The Role of MCP-1 in Tubular-to-Glomerular Crosstalk in Proteinuric Kidney Disease

摘要 慢性肾脏病 (CKD) 定义为肾脏损害或肾小球滤过率降低的三种疾病 几个月或更长时间，无论原因如何。 CKD 影响全球约 2.76 亿人，导致 生活质量以及发病率、死亡率和医疗费用的增加。对于许多人来说，CKD 已进入末期 肾脏疾病（ESRD）以及透析和移植的需要。蛋白质异常渗漏至尿液中（即 蛋白尿）与较差的预后和进展为 ESRD 的可能性更大有关。同时 蛋白尿疾病通常作为肾小球和常驻足细胞的疾病进行研究，我们建议 肾小管也可能在促进肾小球蛋白尿中发挥关键作用。 β-连环蛋白是一种转录因子 肾损伤期间在肾小管上皮中活跃。初步数据表明，肾小管特异性 β-catenin 敲除 小鼠免受肾小球损伤和蛋白尿的影响，表明肾小管可以在肾小球损伤中发挥作用 疾病。这种保护作用与单核细胞趋化蛋白-1 (MCP- 1)，并且已知 MCP-1 会对肾小球的驻留足细胞产生不利影响。因此，我们假设 损伤后肾小管到肾小球的串扰涉及 β-连环蛋白介导的 MCP-1 释放 肾小管。这一假设将通过三个目标进行检验。首先，我们将研究β-连环蛋白的作用 诱导肾小管 MCP-1 表达。其次，我们将评估MCP-1对狭缝光阑的影响 诚信。第三，我们将研究肾小管特异性 MCP-1 在肾小球发育中的贡献 损伤和足细胞功能障碍。该提案将为 Bondi 博士提供获得额外的机会 具有啮齿动物肾损伤模型、建立条件基因敲除小鼠模型、肾损伤的经验 对 ChIP 和 ChIP-seq 实验的数据进行成像、执行和分析，并及时了解 分子技术的快速进步。 Bondi 博士将亲自与您互动并 由一群卓有成效且经验丰富的导师、顾问和合作者提供指导，以确保成功 完成提案。通过 K01 的支持，Bondi 博士将能够利用核心技术 匹兹堡大学内外提供的资源、研讨会和课程。邦迪博士将 利用该提案来实现获得额外技术和专业培训的短期目标， 以及成为肾脏疾病领域领先的初级研究者教育者并拥有充足资金的长期目标 实验室，保持生产力、促进合作并提供指导。总体而言，结果 该提案不仅将构成 R01 研究的基础，还将带来对 CKD 和 提供重要的机制数据，这对于未来治疗干预措施的发展至关重要 蛋白尿慢性肾病。

ABSTRACT Chronic kidney disease (CKD) is defined as kidney damage or reduction in glomerular filtration rate for three months or more, irrespective of cause. CKD affects an estimated 276 million people worldwide, leads to reduced quality of life and increased morbidity, mortality, and healthcare costs. For many, CKD progresses to end-stage renal disease (ESRD) and the need for dialysis and transplantation. Abnormal leak of protein into the urine (i.e., proteinuria) is associated with a worse prognosis and greater likelihood of progression to ESRD. While proteinuric diseases are generally studied as a disease of the glomeruli and resident podocytes, we propose that the renal tubules may also play a key role in promoting glomerular proteinuria. β-catenin is a transcription factor active in tubular epithelia during kidney injury. Preliminary data show that tubule-specific β-catenin knockout mice are protected from glomerular injury and proteinuria, suggesting that tubules can play a role in glomerular disease. This protection was associated with reduced expression of monocyte chemoattractant protein-1 (MCP- 1), and MCP-1 is known to adversely affect the resident podocytes of the glomerulus. Therefore, we hypothesize that tubular-to-glomerular crosstalk in response to injury involves the β-catenin-mediated release of MCP-1 from kidney tubules. This hypothesis will be tested through three aims. First, we will investigate the effect of β-catenin on inducing MCP-1 expression in renal tubules. Second, we will assess the effect of MCP-1 on slit diaphragm integrity. Third, we will investigate the contribution of tubule-specific MCP-1 in the development of glomerular injury and podocyte dysfunction. This proposal will provide Dr. Bondi with the opportunity to acquire additional experience with rodent models of kidney injury, establishing conditional genetic knockout mouse models, kidney imaging, performing and analyzing data from both ChIP and ChIP-seq experiments as well as staying abreast of the rapid, technological advances in molecular technologies. Dr. Bondi will personally interact with and be mentored by a team of accomplished and experienced mentors, advisors, and collaborators to ensure successful completion of the proposal. By having the K01 support, Dr. Bondi will be able to take advantage of core resources, workshops, and courses offered within and outside of the University of Pittsburgh. Dr. Bondi will use this proposal to accomplish the short-term goal of acquiring additional technical and professional training, and the long-term goal of becoming a leading primary investigator-educator in kidney disease with a fully-funded laboratory, which maintains productivity, fosters collaborations, and provides mentorship. Overall, the results from this proposal will not only form the basis for a R01 study but will lead to a new understanding of CKD and provide important mechanistic data that is critical for the development of future therapeutic interventions for proteinuric CKD.