TROPHOBLAST GENE EXPRESSION AND DIFFERENTIATION

滋养层基因表达和分化

• 批准号: 2403293
• 负责人: DANIEL I LINZER
• 金额: $ 19.99万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-12-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2403293
• 关键词: DNA footprinting; cell differentiation; cell growth regulation; cell line; cell type; developmental genetics; embryo /fetus cell /tissue; gel mobility shift assay; gene expression; genetic promoter element; genetically modified animals; gestational age; hormone regulation /control mechanism; in situ hybridization; laboratory mouse; mammalian embryology; molecular cloning; nucleic acid sequence; placenta; placental hormones; pregnancy; protein purification; reporter genes; site directed mutagenesis; somatomammotropin; tissue /cell culture; transcription factor; transfection; trophoblast

The placenta functions in several important ways in promoting fetal development. This organ serves to implant the developing embryo in the uterus; as a conduit for the exchange of nutritional supplies and excreted waste between the mother and the fetus; as a barrier preventing attack on the fetus by the maternal immune system, and preventing transport into the fetal circulation of hazardous compounds such as heavy metals; and as a source of secreted proteins that regulate both maternal and fetal physiology. In regard to this last role, the placenta in several species (including rodents, sheep, cows, and humans) is the site of synthesis of proteins that are structurally related to pituitary prolactin. These hormones regulate maternal ovarian steroidogenesis (inducing progesterone production to maintain pregnancy), liver metabolism (to release glucose from storage forms for use by the fetus), and mammary development (to prepare for lactation); these hormones also enter the fetal compartment, where they may have direct effects on fetal development, for example in lung development. In the mouse, the prolactin family of proteins synthesized specifically in the placenta includes placental lactogen I, placental lactogen II, proliferin, and proliferin-related protein. We propose to define the genetic elements that regulate the trophoblast- and temporal-specific expression of these prolactin family genes in the mouse. Initial efforts will focus on placental lactogen I and proliferin-related protein, since the activity of these gene promoters is trophoblast-specific in cell culture transfection assays. Placental lactogen I provides the further advantage of being expressed early during gestation, and therefore may represent a target for a transcription/differentiation factor acting at an early stage of placental development; the placental lactogen I gene promoter will therefore also be used to generate immortalized trophoblast cell lines. The proliferin-related protein, meanwhile, provides a unique handle on mouse trophoblast differentiation since it is expressed in two trophoblast cell types, unlike the other members of the prolactin family. Both transient transfections into rodent choriocarcinoma cells and in vivo expression in transgenic mice will be assayed to define these regulatory elements. Once defined, these elements will then be used to identify a trans-acting regulatory factor(s) responsible for the expression of these genes in trophoblast cells. The expression of this factor during placental and fetal development, as well as in the adult, will then be investigated. Identification and characterization of this factor(s) will provide a means to examine placental trophoblast cell differentiation on a molecular level. Since the trophoblast cells are intimately involved in embryonic development, identifying the genetic elements and factors involved in trophoblast cell differentiation and function will aid in detecting, preventing, and treating birth defects.

胎盘在促进胎儿方面以几种重要的方式起作用 发展。 该器官可将发育的胚胎植入 子宫;作为交换营养用品的渠道和 母亲和胎儿之间的废物排泄；作为防止障碍 孕产妇免疫系统对胎儿攻击，并防止 运输到危险化合物的胎儿循环中，例如重物 金属；作为调节两种母体的分泌蛋白质的来源 和胎儿生理。 关于最后一个角色，胎盘在 几个物种（包括啮齿动物，绵羊，牛和人类）是该地点 与垂体结构相关的蛋白质的合成 催乳素。 这些激素调节母体卵巢类固醇生成 （诱导孕酮生产以保持怀孕），肝脏 代谢（从储存形式释放葡萄糖以供胎儿使用）， 和乳腺发育（准备哺乳）；这些激素也是如此 进入胎儿室，可能会对胎儿产生直接影响 开发，例如肺部发育。 在鼠标中， 在胎盘中特别合成的蛋白质催乳素家族 包括胎盘泌乳素I，胎盘泌乳素II，增殖蛋白和 增殖蛋白相关的蛋白质。 我们建议定义遗传元素 调节这些调节这些滋养细胞和时间特异性表达 小鼠中的催乳素家族基因。 最初的努力将集中在 由于活性 这些基因启动子在细胞培养中是滋养细胞特异性的 转染测定法。 胎盘泌乳素I提供了进一步的优势 在妊娠期间早期表达，因此可能代表 作用于早期的转录/分化因子的目标 胎盘发展的阶段；胎盘泌乳I基因启动子 因此，还将用于生成永生的滋养细胞细胞 线。 同时，增殖蛋白相关的蛋白质提供了独特的 处理小鼠滋养细胞的分化，因为它在两个中表达 与催乳素家族的其他成员不同，滋养细胞细胞类型。 两种瞬时转染到啮齿动物绒毛膜瘤细胞和 将分析转基因小鼠中的体内表达来定义这些 监管要素。 定义后，这些元素将用于 确定负责 这些基因在滋养细胞中的表达。 这个表达 胎盘和胎儿发育期间以及成年人的因素 然后将研究。 识别和表征 因子将提供一种检查胎盘滋养细胞细胞的方法 分子水平的分化。 由于滋养细胞是 密切参与胚胎发育，确定遗传 滋养细胞细胞分化和涉及的因素和因素 功能将有助于检测，预防和治疗先天缺陷。