Small Molecule-Mediated Augmentation of Kidney Regeneration

描述（由申请人提供）：本申请涉及本RFA的三个主题领域：1)应用基因组学和其他高通量技术；2)将基础科学发现转化为新的更好的治疗方法；3)重振生物医学研究界。我们的重点是鉴定新的化合物，这些化合物可以在急性肾损伤（AKI）患者损伤后给药时加速肾脏恢复的速度。严重AKI是一种常见的疾病，死亡率很高。在过去的二十年中，尽管采用了肾脏替代治疗，但缺血性、肾毒性或脓毒性肾小管损伤引起的AKI的死亡率和发病率并没有下降。由于先天性肾小管再生发生在组织损伤后，因此在损伤诱导后给予肾脏增强再生能力的治疗方法的发展引起了相当大的兴趣。这将是该领域的一个重大进展，因为大多数AKI治疗方法在实验模型中显示在肾损伤发生之前施用时有效，但在人类中未能显示出治疗效果。肾小管再生的第一个分子标志是器官发生过程中通常需要的胚胎基因的再激活。因此，我们假设任何在胚胎发育期间引起这些祖细胞扩增的治疗也会加速AKI的恢复速度。为了验证这一假设，我们开发了一种高含量的筛选技术来鉴定促进斑马鱼胚胎肾祖细胞扩张的化合物。使用这种方法，我们已经确定了一类新的组蛋白去乙酰化酶抑制剂（HDACi），它在胚胎肾脏发育过程中引起肾祖细胞的扩增。重要的是，我们现在已经证明，这种新型HDACi增加了AKI小鼠模型中肾脏恢复的速度。该应用程序的目标是利用我们已经建立的斑马鱼筛选来开发HDACi类似物，这些类似物比第一代化合物具有更强的活性和更低的毒性。除了筛选HDACi类的一系列类似物外，我们还将扩展我们的初始筛选，包括含有fda批准药物的化合物库，以便加快从实验室到临床的转化应用。优先的第二代化合物将在斑马鱼和小鼠模型中进行靶效、毒性和损伤后再生潜力的测试。使用这种方法，我们期望确定一些具有确定的潜在应用于人类疾病的候选化合物。这个应用程序是匹兹堡大学和范德比尔特大学之间的合资企业。研究的目的是利用这些机构的研究人员的具体和互补的专业知识。组合化学、高含量筛选和化合物验证将在匹兹堡大学进行，以确定更有效的HDACi类似物，并使用我们最先进的筛选技术确定协同化合物。包括靶标验证、毒性试验和AKI研究在内的小鼠研究将在范德比尔特大学进行，并将确定第二代化合物是否能加速小鼠AKI的恢复速度。由于这类药物已经被用于治疗其他人类疾病，我们预测这些研究的结果可以很容易地应用于降低严重AKI患者的死亡率。2.

DESCRIPTION (provided by applicant): This application addresses three of the thematic areas of this RFA: 1) Applying Genomics and Other High Throughput Technologies; 2) Translating Basic Science Discoveries into New and Better Treatments; and 3) Reinvigorating the Biomedical Research Community. Our specific focus is the identification of new compounds that can accelerate the rate of renal recovery when administered post-injury to patients with acute kidney injury (AKI). Severe AKI is a common disorder with a high mortality rate. The mortality and morbidity associated with AKI resulting from ischemic, nephrotoxic or septic renal tubular injury has not decreased over the last twenty years despite renal replacement therapy. Since innate renal tubular regeneration occurs after tissue injury, there has been considerable interest in the development of treatments that enhance the regenerative capacity of the kidney when administered after induction of injury. This would be a significant advance in the field, since most therapies for AKI, which have been shown to be of use when administered prior to the onset of renal injury in experimental models, have failed to show therapeutic benefit in humans. One of the first molecular hallmarks of renal tubular regeneration in AKI is the reactivation of embryonic genes normally required during organogenesis. We therefore hypothesized that any treatment that causes expansion of these progenitor cells during embryonic development would also accelerate the rate of recovery in AKI. To test this hypothesis, we have developed a high-content screening technology to identify compounds that promote expansion of embryonic renal progenitor cells in zebrafish embryos. Using this approach we have identified a novel class of histone deacetylase inhibitors (HDACi), which caused an expansion of renal progenitor cells during embryonic renal development. Importantly, we have now shown that this novel class of HDACi increases the rate of renal recovery in a mouse model of AKI. The goal of this application is to exploit our established zebrafish screen to develop HDACi analogues that show more potent activity and lower toxicity than the first-generation compound. In addition to screening a set number of analogues from our HDACi class, we will also extend our initial screen to include libraries of compounds that contain FDA-approved drugs so that translational applications from the bench to the clinic can be expedited. Priority second-generation compounds will be subjected to target efficacy, toxicity, and post-damage regeneration potential assays in zebrafish and mouse models. Using this approach we expect to identify a number of candidate compounds with defined potential applications for use in human disease. This application is a joint venture between the University of Pittsburgh and Vanderbilt University. Studies are designed to take advantage of specific and complementary expertise of investigators at these institutions. Combinatorial chemistry, high-content screening and compound validation will be performed at the University of Pittsburgh to identify more potent HDACi analogues, and to identify synergistic compounds using our state of the art screen. Al mouse work, including target validation, toxicity assays and AKI studies will be performed at Vanderbilt University and will determine whether the second- generation compounds can accelerate the rate of recovery from AKI in mice. As this general class of agents is already being used for treatment of other human diseases, we predict that the results of these studies could be easily applied to reduce the mortality in patients with severe AKI. 2. PUBLIC HEALTH RELEVANCE: Severe acute kidney injury is common and largely reversible disorder that has a high mortality and for which there is no specific clinical treatment. Our studies have identified a new class of histone deacetylase inhibitors (HDACi) that accelerate the rate of renal recovery in a mouse model of acute kidney injury. The purpose of these studies is to identify new HDACi analogues that have a high potential for moving to clinical trials. 1.