GENETIC AND PATHOLOGIC ALTERATIONS IN MURINE DIABETES

糖尿病(DM)小鼠体内存在多种实验性糖尿病模型。非肥胖糖尿病株(NOD/LT)发展为胰岛素依赖型糖尿病，并伴有免疫性胰岛β细胞破坏和多基因遗传的胰岛素减少症。Leprdb菌株发展为非胰岛素依赖型糖尿病，其特征是肥胖和胰岛素抵抗，这是由于瘦素受体基因(LEPR)的单核苷酸替换造成的。有证据表明，这两种类型的糖尿病小鼠的肾脏功能和形态变化与临床上在人类中看到的大部分相似，包括蛋白尿和肾小球基质堆积。大量的努力和技术的进步使得对表达基因的持续鉴定和测序成为可能，其中一些与已知基因家族有关，一些与新基因有关。在大多数情况下，这些基因序列都在可访问的数据库中。为了确定这些基因产物在不同情况下的相关性，许多小组正在开发大规模并行DNA分析技术。这种方法可以确定哪些基因在特定的时间在特定的组织中表达。在这些研究中，NOD/LT组和Leprdb组小鼠将被纵向跟踪。在不同的时间，选定的动物将被处死，以详细评估与人类糖尿病肾病相关的肾脏病理变化。糖尿病中可能改变的基因的信使核糖核酸的表达将被确定。根据申请中详细说明的逻辑选择的基因将使用大规模并行DNA分析技术进行评估。来自糖尿病肾小球和对照肾小球的mRNA将被差异标记并与含有cDNA微芯片杂交。这些基因表达的相对增加或减少将被确定。该策略将允许识别在实验性胰岛素依赖型和非胰岛素依赖型糖尿病中可能受到影响的已知和新基因，并将这些基因与肾脏功能和病理变化相关联。此外，这些初步研究的成功完成将证明有必要开展更多工作，以：1)确定人类糖尿病肾病中可能发生改变的类似基因；2)确定已确定的基因产物在实验性糖尿病肾病中的重要性；以及3)研究糖尿病中受影响的其他基因和器官系统。

A number of experimental models of diabetes mellitus (DM) exist in mice. The non-obese diabetic strain (NOD/Lt) develops insulin-dependent DM with immunologic pancreatic beta cell destruction and insulinopenia inherited in a polygenic fashion. The Leprdb strain develops non-insulin dependent DM characterized by obesity and insulin resistance due to a single nucleotide substitution in the leptin receptor gene (Lepr). There is evidence that the renal functional and morphological changes occurring in both strains of diabetic mice parallel much of what is seen clinically in humans, including the development of albuminuria and glomerular matrix accumulation. A great deal of effort and technological advancements have allowed the continual identification and sequencing of expressed genes, some related to known gene families and some novel. For the most part, these gene sequences are in accessible data bases. To determine the relevance of these gene products in various circumstances, he technique of massively parallel DNA analysis is being developed by a number of groups. This approach allows the determination of which genes are expressed in a given tissue at a particular time. In these studies, groups of NOD/Lt and Leprdb mice will be followed longitudinally. At different times, selected animals will be sacrificed for detailed evaluation of renal pathological changes relevant to human diabetic nephropathy. The expression of mRNA for genes potentially altered in Dm will be determined. Genes chosen based on logic detailed in the application will be evaluated using the technique of massively parallel DNA analysis. mRNA from diabetic and control glomeruli will be differentially labeled and hybridized with cDNA-containing microchips. A relative increase or decrease in the expression of these genes will be determined. The strategy will permit identification of known and novel genes that may be affected in experimental insulin- and noninsulin- dependent DM and correlate these with renal functional and pathological changes. Furthermore, successful completion of these pilot studies will justify additional work to: 1) identify analogous genes potentially altered in human diabetic nephropathy; 2) determine the importance of identified gene products in experimental diabetic nephropathy; and, 3) study additional genes and organ systems affected in DM.