Regulation of Renal Progenitor Cells in Regenerating Kidneys

描述(由申请者提供)：肾脏具有固有的再生能力。这种修复伴随着转录因子基因的表达，如Pax2和Lhx1，这是启动正常肾脏器官发生所必需的，这表明再生的肾小管细胞来自原始的祖细胞样状态的细胞。肾脏祖细胞可能是在肾小管上皮细胞重新编程后形成的，比如哺乳动物，或者是永久存在于肾脏中的细胞，比如成年斑马鱼。我们假设，任何扩大或增强肾祖细胞的治疗都将加快急性肾损伤(AKI)后的恢复速度。为了测试这一点，我们在斑马鱼中开发了AKI的幼体和成体模型，并开发了独特的工具和方法来操纵肾脏祖细胞。我们进行了一项高含量的筛选，以确定可以增加肾祖细胞数量的化合物，并确定了一类新的组蛋白脱乙酰酶抑制剂(HDACis)，当在诱导损伤后给予斑马鱼和AKI小鼠模型时，它可以加速肾脏恢复。拟议的工作分为三个具体目标，这三个目标利用两个不同机构的调查人员的互补专业知识。目的1：我们将测试HDAC抑制是否通过诱导肾祖细胞的增殖和/或肾脏器官发生相关基因的表达来加快AKI后的恢复速度。目的：通过功能丧失和功能获得实验，确定Pax2/Pax8和Lhx1在正常肾脏器官发生和再生反应中的重要性。目的3：我们将确定组成Lhx1转录复合体的辅因子，以便更好地了解这一关键因子如何参与激活肾前体细胞的肾脏程序。

DESCRIPTION (provided by applicant): The kidney has an inherent ability to regenerate following damage. This repair is concomitant with the expression of transcription factor genes such as Pax2 and Lhx1, which are essential for initiating normal kidney organogenesis, suggesting that regenerating tubular cells arise from cells with a primitive, progenitor-like state. Renal progenitors may be formed following the 're-programming' of tubular epithelial cells, such as in mammals, or from cells that permanently reside in the kidney, such as in the adult zebrafish. We hypothesize that any treatment that expands or enhances renal progenitors will accelerate the rate of recovery following acute kidney injury (AKI). To test this we developed larval and adult models of AKI in zebrafish and developed unique tools and methodologies to manipulate renal progenitors. We performed a high-content screen to identify compounds that enhance renal progenitor cell number and identified a novel class of histone deacetylase inhibitors (HDACis) that accelerates renal recovery in zebrafish and mouse models of AKI when given after the induction of injury. The proposed work is divided into three specific aims, which take advantage of the complementary expertise of investigators at two different institutions. Aim 1: We will test whether HDAC inhibition accelerates the rate of recovery following AKI by inducing the proliferation of renal progenitor cells and/or the expression of genes involved in kidney organogenesis. Aim 2: We will determine the importance of Pax2/Pax8 and Lhx1 during normal kidney organogenesis and during the regenerative response by performing loss-of-function and gain-of-function experiments. Aim 3: We wil identify cofactors that comprise the Lhx1 transcriptional complex in order to better understand how this critical factor is involved in activating a kidney program in renal progenitors.