A Pathogenic Role for the Natriuretic Peptide Clearance Receptor in Heart Failure with Preserved Ejection Fraction.

项目摘要 射血分数正常的心力衰竭（HFpEF）影响了近2.5%的美国退伍军人， 导致退伍军人中近1/14的死亡。与其他形式的心力衰竭不同，目前没有 HFpEF的治疗选择，降低死亡率。HFpEF发病和死亡的常见原因是 右心室（RV）衰竭，目前还没有直接针对心力衰竭中RV衰竭的治疗方法。 不管原因如何，研究表明，失败的RV经历了代谢转变，其特征是 减少了用于能量产生的脂肪酸氧化的利用，并增加了线粒体功能障碍。 虽然恢复脂肪酸氧化和线粒体功能被认为是有益的，但目前有 没有治疗方法可以成功地在失败的RV中做到这一点。该提案的目标是支持职业生涯 通过为Vineet Agrawal博士提供培训，指导和资源来发展他的职业生涯 在确定肥胖和代谢功能障碍从根本上改变RV代谢的机制， 促进失败，其次确定可行的治疗方法，以改善患者人群的结局， 目前没有。这项工作得到了主要导师Julie Bastarache博士和安娜Hemnes博士的支持， 一个辅助研究咨询委员会。Agrawal博士将利用他们的联合导师学习 一种新的治疗靶点，利钠肽清除受体NPRC，在肥胖症治疗中的作用- 诱导HFpEF。该建议的中心假设是HFpEF RV中NPRC表达增加 通过受损的线粒体生物合成和脂肪酸氧化导致RV衰竭。这个核心假设 将在两个具体的目标，将测试以下假设进行测试：（1），敲除NPRC在 肥胖诱导的HFpEF模型通过恢复脂肪酸氧化和逆转RV衰竭 线粒体生物合成，和（2）NPRC直接抑制线粒体生物合成和脂肪酸氧化， 体外通过cAMP和cGMP介导的PGC 1a调节。该提案将利用一种新的转基因 小鼠，其中NPRC可以被诱导敲除以研究NPRC在体内的作用，并且CRISPR编辑 人诱导多能干细胞和H9 C2心肌细胞样细胞来研究NPRC在 调节体外心肌细胞功能。通过对上述假设的验证，Dr. Agrawal还将完成以下职业发展和培训目标：（1）掌握 研究组织和细胞线粒体功能和代谢的技术，（2）掌握技术， 产生并分化人诱导多能干细胞和心肌细胞（hiPSC），（3）掌握 体外基因编辑技术，以及（4）完善专业发展和沟通技能， 实现学术进步，有效沟通和成功的VA Merit提交的目标。

PROJECT SUMMARY Heart failure with preserved ejection fraction (HFpEF) affects almost 2.5% of all US Veterans, and it contributes to nearly 1 in 14 deaths in Veterans. Unlike other forms of heart failure, there are currently no treatment options for HFpEF that reduce mortality. A common cause of morbidity and mortality in HFpEF is right ventricular (RV) failure, and there are currently no therapies directly targeting RV failure in heart failure. Regardless of the cause, studies have shown that the failing RV undergoes a metabolic shift characterized by decreased utilization of fatty acid oxidation for energy generation and increased mitochondrial dysfunction. While restoring fatty acid oxidation and mitochondrial function are thought to be beneficial, there are currently no therapies that can successfully do so in the failing RV. The goal of the proposal is to support the career development of Dr. Vineet Agrawal by providing him the training, mentorship, and resources to pursue a career in identifying mechanisms by which obesity and metabolic dysfunction fundamentally alter RV metabolism to promote failure, and secondarily identify viable therapies to improve outcomes in a patient population that currently has none. This work is supported by primary mentors, Drs. Julie Bastarache and Anna Hemnes, and a complementary research advisory committee. Dr. Agrawal will leverage their combined mentorship to study the role of a novel therapeutic target, natriuretic peptide clearance receptor NPRC, in the treatment of obesity- induced HFpEF. The central hypothesis of this proposal is that increased NPRC expression in the HFpEF RV results in RV failure through impaired mitochondrial biogenesis and fatty acid oxidation. This central hypothesis will be tested in two specific aims that will test the following hypotheses: (1) that knockdown of NPRC in a model of obesity-induced HFpEF prevents and reverses RV failure by restoring fatty acid oxidation and mitochondrial biogenesis, and (2) NPRC directly inhibits mitochondrial biogenesis and fatty acid oxidation in vitro through cAMP and cGMP-mediated regulation of PGC1a. This proposal will utilize a novel transgenic mouse in which NPRC can inducibly be knocked out to study the role of NPRC in vivo, and CRISPR edited human induced pluripotent stem cells and H9C2 cardiomyocyte-like cells to study the role of NPRC in modulating cardiomyocyte function in vitro. Through the studies proposed to test the hypotheses above, Dr. Agrawal will also accomplish the following career development and training objectives to: (1) master techniques to study mitochondrial function and metabolism of tissue and cells, (2) master techniques to generate and differentiate human induced pluripotent stem cells and cardiomyocytes (hiPSCs), (3) master techniques in gene editing in vitro, and (4) refine professional development and communication skills to achieve goals of academic progress, effective communication, and successful VA Merit submission.