RENAL AND CELLULAR STUDIES IN TYPE I DIABETIC PATIENTS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 研究中心，而研究中心不一定是研究者所在的机构。 糖尿病肾病（diabetic nephropathy，DN）是导致肾功能衰竭的主要原因，但其发病机制尚不清楚. 这些研究的目的是（a）基于来自个体胰岛素依赖型糖尿病（IDDM）患者的细胞的体外研究开发风险标志物，其与肾活检终点相关，（B）询问这些标志物是否代表遗传决定的过程，以及（c）定义细胞凋亡与肾活检终点之间的关系。（体外）细胞外基质（ECM）分子、其酶和酶调节剂、生长因子、葡萄糖转运蛋白的mRNA表达，和钠/氢逆向转运蛋白与肾脏结构和功能指标的关系，探讨DN的基本发病机制;开发一个DNA和培养细胞的储存库，以评估显示与DN相关的遗传变异的细胞功能后果风险 将研究三个患者组：（a）早期（~10年）和长期（~20年）持续的IDDM患者，分为2组，DM病变发展缓慢或快速，（B）同胞对与IDDM一致，（c）同卵双胞胎与IDDM不一致。 DN将通过形态学定量，并考虑持续时间或表示为间隔5年的2次活检确定的发生率。 主要终点将是通过电子显微镜形态测定分析测量的系膜体积分数[Vv（Mes/glom）]。 对长期IDDM患者的横断面研究将允许鉴定与DN病变和临床肾脏异常的非常快速或非常缓慢的发展相关的细胞标志物。 在短期“快速”和“慢通道”患者以及IDDM同胞对中进行的纵向研究（5年）将考虑到糖尿病、血压和其他“环境变量”。“将使用逆转录酶聚合酶链反应评价来自个体患者的培养皮肤成纤维细胞（SF）的上述分子的mRNA表达。 选择SF是因为其表型变化发生在“快速通道”IDDM患者中，并且在兄弟姐妹中相关。 这些研究将确定DN病变与SF行为的关系，并评估这种行为在DN病变一致的IDDM同胞对中是否一致。 来自非糖尿病同卵双胞胎的SF将回答高血糖是否是DN风险细胞标志物表达所必需的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Diabetic nephropathy (DN) is the leading cause of renal failure, yet pathogenetic understanding remains limited. Objectives of these studies are (a) to develop risk markers based on in vitro studies of cells derived from individual insulin dependent diabetic (IDDM) patients, which are related to renal biopsy endpoints, (b) to ask if these markers represent genetically determined processes and (c) to define relationships between cellular (in vitro) expression of mRNA for extracellular martix (ECM) molecules, their enzymes and enzyme regulators, growth factors, glucose transporters, and sodium/hydrogen antiporter and renal structural and functional endpoints in order to explore basic pathogenic mechanisms in DN; to develop a repository of DNA and cultured cells that will allow evaluation of the cellular functional consequences of genetic variations shown to be linked to DN risk. Three patient groups will be studied: (a) early (~10 years) and long-term (~20 years) IDDM duration patients dichotomized into 2 groups with slow or rapid development of DM lesions, (b) sibling pairs concordant for IDDM, and (c) identical twins discordant for IDDM. DN will be quantitated morphometrically, and factored for duration or expressed as a rate determined by 2 biopsies 5 years apart. The primary endpoint will be mesangial volume fraction [Vv(Mes/glom)] measured by electron microscopic morphometric analysis. Cross-sectional studies of long-term IDDM patients will allow the identification of cellular markers associated with very rapid or very slow development of DN lesions and clinical renal abnormalities. Longitudinal studies (5 year) in shorter-term "fast" and "slow-track" patients and IDDM sibling pairs will allow factoring for glycemia and blood pressure and other "environmental variables." Cultured skin fibroblasts (SF) from individual patients will be evaluated for mRNA expression for the above listed molecules using reverse transcriptase polymerase chain reaction. SF are selected since changes in their phenotype occur in "fast-track" IDDM patients and are correlated in sibling pairs. These studies will determine the relationship of DN lesions to SF behavior and evaluate whether this behavior is concordant in IDDM sibling pairs who are concordant for DN lesions. SF from nondiabetic identical twins will answer whether hyperglycemia is necessary for the expression of cellular markers of DN risk.