title: Transcription factors MYOCD, SRF, Mesp1 and SMARCD3 enhance the cardio-inducing effect of GATA4, TBX5, and MEF2C during direct cellular reprogramming.
abstract: Transient overexpression of defined combinations of master regulator genes can effectively induce cellular reprogramming: the acquisition of an alternative predicted phenotype from a differentiated cell lineage. This can be of particular importance in cardiac regenerative medicine wherein the heart lacks the capacity to heal itself, but simultaneously contains a large pool of fibroblasts. In this study we determined the cardio-inducing capacity of ten transcription factors to actuate cellular reprogramming of mouse embryonic fibroblasts into cardiomyocyte-like cells. Overexpression of transcription factors MYOCD and SRF alone or in conjunction with Mesp1 and SMARCD3 enhanced the basal but necessary cardio-inducing effect of the previously reported GATA4, TBX5, and MEF2C. In particular, combinations of five or seven transcription factors enhanced the activation of cardiac reporter vectors, and induced an upregulation of cardiac-specific genes. Global gene expression analysis also demonstrated a significantly greater cardio-inducing effect when the transcription factors MYOCD and SRF were used. Detection of cross-striated cells was highly dependent on the cell culture conditions and was enhanced by the addition of valproic acid and JAK inhibitor. Although we detected Ca(2+) transient oscillations in the reprogrammed cells, we did not detect significant changes in resting membrane potential or spontaneously contracting cells. This study further elucidates the cardio-inducing effect of the transcriptional networks involved in cardiac cellular reprogramming, contributing to the ongoing rational design of a robust protocol required for cardiac regenerative therapies.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Christoforou
authors.forename: Malathi
authors.initials: M
authors.lastname: Chellappan
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Adler
authors.forename: Robert D
authors.initials: RD
authors.lastname: Kirkton
authors.forename: Tianyi
authors.initials: T
authors.lastname: Wu
authors.forename: Russell C
authors.initials: RC
authors.lastname: Addis
authors.forename: Nenad
authors.initials: N
authors.lastname: Bursac
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D065150:Cellular Reprogramming; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D055724:Electrophysiological Phenomena; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000378:metabolism; D050991:GATA4 Transcription Factor / Q000378:metabolism*; D005786:Gene Expression Regulation; D053263:Gene Regulatory Networks / Q000235:genetics; D064326:MEF2 Transcription Factors / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009124:Muscle Proteins / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D041681:NIH 3T3 Cells; D009687:Nuclear Proteins / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D026362:Serum Response Factor / Q000378:metabolism; D034421:Sus scrofa; D020825:T-Box Domain Proteins / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D059467:Transcriptome / Q000235:genetics; D000099251:Myocardin
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D002868:Chromosomal Proteins, Non-Histone; D050991:GATA4 Transcription Factor; D064326:MEF2 Transcription Factors; D009124:Muscle Proteins; D009687:Nuclear Proteins; D026362:Serum Response Factor; D020825:T-Box Domain Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000099251:Myocardin; C101538:Mesp1 protein, mouse; C494055:Smarcd3 protein, mouse; C103172:T-box transcription factor 5