FUNCTIONAL CYTOLOGY OF THE PLACENTA AND FETAL MEMBRANES

胎盘和胎膜的功能细胞学

• 批准号: 3311633
• 负责人: BARRY F KING
• 金额: $ 20.87万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 1989-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3311633
• 关键词: Cercopithecidae; Macaca; Macaca mulatta; amnion; autoradiography; capillary; cell membrane; cytology; cytoskeleton; density gradient ultracentrifugation; electron microscopy; embryo /fetus; embryo /fetus disorder; embryo /fetus membrane; gel electrophoresis; gel filtration chromatography; gestational age; glycoproteins; histochemistry /cytochemistry; human pregnant subject; human tissue; immunoelectron microscopy; immunoglobulin G; immunoglobulins; ion transport; low density lipoprotein; membrane activity; membrane structure; microfilaments; microtubules; phase contrast microscopy; pinocytosis; placenta; placental transfer; radiation detector; radiotracer; receptor mediated endocytosis; scanning electron microscopy; transferrin; transport proteins; trophoblast; vascular endothelium permeability; vitelline membrane

In humans and non-human primates, the vast majority of maternal-fetal exchanges are mediated by the placenta. It is, therefore, of fundamental importance to our understanding of fetal nutritional and neonatal health problems to ascertain the mechanisms by which the placenta selectively absorbs substances from the maternal blood and transports them to the fetus. The major components separating the maternal and fetal bloodstreams are: 1) syncytial trophoblast 2) a basal lamina and 3) fetal capillaries. The experiments encompassed in this proposal will examine various structural and functional aspects of each of these components, especially as they relate to absorption and permeability. Receptor-mediated endocytosis is one important mechanism by which cells, including trophoblast, take up macromolecules from their environment. This process will be examined in detail by combined ultrastructural and biochemical methods in order to quantitatively detemine the manner in which various ligands interact with trophoblast, and ultrastructurally and immunocytochemically to determine the intracellular pathways followed by ligands and their receptors. The ligands selected include IgG, because of its importance in providing passive immunity to the fetus, LDL because of its importance as a precursor for hormone synthesis and transferrin because of its role in iron transport tothe fetus. Because of the potentially important role of the cytoskeleton in many cellular functions, including endocytosis, other studies will determine the composition and localization of major cytoskeletal proteins in human placenta using immunofluorescent and ultrastructural immunocytochemical methods. In addition to macromolecules, the transport of ions to the developing fetus is another vitally important placental function. In order to better understand the subcellular structures associated with active ion transport by placenta we will localize Na+, K+ ATPase, Ca++ ATPase, and Ca++ in human placenta using ultratructural cytochemistry. The structural and functional basis of trophoblast and amnion basal lamina permeability will be studied. Isolated basal laminas will be exposed to tracer proteins with and without selective removal of basal lamina will be exposed to tracer proteins with and without selective removal of basal lamina glycosaminoglycans, particularly heparan sulfate to determine if these components influence permeability. Finally, the three-dimensional arrangement of the fetal capillary bed in terminal and intermediate human and non-human primate placental villi will be examined in order to determine how their structural organization may affect maternal-fetal exchange.

在人类和非人类灵长类动物中，绝大多数母胎 交换是由胎盘介导的。 因此，它具有根本性 对我们了解胎儿营养和新生儿健康的重要性 确定胎盘选择性机制的问题 从母体血液中吸收物质并将其输送到 胎儿。 分离母体和胎儿血流的主要成分 是：1）合体滋养层2）基底层和3）胎儿毛细血管。 该提案中包含的实验将检查各种 每个组件的结构和功能方面，特别是 因为它们与吸收性和渗透性有关。 受体介导 内吞作用是细胞的一种重要机制，包括 滋养层，从环境中吸收大分子。 这个过程 将通过超微结构和生化相结合的详细检查 方法，以定量确定各种 配体与滋养层相互作用，并且在超微结构和 免疫细胞化学法确定细胞内途径 配体及其受体。 选择的配体包括 IgG，因为 低密度脂蛋白在为胎儿提供被动免疫方面的重要性，因为 它作为激素合成和转铁蛋白前体的重要性，因为 其在铁向胎儿运输中的作用。 由于潜在的 细胞骨架在许多细胞功能中发挥重要作用，包括 内吞作用，其他研究将确定其组成和定位 使用免疫荧光法分析人胎盘中的主要细胞骨架蛋白 和超微结构免疫细胞化学方法。 此外 大分子，离子向发育中的胎儿的运输是另一个 极其重要的胎盘功能。 为了更好地了解 与胎盘活性离子转运相关的亚细胞结构 将使用人胎盘定位 Na+、K+ ATPase、Ca++ ATPase 和 Ca++ 超微结构细胞化学。 结构和功能基础 将研究滋养层和羊膜基底层的通透性。 孤立 基底层将暴露于示踪蛋白，有或没有选择性 去除基底层将暴露于示踪蛋白，有或没有 选择性去除基底层糖胺聚糖，特别是乙酰肝素 硫酸盐以确定这些成分是否影响渗透性。 最后， 临终胎儿毛细血管床的三维排列 和中间人类和非人类灵长类动物胎盘绒毛将是 检查以确定其结构组织如何影响 母胎交换。