title: Cardiac ankyrin repeat protein attenuates cardiac hypertrophy by inhibition of ERK1/2 and TGF-β signaling pathways.
abstract: OBJECTIVE
  It has been reported that cardiac ankyrin repeat protein is associated with heart development and diseases. This study is aimed to investigate the role of CARP in heart hypertrophy in vivo.
  
  
  RESULTS
  We generated a cardiac-specific CARP-overexpressing transgenic mouse. Although such animals did not display any overt physiological abnormality, they developed less cardiac hypertrophy in response to pressure overload than did wildtype mice, as indicated by heart weight/body weight ratios, echocardiographic and histological analyses, and expression of hypertrophic markers. These mice also exhibited less cardiac hypertrophy after infusion of isoproterenol. To gain a molecular insight into how CARP attenuated heart hypertrophy, we examined expression of the mitogen-activated protein kinase cascade and found that the concentrations of phosphorylated ERK1/2 and MEK were markedly reduced in the hearts of transgenic mice subjected to pressure overload. In addition, the expressions of TGF-β and phosphorylated Smad3 were significantly downregulated in the hearts of CARP Tg mice in response to pressure overload. Furthermore, addition of human TGF-β1 could reverse the inhibitory effect of CARP on the hypertrophic response induced by phenylephrine in cardiomyocytes. It was also evidenced that the inhibitory effect of CARP on cardiac hypertrophy was not attributed to apoptosis.
  
  
  CONCLUSIONS
  CARP attenuates cardiac hypertrophy, in which the ERK and TGF-β pathways may be involved. Our findings highlight the significance of CARP as an anti-hypertrophic factor in therapy of cardiac hypertrophy.
authors.affiliation: Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Beijing, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Song
authors.forename: Jialin
authors.initials: J
authors.lastname: Xu
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Li
authors.forename: Chunshi
authors.initials: C
authors.lastname: Jia
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ma
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Xie
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Youyi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dahai
authors.initials: D
authors.lastname: Zhu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D006332:Cardiomegaly / Q000517:prevention & control*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D009124:Muscle Proteins / Q000235:genetics / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D010656:Phenylephrine / Q000494:pharmacology; D010766:Phosphorylation; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: C104844:Ankrd1 protein, mouse; D009124:Muscle Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D016212:Transforming Growth Factor beta; D010656:Phenylephrine