Juxta-glomerular cells serve as glomerular epithelial cell progenitors in glomerular disease

项目摘要 慢性肾脏疾病（CKD）在美国正在增加，现在至少有十分之一的人受到影响。CKD通常 导致终末期肾病（ESRD），需要透析或肾移植。蛋白尿 肾小球疾病是CKD和ESRD的主要原因，并且通常由进行性肾小球疾病引起。 肾小球瘢痕形成后出现足细胞损失。因为足细胞是终末分化的上皮细胞 它们不能再生。因此，在疾病丧失后，部分或完全的足细胞替代依赖于 对相邻祖细胞的转分化的影响。这些细胞包括壁上皮细胞， 谱系（CoRL），后者是这次竞争性更新的重点。不幸的是，内源性足细胞 替换通常不够坚固以确保保护。鉴于这种情况，为了解决未得到满足的问题， 需要通过发现新的靶点来增加足细胞替代，我们的长期目标是了解 足细胞再生的潜在机制，并确定恢复足细胞的治疗方案 并防止肾小球瘢痕形成。我们最近报道了CoRL是多能祖细胞， 可以向足细胞、壁上皮细胞、肠系膜细胞和周细胞转分化。我们还 表明转录因子Wt 1是一个关键的球员，是必要的CoRL增殖， 迁移和其向足细胞命运的转分化。然而，精确的分子机制（S） 这种CoRL生物学的基础仍然知之甚少。为了解决这个问题，本申请的总体目标是 是研究增强CoRL祖细胞功能的机制和途径， 分化成足细胞。我们的中心假设是，我们可以提高这些CoRL的能力， 成为足细胞，并通过调节不同的信号传导系统如Wnt信号传导来取代那些丢失的。到 为了验证这一点，我们将追求两个具体的目的：（1）测试假设，即祖细胞的能力，肾素 谱系（CoRL）转分化为足细胞命运受WT 1和Wnt信号传导的平衡支配， 以及（2）确定肾素谱系细胞向不同成体肾细胞的多能性的潜在途径 肾小球疾病的类型命运。这种方法是创新的，因为它是基于培养CoRL的独特能力 体外，创新的生物工程细胞培养装置，一种新开发的双报告小鼠， 跟踪CoRL-足细胞转分化，和基于质量设计（QbD）的方法，以识别 复杂和强大的培养条件。这项研究是重要的，因为它提供了一个深入了解， CoRL分化成多种肾细胞类型的潜力，即使在成年人中也是如此。此外，还将推进 该领域通过确定潜在的新的治疗选择，以恢复足细胞的数量，并在做 从而预防甚至逆转蛋白尿性肾小球疾病中的肾小球瘢痕形成。

PROJECT SUMMARY Chronic kidney disease (CKD) is increasing in the US, now impacting at least one in ten people. CKD typically results in end-stage kidney disease (ESRD), that requires either dialysis or kidney transplantation. Proteinuric glomerular diseases are the major cause of CKD and ESRD and are generally caused by progressive podocyte loss followed by glomerular scarring. Because podocytes are terminally differentiated epithelial cells they cannot regenerate. Therefore, following loss in disease, partial or complete podocyte replacement relies on trans-differentiation of adjacent progenitor cells. These include parietal epithelial cells, and cells of the renin lineage (CoRL), the latter being the focus of this competitive renewal. Unfortunately, endogenous podocyte replacement is often not robust enough to assure protection. Given this situation, and to address the unmet need to augment podocyte replacement through discovery of new targets, our long-term goal is to understand the mechanisms underlying podocyte regeneration, and identify therapeutic options towards restoring podocyte numbers and preventing glomerular scaring. We recently reported that CoRL are pluri-potent progenitors that can trans-differentiate towards podocytes, parietal epithelial cells, mesengial cells and pericytes. We have also shown that the transcription factor Wt1 is a critical player and is necessary for CoRL proliferation and migration, and its trans-differentiation to a podocyte fate. However, the precise molecular mechanism(s) underlying this CoRL biology are still poorly understood. To resolve this, the overall objective of this application is to investigate the mechanisms and pathways to augment CoRL progenitor function and its trans- differentiation into podocytes. Our central hypothesis is that we can ramp up the ability of these CoRL to become podocytes, and replace those lost by modulating distinct signaling systems such as Wnt signaling. To test this, we will pursue two Specific Aims: (1) Test the hypothesis that the progenitor capacity of cells of renin lineage (CoRL) to trans-differentiate to a podocyte fate is governed by the balance of WT1 and Wnt signaling, and (2) Identify pathways underlying the pluripotency of cells of renin lineage towards different adult kidney cell type fates in glomerular diseases. The approach is innovative as it is based on a unique ability to culture CoRL ex vivo, innovative bioengineered cell culture devices, a newly developed dual-reporter mice to definitively trace CoRL-podocyte trans-differentiation, and Quality-by-Design (QbD)-based methodologies to identify complex and robust culture conditions. The research is significant as it provides an in depth understanding of the potential of CoRL to differentiate into multiple kidney cell types even in adults. In addition, it will advance the field by identifying potentially novel therapeutic options towards restoring podocyte numbers, and in doing so, preventing and even reversing glomerular scaring in proteinuric glomerular diseases.