Whole transcriptional analysis of induced cardiomyocytes from MICFs

We report that Sall4 and Myocd empower direct cardiac reprogramming from adult cardiac fibroblasts after myocardial infarction (MICFs). To examine the gene expression of induced cardiomyocytes (iCMs) on the genome-wide scale, we performed RNA-sequencing of MICFs and iCMs induced by GMTMS (our cocktails) or GMTMM (cocktails reported by Weda et al). We found significant changes in the global gene expression profiles of MICFs after GMTMS or GMTMM overexpression. Compared to MICFs, 1318 genes were significantly up-regulated and 1302 genes were significantly down-regulated in GMTMS-induced iCMs, in which high expression of many cardiac genes and concomitant suppression of fibroblast genes were observed. Go analysis revealed that many cardiac-related clusters were enriched in iCMs as well. These results demonstrate a cardiac-like phenotype reprogrammed from MICFs by GMTMS. Myh6-mCherry+ iCMs from GMTMS- and GMTMM-transduced MICFs were collected by FACS after a four-week induction. Due to low percent of mCherry+ iCMs (< 5%), five samples in each group were mixed together after FACS for the next RNA extraction and sequencing. MICFs without virus infection were also dissociated after the same culture time.