Pathologic Roles of TRP channels in Idiopathic Pulmonary Arterial Hypertension

TRP 通道在特发性肺动脉高压中的病理作用

• 批准号: 8518455
• 负责人: JAMES SK SHAM
• 金额: $ 7.71万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8518455
• 关键词: Animal Model; Appearance; Arteries; Blood Vessels; Cations; Cell Culture Techniques; Cell Proliferation; Cells; Cessation of life; Chronic; Complement; Data; Development; Disease; Functional disorder; Genes; Goals; Heart failure; Homeostasis; Human; Hypertrophy; Hypoxia; Image; Ion Channel; Lung; Mediating; Monocrotaline; Muscle Cells; Pathologic; Pathway interactions; Patients; Phenotype; Physiological; Play; Pulmonary Hypertension; Pulmonary Vascular Resistance; Pulmonary artery structure; Rattus; Research; Research Personnel; Rest; Rodent; Role; Ruthenium Red; Signal Transduction; Single Nucleotide Polymorphism; Small Interfering RNA; Smooth Muscle Myocytes; Surveys; TRP channel; Techniques; Testing; Up-Regulation; Vanilloid; Vascular Diseases; abstracting; base; channel blockers; interest; ionic balance; member; migration; new therapeutic target; novel; patch clamp; pulmonary arterial hypertension; receptor; research study; response; sulfated glycoprotein 2

DESCRIPTION: Idiopathic pulmonary arterial hypertension (IPAH) is a severe form of pulmonary arterial hypertension (PAH) characterized by progressive remodeling of the pulmonary vasculature, resulting in elevated pulmonary vascular resistance and eventually leading to right heart failure and death (16). IPAH is incurable and the cause of the disease is unknown. Increasing evidence suggests that there are major intrinsic changes in Ca2+ homeostasis of IPAH-PASMCs that may involve multiple Ca2+ pathways. The goal of our research is to elucidate the regulatory mechanisms of the Ca2+ pathways responsible for the pathologic changes of Ca2+ homeostasis in PASMCs during IPAH. The transient receptor potential (TRP) gene superfamily encodes a large repertoire of non-selective ion channels with diverse physiological functions. Many of these channels have been detected in human PASMCs. Previous studies have found an upregulation of TRPC3 and TRPC6 expression in IPAH-PASMCs; a functional single nucleotide polymorphism of TRPC6 has also found in these cells. Our previous studies also show that that TRPC1 and TRPC6 expression are upregulated, and store- operated (SOCE) and receptor-operated Ca2+ entry (ROCE) are enhanced in PASMCs of chronic hypoxic and monocrotaline-induced PH rats. Moverover, the mechanosensitive TRPV4 channel is also up-regulated and mechanosensitive cation entry (MSCE) is enhanced in PASMCs of chronic hypoxia rats. Even though no animal model can recapitulate human IPAH, these results suggest that alterations in multiple TRP-dependent pathways may contribute to the development of PH. However, the expression and the pathophysiological functions of many TRP channels (TRPC, TRPV and TRPM subfamilies) have not been investigated systematically in IPAH-PASMCs. In this application, we propose that the expression of multiple TRPC, TRPV, and TRPM channels are intrinsically altered in IPAH-PASMCs, and these changes contribute significantly to the aberrant phenotypes of these vascular myocytes. To test this hypothesis, we will apply a combination of Ca2+ imaging, patch clamping, and siRNA gene knockdown and over-expression techniques on human PASMCs cultured from main elastic arteries, type I - III small pulmonary arteries of control and IPAH lung provided by the Pulmonary Hypertension Breakthrough Initiative (PHBI) to: (1) identify the TRP channels with their expression altered in IPAH-PASMCs; (2) determine the TRP channels responsible for the altered SOCE, ROCE and MSCE in IPAH-PASMCs; and (3) determine the TRP channels contribute to the enhanced proliferation of IPAH-PASMCs. The proposed experiments will identify the full complement of TRP channel dependent pathways that are responsible for the intrinsic differences in Ca2+ signaling in IPAH-PASMCs. These results are expected to have important positive impact because the novel mechanistic information on the pathophysiology of IPAH may help to identify new therapeutic targets for the treatments of this deadly disease.

描述：特发性肺动脉高压（IPAH）是一种严重的肺动脉高压（PAH）形式，其特征是肺血管进行了逐步重塑，导致肺血管耐药性升高，最终导致正确的心力衰竭和死亡（16）。 IPAH是无法治愈的，疾病的原因尚不清楚。越来越多的证据表明，IPAH-PASMC的Ca2+稳态存在可能涉及多个CA2+途径的主要内在变化。我们研究的目的是阐明负责IPAH期间PASMC中Ca2+稳态病理变化的CA2+途径的调节机制。瞬态受体电位（TRP）基因超家族编码具有不同生理功能的非选择性离子通道的大量曲目。在人PASMC中检测到了许多这些通道。先前的研究发现IPAH-PASMC中TRPC3和TRPC6表达的上调。在这些细胞中也发现了TRPC6的功能性单核苷酸多态性。我们以前的研究还表明，在慢性低氧和单蛋白诱导的pH大鼠的PASMC中，TRPC1和TRPC6表达被上调，并增强了储存量（SOCE）和受体操作的Ca2+进入（ROCE）。换工程，机械敏感的TRPV4通道也被上调，并且在慢性低氧大鼠的PASMC中增强了机械敏感的阳离子进入（MSCE）。即使没有动物模型可以概括人类IPAH，这些结果表明，多种TRP依赖性途径的改变可能有助于pH的发展。但是，在IPAH-PASMC中，尚未系统地研究许多TRP通道（TRPC，TRPV和TRPM亚家族）的表达和病理生理功能。在此应用中，我们建议在IPAH-PASMC中本质上改变了多个TRPC，TRPV和TRPM通道的表达，并且这些变化对这些血管肌细胞的异常表型产生了显着贡献。为了检验这一假设，我们将应用Ca2+成像，斑块夹紧和siRNA基因敲低和siRNA基因敲低和过表达技术，这些技术是从主要弹性动脉培养的人类PASMC，I -III -III -III控制的小动脉和iPah肺部的小动脉和伊普阿肺肺部由肺部高血压突破性的启动性（phbi）识别为（1） IPAH-PASMC； （2）确定负责IPAH-PASMC中SOCE，ROCE和MSCE改变的TRP通道； （3）确定TRP通道有助于增强IPAH-PASMC的增殖。提出的实验将确定造成IPAH-PASMC中Ca2+信号固有差异的TRP通道依赖途径的完整补体。预计这些结果将产生重要的积极影响，因为有关IPAH病理生理学的新机械信息可能有助于确定这种致命疾病治疗的新治疗靶标。