Characterization of Novel Signaling Pathways Involved in Water Balance Disorders

项目概要/摘要 水平衡的维持是肾脏的重要功能， 适应陆地生活。为了有效地重吸收水分，加压素（VP）被释放， 诱导肾脏内水通道蛋白2（AQP 2）磷酸化和肌动蛋白细胞骨架重塑 集合管中的主细胞，这增加了AQP 2的顶膜表达。 AQP 2运输失调导致水平衡紊乱; AQP 2减少 膜表达导致肾源性尿崩症（NDI），而膜表达的增加导致尿崩症。 质膜AQP 2与不适当的综合征中的液体潴留相关， ADH分泌（SIADH）、充血性心力衰竭和肝硬化。而VP/cAMP/PKA是 促进AQP 2膜运输和水重吸收的主要信号通路是 这个过程实际上要复杂得多，可以被其他信号传导所诱导或抑制。 途径。一个这样的“替代”途径涉及表皮生长因子受体 （EGFR），其抑制诱导AQP 2膜积累和磷酸化类似 到VP，但绕过V2 R，cAMP和PKA，我的目标是加深我们对 调节AQP 2的VP和EGFR通路之间的串扰，长期职业目标是 描述了这种新的信号通路在观察到的水潴留失调中的作用， 在SIADH、充血性心力衰竭和肝硬化患者中， 缓解临床上遇到的疾病症状的疗法。 在过去的一年半里，我在解剖相关的 VP和EGFR之间的途径，调节水平衡。然而，当我专注于 我的科研事业发展，生活带给我们的不仅是惊喜，还有关注 研究进展中断。因此，我申请了这个新的NIH-NIDDK 行政补助金，以便在我产假期间雇用一名技术人员，预计 从2020年7月初到10月初，为了保持甚至增加 研究生产力。布朗实验室，包括我的导师丹尼斯·布朗博士，我的亲密朋友， 理查德·布利博士和我将最大限度地利用智力和技术资源， 在我休假期间，我将确保进展，我将继续更新进展，以恢复全面 生产力在我的回归这个研究计划是从我的父母K 08的目标1中分割出来的， 并且所提出的实验是精心设计的，预计将在年底前完成 的补充期。获得这笔补充资金将提供非常宝贵的 在我研究生涯的这个关键时刻支持我。

PROJECT SUMMARY/ABSTRACT Maintenance of water homeostasis is a vital function of the kidneys and is essential for adaptation to terrestrial life. To reabsorb water effectively, vasopressin (VP) is released to induce aquaporin-2 (AQP2) phosphorylation and actin cytoskeletal remodeling within kidney principal cells in the collecting ducts, which increases apical membrane expression of AQP2. Dysregulation of AQP2 trafficking results in disorders of water balance; decreased AQP2 membrane expression causes nephrogenic diabetes insipidus (NDI), whereas an increase in plasma membrane AQP2 is associated with fluid retention in the syndrome of inappropriate ADH secretion (SIADH), congestive heart failure and cirrhosis. While VP/cAMP/PKA is the major signaling pathway that facilitates AQP2 membrane trafficking and water reabsorption, the process is in fact far more complex, and can be induced or inhibited by other signaling pathways. One such “alternative” pathway involves the epidermal growth factor receptor (EGFR), whose inhibition induces AQP2 membrane accumulation and phosphorylation similar to VP, but bypasses V2R, cAMP and PKA, and my goal is to deepen our understanding of the crosstalk between VP and EGFR pathways that modulate AQP2, with a long term career goal to characterize the role of this novel signaling pathways in dysregulated water retention observed in patients with SIADH, congestive heart failure and liver cirrhosis, in order to eventually design therapies to alleviate disease symptoms encountered in the clinic. For the last year and a half, I have been making significant progress in dissecting the pertinent pathways between VP and EGFR that regulate water balance. However, as I am focusing on my research career development, life not only brings us surprises, but also concerns about interruption in research progress. Therefore, I am applying for this new NIH-NIDDK Administrative Supplement in order to hire a technician during my maternity leave, expected to span between early to mid-July to early October 2020, in order to preserve or even increase research productivity. The Brown Laboratory, including my mentor Dr. Dennis Brown, my close collaborator Dr. Richard Bouley, and I will maximize the intellectual and technical resources to ensure progress during my leave, and I will remain updated on the progress to resume full productivity upon my return. This research proposal is carved out of Aim 1 of my parent K08, and the proposed experiments are carefully designed and expected to be completed by the end of the supplemental period. Obtaining this supplement funding would provide highly valuable support at this critical time of my research career.