MOLECULAR MECHANISMS IN HEREDITARY NEPHRITIS

遗传性肾炎的分子机制

• 批准号: 6335030
• 负责人: BILLY GERALD HUDSON
• 金额: $ 24.77万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6335030
• 关键词: Alport syndrome; basement membrane; chronic renal failure; collagen; developmental genetics; dogs; glomerulonephritis; molecular pathology; pathologic process; protein structure function; renal glomerulus; sex linked trait

Alport Syndrome is a hereditary disorder characterized by progressive nephropathy which is frequently associated with sensorineural deafness and ocular abnormalities. The nephropathy has been linked to a structural abnormality in the glomerular basement membrane (GBM) which is caused by mutations in the gene encoding the alpha3, alpha4 and alpha 5 chains of type IV collagen. The most common form is X-linked, in which over 200 mutations have been found in the COL4A5 gene encoding the alpha5 chain. These mutations interfere with the formation of the alpha3(IV)/alpha4(IV)/alpha5(IV) supramolecular network of type IV collagen. Most male patients have near normal kidney function at birth, which deteriorates over time leading to end-stage renal disease by mechanisms that are not understood. The central thrust of this proposal is to test the hypothesis that the progression to end-stage renal disease in X -linked hereditary nephritis evolves from a congenital malformation of the glomerular basement membrane (GBM) which involves COL4A5 mutations that arrest a developmental switch from the immature alpha1(IV)/alpha2(IV) network to the nature alpha3(IV)/alpha4(IV)/alpha5(IV) network, and the persistence of this immature network predisposes the GBM to proteolytic degradation. The cornerstone of the research plan is a use of the canine X-linked model of the human disease in which the COL4A5 gene mutation is a premature stop codon. The specific aims are: Aim 1: Determine the nature and timing of the switch from immature to mature GBM in normal dog kidney in comparison to affected male dogs. Aim 2: Determine which glomerular cells synthesize the alpha3(IV), alpha4(IV) chains. Aim 3: Examine the relationship between the expression of the alpha3(IV), alpha4(IV) and alpha5(IV) chains. Aim 4: Determine the temporal relationship at both the message nd protein levels of the expression of the alpha1(IV)-alpha6(IV) chains in normal dogs compared to affected male dogs during progression of their disease. Aim 5: Determine the susceptibility of type IV collage of GBM to proteolytic degradation in normal and affected male dogs. The achievement of these aims requires application of the techniques of molecular biology, biochemistry, immunochemistry and cell biology. It is anticipated that the achievement of the aims will yield new insights into the mechanisms underlying the pathogenesis of Alport Syndrome. An understanding of these mechanisms is fundamental to the development of therapeutic measures to correct the disorder by gene therapy or to delay progression to end stage renal disease.

阿尔波特综合症是一种遗传性疾病，其特征是进行性进展 nephropathy which is frequently associated with sensorineural deafness and 眼部异常。肾病与结构性肾病有关 肾小球基底膜（GBM）异常，其原因是 编码α3、α4和α5链的基因发生突变 IV型胶原蛋白。最常见的形式是X连锁，其中超过200 在编码 alpha5 链的 COL4A5 基因中发现了突变。 这些突变干扰了 IV型α3(IV)/α4(IV)/α5(IV)超分子网络 胶原。大多数男性患者出生时肾功能接近正常， 随着时间的推移，病情恶化，导致终末期肾病 不被理解的机制。 该提案的中心目标是检验以下假设： X连锁遗传性肾炎进展为终末期肾病 由肾小球基底膜先天性畸形演变而来 (GBM) which involves COL4A5 mutations that arrest a developmental switch 从不成熟的alpha1(IV)/alpha2(IV)网络到自然 alpha3(IV)/alpha4(IV)/alpha5(IV) 网络，以及该网络的持久性 不成熟的网络使 GBM 易于蛋白水解降解。这 该研究计划的基石是使用犬X连锁模型 COL4A5基因突变导致的人类疾病提前停止 密码子。具体目标是： 目标 1：确定从不成熟到成熟转变的性质和时机 mature GBM in normal dog kidney in comparison to affected male dogs. 目标 2：确定哪些肾小球细胞合成 alpha3(IV)， α4(IV) 链。 目标 3：检查 alpha3(IV) 的表达之间的关系， α4(IV) 和 α5(IV) 链。 目标 4：确定消息和蛋白质的时间关系 正常情况下 α1(IV)-α6(IV) 链的表达水平 在疾病进展期间，狗与受影响的雄性狗进行比较。 目标 5：确定 GBM IV 型拼贴的敏感性 正常和受影响的雄性狗的蛋白水解降解。 实现这些目标需要应用以下技术 分子生物学、生物化学、免疫化学和细胞生物学。这是 预计目标的实现将产生新的见解 阿尔波特综合征发病机制的潜在机制。一个 对这些机制的理解是发展的基础 therapeutic measures to correct the disorder by gene therapy or to delay 进展至终末期肾病。