Autosomal Mutagenesis and Polycystic Kidney Disease

常染色体突变和多囊肾病

• 批准号: 7074382
• 负责人: MITCHELL S TURKER
• 金额: $ 15.48万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7074382
• 关键词: disease /disorder etiology; gene environment interaction; gene frequency; gene mutation; histology; immunocytochemistry; ionizing radiation; kidney cell; laboratory mouse; mutant; nucleic acid structure; polycystic kidney; polymerase chain reaction; radiobiology

DESCRIPTION (provided by applicant): Polycystic kidney disease (PKD) is characterized by kidney cysts and may account for 5-8% of all end stage renal disease in the United States. The autosomal dominant form of PKD is due to inherited mutation of either PKD1 or PKD2 and cyst formation is believed to begin with "second step" autosomal mutations that occur in kidney epithelial cells. The relationship between second step autosomal mutation and kidney cyst development in two mouse models of autosomal dominant PKD is the focus of this exploratory R21 application. The major hypothesis to be tested is that environmental and genetic approaches that increase somatic mutations in renal epithelial cells will proportionally increase cyst formation in mice heterozygous for Pkd1 or Pkd2. Two specific aims are offered. The first will use ionizing radiation to induce mutations in the right kidneys of mice whose left kidneys will be shielded from exposure. Cyst formation will then be quantified with histological methods in the exposed and shielded kidneys as a function of time after exposure. By controlling mutation induction with ionizing radiation exposure the amount of time necessary for a somatic mutational event to translate into a kidney cyst can be determined. The second aim will use mismatch repair deficiency to increase autosomal mutations 10-fold or greater in the kidney cells. The presence of mononucleotide runs in the coding sequence of Pkd1, but not in Pkd2, is predicted to make the Pkd1 gene significantly more mutable in the mismatch repair deficient background, and thereby demonstrate a potential role for gene structure in cyst formation. Immunohistochemistry will be used in both specific aims to provide evidence that the types of mutations present in the cells surrounding the kidney cysts are consistent with the mutational approaches taken because the presence or absence of PKD protein will reflect small and large mutational events, respectively. Successful completion of the proposed experiments will provide basic information about the etiology and pathogenesis of PKD by directly demonstrating quantitative and temporal relationships between autosomal mutation and cyst formation.

描述（由申请人提供）：多囊性肾脏疾病（PKD）的特征是肾脏囊肿，在美国可能占所有末期肾脏疾病的5-8％。 PKD的常染色体显性形式是由于PKD1或PKD2的遗传突变所致，并且囊肿的形成被认为是从肾上皮细胞中发生的“第二步”常染色体突变开始。常染色体显性PKD的两个小鼠模型中，第二步常染色体突变与肾囊肿发育之间的关系是该探索性R21应用的重点。要测试的主要假设是，增加肾上皮细胞中体细胞突变的环境和遗传方法将按比例增加PKD1或PKD2的杂合小鼠的囊肿形成。提供了两个具体目标。第一个将使用电离辐射在右肾脏的右肾脏中诱导突变，其左肾脏将免受暴露。然后，将用暴露和屏蔽肾脏中的组织学方法对囊肿形成作为暴露后时间的函数进行量化。通过电离辐射暴露控制突变诱导，可以确定躯体突变事件转化为肾脏囊肿所需的时间。第二个目标将使用不匹配的修复缺乏来增加肾细胞10倍或更高的常染色体突变。预测在PKD1的编码序列中存在单核苷酸的存在，而不是在PKD2中运行，可以使PKD1基因在不匹配修复缺陷的背景中明显更为突出，从而证明了基因结构在囊肿形成中的潜在作用。两种特定目的都将使用免疫组织化学，以提供证据表明肾脏囊肿周围存在的突变类型与采用的突变方法一致，因为PKD蛋白的存在或不存在将分别反映出大和大突变事件。成功完成所提出的实验将通过直接证明常染色体突变与囊肿形成之间的定量和时间关系来提供有关PKD病因和发病机理的基本信息。