The role of PGC-1alpha in repeated low-dose cisplatin-induced kidney injury and the progression to chronic kidney disease

项目摘要： 顺铂是许多实体器官癌类型的一线化疗药物，但其使用受到其化疗药物的限制。 肾毒性接受顺铂治疗的患者中有30%发生急性肾损伤（阿基）， 慢性肾脏疾病（CKD）和死亡率的风险。目前没有治疗方案来预防或 治疗顺铂诱导的肾损伤（CDDP-KI）。顺铂诱导的肾损伤（CDDP-KI）已被广泛研究 过去我们实验室和许多其他实验室使用单一的高剂量模型进行了研究。然而，患者 通常用周期性的低剂量顺铂治疗，而不是单次高剂量。我们的实验室和其他实验室最近 开发了一种利用重复低剂量顺铂（RLDC）治疗的潜在更临床相关的模型。在 在这种新的模型中，小鼠每周接受4次低剂量顺铂，并能够存活6个月以上。 后处理。RLDC模型可以分为两个阶段。反复的低水平损伤阶段， 包括四周的顺铂治疗并且特征在于肾功能的轻度下降， 小管细胞死亡、炎症和纤维化的发展水平不显著。受伤后， 是一个进展阶段，其特征在于持续的炎症、恶化的纤维化和 CKD的发展。该模型的两个阶段所涉及的机制在很大程度上仍然未知。的 肾脏每个器官的线粒体密度最高，仅次于心脏。大多数 在肾近曲小管上皮细胞（RPTEC）中进行重吸收。这些细胞高度 富含线粒体，并依赖脂肪酸氧化（FAO）作为其许多能量来源。顺铂已经 RPTEC中的缺陷FAO在其他纤维化模型中可见。我们的初步数据 表明RLDC模型导致肾功能、线粒体含量和PGC-1α降低。PGC- 1α是线粒体生物合成、脂肪酸氧化、脂肪生成 产热和葡萄糖代谢。本研究计划将探讨PGC-1α 在RLDC模型的两个阶段中的表达和纤维化/CKD的发展。我们假设 在RLDC的损伤和/或进展阶段增加PGC-1α表达将保护 肾损伤和防止进展为CKD。这一假设将通过以下方式进行检验： 具体目的：目的1：确定PGC-1α在RLDC模型损伤阶段的作用。我们假设 PGC-1α可防止RLDC诱导的肾损伤和纤维化的发生。我们将通过以下方式检验这一假设： 在RLDC模型的损伤阶段过表达和敲除PGC-1α。目标2：确定角色 PGC-1α在RLDC模型的进展阶段。我们假设PGC-1α表达的增加 在顺铂给药后，将预防RLDC诱导的纤维化和进展为CKD。我们会过度表达， 在RLDC给药后敲除PGC-1α。

Project Summary: Cisplatin is a first-line chemotherapeutic for many solid organ cancer types, but its usages are limited by its nephrotoxicity. Thirty percent of patients who receive cisplatin develop acute kidney injury (AKI), which increases the risk of chronic kidney disease (CKD) and mortality. There are currently no treatment options to prevent or treat cisplatin-induced kidney injury (CDDP-KI). Cisplatin-induced kidney injury (CDDP-KI) has been extensively investigated in the past by our lab and many other labs using a single, high-dose model. However, patients are typically treated with periodic low doses of cisplatin, not a single high dose. Our lab and others have recently developed a potentially more clinically relevant model utilizing repeated low-dose cisplatin (RLDC) treatment. In this new model, mice receive 4 weekly doses of low dose cisplatin and are able to survive more than 6-months post-treatment. The RLDC model can be broken up into two phases. The repeated low-level injury phase, which consists of the four weeks of cisplatin treatment and is characterized by a mild decline in kidney function, insignificant levels of tubule cell death, inflammation, and development of fibrosis. After the injury phase, there is a progression phase that is characterized by persistent inflammation, exacerbated fibrosis, and the development of CKD. The mechanisms involved in both phases of this model remain largely unknown. The kidneys have the highest density of mitochondria per organ, second only to the heart. The majority of the reabsorption performed occurs in the renal proximal tubule epithelial cells (RPTECs). These cells are highly enriched in mitochondria and rely on fatty acid oxidation (FAO) as their many energy source. Cisplatin has been shown to disrupt FAO, and defective FAO in RPTEC is seen in other models of fibrosis. Our preliminary data suggest that the RLDC model causes a decrease in renal function, mitochondrial content, and PGC-1α. PGC- 1α is a master transcriptional regulator of mitochondrial biogenesis, fatty acid oxidation, lipogenesis, thermogenesis, and glucose metabolism. This research proposal will examine the relationship between PGC-1α expression and the development of fibrosis/CKD in both phases of the RLDC model. We hypothesize that increasing PGC-1α expression during the injury and/ or progression phases of RLDC will protect against kidney injury and prevent progression to CKD, respectively. This hypothesis will be tested with the following specific aims: Aim 1: Determine the role of PGC-1α in the injury phase of the RLDC model. We hypothesize that PGC-1α protects from RLDC-induced kidney injury and initiation of fibrosis. We will test this hypothesis by overexpressing and knocking out PGC-1α during the injury phase of the RLDC model. Aim 2: Determine the role of PGC-1α in the progression phase of the RLDC model. We hypothesize that increased PGC-1α expression following cisplatin dosing will prevent RLDC-induced fibrosis and progression to CKD. We will overexpress and knockout PGC-1α following RLDC dosing.