magnetic resonance imaging (MRI) contrast agent to measure N glom and V glom in viable human kidneys donated to science. The kidneys were obtained from patients with varying levels of cardiovascular and renal disease. CF was intravenously injected into three viable human kidneys. A fourth control kidney was perfused with saline. After fixation, immunofluorescence and electron microscopy confirmed binding of CF to the glomerulus. The intact kidneys were imaged with three-dimensional MRI and CF-labeled glomeruli appeared as punctate spots. Custom software identified, counted, and measured the apparent volumes of CF-labeled glomeruli, with an ∼6% false positive rate. These measurements were comparable to stereological estimates. The MRI-based technique yielded a novel whole kidney distribution of glomerular volumes. Histopathology demonstrated that the distribution of CF-labeled glomeruli may be predictive of glomerular and vascular disease. Variations in CF distribution were quantified using image texture analyses, which be a useful marker of glomerular sclerosis. This is the first report of direct measurement of glomerular number and volume in intact human kidneys.

The Contribution of Bone Marrow-Derived Cells to the Development of Renal Interstitial Fibrosis

Publisher: Oxford University Press (OUP)

Date: 14-12-2006

DOI: 10.1634/STEMCELLS.2006-0133

Abstract: Recent evidence suggests that bone marrow (BM)-derived cells may integrate into the kidney, giving rise to functional renal cell types, including endothelial and epithelial cells and myofibroblasts. BM-derived cells can contribute to repair of the renal peritubular capillary (PTC) network following acute ischemic injury. However, the cell fate and regulation of BM-derived cells during the progression of chronic renal disease remains unclear. Using chimeric mice transplanted with enhanced green fluorescent protein (EGFP)-expressing BM, we demonstrate that the number of BM-derived myofibroblasts coincided with the development of fibrosis in a mouse adriamycin (ADR)-induced nephrosis model of chronic, progressive renal fibrosis. Four weeks after ADR injection, increased numbers of BM-derived myofibroblasts were observed in the interstitium of ADR-injected mice. Six weeks after ADR injection, more than 30% of renal α-smooth muscle actin (+) (α-SMA+) interstitial myofibroblasts were derived from the BM. In addition, BM-derived cells were observed to express the endothelial cell marker CD31 and the myofibroblast marker α-SMA. Blockade of p38 mitogen-activated protein kinase (MAPK) and transforming growth factor (TGF)-β1/Smad2 signaling was found to protect BM-derived PTC endothelial cells and inhibit the number of BM-derived von Willebrand factor (vWF)(+)/EGFP(+)/α-SMA(+) cells, EGFP(+)/α-SMA(+) cells, and total α-SMA(+) cells in ADR-injected mice. Inhibition of the p38 MAPK and TGF-β1/Smad signaling pathways enhanced PTC repair by decreasing endothelial-myofibroblast transformation, leading to structural and functional renal recovery and the attenuation of renal interstitial fibrosis. Investigation of the signaling pathways that regulate the differentiation and survival of BM-derived cells in a progressive disease setting is vital for the successful development of cell-based therapies for renal repair.

Measuring glomerular number and size in perfused kidneys using MRI

Publisher: American Physiological Society

Date: 06-2011

DOI: 10.1152/AJPRENAL.00044.2011

Abstract: The goal of this work was to nondestructively measure glomerular (and thereby nephron) number in the whole kidney. Variations in the number and size of glomeruli have been linked to many renal and systemic diseases. Here, we develop a robust magnetic resonance imaging (MRI) technique based on injection of cationic ferritin (CF) to produce an accurate measurement of number and size of in idual glomeruli. High-field (19 Tesla) gradient-echo MR images of perfused rat kidneys after in vivo intravenous injection of CF showed specific labeling of in idual glomeruli with CF throughout the kidney. We developed a three-dimensional image-processing algorithm to count every labeled glomerulus. MRI-based counts yielded 33,786 ± 3,753 labeled glomeruli ( n = 5 kidneys). Acid maceration counting of contralateral kidneys yielded an estimate of 30,585 ± 2,053 glomeruli ( n = 6 kidneys). Disector/fractionator stereology counting yielded an estimate of 34,963 glomeruli ( n = 2). MRI-based measurement of apparent glomerular volume of labeled glomeruli was 4.89 × 10 −4 mm 3 ( n = 5) compared with the average stereological measurement of 4.99 × 10 −4 mm 3 ( n = 2). The MRI-based technique also yielded the intrarenal distribution of apparent glomerular volume, a measurement previously unobtainable in histology. This work makes it possible to nondestructively measure whole-kidney glomerular number and apparent glomerular volumes to study susceptibility to renal diseases and opens the door to similar in vivo measurements in animals and humans.

Nephron number, glomerular volume, renal disease and hypertension

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 05-2008

DOI: 10.1097/MNH.0B013E3282F9B1A5

Maternal hypoxia developmentally programs low podocyte endowment in male, but not female offspring

Publisher: Wiley

Date: 27-01-2020

DOI: 10.1002/AR.24369

Abstract: Fetal hypoxia is a common complication of pregnancy. We have previously reported that maternal hypoxia in late gestation in mice gives rise to male offspring with reduced nephron number, while females have normal nephron number. Male offspring later develop proteinuria and renal pathology, including glomerular pathology, whereas female offspring are unaffected. Given the central role of podocyte depletion in glomerular and renal pathology, we examined whether maternal hypoxia resulted in low podocyte endowment in offspring. Pregnant CD1 mice were allocated at embryonic day 14.5 to normoxic (21% oxygen) or hypoxic (12% oxygen) conditions. At postnatal day 21, kidneys from mice were immersion fixed, and one mid-hilar slice per kidney was immunostained with antibodies directed against p57 and synaptopodin for podocyte identification. Slices were cleared and imaged with a multiphoton microscope for podometric analysis. Male hypoxic offspring had significantly lower birth weight, nephron number, and podocyte endowment than normoxic male offspring (podocyte number normoxic 62.86 ± 2.26 podocytes per glomerulus, hypoxic 53.38 ± 2.25 p < .01, mean ± SEM). In contrast, hypoxic female offspring had low birth weight but their nephron and podocyte endowment was the same as normoxic female offspring (podocyte number normoxic 62.38 ± 1.86 podocytes per glomerulus, hypoxic 61.81 ± 1.80 p = .88). To the best of our knowledge, this is the first report of developmentally programmed low podocyte endowment. Given the well-known association between podocyte depletion in adulthood and glomerular pathology, we postulate that podocyte endowment may place offspring at risk of renal disease in adulthood, and explain the greater vulnerability of male offspring.

Indomethacin administered early in the postnatal period results in reduced glomerular number in the adult rat

Publisher: American Physiological Society

Date: 15-11-2014

DOI: 10.1152/AJPRENAL.00328.2014

Abstract: Indomethacin and ibuprofen are administered to close a patent ductus arteriosus (PDA) during active glomerulogenesis. Light and electron microscopic glomerular changes with no change in glomerular number were seen following indomethacin and ibuprofen treatment during glomerulogenesis at 14 days after birth in a neonatal rat model. This present study aimed to determine whether longstanding renal structural changes are present at 30 days and 6 mo (equivalent to human adulthood). Rat pups were administered indomethacin or ibuprofen antenatally on days 18–20 (0.5 mg·kg −1 ·dose −1 indomethacin 10 mg·kg −1 ·dose −1 ibuprofen) or postnatally intraperitoneally from day 1 to 3 or day 1 to 5 (0.2 mg·kg −1 ·dose −1 indomethacin 10 mg·kg −1 ·dose −1 ibuprofen). Control groups received no treatment or normal saline intraperitoneally. Pups were killed at 30 days of age and 6 mo of age. Tissue blocks from right kidneys were prepared for light and electron microscopic examination, while total glomerular number was determined in left kidneys using unbiased stereology. Eight pups were included in each group from 14 maternal rats. At 30 days and 6 mo, there were persistent electron microscopy abnormalities of the glomerular basement membrane in those receiving postnatal indomethacin and ibuprofen. There were no significant light microscopy findings at 30 days or 6 mo. At 6 mo, there were significantly fewer glomeruli in those receiving postnatal indomethacin but not ibuprofen ( P = 0.003). In conclusion, indomethacin administered during glomerulogenesis appears to reduce the number of glomeruli in adulthood. Alternative options for closing a PDA should be considered including ibuprofen as well as emerging therapies such as paracetamol.

Glomerular podocytes in cultured rat kidney slices

Publisher: Springer Science and Business Media LLC

Date: 05-1989

DOI: 10.1007/BF00218900

Abstract: Cancer cells interact with surrounding stromal fibroblasts during tumorigenesis, but the complex molecular rules that govern these interactions remain poorly understood thus hindering the development of therapeutic strategies to target cancer stroma. We have taken a mathematical approach to begin defining these rules by performing the first large-scale quantitative analysis of fibroblast effects on cancer cell proliferation across more than four hundred heterotypic cell line pairings. Systems-level modeling of this complex dataset using singular value decomposition revealed that normal tissue fibroblasts variably express at least two functionally distinct activities, one which reflects transcriptional programs associated with activated mesenchymal cells, that act either coordinately or at cross-purposes to modulate cancer cell proliferation. These findings suggest that quantitative approaches may prove useful for identifying organizational principles that govern complex heterotypic cell-cell interactions in cancer and other contexts.

Fibroblast growth factor receptors and their ligands in the adult rat kidney

Publisher: Elsevier BV

Date: 07-2001

DOI: 10.1046/J.1523-1755.2001.00781.X

Abstract: Fibroblast growth factors (FGFs) are a family of at least 21 heparin-binding proteins involved in many biological processes, both during development and in the adult, including cell proliferation, differentiation, and angiogenesis. FGFs mediate their effects through high-affinity tyrosine kinase receptors (FGFRs), which are encoded by four genes. The aims of the present study were to localize FGFR-1 through FGFR-3 in the normal adult rat kidney and to determine which functional FGFR variants and FGFs were expressed. Avidin-biotin-enhanced horseradish peroxidase immunohistochemistry was used on paraffin sections of rat kidney to localize FGFR-1 through FGFR-3, whereas reverse transcriptase-polymerase chain reaction was used to examine expression of the receptor variants and also of FGF-1 through FGF-10 in cortex, outer medulla, and inner medulla. By immunohistochemistry, each receptor was localized to distinct and overlapping nephron segments, such that one or more FGFRs were localized to all nephron and collecting duct epithelia. FGFR-1 and FGFR-3 were localized to glomeruli, FGFR-3 to proximal tubules and FGFR-1 to thin limbs. FGFR-1 through FGFR-3 were localized to distal straight tubules, with FGFR-1 and FGFR-3 localized to distal convoluted tubules. FGFR-1 and FGFR-3 were localized to medullary collecting ducts. In addition, FGFR-1 was localized to the smooth muscle of renal arteries. All seven FGFR variants were expressed in the cortex and outer medulla, with fewer FGFRs in the inner medulla. FGF-1, FGF-2, FGF-7, FGF-8, and FGF-9 were expressed in the kidney, with FGF-10 expression found only in the cortex. Mapping of these receptors is critical to the determination of the effects of FGF ligands in discrete regions of the kidney. The distributions of the FGFRs in the normal adult kidney and the restricted expression of FGF ligands suggest that specific FGFs have distinct and important roles in the maintenance of normal kidney structure and function.

Distribution of volumes of individual glomeruli in kidneys at autopsy: Association with physical and clinical characteristics and with ethnic group

Publisher: S. Karger AG

Date: 2011

DOI: 10.1159/000327044

Abstract: We have demonstrated considerable variability in the volumes of different glomeruli in given in iduals (in idual glomerular volume: IGV) in a stereologic study of kidneys at forensic autopsy performed to investigate sudden or unexpected death in people without manifest kidney disease. We review some important associations of IGV by subject characteristics and by ethnic groups. IGVs were measured by the Cavalieri method in 30 glomeruli in each of 111 adult males who belonged to 4 ethnic groups, i.e. US Whites, African-Americans, Africans from Senegal, and Australian Aborigines. Correlations of pooled IGV values with certain subject characteristics were evaluated in the US Whites. Pooled IGV data were compared in subjects across the 4 ethnic groups. In US Whites, mean IGV and its variance were greater with higher age, lower nephron number, lower birth weight, and with gross obesity, hypertension and cardiovascular death. In comparisons by ethnic group, mean IGV and IGV ranges were higher in African-Americans and Australian Aborigines than in US Whites and African Senegalese subjects. We conclude that glomerular enlargement with volume heterogeneity marks more advanced age, relative nephron deficiency, lower birth weight, obesity, hypertension, and advanced cardiovascular disease. The findings in African-Americans and Australian Aborigines suggest that larger IGVs and volume heterogeneity might mark populations with accentuated susceptibility to hypertension and kidney disease, but the data need to be further examined in the context of the determining characteristics defined in the US Whites.

The early development of the kidney and implications for future health (Review)

Publisher: Cambridge University Press (CUP)

Date: 20-05-2010

DOI: 10.1017/S204017441000022X

Morphometric and statistical analyses describing the In utero growth of human epidermis

Publisher: Wiley

Date: 10-1988

DOI: 10.1002/AR.1092220213

Abstract: Epidermal development of human embryonic and fetal skin from the lower limb was studied using morphometric and statistical methods. Epidermal growth, as defined by an increase in epidermal thickness and the number of cell layers, occurred in three distinct stages during the first and second trimesters. The first growth spurt occurred between 5 and 13 weeks estimated gestational age (EGA) and was followed by a plateau phase with little change in epidermal thickness from 14 to 21 weeks, after which the epidermis began to increase in height again. The periderm reached its maximal height by approximately 13 weeks EGA, and by 25 weeks was shed into the amniotic fluid. Thus, within a five-month period (5 to 25 weeks EGA) the epidermis changed from a single cell layer less than 10 micron thick to a 10 to 12-cell layer, keratinized epithelium greater than 60 micron thick. In contrast, epidermis from adult lower limb consisted of about 25 cell layers and was almost 75 micron in thickness. The age-related differences in epidermal thickness probably reflect changes in cell size and shape more than changes in the directional movement (apically vs. laterally) of proliferating keratinocytes, because the addition of cell layers throughout development was relatively constant. During the plateau phase, when there is a rapid increase in fetal growth rate, the suprabasal keratinocytes become more flattened, thereby allowing for the addition of new cell layers while maintaining a relatively constant epidermal thickness.(ABSTRACT TRUNCATED AT 250 WORDS)

Review: Endothelial‐myofibroblast transition, a new player in diabetic renal fibrosis

Publisher: Wiley

Date: 23-07-2010

DOI: 10.1111/J.1440-1797.2010.01319.X

Abstract: Diabetic nephropathy (DN) is the most common cause of chronic kidney failure and end-stage renal disease in the Western world. Studies from diabetic animal models and clinical trials have shown that inhibition of the renin-angiotensin system delays the progression of advanced DN. However, a recent large-scale clinical trial has revealed that inhibition of renin-angiotensin system in early phases of DN does not slow the decline of renal function or the development of morphological lesions, suggesting that different mechanism(s) may be involved in the different stages of DN. The role of epithelial-mesenchymal transition in renal fibrosis has been intensively investigated. Recently, endothelial-mesenchymal transition, or endothelial-myofibroblast transition (EndoMT) has emerged as another mechanism involved in both developmental and pathological processes. The essential role of EndoMT in cardiac development has been thoroughly studied. EndoMT also exists and contributes to the development and progression of cardiac fibrosis, lung fibrosis, liver fibrosis and corneal fibrosis. EndoMT is a specific form of epithelial-mesenchymal transition. During EndoMT, endothelial cells lose endothelial markers and obtain mesenchymal markers. Recent evidence from our laboratory and others suggests that EndoMT plays an important role in the development of renal fibrosis in several pathological settings, including experimental DN. This review considers the evidence supporting the occurrence of EndoMT in normal development and in pathology, as well as the latest findings suggesting EndoMT contributes to fibrosis in DN. Whether experimental findings of EndoMT will be reproduced in human studies remains to be determined.

RENAL MEDULLA AND BRADYKININ DURING THE DEVELOPMENT OF HYPERTENSION IN SHR

Publisher: Wiley

Date: 07-1995

DOI: 10.1111/J.1440-1681.1995.TB02045.X

Abstract: 1. The long‐term reduction in blood pressure following ACE inhibitor treatment in young spontaneously hypertensive rats (SHR) appears to depend on both the kidney and brady‐kinin. 2. The aim of this experiment was to examine the effects of ACE inhibition and bradykinin on renal morphology and blood pressure in SHR. 3. Between 6 and 10 weeks of age male SHR received one of four treatments: water ( n = 26), ramipril (1 mg/kg per day n = 24), ramipril (1 mg/kg per day) plus Hoe 140 (0.5 mg/kg per day n = 25) or Hoe 140 (0.5 mg/kg per day n = 25). 4. Renal medullary and cortical volumes were determined stereologically at 10 and 20 weeks of age. 5. After 4 weeks of treatment, ramipril reduced the size of the renal medulla while Hoe 140 increased medullary volumes compared to control. Ten weeks after treatment was stopped the renal medulla of the ramipril group had returned to normal, however, there was a persistent increase in medullary volume of both Hoe 140 treated groups. 6. Our results imply that bradykinin may influence the size of the renal medulla which may have important effects on the development of hypertension in SHR.

Glomerular number and size variability and risk for kidney disease

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 2011

DOI: 10.1097/MNH.0B013E3283410A7D

In vitro studies on the roles of transforming growth factor-β1 in rat metanephric development

Publisher: Elsevier BV

Date: 05-2001

DOI: 10.1046/J.1523-1755.2001.0590051641.X

Abstract: The development of the permanent kidney (metanephros) involves the interplay between both positive and negative regulatory molecules. Transforming growth factor-beta1 (TGF-beta 1) has previously been shown to negatively regulate ureteric duct growth. However, its potential role in nephron development and glomerulogenesis has been largely ignored. In situ hybridization and reverse transcription-polymerase chain reaction were employed to examine the temporal and spatial localization of TGF-beta 1 mRNA and a TGF-beta type I receptor (activin-like receptor kinase-5 ALK-5) mRNA in developing rat metanephroi. The addition of exogenous TGF-beta 1 to rat metanephric organ culture at different time points was used to examine the role of TGF-beta 1 in ureteric duct growth and nephron development. TGF-beta 1 mRNA did not colocalize with ALK-5 mRNA. Instead, TGF-beta1 mRNA colocalized with the TGF-beta type II receptor mRNA. The addition of recombinant human TGF-beta 1 to rat metanephric organ culture at the beginning of the culture period inhibited total metanephric growth and the growth of the ureteric tree, resulting in a decrease in nephron number. Similarly, the addition of TGF-beta 1 to metanephroi after 48 hours of culture inhibited ureteric duct growth, decreasing nephron number. The addition of TGF-beta 1 at days 0 or 2 of culture promoted hypertrophy of the renal capsule. These findings confirm that TGF-beta 1 inhibits ureteric duct growth and thereby nephron endowment in developing rat metanephroi in vitro. However, TGF-beta 1 does not appear to play a significant role in nephron development per se once the epithelial vesicle has formed.

Betaglycan is required for the establishment of nephron endowment in the mouse

Publisher: Public Library of Science (PLoS)

Date: 18-04-2011

DOI: 10.1371/JOURNAL.PONE.0018723

Endothelial-Myofibroblast Transition Contributes to the Early Development of Diabetic Renal Interstitial Fibrosis in Streptozotocin-Induced Diabetic Mice

Publisher: Elsevier BV

Date: 10-2009

DOI: 10.2353/AJPATH.2009.090096

Validation of a Three-Dimensional Method for Counting and Sizing Podocytes in Whole Glomeruli

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 14-03-2016

DOI: 10.1681/ASN.2015121340

Abstract: Podocyte depletion is sufficient for the development of numerous glomerular diseases and can be absolute (loss of podocytes) or relative (reduced number of podocytes per volume of glomerulus). Commonly used methods to quantify podocyte depletion introduce bias, whereas gold standard stereologic methodologies are time consuming and impractical. We developed a novel approach for assessing podocyte depletion in whole glomeruli that combines immunofluorescence, optical clearing, confocal microscopy, and three-dimensional analysis. We validated this method in a transgenic mouse model of selective podocyte depletion, in which we determined dose-dependent alterations in several quantitative indices of podocyte depletion. This new approach provides a quantitative tool for the comprehensive and time-efficient analysis of podocyte depletion in whole glomeruli.

Moderate prenatal ethanol exposure in the rat promotes kidney cell apoptosis, nephron deficits, and sex‐specific kidney dysfunction in adult offspring

Publisher: Wiley

Date: 27-01-2020

DOI: 10.1002/AR.24370

Abstract: Alcohol during pregnancy can impair fetal development and result in offspring with neurodevelopmental deficits. Less is known about how low to moderate alcohol exposure can affect other organs, such as the kidney. Here, the effects of moderate ethanol exposure throughout pregnancy on kidney development were examined using a rat model. Rats were fed a liquid diet containing 6% ethanol (vol/vol) or control (0% ethanol) throughout pregnancy. Kidneys were collected at embryonic day (E) 20 or postnatal day (PN) 30 and total glomerular (nephron) number determined using unbiased stereology. Kidney function was examined in offspring at 8 and 19 months. At E20, fetuses exposed to ethanol had fewer nephrons with increased apoptosis. Alcohol exposure caused kidney dysregulation of pro- (Bax) and anti- (Bcl-2) apoptotic factors, and reduced expression of the cell proliferation marker, Ki67. Prenatal alcohol decreased expression of Gdnf and Tgfb1, important regulators of branching morphogenesis, in male fetuses. At PN30, kidney volume and nephron number were lower in offspring exposed to prenatal alcohol. Urine flow and osmolality were normal in offspring exposed to alcohol however sodium excretion tended to be lower in females prenatally exposed to alcohol. Findings suggest exposure to moderate levels of alcohol during pregnancy results in impaired kidney development and leads to a permanent nephron deficit. Although the impact on adult kidney function was relatively minor, these data highlight that even at moderate levels, alcohol consumption during pregnancy can have deleterious long-term outcomes and should be avoided.

Corrigendum to A high-resolution anatomical ontology of the developing murine genitourinary tract [Gene Expression Patterns 7 (2007) 680-699] (DOI:10.1016/j.modgep.2007.03.002)

Publisher: Elsevier BV

Date: 12-2007

DOI: 10.1016/J.MODGEP.2007.07.003

Barker and Brenner: A Basis for Hypertension?

Publisher: Bentham Science Publishers Ltd.

Date: 08-2006

DOI: 10.2174/157340206778132581

Estimating individual glomerular volume in the human kidney: clinical perspectives

Publisher: Oxford University Press (OUP)

Date: 09-10-2012

DOI: 10.1093/NDT/GFR539

Regulation of Kidney Development by Shp2: An Unbiased Stereological Analysis

Publisher: Wiley

Date: 23-08-2010

DOI: 10.1002/AR.21236

Kidney Development: Core Curriculum 2011

Publisher: Elsevier BV

Date: 06-2011

DOI: 10.1053/J.AJKD.2011.03.009

Fetal uninephrectomy in male sheep alters the systemic and renal responses to angiotensin II infusion and AT1R blockade

Publisher: American Physiological Society

Date: 08-2011

DOI: 10.1152/AJPRENAL.00139.2011

Abstract: Fetal uninephrectomy (uni-x) at 100 days of gestation results in compensatory nephrogenesis in the remaining kidney, resulting in a 30% reduction in total nephron number in male sheep. Recently, we showed that uni-x males at 6 mo of age have elevated arterial pressure, reduced renal blood flow (RBF), glomerular filtration rate (GFR), and low plasma renin levels (Singh R, Denton K, Bertram J, Jefferies A, Head G, Lombardo P, Schneider-Kolsky M, Moritz K. J Hypertens 27: 386–396, 2009 Singh R, Denton K, Jefferies A, Bertram J, Moritz K. Clin Sci (Lond) 118: 669–680, 2010). We hypothesized this was due to upregulation of the intrarenal renin-angiotensin system (RAS). In this study, renal responses to ANG II infusion and ANG II type 1 receptor (AT1R) blockade were examined in the same 6-mo-old male sheep. Uni-x animals had reduced levels of renal tissue and plasma renin and ANG II. Renal gene expression of renin, and gene and protein levels of AT1R and AT2R, were significantly lower in uni-x animals. In response to graded ANG II infusion, sham animals had the expected decrease in conscious RBF and GFR. Interestingly, the response was biphasic in uni-x sheep, with GFR initially decreasing, but then increasing at higher ANG II doses (34 ± 7% P group × treatment 0.001), due to a paradoxical decrease in renal vascular resistance ( P group × treatment 0.001). In response to AT1R blockade, while GFR and RBF responded similarly between groups, there was a marked increase in sodium excretion in uni-x compared with sham sheep (209 ± 35 vs. 25 ± 12% P 0.001). In conclusion, in 6-mo-old male sheep born with a single kidney, these studies demonstrate that this is a low-renin form of hypertension, in which responses to ANG II are perturbed and the intrarenal RAS is downregulated.

Nephron number and individual glomerular volumes in male Caucasian and African American subjects

Publisher: Oxford University Press (OUP)

Date: 18-03-2009

DOI: 10.1093/NDT/GFP116

Towards a definition of glomerulomegaly: Clinicalpathological and methodological considerations

Publisher: Oxford University Press (OUP)

Date: 29-11-2011

DOI: 10.1093/NDT/GFQ688

Angiotensin‐converting enzyme inhibition in adult hypertensive rats: A stereological study of renal filtration surface area

Publisher: Wiley

Date: 2003

DOI: 10.1046/J.1440-1681.2003.03793.X

Abstract: 1. Angiotensin‐converting enzyme (ACE) inhibitor treatment leads to beneficial effects on kidney function. The aim of the present study was to determine whether ACE inhibition at high or low doses affects glomerular capillary surface area and length, glomerular number or total renal filtration surface area in rats with established hypertension and, if so, to determine whether these effects are mediated through bradykinin potentiation. 2. Spontaneously hypertensive rats (SHR) were treated with the ACE inhibitor perindopril at either 3 or 0.1 mg/kg per day (high and low doses, respectively) from 16 to 24 weeks of age. Some rats were concomitantly treated with the bradykinin B 2 receptor antagonist S16118 (10 nmol/kg per day). Blood pressure was measured twice weekly during the treatment period. At 24 weeks of age, rats were perfusion fixed at 140 mmHg, the kidneys removed, embedded in resin and examined stereologically to estimate glomerular number and volume, length and surface area of glomerular capillaries and total renal filtration surface area. 3. High‐ and low‐perindopril treatment significantly reduced systolic blood pressure compared with control SHR. However, the rats treated with low‐dose perindopril were still considered hypertensive. Neither low‐dose nor high‐dose perindopril treatment had any observable effect on glomerular number (23 876 ± 1201 vs 26 240 ± 1465 glomeruli/kidney, respectively) or volume (2.25 ± 0.21 and 1.96 ± 0.06 × 10 −3 mm 3 , respectively) compared with controls (glomerular number 25 866 ± 1210 glomeruli/kidney glomerular volume 2.24 ± 0.21 × 10 −3 mm 3 ). As a result, there was no significant difference in total renal filtration surface area between any of the experimental groups (8161.6 ± 550.9, 8699.7 ± 427.6, 9081.9 ± 453.6, 8830.2 ± 521.2 and 8559.4 ± 341.4 mm 2 for SHR, SHR low‐dose perindopril, SHR low‐dose perindopril + B 2 antagonist, SHR high‐dose perindopril and SHR high‐dose perindopril + B 2 antagonist, respectively). Coadministration of the bradykinin antagonist had no observable effect on any of the parameters studied. 4. In conclusion, because neither high‐dose nor low‐dose perindopril had any effect on total renal filtration surface area, the observed beneficial effects of ACE inhibition on kidney function are not the result of enhancement in glomerular capillary surface area.

Prenatal Exposure to Alcohol Reduces Nephron Number and Raises Blood Pressure in Progeny

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 11-2010

DOI: 10.1681/ASN.2010040368

Role of microRNAs in kidney homeostasis and disease

Publisher: Elsevier BV

Date: 04-2012

DOI: 10.1038/KI.2011.448

Abstract: MicroRNAs (miRNAs) are endogenous short (20-22 nucleotides) non-coding RNA molecules that mediate gene expression. This is an important regulatory mechanism to modulate fundamental cellular processes such as differentiation, proliferation, death, metabolism, and pathophysiology of many diseases. The miRNA expression profile of the kidney differs greatly from that of other organs, as well as between the different regions in the kidney. In kidneys, miRNAs are indispensable for development and homeostasis. In this review, we explore the involvement of miRNAs in the regulation of blood pressure, hormone, water, and ion balance pertaining to kidney homeostasis. We also highlight their importance in renal pathophysiology, such as in polycystic disease, diabetic nephropathy, nephrogenic diabetes insipidus, hypertension, renal cancer, and kidney fibrosis (epithelial-mesenchymal transition). In addition, we highlight the need for further investigations on miRNA-based studies in the development of diagnostic, prognostic, and therapeutic tools for renal diseases.

Nephron deficit and low podocyte density increase risk of albuminuria and glomerulosclerosis in a model of diabetes

Publisher: Wiley

Date: 2023

DOI: 10.14814/PHY2.15579

Abstract: Podocytes are terminally differentiated epithelial cells in glomeruli. Podocyte injury and loss are features of many diseases leading to chronic kidney disease (CKD). The developmental origins of health and disease hypothesis propose an adverse intrauterine environment can lead to CKD later in life, especially when a second postnatal challenge is experienced. The aim of this study was to examine whether a suboptimal maternal environment would result in reduced podocyte endowment, increasing susceptibility to diabetes‐induced renal injury. Female C57BL/6 mice were fed a low protein diet (LPD) to induce growth restriction or a normal protein diet (NPD) from 3 weeks before mating until weaning (postnatal Day 21, P21) when nephron and podocyte endowment were assessed in one male and one female offspring per litter. Littermates were administered streptozotocin or vehicle at 6 weeks of age. Urinary albumin excretion, glomerular size, and podometrics were assessed following 18 weeks of hyperglycemia. LPD offspring were growth restricted and had lower nephron and podocyte number at P21. However, by 24 weeks the podocyte deficit was no longer evident and despite low nephron endowment neither albuminuria nor glomerulosclerosis were observed. Podocyte number was unaffected by 18 weeks of hyperglycemia in NPD and LPD offspring. Diabetes increased glomerular volume reducing podocyte density, with more pronounced effects in LPD offspring. LPD and NPD diabetic offspring developed mild albuminuria with LPD demonstrating an earlier onset. LPD offspring also developed glomerular pathology. These findings indicate that growth‐restricted LPD offspring with low nephron number and normalized podocyte endowment were more susceptible to alterations in glomerular volume and podocyte density leading to more rapid onset of albuminuria and renal injury than NPD offspring.

White adipocytes: More than just fat depots

Publisher: Elsevier BV

Date: 03-2012

DOI: 10.1016/J.BIOCEL.2011.12.011

Abstract: Globally 30% of adults are overweight or obese. The white adipocyte is a major component of adipose tissue, and as the obesity epidemic increases it is critically important to understand the factors determining adipocyte development and function. Adipogenesis has two distinct phases determination of the adipocyte from a multipotent stem cell, and terminal differentiation of a pre-adipocyte into a mature adipocyte. The environment encountered in early life can alter adipocyte number and size and potentially impact upon adipocyte endocrine function in adulthood. These alterations may contribute to the pathophysiology of chronic diseases and thus targeted therapy of the adipocyte has great potential for treating the current obesity epidemic.

Quantitative analysis of the developing rat kidney: Absolute and relative volumes and growth curves

Publisher: Wiley

Date: 02-2000

DOI: 10.1002/(SICI)1097-0185(20000201)258:2<128::AID-AR2>3.0.CO;2-P

A high-resolution anatomical ontology of the developing murine genitourinary tract

Publisher: Elsevier BV

Date: 06-2007

DOI: 10.1016/J.MODGEP.2007.03.002

Development of the Kidney

Publisher: Elsevier

Date: 2017

DOI: 10.1016/B978-0-323-35214-7.00099-8

A mouse splice-site mutant and individuals with atypical chromosome 22q11.2 deletions demonstrate the crucial role for crkl in craniofacial and pharyngeal development

Publisher: S. Karger AG

Date: 2014

DOI: 10.1159/000368865

Abstract: The 22q11.2 deletion syndrome (22q11DS) is thought to be a contiguous gene syndrome caused by haploinsufficiency for a variable number of genes with overlapping function during the development of the craniofacial, pharyngeal and cardiac structures. The complexity of genetic and developmental anomalies resulting in 22q11DS has made attributing causation to specific genes difficult. The i CRKL /i gene resides within the common 3-Mb region, most frequently affected in 22q11DS, and has been shown to play an essential role in the development of tissues affected in 22q11DS. Here, we report the characterisation of a mouse strain we named ‘snoopy', harbouring a novel i Crkl /i splice-site mutation that results in a loss of i Crkl /i expression. The snoopy strain exhibits a variable phenotype that includes micrognathia, pharyngeal occlusion, aglossia and holoprosencephaly, and altered retinoic acid and endothelin signalling. Together, these features are reminiscent of malformations occurring in auriculocondylar syndrome and agnathia-otocephaly complex, 2 conditions not previously associated with the i CRKL /i function. Comparison of the features of a cohort of patients harbouring small 22q11.2 deletions centred over the i CRKL /i gene, but sparing i TBX1 /i , highlights the role of i CRKL /i in contributing to the craniofacial features of 22q11DS. These analyses demonstrate the central role of i Crkl /i in regulating signalling events in the developing oropharyngeal complex and its potential to contribute to dysmorphology.

Glomerular endothelial cell injury and damage precedes that of podocytes in adriamycin-induced nephropathy

Publisher: Public Library of Science (PLoS)

Date: 24-01-2013

DOI: 10.1371/JOURNAL.PONE.0055027

Mechanism of alcohol‐induced impairment in renal development: Could it be reduced by retinoic acid?

Publisher: Wiley

Date: 28-08-2012

DOI: 10.1111/J.1440-1681.2011.05597.X

Abstract: 1. Prenatal alcohol exposure impairs kidney development, resulting in a reduced nephron number. However, the mechanism through which alcohol acts to disrupt renal development is largely unknown. Retinoic acid (RA) is critically involved in kidney development and it has been proposed that a diminished concentration of RA is a contributing factor to fetal alcohol syndrome. 2. In the present study we proposed that the ethanol-induced inhibition of ureteric branching morphogenesis and glomerular development in the cultured rat kidney would be ameliorated by coculture with exogenous RA and that examining the expression profile of key genes involved in the development of the kidney would provide insights into the potential molecular pathways involved. 3. Whole rat metanephroi cultured in the presence of exogenous RA (10-20 nmol/L) without ethanol appeared larger and had significantly more ureteric branch points, tips and glomeruli than metanephroi cultured in control media. Those cultured in the presence of ethanol alone (0.2%) had 20% fewer ureteric branch points, tips and glomeruli, which was ameliorated by coculture with retinoic acid. 4. Gene expression analysis identified changes in the expression of enzymes involved in the metabolism of alcohol in conjunction with changes in key regulators of kidney development, including cRET. 5. These results demonstrate that the teratogenic effects of alcohol in vitro on kidney development resulting in reduced ureteric branching morphogenesis and glomerular development can be ameliorated through coculture with RA. These results provide the foundation for future research into the mechanism through which alcohol acts to disrupt kidney development.

Alcohol exposure during late gestation: multiple developmental outcomes in sheep

Publisher: Cambridge University Press (CUP)

Date: 30-04-2012

DOI: 10.1017/S2040174412000244

Abstract: Alcohol consumption during pregnancy remains common in many countries. Exposure to even low amounts of alcohol (i.e. ethanol) in pregnancy can lead to the heterogeneous fetal alcohol spectrum disorders (FASD), while heavy alcohol consumption can result in the fetal alcohol syndrome (FAS). FAS is characterized by cerebral dysfunction, growth restriction and craniofacial malformations. However, the effects of lower doses of alcohol during pregnancy, such as those that lead to FASD, are less well understood. In this article, we discuss the findings of recent studies performed in our laboratories on the effects of fetal alcohol exposure using sheep, in which we investigated the effects of late gestational alcohol exposure on the developing brain, arteries, kidneys, heart and lungs. Our studies indicate that alcohol exposure in late gestation can (1) affect cerebral white matter development and increase the risk of hemorrhage in the fetal brain, (2) cause left ventricular hypertrophy with evidence of altered cardiomyocyte maturation, (3) lead to a decrease in nephron number in the kidney, (4) cause altered arterial wall stiffness and endothelial and smooth muscle function and (5) result in altered surfactant protein mRNA expression, surfactant phospholipid composition and pro-inflammatory cytokine mRNA expression in the lung. These findings suggest that fetal alcohol exposure in late gestation can affect multiple organs, potentially increasing the risk of disease and organ dysfunction in later life.

Prenatal glucocorticoid exposure in the sheep alters renal development in utero: implications for adult renal function and blood pressure control

Publisher: American Physiological Society

Date: 08-2011

DOI: 10.1152/AJPREGU.00818.2010

Abstract: Treatment of the pregnant ewe with glucocorticoids early in pregnancy results in offspring with hypertension. This study examined whether glucocorticoids can reduce nephron formation or alter gene expression for sodium channels in the late gestation fetus. Sodium channel expression was also examined in 2-mo-old lambs, while arterial pressure and renal function was examined in adult female offspring before and during 6 wk of increased dietary salt intake. Pregnant ewes were treated with saline (SAL), dexamethasone (DEX 0.48 mg/h) or cortisol (CORT 5 mg/h) over days 26–28 of gestation (term = 150 days). At 140 days of gestation, glomerular number in CORT and DEX animals was 40 and 25% less, respectively, compared with SAL controls. Real-time PCR showed greater gene expression for the epithelial sodium channel (α-, β-, γ-subunits) and Na + -K + -ATPase (α-, β-, γ-subunits) in both the DEX and CORT group fetal kidneys compared with the SAL group with some of these changes persisting in 2-mo-old female offspring. In adulthood, sheep treated with dexamethasone or cortisol in utero had elevated arterial pressure and an apparent increase in single nephron glomerular filtration rate, but global renal hemodynamics and excretory function were normal and arterial pressure was not salt sensitive. Our findings show that the nephron-deficit in sheep exposed to glucocorticoids in utero is acquired before birth, so it is a potential cause, rather than a consequence, of their elevated arterial pressure in adulthood. Upregulation of sodium channels in these animals could provide a mechanistic link to sustained increases in arterial pressure in cortisol- and dexamethasone-exposed sheep, since it would be expected to promote salt and water retention during the postnatal period.

Transforming growth factor‐β superfamily members: roles in branching morphogenesis in the kidney

Publisher: Wiley

Date: 12-2001

DOI: 10.1046/J.1440-1797.2001.00070.X

Three-Dimensional Imaging Reveals Ureteric and Mesenchymal Defects in Fgfr2-Mutant Kidneys

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 12-2009

DOI: 10.1681/ASN.2009050532

A design-based method for estimating glomerular number in the developing kidney

Publisher: American Physiological Society

Date: 06-2011

DOI: 10.1152/AJPRENAL.00055.2011

Abstract: Low glomerular (nephron) endowment has been associated with an increased risk of cardiovascular and renal disease in adulthood. Nephron endowment in humans is determined by 36 wk of gestation, while in rats and mice nephrogenesis ends several days after birth. Specific genes and environmental perturbations have been shown to regulate nephron endowment. Until now, design-based method for estimating nephron number in developing kidneys was unavailable. This was due in part to the difficulty associated with unambiguously identifying developing glomeruli in histological sections. Here, we describe a method that uses lectin histochemistry to identify developing glomeruli and the physical disector/fractionator principle to provide unbiased estimates of total glomerular number ( N glom ). We have characterized N glom throughout development in kidneys from 76 rats and model this development with a 5-parameter logistic equation to predict N glom from embryonic day 17.25 to adulthood ( r 2 = 0.98). This approach represents the first design-based method with which to estimate N glom in the developing kidney.

Expression and localization of fibroblast growth factors and fibroblast growth factor receptors in the developing rat kidney

Publisher: Elsevier BV

Date: 12-1999

DOI: 10.1046/J.1523-1755.1999.00781.X

Abstract: Expression and localization of fibroblast growth factors and fibroblast growth factor receptors in the developing rat kidney. The permanent kidney, or metanephros, develops through a complex series of reciprocal inductive events and involves branching morphogenesis, tubulogenesis, angiogenesis, and tissue remodeling. Fibroblast growth factors (FGFs) are a family of growth and differentiation factors that have been implicated in metanephric development. FGFs exert their actions through tyrosine kinase receptors, FGFRs, which are encoded by four FGFR genes (FGFR1 through FGFR4). Reverse transcriptase-polymerase chain reaction was used to detect the expression of FGFs and FGFRs in rat metanephroi from embryonic day (E) 14 to E21. Nonradioactive in situ hybridization was used to localize FGF1 mRNA in E20 rat metanephroi, and immunohistochemistry was used to localize FGFRs in E15 and E20 rat metanephroi. We detected the expression of mRNAs for FGF1 through FGF5, FGF7 through FGF10, and FGFR1 through FGFR4 (IIIb and IIIc splice variants) in rat metanephroi from E14 to E21. By in situ hybridization, FGF1 mRNA was detected in the nephrogenic zone, ureteric epithelium, and developing nephron elements. FGFR proteins were localized in a distinct pattern that altered with maturation. FGFR1 was widely distributed in developing metanephric epithelia and mesenchyme, but not in developing interstitium. FGFR2 was also widely distributed in nephron epithelia, particularly in proximal convoluted tubules, but was not detected in metanephric mesenchyme, mesenchymal condensates, or developing interstitium. FGFR3 was localized to mesenchymal condensates, nephron elements, and medullary interstitium but not proximal convoluted tubules. FGFR4 was localized mostly to maturing nephron structures and was not detected in nephrogenic mesenchyme, mesenchymal condensates, or developing interstitium. These results indicate that FGFs and FGFRs are expressed in the developing rat metanephros from at least E14 and that they likely play important roles in metanephric development and maturation.

Renal cilia display length alterations following tubular injury and are present early in epithelial repair

Publisher: Oxford University Press (OUP)

Date: 15-10-2007

DOI: 10.1093/NDT/GFM743

Abstract: Renal cilia are flow sensors that are required for the maintenance of normal kidney architecture. Defects in this organelle are frequently associated with polycystic kidney disease, but the role of renal cilia during acute tubular injury has not been investigated. We have analysed the presence and dimensions of renal cilia following renal ischaemia-reperfusion and ureteral obstruction injury in the mouse, and related these results to injury and repair of the renal tubule. The expression of genes encoding cilium-localized proteins was measured following ischaemia-reperfusion injury. Ischaemia-reperfusion injury was demonstrated to affect the length of cilia in the renal tubule and duct. The average length of renal cilia in the proximal tubule decreases 1 day (2.8 +/- 0.4 microm) and 2 days (3.0 +/- 0.2 microm) after injury, as compared to the control uninjured proximal tubule (4.2 +/- 0.3 microm). Later in the injury and repair process at 4 and 7 days, the average length of cilia increases in both the proximal (7 days = 6.2 +/- 0.3 microm) and distal tubule/collecting duct (4 days = 4.4 +/- 0.3 microm 7 days = 5.5 +/- 0.4 microm control 2.5 +/- 0.1 microm). The expression level of genes encoding cilium-localized products did not correlate with the increase in cilium length following ischaemia-reperfusion injury. Ureteral obstruction for 8 days also caused lengthening (8 days UUO = 5.8 +/- 0.3 microm control 2.5 +/- 0.1 microm) of renal cilia in the distal tubule/collecting duct. During the repair process that follows ischaemia-reperfusion injury, cilia were present on the dedifferentiated cells that proliferate and adopt an epithelial phenotype to facilitate the repair of the ischaemic renal tubule. We propose roles for the renal cilium in responding to changes in the renal environment caused by injury, and in the repair process that re-establishes the epithelial layer of the damaged renal tubule.

Congenital anomalies of the kidney and urinary tract genetics in mice and men

Publisher: Wiley

Date: 15-04-2015

DOI: 10.1111/NEP.12402

Abstract: The most common cause of paediatric end-stage kidney disease results from congenital anomalies of the kidney and urinary tract (CAKUT). Genetic manipulation in mice has provided insight into the developmental events that give rise to the broad spectrum of malformations associated with CAKUT. Despite the increase in the number of identified CAKUT-causing genes, the underlying genetic cause for the majority of patients with CAKUT remains unknown. In this mini-review, we provide an overview of the genetic causes of CAKUT based on current mouse mutant models, as well as next-generation sequencing approaches in humans that are helping to bridge the gaps in our understanding.

Resolvin D1 protects podocytes in adriamycin-induced nephropathy through modulation of 14-3-3beta acetylation

Publisher: Public Library of Science (PLoS)

Date: 28-06-2013

DOI: 10.1371/JOURNAL.PONE.0067471

The use of the optical disector to estimate the total number of neurons in the developing chick lateral motor column: Effects of purified growth factors

Publisher: Wiley

Date: 12-1991

DOI: 10.1002/AR.1092310404

Abstract: Competition between neurons for limited amounts of trophic factors is believed to be the basis for large-scale neuronal death during the normal development of the vertebrate nervous system. In this study, an unbiased stereological counting method, an optical disector/Cavalieri combination, was used to estimate the total number of motor neurons in the lateral motor column of the developing chick and to assess the effects of four growth factors on neuronal numbers. The total number of neurons in lateral motor columns at embryonic day 6 (E6), E8, E10 and E12 were 18,747 +/- 1,369 (mean +/- SD), 15,037 +/- 1,816, 10,245 +/- 940, and 8,802 +/- 797, respectively. Daily exposure from E6 to E9 to three of the growth factors (basic fibroblast growth factor, bFGF leukemia inhibitory factor, LIF nerve growth factor, NGF) had no effect on total neuron number at E10. However, exposure to ciliary neurotrophic factor (CNTF) from E6 to E9 significantly increased (P less than 0.05) the number of neurons in the lateral motor column (13,610 +/- 725, compared with 10,058 +/- 204 in normal saline controls). These results are in agreement with previous reports of large scale neuronal death in the developing chick lumbar lateral motor column between E6 and E12 and confirm that exposure to growth factors such as CNTF can mitigate the course of normal ontogenetic cell death. The optical disector/Cavalieri combination is an efficient method for counting neurons: on average, following sectioning and staining, less than 30 min was required to estimate the total number of motor neurons in a lateral motor column with a coefficient of error of approximately 10%.

Augmented and Accelerated Nephrogenesis in TGF-β2 Heterozygous Mutant Mice

Publisher: Springer Science and Business Media LLC

Date: 06-2008

DOI: 10.1203/PDR.0B013E31816D9130

Morphological Development of the Mammalian Kidney

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_2

Introduction

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_1

Variation in Human Nephron Number and Association with Disease

Publisher: Elsevier

Date: 2016

DOI: 10.1016/B978-0-12-800102-8.00014-X

Development of Function in the Fetus

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_6

Methodology to Examine Kidney Development

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_5

Renal pathology, glomerular number and volume in a West African urban community

Publisher: Oxford University Press (OUP)

Date: 02-04-2008

DOI: 10.1093/NDT/GFN039

A stereological study of the renal glomerular vasculature in the db/db mouse model of diabetic nephropathy

Publisher: Wiley

Date: 12-2005

DOI: 10.1111/J.1469-7580.2005.00492.X

Abnormalities of Renal Development in the Human

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_4

Genetic Regulation of Metanephric Development

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_3

Counting glomeruli and podocytes

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 04-2015

DOI: 10.1097/MNH.0000000000000121

Effect of fetal and child health on kidney development and long-term risk of hypertension and kidney disease

Publisher: Elsevier BV

Date: 07-2013

DOI: 10.1016/S0140-6736(13)60311-6

Future Directions

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_9

Developmental Programming of the Kidney

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_8

Nephron Endowment

Publisher: Springer Berlin Heidelberg

Date: 2008

DOI: 10.1007/978-3-540-77768-7_7

Angiogenesis occurs by vessel elongation in proliferative phase human endometrium

Publisher: Oxford University Press (OUP)

Date: 05-2002

DOI: 10.1093/HUMREP/17.5.1199

Abstract: Angiogenesis occurs by at least three mechanisms: sprouting, intussusception and elongation. Studies to date have failed to identify the mechanisms or timing of endometrial angiogenesis during the menstrual cycle. The aim of this study was to determine if vessel elongation plays a role in human endometrial angiogenesis. Forty-nine full thickness endometrial sections from 27 hysterectomy s les were immunostained for CD34 to identify blood vessels, and analysed using an interactive computerized stereological program. Based on counts from 9746 in idual microscope fields, blood vessel length density (L(v)), branch point density (N(v)) and mean vessel length per branch point (L(v)/N(v)) were calculated for three endometrial zones during five phases of the menstrual cycle. There was an increase in L(v)/N(v) in the mid-late proliferative compared with early proliferative, early-mid secretory and late secretory phases of the menstrual cycle in the functionalis (mean +/- SEM: 174.5 +/- 20.1 versus 76.6 +/- 8.4, 118.6 +/- 9.4 and 104.2 +/- 4.1 microm respectively, P < 0.001) and between the mid-late proliferative and the menstrual phases in the basalis (158.0 +/- 18.2 versus 95.4 +/- 10.0 microm, P = 0.025). An increase in L(v) occurred in the subepithelial capillary plexus in the mid-late proliferative and early-mid secretory phases compared with the early proliferative phase (316.7 +/- 32.4 and 338.8 +/- 45.3 versus 178.5 +/- 8.9 mm/mm(3), P = 0.027). These data are the first evidence that vessel elongation is a major angiogenic mechanism in mid-late proliferative phase human endometrium.

Cauli: a mouse strain with an Ift140 mutation that results in a skeletal ciliopathy modelling Jeune syndrome

Publisher: Public Library of Science (PLoS)

Date: 29-08-2013

DOI: 10.1371/JOURNAL.PGEN.1003746

Human podocyte depletion in association with older age and hypertension

Publisher: American Physiological Society

Date: 04-2016

DOI: 10.1152/AJPRENAL.00497.2015

Abstract: Podocyte depletion plays a major role in the development and progression of glomerulosclerosis. Many kidney diseases are more common in older age and often coexist with hypertension. We hypothesized that podocyte depletion develops in association with older age and is exacerbated by hypertension. Kidneys from 19 adult Caucasian American males without overt renal disease were collected at autopsy in Mississippi. Demographic data were obtained from medical and autopsy records. Subjects were categorized by age and hypertension as potential independent and additive contributors to podocyte depletion. Design-based stereology was used to estimate in idual glomerular volume and total podocyte number per glomerulus, which allowed the calculation of podocyte density (number per volume). Podocyte depletion was defined as a reduction in podocyte number (absolute depletion) or podocyte density (relative depletion). The cortical location of glomeruli (outer or inner cortex) and presence of parietal podocytes were also recorded. Older age was an independent contributor to both absolute and relative podocyte depletion, featuring glomerular hypertrophy, podocyte loss, and thus reduced podocyte density. Hypertension was an independent contributor to relative podocyte depletion by exacerbating glomerular hypertrophy, mostly in glomeruli from the inner cortex. However, hypertension was not associated with podocyte loss. Absolute and relative podocyte depletion were exacerbated by the combination of older age and hypertension. The proportion of glomeruli with parietal podocytes increased with age but not with hypertension alone. These findings demonstrate that older age and hypertension are independent and additive contributors to podocyte depletion in white American men without kidney disease.

Effect of angiotensin-converting enzyme inhibition on renal filtration surface area in hypertensive rats

Publisher: Elsevier BV

Date: 11-2001

DOI: 10.1046/J.1523-1755.2001.00996.X

Abstract: Angiotensin-converting enzyme (ACE) inhibitor treatment leads to protective effects on the cellular structure of the glomerulus and the kidney. The aim of this study was to determine whether ACE inhibition increases renal filtration surface area in the spontaneously hypertensive rat (SHR). SHR were treated with the ACE inhibitor perindopril at a high dose (3 mg/kg/day) or a low dose (0.1 mg/kg/day) during the period of hypertension development, from 7 to 14 weeks of age. Some animals were treated concomitantly with the bradykinin B2 receptor antagonist, S16118. Tail-cuff systolic blood pressure and body weights were measured twice weekly. At termination of treatment, glomerular number and volume, length, and surface area of glomerular capillaries and renal filtration surface area were estimated using unbiased stereological techniques. There were significant dose-related reductions in blood pressure with high- and low-dose perindopril treatment. Neither low- nor high-dose perindopril treatment had any effect on glomerular number or size or glomerular capillary length and surface area. Hence, there was no significant difference in total renal filtration surface area between any of the experimental groups (8721 +/- 610 mm2 in untreated SHR and 7879 +/- 338 mm2 and 8767 +/- 437 mm2 in the low and high dose perindopril-treated groups, respectively). Coadministration of the bradykinin antagonist did not affect any of the glomerular parameters. ACE inhibition during the period of hypertension development does not lead to an enhanced glomerular capillary growth or increases in total renal filtration surface area in this model.

Human nephron number: Implications for health and disease

Publisher: Springer Science and Business Media LLC

Date: 09-2011

DOI: 10.1007/S00467-011-1843-8

Abstract: Several studies have shown that total nephron (glomerular) number varies widely in normal human kidneys. Whereas the studies agree that average nephron number is approximately 900,000 to 1 million per kidney, numbers for in idual kidneys range from approximately 200,000 to >2.5 million. Several studies have shown loss of glomeruli due to age-related glomerulosclerosis. The rates of loss vary among in iduals depending upon blood pressure, diseases affecting the kidney, and other attributes of health, but most of the variation in nephron number is present at birth and is therefore developmentally determined. For ex le, in a relatively small study of nephron number in 15 children <3 months of age, we found that nephron number ranged from approximately 250,000 to 1.1 million. Given that no new nephrons are formed in human kidneys after approximately 36 weeks' gestation, much interest has focused on renal function and health in in iduals born with relatively low nephron endowment. Several studies have reported a direct correlation between birth weight and nephron number and an indirect association between nephron number and blood pressure. Associations between low birth weight and cardiovascular disease, including hypertension, have also been widely reported. This report provides an update on our current knowledge of human nephron number and the associations with adult health and disease.

Angiotensin II induces cardiovascular hypertrophy in perindopril-treated rats

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 06-1995

DOI: 10.1097/00004872-199506000-00016

Abstract: To investigate whether angiotensin II (Ang II) exerts a direct effect on cardiovascular hypertrophy in the spontaneously hypertensive rat or acts indirectly through elevation of blood pressure. Immature (7-week-old) and mature (14-week-old) spontaneously hypertensive rats were treated for 8 and 6 weeks, respectively, with an angiotensin converting enzyme inhibitor to block the in vivo production of Ang II and concomitantly infused with either a pressor dose of Ang II or noradrenaline. At the termination of treatment, vascular smooth muscle cell growth was assessed in the aorta and mesenteric arterioles. In the young rats systolic blood pressure was not significantly different in the Ang II- and noradrenaline-infused groups. In the mature rats blood pressure was elevated in the Ang II-infused rats above that in the untreated and noradrenaline-infused groups, in which blood pressure was not significantly different. Ang II infusion induced cardiac hypertrophy and medial hypertrophy both in the aorta and in first-order mesenteric arterioles, accompanied by induction of smooth muscle polyploidy. The growth response to Ang II differed in the large and small vessels, with a marked induction of smooth muscle hyperplasia in the mesenteric arterioles but no change in cell number in the aorta. Infusion of noradrenaline did not induce cardiac or vascular hypertrophy, levels being similar to those in the rats treated with perindopril only. These results suggest that Ang II can directly stimulate cardiac and vascular hypertrophy in the spontaneously hypertensive rat, independently of its effect on blood pressure.

Reduced nephron number and glomerulomegaly in Australian Aborigines: A group at high risk for renal disease and hypertension

Publisher: Elsevier BV

Date: 07-2006

DOI: 10.1038/SJ.KI.5000397

Abstract: Aborigines in remote areas of Australia have much higher rates of renal disease, as well as hypertension and cardiovascular disease, than non-Aboriginal Australians. We compared kidney findings in Aboriginal and non-Aboriginal people in one remote region. Glomerular number and mean glomerular volume were estimated with the disector/fractionator combination in the right kidney of 19 Aborigines and 24 non-Aboriginal people undergoing forensic autopsy for sudden or unexpected death in the Top End of the Northern Territory. Aborigines had 30% fewer glomeruli than non-Aborigines--202,000 fewer glomeruli per kidney, or an estimated 404,000 fewer per person (P=0.036). Their mean glomerular volume was 27% larger (P=0.016). Glomerular number was significantly correlated with adult height, inferring a relationship with birthweight, which, on average, is much lower in Aboriginal than non-Aboriginal people. Aboriginal people with a history of hypertension had 30% fewer glomeruli than those without--250,000 fewer per kidney (P=0.03), or 500,000 fewer per person, and their mean glomerular volume was about 25% larger. The lower nephron number in Aboriginal people is compatible with their susceptibility to renal failure. The additional nephron deficit associated with hypertension is compatible with other reports. Lower nephron numbers are probably due in part to reduced nephron endowment, which is related to a suboptimal intrauterine environment. Compensatory glomerular hypertrophy in people with fewer nephrons, while minimizing loss of total filtering surface area, might be exacerbating nephron loss. Optimization of fetal growth should ultimately reduce the florid epidemic of renal disease, hypertension, and cardiovascular disease.

In vitro effects of puromycin aminonucleoside on the ultrastructure of rat glomerular podocytes

Publisher: Springer Science and Business Media LLC

Date: 1990

DOI: 10.1007/BF00297236

Maternal fat feeding augments offspring Nephron endowment in mice

Publisher: Public Library of Science (PLoS)

Date: 22-08-2016

DOI: 10.1371/JOURNAL.PONE.0161578

Retinal Neovascularization Is Prevented by Blockade of the Renin-Angiotensin System

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 12-2000

DOI: 10.1161/01.HYP.36.6.1099

Abstract: Both angiotensin II and vascular endothelial growth factor are angiogenic agents that have recently been implicated in the pathogenesis of proliferative diabetic retinopathy. In this study, retinal neovascularization was examined in a model of retinopathy of prematurity with the use of neonatal transgenic (mRen-2)27 rats, which overexpress renin in tissues, and Sprague-Dawley rats. Blockers of the renin-angiotensin system were administered during the neovascularization period. The ACE inhibitor lisinopril and the angiotensin type 1 receptor antagonist losartan both increased retinal renin levels and prevented inner retinal blood vessel growth. Quantitative in situ hybridization revealed that the expression of vascular endothelial growth factor and its type 2 receptor in the inner retina and proliferating blood vessels were increased in rats with retinopathy of prematurity. Lisinopril reduced both retinal vascular endothelial growth factor and its type 2 receptor mRNA in retinopathy of prematurity rats, whereas losartan had no effect. It is predicted that agents that interrupt the renin-angiotensin system may play an important role as retinoprotective agents in various forms of proliferative retinopathy.

Renal vascular resistance properties and glomerular protection in early established SHR hypertension

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 08-2001

DOI: 10.1097/00004872-200108000-00020

Abstract: To characterize the in vivo vascular properties of the spontaneously hypertensive rat (SHR) renal vascular bed by examining vascular conductance/resistance responsiveness to vasoactive agents in vivo and determining whether the filtration surface area of glomerular capillaries is reduced. in vivo renal blood flow responses to intrarenally administered angiotensin II, phenylephrine and acetylcholine were compared in 10-week-old SHR and Wistar-Kyoto (WKY) rats using a wide range of doses from near threshold to near maximal effect. Unbiased stereological techniques and high-resolution light microscopy were used to estimate the surface area and length of glomerular capillaries, and evidence of capillary damage. The SHR renal bed demonstrated significantly enhanced dose-vascular resistance responses to vasoconstrictors. For vascular conductance and calculated radius of resistance vessels, the SHR curves were significantly lower across the full dilator-constrictor range examined, but the dose-related changes were similar to those of WKY rats. There were only modest enhancements of the renal blood flow responses in the SHR, evident only when renal blood flow was reduced by more than 50% SHR and WKY rats did not differ in mean glomerular capillary surface area (0.13+/-0.02 mm2 and 0.14+/-0.02 mm2, respectively) or length (5.76+/-0.85 mm and 5.48+/-0.90 mm, respectively) nor was there evidence of glomerular capillary damage in either strain. The renal vascular bed of the SHR in vivo exhibits reduced vascular conductance across a wide vasomotor range, compatible with findings in other vascular beds. We have further shown no evidence of reduced glomerular capillary surface area or damage. These findings are compatible with the hypothesis that the reduced conductance of the SHR pre-glomerular vasculature increases the aorta-capillary pressure gradient thus protecting the glomerular capillaries from systemic hypertension at this age.

The emerging role of MRI in quantitative renal glomerular morphology

Publisher: American Physiological Society

Date: 15-05-2013

DOI: 10.1152/AJPRENAL.00714.2012

Abstract: Techniques to measure morphological parameters, such as glomerular (and thereby nephron) number, glomerular size, and kidney volume, have been vital to understanding factors contributing to chronic kidney disease (CKD). These techniques have also been important to understanding the associations between CKD and other systemic and cardiovascular diseases and have led to the identification of developmental risk factors for these pathologies. However, existing techniques in quantitative kidney morphology are resource- and time-consuming and are destructive to the organ. This review discusses the emerging generation of techniques to study kidney morphology quantitatively using magnetic resonance imaging (MRI) using the intravenous injection of the superparamagnetic nanoparticle cationic ferritin, which binds to the glomerular basement membrane. A primary advantage of MRI over previously established techniques is the ability to quantify morphology in the intact organ with minimal s le preparation. We highlight areas of research where MRI-based morphological measurements will be helpful in animal models and possibly diagnostic clinical nephrology, discuss technical challenges in light of the progress in MRI techniques to date, and identify novel measurements that may be possible using MRI, both ex vivo and in vivo.

Glomerular surface area is normalized in mice born with a nephron deficit: no role for AT₁receptors

Publisher: American Physiological Society

Date: 03-2009

DOI: 10.1152/AJPRENAL.90359.2008

Abstract: We examined whether deficits in glomerular capillary surface area associated with a congenital nephron deficit could be corrected by glomerular hypertrophy. Using unbiased stereological techniques, we examined the time course and mode of glomerular hypertrophy in mice lacking one allele for glial cell line-derived neurotrophic factor (GDNF). These GDNF heterozygous (Het) mice are born with ∼30% less nephrons than wild-type (WT) littermates. An additional group of GDNF Het mice received the angiotensin type 1 (AT 1 )-receptor antagonist candesartan (Cand 10 mg·kg −1 ·day −1 ) from 5 wk of age to determine the role of AT 1 receptors in the compensatory hypertrophy. At 10 wk of age, the total volume of renal corpuscles, glomerular capillary surface area, and length of glomerular capillaries in the kidneys of GDNF Het mice were all markedly (∼45%) less than that of WT mice ( P 0.001). However, by 30 wk, and persisting at 60 wk of age, GDNF Het and WT mice did not significantly differ in any of these parameters. Furthermore, conscious 24-h mean arterial pressure (MAP) did not differ between GDNF Het and WT mice at any time point. MAP of GDNF Het-Cand mice was 20–30 mmHg less than that of GDNF Het-vehicle mice at all three ages, but Cand treatment did not significantly alter glomerular capillary dimensions. In conclusion, we have demonstrated that the deficit in glomerular capillary surface area associated with a congenital nephron deficit can be corrected for in adulthood by an increase in the total length of glomerular capillaries. This process does not require AT 1 receptor activation.

Ureteric branching morphogenesis in BMP4 heterozygous mutant mice

Publisher: Wiley

Date: 02-11-2006

DOI: 10.1111/J.1469-7580.2006.00655.X

Nephron endowment and blood pressure: What do we really know?

Publisher: Springer Science and Business Media LLC

Date: 04-2004

DOI: 10.1007/S11906-004-0089-2

Abstract: It has been hypothesized that a reduced number of nephrons at birth contributes to the development of essential hypertension. Nephron number in normal human kidneys has been shown to vary up to eightfold. Therefore, a significant proportion of the population appears to be at risk for developing hypertension. Furthermore, nephron deficits might explain why some racial groups have a higher incidence of hypertension and end-stage renal disease than others. Animal studies have demonstrated that maternal limitations in nutrient supply, both gross and nutrient-specific exposure to elevated levels of hormones or toxins and genetic factors can lead to permanent deficits in nephron number and, when examined, elevated blood pressure. In this review, maternal and genetic factors influencing nephron endowment and the implications of nephron deficit for hypertension and renal disease in humans are discussed.

Estimating glomerular number: Why we do it and how

Publisher: Wiley

Date: 27-10-2013

DOI: 10.1111/1440-1681.12133

Abstract: There is currently much interest in determining the number of glomeruli, and thereby nephrons, in the kidney. Researchers have been trying to count glomeruli since the 19th century and currently four general approaches are available: (i) acid maceration (ii) counting glomerular profiles in histological sections (iii) model-based stereology and (iv) design-based stereology. Although design-based stereological methods are generally considered the gold-standard method, all current methods have limitations. A new approach using magnetic resonance imaging has recently been described and may ultimately enable glomerular imaging and quantification in vivo. This report considers the advantages and disadvantages of current methods for counting glomeruli and describes the new magnetic resonance approach. In addition, a method for counting glomeruli in developing kidneys is described.

Hypertension, glomerular hypertrophy and nephrosclerosis: the effect of race

Publisher: Oxford University Press (OUP)

Date: 09-12-2013

DOI: 10.1093/NDT/GFT480

Why and how we determine nephron number

Publisher: Springer Science and Business Media LLC

Date: 11-09-2013

DOI: 10.1007/S00467-013-2600-Y

Abstract: The total number of glomeruli (nephrons) in a kidney is an important microanatomical parameter for at least three reasons: it provides an index of the success/extent of nephrogenesis and can thereby provide insights into the roles of specific genes and feto-maternal environmental factors in nephrogenesis low nephron number has been linked to an increased risk of cardiovascular and renal disease in adulthood and knowledge of quantitative kidney microanatomy can illuminate our understanding of physiological mechanisms in health and disease. A range of methods has been used to count glomeruli in kidneys over the past 100 years, with design-based stereology (the physical disector/fractionator combination) considered the gold standard. However, this approach is labor-intensive and expensive, and therefore is not utilized by most laboratories. A new method for counting and sizing every glomerulus in the kidney has recently been described. This method involves in vivo labeling of glomeruli with cationic ferritin, and then magnetic resonance imaging (MRI) of the ex vivo kidney. Values are obtained in one sixth of the time of disector-based approaches. This new MRI method holds great promise for studies of glomerular number and size ex vivo and in vivo.

A rodent model of low- to moderate-dose ethanol consumption during pregnancy: patterns of ethanol consumption and effects on fetal and offspring growth

Publisher: CSIRO Publishing

Date: 2012

DOI: 10.1071/RD11200

Abstract: It is unknown whether low to moderate maternal alcohol consumption adversely affects postnatal health. The aim of the present study was to develop a rodent model of low–moderate-dose prenatal ethanol (EtOH) exposure. Sprague-Dawley rats were fed a liquid diet with or without 6% v/v EtOH throughout gestation and the pattern of dietary consumption determined. Fetal bodyweights and hepatic alcohol-metabolising gene expression were measured on embryonic Day (E) 20 and offspring growth studied until 1 year. At E8 the plasma EtOH concentration was 0.03%. There was little difference in dietary consumption between the two treatment groups. At E20, EtOH-exposed fetuses were significantly lighter than controls and had significantly decreased ADH4 and increased CYP2E1 gene expression. Offspring killed on postnatal Day (PN) 30 did not exhibit any growth deficits. Longitudinal repeated measures of offspring growth demonstrated slower growth in males from EtOH-fed dams between 7 and 12 months of age a cohort of male pups killed at 8 months of age had a reduced crown–rump length and kidney weight. In conclusion, a liquid diet of 6% v/v EtOH fed to pregnant dams throughout gestation caused a 3–8% reduction in fetal growth and brain sparing, with growth differences observed in male offspring later in life. This model will be useful for future studies on the effects of low–moderate EtOH on the developmental origins of health and disease.

Spatial gene expression in the T-stage mouse metanephros

Publisher: Elsevier BV

Date: 10-2006

DOI: 10.1016/J.MODGEP.2006.02.001

Abstract: The E11.5 mouse metanephros is comprised of a T-stage ureteric epithelial tubule sub- ided into tip and trunk cells surrounded by metanephric mesenchyme (MM). Tip cells are induced to undergo branching morphogenesis by the MM. In contrast, signals within the mesenchyme surrounding the trunk prevent ectopic branching of this region. In order to identify novel genes involved in the molecular regulation of branching morphogenesis we compared the gene expression profiles of isolated tip, trunk and MM cells using Compugen mouse long oligo microarrays. We identified genes enriched in the tip epithelium, sim-1, Arg2, Tacstd1, Crlf-1 and BMP7 genes enriched in the trunk epithelium, Innp1, Itm2b, Mkrn1, SPARC, Emu2 and Gsta3 and genes spatially restricted to the mesenchyme surrounding the trunk, CSPG2 and CV-2, with overlapping and complimentary expression to BMP4, respectively. This study has identified genes spatially expressed in regions of the developing kidney involved in branching morphogenesis, nephrogenesis and the development of the collecting duct system, calyces, renal pelvis and ureter.

Hypertension, glomerular number, and birth weight in African Americans and white subjects in the southeastern United States

Publisher: Elsevier BV

Date: 02-2006

DOI: 10.1038/SJ.KI.5000041

Abstract: Low nephron number has been related to low birth weight and hypertension. In the southeastern United States, the estimated prevalence of chronic kidney disease due to hypertension is five times greater for African Americans than white subjects. This study investigates the relationships between total glomerular number (Nglom), blood pressure, and birth weight in southeastern African Americans and white subjects. Stereological estimates of Nglom were obtained using the physical disector/fractionator technique on autopsy kidneys from 62 African American and 60 white subjects 30-65 years of age. By medical history and recorded blood pressures, 41 African Americans, and 24 white subjects were identified as hypertensive and 21 African Americans and 36 white subjects as normotensive. Mean arterial blood pressure (MAP) was obtained on 81 and birth weights on 63 subjects. For African Americans, relationships between MAP, Nglom, and birth weight were not significant. For white subjects, they were as follows: MAP and Nglom (r=-0.4551, P=0.0047) Nglom and birth weight (r=0.5730, P=0.0022) MAP and birth weight (r=-0.4228, P=0.0377). For African Americans, average Nglom of 961 840+/-292 750 for normotensive and 867 358+/-341 958 for hypertensive patients were not significantly different (P=0.285). For white subjects, average Nglom of 923 377+/-256 391 for normotensive and 754 319+/-329 506 for hypertensive patients were significantly different (P=0.03). The data indicate that low nephron number and possibly low birth weight may play a role in the development of hypertension in white subjects but not African Americans.

Inhibition of p38 Mitogen-Activated Protein Kinase and Transforming Growth Factor-β1/Smad Signaling Pathways Modulates the Development of Fibrosis in Adriamycin-Induced Nephropathy

Publisher: Elsevier BV

Date: 11-2006

DOI: 10.2353/AJPATH.2006.060169

Abstract: Inflammation and fibrogenesis are the two determinants of the progression of renal fibrosis, the common pathway leading to end-stage renal disease. The p38 mitogen-activated protein kinase (MAPK) and transforming growth factor (TGF)-beta1/Smad signaling pathways play critical roles in inflammation and fibrogenesis, respectively. The present study examined the beneficial renoprotective effect of combination therapy using the p38 MAPK pathway inhibitor (SB203580) and a TGF-beta receptor I (ALK5) inhibitor (ALK5I) in a mouse model of adriamycin (ADR) nephrosis. The p38 MAPK and TGF-beta1/Smad2 signaling pathways were activated in ADR-induced nephropathy in a sequential time course manner. Two weeks after ADR injection, the combined administration of SB203580 (1 mg/kg/24 hours) and ALK5I (1 mg/kg/24 hours) markedly reduced p38 MAPK and Smad2 activities. Moreover, the co-administration of SB203580 and ALK5I to ADR-injected mice resulted in a down-regulation of total and active TGF-beta1 production, reduced myofibroblast accumulation, and decreased expression of collagen type IV and fibronectin. In these mice, retardation in the development of glomerulosclerosis and interstitial fibrosis was observed. In conclusion, although p38 MAPK and TGF-beta1/Smad signaling pathways are distinct they coordinate the progression of renal fibrosis in ADR nephrosis. The co-administration of a p38 MAPK inhibitor and an ALK5 inhibitor may have potential applications in the treatment of renal fibrosis.

Light-microscopic immunolocalization of fibroblast growth factor-1 and -2 in adult rat kidney

Publisher: Springer Science and Business Media LLC

Date: 15-07-1996

DOI: 10.1007/S004410050635

Abstract: The fibroblast growth factors (FGFs) are a family of conserved polypeptides known to regulate cell differentiation and proliferation. We have used avidin-biotin-enhanced indirect immunohistochemistry to localize FGF-1 and FGF-2 in the rat kidney. The most consistent specific immunostaining pattern is found in paraffin sections from kidneys perfusion-fixed with 4% paraformaldehyde in 0.1 M phosphate buffer. Intracellular immunoreactivity for FGF-1 and FGF-2 is co-localized in visceral (podocytes) and parietal (Bowman's capsule) glomerular epithelial cells, S3 segments of proximal tubules, distal tubules and collecting ducts in the cortex, and thick ascending limbs and collecting ducts in the medulla. Immunoreactivity is also observed within urothelium and the tunica adventitia of large blood vessels. No immunostaining is found in cortical S1 or S2 segments of proximal tubules, in frozen sections prepared from unfixed or 4% paraformaldehyde perfusion-fixed kidneys, or in paraffin sections from Bouin-fixed kidneys. Immersion fixation with 4% paraformaldehyde gives a similar staining pattern in paraffin sections to that achieved with perfusion fixation. However, in paraffin sections fixed with methyl Carnoy's fixative, immunoreactivity is primarily localized to the tunica media of blood vessels, with little tubular or glomerular immunostaining. Thus, variation in immunolocalization patterns for FGFs can be partially attributed to differences in fixative, preparative technique and antibody specificity.

Determinants of glomerular volume in different cortical zones of the human kidney

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 10-2005

DOI: 10.1681/ASN.2005010123

Is nephrogenesis affected by preterm birth? Studies in a non-human primate model

Publisher: American Physiological Society

Date: 12-2009

DOI: 10.1152/AJPRENAL.00163.2009

Abstract: Nephrogenesis occurs predominantly in late gestation at a time when preterm infants are already delivered. The aims of this study were to assess the effect of preterm birth and the effect of antenatal glucocorticoid treatment on nephrogenesis. Preterm baboons, which were delivered at 125 days gestation and ventilated for up to 21 days postnatally, were compared with gestational controls. A cohort of preterm baboons that had been exposed to antenatal glucocorticoids were compared with unexposed preterm baboons. The number of glomerular generations was estimated using a medullary ray glomerular-counting method, and glomerular number was estimated using unbiased stereology. CD31 and WT-1 localization was examined using immunohistochemistry and VEGF was localized using in situ hybridization. The number of glomerular generations was not affected by preterm birth, and total glomerular numbers were within the normal range. Kidneys were significantly enlarged in preterm baboons with a significant decrease in glomerular density (number of glomeruli per gram of kidney) in the preterm kidney compared with gestational controls. Neonates exposed to antenatal steroids had an increased kidney-to-body weight ratio and also more developed glomeruli compared with unexposed controls. Abnormal glomeruli, with a cystic Bowman's space and shrunken glomerular tuft, were often present in the superficial renal cortex of both the steroid-exposed and unexposed preterm kidneys steroid exposure had no significant effect on the proportion of abnormal glomeruli. The proportion of abnormal glomeruli in the preterm kidneys ranged from 0.2 to 18%. In conclusion, although nephrogenesis is ongoing in the extrauterine environment, our findings demonstrate that preterm birth, independent of steroid exposure, is associated with a high proportion of abnormal glomeruli in some, but not all neonatal kidneys. Whether final nephron endowment is affected in those kidneys exhibiting a high proportion of abnormal glomeruli is yet to be confirmed.

Nephron Number, Renal Function, and Arterial Pressure in Aged GDNF Heterozygous Mice

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 02-2003

DOI: 10.1161/01.HYP.0000050961.70182.56

Abstract: The loss of one allele for glial cell line–derived neurotrophic factor (GDNF) results in ≈30% fewer but normal sized glomeruli in young mice. Low nephron number, inherited or acquired, has been linked to increased risk of development of hypertension and renal failure. This study examines whether GDNF heterozygous mice, with an inherent reduction in nephron number, demonstrate a deterioration in renal structure and function and rise in arterial pressure in later life. Fourteen-month-old male GDNF heterozygous (n=7) and wild-type (n=6) mice were anesthetized and prepared for measurement of mean arterial pressure, glomerular filtration rate (GFR), and renal blood flow. After measurement of renal function, kidneys were fixed for stereological determination of total glomerular number and mean glomerular volume. Mean arterial pressure was, on average, 18 mm Hg higher in GDNF heterozygous (98±4 mm Hg) than wild-type mice (80±2 mm Hg P .01). However, GFR (0.656±0.054 versus 0.688±0.076 mL/min per g kidney wt) and renal blood flow (5.29±0.42 versus 4.70±0.34 mL/min per g kidney wt) were not different between groups. Fourteen-month-old GDNF heterozygous mice had ≈30% fewer glomeruli than wild-type mice (9206±934 versus 13440±1275 P .01) and significantly larger glomeruli (4.51±0.39 versus 3.72±0.63×10 −4 mm 3 P .01). Thus, aged GDNF heterozygous mice maintained a normal GFR and renal blood flow despite reduced nephron numbers. The elevated arterial pressure, glomerular hypertrophy, and hyperfiltration demonstrated in the GDNF heterozygous mice at this age may indicate a compensatory mechanism whereby GFR is maintained in the presence of a reduced nephron endowment.

Nephron Hypertrophy and Glomerulosclerosis in Normal Donor Kidneys

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 11-2014

DOI: 10.2215/CJN.08680814

Erratum

Publisher: Springer Science and Business Media LLC

Date: 10-1990

DOI: 10.1007/BF00327764

Estimation of Glomerular Podocyte Number

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 08-2013

DOI: 10.1681/ASN.2012111078

Kidney disease in children: latest advances and remaining challenges

Publisher: Springer Science and Business Media LLC

Date: 02-2016

DOI: 10.1038/NRNEPH.2015.219

Abstract: To mark World Kidney Day 2016, Nature Reviews Nephrology invited six leading researchers to highlight the key advances and challenges within their specialist field of paediatric nephrology. Here, advances and remaining challenges in the fields of prenatal patterning, acute kidney injury, renal transplantation, genetics, cardiovascular health, and growth and nutrition, are all discussed within the context of paediatric and neonatal patients with kidney disease. Our global panel of researchers describe areas in which further studies and clinical advances are needed, and suggest ways in which research in these areas should progress to optimize renal care and long-term outcomes for affected patients.

Deletion of Frs2α from the ureteric epithelium causes renal hypoplasia

Publisher: American Physiological Society

Date: 11-2009

DOI: 10.1152/AJPRENAL.00262.2009

Abstract: Fibroblast growth factor receptor 2 (Fgfr2) signaling is critical in maintaining ureteric branching architecture and mesenchymal stromal morphogenesis in the kidney. Fibroblast growth factor receptor substrate 2α (Frs2α) is a major docking protein for Fgfr2 with downstream targets including Ets variant (Etv) 4 and Etv5 in other systems. Furthermore, global deletion of Frs2α causes early embryonic lethality. The purpose of the study was to determine the role of Frs2α in mediating Fgfr2 signaling in the ureteric epithelium. To that end, we generated mice with conditional deletion of Frs2α in the ureteric epithelium ( Frs2α UB−/− ) and mice with point mutations in the Frs2α binding site of Fgfr2 ( Fgfr2 LR/LR ). Frs2α UB−/− mice developed mild renal hypoplasia characterized by decreased ureteric branching morphogenesis but maintained normal overall branching architecture and had normal mesenchymal stromal development. Reduced nephron endowment in postnatal mutant mice was observed, corresponding with the reduction in branching morphogenesis. Furthermore, there were no apparent renal abnormalities in Fgfr2 LR/LR mice. Interestingly, Etv4 and Etv5 expression was unaltered in Frs2α UB−/− mice, as was Sprouty1, an antagonist of Frs2α signaling. However, Ret and Wnt11 (molecules critical for ureteric branching morphogenesis) mRNA levels were lower in mutants vs. controls. Taken together, these findings suggest that Fgfr2 signals through adapter molecules other than Frs2α in the ureteric epithelium. Furthermore, Frs2α may transmit signals through other receptor kinases present in ureteric epithelium. Finally, the renal hypoplasia observed in Frs2α UB−/− mice is likely secondary to decreased Ret and Wnt11 expression.

Associations of Glomerular Number and Birth Weight With Clinicopathological Features of African Americans and Whites

Publisher: Elsevier BV

Date: 07-2008

DOI: 10.1053/J.AJKD.2008.03.023

Abstract: Hypertension and its cardiovascular complications affect African Americans more severely than whites, a disparity variously ascribed to low birth weight, low glomerular number, an exaggerated arteriolonephrosclerotic blood pressure response, and inflammation-induced oxidative stress. Case series. Autopsy kidneys of 107 African Americans and 87 whites aged 18 to 65 years at a single medical center between 1998 and 2005. Excluded were persons with known premorbid kidney disease pathological findings of severe arterioarteriolonephrosclerosis, nodular and diffuse diabetic glomerulosclerosis, or nonischemic cardiomyopathy. Associations of: (1) race, age, sex, birth weight, obesity, and glomerular number (predictors) with hypertension and death from coronary artery (CAD) and cerebrovascular disease (CVD outcomes) and (2) age, blood pressure, and race (predictors) with arteriolonephrosclerotic changes, including chronic tubulointerstitial inflammation (outcomes). Hypertension ascertained from chart review and heart weight. Cause of death determined from chart review and autopsy findings. Birth weight obtained from birth records (115 persons). Total glomerular number (N(glom)) estimated by using the dissector/fractionator technique. Arteriolosclerosis, glomerulosclerosis, cortical fibrosis, and chronic inflammation by using CD68 density were measured morphometrically. 59 African Americans (55%) and 32 whites (37%) were classified as hypertensive. CAD and CVD were the cause of death in 64 (33%) and 18 persons (9%), respectively. By using multiple linear regression, birth weight (P < 0.001) and sex (P < 0.01), but not race (P = 0.3) or age (P = 0.2), predicted N(glom) (P < 0.001 adjusted r(2) = 0.176). Hypertension was associated with African American race (P = 0.04), older age (P < 0.001), and male sex (P = 0.01), but not with N(glom) (P = 0.9), body mass index (P = 0.9), or birth weight (P = 0.4). Hypertension was the only significant factor associated with CAD and CVD (P < 0.001 for both). Interactions of age and blood pressure with race showed that although African Americans had more severe hypertension (P < 0.001) and arteriolosclerosis (P = 0.01) at a younger age than whites, there were no significant racial differences in degrees of arteriolosclerosis, glomerulosclerosis, cortical fibrosis, or CD68 density for any level of increased blood pressure. The study is observational and descriptive. The more severe hypertension found in African Americans could not be attributed to racial differences in N(glom) or birth weight. CAD and CVD death and increased arteriolonephrosclerosis, including CD68 density, were determined by using blood pressure without a significant interacting contribution from race.

The effect of low-to-moderate-dose ethanol consumption on rat mammary gland structure and function and early postnatal growth of offspring

Publisher: American Physiological Society

Date: 15-05-2013

DOI: 10.1152/AJPREGU.00574.2012

Abstract: High levels of alcohol consumption during pregnancy can lead to growth deficits in early postnatal life. However, the effects of low-to-moderate alcohol consumption during pregnancy are less clearly defined. The aim of this study was to determine whether low-to-moderate ethanol (EtOH) consumption throughout pregnancy in the rat alters maternal mammary gland morphology and milk protein levels, thereby affecting lactation and the growth of pups after birth. Sprague-Dawley rats were fed an ad libitum liquid diet ± 6% vol/vol EtOH throughout pregnancy. Mammary glands from dams were collected at embryonic day (E) 20 or postnatal day (PN) 1, and expression of milk proteins (α-lactalbumin, β-casein, and whey acidic protein) was examined. In addition, relative amounts of alveoli, lactiferous ducts, adipose tissue, and blood vessels were determined at PN1. A subset of rats gave birth, and offspring growth and milk intake were recorded. Mammary gland weight was unaltered by EtOH, and stereological analysis showed no differences in gland structure compared with control. Although there were no significant changes in mammary gland gene expression at the RNA level, protein levels of α-lactalbumin were increased and whey acidic protein were decreased by EtOH. Offspring of EtOH-fed dams consumed less milk than controls in the lactational period however, this did not alter their early postnatal growth. Overall, it appears that low-to-moderate-dose prenatal EtOH exposure does not significantly alter mammary gland development but may alter the composition of the various proteins found within the milk in a manner that maintains overall pup growth.

Nephron number, hypertension, renal disease, and renal failure

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 09-2005

DOI: 10.1681/ASN.2005020172

Prenatal corticosterone exposure results in altered AT₁/AT₂, nephron deficit and hypertension in the rat offspring

Publisher: Wiley

Date: 03-2007

DOI: 10.1113/JPHYSIOL.2006.125773

Effect of angiotensin-converting enzyme inhibition on myocardial vascularization in the adolescent and adult spontaneously hypertensive rat

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 04-2001

DOI: 10.1097/00004872-200104000-00016

Abstract: To determine whether angiotensin-converting enzyme (ACE) inhibition treatment enhances myocardial vascularization in adolescent and adult spontaneously hypertensive rats (SHRs). Male SHRs were treated from 7 to 14 or from 16 to 24 weeks of age with the ACE inhibitor, perindopril, in either a low dose (0.1 mg/kg per day) or a high dose (1 mg/kg per day). Some rats were concomitantly treated with a bradykinin antagonist. At termination of treatment, the left ventricular wall was extensively s led and the surface area density and length density of myocardial blood vessels stereologically determined. High-dose perindopril treatment prevented the development of hypertension and left ventricular hypertrophy in adolescent SHRs and markedly reduced blood pressure and left ventricular size in adult SHRs. SHRs treated with the low dose of perindopril remained hypertensive, although there were significant reductions in blood pressure and left ventricular growth. High-dose perindopril treatment in adolescent SHRs led to a significant increase in the surface area density of blood vessels in the left ventricle after 4 weeks of treatment and an increase in both the surface area density and length density of blood vessels after 7 weeks of treatment Co-administration with the bradykinin antagonist did not reverse these effects. In contrast, ACE inhibitor treatment had no effect on myocardial vascularization in adult rats with established hypertension. ACE inhibitor treatment enhances vascularization in the adolescent heart through reductions in myocardial mass, but not capillary growth. ACE inhibition in the adult heart with established hypertension reduces left ventricular hypertrophy, but does not enhance myocardial capillarization.

Immunolocalization of fibroblast growth factor‐1 and ‐2 in the embryonic rat kidney

Publisher: Wiley

Date: 06-1996

DOI: 10.1111/J.1440-1797.1996.TB00083.X

Indomethacin, ibuprofen and gentamicin administered during late stages of glomerulogenesis do not reduce glomerular number at 14 days of age in the neonatal rat

Publisher: Springer Science and Business Media LLC

Date: 06-2009

DOI: 10.1007/S00467-008-1114-5

Abstract: Premature neonates are frequently administered indomethacin, ibuprofen and gentamicin during the period of active glomerulogenesis. These drugs are known to have nephrotoxic effects, but the morphological effect of these drugs is unknown. The purpose of this study was to determine whether administration of these drugs during the late stages of glomerulogenesis in the rat has an effect on glomerular endowment. Rat pups were given, intraperitoneally, indomethacin, ibuprofen or indomethacin and gentamicin for the first 5 days of their postnatal life. The pups were killed at 14 days of age at completion of glomerulogenesis. The total number of glomeruli in the left kidney was determined by the physical disector/fractionator stereological technique. There was no difference between treatment groups in total number of glomeruli per kidney (P = 0.45). There were significantly fewer glomeruli per gram of kidney in those rat pups that had received indomethacin or ibuprofen (P < 0.0001). The reduction in the number of glomeruli per gram of kidney may indicate augmented growth of nephron tubules and/or collecting ducts, and/or be a consequence of oedema secondary to drug exposure. Further study is required to determine whether reduced glomerular number is seen in older animals or following exposure to these drugs at different time-points in kidney development.

Effects of dietary protein restriction on nephron number in the mouse

Publisher: American Physiological Society

Date: 05-2007

DOI: 10.1152/AJPREGU.00442.2006

Abstract: In rats, maternal protein restriction reduces nephron endowment and often leads to adult hypertension. Sex differences in these responses have been identified. The molecular and genetic bases of these phenomena can best be identified in a mouse model, but effects of maternal protein restriction on kidney development have not been examined in mice. Therefore, we determined how combined prenatal and postnatal protein restriction in mice affects organ weight, glomerular number and dimensions, and renal expression of angiotensin receptor mRNA, in both male and female offspring. C57/BL6/129sv mice received either a normal (20% wt/wt NP) or low (9% wt/wt LP) protein diet during gestation and postnatal life. Offspring were examined at postnatal day 30. Protein restriction retarded growth of the kidney, liver, spleen, heart, and brain. All organs except the brain weighed less in female than male offspring. Protein restriction increased normalized (to body weight) brain weight, with females having relatively heavier brains than males. The effects of protein restriction were not sex dependent, except that normalized liver weight was reduced in males but increased in females. Glomerular volume, but not number, was greater in female than in male mice. Maternal protein restriction reduced nephron endowment similarly in male and female mice. Renal expression of AT 1A receptor mRNA was approximately sixfold greater in female than male NP mice, but similar in male LP and female LP mice. We conclude that maternal protein restriction reduces nephron endowment in mice. This effect provides a basis for future studies of developmental programming in the mouse.

Efficient Small Blob Detection Based on Local Convexity, Intensity and Shape Information

Publisher: Institute of Electrical and Electronics Engineers (IEEE)

Date: 04-2016

DOI: 10.1109/TMI.2015.2509463

Redirection of renal mesenchyme to stromal and chondrocytic fates in the presence of TGF-Β2

Publisher: Elsevier BV

Date: 04-2010

DOI: 10.1016/J.DIFF.2010.01.004

Abstract: Many members of the transforming growth factor-beta (TGF-beta) superfamily have been shown to be important regulators of metanephric development. In this study, we characterized the effect of TGF-beta2 on metanephric development. Rat and mouse metanephroi cultured in the presence of exogenous TGF-beta2 for up to 15 days were small, and contained rudimentary ureteric branches and few glomeruli. These metanephroi were mostly comprised of mesenchymal cells, with two cell populations (designated Type 1 and Type 2 cells) evident. Type 1 cells were only observed when TGF-beta2 was added from the commencement of culture, they resembled chondroblasts and were Alcian Blue and Col IIB positive. Type 2 cells were observed whenever TGF-beta2 was added to the media, formed a band at the periphery of the explants consisting of 5-10 layers of spindle-shaped cells, and were alpha-smooth muscle actin positive. Molecular and RNA in situ hybridization analysis of metanephroi cultured in the presence of TGF-beta2 for 6 days demonstrated that Type 1 and 2 cells were negative for Pax2, WT1, GDNF and FoxD1. Gene expression profiling demonstrated an upregulation of chondrocyte, myogenic and stromal genes, some of which were identified as markers of Type 1 and Type 2 cells. In addition, TGF-beta2 was capable of maintaining the survival of mouse isolated metanephric mesenchyme (iMM) in the absence of serum or inductive signals from the ureteric epithelium. TGF-beta2 also induced the differentiation of iMM into Type 1 and 2 cells. The presence of chondrocytes and muscle in these cultures is reminiscent of the cell types found in some Wilms' tumors. These studies demonstrate that TGF-beta2 is capable of differentiating metanephric mesenchyme away from a renal cell fate.

Temporal and spatial transcriptional programs in murine kidney development

Publisher: American Physiological Society

Date: 17-10-2005

DOI: 10.1152/PHYSIOLGENOMICS.00043.2005

Abstract: We have performed a systematic temporal and spatial expression profiling of the developing mouse kidney using Compugen long-oligonucleotide microarrays. The activity of 18,000 genes was monitored at 24-h intervals from 10.5-day-postcoitum (dpc) metanephric mesenchyme (MM) through to neonatal kidney, and a cohort of 3,600 dynamically expressed genes was identified. Early metanephric development was further surveyed by directly comparing RNA from 10.5 vs. 11.5 vs. 13.5dpc kidneys. These data showed high concordance with the previously published dynamic profile of rat kidney development (Stuart RO, Bush KT, and Nigam SK. Proc Natl Acad Sci USA 98: 5649–5654, 2001) and our own temporal data. Cluster analyses were used to identify gene ontological terms, functional annotations, and pathways associated with temporal expression profiles. Genetic network analysis was also used to identify biological networks that have maximal transcriptional activity during early metanephric development, highlighting the involvement of proliferation and differentiation. Differential gene expression was validated using whole mount and section in situ hybridization of staged embryonic kidneys. Two spatial profiling experiments were also undertaken. MM (10.5dpc) was compared with adjacent intermediate mesenchyme to further define metanephric commitment. To define the genes involved in branching and in the induction of nephrogenesis, expression profiling was performed on ureteric bud (GFP+) FACS sorted from HoxB7-GFP transgenic mice at 15.5dpc vs. the GFP− mesenchymal derivatives. Comparisons between temporal and spatial data enhanced the ability to predict function for genes and networks. This study provides the most comprehensive temporal and spatial survey of kidney development to date, and the compilation of these transcriptional surveys provides important insights into metanephric development that can now be functionally tested.

Estimating Total Nephron Number in the Adult Kidney Using the Physical Disector/Fractionator Combination

Publisher: Humana Press

Date: 2012

DOI: 10.1007/978-1-61779-851-1_30

Abstract: Nephron number has emerged as a useful parameter for assessing the roles of specific genes and feto-maternal environmental factors in kidney development. Nephron number is also of clinical interest due to increasing evidence suggesting that low nephron number is associated with increased risk for developing chronic adult disease, including cardiovascular and renal disease. The physical disector/fractionator combination is considered the gold standard method for estimating total nephron number in kidneys. Here we describe the use of this method to estimate total nephron number in mouse and rat kidneys, and variations to the method required to estimate nephron number in larger species, including human.

Biphasic glomerular hypertrophy in rats administered puromycin aminonucleoside

Publisher: Elsevier BV

Date: 09-1996

DOI: 10.1038/KI.1996.375

Abstract: Recent evidence suggests that glomerular hypertrophy is a key event in the development of focal and segmental glomerulosclerosis and hyalinosis (FSGS) in humans and in many experimental models of FSGS. The initial aim of the present study was to determine if glomerular hypertrophy occurs in a puromycin aminonucleoside (PAN) model of FSGS, previously considered not to involve glomerular hypertrophy. Upon identifying significant glomerular hypertrophy, our second aim was to determine the contribution of glomerular capillary growth to this hypertrophy. Female Sprague-Dawley rats (approximately 200 g) were administered either PAN (2 mg/100 g body wt) subcutaneously, or an equivalent volume of 0.9% saline at weeks 0, 1, 2, 4, 6, 8 and 10. Tissue was analyzed at weeks 7 and 13. Unbiased stereological methods were used to estimate a range of glomerular parameters. Mean glomerular tuft volume in PAN-treated rats was 48% greater than in saline-treated rats at seven weeks, and 63% greater at 13 weeks. Similar results were found for mean renal corpuscle volume. FSGS was absent at seven weeks and minor at 13 weeks. Two-way analysis of variance indicated: significant effects (P < 0.05 at least) of PAN on capillary length per glomerulus, capillary surface area per glomerulus, capillary diameter and length of capillaries per unit volume of glomerulus and significant effects of time on capillary diameter, capillary length per unit volume of glomerulus and capillary surface area per unit volume of glomerulus. The mean length of capillaries per glomerulus was 45% greater in PAN-treated rats at week 7 and 22% greater in PAN-treated rats at week 13. Taken together, these results indicate a biphasic pattern of glomerular hypertrophy in this model. In the first phase (to 7 weeks), an increase in capillary length contributes to glomerular hypertrophy. In the second phase (7 to 13 weeks), the continued glomerular enlargement appears more likely to be due to an increase in capillary diameter and/or mesangial matrix expansion.

How Many Glomerular Profiles Must Be Measured to Obtain Reliable Estimates of Mean Glomerular Areas in Human Renal Biopsies?

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 02-2006

DOI: 10.1681/ASN.2005070772

Perinatal Programming of Arterial Pressure

Publisher: Springer International Publishing

Date: 2018

DOI: 10.1007/978-3-319-31107-4_40

Accelerated maturation and abnormal morphology in the preterm neonatal kidney

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 07-2011

DOI: 10.1681/ASN.2010121266

APOL1 Risk Alleles Are Associated with Exaggerated Age-Related Changes in Glomerular Number and Volume in African-American Adults

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 12-2015

DOI: 10.1681/ASN.2014080768

Antigen-induced airway inflammation in the Brown Norway rat results in airway smooth muscle hyperplasia

Publisher: American Physiological Society

Date: 11-2002

DOI: 10.1152/JAPPLPHYSIOL.00738.2001

Abstract: Asthma is characterized by chronic airways inflammation, airway wall remodeling, and airway hyperresponsiveness (AHR). An increase in airway smooth muscle has been proposed to explain a major part of AHR in asthma. We have used unbiased stereological methods to determine whether airway smooth muscle hyperplasia and AHR occurred in sensitized, antigen-challenged Brown Norway (BN) rats. Ovalbumin (OA)-sensitized BN rats chronically exposed to OA aerosol displayed airway inflammation and a modest level of AHR to intravenously administered ACh 24 h after the last antigen challenge. However, these animals did not show an increase in smooth muscle cell (SMC) number in the left main bronchus, suggesting that short-lived inflammatory mechanisms caused the acute AHR. In contrast, 7 days after the last aerosol challenge, there was a modest increase in SMC number, but no AHR to ACh. Addition of FCS to the chronic OA challenge protocol had no effect on the degree of inflammation but resulted in a marked increase in both SMC number and a persistent (7-day) AHR. These results raise the possibility that increases in airway SMC number rather than, or in addition to, chronic inflammation contribute to the persistent AHR detected in this model.

Sex differences in postnatal growth and renal development in offspring of rabbit mothers with chronic secondary hypertension

Publisher: American Physiological Society

Date: 02-2007

DOI: 10.1152/AJPREGU.00458.2006

Abstract: Previously, we demonstrated that adult blood pressure was increased in offspring of rabbit mothers with chronic secondary renal hypertension. Our study identified sex-specific differences in the programming of hypertension, with female, not male, offspring, having increased blood pressure at 30 wk of age. The aim of this study was to characterize the maternal hypertension during pregnancy to determine potential programming stimuli. Further, we examined the impact of chronic maternal hypertension on offspring birth weight, nephron number, and renal noradrenaline content (as an index of renal innervation density). Three groups of mothers and their offspring were studied: two-kidney, one-wrap (2K-1W, n = 9 mothers) hypertensive, two-kidney, two-wrap (2K-2W, n = 8) hypertensive, and a sham-operated group ( n = 9). Mean arterial blood pressure was increased by ∼20 mmHg throughout pregnancy in both hypertensive groups compared with sham mothers (P G 0.001). Plasma renin activity (PRA P G 0.05) and aldosterone (P G 0.05) levels were increased during gestation in the 2K-1W, but not the 2K-2W mothers. Birth weight was increased by ∼20% in offspring of both groups of hypertensive mothers (P T 0.001), though this was associated with a reduction in litter size. Renal noradrenaline content was increased (∼40%, P 0.05) at 5 wk of age in female 2K-1W offspring compared with sham offspring. Glomerular number was not reduced in female offspring of either group of hypertensive mothers however, glomerular tuft volume was reduced in female 2K-2W offspring ( P 0.05), indicative of a reduction in glomerular filtration surface area. In conclusion, the two models of renal hypertension produced differential effects on the offspring. The impact of a stimulated maternal renin-angiotensin system in the 2K-1W model of hypertension may influence development of the renal sympathetic nerves and contribute to programming of adult hypertension.

Chemotherapy Delays Progression of Motor Neuron Disease in the SOD1 G93A Transgenic Mouse

Publisher: S. Karger AG

Date: 2004

DOI: 10.1159/000077888

Abstract: b i Background: /i /b A significant proliferation of glial cells occurs in the spinal cord and brainstem of SOD1 G93A transgenic mice with familial amyotrophic lateral sclerosis (ALS). Since activated glia may contribute to motor neuron degeneration, we tested whether inhibition of gliosis using low-dose chemotherapy is beneficial in this mouse model. b i Methods: /i /b Mice were administered fortnightly intraperitoneal injections of 0.1 mg/kg vincristine (VIN) or saline commencing at postnatal day 68 before disease onset. Mice were sacrificed at end-stage disease, and spinal cords were examined for histology. b i Results: /i /b Survival of VIN-treated mice was significantly increased at 132.0 ± 4.1 days compared to control animals at 117.8 ± 2.1 days (p 0.05). Furthermore, analysis of microglia and astrocyte populations suggests a reduction in the former following VIN therapy. b i Conclusion: /i /b This study suggests that chemotherapy may offer an alternative therapy or co-therapy for ALS.

Phenotyping by magnetic resonance imaging nondestructively measures glomerular number and volume distribution in mice with and without nephron reduction

Publisher: Elsevier BV

Date: 02-2016

DOI: 10.1038/KI.2015.316

Renal biopsy findings among Indigenous Australians: A nationwide review

Publisher: Elsevier BV

Date: 12-2012

DOI: 10.1038/KI.2012.307

Abstract: Australia's Indigenous people have high rates of chronic kidney disease and kidney failure. To define renal disease among these people, we reviewed 643 renal biopsies on Indigenous people across Australia, and compared them with 249 biopsies of non-Indigenous patients. The intent was to reach a consensus on pathological findings and terminology, quantify glomerular size, and establish and compare regional biopsy profiles. The relative population-adjusted biopsy frequencies were 16.9, 6.6, and 1, respectively, for Aboriginal people living remotely/very remotely, for Torres Strait Islander people, and for non-remote-living Aboriginal people. Indigenous people more often had heavy proteinuria and renal failure at biopsy. No single condition defined the Indigenous biopsies and, where biopsy rates were high, all common conditions were in absolute excess. Indigenous people were more often diabetic than non-Indigenous people, but diabetic changes were still present in fewer than half their biopsies. Their biopsies also had higher rates of segmental sclerosis, post-infectious glomerulonephritis, and mixed morphologies. Among the great excess of biopsies in remote/very remote Aborigines, females predominated, with younger age at biopsy and larger mean glomerular volumes. Glomerulomegaly characterized biopsies with mesangiopathic changes only, with IgA deposition, or with diabetic change, and with focal segmental glomerulosclerosis (FSGS). This review reveals great variations in biopsy rates and findings among Indigenous Australians, and findings refute the prevailing dogma that most indigenous renal disease is due to diabetes. Glomerulomegaly in remote/very remote Aboriginal people is probably due to nephron deficiency, in part related to low birth weight, and probably contributes to the increased susceptibility to kidney disease and the predisposition to FSGS.

Differential gene expression in the developing mouse ureter

Publisher: Elsevier BV

Date: 06-2006

DOI: 10.1016/J.MODGEP.2005.10.008

Abstract: In many instances, kidney dysgenesis results as a secondary consequence to defects in the development of the ureter. Through the use of mouse genetics a number of genes associated with such malformations have been identified, however, the cause of many other abnormalities remain unknown. In order to identify novel genes involved in ureter development we compared gene expression in embryonic day (E) 12.5, E15.5 and postnatal day (P) 75 ureters using the Compugen mouse long oligo microarrays. A total of 248 genes were dynamically upregulated and 208 downregulated between E12.5 and P75. At E12.5, when the mouse ureter is comprised of a simple cuboidal epithelium surrounded by ureteric mesenchyme, genes previously reported to be expressed in the ureteric mesenchyme, foxC1 and foxC2 were upregulated. By E15.5 the epithelial layer develops into urothelium, impermeable to urine, and smooth muscle develops for the peristaltic movement of urine towards the bladder. The development of these two cell types coincided with the upregulation of UPIIIa, RAB27b and PPARgamma reported to be expressed in the urothelium, and several muscle genes, Acta1, Tnnt2, Myocd, and Tpm2. In situ hybridization identified several novel genes with spatial expression within the smooth muscle, Acta1 ureteric mesenchyme and smooth muscle, Thbs2 and Col5a2 and urothelium, Kcnj8 and Adh1. This study marks the first known report defining global gene expression of the developing mouse ureter and will provide insight into the molecular mechanisms underlying kidney and lower urinary tract malformations.

Subfractionation of differentiating human embryonic stem cell populations allows the isolation of a mesodermal population enriched for intermediate mesoderm and putative renal progenitors

Publisher: Mary Ann Liebert Inc

Date: 10-2010

DOI: 10.1089/SCD.2010.0017

High nephron endowment protects against salt-induced hypertension

Publisher: American Physiological Society

Date: 15-07-2012

DOI: 10.1152/AJPRENAL.00028.2012

Abstract: While low nephron number is associated with increased risk of developing cardiovascular and renal disease, the functional consequences of a high nephron number are unknown. We tested the hypothesis that a high nephron number provides protection against hypertensive and renal insults. Mean arterial pressure (MAP) and renal function were characterized in male wild-type (WT) and transforming growth factor-β2 heterozygous ( Tgfb2 +/− ) mice under basal conditions and following a chronic high-salt diet. Kidneys were collected for unbiased stereological analysis. Baseline MAP and renal function were indistinguishable between genotypes. The chronic high-salt diet (5% NaCl for 4 wk followed by 8% NaCl for 4 wk) led to similar step-wise increases in urine volume, Na + excretion, and albuminuria in the genotypes. The 5% NaCl diet induced modest and similar increases in MAP (3.5 ± 1.6 and 3.4 ± 0.8 mmHg in WT and Tgfb2 +/− , respectively). After the step up to the 8% NaCl diet, MAP increased further in WT (+15.9 ± 5.1 mmHg), but not Tgfb2 +/− (−0.1 ± 1.0 mmHg), mice. Nephron number was 30% greater in Tgfb2 +/− than WT mice and was not affected by the chronic high-salt diet. Mean glomerular volume was lower in Tgfb2 +/− than WT mice, and the chronic high-salt diet induced significant glomerular hypertrophy. In a separate cohort of mice, an acute, 7-day, 8% NaCl diet induced similar rises in MAP in the genotypes. This is the first study to examine the physiological characteristics of a model of high nephron number, and the findings are consistent with this phenotype providing protection against chronic, but not acute, hypertensive insults.

Quantification of glomerular number and size distribution in normal rat kidneys using magnetic resonance imaging

Publisher: Oxford University Press (OUP)

Date: 03-06-2011

DOI: 10.1093/NDT/GFR273

Abstract: Glomerular number and size are important risk factors for chronic kidney disease (CKD) and cardiovascular disease and have traditionally been estimated using invasive techniques. Here, we report a novel technique to count and size every glomerulus in the rat kidney using magnetic resonance imaging (MRI). The ferromagnetic nature of cationized ferritin allowed visualization of single glomeruli in high-resolution susceptibility-weighted MRI. A segmentation algorithm was used to identify and count all glomeruli within the whole kidney. To prove our concept, we estimated total glomerular number and mean glomerular volume of each kidney using design-based stereology. The glomerular counts obtained with MRI agreed well with estimates obtained using traditional methods [MRI, 32 785 (3117) stereology, 35 132 (3123)]. For the first time, the glomerular volume distribution for the entire kidney is shown. Additionally, the method is substantially faster than the current methods. MRI provides a new method for measuring these important microanatomical markers of disease risk and leads the way to in vivo analysis of these parameters, including longitudinal studies of animal models of CKD.

Immunohistochemical localisation of TRA-1-60, TRA-1-81, GCTM-2 and podocalyxin in the developing baboon kidney

Publisher: Springer Science and Business Media LLC

Date: 12-02-2008

DOI: 10.1007/S00418-008-0398-7

Abstract: The baboon is an ideal animal model to study human kidney development. The aim of the current study was to use immunohistochemistry to localise the antigens TRA-1-60, TRA-1-81, GCTM-2 and podocalyxin in the developing baboon kidney where nephrogenesis was still on-going and in kidneys where nephrogenesis was complete. Fixed kidney sections from baboons delivered at 125, 140, 175 and 185 days gestation (term = 185 days) were immuno-labelled with antibodies directed against TRA-1-60, TRA-1-81, GCTM-2 and podocalyxin. In kidneys with on-going nephrogenesis (125 and 140 days gestation), TRA-1-60, TRA-1-81 and GCTM-2 were specifically localised to the apical plasma membrane of the epithelium of the ureteric ullae and the collecting ducts, while podocalyxin immunostaining was not detected. In kidneys where nephrogenesis was complete (175 and 185 days gestation) localisation of these markers was again very specifically localised to the collecting ducts. In conclusion, although further experimentation is required to confirm the identity of the specific cell types marked by these antibodies, this study provides new insight into the distribution of commonly utilised stem cell antibodies in the developing baboon kidney.

Podocyte Number in Children and Adults

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 09-2015

DOI: 10.1681/ASN.2014070641

The Where, What and Why of the Developing Renal Stroma

Publisher: S. Karger AG

Date: 14-01-2005

DOI: 10.1159/000081792

Abstract: In recent years, a great deal has been learnt about the molecular regulation of kidney development. While most research has focused on the molecular regulation of ureteric branching morphogenesis and nephron formation, significant insights into the definition and functions of the renal stroma have emerged. Many molecules expressed in the developing renal stroma are now known to play significant regulatory roles in kidney development. However, the term ‘renal stroma’ continues to have different meanings to different researchers. This review clarifies this situation and defines the derivation, location and functions of the stroma in the developing metanephros.

Low-dose maternal alcohol consumption: effects in the hearts of offspring in early life and adulthood

Publisher: Wiley

Date: 07-2014

DOI: 10.14814/PHY2.12087

Use of Cationized Ferritin Nanoparticles to Measure Renal Glomerular Microstructure with MRI

Publisher: Springer New York

Date: 17-12-2015

DOI: 10.1007/978-1-4939-3353-2_7

Abstract: Magnetic resonance imaging (MRI) is becoming important for whole-kidney assessment of glomerular morphology, both in vivo and ex vivo. MRI-based renal morphological measurements can be made in intact organs and allow direct measurements of every perfused glomerulus. Cationic ferritin (CF) is used as a superparamagnetic contrast agent for MRI. CF binds to the glomerular basement membrane after intravenous injection, allowing direct, whole-kidney measurements of glomerular number, volume, and volume distribution. Here we describe the production, testing, and use of CF as an MRI contrast agent for quantitative glomerular morphology in intact mouse, rat, and human kidneys.

A stereological study of glomerular number and volume: preliminary findings in a multiracial study of kidneys at autopsy

Publisher: Elsevier BV

Date: 02-2003

DOI: 10.1046/J.1523-1755.63.S83.8.X

Abstract: This report describes preliminary results of a study of glomerular number and volume and their associations, in kidneys of people coming to autopsy. Both kidneys were weighed at autopsy and the right kidney was perfusion-fixed and sub-s led for stereological estimation of total glomerular number, and of mean renal corpuscle volume, using the physical disector/fractionator combination. The 78 kidneys studied so far were from Australian Aborigines, Australian non-Aborigines, US blacks and US whites, ages newborn to 84 years. Glomerular number ranged almost ninefold (from 210,332 to 1,825,380), with mean (SD) of 784,909 (314,686) it decreased throughout adult life (r=-0.32, P=0.009). Mean renal corpuscle volume varied 5.6-fold in adults and was inversely correlated with glomerular number (r=-0.38, P=0.001). Total renal corpuscle volume varied in adults by a factor of 15.8. Kidney weight correlated with body surface area (BSA) at all ages (r=0.76, P < 0.001) it varied 3.4-fold among adults, while kidney weight/m2 varied 3.7-fold. The percentage of sclerosed glomeruli varied from 0 to 23%, and it correlated strongly with age (r=0.58, P < 0.001). Females had smaller kidneys than males, and, marginally, fewer glomeruli. There were no significant variations by ethnic group. These extraordinary ranges of glomerular number and size among ostensibly "normal" people, and their inverse relationship, probably have important implications for susceptibility to renal insufficiency. People with low glomerular (nephron) numbers are likely to be particularly predisposed, with the process marked by compensatory hypertrophy of residual nephrons, which, in turn, accelerates their obsolescence. Much, however, remains to be done, including evaluation of history, clinical features, accompanying pathology, detailed renal morphology, and further pursuit of potentially defining characteristics in high risk groups.

Studies on the effects of gentamicin on rat metanephric development in vitro

Publisher: Wiley

Date: 03-2000

DOI: 10.1046/J.1440-1797.2000.00512.X

Abstract: Reduced nephron endowment has been associated with increased risk of developing essential hypertension and chronic renal failure. Both in vivo and in vitro exposure of developing rat metanephroi to gentamicin has been reported to inhibit metanephric development resulting in reduced nephron endowment. The aim of the present study was to confirm that gentamicin results in reduced nephron endowment in vitro , and to extend understanding of the mechanisms responsible for this reduced endowment. Embryonic day 14 (E14) rat metanephroi were cultured for up to 4 days in serum‐free medium with or without 50 μg/mL gentamicin. Metanephroi cultured in the presence of gentamicin were 25% smaller than control metanephroi after 2 days culture and 30% smaller after 4 days ( P 0.001). This decrease in total metanephric volume was reflected in reduced volumes of ureteric duct epithelium, mesenchyme/interstitium and nephron epithelia. The reduced volume of ureteric duct epithelium in gentamicin‐treated metanephroi was associated with a 30% reduction in the number of ureteric duct branch points at 2 days. Metanephroi cultured with gentamicin contained 20% fewer glomeruli than control metanephroi ( P 0.005) at 4 days. These glomeruli were 30% smaller than control glomeruli ( P 0.05). Qualitative observations of Pax‐2 immunostained mesenchymal condensates indicated no difference in condensate size, location or morphology. These results confirm that in vitro exposure of developing rat metanephroi to gentamicin results in reduced nephron endowment. The defect in nephrogenesis centres around the inhibition of ureteric duct branching.

Analysis of structure and gene expression in developing kidneys of male and female rats exposed to low protein diets in utero.

Publisher: Wiley

Date: 21-06-2020

DOI: 10.1002/AR.24417

DNA copy number variants: A potentially useful predictor of early onset renal failure in boys with posterior urethral valves

Publisher: Elsevier BV

Date: 08-2016

DOI: 10.1016/J.JPUROL.2016.02.020

Abstract: Posterior urethral valves (PUV) are among the most common urological causes of chronic kidney disease (CKD) in childhood. Recently, genomic imbalances have been cited as potential risk factors for altered kidney function and have been associated with CKD. The phenotypic effects of a copy number variant (CNV) in boys with PUV are unknown. Here, it was hypothesised that the progression to early renal failure in PUV patients may be influenced by genetic aberrations. To assess the relationship between CNVs and renal outcomes. Between September 2012 and July 2015, 45 children with PUV were recruited to evaluate the presence of CNVs in their DNA. The patients' medical records were retrospectively reviewed. The criteria for outcomes of renal function included: assessments of the nadir serum creatinine in the first year of life, the estimated glomerular filtration rate at 1 and 5 years, and the requirement for renal replacement. Thirteen CNVs were identified in 12 boys (29% of the cohort). Microarray analysis revealed two pathogenic CNVs (well-established CNVs known to be associated with genetic disease) and 11 of unknown significance (CNVs with insufficient current available evidence for unequivocal determination of clinical significance), including genes that have been previously implicated in kidney diseases and urogenital disorders. The median follow-up was 10.2 years (range 3-17.5) in the group of patients with CNV compared with 5.8 years (range 1-16.6) in those CNV-. The nadir creatinine values were significantly higher in boys with CNVs than in those without CNVs (57.5 μmol/L (range 23-215) and 28 μmol/L (range 18-155), respectively (P = 0.05) (Figure). Boys CNV+ had a worse prognosis, with a higher incidence of Stage-V CKD compared with the control group (33% with CNVs vs. 9% in CNV-, P = 0.06) at a median age of 22 months (range 8 months-16 years). Four (33%) patients CNV+ underwent renal transplantation. The role of CNVs in the deterioration of renal function remains unknown. It can be hypothesised that CNVs could be a contributing factor or may serve as an accelerant for the progression to renal failure. The CNVs >100 Kb were significantly associated with early onset renal failure in children with PUV. Prenatal detection of CNV could help to identify foetuses at high risk of severe renal impairment in cases of suspected PUV, especially in cases without oligohydramnios or severe pulmonary hypoplasia. These preliminary results should be confirmed in a larger cohort of patients.

Stereological analysis of synaptogenesis in the molecular layer of piriform cortex in the prenatal rat

Publisher: Wiley

Date: 08-07-1987

DOI: 10.1002/CNE.902610210

Abstract: The development of synapses in the molecular layer of the rat piriform cortex was studied at embryonic days 15, 17, 19, and 21. The present study has sought to extend past studies of synaptogenesis by identifying not only changes in numbers of synapses, but also changes in numbers of potential precursors of synapses. A stereological method (Cruz-Orive, '80) was used to make volumetric estimations of the numbers of synapses, axonal puncta, vesicle-associated puncta, and unapposed postsynaptic specializations. This stereological method was preferred to other morphometric methods because it is not influenced by changes in the size, shape, or orientation of the structures of interest. This was considered important since such changes might be expected during development. Large numbers of unapposed axonal specializations (axonal puncta and vesicle-associated puncta) were found in all three sublaminae (lateral olfactory tract, Ia, and Ib) at all ages. The numerical density (number per unit volume of neuropil) and relative frequency of these structures changed significantly with time. In all three sublaminae, these changes were associated with changes in the number of synapses, although the numerical density and relative proportions varied between the sublaminae. These results suggested that axonal puncta could accumulate vesicles, thus becoming vesicle-associated puncta, and that vesicle-associated puncta could contact dendrites, thus forming synapses. In contrast, the numerical density of lone postsynaptic specializations remained low and no significant changes in their relative proportion in the population were found. This suggested that although lone postsynaptic sites were observed, they did not appear to play a major role in synaptogenesis in this region of the cortex. In addition to documenting developmental differences between the three sublaminae in the molecular layer, the results support a synaptogenic hypothesis in which the axon can form surface specializations that appear to be involved in synaptogenesis, independent of direct dendritic contact.

Estimating nephron number in the developing kidney using the physical disector/fractionator combination

Publisher: Humana Press

Date: 2012

DOI: 10.1007/978-1-61779-851-1_10

Abstract: Design-based stereology is considered the gold-standard method for estimating the total number of glomeruli, and thereby nephrons, in the adult kidney. However, until recently, a design-based method for estimating nephron number in the developing kidney was not available. For such a method to provide accurate and precise estimates, unambiguous identification of developing nephrons is essential. Here, we describe a combined histochemical/stereological technique for estimating total nephron number in the developing mouse and rat kidney. The method can be modified for use in other species.

Maternal glucose intolerance reduces offspring nephron endowment and increases glomerular volume in adult offspring

Publisher: Wiley

Date: 03-05-2016

DOI: 10.1002/DMRR.2805

Abstract: Animal studies report a nephron deficit in offspring exposed to maternal diabetes, yet are limited to models of severe hyperglycaemia which do not reflect the typical clinical condition and which are associated with foetal growth restriction that may confound nephron endowment. We aimed to assess renal morphology and function in offspring of leptin receptor deficient mice (Lepr Nephron endowment was assessed in offspring of C57BKS/J Lepr Compared with +/+ dams, Lepr IGT throughout gestation resulted in a nephron deficit that was established early in renal development. Maternal IGT was associated with glomerular hypertrophy in adult offspring, likely a compensatory response to maintain normal renal function. Given the increasing prevalence of IGT, monitoring glucose from early in gestation may be important to prevent altered kidney morphology. Copyright © 2016 John Wiley & Sons, Ltd.

Blockade of p38 Mitogen-Activated Protein Kinase and TGF-β1/Smad Signaling Pathways Rescues Bone Marrow–Derived Peritubular Capillary Endothelial Cells in Adriamycin-Induced Nephrosis

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 10-2006

DOI: 10.1681/ASN.2006020130

Total numbers of glomeruli and individual glomerular cell types in the normal rat kidney

Publisher: Springer Science and Business Media LLC

Date: 10-1992

DOI: 10.1007/BF00381877

Indirect estimation of nephron number: a new tool to predict outcomes in renal transplantation?

Publisher: Oxford University Press (OUP)

Date: 24-03-2016

DOI: 10.1093/NDT/GFW034

Lengths of nephron tubule segments and collecting ducts in the CD-1 mouse kidney

Publisher: American Physiological Society

Date: 11-2016

DOI: 10.1152/AJPRENAL.00435.2016

Abstract: The kidney continues to mature postnatally, with significant elongation of nephron tubules and collecting ducts to maintain fluid/electrolyte homeostasis. The aim of this project was to develop methodology to estimate lengths of specific segments of nephron tubules and collecting ducts in the CD-1 mouse kidney using a combination of immunohistochemistry and design-based stereology (vertical uniform random sections with cycloid arc test system). Lengths of tubules were determined at postnatal day 21 (P21) and 2 and 12 mo of age and also in mice fed a high-salt diet throughout adulthood. Immunohistochemistry was performed to identify in idual tubule segments [aquaporin-1, proximal tubules (PT) and thin descending limbs of Henle (TDLH) uromodulin, distal tubules (DT) aquaporin-2, collecting ducts (CD)]. All tubular segments increased significantly in length between P21 and 2 mo of age (PT, 602% increase DT, 200% increase TDLH, 35% increase CD, 53% increase). However, between 2 and 12 mo, a significant increase in length was only observed for PT (76% increase in length). At 12 mo of age, kidneys of mice on a high-salt diet demonstrated a 27% greater length of the TDLH, but no significant change in length was detected for PT, DT, and CD compared with the normal-salt group. Our study demonstrates an efficient method of estimating lengths of specific segments of the renal tubular system. This technique can be applied to examine structure of the renal tubules in combination with the number of glomeruli in the kidney in models of altered renal phenotype.

Analyzing Renal Glomeruli with the New Stereology

Publisher: Elsevier

Date: 1995

DOI: 10.1016/S0074-7696(08)62497-3

Abstract: The highly specialized architecture of the renal glomerulus is altered in a variety of disease states. Morphometric methods, including stereological methods, have been widely used to analyze these changes in both animal and human glomeruli. However, many of the methods available until recently were biased and provided incomplete information. The past few years have witnessed the development of a new generation of unbiased stereological methods. Another advantage of these new methods and strategies is that they are less influenced by technical artifacts than the traditional methods. This chapter describes how these new stereological methods can be used to quantify glomerular morphology. Parameters considered include glomerular number and volume glomerular cell number and size and the length, surface area, and number of glomerular capillaries. Methods for obtaining data for average glomeruli as well as in idual glomeruli are described. Technical details are included wherever possible.

Vascular geometry and oxygen diffusion in the vicinity of artery-vein pairs in the kidney

Publisher: American Physiological Society

Date: 15-11-2014

DOI: 10.1152/AJPRENAL.00382.2014

Abstract: Renal arterial-to-venous (AV) oxygen shunting limits oxygen delivery to renal tissue. To better understand how oxygen in arterial blood can bypass renal tissue, we quantified the radial geometry of AV pairs and how it differs according to arterial diameter and anatomic location. We then estimated diffusion of oxygen in the vicinity of arteries of typical geometry using a computational model. The kidneys of six rats were perfusion fixed, and the vasculature was filled with silicone rubber (Microfil). A single section was chosen from each kidney, and all arteries ( n = 1,628) were identified. Intrarenal arteries were largely isible into two “types,” characterized by the presence or absence of a close physical relationship with a paired vein. Arteries with a close physical relationship with a paired vein were more likely to have a larger rather than smaller diameter, and more likely to be in the inner-cortex than the mid- or outer cortex. Computational simulations indicated that direct diffusion of oxygen from an artery to a paired vein can only occur when the two vessels have a close physical relationship. However, even in the absence of this close relationship oxygen can diffuse from an artery to periarteriolar capillaries and venules. Thus AV oxygen shunting in the proximal preglomerular circulation is dominated by direct diffusion of oxygen to a paired vein. In the distal preglomerular circulation, it may be sustained by diffusion of oxygen from arteries to capillaries and venules close to the artery wall, which is subsequently transported to renal veins by convection.

Enalapril Does Not Prevent Renal Arterial Hypertrophy in Spontaneously Hypertensive Rats

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 03-1995

DOI: 10.1161/01.HYP.25.3.335

Abstract: Abstract Angiotensin-converting enzyme inhibitors prevent the development of vessel wall hypertrophy in some vascular beds in spontaneously hypertensive rats (SHR), but their effects on hypertrophy of renal arterial vessels have not been studied. We therefore used stereological techniques to study wall and lumen dimensions of the interlobular (cortical radial) and arcuate arteries in the kidneys of SHR (n=7), SHR treated from 4 to 10 weeks of age with enalapril (25 to 30 mg/kg per day SHR-E, n=7), and Wistar-Kyoto rats (WKY, n=7). All kidneys were perfusion-fixed at 10 weeks. Systolic blood pressure was 199±9, 139±11, and 156±8 mm Hg in the SHR, SHR-E, and WKY groups, respectively. For the interlobular arteries, the volume density of artery wall, wall-to-lumen ratio, and wall thickness in the untreated SHR were significantly greater than in the WKY (0.84±0.09 versus 0.69±0.07×10 −3 , 0.75±0.20 versus 0.53±0.08, and 13.6±3.3 versus 10.6±0.8 μm, respectively), but values in the SHR-E were similar to those in the untreated SHR (1.10±0.20×10 −3 , 0.88±0.22, and 14.0±2.6 μm, respectively). For the arcuate arteries, wall thickness and volume density were significantly greater in SHR than WKY (17.3±3.0 versus 13.9±1.7 μm and 1.63±0.51 versus 1.14±0.27×10 −3 , respectively), and values in the SHR-E (15.7±1.7 μm and 1.69±0.50×10 −3 , respectively) were not significantly different from those in SHR. Thus, enalapril treatment did not prevent vessel wall hypertrophy of both the interlobular and arcuate arteries in SHR despite the normalization of arterial pressure. These results suggest that renal arterial hypertrophy in SHR is not caused by either angiotensin II or elevated arterial pressure.

CARDIAC GROWTH DURING HIGH AND LOW DOSE PERINDOPRIL TREATMENT IN SPONTANEOUSLY HYPERTENSIVE RATS

Publisher: Wiley

Date: 07-1996

DOI: 10.1111/J.1440-1681.1996.TB02794.X

Abstract: 1. The effect of high and low dose angiotensin converting enzyme (ACE) inhibition and the contribution of bradykinin potentiation in this treatment on left and right ventricle weights and wall volume was investigated in immature spontaneously hypertensive rats (SHR). 2. Male SHR were treated from 7 to 11 weeks of age with perindopril (an ACE inhibitor) at a low dose of 0.1 mg/kg per day or a high dose of 1 mg/kg per day. Half the animals were also treated with a bradykinin receptor antagonist, HOE 140 (500 μg/kg per day). 3. After 4 weeks of treatment, hearts were arrested in diastole and perfusion fixed. The right and left ventricle plus septum were weighed, cut into 1 mm slices and volume was determined using the Cavalieri principle. 4. Low dose perindopril treatment did not significantly affect blood pressure in the SHR. High dose perindopril treatment maintained blood pressure at a level similar to Wistar‐Kyoto (WKY) rats. 5. Growth of the right ventricle was not influenced by ACE inhibition. However, high dose treatment significantly lowered the left ventricle plus septum volume: bodyweight ratio (LV + S VOL:BWT) compared with control SHR (2.85 ± 0.02 vs 3.36 ± 0.08 mm 3 /g, respectively) to a level similar to the normotensive WKY rats (2.80 ± 0.11 mm 3 /g). Similarly, low dose treatment significantly lowered the LV + S VOL:BWT ratio (2.89 ± 0.09 mm 3 /g). HOE 140 treatment did not reverse the effect of ACE inhibition. Similar effects were observed on left ventricular weights. 6. ACE inhibition, independent of its blood pressure lowering effect, prevents the development of left ventricular hypertrophy in the SHR but does not influence growth of the right ventricle. This effect of ACE inhibition does not appear to be mediated by bradykinin potentiation.

Renal responses to furosemide are significantly attenuated in male sheep at 6 months of age following fetal uninephrectomy

Publisher: American Physiological Society

Date: 04-2012

DOI: 10.1152/AJPREGU.00579.2011

Abstract: We have previously shown that fetal uninephrectomy (uni-x) at 100 days of gestation (term = 150 days) in male sheep results in a 30% nephron deficit, reduction in glomerular filtration rate (GFR) and renal blood flow, and elevation in arterial pressure at 6 mo of age. Furthermore, in response to an acute 0.9% saline load, sodium excretion was significantly delayed in uni-x animals leading us to speculate that tubuloglomerular feedback (TGF) activity was reset in uni-x animals. In the present study, we induced TGF blockade by furosemide administration (1.5 mg/kg iv over 90 min) and determined GFR, effective renal plasma flow, and urine and sodium excretion responses in 6-mo-old male sheep. In response to furosemide, a significant diuresis and natriuresis was observed in the sham group however, the response was significantly delayed and reduced in uni-x animals (both, P treatment×time 0.001). Cummulative urinary and sodium output was significantly less in the uni-x compared with the sham sheep (both, P treatment×time 0.001). GFR was increased in the sham but not the uni-x sheep ( P treatment×time 0.0001). In conclusion, the excretory response to furosemide was attenuated in the uni-x sheep, and this suggests a rightward resetting of the TGF operating point. The TGF mechanism is important in the fine tuning of sodium homeostasis and is likely a contributing factor for the dysfunction in sodium regulation we have previously observed in the uni-x animals.

Renomedullary interstitial cell lipid droplet content is increased in spontaneously hypertensive rats and by low salt diet

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 07-2001

DOI: 10.1097/00004872-200107000-00017

Abstract: To compare the volumes of renomedullary interstitial cell (RMIC) lipid droplets (putative source of vasodepressor substance) in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats on high and low salt diets as an indication of whether the renomedullary vasodepressor system of the SHR is defective. Ten-week-old male SHR and WKY rats received a low (0.05% w/w) or high salt (5.0%) diet for 21 days. Conscious mean arterial pressure (MAP) was measured and the renal papilla perfusion fixed with a high osmolarity fixative. Using electron microscopic stereological techniques, the volume density of lipid in RMIC (VVLipid,RMIC) and the total volumes of lipid (VLipid) and RMIC (VRMIC) in papilla were measured. MAP of SHR (high 155 +/- 3 mmHg low 151 +/- 3 mmHg) was significantly greater than WKY rats (high 126 +/- 2 mmHg low 129 +/- 2 mmHg P< 0.001), however salt diet had no significant effect on MAP. The VLipid of rats on the low salt diet was approximately 2.5 times greater than in rats on the high salt diet (P < 0.01). SHR had significantly greater VLipid than WKY rats irrespective of salt diet (P< 0.05 SHR-low 0.245 +/- 0.031 mm3, SHR-high 0.093 +/- 0.007 mm3 WKY-low 0.126 +/- 0.032 mm3, WKY-high 0.051 +/- 0.020 mm3). Similar differences were seen for VVLipid,RMIC, however VRMIC was not different between rat strains or salt diet groups. SHR and WKY rats responded similarly to the altered salt diets, and SHR demonstrated greater volumes of stored RMIC lipid droplets irrespective of the level of salt intake. These results indicate that SHR hypertension is not due to a deficiency in the amount of lipid droplets, the putative source of the renomedullary vasodepressor substance and that the renomedullary vasodepressor system of the SHR is capable of responding normally to the physiological stimulus of altered salt intake.

CKD in aboriginal Australians

Publisher: Elsevier BV

Date: 11-2010

DOI: 10.1053/J.AJKD.2010.05.010

Abstract: Chronic kidney disease (CKD) is one component of a spectrum of chronic disease in Aboriginal Australians. CKD is marked by albuminuria, which predicts renal failure and nonrenal natural death. Rates vary greatly by community and region and are much higher in remote areas. This reflects the heterogeneous characteristics and circumstances of Aboriginal people. CKD is multideterminant, and early-life influences (notably low birth weight), infections (including poststreptococcal glomerulonephritis), metabolic/hemodynamic parameters, and epigenetic/genetic factors probably contribute. CKD is associated intimately with cardiovascular risk. Albuminuria progresses over time, with a high incidence of new onset of pathologic levels of albuminuria in all age groups. All the usual morphologic findings are found in renal biopsy specimens. However, glomerular enlargement is notable in in iduals from remote regions, but not those living closer to population centers. Glomerulomegaly probably represents compensatory hypertrophy caused by low nephron number, which probably underlies the accentuated susceptibility to renal disease. In the last decade, health care services have been transformed to accommodate systematic chronic disease surveillance and management. After a relentless increase for 3 decades, rates of Aboriginal people starting renal replacement therapy, as well as chronic disease deaths, appear to be stabilizing in some regions. Official endorsement of these system changes, plus ongoing reductions in the incidence of low birth weight and infections, hold promise for continued better outcomes.

The fate of bone marrow-derived cells carrying a polycystic kidney disease mutation in the genetically normal kidney

Publisher: Springer Science and Business Media LLC

Date: 29-08-2012

DOI: 10.1186/1471-2369-13-91

Abstract: Polycystic Kidney Disease (PKD) is a genetic condition in which dedifferentiated and highly proliferative epithelial cells form renal cysts and is frequently treated by renal transplantation. Studies have reported that bone marrow-derived cells give rise to renal epithelial cells, particularly following renal injury as often occurs during transplantation. This raises the possibility that bone marrow-derived cells from a PKD-afflicted recipient could populate a transplanted kidney and express a disease phenotype. However, for reasons that are not clear the reoccurrence of PKD has not been reported in a genetically normal renal graft. We used a mouse model to examine whether PKD mutant bone marrow-derived cells are capable of expressing a disease phenotype in the kidney. Wild type female mice were transplanted with bone marrow from male mice homozygous for a PKD-causing mutation and subjected to renal injury. Y chromosome positive, bone marrow-derived cells in the kidney were assessed for epithelial markers. Mutant bone marrow-derived cells were present in the kidney. Some mutant cells were within the bounds of the tubule or duct, but none demonstrated convincing evidence of an epithelial phenotype. Bone marrow-derived cells appear incapable of giving rise to genuine epithelial cells and this is the most likely reason cysts do not reoccur in kidneys transplanted into PKD patients.

Experiences and lessons learned as a Chair of anatomy—An 18‐year journey

Publisher: Wiley

Date: 08-01-2020

DOI: 10.1002/AR.24345

Abstract: In 1998, I was appointed Chair of the Department of Anatomy at Monash University in Melbourne, Australia. On commencing as Chair, I had three main goals: (a) to maintain and extend the high quality of anatomy teaching in the medical program (b) to introduce significantly more developmental biology, cell biology, and neuroscience into our existing Bachelor of Science major in human anatomy and (c) to establish an active research program in the department. Over the next 18 years, I worked with staff and students at all levels of the university to turn this vision into a reality, with the Monash Department of Anatomy and Developmental Biology now arguably the top ranked anatomy department in Australia. During my tenure, countless challenges were faced and while some errors were made, and a good number of goals were never realized the general outcome was a vibrant scholarly environment where that rich nexus of research and teaching was realized. This personal account provides some insights into that 18-year journey, which I hope may prove useful for current and future Chairs of anatomy. For me personally, it was definitely a journey worth taking.

Diffusive oxygen shunting between vessels in the preglomerular renal vasculature: anatomic observations and computational modeling

Publisher: American Physiological Society

Date: 09-2012

DOI: 10.1152/AJPRENAL.00186.2012

Abstract: To understand how geometric factors affect arterial-to-venous (AV) oxygen shunting, a mathematical model of diffusive oxygen transport in the renal cortex was developed. Preglomerular vascular geometry was investigated using light microscopy (providing vein shape, AV separation, and capillary density near arteries) and published micro-computed tomography (CT) data (providing vessel size and AV separation Nordsletten DA, Blackett S, Bentley MD, Ritman EL, Smith NP. IUPS Physiome Project. www.physiome.org.nz ublications/nordsletten_blackett_ritman_bentley_smith_2005/folder_contents ). A “U-shaped” relationship was observed between the arterial radius and the distance between the arterial and venous lumens. Veins were found to partially wrap around the artery more consistently for larger rather than smaller arteries. Intrarenal arteries were surrounded by an area of fibrous tissue, lacking capillaries, the thickness of which increased from ∼5 μm for the smallest arteries ( -μm diameter) to ∼20 μm for the largest arteries ( -μm diameter). Capillary density was greater near smaller arteries than larger arteries. No capillaries were observed between wrapped AV vessel pairs. The computational model comprised a single AV pair in cross section. Geometric parameters critical in renal oxygen transport were altered according to variations observed by CT and light microscopy. Lumen separation and wrapping of the vein around the artery were found to be the critical geometric factors determining the amount of oxygen shunted between AV pairs. AV oxygen shunting increases both as lumen separation decreases and as the degree of wrapping increases. The model also predicts that capillaries not only deliver oxygen, but can also remove oxygen from the cortical parenchyma close to an AV pair. Thus the presence of oxygen sinks (capillaries or tubules) near arteries would reduce the effectiveness of AV oxygen shunting. Collectively, these data suggest that AV oxygen shunting would be favored in larger vessels common to the cortical and medullary circulations (i.e., arcuate and proximal interlobular arteries) rather than the smaller vessels specific to the cortical circulation (distal interlobular arteries and afferent arterioles).

Glomerular hypertrophy in subjects with low nephron number: contributions of sex, body size and race

Publisher: Oxford University Press (OUP)

Date: 02-05-2014

DOI: 10.1093/NDT/GFU088

Altered ureteric branching morphogenesis and nephron endowment in offspring of diabetic and insulin-treated pregnancy

Publisher: Public Library of Science (PLoS)

Date: 13-03-2013

DOI: 10.1371/JOURNAL.PONE.0058243

Characterization of an animal model of hepatic metastasis

Publisher: Wiley

Date: 1996

DOI: 10.1111/J.1440-1746.1996.TB00006.X

Abstract: The experimental study of possible therapies for control of the growth of liver metastases requires the availability of a model which is technically feasible and appears to exhibit growth characteristics similar to human tumours. We report on the development of an intrasplenic injection model of liver metastases, and describe the histology, growth pattern and blood flow demonstrated by light microscopy, stereology and laser Doppler flowmetry. The hepatic metastases were induced in mice by intrasplenic injection of dimethylhydrazine (DMH) induced primary colonic carcinoma cells (10(6) cells in 1 mL). The growth and development of metastases was studied over a period of 3 weeks at predetermined time points. Tumour cells were visible in the hepatic sinusoids by day 7 by light microscopy. Macroscopically visible tumours with a diameter of 0.18 +/- 0.02 cm (mean +/- s.d.) were seen by day 10. By this time the tumours had derived a blood supply from the hepatic sinusoids adjacent to the tumour periphery. With further vascularization the tumours reached a diameter of 0.96 +/- 0.50 cm by day 22. Metastatic growth was quantitated by stereological analysis of tumour volume in relation to non-diseased hepatic tissue. Normal mouse liver had a mean volume of 1.13 +/- 0.14 cm3. Tumour growth occurred in three phases. During the initial slow phase the volume of metastases increased from 0.03 +/- 0.02 cm3 at day 10 to 0.22 +/- 0.24 cm3 by day 16. Rapid tumour growth, occurring over the next 3 days, constituted the intermediate phase with metastatic volume reaching 1.21 +/- 0.74 cm3 by day 19 (P = 0.0003 compared with day 16). This growth was followed by a plateau phase when the metastatic volume was 1.40 +/- 0.55 cm3 at day 22. The volume of total liver and of tumour necrosis followed a similar growth pattern. A necrotic tumour volume of 0.004 +/- 0.006 cm3 first seen on day 10 increased to 0.05 +/- 0.06 cm3 by day 16, and to 0.25 +/- 0.20 cm3 by day 22 (P = 0.0022 compared with day 16). The blood flow in metastases measured by laser Doppler flowmetry was lower compared to the non-diseased liver. Tumour blood flow, expressed as a percentage of normal liver blood flow, was 63.31 +/- 26.28% at day 10 and diminished to 27.91 +/- 8.99% by day 22, with an increase in tumour size and age. The decrease in flow was significant between days 13 and 16 (P = 0.0015). This intrasplenic mouse model of metastases is reproducible and should prove useful in the study of treatment of hepatic metastases.

Combined prenatal and postnatal protein restriction influences adult kidney structure, function, and arterial pressure

Publisher: American Physiological Society

Date: 2007

DOI: 10.1152/AJPREGU.00079.2006

Abstract: The effects of prenatal protein restriction on adult renal and cardiovascular function have been studied in considerable detail. However, little is known about the effects of life-long protein restriction, a common condition in the developing world. Therefore, we determined in rats the effects of combined pre- and postnatal protein restriction on adult arterial pressure and renal function and responses to increased dietary sodium. Nephron number was also determined. Male Sprague-Dawley rats were born to mothers fed a low [8% (wt/wt), LP] or normal [20% (wt/wt), NP] isocaloric protein diet throughout pregnancy and maintained on these diets after birth. At postnatal day 135, nephron number, mean arterial pressure (MAP), and renal function were determined. A high-NaCl [8.0% (wt/wt), high-salt] diet was fed to a subset of rats from weaning. MAP was less in LP than in NP rats (120 ± 2 vs. 128 ± 2 mmHg, P 0.05) and was not significantly altered by increased salt intake. Nephron number was 31% less in LP than in NP rats ( P 0.001). The volume of in idual glomeruli was also less in LP than in NP rats, as were calculated effective renal plasma flow and glomerular filtration rate. Glomerular filtration rate, but not effective renal plasma flow, appeared to be increased by high salt intake, particularly in LP rats. In conclusion, protein restriction induced a severe nephron deficit, but MAP was lower, rather than higher, in protein-restricted than in control rats in adulthood. These findings indicate that the postnatal environment plays a key role in determining the outcomes of developmental programming.

Genome-Wide ENU Mutagenesis in Combination with High Density SNP Analysis and Exome Sequencing Provides Rapid Identification of Novel Mouse Models of Developmental Disease

Publisher: Public Library of Science (PLoS)

Date: 03-2013

DOI: 10.1371/JOURNAL.PONE.0055429

Development of cardiovascular disease due to renal insufficiency in male sheep following fetal unilateral nephrectomy

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 02-2009

DOI: 10.1097/HJH.0B013E32831BC778

Applicability of the glomerular size distribution coefficient in assessing human glomerular volume: The Weibel and Gomez method revisited

Publisher: Wiley

Date: 19-04-2007

DOI: 10.1111/J.1469-7580.2007.00715.X

A comparison of nephron number, glomerular volume and kidney weight in Senegalese Africans and African Americans

Publisher: Oxford University Press (OUP)

Date: 11-02-2010

DOI: 10.1093/NDT/GFQ030

Renal Structural and Functional Repair in a Mouse Model of Reversal of Ureteral Obstruction

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 12-2005

DOI: 10.1681/ASN.2004090771

Organisation of Bone Morphogenetic Proteins in Renal Development

Publisher: S. Karger AG

Date: 17-11-2004

DOI: 10.1159/000066649

Abstract: Bone morphogenetic proteins (BMPs) comprise the largest subfamily of the transforming growth factor-β (TGF-β) superfamily of secreted proteins. Evidence for the involvement of BMPs in metanephric development emerged recently when renal phenotypes were observed in BMP7 null mutant mice. Since then, several other BMPs, BMP receptor serine/threonine kinases and BMP signal transduction molecules (Smads) have been implicated in mammalian metanephric development. It appears that particular BMPs have pivotal roles in specific aspects of metanephric development. Current knowledge and evidence of specific roles of particular BMPs are presented in this review.

bfb, a Novel ENU-Induced blebs Mutant Resulting from a Missense Mutation in Fras1

Publisher: Public Library of Science (PLoS)

Date: 15-10-2013

DOI: 10.1371/JOURNAL.PONE.0076342

Counting in the kidney

Publisher: Elsevier BV

Date: 02-2001

DOI: 10.1046/J.1523-1755.2001.059002792.X

Chronic kidney cortical damage is associated with baseline kidney function and albuminuria in patients managed with radical nephrectomy for kidney tumours

Publisher: Elsevier BV

Date: 2019

DOI: 10.1016/J.PATHOL.2018.10.009

Abstract: This study evaluated the relationship between histological markers of chronic kidney damage in patients undergoing radical nephrectomy for kidney tumours and preoperative kidney function, degree of albuminuria, and changes in glomerular volume. A schema to grade chronic kidney damage could be used to identify patients at risk of developing CKD following nephrectomy. Non-neoplastic cortical tissue was sourced from 150 patients undergoing radical nephrectomy for suspected kidney cancer. This tissue was evaluated for indicators of chronic damage, specifically: glomerulosclerosis, arteriosclerosis, interstitial fibrosis, and tubular atrophy. Glomerular volume was determined using the Weibel and Gomez method. Associations between these parameters and both estimated glomerular filtration rate (eGFR) and albumin-creatinine ratio (ACR) were determined using either a Mann-Whitney U-test or a Kruskal-Wallis ANOVA. Associations between both eGFR and ACR and glomerular volume were assessed using linear regression. eGFR was inversely associated with the degree of glomerulosclerosis (p < 0.001), vascular narrowing (p = 0.002), tubular atrophy (p < 0.001), and interstitial fibrosis (p < 0.001). ACR was associated only with the degree of interstitial fibrosis (p = 0.02) and tubular atrophy (p = 0.02). Glomerular volume was greater for males, diabetics, hypertensive patients, and patients with a greater degree of interstitial fibrosis. Glomerular volume was positively associated with ACR. A schema to grade chronic damage was developed. The proposed schema is associated with baseline clinical indices of kidney function and damage. Longitudinal validation is necessary to determine the prognostic utility of this schema.

Sexual Dimorphism in Mouse Metanephroi Exposed to 17β-Estradiol in vitro

Publisher: S. Karger AG

Date: 13-01-2009

DOI: 10.1159/000191104

Abstract: 17β-Estradiol, the most potent circulating estrogen, has been shown to greatly impact on the development and formation of tissues of the urogenital tract. The adult kidney has previously been shown to be highly responsive to 17β-estradiol stimulation. However, the direct effect of 17β-estradiol on kidney development remains unclear. i Aim: /i To investigate the direct effect of 17β-estradiol on male and female metanephric kidney development. i Methods: /i Whole embryonic-day-12.5 (E12.5) C57Bl/6 male and female mouse metanephroi were cultured in the presence of varying concentrations of 17β-estradiol (0.1–5.0 n i M /i ) for 72 h. Metanephric development was assessed using immunofluorescence labeling techniques. The real-time polymerase chain reaction was used to investigate estrogen receptor-α i (ER /i α i ), /i glial-cell-line-derived neurotrophic factor i (GDNF) /i and its associated receptor i cRET, /i transforming growth factor-β (TGFβ1), i TGF /i β i /i and TGFβ3 mRNA expression levels. i Results: /i i ER /i α was present in developing metanephroi at E12.5 however, i ER /i β was absent. No significant sex difference in i ER /i α mRNA expression was observed. Significant increases in the number of ureteric branch points, terminal tips and developing glomeruli were observed in female metanephroi cultured in the presence of 1.0 and 5.0 n i M /i 17β-estradiol. Conversely, no significant effect was observed in male metanephroi cultured with 17β-estradiol. i GDNF /i and i cRET /i mRNA expression was increased in both male and female metanephroi, whilst i TGF /i β i /i and i TGF /i β i /i mRNA expression was decreased following culture in the presence of 17β-estradiol. i Conclusion: /i This study is the first to establish that the mouse metanephros displays a sexual dimorphism in response to specific concentrations of estrogens.

We can see clearly now

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 05-2017

DOI: 10.1097/MNH.0000000000000314

Computer‐based detection of neonatal changes to branching morphogenesis reveals different mechanisms of and predicts prostate enlargement in mice haplo‐insufficient for bone morphogenetic protein 4

Publisher: Wiley

Date: 17-03-2005

DOI: 10.1002/PATH.1753

Abstract: Early changes to branching morphogenesis of the prostate are believed to lead to enlargement of the gland in adult life. However, it has not been possible to demonstrate directly that alterations to branching during the developmental period have a permanent effect on adult prostate size. In order to examine branching morphogenesis in a quantitative manner in neonatal mice, a combination of imaging and computational technology was used to detect and quantify branching using bone morphogenetic protein 4 haplo-insufficient mice that develop enlarged prostate glands in adulthood. Accurate estimates were made of six parameters of branching, including prostate ductal length and volume and number of main ducts, branches, branch points, and tips. The results show that the prostate is significantly larger on day 3, well before the emergence of the phenotype in older animals. The ventral prostate is enlarged because the number of main epithelial ducts is increased enlargement of the anterior prostate in mutant animals occurs because there are more branches. These lobe-specific mechanisms underlying prostate enlargement indicate the complex nature of gland pathology in mice, rather than a simple increase in weight or volume. This method provides a powerful means to investigate the aetiology of prostate disease in animal models prior to emergence of a phenotype in later life.

Nephron number and blood pressure in rat offspring with maternal high-protein diet

Publisher: Springer Science and Business Media LLC

Date: 12-2002

DOI: 10.1007/S00467-002-0998-8

Abstract: This study investigated the effects of a high-protein diet during pregnancy on nephron endowment and subsequent levels of blood pressure in the offspring. Female WKY rats were fed either a normal (20%, NPD) or a high (54%, HPD) protein diet during pregnancy. Male offspring were paired at birth. At 4 weeks of age, 1 of the pair was randomly chosen for perfusion fixation, and total glomerular number, and thereby nephron number, was estimated using an unbiased stereological technique. The other rat of the pair was allowed to grow to 30 weeks of age, during which time tail cuff systolic blood pressure was monitored twice weekly. There was no effect of the HPD on birth weight (NPD 4.23+/-0.53 g, HPD 4.26+/-0.45 g, mean+/-SD), kidney weight (NPD 0.372+/-0.049 g, HPD 0.337+/-0.090 g), or total nephron number (NPD 27,191+/-3,512, HPD 26,738+/-4,735). Systolic blood pressure at 30 weeks was 170+/-14 mmHg in NPD and 169+/-14 in HPD offspring. These findings show that a HPD during pregnancy did not lead to an increase in birth weight, kidney weight, or nephron endowment, nor did the HPD affect adult blood pressure.

Counting cells with stereology: Random versus serial sectioning

Publisher: Wiley

Date: 1990

DOI: 10.1002/JEMT.1060140106

Abstract: Counts of cells and nuclei from sections provide information central to studying structural changes in cells, tissues, and organs. This study considers some of the practical problems associated with counting cells with the newer random and serial sectioning methods of stereology and tests the hypothesis that similar cell counts can be obtained with both random and serial sectioning methods. Using irregularly shaped nuclei from alveolar cells of the goat lung, we compared cell counts derived from random (electron microscopic) and serial sectioning (light microscopic) methods. The results showed that both sectioning methods gave similar cell counts (10(7)/cm3 of parenchyma) for type 1 epithelial cells (5.0 vs. 5.0 P=1.0), type 2 epithelial cells (8.6 vs. 9.8 P= 0.42) and interstitial cells (34.6 vs. 33.4 P=0.64), provided that corrections were introduced for section-related biases and that the nuclei of the random sectioning method were corrected for shape. We found counting biases of 5%-7% for nuclear shape and 16% for section compression. These observations support the hypothesis that similar cell counts can be obtained with random and serial sectioning, even when nuclei have irregular shapes.

CARDIAC HYPERTROPHY IN DIABETIC SPONTANEOUSLY HYPERTENSIVE RATS: ROLE OF ANGIOTENSIN II?

Publisher: Wiley

Date: 06-1997

DOI: 10.1111/J.1440-1681.1997.TB01221.X

Abstract: 1. In the present study the role of angiotensin II (AngII) in the development of cardiac hypertrophy in diabetes combined with hypertension was investigated. 2. Diabetes was induced in 8-week-old male spontaneously hypertensive rats (SHR) by intravenous injection of streptozotocin (45 mg/kg bodyweight). Diabetic SHR were treated with the angiotensin-converting enzyme (ACE) inhibitor ramipril at a dose of 0.4 mg/kg per day. 3. Twelve weeks following the onset of diabetes, hearts were arrested in diastole and were perfusion-fixed. The right ventricle and left ventricle plus septum were weighted and the volume of the ventricular walls was determined using the Cavalieri principle. 4. Induction of diabetes in SHR led to a significant reduction in bodyweight compared with non-diabetic control SHR and this was not affected by ramipril treatment. The development of hypertension was not as great in diabetic SHR compared with controls, such that at 12 weeks following the onset of diabetes systolic blood pressure (SBP) averaged 191 +/- 3 and 230 +/- 4 mmHg in diabetic SHR and controls, respectively. Ramipril treatment significantly lowered SBP in diabetic SHR. 5. The left ventricle plus septum volume:bodyweight ratio (LV vol:BW) was significantly higher in diabetic SHR compared with controls (3.83 +/- 0.19 and 3.26 +/- 0.16 mm3/g, respectively). Ramipril treatment did not affect growth of the left ventricle in diabetic SHR with the LV vol:BW ratio averaging 3.95 +/- 0.14 mm3/g. Similar trends on growth were observed in the right ventricle. 6. In conclusion, the development of cardiac hypertrophy in diabetic SHR appears to occur by mechanisms independent of AngII and the elevation of blood pressure.

Design-based stereological methods for estimating numbers of glomerular podocytes

Publisher: Elsevier BV

Date: 2014

DOI: 10.1016/J.AANAT.2013.04.007

Abstract: The podocyte depletion hypothesis has emerged as a unifying concept in glomerular pathology. According to this hypothesis podocyte depletion may be absolute (decrease in number of healthy mature podocytes), relative (fewer podocytes per unit of glomerular volume) or involve alterations to the specialized podocyte architecture (such as foot process effacement). To study and understand podocyte depletion it is important to be able to accurately and precisely count these cells. Here we present new design-based stereological methods for estimating podocyte number in in idual glomeruli of known volume, and in average glomeruli. Both methods involve serial histological sectioning, triple label immunohistochemistry, laser confocal microscopy and cell counting with the optical disector/fractionator.

Mutagenesis of the epithelial polarity gene, discs large 1, perturbs nephrogenesis in the developing mouse kidney

Publisher: Elsevier BV

Date: 09-2005

DOI: 10.1111/J.1523-1755.2005.00489.X

Abstract: During development of the permanent mammalian kidney (metanephros) several key epithelial events occur such as ureteric branching morphogenesis and nephrogenesis. One of the first stages of nephrogenesis involves the conversion of mesenchymal cells to epithelial cells, and thus the metanephros provides an excellent model to study epithelial polarization. The aim of this study was to investigate the role of the epithelial polarity gene, discs large 1 (dlg1), during development of the mouse kidney. We utilized mice with a gene trap vector insertion within dlg1 (dlg(gt)) resulting in a truncated Dlg1 protein, lacking the SH3, protein 4.1 and guanylate kinase-like (GUK) domains, fused to a LacZ reporter. These mice were used to analyze the expression of Dlg1 during kidney development, the subcellular localization of Dlg1 in epithelial cells, and the ability of Dlg1 to bind to calmodulin-associated serine/threonine kinase (CASK). Metanephric organ culture was used to study branching morphogenesis and nephrogenesis in wild-type and dlg(gt) mutant mice. Dlg1 was expressed in ureteric and mesenchyme-derived epithelial cells during kidney development. Truncation of Dlg1 altered the normal basolateral localization of Dlg1 restricting it to the adherens junction. Due to the loss of the SH3 domain the binding capacity of Dlg1 to CASK was reduced. Nephrogenesis was altered in dlg(gt)/dlg(gt) metanephroi with a 30% decrease in nephron number. Our results indicate that the loss of the SH3, protein 4.1 and/or GUK domains of Dlg1 disrupt epithelial polarity and perturb nephrogenesis either as a secondary consequence to a defect in ureteric branching morphogenesis and/or delay in mesenchyme-to- epithelial transition.

Effects of dexamethasone exposure on rat metanephric development: in vitro and in vivo studies

Publisher: American Physiological Society

Date: 08-2007

DOI: 10.1152/AJPRENAL.00156.2007

Abstract: Maternal administration of dexamethasone (DEX) for 48 h early in rat kidney development results in offspring with a reduced nephron endowment. However, the mechanism through which DEX inhibits nephrogenesis is unknown. In this study, we hypothesized that DEX may indirectly inhibit nephrogenesis by inhibiting ureteric branching morphogenesis. Whole metanephroi from embryonic day 14.5 ( E14.5) rat embryos were cultured in the presence of DEX. DEX (10 −5 M) exposure for 2 days significantly inhibited ureteric branching compared with metanephroi grown in control media or DEX (10 −7 M). Culturing metanephroi for a further 3 days (in control media only) reduced total glomerular number in metanephroi previously exposed to DEX (10 −5 M) or (10 −7 M) compared with control cultures. Expression of genes known to regulate ureteric branching morphogenesis was determined by real-time PCR in metanephroi after 2 days in culture. DEX exposure in vitro decreased expression of glial cell line-derived neurotrophic factor (GDNF) and increased expression of bone morphogenetic protein-4 (BMP-4) and transforming growth factor-β1 (TGF-β1). Similar gene expression changes were found in E16.5 metanephroi in which the dam had been exposed to 2 days of DEX (0.2 mg·kg −1 ·day −1 ) at E14.5/15.5 in vivo. However, in kidneys collected at E20.5 after in vivo exposure for 2 days, GDNF expression was increased and BMP-4 and TGF-β1 expression decreased suggesting a biphasic response in gene expression to DEX exposure. These results show for the first time that inhibition of ureteric branching morphogenesis may be a key mechanism through which DEX exposure results in a reduced nephron endowment.

Does a Nephron Deficit in Rats Predispose to Salt-Sensitive Hypertension?

Publisher: S. Karger AG

Date: 2004

DOI: 10.1159/000079868

Abstract: i Aim: /i This study tested the hypothesis that a nephron deficit predisposes rats to salt-sensitive hypertension in adulthood. i Methods: /i Female Wistar-Kyoto rats were fed a low (9%) or a normal (20%) protein diet during pregnancy and lactation. Male, birth-weight-matched offspring were paired. One rat from each pair was perfusion fixed at 4 weeks of age and the other rat at 40 weeks of age. Kidneys were removed and nephron number and total renal filtration surface area (FSA) determined using unbiased stereological techniques. The rats that were allowed to grow to adulthood had tail-cuff systolic blood pressure and body weight determined twice weekly. Between 30 and 40 weeks of age, a normal or a high-salt diet was fed to the rats. i Results: /i The offspring of rats fed the low-protein diet were significantly smaller at birth, and at 4 weeks of age they had a significant reduction in kidney volume, nephron number, and total renal FSA when compared to controls. Tail-cuff systolic blood pressure in the offspring from 4 to 29 weeks of age did not significantly differ between the two groups. Administration of a high-salt diet from 30 to 40 weeks of age led to a significant increase in blood pressure in both dietary treatment groups however, it was not exacerbated in the rats exposed to the low-protein diet in utero. i Conclusions: /i Maternal protein restriction in rats did not lead to salt-sensitive hypertension. Nephron endowment and FSA did not correlate with blood pressure in adulthood.

The Smad3/Smad4/CDK9 complex promotes renal fibrosis in mice with unilateral ureteral obstruction

Publisher: Elsevier BV

Date: 12-2015

DOI: 10.1038/KI.2015.235

Abstract: Transforming growth factor-β1 (TGF-β1)/Smad signaling has a central role in the pathogenesis of renal fibrosis. Smad3 and Smad4 are pro-fibrotic, while Smad2 is anti-fibrotic. However, these Smads form heterogeneous complexes, the functions of which are poorly understood. Here we studied Smad complex function in renal fibrosis using the mouse model of unilateral ureteric obstruction. Mice heterozygous for Smad3/4 (Smad3/4

Long‐term effects of a midgestational asphyxial episode in the ovine fetus

Publisher: Wiley

Date: 09-2006

DOI: 10.1002/AR.A.20381

Abstract: We and others have shown previously that fetuses at midgestation can survive 30 min of complete umbilical cord occlusion, although hydrops fetalis (or gross fetal edema) results. To investigate whether this hydrops resolves by late gestation and if there are any long-term consequences of the asphyxial insult on the heart and kidneys, eight fetuses were subjected to 30 min of complete umbilical cord occlusion at 0.6 gestation (90 days term 150 days) and were compared to a sham group (n = 10). During the occlusion period, fetuses became severely hypoxemic, hypercapnemic, and acidotic, with both blood pressure and heart rate decreasing. Most variables had returned to normal by 2-hr recovery. At 129 +/- 1 days of gestation, approximately 40 days post occlusion, some fetuses were still slightly hydropic as skin fold measurements were increased (P < 0.01), although fetal body weight was not different from the sham group. The two groups had similar heart and kidney weights, ventricular cardiac myocyte nucleation, and glomerular number. By contrast, brain weight was reduced by 37% (P < 0.001) and the cerebral lateral ventricles were grossly dilated. Lungs were 50% smaller than in sham fetuses (P < 0.001). Thus, the hydrops that develops at midgestation as a result of a severe asphyxial episode can, but does not always, fully resolve by late gestation. Also, while fetuses at midgestation can survive this asphyxial episode with no long-term impact in renal or cardiac size, nephron number, or cardiomyocyte nucleation, the brain and lungs are severely affected.

Development of the Human Fetal Kidney from Mid to Late Gestation in Male and Female Infants

Publisher: Elsevier BV

Date: 12-0012

DOI: 10.1016/J.EBIOM.2017.12.016

A morphometric study of the effects of maturation and aging on synaptic patterns in the spinal trigeminal nucleus of the cat

Publisher: Elsevier BV

Date: 10-1985

DOI: 10.1016/0006-8993(85)90832-7

Abstract: Morphometric methods have been used to study the synaptic and terminal patterns in cat trigeminal nucleus, pars interpolaris, during development and aging. Ages 1, 3, 6, 11, 16, 21, 27, 110, 600 days and 8 and 11 years were studied. Both proportions and densities (number per unit area) of certain terminals and synapses showed significant changes with age. Axoaxonic synapses especially showed two major periods of increase (3-6 days and 21-27 days). The values of most parameters increased in the 21-27 day period to peak levels and then decreased gradually with age. The results indicate two separate critical synaptogenic periods of development and a loss of synaptic elements in aging. Factors contributing to these changes are discussed as is the potential for plasticity in the different afferents at each period.

Podocyte foot process broadening in experimental diabetic nephropathy: Amelioration with renin-angiotensin blockade

Publisher: Springer Science and Business Media LLC

Date: 07-2001

DOI: 10.1007/S001250100561

Abstract: Changes in podocyte number and morphology have been implicated in the pathogenesis of proteinuria and the progression of human and experimental kidney disease. This study sought to examine podocyte foot process and slit pore architecture in experimental diabetic nephropathy and to determine whether such changes were modified with renoprotective intervention by blockade of the renin-angiotensin system. The number of filtration slits per 100 microm of glomerular basement membrane was assessed by transmission electron microscopy and quantitated histomorphometrically in control animals and in rats with 24 weeks of streptozotocin-induced diabetes. Diabetic rats were either untreated or received the angiotensin converting enzyme inhibitor ramipril, or the angiotensin II type 1 receptor antagonist, valsartan. When compared with control animals, diabetes was associated with a decrease in the number of slit pores per unit length of glomerular basement membrane, indicative of podocyte foot process broadening. Both ramipril and valsartan attenuated these ultrastructural changes to a similar degree. These differences remained after correcting for glomerular volume as a possible confounding variable. Preservation of podocyte architecture could contribute to the renoprotective effects of renin-angiotensin system blockade in diabetic nephropathy.

APOL1 Risk Variants Independently Associated With Early Cardiovascular Disease Death

Publisher: Elsevier BV

Date: 2018

DOI: 10.1016/J.EKIR.2017.08.007

Bone morphogenetic protein signaling in the developing kidney: present and future

Publisher: Elsevier BV

Date: 10-2008

DOI: 10.1111/J.1432-0436.2008.00265.X

Abstract: Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta superfamily. A critical role for BMP signaling in the development of the metanephric kidney is supported by a growing number of studies using in vitro assays and in vivo animal models. Here we review current knowledge of BMPs, BMP receptors and regulators of the BMP signaling pathway in the developing kidney. We highlight major gaps in our knowledge of the roles of BMP signaling in the development of the normal and abnormal kidney and identify areas and techniques likely to improve our understanding.

Reduced nephron endowment due to fetal uninephrectomy impairs renal sodium handling in male sheep

Publisher: Portland Press Ltd.

Date: 09-03-2010

DOI: 10.1042/CS20090479

Abstract: Reduced nephron endowment is associated with development of renal and cardiovascular disease. We hypothesized this may be attributable to impaired sodium homoeostasis by the remaining nephrons. The present study investigated whether a nephron deficit, induced by fetal uninephrectomy at 100 days gestation (term=150 days), resulted in (i) altered renal sodium handling both under basal conditions and in response to an acute 0.9% saline load (50 ml·kg−1 of body weight·30 min−1) (ii) hypertension and (iii) altered expression of renal channels/transporters in male sheep at 6 months of age. Uninephrectomized animals had significantly elevated arterial pressure (90.1±1.6 compared with 77.8±2.9 mmHg P& .001), while glomerular filtration rate and renal blood flow (per g of kidney weight) were 30% lower than that of the sham animals. Total kidney weight was similar between the groups. Renal gene expression of apical NHE3 (type 3 Na+/H+ exchanger), ENaC (epithelium Na+ channel) β and γ subunits and basolateral Na+/K+ ATPase β and γ subunits were significantly elevated in uninephrectomized animals, while ENaC α subunit expression was reduced. Urine flow rate and sodium excretion increased in both groups in response to salt loading, but this increase in sodium excretion was delayed by approximately 90 min in the uninephrectomized animals, while total sodium output was 12% in excess of the infused load (P& .05). In conclusion, the present study shows that animals with a congenital nephron deficit have alterations in tubular sodium channels/transporters and cannot rapidly correct for variations in sodium intake probably contributing to the development of hypertension. This suggests that people born with a nephron deficit should be monitored for early signs of renal and cardiovascular disease.

Imaging the Embryonic Kidney

Publisher: S. Karger AG

Date: 13-03-2006

DOI: 10.1159/000090618

Abstract: The structural and functional development of the permanent mammalian kidney or metanephros is a complex process involving the actions of thousands of gene products, complex cell movements and tissue patterning in three dimensions (3D). This review focuses on the recent advances made in imaging technology, processing and analysis combined with mouse genetics and the generation of protein-reporter mice which has enabled us to monitor the development and movement of defined cell populations within the developing kidney in 3D and over time (4D).

Vascular Growth Responses in SHR and WKY During Development of Renal (1K1C) Hypertension

Publisher: Oxford University Press (OUP)

Date: 1997

DOI: 10.1016/S0895-7061(96)00255-5

Abstract: Intrinsic differences between vascular smooth muscle cells (VSMC) in normotension and genetic hypertension may account for the exaggerated growth response often observed in the hypertensive vasculature. To test this hypothesis, in this study we compared the vascular growth response of the spontaneously hypertensive rat (SHR) and Wistar-Kyoto rat (WKY) following induction of one kidney, one clip (1KlC) renal hypertension. SHR and WKY rats were uninephrectomized and renal hypertension (RH) induced using silver clips of 0.22 and 0.24 mm width. Four weeks later, vessel and VSMC growth were assessed in small mesenteric arteries. The systolic blood pressure (SBP) in the RH animals was significantly higher than in uninephrectomised controls, in RH-SHR with a 0.24 mm clip SBP averaged 215 +/- 4 mm Hg and in RH-WKY with a 0.22 or 0.24 mm clip the SBPs averaged 214 +/- 5 mm Hg and 190 +/- 2 mm Hg, respectively. For the same SBP, there were no differences in medial cross-sectional areas of the small mesenteric arteries between RH-SHR and RH0.22-WKY, which averaged 1.73 +/- 0.19 x 10(4) microm2 and 1.66 +/- 0.15 x 10(4) microm2, respectively. Likewise, the number of VSMCs (within a precise anatomical site of the mesenteric vasculature) were not different between the RH-SHR and the RH0.22-WKY with VSMC number 7.6 +/- 0.8 x 10(4) cells and 6.9 +/- 0.4 x 10(4) cells, respectively. In the RH0.22-WKY vascular growth responses were generally unchanged compared with the RH0.24-WKY except for a further increase in the incidence of polyploid cells. In conclusion, the results of this study demonstrate that smooth muscle cells of the SHR are not hyperresponsive to all growth-promoting stimuli. Taken together with previous observations, it appears that sustained activity of the renin-angiotensin system may be required for exaggerated vascular growth responses in SHR.

Expression Patterns and Roles of Periostin During Kidney and Ureter Development

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 10-2011

DOI: 10.1016/J.JURO.2011.05.042

Abstract: Periostin is a secreted extracellular matrix protein that is differentially expressed in the developing kidney. We analyzed the temporal-spatial expression of periostin in the developing kidney and ureter as well as its roles in ureter branching morphogenesis, nephrogenesis and ureter development. RNA in situ hybridization and immunofluorescence histochemistry were used to investigate the expression of periostin, αv integrin and α-smooth muscle actin during mouse renal and ureteral development. Metanephric explants were cultured in the presence of recombinant periostin, and ureteral branch points/tips and the glomerular number were quantified. Explants were also cultured in the presence of exogenous bone morphogenetic protein 4 and the effect on periostin mRNA levels was determined by quantitative real-time polymerase chain reaction. Periostin expression was observed in the mesenchyme surrounding the kidney and ureter, renal stroma, metanephric mesenchyme, ureter epithelium and developing nephrons. At embryonic day 15.5 periostin and αv integrin, a common subunit of periostin receptors, were co-expressed in smooth muscle cells of the ureter, renal artery and intrarenal arteries. Bone morphogenetic protein 4 up-regulated periostin mRNA expression and exogenous periostin inhibited branching morphogenesis and glomerular number. Bone morphogenetic protein 4 which inhibits ureteral branching morphogenesis and promotes smooth muscle cell migration in the ureter up-regulated periostin mRNA expression in the developing kidney. Ureteral smooth muscle cells express periostin and αv integrin. Periostin inhibited ureteral branching morphogenesis and glomerular number. Together these results suggest that periostin and bone morphogenetic protein 4 may have a role in branching morphogenesis, nephrogenesis and possibly smooth muscle cell migration.

Smad3 deficiency protects mice from obesity-induced podocyte injury that precedes insulin resistance

Publisher: Elsevier BV

Date: 08-2015

DOI: 10.1038/KI.2015.121

Abstract: Signaling by TGF-β/Smad3 plays a key role in renal fibrosis. As obesity is one of the major risk factors of chronic and end-stage renal disease, we studied the role of Smad3 signaling in the pathogenesis of obesity-related renal disease. After switching to a high fat diet, the onset of Smad3 C-terminal phosphorylation, increase in albuminuria, and the early stages of peripheral and renal insulin resistance occurred at 1 day, and 4 and 8 weeks, respectively, in C57BL/6 mice. The loss of synaptopodin, a functional marker of podocytes, and phosphorylation of the Smad3 linker region (T179 and S213) appeared after 4 weeks of the high fat diet. This suggests a temporal pattern of Smad3 signaling activation leading to kidney injury and subsequent insulin resistance in the development of obesity-related renal disease. In vivo, Smad3 knockout attenuated the high fat diet-induced proteinuria, renal fibrosis, overall podocyte injury, and mitochondrial dysfunction in podocytes. In vitro palmitate caused a rapid activation of Smad3 in 30 min, loss of synaptopodin in 2 days, and impaired insulin signaling in 3 days in isolated mouse podocytes. Blockade of either Smad3 phosphorylation by SIS3 (a Smad3 inhibitor) or T179 phosphorylation by flavopiridol (a CDK9 inhibitor) prevented the palmitate-induced loss of synaptopodin and mitochondrial function in podocytes. Thus, Smad3 signaling plays essential roles in obesity-related renal disease and may be a novel therapeutic target.

Decreased developmental cell death in sympathetic and spinal sensory nervous systems of the Kyoto spontaneously hypertensive rat

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 09-1996

DOI: 10.1097/00004872-199609000-00011

Abstract: To investigate the hypotheses that Kyoto spontaneously hypertensive rats (SHR) possess more sympathetic neurons than do normotensive Wistar-Kyoto (WKY) animals due to reduced perinatal cell death and that this is due to increased availability of the sympathetic survival neurotrophin, nerve growth factor. Total cell counts of neuron numbers were performed in neonatal and adult SHR and WKY rat superior cervical ganglia and correlated with counts of apoptotic cells. The values for sympathetic neuron numbers were compared with those for a spinal sensory ganglion. Immunocytochemistry was used to obtain more information about the phenotypes of neurons counted. Adult SHR sympathetic ganglia contained about 25% more sympathetic neurons than did those of WKY animals. Similar elevation of numbers was found both for neurons containing and for those devoid of neuropeptide Y. In neonatal animals, in contrast, there was no strain difference in sympathetic cell numbers but the number of apoptotic cells was reduced in SHR. Spinal sensory neuron numbers in adult SHR were elevated to a similar extent as were sympathetic neurons, but biochemical and morphometric data suggested that this change does not involve cells that are sensitive to nerve growth factor. Although our results support the view that there is reduced developmental cell death both in sympathetic and in sensory systems, they also suggest that this is unlikely to be due to a simple excess of nerve growth factor during development.

Expression of fibroblast growth factors and their receptors in rat glomeruli

Publisher: Elsevier BV

Date: 06-1997

DOI: 10.1038/KI.1997.238

Abstract: Fibroblast growth factors (FGFs) regulate cell proliferation and differentiation, and are also important regulators of extracellular matrix. They are among the most potent angiogenic factors known. Evidence suggests the FGFs play a role in glomerular development and pathology. The aim of the present study was to determine whether FGF-1 (acidic FGF) and FGF-2 (basic FGF) and their receptors (FGFRs) were expressed in normal adult rat glomeruli, using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. For RT-PCR studies, the kidneys of 200 g female Sprague-Dawley rats were perfused with buffer and glomeruli isolated using conventional sieving techniques followed by micropipetting. FGF-1 and FGF-2 were expressed in cortex and in glomeruli. All seven receptor isoforms assayed (FGFR1, 2 and 3 IIIb and IIIc splice variants, and FGFR4) were expressed in whole cortex. However, only the IIIc variants and FGFR4 were expressed in glomeruli. The relative levels of glomerular expression of these isoforms were determined using a semiquantitative RT-PCR assay using primers designed against three transmembrane regions FGFR1 (100%) FGFR2 (0.1%) and FGFR4 (6%). Immunohistochemistry revealed specific immunostaining for all four FGFRs within glomeruli. The differential expression pattern of FGFR isoforms between glomeruli and whole cortex, and the mutually exclusive nature of the expression of IIIc but not IIIb isoforms within glomeruli, indicates that FGFR expression and thereby FGF activity is tightly regulated in glomeruli. These findings have important implications for the roles of the FGFs in glomerular health and disease.

Imaging Tools for Analysis of the Ureteric Tree in the Developing Mouse Kidney

Publisher: Springer New York

Date: 24-08-2013

DOI: 10.1007/978-1-60761-847-8_16

Abstract: The structure of the ureteric tree in developing mouse and rat kidneys has previously been quantified in two dimensions. While this type of analysis may provide evidence of changes in ureteric growth, these measurements are effectively inaccurate, as the ureteric tree is a three-dimensional (3D) object. Here we describe a method for measuring the ureteric tree in three dimensions. This technique involves (1) culture of the metanephric kidney at embryonic day 12 (mouse) or 14 (rat), (2) whole-mount immunofluorescence to selectively stain ureteric tree epithelium, (3) confocal microscopy to obtain a complete Z series through the ureteric tree, and (4) image analysis algorithms to binarize, skeletonize, and measure in idual branch lengths in 3D. This method has been extended to analysis of the same ureteric tree over time (4D). The results obtained provide accurate and precise quantitation of ureteric tree growth in the developing mouse or rat kidney.

Combining new tools to assess renal function and morphology: a holistic approach to study the effects of aging and a congenital nephron deficit

Publisher: American Physiological Society

Date: 09-2017

DOI: 10.1152/AJPRENAL.00329.2015

Abstract: Recently, new methods for assessing renal function in conscious mice (transcutaneous assessment) and for counting and sizing all glomeruli in whole kidneys (MRI) have been described. In the present study, these methods were used to assess renal structure and function in aging mice, and in mice born with a congenital low-nephron endowment. Age-related nephron loss was analyzed in adult C57BL/6 mice (10–50 wk of age), and congenital nephron deficit was assessed in glial cell line-derived neurotrophic factor heterozygous (GDNF HET)-null mutant mice. Renal function was measured through the transcutaneous quantitation of fluorescein isothiocyanate-sinistrin half-life ( t 1/2 ) in conscious mice. MRI was used to image, count, and size cationic-ferritin labeled glomeruli in whole kidneys ex vivo. Design-based stereology was used to validate the MRI measurements of glomerular number and mean volume. In adult C57BL/6 mice, older age was associated with fewer and larger glomeruli, and a rightward shift in the glomerular size distribution. These changes coincided with a decrease in renal function. GNDF HET mice had a congenital nephron deficit that was associated with glomerular hypertrophy and exacerbated by aging. These findings suggest that glomerular hypertrophy and hyperfiltration are compensatory processes that can occur in conjunction with both age-related nephron loss and congenital nephron deficiency. The combination of measurement of renal function in conscious animals and quantitation of glomerular number, volume, and volume distribution provides a powerful new tool for investigating aspects of renal aging and functional changes.

Is There Such a Thing as a Renal Stem Cell?

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 10-2009

DOI: 10.1681/ASN.2009010066

Copy-number variation associated with congenital anomalies of the kidney and urinary tract

Publisher: Springer Science and Business Media LLC

Date: 10-2014

DOI: 10.1007/S00467-014-2962-9

Abstract: The most common cause of end-stage renal disease in children can be attributed to congenital anomalies of the kidney and urinary tract (CAKUT). Despite this high incidence of disease, the genetic mutations responsible for the majority of CAKUT cases remain unknown. To identify novel genomic regions associated with CAKUT, we screened 178 children presenting with the entire spectrum of structural anomalies associated with CAKUT for submicroscopic chromosomal imbalances (deletions or duplications) using single-nucleotide polymorphism (SNP) microarrays. Copy-number variation (CNV) was detected in 10.1 % (18/178) of the patients in 6.2 % of the total cohort, novel duplications or deletions of unknown significance were identified, and the remaining 3.9 % harboured CNV of known pathogenicity. CNVs were inherited in 90 % (9/10) of the families tested. In this cohort, patients diagnosed with multicystic dysplastic kidney (30 %) and posterior urethral valves (24 %) had a higher incidence of CNV. The genes contained in the altered genomic regions represent novel candidates for CAKUT. This study has demonstrated that a significant proportion of patients with CAKUT harbour submicroscopic chromosomal imbalances, warranting screening in clinics for CNV.

Glomerular Hypertrophy in Offspring of Subtotally Nephrectomized Ewes

Publisher: Wiley

Date: 28-01-2008

DOI: 10.1002/AR.20651

Abstract: We have shown that fetuses whose mothers underwent subtotal nephrectomy (STNx) before pregnancy had high urine flow rates and sodium excretions, but lower hematocrits, plasma chloride, and plasma renin levels compared with controls. To see if these functional differences in utero persist after birth and are the result of altered renal development, we studied 8 lambs born to STNx mothers (STNxL) and 10 controls (ConL) in the second week of life. These lambs were of similar body weights, nose-rump lengths and abdominal girths. Their kidney weights were not different (ConL 36.1 +/- 1.9 vs. STNxL 39.8 +/- 3.3 g), nor were kidney dimensions or glomerular number (ConL 423,520 +/- 22,194 vs. STNxL 429,530 +/- 27,471 glomeruli). However, STNxL had 30% larger glomerular volumes (both mean and total, P < 0.01) and there was a positive relationship between total glomerular volume and urinary protein excretion (P < 0.05) in STNxL. Despite this change in glomerular morphology, glomerular filtration rate, tubular function, urine flow, and sodium excretion rates were not different between STNxL and ConL, nor were plasma electrolytes, osmolality, and plasma renin levels. Thus while many of the functional differences seen in late gestation were not present at 1-2 weeks after birth, the alteration in glomerular size and its relationship to protein excretion suggests that exposure to this altered intrauterine environment may predispose offspring of mothers with renal dysfunction to renal disease in adult life.

Glomerular number and size in autopsy kidneys: The relationship to birth weight

Publisher: Elsevier BV

Date: 06-2003

DOI: 10.1046/J.1523-1755.2003.00018.X

Abstract: In the Southeast United States, African Americans have an estimated incidence of hypertension and end-stage renal disease (ESRD) that is five times greater than Caucasians. Higher rates of low birth weight (LBW) among African Americans is suggested to predispose African Americans to the higher risk, possibly by reducing the number of glomeruli that develop in the kidney. This study investigates the relationships between age, race, gender, total glomerular number (Nglom), mean glomerular volume (Vglom), body surface area (BSA), and birth weight. Stereologic estimates of Nglom and Vglom were obtained using the physical disector/fractionator combination for autopsy kidneys from 37 African Americans and 19 Caucasians. Nglom was normally distributed and ranged from 227,327 to 1,825,380, an 8.0-fold difference. A direct linear relationship was observed between Nglom and birth weight (r = 0.423, P = 0.0012) with a regression coefficient that predicted an increase of 257,426 glomeruli per kilogram increase in birth weight (alpha = 0.050:0.908). Among adults there was a 4.9-fold range in Vglom, and in adults, Vglom was strongly and inversely correlated with Nglom (r =-0.640, P = 0.000002). Adult Vglom showed no significant correlation with BSA for males (r = -0.0150, P = 0.936), although it did for females (r = 0.606, P = 0.022). No racial differences in average Nglom or Vglom were observed. Birth weight is a strong determinant of Nglom and thereby of glomerular size in the postnatal kidney. The findings support the hypothesis that LBW by impairing nephron development is a risk factor for hypertension and ESRD in adulthood.

Resveratrol inhibits renal fibrosis in the obstructed kidney: Potential role in deacetylation of Smad3

Publisher: Elsevier BV

Date: 09-2010

DOI: 10.2353/AJPATH.2010.090923

University Of Western Australia

Location: No location found

View Organisation

Flinders University

Location: Australia

View Organisation

University Of Western Australia

Location: Australia

View Organisation

Monash University

Location: Australia

View Organisation

Understanding The Causes Of Childhood Congenital Anomalies Of The Kidney And Urinary Tract

Start Date: 2012

End Date: 2014

Funder: National Health and Medical Research Council

Birth Weight, Adult Weight And Podocyte Depletion

Start Date: 2014

End Date: 2017

Funder: National Health and Medical Research Council

Human Podocyte Depletion, Glomerular Hypertrophy And Glomerulosclerosis

Start Date: 2010

End Date: 2013

Funder: National Health and Medical Research Council

SP8 Confocal/multiphoton Instrumentation For Imaging Complex Tissues And Whole Organisms

Start Date: 2014

End Date: 2014

Funder: Faculty of Medicine, Nursing and Health Sciences, Monash University

Novel Methods For Promoting Organ Development And Growth

Start Date: 2010

End Date: 2012

Funder: National Health and Medical Research Council

Discovery Projects - Grant ID: DP180103039

Start Date: 2018

End Date: 12-2021

Amount: $392,664.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0561229

Start Date: 03-2005

End Date: 08-2007

Amount: $518,427.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP220102042

Start Date: 06-2022

End Date: 05-2025

Amount: $485,575.00

Funder: Australian Research Council

Research Networks - Grant ID: RN0457079

Start Date: 09-2004

End Date: 08-2009

Amount: $1,500,000.00

Funder: Australian Research Council

Special Research Initiatives - Grant ID: SR0354622

Start Date: 11-2003

End Date: 03-2005

Amount: $20,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0561030

Start Date: 02-2005

End Date: 02-2006

Amount: $441,100.00

Funder: Australian Research Council

Industrial Transformation Training Centres - Grant ID: IC190100026

Start Date: 01-2021

End Date: 11-2027

Amount: $4,969,663.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0668435

Start Date: 2006

End Date: 03-2007

Amount: $1,300,000.00

Funder: Australian Research Council