The role of PLIN5 deficiency in podocyte lipotoxicity and progression of Alport Syndrome

项目摘要/摘要 Alport综合征(AS)是一种遗传性疾病，由IV型胶原突变引起，IV型胶原是 肾小球基底膜(GBM)。足细胞是肾小球滤过屏障的关键成分， 它们与GBM的相互作用对于维持这一屏障的渗透性至关重要。我们已经证明了 在实验性AS模型中发生病理性肾脏脂质堆积，足细胞脂毒性是 其他肾小球疾病中足细胞损伤的关键决定因素。我的初步数据显示细胞内 COL4A3KO小鼠肾小球甘油三酯(TG)含量升高 我从这些小鼠身上建立的永生足细胞(作为足细胞)。然而，详细的机制由 在AS中，哪些脂质堆积有助于足细胞的脂毒性仍有待阐明。 这项拟议的研究将探索一种新的机制，将PLIN5缺乏与足细胞脂毒性联系起来。 PLIN5是一种控制脂解和调节从脂滴(LDs)到游离脂肪酸(FFA)流量的蛋白质 线粒体通过在这些细胞器之间建立物理联系来实现。根据我的初步数据，我生成了 AS中PLIN5缺乏导致甘油三酯过度脂解和LD-线粒体丢失的假说 接触导致FFA积聚和线粒体功能障碍。 利用创新的细胞生物学、成像分析和小鼠模型，我提出了以下具体目标 方法：(SA1)研究足细胞PLIN5在将LDS募集到线粒体中的作用。(Sa2)定义 PLIN5缺乏在AS患者线粒体功能障碍和肾功能衰竭中的作用。 我已经创建了一个全面的职业发展计划，由我的导师和共同导师支持，以 (1)确保我在执行这项研究建议方面取得进展和成功；及(2)促进我的 过渡到专注于脂类代谢的独立研究生涯 Alport综合征患者的线粒体功能。该计划包括(1)定期与我的导师、合作伙伴- 导师和咨询委员会(全国和全球医学和科学学术读者)提供 研究和职业指导，(2)研究和职业发展研讨会，学习新的方法 显微镜、线粒体功能和脂质组学，以及(3)职业成长活动，包括指导， 发表、发表和申请独立研究经费。我的导师和我也同意 为了让自己与导师的实验室脱颖而出的过渡计划。我的训练将在一个 迈阿密大学米勒医学院无与伦比的学术环境，提供专门的 职业发展计划和所有必要的研究支持和用品，通过他的导师，共同导师， 和机构核心服务。总体而言，这项研究和职业发展建议是 我向独立研究事业过渡的雄心和能力。

PROJECT SUMMARY/ABSTRACT Alport Syndrome (AS) is a hereditary disease caused by mutations in collagen type IV, a main component of the glomerular basement membrane (GBM). Podocytes are key components of the glomerular filtration barrier, and their interaction with the GBM is crucial to maintain the permeability of this barrier. We have demonstrated that pathogenic renal lipid accumulation occurs in an experimental model of AS and that podocyte lipotoxicity is the key determinant of podocyte injury in other glomerular disease. My preliminary data show that the intracellular triglyceride (TG) content is increased in glomeruli of Col4a3 KO mice, a mouse model for AS as well as in immortalized podocytes which I established from these mice (AS podocytes). Yet, the detailed mechanism by which lipid accumulation contributes to podocyte lipotoxicity in AS remains to be elucidated. The proposed research will explore a novel mechanism linking PLIN5 deficiency to podocyte lipotoxicity. PLIN5 is a protein controls lipolysis and regulates free fatty acid (FFA) flux from lipid droplets (LDs) to mitochondrial by establishing physical contact between these organelles. From my preliminary data, I generated the hypothesis that PLIN5 deficiency in AS causes excessive TG lipolysis and loss of LD-mitochondrial contacts resulting in FFA accumulation and mitochondrial dysfunction. I propose the following specific aims using innovative cell biological, imaging analysis, and mouse model approaches: (SA1) investigate the role of podocyte PLIN5 in recruiting LDs to mitochondria. (SA2) Define the contribution of PLIN5 deficiency to mitochondrial dysfunction and renal failure in AS. I have created a comprehensive career development plan supported by my mentor and co-mentors to (1) ensure my progress and success in carrying out this research proposal and (2) to facilitate my transition to an independent research career focused on lipid metabolism in association with mitochondrial function in Alport Syndrome. This plan includes (1) regular meetings with my mentor, co- mentors, and advisory committee, (national and global academic readers in medicine and science) to provide research and career guidance, (2) research and career development seminars, learning new methodologies of microscopy, mitochondrial function, and lipidomics, and (3) activities for career growth including mentoring, publication, presentation, and application for independent research funding. My mentor and I have also agreed upon a transition plan to distinguish myself from my mentor’s laboratory. My training will be carried out in an unparalleled academic environment at University of Miami, Miller School of Medicine, which provides dedicated career development programs and all necessary research support and supplies through his mentor, co-mentors, and institutional core services. Collectively, this research and career development proposal is a product of my ambition and capacity to transition to an independent research career.