PATHOBIOLOGY OF GLOMERULAR MATRIX METABOLISM

该项目的长期目标是更好地了解 控制肾小球结构和功能的因素 细胞外基质 这是一个高度专业化的结构， 负责维持肾小球滤过功能。 肾小球疾病通常与以下改变有关： 肾小球基质的结构完整性或积聚 异常数量的这种物质 肾小球系膜细胞具有 已经发现向培养基中分泌一种酶活性， 降解关键的基底膜成分IV型胶原蛋白。 这 酶活性进行纯化和表征，发现是IV型 胶原酶/明胶酶。 广泛的结构分析表明， 酶可能是独特的和初步的实验使用特定的抗体 已经将这种酶定位于肾小球系膜或正常， 肾炎动物 建议继续进行结构性 通过分子克隆和序列分析对该酶进行表征 并确定该酶在几种模型中的表达程度 肾炎。 这些表达研究将在 免疫组织化学和原位杂交水平，使用一种新的方法， 在我们的实验室里开发的。 最后，聚合酶链反应将 可用于扩增相关金属蛋白酶的序列， 正常和肾炎动物的肾小球，从而大大延长 我们目前对蛋白水解酶的类型和模式的理解 由固有肾小球细胞表达。 这种类型的信息 可能会导致高度特异性抑制剂的发展， 可用于阻断这些酶在炎症中的过度活性， states.

The long-term goals of this project concern a better understanding of the factors controlling the structure and function of the glomerular extracellular matrix. This is a highly specialized structure which is responsible for the maintenance of the glomerular filtration function. Diseases of the glomerulus are frequently associated with alterations in the structural integrity of the glomerular matrix or with the accumulation of abnormal quantities of this material. Glomerular mesangial cells have been found to secrete into culture medium an enzyme activity which can degrade a critical basement membrane component, type IV collagen. This enzyme activity was purified and characterized and found to be a type IV collagenase/gelatinase. Extensive structural analyses suggest that this enzyme may be unique and preliminary experiments using specific antibodies have localized this enzyme to the glomerular mesangium or normal and nephritianimals. It is proposed to continue the structural characterization of this enzyme by molecular cloning and sequence analysis and to determine the degree of expression of this enzyme in several models of nephritis. These expression studies will be performed at the immunohistochemical and in situ hybridization levels, using a new method developed in our laboratory. Finally, the polymerase chain reaction will be used to amplify sequences for related metalloproteases from the glomeruli of normal and nephritic animals, thereby considerably extending our current understanding of the types and patterns of proteolytic enzymes expressed by the intrinsic glomerular cells. This type of information could possibly lead to the development of highly specific inhibitors which could be used to block excessive activity of these enzymes in inflammatory states.