Regulation of Lymphatic and Vascular Remodeling in Acute Kidney Injury

项目摘要：这份NIH F30申请描述了指导研究和职业发展的计划 对于PI，Gelare Ghajar-Rahimi。这一建议的科学前提是关注肾脏的反应。 内皮系统与急性肾损伤(AKI)有关，这是高达20%的住院患者和60%的患者的主要并发症 危重病人。尽管AKI的死亡率和发病率很高，但治疗AKI的靶向疗法尚未得到 开发成功。淋巴管和血液内皮细胞的动态平衡对维持肾脏健康至关重要 并影响AKI的发病机制。作为对损伤的反应，肾脏淋巴管(LV)经历了一个 称为淋巴管生成(LA)的扩张，可减轻肾损害；管周毛细血管密度 减少，导致持续低氧，损害肾功能。在增强LA的同时 因此，阻止肾小管周围毛细血管疏松作为一种治疗方法具有巨大的前景。这些 在AKI的背景下，从来没有同时研究过两个群体，这限制了我们发展的能力 血管内皮细胞调节疗法。在这里，我的目的是阐明新生LA的细胞起源及其机制 治疗急性心肌梗死后血管内皮细胞重塑。我的初步数据和现有文献表明，1) De nevo LA起源于预先存在的淋巴管内皮细胞(而不是髓系细胞)的祖细胞群 和2)血液和淋巴管内皮细胞的不同反应 损伤人群对损伤的影响可能是通过损伤近端小管细胞内的核因子-kB信号的影响来解释的。 我的中心假设是，通过核因子-kB信号，损伤的近端小管促进转录 导致淋巴管扩张和血管疏松的内皮细胞变化。我要测试一下这个 假说通过先进的显微镜和单细胞转录以及各种体外和体内实验 实验，包括使用可诱导的淋巴报告小鼠和缺乏核因子-kB表达的小鼠 在近端小管中。这些发现将极大地促进我们对 肾内皮细胞对损伤做出反应，并可使核因子-kB成为急性肾损伤治疗的新靶点。 建议的PI培训计划由共同导师阿努帕姆·阿加瓦尔医学博士和詹姆斯·乔治赞助， 博士学位。培训计划包括帮助Gelare在三个主要领域发展的经验：1)严谨 淋巴和肾脏研究，包括熟悉现有文献，批判性评估 数据和负责任的研究行为培训；2)高级生物信息学和 下一代测序分析以及3)职业和职业发展，包括格兰特和 手稿写作，科学交流，以及将研究成果转化为临床应用。 这一提议推动了严谨科学研究、关键分子生物学所需技能的发展 和高级生物信息学技能是PI未来职业生涯所必需的，专注于 疾病的细胞和分子机制。

PROJECT SUMMARY: This NIH F30 application describes plan for mentored research and career development for the PI, Gelare Ghajar-Rahimi. The scientific premise of this proposal is focused on the response of the kidney endothelial system to acute kidney injury (AKI), a major complication in up to 20% of hospitalized and 60% of critically ill patients. Despite the high mortality rate and incidence, targeted therapies to treat AKI have not been successfully developed. Homeostasis of lymphatic and blood endothelial cells is vital to maintaining kidney health and influences AKI pathogenesis. In response to injury, kidney lymphatic vessels (LV) undergo a process of expansion termed lymphangiogenesis (LA) that mitigates kidney damage; density of peritubular blood capillaries decreases, contributes to sustained hypoxia and impairs kidney function. Enhancing LA while simultaneously impeding peritubular capillary rarefaction therefore holds immense promise as a therapeutic approach. These two populations have never been studied concurrently in the context of AKI, limiting our ability to develop endothelia-modulating therapies. Here, I aim to elucidate the cellular origins of de novo LA and the mechanisms governing the endothelial remodeling following AKI. My preliminary data and existing literature suggest that 1) de novo LA arises from a progenitor population of pre-existing lymphatic endothelial cells (rather than myeloid- lineage as some older studies posit) and 2) the divergent responses of blood and lymphatic endothelial populations to injury may be explained by the influence of NF-kB signaling within injured proximal tubule cells. My central hypothesis is that that damaged proximal tubules, through NF-kB signaling, promote transcriptional changes in endothelial cells that contribute to lymphatic expansion and vascular rarefaction. I will test this hypothesis through advanced microscopy and single cell transcriptomics and a variety of in vitro and in vivo experiments, including the use of an inducible lymphatic reporter mouse and mice deficient in NF-kB expression in proximal tubules. These findings will significantly advance our understanding of the mechanisms by which kidney endothelial populations respond to injury and could establish NF-kB as a novel therapeutic target in AKI. The proposed training plan for the PI is sponsored by co-mentors Anupam Agarwal, MD, and James George, PhD. Included in the training plan are experiences that will help Gelare develop in three major areas: 1) rigorous lymphatic and kidney research, which includes developing familiarity with the existing literature, critical evaluation of data, and training in the responsible conduct of research; 2) rigorous training in advanced bioinformatics and next-generation sequencing analysis and 3) career and professional development, including grant and manuscript writing, scientific communications, and the translation of research findings to clinical applications. This proposal drives the development of skills required for rigorous scientific research, critical molecular biology and advanced bioinformatics skills necessary for the PI’s future career as a physician-scientist focused on cellular and molecular mechanisms of disease.