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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要心力衰竭与心脏成纤维细胞 (Fib) 的激活有关，从而促进心脏纤维化和病理性心脏重塑。我们在成年小鼠心脏中采用单细胞 RNA 测序 (scRNA-seq) 发现了 Zeste 同源物增强子 2 (EZH2)，已知催化转录的主要酶抑制标记 H3K27me3 在特定的 POSTN+ Fib 亚群（肌成纤维细胞，MFib）中高度表达。值得注意的是，人们对 EZH2 在调节心脏 MFib 中的功能作用知之甚少，而这是一个关键知识考虑到它们的表观遗传变异性和病理作用。我们证明虽然这些 MFib 表达 GATA4，一种早期心脏转录因子，它们无法表达心血管祖细胞（CPC）基因程序，例如 NKX2.5。重要的是，EZH2 的缺失抑制了 MFib 增殖并开启心血管祖细胞（CPC）基因程序。此外，EZH2 的缺失增加了促血管生成 MFib 的旁分泌作用和改善心肌梗塞 (MI) 后的心脏功能这些有益作用在给予新型 rAAV-FLEX-DTA 载体的小鼠中，心脏功能丧失，该载体消除了缺乏的 MFib EZH2，证实了该细胞群的重要功能作用。这些发现表明 EZH2 是抑制 MFib 向有益表型的转变，并且抑制 EZH2 提供了独特的减少 MFib 增殖同时激活修复机制的治疗方法。总体目标为该项目旨在测试肌成纤维细胞中 EZH2 抑制可以改变细胞命运的中心假设从促纤维化肌成纤维细胞转变为促血管生成 CPC，从而减轻纤维化，改善心脏功能血管生成，促进缺血心肌的心脏修复。这个提议的项目具有创新性因为它将通过心脏再生的新方法产生独特的机制见解将心肌成纤维细胞从增殖和促纤维化表型转变为促血管生成和促纤维化表型再生表型。我们的重点是 EZH2 介导的染色质重塑在表观遗传抑制中的作用 GATA4 介导的 CPC 程序具有重要的转化意义，因为 EZH2 抑制剂已在临床上可用并且已最近被批准用于治疗滤泡性淋巴瘤。我们的初步研究结果凸显了潜力该途径成为减轻心脏纤维化和促进心脏功能的新策略的焦点缺血性损伤后的血管生成。