Restoration of Myocardial Healing through G-coupled Protein Receptor Signaling

通过 G 偶联蛋白受体信号转导恢复心肌愈合

• 批准号: 8452816
• 负责人: JOAN HELLER BROWN
• 金额: $ 32.83万
• 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
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8452816
• 关键词: AGTR2 gene; Adrenergic Agents; Adrenergic Antagonists; Adrenergic Receptor; Adult; Affect; Agonist; Angiotensins; 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; GTP-Binding Proteins; Gene Expression; Genetic; Genetic Engineering; Genetically Engineered Mouse; Goals; Healed; Heart; Heart failure; In Vitro; Injury; Instruction; Intervention; Investigation; Knockout Mice; Learning; Ligands; Mediating; Messenger RNA; Mitochondria; Modeling; Mus; Myocardial; Myocardial Infarction; Natural regeneration; Orphan; Oxidative Stress; Oxygen; Pathway interactions; Pharmaceutical Preparations; Physiological; Population; Principal Investigator; Process; Proliferating; Property; Receptor Activation; Regulation; Research; Role; Signal Pathway; Signal Transduction; Simulate; Site; Small Interfering RNA; Sphingosine-1-Phosphate Receptor; Stem cells; Stress; Testing; Thrombin; adhesion receptor; adrenergic; anthrax toxin receptors; base; cardiac repair; healing; human SMO protein; 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）表达了G蛋白偶联受体（GPCR）的令人印象深刻的补体 与成人心肌细胞发现的不同。该提案检验了以下假设 GPCR和在受伤部位的配体的可用性可以使或损害增殖，生存 和内源性CPC的分化。我们提出了三个目标，其中使用与WT隔离的CPC 和基因工程的小鼠心脏，以检查有助于这些的GPCR调节途径 响应并将我们的发现扩展到体内心肌梗死模型。在AIM＃1中，我们使用mRNA阵列， QPCR和蛋白质表达测定法在培养的CPC上定义居民GPCR并确定它们是否是 由缺血应力，ER应力或分化动态调节。进一步的研究定义了GPCR 最有效地引发CPC增殖，生存，迁移和分化以及特定的 他们使用的G蛋白和效应子。在AIM＃2中，我们测试了Rhoa信号及其调节的假设 通过SIP和其他GPCR可以增强CPC的修复特性。拟议的研究使用CPC 基因设计的RhoA和SIP受体敲除小鼠，以确定SIP受体亚型和 激动剂中RhoA信号传导的需求刺激了CPC响应。 Rhoa在激活和 还检查了使用下游转录共激活因子MRTF-A和YAP。体内研究 SIP受体和Rhoa Ko小鼠检查心肌后居民CPC的再生能力 梗塞（ML）。 AIM＃3检验了以下假设，即肾上腺素能（ADR）和Angll的补充变化 受体（ATR）亚型改变了CPC的增殖和存活，可以诱导线粒体损伤 通过氧化应激和细胞死亡。我们比较了CPC，其中PI与P2和ATI与ATI VS的补体。 AT2亚型改变并检查ATR阻滞剂和P-ADR阻滞剂对增殖和 CPC的生存。最终的重点是Apadr在CPC中的可能有益作用 交感神经肾上腺素能刺激和ML。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，其长期目标的 使用这些高度可访问的药物靶标作为干预部位，以促进心肌愈合。 相关性（请参阅说明）： 当缺氧时，心脏中的心肌细胞死亡，因此心脏变得虚弱。 如果适当刺激，心脏中的干细胞可能会形成新的心肌细胞并预防心力衰竭。 我们认为，这些心脏祖细胞上的特定G蛋白偶联受体可能会增强 可以开发出调节这些受体的药物来治愈心脏。