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) 是肺动脉高压 (PAH) 的一种严重形式，其特征是肺血管系统进行性重塑，导致肺血管阻力升高，最终导致右心衰竭和死亡 (16)。 IPAH 无法治愈，其病因尚不清楚。越来越多的证据表明，IPAH-PASMC 的 Ca2+ 稳态存在重大内在变化，可能涉及多种 Ca2+ 途径。我们研究的目的是阐明 IPAH 期间 PASMCs 中 Ca2+ 稳态病理变化的 Ca2+ 途径的调节机制。瞬时受体电位（TRP）基因超家族编码大量具有不同生理功能的非选择性离子通道。其中许多通道已在人类 PASMC 中检测到。先前的研究发现 IPAH-PASMCs 中 TRPC3 和 TRPC6 表达上调；在这些细胞中还发现了 TRPC6 的功能性单核苷酸多态性。我们之前的研究还表明，在慢性缺氧和野百合碱诱导的PH大鼠的PASMCs中，TRPC1和TRPC6表达上调，并且钙池操纵（SOCE）和受体操纵Ca2+进入（ROCE）增强。此外，在慢性缺氧大鼠的 PASMC 中，机械敏感性 TRPV4 通道也上调，并且机械敏感性阳离子进入 (MSCE) 增强。尽管没有动物模型可以重现人类 IPAH，但这些结果表明多种 TRP 依赖性途径的改变可能有助于 PH 的发展。然而，许多TRP通道（TRPC、TRPV和TRPM亚家族）在IPAH-PASMCs中的表达和病理生理功能尚未得到系统研究。在本申请中，我们提出多个 TRPC、TRPV 和 TRPM 通道的表达在 IPAH-PASMC 中发生本质改变，并且这些变化对这些血管肌细胞的异常表型有显着影响。为了检验这一假设，我们将结合 Ca2+ 成像、膜片钳、siRNA 基因敲除和过表达技术，对从主弹性动脉、对照 I-III 型小肺动脉和由 IPAH 肺提供的 IPAH 肺培养的人 PASMC。肺动脉高压突破计划 (PHBI) 旨在：(1) 识别 IPAH-PASMC 中表达发生改变的 TRP 通道； (2)确定导致IPAH-PASMCs中SOCE、ROCE和MSCE改变的TRP通道； (3)确定促进IPAH-PASMCs增殖的TRP通道。拟议的实验将确定 TRP 通道依赖性途径的完整补充，这些途径负责 IPAH-PASMC 中 Ca2+ 信号传导的内在差异。这些结果预计将产生重要的积极影响，因为有关 IPAH 病理生理学的新机制信息可能有助于确定治疗这种致命疾病的新治疗靶点。