title: Interleukin-33 prevents apoptosis and improves survival after experimental myocardial infarction through ST2 signaling.
abstract: BACKGROUND
  ST2 is an interleukin (IL)-1 receptor family member with membrane-bound (ST2L) and soluble (sST2) isoforms, and sST2 is a biomarker for poor outcome in patients with myocardial infarction (MI). IL-33, the recently discovered ligand for ST2, activates nuclear factor kappaB and thus may regulate apoptotic cell death. We tested the hypothesis that IL-33 is cardioprotective after MI through ST2 signaling.
  
  
  RESULTS
  IL-33 protected cultured cardiomyocytes from hypoxia-induced apoptosis, and this cardioprotection was partially inhibited by sST2. IL-33 induced expression of the antiapoptotic factors XIAP, cIAP1, and survivin. To define the cardioprotective role of IL-33 in vivo, we performed a blinded and randomized study of ischemia/reperfusion in rats. IL-33 reduced cardiomyocyte apoptosis, suppressed caspase-3 activity, and increased expression of IAP family member proteins. IL-33 decreased both infarct and fibrosis volumes at 15 days; furthermore, both echocardiographic and hemodynamic studies revealed that IL-33 improved ventricular function. To determine whether cardioprotection by IL-33 is mediated through ST2 signaling, a randomized and blinded study of ST2(-/-) versus wild-type littermate mice was performed in 98 mice subjected to MI. At 4 weeks after MI, IL-33 reduced ventricular dilation and improved contractile function in wild-type mice but not in ST2(-/-) mice. Finally, IL-33 improved survival after MI in wild-type but not in ST2(-/-) mice.
  
  
  CONCLUSIONS
  IL-33 prevents cardiomyocyte apoptosis and improves cardiac function and survival after MI through ST2 signaling.
authors.affiliation: Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass, USA.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Seki
authors.forename: Shoji
authors.initials: S
authors.lastname: Sanada
authors.forename: Anastacia Y
authors.initials: AY
authors.lastname: Kudinova
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Steinhauser
authors.forename: Vandna
authors.initials: V
authors.lastname: Handa
authors.forename: Joseph
authors.initials: J
authors.lastname: Gannon
authors.forename: Richard T
authors.initials: RT
authors.lastname: Lee
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005355:Fibrosis; D000072179:Interleukin-1 Receptor-Like 1 Protein; D007378:Interleukins / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009200:Myocardial Contraction / Q000187:drug effects; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018123:Receptors, Interleukin / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D013997:Time Factors
chemical_list: D051017:Apoptosis Regulatory Proteins; D002316:Cardiotonic Agents; C486189:Il1rl1 protein, mouse; D000072179:Interleukin-1 Receptor-Like 1 Protein; D007378:Interleukins; D018123:Receptors, Interleukin; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins