title: Testosterone enhances cardiomyogenesis in stem cells and recruits the androgen receptor to the MEF2C and HCN4 genes.
abstract: Since a previous study (Goldman-Johnson et al., 2008 [4]) has shown that androgens can stimulate increased differentiation of mouse embryonic stem (mES) cells into cardiomyocytes using a genomic pathway, the aim of our study is to elucidate the molecular mechanisms regulating testosterone-enhanced cardiomyogenesis. Testosterone upregulated cardiomyogenic transcription factors, including GATA4, MEF2C, and Nkx2.5, muscle structural proteins, and the pacemaker ion channel HCN4 in a dose-dependent manner, in mES cells and P19 embryonal carcinoma cells. Knock-down of the androgen receptor (AR) or treatment with anti-androgenic compounds inhibited cardiomyogenesis, supporting the requirement of the genomic pathway. Chromatin immunoprecipitation (ChIP) studies showed that testosterone enhanced recruitment of AR to the regulatory regions of MEF2C and HCN4 genes, which was associated with increased histone acetylation. In summary, testosterone upregulated cardiomyogenic transcription factor and HCN4 expression in stem cells. Further, testosterone induced cardiomyogenesis, at least in part, by recruiting the AR receptor to the regulatory regions of the MEF2C and HCN4 genes. These results provide a detailed molecular analysis of the function of testosterone in stem cells and may offer molecular insight into the role of steroids in the heart.
authors.affiliation: Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Ashraf Said
authors.initials: AS
authors.lastname: Al Madhoun
authors.forename: Anastassia
authors.initials: A
authors.lastname: Voronova
authors.forename: Tammy
authors.initials: T
authors.lastname: Ryan
authors.forename: Abeer
authors.initials: A
authors.lastname: Zakariyah
authors.forename: Christian
authors.initials: C
authors.lastname: McIntire
authors.forename: Laura
authors.initials: L
authors.lastname: Gibson
authors.forename: Michael
authors.initials: M
authors.lastname: Shelton
authors.forename: Marc
authors.initials: M
authors.lastname: Ruel
authors.forename: Ilona S
authors.initials: IS
authors.lastname: Skerjanc
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology*; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / Q000096:biosynthesis* / Q000235:genetics; D064326:MEF2 Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D038081:Organogenesis / Q000187:drug effects* / Q000502:physiology; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements / Q000502:physiology; D013739:Testosterone / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D000728:Androgens; C578706:Hcn4 protein, mouse; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D064326:MEF2 Transcription Factors; C578041:Mef2c protein, mouse; D009124:Muscle Proteins; D011944:Receptors, Androgen; D013739:Testosterone