REGULATION OF VEGF EXPRESSION IN PLACENTA AND MEMBRANES

全面了解羊水量的控制， 具有重要的临床意义，并促使许多研究 其调控机制。本申请提出阐明 血管内皮生长因子（VEGF）在促进 羊膜、绒毛膜和子叶的血管生成和通透性 血管，并检查其在羊水量调节中的作用 和组成。以妊娠绵羊为动物模型， 结合分子和生理学方法，五个具体目标， 提出了 目标1将描述组织分布和丰度 胎儿羊膜、绒毛膜和胎盘子叶中VEGF蛋白和mRNA的表达 免疫组化、免疫测定、原位杂交、北方印迹 分析和竞争性RT-PCR。假设VEGF的表达是 存在于羊膜、绒毛膜和胎盘血附近的细胞中 血管中的水平高于其他细胞类型。目标2将 测定VEGF受体mRNA的细胞分布和表达 在胎膜和胎盘中。假设VEGF受体是 在这些组织的血管内皮细胞中表达。 目标3将 探讨VEGF基因在胎膜中表达的调控， 胎盘缺氧和胎儿食管结扎。前提是 胎儿缺氧或食管阻塞诱导VEGF基因表达。目标4 将决定胎膜中VEGF的生物学功能， 胎盘 血管新生将通过形态计量学评价。 分析和血管渗透性估计的渗透性， 放射性白蛋白钠和尿素假设是VEGF既具有 这些组织中的血管生成和渗透性。目标5将 利用转基因小鼠模型携带显性阴性突变体， 使受体无效的VEGF受体。的假设 缺乏功能性VEGF受体会导致 羊水量和成分在怀孕期间由于减少， 微血管密度和膜的渗透性。拟议 这些研究将提供有关监管的重要信息， 微血管网，其灌注胎膜和胎儿表面 胎盘这些信息将大大改善 了解妊娠期间羊水量的调节。

A comprehensive understanding of the control of amniotic fluid volume is of major clinical importance and has prompted much research into the mechanism of its regulation. The present application proposes to elucidate the role of vascular endothelial growth factor (VEGF) in promoting angiogenesis and permeability of amniotic, chorionic and cotyledonary blood vessels and examine its role in regulation of amniotic fluid volume and composition. Using the pregnant sheep as the animal model, and combining molecular with physiological approaches, five specific aims are proposed. Aim 1 will characterize the tissue distribution and abundance of VEGF protein and mRNA in fetal amnion, chorion and placental cotyledons by immunohistochemistry, immunoassay, in situ hybridization, Northern blot analysis and competitive RT-PCR. The hypothesis is that VEGF expression is present in cells adjacent to the amniotic, chorionic and placental blood vessels at levels higher than that in other cell types. Aim 2 will determine the cellular distribution and expression of VEGF receptor mRNA in fetal membranes and placenta. The hypothesis is that VEGF receptors are expressed in vascular endothelial cells of these tissues. Aim 3 will investigate the regulation of VEGF gene expression in fetal membranes and placenta by hypoxia and fetal esophageal ligation. The hypothesis is that fetal hypoxia or esophageal occlusion induces VEGF gene expression. Aim 4 will determine the biological function of VEGF in fetal membranes and placenta. Vascular angiogenesis will be evaluated by morphometric analysis, and vascular permeability estimated by permeability to radioactive albumin, sodium and urea. The hypothesis is that VEGF has both angiogenic and permeability properties in these tissues. Aim 5 will utilize a transgenic mouse model carrying a dominant-negative mutant of the VEGF receptor which renders the receptor ineffective. The hypothesis is that the lack of a functional VEGF receptor results in abnormal amniotic fluid volume and composition during pregnancy due to reduction in microvessel density and permeability in the membranes. The proposed studies will provide important information on the regulation of the microvascular network which perfuses the fetal membranes and fetal surface of the placenta. This information will significantly improve the understanding of amniotic fluid volume regulation during pregnancy.