FUNCTIONAL CYTOLOGY OF THE PLACENTA AND FETAL MEMBRANES

胎盘和胎膜的功能细胞学

基本信息

批准号：
3311628
负责人：
BARRY F KING
金额：
$ 16.73万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
1978
资助国家：
美国
起止时间：
1978-07-01 至 1994-03-31
项目状态：
已结题

项目摘要

In humans the vast majority of maternal-fetal exchanges of nutrients, toxins or harmful organisms is mediated by the placenta. It is therefore of great importance to our understanding of fetal and neonatal nutritional and health problems to ascertain the mechanisms by which the placental trophoblast selectively absorbs substances from the maternal blood. The experiments encompassed in this proposal will examine various structural and functional aspects of placental trophoblast. An important feature of placental development and function is the differentiation of cytotrophoblast into syncytiotrophoblast, accompanied by the process of cell fusion. At present, little is known about the regulation of this critical, but unusual, transition. In the first specific aim, we will take advantage of our ability to isolate a pure cytotrophoblast population and examine the regulation of trophoblast differentiation in vitro, employing a variety of factors known to affect differentiation in other systems, particularly those few where cell fusion occurs. These agents include EGF, insulin, IGF's, prostaglandins, conditioned media from cultures of placental fibroblasts and macrophages, drugs which perturb the cytoskeleton, and extracellular matrix components. We will determine the extent of syncytium formation by a variety of morphological and biochemical techniques. As the trophoblast undergoes differentiation we will examine changes in the distribution and synthesis of two important proteins expressed on the cell surface, transferrin receptor and EGF receptor, and changes in two important cytoskeletal proteins, cytokeratin and desmoplakin. The latter are of particular interest in a cell system undergoing fusion since rearrangement of the cytoskeleton and disappearance of cell junctions would accompany this transition. Specific aim two will extend our earlier studies of iron metabolism by trophoblast cells. We will examine the transferrin-mediated uptake of iron and the release of iron at different stages of differentiation. Other studies will examine developmental changes in the regulation of transferrin receptor synthesis and distribution. Related studies will define the role of ferritin in trophoblast iron metabolism by examining its uptake, biosynthesis and release. The third specific aim is to demonstrate the distribution of acidic intracellular compartments in placental villi and in isolated trophoblast cells. Acidic intracellular compartments are important locations of receptor-ligand dissociation and sorting and are also the site of iron dissociation from transferrin. Together these aims should result in significant new information on trophoblast differentiation and function.

在人类中，绝大多数母婴营养物质的交换，毒素或有害生物是由胎盘介导的。这是因此对于我们了解胎儿和新生儿非常重要营养和健康问题，以确定其机制胎盘滋养层选择性地吸收来自胎盘的物质母血。本提案中包含的实验将检查胎盘的各个结构和功能方面滋养层。胎盘发育和功能的重要特征是细胞滋养层分化为合体滋养层，伴随着细胞融合的过程。目前，人们知之甚少关于这一关键但不寻常的转变的监管。在第一个具体目标，我们将利用我们的能力来隔离纯细胞滋养层群体并检查调节利用多种因素进行体外滋养层分化已知会影响其他系统的分化，特别是那些少数系统细胞融合发生的地方。这些药物包括 EGF、胰岛素、IGF、前列腺素，来自胎盘成纤维细胞培养物的条件培养基和巨噬细胞、扰乱细胞骨架的药物和细胞外矩阵成分。我们将确定合胞体形成的程度通过各种形态学和生化技术。作为滋养层经历分化，我们将检查表达的两种重要蛋白质的分布和合成细胞表面、转铁蛋白受体和EGF受体，以及两者的变化重要的细胞骨架蛋白、细胞角蛋白和桥粒斑蛋白。这后者对正在进行融合的细胞系统特别感兴趣由于细胞骨架的重排和细胞的消失交汇点将伴随这种转变。具体目标二将扩展我们早期对滋养层细胞铁代谢的研究。我们将检查转铁蛋白介导的铁吸收和铁释放处于分化的不同阶段。其他研究将检验转铁蛋白受体调节的发育变化合成和分配。相关研究将明确其作用通过检查铁蛋白在滋养层铁代谢中的摄取情况，生物合成和释放。第三个具体目标是展示胎盘绒毛中酸性细胞内区室的分布在分离的滋养层细胞中。酸性细胞内区室是受体-配体解离和分选的重要位置，是也是铁从转铁蛋白解离的位点。一起这些目标应产生有关滋养层的重要新信息分化和功能。