Restoration of Myocardial Healing through G-coupled Protein Receptor Signaling

通过 G 偶联蛋白受体信号传导恢复心肌愈合

• 批准号: 9324068
• 负责人: JOAN HELLER BROWN
• 金额: $ 28.45万
• 依托单位: SAN DIEGO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9324068
• 关键词: AGTR2 gene; Adrenergic Agents; Adrenergic Antagonists; Adrenergic Receptor; Adult; Affect; Agonist; Angiotensin I; Biological Assay; Cardiac; Cardiac Myocytes; Cell Death; Cell Proliferation; Cell Survival; Cell physiology; Complement; Down-Regulation; Drug Targeting; Drug or chemical Tissue Distribution; Environment; Fibronectins; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; G-substrate; GTP-Binding Proteins; Gene Expression; Genetic; Genetically Engineered Mouse; Goals; Heart; Heart failure; Impairment; In Vitro; Injury; Instruction; Intervention; Investigation; Knockout Mice; Ligands; Mediating; Messenger RNA; Mitochondria; Modeling; Myocardial; Myocardial Infarction; Natural regeneration; Orphan; Oxidative Stress; Oxygen; Pathologic; Pathway interactions; Pharmaceutical Preparations; Pharmacology; Physiological; Population; Principal Investigator; Process; Proliferating; Property; Receptor Activation; Recruitment Activity; Regulation; Research; Role; Signal Pathway; Signal Transduction; Site; Small Interfering RNA; Sphingosine-1-Phosphate Receptor; Stem cells; Stress; Testing; Thrombin; Transcription Coactivator; adhesion receptor; base; cardiac regeneration; cardiac repair; genetically modified cells; healing; in vivo; migration; prevent; protein expression; receptor; regenerative; response; restoration; therapeutic target

Cardiac progenitor cells (CPCs) express an impressive complement of G-protein coupled receptors (GPCRs) distinct from those found on adult cardiomyocytes. This proposal tests the hypothesis that the expression of GPCRs and availability of their ligands at sites of injury can either enable or impair the proliferation, survival and differentiation of endogenous CPCs. We propose three aims in which we use CPCs isolated from WT and genetically engineered mouse hearts to examine GPCR regulated pathways that contribute to these responses and extend our findings to an in vivo myocardial infarct model. In Aim # 1 we use mRNA arrays, qPCR and protein expression assays to define resident GPCRs on cultured CPCs and determine if they are dynamically regulated by ischemic stress, ER stress, or differentiation. Further studies define the GPCRs that are most efficacious for eliciting CPC proliferation, survival, migration and differentiation and the specific G-proteins and effectors they utilize. In Aim #2 we test the hypothesis that RhoA signaling, and its regulation by SIP and other GPCRs can enhance the reparative properties of CPCs. Proposed studies use CPCs from genetically engineered RhoA and SIP receptor knockout mice to determine the SIP receptor subtypes and requirement for RhoA signaling in agonist stimulated CPC responses. The role of RhoA in activating and utilizing the downstream transcriptional co-activators MRTF-A and YAP is also examined. In vivo studies in SIP receptor and RhoA KO mice examine the regenerative capacity of resident CPCs following myocardial infarction (Ml). Aim #3 tests the hypothesis that changes in the complement of adrenergic (AdR) and Angll receptor (ATR) subtypes alter the proliferation and survival of CPCs and can induce mitochondrial damage and cell death through oxidative stress.We compare CPCs in which the complement of Pi vs. P2 and ATi vs. AT2 subtypes are altered and examine effects of ATR blockers and p-AdR blockers on proliferation and survival of CPCs. A final focus is on the possible salutary role of apAdR on CPCs in responses to sympathetic adrenergic stimulation and Ml. Our overall objective is to demonstrate that specific GPCRs and their signaling pathways can be used to maintain and enhance CPC function, with the long term goal of using these highly accessible drug targets as sites of intervention to promote myocardial healing. RELEVANCE (See instructions): Cardiomyocytes in the heart die when deprived of oxygen and as a consequence the heart becomes weak. Stem cells in the heart, if appropriately stimulated, could form new cardiomyocytes and prevent heart failure. We believe that specific G-protein coupled receptors on these cardiac progenitor cells may enhance this process and that drugs that regulate these receptors could be developed to heal the heart.

心脏祖细胞（CPC）表达令人印象深刻的G蛋白偶联受体（GPCRs） 不同于在成年心肌细胞上发现的那些。这一提议检验了一个假设，即 GPCR及其配体在损伤部位的可用性可以使或损害细胞的增殖、存活和/或分化。 和内源性CPC的分化。我们提出了三个目标，我们使用从WT分离的CPC 和基因工程小鼠心脏，以检查GPCR调节的途径，有助于这些 反应，并将我们的研究结果扩展到体内心肌梗死模型。在目标1中，我们使用mRNA阵列， qPCR和蛋白质表达测定，以确定培养的CPC上的常驻GPCR，并确定它们是否 由缺血应激、ER应激或分化动态调节。进一步的研究定义了GPCR 最有效地诱导CPC增殖、存活、迁移和分化， G蛋白及其利用的效应器。在目标#2中，我们测试了RhoA信号传导及其调控的假设， 通过SIP和其他GPCR可以增强CPC的修复性能。拟议的研究使用来自 基因工程改造的RhoA和SIP受体敲除小鼠以确定SIP受体亚型， 在激动剂刺激的CPC反应中需要RhoA信号传导。RhoA在激活和 还检测了利用下游转录共激活因子MRTF-A和雅普。体内研究 SIP受体和RhoA KO小鼠检查了心肌缺血后常驻CPC的再生能力。 梗死（MI）。目标#3测试肾上腺素能（AdR）和Angl的补体变化的假设 ATR受体亚型改变CPC的增殖和存活，并可诱导线粒体损伤 我们比较了其中P1与P2的补体以及AT 1与AT 2的补体的CPC。 AT 2亚型改变，并检查ATR阻断剂和p-AdR阻断剂对增殖和增殖的影响。 CPC的生存。最后一个重点是apAdR对CPC在应答以下疾病中可能的有益作用： 交感肾上腺素能刺激和MI.我们的总体目标是证明特定的GPCR和 它们的信号通路可用于维持和增强CPC功能，长期目标是 使用这些高度可及的药物靶点作为干预部位以促进心肌愈合。 相关性（参见说明）： 心脏中的心肌细胞在缺氧时死亡，因此心脏变得虚弱。 心脏中的干细胞，如果受到适当的刺激，可以形成新的心肌细胞，防止心力衰竭。 我们认为，这些心脏祖细胞上的特异性G蛋白偶联受体可能会增强这种作用。 这一过程，并且可以开发出调节这些受体的药物来治愈心脏。