Investigating the role of NBCe1-B in renal and cardiac acid-base handling

项目摘要 据估计，15%的美国成年人患有慢性肾脏疾病(CKD)，并伴有心血管疾病 疾病(心血管疾病)是该人群死亡的最大原因。代谢性酸中毒在慢性肾脏病中很常见， 对肾脏和心脏都有不良影响。使我们的理解复杂化，并限制我们的能力 防止这些影响的是我们对酸中毒的心肾综合反应的认识空白，这是 很大程度上受细胞水平的酸碱转运体的影响。Na+/HCO3-共转运体(NBCe1-B)就是这样的一个 传送器。越来越多的证据表明，NBCe1-B参与了肾脏对酸中毒的反应，而 心肌肥厚的病理生理发展，但NBCe1-B丢失对这些系统的影响 从来没有在整个动物层面上进行过测试。该项目的目标是确定NBCe1-B在 比较野生型(WT)和NBCe1-B基因敲除的肾脏和心脏的表型 (KO)小鼠。这一建议的总体假设是NBCe1-B对肾脏是必需的(目标1)和 心脏(目标2)酸碱处理。目标1的目的是确定丰度、分布和 NBCe1-B在酸刺激条件下WT小鼠肾脏中的作用这项工作将包括一系列 蛋白印迹和荧光免疫组织化学实验及肾脏酸碱的比较 用血气参数、氨评估WT和NBCe1-B KO小鼠在酸中毒期间的处理 排泄物和可滴定酸的排泄物。目标2的目的是确定确切的类型和机制 NBCe1-B-KO小鼠的心脏损害。小鼠将接受类似于心脏病患者的心脏检查- 失败，合并心电图、超声心动图和左心室压力导管术 测量。心肌细胞的细胞水平研究将包括组织学分析、分子生物学 用Western印迹和RT-qPCR评价促肥大机制的证据，并评价 用钙离子敏感显微镜观察心肌细胞内钙离子的处理。这篇文章中概述的实验 该提案将确定NBCe1-B在肾脏和心脏系统中的作用，为深入了解 心肾对酸中毒的反应。这项工作将在布法罗大学雅各布斯医学院进行 和生物医学科学(JSMBS)，在马克·帕克博士的实验室里，他是离子传输和 PH值调节。培训计划是为发展成为肾病领域的内科科学家而量身定做的， 并将包括肾病学和心脏病学的临床指导，以获得跨学科 经验，反映了这一提案的研究目标。这些纵向的临床指导将与 成功的内科科学家，他们也将直接参与拟议的研究，从而提供 在团契的过程中进行综合辅导。

Project Summary An estimated 15% of U.S. adults are estimated to have chronic kidney disease (CKD), with cardiovascular disease (CVD) the greatest cause of death in this population. Metabolic acidosis is common in CKD, and has deleterious effects on both the kidney and the heart. Complicating our understanding and limiting our ability to prevent these effects are gaps in our knowledge of the integrated cardiorenal response to acidosis, which is largely influenced by cellular level acid-base transporters. The Na+/HCO3- co-transporter (NBCe1-B) is one such transporter. There is accumulating evidence that NBCe1-B is involved in the renal response to acidosis and the pathophysiologic development of cardiac hypertrophy, but the consequence of NBCe1-B loss on these systems has never been tested at the whole animal level. The goal of this project is to determine the role of NBCe1-B in the kidney and heart by comparing the renal and cardiac phenotypes of wild-type (WT) and NBCe1-B knockout (KO) mice. The over-arching hypothesis of this proposal is that NBCe1-B is essential for renal (Aim 1) and cardiac (Aim 2) acid-base handling. The purpose of Aim 1 is to determine the abundance, distribution, and function of NBCe1-B in the WT mouse kidney during acid-challenged conditions. This work will include a series of western-blot and fluorescent immunohistochemistry experiments as well as a comparison of renal acid-base handling during acidosis in WT and NBCe1-B KO mice as assessed by blood-gas parameters, ammonia excretion, and titratable acid excretion. The purpose of Aim 2 is to determine the exact type and mechanism of cardiac impairment in NBCe1-B-KO mice. The mice will receive a cardiac work-up similar to patients with heart- failure, incorporating electrocardiogram, echocardiogram, and left-ventricular pressure catheterization measurements. Cellular level investigation of cardiomyocytes will include histological analysis, molecular assessment for evidence of pro-hypertrophic mechanisms using Western blot and RT-qPCR, and evaluation of Ca2+ handling in isolated cardiomyocytes using Ca2+ sensitive microscopy. The experiments outlined in this proposal will determine the role of NBCe1-B in the renal and cardiac systems, providing insights into the cardiorenal response to acidosis. This work will take place at the University at Buffalo, Jacobs School of Medicine and Biomedical Sciences (JSMBS), in the laboratory of Dr. Mark Parker, who is an expert in ion transport and pH regulation. The training plan is tailored for development as a physician-scientist in the field of nephrology, and will include clinical preceptorships in nephrology and cardiology in order to gain cross-disciplinary experience, reflecting the research goals of this proposal. These longitudinal clinical preceptorships will be with successful physician-scientists, who will also be directly involved in the proposed research, thereby providing integrated mentorship over the course of the fellowship.