Anatomic microniches and their contribution to vascular remodeling in pulmonary hypertension

肺动脉高压（PH）是一种知之甚少的疾病，其引起肺动脉的病理性重塑， 肺血管直径变小，导致进行性心力衰竭。该提案将支持 迫切需要的研究，以促进我们目前有限的了解肺的发展， 高血压从她的职业发展奖调查结果开始，PI（Lavannya Pandit，MD）概述了 一项为期五年的计划，研究钾离子的K2 P（双孔结构域）家族 归因于血管平滑肌细胞的通道参与靶向血管的血管重塑。 肺动脉阻力血管直径较小，是肺动脉高压的病理特征。 这项工作将在迈克尔E。DeBakey退伍军人事务医疗中心（MEDVAMC）， 附属于休斯敦德克萨斯医学中心的贝勒医学院。重要的合作研究 将在德克萨斯州医学中心（德克萨斯大学健康中心）的邻近机构内进行 科学中心和休斯顿大学。该项目是在咨询指导下制定的， 离子通道和肺血管细胞生物学领域的知名专家，他们将继续积极 在拟议的研究的五年期间参加。初步的微阵列数据， 人PH肺动脉牵涉K2 P通道功能障碍的作用。我们假设K2 P离子 通道功能障碍引起平滑肌细胞的病理性生长和收缩， 直径阻力血管。科学的方法利用原代肺血管平滑肌细胞 来自非吸烟尸体对照的较大管道和较小阻力肺血管， 利用PH小鼠模型进行平行研究的PH人肺组织，我们将测试如何 K2 P通道的解剖位置决定了其对肺血管平滑肌细胞的作用 生长和收缩的细胞内途径。本提案的第一个目标是研究解剖学如何 肺血管床内的位置影响血管平滑肌中K2 P离子通道的表达和功能 肌肉.我们将测量K2 P通道表达、电流密度和静息膜电位。 肺血管平滑肌细胞，归因于K2 P离子通道表达和功能的变化， 解剖起源本提案的第二个目标是绘制K2 P渠道与 内皮素-1（ETR）和血栓素A2受体（TXA 2），通过测量细胞内ETR和TXA 2运输 使用放射性配体测定和共聚焦显微成像。这些结果将K2 P的解剖位置联系起来 平滑肌细胞受体配体信号传导通道（血管收缩剂：内皮素-1和血栓素A2） 第三个目标是建立K2 P离子通道在PH中的功能作用。 通过实验遗传学和药理学研究导致PH血管重塑的细胞过程 修改和恢复。在这些翻译人类组织研究的结论，我们将描绘 K2 P离子通道在PH血管病变发展中的作用。

Pulmonary hypertension (PH) is a poorly understood disease that causes pathologic remodeling of the smaller diameter vessels of the lung, leading to progressive heart failure. This proposal will support the critically needed studies to advance our currently limited understanding of the development of pulmonary hypertension. Launching from her career development award findings, the PI (Lavannya Pandit, MD) outlines a five-year plan to investigate the mechanism by which the K2P (two-pore domain) family of potassium ion channels attributed to vascular smooth muscle cells participates in the vascular remodeling targeted to the smaller diameter resistance-vessels of the lung, a defining pathologic characteristic of pulmonary hypertension. This work will be performed at the Michael E. DeBakey Veterans Affairs medical center (MEDVAMC), which is affiliated with Baylor College of Medicine in the Texas Medical Center, Houston. Important collaborative studies will be performed within neighboring institutions at the Texas Medical Center (University of Texas Health Science Center and University of Houston.) The project has been developed with consultative guidance from renowned experts in the field of ion channel and pulmonary vascular cell biology who will continue their active participation over the five-year duration of the proposed studies. Preliminary microarray data from explanted human PH pulmonary arteries implicated a role for K2P channel dysfunction. We hypothesize that the K2P ion channel dysfunction causes pathologic growth and constriction of smooth muscle cells specific to the smaller diameter resistance vessels. The scientific approach utilizes primary pulmonary vascular smooth muscle cells from both larger conduit and smaller resistance pulmonary vessels of both nonsmoking cadaveric controls and explanted PH human lung tissues with parallel studies utilizing a mouse model of PH. We will test how anatomic location determines specific K2P ion channels’ effect on the pulmonary vascular smooth cell intracellular pathways for growth and contractility. The first objective of this proposal examines how anatomic location within the pulmonary vascular bed affects K2P ion channel expression and function in vascular smooth muscles. We will measure K2P channel expression, current density and resting membrane potential in pulmonary vascular smooth muscle cells, attributing changes in K2P ion channel expression and function to anatomic origin. The second objective of this proposal maps the interaction between the K2P channel and endothelin-1(ETR) and thromboxaneA2 receptors (TXA2) by measuring intracellular ETR and TXA2 trafficking using a radioligand assay and confocal microscopic imaging. These results link anatomic location of the K2P channels to smooth muscle cell receptor ligand signaling (vasoconstrictors: endothelin-1 and thromboxaneA2) that are currently implicated in PH. The third objective is to establish a functional role of K2P ion channels in the cellular processes leading to PH vascular remodeling by experimental genetic and pharmacologic modification and restoration. At the conclusion of these translational human tissue studies, we will delineate the role of K2P ion channels in the development of PH vasculopathy.