Mechanical Control of Coronary Angiogenesis in Myocardial Adaptation to Ischemia

心肌缺血适应中冠状动脉血管生成的机械控制

• 批准号: 10019590
• 负责人: Charles K Thodeti
• 金额: $ 43.72万
• 依托单位: NORTHEAST OHIO MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-19 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10019590
• 关键词: Affect; B-Lymphocytes; Binding Sites; Blood Vessels; Blood capillaries; Calcium; Cell membrane; Cells; Cessation of life; Chemicals; Chronic; Consequentialism; Contrast Echocardiography; Coronary; Data; Endothelial Cells; Endothelium; Engineering; Equilibrium; Event; Exhibits; Extracellular Matrix; Fluorescence Resonance Energy Transfer; Focal Adhesions; Gel; Growth; Growth Factor; Growth Factor Gene; Half-Life; Heart; Heart Injuries; Heart failure; Human; Hydrogels; Hypertension; Hypertrophy; Impairment; In Vitro; Integrins; Ion Channel; Ischemia; KDR gene; Knockout Mice; LATS1 gene; Left Ventricular Hypertrophy; Measures; Mechanics; Mediating; Membrane; Metabolic; Microscopic; Microscopy; Modality; Modeling; Molecular; Mus; Myocardial; Myocardial Infarction; Myocardial Ischemia; Myocardial perfusion; Myocardium; Null Lymphocytes; Organ; Pathology; Perfusion; Pharmacology; Play; Protein Engineering; Retina; Role; Signal Transduction; Stimulus; Stress; Structure; Techniques; Testing; Time; Tube; Two-Dimensional Echocardiography; Ultrasonography; United States; Vanilloid; Vascular Endothelial Growth Factors; Ventricular Function; angiogenesis; base; constriction; coronary fibrosis; gene therapy; heart function; hemodynamics; improved; in vivo; innovation; insight; matrigel; mechanical force; mechanotransduction; migration; multi-photon; mutant; pressure; receptor; response; restraint; retinal angiogenesis; rho; small molecule inhibitor; therapeutic angiogenesis; therapeutic development; trafficking; tumor

Inadequate capillary growth; inadequate perfusion and the consequential ischemia can initiate the sequelae of events causing the progression from an initial compensatory left ventricular hypertrophy (LVH) (in response to hemodynamic challenge) to maladaptation leading to heart failure. Although pro-angiogenic strategies such as delivery of growth factors and gene therapy are promising, there are limitations and concerns, including delivery modalities, uncontrolled angiogenesis, limited half-life of growth factors, and effects on other organs. Our proposal takes an alternative approach to test the hypothesis that mechanical forces in the hypertrophied ventricle adversely affect coronary angiogenesis during heart failure. The central objective of this proposal is to demonstrate that mechanical forces impede coronary angiogenesis during ischemia and hypertrophy. Our objective is based on the counterintuitive observations that a) endothelial cells (EC) null for a mechanosensitive ion channel, Transient Receptor Potential Vanilloid-4 (TRPV4) exhibited increased proliferation, migration, Rho activity, and tube formation compared to wild type EC b) both ex vivo (aortic sprouting) and in vivo (Matrigel, tumor and retinal) angiogenesis is enhanced in TRPV4KO mice compared WT and c) global (TRPV4KO) or endothelial specific (TRPV4ECKO) TRPV4 knockout mice exhibited improved cardiac function that correlated with reduced cardiac fibrosis and increased coronary angiogenesis compared to WTs subjected to LVH induced by either myocardial infarction (MI) or pressure-overload (transverse aortic constriction (TAC). These findings suggest that mechanical forces exert restraint on angiogenesis and uncoupling this mechanical effect (endothelial TRPV4 mechanotransduction) restores angiogenesis and cardiac function. Thus, our working hypothesis is that TRPV4 channels regulate angiogenesis via modulation of Rho activity that regulates EC contraction and VEGFR2 trafficking via YAP and that the absence of TRPV4 increases angiogenesis in myocardium and protects heart from ischemia- or pressure-overload- induced cardiac injury. We will test this hypothesis in the following specific aims 1) To identify the structural domains within TRPV4 that are required for the modulation of endothelial mechanosensitivity, Rho activation and angiogenesis 2) To define the molecular mechanism(s) by which TRPV4 integrates Rho/YAP and VEGF signaling in coronary angiogenesis and 3) To ascertain the functional significance of endothelial TRPV4 and to target TRPV4 with a small molecule inhibitor to induce angiogenesis in the myocardium. To accomplish this, we propose to use an innovative combination of advanced in vitro and in vivo techniques such as FRET, contrast echocardiography, multi-photon microscopy, engineered ECM gels that mimic stiffness of heart, endothelial-specific TRPV4KO mice (conventional and inducible) in conjunction with MI and TAC models. Our proposed studies will provide insights into the mechanism by which mechanical forces regulate coronary angiogenesis and may open entirely new avenues for development of therapeutics for angiogenesis.

毛细血管生长不足；血流灌注不足以及由此导致的缺血可引发 导致从最初的代偿性左心室肥厚(LVH)进展的事件(对 血液动力学挑战)到导致心力衰竭的适应不良。尽管促血管生成的策略，如 提供生长因子和基因疗法是有希望的，但也有局限性和担忧，包括 给药方式，不受控制的血管生成，有限的生长因子半衰期，以及对其他器官的影响。 我们的建议采用了另一种方法来检验这一假设，即肥厚症患者体内的机械力 心力衰竭时，脑室会对冠状动脉血管生成产生不利影响。这项提议的中心目标是 为了证明机械力在缺血和肥厚时阻碍冠状动脉血管生成。我们的 目标基于a)内皮细胞(EC)为空的违反直觉的观察 机械敏感离子通道、瞬时受体电位香草酸-4(TRPV4)升高 与野生型EC相比，其增殖、迁移、Rho活性和管状形成均为体外(主动脉 与体内(Matrigel、肿瘤和视网膜)血管生成相比，TRPV4KO小鼠的血管生成增强 WT和c)全局(TRPV4KO)或内皮特异性(TRPV4ECKO)TRPV4基因敲除小鼠表现出改善 与减少心脏纤维化和增加冠状动脉血管生成相关的心功能比较 心肌梗死(MI)或压力超负荷(横主动脉)引起的左心室肥厚 收缩(TAC)。这些发现表明，机械力对血管生成和 解偶联这种机械效应(内皮TRPV4机械转导)可以恢复血管生成和 心脏功能。因此，我们的工作假设是TRPV4通道通过 通过YAP调控EC收缩和VEGFR2转运的Rho活性以及缺失 TRPV4可增加心肌血管生成，保护心脏免受缺血或压力超负荷的影响。 致心脏损伤。我们将在以下具体目标中测试这一假设1)以确定结构 TRPV4内调节内皮细胞机械敏感性、Rho激活所需的结构域 和血管生成2)以确定TRPV4整合Rho/YAP和血管内皮生长因子的分子机制(S 冠状动脉血管生成中的信号转导；3)确定内皮细胞TRPV4的功能意义 靶向TRPV4的小分子抑制剂，以诱导心肌血管生成。要做到这一点， 我们建议使用先进的体外和体内技术的创新组合，如FRET， 对比超声心动图，多光子显微镜，模拟心脏僵硬的工程ECM凝胶， 内皮特异性TRPV4KO小鼠(常规和诱导型)与MI和TAC模型相结合。我们的 拟议的研究将为机械力调节冠状动脉的机制提供洞察力 血管生成，并可能为血管生成疗法的开发开辟全新的途径。