KININS ROLE IN MESANGIAL CELL PROLIFERATION

本提案的总体目标是探讨 激肽在肾小球系膜细胞增殖中的作用及其特征 参与调节这些事件的信号通路。 增加 有证据表明，系膜细胞增殖是重要的， 系膜扩张的发病机制;系膜细胞肥大， 增生和基质积累可能最终导致 肾小球硬化 启动增殖的信号不是 虽然有一些调解人被牵连在内，但定义明确。 我们 已经积累的证据表明，肾脏激肽释放酶-激肽系统介导 糖尿病和膳食蛋白引起的肾血流动力学改变。 一 肾激肽释放酶和激肽作为系膜细胞生长因子的作用 还没有探索过扩张。 我们最近的初步数据显示， 第一次，激肽直接增加DNA合成，诱导 血管平滑肌癌基因表达与MAP激酶活性 细胞，并刺激细胞质和细胞核的酪氨酸磷酸化 肾小球系膜细胞中的蛋白质。 因此，我们建议调查 激肽在肾小球系膜细胞增殖中的作用， 激肽通过细胞内途径将它们的作用从 细胞表面到细胞核。 我们将：检验激肽 促进肾小球系膜细胞增殖。 为此，我们将 确定激肽是否诱导系膜细胞肥大和/或增生 通过评估激肽对蛋白质和DNA合成的影响， 存活力和细胞数量。 我们将评估内源性生成是否 系膜细胞中一氧化氮或类二十烷酸调节生长 激肽的促进作用。 识别早期反应原癌基因 （c-myc、c-jun、c-fos），其可响应于激肽激发而被诱导。 评估激活蛋白（AP-1）的转录激活是否 1)复合物通过激肽促进核信号传导。 表征 连接激肽-受体相互作用的信号通路 刺激系膜细胞生长。 我们将鉴定细胞质和 在对激肽的反应中可能被磷酸化的核蛋白 刺激. 具体来说，我们将研究pp/60 c的磷酸化- src、微管蛋白、MAP-激酶和c-Jun。 激活，如果是这样，MAP激酶是否易位 从细胞质到细胞核。

The overall objective of the present proposal is to explore the role of kinins in mesangial cell proliferation and to characterize the kinin signaling pathways involved in mediating these events. Increasing evidence indicates that mesangial cell proliferation is important in the pathogenesis of mesangial expansion; mesangial cell hypertrophy, hyperplasia and matrix accumulation may ultimately lead to glomerulosclerosis. The signals which initiate proliferation are not clearly defined although a number of mediators have been implicated. We have accumulated evidence that the renal kallikrein-kinin system mediates the renal hemodynamic changes induced by diabetes and dietary protein. A role for renal kallikrein and kinins as growth factors for mesangial cell expansion has not been explored. Our recent preliminary data, indicate for the first time, that kinins directly increase DNA synthesis, induce oncogene expression and MAP-kinase activation in vascular smooth muscle cells, and stimulate tyrosyl phosphorylation of cytoplasmic and nuclear proteins in mesangial cells. Therefore, we propose to investigate the role of kinins in mesangial cell proliferation and to dissect the intracellular pathways by which kinins propagate their effects from the cell surface to the nucleus. We will: Test the hypothesis that kinins promote proliferation of glomerular mesangial cells. To do this we will determine if kinins induce mesangial cell hypertrophy and/or hyperplasia by assessing the influence of kinins on protein and DNA synthesis, cell viability and cell number. We will evaluate whether endogenous generation of nitric oxide or eicosanoids in mesangial cells modulate the growth promoting effects of kinins. Identify the early response proto-oncogenes (c-myc, c-jun, c-fos) that may be induced in response to kinin challenge. Evaluate whether transcriptional activation of the activator protein (AP- 1) complex contributes to nuclear signaling by kinins. To characterize the signaling pathway(s) that link kinin-receptor interactions to stimulation of mesangial cell growth. We will identify cytoplasmic and nuclear proteins that may be phosphorylated in response to kinin stimulation. Specifically, we will study the phosphorylation of pp/60c- src, tubulin, MAP-kinase and c-Jun. Determine whether MAP-kinase is activated in response to kinin and if so, whether MAP-kinase translocates from the cytoplasm to the nucleus.