MYOCD is required for cardiomyocytes induction from human urine cells and fibroblasts through remodeling chromatin [RNA-seq]

Despite direct reprogramming of human cardiac fibroblasts into induced cardiomyocytes (iCM) holds great potential for heart regeneration, the mechanisms are poorly understood. Whether other human somatic cells could be reprogrammed into cardiomyocytes is also unknown. Here, we report human urine cells (hUCs) could be efficiently converted into CM-like cells and the associated chromatin accessibility dynamics (CAD) by assay for transposase accessible chromatin(ATAC)-seq. hUCs transduced by MEF2C, TBX5, MESP1 and MYOCD but without GATA4 expressed multiple cardiac specific genes, exhibited Ca2+ oscillation potential and sarcomeric structures, and contracted synchronously in coculture with mouse CM. Additionally, we found that MYOCD is required for both closing and opening critical loci, mainly by hindering the opening of loci enriched with motifs for the TEAD and AP1 family and promoting the closing of loci enriched with ETS motifs. These changes differe partially from CAD observed during iCM induction from human fibroblasts. Collectively, our study offers one robust platform for iCM generation and insights into mechanisms for iCM fate determination.

尽管将人类心脏成纤维细胞直接重编程为诱导型心肌细胞（induced cardiomyocytes, iCM）在心脏再生领域具备巨大应用潜力，但其背后的分子机制仍未被充分阐明。目前尚不清楚是否可将其他人类体细胞重编程为心肌细胞。本研究通过转座酶可及性染色质测序（assay for transposase accessible chromatin sequencing, ATAC-seq）技术发现，可高效将人类尿液细胞（human urine cells, hUCs）转化为心肌样细胞，并解析其相关染色质可及性动力学（chromatin accessibility dynamics, CAD）。仅转导MEF2C、TBX5、MESP1与MYOCD四种转录因子（无需GATA4）的hUCs，可表达多种心肌特异性基因，具备钙振荡潜能与肌节结构，并可在与小鼠心肌细胞共培养时实现同步收缩。此外，本研究发现MYOCD在关键染色质位点的开放与闭合过程中均发挥关键调控作用：其主要通过抑制富集TEAD与AP1家族基序的位点开放，同时促进富集ETS基序的位点闭合来实现该调控。上述染色质可及性动力学变化与人类成纤维细胞诱导iCM过程中观察到的变化存在部分差异。综上，本研究为诱导型心肌细胞的生成提供了一套高效可靠的实验平台，并为阐明诱导型心肌细胞的命运决定机制提供了全新的研究视角。

搜集汇总

背景与挑战

背景概述

该数据集是一个RNA-Seq研究，专注于探讨MYOCD基因在将人类尿液细胞和成纤维细胞重编程为诱导心肌细胞（iCM）过程中的关键作用，涉及染色质重塑机制。数据集包含26个样本，数据规模17.24 GB，来源于人类心肌细胞、成纤维细胞和尿液细胞，使用Illumina NovaSeq 6000平台进行转录组测序。研究发现，MYOCD通过调控染色质可及性，促进心肌细胞特异性基因表达和功能，为心脏再生提供了新的实验平台和机制见解。