A MODEL FOR BASEMENT MEMBRANE THICKENING IN DIABETES

糖尿病进行性继发并发症涉及病理 肾脏、视网膜和一般的血管系统。一个共同的特征 这些继发性并发症中有一种是细胞基底的异常。 膜(BM)。这些异常表现在许多组织中。 作为一种普遍的基底膜增厚，某种程度上是由于 糖尿病患者存在的高血糖状态。这个 糖尿病患者基底膜的结构改变 被认为是导致肾功能不全的基本缺陷， 与失明和一般血管疾病相关的视网膜病变 与感染和组织坏死有关。细胞和分子 糖尿病患者基底膜改变的基础尚不清楚，但 目前的解释包括：1)基底膜合成改变 分子，2)改变基底膜成分的周转，3) 基底膜格子的改变组装和拆卸 由这种化学物质引起的单个成分的结构变化 修饰为非酶糖基化。实验方法： 评估这些假说因缺乏体外和活体实验而受阻。 细胞模型。为了解决这个问题，我们开发了一种 体内基底膜形成的细胞模型 为随后的细胞机制分析而进行的实验诱导 参与了这一过程。该模型由上皮双分子层组成。 具有中间的基底膜(即，模型简化为 假设中感兴趣的基本要素)。此外，我们还有 确定这个体内模型通过以下方式对高血糖条件做出反应 糖尿病患者基底膜增厚。而不是 然而，目前可用的糖尿病脊椎动物模型，细胞 我们使用的系统在96小时内形成一层基底膜，并使 在相同的时间范围内该基底膜的厚度 暴露于高水平的葡萄糖。这一模型是使用 刺蛇，九头蛇。拟议的项目将在体内利用这一点。 确定葡萄糖介导的基底膜增厚结果的模型 基底膜合成过程中的细胞异常 组件。使用博德博士的实验室(东道主)开发的专业知识 实验室)与九头蛇的分子生物学有关，P.I.将使用 C DNA、合成寡核苷酸和聚合酶链式反应 筛选现有Hydra cDNA文库以开发HydrasSpecitic的技术 用于检验有关效应的假说的研究中使用的探头 葡萄糖水平升高对基底膜合成的影响 组件。

Progressive secondary complications of diabetes mellitus involve pathology of the kidney, retina, and general vasculature system. A common feature of these secondary complications is abnormalities of cell basement membranes (BM). These abnormalities are characterized in numerous tissues as a general thickening of basement membrane somehow resulting from the hyperglycemic conditions existing in individuals with diabetes. The structural alterations associated with the basement membranes of diabetics has been implicated as the basic defect leading to kidney malfunction, retinal lesions associated with blindness, and general vascular disorders associated with infection and tissue necrosis. The cellular and molecular basis for basement membrane alterations in diabetes is not understood, but current explanations include: 1) altered synthesis of basement membrane molecules, 2) altered turnover of basement membrane components, and 3) altered assembly and disassembly of the basement membrane lattice due to altered structure of individual components resulting from such chemical modifications as non-enzymatic glycation. Experimental approaches to evaluate these hypotheses are hampered by a lack of in vitro and in vivo cellular models. In order to approach this problem we have developed an in vivo cellular model in which basement membrane formation can be experimentally induced for subsequent analysis of the cellular mechanisms involved in the process. This model is comprised of an epithelial bilayer with an intervening basement membrane (i.e. a model reduced to the essential elements of interest in the hypotheses). In addition, we have determined that this in vivo model responds to hyperglycemic conditions by thickening its basement membrane as observed in diabetics. As opposed to vertebrate animal models of diabetes currently available however, the cell system we utilize develops a basement membrane within 96 hr and doubles the thickness of this basement membrane within this same time frame when exposed to elevated levels of glucose.This model was developed using the Cnidarian, Hydra vulgaris. The proposed project will utilize this in vivo model to determine if glucose-mediated basement membrane thickening results from cellular abnormalities in the synthesis of basement membrane components. Using expertise developed in the Dr. Bode's laboratory (host laboratory) related to the molecular biology of Hydra, the P.I. will use cDNA, synthetic oligonucleotides, and polymerase chain reaction (PCR) technology to screen existing Hydra cDNA libraries to develop Hydraspecific probes for use in studies designed to test hypotheses regarding the effect of elevated glucose levels on the synthesis of basement membrane components.