The role of corticotropin-releasing hormone receptors in placenta and fetal membranes during human pregnancy

Corticotropin-releasing hormone (CRH) is a 41 amino acid polypeptide that exerts a wide spectrum of hypothalamic and extrahypothalamic functions. Moreover, the placenta and other intrauterine tissues produce and secrete immunoreactive CRH. It has been demonstrated that placental CRH is secreted into the maternal circulation in large amounts during the third trimester of human pregnancy and may play an important role in the onset of labor. CRH exerts a number of functions within the intratuterine environment like induction of prostaglandin production and maintenance of the placental blood flow. Here we present an overview of current knowledge about the CRH receptor subtypes and their signaling properties within the feto-placental unit.     

Expression and function of macrophage-inducible C-type lectin (Mincle) in inflammation driven parturition in fetal membranes and myometrium

The pivotal role of inflammatory processes in human parturition is well known, but not completely understood. We have performed a study to examine the role of macrophage-inducible C-type lectin (Mincle) in inflammation-associated parturition. Using human samples, we show that spontaneous labour is associated with up-regulated Mincle expression in the myometrium and fetal membranes. Mincle expression was also increased in fetal membranes and myometrium in the presence of pro-labour mediators, the proinflammatory cytokines interleukin (IL)-1B and tumour necrosis factor (TNF), and Toll-like receptor (TLR) ligands fsl-1, poly(I:C), lipopolysaccharide (LPS) and flagellin. These clinical studies are supported by mouse studies, where an inflammatory challenge in a mouse model of preterm birth increased Mincle expression in the uterus. Importantly, elimination of Mincle decreased the effectiveness of proinflammatory cytokines and TLR ligands to induce the expression of pro-labour mediators; namely, proinflammatory cytokines and chemokines, contraction-associated proteins and prostaglandins, and extracellular matrix remodelling enzymes, matrix metalloproteinases. The data presented in this study suggest that Mincle is required when inflammatory activation precipitates parturition.     

水通道蛋白3在人胎盘和胎膜中的表达及分布

目的研究正常妊娠晚期人胎盘和胎膜水通道蛋白3(AQP3)的表达及分布。方法收集5例正常足月妊娠剖宫分娩的胎盘和胎膜样本,用RT-PCR测定AQP3 mRNA在胎盘和胎膜组织中的表达;用Western印迹和免疫组织化学方法检测AQP3蛋白质水平在胎盘和胎膜的表达。结果RT-PCR显示AQP3 mRNA在胎盘和胎膜组织均有表达。Western印迹结果显示胎盘组织在29 000左右有一特异性条带。免疫组织化学结果显示AQP3表达于合体滋养细胞,而在羊膜上皮细胞未见表达。结论AQP3在胎盘母儿液体平衡中可能发挥重要作用。     

Ultrastructure of fetal stem arteries of human placenta in normal pregnancy

Summary Fetal stem arteries of the 3rd order of 50 normal placentas obtained at term of unevenful pregnancies were examined by transmission electron microscopy with the aim at providing a base-line information for the assessment of similar arteries in hypertensive disorders of pregnancy.The results showed that the endothelial cells often protruded with a considerable portion of their cellular body into the lumen, and that the intercellular junctions between the neighbouring cells were confined largely to their short basal segments. Numerous myoepithelial junctions were formed between the processes of the endothelial cells and those extending from the smooth muscle cells (SMC) of the adjacent medial layer. At times the participating processes of the SMC were entirely enclosed within the endothelial body.Collagen fibrils increased in number between the SMC and the interstitium broadened progressively from the inner to the outer arterial layers. Small cellular processes devoided of a basement membrane and of most cytoplasmic organelles were numerous in the interstitium; these were traced to the main bodies of the medial SMC.It is postulated that the naked SMC-processes are susceptible to injury of a nature much more subtle than that affecting the main body of the SMC, since these processes were often swollen and appeared edematous in an otherwise innocuous mural environment.Supported by grants-in-aid of research No. PR 499 from the Ministry of Health, Province of Ontario, and T.3–11 from the Ontario Heart Foundation, Toronto, Ontario, CanadaPresented in part at the Annual Meeting of the USA/Canadian Division of the International Academy of Pathology, New Orleans, Louisiana, February 23–29, 1980Recipient of a Medical Research Council of Canada Fellowship, 1975–978     

水通道蛋白3在人胎盘和胎膜中的表达及分布

目的 研究正常妊娠晚期人胎盘和胎膜水通道蛋白3(AQP3)的表达及分布.方法 收集5例正常足月妊娠剖宫分娩的胎盘和胎膜样本,用RT-PCR测定AQP3 mRNA在胎盘和胎膜组织中的表达;用Western印迹和免疫组织化学方法检测AQP3蛋白质水平在胎盘和胎膜的表达.结果 RT-PCR显示AQP3 mRNA在胎盘和胎膜组织均有表达.Western印迹结果显示胎盘组织在29 000左右有一特异性条带.免疫组织化学结果显示AQP3表达于合体滋养细胞,而在羊膜上皮细胞未见表达.结论 AQP3在胎盘母儿液体平衡中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Toll样受体2在人胎盘和胎膜组织中的表达

目的 检测正常胎盘和胎膜组织中Toll样受体2(TLR2)的表达.方法 收集5例足月剖宫分娩胎盘和胎膜样本,运用RT-PCR法检测胎盘和胎膜组织中TLR2 mRNA的表达,运用免疫组织化学和Westen blot印迹方法检测TLR2蛋白质在胎盘和胎膜组织中的表达.结果 RT-PCR显示在mRNA水平,胎盘和胎膜组织中均有TLR2表达;Westen blot印迹显示TLR2抗体在胎盘和胎膜组织中相对分子质量为50000左右的位置有一条明显的条带;免疫组化研究显示TLR2在胎盘的合体滋养细胞、胎膜的羊膜上皮细胞及平滑绒毛膜滋养细胞中有表达.结论 TLR2在人胎盘和胎膜组织中的表达,提示其在妊娠期先天性免疫中可能发挥重要作用.     

Lead and mercury mutagenesis: Role of H2O2, superoxide dismutase,and xanthine oxidase

It has been suggested that reactive oxygen intermediates (ROIs) may have a role in the genotoxic effects of lead (Pb²⁺) and mercury (Hg²⁺), but there have not been any definitive studies demonstrating a causal relationship between the induction of ROIs by these metals and mutagenesis. We previously demonstrated, using the transgenic Chinese hamster ovary cell line AS52, that low concentrations (0.1–1 μM) of Pb²⁺ and Hg²⁺ are mutagenic. In the present study, using a novel histochemical computer-enhanced image analysis technique, we demonstrate that Pb²⁺ and Hg²⁺ induce the formation of H₂O₂ in AS52 cells by at least two distinct mechanisms. One is characterized by the rapid induction of H₂O₂ following treatment of cells with concentrations of Pb²⁺ or Hg²⁺ below 0.8 and 1 μM, respectively, while the second occurs in AS52 cells treated with concentrations of Pb²⁺ or Hg²⁺ greater than 0.8 and 1 μM, respectively. Pb²⁺ and Hg²⁺ (0.1–1 μM) had no effect on the activities of partially purified catalase, glutathione peroxidase, or glutathione reductase, important enzymes involved with antioxidant defense, but these metals stimulated the activities of copper-zinc superoxide dismutase (CuZn-SOD) and xanthine oxidase (XO). Allopurinol (50 μM), a specific inhibitor of xanthine oxidase, inhibited the induction of H₂O₂ by Pb²⁺ (0.8–1 μM) and Hg²⁺ (1 μM) and also inhibited Pb²⁺- and Hg²⁺-induced mutagenesis. These results demonstrate that Pb²⁺ and Hg²⁺ disrupt the redox status of AS52 cells by enhancing the activities of CuZn-SOD and XO. Furthermore, the results of these studies also demonstrate that there is a causal relationship between the induction of H₂O₂ by these metals and mutagenesis. Environ. Mol. Mutagen. 31:352–361, 1998. © 1998 Wiley-Liss, Inc.     

Production of inhibin forms by the fetal membranes, decidua, placenta and fetus at parturition

Inhibins are regulators of paracrine and endocrine function during pregnancy, but their intrauterine sites of secretion are not well established. In amniotic fluid, inhibin A-, inhibin B- and inhibin pro-alphaC-containing isoforms were present in high concentrations, whereas in maternal serum, inhibin A and pro-alphaC forms were present in high amounts, with low concentrations of inhibin B. In fetal cord serum, inhibin pro-alphaC was present in all samples, inhibin B was detectable in male but not female fetuses, with no detectable inhibin A in either sex. From cultured explants, both inhibin A and B were secreted by chorion laeve, whereas only inhibin A was secreted by placenta, with both tissues secreting inhibin pro-alphaC. Only low concentrations of both dimeric inhibins and pro-alphaC forms were secreted by decidua parietalis and amnion. The dual perfused placental cotyledon secreted both inhibin A and pro-alphaC into maternal perfusate, but only inhibin pro-alphaC into the fetal circulation and less than to the maternal side. We conclude that trophoblast is the predominant source of dimeric inhibins, but with markedly different secretion depending on its intrauterine location. There was a significant decrease in inhibin A and pro-alphaC in amniotic fluid collected at term active labour compared to elective Caesarean section (P < 0.001). This may reflect a local change in inhibin/activin processing at labour, likely in chorion laeve trophoblast cells, which may be important in the paracrine control of the feto-maternal communication required to maintain pregnancy and initiate labour.     

Expression of proliferation and apoptotic markers in human placenta during pregnancy

Trophoblast has unique properties in relation to its wide range of metabolic, endocrine and angiogenic functions. Trophoblastic cells invade endometrium and adjacent myometrium in a way that is imitated by malignant tumours. The aim of the present study was to analyse the expression of markers of proliferation and apoptosis in trophoblastic cells in normal human placenta during pregnancy. A total of 22 placentas, 12 of which were obtained from curettage and induced legal abortion and 10 placentas obtained from normal deliveries or caesarean sections were included in this study. Proliferation markers were strongly expressed in cytotrophoblast in early stages of gestation. In late term placentas, a distinct decrease in expression of these markers was observed. Syncytiotrophoblast was negative for proliferation markers in all placentas. Positive immunostaining for bcl-2, an anti-apoptotic marker, was observed only in syncytiotrophoblastic cells in first-trimester but also in third-trimester placentas. Cytotrophoblast and stromal mesenchymal cells of chorionic villi were negative for bcl-2. Expression of bcl-2 protein in syncytiotrophoblast may be one of the major factors preventing these structures from early cell death, which is indispensable for the maintenance of physiological pregnancy.     

Neuropeptide Y and noradrenaline in human uterus and myometrium during normal and pre-eclamptic pregnancy

The myometrial levels of noradrenaline (NA) and neuropeptideV (NPY), a recently discovered neuropeptide that coexists withNA in many sympathetic nerves, have been measured by immunohistochemistryand biochemistry in normal and pre-eclamptic pregnancy and comparedwith non-pregnant controls. In the non-pregnant uterus therewere high levels of NA and NPY and a rich presence of NA/NPYnerves in the myometrium and around blood vessels. In pregnancyboth substances were significantly lower as compared with non-pregnantwomen. Five patients with pre-eclampsia had levels of NA/NPYthat were less markedly reduced than in normal pregnant women.The results show that NA and NPY coexist also in human uterinenerves, and that both decrease significantly during pregnancy.Since both substances are vasoactive, the observed reductionmight be of physiological importance for normal pregnancy.