title: MicroRNA-150 Inhibits the Activation of Cardiac Fibroblasts by Regulating c-Myb.
abstract: OBJECTIVE
  Cardiac fibrosis is the primary cause of deteriorated cardiac function in various cardiovascular diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are critical regulators of myocardial fibrosis. Specifically, many studies have reported that miR-150 is downregulated in cardiovascular diseases, such as acute myocardial infarction (AMI), myocardial hypertrophy and myocardial fibrosis. However, the exact role of miR-150 in these pathological processes remains unknown.
  
  
  METHODS
  We used the transverse aortic constriction (TAC) mouse model to study the role of miR-150 in cardiac fibrosis induced by pressure overload. After the TAC operation, qRT-PCR was used to measure the expression profiles of miR-150 in left ventricle tissues and populations of primary heart cell types. Then, we used both miR-150 knockout mice and wild type (WT) mice in the TAC model. Changes in cardiac function and pathology were measured using transthoracic echocardiography and pathological analysis, respectively. Furthermore, we predicted the target of miR-150 in cardiac fibroblasts (CFs) and completed in vitro CF transfection experiments using miR-150 analogs and siRNA corresponding to the predicted target.
  
  
  RESULTS
  We observed decreased expression levels of miR-150 in hearts suffering pressure overload, and these levels decreased more sharply in CFs than in cardiomyocytes. In addition, the degrees of cardiac function deterioration and cardiac fibrosis in miR-150-/- mice were more severe than were those in WT mice. By transfecting CFs with an miR-150 analog in vitro, we observed that miR-150 inhibited cardiac fibroblast activation. We predicted that the transcription factor c-Myb was the target of miR-150 in CFs. Transfecting CFs with c-Myb siRNA eliminated the effects of an miR-150 inhibitor, which promoted CF activation.
  
  
  CONCLUSIONS
  These findings reveal that miR-150 acts as a pivotal regulator of pressure overload-induced cardiac fibrosis by regulating c-Myb.
authors.forename: Peng
authors.initials: P
authors.lastname: Deng
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Ye
authors.forename: Sihua
authors.initials: S
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Yao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Xiaofan
authors.initials: X
authors.lastname: Huang
authors.forename: Linyun
authors.initials: L
authors.lastname: Ren
authors.forename: Anchen
authors.initials: A
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.forename: Chuangyan
authors.initials: C
authors.lastname: Wu
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yue
authors.forename: Xuezeng
authors.initials: X
authors.lastname: Xu
authors.forename: Manhua
authors.initials: M
authors.lastname: Chen
mesh_terms: D000818:Animals; D009202:Cardiomyopathies / Q000235:genetics / Q000473:pathology; D002454:Cell Differentiation; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D005355:Fibrosis; D005786:Gene Expression Regulation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics*; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism / Q000473:pathology*; D058628:Myofibroblasts / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics*
chemical_list: D035683:MicroRNAs; C529101:Mirn150 microRNA, mouse; D020598:Proto-Oncogene Proteins c-myb