ORCID Profile
0000-0001-8846-6443
Current Organisation
Monash University
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Publisher: MDPI AG
Date: 22-01-2019
DOI: 10.3390/NU11020215
Abstract: The formation of advanced glycation end products (AGEs) in foods is accelerated with heat treatment, particularly within foods that are cooked at high temperatures for long periods of time using dry heat. The modern processed diet is replete with AGEs, and excessive AGE consumption is thought to be associated with a number of negative health effects. Many dietary AGEs have high molecular weight and are not absorbed in the intestine, and instead pass through to the colon, where they are available for metabolism by the colonic bacteria. Recent studies have been conducted to explore the effects of AGEs on the composition of the gut microbiota as well as the production of beneficial microbial metabolites, in particular, short-chain fatty acids. However, there is conflicting evidence regarding the impact of dietary AGEs on gut microbiota reshaping, which may be due, in part, to the formation of alternate compounds during the thermal treatment of foods. This review summarises the current evidence regarding dietary sources of AGEs, their gastrointestinal absorption and role in gut microbiota reshaping, provides a brief overview of the health implications of dietary AGEs and highlights knowledge gaps and avenues for future study.
Publisher: Elsevier BV
Date: 05-2021
Publisher: Springer Science and Business Media LLC
Date: 13-04-2011
Publisher: Springer Science and Business Media LLC
Date: 13-08-2014
Publisher: Cold Spring Harbor Laboratory
Date: 21-05-2021
DOI: 10.1101/2021.05.20.443346
Abstract: Metabolic conditions such as obesity, insulin resistance and glucose intolerance are frequently associated with impairments in skeletal muscle function and metabolism. This is often linked to dysregulation of homeostatic pathways including an increase in reactive oxygen species (ROS) and oxidative stress. One of the main sites of ROS production is the mitochondria, where the flux of substrates through the electron transport chain (ETC) can result in the generation of oxygen free radicals. Fortunately, several mechanisms exist to buffer bursts of intracellular ROS and peroxide production, including the enzymes Catalase, Glutathione Peroxidase and Superoxide Dismutase (SOD). Of the latter there are two intracellular isoforms SOD1 which is mostly cytoplasmic, and SOD2 which is found exclusively in the mitochondria. Developmental and chronic loss of these enzymes has been linked to disease in several studies, however the temporal effects of these disturbances remain largely unexplored. Here, we induced a post-developmental (8-week old mice) deletion of SOD2 in skeletal muscle (SOD2-iMKO) and demonstrate that 16 weeks of SOD2 deletion leads to no major impairment in whole body metabolism, despite these mice displaying alterations in aspects of mitochondrial abundance and voluntary ambulatory movement. Furthermore, we demonstrated that SOD2 deletion impacts on specific aspects of muscle lipid metabolism, including the abundance of phospholipids and phosphatidic acid (PA), the latter being a key intermediate in several cellular signaling pathways. Thus, our findings suggest that post-developmental deletion of SOD2 induces a more subtle phenotype than previous embryonic models have shown, allowing us to highlight a previously unrecognized link between SOD2, mitochondrial function and bioactive lipid species including PA.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2014
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.JVS.2009.05.058
Abstract: Abdominal aortic aneurysms (AAAs) share common risk factors with atherosclerosis, except for diabetes which appears protective. The reason for this is unknown. Although increased circulating concentrations of advanced glycation endproducts (AGEs) such as carboxymethyllysine (CML) are associated with occlusive vascular disease, it is possible that their effects on the aortic wall explain the paradoxically low incidence of AAAs in diabetes. We studied 234 community-dwelling men aged 65 to 79 years. The cases comprised all identifiable diabetic men with AAA (aortic diameter > or =30 mm on ultrasound n = 27) and randomly-selected non-diabetic men with AAA (n = 67). Controls were age-matched randomly-selected diabetic men (n = 69) and age-matched randomly-selected non-diabetic men (n = 71) without AAA (aortic diameter 18 to 22 mm). Serum CML concentrations were measured by validated indirect enzyme-linked immunosorbent assay (ELISA). Serum CML concentrations were significantly lower in men with AAAs than those without (6627 +/- 1544 vs 7309 +/- 1490 nmol/mol lysine P = .001). Variables positively associated with AAA were height, diastolic blood pressure, smoking, a history of coronary heart disease, and serum creatinine (P < or = .040), while serum CML (odds ratio [95% confidence interval] per 1000 nmol/mol lysine 0.80 [0.64-0.98]) and a history of diabetes were inversely associated (P < or = .040). After adjusting, the interaction between diabetes status and serum CML was negatively associated with AAA (P = .016). These cross-sectional data show that circulating concentrations of CML are reduced in diabetic men with AAAs. This is in contrast to studies of the relationship between AGEs and occlusive manifestations of cardiovascular disease and could explain the inverse association between diabetes and AAA.
Publisher: Wiley
Date: 22-08-2018
DOI: 10.1111/NEP.13251
Abstract: The role of autophagy in the kidney and many nephrological diseases has gained prominence in recent years. Much of this research has been focused on markers of autophagy that are static and reveal little about the state of this dynamic pathway. Other mechanistic investigations are limited to in vitro studies, that often provide circumstantial evidence of autophagic flux. Here we describe a method for measuring autophagic flux ex vivo that allows more direct observations to be made in situ regarding the state of autophagic flux within the renal cortex of a single animal.
Publisher: Oxford University Press (OUP)
Date: 25-08-2019
Publisher: American Diabetes Association
Date: 28-01-2016
DOI: 10.2337/DB15-0864
Abstract: Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein with dual roles in redox signaling and programmed cell death. Deficiency in AIF is known to result in defective oxidative phosphorylation (OXPHOS), via loss of complex I activity and assembly in other tissues. Because the kidney relies on OXPHOS for metabolic homeostasis, we hypothesized that a decrease in AIF would result in chronic kidney disease (CKD). Here, we report that partial knockdown of Aif in mice recapitulates many features of CKD, in association with a compensatory increase in the mitochondrial ATP pool via a shift toward mitochondrial fusion, excess mitochondrial reactive oxygen species production, and Nox4 upregulation. However, despite a 50% lower AIF protein content in the kidney cortex, there was no loss of complex I activity or assembly. When diabetes was superimposed onto Aif knockdown, there were extensive changes in mitochondrial function and networking, which augmented the renal lesion. Studies in patients with diabetic nephropathy showed a decrease in AIF within the renal tubular compartment and lower AIFM1 renal cortical gene expression, which correlated with declining glomerular filtration rate. Lentiviral overexpression of Aif1m rescued glucose-induced disruption of mitochondrial respiration in human primary proximal tubule cells. These studies demonstrate that AIF deficiency is a risk factor for the development of diabetic kidney disease.
Publisher: The Endocrine Society
Date: 07-2004
Publisher: Springer Science and Business Media LLC
Date: 15-02-2020
Publisher: Elsevier BV
Date: 05-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2019
Publisher: Springer Science and Business Media LLC
Date: 14-10-2022
DOI: 10.1038/S41440-022-01051-7
Abstract: We investigated whether diabetes mellitus (DM) affects the efficacy of a low-dose triple combination pill and usual care among people with mild-moderate hypertension. TRIUMPH (TRIple pill vs Usual care Management for Patients with mild-to-moderate Hypertension) was a randomised controlled open-label trial of patients requiring initiation or escalation of antihypertensive therapy. Patients were randomised to a once-daily low-dose triple combination polypill (telmisartan-20mg/amlodipine-2.5 mg/chlorthalidone-12.5 mg) or usual care. This analysis compared BP reduction in people with and without DM, both in the intervention and control groups over 24-week follow-up. Predicted efficacy of prescribed therapy was calculated (estimation methods of Law et al.). The trial randomised 700 patients (56 ± 11 yrs, 31% DM). There was no difference in the number of drugs prescribed or predicted efficacy of therapy between people with DM and without DM. However, the observed BP reduction from baseline to week 24 was lower in those with DM compared to non-diabetics in both the triple pill (25/11 vs 31/15 mmHg, p ≤ 0.01) and usual care (17/7 vs 22/11 mmHg, p ≤ 0.01) groups, and these differences remained after multivariable adjustment. DM was a negative predictor of change in BP (β-coefficient -0.08, p = 0.02). In conclusion, patients with DM experienced reduced efficacy of BP lowering therapies as compared to patients without DM, irrespective of the type of BP lowering therapy received.
Publisher: American Diabetes Association
Date: 02-2008
DOI: 10.2337/DB07-1119
Abstract: OBJECTIVE—Excessive production of reactive oxygen species (ROS) via NADPH oxidase has been implicated in the pathogenesis of diabetic nephropathy. Since NADPH oxidase activation is closely linked to other putative pathways, its interaction with changes in protein kinase C (PKC) and increased advanced glycation was examined. RESEARCH DESIGN AND METHODS—Streptozotocin-induced diabetic or nondiabetic Sprague Dawley rats were followed for 32 weeks, with groups randomized to no treatment or the NADPH oxidase assembly inhibitor apocynin (15 mg · kg−1 · day−1 weeks 16–32). Complementary in vitro studies were performed in which primary rat mesangial cells, in the presence and absence of advanced glycation end products (AGEs)-BSA, were treated with either apocynin or the PKC-α inhibitor Ro-32-0432. RESULTS—Apocynin attenuated diabetes-associated increases in albuminuria and glomerulosclerosis. Circulating, renal cytosolic, and skin collagen–associated AGE levels in diabetic rats were not reduced by apocynin. Diabetes-induced translocation of PKC, specifically PKC-α to renal membranes, was associated with increased NADPH-dependent superoxide production and elevated renal, serum, and urinary vascular endothelial growth factor (VEGF) concentrations. In both diabetic rodents and in AGE-treated mesangial cells, blockade of NADPH oxidase or PKC-α attenuated cytosolic superoxide and PKC activation and increased VEGF. Finally, renal extracellular matrix accumulation of fibronectin and collagen IV was decreased by apocynin. CONCLUSIONS—In the context of these and previous findings by our group, we conclude that activation of NADPH oxidase via phosphorylation of PKC-α is downstream of the AGE–receptor for AGE interaction in diabetic renal disease and may provide a novel therapeutic target for diabetic nephropathy.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2010
Publisher: Elsevier BV
Date: 05-2019
Publisher: Springer Science and Business Media LLC
Date: 26-09-2020
DOI: 10.1007/S10557-020-07086-7
Abstract: HFpEF (heart failure with preserved ejection fraction) is a major consequence of diabetic cardiomyopathy with no effective treatments. Here, we have characterized Akita mice as a preclinical model of HFpEF and used it to confirm the therapeutic efficacy of the mitochondria-targeted dicarbonyl scavenger, MitoGamide. A longitudinal echocardiographic analysis confirmed that Akita mice develop diastolic dysfunction with reduced E peak velocity, E/A ratio and extended isovolumetric relaxation time (IVRT), while the systolic function remains comparable with wild-type mice. The myocardium of Akita mice had a decreased ATP/ADP ratio, elevated mitochondrial oxidative stress and increased organelle density, compared with that of wild-type mice. MitoGamide, a mitochondria-targeted 1,2-dicarbonyl scavenger, exhibited good stability in vivo, uptake into cells and mitochondria and reactivity with dicarbonyls. Treatment of Akita mice with MitoGamide for 12 weeks significantly improved the E/A ratio compared with the vehicle-treated group. Our work confirms that the Akita mouse model of diabetes replicates key clinical features of diabetic HFpEF, including cardiac and mitochondrial dysfunction. Furthermore, in this independent study, MitoGamide treatment improved diastolic function in Akita mice.
Publisher: Wiley
Date: 24-03-2019
DOI: 10.1111/JCH.13522
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2005
Publisher: Wiley
Date: 15-01-2016
Publisher: Bentham Science Publishers Ltd.
Date: 29-07-2016
DOI: 10.2174/1389450116666150722141418
Abstract: Diabetic nephropathy is the major cause of end-stage renal disease in Western societies. To date, interruption of the Renin-Angiotensin System is the most effective intervention for diabetic nephropathy, however these agents only slow progression of the disease. Thus, there is a major unmet need for new therapeutic targets. Aberrant activation of the receptor for advanced glycation end products (RAGE) is involved in the pathogenesis of diabetic nephropathy via binding to a variety of ligands and inciting reactive oxygen species (ROS) production, inflammation and fibrosis. In recent years there have been considerable efforts in the development of effective RAGE antagonists, however, direct RAGE targeting may be problematic. Glucagon like peptide-1 (GLP-1) is an incretin hormone released by the L-cells of the small intestine to mediate glucose-dependent insulin release from pancreatic islets. The incretin-based therapies, GLP-1 receptor agonists and dipeptidylpeptidase-4 (DPP4) inhibitors, are novel glucose-lowering agents used in type 2 diabetes. However, the extra pancreatic functions of GLP-1 have gained attention, including putative anti-apoptotic and anti-inflammatory properties. In rodent models of diabetes, incretin-based therapies are renoprotective. Interestingly, GLP-1 has been shown to interfere with the signalling and expression of RAGE. The current review aims to give an overview of the interactions between the RAGE and incretin pathways and to discuss the utility of targeting the GLP-1/incretin pathway in DN. It is possible that indirect targeting of RAGE through GLP-1 agonism will be of clinical benefit to patients with diabetic nephropathy.
Publisher: American Diabetes Association
Date: 15-10-2011
DOI: 10.2337/DB10-0892
Abstract: Progressive fibrosis in the diabetic kidney is driven and sustained by a erse range of profibrotic factors. This study examines the critical role of microRNAs (miRNAs) in the regulation of the key fibrotic mediators, TGF-β1 and TGF-β2. Rat proximal-tubular epithelial cells (NRK52E) were treated with TGF-β1 and TGF-β2 for 3 days, and expression of markers of epithelial-to-mesenchymal transition (EMT) and fibrogenesis were assessed by RT-PCR and Western blotting. The expression of miR-141 and miR-200a was also assessed, as was their role as translational repressors of TGF-β signaling. Finally, these pathways were explored in two different mouse models, representing early and advanced diabetic nephropathy. Both TGF-β1 and TGF-β2 induced EMT and fibrogenesis in NRK52E cells. TGF-β1 and TGF-β2 also downregulated expression of miR-200a. The importance of these changes was demonstrated by the finding that ectopic expression miR-200a downregulated smad-3 activity and the expression of matrix proteins and prevented TGF-β–dependent EMT. miR-200a also downregulated the expression of TGF-β2, via direct interaction with the 3′ untranslated region of TGF-β2. The renal expression of miR-141 and miR-200a was also reduced in mouse models representing early and advanced kidney disease. miR-200a and miR-141 significantly impact on the development and progression of TGF-β–dependent EMT and fibrosis in vitro and in vivo. These miRNAs appear to be intricately involved in fibrogenesis, both as downstream mediators of TGF-β signaling and as components of feedback regulation, and as such represent important new targets for the prevention of progressive kidney disease in the context of diabetes.
Publisher: Springer International Publishing
Date: 09-09-2016
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.FREERADBIOMED.2011.11.017
Abstract: Cardiovascular benefits of ubiquinone have been previously demonstrated, and we administered it as a novel therapy in an experimental model of type 2 diabetic nephropathy. db/db and dbH mice were followed for 10 weeks, after randomization to receive either vehicle or ubiquinone (CoQ10 10mg/kg/day) orally. db/db mice had elevated urinary albumin excretion rates and albumin:creatinine ratio, not seen in db/db CoQ10-treated mice. Renal cortices from db/db mice had lower total and oxidized CoQ10 content, compared with dbH mice. Mitochondria from db/db mice also contained less oxidized CoQ10(ubiquinone) compared with dbH mice. Diabetes-induced increases in total renal collagen but not glomerulosclerosis were significantly decreased with CoQ10 therapy. Mitochondrial superoxide and ATP production via complex II in the renal cortex were increased in db/db mice, with ATP normalized by CoQ10. However, excess renal mitochondrial hydrogen peroxide production and increased mitochondrial membrane potential seen in db/db mice were attenuated with CoQ10. Renal superoxide dismutase activity was also lower in db/db mice compared with dbH mice. Our results suggest that a deficiency in mitochondrial oxidized CoQ10 (ubiquinone) may be a likely precipitating factor for diabetic nephropathy. Therefore CoQ10 supplementation may be renoprotective in type 2 diabetes, via preservation of mitochondrial function.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 03-2007
Publisher: Mary Ann Liebert Inc
Date: 08-2013
Abstract: Defects in the activity of enzyme complexes of the mitochondrial respiratory chain are thought to be responsible for several disorders, including renal impairment. Gene mutations that result in complex I deficiency are the most common oxidative phosphorylation disorders in humans. To determine whether an abnormality in mitochondrial complex I per se is associated with development of renal disease, mice with a knockdown of the complex I gene, Ndufs6 were studied. Ndufs6 mice had a partial renal cortical complex I deficiency Ndufs6gt/gt, 32% activity and Ndufs6gt/+, 83% activity compared with wild-type mice. Both Ndufs6gt/+ and Ndufs6gt/gt mice exhibited hallmarks of renal disease, including albuminuria, urinary excretion of kidney injury molecule-1 (Kim-1), renal fibrosis, and changes in glomerular volume, with decreased capacity to generate mitochondrial ATP and superoxide from substrates oxidized via complex I. However, more advanced renal defects in Ndufs6gt/gt mice were observed in the context of a disruption in the inner mitochondrial electrochemical potential, 3-nitrotyrosine-modified mitochondrial proteins, increased urinary excretion of 15-isoprostane F2t, and up-regulation of antioxidant defence. Juvenile Ndufs6gt/gt mice also exhibited signs of early renal impairment with increased urinary Kim-1 excretion and elevated circulating cystatin C. We have identified renal impairment in a mouse model of partial complex I deficiency, suggesting that even modest deficits in mitochondrial respiratory chain function may act as risk factors for chronic kidney disease. These studies identify for the first time that complex I deficiency as the result of interruption of Ndufs6 is an independent cause of renal impairment.
Publisher: S. Karger AG
Date: 2010
DOI: 10.1159/000314924
Abstract: i Background/Aims: /i Antihypertensive therapies such as angiotensin-converting enzyme-1 inhibitors (ACEi) slow the decline in renal function seen with diabetic nephropathy, although there is still progression ultimately to end-stage renal disease. The aim of this study was to determine if there were added renoprotective benefits seen by combining ACEi with blockade of NADPH oxidase. i Methods: /i Sprague-Dawley diabetic and non-diabetic rats were randomized to receive intervention therapy with apocynin (15 mg/kg/day, weeks 16–32), apocynin + the ACEi ramipril (1 mg/kg/day, weeks 16–32), or ramipril alone (1 mg/kg). i Results: /i All three treatments retarded the development of albuminuria in the diabetic rats. Apocynin conferred its benefit either as a monotherapy or in combination with ramipril without affecting blood pressure per se. Renal morphological injury was attenuated by all three treatment strategies. Diabetes was associated with increasing renal fibronectin and type IV collagen protein expression, with the combination regimen resulting in the highest decrease in extracellular matrix accumulation. All three treatments prevented the diabetes-associated increases in renal cytosolic superoxide generation as well as urinary isoprostanes. While renal TGF-β1 activation was reduced by ramipril treatment but not by apocynin as a monotherapy, kidney cortical membranous VEGF was reduced by apocynin as monotherapy and dual therapy but not by ramipril alone. i Conclusions: /i Combination of NADPH oxidase blockade with ACE inhibitors is a promising regimen which warrants further investigation as a way to confer additional renoprotection in diabetes.
Publisher: American Diabetes Association
Date: 09-2008
DOI: 10.2337/DB07-1808
Abstract: OBJECTIVE—Activation of the receptor for advanced glycation end products (RAGE) in diabetic vasculature is considered to be a key mediator of atherogenesis. This study examines the effects of deletion of RAGE on the development of atherosclerosis in the diabetic apoE−/− model of accelerated atherosclerosis. RESEARCH DESIGN AND METHODS—ApoE−/− and RAGE−/−/apoE−/− double knockout mice were rendered diabetic with streptozotocin and followed for 20 weeks, at which time plaque accumulation was assessed by en face analysis. RESULTS—Although diabetic apoE−/− mice showed increased plaque accumulation (14.9 ± 1.7%), diabetic RAGE−/−/apoE−/− mice had significantly reduced atherosclerotic plaque area (4.9 ± 0.4%) to levels not significantly different from control apoE−/− mice (4.3 ± 0.4%). These beneficial effects on the vasculature were associated with attenuation of leukocyte recruitment decreased expression of proinflammatory mediators, including the nuclear factor-κB subunit p65, VCAM-1, and MCP-1 and reduced oxidative stress, as reflected by staining for nitrotyrosine and reduced expression of various NADPH oxidase subunits, gp91phox, p47phox, and rac-1. Both RAGE and RAGE ligands, including S100A8/A9, high mobility group box 1 (HMGB1), and the advanced glycation end product (AGE) carboxymethyllysine were increased in plaques from diabetic apoE−/− mice. Furthermore, the accumulation of AGEs and other ligands to RAGE was reduced in diabetic RAGE−/−/apoE−/− mice. CONCLUSIONS—This study provides evidence for RAGE playing a central role in the development of accelerated atherosclerosis associated with diabetes. These findings emphasize the potential utility of strategies targeting RAGE activation in the prevention and treatment of diabetic macrovascular complications.
Publisher: Springer Science and Business Media LLC
Date: 25-10-2019
DOI: 10.1007/S10557-019-06914-9
Abstract: Methylglyoxal, a by-product of glycolysis and a precursor in the formation of advanced glycation end-products, is significantly elevated in the diabetic myocardium. Therefore, we sought to investigate the mitochondria-targeted methylglyoxal scavenger, MitoGamide, in an experimental model of spontaneous diabetic cardiomyopathy. Male 6-week-old Akita or wild type mice received daily oral gavage of MitoGamide or vehicle for 10 weeks. Several morphological and systemic parameters were assessed, as well as cardiac function by echocardiography. Akita mice were smaller in size than wild type counterparts in terms of body weight and tibial length. Akita mice exhibited elevated blood glucose and glycated haemoglobin. Total heart and in idual ventricles were all smaller in Akita mice. None of the aforementioned parameters was impacted by MitoGamide treatment. Echocardiographic analysis confirmed that cardiac dimensions were smaller in Akita hearts. Diastolic dysfunction was evident in Akita mice, and notably, MitoGamide treatment preferentially improved several of these markers, including e′/a′ ratio and E/e′ ratio. Our findings suggest that MitoGamide, a novel mitochondria-targeted approach, offers cardioprotection in experimental diabetes and therefore may offer therapeutic potential for the treatment of cardiomyopathy in patients with diabetes.
Publisher: Wiley
Date: 06-2005
Abstract: Although advanced glycation end products (AGEs) have been postulated to contribute to diabetic nephropathy in their own right, advanced glycation is clearly only one pathway by which renal injury may be induced in diabetes. The interaction between metabolic and hemodynamic factors lifies the deleterious effects of the diabetic milieu, thereby reducing the threshold for microvascular injury via common mechanisms. This includes interactions between AGE-mediated pathways and the renin angiotensin system, oxidative stress, protein kinase C, and growth factors, which play a significant role in the development and progression of diabetic renal disease. As it is likely that the future of preventive therapy will not involve a single "cure-all" agent, it seems that a highly relevant question in diabetic nephropathy should be, which pathogenic pathways are already addressed by currently available therapies? Combination therapies that target multiple pathways may ultimately be more successful than those that modify a single pathway. Therefore, research into synergistic interactions among the various pathogenic pathways leading to diabetic complications is critical in order to develop interventions that confer optimal end-organ protection.
Publisher: Cold Spring Harbor Laboratory
Date: 09-05-2019
DOI: 10.1101/632596
Abstract: The AGER gene encodes for a number of RAGE isoforms, with the membrane bound signal transduction and “decoy” circulating soluble RAGE being the best characterised. Here we demonstrate a novel nuclear isoform of RAGE in mice and human kidney cortex which by cell and size fractionation we determined to be approximately 37kda. This nuclear RAGE isoform is functional and binds to DNA sequences within the upstream 5’ promoter region of its own gene, AGER . This binding was shown to be abrogated by mutating the DNA consensus binding sequences during electromobility shift assay (EMSA) and was independent of NF-□B or AP-1 binding. Cotransfection of expression constructs encoding various RAGE isoforms along with AGER gene promoter reporter-plasmids identified that the most likely source of the nuclear isoform of RAGE was a cleavage product of the nt-RAGE isoform. In obese mice with impaired kidney function, there was increased binding of nuclear RAGE within the A. Region of ager gene promoter with corresponding increases in membrane bound RAGE in renal cells. These findings were reproduced in vitro using proximal tubule cells. Hence, we postulate that RAGE expression is in part, self-regulated by the binding of a nuclear RAGE isoform to the promoter of the AGER gene (encoding RAGE) in the kidney. We also suggest that this RAGE self-regulation is altered under pathological conditions and this may have implications for chronic kidney disease.
Publisher: American Physiological Society
Date: 03-2010
DOI: 10.1152/AJPRENAL.00591.2009
Abstract: Advanced glycation end products (AGEs) and the receptor for AGEs (RAGE) generate ROS, and therefore this study evaluated the effects of RAGE deletion, decreasing AGE accumulation, or lowering dietary AGE content on oxidative parameters in diabetic nephropathy (DN). Control and diabetic male wild-type and RAGE-deficient (RAGE −/− ) mice were fed high- or low-AGE diets, with two groups given the inhibitor of AGE accumulation, alagebrium chloride, and followed for 24 wk. Diabetic RAGE −/− mice were protected against albuminuria, hyperfiltration, glomerulosclerosis, decreased renal mitochondrial ATP production, and excess generation of both mitochondrial and cytosolic superoxide. Whereas glomerulosclerosis, tubulointerstitial expansion, and hyperfiltration were improved in diabetic mice treated with alagebrium, there was no effect on urinary albumin excretion. Both diabetic RAGE −/− and alagebrium-treated mice had an attenuation of renal RAGE expression and decreased renal and urinary AGE (carboxymethyllysine) levels. Low-AGE diets did not confer renoprotection, lower the AGE burden or renal RAGE expression, or improve cytosolic or mitochondrial superoxide generation. Renal uncoupling protein-2 gene expression and mitochondrial membrane potential were attenuated by all therapeutic interventions in diabetic mice. In the present study, erse approaches to block the AGE-RAGE axis had disparate effects on DN, which has potential clinical implications for the way this axis should be targeted in humans.
Publisher: Cold Spring Harbor Laboratory
Date: 22-07-2019
DOI: 10.1101/710558
Abstract: The accumulation of advanced glycation end products (AGEs) have been implicated in the development and progression of diabetic kidney disease (DKD). There has been interest in investigating the potential of AGE clearance receptors, such as oligosaccharyltransferase-48kDa subunit (OST48) to prevent the detrimental effects of excess AGE accumulation seen in the diabetic kidney. Here the objective of the study was to increase the expression of OST48 to examine if this slowed the development of DKD by facilitating the clearance of AGEs. Groups of 8-week-old heterozygous knock-in male mice (n=9-12/group) over-expressing the gene encoding for OST48, dolichyl-diphosphooligosaccharide-protein glycosyltransferase ( DDOST +/-) and litter mate controls were randomised to either (i) no diabetes or (ii) diabetes induced via multiple low-dose streptozotocin and followed for 24 weeks. By the study end, global over expression of OST48 increased glomerular OST48. This facilitated greater renal excretion of AGEs but did not affect circulating or renal AGE concentrations. Diabetes resulted in kidney damage including lower glomerular filtration rate, albuminuria, glomerulosclerosis and tubulointerstitial fibrosis. In diabetic mice, tubulointerstitial fibrosis was further exacerbated by global increases in OST48. There was significantly insulin effectiveness, increased acute insulin secretion, fasting insulin concentrations and AUC insulin observed during glucose tolerance testing in diabetic mice with global elevations in OST48 when compared to diabetic wild-type littermates. Overall, this study suggested that despite facilitating urinaryrenal AGE clearance, there were no benefits observed on kidney functional and structural parameters in diabetes afforded by globally increasing OST48 expression. However, the improvements in insulin secretion seen in diabetic mice with global over-expression of OST48 and their dissociation from effects on kidney function warrant future investigation.
Publisher: Wiley
Date: 25-02-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2019
Publisher: Wiley
Date: 22-06-2021
DOI: 10.1002/EDM2.278
Abstract: The accumulation of advanced glycation end products is implicated in the development and progression of diabetic kidney disease. No study has examined whether stimulating advanced glycation clearance via receptor manipulation is reno‐protective in diabetes. Podocytes, which are early contributors to diabetic kidney disease and could be a target for reno‐protection. To examine the effects of increased podocyte oligosaccharyltransferase‐48 on kidney function, glomerular sclerosis, tubulointerstitial fibrosis and proteome (PXD011434), we generated a mouse with increased oligosaccharyltransferase‐48kDa subunit abundance in podocytes driven by the podocin promoter. Despite increased urinary clearance of advanced glycation end products, we observed a decline in renal function, significant glomerular damage including glomerulosclerosis, collagen IV deposition, glomerular basement membrane thickening and foot process effacement and tubulointerstitial fibrosis. Analysis of isolated glomeruli identified enrichment in proteins associated with collagen deposition, endoplasmic reticulum stress and oxidative stress. Ultra‐resolution microscopy of podocytes revealed denudation of foot processes where there was co‐localization of oligosaccharyltransferase‐48kDa subunit and advanced glycation end‐products. These studies indicate that increased podocyte expression of oligosaccharyltransferase‐48 kDa subunit results in glomerular endoplasmic reticulum stress and a decline in kidney function.
Publisher: MDPI AG
Date: 03-02-2022
DOI: 10.3390/IJMS23031766
Abstract: There is increasing evidence for the role of intestinal permeability as a contributing factor in the pathogenesis of diabetes however, the molecular mechanisms are poorly understood. Advanced glycation endproducts, of both exogenous and endogenous origin, have been shown to play a role in diabetes pathophysiology, in part by their ligation to the receptor for advanced glycation endproducts (RAGE), leading to a proinflammatory signalling cascade. RAGE signalling has been demonstrated to play a role in the development of intestinal inflammation and permeability in Crohn’s disease and ulcerative colitis. In this review, we explore the role of AGE-RAGE signalling and intestinal permeability and explore whether activation of RAGE on the intestinal epithelium may be a downstream event contributing to the pathogenesis of diabetes complications.
Publisher: Springer Science and Business Media LLC
Date: 20-06-2007
DOI: 10.1007/S00125-007-0718-9
Abstract: AGE contribute to the pathogenesis of diabetic complications, including dyslipidaemia and atherosclerosis. However, the precise mechanisms remain to be established. In the present study, we examined whether AGE modification of apolipoprotein A-I (apoA-I) affects its functionality, thus altering its cardioprotective profile. The ability of AGE-modified apoA-I to facilitate cholesterol and phospholipid efflux, stabilise ATP-binding cassette transporter A1 (ABCA1) and inhibit expression of adhesion molecules in human macrophages and monocytes was studied. The ability of AGE-modified apoA-I to promote cholesterol efflux from THP-1 macrophages, isolated human monocytes and from ABCA1-transfected HeLa cells was significantly reduced (>70%) compared with unmodified apoA-I. This effect was reversed by preventing AGE formation with aminoguanidine or reversing AGE modification using the cross-link breaker alagebrium chloride. AGE-modification of HDL also reduced its capacity to promote cholesterol efflux. AGE-apoA-I was also less effective than apoA-I in stabilising ABCA1 in THP-1 cells as well as in inhibiting expression of CD11b in human monocytes. AGE modification of apoA-I considerably impairs its cardioprotective, antiatherogenic properties, including the ability to promote cholesterol efflux, stabilise ABCA1 and inhibit the expression of adhesion molecules. These findings provide a rationale for targeting AGE in the management of diabetic dyslipidaemia.
Publisher: Springer Science and Business Media LLC
Date: 25-09-2017
DOI: 10.1038/S41598-017-12548-4
Abstract: The protein oligosaccharyltransferase-48 (OST48) is integral to protein N-glycosylation in the endoplasmic reticulum (ER) but is also postulated to act as a membrane localised clearance receptor for advanced glycation end-products (AGE). Hepatic ER stress and AGE accumulation are each implicated in liver injury. Hence the objective of this study was to increase the expression of OST48 and examine the effects on hepatic function and structure. Groups of 8 week old male mice (n = 10–12/group) over-expressing the gene for OST48, dolichyl-diphosphooligosaccharide-protein glycosyltransferase ( DDOST +/−), were followed for 24 weeks, while randomised to diets either low or high in AGE content. By week 24 of the study, either increasing OST48 expression or consumption of high AGE diet impaired liver function and modestly increased hepatic fibrosis, but their combination significantly exacerbated liver injury in the absence of steatosis. DDOST +/− mice had increased both portal delivery and accumulation of hepatic AGEs leading to central adiposity, insulin secretory defects, shifted fuel usage to fatty and ketoacids, as well as hepatic glycogen accumulation causing hepatomegaly along with hepatic ER and oxidative stress. This study revealed a novel role of the OST48 and AGE axis in hepatic injury through ER stress, changes in fuel utilisation and glucose intolerance.
Publisher: Frontiers Media SA
Date: 22-05-2018
Publisher: Wiley
Date: 17-12-2013
DOI: 10.1111/J.1440-1797.2012.01665.X
Abstract: Mouse chow is commonly high in advanced glycation end-products, known contributors to diabetic nephropathy. The aim of this study was to evaluate if targeting of the AGE-RAGE axis was still effective in the context of a diet low in AGE content, which is more comparable to diets consumed by in iduals with type 1 diabetes. C57BL/6J wild-type and mice deficient in the receptor for AGEs (RAGE-KO) consumed a diet low in AGE content. Groups of mice were given (i) vehicle (ii) streptozotocin or (iii) streptozotocin + AGE lowering therapy (alagebrium chloride) and followed for 24 weeks. Diabetic mice had high urinary albumin excretion rates, hyperfiltration and release of urinary Kim-1, not seen in diabetic RAGE-KO mice. Diabetic mice also had renal fibrosis, measured by glomerulosclerosis, tubulointerstitial expansion, TGF-β1 and glomerular collagen-IV deposition which almost all improved by RAGE-KO or alagebium. Diabetic mice had a greater renal burden of AGEs and increased expression of renal specific PKC-α phosphorylation, which was improved in RAGE-KO mice, or those treated with alagebrium. Diabetic mice given a low-AGE diet still developed renal disease, which could be attenuated by targeting of the AGE-RAGE axis.
Publisher: Elsevier BV
Date: 2022
DOI: 10.2139/SSRN.4107711
Publisher: Springer Science and Business Media LLC
Date: 05-05-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2009
Publisher: American Diabetes Association
Date: 11-03-2022
DOI: 10.2337/DB21-1079
Abstract: Excessive production of renal reactive oxygen species (ROS) plays a major role in diabetic kidney disease (DKD). Here, we provide key findings demonstrating the predominant pathological role of the pro-oxidant enzyme NADPH oxidase 5 (NOX5) in DKD, independent of the previously characterized NOX4 pathway. In patients with diabetes, we found increased expression of renal NOX5 in association with enhanced ROS formation and upregulation of ROS-sensitive factors early growth response 1 (EGR-1), protein kinase C-α (PKC-α), and a key metabolic gene involved in redox balance, thioredoxin-interacting protein (TXNIP). In preclinical models of DKD, overexpression of NOX5 in Nox4-deficient mice enhances kidney damage by increasing albuminuria and augmenting renal fibrosis and inflammation via enhanced ROS formation and the modulation of EGR1, TXNIP, ERK1/2, PKC-α, and PKC-ε. In addition, the only first-in-class NOX inhibitor, GKT137831, appears to be ineffective in the presence of NOX5 expression in diabetes. In vitro, silencing of NOX5 in human mesangial cells attenuated upregulation of EGR1, PKC-α, and TXNIP induced by high glucose levels, as well as markers of inflammation (TLR4 and MCP-1) and fibrosis (CTGF and collagens I and III) via reduction in ROS formation. Collectively, these findings identify NOX5 as a superior target in human DKD compared with other NOX isoforms such as NOX4, which may have been overinterpreted in previous rodent studies.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-09-2022
Abstract: Published randomized controlled trials are underpowered for binary clinical end points to assess the safety and efficacy of renin‐angiotensin system inhibitors (RASi) in adults with COVID‐19. We therefore performed a meta‐analysis to assess the safety and efficacy of RASi in adults with COVID‐19. MEDLINE, EMBASE, ClinicalTrials.gov , and the Cochrane Controlled Trial Register were searched for randomized controlled trials that randomly assigned patients with COVID‐19 to RASi continuation/commencement versus no RASi therapy. The primary outcome was all‐cause mortality at ≤30 days. A total of 14 randomized controlled trials met the inclusion criteria and enrolled 1838 participants (aged 59 years, 58% men, mean follow‐up 26 days). Of the trials, 11 contributed data. We found no effect of RASi versus control on all‐cause mortality (7.2% versus 7.5% relative risk [RR], 0.95 [95% CI, 0.69–1.30]) either overall or in subgroups defined by COVID‐19 severity or trial type. Network meta‐analysis identified no difference between angiotensin‐converting enzyme inhibitors versus angiotensin II receptor blockers. RASi users had a nonsignificant reduction in acute myocardial infarction (2.1% versus 3.6% RR, 0.59 [95% CI, 0.33–1.06]), but increased risk of acute kidney injury (7.0% versus 3.6% RR, 1.82 [95% CI, 1.05–3.16]), in trials that initiated and continued RASi. There was no increase in need for dialysis or differences in congestive cardiac failure, cerebrovascular events, venous thromboembolism, hospitalization, intensive care admission, inotropes, or mechanical ventilation. This meta‐analysis of randomized controlled trials evaluating angiotensin‐converting enzyme inhibitors/angiotensin II receptor blockers versus control in patients with COVID‐19 found no difference in all‐cause mortality, a borderline decrease in myocardial infarction, and an increased risk of acute kidney injury with RASi. Our findings provide strong evidence that RASi can be used safely in patients with COVID‐19.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2019
DOI: 10.1161/HYPERTENSIONAHA.118.12414
Abstract: The optimal blood pressure (BP) goal in patients with diabetes mellitus remains controversial. We examined whether benefits and risks of intensified antihypertensive therapy in diabetes mellitus are influenced by either baseline BP or cardiovascular disease (CVD) risk. We studied 10 948 people with diabetes mellitus, at moderate-to-high risk, in the ADVANCE trial (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation). Cox models were used to determine whether baseline BP category or CVD risk modified the outcomes of combination perindopril-indapamide treatment, compared with placebo. During 4.3 years of follow-up, treatment with perindopril-indapamide versus placebo reduced mortality and major vascular (macrovascular or microvascular) events. There was no evidence of differences in these effects, regardless of baseline systolic BP (evaluated down to mm Hg P for heterogeneity, 0.85), diastolic BP (evaluated down to mm Hg P =0.49), or whether 10-year CVD risk was ≥20% or % ( P =0.08). The effects of randomized treatment on discontinuation of treatment because of cough or hypotension/dizziness were also statistically consistent across subgroups defined by baseline BP and CVD risk (all P ≥0.08). Adults with diabetes mellitus appear to benefit from more intensive BP treatment even at levels of BP and CVD risk that some guidelines do not currently recommend for intervention. URL: www.clinicaltrials.gov . Unique identifier: NCT00751972.
Publisher: Springer Science and Business Media LLC
Date: 06-02-2011
DOI: 10.1007/S00125-011-2058-Z
Abstract: This group of studies examines human genetic susceptibility conferred by the receptor for advanced glycation end-products (RAGE) in type 1 diabetes and investigates how this may interact with a western environment. We analysed the AGER gene, using 13 tag SNPs, in 3,624 Finnish in iduals from the FinnDiane study, followed by AGER associations with a high risk HLA genotype (DR3)-DQA1*05-DQB1*02/DRB1*0401-DQB1*0302 (n = 546 HLA-DR3/DR4), matched in healthy newborn infants from the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Study (n = 373) using allelic analysis. We also studied islets and circulating RAGE in NODLt mice. The rs2070600 and rs17493811 polymorphisms predicted increased risk of type 1 diabetes, whereas the rs9469089 SNP was related to decreased risk, on a high risk HLA background. Children from the DIPP study also showed a decline in circulating soluble RAGE levels, at seroconversion to positivity for type 1 diabetes-associated autoantibodies. Islet RAGE and circulating soluble RAGE levels in prediabetic NODLt mice decreased over time and were prevented by the AGE lowering therapy alagebrium chloride. Alagebrium chloride also decreased the incidence of autoimmune diabetes and restored islet RAGE levels. These studies suggest that inherited AGER gene polymorphisms may confer susceptibility to environmental insults. Declining circulating levels of soluble RAGE, before the development of overt diabetes, may also be predictive of clinical disease in children with high to medium risk HLA II backgrounds and this possibility warrants further investigation in a larger cohort.
Publisher: Springer Science and Business Media LLC
Date: 06-07-2014
DOI: 10.1007/S00726-013-1542-9
Abstract: It has been postulated that chronic exposure to high levels of advanced glycation end products (AGEs), in particular from dietary sources, can impair insulin secretion. In the present study, we investigated the cross-sectional relationship between AGEs and acute insulin secretion during an intravenous glucose tolerance test (IVGTT) and following a 75 g oral glucose tolerance test (OGTT) in healthy humans. We report the cross-sectional association between circulating AGE concentrations and insulin secretory function in healthy humans (17 F: 27 M, aged 30 ± 10 years) with a wide range of BMI (24.6-31.0 kg/m(2)). Higher circulating concentrations of AGEs were related to increased first phase insulin secretion during IVGTT (r = 0.43 p < 0.05) and lower 2-h glucose concentrations during OGTT (r = -0.31 p < 0.05). In addition, fasting (r = -0.36 p < 0.05) and 2-h glucose concentrations were negatively related to circulating levels of soluble receptor for AGE (RAGE) isoforms (r = -0.39 p < 0.01). In conclusion, in healthy humans, we show a cross-sectional association between advanced glycation end products and acute insulin secretion during glucose tolerance testing.
Publisher: Elsevier BV
Date: 03-2019
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2021
Publisher: Elsevier BV
Date: 11-2021
Publisher: Frontiers Media SA
Date: 09-2021
DOI: 10.3389/FPHYS.2021.672252
Abstract: People affected by diabetes are at an increased risk of developing heart failure than their non-diabetic counterparts, attributed in part to a distinct cardiac pathology termed diabetic cardiomyopathy. Mitochondrial dysfunction and excess reactive oxygen species (ROS) have been implicated in a range of diabetic complications and are a common feature of the diabetic heart. In this study, we sought to characterise impairments in mitochondrial structure and function in a recently described experimental mouse model of diabetic cardiomyopathy. Diabetes was induced in 6-week-old male FVB/N mice by the combination of three consecutive-daily injections of low-dose streptozotocin (STZ, each 55 mg/kg i.p.) and high-fat diet (42% fat from lipids) for 26 weeks. At study end, diabetic mice exhibited elevated blood glucose levels and impaired glucose tolerance, together with increases in both body weight gain and fat mass, replicating several aspects of human type 2 diabetes. The myocardial phenotype of diabetic mice included increased myocardial fibrosis and left ventricular (LV) diastolic dysfunction. Elevated LV superoxide levels were also evident. Diabetic mice exhibited a spectrum of LV mitochondrial changes, including decreased mitochondria area, increased levels of mitochondrial complex-III and complex-V protein abundance, and reduced complex-II oxygen consumption. In conclusion, these data suggest that the low-dose STZ-high fat experimental model replicates some of the mitochondrial changes seen in diabetes, and as such, this model may be useful to study treatments that target the mitochondria in diabetes.
Publisher: Cold Spring Harbor Laboratory
Date: 22-07-2019
DOI: 10.1101/710186
Abstract: The accumulation of advanced glycation end products is implicated in the development and progression of diabetic kidney disease. No study has examined whether stimulating advanced glycation clearance via receptor manipulation is reno-protective in diabetes. Podocytes, which are early contributors to diabetic kidney disease and could be a target for reno-protection. To examine the effects of increased podocyte oligosaccharyltransferase-48 on kidney function, glomerular sclerosis, tubulointerstitial fibrosis and proteome (PXD011434), we generated a mouse with increased oligosaccharyltransferase-48kDa subunit abundance in podocytes driven by the podocin promoter. Despite increased urinary clearance of advanced glycation end products, we observed a decline in renal function, significant glomerular damage including glomerulosclerosis, collagen IV deposition, glomerular basement membrane thickening and foot process effacement and tubulointerstitial fibrosis. Analysis of isolated glomeruli identified enrichment in proteins associated with collagen deposition, endoplasmic reticulum stress and oxidative stress. Ultra-resolution microscopy of podocytes revealed denudation of foot processes where there was co-localization of oligosaccharyltransferase-48kDa subunit and advanced glycation end-products. These studies indicate that increased podocyte expression of oligosaccharyltransferase-48kDa subunit results in glomerular endoplasmic reticulum stress and a decline in kidney function.
Publisher: Springer Science and Business Media LLC
Date: 10-2022
DOI: 10.1038/S41591-022-01974-1
Abstract: High systolic blood pressure (SBP) is a major risk factor for ischemic heart disease (IHD), the leading cause of death worldwide. Using data from published observational studies and controlled trials, we estimated the mean SBP–IHD dose–response function and burden of proof risk function (BPRF), and we calculated a risk outcome score (ROS) and corresponding star rating (one to five). We found a very strong, significant harmful effect of SBP on IHD, with a mean risk—relative to that at 100 mm Hg SBP—of 1.39 (95% uncertainty interval including between-study heterogeneity 1.34–1.44) at 120 mm Hg, 1.81 (1.70–1.93) at 130 mm Hg and 4.48 (3.81–5.26) at 165 mm Hg. The conservative BPRF measure indicated that SBP exposure between 107.5 and 165.0 mm Hg raised risk by 101.36% on average, yielding a ROS of 0.70 and star rating of five. Our analysis shows that IHD risk was already increasing at 120 mm Hg SBP, rising steadily up to 165 mm Hg and increasing less steeply above that point. Our study endorses the need to prioritize and strengthen strategies for screening, to raise awareness of the need for timely diagnosis and treatment of hypertension and to increase the resources allocated for understanding primordial prevention of elevated blood pressure.
Publisher: MDPI AG
Date: 03-2016
DOI: 10.3390/NU8030125
Publisher: Portland Press Ltd.
Date: 18-03-2016
DOI: 10.1042/CS20150838
Abstract: Oxidative phosphorylation (OXPHOS) drives ATP production by mitochondria, which are dynamic organelles, constantly fusing and iding to maintain kidney homoeostasis. In diabetic kidney disease (DKD), mitochondria appear dysfunctional, but the temporal development of diabetes-induced adaptations in mitochondrial structure and bioenergetics have not been previously documented. In the present study, we map the changes in mitochondrial dynamics and function in rat kidney mitochondria at 4, 8, 16 and 32 weeks of diabetes. Our data reveal that changes in mitochondrial bioenergetics and dynamics precede the development of albuminuria and renal histological changes. Specifically, in early diabetes (4 weeks), a decrease in ATP content and mitochondrial fragmentation within proximal tubule epithelial cells (PTECs) of diabetic kidneys were clearly apparent, but no changes in urinary albumin excretion or glomerular morphology were evident at this time. By 8 weeks of diabetes, there was increased capacity for mitochondrial permeability transition (mPT) by pore opening, which persisted over time and correlated with mitochondrial hydrogen peroxide (H2O2) generation and glomerular damage. Late in diabetes, by week 16, tubular damage was evident with increased urinary kidney injury molecule-1 (KIM-1) excretion, where an increase in the Complex I-linked oxygen consumption rate (OCR), in the context of a decrease in kidney ATP, indicated mitochondrial uncoupling. Taken together, these data show that changes in mitochondrial bioenergetics and dynamics may precede the development of the renal lesion in diabetes, and this supports the hypothesis that mitochondrial dysfunction is a primary cause of DKD.
Publisher: Oxford University Press (OUP)
Date: 20-02-2018
Abstract: Do obese levels of advanced glycation end products (AGEs) within the uterine cavity detrimentally alter tissue function in embryo implantation and placental development? Obese levels of AGEs activate inflammatory signaling (p65 NFκB) within endometrial epithelial cells and alter their function, cause endoplasmic reticulum (ER) stress in endometrial stromal cells and impair decidualization, compromise implantation of blastocyst mimics and inhibit trophoblast invasion. Obese women experience a higher incidence of infertility, recurrent miscarriage and pregnancy complications compared with lean women. Oocyte donation cycles suggest a detrimental uterine environment plays a role in these outcomes. Uterine lavage and tissues from lean (BMI 19.5-24.9, n = 17) and obese (BMI > 30, n = 16) women examined. Cell culture experiments utilizing human endometrial epithelial, trophectoderm and trophoblast cell lines and primary human stromal cells used to examine the functional impact of obese levels of AGEs. Levels of AGEs examined within uterine lavage assessed by ELISA to determine differences between lean and obese women. Expression and localization of AGEs, receptor for AGEs (RAGE) and NFκB within endometrial tissues obtained from lean and obese women determined by immunohistochemistry. Endometrial epithelial cells (ECC-1), primary human stromal cells and trophoblast cells (HTR8-SVneo) treated with lean (2000 nmol/mol lysine) or obese (8000 nmol/mol lysine) uterine levels of AGEs and p65 NFκB (western immunoblot), real-time adhesion, proliferation migration and invasion (xCelligence real-time cell function analysis), decidualization (cell morphology and prolactin release), ER stress (western immunoblot for p-PERK) determined. Co-cultures of endometrial epithelial cells and blastocyst mimics (trophectoderm spheroids) similarly treated with lean or obese uterine levels of AGEs to determine their impact on embryo implantation. AGEs were significantly elevated (P = 0.004) within the obese (6503.59 μmol/mol lysine) versus lean (2165.88 μmol/mol lysine) uterine cavity (uterine lavage) with increased immunostaining for AGEs, RAGE and NFkB within obese endometrial tissues during the proliferative phase of the menstrual cycle. Obese uterine levels of AGEs inhibited adhesion and proliferation of endometrial epithelial (ECC-1) cells compared to treatment with lean uterine levels of AGEs. Obese uterine AGE levels impacted primary human endometrial stromal cell decidualization and activated ER stress within these cells. Obese uterine levels of AGEs also inhibited trophectodermal spheroid adhesion to hormonally primed endometrial epithelial cells and trophoblast cell line HTR8/SV-neo invasion. N/A. Mechanistic studies are performed in vitro and may not completely recapitulate cell function in vivo. These data corroborate clinical data suggesting the presence of an altered uterine environment in obese women and demonstrate that elevated uterine levels of AGEs within these women may detrimentally impact endometrial function, embryo implantation and placental development. Uterine AGE assessment in infertility work up may prove useful in determining underlying causes of infertility. AGEs can be targeted pharmacologically and such treatments may prove effective in improving reproductive complications experience by obese women. Supported by NHMRC Fellowship (#1002028 to L.A.S.), and the Victorian Government's Operational Infrastructure Support Program. MTC is supported by a JDRF Australia Clinical Research Network Career Development Award. The authors have declared that no conflict of interest exists.
Publisher: American Diabetes Association
Date: 07-09-2010
DOI: 10.2337/DB10-0195
Abstract: To investigate the effect of the GPx1-mimetic ebselen on diabetes-associated atherosclerosis and renal injury in a model of increased oxidative stress. The study was performed using diabetic apolipoprotein E/GPx1 (ApoE−/−GPx1−/−)-double knockout (dKO) mice, a model combining hyperlipidemia and hyperglycemia with increased oxidative stress. Mice were randomized into two groups, one injected with streptozotocin, the other with vehicle, at 8 weeks of age. Groups were further randomized to receive either ebselen or no treatment for 20 weeks. Ebselen reduced diabetes-associated atherosclerosis in most aortic regions, with the exception of the aortic sinus, and protected dKO mice from renal structural and functional injury. The protective effects of ebselen were associated with a reduction in oxidative stress (hydroperoxides in plasma, 8-isoprostane in urine, nitrotyrosine in the kidney, and 4-hydroxynonenal in the aorta) as well as a reduction in VEGF, CTGF, VCAM-1, MCP-1, and Nox2 after 10 weeks of diabetes in the dKO aorta. Ebselen also significantly reduced the expression of proteins implicated in fibrosis and inflammation in the kidney as well as reducing related key intracellular signaling pathways. Ebselen has an antiatherosclerotic and renoprotective effect in a model of accelerated diabetic complications in the setting of enhanced oxidative stress. Our data suggest that ebselen effectively repletes the lack of GPx1, and indicate that ebselen may be an effective therapeutic for the treatment of diabetes-related atherosclerosis and nephropathy. Furthermore, this study highlights the feasibility of addressing two diabetic complications with one treatment regimen through the unifying approach of targeted antioxidant therapy.
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.KINT.2016.02.043
Abstract: The paradigm that high glucose drives overproduction of superoxide from mitochondria as a unifying theory to explain end organ damage in diabetes complications has been tightly held for more than a decade. With the recent development of techniques and probes to measure the production of distinct reactive oxygen species (ROS) in vivo, this widely held dogma is now being challenged with the emerging view that specific ROS moieties are essential for the function of specific intracellular signaling pathways and represent normal mitochondrial function. This review will provide a balanced overview of the dual nature of ROS, detailing current evidence for ROS overproduction in diabetic kidney disease, with a focus on cell types and sources of ROS. The technical aspects of measurement of mitochondrial ROS, both in isolated mitochondria and emerging in vivo methods will be discussed. The counterargument, that mitochondrial ROS production is reduced in diabetic complications, is consistent with a growing recognition that stimulation of mitochondrial biogenesis and oxidative phosphorylation activity reduces inflammation and fibrosis. It is clear that there is an urgent need to fully characterize ROS production paying particular attention to spatiotemporal aspects and to factor in the relevance of ROS in the regulation of cellular signaling in the pathogenesis of diabetic kidney disease. With improved tools and real-time imaging capacity, a greater understanding of the complex role of ROS will be able to guide novel therapeutic regimens.
Publisher: Wiley
Date: 11-2014
DOI: 10.14814/PHY2.12192
Publisher: Informa UK Limited
Date: 22-12-2017
Publisher: Springer Science and Business Media LLC
Date: 24-11-2022
DOI: 10.1038/S41598-022-24851-W
Abstract: Despite increasing knowledge about the factors involved in the progression of diabetic complications, diabetic kidney disease (DKD) continues to be a major health burden. Current therapies only slow but do not prevent the progression of DKD. Thus, there is an urgent need to develop novel therapy to halt the progression of DKD and improve disease prognosis. In our preclinical study where we administered a histone deacetylase (HDAC) inhibitor, valproic acid, to streptozotocin-induced diabetic mice, albuminuria and glomerulosclerosis were attenuated. Furthermore, we discovered that valproic acid attenuated diabetes-induced upregulation of complement C5a receptors, with a concomitant reduction in markers of cellular senescence and senescence-associated secretory phenotype. Interestingly, further examination of mice lacking the C5a receptor 1 (C5aR1) gene revealed that cellular senescence was attenuated in diabetes. Similar results were observed in diabetic mice treated with a C5aR1 inhibitor, PMX53. RNA-sequencing analyses showed that PMX53 significantly regulated genes associated with cell cycle pathways leading to cellular senescence. Collectively, these results for the first time demonstrated that complement C5a mediates cellular senescence in diabetic kidney disease. Cellular senescence has been implicated in the pathogenesis of diabetic kidney disease, thus therapies to inhibit cellular senescence such as complement inhibitors present as a novel therapeutic option to treat diabetic kidney disease.
Publisher: Springer Science and Business Media LLC
Date: 20-09-2019
DOI: 10.1038/S41598-019-50221-0
Abstract: The accumulation of advanced glycation end products (AGEs) have been implicated in the development and progression of diabetic kidney disease (DKD). There has been interest in investigating the potential of AGE clearance receptors, such as oligosaccharyltransferase-48 kDa subunit (OST48) to prevent the detrimental effects of excess AGE accumulation seen in the diabetic kidney. Here the objective of the study was to increase the expression of OST48 to examine if this slowed the development of DKD by facilitating the clearance of AGEs. Groups of 8-week-old heterozygous knock-in male mice (n = 9–12/group) over-expressing the gene encoding for OST48, dolichyl-diphosphooligosaccharide-protein glycosyltransferase ( DDOST +/−) and litter mate controls were randomised to either (i) no diabetes or (ii) diabetes induced via multiple low-dose streptozotocin and followed for 24 weeks. By the study end, global over expression of OST48 increased glomerular OST48. This facilitated greater renal excretion of AGEs but did not affect circulating or renal AGE concentrations. Diabetes resulted in kidney damage including lower glomerular filtration rate, albuminuria, glomerulosclerosis and tubulointerstitial fibrosis. In diabetic mice, tubulointerstitial fibrosis was further exacerbated by global increases in OST48. There was significantly insulin effectiveness, increased acute insulin secretion, fasting insulin concentrations and AUC insulin observed during glucose tolerance testing in diabetic mice with global elevations in OST48 when compared to diabetic wild-type littermates. Overall, this study suggested that despite facilitating urinary-renal AGE clearance, there were no benefits observed on kidney functional and structural parameters in diabetes afforded by globally increasing OST48 expression. However, the improvements in insulin secretion seen in diabetic mice with global over-expression of OST48 and their dissociation from effects on kidney function warrant future investigation.
Publisher: American Physiological Society
Date: 08-2008
DOI: 10.1152/AJPENDO.00024.2008
Abstract: A diet high in fat induces cardiac hypertrophy, inflammation, and oxidative stress. Although such actions have largely been ascribed to fat deposition, the accumulation of advanced glycation end products (AGEs) and subsequent activation of the receptor for AGEs (RAGE) may also represent important mediators of cardiac injury following exposure to a Western diet. In this study, male C57BL6J and RAGE knockout mice were placed on either a standard diet (7% fat) or a Western “fast-food” diet (21% fat). Animals receiving a high-fat diet were further randomized to receive the AGE inhibitor alagebrium chloride (1 mg·kg −1 ·day −1 ) and followed for 16 wk. A Western diet was associated with cardiac hypertrophy, inflammation, mitochondrial-dependent superoxide production, and cardiac AGE accumulation in wild-type mice. Although RAGE-KO mice fed a Western diet also became obese and accumulated intramyocardial lipid, cardiomyocyte hypertrophy, inflammation, and oxidative stress were attenuated compared with wild-type mice. Similarly, mice of both strains receiving alagebrium chloride had reduced levels of inflammation and oxidative stress, in association with a reduction in cardiac AGEs and RAGE. This study suggests that AGEs represent important mediators of cardiac injury associated with a Western fast-food diet. These data point to the potential utility of AGE-reducing strategies in the prevention and management of cardiac disease.
Publisher: Portland Press Ltd.
Date: 2020
DOI: 10.1042/CS20190787
Abstract: Mitochondrial stress has been widely observed in diabetic kidney disease (DKD). Cyclophilin D (CypD) is a functional component of the mitochondrial permeability transition pore (mPTP) which allows the exchange of ions and solutes between the mitochondrial matrix to induce mitochondrial swelling and activation of cell death pathways. CypD has been successfully targeted in other disease contexts to improve mitochondrial function and reduced pathology. Two approaches were used to elucidate the role of CypD and the mPTP in DKD. Firstly, mice with a deletion of the gene encoding CypD (Ppif−/−) were rendered diabetic with streptozotocin (STZ) and followed for 24 weeks. Secondly, Alisporivir, a CypD inhibitor was administered to the db/db mouse model (5 mg/kg/day oral gavage for 16 weeks). Ppif−/− mice were not protected against diabetes-induced albuminuria and had greater glomerulosclerosis than their WT diabetic littermates. Renal hyperfiltration was lower in diabetic Ppif−/− as compared with WT mice. Similarly, Alisporivir did not improve renal function nor pathology in db/db mice as assessed by no change in albuminuria, KIM-1 excretion and glomerulosclerosis. Db/db mice exhibited changes in mitochondrial function, including elevated respiratory control ratio (RCR), reduced mitochondrial H2O2 generation and increased proximal tubular mitochondrial volume, but these were unaffected by Alisporivir treatment. Taken together, these studies indicate that CypD has a complex role in DKD and direct targeting of this component of the mPTP will likely not improve renal outcomes.
Publisher: SAGE Publications
Date: 02-2019
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4326806
Publisher: MDPI AG
Date: 11-03-2017
DOI: 10.3390/NU9030265
Publisher: Elsevier BV
Date: 08-2007
Abstract: The biochemical process of advanced glycation appears to play a central role in the development and progression of diabetic vascular complications. A number of strategies to influence this pathway have been designed, one of which involves the putative advanced glycation end-product (AGE) crosslink breaker, alagebrium which has been shown in in vitro studies to cleave preformed AGE crosslinks. This agent has been studied in various models of diabetic complications and has been shown to attenuate diabetic renal disease, cardiac dysfunction, and atherosclerosis. In addition to the ability of alagebrium to reduce tissue levels of AGEs, this drug appears to inhibit activation of certain protein kinase C isoforms. Planned clinical studies in diabetic subjects at risk of complications should assist in determining the role of alagebrium in the prevention, retardation, and reversal of diabetic micro- and macrovascular disease.
Publisher: Frontiers Media SA
Date: 30-08-2019
Publisher: Wiley
Date: 28-03-2014
DOI: 10.1111/BPH.12503
Publisher: Public Library of Science (PLoS)
Date: 07-03-2019
Publisher: BMJ
Date: 10-2019
DOI: 10.1136/BMJOPEN-2019-030536
Abstract: Forgetting to take a medication is the most common reason for non-adherence to self-administered medication. Dose administration aids (DAAs) are a simple and common solution to improve unintentional non-adherence for oral tablets. DAAs can be in the form of compartmentalised pill boxes, automated medication dispensing devices, blister packs and sachets packets. This protocol aims to outline the methods that will be used in a systematic review of the current literature to assess the impact of DAAs on adherence to medications and health outcomes. Randomised controlled trials will be identified through electronic searches in databases including EMBASE, MEDLINE, CINAHL and the Cochrane Library, from the beginning of each database until January 2020. Two reviewers will independently screen studies and extract data using the standardised forms. Data extracted will include general study information, characteristics of the study, participant characteristics, intervention characteristics and outcomes. Primary outcome is to assess the effects of DAAs on medication adherence. Secondary outcome is to evaluate the changes in health outcomes. The risk of bias will be ascertained by two reviewers in parallel using The Cochrane Risk of Bias Tool. A meta-analysis will be performed if data are homogenous. Ethics approval will not be required for this study. The results of the review described within this protocol will be disseminated through publication in a peer-reviewed journal and relevant conference presentations. CRD42018096087
Publisher: Elsevier BV
Date: 07-2018
Publisher: JCFCorp SG PTE LTD
Date: 2015
Publisher: American Diabetes Association
Date: 16-09-2011
DOI: 10.2337/DB10-1033
Abstract: Excess accumulation of advanced glycation end products (AGEs) contributes to aging and chronic diseases. We aimed to obtain evidence that exposure to AGEs plays a role in the development of type 1 diabetes (T1D). The effect of AGEs was examined on insulin secretion by MIN6N8 cells and mouse islets and in vivo in three separate rodent models: AGE-injected or high AGE–fed Sprague-Dawley rats and nonobese diabetic (NODLt) mice. Rodents were also treated with the AGE-lowering agent alagebrium. β-Cells exposed to AGEs displayed acute glucose-stimulated insulin secretory defects, mitochondrial abnormalities including excess superoxide generation, a decline in ATP content, loss of MnSOD activity, reduced calcium flux, and increased glucose uptake, all of which were improved with alagebrium treatment or with MnSOD adenoviral overexpression. Isolated mouse islets exposed to AGEs had decreased glucose-stimulated insulin secretion, increased mitochondrial superoxide production, and depletion of ATP content, which were improved with alagebrium or with MnTBAP, an SOD mimetic. In rats, transient or chronic exposure to AGEs caused progressive insulin secretory defects, superoxide generation, and β-cell death, ameliorated with alagebrium. NODLt mice had increased circulating AGEs in association with an increase in islet mitochondrial superoxide generation, which was prevented by alagebrium, which also reduced the incidence of autoimmune diabetes. Finally, at-risk children who progressed to T1D had higher AGE concentrations than matched nonprogressors. These findings demonstrate that AGEs directly cause insulin secretory defects, most likely by impairing mitochondrial function, which may contribute to the development of T1D.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2022
DOI: 10.2215/CJN.00180122
Abstract: Hyperkalemia after starting renin-angiotensin system inhibitors has been shown to be subsequently associated with a higher risk of cardiovascular and kidney outcomes. However, whether to continue or discontinue the drug after hyperkalemia remains unclear. Data came from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial, which included a run-in period where all participants initiated angiotensin-converting enzyme inhibitor–based therapy (a fixed combination of perindopril and indapamide). The study population was taken as patients with type 2 diabetes with normokalemia (serum potassium of 3.5 to .0 mEq/L) at the start of run-in. Potassium was remeasured 3 weeks later when a total of 9694 participants were classified into hyperkalemia (≥5.0 mEq/L), normokalemia, and hypokalemia ( .5 mEq/L) groups. After run-in, patients were randomized to continuation of the angiotensin-converting enzyme inhibitor–based therapy or placebo major macrovascular, microvascular, and mortality outcomes were analyzed using Cox regression during the following 4.4 years (median). During active run-in, 556 (6%) participants experienced hyperkalemia. During follow-up, 1505 participants experienced the primary composite outcome of major macrovascular and microvascular events. Randomized treatment of angiotensin-converting enzyme inhibitor–based therapy significantly decreased the risk of the primary outcome (38.1 versus 42.0 per 1000 person-years hazard ratio, 0.91 95% confidence interval, 0.83 to 1.00 P =0.04) compared with placebo. The magnitude of effects did not differ across subgroups defined by short-term changes in serum potassium during run-in ( P for heterogeneity =0.66). Similar consistent treatment effects were also observed for all-cause death, cardiovascular death, major coronary events, major cerebrovascular events, and new or worsening nephropathy ( P for heterogeneity ≥0.27). Continuation of angiotensin-converting enzyme inhibitor–based therapy consistently decreased the subsequent risk of clinical outcomes, including cardiovascular and kidney outcomes and death, regardless of short-term changes in serum potassium. Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE), NCT00145925
Publisher: American Diabetes Association
Date: 17-10-2019
DOI: 10.2337/DB19-0043
Abstract: The sequelae of diabetes include microvascular complications such as diabetic kidney disease (DKD), which involves glucose-mediated renal injury associated with a disruption in mitochondrial metabolic agility, inflammation, and fibrosis. We explored the role of the innate immune complement component C5a, a potent mediator of inflammation, in the pathogenesis of DKD in clinical and experimental diabetes. Marked systemic elevation in C5a activity was demonstrated in patients with diabetes conventional renoprotective agents did not therapeutically target this elevation. C5a and its receptor (C5aR1) were upregulated early in the disease process and prior to manifest kidney injury in several erse rodent models of diabetes. Genetic deletion of C5aR1 in mice conferred protection against diabetes-induced renal injury. Transcriptomic profiling of kidney revealed diabetes-induced downregulation of pathways involved in mitochondrial fatty acid metabolism. Interrogation of the lipidomics signature revealed abnormal cardiolipin remodeling in diabetic kidneys, a cardinal sign of disrupted mitochondrial architecture and bioenergetics. In vivo delivery of an orally active inhibitor of C5aR1 (PMX53) reversed the phenotypic changes and normalized the renal mitochondrial fatty acid profile, cardiolipin remodeling, and citric acid cycle intermediates. In vitro exposure of human renal proximal tubular epithelial cells to C5a led to altered mitochondrial respiratory function and reactive oxygen species generation. These experiments provide evidence for a pivotal role of the C5a/C5aR1 axis in propagating renal injury in the development of DKD by disrupting mitochondrial agility, thereby establishing a new immunometabolic signaling pathway in DKD.
Publisher: Wiley
Date: 08-06-2022
DOI: 10.1111/IMCB.12558
Abstract: A recently published study by Bell et al. shows altered immunotolerance in people with type 1 diabetes by dietary supplementation of modified resistant starch fibre.
Publisher: BMJ
Date: 02-2019
DOI: 10.1136/BMJOPEN-2018-022637
Abstract: We aimed to evaluate the effects on depression scores of a lifestyle-focused cardiac support programme delivered via mobile phone text messaging among patients with coronary heart disease (CHD). Substudy and secondary analysis of a parallel-group, single-blind randomised controlled trial of patients with CHD. A tertiary hospital in Sydney, Australia. The Tobacco, Exercise and dieT MEssages programme comprised four text messages per week for 6 months that provided education, motivation and support on diet, physical activity, general cardiac education and smoking, if relevant. The programme did not have any specific mental health component. Depression scores at 6 months measured using the Patient Health Questionnaire-9 (PHQ-9). Treatment effect across subgroups was measured using log-binomial regression model for the binary outcome (depressed/not depressed, where depressed is any score of PHQ-9 ≥5) with treatment, subgroup and treatment by subgroup interaction as fixed effects. Depression scores at 6 months were lower in the intervention group compared with the control group, mean difference 1.9 (95% CI 1.5 to 2.4, p .0001). The frequency of mild or greater depressive symptoms (PHQ-9 scores≥5) at 6 months was 21/333 (6.3%) in the intervention group and 86/350 (24.6%) in the control group (relative risk (RR) 0.26, 95% CI 0.16 to 0.40, p .001). This proportional reduction in depressive symptoms was similar across groups defined by age, sex, education, body mass index, physical activity, current smoking, current drinking and history of depression, diabetes and hypertension. In particular, the rates of PHQ-9 ≥5 among people with a history of depression were 4/44 (9.1%) vs 29/62 (46.8%) in intervention vs control (RR 0.19, 95% CI 0.07 to 0.51, p .001), and were 17/289 (5.9%) vs 57/288 (19.8%) among others (RR 0.30, 95% CI 0.18 to 0.50, p .001). Among people with CHD, a cardiac support programme delivered via mobile phone text messaging was associated with fewer symptoms of mild-to-moderate depression at 6 months in the treatment group compared with controls. ACTRN12611000161921.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-08-2022
Publisher: Wiley
Date: 05-03-2020
Publisher: Elsevier BV
Date: 12-2018
Publisher: MDPI AG
Date: 28-10-2022
DOI: 10.3390/NU14214547
Abstract: Diabetes is the leading cause of kidney disease, and as the number of in iduals with diabetes increases there is a concomitant increase in the prevalence of diabetic kidney disease (DKD). Diabetes contributes to the development of DKD through a number of pathways, including inflammation, oxidative stress, and the gut-kidney axis, which may be amenable to dietary therapy. Resistant starch (RS) is a dietary fibre that alters the gut microbial consortium, leading to an increase in the microbial production of short chain fatty acids. Evidence from animal and human studies indicate that short chain fatty acids are able to attenuate inflammatory and oxidative stress pathways, which may mitigate the progression of DKD. In this review, we evaluate and summarise the evidence from both preclinical models of DKD and clinical trials that have utilised RS as a dietary therapy to limit the progression of DKD.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2019
Publisher: Mary Ann Liebert Inc
Date: 10-2022
Publisher: Mary Ann Liebert Inc
Date: 03-2007
Abstract: Diabetic nephropathy remains a major cause of morbidity and mortality in the diabetic population and is the leading cause of end-stage renal failure in the Western World. Despite current therapeutics including intensified glycemic control and blood pressure lowering agents, renal disease continues to progress relentlessly in diabetic patients, albeit at a lower rate. It is well recognized that metabolic and hemodynamic factors play a central role in accelerating renal disease in diabetes. However, recent experimental studies have suggested that increased generation of reactive oxygen species (ROS) as a result of the diabetic milieu may play a central role in the progression of diabetic microvascular complications. These ROS appear to be generated primarily from mitochondrial sources and via the enzyme, NADPH oxidase. This review focuses on how ROS play a deleterious role in the diabetic kidney and how they are involved in crosstalk among various signaling pathways, ultimately leading to renal dysfunction and structural injury.
Publisher: American Physiological Society
Date: 09-2023
DOI: 10.1152/AJPRENAL.00072.2023
Abstract: Gut microbiome research has increased dramatically in the last decade, including in renal health and disease. The field is moving from experiments showing mere association to causation using both forward and reverse microbiome approaches, leveraging tools such as germ-free animals, treatment with antibiotics, and fecal microbiota transplantations. However, we are still seeing a gap between discovery and translation that needs to be addressed, so that patients can benefit from microbiome-based therapies. In this guideline paper, we discuss the key considerations that affect the gut microbiome of animals and clinical studies assessing renal function, many of which are often overlooked, resulting in false-positive results. For animal studies, these include suppliers, acclimatization, baseline microbiota and its normalization, littermates and cohort/cage effects, diet, sex differences, age, circadian differences, antibiotics and sweeteners, and models used. Clinical studies have some unique considerations, which include s ling, gut transit time, dietary records, medication, and renal phenotypes. We provide best-practice guidance on s ling, storage, DNA extraction, and methods for microbial DNA sequencing (both 16S rRNA and shotgun metagenome). Finally, we discuss follow-up analyses, including tools available, metrics, and their interpretation, and the key challenges ahead in the microbiome field. By standardizing study designs, methods, and reporting, we will accelerate the findings from discovery to translation and result in new microbiome-based therapies that may improve renal health.
Publisher: Cold Spring Harbor Laboratory
Date: 31-07-2019
DOI: 10.1101/713354
Abstract: Alterations in gut homeostasis may contribute to the progression of diabetic nephropathy. There has been recent attention on the renoprotective effects of metabolite-sensing receptors in chronic renal injury, including the G-protein-coupled-receptor (GPR)109a, which ligates the short chain fatty acid butyrate. However, the role of GPR109a in the development of diabetic nephropathy, a milieu of diminished microbiome-derived metabolites, has not yet been determined. This study aimed to assess the effects of insufficient GPR109a signalling via genetic deletion of GPR109a on the development of renal injury in diabetic nephropathy. Gpr109a −/− mice or their wildtype littermates ( Gpr109a +/+) were rendered diabetic with streptozotocin (STZ). Mice received a control diet or an isocaloric high fiber diet (12.5% resistant starch) for 24 weeks and gastrointestinal permeability and renal injury were determined. Diabetes was associated with increased albuminuria, glomerulosclerosis and inflammation. In comparison, Gpr109a −/− mice with diabetes did not show an altered renal phenotype. Resistant starch supplementation did not afford protection from renal injury in diabetic nephropathy. Whilst diabetes was associated with alterations in intestinal morphology, intestinal permeability assessed in vivo using the FITC-dextran test was unaltered. GPR109a deletion did not worsen gastrointestinal permeability. Further, 12.5% resistant starch supplementation, at physiological concentrations, had no effect on intestinal permeability or morphology. These studies indicate that GPR109a does not play a critical role in intestinal homeostasis in a model of type 1 diabetes or in the development of diabetic nephropathy.
Publisher: Springer Science and Business Media LLC
Date: 15-07-2010
Publisher: Wiley
Date: 12-2022
DOI: 10.1002/JPPR.1843
Abstract: Tablet splitting is a widely prevalent practice resulting from the need to alter doses into two or more parts and optimise medicine in in idual patients. If a tablet is split unequally problems may arise. The aim of the study was to summarise the literature measuring the effect of tablet splitting on dose accuracy. MEDLINE, EMBASE, CINAHL and Cochrane were searched and studies published prior to January 2020 investigating the effect of splitting tablets on dose accuracy were included. Studies investigating any drug, where the tablet was split, were potentially eligible. Two independent reviewers conducted the screening and extracted the data. Meta‐analyses assessing the effect of tablet splitting on dose accuracy were performed. (Study registration: PROSPERO CRD42018106252). Of 25 included studies, 16 examined the effect of tablet splitting on weight of the tablet, one on drug concentration and eight examined both. Meta‐analysis found small variation between split tablets (0.87% weight variation, 95% confidence interval 0.63%–1.11% and 0.24% drug content variation, 95% confidence interval 0.06%–0.43%). There was some inconsistency across trial results for weight but not for drug content variation ( I 2 50% and I 2 1%, respectively). Splitting method and tablet characteristics were predictors of accuracy. Although tablet splitting may influence dose accuracy, this analysis suggests that the weight and drug content variation is minimal, regardless of method and tablet characteristics. Additional studies, such as those examining drug plasma concentrations and effect on patient health outcomes for ex le blood pressure and cholesterol levels, are needed to better understand the role of tablet splitting on dose accuracy.
Publisher: The Endocrine Society
Date: 02-2007
DOI: 10.1210/EN.2006-1300
Abstract: Blockade of advanced glycation end product (AGE) accumulation with alagebrium with concomitant angiotensin converting enzyme inhibition was tested for effects on renal function and on other postulated mediators of diabetic renal disease including the renin-angiotensin system, AGEs, mitochondrial and cytosolic oxidative stress, and intracellular signaling molecules. Sprague Dawley rats were rendered diabetic with streptozocin and followed consecutively for 32 wk with nondiabetic controls. Groups were treated with ramipril (1 mg/kg.d wk 0-32) alagebrium (10 mg/kg.d wk 16-32) or a combination of both. Although in idual treatments had significant effects on albuminuria, no further improvements were seen with combination therapy. Changes in urinary vascular endothelial growth factor excretion mirrored those seen in albuminuria. Diabetes was associated with suppression of circulating angiotensin II in the context of increased circulating and renal levels of the AGE, carboxymethyllysine. All treatments attenuated circulating but not renal carboxymethyllysine levels. The renal gene expression of AGE receptor 1 and soluble receptor for advanced glycation end products were markedly reduced by diabetes and normalized with alagebrium. Diabetes induced renal mitochondrial oxidative stress, which was reduced with alagebrium. In the cytosol, both therapies were equally effective in reducing reactive oxygen species production. Increases in membranous protein kinase C activity in diabetes were attenuated by all treatments, whereas diabetes-associated increases in nuclear factor-kappaB p65 translocation remained unaltered by any therapy. It is evident that renin-angiotensin system blockade and AGE inhibition have specific effects. However, many of their downstream effects appear to be similar, suggesting that their renoprotective benefits may ultimately involve common pathways and key points of convergence, which could be important targets for new therapies in diabetic nephropathy.
Publisher: Oxford University Press (OUP)
Date: 15-09-2015
Abstract: Advanced glycation end products (AGEs) formed via the Maillard reaction during the thermal processing of food contributes to the flavor, color, and aroma of food. A proportion of food-derived AGEs and their precursors is intestinally absorbed and accumulates within cells and tissues. AGEs have been implicated in the pathogenesis of diabetes-related complications and several chronic diseases via interaction with the receptor for AGEs, which promotes the transcription of genes that control inflammation. The dicarbonyls, highly reactive intermediates of AGE formation, are also generated during food processing and may incite inflammatory responses through 1) the suppression of protective pathways, 2) the incretin axis, 3) the modulation of immune-mediated signaling, and 4) changes in gut microbiota profile and metabolite sensors. In animal models, restriction of dietary AGEs attenuates chronic low-grade inflammation, but current evidence from human studies is less clear. Here, the emerging relationship between excess dietary AGE consumption and inflammation is explored, the utility of dietary AGE restriction as a therapeutic strategy for the attenuation of chronic diseases is discussed, and possible avenues for future investigation are suggested.
Publisher: American Diabetes Association
Date: 26-07-2017
DOI: 10.2337/DB16-1585
Abstract: NADPH oxidase–derived excessive production of reactive oxygen species (ROS) in the kidney plays a key role in mediating renal injury in diabetes. Pathological changes in diabetes include mesangial expansion and accumulation of extracellular matrix (ECM) leading to glomerulosclerosis. There is a paucity of data about the role of the Nox5 isoform of NADPH oxidase in animal models of diabetic nephropathy since Nox5 is absent in the mouse genome. Thus, we examined the role of Nox5 in human diabetic nephropathy in human mesangial cells and in an inducible human Nox5 transgenic mouse exposed to streptozotocin-induced diabetes. In human kidney biopsies, Nox5 was identified to be expressed in glomeruli, which appeared to be increased in diabetes. Colocalization demonstrated Nox5 expression in mesangial cells. In vitro, silencing of Nox5 in human mesangial cells was associated with attenuation of the hyperglycemia and TGF-β1–induced enhanced ROS production, increased expression of profibrotic and proinflammatory mediators, and increased TRPC6, PKC-α, and PKC-β expression. In vivo, vascular smooth muscle cell/mesangial cell–specific overexpression of Nox5 in a mouse model of diabetic nephropathy showed enhanced glomerular ROS production, accelerated glomerulosclerosis, mesangial expansion, and ECM protein (collagen IV and fibronectin) accumulation as well as increased macrophage infiltration and expression of the proinflammatory chemokine MCP-1. Collectively, this study provides evidence of a role for Nox5 and its derived ROS in promoting progression of diabetic nephropathy.
Publisher: Elsevier BV
Date: 11-2020
Publisher: American Diabetes Association
Date: 06-2008
DOI: 10.2337/DB08-0057
Abstract: It is postulated that localized tissue oxidative stress is a key component in the development of diabetic nephropathy. There remains controversy, however, as to whether this is an early link between hyperglycemia and renal disease or develops as a consequence of other primary pathogenic mechanisms. In the kidney, a number of pathways that generate reactive oxygen species (ROS) such as glycolysis, specific defects in the polyol pathway, uncoupling of nitric oxide synthase, xanthine oxidase, NAD(P)H oxidase, and advanced glycation have been identified as potentially major contributors to the pathogenesis of diabetic kidney disease. In addition, a unifying hypothesis has been proposed whereby mitochondrial production of ROS in response to chronic hyperglycemia may be the key initiator for each of these pathogenic pathways. This postulate emphasizes the importance of mitochondrial dysfunction in the progression and development of diabetes complications including nephropathy. A mystery remains, however, as to why antioxidants per se have demonstrated minimal renoprotection in humans despite positive preclinical research findings. It is likely that the utility of current study approaches, such as vitamin use, may not be the ideal antioxidant strategy in human diabetic nephropathy. There is now an increasing body of data to suggest that strategies involving a more targeted antioxidant approach, using agents that penetrate specific cellular compartments, may be the elusive additive therapy required to further optimize renoprotection in diabetes.
Publisher: Wiley
Date: 11-07-2022
DOI: 10.1002/DMRR.3556
Abstract: Diabetic kidney disease is expected to increase rapidly over the coming decades with rising prevalence of diabetes worldwide. Current measures of kidney function based on albuminuria and estimated glomerular filtration rate do not accurately stratify and predict in iduals at risk of declining kidney function in diabetes. As a result, recent attention has turned towards identifying and assessing the utility of biomarkers in diabetic kidney disease. This review explores the current literature on biomarkers of inflammation and kidney injury focussing on studies of single or multiple biomarkers between January 2014 and February 2020. Multiple serum and urine biomarkers of inflammation and kidney injury have demonstrated significant association with the development and progression of diabetic kidney disease. Of the inflammatory biomarkers, tumour necrosis factor receptor‐1 and ‐2 were frequently studied and appear to hold most promise as markers of diabetic kidney disease. With regards to kidney injury biomarkers, studies have largely targeted markers of tubular injury of which kidney injury molecule‐1, beta‐2‐microglobulin and neutrophil gelatinase‐associated lipocalin emerged as potential candidates. Finally, the use of a small panel of selective biomarkers appears to perform just as well as a panel of multiple biomarkers for predicting kidney function decline.
Publisher: Cambridge University Press (CUP)
Date: 13-11-2013
DOI: 10.1017/S0007114513003607
Abstract: Complex relationships exist between the gut microflora and their human hosts. Emerging evidence suggests that bacterial dysbiosis within the colon may be involved in the pathogenesis of the metabolic syndrome, type 2 diabetes and CVD. The use of dietary prebiotic supplements to restore an optimal balance of intestinal flora may positively affect host metabolism, representing a potential treatment strategy for in iduals with cardiometabolic disorders. The present review aimed to examine the current evidence supporting that dietary prebiotic supplementation in adults has beneficial effects on biochemical parameters associated with the development of metabolic abnormalities including obesity, glucose intolerance, dyslipidaemia, hepatic steatosis and low-grade chronic inflammation. Between January 2000 and September 2013, eight computer databases were searched for randomised controlled trials published in English. Human trials were included if at least one group received a dietary prebiotic intervention. In the present review, twenty-six randomised controlled trials involving 831 participants were included. Evidence indicated that dietary prebiotic supplementation increased self-reported feelings of satiety in healthy adults (standardised mean difference − 0·57, 95 % CI − 1·13, − 0·01). Prebiotic supplementation also significantly reduced postprandial glucose ( − 0·76, 95 % CI − 1·41, − 0·12) and insulin ( − 0·77, 95 % CI − 1·50, − 0·04) concentrations. The effects of dietary prebiotics on total energy intake, body weight, peptide YY and glucagon-like peptide-1 concentrations, gastric emptying times, insulin sensitivity, lipids, inflammatory markers and immune function were contradictory. Dietary prebiotic consumption was found to be associated with subjective improvements in satiety and reductions in postprandial glucose and insulin concentrations. Additional evidence is required before recommending prebiotic supplements to in iduals with metabolic abnormalities. Large-scale trials of longer duration evaluating gut microbial growth and activity are required.
Publisher: Elsevier BV
Date: 06-2017
Publisher: SAGE Publications
Date: 07-01-2022
DOI: 10.1177/17474930211068671
Abstract: Patients who suffer intracerebral hemorrhage (ICH) are at very high risk of recurrent ICH and other serious cardiovascular events. A single-pill combination (SPC) of blood pressure (BP) lowering drugs offers a potentially powerful but simple strategy to optimize secondary prevention. The Triple Therapy Prevention of Recurrent Intracerebral Disease Events Trial (TRIDENT) aims to determine the effects of a novel SPC “Triple Pill,” three generic antihypertensive drugs with demonstrated efficacy and complementary mechanisms of action at half standard dose (telmisartan 20 mg, amlodipine 2.5 mg, and indapamide 1.25 mg), with placebo for the prevention of recurrent stroke, cardiovascular events, and cognitive impairment after ICH. An international, double-blind, placebo-controlled, randomized trial in adults with ICH and mild-moderate hypertension (systolic BP: 130–160 mmHg), who are not taking any Triple Pill component drug at greater than half-dose. A total of 1500 randomized patients provide 90% power to detect a hazard ratio of 0.5, over an average follow-up of 3 years, according to a total primary event rate (any stroke) of 12% in the control arm and other assumptions. Secondary outcomes include recurrent ICH, cardiovascular events, and safety. Recruitment started 28 September 2017. Up to 31 October 2021, 821 patients were randomized at 54 active sites in 10 countries. Triple Pill adherence after 30 months is 86%. The required s le size should be achieved by 2024. Low-dose Triple Pill BP lowering could improve long-term outcome from ICH.
Publisher: Cold Spring Harbor Laboratory
Date: 22-02-2021
DOI: 10.1101/2021.02.19.431993
Abstract: Mitochondrial defects are implicated in multiple diseases and aging. Exercise training is an accessible and inexpensive therapeutic intervention improving mitochondrial bioenergetics and quality of life. By combining a multi-omics approach with biochemical and in silico normalization, we removed the bias arising from the training-induced increase in human skeletal muscle mitochondrial content to unearth an intricate and previously undemonstrated network of differentially prioritized mitochondrial adaptations. We show that changes in hundreds of transcripts, proteins, and lipids are not stoichiometrically linked to the increase in mitochondrial content. We demonstrate that enhancing electron flow to oxidative phosphorylation (OXPHOS) is more important to improve ATP generation than increasing the abundance of the OXPHOS machinery, and that training-induced supercomplex formation does not confer enhancements in mitochondrial bioenergetics. Our study provides a new analytical approach allowing unbiased and in-depth investigations of training-induced mitochondrial adaptations, challenging our current understanding and calling for careful reinterpretation of previous findings.
Publisher: Springer Science and Business Media LLC
Date: 03-09-2020
DOI: 10.1038/S41598-020-71475-Z
Abstract: Fatty acid oxidation is the major energy pathway used by the kidney, although glycolysis becomes more important in the low oxygen environment of the medulla. Fatty acid oxidation appears to be reduced in renal fibrosis, and drugs that reverse this improve fibrosis. Expression of glycolytic genes is more variable, but some studies have shown that inhibiting glycolysis reduces renal fibrosis. To address the role of glycolysis in renal fibrosis, we have used a genetic approach. The crucial control point in the rate of glycolysis is 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase. Phosphorylation of the kidney isoform, PFKFB2, on residues Ser 468 and Ser 485 stimulates glycolysis and is the most important mechanism regulating glycolysis. We generated transgenic mice with inactivating mutations of Ser 468 and Ser 485 in PFKFB2 (PFKFB2 KI mice). These mutations were associated with a reduced ability to increase glycolysis in primary cultures of renal tubular cells from PFKFB2 KI mice compared to WT cells. This was associated in PFKFB2 KI mice with increased renal fibrosis, which was more severe in the unilaternal ureteric obstruction (UUO) model compared with the folic acid nephropathy (FAN) model. These studies show that phosphorylation of PFKFB2 is important in limiting renal fibrosis after injury, indicating that the ability to regulate and maintain adequate glycolysis in the kidney is crucial for renal homeostasis. The changes were most marked in the UUO model, probably reflecting a greater effect on distal renal tubules and the greater importance of glycolysis in the distal nephron.
Publisher: SAGE Publications
Date: 09-09-2020
Abstract: There has been extensive discussion about gender gaps in representation and career advancement in the sciences. However, psychological science itself has yet to be the focus of discussion or systematic review, despite our field’s investment in questions of equity, status, well-being, gender bias, and gender disparities. In the present article, we consider 10 topics relevant for women’s career advancement in psychological science. We focus on issues that have been the subject of empirical study, discuss relevant evidence within and outside of psychological science, and draw on established psychological theory and social-science research to begin to chart a path forward. We hope that better understanding of these issues within the field will shed light on areas of existing gender gaps in the discipline and areas where positive change has happened, and spark conversation within our field about how to create lasting change to mitigate remaining gender differences in psychological science.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2019
DOI: 10.1161/HYPERTENSIONAHA.118.12060
Abstract: Discontinuation of angiotensin-converting enzyme (ACE) inhibitor is recommended if patients experience ≥30% acute increase in serum creatinine after starting this therapy. However, the long-term effects of its continuation or discontinuation on major clinical outcomes after increases in serum creatinine are unclear. In the ADVANCE trial (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation), 11 140 diabetes mellitus patients were randomly assigned to perindopril-indapamide or placebo after a 6-week active run-in period. The current study included 11 066 participants with 2 serum creatinine measurements recorded before and during the active run-in period (3 weeks apart). Acute increase in creatinine was determined using these 2 measurements and classified into 4 groups: increases in serum creatinine of %, 10% to 19%, 20% to 29%, and ≥30%. The primary study outcome was the composite of major macrovascular events, new or worsening nephropathy, and all-cause mortality. An acute increase in serum creatinine was associated with an elevated risk of the primary outcome ( P for trend .001). The hazard ratios were 1.11 (95% CI, 0.97–1.28) for those with an increase of 10% to 19%, 1.34 (1.07–1.66) for 20% to 29%, and 1.44 (1.15–1.81) for ≥30%, compared with %. However, there was no evidence of heterogeneity in the benefit of randomized treatment effects on the outcome across subgroups defined by acute serum creatinine increase ( P for heterogeneity=0.94). Acute increases in serum creatinine after starting perindopril-indapamide were associated with greater risks of subsequent major clinical outcomes. However, the continuation of angiotensin-converting enzyme inhibitor-based therapy reduced the long-term risk of major clinical outcomes, irrespective of acute increase in creatinine. URL: www.clinicaltrials.gov . Unique identifier: NCT00145925.
Publisher: Elsevier BV
Date: 07-2019
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 28-04-2020
DOI: 10.1161/CIRCULATIONAHA.119.043081
Abstract: High blood pressure (BP) continues to be a major, poorly controlled but modifiable risk factor for cardiovascular death. Among key Western lifestyle factors, a diet poor in fiber is associated with prevalence of high BP. The impact of lack of prebiotic fiber and the associated mechanisms that lead to higher BP are unknown. Here we show that lack of prebiotic dietary fiber leads to the development of a hypertensinogenic gut microbiota, hypertension and its complications, and demonstrate a role for G-protein coupled-receptors (GPCRs) that sense gut metabolites. One hundred seventy-nine mice including C57BL/6J, gnotobiotic C57BL/6J, and knockout strains for GPR41, GPR43, GPR109A, and GPR43/109A were included. C57BL/6J mice were implanted with minipumps containing saline or a slow-pressor dose of angiotensin II (0.25 mg·kg -1 ·d -1 ). Mice were fed diets lacking prebiotic fiber with or without addition of gut metabolites called short-chain fatty acids ([SCFA)] produced during fermentation of prebiotic fiber in the large intestine), or high prebiotic fiber diets. Cardiac histology and function, BP, sodium and potassium excretion, gut microbiome, flow cytometry, catecholamines and methylation-wide changes were determined. Lack of prebiotic fiber predisposed mice to hypertension in the presence of a mild hypertensive stimulus, with resultant pathological cardiac remodeling. Transfer of a hypertensinogenic microbiota to gnotobiotic mice recapitulated the prebiotic-deprived hypertensive phenotype, including cardiac manifestations. Reintroduction of SCFAs to fiber-depleted mice had protective effects on the development of hypertension, cardiac hypertrophy, and fibrosis. The cardioprotective effect of SCFAs were mediated via the cognate SCFA receptors GPR43/GPR109A, and modulated L-3,4-dihydroxyphenylalanine levels and the abundance of T regulatory cells regulated by DNA methylation. The detrimental effects of low fiber Westernized diets may underlie hypertension, through deficient SCFA production and GPR43/109A signaling. Maintaining a healthy, SCFA-producing microbiota is important for cardiovascular health.
Publisher: Wiley
Date: 16-11-2022
DOI: 10.1111/JVH.13629
Abstract: The availability of direct‐acting antivirals (DAAs) sparked efforts to eliminate hepatitis C virus (HCV) in Australia. We evaluated whether an educational intervention of a 1‐h discussion among staff using audit and feedback data from the MedicineInsight GP programme would improve DAA uptake. Of 296 eligible general practices in MedicineInsight, 11% opted out. Randomization stratified by practice caseload allocated 130 practices to the intervention arm and 129 to control. The primary outcome was the number of patients started on DAAs over 6 months using the negative binomial regression model adjusted for DAA prescription history and clustering by practice. Data for analysis were available for 78% of practices, which included 101 practices and 2469 DAA‐naive patients with confirmed ossible HCV in the intervention arm, and 100 practices and 2466 patients in the control arm. At baseline, 49.5% of practices had prescribed ≥1 DAA in the past year 18.9% of HCV patients had already been treated with DAAs the mean age of DAA‐naive HCV patients was 43 years old, and 57% were men. Over 6 months, 43 patients in the intervention arm and 36 in the control arm started DAAs (adjusted IRR 1.19 95% CI 0.67–2.11, p = 0.55). In the first 3 months, 27 vs 16 patients started DAAs (adjusted IRR 1.77, 0.88–3.58 p = 0.111). Few patients were started on DAAs, and a facilitated discussion in HCV management did not lead to a significant increase. Alternative measures, such as incentivizing GP initiations or patients, are suggested to address remaining barriers to DAA uptake in Australian primary care. Australian New Zealand Clinical Trial Registry (ANZCTR) Registration Number: ACTRN12619000508178p.
Publisher: Wiley
Date: 30-10-2020
DOI: 10.1111/DOM.13878
Abstract: To assess the effects of intensive glucose control on the risk of major clinical outcomes according to estimated glomerular filtration rate (eGFR) levels in people with type 2 diabetes. Of 11 140 ADVANCE trial participants, 11 096 with baseline eGFR measurements were included, and classified into three eGFR groups: ≥90 mL/min/1.73 m
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2022
DOI: 10.1161/CIRCOUTCOMES.121.008552
Abstract: Mendelian randomization studies use genetic variants as natural experiments to provide evidence about causal relations between modifiable risk factors and disease. Recent Mendelian randomization studies suggest each mmol/L reduction in low-density lipoprotein cholesterol (LDL-C) sustained over a lifetime can reduce the risk of cardiovascular disease by more than half. However, these findings have not been replicated in randomized clinical trials, and the effect of treatment duration on the magnitude of risk reduction remains uncertain. The aim of this article was to evaluate the relationship between lipid-lowering drug exposure time and relative risk reduction of major cardiovascular events in randomized clinical trials. We conducted a systematic review and meta-analysis of randomized clinical trials of statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors that report LDL-C levels and effect sizes for each year of follow-up. The primary end point was major vascular events, defined as the composite of cardiovascular death, myocardial infarction, stroke, and coronary revascularization. Hazard ratios during each year of follow-up were meta-analyzed using random-effects models. A total of 21 trials with 184 012 patients and an average mean follow-up of 4.4 years were included. Meta-regression showed there was greater relative risk reduction in major vascular events with increasing duration of treatment ( P .001). For ex le, each mmol/L LDL-C lowered was associated with a relative risk reduction in major vascular events of 12% (95% CI, 8%–16%) for year 1, 20% (95% CI, 16%–24%) for year 3, 23% (95% CI, 18%–27%) for year 5, and 29% (95% CI, 14%–42%) for year 7. The benefits of LDL-C lowering do not seem to be fixed but increase steadily with longer durations of treatment. The results from short-term randomized trials are compatible with the very strong associations between LDL-C and cardiovascular events seen in Mendelian randomization studies.
Publisher: American Physiological Society
Date: 03-2020
DOI: 10.1152/AJPRENAL.00505.2019
Abstract: Alterations in gut homeostasis may contribute to the progression of diabetic nephropathy. There has been recent attention on the renoprotective effects of metabolite-sensing receptors in chronic renal injury, including the G protein-coupled receptor (GPR)109a, which ligates the short-chain fatty acid butyrate. However, the role of GPR109a in the development of diabetic nephropathy, a milieu of diminished microbiome-derived metabolites, has not yet been determined. The present study aimed to assess the effects of insufficient GPR109a signaling, via genetic deletion of GPR109a, on the development of renal injury in diabetic nephropathy. Gpr109a −/− mice or their wild-type littermates ( Gpr109a +/+ ) were rendered diabetic with streptozotocin. Mice received a control diet or an isocaloric high-fiber diet (12.5% resistant starch) for 24 wk, and gastrointestinal permeability and renal injury were determined. Diabetes was associated with increased albuminuria, glomerulosclerosis, and inflammation. In comparison, Gpr109a −/− mice with diabetes did not show an altered renal phenotype. Resistant starch supplementation did not afford protection from renal injury in diabetic nephropathy. While diabetes was associated with alterations in intestinal morphology, intestinal permeability assessed in vivo using the FITC-dextran test was unaltered. GPR109a deletion did not worsen gastrointestinal permeability. Furthermore, 12.5% resistant starch supplementation, at physiological concentrations, had no effect on intestinal permeability or morphology. The results of this study indicate that GPR109a does not play a critical role in intestinal homeostasis in a model of type 1 diabetes or in the development of diabetic nephropathy.
Publisher: Springer Science and Business Media LLC
Date: 03-12-2021
DOI: 10.1038/S41467-021-27153-3
Abstract: Mitochondrial defects are implicated in multiple diseases and aging. Exercise training is an accessible, inexpensive therapeutic intervention that can improve mitochondrial bioenergetics and quality of life. By combining multiple omics techniques with biochemical and in silico normalisation, we removed the bias arising from the training-induced increase in mitochondrial content to unearth an intricate and previously undemonstrated network of differentially prioritised mitochondrial adaptations. We show that changes in hundreds of transcripts, proteins, and lipids are not stoichiometrically linked to the overall increase in mitochondrial content. Our findings suggest enhancing electron flow to oxidative phosphorylation (OXPHOS) is more important to improve ATP generation than increasing the abundance of the OXPHOS machinery, and do not support the hypothesis that training-induced supercomplex formation enhances mitochondrial bioenergetics. Our study provides an analytical approach allowing unbiased and in-depth investigations of training-induced mitochondrial adaptations, challenging our current understanding, and calling for careful reinterpretation of previous findings.
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1038/KI.2010.134
Abstract: The accumulation of advanced glycation end products is thought to be a key factor in the initiation and progression of diabetic nephropathy. Here we determined whether the size of the ligands for the receptor for advanced glycation end products (RAGEs) that were present in the serum of patients with type 2 diabetes modulates their pathogenic potential. Serum was collected from control subjects and patients with type 2 diabetes with varying degrees of renal disease (normo-, micro-, or macroalbuminuria). The titers of the RAGE ligands N-carboxymethyllysine (CML), S100A, S100B, and high-mobility group box 1 (HMGB1) were measured by enzyme-linked immunosorbent assay in serum as well as in pooled size-fractionated serum. We also measured cellular binding of serum fractions to mesangial cells transfected with RAGE and examined the downstream signaling pathways. Circulating CML was increased in patients with type 2 diabetes, whereas HMGB1 was decreased. S100A8, S100BA9, and soluble RAGE were unchanged. The high-molecular-weight (over 50 kDa) serum fraction contained the greatest proportion of RAGE ligands, with all immunoreactivity and cellular binding observed only with serum fractions over 30 kDa. High-molecular-weight serum from macroalbuminuric patients showed greater RAGE binding capacity, modulation of cell-surface RAGE expression, increased phospho-protein kinase C-alpha, and p65 nuclear factor kappaB DNA-binding activity, which were competitively inhibited by soluble RAGE or CML neutralizing antibodies. These data show that ligands that activate RAGE present in the circulation of patients with type 2 diabetes and nephropathy are predominantly of high molecular weight.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.JNUTBIO.2012.09.009
Abstract: Chronic overconsumption of a Western diet has been identified as a major risk factor for diabetes, yet precisely how each in idual component contributes to defects in glucose homeostasis independent of consumption of other macronutrients remains unclear. Eight-week-old male Sprague Dawley rats were randomized to feeding with one of six semi-pure diets: control, processed (high advanced glycation end products/AGE), high protein, high dextrose (glucose polymer), high in saturated fat (plant origin), or high in saturated fat (animal origin). After chronic feeding for 24 weeks, body composition was determined by bioelectrical impedance spectroscopy and glucose homeostasis was assessed. When compared to the control and high AGE diets, excess consumption of the diet high in saturated fat (animal source) increased body weight and adiposity, and decreased insulin sensitivity, as defined by HOMA IR, impaired skeletal muscle insulin signaling and insulin hypersecretion in the context of increased circulating glucagon-like peptide (GLP-1). Compared to the control diet, chronic consumption of the high AGE, protein or dextrose diet increased fasting plasma glucose, decreased fasting plasma insulin and insulin secretion. These diets also reduced circulating GLP-1 concentrations. These data suggest that in idual components of a western diet have differential effects in modulating glucose homeostasis and adiposity. These data provide clear evidence of a link between over-consumption of a western diet and the development of diabetes.
Publisher: Wiley
Date: 22-01-2013
DOI: 10.1111/JGH.12042
Abstract: Advanced glycation end products (AGEs) are nonenzymatic modifications of proteins by reducing sugars. These compounds accumulate in a number of chronic disease states, contributing to tissue injury via several mechanisms, including activation of the receptor for advanced glycation end products (RAGE). We aimed to investigate whether AGEs can exacerbate chronic liver injury and contribute to hepatic fibrosis. We initially studied the effects of chronic hepatic exposure to high levels of AGEs given intraperitoneally as AGE-rat serum albumin. In a separate experiment, we examined the impact of high AGE exposure in rats following bile duct ligation (BDL). In normal rats, chronic AGE-rat serum albumin administration induced significant increases in α-smooth muscle actin gene and protein expression but did not induce fibrosis or biochemical evidence of liver injury. However, in BDL animals, AGE-bovine serum albumin administration significantly increased hepatic fibrosis as evidenced by increased collagen content and α-smooth muscle actin expression, compared with BDL alone. Furthermore, AGEs increased hepatic oxidative stress and receptor for advanced glycation end products gene expression. These findings suggest that AGEs may contribute to the pathogenesis of chronic liver injury and fibrosis.
Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1038/KI.2011.57
Abstract: Obesity is highly prevalent in Western populations and is considered a risk factor for the development of renal impairment. Interventions that reduce the tissue burden of advanced glycation end-products (AGEs) have shown promise in stemming the progression of chronic disease. Here we tested if treatments that lower tissue AGE burden in patients and mice would improve obesity-related renal dysfunction. Overweight and obese in iduals (body mass index (BMI) 26-39 kg/m(2)) were recruited to a randomized, crossover clinical trial involving 2 weeks each on a low- and a high-AGE-containing diet. Renal function and an inflammatory profile (monocyte chemoattractant protein-1 (MCP-1) and macrophage migration inhibitory factor (MIF)) were improved following the low-AGE diet. Mechanisms of advanced glycation-related renal damage were investigated in a mouse model of obesity using the AGE-lowering pharmaceutical, alagebrium, and mice in which the receptor for AGE (RAGE) was deleted. Obesity, resulting from a diet high in both fat and AGE, caused renal impairment however, treatment of the RAGE knockout mice with alagebrium improved urinary albumin excretion, creatinine clearance, the inflammatory profile, and renal oxidative stress. Alagebrium treatment, however, resulted in decreased weight gain and improved glycemic control compared with wild-type mice on a high-fat Western diet. Thus, targeted reduction of the advanced glycation pathway improved renal function in obesity.
Publisher: Wiley
Date: 22-10-2019
Publisher: American Diabetes Association
Date: 15-02-2018
DOI: 10.2337/DB17-0538
Abstract: Signaling via the receptor of advanced glycation end products (RAGE)—though complex and not fully elucidated in the setting of diabetes—is considered a key injurious pathway in the development of diabetic nephropathy (DN). We report here that RAGE deletion resulted in increased expression of fibrotic markers (collagen I and IV, fibronectin) and the inflammatory marker MCP-1 in primary mouse mesangial cells (MCs) and in kidney cortex. RNA sequencing analysis in MCs from RAGE−/− and wild-type mice confirmed these observations. Nevertheless, despite these gene expression changes, decreased responsiveness to transforming growth factor-β was identified in RAGE−/− mice. Furthermore, RAGE deletion conferred a more proliferative phenotype in MCs and reduced susceptibility to staurosporine-induced apoptosis. RAGE restoration experiments in RAGE−/− MCs largely reversed these gene expression changes, resulting in reduced expression of fibrotic and inflammatory markers. This study highlights that protection against DN in RAGE knockout mice is likely to be due in part to the decreased responsiveness to growth factor stimulation and an antiapoptotic phenotype in MCs. Furthermore, it extends our understanding of the role of RAGE in the progression of DN, as RAGE seems to play a key role in modulating the sensitivity of the kidney to injurious stimuli such as prosclerotic cytokines.
Publisher: Oxford University Press (OUP)
Date: 28-08-2019
Abstract: Serotonergic dysfunction, including reduced central serotonin levels, is associated with different psychiatric syndromes, including depression. As a serotonin precursor, 5-hydroxytryptophan has long been used as a nonpharmacological treatment for depression. A systematic review and meta-analysis was conducted to determine the antidepressant effects of 5-hydroxytryptophan in depressed patients. MEDLINE (via PubMed) and Google Scholar were searched from inception to May 2018. Thirteen investigations were included in the systematic review (using PRISMA guidelines), and 7 in the full meta-analysis (pre-registered on PROSPERO: CRD42018104415). Analyses revealed a depression remission rate of 0.65 (95% confidence interval [CI], 0.55–0.78 remission rate [k] = 13), and this was confirmed by the questionnaire results, which revealed a large Hedges’ g (1.11 95%CI, 0.53–1.69). Methodological variability (in treatment duration, type of depression studied, experimental design, 5-hydroxytryptophan dosage) contributes to heterogeneity in the results (I2 = 76%, τ2 = 0.379). In addition, the OHAT (Office of Health Assessment and Translation risk of bias rating) tool suggested that, on the whole, current studies are relatively weak (few include placebo groups). Further trials should overcome these limitations by using placebo-controlled studies that include patients with well-defined depression diagnoses, along with strong characterization of psychological and physiological patient characteristics.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2019
Publisher: Elsevier BV
Date: 12-2020
Publisher: BMJ
Date: 10-2019
DOI: 10.1136/OPENHRT-2019-001017
Abstract: A variety of small mobile phone text-messaging interventions have indicated improvement in risk factors for cardiovascular disease (CVD). Yet the extent of this improvement and whether it impacts multiple risk factors together is uncertain. We aimed to conduct a systematic review and in idual patient data (IPD) meta-analysis to investigate the effects of text-messaging interventions for CVD prevention. Electronic databases were searched to identify trials investigating a text-messaging intervention focusing on CVD prevention with the potential to modify at least two CVD risk factors in adults. The main outcome was blood pressure (BP). We conducted standard and IPD meta-analysis on pooled data. We accounted for clustering of patients within studies and the primary analysis used random-effects models. Sensitivity and subgroup analyses were performed. Nine trials were included in the systematic review involving 3779 participants and 5 (n=2612) contributed data to the IPD meta-analysis. Standard meta-analysis showed that the weighted mean differences are as follows: systolic blood pressure (SBP), −4.13 mm Hg (95% CI −11.07 to 2.81, p .0001) diastolic blood pressure (DBP), −1.11 mm Hg (−1.91 to −0.31, p=0.002) and body mass index (BMI), −0.32 (−0.49 to −0.16, p=0.000). In the IPD meta-analysis, the mean difference are as follows: SBP, −1.3 mm Hg (−5.4 to 2.7, p=0.5236) DBP, −0.8 mm Hg (−2.5 to 1.0, p=0.3912) and BMI, −0.2 (−0.8 to 0.4, p=0.5200) in the random-effects model. The impact on other risk factors is described, but there were insufficient data to conduct meta-analyses. Mobile phone text-messaging interventions have modest impacts on BP and BMI. Simultaneous but small impacts on multiple risk factors are likely to be clinically relevant and improve outcome, but there are currently insufficient data in pooled analyses to examine the extent to which simultaneous reduction in multiple risk factors occurs. CRD42016033236.
Publisher: Elsevier BV
Date: 08-2019
Publisher: Bentham Science Publishers Ltd.
Date: 04-2012
DOI: 10.2174/138945012799499758
Abstract: The globally rising incidence of Type 1 diabetes (T1D) is no longer restricted to in iduals with higher risk genotypes, but is now significantly increasing in a population with lower risk genotypes, likely as the result of environmental factors. In this review, we discuss the potential of advanced glycation end products (AGEs) as environmental contributors to the development of T1D. AGEs are nonenzymatically formed protein modifications found in the body, as well as, consumed in our daily diets. To date, many studies have provided evidence of AGE involvement in β cell dysfunction, whether by AGE modification itself or via interaction with AGE receptors. The receptor for AGE (RAGE) and AGE-receptor-1 (AGE-R1) are of particular interest, given that studies have demonstrated the deleterious effects of RAGE modulation and the protection afforded by AGE-R1 in the context of diabetes. More interestingly, we have recently found that two RAGE polymorphism are predictive of T1D in humans while the third is protective. Moreover, soluble RAGE (sRAGE) levels (a circulating competitive inhibitor of RAGE) were greatly reduced at seroconversion to autoantibodies in both children on high risk of T1D background and in an animal model of autoiummune diabetes. Taken together with the fact that AGEs have also shown to be involved in immunomodulation, it is tempting to postulate that dietary AGEs, RAGE and even AGE-R1 could be working synergistically or independently to breach the tightly regulated immune system, providing a missing link in the development of T1D.
Publisher: Wiley
Date: 04-2008
Abstract: Nephropathy remains a significant cause of morbidity and mortality in the diabetic population and is the leading cause of end-stage renal failure in the Western World. As a result of the diabetic milieu, increased generation of reactive oxygen species (ROS) is thought to play a key role in the progression of diabetic nephropathy. Recent experimental studies have suggested that the receptor for advanced glycation end products (RAGE), which is central to the advanced glycation pathway, may mediate renal structural and functional damage via oxidative stress. This review focuses on how RAGE and subsequent ROS generation play a deleterious role in the diabetic kidney, promoting cross-talk among signaling pathways, ultimately leading to renal dysfunction.
Publisher: MDPI AG
Date: 25-04-2021
DOI: 10.3390/NU13051457
Abstract: Diabetic kidney disease (DKD) remains the number one cause of end-stage renal disease in the western world. In experimental diabetes, mitochondrial dysfunction in the kidney precedes the development of DKD. Reactive 1,2-dicarbonyl compounds, such as methylglyoxal, are generated from sugars both endogenously during diabetes and exogenously during food processing. Methylglyoxal is thought to impair the mitochondrial function and may contribute to the pathogenesis of DKD. Here, we sought to target methylglyoxal within the mitochondria using MitoGamide, a mitochondria-targeted dicarbonyl scavenger, in an experimental model of diabetes. Male 6-week-old heterozygous Akita mice (C57BL/6-Ins2-Akita/J) or wildtype littermates were randomized to receive MitoGamide (10 mg/kg/day) or a vehicle by oral gavage for 16 weeks. MitoGamide did not alter the blood glucose control or body composition. Akita mice exhibited hallmarks of DKD including albuminuria, hyperfiltration, glomerulosclerosis, and renal fibrosis, however, after 16 weeks of treatment, MitoGamide did not substantially improve the renal phenotype. Complex-I-linked mitochondrial respiration was increased in the kidney of Akita mice which was unaffected by MitoGamide. Exploratory studies using transcriptomics identified that MitoGamide induced changes to olfactory signaling, immune system, respiratory electron transport, and post-translational protein modification pathways. These findings indicate that targeting methylglyoxal within the mitochondria using MitoGamide is not a valid therapeutic approach for DKD and that other mitochondrial targets or processes upstream should be the focus of therapy.
Publisher: Wiley
Date: 11-2001
DOI: 10.1046/J.1464-5491.2001.00614.X
Abstract: The cytokine tumour necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of insulin resistance in Type 2 diabetes mellitus, but limited data are available in relation to gestational diabetes mellitus (GDM), a disease in which similar biochemical abnormalities exist. We investigated the effect of exogenous glucose on the release of TNF-alpha from placental and adipose (omental and subcutaneous) tissue obtained from normal pregnant women, and women with GDM. Human tissue explants were incubated for up to 24 h and TNF-alpha concentration in the incubation medium quantified by ELISA. The effect of normal (5 mmol/l) and high (15 and 25 mmol/l) glucose concentrations on the release of TNF-alpha was assessed. In placental and subcutaneous adipose tissues obtained from women with GDM (n = 6), TNF-alpha release was significantly greater under conditions of high glucose compared with normal glucose (placenta, 25 mmol/l 5915.7 +/- 2579.6 and 15 mmol/l 4547.1 +/- 2039.1 vs. 5 mmol/l 1897.1 +/- 545.5 subcutaneous adipose tissue, 25 mmol/l 423.5 +/- 207.0 and 15 mmol/l 278.5 +/- 138.7 vs. 5 mmol/l 65.3 +/- 28.5 pg/mg protein P < 0.05). In contrast, there was no stimulatory effect of high glucose on TNF-alpha release by tissues obtained from normal pregnant women (n = 6) (placenta, 25 mmol/l 1542.1 +/- 486.2 and 15 mmol/l 4263.3 +/- 2737.7 vs. 5 mmol/l 5422.4 +/- 1599.0 subcutaneous adipose tissue, 25 mmol/l 189.8 +/- 120.4 and 15 mmol/l 124.5 +/- 32.3 vs. 5 mmol/l 217.9 +/- 103.5 pg/mg protein). These observations suggest that tissues from patients with GDM release greater amounts of TNF-alpha in response to high glucose. As TNF-alpha has been previously implicated in the regulation of glucose and lipid metabolism, and of insulin resistance, these data are consistent with the hypothesis that TNF-alpha may be involved in the pathogenesis and/or progression of GDM.
Publisher: Springer Science and Business Media LLC
Date: 27-06-2017
DOI: 10.1007/S00394-017-1495-Y
Abstract: Advanced glycation endproducts (AGEs) are produced endogenously and also enter the body during the consumption of AGEs present in heat-processed food. It is unknown whether AGEs of dietary origin accumulate within the body of healthy in iduals. AGEs can deposit within skin tissue long-term by crosslinking extracellular matrix proteins. The fluorescent nature of many AGEs enables their detection within the skin by non-invasively measuring skin autofluorescence (SAF). This study aimed to identify habitual dietary and lifestyle behaviours cross-sectionally associated with SAF in an adult population s le. 251 Healthy adult volunteers completed validated food frequency and physical activity questionnaires. Waist circumference, BMI, blood pressure and blood glucose was also measured. SAF was measured using an AGE Reader. Significant positive correlations were found between SAF and chronological age (r = 0.63, P < 0.001), waist circumference (r = 0.28, P < 0.01), body weight (r = 0.24, P < 0.05), BMI (r = 0.23, P < 0.05) and consumption of meat and meat products (r = 0.22, P < 0.05). A negative correlation was found between SAF and cereal consumption (r = -0.21, P < 0.05). Cigarette smokers also had a significantly higher SAF than non-smokers (2.4 vs 2.0 U, P < 0.05). Regression analysis identified age, cigarette smoking, waist circumference and intake of meat products as significant predictors of SAF. The regression model explained 48% of the variation in SAF. Age, cigarette smoking, waist circumference and dietary consumption of meat/meat products were positively associated with SAF in this s le. Further research is required to determine whether frequent consumption of foods containing large quantities of dietary AGEs contribute to pathological disease processes in healthy in iduals.
Publisher: Cold Spring Harbor Laboratory
Date: 26-10-2023
Publisher: S. Karger AG
Date: 2011
DOI: 10.1159/000328581
Abstract: i Background/Aims: /i Advanced glycation end products (AGEs) mediate progressive tissue damage in diabetic nephropathy however, their utility as a noninvasive reliable biomarker of progressive diabetic nephropathy remains to be determined. In this study, we investigated the temporal accumulation of the AGE carboxymethyllysine (CML) at various sites in a model of experimental diabetic nephropathy. i Methods: /i Diabetic rats were followed for 1, 4, 8, 16 and 32 weeks. Glomerular filtration rate and urinary albumin excretion were measured. CML was determined in the plasma, urine, renal cortical mitochondria and cytosol by an in-house ELISA. Gene expression of AGE receptors were quantified by real-time PCR and urinary excretion of 8-hydroxy-2′-deoxyguanosine (8-OHdG) was determined by EIA. i Results: /i Four weeks after diabetes induction, urinary CML excretion was increased, which preceded the excretion of urinary albumin and continued to rise progressively until 32 weeks. Circulating, mitochondrial and cytosolic CML content and urinary excretion of 8-OHdG were increased 4 weeks after diabetes induction, but did not increase further with diabetes duration. Renal gene expression of AGE receptors was transiently upregulated at 1 week of diabetes, but this was not a sustained phenomenon. i Conclusions: /i The most informative marker of progressive renal damage linked to the AGE pathway in experimental diabetic nephropathy is urinary excretion of CML, which now warrants clinical investigation as a potential noninvasive sensitive marker of progressive diabetic nephropathy.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2019
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2019
Publisher: Elsevier BV
Date: 10-2019
Publisher: Wiley
Date: 21-06-2022
DOI: 10.1111/BCP.15435
Abstract: Gout is the most common form of inflammatory arthritis in men. Despite the availability of effective urate-lowering therapies (ULT), the management of gout is suboptimal due to poor persistence with ULT. This study examined national prescribing patterns of ULT to determine persistence with allopurinol in Australia. A 10% s le of the Australian Pharmaceutical Benefits Scheme dispensing claims database was used to identify in iduals initiated on allopurinol between April 2014 and December 2019. The number of allopurinol scripts dispensed was used to estimate persistence with allopurinol. Persistence was defined as the number of months from initiation until discontinuation (last prescription with no further scripts acquired for a period thereafter). Kaplan-Meier curves were used to examine persistence, while Cox regression analysis was used to examine the influence of gender, concomitant colchicine and age. The largest drop in persistence occurred immediately after initiation, with 34% of patients discontinuing allopurinol 300-mg therapy in the first month. Median persistence with allopurinol 300 mg was 5 months (95% confidence interval 4.76-5.24), with around 63% of in iduals not persisting with this therapy for more than 12 months. Concomitant prescription of colchicine on the day of allopurinol initiation only occurred in 7% of allopurinol initiations. No increase in persistence was observed for those co-prescribed colchicine. Persistence with allopurinol was poor. More effective methods targeting prescribers, patients and systems are required to promote persistence with allopurinol. Improving persistence to allopurinol is an important public health goal given the proven potential of this medication to eliminate gout.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-04-2021
Abstract: This study shows how highly processed foods can cause innate immune inflammation that promotes chronic microvascular disease.
Publisher: S. Karger AG
Date: 2011
DOI: 10.1159/000331064
Abstract: i Background/Aims: /i The formation of advanced glycation end products (AGEs) is accelerated in patients with diabetic nephropathy. The aim of this study was to ascertain if the urinary excretion of proteins modified by advanced glycation can be used as biomarkers for albuminuria in in iduals with type 1 or type 2 diabetes. i Methods: /i Community-based patients with type 1 (n = 68) or type 2 diabetes (n = 216) attending a diabetes clinic of a tertiary referral hospital were classified as having normoalbuminuria (Normo, albumin excretion rate (AER) µg/min), microalbuminuria (Micro, AER 20–200 µg/min) or macroalbuminuria (Macro, AER ≧200 µg/min). Serum and urine AGE-modified proteins were measured. i Results: /i In patients with both type 1 diabetes and type 2 diabetes, there was a clear association between the degree of albuminuria and urinary AGE-modified proteins (p 0.0001). Exclusive to patients with type 1 diabetes, urinary excretion of the AGE carboxymethyllysine correlated with AER, whereas patients with type 2 diabetes and macroalbuminuria had an increase in urinary methylglyoxal, an AGE intermediate. These changes were independent of isotopic glomerular filtration rate levels. Serum concentrations of AGEs or soluble receptor for AGEs were not consistently associated with albuminuria in either type 1 or type 2 diabetes. i Conclusions: /i Urinary excretion of proteins modified by AGEs may be useful biomarkers of albuminuria in in iduals with type 1 and type 2 diabetes, warranting prospective investigation in larger diabetic cohorts.
Publisher: Oxford University Press (OUP)
Date: 24-12-2021
DOI: 10.1093/NDT/GFAA376
Abstract: The nicotinamide adenine dinucleotide phosphate oxidase isoform 4 (Nox4) mediates reactive oxygen species (ROS) production and renal fibrosis in diabetic kidney disease (DKD) at the level of the podocyte. However, the mitochondrial localization of Nox4 and its role as a mitochondrial bioenergetic sensor has recently been reported. Whether Nox4 drives pathology in DKD within the proximal tubular compartment, which is densely packed with mitochondria, is not yet known. We generated a proximal tubular–specific Nox4 knockout mouse model by breeding Nox4flox/flox mice with mice expressing Cre recombinase under the control of the sodium–glucose cotransporter-2 promoter. Subsets of Nox4ptKO mice and their Nox4flox/flox littermates were injected with streptozotocin (STZ) to induce diabetes. Mice were followed for 20 weeks and renal injury was assessed. Genetic ablation of proximal tubular Nox4 (Nox4ptKO) resulted in no change in renal function and histology. Nox4ptKO mice and Nox4flox/flox littermates injected with STZ exhibited the hallmarks of DKD, including hyperfiltration, albuminuria, renal fibrosis and glomerulosclerosis. Surprisingly, diabetes-induced renal injury was not improved in Nox4ptKO STZ mice compared with Nox4flox/flox STZ mice. Although diabetes conferred ROS overproduction and increased the mitochondrial oxygen consumption rate, proximal tubular deletion of Nox4 did not normalize oxidative stress or mitochondrial bioenergetics. Taken together, these results demonstrate that genetic deletion of Nox4 from the proximal tubules does not influence DKD development, indicating that Nox4 localization within this highly energetic compartment is dispensable for chronic kidney disease pathogenesis in the setting of diabetes.
Publisher: JMIR Publications Inc.
Date: 19-10-2022
Abstract: ven modest reductions in blood pressure (BP) can have an important impact on population-level morbidity and mortality from cardiovascular disease. There are 2 promising approaches: the SaltSwitch smartphone app, which enables users to scan the bar code of a packaged food using their smartphone camera and receive an immediate, interpretive traffic light nutrition label on-screen alongside a list of healthier, lower-salt options in the same food category and reduced-sodium salts (RSSs), which are an alternative to regular table salt that are lower in sodium and higher in potassium but have a similar mouthfeel, taste, and flavor. ur aim was to determine whether a 12-week intervention with a sodium-reduction package comprising the SaltSwitch smartphone app and an RSS could reduce urinary sodium excretion in adults with high BP. 2-arm parallel randomized controlled trial was conducted in New Zealand (target n=326). Following a 2-week baseline period, adults who owned a smartphone and had high BP (≥140/85 mm Hg) were randomized in a 1:1 ratio to the intervention (SaltSwitch smartphone app + RSS) or control (generic heart-healthy eating information from The Heart Foundation of New Zealand). The primary outcome was 24-hour urinary sodium excretion at 12 weeks estimated via spot urine. Secondary outcomes were urinary potassium excretion, BP, sodium content of food purchases, and intervention use and acceptability. Intervention effects were assessed blinded using intention-to-treat analyses with generalized linear regression adjusting for baseline outcome measures, age, and ethnicity. total of 168 adults were randomized (n=84, 50% per group) between June 2019 and February 2020. Challenges associated with the COVID-19 pandemic and smartphone technology detrimentally affected recruitment. The adjusted mean difference between groups was 547 (95% CI −331 to 1424) mg for estimated 24-hour urinary sodium excretion, 132 (95% CI −1083 to 1347) mg for urinary potassium excretion, −0.66 (95% CI −3.48 to 2.16) mm Hg for systolic BP, and 73 (95% CI −21 to 168) mg per 100 g for the sodium content of food purchases. Most intervention participants reported using the SaltSwitch app (48/64, 75%) and RSS (60/64, 94%). SaltSwitch was used on 6 shopping occasions, and approximately 1/2 tsp per week of RSS was consumed per household during the intervention. n this randomized controlled trial of a salt-reduction package, we found no evidence that dietary sodium intake was reduced in adults with high BP. These negative findings may be owing to lower-than-anticipated engagement with the trial intervention package. However, implementation and COVID-19–related challenges meant that the trial was underpowered, and it is possible that a real effect may have been missed. ustralian New Zealand Clinical Trials Registry ACTRN12619000352101 www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377044 and Universal Trial U1111-1225-4471
Publisher: Elsevier BV
Date: 02-2023
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 17-11-2020
DOI: 10.1161/CIRC.142.SUPPL_3.13354
Abstract: Introduction: Cardiovascular disease (CVD) risk management is suboptimal in Australian primary healthcare. Following trials demonstrating efficacy of in idual components, we developed a complex intervention comprised primarily of electronic point-of-care decision support, availability of cardiovascular polypills and a pharmacy-based adherence program. We sought to determine whether this combined multifaceted intervention, compared with usual care, would improve control of CVD risk factors in the Australian primary care setting. Methods and Results: In a parallel-arm cluster randomized trial, 71 general practices were allocated 1:1 either to the intervention or usual care. The primary outcome was the proportion of patients at high CVD risk and not on optimal preventive treatments at baseline (“high-risk under-treated”) achieving both blood pressure (BP) and low density lipoprotein (LDL) cholesterol targets at study end (BP ≤140/90 mmHg, or ≤130/80 mmHg in people with diabetes or albuminuria LDL .0 mmol/L). All outcomes were evaluated using automated extracts from the electronic medical record. After a median period of 15 months follow-up, among 4477 high-risk under-treated patients in whom follow-up data were available, there was a negligible difference between randomized groups in the proportion achieving SBP and LDL cholesterol targets (19.6% vs. 20.1% RR 1.06 [95% CI: 0.85 to 1.32] p=0.59). There was also no major impact of the intervention on any pre-specified secondary outcomes, mostly relating to risk factor screening, preventive medication prescription and risk factor levels. Uptake of all components of the intervention was poor, with greatest use observed for the electronic decision support component (used at least once in 10.7% of high-risk under-treated patients) and minimal use of the other two interventions. Conclusions: Despite the proven efficacy of in idual components, this complex multifaceted intervention was poorly adopted and did not lead to relevant improvements in cardiovascular risk factor outcomes.
Publisher: MDPI AG
Date: 15-05-2023
DOI: 10.3390/IJMS24108758
Abstract: Diabetic kidney disease (DKD) affects 30–40% of patients with diabetes and is currently the leading cause of end-stage renal disease (ESRD). The activation of the complement cascade, a highly conserved element of the innate immune system, has been implicated in the pathogenesis of diabetes and its complications. The potent anaphylatoxin C5a is a critical effector of complement-mediated inflammation. Excessive activation of the C5a-signalling axis promotes a potent inflammatory environment and is associated with mitochondrial dysfunction, inflammasome activation, and the production of reactive oxygen species. Conventional renoprotective agents used in the treatment of diabetes do not target the complement system. Mounting preclinical evidence indicates that inhibition of the complement system may prove protective in DKD by reducing inflammation and fibrosis. Targeting the C5a-receptor signaling axis is of particular interest, as inhibition at this level attenuates inflammation while preserving the critical immunological defense functions of the complement system. In this review, the important role of the C5a/C5a-receptor axis in the pathogenesis of diabetes and kidney injuries will be discussed, and an overview of the status and mechanisms of action of current complement therapeutics in development will be provided.
No related grants have been discovered for Melinda Coughlan.