A Genetic Model of Urogenital Development & Obstruction

描述（由申请人提供）：膀胱疾病影响美国估计3500万人，仅儿童终末期肾衰竭估计每年花费超过150亿美元。尽管膀胱疾病的患病率，目前知之甚少的机制控制这些过程。我们已经确定了一个独特的插入突变小鼠模型，在子宫内的巨梯形发展，导致可变的输尿管肾积水和慢性肾功能衰竭继发于梗阻性尿路病。这些被命名为megabladder的动物，在胚胎第15天就有明显的膀胱平滑肌发育的主要缺陷，其功能结果似乎受到性别的影响。阐明在mgb小鼠中发现的精确的发育和功能缺陷，并确定导致这些异常的遗传位点，将为控制泌尿生殖系统发育和疾病的分子机制提供有价值的信息。该项目的长期目标是更好地了解控制正常膀胱发育和发病机制的复杂分子途径，在具体目标1中，我们建议使用组织学和免疫组化技术完成对mgb表型的表征。在具体目标2中，我们打算使用重叠、多方面的方法来识别负责mgb表型的遗传位点，其中包括转基因插入位点的细胞遗传学表征、基因组断点的识别、候选基因的表达分析以及通过反向转基因进行表型拯救。最后，在具体目标3中，我们将进行形态学分析、体外膀胱测压和超声，以表征mgb小鼠的功能状态，并使用尿量和血清化学将其与动物的临床状态相关联。这些研究的完成将大大提高我们对正常膀胱发育和发病机制的理解，并允许制定和评估未来的治疗策略。

DESCRIPTION (provided by applicant): Diseases of the urinary bladder affect an estimated 35 million people in the United States, with end-stage renal failure in children alone estimated to cost over $15 billion dollars annually. Despite the prevalence of bladder disease, little is currently known regarding the mechanisms controlling these processes. We have identified a unique insertional mutant mouse model that develops in utero megabladder resulting in variable hydroureteronephrosis and chronic renal failure secondary to obstructive uropathy. These animals, designated mgb for megabladder, possess a primary defect in bladder smooth muscle development that is apparent by embryonic day 15, and whose functional outcome appears gender-influenced. Clarifying the precise developmental and functional defects found in mgb mice and determining the genetic locus responsible for these abnormalities will provide valuable information regarding the molecular mechanisms controlling urogenital development and disease. The long-term objectives of this project are to gain a better understanding of the complex molecular pathways that control normal bladder development and pathogenesis, In Specific Aim 1 we propose to complete the characterization of the mgb phenotype using both histological and immunohistochemical techniques. In Specific Aim 2, we intend to identify the genetic locus responsible for the mgb phenotype using an overlapping, multifaceted approach that includes cytogenetic characterization of the transgene insertion site, identification of genomic break points, expression analysis of candidate genes, and phenotype rescue by reverse transgenesis. Finally, in Specific Aim 3, we will perform morphometric analysis, in vitro cystometry and ultrasound to characterize the functional state of mgb mice, and correlate this to the clinical state of the animals using urine output and serum chemistry. Completion of these studies will significantly enhance our understanding of normal bladder development and pathogenesis, and permit the formulation and evaluation of therapeutic strategies in the future.