ORCID Profile
0000-0002-2552-4885
Current Organisation
University of Sydney
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Zoology | Physiology | Zoology Not Elsewhere Classified | Animal Structure and Function | Vertebrate Biology | Evolution of Developmental Systems | Comparative Physiology | Biochemistry and Cell Biology | Ecology And Evolution Not Elsewhere Classified | Composite Materials | Animal Anatomy And Histology | Biomaterials | Nanotechnology | Nanochemistry and Supramolecular Chemistry | Biochemistry and Cell Biology not elsewhere classified | Structural Biology (incl. Macromolecular Modelling) | Instruments And Techniques | Protein Targeting And Signal Transduction | Medical Virology | Medical Bacteriology | Characterisation of Biological Macromolecules | Molecular Medicine | Physiology Not Elsewhere Classified | Biologically Active Molecules | Biotechnology Not Elsewhere Classified | Cell Physiology | Other Physical Sciences | Sustainable Agricultural Development | Cell Development, Proliferation and Death |
Biological sciences | Chemical sciences | Physical sciences | Higher education | Expanding Knowledge in the Biological Sciences | Other | Prevention—biologicals (e.g. vaccines) | Diagnostics | Reproductive system and disorders | Treatments (e.g. chemicals, antibiotics) | Organs, diseases and abnormal conditions not elsewhere classified | Flora, Fauna and Biodiversity at Regional or Larger Scales | Infectious diseases | Nervous system and disorders | Cardiovascular system and diseases | Cancer and related disorders | Other | Diagnostic methods | Expanding Knowledge in the Medical and Health Sciences | Dental health | Other
Publisher: Portico
Date: 04-2000
DOI: 10.1076/0924-3860(200004)38:2;1-F;FT122
Abstract: Ultrastructural changes in the plasma membrane of uterine epithelial cells in the pseudopregnant rat were examined to determine if these changes resemble those found during normal pregnancy and also to examine if the well-known membrane alterations of early pregnancy are intrinsic to uterine epithelial cells. Changes in the surface contours of uterine epithelial cells from the afternoon of day 6 to the morning of day 9 of pseudopregnancy were similar to those present after attachment in normal pregnancy although somewhat delayed. The presence of short, irregular microvilli was seen from as early as day 7 of pseudopregnancy, with regular microvilli returning to the epithelial surface by days 8-9 of pseudopregnancy but to a slightly lesser extent as compared to normal pregnancy. Furthermore, observations made on the afternoon of day 6 to the morning of day 7 of pseudopregnancy showed that the uterine lumen was closed down and that complete membrane flattening between opposing uterine epithelial cells was seen all along the uterus in the absence of a blastocyst. These observations establish that the "plasma membrane transformation" does not depend on blastocyst implantation.
Publisher: Wiley
Date: 2005
DOI: 10.1002/JMOR.10390
Abstract: Displacement of uterine epithelial cells is an important aspect of implantation in the rat and other species, allowing invasion of the blastocyst into the endometrial stroma. Desmosomes, which are part of the lateral junctional complex, function in cell-to-cell adhesion, and are therefore likely to be involved in displacement of uterine epithelial cells at the time of implantation. This study used transmission electron microscopy to study rat uterine epithelial cells during the peri-implantation period to investigate the change in the number of structural desmosomes along the lateral plasma membrane of uterine epithelial cells. We found a significant decrease in the number of desmosomes along the entire lateral plasma membrane as pregnancy progressed. Furthermore, there were also significant decreases in the number of desmosomes on the apical portion of the lateral plasma membrane between all days of pregnancy examined. In addition, on day 6 of pregnancy, the time of attachment, desmosomes were larger and seen as "giant desmosomes." For the first time, this study has shown that there is a significant reduction in cell height and actual number of ultrastructurally observable desmosomes at the time of implantation in the rat. It is proposed that this reduction in desmosome number leads to a decrease in lateral adhesion between uterine epithelial cells at the time of implantation, and hence is involved in the loss of uterine epithelial cells to facilitate blastocyst invasion.
Publisher: Wiley
Date: 24-03-2011
Publisher: Wiley
Date: 2005
DOI: 10.1002/JMOR.10314
Abstract: The structural features of the uterine epithelium of the chorioallantoic placenta and omphalloplacenta in the viviparous Australian skink, Pseudemoia entrecasteauxii, were investigated using SEM and TEM techniques. In particular, the structural characteristics that would allow interpretation of function were analyzed, particularly those of gas exchange in the chorioallantoic placenta and histotrophy in the omphaloplacenta. Pseudemoia entrecasteauxii has a complex placenta consisting of a placentome, paraplacentome, and omphaloplacenta. The paraplacentome has a well-vascularized lamina propria in which projecting uterine capillaries displace the overlying uterine epithelial cells, reducing them to attenuated cytoplasmic extensions. Associated cell nuclei and organelles are lost from this region, to provide a capillary lumen to uterine lumen barrier of 0.5-1.0 microm. Hence, the paraplacentome is likely a prominent site for gaseous exchange via simple diffusion. The omphaloplacenta has a similar cytology to that of the placentome, but the uterine epithelial cells are hypertrophied and the apical plasma membrane actively secretes vesicles into the uterine lumen. The omphaloplacenta shows features that are associated with histotrophic transport of nutrients via vesicle secretion, very similar to that of lipid apocrine secretion. The placentome consists of cuboidal cells in the uterine epithelium, with large centrally located nuclei overlying the well-vascularized lamina propria. Although the placentome has a similar cytological structure to that of the omphaloplacenta, granules or active vesicle secretion were not observed. Thus, the placentome may be associated with histotrophy, but not via apocrine secretion. Squamate placentation is epitheliochorial however, we propose a new term be used to describe the type of placentation in P. entrecasteauxii: "cyto-epitheliochorial," because of the extreme attenuation of uterine epithelial cells of the paraplacentome.
Publisher: Springer Science and Business Media LLC
Date: 25-09-2009
DOI: 10.1007/S00418-009-0641-X
Abstract: During early pregnancy in the rat, focal adhesions disassemble in uterine luminal epithelial cells at the time of implantation to facilitate their removal so that the implanting blastocyst can invade into the underlying endometrial decidual cells. This study investigated the effect of ovarian hormones on the distribution and protein expression of two focal adhesion proteins, talin and paxillin, in rat uterine luminal and glandular epithelial cells under various hormone regimes. Talin and paxillin showed a major distributional change between different hormone regimes. Talin and paxillin were highly concentrated along the basal cell surface of uterine luminal epithelial cells in response to oestrogen treatment. However, this prominent staining of talin and paxillin was absent and also a corresponding reduction of paxillin expression was demonstrated in response to progesterone alone or progesterone in combination with oestrogen, which is also observed at the time of implantation. In contrast, the distribution of talin and paxillin in uterine glandular epithelial cells was localised on the basal cell surface and remained unchanged in all hormone regimes. Thus, not all focal adhesions are hormonally dependent in the rat uterus however, the dynamics of focal adhesion in uterine luminal epithelial cells is tightly regulated by ovarian hormones. In particular, focal adhesion disassembly in uterine luminal epithelial cells, a key component to establish successful implantation, is predominantly under the influence of progesterone.
Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: Subtype-specific antibodies were used to measure purinergic (P2X) receptor expression in the rat prostate. In mature Wistar rats, apoptosis and expression of P2X1, P2X2, P2X5 and P2X7 subtypes were all significantly decreased compared with the levels found in immature rat prostates. Accompanying this age-related reduction in purinergic calcium channel expression was a reduction in epithelial and stromal calcium as well as the calcium-regulating hormone stanniocalcin. In contrast, expression of P2X3, P2X4 and P2X6 increased with age. These results suggest that distinct changes in P2X subtype expression accompany apoptosis in the rat prostate.
Publisher: Wiley
Date: 15-08-2012
DOI: 10.1002/JMOR.11002
Abstract: We used immunofluorescent confocal microscopy and scanning electron microscopy to quantify uterine vascularity and to describe uterine surface morphology during gestation in pregnant females of the lecithotrophic lizard Niveoscincus coventryi. As uterine angiogenesis and epithelial cell morphology are thought to be under progesterone control, we studied the effect of a progesterone receptor antagonist (mifepristone) on uterine and chorioallantoic microvasculature and features of the uterine epithelial surfaces. Although intussuceptive angiogenesis was observed in both, uterine and chorioallantoic, vascular beds during gestation, the only significant increases were in the diameters of the uterine vessels. An ellipsoid vessel-dense area grows in the mesometrial hemisphere of the developing conceptus, which parallels the expansion of the allantois to form the chorioallantoic placenta. Uterine surface topography changed during gestation. In particular, uterine blood vessels bulge over the luminal surface to form marked ridges on the uterine embryonic hemisphere, especially during the last stage of pregnancy, and ciliated cells are maintained in the embryonic and abembryonic hemispheres but disappear in both the mesometrial and antimesometrial poles. This distinct regionalization of uterine ridges and ciliated cells in the uterine surface and in the shape of the epithelial component of the chorion might be related to the function of both chorioallantoic and yolk sac placentae during gestation. There was no significant difference between females treated with or without mifepristone, which may be related to the partial function of mifepristone as a progestin antagonist and/or with the function and time of action of progesterone in the uterus during gestation in N. coventryi. Differences in the pattern of angiogenesis and uterine surface morphology during gestation among squamates may be related to the functional ersity of the uterine component of the different placentae and probably reflect its erse evolutionary history.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/RD08086
Abstract: The aim of the present study was to conduct a semiquantitative immunohistochemical investigation into the levels of intermediary proteins within the nuclear factor (NF)-κB pathway throughout the menstrual cycle in a non-human primate, namely the baboon (Papio anubis), with and without endometriosis. Formalin-fixed eutopic (n = 2–4) and ectopic (n = 6–7) endometrial tissues from baboons at the mid-luteal phase were embedded in paraffin and examined for NF-κB pathway components (i.e. IκB kinase (IKK) α, IKKβ, phosphorylated (phospho-) IκBα and phospho-NF-κB p65 subunit), ubiquitin, 19S proteasome and the NF-κB activator tumour necrosis factor (TNF)-α. Similarly, endometrial tissues from baboons at the late follicular, mid-luteal and menses phase (n = 2–4) were investigated to determine the levels of these proteins throughout the menstrual cycle. Cytoplasmic stromal IKKα and glandular 19S proteasome immunostaining was elevated in the ectopic endometrium, whereas levels of ubiquitin, phospho-p65, IKKβ, TNF-α and nuclear 19S proteasome were similar in the eutopic and ectopic endometrium. A significant decrease in phospho-IκBα nuclear immunostaining was observed within glandular cells of the ectopic endometrium. In the eutopic endometrium, IKKα, ubiquitin and 19S proteasome immunostaining was elevated in different phases of the menstrual cycle, whereas levels of phospho-p65, IKKβ, phospho-IκBα and TNF-α remained unchanged. We have demonstrated that, in the baboon endometriosis model, levels of IKKα immunostaining are elevated, whereas those of phospho-IκBα are reduced, consistent with the hypothesis that excessive NF-κB activity plays a role in reducing ectopic endometrial apoptosis, which contributes to the pathophysiology of endometriosis. Further studies are required to confirm a causal association between elevated IKKα levels and reduced endometrial apoptosis.
Publisher: Wiley
Date: 1993
DOI: 10.1111/J.1768-322X.1993.TB00900.X
Abstract: During early pregnancy, in the lead up to blastocyst implantation, the apical cell surface of luminal epithelial cells of the rat uterus undergo a dramatic shape transformation. This study aims to investigate the role of the cytoskeleton in this apical transformation by considering the effects of the drugs cytochalasin D and colchicine on the uterine luminal cell surface. The results are determined using transmission and scanning electron microscopy. In vivo exposure to cytochalasin D during oestrus, as well as on day 1 of pregnancy, did not affect the long, regular surface microvilli. This drug, however, did disrupt the terminal web within the apical cytoplasm of these cells. Disruption of microfilament (MF) polymerization by cytochalasin D on day 4 of pregnancy induced a cell surface transformation, resulting in the appearance of numerous irregular projections normally present during blastocyst implantation on day 6 of pregnancy. Colchicine did not alter the uterine microvilli of oestrus or day 1 pregnant tissue. Unlike the effect of cytochalasin D, colchicine-induced microtubule (MT) disruption on day 4 of pregnancy did not increase irregular projections and hence this treatment did not result in the cell surface appearance associated with blastocyst implantation. These results indicate that the disruption of MF, rather than MT, contributes to the transformation of the uterine luminal cell surface during the lead up to blastocyst attachment.
Publisher: Springer Science and Business Media LLC
Date: 27-07-2007
DOI: 10.1007/S00360-007-0192-1
Abstract: Occludin, an integral protein associated with the mammalian tight junction, has for the first time been identified in the uterus of squamate reptiles. The tight junction is made up of anastamosing strands and forms a selective barrier that regulates paracellular diffusion of solutes across uterine epithelium. Occludin exclusively labels tight junctional strands and is an excellent marker for tight junction permeability. Using western blotting and immunohistochemistry, occludin expression was examined in the uterine epithelium of five species of Australian skinks at different stages of gestation. More occludin was detected during late stage pregnancy/gravidity compared to the lower levels of occludin detected in vitellogenic and post-parturient females in three of the five species. We conclude that the paracellular permeability of the squamate uterine epithelium decreases as gestation progresses. As placental transport of ions and solutes to the embryo is highest during the last third of pregnancy in viviparous squamates, it is likely that a decrease in paracellular permeability is compensated by an upregulation of other transporting mechanisms such as histotrophy.
Publisher: Springer Science and Business Media LLC
Date: 12-2010
DOI: 10.1007/S00441-010-1088-Z
Abstract: Uterine epithelial cells (UECs) undergo extensive morphological remodelling in preparation for an implanting blastocyst. This remodelling involves changes in the actin cytoskeleton and surface structures including microvilli. Ezrin and ezrin-radixin-moesin-binding protein-50-kDa (EBP50) link actin filaments to intra-membranous adhesion molecules and are important molecules in polarised epithelia. The current study is the first to describe the colocalisation and molecular association of ezrin and EBP50 in rat UECs by using immunofluorescence microscopy and immunoprecipitation techniques. These proteins have also been localised in relation to uterine epithelial cytoskeletal rearrangement during early pregnancy in the rat and to the effect of apical surface contact between opposing epithelial cells, blastocyst contact and contact with a silicon filament. Immunofluorescence microscopy has revealed that ezrin and EBP50 respond to contact between opposing epithelial cells and increase apically on day 6 of pregnancy. This apical distribution is also observed in UECs in contact with a silicon filament. Ezrin and EBP50 are however absent within the implantation chamber itself, seemingly mimicking the events that take place in leucocyte-endothelium binding. Thus, ezrin and EBP50 occur apically in UECs at the time of implantation in the rat and in response to a substitute blastocyst (filament) suggesting a role for these proteins in the cytoskeletal rearrangements that facilitate uterine receptivity and blastocyst-epithelial adhesion. Their loss within the implantation chamber possibly allows the subsequent invasion of the embryo.
Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: The alterations in expression of six growth factors known to be regulators of prostatic function have been examined in the ventral lobe of prostates from young adult (14 week) and ageing (1.5 year) Wistar rats. The selected growth factors were transforming growth factor beta (TGFbeta1), insulin-like growth factor I (IGF-I), insulin-like growth factor II (IGF-II), platelet derived growth factor (PDGF), basic fibroblast growth factor (FGF2) and epidermal growth factor (EGF). The extracellular matrix growth co-factor thrombospondin (TSP) was also examined. Our study demonstrated a 2.9-fold up-regulation of TGFbeta1 (p < 0.0001), a 2.0-fold increase in FGF2 (p < 0.0002), an 8.3-fold increase in IGF-II (p < 0.0007) and a 5.4-fold increase in EGF (p < 0.0001) in ageing compared to adult prostate tissue. Conversely, we observed a 2.7-fold down-regulation of IGF-I (p < 0.0005), a 1.7-fold decrease in PDGF (p < 0.0097) and a 5.8-fold decrease in TSP (p < 0.0079) in ageing rat prostate tissue. The observed alterations in growth factor expression in this study may be the result or cause of, an imbalance in the proliferative-apoptotic balance during ageing. This imbalance may explain the increase in epithelial proliferation that is characteristic of the normal ageing prostate. As in other systems it seems likely that these factors work synergistically rather than in isolation.
Publisher: Springer Science and Business Media LLC
Date: 08-10-2016
DOI: 10.1007/S00360-016-1040-Y
Abstract: Vascular endothelial growth factor A is a major mediator of angiogenesis, a critically important process in vertebrate growth and development as well as pregnancy. Here we report for the first time the expression of a rare and unusually potent splice variant, VEGF
Publisher: Elsevier BV
Date: 04-1999
Publisher: Wiley
Date: 29-03-2011
DOI: 10.1002/MRD.21307
Abstract: Uterine epithelial cells transform into a receptive state to adhere to an implanting blastocyst. Part of this transformation includes the apical concentration of cell adhesion molecules at the time of implantation. This study, for the first time, investigates the expression of ICAM1 and fibrinogen-γ (FGG) in uterine epithelial cells during normal pregnancy, pseudopregnancy and in hormone-treated rats. An increase (P < 0.05) in ICAM1 was seen at the apical membrane of uterine epithelial cells at the time of implantation compared with day 1 of pregnancy. ICAM1 was also increased (P < 0.05) on day 6 of pseudopregnancy as well as in ovariectomized rats treated with progesterone plus oestrogen. These results show that ICAM1 up-regulation at the time of implantation is under the control of progesterone, and is not dependent on cytokine release from the blastocyst or in semen. FGG dimerization increased (P < 0.05) on day 6 of pregnancy compared with day 1, and was not up-regulated in day 6 pseudopregnant animals, suggesting this increase is dependent on a developing blastocyst. The presence of ICAM1 and FGG in the uterine epithelium at the time of implantation in the rat is similar to that seen in lymphocyte-endothelium adhesion, and we suggest a similar mechanism in embryo-uterine epithelium adhesion is utilized.
Publisher: Elsevier BV
Date: 2010
DOI: 10.1016/J.ACTHIS.2008.07.003
Abstract: Regulation of the uterine luminal environment is important for successful attachment and implantation of the blastocyst. The contents and volume of luminal fluid are regulated in part by the tight junctions. Using immunofluorescence microscopy, protein and RNA analysis, the cellular distributions of tight junction components claudins and occludin were observed during early pregnancy and under various hormonal regimens. Results indicate that occludin and claudin-4 distribution changed during early pregnancy and in response to ovarian hormones. At the time of implantation and in response to progesterone administration to ovariectomised rats, occludin and claudin-4 showed increased immunolabelling in luminal epithelium. Interestingly, occludin protein detection in uterine luminal epithelial cells at the time of implantation was statistically significantly decreased at the time of implantation compared to day 1 of pregnancy. This suggests that a cytoplasmic pool of occludin is present at day 1 of pregnancy and is redistributed to the tight junctions at the time of implantation. The presence of occludin and claudin-4 in the tight junctions at the time of implantation and in response to progesterone suggests that the paracellular pathway is impermeable to water and Na(+) at this time, and that the transport of such substances takes place via the transcellular pathway.
Publisher: Elsevier BV
Date: 1987
DOI: 10.1016/S0065-1281(87)80028-4
Abstract: Comparison of mortality among patients with positive and negative blood cultures may indicate the contribution of bacteremia to mortality. This study (1) compared mortality among patients with community-acquired bacteremia with mortality among patients with negative blood cultures and (2) determined the effects of bacteremia type and comorbidity level on mortality among patients with positive blood cultures. This cohort study included 29,273 adults with blood cultures performed within the first 2 days following hospital admission to an internal medical ward in northern Denmark during 1995-2006. We computed product limit estimates and used Cox regression to compute adjusted mortality rate ratios (MRRs) within 0-2, 3-7, 8-30, and 31-180 days following admission for bacteremia patients compared to culture-negative patients. Mortality in 2,648 bacteremic patients and 26,625 culture-negative patients was 4.8% vs. 2.0% 0-2 days after admission, 3.7% vs. 2.7% 3-7 days after admission, 5.6% vs. 5.1% 8-30 days after admission, and 9.7% vs. 8.7% 31-180 days after admission, corresponding to adjusted MRRs of 1.9 (95% confidence interval (CI): 1.6-2.2), 1.1 (95% CI: 0.9-1.5), 0.9 (95% CI: 0.8-1.1), and 1.0 (95% CI: 0.8-1.1), respectively. Mortality was higher among patients with Gram-positive (adjusted 0-2-day MRR 1.9, 95% CI: 1.6-2.2) and polymicrobial bacteremia (adjusted 0-2-day MRR 3.5, 95% CI: 2.2-5.5) than among patients with Gram-negative bacteremia (adjusted 0-2-day MRR 1.5, 95% CI 1.2-2.0). After the first 2 days, patients with Gram-negative bacteremia had the same risk of dying as culture-negative patients (adjusted MRR 0.8, 95% CI: 0.5-1.1). Only patients with polymicrobial bacteremia had increased mortality within 31-180 days following admission (adjusted MRR 1.3, 95% CI: 0.8-2.1) compared to culture-negative patients. The association between blood culture status and mortality did not differ substantially by level of comorbidity. Community-acquired bacteremia was associated with an increased risk of mortality in the first week of medical ward admission. Higher mortality among patients with Gram-positive and polymicrobial bacteremia compared with patients with Gram-negative bacteremia and negative cultures emphasizes the prognostic importance of these infections.
Publisher: Wiley
Date: 13-09-2012
DOI: 10.1002/JMOR.20076
Abstract: Integrins are expressed in a highly regulated manner at the maternal-fetal interface during implantation. However, the significance of extracellular matrix (ECM) ligands during the integrin-mediated embryo attachment to the endometrium is not fully understood. Thus, the distribution of fibronectin in the rat uterus and blastocyst was studied at the time of implantation. Fibronectin was absent in the uterine luminal epithelial cells but was intensely expressed in the trophoblast cells and the inner cell mass suggesting that fibronectin secreted from the blastocyst may be a possible bridging ligand for the integrins expressed at the maternal-fetal interface. An Arg-Gly-Asp (RGD) peptide was used to block the RGD recognition sites on integrins, and the effect on rat blastocyst attachment to Ishikawa cells was examined. There was a significant reduction in blastocyst attachment when either the blastocysts or the Ishikawa cells were pre-incubated with the RGD-blocking peptide. Thus, successful attachment of the embryo to the endometrium requires the interaction of integrins on both the endometrium and the blastocyst with the RGD sequence of ECM ligands, such as fibronectin. Pre-treatment of both blastocysts and Ishikawa cells with the RGD peptide also inhibited blastocyst attachment, but not completely, suggesting that ECM bridging ligands that do not contain the RGD sequence are also involved in embryo attachment.
Publisher: Springer Science and Business Media LLC
Date: 25-01-2015
DOI: 10.1007/S00418-015-1308-4
Abstract: The plasma membrane of uterine epithelial cells undergoes a number of changes during early pregnancy. The changes in the basolateral membrane at the time of implantation in particular change from being smooth to highly tortuous in morphology, along with a dramatic increase in the number of morphological caveolae at this time. The major protein of caveolar membranes is caveolin, and previous studies have shown that RNA pol I transcription factor (PTRF) and serum deprivation protein response (SDPR) are the two members of the cavin protein family. These proteins are known to be involved in caveolae biogenesis, where they directly bind to cholesterol and lipids and have been reported to promote membrane curvature. As there is an increase in membrane tortuosity and caveolae at the time of implantation, this study investigated PTRF and SDPR to explore the possible roles that they play in the morphology of the uterine epithelium during early pregnancy. PTRF protein abundance did not change in uterine epithelial cells during early pregnancy or in response to ovarian hormones. At the time of implantation in uterine epithelial cells, PTRF co-immunoprecipitated with caveolin 1, thereby demonstrating an association with caveolin-1 at the basal plasma membrane in caveolae. SDPR protein was observed to be present only at the time of fertilisation, and also under the influence of oestrogen alone, where a cytoplasmic localisation in uterine epithelial cells was observed. The localisation and expression PTRF and SDPR in uterine epithelial cells during early pregnancy suggest that they have roles in the maintenance of lipids and cholesterol in the plasma membrane. PTRF and lack of SDPR may contribute not only to the morphology of the basal plasma membrane as observed at the time of implantation, but also to the maintenance of epithelial polarity during early pregnancy.
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/RD18202
Abstract: The uterine epithelium undergoes remodelling to become receptive to blastocyst implantation during pregnancy in a process known as the plasma membrane transformation. There are commonalities in ultrastructural changes to the epithelium, which, in eutherian, pregnancies are controlled by maternal hormones, progesterone and oestrogens. The aim of this study was to determine the effects that sex steroids have on the uterine epithelium in the fat-tailed dunnart Sminthopsis crassicaudata, the first such study in a marsupial. Females were exposed to exogenous hormones while they were reproductively quiescent, thus not producing physiological concentrations of ovarian hormones. We found that changes to the protein E-cadherin, which forms part of the adherens junction, are controlled by progesterone and that changes to the desmoglein-2 protein, which forms part of desmosomes, are controlled by 17β-oestradiol. Exposure to a combination of progesterone and 17β-oestradiol causes changes to the microvilli on the apical surface and to the ultrastructure of the uterine epithelium. There is a decrease in lateral adhesion when the uterus is exposed to progesterone and 17β-oestradiol that mimics the hormone environment of uterine receptivity. We conclude that uterine receptivity and the plasma membrane transformation in marsupial and eutherian pregnancies are under the same endocrine control and may be an ancestral feature of therian mammals.
Publisher: Elsevier BV
Date: 11-2004
DOI: 10.1016/J.ACTHIS.2004.07.004
Abstract: Uterine epithelium undergoes dramatic changes during early pregnancy in preparation for implantation. We have studied distribution patterns of the desmosomal marker, desmoglein 1 , in rat uterine epithelial cells during early pregnancy as well as in hormonally stimulated ovariectomised animals. On day 1 of pregnancy as well as in oestradiol treated rats, desmoglein 1 staining was localized along the entire length of the lateral plasma membrane. By day 3 and on subsequent days of pregnancy as well as in ovariectomised animals treated with progesterone alone or in combination with oestradiol, desmoglein 1 staining was concentrated at the apical portion of the lateral plasma membrane. We suggest that the reorganisation of these desmosomal cadherins is an important component of uterine epithelial receptivity and this relocation is under the control of the ovarian hormone progesterone.
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/RD14240
Abstract: During early pregnancy the endometrium undergoes a major transformation in order for it to become receptive to blastocyst implantation. The actin cytoskeleton and plasma membrane of luminal uterine epithelial cells (UECs) and the underlying stromal cells undergo dramatic remodelling to facilitate these changes. Filamin A (FLNA), a protein that crosslinks actin filaments and also mediates the anchorage of membrane proteins to the actin cytoskeleton, was investigated in the rat uterus at fertilisation (Day 1) and implantation (Day 6) to determine the role of FLNA in actin cytoskeletal remodelling of UECs and decidua during early pregnancy. Localisation of FLNA in UECs at the time of fertilisation was cytoplasmic, whilst at implantation it was distributed apically its localisation is under the influence of progesterone. FLNA was also concentrated to the first two to three stromal cell layers at the time of fertilisation and shifted to the primary decidualisation zone at the time of implantation. This shift in localisation was found to be dependent on the decidualisation reaction. Protein abundance of the FLNA 280-kDa monomer and calpain-cleaved fragment (240 kDa) did not change during early pregnancy in UECs. Since major actin cytoskeletal remodelling occurs during early pregnancy in UECs and in decidual cells, the changing localisation of FLNA suggests that it may be an important regulator of cytoskeletal remodelling of these cells to allow uterine receptivity and decidualisation necessary for implantation in the rat.
Publisher: Georg Thieme Verlag KG
Date: 02-2007
Publisher: Wiley
Date: 15-12-2009
DOI: 10.1002/JEZ.B.21297
Abstract: In addition to water and small inorganic ions, macromolecules traverse the uterine epithelium in viviparous skinks to be absorbed by the developing fetus. In some species of lizards with complex placenta, the paracellular pathway across the uterine epithelium becomes tighter and more highly regulated as gestation progresses, suggesting that the transcellular pathway may be an alternative route for molecules to travel across the epithelium. In this study, we identified an extensive formation of a lysosomal system in the apical region of uterine epithelial cells in the highly secretory omphaloplacental region of the skink placenta in two species from the Pseudemoia genus. We suggest that this lysosomal system assists apocrine secretion by digesting large macromolecules into smaller particles, allowing more effective transport across the plasma membrane of uterine epithelial cells. We also demonstrate alkaline phosphatase (AP) activity along the apical plasma membrane of uterine epithelial cells in the omphaloplacental region of skink uterus, an enzyme usually associated with active transport in secretory cells. Apocrine secretion, an extensive lysosomal system and AP activity, offer strong evidence that macromolecules are transported across uterine epithelium of the omphaloplacenta. Our study is the first to provide histochemical evidence of macromolecular transport across this region of the placenta in two species of skinks from the genus with the most complex placenta described in Australia.
Publisher: Wiley
Date: 2004
DOI: 10.1002/JMOR.10262
Abstract: We describe changes in the morphology of the oviductal epithelium of an oviparous skink, L ropholis guichenoti, during the course of egg production and oviposition: to characterize the luminal epithelial changes to provide a baseline for understanding uterine changes in viviparous species and to establish whether the plasma membrane transformation of uterine epithelial cells is indeed a feature restricted to viviparous species. Oviducts from vitellogenic, gravid, and postgravid females were observed using scanning electron microscopy. Cellular characteristics of the oviductal epithelium previously used to determine the plasma membrane transformation were assessed morphologically. Three anatomically different areas were defined within the oviduct, but no plasma membrane transformation was observed in the oviparous skink, suggesting that this is a phenomenon particular to viviparity.
Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: In a study of early pregnancy in the rat, a high proportion of morphologically apoptotic, TUNEL and P2X7 positive cells were found to be present in the luminal epithelium and stroma prior to implantation. At the time of implantation on Day 6, apoptosis as measured by these indicators was reduced up to 4-fold in the non-implantation uterine epithelium but was markedly increased adjacent to the implanting blastocyst. It is proposed that apoptotic cell death is an important regulatory factor involved in uterine remodelling prior to and during implantation.
Publisher: Springer Science and Business Media LLC
Date: 03-1982
DOI: 10.1007/BF01258489
Abstract: Proton minibeam radiation therapy (pMBRT) is a novel therapeutic strategy that combines the benefits of proton therapy with the remarkable normal tissue preservation observed with the use of submillimetric spatially fractionated beams. This promising technique has been implemented at the Institut Curie-Proton therapy centre (ICPO) using a first prototype of a multislit collimator. The purpose of this work was to develop a Monte Carlo-based dose calculation engine to reliably guide preclinical studies at ICPO. The whole "Y1"-passive beamline at the ICPO, including pMBRT implementation, was modelled using the Monte Carlo GATE v. 7.0 code. A clinically relevant proton energy (100 MeV) was used as starting point. Minibeam generation by means of the brass collimator used in the first experiments was modelled. A virtual source was modelled at the exit of the beamline nozzle and outcomes were compared with dosimetric measurements performed with EBT3 gafchromic films and a diamond detector in water. Dose distributions were recorded in a water phantom and in rat CT images (7-week-old male Fischer rats). The dose calculation engine was benchmarked against experimental data and was then used to assess dose distributions in CT images of a rat, resulting from different irradiation configurations used in several experiments. It reduced computational time by an order of magnitude. This allows us to speed up simulations for A Monte Carlo dose calculation engine for pMBRT implementation with mechanical collimation has been developed. This tool can be used to guide and interpret the results of This is the first Monte Carlo dose engine for pMBRT that is being used to guide preclinical trials in a clinical proton therapy centre.
Publisher: Elsevier BV
Date: 2002
Abstract: Distribution patterns of the tight junction associated proteins ZO-1, claudin-1 and occludin were investigated in rat uterine epithelial cells during early pregnancy. Light microscopy and immunohistochemical labelling were used to detect these proteins on days 1, 3, 6 and 7 of pregnancy. Intense staining of claudin-1 at the apical region of the lateral plasma membrane accompanied diffuse staining throughout the cytoplasm. ZO-1 was also localised in the apical region, but ZO-1 was not present in the lower two thirds of the lateral plasma membrane or in the cytoplasm. Occludin was present only on days 6 and 7 of pregnancy. Labelling was also localised in the apical region of the lateral plasma membrane where tight junctions are known to be present. Our results show that ZO-1, claudin-1 and occludin are present in the apical region of uterine epithelial cells, and appear to play a role in the very dynamic tight-junctional network of uterine epithelial cells during early pregnancy. In particular, occludin appears only during uterine receptivity for implantation.
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/RD10211
Abstract: The present study investigated the expression of integrin subunits that are known to be associated with focal adhesions, namely β1 and β3 integrins in rat uterine luminal epithelial cells during early pregnancy. The β1 and β3 integrins were concentrated along the basal cell surface and were colocalised and structurally interacted with talin, a principal focal adhesion protein, on Day 1 of pregnancy. At the time of implantation, β1 and β3 integrins disassembled from the site of focal adhesions, facilitating the removal of uterine luminal epithelial cells for embryo invasion. Also at this time, β3 integrin markedly increased along the apical membrane, suggesting a role in embryo attachment. This distributional change in β1 and β3 integrins seen at the time of implantation was predominantly under the influence of progesterone. Taken together, β1 and β3 integrin disassembly from focal adhesions and the increase in β3 integrin apically are key components of hormonally regulated endometrial receptivity.
Publisher: Springer Science and Business Media LLC
Date: 24-06-2014
DOI: 10.1007/S00418-014-1236-8
Abstract: At the time of implantation, uterine luminal epithelial cells undergo a dramatic change in all plasma membrane domains. Changes in the basolateral plasma membrane at the time of implantation include progression from smooth to highly tortuous, as well as a loss of integrin-based focal adhesions. Another aspect of the basolateral plasma membrane that has not been studied in uterine epithelial cells are caveolae, which are omega-shaped invaginations of the plasma membrane known to be involved in endocytosis and contribute to membrane curvature. The current study investigated caveolin, a major protein of caveolae, to explore the possible roles that they play in the remodelling of the basolateral plasma membrane of uterine epithelial cells during early pregnancy in the rat. Morphological caveolae were found at the time of implantation and were significantly increased compared to day 1 of pregnancy. Caveolins 1 and 2 were found to shift to the basolateral plasma membrane of uterine epithelial cells at the time of implantation as well as when treated with progesterone alone, and in combination with oestrogen. A statistically significant increase in the amount of caveolin-1 and a decrease in caveolin-2 protein in uterine epithelial cells was observed at the time of implantation. Caveolin-1 also co-immunoprecipitated with integrin β1 on day 1 of pregnancy, which is a protein that has been reported to be found in integrin-based focal adhesions at the basolateral membrane on day 1 of pregnancy. The localisation and expression of caveolin-1 at the time of implantation is consistent with the presence and increase of morphological caveolae seen at this time. The localisation and expression of caveolins 1 and 2 in luminal uterine epithelium at the time of implantation suggest a role in trafficking proteins and the maintenance of a polarised epithelium.
Publisher: Oxford University Press (OUP)
Date: 07-1992
DOI: 10.1093/OXFORDJOURNALS.HUMREP.A137754
Abstract: Eleven endometrial biopsies, taken from six Turner's syndrome patients receiving hormone replacement therapy prior to treatment by oocyte donation and embryo transfer, were assessed by freeze fracture followed by electron microscopy for epithelial tight junctions. Nine of the eleven biopsies had no discernible tight junctions the other two biopsies had reduced and disorganized junctional structures. Two patients subsequently became pregnant following embryo transfer. It is concluded that compromised epithelial integrity does not prevent embryo implantation in the human, an observation that is consistent with a barrier role for the epithelium except at times when appropriately conditioned with oestrogen and progesterone to induce receptivity for implantation.
Publisher: Oxford University Press (OUP)
Date: 02-1996
Abstract: The human uterine glandular epithelium undergoes a sequence of well characterized changes during the menstrual cycle that presumably play an important role in preparation for blastocyst implantation. The aim of this study was to measure objectively glandular volume over the entire menstrual cycle and compare the results with eight different clinical superovulation or hormone replacement therapy (HRT) subject groups. Endometrial biopsies were taken from control normal menstrual cycle subjects (n = 96), and eight other smaller groups of women who had received different in-vitro fertilization (IVF) related treatments. The total area of glandular epithelium was objectively measured from routine histological slides using computerized image analysis. Control menstrual cycle results showed a significantly greater gland area in the early secretory stage of the cycle than at any time between the early proliferative through to the mid-late proliferative stages (P < 0.05). IVF patients receiving clomiphene citrate and human menopausal gonadotrophin had a significantly smaller glandular area than those in the control groups at equivalent stages of the menstrual cycle. The use of progesterone supplementation removed this significant difference. Patients on the ¿Flare' regime had the highest gland area, although this was not significantly different from controls. Buserelin down-regulation gave a gland area that was closest to the normal cycle controls. The three HRT groups showed high variability in gland volume between patients. The results from this study demonstrate that superovulation can cause significant alterations in endometrial gland volume, but that these do not necessarily preclude implantation.
Publisher: Springer Science and Business Media LLC
Date: 24-03-2010
DOI: 10.1007/S00418-010-0693-Y
Abstract: Adhesion molecules play an important part in preparing uterine epithelial cells for receptivity to the implanting embryo, and their rearrangement is crucial in allowing successful implantation. CD43 is an adhesion molecule which has previously been suggested to take part in implantation in mice. Indirect immunofluorescence microscopy localising CD43 was performed on uterine tissue during early pregnancy, and tissue obtained from ovariectomised rats administered with ovarian hormones. Western blotting was performed during early pregnancy on isolated epithelial cells and ovariectomised rats for comparison of the amount of CD43. Immunofluorescence microscopy showed CD43 was situated basally in uterine luminal epithelial cells on day 1 of pregnancy and during oestrogen administration, corresponding to a 95-kDa band of CD43 seen in western blotting. At the time of implantation, and during progesterone or progesterone plus oestrogen combined treatment, CD43 is apical in uterine luminal epithelial cells, resulting in an 85-kDa form of CD43. We suggest that a de-glycosylated form of CD43 moves from basally to apically at the time of implantation, thus facilitating blastocyst attachment to uterine epithelial cells as well as their removal.
Publisher: Wiley
Date: 07-1995
Abstract: Intra-uterine injection of the lectin Concanavalin A (ConA) on day 5 of PSP induced a rapid and persistent infiltration of leucocytes into the rat uterine stroma. Although the infiltration of leucocytes was witnessed along the entire length of the uterine horn, areas of stromal oedema, indicative of decidualisation (as indicated by the positive Pontamine Sky Blue reaction), were only associated with regions in which the movement of leucocytes across the uterine epithelium was evident. Epithelial disruption and trauma was frequently noted within these regions. We believe that ConA may initiate decidualisation through indirectly causing epithelial trauma.
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0015-0282(98)00275-1
Abstract: To investigate the embryonic and/or endometrial molecular mechanisms underlying the antiimplantation effect of interleukin-1 receptor antagonist (IL-1ra). Controlled experiment. Animal facilities at Stanford University and laboratories of the Instituto Valenciano de Infertilidad and the University of Sydney. Twelve-week-old B6C3F-1 female mice. Intraperitoneal injections of recombinant human IL-1ra during the periimplantation period. Implantation sites, embryonic morphology, and viability. Polymerase chain reaction and immunohistochemistry for integrins and extracellular matrices and transmission electron microscopy of endometrium in IL-1ra-treated versus control animals. Pregnancy rates in control and IL-1ra-injected animals were 60% and 13%, respectively. At day 8 of pregnancy, flushing of uteri obtained from the treated group resulted in 32 blastocysts. Six pseudopregnant animals received IL-1ra-treated blastocysts (left horn) and control blastocysts (right horn), resulting in one pregnancy, with two embryos and one embryo in the left and right horns, respectively. At day 4 of pregnancy, IL- 1ra down-regulated alpha4 mRNA with use of the polymerase chain reaction. Immunohistochemistry showed a decrease of alpha4, alpha v, and beta3, and transmission electron microscopy revealed inhibition of transformation of the plasma membrane. Impairment of embryonic adhesion with IL-1ra is mediated through a direct effect on transformation of the epithelial plasma membrane at the time of implantation as a result of down-regulation of alpha4, alpha v, and beta3.
Publisher: Wiley
Date: 07-08-2017
DOI: 10.1002/MRD.22861
Abstract: Pregnancy in mammals requires remodeling of the uterus to become receptive to the implanting embryo. Remarkably similar morphological changes to the uterine epithelium occur in both eutherian and marsupial mammals, irrespective of placental type. Nevertheless, molecular differences in uterine remodeling indicate that the marsupial uterus employs maternal defences, including molecular reinforcement of the uterine epithelium, to regulate embryonic invasion. Non-invasive (epitheliochorial) embryonic attachment in marsupials likely evolved secondarily from invasive attachment, so uterine defences in these species may prevent embryonic invasion. We tested this hypothesis by identifying localization patterns of Talin, a key basal anchoring molecule, in the uterine epithelium during pregnancy in the tammar wallaby (Macropus eugenii Macropodidae) and the brush tail possum (Trichosurus vulpecula Phalangeridae). Embryonic attachment is non-invasive in both species, yet Talin undergoes a clear distributional change during pregnancy in M. eugenii, including recruitment to the base of the uterine epithelium just before attachment, that closely resembles that of invasive implantation in the marsupial species Sminthopsis crassicaudata. Basal localization occurs throughout pregnancy in T. vulpecula, although, as for M. eugenii, this pattern is most specific prior to attachment. Such molecular reinforcement of the uterine epithelium for non-invasive embryonic attachment in marsupials supports the hypothesis that less-invasive and non-invasive embryonic attachment in marsupials may have evolved via accrual of maternal defences. Recruitment of basal molecules, including Talin, to the uterine epithelium may have played a key role in this transition.
Publisher: Elsevier BV
Date: 02-1998
DOI: 10.1016/S0065-1281(98)80007-X
Abstract: This scoping review examines the current research on the effect of cannabis upon pain intensity in spinal cord injury (SCI) pain. Chronic pain is a significant secondary condition following SCI, and traditional treatments (e.g. opioids, NSAIDs) are often criticized for providing inadequate relief. As a result, there is increasing interest in and use of cannabis and cannabinoid-based medications as an alternative means of pain control. The purpose of this review was to examine the scientific evidence on the effect of cannabis/cannabinoids upon pain intensity in SCI by mapping the current literature. Two hundred and fifty-two studies were identified by searching electronic databases for articles published through February 2020. In addition, reviewers scanned the reference lists of identified articles and examined clinicaltrials.gov for unpublished data in this area. Title, abstract, and full-text reviews were completed by two independent reviewers. Data extraction was performed by a single reviewer and verified by a second reviewer. Six articles covering five treatment studies were included. Studies yielded mixed findings likely due to large variability in methodology, including lack of standardized dosing paradigms, modes of use, and duration of trial. The current quality and level of evidence is insufficient to draw reliable conclusions of the efficacy of cannabis upon SCI-related pain itensity. We identify specific limitations of past studies and present guidelines for future research.
Publisher: Springer Science and Business Media LLC
Date: 2004
Publisher: Wiley
Date: 16-03-2012
Publisher: Springer Science and Business Media LLC
Date: 12-1981
DOI: 10.1007/BF02785116
Abstract: High mountain ecosystems and their biota are governed by low-temperature conditions and thus can be used as indicators for climate warming impacts on natural ecosystems, provided that long-term data exist. We used data from the largest alpine to nival permanent plot site in the Alps, established in the frame of the Global Observation Research Initiative in Alpine Environments (GLORIA) on Schrankogel in the Tyrolean Alps, Austria, in 1994, and resurveyed in 2004 and 2014. Vascular plant species richness per plot increased over the entire period, albeit to a lesser extent in the second decade, because disappearance events increased markedly in the latter period. Although presence/absence data could only marginally explain range shift dynamics, changes in species cover and plant community composition indicate an accelerating transformation towards a more warmth-demanding and more drought-adapted vegetation, which is strongest at the lowest, least rugged subsite. Divergent responses of vertical distribution groups of species suggest that direct warming effects, rather than competitive displacement, are the primary causes of the observed patterns. The continued decrease in cryophilic species could imply that trailing edge dynamics proceed more rapidly than successful colonisation, which would favour a period of accelerated species declines.
Publisher: Springer Science and Business Media LLC
Date: 20-07-2018
DOI: 10.1007/S00441-018-2887-X
Abstract: For the development of uterine receptivity, many morphological and molecular changes occur in the apical surface of luminal uterine epithelial cells (UECs) including an increase in vesicular activity. Vesicular movements for exocytosis and endocytosis are dependent on microtubules however, changes in microtubules in UECs during early pregnancy have received little attention. β-tubulin, one of the main component of microtubules, is distributed throughout the cytoplasm of UECs on day 1 (non-receptive) of pregnancy in the rat. On day 5.5, β-tubulin is concentrated above the nuclei and by day 6 (receptive), β-tubulin is concentrated in a band-like fashion above the nucleus. Western blot analysis of isolated UECs found two bands (50 and 34 kDa) for β-tubulin in UECs during early pregnancy. The intensity of the 34 kDa band was significantly higher on day 6 compared to day 1. The increase in the 34 kDa band may be due to higher proteolytic activity associated with microtubule polymerisation during the receptive state. Transmission electron microscopy showed fragmented microtubules at the time of receptivity in UECs. This is the first study to show that microtubules are reorganised during uterine receptivity. This re-organisation likely facilitates vesicular movement and promotes the reorganisation of the apical plasma membrane for uterine receptivity.
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.CBPA.2007.03.029
Abstract: L ropholis guichenoti is an oviparous lizard that lays eggs with a calcareous outer shell. We used immunofluorescence microscopy to describe the occurrence and distribution of Ca2+ ATPase pumps in the uterus of L. guichenoti at different stages of the reproductive and egg-shelling cycles. Ca2+ ATPase pumps were not demonstrated by immunofluorescent techniques in any uterine tissue until egg-shelling had commenced and at least partly calcified eggs were in the uterus. During egg-shelling, Ca2+ ATPase pumps occur on the apical and baso-lateral surfaces of uterine epithelial cells, and those of associated shell glands in the stroma of the uterus. We conclude that Ca2+ ATPase pumps provide a major mechanism for deposition of the calcareous eggshell of L. guichenoti and that the pumps are up-regulated when required in the reproductive cycle. Furthermore, it is likely that specific calcium glands in the stroma of the uterus are involved in the rapid transport required for egg-shelling, but the differential contribution of luminal and glandular epithelial cells is not known.
Publisher: Elsevier BV
Date: 05-2006
DOI: 10.1016/J.ACTHIS.2006.01.004
Abstract: In this retrospective and quantitated study on banked tissue we found that, compared to normal uterine epithelial cells, growth hormone (GH) is increased 3.4-fold in endometriosis and 3.8-fold in endometrial adenocarcinoma. Similarly, interleukin-6 (IL-6) is increased 2.4-fold in endometriosis and 4.4-fold in endometrial adenocarcinoma. These proteins appear to be involved in the progression of both these conditions. GH is particularly interesting in this context since it is known to not only promote cellular proliferation but also reduces cell-cell adhesion, thus allowing in idual cells to break away from their parent architecture. Our results suggest that both IL-6 and GH may play a role in the progression of both endometriosis and endometrial carcinoma.
Publisher: Springer Science and Business Media LLC
Date: 29-06-2006
DOI: 10.1007/S10735-006-9027-8
Abstract: Prostate cancer is the most common cancer in American men and the second leading cause of cancer deaths in this group. Both growth hormone (GH) and the inflammatory cytokine interleukin 6 (IL-6) have been implicated in prostate cancer progression. Studies in other systems have shown that an increase in GH results in an increase in IL-6 also. The current study demonstrated a parallel spatial and temporal expression of GH and IL-6 in cells in prostate cancer glandular acina cells. This study cannot determine if this expression is coincidental or causative, but it seems likely that the increase in GH could induce the expression of IL-6, since this is the case in other tissues. Optimal labelling for IL-6 in our study was achieved with low pH, high temperature antigen retrieval.
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.BIOCEL.2012.10.012
Abstract: Uterine epithelial cells are unique cells in that they are both epithelial in the typical barrier sense but in many mammalian species, they characteristically allow the blastocyst to penetrate them from the apical surface. Here we examine how these cells subserve both functions and in particular we synthesize recent evidence on focal adhesions and how these membrane structures contribute to uterine receptivity for blastocyst implantation. Focal adhesions emerge as a dynamic new player in the 'plasma membrane transformation' of early pregnancy and uterine receptivity in that they disassemble at the time of implantation in common with many other structures on the basolateral plasma membrane of these cells.
Publisher: Bioscientifica
Date: 07-1983
Abstract: An i.v. infusion of porcine relaxin was administered to rats from the afternoon of Day 4 of pregnancy to the morning of Day 6, a time by which implantation has normally occurred. Implantation sites were irregularly distributed and confined to the cranial half of each uterine horn. Histological sections of uteri fixed by vascular perfusion with osmium tetroxide revealed that the blastocyst was no longer invariably positioned antimesometrially within the lumen and that embryonic disc orientation was often abnormal. A reduced decidual cell reaction was observed around several of the implanting blastocysts.
Publisher: Springer Science and Business Media LLC
Date: 1987
DOI: 10.1007/BF00518718
Publisher: Oxford University Press (OUP)
Date: 30-04-2011
Abstract: Integrins are involved in the process of embryo-endometrium interaction during implantation. We investigated the localization of integrin β3 in the rat blastocyst and Ishikawa cells using an in vitro co-culture model of implantation. Zona pellucida-free rat blastocysts were co-cultured with the Ishikawa cells (endometrial adenocarcinoma cell line) to observe the attachment between the embryo and endometrium. Immunofluorescence staining was used to investigate the localization of integrin β3 in rat embryos at different stages of development (each n= 3 embryos) and at the embryo/endometrium interface, observed by confocal microscopy. The Ishikawa cells were transfected with integrin β3 small interfering RNA (siRNA) for 48 h and then co-cultured with Day 5 rat blastocysts to observe the effect on attachment. Integrin β3 staining in the rat embryos increased at the blastocyst stage being highly concentrated in the cytoplasm of trophoblast cells (n= 9 embryos). Integrin β3 was localized on the apical surface of the Ishikawa cells (n= 3 experiments). However, integrin β3 relocated to the apical membrane of trophoblast cells in response to attachment to Ishikawa cells (n= 6 embryos). Moreover, when Ishikawa cells were transfected with integrin β3 siRNA, blastocyst attachment was significantly reduced compared with those transfected with control siRNA (16.7 versus 92.3%, respectively, P< 0.05). Integrin β3, localized apically in the blastocyst and the Ishikawa cells, is important during initial attachment of the blastocyst to endometrial cells. This study provides further evidence of the importance of integrins during implantation and may aid in elucidating the molecular mechanism of implantation failure and infertility in women.
Publisher: Wiley
Date: 03-07-2017
DOI: 10.1111/JOA.12648
Publisher: Wiley
Date: 18-02-2010
DOI: 10.1002/AR.21093
Abstract: Australian species of viviparous skinks have noninvasive epitheliochorial placentation where there is no breeching or interruption of the uterine epithelial cell barrier. This is contrary to some African and South American species of skinks which exhibit invading chorionic cells and a localized endotheliochorial placenta. The desmosomes, which maintain the adhesive properties of the junctional complex between uterine epithelial cells, were found to decrease as gestation progressed in the uterus of two highly placentotrophic Australian skinks, but no changes in desmosomal numbers were present in the uterus of two Australian oviparous skinks or viviparous skinks with a simple placenta. In mammals, desmosomes decrease in the uterine epithelium of species with invasive hemochorial placentation, where less chemical and mechanical adhesion between cells assists the invading trophoblast at the time of implantation. However, Australian viviparous skinks do not have an invasive trophoblast yet, similarities in decreasing lateral cellular adhesion exist in the uterus of both invasive and noninvasive placental types. This similarity in cellular mechanisms suggests a conservation of plasma membrane changes across placentation irrespective of reptilian or mammalian origin.
Publisher: Elsevier BV
Date: 11-2008
DOI: 10.1016/J.ACTHIS.2008.02.002
Abstract: The extensive actin cytoskeletal remodelling of the uterine stroma during early pregnancy involves changes in actin-binding proteins. This study provides the first detailed localisation of the actin-binding protein, moesin, in rat uterine endometrium during this period. Western blot analysis and immunofluorescence microscopy showed that the amount of moesin in the uterus peaked at the time of implantation, corresponding to the presence of intensely immunolabelling decidual cells. Furthermore, moesin increased in active membrane/cytoskeleton bound protein at the time of implantation, concomitantly decreasing in cytosolic protein. The increase of moesin at decidualisation corresponds with the appearance of alpha smooth muscle actin (alphaSMA) suggesting that decidual cells have contractile abilities that may aid in containing an invasive trophoblast. The results of this study suggest that moesin is important in developing a specialised cytoskeleton and increased adhesiveness of decidual cells, possibly functioning to bridge adhesion molecules to the underlying cytoskeleton.
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/RD15432
Abstract: In preparation for uterine receptivity, the uterine epithelial cells (UECs) exhibit a loss of microvilli and glycocalyx and a restructuring of the actin cytoskeleton. The prominin-1 protein contains large, heavily glycosylated extracellular loops and is usually restricted to apical plasma membrane (APM) protrusions. The present study examined rat UECs during early pregnancy using immunofluorescence, western blotting and deglycosylation analyses. Ovariectomised rats were injected with oestrogen and progesterone to examine how these hormones affect prominin-1. At the time of fertilisation, prominin-1 was located diffusely in the apical domain of UECs and 147- and 120-kDa glycoforms of prominin-1 were identified, along with the 97-kDa core protein. At the time of implantation, prominin-1 concentrates towards the APM and densitometry revealed that the 120-kDa glycoform decreased (P 0.05), but there was an increase in the 97-kDa core protein (P 0.05). Progesterone treatment of ovariectomised rats resulted in prominin-1 becoming concentrated towards the APM. The 120-kDa glycoform was increased after oestrogen treatment (P 0.0001), whereas the 97-kDa core protein was increased after progesterone treatment (P 0.05). Endoglycosidase H analysis demonstrated that the 120-kDa glycoform is in the endoplasmic reticulum, undergoing protein synthesis. These results indicate that oestrogen stimulates prominin-1 production, whereas progesterone stimulates the deglycosylation and concentration of prominin-1 to the apical region of the UECs. This likely presents the deglycosylated extracellular loops of prominin-1 to the extracellular space, where they may interact with the implanting blastocyst.
Publisher: Wiley
Date: 10-02-2012
DOI: 10.1002/JMOR.20010
Abstract: Focal adhesions play an important role in promoting embryo invasion in particular, focal adhesions disassemble at the time of implantation in the rat, facilitating the detachment of the uterine luminal epithelium to allow the embryo to invade the endometrium. This study investigated focal adhesion protein, focal adhesion kinase (FAK) in the rat uterine luminal, and glandular epithelial cells to understand the dynamics of focal adhesions during early pregnancy. FAK undergoes extensive distributional change during early pregnancy, and surprisingly, FAK was not localized at the site of focal adhesions, instead being localized to the site of cell-to-cell contact and colocalizing with ZO-1 on day 1 of pregnancy. At the time of implantation, FAK increases in the apical region of the uterine luminal epithelial cells which was regulated by progesterone. Using an in vitro co-culture model of rat blastocysts attached to Ishikawa cells, FAK was present apically both in the rat blastocyst and the Ishikawa cells, suggesting a role in attachment andin mediating signal transduction between these two genetically different cell types.
Publisher: Frontiers Media SA
Date: 22-01-2015
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/RD17184
Abstract: Angiogenesis is a critical step in the development of ectopic lesions during endometriosis. Although total vascular endothelial growth factor (VEGF) A is elevated in the peritoneal fluid of women with endometriosis, there are contradictory reports on how levels of total endometrial VEGFA are altered in this disease. Furthermore, limited research is available on different VEGFA isoforms in women with endometriosis. Thus, the aim of the present study was to analyse levels of various VEGFA isoforms in women with and without endometriosis at different stages of the menstrual cycle. Quantitative polymerase chain reaction analysis showed that total VEGFA was highest during menstruation in endometriosis compared with controls (P = 0.0373). VEGF121 and VEGF189 were similarly highest during menstruation in endometriosis compared with controls (P = 0.0165 and 0.0154 respectively). The present study is also the first to identify the natural expression of VEGF111 in human tissue, which is also highest during menstruation in endometriosis (P = 0.0464). This discovery of the natural production of VEGF111 in human endometrium, as well as the upregulation of VEGFA isoforms during menstruation in endometriosis, may shed further light on the development and progression of the disease, and improve our understanding of the regulation of endometrial angiogenesis.
Publisher: Springer Science and Business Media LLC
Date: 1999
Abstract: Avidin binds to damaged DNA with high specificity. Avidin conjugated to horseradish peroxidase may therefore be used to label apoptotic DNA damage, using standard immunohistochemical protocols. However, the resulting label may be too weak to visualise. We used tyramide signal lification to enhance the avidin-peroxidase signal in a rat model of apoptotic damage in hyperplasic prostate tissue. After lification, the difference between normal levels of apoptosis in the young rat prostate and the greatly reduced levels evident in aged rats was readily appreciated. The label was specific and the non-specific background was minimal. This method is particularly useful for the detection of weak apoptotic signals in tissue sections.
Publisher: Springer Science and Business Media LLC
Date: 11-2016
Abstract: Uterine luminal epithelial cells (UECs) undergo the plasma membrane transformation in the transition to receptivity. This involves transient alterations in the apical junctional complex (AJC) including increases to the depth and complexity of the tight junction, loss of the adherens junction, and a decrease in the number of desmosomes along the lateral cell membranes. Nectin-3 is key protein involved in the structure and function of the AJC. This study, used immunofluorescence, Western blotting, colocalization, and coimmunoprecipitation analyses, to investigate whether nectin-3 was present in the rat uterus and was regulated by hormones and the blastocyst during early pregnancy. The results showed that nectin-3 was present in UECs as 3 molecular weight protein isoforms (80 kDa, 60 kDa, and 32 kDa). At the time of fertilization (day 1 of pregnancy), nectin-3 was localized basally, but at the time of implantation, (day 6 of pregnancy) when UECs were receptive, nectin-3 increased in the cellular junctions. When UECs returned to the nonreceptive state (day 9 of pregnancy), nectin-3 redistributed back to the cell cytoplasm. This study also showed that nectin-3 localization at the cell junctions was likely to be controlled by progesterone however, neither ovarian hormones nor the blastocyst regulated protein abundance. This study further showed that while nectin-3 localized to the tight junction at the time of implantation, it did not interact with occludin or l-afadin. These results suggest that at the time of implantation, nectin-3 may contribute to the formation of the tight junction in a protein complex independent from occludin and l-afadin.
Publisher: Wiley
Date: 23-10-2003
DOI: 10.1002/JMOR.10163
Abstract: The "plasma membrane transformation" describes a series of ultrastructural, biochemical, and morphological changes that occur in the uterus of many mammals at the time of blastocyst attachment. These changes, regardless of placental type or length of gestation, include alterations to microvillar length and density and the presence or absence of pinopods or uterodomes. Scanning electron microscopy (SEM) was used to 1) document the topographical ultrastructure of the uterus of Eul rus tympanum, an eastern Australian viviparous skink with a simple chorioallantoic placenta, for the first time and 2) determine whether changes identified as "plasma membrane transformation" in mammals occur in E. tympanum. Tissues collected over three seasons from nonreproductive subadult females, preovulatory, postovulatory, and early to mid-gestational females were examined. At low magnification the uterine epithelium of subadults displays a distinctive pattern of tissue folding that includes rectangular areas of tissue delineated by deep lateral and transverse folds. At higher magnification, the uterine epithelium surface is composed of two dominant cell types, i.e., those covered by microvilli and ciliated cells. The folding pattern observed in subadults is less evident in vitellogenic females and the cell surfaces appear highly secretory, with bulging cell apices. Tissue from postovulatory lizards has no distinctive folding pattern and cell surfaces are frequently smooth and lack microvilli. Uterine egg chambers lack ciliated cells at the embryonic pole, but display abundant secretory droplets. Thus, the uterus of E. tympanum undergoes a plasma membrane transformation. The scope of this transformation is not fully understood but may be related to the complexity of placental structure and the development of the embryo/fetus at parturition.
Publisher: Wiley
Date: 04-04-2019
DOI: 10.1002/MRD.23140
Abstract: The fluid that surrounds the embryo in the uterus contains important nourishing factors and secretions. To maintain the distinct microenvironment in the uterine lumen, the tight junctions between uterine epithelial cells are remodeled to decrease paracellular movement of molecules and solutes. Modifications to tight junctions between uterine epithelial cells is a common feature of pregnancy in eutherian mammals, regardless of placental type. Here we used immunofluorescence microscopy and western blot analysis to describe distributional changes to tight junctional proteins, claudin-1, -3, -4, and -5, in the uterine epithelial cells of a marsupial species, Sminthopsis crassicaudata. Immunofluorescence microscopy revealed claudin-1, -3, and -5 in the tight junctions of the uterine epithelium of S. crassicaudata during pregnancy. These specific claudins are associated with restricting passive movement of fluid between epithelial cells in eutherians. Hence, their function during pregnancy in S. crassicaudata may be to maintain the uterine luminal content surrounding developing embryos. Claudin-4 disappears from all uterine regions of S. crassicaudata at the time of implantation, in contrast with the distribution of this claudin in some eutherian mammals. We conclude that like eutherian mammals, distributional changes to claudins in the uterine epithelial cells of S. crassicaudata are necessary to support pregnancy. However, the combination of in idual claudin isoforms in the tight junctions of the uterine epithelium of S. crassicaudata differs from that of eutherian mammals. Our findings suggest that the precise permeability of the paracellular pathway of the uterine epithelium is species-specific.
Publisher: Springer Science and Business Media LLC
Date: 2003
DOI: 10.1023/B:HIJO.0000021066.44364.81
Abstract: Immunofluorescence and immunogold techniques were used to determine the presence and distribution of aquaporin-1 (AQP1) within the rat uterus. Uterine tissue from non-pregnant (proestrus) as well as pregnant (days 1, 3, 6 and 7) rats were used. It was found that this water channel was present in the myometrium of the pregnant rat uterus with the intensity of AQP1 immunoreactivity increasing from day 1 to day 6 of pregnancy. In particular, an increase was also observed in mesometrial as compared to antimesometrial myometrium. Immunolocalization at the electron microscope level indicated that AQP1 was localized to the plasma membrane of smooth muscle cells found within the inner circular layer. It is suggested that AQP1 plays a role in stromal oedema, uterine closure and orientation of the blastocyst.
Publisher: Wiley
Date: 14-04-2018
DOI: 10.1002/JEZ.B.22800
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2007
Publisher: Bioscientifica
Date: 02-2006
DOI: 10.1530/REP.1.00914
Abstract: During early pregnancy in the rat there is a dramatic reduction in luminal fluid which is associated with uterine receptivity for blastocyst implantation. This study investigates the presence and distributional changes of several members of the aquaporin (AQP) family in the rat uterus in response to hormonal regime. An increase in apical AQP5 protein expression was found in response to progesterone alone or in combination with oestrogen, which is similar to that seen at the time of implantation. AQP1 was found in endothelial cells of the endometrium and in the inner circular layer of smooth muscle, with maximal protein expression seen after three doses of progesterone plus 8 hr of oestrogen treatment. These results, for the first time, show that the up-regulation of AQP5 in the apical plasma membrane of uterine epithelial cells and AQP1 in the inner circular layer of myometrium, is dependent on progesterone. Furthermore, unlike during normal pregnancy, there is no differential gradient of AQP5 expression between mesometrial and antimesometrial poles of the progesterone treated uterus. Hence it is suggested that the differential gradient of AQP5 is dependent on the presence of a blastocyst, in addition to the appropriate hormonal environment.
Publisher: Wiley
Date: 03-2012
DOI: 10.1002/JEZ.B.22003
Abstract: Structural and functional changes to the uterus associated with maintenance of pregnancy are controlled primarily by steroid hormones such as progesterone. We tested the hypothesis that progesterone regulates uterine structural changes during pregnancy in the viviparous skink, Pseudemoia entrecasteauxii, by treating pregnant females with the progesterone receptor antagonist mifepristone at different stages of pregnancy. Expression and distribution of progesterone receptor was determined using Western blot and immunohistochemistry. During early pregnancy, mifepristone treatment resulted in altered uterine epithelial cell surface morphology and high embryo mortality, but did not affect females at mid and late stages of pregnancy. Females treated with mifepristone in early pregnancy exhibited abnormal uterine epithelial cell morphology such as lateral blebbing and presence of wide gaps between cells indicating loss of intercellular attachment. Chorioallantoic membranes of the embryo were not affected by mifepristone treatment. Two isoforms (55 kDa and 100 kDa) of progesterone receptor were identified using immunoblots and both isoforms were localized to the nucleus of uterine epithelial cells. The 55 kDa isoform was expressed throughout pregnancy, whereas the 100 kDa isoform was expressed during mid and especially late pregnancy. In P. entrecasteauxii, mifepristone may prevent successful embryo attachment in early pregnancy through its effects on uterine epithelial cells but may have little effect on pregnancy once the maternal-embryo structural relationship is established.
Publisher: Springer Science and Business Media LLC
Date: 08-05-2000
Abstract: Semi-quantitative immunoperoxidase light microscopy on unfixed frozen sections of rat uterus was used to examine the expression of transforming growth factors (TGF) alpha and beta before, during and after implantation. TGF beta-1 labelling was present in the lateral plasma membranes and basement membrane from day 3, steadily increased until the time of implantation on day 6 when it formed a dense apical band, but had disappeared by day 7. TGF alpha appeared in the apical epithelium, 3 days prior to TGF beta-1. Ultrastructural immunogold labelling showed the intense TGF beta-1 signal observed at the time of implantation to be present on the apical epithelial surface and microvilli and in the luminal secretions. We suggest that TGF alpha stimulates the expression of TGF beta-1 in rats, as in implanting transgenic mice, and that it is involved in extracellular matrix remodelling in the lateral plasma membranes and basal lamina to inhibit invasion and implantation and to stimulate the production of basement membrane.
Publisher: Springer Science and Business Media LLC
Date: 08-2004
Abstract: This review begins with a brief commentary on the ersity of placentation mechanisms, and then goes on to examine the extensive alterations which occur in the plasma membrane of uterine epithelial cells during early pregnancy across species. Ultrastructural, biochemical and more general morphological data reveal that strikingly common phenomena occur in this plasma membrane during early pregnancy despite the ersity of placental types--from epitheliochorial to hemochorial, which ultimately form in different species. To encapsulate the concept that common morphological and molecular alterations occur across species, that they are found basolaterally as well as apically, and that moreover they are an ongoing process during much of early pregnancy, not just an event at the time attachment, the term 'plasma membrane transformation' is suggested which also emphasises that alterations in this plasma membrane during early pregnancy are key to uterine receptivity.
Publisher: Wiley
Date: 1999
Publisher: Wiley
Date: 11-1996
Abstract: Intra-uterine injection of the lectin Concanavalin A (ConA) on day 5 of pseudopregnancy induced a rapid and persistent infiltration of leucocytes into the rat uterine stroma. Although the infiltration of leucocytes was seen along the entire length of the uterine horn, areas of stromal oedema, indicative of decidualization (as indicated by a positive Pontamine Sky Blue reaction), were only associated with regions in which leucocytes had crossed the uterine epithelium and were present in the uterine lumen. Ultrastructural evaluation of the interaction of the luminal leucocytes with the apical surface of the uterine epithelium appeared strikingly similar to that of the blastocyst and the uterine epithelium during normal implantation. It is proposed that leucocytes, induced by ConA, may initiate a decidual response in a manner analogous to that of the blastocyst through surface epithelial interaction.
Publisher: Springer Science and Business Media LLC
Date: 07-03-2007
DOI: 10.1007/S10735-007-9083-8
Abstract: Regulation of luminal fluid is essential for blastocyst implantation. While it has been known for quite some time that there is a reduction in the amount of luminal fluid at the time of implantation, the mechanisms regulating this process are only just emerging. Previous studies have shown an upregulation of aquaporin (AQP) 5 channels in luminal epithelial cells at the time of implantation providing a mechanism for fluid reabsorption across the surface epithelium. However to date the contribution of fluid reabsorption by glandular epithelial cells has not been established. This study using reverse transcriptase polymerase chain reaction demonstrates the presence of several AQP isoforms in the rat uterus at the time of implantation while immunofluorescence data demonstrates an apical distribution of AQPs5 and 9 in the glandular epithelium at the time of implantation. The presence of AQPs5 and 9 in the apical plasma membrane of the glandular epithelium seen in this study provides a mechanism for transcellular fluid transport across these glandular epithelial cells similar to that seen in luminal epithelial cells. The reabsorption of glandular fluid via AQP channels may also regulate luminal fluid volume and be involved in the reduction in luminal fluid seen at the time of implantation.
Publisher: Elsevier BV
Date: 03-1991
DOI: 10.1016/S0015-0282(16)54190-9
Abstract: The role of endometrial factors in controlling embryo implantation is poorly understood. In the present study, histopathology and morphometry were used to investigate differences in endometrial appearance seen by ultrasound (US) in 107 in vitro fertilization patients receiving different superovulation regimens. Seventy-seven patients received clomiphene citrate (CC)/human menopausal gonadotropin (hMG) and 30 buserelin acetate down regulation/hMG. All patients received an endometrial US at the time of embryo transfer (ET). Endometrial biopsies were taken from 17 women (12 CC/hMG, 5 buserelin acetate/hMG) with fertilization failure at the time when ET would normally have occurred. The morphometry results showed that endometrial glandular volume 2 days after oocyte retrieval was significantly reduced after CC/hMG compared with buserelin acetate/hMG, despite the fact that histopathological dating was similar for both groups. In addition, significant differences in endometrial thickness and echogenicity between CC/hMG and buserelin acetate/hMG were evident by US.
Publisher: Springer Science and Business Media LLC
Date: 05-06-2013
DOI: 10.1007/S00441-013-1656-0
Abstract: Adhesion molecules are redistributed in rat uterine epithelial cells (UECs) during early pregnancy for endometrial receptivity and implantation. Intercellular adhesion molecule-2 (ICAM-2) is located as an oligomer on the basal plasma membrane of non-receptive UECs on day 1 of pregnancy and colocalizes with the lipid raft marker flotillin-2. At the time of implantation in rats and in ovariectomized rats primed with progesterone, ICAM-2 disappears from the basal plasma membrane and lipid rafts redistribute to the apical membrane. The loss of ICAM-2 might render UECs less adherent to the underlying basal lamina and more prone to apoptosis. Flotillin-2 in the apical plasma membrane at the time of implantation might provide an anchoring point for several adhesion molecules that are known to localize to this region at this time. We suggest that flotillin-2 is involved with adhesion between UECs and the implanting blastocyst, whereas ICAM-2 is associated with the ability for UECs to be removed at the time of implantation.
Publisher: Springer Science and Business Media LLC
Date: 11-2014
DOI: 10.1007/S00441-014-2017-3
Abstract: The non-receptive uterine luminal epithelium forms a polarised epithelial barrier, protective against potential pathogenic assault from the external environment and invasion by the blastocyst. However, during the window of implantation, the uterine luminal epithelial cells (UECs) transition to a receptive state by dismantling many of their intercellular and cell-matrix adhesions in preparation for epithelial detachment and subsequent blastocyst implantation. The present study investigated the presence and regulation of the intercellular adhesion protein, Epithelial Cell Adhesion Molecule (EpCAM) during early pregnancy in the rat to understand its role in the transition to receptivity. Immunofluorescence and western blotting analysis were used to study EpCAM expression in normal pregnancy, hormone replacement studies and pseudopregnancy. EpCAM was abundantly expressed and localised to the uterine luminal and glandular epithelium during the non-receptive state but decreased to lower but still observable levels around the time of implantation. This decrease was not dependent on ovarian hormones or the blastocyst. Further, EpCAM colocalised with but did not associate with its frequent binding partner, Tumour necrosis factor α (TNFα)-converting enzyme, also known as A Disintegrin And Metalloprotease 17 (TACE/ADAM17), at the time of fertilisation. These results suggest that, prior to implantation, EpCAM mediates intercellular adhesion in the uterine epithelium, but that, during implantation when UECs lose the majority of their intercellular and cell-matrix adhesions, EpCAM levels are decreased but still present for the maintenance of mucosal integrity.
Publisher: Wiley
Date: 07-02-2017
DOI: 10.1002/AR.23535
Abstract: Alterations to the basal attachment points between the epithelium of the uterus and the underlying tissue in early pregnancy affect how easily the epithelium can be invaded by the implanting embryo. Attachment points- focal adhesions- disassemble to facilitate highly invasive implantation in rats, but species with less invasive implantation, including marsupials, may require different basal alterations for successful pregnancy. Here we used immunofluorescence microscopy and Western blotting to conduct the first study of basal plasma membrane dynamics in the uterus during marsupial pregnancy. We describe localisation patterns of two key anchoring molecules, talin and paxillin, throughout pregnancy in the fat-tailed dunnart (Sminthopsis crassicaudata Dasyuridae). Basal staining of both molecules occurs in early pregnancy, as it does in the rat. However, unlike rats, there is strong basal localisation of talin and paxillin just before implantation in S. crassicaudata, indicating that focal adhesions do not disassemble during pregnancy in this species, and that molecular reinforcement of the epithelium may be a maternal strategy to regulate invasion. Additionally, talin and paxillin do not co-localise at all stages of pregnancy as they do in the rat. Different localisation patterns among mammalian species demonstrate that not all early pregnancy changes are ubiquitous in mammalian pregnancy, as changes to the basal plasma membrane of the epithelium, in particular, may instead be dependent on mode of implantation. Anat Rec, 300:1150-1159, 2017. © 2016 Wiley Periodicals, Inc.
Publisher: Springer Science and Business Media LLC
Date: 1999
Abstract: The expression of thrombospondin on Day 1, Day 3 and Day 6 of pregnancy has been examined in the rat, using light microscopic immunoperoxidase and electron immunogold techniques. The glycoprotein was expressed in the apical, lateral and basal uterine epithelium on Days 1 and 3 but was then de-expressed at the time of implantation on Day 6. We propose that these data suggest a role for thrombospondin in remodellig the uterine epithelium during the plasma membrane transformation, but that it does not play a part in attachment and implantation.
Publisher: Springer Science and Business Media LLC
Date: 2002
Abstract: The presence and distribution of heparin-binding epidermal growth factor in rat uterine epithelial cells was determined immunohistochemically and localized ultrastructurally. Rat uterine tissue was examined on days 1, 3, 6 and 8 of pregnancy and it was found that while presence of this growth factor was evident from day 1, spatial reorganization occurred by the time of blastocyst implantation. Strong apical staining was evident from day 6 to day 8, day 6 being the approximate time of blastocyst implantation. Electron microscopy further revealed that this growth factor while shown to be expressed very strongly apically from day 6, actually localized on the plasma membrane only after attachment of the blastocyst. This suggests that heparin-binding epidermal growth factor is not involved in the initial stages of implantation but is more likely involved in the post attachment stages of pregnancy.
Publisher: Wiley
Date: 12-1994
Abstract: The plasma membrane of uterine epithelial cells and its changes during early pregnancy are reviewed. The review first examines morphological alterations in rats and mice and laboratory rodents and finds that similar changes in membrane organization accompany the peri-implantation period: long, thin, regular microvilli are gradually converted into irregular, flattened projections. It is also found however, that in many other species related plasma membrane alterations are seen during early pregnancy. Molecular alterations in the membrane are also examined and although the evidence is so far limited, striking similarities are noted across species. The review also examines some new morphological studies on the alterations in the plasma membrane of uterine epithelial cells during early pregnancy and concludes that a process of plasma membrane transformation may be a common response across species.
Publisher: Wiley
Date: 05-10-2018
DOI: 10.1002/AR.23891
Abstract: The uterine surface undergoes significant remodeling, termed the "plasma membrane transformation," during pregnancy to allow for implantation of the blastocyst and formation of the placenta in viviparous amniote vertebrates. Unlike other species within the superorder Euarchontoglires, which have a hemochorial (highly invasive) placenta, kangaroo rats (Dipodomys spp.) exhibit a less invasive endotheliochorial placenta. We characterized the changes that occur to membrane molecules and the cellular ultrastructure of the uterine epithelium during early pregnancy in Merriam's kangaroo rat, Dipodomys merriami using electron microscopy and immunofluorescence microscopy. Epithelial cadherin (E-cadherin) is an adhesion protein that forms the adherens junction and is localized to the lateral plasma membrane of uterine epithelium during the nonreproductive state but localizes nonspecifically in the uterine epithelium immediately preceding implantation. Desmosomes are a type of cadherin that form junctional complexes along the lateral plasma membrane of epithelium. Dsg-2, a marker for desmosomes, is localized along the lateral plasma membrane in non-pregnant animals but redistributes to the apical region of the lateral plasma membrane during early pregnancy. The shift in desmosome and cadherin distribution before implantation suggests that there is a reduction in lateral adhesion between epithelial cells to allow for invasion by the blastocyst. Surprisingly, although Kangaroo rats form a less invasive placenta, these same changes occur during pregnancy in species with highly invasive placentation, such as the laboratory rat and human. These commonalities suggest that it is not through the retention of lateral adhesion that the blastocyst is prevented from further invasion in this rodent species. Anat Rec, 301:1928-1935, 2018. © 2018 Wiley Periodicals, Inc.
Publisher: Wiley
Date: 10-2006
DOI: 10.1002/JEZ.A.328
Abstract: Placental nutrient provision has evolved in multiple lineages of squamate reptiles and although possible structural specializations for placentotrophy have been described in a variety of species, neither the pathways nor the mechanisms of placental transfer are known. Lizards of the Australian genus Pseudemoia are placentotrophic and have elaborate placental structures that are thought to enhance nutrient transfer. The chorioallantoic placenta, which occupies the embryonic hemisphere of the egg, is regionally ersified into a large area with low epithelial height and a smaller placentome with cuboidal or columnar epithelia. Both regions are underlain by an extensive vascular bed. The abembryonic hemisphere of the egg is covered by an omphaloplacenta, which is similar to the placentome in having cuboidal or columnar epithelia but with a different embryonic vascular supply. We tested the hypothesis that embryonic epithelial cells of the placentome and the omphaloplacenta of Pseudemoia entrecasteauxii are each capable of endocytosis. Embryos (stages 33-39) with intact extraembryonic membranes were surgically removed from the uterus and incubated in a solution containing fluorescein isothiocyanate-dextran (77,000 MW). The fluorescent label was detected in the cytoplasm of scattered populations of epithelial cells in both placental regions of all embryonic stages. We conclude that both the placentome and the omphaloplacenta of P. entrecasteauxii are sites of histotrophic nutrient transport. However, there are histological and cytological differences in the embryonic epithelia of these two placental regions. The histological differences reflect differences in the evolutionary precursors of each tissue. The cytological differences likely portray different functional specializations.
Publisher: Springer Science and Business Media LLC
Date: 07-1984
DOI: 10.1007/BF00495412
Abstract: The genomic architecture of human complex diseases is thought to be attributable to single markers, polygenic components and epistatic components. No study has examined the ability of tree-based methods to detect epistasis in the presence of a polygenic signal. We sought to apply decision tree-based methods, C5.0 and logic regression, to detect epistasis under several simulated conditions, varying strength of interaction and linkage disequilibrium (LD) structure. We then applied the same methods to the phenotype of educational attainment in a large population cohort. LD pruning improved the power and reduced the type I error. C5.0 had a conservative type I error rate whereas logic regression had a type I error rate that exceeded 5%. Despite the more conservative type I error, C5.0 was observed to have higher power than logic regression across several conditions. In the presence of a polygenic signal, power was generally reduced. Applying both methods on educational attainment in a large population cohort yielded numerous interacting SNPs notably a SNP in RCAN3 which is associated with reading and spelling and a SNP in NPAS3, a neurodevelopmental gene. All methods used are implemented and freely available in R. Supplementary data are available at Bioinformatics online.
Publisher: Elsevier BV
Date: 04-1999
Publisher: Elsevier BV
Date: 05-2002
Publisher: Springer Science and Business Media LLC
Date: 17-07-2001
Abstract: BACKGROUND: Manipulation of the follicular phase uterine epithelium in women undergoing infertility treatment, has not generally shown differing morphological effects on uterine epithelial characteristics using Scanning Electron Microscopy (SEM) and resultant pregnancy rates have remained suboptimal utilising these manipulations. The present study observed manipulation of the proliferative epithelium, with either 7 or 14 days of sequential oestrogen (E) therapy followed by progesterone (P) and assessed the appearance of pinopods (now called uterodomes) for their usefulness as potential implantation markers in seven women who subsequently became pregnant. Three endometrial biopsies per patient were taken during consecutive cycles: day 19 of a natural cycle - (group 1), days 11/12 of a second cycle after 7 days E then P - (group 2), and days 19/22 of a third cycle after 14 days E then P - (group 3). Embryo transfer (ET) was performed in a subsequent long treatment cycle (as per Group 3). RESULTS: Seven pregnancies resulted in seven viable births including one twins and one miscarriage. Analysis of the in idual regimes showed 5 days of P treatment to have a higher correlation for uterodomes in all 3 cycles observed in idually. It was also observed that all 7 women demonstrated the appearance of uterodomes in at least one of their cycles. CONCLUSIONS: We conclude that manipulation of the follicular phase by shortening the period of E exposure to 7 days, does not compromise uterine epithelial morphology and we add weight to the conclusion that uterodomes indicate a receptive endometrium for implantation.
Publisher: Springer Science and Business Media LLC
Date: 10-2001
Abstract: BACKGROUND: Manipulation of the uterine epithelium utilising standard dose exogenous oestrogen (E2) and progesterone (P4) has been shown to achieve a mature secretory morphological response. However, in an in vitro fertilisation (IVF) setting, frozen embryo transfer (ET) has had a low success rate. We propose that in patients with previously failed ET attempts, the uterine epithelium can be directly visualised by biopsy and Scanning Electron Microscopy (SEM) and that with an in idualised fine tuning of the hormone supplementation regime, based on the SEM examination of sequential uterine biopsies, it is possible to provide a uterine environment conducive to successful ET. METHODS: A 47 year old women was chosen for endometrial biopsy, histopathological dating and endometrial observation utilising SEM to determine the integrity of her secretory uterine epithelium because of her age and several previously failed attempts at frozen ET. Exogenous E2 and P4 supplementation was administered in modified doses according to the SEM result, in consecutive cycles until the epithelial response appeared satisfactory for potential implantation. RESULTS: This case study demonstrates the dramatic change in epithelial characteristics that can be achieved as a response to these altered doses of E2 and P4. The uterine morphology changed from a hypotrophic to a mature, receptive epithelium such that ET resulted in the birth of healthy twin boys. CONCLUSION: The comparison between the consecutive biopsies in direct response to the SEM analysis and tailored modification of E2 and P4 dose clearly demonstrates, in this case, the effectiveness of in idual morphological monitoring to maximise the successful outcome of ET.
Publisher: Wiley
Date: 09-2018
DOI: 10.1002/AR.23895
Abstract: Mammals exhibit similar changes in uterine epithelial morphology during early pregnancy despite having a erse range of placental types. The uterine epithelium undergoes rapid morphological and molecular change ("plasma membrane transformation") during the early stages of pregnancy to allow attachment of the blastocyst. The domestic cat, Felis catus is in the order Carnivora all species within the Carnivora studied so far develop an endotheliochorial placenta during pregnancy. The endotheliochorial placental type is a common form of placental invasion in mammals. The molecular changes that allow remodeling of the uterine epithelium in preparation for implantation are unknown in most mammals but would provide us with an understanding of what molecules underpin successful implantation and pregnancy among Carnivora. We used immunofluorescence microscopy to localize the key adherens junction proteins desmoglein-2 and E-cadherin in the lateral plasma membrane of the uterine epithelium of F. catus during pregnancy. We show that redistribution of desmoglein-2 and E-cadherin likely facilitates reduction of cell-to-cell adhesion allowing for implantation of the blastocyst and formation of the placenta. The ultrastructural and molecular changes to the uterine epithelium during early pregnancy in F. catus are similar to that in species with other levels of placental invasiveness, suggesting that key molecules such as desmoglein-2 and E-cadherin are crucial to successful pregnancy across all mammals. Anat Rec, 301:1497-1505, 2018. © 2018 Wiley Periodicals, Inc.
Publisher: Elsevier BV
Date: 11-1999
Publisher: Elsevier BV
Date: 2003
Abstract: The presence and distribution pattern of Muc-1 was determined immunohistochemically in rat uterine epithelial cells and localised ultrastructurally on the plasma membrane of uterine epithelial cells. Rat uterine tissue was examined on days 1, 3 and 6 of pregnancy and it is shown to be expressed in uterine luminal epithelial cells on day 1 of pregnancy with decreasing expression towards the time of implantation on day 6. It was demonstrated ultrastructurally that Muc-1 is expressed at the external surface of the plasma membrane of uterine epithelial cells thus confirming that it is well positioned to act as an anti-adhesive molecule during the nonreceptive stage of pregnancy. Ultrastructural localisation also revealed that Muc-1 was not present on the outer surface of the plasma membrane during the receptive phase.
Publisher: Wiley
Date: 24-05-2011
DOI: 10.1002/JEZ.B.21419
Abstract: The uterine epithelium provides the interface between an embryo and its mother during pregnancy. Calcium-dependent cadherins are adherens junction proteins that undergo major shifts in the uterine epithelium to facilitate the communication between maternal cells and the embryonic milieu during implantation in mammals. They are, therefore, important in trophoblast invasion and the maintenance of pregnancy. We investigated spatiotemporal changes of cadherins throughout pregnancy in the uterine epithelium of two viviparous skinks and one oviparous population, which all exhibit a noninvasive (epitheliochorial) placenta. Cadherins were identified for the first time in squamate reptiles. In all species, cadherins are reduced in the uterine epithelium as gestation progresses, which would lessen the attachment between uterine epithelial cells and allow them to stretch to accommodate embryonic growth. Interestingly, cadherins were reduced sooner after ovulation in the oviparous species than in the viviparous species. In viviparous species, the different expression of cadherins between barren and pregnant uteri from the same mother indicates that expression of cadherins may not be driven solely by maternal hormones, but also by the presence of an embryo. The redistribution of cadherins in squamates is comparable to that of mammals, reflecting establishment of feto-maternal communication during the peri-implantation period. As there is no breaching of maternal tissue in lizards, the change in adherens junctional properties are thus not exclusive to mammals with invasive placentae, which suggests that similar molecular mechanisms regulate changes to uterine epithelia during pregnancy across placental types.
Publisher: Springer Science and Business Media LLC
Date: 03-1981
DOI: 10.1007/BF02782153
Abstract: The menstrual cycle is an essential life rhythm governed by interacting levels of progesterone, estradiol, follicular stimulating, and luteinizing hormones. To study metabolic changes, biofluids were collected at four timepoints in the menstrual cycle from 34 healthy, premenopausal women. Serum hormones, urinary luteinizing hormone and self-reported menstrual cycle timing were used for a 5-phase cycle classification. Plasma and urine were analyzed using LC-MS and GC-MS for metabolomics and lipidomics serum for clinical chemistries and plasma for B vitamins using HPLC-FLD. Of 397 metabolites and micronutrients tested, 208 were significantly (p < 0.05) changed and 71 reached the FDR 0.20 threshold showing rhythmicity in neurotransmitter precursors, glutathione metabolism, the urea cycle, 4-pyridoxic acid, and 25-OH vitamin D. In total, 39 amino acids and derivatives and 18 lipid species decreased (FDR < 0.20) in the luteal phase, possibly indicative of an anabolic state during the progesterone peak and recovery during menstruation and the follicular phase. The reduced metabolite levels observed may represent a time of vulnerability to hormone related health issues such as PMS and PMDD, in the setting of a healthy, rhythmic state. These results provide a foundation for further research on cyclic differences in nutrient-related metabolites and may form the basis of novel nutrition strategies for women.
Publisher: Elsevier BV
Date: 1989
DOI: 10.1016/S0065-1281(89)80043-1
Abstract: Clinical experience has led to a strong belief that tuberculosis is a family disease and contact examination is a sine qua non for case-finding programmes. Considerable doubts are cast on the usefulness of contact examination in tuberculosis control by the present study, which is based on a s le of an entire population rather than on family contacts of known cases only. Cases of tuberculosis occurred mostly singly in households, and contact examination could have revealed only a very small percentage of the cases in this community.Another common belief is that the prevalence of infection among children under five years of age is a good index of disease in households. In this study, however, a large proportion of households with cases of tuberculosis had no children of this age, and even in homes with a bacteriologically confirmed case, about 88% of the children did not show evidence of infection.The tuberculin reactions of infected contacts were, on the average, slightly larger than those among non-contacts. Further, the proportion of large tuberculin reactions among infected persons was found to be greater in the younger age-groups than in the older age-groups. This finding has been taken to indicate that new infection gives rise to large reactions that subsequently wane to some extent in persons not constantly exposed to infection, such as, for ex le, the members of households without cases.
Publisher: Elsevier BV
Date: 12-2000
DOI: 10.1016/S1095-6433(00)00274-9
Abstract: Mechanisms of placentation are very erse in mammals and range from types in which the uterine epithelium is breached by the implanting blastocyst to those where the epithelium remains intact. Despite these differences in mechanisms, the initial response of the plasma membrane of uterine epithelial cells is remarkably similar across mammalian species which has led to the term 'plasma membrane transformation' to encapsulate the concept of a common beginning to implantation. Membrane phenomena similar to those of mammals have now been observed in some viviparous lizards at the ultrastructural level during early pregnancy, and we propose extending the concept of 'plasma membrane transformation' to lizards with live birth.
Publisher: Elsevier BV
Date: 2000
Publisher: Rockefeller University Press
Date: 20-01-1997
Abstract: Cataract, already a major cause of visual impairment and blindness, is likely to become an increasing problem as the world population ages. In a previous study, we showed that transforming growth factor-β (TGFβ) induces rat lenses in culture to develop opacities and other changes that have many features of human subcapsular cataracts. Here we show that estrogen protects against cataract. Lenses from female rats are more resistant to TGFβ-induced cataract than those from males. Furthermore, lenses from ovariectomized females show increased sensitivity to the damaging effects of TGFβ and estrogen replacement in vivo, or exposure to estrogen in vitro, restores resistance. Sex-dependent and estrogen-related differences in susceptibility to cataract formation, consistent with a protective role for estrogen, have been noted in some epidemiological studies. The present study in the rat indicates that estrogen provides protection against cataract by countering the damaging effects of TGFβ. It also adds to an increasing body of evidence that hormone replacement therapy protects postmenopausal women against various diseases.
Publisher: Springer Science and Business Media LLC
Date: 05-2005
DOI: 10.1007/S10735-005-3802-9
Abstract: A widely accepted theory of the etiology of endometriosis is that it originates from the implantation and invasion of cells from retrograde menstruation to various sites in the body particularly the pelvic peritoneal cavity. Little is known of the function of these cells in ectopic sites. Normal endometrium was compared with endometriotic tissue using an antibody to Placental Cadherin (P Cadherin), a recently studied cadherin that is implicated in metaplasia and early neoplasia and also 8-hydroxyguanine, an indicator of oxidative DNA damage. Comparisons of endometrial tissue function were made using expression of transforming growth factor beta-1 (TGFbeta-1) and insulin-like growth factor-I (IGF-I). There was no labelling for anti-P Cadherin or anti-8-hydroxydeoxyguanosine in normal endometrium but marked labelling for both on the apical surface of the endometriotic epithelium. Studies of markers of normal endometrial function were all de-expressed in endometriosis. This study indicates that endometriosis cells are abnormal and exhibit oxidative DNA damage, metaplasia and markedly reduced function compared to normal endometrium.
Publisher: Wiley
Date: 02-04-2008
DOI: 10.1002/AR.20677
Abstract: Claudin-5, a tight junctional protein associated with ion and size selectivity, has been found in the uterus of skinks. This study has generated critical information about the molecular assembly of the tight junction at various stages of the reproductive cycle in the skink uterus. Recent studies looking at tight junctional proteins found occludin expression in the tight junction region of uterine epithelial cells in the skink uterus however, occludin did not disclose any further information about the ions and size of ions permeating across the paracellular pathway. A approximately 22-kDa claudin-5 band was detected in the uterus of the skinks present in this study and immunohistochemistry revealed that claudin-5 redistributes to the tight junction region of the lateral plasma membrane of uterine epithelial cells in late stage pregnancy/gravidity. This finding indicates that the tight junction becomes more assembled to precisely regulate ion and solute permeation in late stage pregnancy/gravidity. Claudin-5 with its functional role as a molecular sieve due to the formation of ion and size selective pores suggests that permeation of ions smaller than 0.8 kDa are restricted when claudin-5 is redistributed to the tight junction region of the later plasma membrane. This report is the first description of the molecular mechanisms that may be involved in regulating nutrient provision in the reptilian uterus.
Publisher: Wiley
Date: 08-1992
Abstract: This study investigates the interaction of hormones and the cytoskeleton within the apical cytoplasm of uterine epithelial cells of the rat. The effects of the hormones estradiol-17 beta and progesterone on the microfilament configuration were studied using myosin subfragment 1 (S1) decoration of actin microfilaments (MF) and transmission electron microscopy. In control ovariectomized animals, a sparse MF distribution was found in the apical cytoplasm underlying short microvilli with S1-decorated core MF. Hormone treatment experiments consisted of injecting ovariectomized rats with either progesterone or estradiol-17 beta. For the study of the MF configuration accompanying an apical surface primed for blastocyst receptivity, progesterone treatment was immediately followed by a single dose of estradiol-17 beta. The long, regular microvilli associated with estradiol only treatment contained bundled, decorated MF with tightly bundled rootlets. Progesterone alone produced numerous short microvilli with decorated core bundle MF and pronounced rootlets that frequently appeared splayed. The irregular microvilli and luminal surface of the uterine epithelial cells associated with the receptivity hormone sequence contained variable MF configurations, including MF bundles, networks, and areas with a "felted" appearance. The results show that the various hormone regimes produce characteristically different MF configurations and that this component of the cytoskeleton appears to be under the control of a delicate hormone balance within these uterine cells. The responses of uterine MF to specific regimes of steroid hormones used in this study are not only important for the understanding of the mechanisms at work during early pregnancy, but also contribute to the body of knowledge concerning the ways in which hormones in general effect the cytoskeleton of target cells.
Publisher: Wiley
Date: 11-1995
Abstract: Ultrastructural and light microscopic cytochemical methods were used to study the distribution and changes in distribution of alkaline phosphatase in the apical plasma membrane of rat uterine epithelial cells during different stages of early pregnancy up to the time of attachment of the blastocyst. Reaction product generated by alkaline phosphatase (AP) was located along the apical plasma membrane at each stage investigated. However, a very different organization of reaction product was observed depending on the time during early pregnancy with a continuous pattern appearing all along the microvilli on day 1. This pattern was subsequently converted into a clumped and highly 'patchy' appearance around the time of blastocyst attachment by day 6 of pregnancy. This change in pattern and distribution was only seen on the luminal epithelial cells with glandular epithelial cells and blood vessels displaying an unchanging distribution.
Publisher: Bioscientifica
Date: 12-2016
DOI: 10.1530/REP-16-0331
Abstract: Controlled ovarian hyperstimulation is an essential component of IVF techniques to ensure proliferation and development of multiple ovarian follicles, but the effects of these hormones on the endometrium are largely unknown. During normal pregnancy in rats, there are significant changes in the basal plasma membrane of uterine epithelial cells (UECs) at the time of receptivity, including loss of focal adhesions. This enables the UECs to be removed from the implantation chamber surrounding the blastocyst, thus allowing invasion into the underlying stroma. This study investigated the influence of ovarian hyperstimulation (OH) on the basal plasma membrane of UECs during early pregnancy in the rat. Immunofluorescence results demonstrate the presence of paxillin, talin, integrin β1 and phosphorylated FAK (Y397FAK) in the basal portion of UECs at the time of implantation in OH pregnancy. TEM analysis demonstrated a flattened basal lamina and the presence of focal adhesions on the basal surface at this time in OH pregnancy. Significantly low full-length paxillin, high paxillin δ and integrin β1 were seen at the time of implantation in OH compared with those in normal pregnancy. The increase in paxillin δ suggests that these cells are less mobile, whereas the increase in integrin β1 and Y397FAK suggests the retention of a stable FA complex. Taken together with the increase in morphological focal adhesions, this represents a cell type that is stable and less easily removed for blastocyst implantation. This may be one mechanism explaining lower implantation rates after fresh embryo transfers compared with frozen cycles.
Publisher: Portico
Date: 02-1997
DOI: 10.1076/EJOM.35.1.19.13061
Abstract: Transmission electron microscopy was used to investigate morphological changes in surface ultrastructure of rat uterine luminal epithelial cells and to determine how quickly and to what extent microvilli return to the apical surface after the period of uterine receptivity for blastocyst attachment. Major, observable, differences in the surface morphology of uterine epithelial cells from six groups of pregnant rats were found. On the afternoon of day 6 of pregnancy, the apical surface is typically flattened and consists mostly of irregular projections, but by the morning of day 7, short, irregular microvilli are already evident among the remaining irregular projections giving the cell surface a 'taller' profile. By the afternoon of day 7, the microvilli have increased in height and frequency. This trend continues until by day 9 of pregnancy, the apical surface bears microvilli that are long, thin, and comparatively regularly distributed. These ultrastructural alterations demonstrate that the plasma membrane transformation of early pregnancy which is essential for uterine receptivity for blastocyst attachment, is transient and is followed by the return of regular microvilli.
Publisher: Wiley
Date: 07-06-2015
DOI: 10.1002/JEZ.B.22621
Abstract: The evolution of viviparity requires the development of mechanisms that facilitate transport of respiratory gases between mother and developing embryo. Of particular importance is maternal excretion of embryonic carbon dioxide (CO2 ), which increases as the embryo grows in size during development. The carbonic anhydrases are a family of enzymes that convert CO2 to bicarbonate for transport throughout the cardiovascular system and which may also be important for CO2 transport from embryo to mother. We used immunohistochemistry to localize carbonic anhydrase II in the placental tissues of a viviparous and highly placentotrophic lizard, Pseudemoia entrecasteauxii. Carbonic anhydrase II is localized in the uterine component of the paraplacentome, presumably to facilitate transport of embryonic CO2 to the mother. Carbonic anhydrase II is also localized in both the uterine and embryonic components of the placentome, a region heavily involved in placental nutrient transport rather than respiratory gas exchange. In contrast, carbonic anhydrase II is not present in the uterine or embryonic components of the omphaloplacenta, another region responsible for nutrient transport. While carbonic anhydrase II in the paraplacentomal uterus is likely to be responsible for embryo-maternal CO2 transport, the distribution of carbonic anhydrase II throughout the placentome indicates a different function. Instead of transporting embryonic CO2 , placentomal carbonic anhydrase II appears to be responsible for transporting CO2 produced by energetically expensive nutrient transport mechanisms in both the uterus and the embryo, which implies that the mechanisms of nutrient transport in the omphaloplacenta may not be as energetically expensive.
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.ACTHIS.2015.12.004
Abstract: During early pregnancy in the rat, the luminal uterine epithelial cells (UECs) must transform to a receptive state to permit blastocyst attachment and implantation. The implantation process involves penetration of the epithelial barrier, so it is expected that the transformation of UECs includes alterations in the lateral junctional complex. Previous studies have demonstrated a deepening of the tight junction (zonula occludens) and a reduction in the number of desmosomes (macula adherens) in UECs at the time of implantation. However, the adherens junction (zonula adherens), which is primarily responsible for cell-cell adhesion, has been little studied during early pregnancy. This study investigated the adherens junction in rat UECs during the early stages of normal pregnancy and ovarian hyperstimulated (OH) pregnancy using transmission electron microscopy. The adherens junction is present in UECs at the time of fertilisation, but is lost at the time of blastocyst implantation during normal pregnancy. Interestingly, at the time of implantation after OH, adherens junctions are retained and may impede blastocyst penetration of the epithelium. The adherens junction anchors the actin-based terminal web, which is known to be disrupted in UECs during early pregnancy. However, artificial disruption of the terminal web, using cytochalasin D, did not cause removal of the adherens junction in UECs. This study revealed that adherens junction disassembly occurs during early pregnancy, but that this process does not occur during OH pregnancy. Such disassembly does not appear to depend on the disruption of the terminal web.
Publisher: Elsevier BV
Date: 2000
Abstract: In the mature rat ventral prostate, epithelial proliferation is accompanied by significant upregulation of tyrosine kinase A, alpha1B and muscarinic acetylcholine M2 receptors as well as the synaptic vesicle-associated membrane proteins synaptobrevin and SV2 as compared with immature prostate tissue. The adrenergic receptors beta1, alpha2A and alpha1 were also up-regulated and translocated in mature rat prostate tissue. Expression of the Schwann cell/axonal marker S100 remained unchanged. These results are suggestive of a marked increase in metabolic activity, calcium influx and autonomic receptor expression in the aging prostate. These changes were not accompanied by an increase in the number of axons.
Publisher: Oxford University Press (OUP)
Date: 12-2000
DOI: 10.1093/HUMREP/15.12.2451
Abstract: The plasma membrane of uterine epithelial cells is very sensitive to ovarian hormones and protrusions of the apical portion of this membrane have been used as indicators of endocrine status and preparation for implantation in the human uterus in particular. Protrusions of the apical plasma membrane were first identified in rats and mice where their established pinocytotic function gave rise to the name 'pinopod'. In humans and many other animals however, little evidence of the functional nature of such protrusions is available but what is available suggests that human 'pinopods' (useful though they are as indicators of endocrine status) might be more similar morphologically to other, larger, membrane protrusions, or apical domes, which have been shown not to be pinocytotic. Hence, I propose that these latter protrusions, including those in the human uterus, should be referred to by a term which does not imply a particular function and have settled on the name 'uterodome'.
Publisher: Elsevier BV
Date: 1987
DOI: 10.1016/S0065-1281(87)80003-X
Abstract: Recent studies suggest that innate immune responses by natural killer (NK) cells play a significant role in restricting human immunodeficiency virus type-1 (HIV-1) pathogenesis. Our aim was to characterize changes in NK cells associated with HIV-1 clade C disease progression. Here we used multiparametric flow cytometry (LSRII) to quantify phenotype and function of NK cells in a cross-sectional analysis of cryopreserved blood s les from a cohort of 41 chronically HIV-1-infected, treatment-naive adult South Africans. These in iduals ranged in disease severity from early (CD4 count >500) to advanced HIV-1 disease (CD4 count <50). We found that the frequency of NK cells expressing KIR2DL1, an inhibitory receptor, and/or KIR2DS1, an activating receptor, tended to decrease with increasing HIV-1 viral load. We also discovered a significant increase (p < 0.05) in overall NK cell degranulation with disease progression. We found that acutely activated NK cells (CD69(pos)) were deficient in NKp46 expression ex vivo. In conclusion, we observed that with viremia and advanced HIV-1 disease, activated NK cells lack NKp46 expression, and KIR2DS1(pos) and/ or KIR2DL1(pos) NK cells are reduced in frequency. These findings suggest that modulation of receptor expression on NK cells may play a role in HIV-1 pathogenesis, and provide new insights on immunological changes in advanced HIV-1 disease.
Publisher: Wiley
Date: 03-2015
DOI: 10.1002/JEZ.B.22615
Abstract: Angiogenesis (blood vessel growth), a key process of mammalian pregnancy, facilitates gas exchange and nutrient transport between the mother and the embryo and is regulated by a suite of growth factors. Vascular endothelial growth factor (VEGF) is crucial to this process in pregnant mammals and potentially pregnant squamates (lizards and snakes), as we investigate here. VEGF111 , an unusual and potent angiogenic splice variant of VEGF, increases its expression during pregnancy in the uterus of a viviparous lizard, in parallel with similar increases in uterine angiogenesis during gestation. However, we also find that VEGF111 is expressed in oviparous skinks, and is not ubiquitous among viviparous skinks. Thus, different mechanisms of uterine angiogenesis during pregnancy may evolve concurrent with viviparity in different lizard lineages.
Publisher: Springer Science and Business Media LLC
Date: 1998
Abstract: In this study, the potential of biogenic zinc oxide nanoparticles (ZnO NPs) in the removal of alizarin yellow R (AY) from aqueous solutions by photocatalytic degradation, as well as adsorption, was investigated. The synthesized ZnO NPs were prepared by the simple wet-combustion method using the plant extract of
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/RD12313
Abstract: The glycocalyx of the uterine luminal epithelium in the rat undergoes considerable reduction before implantation. In particular, the reduction of some mucins is necessary to facilitate blastocyst adhesion and subsequent implantation. The present study investigated the localisation, abundance and hormonal control of two mucin proteins, Muc13 and Muc15, in rat uterine epithelial cells during early pregnancy to determine whether they are likely to play a role in uterine receptivity for implantation. Muc13 and Muc15 are localised to the uterine luminal epithelium but show a presence and an absence, respectively, at the apical cell surface at the time of implantation. This localisation corresponds to changes in the molecular weights of Muc13 and Muc15, as shown with western blotting analysis. Furthermore, the localisation of Muc13 and Muc15 was shown to be controlled by the ovarian hormones, oestrogen and progesterone, and they were also localised in preimplantation rat blastocysts. Our results suggest that Muc15 may operate in an anti-adhesive capacity to prevent implantation while Muc13 potentially functions in either an adhesive or cell-signalling role in the events of implantation.
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/RD12396
Abstract: Controlled ovarian hyperstimulation is commonly used in fertility treatment. Evidence suggests that this could alter the endometrial environment and influence implantation rate. However, the mechanisms underlying this disruption are unknown. A recently developed rat ovarian hyperstimulation (OH) model found alterations in the localisation and expression of several molecules associated with implantation, as well as an increase in luminal fluid at the time of implantation. The present study investigated the effects of OH in rats on the expression of fluid-transporting molecules aquaporin 5 (AQP5) and claudin 4. The expression of these proteins was investigated in uterine luminal epithelial cells of rats undergoing OH and compared with normal pregnancy. There was a significant increase in AQP5 protein in OH rats at the time of implantation, along with a loss of the mesometrial staining gradient, which is thought to contribute to implantation position. At the same time, there was a significant decrease in claudin 4 protein. These results suggest that OH in rats causes a dysregulation in uterine fluid dynamics through modifications to fluid-transporting molecules, resulting in an unfavourable implantation environment for the blastocyst.
Publisher: Wiley
Date: 2001
DOI: 10.1002/AR.1124
Abstract: Light and electron microscopy was used to examine the apical luminal epithelial surface of the uterus at preovulatory and preimplantation stages in the marmoset monkey. Luminal surface charge, detected by cationic ferritin staining, progressively decreased from preovulation to day 11 of pregnancy. The smooth, regular apical plasma membrane at preovulatory stages was in contrast to the convoluted, irregular surface observed during early pregnancy, especially at 1 day before blastocyst implantation. Profiles of microvilli were also altered, becoming thicker and more irregular during early pregnancy. Within the epithelial cell body, cyclic morphologic changes were seen, largely in association with secretory organelles. Giant phagocytic bodies were prominent at all stages examined, although their composition and intensity of staining varied throughout the cycle. Weak to moderate estrogen alpha and progesterone receptor immunostaining of the luminal epithelium was found during preovulatory and early pregnancy stages. This study describes complex cyclic changes in the morphology and biochemical make-up of the uterine luminal epithelial surface in a New World monkey in preparation for blastocyst attachment.
Publisher: Wiley
Date: 2018
DOI: 10.1002/MRD.22940
Abstract: In mammalian pregnancy, the uterus is remodeled to become receptive to embryonic implantation. Since non-invasive placentation in marsupials is likely derived from invasive placentation, and is underpinned by intra-uterine conflict between mother and embryo, species with non-invasive placentation may employ a variety of molecular mechanisms to maintain an intact uterine epithelium and to prevent embryonic invasion. Identifying such modifications to the uterine epithelium of marsupial species with non-invasive placentation is key to understanding how conflict is mediated during pregnancy in different mammalian groups. Desmoglein-2, involved in maintaining lateral cell-cell adhesion of the uterine epithelium, is redistributed before implantation to facilitate embryo invasion in mammals with invasive placentation. We identified localization patterns of this cell adhesion molecule throughout pregnancy in two marsupial species with non-invasive placentation, the tammar wallaby (Macropus eugenii Macropodidae), and the brushtail possum (Trichosurus vulpecula Phalangeridae). Interestingly, Desmoglein-2 redistribution also occurs in both M. eugenii and T. vulpecula, suggesting that cell adhesion, and thus integrity of the uterine epithelium, is reduced during implantation regardless of placental type, and may be an important component of uterine remodeling. Desmoglein-2 also localizes to the mesenchymal stromal cells of M. eugenii and to epithelial cell nuclei in T. vulpecula, suggesting its involvement in cellular processes that are independent of adhesion and may compensate for reduced lateral adhesion in the uterine epithelium. We conclude that non-invasive placentation in marsupials involves erse and complementary strategies to maintain an intact epithelial barrier.
Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: Expression of each of the purinergic receptor subtypes (P2X7) was studied by immunohistochemical localization in the apical, lateral and basal plasma membranes of rat uterine epithelial cells during early pregnancy to the time of implantation on Day 6. Labelling for each P2X subtype was seen in the apical, lateral and basal compartments on Days 1 and 3, except for P2X2 which was only observed in the basement membrane. The P2X5 signal was similar in temporal and spatial expression to the other subtypes, but with a greatly reduced intensity. At the time of implantation on Day 6, this pattern altered dramatically. Apical expression markedly increased for most subtypes while the lateral and basal signals were markedly reduced. The exceptions to this pattern were P2X2, which displayed both a strong basal and apical label, and P2X4 which became de-expressed in all areas. We propose that the changing spatial and temporal expression of the P2X receptors is a significant factor in the regulation of events during early pregnancy. They are expressed in the same location as remodelling. apoptosis, and protein activation events prior to implantation on Day 6. These observations suggest an up-regulation of calcium-mediated events, including cytoskeletal alterations, a decrease in luminal pH and transmembrane molecule activation.
Publisher: Wiley
Date: 09-2001
Publisher: Springer Science and Business Media LLC
Date: 23-11-2013
DOI: 10.1007/S00418-013-1165-Y
Abstract: The present study investigated the role of calpain 2 in rat uterine luminal epithelial cells during early pregnancy. Calpain 2 is an intracellular calcium-dependent proteolytic enzyme which cleaves numerous focal adhesion proteins. Calpain 2 was concentrated along the basal cell surface of uterine luminal epithelial cells at the predicted site of focal adhesions on day 1 of pregnancy and remained unchanged at the time of implantation as observed by immunofluorescence microscopy. However, Western blotting analysis showed a marked increase in the active form and a significant decrease in the latent form of calpain 2 at the time of implantation. The increase in calpain 2 activity coincides with the disassembly of focal adhesion proteins, talin, paxillin, integrin β1 and β3 from the site of focal adhesions. Intraperitoneal injection of calpain inhibitor, calpain inhibitor l (ALLN), significantly reduced the number of implantation sites, implying that calpain 2 plays an important role in implantation. The present study suggests a role for calpain 2 in the disassembly of focal adhesions, which has been previously shown to play a key role in uterine receptivity for implantation.
Publisher: Elsevier BV
Date: 04-1999
DOI: 10.1016/S0945-053X(99)00006-2
Abstract: Chondroitin sulfate proteoglycan (CSPG) and heparan sulfate proteoglycan (HSPG) are extracellular matrix proteins that regulate cell adhesion, growth, migration, differentiation and gene expression in many systems. In this study, stromal CSPG label was intense within 10 microm of the uterine lumen. From that distance to the myometrium, CSPG was de-expressed. From the time of implantation on Day 6, this pattern was reversed. CSPG was de-expressed from the uterine epithelium to a distance of approximately 10 microm from the uterine lumen. From that region to the myometrium, labeling was homogeneously intense. This finding suggests that CSPG may inhibit attachment and implantation. Heparan sulfate core proteoglycan (perlecan) was increasingly expressed in the uterine epithelium from the time of implantation, commencing in the basement membrane on Day 6 and extending to the apical epithelium and lateral plasma membranes by Day 7. Perlecan thus appears to facilitate trophoblast attachment and implantation. We propose that attachment and implantation is regulated, at least in part, by the selective and sequential expression of CSPG and perlecan.
Publisher: Informa UK Limited
Date: 10-2015
Publisher: Springer Science and Business Media LLC
Date: 2004
Publisher: Wiley
Date: 23-04-2010
DOI: 10.1002/AR.21052
Abstract: The evolution of viviparity requires modifications to multiple integrated physiological features to support embryonic development during pregnancy. Embryonic growth during pregnancy is dependent upon the capacity of the uterine vascular system to satisfy increasing embryonic oxygen demand throughout gestation. We tested the hypothesis that total surface area of uterine blood vessels increases in concert with embryonic growth, and hence its oxygen demand, during gestation. We used immunofluorescence and laser-scanning confocal microscopy to quantify uterine microvascular density and morphology during gestation in the oviparous skink Ctenotus taeniolatus and in Saiphos equalis, a skink species with prolonged egg retention. For C. taeniolatus, vessel density (Nv) and vessel length-density (Lv) in the embryonic hemisphere of the uterus is 23% and 17% less, respectively, than that of S. equalis and vascular surface-area does not differ as a function of embryo stage. For S. equalis, overall Nv, Lv, and vessel diameter (Dv), does not change during the first half of gestation but increases by 36% (Nv), 44% (Lv), and 60% (Dv) by near-term embryo stages late in gestation. The chorioallantoic membrane of S. equalis increases in absolute size but vascular density does not differ as a function of embryo stage. The marked increase in uterine vascular density during late gestation coincides with the phase of rapid growth in embryo mass and concomitant increase in metabolic rate. Expansion of the uterine vascular bed in concert with embryo size and metabolism is likely to be an important transitional step in the evolution of viviparity.
Publisher: Springer Science and Business Media LLC
Date: 03-1982
DOI: 10.1007/BF00305552
Publisher: Wiley
Date: 1992
DOI: 10.1016/0248-4900(92)90025-V
Abstract: Actin filaments were identified in the epithelial cells of rat uterus following detergent extraction and decoration of microfilaments (MF) with myosin subfragment 1 (S1). MF connections with cytoplasmic organelles and the apical plasma membrane are also described. Transmission electron microscopy revealed that the regular microvilli of non-pregnant, oestrous animals contain several decorated MF with rootlets descending into a densely filamentous terminal web. Following mating, the actin cytoskeleton was examined on days 1, 3 and 6 of pregnancy. In this period, the irregular projections that replace MV assumed an underlying, dense network of decorated MF, whilst smoother surfaces displayed few cytoplasmic filaments. At the time of blastocyst implantation, a structured terminal web was no longer present. Structural details were revealed concerning the contents of large, bleb-like projections found on the apical surface.
Publisher: Elsevier BV
Date: 2002
Abstract: Immunohistochemical staining of 5 cytoskeletal proteins (actin, alpha-actinin, gelsolin, plectin and plakoglobin) was used to investigate changes in distribution patterns of these proteins after the period of uterine receptivity for blastocyst implantation in the rat. Actin was found throughout the cytoplasm but it was concentrated along the apical plasma membrane on day 1 of pregnancy, decreased by day 6 and then increased again at day 9. Alpha-actinin and gelsolin were localized in distinctive bands along the apical plasma membrane at day 6 of pregnancy but became diffusely distributed at day 9. Plectin was localized along the apical and basal plasma membranes at day 6 but in higher amounts apically and at day 9, it was concentrated in apical and basal zones in the cells. Plakoglobin was found along the lateral and basal membranes with increased intensity along the apical third of the lateral plasma membrane from day 6 to day 9 of pregnancy. These results show that all 5 cytoskeletal proteins redistributed after the period of uterine receptivity: some exhibited a similar pattern of labelling to that found during the prereceptive state, whereas others only partially returned to the pre-receptive state. This change in distribution patterns may reflect differences in the epithelial barrier function before and after the period of receptivity.
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/RD08148
Abstract: During early pregnancy in rodents, invasion of the blastocyst into the endometrial decidual cells is accompanied by the removal of uterine epithelial cells around the implantation sites. The present study investigated the distribution and expression of two focal adhesion proteins, namely talin and paxillin, in rat uterine epithelial cells during early pregnancy and their role in the loss of these cells at the time of implantation. A major distributional change of talin and paxillin was demonstrated in uterine epithelial cells during early pregnancy. From a highly concentrated expression along the basal cell surface on Day 1 of pregnancy, talin and paxillin were lost from the basal cell surface at the time of implantation. There was also a corresponding statistically significant decrease in paxillin seen through western blotting analysis. Together, these observations suggest that uterine epithelial cells are less adherent to the underlying basal lamina due to the disassembly of talin and paxillin from focal adhesions, facilitating removal of these cells at the time of implantation. This phenomenon was restricted to the period of receptivity because talin and paxillin reappeared along the basal cell surface soon after implantation.
Publisher: Elsevier BV
Date: 09-2005
DOI: 10.1016/J.CBPC.2005.07.001
Abstract: The gene HoxA10 and its protein product are essential for the formation of the extensions of the plasma membrane called uterodomes or pinopods in mammalian uterine epithelia. In mice, the presence of the HoxA10 protein and uterodomes is needed for uterine receptivity to blastocyst implantation. The viviparous lizard Eul rus tympanum displays uterodomes whereas the oviparous lizard L ropholis guichenoti does not. To explore the theory that HoxA10 is involved in the formation of uterodomes we investigated whether HoxA10 immunoreactive proteins were present in both species during their reproductive cycles. Oviduct proteins from vitellogenic, gravid or non-reproductive L. guichenoti (n=19) and E. tympanum (n=28) were separated by electrophoresis and analysed by Western blot and specific antibodies to HoxA10. E. tympanum displayed HoxA10 immunoreactive bands at 59 and 63 kDa in 20 out of the 28 s les. All of the L. guichenoti s les displayed HoxA10 immunoreactive bands, 18 had bands at 59 and 64 kDa and 1 animal had a single band at 59 kDa. There were no significant differences in the level of HoxA10 immunoreactivity between the different stages of reproductive cycle in either species. The different molecular mass of the larger band in L. guichenoti (64 kDa) compared to E. tympanum (63 kDa) indicates that the two lizards express different isoforms of the HoxA10-like proteins and it will be interesting in future studies to determine whether there are differences in the biological activity of the proteins that regulate different physiological functions in the uterus of viviparous and oviparous lizards.
Publisher: The Company of Biologists
Date: 10-2010
DOI: 10.1242/JEB.046862
Abstract: We have discovered a modification of the uterus that appears to facilitate maternal-fetal communication during pregnancy in the scincid lizard Eul rus quoyii. A vessel-dense elliptical area (VDE) on the mesometrial side of the uterus expands as the embryo grows, providing a large vascular area for physiological exchange between mother and embryo. The VDE is already developed in females with newly ovulated eggs, and is situated directly adjacent to the chorioallantois of the embryo when it develops. It is likely that signals from the early developing embryo determine the position of the VDE, as the VDE is off-centre in cases where the embryo sits obliquely in the uterus. The VDE is not a modification of the uterus over the entire chorioallantoic placenta, as the VDE is smaller than the chorioallantois after embryonic stage 33, but expansion of the VDE and growth of the chorioallantois during pregnancy are strongly correlated. The expansion of the VDE is also strongly correlated with embryonic growth and increasing embryonic oxygen demand (). We propose that angiogenic stimuli are exchanged between the VDE and the chorioallantois in E. quoyii, allowing the simultaneous growth of both tissues.
Publisher: Bioscientifica
Date: 05-1982
Abstract: The vascular corrosion casting/scanning electron microscope technique was used to investigate differential uterine elongation at the time of implantation in the rat. Casts were made on Days 4, 5 and 6 of pregnancy (Day 1 = the day of finding spermatozoa in the vaginal smear), implantation sites being identified by an i.v. injection of Evans' blue before casting. By Day 6 the endometrial blood vessel network within each implantation site was widely spaced compared with that in other regions. We suggest that blastocyst spacing is achieved, in part, by differential uterine elongation at the implantation sites, apparently as a result of tissue hydration subsequent to increased vascular permeability.
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/RD17530
Abstract: The epithelium of the uterine lumen is the first point of contact with the blastocyst before implantation. To facilitate pregnancy, these uterine epithelial cells (UECs) undergo morphological changes specific to the receptive uterus. These changes include basal, lateral and apical alterations in the plasma membrane of UECs. This study looked at the cytoskeletal and focal adhesion-associated proteins, lasp-1 and palladin, in the uterus during early pregnancy in the rat. Two palladin isoforms, 140 kDa and 90 kDa, were analysed, with the migration-associated 140-kDa isoform increasing significantly at the time of implantation when compared with the time of fertilisation. Lasp-1 was similarly increased at this time, whilst also being located predominantly apically and laterally in the UECs, suggesting a role in the initial contact between the UECs and the blastocyst. This is the first study to investigate palladin and lasp-1 in the uterine luminal epithelium and suggests an importance for these cytoskeletal proteins in the morphological changes the UECs undergo for pregnancy to occur.
Publisher: Elsevier BV
Date: 1990
Publisher: Elsevier BV
Date: 12-1999
DOI: 10.1016/S0945-053X(99)00051-7
Abstract: We have studied the simultaneous expression of insulin-like growth factor I (IGF-I) and insulin-like growth factor II (IGF-II) in the uterine epithelium and extracellular matrix during the time of trophoblast attachment and implantation. These studies reveal that IGF-I and IGF-II display different spatial and temporal patterns of expression during early pregnancy, and suggest a role for them in the process of attachment and implantation. Specifically, IGF-I is strongly expressed in the basal lamina which is the site of trophoblast invasion into the maternal stroma, and also in the apical epithelium, the site of initial trophoblast attachment. IGF-II is expressed to a lesser extent in the basal lamina, lateral plasma membranes and apical epithelium on day 3 but is only prominent apically at the time of implantation, suggesting a role in attachment.
Publisher: Oxford University Press (OUP)
Date: 08-2000
DOI: 10.1093/HUMREP/15.SUPPL_3.182
Abstract: Junctions in the plasma membrane of uterine epithelial cells as well as between these cells and their extracellular environment are examined in this review to see if a synthetic appreciation of their role can be gained from the disparate evidence presently available. Major changes in most junctional components are noted during early pregnancy and the role of progesterone and oestrogen in promoting these changes is examined. In particular it is noted that while tight junctions become deeper and morphologically 'tighter' towards the time of implantation, other basolateral junctional structures as well as their cytoskeletal associations are absent. These junctional alterations are part of the 'plasma membrane transformation' of early pregnancy and allow the conclusion that while paracellular permeability is reduced by the time of blastocyst attachment, the epithelial cells are paradoxically less firmly attached to each other, and to their extracellular environment.
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.CBPA.2007.09.014
Abstract: Calcium ATPase (Ca2+-ATPase) is a key enzyme that participates in the translocation of calcium in the uterus of oviparous amniotes during eggshell formation. We used Western blot and indirect immunofluorescence microscopy to determine expression and localisation of uterine Ca2+-ATPase during the reproductive cycle of king quail and zebra finch. The pattern of Ca2+-ATPase expression and localisation during the reproductive cycle was similar for both species. Immunoblots of uterine extracts from quail and finch indicated that Ca2+-ATPase expression is reduced in non-reproductive compared to reproductive females. Similarly, in non-reproductive females, weak apical immunofluorescent staining of Ca2+-ATPase is localised to epithelial cells in a small number of uterine tubular glands. A large increase in apical immunofluorescent staining of tubular gland epithelia occurs in both vitellogenic and reproductive females. The presence of Ca2+-ATPase on the apical surface of tubular gland epithelial cells suggests that the enzyme is involved in the translocation of calcium out of the tubular gland epithelia and into the concentrated fluid of the uterine lumen. Presence of Ca2+-ATPase in vitellogenic females indicates that the enzyme is expressed prior to the time of ovulation and eggshell calcification.
Publisher: Wiley
Date: 20-10-2015
DOI: 10.1002/JMOR.20333
Abstract: Attachment of the blastocyst and formation of the placenta during pregnancy is dependent on structural and cellular changes occurring in the uterine epithelium and in particular to the plasma membrane of these uterine cells. Desmosome expression decreases during pregnancy in eutherians and some squamates, presumably allowing for remodeling of the uterine epithelium and invasion of the trophoblast during implantation. Marsupials are a distinct mammalian amniote lineage of viviparity, with a short implantation or attachment period and varying levels of invasive placentation. To test the generality of changes to the uterine epithelium during pregnancy across mammals, we characterized the distribution of desmosomes in the uterine epithelial cells of a marsupial, Sminthopsis crassicaudata, using electron microscopy and immunohistochemistry. The absolute number of desmosomes along the lateral plasma membrane decreases during pregnancy and desmosomes are redistributed towards the apical region of the lateral plasma membrane as pregnancy proceeds, similar to what occurs during pregnancy in eutherian mammals. Despite the lower level of maternal investment in pregnancy and the noninvasive structure of fetal membranes in marsupials there are similarities in number and redistribution of desmosomes along the plasma membrane and changes to the morphology of the uterine epithelial cells suggesting that similar plasma membrane changes occur across all lineages of amniote vertebrates.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.YEXCR.2019.111727
Abstract: Following mating, leukocytes are recruited to the uterine epithelium where they phagocytose spermatozoa and mediate maternal immune tolerance as well as a mild inflammatory response. In this ultrastructural study we utilised array tomography, a high-resolution volume scanning electron microscopy approach to 3D reconstruct the cellular relationships formed by leukocytes recruited to the luminal uterine epithelium 12 h post-mating in the rat. We report that following mating, neutrophils and macrophages are internalised by the luminal uterine epithelium, with multiple leukocytes internalised via contortion through a small tunnel in the apical membrane into a large membrane-bound vacuole within the cytoplasm of luminal uterine epithelial cells (UECs). Once internalised within the UECs, recruited leukocytes appear to phagocytose material within the membrane-bound vacuole and most ultimately undergo a specialised cell death, including vacuolisation and loss of membrane integrity. As these observations involve ultrastructurally normal leukocytic cells internalised within non-phagocytic epithelial cells, these observations are consistent with the formation of cell-in-cell structures via entosis, rather than phagocytic engulfment by UECs. Although cell-in-cell structures have been reported in normal and pathological conditions elsewhere, the data collected herein represents the first evidence of the formation of cell-in-cell structures within the uterine epithelium as a novel component of the maternal inflammatory response to mating.
Publisher: Springer Science and Business Media LLC
Date: 2002
Abstract: The calcium-activated cell-adhesion proteins tenascin, E-cadherin and the purinergic (P2X) calcium channel receptors are expressed in an identical spatial and temporal pattern in uterine epithelium in the rat during implantation. On Day 1 of pregnancy (estrous), a diffuse cytoplasmic and specific basement membrane label for each of the proteins was observed throughout the uterine epithelium. On Day 3 of pregnancy, a specific and prominent lateral plasma membrane label for each protein was seen. At the time of implantation on Day 6, an additional and significant increase in the label for each was observed on the apical epithelium. At this time, the label for tenascin in the apical epithelium was increased 2.1-fold (p < 0.0004), that of E-cadherin was increased 2.5-fold (p < 0.0001) and the P2X receptor label was increased 2.0-fold (p < 0.0001). These observations suggest a major role for the calcium-activated adhesion proteins tenascin and E-cadherin in attachment and implantation, with ionic calcium for protein activation possibly provided by the P2X calcium channels. These events occur along the entire length of the uterine epithelium in preparation for blastocyst adhesion.
Publisher: Springer Science and Business Media LLC
Date: 05-12-2018
DOI: 10.1007/S00418-018-1761-Y
Abstract: During early pregnancy, the uterine luminal epithelial cells (UECs) and endometrial stromal cells (ESCs) undergo morphological changes to enable blastocyst implantation. The present study investigates, for the first time, the cytoskeletal-associated proteins and α-actinin superfamily members, α-parvin and β-parvin, during early pregnancy in the rat uterus. These two PARVA proteins are involved in cell adhesion, morphological changes and regulation of other cytoskeletal proteins, through binding with proteins such as actin and integrin-linked kinase. α-parvin is present in UECs at fertilisation and significantly decreases by the time of implantation. β-parvin acts in opposition significantly increasing in both UECs and ESCs at the time of implantation, suggesting a role in the process of decidualisation. Additionally, the presence of a serine-8 residue-phosphorylated α-parvin, which is associated with cell morphology changes, was found in the nuclear region of both UECs and ESCs during implantation and decidualisation. We also show that the presence of both β-parvin and phosphorylated α-parvin in ESCs is dependent on decidualisation occurring. This study demonstrates that the changing balance and localisation of the two PARVA proteins are dependent on the time of uterine receptivity, suggesting a co-dependent role in the cytoskeletal re-organisation crucial to the changing conditions necessary for implantation and decidualisation.
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.MICRON.2016.02.010
Abstract: In order to perform correlative light and electron microscopy (CLEM) more precisely, we have modified existing specimen preparation protocols allowing fluorescence retention within embedded and sectioned tissue, facilitating direct observation across length scales. We detail a protocol which provides a precise correlation accuracy using accessible techniques in biological specimen preparation. By combining a pre-embedding uranyl acetate staining step with the progressive lowering of temperature (PLT) technique, a methacrylate embedded tissue specimen is ultrathin sectioned and mounted onto a TEM finder grid for immediate viewing in the confocal and electron microscope. In this study, the protocol is applied to rat uterine epithelial cells in vivo during early pregnancy. Correlative overlay data was used to track changes in filamentous actin that occurs in these cells from fertilization (Day 1) to implantation on Day 6 as part of the plasma membrane transformation, a process essential in the development of uterine receptivity in the rat. CLEM confirmed that the actin cytoskeleton is disrupted as apical microvilli are progressively lost toward implantation, and revealed the thick and continuous terminal web is replaced by a thinner and irregular actin band, with in idually distinguishable filaments connecting actin meshworks which correspond with remaining plasma membrane protrusions.
Publisher: Elsevier BV
Date: 1989
Publisher: Wiley
Date: 2007
DOI: 10.1002/JMOR.10522
Abstract: Distinct differences in epithelial response between oviparous and viviparous species of skinks led us to investigate morphological differences in the uterus of a species that exhibits bi-modal reproduction and that may indicate specialities for the different requirements of viviparity and oviparity. The uteri of females from oviparous and viviparous populations of the Australian scincid lizard, Lerista bougainvillii, are described in detail to determine whether the occurrence of uterodomes and the plasma membrane transformation, found in other viviparous species but not oviparous species, are indeed features characteristic of viviparity. Oviductal tissue was dissected at three different stages of reproduction from lizards from both populations: 1) vitellogenic, 2) gravid or pregnant, and 3) non-reproductive or quiescent. Tissue was observed using both scanning and transmission electron microscopy. Lerista bougainvillii has a simple placental morphology with simple squamous epithelium. In contrast to mammals and other viviparous skinks, L. bougainvillii does not undergo a plasma membrane transformation, but early signs of placentation in viviparous in iduals are indicated by changes in the uterine surface that occur largely after embryonic stage 30. There are no obvious cellular differences between the uteri of oviparous and viviparous L. bougainvillii at the non-reproductive and vitellogenic phase of the reproductive cycle but throughout gestation/gravidity, the cellular differences that could be related to the changing functional requirements with the retention of the viviparous embryo, became apparent. A plasma membrane transformation with ensuing uterodome formation does not occur, which suggests that these more sophisticated changes are a feature of advanced placental development in reptiles.
Publisher: Springer Science and Business Media LLC
Date: 1984
DOI: 10.1007/BF00492770
Abstract: Previously, our group isolated and evaluated anti-ricin single domain antibodies (sdAbs) derived from llamas, engineered them to further increase their thermal stability, and utilized them for the development of sensitive immunoassays. In work focused on the development of therapeutics, Vance et al. 2013 described anti-ricin sdAbs derived from alpacas. Herein, we evaluated the utility of selected alpaca-derived anti-ricin sdAbs for detection applications, and engineered an alpaca-derived sdAb to increase its melting temperature, providing a highly thermal stable reagent for use in ricin detection. Four of the alpaca-derived anti-ricin A-chain sdAbs were produced and characterized. All four bound to epitopes that overlapped with our previously described llama sdAbs. One alpaca sdAb, F6, was found to possess both a high melting temperature (73 °C) and to work optimally with a thermally stable llama anti-ricin sdAb in sandwich assays for ricin detection. We employed a combination of consensus sequence mutagenesis and the addition of a non-canonical disulfide bond to further enhance the thermal stability of F6 to 85 °C. It is advantageous to have a choice of recognition reagents when developing assays. This work resulted in defining an additional pair of highly thermal stable sdAbs for the sensitive detection of ricin.
Publisher: Elsevier BV
Date: 04-2002
DOI: 10.1016/S1096-4959(02)00013-1
Abstract: Historically, Australia has been important in the study of, and the development of hypotheses aimed at understanding, the evolution of viviparity in amniote vertebrates. Part of the importance of Australia in the field results from a rich fauna of skinks, including one of the broadest ranges of ersity of placental structures within one geographic region. During the last decade, we have focussed our studies on one lineage, the Eugongylus group of skinks of the subfamily Lygosominae because it contains oviparous species and some that exhibit complex placentae. Our specific objective has been to attempt to understand the fundamental steps required when viviparity, and ultimately complex placentae, evolve from oviparous ancestors. We have taken a three-prong approach: (1) detailed study of the morphology and ontogeny of the placentae of key species at the light microscope level (2) study of changes in the uterus associated with pregnancy, or the plasma membrane transformation and (3) measures of the net exchange of nutrients across the placenta or eggshell of key species. In turn, we have found that: (1) details of the morphology and ontogeny of placentae are more complex that originally envisaged, and that the early conclusions about a sequence in the evolution of complex placentae was naïve (2) a plasma membrane transformation occurs in viviparous, but not oviparous lizards, and thus may be a fundamental feature of the evolution of viviparity in amniotes and (3) species with more complex chorioallantoic placentae tend to transport more nutrients across the placenta during pregnancy than those with simpler chorioallantoic placentae but, because the correlation is not tight, the importance of the omphaloplacenta in transporting nutrients may have been overlooked. Also, the composition of yolk of highly matrotrophic species is broadly similar, but not identical, to the yolk of oviparous species. Some of the interpretation of our data within the context of our specific objective is not yet possible, pending the publication of a robust phylogeny of Eugongylus group skinks. Once such a phylogeny is available, we are in a position to propose specific hypotheses about the evolution of viviparity that can be tested using another lineage of amniotes, possibly Mabuya group skinks.
Publisher: Springer Science and Business Media LLC
Date: 06-2001
Publisher: Wiley
Date: 03-1998
Abstract: Immunohistochemistry was used to investigate the involvement of the actin-associated binding proteins, tropomyosin, alpha-actinin and gelsolin with the formation of the decidual cell reaction during early pregnancy in the rat. Tropomyosin was present in the uterine myometrium, but absent from the both decidual and non-decidual stromal cells. alpha-Actinin was absent from non-decidual stromal cells, but present in decidual cells. Gelsolin was present in non-decidual cells close to the uterine stroma as well as in transformed decidual cells. Both gelsolin and alpha-actinin were concentrated around the periphery of the cell. It is proposed that these actin-binding proteins may be involved with the cellular transformations associated with decidualization.
Publisher: Oxford University Press (OUP)
Date: 08-2002
Publisher: Portico
Date: 02-1998
DOI: 10.1076/EJOM.36.1.49.9025
Abstract: The presence and distribution of the carbohydrate antigen CD15 in rat uterine epithelial cells was determined using immunohistochemical localisation at both light and electron microscopical levels. Rat uterine tissue was examined on days 1, 3 and 6 of pregnancy and it was found that expression of CD15 was highly stage specific with negligible detection on days 1 or 3 of pregnancy but very strong expression at both light and electron microscopic levels on day 6. Electron microscopy using ferritin as marker revealed expression in the glycocalyx of the plasma membrane of uterine epithelial cells. This strongly stage-specific expression of CD15 and the extracellular surface localisation suggests an important role for this antigen during the early stages of pregnancy in the rat and implicates the molecule in attachment to the uterine epithelium.
Publisher: Springer Science and Business Media LLC
Date: 21-11-2012
DOI: 10.1007/S00418-012-1052-Y
Abstract: The non-receptive uterine luminal epithelium forms an intact polarised epithelial barrier that is refractory to blastocyst invasion. During implantation, organised dismantling of this barrier leads to a receptive state promoting blastocyst attachment. Claudins are tight junction proteins that increase in the uterine epithelium at the time of implantation. Claudin 7 is a member of this family but demonstrates a basolateral localisation pattern that is distinct from other claudins. The present study investigated the localisation, abundance and hormonal regulation of claudin 7 to elucidate a role for the protein during implantation. The results showed that claudin 7 demonstrates a distinct basal and lateral localisation in the uterine luminal and glandular epithelium throughout early pregnancy. On day 1, claudin 7 is abundantly present in response to ovarian estrogen. At the time of implantation, claudin 7 decreases in abundance. This decrease is not dependent on blastocyst presence, as shown by results in pseudopregnant animals. We propose that claudin 7 mediates intercellular adhesions in the uterine epithelium and also may be responsible for stabilising adhesion proteins at the basolateral cell surface. Thus, claudin 7 may function under the maintenance of the uterine luminal epithelial barrier, in the non-receptive state preventing implantation from occurring.
Publisher: Springer Science and Business Media LLC
Date: 25-01-2021
DOI: 10.1038/S42003-020-01631-8
Abstract: Dual Bcl-2/Bcl-x L inhibitors are expected to deliver therapeutic benefit in many haematological and solid malignancies, however, their use is limited by tolerability issues. AZD4320, a potent dual Bcl-2/Bcl-x L inhibitor, has shown good efficacy however had dose limiting cardiovascular toxicity in preclinical species, coupled with challenging physicochemical properties, which prevented its clinical development. Here, we describe the design and development of AZD0466, a drug-dendrimer conjugate, where AZD4320 is chemically conjugated to a PEGylated poly-lysine dendrimer. Mathematical modelling was employed to determine the optimal release rate of the drug from the dendrimer for maximal therapeutic index in terms of preclinical anti-tumour efficacy and cardiovascular tolerability. The optimised candidate is shown to be efficacious and better tolerated in preclinical models compared with AZD4320 alone. The AZD4320-dendrimer conjugate (AZD0466) identified, through mathematical modelling, has resulted in an improved therapeutic index and thus enabled progression of this promising dual Bcl-2/Bcl-x L inhibitor into clinical development.
Publisher: Wiley
Date: 2007
DOI: 10.1002/JMOR.10520
Abstract: We used scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to describe the complete ontogeny of simple placentation and the development of both the yolk sac placentae and chorioallantoic placentae from nonreproductive through postparturition phases in the maternal uterine epithelium of the Australian skink, Eul rus tympanum. We chose E. tympanum, a species with a simple, noninvasive placenta, and which we know, has little net nutrient uptake during gestation to develop hypotheses about placental function and to identify any difference between the oviparous and viviparous conditions. Placental differentiation into the chorioallantoic placenta and yolk sac placenta occurs from embryonic Stage 29 both placentae are simple structures without specialized features for materno/fetal connection. The uterine epithelial cells are not squamous as previously described by Claire Weekes, but are columnar, becoming increasingly attenuated because of the pressure of the impinging underlying capillaries as gestation progresses. When the females are nonreproductive, the luminal uterine surface is flat and the microvillous cells that contain electron-dense vesicles partly obscure the ciliated cells. As vitellogenesis progresses, the microvillous cells are less hypertrophied than in nonreproductive females. After ovulation and fertilization, there is no regional differentiation of the uterine epithelium around the circumference of the egg. The first differentiation, associated with the chorioallantoic placentae and yolk sac placentae, occurs at embryonic Stage 29 and continues through to Stage 39. As gestation proceeds, the uterine chorioallantoic placenta forms ridges, the microvillous cells become less hypertrophied, ciliated cells are less abundant, the underlying blood vessels increase in size, and the gland openings at the uterine surface are more apparent. In contrast, the yolk sac placenta has no particular folding with cells having a random orientation and where the microvillous cells remain hypertrophied throughout gestation. However, the ciliated cells become less abundant as gestation proceeds, as also seen in the chorioallantoic placenta. Secretory vesicles are visible in the uterine lumen. All placental differentiation and cell detail is lost at Stage 40, and the uterine structure has returned to the nonreproductive condition within 2 weeks. Circulating progesterone concentrations begin to rise during late vitellogenesis, peak at embryonic Stages 28-30, and decline after Stage 35 in the later stages of gestation. The coincidence between the time of oviposition and placental differentiation demonstrates a similarity during gestation in the uterus between oviparous and simple placental viviparous squamates.
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/RD9920265
Abstract: This paper reviews recent morphological work on peri-implantation endometrium collected from the Monash University In vitro Fertilization (IVF) Programme. Comparisons of endometrial tissue collected from women who had undergone different superovulation regimens demonstrated that significant structural differences could be detected by morphometry and ultrasound, but not by routine histopathology. Morphometric studies on endometrium from agonadal women receiving hormone replacement therapy demonstrated major differences between women with identical endocrine profiles. A biopsy inadvertently taken from one of these patients at the time of implantation was not of the appearance classically believed to be associated with receptivity for implantation. Studies have shown that the tight junction structure of endometrial epithelium is regulated during the menstrual cycle, suggesting that the integrity of the epithelial barrier may be important in the preparation of the endometrium for implantation.
Publisher: Springer Science and Business Media LLC
Date: 07-11-2017
Abstract: During early pregnancy, uterine epithelial cells (UECs) become less adherent to the underlying basal lamina and are subsequently removed so the blastocyst can invade the underlying stroma. This process involves the removal of focal adhesions from the basal plasma membrane of UECs. These focal adhesions are thought to be internalized by caveolae, which significantly increase in abundance at the time of blastocyst implantation. A recent in vitro study indicated that prominin-2 prevents the formation of caveolae by sequestering membrane cholesterol. The present study examines whether prominin-2 affects the formation of caveolae and loss of focal adhesions in UECs during normal and ovarian hyperstimulation (OH) pregnancy in the rat. At the time of fertilization during normal pregnancy, prominin-2 is distributed throughout the basolateral plasma membrane. However, at the time of implantation and coincident with an increase in caveolae, prominin-2 is lost from the basal plasma membrane. In contrast, prominin-2 remains in the basolateral plasma membrane throughout OH pregnancy. Transmission electron microscopy showed that this membrane contained few caveolae throughout OH pregnancy. Our results indicate that prominin-2 prevents the formation of caveolae. We suggest the retention of prominin-2 in the basal plasma membrane during OH pregnancy prevents the formation of caveolae and is responsible for the retention of focal adhesions in this membrane, thereby contributing to the reduced implantation rate observed after such treatments.
Publisher: Oxford University Press (OUP)
Date: 11-1995
Abstract: During early pregnancy and the period of blastocyst attachment, the plasma membrane of uterine epithelial cells, which is the first site of contact between maternal and fetal cells, undergoes a remarkable change in configuration, with morphological and biochemical alterations occurring apically and basolaterally. These alterations are collectively referred to as 'the plasma membrane transformation' of early pregnancy. It would be remarkable if this transformation did not also involve alterations in cytoskeletal elements and, in particular, the membrane-associated cytoskeleton. This review therefore, after an overview of the morphological and molecular aspects of the membrane transformation as background, proceeds to examine what is known about the cytoskeleton of uterine epithelial cells. Cytoskeletal elements particularly associated with the plasma membrane are then examined and some new approaches to understanding membrane-skeletal dynamics, including detergent-permeabilization techniques for transmission and high-resolution scanning electron microscopy of uterine epithelial cells, are reported, together with recent work on these structures. The review concludes with an examination of how membrane-skeletal elements could contribute to the membrane transformation.
Publisher: Elsevier BV
Date: 08-2004
Publisher: Wiley
Date: 11-04-2017
DOI: 10.1111/JOA.12610
Publisher: Wiley
Date: 16-04-2014
DOI: 10.1002/JMOR.20282
Abstract: Formation of a placenta requires intimate contact between the embryonic and maternal uterine epithelia in early pregnancy. Contact is accompanied by a characteristic suite of changes to the plasma membranes of uterine epithelial cells, termed the plasma membrane transformation. The plasma membrane transformation occurs in eutherian mammals and in viviparous (live-bearing) squamate reptiles, and may be fundamental to the evolution of viviparity in amniotes. Marsupials provide an excellent opportunity to test the generality of this phenomenon. Here, we present the first detailed study of the plasma membrane transformation in a marsupial. We combine electron microscopy and immunohistochemistry to describe morphological and molecular features of uterine epithelial cells during pregnancy in the fat-tailed dunnart (Sminthopsis crassicaudata Dasyuridae). Cell morphology changes dramatically in S. crassicaudata during pregnancy. Apical microvilli are replaced by irregular blunt projections, then by spiky projections postimplantation. Cell surfaces flatten and ciliated cells are lost. Junctional complexes between adjacent cells increase in depth, then decrease just before implantation, which is consistent with junctional protein localization in this region of the cell membrane. The uterine cellular changes in S. crassicaudata are consistent with a plasma membrane transformation, and support the idea that this phenomenon is fundamental to the evolution of viviparity in amniote vertebrates.
Publisher: Springer Science and Business Media LLC
Date: 06-1979
DOI: 10.1007/BF02781350
Abstract: Population genetic studies suggest that Yersinia pestis, the cause of plague, is a clonal pathogen that has recently emerged from Yersinia pseudotuberculosis. Plasmid acquisition is likely to have been a key element in this evolutionary leap from an enteric to a flea-transmitted systemic pathogen. However, the origin of Y. pestis-specific plasmids remains obscure. We demonstrate specific plasmid rearrangements in different Y. pestis strains which distinguish Y. pestis bv. Orientalis strains from other biovars. We also present evidence for plasmid-associated DNA exchange between Y. pestis and the exclusively human pathogen Salmonella enterica serovar Typhi.
Publisher: Springer Science and Business Media LLC
Date: 02-2019
Abstract: The angiogenic factor vascular endothelial growth factor-A (VEGFA) plays a critical role during early pregnancy in many species including the rat, and any alterations in VEGFA levels can severely impact blastocyst implantation rates. The rat ovarian hyperstimulation (OH) model is useful in studying how the induction of superovulation affects VEGFA levels and endometrial receptivity to blastocyst implantation. The present study shows that the major isoform in the rat uterus, Vegf
Start Date: 10-2008
End Date: 11-2008
Amount: $1,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 12-2005
Amount: $330,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2008
End Date: 12-2011
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 06-2016
Amount: $310,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2005
End Date: 05-2010
Amount: $520,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 12-2010
End Date: 12-2010
Amount: $720,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2012
End Date: 08-2015
Amount: $550,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 09-2008
End Date: 01-2011
Amount: $450,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2009
End Date: 12-2010
Amount: $1,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 12-2009
Amount: $900,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 12-2022
Amount: $572,496.00
Funder: Australian Research Council
View Funded Activity