Cardioprotection and uncoupling myofibroblast-myocyte communications

心脏保护和解偶联肌成纤维细胞-肌细胞通讯

• 批准号: 10202720
• 负责人: Simon James Conway
• 金额: $ 39.38万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10202720
• 关键词: Ablation; Action Potentials; Acute; Acute myocardial infarction; Adrenergic Agents; Agonist; Angiotensin II; Angiotensin II Receptor; Arrhythmia; Biological Assay; CCL2 gene; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cells; Cessation of life; Chronic; Collagen; Communication; Connexin 43; Connexins; Coupling; Data; Electrophysiology (science); Enhancers; Enterobacteria phage P1 Cre recombinase; Exhibits; Fibrosis; Functional disorder; Gap Junctions; Heart; Heart Injuries; Histologic; Hypertrophy; Image; Immunohistochemistry; In Vitro; Infusion procedures; Injury; Isoproterenol; Mediating; Messenger RNA; Molecular; Mus; Muscle Cells; Myocardial; Myocardial Infarction; Myocardium; Myofibroblast; Pathologic; Patients; Performance; Play; Population; Predisposition; Prevalence; Property; Reporter; Role; Shapes; Signal Transduction; Site; Stretching; Structure; Tamoxifen; Testing; Transforming Growth Factor beta; Up-Regulation; Ventricular; cardioprotection; chemokine receptor; coronary fibrosis; cytokine; data modeling; experimental study; genetic manipulation; heart rhythm; in vivo; injured; monocyte chemoattractant protein 1 receptor; mouse model; novel; paracrine; periostin; pressure; prevent; recombinase; response; tool; voltage

PROJECT SUMMARY/ABSTRACT In response to damage, pathological cardiac remodeling frequently manifests as myocardial hypertrophy, fibrosis, contractile dysfunction and/or increased arrhythmia vulnerability. Myofibroblasts (Mfbs) are not normally present in the working myocardium but accumulate in large numbers in the injured heart. Hypersecretion of collagen and paracrine factors from activated Mfbs results in the formation of electrically insulating septa and ionic remodeling of cardiomyocytes (CMs), respectively, promoting arrhythmia. Besides their barrier and paracrine function, preliminary experiments using intravital voltage imaging and immunohistochemistry, suggest the intriguing possibility that Mfbs influence the functional properties of fibrotically remodeled myocardium via direct electrotonic interactions with surrounding CMs via gap junctions composed of cell-to-cell Connexin(Cx)43 subunits. Preliminary mouse modeling data also revealed that chronic systemic infusion of β-adrenergic or angiotensin-II receptor agonists, as well as acute myocardial infarction (MI) result in Mfb-restricted misexpression of Cx43, a stretch-induced profibrotic cytokine Ccl2 (MCP-1) and profibrotic matricellular Periostin (Postn) coincident with pathological remodeling. Likewise, in patients with acute MI or pressure overload, POSTN and MCP-1 are robustly upregulated and Cx43 (GJA1) distribution is perturbed. Cx43, the principal gap junction protein responsible for action potential propagation in ventricles, is often mis-expressed in hypertrophied and ischemic patient hearts. We and others have demonstrated that Cx43 is also present in the pathological Mfb population, and additional preliminary data revealed Ccl2 is transcribed in Mfbs (whereas its receptor Ccr2 is in CMs). Endogenous Postn functionally promotes cardiac fibrosis/ventricular stiffness, as surviving Postn nulls exhibit less fibrosis and better function after MI. Moreover, we generated a unique 3.9kb-driven Postn enhancer reporter line that drives Cre-recombinase expression only in Mfbs in injured hearts (designated Postn-Cre). Thus, this is a most useful tool for genetic manipulation of cardiac activated injury-site Mfbs. However, the actual role that electrical coupling in Postn-expressing Mfb-lineage plays and the mechanism underlying Mfb-CM interactions during pathological remodeling remain unknown. Thus, three interrelated aims are proposed to examine these preliminary data. Aim 1 will test the hypothesis that uncoupling Mfb-CM electrical signaling via Mfb-restricted cKO of Cx43 prevents adverse cardiac remodeling. Aim 2 will test whether Mfb-restricted Cx43 cKO offers arrhythmia protection. Aim 3 will determine if Mfb-restricted loss of the Ccl2 cytokine ameliorates adjacent CM contractile dysfunction.

项目摘要/摘要 为了响应损害，病理心脏重塑经常表现为心肌肥大， 纤维化，收缩功能障碍和/或心律不齐的脆弱性增加。肌纤维细胞（MFB）通常不是 在工作心肌中存在，但在受伤的心脏中大量丙烯酸。过度分泌 活化MFB的胶原蛋白和旁分泌因子导致形成电绝缘隔和 心肌细胞（CMS）的离子重塑，促进心律不齐。除了他们的障碍和 旁分泌功能，使用浸润电压成像和免疫组织化学的初步实验表明 MFB会影响纤维化重塑心肌的功能特性的有趣可能性 通过由细胞到细胞连接蛋白（CX）组成的间隙连接与周围CM的直接电子相互作用43 亚基。初步的小鼠建模数据还表明，慢性全身输注β-肾上腺素或 血管紧张素-II受体激动剂以及急性心肌梗塞（MI）导致MFB限制的Misexpression CX43，一种拉伸诱导的纤维化细胞因子CCL2（MCP-1）和纤维化基质骨蛋白（Postn） 与病理重塑一致。同样，在急性MI或压力超负荷的患者中， MCP-1进行了强大的更新，CX43（GJA1）分布受到干扰。 CX43，主要间隙连接处 负责动作电位传播的蛋白质在肥厚和 缺血患者心。我们和其他人已经证明了CX43也存在于病理MFB中 人口和其他初步数据显示，CCL2在MFB中转录（而其受体CCR2在 CMS）。内源性邮政在功能上促进心脏纤维化/心室刚度，因为存活的后无效 MI后表现出较小的纤维化和更好的功能。此外，我们产生了一个独特的3.9kb驱动的邮政增强器 仅在受伤的心脏中的MFB中驱动CRE聚集酶表达的记者线（指定的邮政）。那， 这是对心脏激活损伤部位MFB的基因操纵的最有用工具。但是，实际角色 在表达MFB的Linege戏剧和MFB-CM基础机构中的电气耦合 病理重塑期间的相互作用仍然未知。这是提出三个相互关联的目标 检查这些初步数据。 AIM 1将检验以下假设：通过 CX43的MFB限制CKO可防止心脏重塑。 AIM 2将测试MFB限制的CX43 CKO提供心律不齐的保护。 AIM 3将确定CCL2细胞因子的MFB限制损失是否可以改善 相邻的CM收缩功能障碍。