REGULATION OF VEGF EXPRESSION IN PLACENTA AND MEMBRANES

对羊水量控制的全面理解是 具有重要的临床意义，并促使许多研究 其调控机制。本申请拟澄清 血管内皮生长因子在促血管生成中的作用 羊膜、绒毛膜和子叶的血管生成和通透性 血管及其在羊水量调节中的作用 和构图。以怀孕的绵羊为动物模型， 结合分子和生理方法，五个具体目标是 建议。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血管内皮生长因子蛋白和mRNA的表达 通过免疫组织化学、免疫分析、原位杂交、Northern印迹 分析和竞争性RT-PCR法。假设血管内皮生长因子的表达是 存在于与羊膜、绒毛和胎盘血液相邻的细胞中 血管水平高于其他细胞类型。目标2将 血管内皮生长因子受体mRNA在细胞内的分布和表达 在胎膜和胎盘中。假设血管内皮生长因子受体是 在这些组织的血管内皮细胞中表达。目标3将 探讨胎膜组织中血管内皮生长因子基因表达的调控 胎盘通过缺氧和胎儿食道结扎。假设是这样的 胎儿缺氧或食道闭塞可诱导血管内皮生长因子基因表达。目标4 将确定血管内皮生长因子在胎膜中的生物学功能 胎盘。血管生成将通过形态计量学进行评估 分析，并通过渗透率估计血管渗透性 放射性白蛋白、钠和尿素。假设是血管内皮细胞生长因子既有 这些组织中的血管生成和通透性。目标5将 利用携带显性-负性突变体的转基因小鼠模型 使受体失效的血管内皮生长因子受体。假说 缺乏功能性的血管内皮生长因子受体会导致异常 妊娠期羊水量和羊水成分减少 膜内微血管密度和通透性。建议数 研究将提供有关监管的重要信息 分布于胎膜和胎面的微血管网 胎盘的位置。这一信息将显著改善 对孕期羊水量调节的认识。

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.