Targeting cardiac fibroblast-myocyte cross talk to enhance heart function after cardiac injury

项目摘要/摘要 缺血性心肌损伤后的心脏修复涉及一系列精心策划的细胞事件。这个 心脏损伤后心肌细胞数量发生了实质性变化，最初有中性粒细胞的渗透，然后 巨噬细胞和成纤维细胞和内皮细胞的旺盛增殖。毫无疑问，细胞间的串扰 影响心脏伤口的愈合，但细胞间的串扰是否可以作为靶点尚不清楚。 加强心脏修复。在这个提议中，我们确定了心肌细胞和非心肌细胞之间的一种不寻常的串扰 调节心脏伤口愈合的肌细胞。我们证明心脏成纤维细胞戏剧性地 在缺血性心脏损伤后上调ENPP1蛋白(外核苷酸焦磷酸酶1)。ENPP1 水解胞外三磷酸腺苷，我们发现三磷酸腺苷水解物诱导心肌细胞释放 促炎代谢产物，可诱导多种非心肌细胞调节伤口的细胞死亡 巨噬细胞、内皮细胞、成纤维细胞和平滑肌细胞等的愈合。我们确定了这样的 心肌细胞分泌促炎代谢物及其分子作用机制的研究 非心肌细胞上的代谢物。我们提供了心脏组织中ENPP1基因缺失的初步数据 成纤维细胞可显著改善损伤后的心功能，并与减少瘢痕形成和 损伤后心脏扩张减少。我们鉴定了ENPP1的小分子抑制剂以及单抗 针对ENPP1的抗体，并证明ENPP1的药理学靶向可以作为一种 心肌梗死后心脏重构的治疗策略。这些观察形成了一个合理的基础 深入探讨ENPP1介导的心肌细胞-非心肌细胞串扰的生理意义 心脏修复及确定ENPP1介导的成纤维细胞-非心肌细胞是否具有药理靶向性 串扰是一种潜在的治疗缺血性心脏损伤的策略。

Project Summary/Abstract Cardiac repair following ischemic myocardial injury involves a carefully orchestrated set of cellular events. The cardiac cell population substantially changes after cardiac injury with infiltration of initially neutrophils, then macrophages and robust proliferation of fibroblasts and endothelial cells. Cell-cell cross talk undoubtedly affects cardiac wound healing but little is known about whether cell-cell cross talk can be targeted for enhancing cardiac repair. In this proposal, we identify an unusual cross talk between myocytes and non- myocytes that regulates cardiac wound healing. We demonstrate that cardiac fibroblasts dramatically upregulate the protein ENPP1 (ectonucleotide pyrophosphatase 1) following ischemic cardiac injury. ENPP1 hydrolyzes extracellular ATP and we show that ATP hydrolytic products induces myocytes to release metabolites that are pro-inflammatory and induce cell death of various non-myocyte cells regulating wound healing such as macrophages, endothelial cells, fibroblasts and smooth muscle cells. We identify such myocyte secreted pro-inflammatory metabolites and investigate molecular mechanisms of action of such metabolites on non-myocyte cells. We provide preliminary data that genetic deletion of ENPP1 in cardiac fibroblasts dramatically ameliorates post injury heart function and is associated with decreased scarring and decreased post injury cardiac dilatation. We identify small molecule inhibitors of ENPP1 as well as monoclonal antibodies targeting ENPP1 and demonstrate that pharmacologic targeting of ENPP1 can serve as a therapeutic strategy for post infarction cardiac remodeling. These observations form a rational basis for investigating in depth the physiological significance of ENPP1 mediated myocyte-non myocyte cross talk in cardiac repair and determine whether pharmacologic targeting of ENPP1 mediated fibroblast-non myocyte cross talk is potentially a therapeutic strategy for ischemic cardiac injury.