Beclin1 Shapes Cardiomyocyte Cell Identity Independent of Its Autophagic Function during Cardiac Reprogramming. Beclin1 Shapes Cardiomyocyte Cell Identity Independent of Its Autophagic Function during Cardiac Reprogramming

This study aimed to compare the transcriptome profiling (RNA-seq) and chromatin accessibility landscape (ATACseq) of induced cardiomyocytes (iCMs) with Beclin1 (Becn1) knockdown and control iCMs (shNT). we generated ATAC-Seq data from day 3 shNT- and shBecn1-treated MGT or control LacZ transduced fibroblasts. We interrogated the enrichment of ATAC-seq reads at +1 and -1 Kb around TSS (Transcription starting site). Comparing MGT-iCMs with LacZ transduced cells, we found that MGT-iCMs gained numerous open chromatin regions compared to LacZ transduced cells. In total, 22,262 high-confidence open chromatin regions were identified when comparing MGT-shNT iCMs with LacZ-shNT cells, and 11,401 open regions were found in MGT-shBecn1 iCMs when comparing to LacZ-shBecn1 cells. However, MGT-shBecn1 iCMs exhibited minimal differences that did not reach statistical significance when compared with MGT-shNT cells. MGT-shBecn1 iCMs had same number of open chromatin regions as the MGT-shNT cells. In parallel, we performed RNA-seq to profile transcriptome changes among day 3 and day 5 shNT- or shBecn1-treated reprogramming and control cells. Next, we profiled the differentially expressed genes (DEGs) at each time point. Gene set enrichment analysis (GSEA) revealed that shBecn1 significantly up-regulated gene sets related to myogenesis, such as those involved in the formation of contractile fiber and myofibril assembly and down-regulated gene sets related to cell proliferation and inflammation. Interestingly, GSEA analysis demonstrated additional enrichment plots of Wnt/β-Catenin signaling in shBecn1 iCMs. Overall design: mRNA profile and chromatin accessibility profile of neonatal cardiac fibroblasts that were transduced with MGT or control LacZ retroviras plus shBecn1 or shNT treatment.