GENETIC AND PATHOLOGIC ALTERATIONS IN MURINE DIABETES

糖尿病（DM）的实验模型在小鼠中存在许多。 非肥胖型糖尿病品系（NOD/Lt）发展为胰岛素依赖型糖尿病，伴有免疫胰腺β细胞破坏和以多基因方式遗传的胰岛素减少症。Leprdb菌株发展非胰岛素依赖性DM，其特征在于肥胖和胰岛素抵抗，这是由于瘦素受体基因（Lepr）中的单核苷酸取代。 有证据表明，在两种品系的糖尿病小鼠中发生的肾功能和形态学变化与临床上在人类中观察到的大部分相似，包括白蛋白尿和肾小球基质蓄积的发生。大量的努力和技术进步已经允许持续鉴定和测序表达的基因，一些与已知的基因家族相关，一些是新的。 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，许多研究小组正在开发大规模并行DNA分析技术。 这种方法允许确定哪些基因在特定时间在给定组织中表达。在这些研究中，将对NOD/Lt和Leprdb小鼠组进行纵向随访。 在不同时间，将处死选定的动物，以详细评价与人糖尿病肾病相关的肾脏病理变化。 将测定Dm中潜在改变的基因的mRNA表达。将使用大规模并行DNA分析技术评价基于申请中详述的逻辑选择的基因。来自糖尿病和对照肾小球的mRNA将被差异标记并与含有cDNA的微芯片杂交。 将确定这些基因表达的相对增加或减少。该策略将允许鉴定可能在实验性胰岛素和非胰岛素依赖性DM中受影响的已知和新基因，并将这些基因与肾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额外的工作是合理的：1）鉴定在人类糖尿病肾病中可能改变的类似基因; 2）确定鉴定的基因产物在实验性糖尿病肾病中的重要性; 3）研究DM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.