Cross J C
Samuel Lunenfeld Research Institute, Mount Sinai Hospital, and the Departments of Obstetrics & Gynaecology, and Molecular & Medical Genetics, University of Toronto, Toronto, Ontario, M5G 1X5, Canada.
Semin Cell Dev Biol. 2000 Apr;11(2):105-13. doi: 10.1006/scdb.2000.0156.
The placenta is comprised of an inner vascular network covered by an outer epithelium, called trophoblast, all designed to promote the delivery of nutrients to the fetus. Several specialized trophoblast cell subtypes arise during development to promote this function, including cells that invade the uterus to promote maternal blood flow to the implantation site, and other cells that fuse into a syncytium, expand and fold to increase the surface area for efficient transport. Mutation of many genes in mice results in embryonic mortality or fetal growth restriction due to defects in placental development. Several important principles about placental development have emerged from these studies. First, distinct molecular pathways regulate the differentiation of the various trophoblast cell subtypes. Second, trophoblast proliferation, differentiation and morphogenesis are highly regulated by interactions with adjacent cell types. Finally, the specific classes of mutant phenotypes observed in the placenta of knockout mice resemble those seen in humans that are associated with preeclampsia and intrauterine growth restriction.
胎盘由一个内部血管网络和覆盖在其外的上皮细胞组成，该上皮细胞称为滋养层，其设计目的是促进营养物质向胎儿的输送。在发育过程中会出现几种特殊的滋养层细胞亚型来促进这一功能，包括侵入子宫以促进母体血液流向着床部位的细胞，以及融合形成合体滋养层、扩展并折叠以增加有效运输表面积的其他细胞。小鼠中许多基因的突变会由于胎盘发育缺陷而导致胚胎死亡或胎儿生长受限。这些研究得出了一些关于胎盘发育的重要原则。首先，不同的分子途径调节各种滋养层细胞亚型的分化。其次，滋养层的增殖、分化和形态发生受到与相邻细胞类型相互作用的高度调节。最后，在基因敲除小鼠胎盘中观察到的特定类型的突变表型与人类中与先兆子痫和宫内生长受限相关的表型相似。
