title: Differential membrane type 1 matrix metalloproteinase substrate processing with ischemia-reperfusion: relationship to interstitial microRNA dynamics and myocardial function.
abstract: OBJECTIVE
  Membrane type 1 matrix metalloproteinase (MT1-MMP) is critical to a number of proteolytic and profibrotic events. However, upstream regulation of MT1-MMP with myocardial ischemia-reperfusion remains poorly understood. MicroRNAs regulate post-transcriptional events, and in silico mapping has identified a conserved sequence in MT1-MMP for microRNA-133a. This study tested the hypothesis that changes in microRNA-133a regulation occur with myocardial ischemia-reperfusion, which contributes to time- and region-dependent changes in MT1-MMP activity and processing of MT1-MMP substrates.
  
  
  METHODS
  Yorkshire pigs (n = 12) underwent ischemia-reperfusion (90 minutes ischemia and 120 minutes reperfusion), where regional preload recruitable stroke work (sonomicrometry), interstitial MT1-MMP activity (microdialysis), Smad2 abundance (immunoblotting), and interstitial microRNA-133a (polymerase chain reaction) were determined within the ischemia-reperfusion and remote regions. Human left ventricular fibroblasts were transduced with microRNA-133a and anti-microRNA-133a (lentivirus) to determine the effects on MT1-MMP protein abundance.
  
  
  RESULTS
  With ischemia-reperfusion, regional preload recruitable stroke work decreased from steady state (139 ± 20 mm Hg to 44 ± 11 mm Hg, P < .05) within the ischemia-reperfusion region. MT1-MMP activity increased in both regions. Phosphorylated Smad2 increased within the ischemia-reperfusion region. Both in vitro and in vivo interstitial levels of microRNA-133a decreased with ischemia and returned to steady-state levels with reperfusion. In vitro transduction of microRNA-133a in left ventricular fibroblasts decreased MT1-MMP levels.
  
  
  CONCLUSIONS
  Modulation of MT1-MMP activity and microRNA-133a exportation into the myocardial interstitium occurred in the setting of acute myocardial ischemia-reperfusion. In addition, changes in microRNA-133a expression in left ventricular fibroblasts resulted in an inverse modulation of MT1-MMP abundance. Therefore, targeting of microRNA-133a represents a potentially novel means for regulating the cascade of profibrotic events after ischemia-reperfusion.
authors.affiliation: Division of Cardiothoracic Surgery, Medical University of South Carolina, and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA.
authors.forename: Shaina R
authors.initials: SR
authors.lastname: Eckhouse
authors.forename: Adam W
authors.initials: AW
authors.lastname: Akerman
authors.forename: Christina B
authors.initials: CB
authors.lastname: Logdon
authors.forename: J Marshall
authors.initials: JM
authors.lastname: Oelsen
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: O'Quinn
authors.forename: Elizabeth K
authors.initials: EK
authors.lastname: Nadeau
authors.forename: Robert E
authors.initials: RE
authors.lastname: Stroud
authors.forename: Rupak
authors.initials: R
authors.lastname: Mukherjee
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Jones
authors.forename: Francis G
authors.initials: FG
authors.lastname: Spinale
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006439:Hemodynamics; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000378:metabolism*; D017551:Microdialysis; D009200:Myocardial Contraction; D015428:Myocardial Reperfusion Injury / Q000201:enzymology* / Q000235:genetics / Q000503:physiopathology; D009206:Myocardium / Q000201:enzymology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D051899:Smad2 Protein / Q000378:metabolism; D013552:Swine; D013997:Time Factors; D014161:Transduction, Genetic; D014162:Transfection; D016277:Ventricular Function, Left / Q000235:genetics
chemical_list: C548234:MIRN133 microRNA, human; D035683:MicroRNAs; D018125:Receptors, Transforming Growth Factor beta; D051899:Smad2 Protein; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14