Chemokines in Healing Myocardial Infarcts

趋化因子在治疗心肌梗塞中的作用

• 批准号: 7414120
• 负责人: Nikolaos G Frangogiannis
• 金额: $ 28.45万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-06 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7414120
• 关键词: Address; Adhesions; Adoptive Transfer; Affect; Angiogenesis Inhibitors; Animals; Antibodies; Area; Blood; Blood Circulation; Bone Marrow Cells; Bone Marrow Transplantation; CX3CL1 gene; CXC Chemokines; CXCR3 gene; Canis familiaris; Cardiac; Cardiac Myocytes; Cell Adhesion; Cells; Characteristics; Chemotactic Factors; Cicatrix; Deposition; Endothelial Cells; Engineering; Extracellular Matrix Proteins; Family; Fibrin; Fibroblasts; Fibrosis; Focal Adhesions; Gene Expression; Gene Targeting; Genes; Goals; Granulation Tissue; Green Fluorescent Proteins; Growth Factor; Hand; Healed; Hematopoietic; In Vitro; Infarction; Infiltration; Inflammation; Inflammatory; Inflammatory Response; Integrins; Interferon Type II; Interferons; Knockout Mice; Leukocytes; Macrophage Activation; Mediator of activation protein; Microarray Analysis; Modeling; Monocyte Chemoattractant Protein-1; Monocyte Chemoattractant Proteins; Mononuclear; Mus; Myocardial; Myocardial Infarction; Myocardium; Myofibroblast; Pathologic; Phase; Phenotype; Play; Process; Property; Proteins; Recruitment Activity; Relative (related person); Research Personnel; Role; Series; Signal Transduction; Testing; Tissues; angiogenesis; base; beta-Chemokines; chemokine; cytokine; density; gene repression; healing; human CX3CR1 protein; in vivo; injured; irradiation; knockout animal; macrophage; member; migration; monocyte; monocyte chemoattractant protein 1 receptor; novel; novel therapeutics; prevent; programs; receptor; repaired; research study; response; therapeutic target; wound

DESCRIPTION (provided by applicant. Chemokines are induced in the infarcted myocardium and may play a role in inflammatory leukocyte infiltration, fibrous tissue deposition, and cardiac repair. Monocyte Chemoattractant Protein (MCP)-1, a potent mononuclear cell chemoattractant is rapidly upregulated in infarcts and may contribute to infarct healing. The CXC chemokine Interferon-gamma inducible Protein (IP)-10, a weak mononuclear cell chemoattractant, but potent angiostatic agent with anti-fibrotic properties, is markedly induced in the infarcted heart and may have a role in regulating infarct angiogenesis and fibrosis. This proposal will examine the role of MCP-1 and IP-10 in healing myocardial infarcts. Specific aim 1 will elucidate the functional role of MCP-1 in infarct healing, using gene-targeted animals in a murine model of myocardial infarction. MCP-1 may affect hematopoietic cells (predominantly mononuclear cells) as well as resident myocardial cells (fibroblasts and endothelial cells). In order to examine the relative importance of MCP-1 signaling in resident and blood-derived cells of the infarct, animals deficient in CCR2, the MCP-1 receptor, will be used to create chimeric mice after adoptive transfer of WT or CCR2 -/- bone marrow cells. In order to dissect the mechanisms responsible for suppressed macrophage activation and cytokine expression in the infarct we will test two intriguing hypotheses: a) that MCP-1 selectively recruits a specific monocvte subset [identified as CCR2 hi/fraktalkine receptor (CX3CR1) lo] that is more responsive to activation by inflammatory mediators, and b) that MCP-1 may directly regulate macrophage activation, differentiation and gene expression. These questions will be addressed using in vivo experiments with CX3CR1GFP/+ mice (in which GFP expression determines two distinct monocyte subpopulations in the bloodstream) and in vitro studies with isolated murine monocytes and macrophages. Specific aim 2 will investigate the role of IP-10 in healing mvocardial infarcts. Preliminary experiments suggest that IP-10 may be less important as a leukocyte chemoattractant. but may have a crucial role in preventing premature fibroblast accumulation and angiogenesis before the infarcted area is debrided and a fibrin-based provisional matrix, necessary to support fibrous tissue deposition is formed. This hypothesis will be tested using IP-10 and CXCR3 deficient mice; in addition the relative importance of IP-10/CXCR3 interactions in resident and hematopoietic cells infiltrating the infarct will be examined using chimeric mice with adoptive transfer of WT and CXCR3 -/- bone marrow cells. Specific aim 3 will explore the mechanisms responsible for the opposing effects of MCP-1 and IP-10 on fibrous tissue deposition using isolated cardiac fibroblasts and infarct myofibroblasts. The effects of MCP-1 and IP-10 on proliferation, migration and activation of cardiac fibroblasts and infarct myofibroblasts will be studied. Infarct myofibroblasts will be isolated from mice with defective MCP-1 (CCR2 and MCP-1 KO) and IP-10 (CXCR3 and IP-10 KO) signaling: their phenotvpe, motilitv, proliferative activity and gene expression will be compared with WT infarct myofibroblasts. Using gene microarray analysis, we identified novel actions of IP-10 in repression of genes associated with fibroblast adhesion, proliferation and migration. Accordingly we will study the effects of IP-10 on focal adhesion assembly and disassembly, fibroblast migration and proliferation. Understanding the role of chemokines in infarct healing may identify novel therapeutic targets aiming at optimizing cardiac repair and decreasing adverse remodeling.

DESCRIPTION (provided by applicant. Chemokines are induced in the infarcted myocardium and may play a role in inflammatory leukocyte infiltration, fibrous tissue deposition, and cardiac repair. Monocyte Chemoattractant Protein (MCP)-1, a potent mononuclear cell chemoattractant is rapidly upregulated in infarcts and may contribute to infarct healing. The CXC chemokine干扰素可诱导的蛋白质（IP）-10，一种弱的单核细胞趋化剂，但具有抗纤维化特性的有效血管静脉剂在梗塞心脏中明显诱导，并且可能在调节梗塞血管生成和纤维化方面起作用。 MCP-1在心肌梗死的鼠模型中使用基因靶向动物的MCP-1可能会影响造血细胞（主要是单核细胞）以及常驻的心肌细胞（成纤维细胞和内皮细胞）。为了检查MCP-1信号传导在梗死的驻留细胞和血液衍生细胞中的相对重要性，将使用MCP-1受体缺乏CCR2的动物，用于在继发wt或CCR2或CCR2 - / - 骨髓细胞后产生嵌合小鼠。为了阐述负责抑制巨噬细胞激活和细胞因子在梗死中的机制，我们将测试两个有趣的假设：a）MCP-1选择性地募集了特定的单腔子群[被识别为CCR2 HI/FRAKTALKINE受体（CX3CR1），该ccr2 hi/fraktalkine受体（cx3cr1）均通过激活的速度统治者，并且是在易转型级别的反应典礼，并且激活，分化和基因表达。这些问题将使用CX3CR1GFP/+小鼠的体内实验解决（其中GFP表达决定了血液中的两个不同的单核细胞亚群）和对分离的鼠单核细胞和巨噬细胞的体外研究。特定的目标2将研究IP-10在愈合M varcardial梗死中的作用。初步实验表明，作为白细胞趋化剂，IP-10可能不太重要。但是，在梗塞区域被清除和基于纤维蛋白的基于纤维蛋白的临时基质之前，可能具有至关重要的作用，在防止成纤维细胞积累和血管生成中起着至关重要的作用，这是支持纤维组织沉积所必需的。该假设将使用IP-10和CXCR3缺乏小鼠进行检验。此外，将使用WT和CXCR3和CXCR3 - / - 骨髓细胞的嵌合小鼠检查渗透梗塞的常驻和造血细胞中IP-10/CXCR3相互作用的相对重要性。特定的目标3将探索负责使用孤立心脏成纤维细胞和梗死肌纤维细胞对MCP-1和IP-10对纤维组织沉积的相反作用的机制。将研究MCP-1和IP-10对心脏成纤维细胞和梗死肌纤维细胞的增殖，迁移和激活的影响。梗死的肌纤维细胞将从有缺陷的MCP-1（CCR2和MCP-1 KO）和IP-10（CXCR3和IP-10 KO）信号的小鼠中分离出来：它们的现表剂，motilitv，增殖活性和基因表达将与WT Inmarct Ilsarct肌肌纤维肌瘤相比。使用基因微阵列分析，我们确定了IP-10在与成纤维细胞粘附，增殖和迁移相关的基因抑制中的新作用。因此，我们将研究IP-10对焦点粘附组装和拆卸，成纤维细胞迁移和增殖的影响。了解趋化因子在梗塞愈合中的作用可能会确定旨在优化心脏修复和减少不良重塑的新型治疗靶标。