title: Myocardin-related transcription factor-A induces cardiomyocyte hypertrophy.
abstract: Myocardin is a remarkably potent transcriptional coactivator expressed specifically in cardiac muscle lineages and smooth muscle cells during postnatal development. Myocardin shares homology with myocardin-related transcription factor-A (MRTF-A), which are expressed in a broad range of embryonic and adult tissues. Our previous results show that myocardin induces cardiac hypertrophy. However, the effects of MRTF-A in cardiac hypertrophy remain poorly understood. Our present work further demonstrates that myocardin plays an important role in inducing hypertrophy. At the same time, we find that overexpression of MRTF-A in neonatal rat cardiomyocytes might induce cardiomyocyte hypertrophy. Furthermore, MRTF-A expression is induced in phenylephrine, angiotensin-II, and transforming growth factor-β-stimulated cardiac hypertrophy, whereas a dominant-negative form of MRTF-A or MRTF-A siRNA strongly inhibited upregulation of hypertrophy genes in response to hypertrophic agonists in neonatal rat cardiomyocytes. Our studies indicate that besides myocardin, MRTF-A might play an important role in cardiac hypertrophy. Our findings provide novel evidence for the future studies to explore the roles of MRTFs in cardiac hypertrophy.
authors.affiliation: Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin, Tianjin, China.
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Liao
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.forename: Qing-Xi
authors.initials: QX
authors.lastname: Liu
authors.forename: Tao
authors.initials: T
authors.lastname: Qin
authors.forename: Bo
authors.initials: B
authors.lastname: Cao
authors.forename: Dong-Sun
authors.initials: DS
authors.lastname: Cao
authors.forename: Tong-Cun
authors.initials: TC
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D007150:Immunohistochemistry; D009206:Myocardium / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D014157:Transcription Factors; C557977:myocardin-related transcription factor-A, rat