A Genetic Model of Urogenital Development & Obstruction

描述(由申请人提供)：据估计，美国有3500万人患有膀胱病，仅儿童终末期肾功能衰竭每年的成本估计就超过150亿美元。尽管膀胱疾病很普遍，但目前对控制这些过程的机制知之甚少。我们已经确定了一种独特的插入突变小鼠模型，该模型发生在子宫巨大膀胱，导致梗阻性尿路疾病继发的可变性输尿管肾积水和慢性肾功能衰竭。这些动物被命名为MGB，意为巨型膀胱，在胚胎第15天时明显存在膀胱平滑肌发育的原发缺陷，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。这个项目的长期目标是更好地了解控制正常膀胱发育和发病的复杂分子途径，具体目标1我们建议使用组织学和免疫组织化学技术来完成MGB表型的表征。在特定的目标2中，我们打算使用重叠的、多方面的方法来确定MGB表型的遗传位点，包括转基因插入位点的细胞遗传学特征、基因组断裂点的鉴定、候选基因的表达分析以及通过反向转基因拯救表型。最后，在特定的目标3中，我们将进行形态计量分析、体外膀胱测压和超声来表征MGB小鼠的功能状态，并通过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增强我们对正常膀胱发育和发病机制的了解，并为未来治疗策略的制定和评估奠定基础。

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.