Chemokines in Healing Myocardial Infarcts

趋化因子在治疗心肌梗塞中的作用

• 批准号: 7617523
• 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/7617523
• 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; Growth Factor; Hand; Healed; Hematopoietic; In Vitro; Infarction; Infiltration; Inflammation; Inflammation Mediators; 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; in vivo; injured; irradiation; knockout animal; macrophage; member; migration; monocyte; monocyte chemoattractant protein 1 receptor; new therapeutic target; novel; premature; prevent; programs; receptor; repaired; research study; response; 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.

描述（由申请人提供。趋化因子在梗塞心肌中被诱导，可能在炎症白细胞浸润、纤维组织沉积和心脏修复中发挥作用。单核细胞趋化蛋白（MCP）-1，一种有效的单核细胞趋化蛋白，在梗塞中迅速上调CXC 趋化因子干扰素-γ 诱导蛋白可能有助于梗塞愈合。 (IP)-10是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抑制剂，在梗塞心脏中被显着诱导，并且可能在调节梗塞血管生成和纤维化中发挥作用。该提案将检查MCP-的作用。 1 和 IP-10 在治愈心肌梗塞中的具体目标 1 将使用基因靶向动物来阐明 MCP-1 在梗塞愈合中的功能作用。 MCP-1 小鼠心肌梗塞模型可能影响造血细胞（主要是单核细胞）以及驻留心肌细胞（成纤维细胞和内皮细胞）。为了检查 MCP-1 信号传导在梗塞的常驻细胞和血源细胞中的相对重要性，在过继转移 WT 或 CCR2 后，将使用缺乏 CCR2（MCP-1 受体）的动物来创建嵌合小鼠 -/ - 骨髓细胞。为了剖析梗塞中抑制巨噬细胞活化和细胞因子表达的机制，我们将测试两个有趣的假设：a) MCP-1 选择性地招募特定的单核细胞子集 [鉴定为 CCR2 hi/fraktalkine 受体 (CX3CR1) lo] b) MCP-1 可以直接调节巨噬细胞的激活、分化和基因表达。这些问题将通过 CX3CR1GFP/+ 小鼠的体内实验（其中 GFP 表达决定血液中两种不同的单核细胞亚群）和分离的小鼠单核细胞和巨噬细胞的体外研究来解决。具体目标 2 将研究 IP-10 在治疗心肌梗塞中的作用。初步实验表明，IP-10 作为白细胞趋化剂可能不太重要。但在梗塞区域清创和形成支持纤维组织沉积所必需的基于纤维蛋白的临时基质之前，可能在防止成纤维细胞过早积聚和血管生成方面发挥关键作用。该假设将使用 IP-10 和 CXCR3 缺陷小鼠进行测试；此外，将使用过继转移WT和CXCR3 -/- 骨髓细胞的嵌合小鼠来检查IP-10/CXCR3相互作用在浸润梗塞的常驻细胞和造血细胞中的相对重要性。具体目标 3 将利用分离的心脏成纤维细胞和梗塞肌成纤维细胞探讨 MCP-1 和 IP-10 对纤维组织沉积产生相反作用的机制。研究MCP-1和IP-10对心脏成纤维细胞和梗死肌成纤维细胞增殖、迁移和活化的影响。将从 MCP-1（CCR2 和 MCP-1 KO）和 IP-10（CXCR3 和 IP-10 KO）信号传导缺陷的小鼠中分离梗塞肌成纤维细胞：将其表型、运动性、增殖活性和基因表达与 WT 梗塞进行比较肌成纤维细胞。通过基因微阵列分析，我们发现了 IP-10 在抑制与成纤维细胞粘附、增殖和迁移相关的基因方面的新作用。因此我们将研究IP-10对粘着斑组装和分解、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以确定旨在优化心脏修复和减少不良重塑的新治疗靶点。