MODEL FOR GLUCOSE INDUCED BASEMENT MEMBRANE THICKENING

基底膜增厚（或上皮相关细胞外膜增厚） 基质（ECM））是许多疾病状态的共同特征。 为 例如，已经观察到ECM增厚1）与肾脏 多囊肾患者的肾小管和肾小球（GBM） (PKD)，2）与男性患者的曲细精管相关， 某些形式的生育能力受损，3）与GBM相关， Alport综合征患者; 4）糖尿病患者。 这些疾病的进行性继发性并发症与以下因素有关： 与ECM增厚相关的异常。 虽然 解释异常ECM增厚发生的机制 目前还没有，很明显，正常的生物合成和 ECM的维持是健康分化的重要方面， 组织中 正如所指出的，改变的细胞和分子基础 在ECM的形成是不理解的，但可以解释为 ECM组分合成、聚合和降解平衡中的问题 周转 这些过程都涉及细胞/ECM相互作用， 程度，并意味着ECM的形成通常是严格控制的， 细胞和细胞外过程。 评价的实验方法 控制正常ECM形成的机制和 异常增厚的ECM的发生受到缺乏胰岛素的阻碍， 体外和体内细胞模型。 为了解决这些问题，我们 已经开发了一种体内细胞模型，其中上皮相关的 ECM形成可以在短时间内通过实验诱导， 随后对该过程中涉及的细胞机制进行分析。 此外，还开发了触发形成 异常增厚的ECM，使得正常和异常过程都可以 直接比较和评价。 我们开发的模型简单地说， 包括具有居间ECM的上皮双层。 此外，本发明还提供了一种方法， 我们已经确定，这种体内模型对高血糖有反应， 通过增厚其ECM的条件，如在各种病理 条件 与目前可用的脊椎动物模型相反， 然而，我们使用的细胞系统在24-96小时内形成ECM， 在暴露的同一时间内， 葡萄糖水平升高 该模型是使用 刺胞动物，普通水螅。 拟议的项目将在体内利用这一点 分析正常ECM形成并确定是否异常增厚的模型 ECM的结果来自1）合成中的细胞异常， ECM成分的积累，2）细胞外基质中的异常， ECM部件的装配，和/或3）降解异常， ECM组件。 形态学、生物化学和 将利用分子方法来检验这些假设。 这 该项目将提供ECM细胞机制的基本信息 在正常条件下和在ECM 发生增厚。

A thickening in basement membranes (or epithelial-associated extracellular matrix (ECM)) is a common feature of a number of disease states. For example, ECM thickening has been observed 1) associated with the renal tubules and glomeruli (GBM) of patients with polycystic kidney disease (PKD), 2) associated with the seminiferous tubules in male patients with certain forms of impaired fertility, 3) associated with the GBM of patients with Alport syndrome, and 4) in patients with diabetes mellitus. Progressive secondary complications of these diseases have been tied to abnormalities associated with this ECM thickening. Although an explanation as to the mechanisms by which abnormal ECM thickening occurs is not currently available, it is evident that the normal biosynthesis and maintenance of ECM is an important aspect of healthy differentiated tissues. As indicated, the cellular and molecular basis for alterations in ECM formation is not understood, but may be explained in terms of problems in the balance of ECM component synthesis, polymerization, and turnover. These processes all involve cell/ECM interactions to some degree and imply that ECM formation is normally tightly controlled by both cellular and extracellular processes. Experimental approaches to evaluate the mechanisms which govern normal ECM formation and the mechanisms by which abnormally thickened ECM occurs have been hampered by a lack of in vitro and in vivo cellular models. In order to approach these problems we have developed an in vivo cellular model in which epithelial-associated ECM formation can be experimentally induced in a short time frame for subsequent analysis of the cellular mechanisms involved in the process. In addition, methods have been developed to trigger the formation of abnormally thickened ECM so that both the normal and abnormal process can be directly compared and evaluated. The model we have developed is simply comprised of an epithelial bilayer with an intervening ECM. In addition, we have determined that this in vivo model responds to hyperglycemic conditions by thickening its ECM as observed in various pathological conditions. As opposed to vertebrate animal models currently available however, the cell system we utilize develops an ECM within 24-96 hr and doubles the thickness of this ECM 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 analyze normal ECM formation and determine if abnormal thickening of ECM results from 1) cellular abnormalities in the synthesis and accumulation of ECM components, 2) abnormalities in the extracellular assembly of ECM components., and/or 3) abnormalities in the degradation of ECM components. A combination of morphological, biochemical, and molecular approaches will be utilized to test these hypotheses. This project will provide basic information on the cellular mechanisms of ECM formation under normal conditions and under conditions in which ECM thickening occurs.