title: Expression of MicroRNA-29 and Collagen in Cardiac Muscle after Swimming Training in Myocardial-Infarcted Rats.
abstract: BACKGROUND
  Myocardial infarction (MI) is accompanied by cardiac growth, increased collagen deposition, cell death and new vascularization of the cardiac tissue, which results in reduced ventricular compliance. The MiRNA-29 family (29a, 29b, and 29c) targets mRNAs that encode collagens and other proteins involved in fibrosis. In this study we assessed the effects of swimming training (ST) on expression of the cardiac miRNA-29 family and on genes encoding collagen after MI in rats.
  
  
  METHODS
  ST consisted of 60 min/day/10 weeks and began four weeks after MI. MiRNA and collagen expression analysis were performed in the infarcted region (IR), border region (BR) of the infarcted region and in the remote myocardium (RM) of the left ventricle.
  
  
  RESULTS
  MiRNA-29a expression increased 32% in BR and 52% in RM in the TR-INF compared with SED-INF. MiRNA-29c increased by 63% in BR and 55% in RM in TR-INF compared with SED-INF group. COL IAI and COL IIIAI decreased by 63% and 62% in TR-INF, respectively, compared with SED-INF. COLIIIAI expression decreased by 16% in TR-INF compared with SED-INF.
  
  
  CONCLUSIONS
  Altogether, our results showed that ST restores cardiac miRNA-29 (a and c) levels and prevents COL IAI and COL IIIAI expression in BR and RM, which may contribute to the improvement in ventricular function induced by swimming training, after MI. © 2014 S. Karger AG, Basel.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology of the Exercise, Department of Human Movement Biodynamic, School of Physical Education and Sport University of São Paulo, São Paulo, Brazil.
authors.forename: Stéphano F S
authors.initials: SF
authors.lastname: Melo
authors.forename: Tiago
authors.initials: T
authors.lastname: Fernandes
authors.forename: Valério G
authors.initials: VG
authors.lastname: Baraúna
authors.forename: Katt C
authors.initials: KC
authors.lastname: Matos
authors.forename: Alexandra A S
authors.initials: AA
authors.lastname: Santos
authors.forename: Paulo J F
authors.initials: PJ
authors.lastname: Tucci
authors.forename: Edilamar M
authors.initials: EM
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D003094:Collagen / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis*; D009203:Myocardial Infarction / Q000378:metabolism* / Q000473:pathology; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming
chemical_list: C526366:MIRN29 microRNA, rat; D035683:MicroRNAs; D003094:Collagen