MOLECULAR ASPECTS OF ALPORT RENAL DISEASE PROGRESSION

Alport综合征是由IV型胶原基因突变引起的 Col4A3、Col4A4或Col4A5基因。病理学包括青少年发病 进行性肾小球肾炎伴肾小球基底膜 系膜矩阵的稀疏化和扩展，最终导致 死于肾功能衰竭。Alport基因敲除小鼠模型的建立 本实验室产生的综合征，其肾脏病理 与在人类身上观察到的非常相似。特定物品的沉积 基底膜中的细胞外基质蛋白随基底膜的变化而变化 膜稀疏化。这一定是由于它们的合成发生了变化。 和/或营业额..这项提案的目的是澄清 基底膜胶原蛋白的合成和降解 Aport GBM疾病进展中的相关蛋白。可能扮演的角色 在整合素受体中，转化生长因子β1(TGF-β1)， 并将探索金属蛋白酶(及其抑制物)。 定量分析(使用分离肾小球的材料)将 用于确定特定mRNAs的相对水平(通过Norther印迹) 以及相应的蛋白质(通过蛋白质印迹)。就地 杂交研究将确定哪些类型的肾小球细胞 合成这些蛋白质。潜在机械论的观察 将使用正常人的肾活检组织来测试其意义。 和Alport的病人。转化生长因子-β1或蛋白尿是否与 编码细胞外基质分子的基因的诱导将是 联合应用转化生长因子-βI型和II型受体的探讨 将使用组合方法探测抑制剂(FK506)分子 转化生长因子-β1。Col4A3和整合素α1链的双重敲除 已生产，并显示Alport的速度显著下降 肾脏疾病进展。这一令人惊讶的分子机制 将探索其影响。分子机制的鉴定 Alport综合征的GBM动态平衡失衡可能 揭示药物干预的潜在靶点。

Alport syndrome results from mutations in either the type IV collagen COL4A3, COL4A4, or COL4A5 genes. Pathology includes a juvenile onset progressive glomerulonephritis with glomerular basement membrane (GBM) rarefication and expansions of the mesangial matrix, culminating in death due to renal failure. A gene-knockout mouse model for Alport syndrome was produced in this laboratory, the renal pathology of which is remarkably similar to that observed in humans. Deposition of specific extracellular matrix proteins in the GBM follows course with basement membrane rarefication. This must be due to changes in their synthesis and/or turnover.. The aims of this proposal focus on clarifying the role of synthesis and degradation of basement membrane collagens and associated proteins in Aport GBM disease progression. The possible role of integrin receptors, transforming growth factor beta 1 (TGF-beta1), and metalloproteinases (and their inhibitors) will be explored. Quantitative analysis (employing material from isolated glomeruli) will be used to determine relative levels of specific mRNAs (by norther blot) and their corresponding proteins (by western blot). In situ hybridization studies will determine which glomerular cell types synthesize these proteins. Observations with potential mechanistic significance will be tested using human renal biopsy tissues from normal and Alport patients. Whether TGF-beta1 or proteinuria is linked to induction of genes encoding extracellular matrix molecules will be probed using a combination approach of TGF-beta type I and II receptor inhibitor (FK506) molecules will be probed using a combination approach of TGF-beta1. A double knockout of the COL4A3 and integrin alpha1 chain has been produced, and shows a marked reduction in the rate of Alport renal disease progression. The molecular mechanism of this surprising effect will be explored. Identification of the molecular mechanisms underlying the imbalance in GBM homeostasis in Alport syndrome may reveal potential targets for pharmacologic intervention.