Capacitative Ca2+ Entry and TRP Channels in Thromboembolic Pulmonary Hypertension

血栓栓塞性肺动脉高压中的电容性 Ca2+ 进入和 TRP 通道

• 批准号: 7822795
• 负责人: Jason X J Yuan
• 金额: $ 2.36万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7822795
• 关键词: Acute; Antisense Oligonucleotides; Arterial Disorder; Arteries; Attenuated; Blood Clot; Blood Coagulation Factor; Blood Platelets; Blood Vessels; Blood coagulation; CREB1 gene; Calcium/calmodulin-dependent protein kinase; Cations; Cell Proliferation; Cells; Chronic; Coagulation Process; Complex; Data; Distal; Embolism; FOS gene; Family; Fibrin; Fibrinogen; Functional disorder; Gene Expression; Human; Hypertrophy; Interleukin-2; Lesion; Lung; MAP Kinase Gene; MYB gene; Medial; Mediating; Membrane; Messenger RNA; Molecular; Obstruction; Patients; Permeability; Pharmacia brand of estropipate; Predisposition; Proto-Oncogene Proteins c-myb; Pulmonary Embolism; Pulmonary Hypertension; Pulmonary Vascular Resistance; Pulmonary artery structure; Research Personnel; Signaling Protein; Small Interfering RNA; Stimulus; Testing; Thrombin; Thromboendarterectomy; Thrombus; Tunica Media; United States; Vascular Diseases; Vascular Smooth Muscle; Vascular remodeling; base; macrophage; migration; normotensive; protein expression; pulmonary arterial hypertension; receptor; transcription factor

DESCRIPTION (provided by applicant): In patients with chronic thromboembolic pulmonary hypertension (CTEPH), elevated pulmonary vascular resistance (PVR) is caused by obstruction of proximal and distal pulmonary arteries with thromboemboli, and by pulmonary vascular remodeling due to excessive migration and proliferation of pulmonary vascular smooth muscle (PASMC) and endothelial (PAEC) cells. The thromboemboli attached to the pulmonary vascular wall include a large amount of blood coagulation factors (e.g., thrombin, fibrinogen), which may serve as triggers for vascular remodeling. A rise in cytosolic [Ca2+] in PAEC induced by thrombin increases endothelial permeability, which allows mitogenic factors to penetrate into the vascular media and cause medial hypertrophy. A rise in cytosolic [Ca2+] in PASMC stimulates cell proliferation by upregulating Ca2+- sensitive signaling proteins and transcription factors. By activating receptors in PASMC, the coagulation factors (e.g., thrombin and fibrinogen) also cause increases in cytosolic [Ca2+] by promoting Ca2+ influx through transient receptor potential (TRP) channels. We have recently demonstrated that a) TRP expression is increased and Ca2+ entry through TRP channels is augmented in normal PASMC during proliferation, b) inhibition of TRP expression with siRNA attenuates PASMC proliferation, c) mRNA and protein expression of TRP (e.g., TRPC3/6) is upregulated in PASMC from patients with idiopathic pulmonary arterial hypertension. Based on these data, we hypothesize that abnormally enhanced gene expression of TRP channels in the pulmonary vasculature serves as a predisposition for thromboemboli-mediated pulmonary vascular remodeling in CTEPH patients. Three specific aims are proposed to test the hypothesis: 1) To examine whether and which TRP channels are transcriptionally upregulated, and whether TRP-encoded store- and receptor-operated cation channels are functionally enhanced, in PASMC isolated from CTEPH patients; 2) To examine whether coagulation factors (thrombin nd fibrinogen) increase cytosolic [Ca2+] by activating TRP channels in PASMC and, if so, which TRP channel subunits are functionally regulated by thrombin and fibrinogen; and 3) To examine whether the mitogenic effect of thrombin and fibrinogen depends on increases in cytosolic [Ca2+] due to Ca2+ entry through TRP channels in normal PASMC and is enhanced in PASMC from CTEPH patients.

描述（由申请方提供）：在慢性血栓栓塞性肺动脉高压（CTEPH）患者中，肺血管阻力（PVR）升高是由血栓栓塞导致的近端和远端肺动脉阻塞以及肺血管平滑肌（PASMC）和内皮（PAEC）细胞过度迁移和增殖导致的肺血管重塑引起的。附着于肺血管壁的血栓栓塞包括大量的凝血因子（例如，凝血酶、纤维蛋白原），其可充当血管重塑的触发剂。凝血酶诱导的PAEC中胞浆[Ca 2 +]升高增加了内皮通透性，这使得促有丝分裂因子渗透到血管介质中并引起中膜肥大。PASMC胞浆[Ca 2 +]升高通过上调Ca 2+敏感性信号蛋白和转录因子刺激细胞增殖。通过激活PASMC中的受体，凝血因子（例如，凝血酶和纤维蛋白原）也通过促进经由瞬时受体电位（TRP）通道的Ca 2+内流而引起细胞溶质[Ca 2 +]的增加。我们最近已经证明，a）在正常PASMC增殖期间，TRP表达增加，并且通过TRP通道的Ca 2+进入增加，B）用siRNA抑制TRP表达减弱PASMC增殖，c）TRP的mRNA和蛋白质表达（例如，TRPC 3/6）在特发性肺动脉高压患者的PASMC中上调。基于这些数据，我们假设肺血管中TRP通道的基因表达异常增强是CTEPH患者血栓栓塞介导的肺血管重塑的易感因素。提出了三个具体的目标来验证这一假设：1）检查从CTEPH患者分离的PASMC中TRP通道是否以及哪些TRP通道在转录上上调，以及TRP编码的储存和受体操纵的阳离子通道是否在功能上增强; 2）检查凝血因子是否（凝血酶和纤维蛋白原）通过激活PASMC中的TRP通道增加胞质[Ca 2 +]，并且如果是这样，则TRP通道亚基在功能上受凝血酶和纤维蛋白原调节;以及3）检测凝血酶和纤维蛋白原的促有丝分裂作用是否依赖于正常PASMC中由于Ca 2+通过TRP通道进入而引起的胞质[Ca 2 +]增加，以及在CTEPH患者的PASMC中是否增强。