The Calpain/CaMKII/NHE Signaling Pathway in PAH

项目摘要/摘要 K08提案的目标有两个：1)为候选人提供必要的科学和 成为一名独立的内科医生的专业技能-专注于分子和细胞的科学家 肺动脉高压的发病机制，以及2)探讨其病理机制 肺动脉高压时肺血管平滑肌细胞的增殖和迁移 (PAH)。Huetsch博士和他的导师Larissa Shimoda博士设计了一个结合了 实验室经验、课程和专业指导，以培养实验设计和设计方面的专业知识 技术、数据分析和科学交流。这项培训将通过调查一名 PAH中PASMC功能障碍和肺血管重构的新信号通路 由于缺乏旨在逆转的治疗方法，这种疾病继续造成显著的发病率和死亡率 血管重塑。根据我们的初步数据，我们假设，在PAH中，钙蛋白酶活性在 PASMCs导致钙/钙调蛋白依赖性蛋白激酶II(CaMKII)激活，进而诱导 Na+/H+交换器(NHE)活性增加，导致病理性PASMC增殖 迁移和肺血管重塑。使用从PAH患者分离的PASMC以及 因此，我们计划通过三个目标来研究这一假说：1) 2)确定CaMKII是否是PAH血管重塑所必需的 对于PAH的血管重塑是必要的，以及3)确定NHE对血管是否必要 肺动脉高压的重塑。我们计划利用遗传、分子和药理学技术来诱导- 这一途径的每个组成部分的功能和功能丧失，以及随后对1)活性的测量 2)PASMC在体外的增殖和迁移，3)预防 和/或体内肺血管重塑逆转。这些目标的实现将提供一个 为Huetsch博士提供严格的培训计划，并发现病理性PASMC的新机制 在PAH中的作用，有望转化为新的治疗靶点。

PROJECT SUMMARY / ABSTRACT The objectives of this K08 proposal are two-fold: 1) to provide the candidate with the essential scientific and professional skills to become an independent physician-scientist focused on the molecular and cellular pathogenesis of pulmonary hypertension, and 2) to investigate the mechanisms underlying pathologic pulmonary arterial smooth muscle cell (PASMC) proliferation and migration in pulmonary arterial hypertension (PAH). Dr. Huetsch and his mentor, Dr. Larissa Shimoda, have designed a training plan that combines laboratory experience, coursework, and professional mentorship to foster expertise in experimental design and techniques, data analysis, and scientific communication. This training will occur through the investigation of a novel signaling pathway underlying PASMC dysfunction and pulmonary vascular remodeling in PAH, a disease which continues to cause significant morbidity and mortality owing to the lack of therapies designed to reverse vascular remodeling. Based on our preliminary data, we hypothesize that, in PAH, increased calpain activity in PASMCs leads to activation of Ca2+/calmodulin dependent protein kinase II (CaMKII), which then induces increased activity of the Na+/H+ exchanger (NHE), resulting in pathologically elevated PASMC proliferation and migration and pulmonary vascular remodeling. Using PASMCs isolated from PAH patients as well as the Sugen/hypoxia rodent model of PAH, we plan to investigate this hypothesis through three aims: 1) to determine whether calpains are necessary for vascular remodeling in PAH, 2) to determine whether CaMKII is necessary for vascular remodeling in PAH, and 3) to determine whether NHE is necessary for vascular remodeling in PAH. We plan to utilize genetic, molecular, and pharmacologic techniques to induce gain-of- function and loss-of-function of each component of this pathway with subsequent measurements of 1) activity of downstream components of the pathway, 2) PASMC proliferation and migration in vitro, and 3) prevention and/or reversal of pulmonary vascular remodeling in vivo. Accomplishment of these aims will provide a rigorous training program for Dr. Huetsch and uncover novel mechanisms underlying pathologic PASMC function in PAH which could hopefully be translated into new therapeutic targets.