Biological function of testican-2 in podocyte health

项目摘要/摘要 使用从受试者的主动脉和肾静脉获得的样本的蛋白质组筛选，我们 最近发现睾丸蛋白-2是一种足细胞来源的蛋白质，由肾脏释放到循环中。此外， 我们发现睾丸素-2水平与估计的肾小球滤过率(EGFR)和 随着时间的推移，较高的睾丸素-2基线水平与较少的EGFR丢失相关，从而推动了这一概念 Teccan-2提供了对肾脏健康和预后的洞察。然而，睾丸素-2的生物学功能在 足细胞和肾脏尚不清楚。睾丸蛋白-2由SPOCK2基因编码，是一种糖蛋白，是一种 细胞外基质(ECM)的组成部分。在PI生成的初步数据中，我们发现TestCan-2 减轻阿霉素对培养的人足细胞和小鼠足细胞的损伤。我们进一步发现 TestCan-2与另一种细胞外基质蛋白Vitronectin结合，并降低其与整合素αVβ3的结合亲和力。 足细胞表面的黏附蛋白。以这些发现为跳板，该提案将测试 核心假说：睾丸粘连蛋白-2通过减少玻璃体连结蛋白介导的方式在足细胞健康中发挥作用 整合素αVβ3的激活和信号转导：目的1)确定睾丸蛋白-2结合所需的蛋白结构域 目的2)研究睾丸蛋白-2对整合素αVβ3活化和足细胞损伤的影响； 目的3)评估糖尿病肾病和原发病灶节段性病变患者睾丸粘连蛋白-2的表达。 肾小球硬化。这位候选人名为温医生，他坚定地致力于肾脏病学术生涯。他 以前在肾脏学方面进行了基础广泛的研究培训，特别侧重于肾脏生理学。 自2018年申请肾脏病研究员以来，他将重点转移到了一个新的领域-生物功能 对足细胞健康中的睾丸蛋白-2的研究，包括基本方法和翻译方法。温博士近期的职业目标 包括获取以下领域新兴技术的内容知识和实践经验 足细胞生物学；蛋白质-蛋白质相互作用和结构；以及血液和组织生物标志物。此外，他还 寻求公开演讲、赠款和手稿写作方面的培训。温博士的长期职业目标是 成为一名独立的内科科学家，既追求基本的方法，也追求翻译的方法来开发 足细胞损伤和肾脏疾病患者的新治疗策略。他将受益于 来自肾脏专家Eugene Rhee(导师；MGH肾病首席)的补充指导 代谢和生物标记物；以及马丁·波拉克(共同导师，BIDMC肾病首席)，遗传学和生物标记物的领导者 足细胞生物学。温博士、李博士和波拉克博士将经常会面，讨论科学和职业生涯 并清楚地确定了将构成HIS基础的拟议研究的各个方面 独立的事业。咨询委员会将提供额外的指导，评估进展情况，并帮助制定计划 未来的发展方向。

PROJECT SUMMARY/ABSTRACT Using a proteomic screen of samples obtained from the aorta and renal vein of human subjects, we recently identified testican-2 as a podocyte-derived protein that is released by the kidney into circulation. Further, we found that testican-2 levels are positively correlated with estimated glomerular filtration rate (eGFR) and higher baseline levels of testican-2 are associated with less eGFR loss over time, advancing the concept that testican-2 provides insight on kidney health and prognosis. However, the biological function of testican-2 in podocytes and the kidney is unknown. Encoded by the SPOCK2 gene, testican-2 is a glycoprotein that is a component of the extracellular matrix (ECM). In preliminary data generated by the PI, we find that testican-2 attenuates podocyte injury induced by Adriamcyin both in cultured human podocytes and mice. We further find that testican-2 binds to another ECM protein vitronectin and reduces its binding affinity to integrin αVβ3, an adhesion protein on the podocyte surface. Using these findings as a springboard, this proposal will test the central hypothesis that testican-2 plays a functional role in podocyte health by reducing vitronectin-mediated integrin αVβ3 activation and signaling: Aim 1) To determine the protein domain required for testican-2 binding with vitronectin; Aim 2) To determine the impact of testican-2 on integrin αVβ3 activation and podocyte injury; and Aim 3) To assess testican-2 expression in patients with diabetic nephropathy and primary focal segmental glomerulosclerosis. The candidate, Dr. Wen, is deeply committed to a career in academic nephrology. He previously pursued broad-based research training in nephrology, with a particular focus on renal physiology. Since pursuing a nephrology fellowship in 2018, he has shifted his focus to a new area—the biological function of testican-2 in podocyte health, with both basic and translational approaches. Dr. Wen’s immediate career goals include acquiring content knowledge and hands-on experience with emerging technologies in the areas of podocyte biology; protein-protein interaction and structure; and blood and tissue biomarkers. In addition, he seeks training with public speaking and grant and manuscript writing. Dr. Wen’s long-term career goal is to become an independent physician-scientist who pursues both basic and translational approaches to develop new therapeutic strategies for patients with podocytes injury, and kidney disease in general. He will benefit from complementary mentorship from Eugene Rhee (mentor; Chief, MGH Nephrology), an expert in kidney metabolism and biomarkers; and Martin Pollak (co-mentor, Chief, BIDMC Nephrology), a leader in genetics and podocyte biology. Drs. Wen, Rhee, and Pollak will meet frequently to discuss both science and career development and have clearly identified aspects of the research proposed that will form the basis of his independent career. An advisory committee will provide additional guidance, evaluate progress, and help plan future directions.