TSC2 signaling in Pulmonary Arterial Hypertension

肺动脉高压中的 TSC2 信号传导

• 批准号: 9893011
• 负责人: Elena Goncharova
• 金额: $ 2.53万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893011
• 关键词: Affect; Apoptosis; Apoptotic; Area; Attenuated; Blood Vessels; Cell Communication; Cell Proliferation; Cell Survival; Cells; Cessation of life; Clinical Data; Clinical Trials; Collagen; Complex; Data; Development; Disease; Disease Progression; Distal; Epigenetic Process; Extracellular Matrix; Extracellular Matrix Proteins; FRAP1 gene; Fibronectins; Funding; Growth; Heart failure; Homeostasis; Human; Hypoxia; Impairment; In Vitro; Knock-out; Knockout Mice; Link; Lung; Modeling; Molecular; Molecular Target; Mus; Mutation; Outcome; Pathogenesis; Pathologic; Patients; Pharmaceutical Preparations; Phenotype; Production; Publishing; Pulmonary Vascular Resistance; Pulmonary artery structure; Reporting; Resistance; Rodent; Role; SIRT1 gene; SU 5416; Signal Transduction; Smooth Muscle Myocytes; Structure of parenchyma of lung; Testing; Therapeutic; Therapeutic Intervention; Tissue Sample; Transcription Coactivator; Tuberous sclerosis protein complex; Up-Regulation; Vascular Smooth Muscle; Vascular remodeling; Ventricular; base; cell growth; in vivo; inhibitor/antagonist; insight; member; molecular targeted therapies; new therapeutic target; novel; pre-clinical; primary pulmonary hypertension; pulmonary arterial hypertension; restoration; targeted treatment; vascular factor; vascular smooth muscle cell proliferation

Pulmonary arterial hypertension (PAH), a progressive fatal disease, manifests by vascular remodeling of pulmo- nary arteries (PA), elevated right ventricular afterload, right heart failure and death. A key component of PA remodeling is the progressive vessel wall thickening due to increased proliferation and impaired apoptosis of pulmonary arterial vascular smooth muscle cells (PAVSMC). We previously identified mTOR signaling as a key positive regulator of proliferative/apoptosis-resistant PAH PAVSMC and provided pre-clinical data for a clinical trial to test mTOR inhibitor ABI-009 for patients with PAH. Recently, bi-directional cross-talk between PAVSMC and extracellular matrix (ECM) composition and stiffness was identified as a key regulator of pulmonary vascular remodeling and PAH. The mechanism(s) linking ECM, mTOR-supported PAVSMC remodeling, and proliferation of other resident PA cells are not known, and safe and easily translatable therapeutic options remain to be determined. We have found that growth suppressor TSC2, a key inhibitor of mTOR complex 1 (mTORC1), also acts as a mechanosensor and forms negative bi-directional cross-talk with mechanotransducers Yap/Taz, hyper- activation of which in PAH promotes ECM stiffening and pulmonary vascular remodeling. We report that TSC2 is deficient in PAVSMC from subjects with PAH, resulting in activation of mTORC1, Yap/Taz, consequent up- regulation of pro-survival mTORC2-Akt, increased proliferation, survival, and over-production of ECM proteins. ECM, produced by human PAH PAVSMC, activates mTORC1, and up-regulates Yap/Taz, mTORC2-Akt and PAVSMC proliferation, as well as growth of PAEC and PAAF. Last, the restoration of TSC2 by Sirt1 activator SRT2104 down-regulates both Yap/Taz and mTORC1/2, reduces ECM production, inhibits proliferation and in- duces apoptosis in human PAH PAVSMC, and reduces SU5416/hypoxia PH in mice. During the next funding period, we propose to elucidate the role of TSC2 as a critical coordinator of ECM-pulmonary vascular cell inter- actions and explore the benefits of TSC2 restoration by a novel well-tolerated drug with high translational poten- tial to correct deregulation of both mTOR and Yap/Taz networks, and reverse PA remodeling and PH. Specifi- cally, we will (1) critically test the status of TSC2, its relationship with Yap/Taz, mTORC1 and 2, and its role in PAVSMC proliferation, survival, pulmonary vascular remodeling and PH using de-identified lung tissues and cells from PAH and healthy subjects and mice with VSM-specific Tsc2 knockout; (2) determine whether TSC2 deficiency in PAVSMC is induced by increased matrix stiffness and self-supported via a Yap/Taz-dependent ECM loop, and evaluate the role of TSC2 in ECM remodeling and ECM-dependent proliferation of PAEC and PAAF; and (3) test whether restoration of TSC2 by SRT2104 suppresses PAH PAVSMC proliferation, induces apoptosis, reduces pathological ECM production and consequent hyper-proliferation of PAEC and PAAF, and reverses pulmonary vascular remodeling and PH. The proposed study will identify new critical mechanisms of pulmonary vascular remodeling and dissect new important molecular target for therapeutic intervention.

肺动脉高压（PAH）是一种进行性致死性疾病，表现为肺动脉的血管重构， 无动脉（PA）、右心室后负荷升高、右心力衰竭和死亡。PA的关键组成部分 血管重塑是由于增殖增加和细胞凋亡受损而导致的进行性血管壁增厚。 肺动脉血管平滑肌细胞（PAVSMC）。我们之前确定mTOR信号是一个关键， 增殖性/抗肺动脉高压PAVSMC的正调节因子，并为临床研究提供了临床前数据。 试验测试mTOR抑制剂ABI-009用于PAH患者。最近，PAVSMC之间的双向串扰 细胞外基质（ECM）的组成和硬度被确定为肺血管的关键调节因子， 重塑和PAH。ECM、mTOR支持的PAVSMC重塑和增殖之间的联系机制 其他常驻PA细胞的数量尚不清楚，安全且易于翻译的治疗选择仍有待进一步研究。 测定我们已经发现，生长抑制因子TSC 2是mTOR复合物1（mTORC 1）的关键抑制剂， 作为机械传感器，并与机械传感器雅普/Taz、超声波传感器和超声波传感器形成负双向串扰。 在PAH中其活化促进ECM硬化和肺血管重塑。我们报告说，TSC 2 PAH受试者的PAVSMC缺乏，导致mTORC 1、雅普/Taz激活，随后上调- 促存活mTORC 2-Akt的调节，增加的增殖、存活和ECM蛋白的过度产生。 由人PAH PAVSMC产生的ECM激活mTORC 1，并上调雅普/Taz、mTORC 2-Akt和 PAVSMC增殖，以及PAEC和PAAF的生长。最后，通过Sirt 1激活剂恢复TSC 2 SRT 2104下调雅普/Taz和mTORC 1/2，减少ECM产生，抑制增殖和细胞内分泌。 诱导人PAH PAVSMC凋亡，降低小鼠SU 5416/缺氧PH。在下一次融资中 期间，我们建议阐明TSC 2作为ECM-肺血管细胞间的关键协调者的作用， 的作用，并探索通过一种具有高翻译潜力的新型耐受性良好的药物恢复TSC 2的益处。 有助于纠正mTOR和雅普/Taz网络的失调，逆转PA重塑和PH。 因此，我们将（1）严格检测TSC 2的状态，它与雅普/Taz，mTORC 1和2的关系，以及它在 PAVSMC增殖、存活、肺血管重塑和PH，使用去识别的肺组织， 来自PAH和健康受试者以及具有VSM特异性Tsc 2敲除的小鼠的细胞;（2）确定Tsc 2是否 PAVSMC中的缺陷是由基质刚度增加引起的，并通过依赖于雅普/Taz的 ECM环，并评估TSC 2在PAEC的ECM重塑和ECM依赖性增殖中的作用， （3）测试通过SRT 2104恢复TSC 2是否抑制PAH PAVSMC增殖，诱导PAVSMC增殖， 细胞凋亡，减少病理性ECM产生以及随后的PAEC和PAAF过度增殖，以及 逆转肺血管重构和PH。拟议的研究将确定新的关键机制， 肺血管重塑和解剖新的重要分子靶点进行治疗干预。