Defining the renal urothelium progenitor and its regulation during development and repair

项目总结/摘要 先天性尿路梗阻（UTO）是慢性肾病和终末期肾病的主要原因， 儿童疾病。目前的管理策略不能预防慢性肾脏疾病的进展。 最近发表的来自我的F32资助的博士后研究的数据将肾尿路上皮重塑确定为 对UTO的保护性适应先天性和获得性UTO均触发尿斑蛋白（Uroplakin，Upk）的形成 表达合成膀胱样尿路上皮斑块的尿路上皮细胞（UC）。尿路上皮斑块的耗竭 患有先天性UTO的小鼠加速肾实质丧失、功能损害和死亡， Upk-UC在预防梗阻性肾病中的关键作用。对肾尿路上皮的更深入了解 发展和修复可能导致旨在减轻阻塞性肾病的治疗。基本 然而，在我们对Upk-UCs在发展和UTO期间形成的理解方面存在知识差距。 我最近证明了表达角蛋白5（K5）的UC在发育过程中分化为Upk-UC 跟随UTO。该应用直接针对K5-UC是其命运与K5-UC无关的祖细胞的假设。 是由一个内在的分子程序，随着时间的推移和对损伤的反应而变化。预期 这项研究的结果是建立控制K5-UC祖细胞活性的分子机制， 确定K5-UC祖细胞在发育期间和UTO后的贡献。在目标1中，我将 使用类器官测定研究时间限制的K5-UC祖细胞活性是否是细胞内在的; 检查Notch信号在K5-UC命运调节中的作用;并定义调节K5-UC命运的分子程序。 尿路上皮发育和修复。在目标2中，我将通过评估K5-UC的重要性， 在UTO期间K5-UC的消耗和扩增对尿路上皮发育和修复的影响。研究 本申请中提出的方法将揭示Upk-UC形成的细胞和分子基础-假设 K5-UC以Notch依赖的方式形成Upk-UC。这些目标的成功实现将提供 为开发靶向K5-UC分化以减轻梗阻性肾脏的治疗奠定了基础 UTO患者的疾病。在实现这些目标，我将发展在稀有细胞分离，类器官 发展，信号通路分析，生物信息学，肾生理学和病理生理学的阻塞性 肾病掌握这些技能，结合根据《职业发展战略》开展的有组织的职业发展活动， 我的导师和研究咨询团队的指导，将使我准备成功地竞争R 01资金 作为一名独立的科学家，我的职业生涯将开始， UTO患儿的肾脏疾病进展。

PROJECT SUMMARY/ABSTRACT Congenital urinary tract obstruction (UTO) is a leading cause of chronic kidney disease and end stage renal disease in children. Current management strategies cannot prevent chronic kidney disease progression. Recently published data from my F32-funded postdoctoral studies identify renal urothelial remodeling as a protective adaptation to UTO. Both congenital and acquired UTO trigger the formation of Uroplakin (Upk) expressing urothelial cells (UC) that synthesize a bladder-like urothelial plaque. Depletion of urothelial plaque in mice with congenital UTO accelerates renal parenchymal loss, functional impairment, and death – attesting to key roles for Upk-UCs in preventing obstructive nephropathy. A greater understanding of renal urothelial development and repair may lead to therapies aimed at attenuating obstructive kidney disease. Fundamental knowledge gaps exist, however, in our understanding of the formation of Upk-UCs during development and UTO. I have recently demonstrated that Keratin 5 (K5)-expressing UCs differentiate into Upk-UCs during development and following UTO. This application takes direct aim at the hypothesis that K5-UCs are progenitors whose fate is governed by an intrinsic molecular program that varies over time and in response to injury. The anticipated outcome of this research is to establish molecular mechanisms that govern K5-UC progenitor activity, and to determine the contributions of K5-UC progenitors during development and following UTO. In Aim 1, I will investigate whether temporally restricted K5-UC progenitor activity is cell-intrinsic using organoid assays; examine the role of Notch signaling in the regulation of K5-UC fate; and define molecular programs that regulate urothelial development and repair. In Aim 2, I will investigate the significance of the K5-UCs by evaluating the impact of depletion and expansion of K5-UCs on urothelial development and repair during UTO. The studies proposed in this application will reveal the cellular and molecular basis of Upk-UC formation – with the hypothesis that K5-UCs form Upk-UCs in a Notch dependent manner. Successful completion of these aims will provide the foundation for the development of therapies that target K5-UCs for differentiation to attenuate obstructive kidney disease in patients with UTO. In fulfilling these Aims, I will develop critical skills in rare cell isolation, organoid development, signaling pathway analysis, bioinformatics, renal physiology and pathophysiology of obstructive nephropathy. Mastery of these skills, in combination with structured career development activities under the guidance of my mentors and research advisory team, will prepare me to successfully compete for R01 funding and launch my career as an independent scientist focused on developing therapies aimed at attenuating chronic kidney disease progression in children with UTO.