REGULATION OF NORMAL AND CYSTIC RENAL TUBULOGENESIS

正常和囊性肾管发生的调节

• 批准号: 3247050
• 负责人: W. James Nelson
• 金额: $ 20.04万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-30 至 1997-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3247050
• 关键词: MDCK cell; active sites; adenosinetriphosphatase; cell adhesion molecules; cell cell interaction; cell differentiation; cell growth regulation; confocal scanning microscopy; embryo /fetus tissue /cell culture; enzyme induction /repression; epithelium; gene expression; glycosphingolipids; growth factor; immunocytochemistry; in situ hybridization; laboratory mouse; mammalian embryology; membrane lipids; mesenchyme; mixed tissue /cell culture; ouabain; pathologic process; polycystic kidney; renal tubule

Developmental abnormalities in renal tubule morphogenesis and function are characteristic of polycystic kidney disease, a major genetic disorder in humans that affects over 500,000 people in the United Stats. The cause of the disease is unknown, but it has been postulated that increased cell proliferation and altered transtubular fluid transport are important. Our long term objectives are to understand the morphoregulatory mechanisms involved in the development of normal renal tubule epithelia organization, and to determine whether these mechanisms are altered during development of polycystic kidney disease. We have established in vitro methods to analyze renal epithelial cell development (Transfilter Cultures), and the role of candidate morphogenetic factors in tubulogenesis that will be extended to analyze cells from cystic tubule epithelia of cpk mice, a murine model of polycystic kidney disease. Our preliminary studies show that in early development Na/K-ATPase is transiently localized to the apical membrane domain of normal cells, but is continuously expressed on the apical membrane in cystic epithelial cells. Our previous results indicate that the normal distribution of Na/K-ATPase at the basal-lateral membrane is generated by cell-cell contact and interactions with the membrane- cytoskeleton and membrane lipids. We will test the hypothesize that abnormal regulation of soluble factors that induce tubulogenesis in development could lead to increased cell proliferation of tubular epithelia and, combined with the retention of active Na/K-ATPase on the apical membrane, the formation of cystic tubules: 1. Define the temporal and spatial regulation of Na/K-ATPase distribution following mesenchyme induction and conversion to epithelial cells during normal development. Patterns of expression and distribution of Na/K- ATPase, membrane-cytoskeleton, and membrane lipids will be determined. 2. Modulate the timing of E-cadherin-induced cell-cell interactions during mesenchyme conversion and epithelial cell differentiation. Effects of inhibiting cell-cell contacts on cell differentiation and tubulogenesis during metanephrogenic mesenchyme induction and conversion in culture will be analyzed. 3. Investigate mesenchyme induction and epithelial cell differentiation in transfilter cultures from metanephroi of CPK mice. Patterns of expression and distribution of Na/K-ATPase, membrane-cytoskeleton, and membrane lipids will be determined and compared temporally and spatially to those in normal development. 4. Analyze the expression and function of soluble factors, that regulate tubulogenesis in vitro, on normal and cystic epithelial cell differentiation and tubulogenesis. Expression and function of Scatter Factor/Hepatocyte Growth Factor (SC/HGF), a potent inducer of tubulogenesis in renal epithelial cells in vitro, will be examined in cultures of developing renal tubules from normal and cystic metanephroi, and in purified populations of normal and cystic epithelial cells induced to form branching tubular networks in vitro.

肾小管形态发生和功能的发育异常是 多囊肾病的特征是一种主要的遗传性疾病 影响美国超过 500,000 人的人类。 其原因是 这种疾病尚不清楚，但据推测，细胞增多 增殖和改变的肾小管液体运输很重要。 我们的 长期目标是了解形态调节机制 参与正常肾小管上皮组织的发育， 并确定这些机制在开发过程中是否发生改变 多囊肾。 我们已经建立了体外方法来分析 肾上皮细胞发育（转滤培养物），以及 肾小管发生中的候选形态发生因子将扩展到 分析 cpk 小鼠囊性小管上皮细胞，这是一种小鼠模型 多囊肾。 我们的初步研究表明，在早期 发育 Na/K-ATP酶暂时定位于顶膜 正常细胞的结构域，但在顶端持续表达 囊性上皮细胞的膜。 我们之前的结果表明 基底侧膜 Na/K-ATPase 的正态分布为 由细胞与细胞的接触以及与膜的相互作用产生 细胞骨架和膜脂。 我们将测试以下假设 诱导肾小管发生的可溶性因子的异常调节 发育可能导致肾小管上皮细胞增殖增加 并且，结合根尖上活性 Na/K-ATP 酶的保留 膜，囊性小管的形成： 1. 定义Na/K-ATPase分布的时空调控 间充质诱导并转化为上皮细胞后 正常发育。 Na/K-的表达和分布模式 将测定 ATP 酶、膜细胞骨架和膜脂质。 2. 调节E-钙粘蛋白诱导的细胞间相互作用的时间 间充质转化和上皮细胞分化。 的影响 抑制细胞间接触对细胞分化和肾小管发生的影响 在培养物中的后肾间充质诱导和转化过程中将 进行分析。 3. 研究间充质诱导和上皮细胞分化 来自 CPK 小鼠后肾的转滤培养物。 表达模式 Na/K-ATP酶、膜细胞骨架和膜脂质的分布和分布 将被确定并在时间和空间上与正常情况下进行比较 发展。 4. 分析调节可溶性因子的表达和功能 正常和囊性上皮细胞的体外肾小管发生 分化和管状发生。 Scatter的表达及作用 因子/肝细胞生长因子 (SC/HGF)，肾小管发生的有效诱导剂 在体外肾上皮细胞中，将在培养物中进行检查 肾小管由正常和囊性后肾发育而来，并且在 诱导形成纯化的正常和囊性上皮细胞群 体外分支管状网络。