Epigenetic reprogramming of cardiac myofibroblasts for cardiac repair

心肌成纤维细胞的表观遗传重编程用于心脏修复

• 批准号: 10713647
• 负责人: YAO LIANG TANG
• 金额: $ 50.9万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10713647
• 关键词: ATAC-seq; Ablation; Adult; Cardiac; Cardiovascular system; Cells; Clinical; Data; Enhancers; Enzymes; Epigenetic Process; Fibroblasts; Fibrosis; Follicular Lymphoma; GATA4 gene; Gene Deletion; Gene Expression; Genes; Genetic Transcription; Goals; Heart; Heart failure; Homologous Gene; In Vitro; Knockout Mice; Knowledge; Mediating; Mus; Myocardial Infarction; Myocardial Ischemia; Myofibroblast; Natural regeneration; Nucleic Acid Regulatory Sequences; Pathologic; Pathway interactions; Phenotype; Population; Process; Proliferating; Pump; Recombinant adeno-associated virus (rAAV); Repression; Role; Running; Testing; Therapeutic; angiogenesis; cardiac angiogenesis; cardiac regeneration; cardiac repair; cell transformation; chromatin remodeling; coronary fibrosis; epigenomics; gene repression; heart function; improved; inhibitor; innovation; insight; ischemic injury; mouse model; novel; novel strategies; paracrine; progenitor; programs; regenerative; repaired; response; restraint; single-cell RNA sequencing; stem cells; transcription factor; transcriptome sequencing; transcriptomics; vector

PROJECT SUMMARY Heart failure is associated with activation of cardiac fibroblasts (Fib), which promotes cardiac fibrosis and pathological cardiac remodeling. Employing single-cell RNA-sequencing (scRNA-seq) in adult mouse hearts, we discovered that Enhancer of Zeste homolog 2 (EZH2), the major enzyme known to catalyze the transcriptional repression mark H3K27me3, is highly expressed in a specific POSTN+ Fib subpopulation (myofibroblasts, MFib). Of note, little is known about the functional role of EZH2 in regulating cardiac MFib, which is a critical knowledge gap given their epigenetic variability and pathological role. We demonstrate that although these MFib express GATA4, an early cardiac transcription factor, they fail to express the cardiovascular progenitor (CPC) gene programs, such as NKX2.5. Importantly, deletion of EZH2 inhibited MFib proliferation and switched on cardiovascular progenitor cell (CPC) gene programs. Moreover, deletion of EZH2 increased the pro-angiogenic paracrine effects of MFib and improved cardiac function post myocardial infarction (MI) These beneficial effects on cardiac function were lost in mice administered a novel rAAV-FLEX-DTA vector, which ablates MFib lacking EZH2, confirming the important functional role of this cell population. These findings suggest that EZH2 is a restraint on the transition of MFib to beneficial phenotypes and that inhibition of EZH2 provides a unique therapeutic approach to diminishing MFib proliferation while activating repair mechanisms. The overall goal of this project is to test the central hypothesis that EZH2 inhibition in myofibroblasts can transform the cell fate from pro-fibrotic myofibroblasts into pro-angiogenic CPC, thus attenuating fibrosis, improving cardiac angiogenesis, and boosting cardiac repair in the ischemic myocardium. This proposed project is innovative because it will generate unique mechanistic insights from novel approaches to cardiac regeneration by transforming cardiac myofibroblasts from a proliferative and pro-fibrotic phenotype to a pro-angiogenic and pro- regenerative phenotype. Our focus on EZH2-mediated chromatin remodeling in epigenetic repression of GATA4-mediated CPC program is translationally significant, as EZH2 inhibitors are available clinically and have recently been approved for the treatment of follicular lymphoma. Our preliminary findings highlight the potential for this pathway to be the focus of novel strategies for mitigating cardiac fibrosis and promoting cardiac angiogenesis after ischemic injury.

项目摘要 心力衰竭与心脏成纤维细胞（Fib）的活化有关，其促进心脏纤维化和心肌纤维化。 病理性心脏重塑在成年小鼠心脏中采用单细胞RNA测序（scRNA-seq）， 发现Zeste增强子同源物2（EZH 2），已知催化转录的主要酶， 阻遏标记H3 K27 me 3在特定的POF + Fib亚群（肌成纤维细胞，MFib）中高度表达。 值得注意的是，关于EZH 2在调节心脏MFib中的功能作用知之甚少，这是一个关键的知识 鉴于其表观遗传变异性和病理作用，我们证明，虽然这些MFib表达 GATA 4是一种早期心脏转录因子，它们不能表达心血管祖细胞（CPC）基因 例如NKX2.5。重要的是，EZH 2的缺失抑制了MFib的增殖，并开启了 心血管祖细胞（CPC）基因程序。此外，EZH 2的缺失增加了促血管生成因子的表达。 MFib的旁分泌作用和改善心肌梗死（MI）后的心脏功能 在给予新型rAAV-FLEX-DTA载体的小鼠中， EZH 2，证实了该细胞群的重要功能作用。这些发现表明EZH 2是一种 抑制MFib向有益表型的转变，并且抑制EZH 2提供了独特的 治疗方法，以减少MFib增殖，同时激活修复机制。的总目标 本项目旨在验证肌成纤维细胞中EZH 2抑制可以改变细胞命运的中心假设 从促纤维化的肌成纤维细胞转化为促血管生成的CPC，从而减轻纤维化，改善心脏功能， 血管生成和促进缺血心肌中的心脏修复。该项目具有创新性 因为它将从心脏再生的新方法中产生独特的机制见解， 将心脏肌成纤维细胞从增殖和促纤维化表型转化为促血管生成和促纤维化表型， 再生表型我们关注EZH 2介导的染色质重塑在表观遗传抑制中的作用， GATA 4介导的CPC程序具有翻译意义，因为EZH 2抑制剂在临床上可用并且具有 最近被批准用于治疗滤泡性淋巴瘤。我们的初步发现强调了 这一途径将成为减轻心脏纤维化和促进心脏纤维化的新策略的焦点。 缺血性损伤后的血管生成。