REGULATION OF RENIN AND PREECLAMPTIC HYPERTENSION

肾素和子痫前期高血压的调节

基本信息

批准号：
7217183
负责人：
Dinesh Manilal Shah
金额：
$ 14.72万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-04-19 至 2006-03-31
项目状态：
已结题

项目摘要

DESCRIPTION: (Adapted from the Investigator's Abstract) Many tissues secrete an inactive pro-form of renin. A 43 amino acid pro- segment removal to produce active renin is believed to occur, primarily in the kidney. Recent data on transgenic mouse model of preeclampsia support a role of reproductive renin in its pathogenesis and our data on increased decidual renin expression in human preeclampsia confirms this role. For renin to have such a functional role, cellular processing to active renin should occur locally. The cellular and molecular aspects of the uterine renin- angiotensin system have not been adequately investigated. Presence of estrogen and progesterone response elements in the promoter of renin gene suggests a role for the sex steroids in the regulation of prorenin expression. Our recent data suggest that progesterone treatment of endometrial stromal cells (in vitro decidualization) increases active renin secretion by increasing prorenin expression and by increasing conversion of prorenin to renin in a hormone- specific manner, and that decidual cells from human gestation process prorenin to renin. Our most recent co-transfection experiment in HEK293 cells and cathepsin B inhibition in decidual cells suggest that cathepsin B may function as a prorenin convertase. We hypothesize that pathologic increase in decidual renin may proximately initiate preeclampsia, and sex steroids may induce expression of prorenin and its proconvertase (PC), thereby regulating mature renin secretion. Therefore, the objectives are: 1) To demonstrate that decidual stromal cells in vitro secrete active mature renin, as assayed by activity and by N terminal sequencing; 2) To identify the decidual cell endoprotease responsible for prorenin activation by (i) northern analysis with probes for PCs and cathepsin B, and (ii) defining constitutive versus regulated renin secretion, and (iii) examining the effect of cathepsin B inhibition on prorenin processing; (b) To examine regulation of endoprotease expression; 3) To confirm that the candidate-activating enzyme is the specific prorenin convertase by (a) immuno-microscopic co-localization with prorenin in the vesicles and (b) functional verification by co-transfection of prorenin and candidate-activating enzyme expression vectors in a standard cell line and demonstration of processing to mature active renin. These studies will improve our understanding of the role of progesterone in the regulation of reproductive renin and may provide a novel direction for investigating the pathophysiology of preeclampsia.

描述：（改编自研究者摘要）许多组织分泌一种无活性的肾素前体。据信主要在肾脏中发生 43 个氨基酸前片段去除以产生活性肾素。关于先兆子痫转基因小鼠模型的最新数据支持生殖肾素在其发病机制中的作用，并且我们关于人类先兆子痫中蜕膜肾素表达增加的数据证实了这一作用。为了使肾素具有这样的功能作用，活性肾素的细胞加工应该发生在局部。子宫肾素-血管紧张素系统的细胞和分子方面尚未得到充分研究。肾素基因启动子中雌激素和孕激素反应元件的存在表明性类固醇在肾素原表达调节中的作用。我们最近的数据表明，子宫内膜基质细胞的黄体酮处理（体外蜕膜化）通过增加肾素原表达和以激素特异性方式增加肾素原向肾素的转化来增加活性肾素分泌，并且来自人类妊娠的蜕膜细胞将肾素原转化为肾素。我们最近在 HEK293 细胞中进行的共转染实验和在蜕膜细胞中的组织蛋白酶 B 抑制表明组织蛋白酶 B 可能起到肾素原转化酶的作用。我们假设蜕膜肾素的病理性增加可能直接引发先兆子痫，性类固醇可能诱导肾素原及其原转化酶（PC）的表达，从而调节成熟肾素的分泌。因此，我们的目标是： 1) 证明蜕膜基质细胞在体外分泌活性成熟肾素，通过活性和 N 末端测序进行测定； 2) 通过以下方式鉴定负责肾素原激活的蜕膜细胞内切蛋白酶：(i) 使用 PC 和组织蛋白酶 B 探针进行 Northern 分析，以及 (ii) 定义组成型与调节性肾素分泌，以及 (iii) 检查组织蛋白酶 B 抑制对肾素原的影响加工; (b) 检查内切蛋白酶表达的调节； 3) 通过以下方式确认候选激活酶是特异性肾素原转化酶：(a) 与肾素原在囊泡中的免疫显微镜共定位，以及 (b) 通过肾素原和候选激活酶表达载体在囊泡中的共转染进行功能验证标准细胞系和成熟活性肾素的加工演示。这些研究将提高我们对孕酮在生殖肾素调节中的作用的理解，并可能为研究先兆子痫的病理生理学提供新的方向。