REGULATION OF RENIN AND PREECLAMPTIC HYPERTENSION

描述：（改编自研究者摘要）许多组织分泌一种无活性的前体形式的肾素。据信主要在肾中发生43个氨基酸的前片段去除以产生活性肾素。最近的数据显示，子痫前期转基因小鼠模型支持生殖性肾素在其发病机制中的作用，我们的数据显示，人类子痫前期蜕膜中肾素表达增加，证实了这一作用。对于具有这种功能性作用的肾素，细胞加工成活性肾素应该发生在局部。子宫肾素-血管紧张素系统的细胞和分子方面还没有得到充分的研究。雌激素和孕激素反应元件在肾素基因启动子中的存在表明性类固醇激素在调节前肾素表达中的作用。我们最近的数据表明，孕激素处理子宫内膜间质细胞（体外蜕膜化）通过增加原肾素表达和以激素特异性方式增加原肾素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原肾素加工成肾素。我们最近在HEK 293细胞中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可能起着前肾素转化酶的作用。我们推测，病理性增加，在蜕膜肾素可能prominent启动先兆子痫，性类固醇可能会诱导表达的原肾素及其前转化酶（PC），从而调节成熟的肾素分泌。因此，目标是：2）通过（i）用PC和组织蛋白酶B的探针进行北方分析，和（ii）确定组成型与调节型的肾素分泌，和（iii）检查组织蛋白酶B抑制对原肾素加工的影响，鉴定负责原肾素活化的蜕膜细胞内切蛋白酶;（B）检查内切蛋白酶表达的调节; 3）通过（a）在囊泡中与原肾素的免疫显微镜共定位和（B）通过在标准细胞系中共转染原肾素和候选物活化酶表达载体并证明加工成成熟活性肾素的功能验证，确认候选物活化酶是特异性原肾素转化酶。这些研究将提高我们对孕激素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。

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.