TY - JOUR
T1 - Profound cardioprotection with chloramphenicol succinate in the swine model of myocardial ischemia-reperfusion injury
AU - Sala-Mercado, Javier A.
AU - Wider, Joseph
AU - Reddy Undyala, Vishnu Vardhan
AU - Jahania, Salik
AU - Yoo, Wonsuk
AU - Mentzer, Robert M.
AU - Gottlieb, Roberta A.
AU - Przyklenk, Karin
PY - 2010/9/14
Y1 - 2010/9/14
N2 - Background-: Emerging evidence suggests that "adaptive" induction of autophagy (the cellular process responsible for the degradation and recycling of proteins and organelles) may confer a cardioprotective phenotype and represent a novel strategy to limit ischemia-reperfusion injury. Our aim was to test this paradigm in a clinically relevant, large animal model of acute myocardial infarction. Methods and results-: Anesthetized pigs underwent 45 minutes of coronary artery occlusion and 3 hours of reperfusion. In the first component of the study, pigs received chloramphenicol succinate (CAPS) (an agent that purportedly upregulates autophagy; 20 mg/kg) or saline at 10 minutes before ischemia. Infarct size was delineated by tetrazolium staining and expressed as a % of the at-risk myocardium. In separate animals, myocardial samples were harvested at baseline and 10 minutes following CAPS treatment and assayed (by immunoblotting) for 2 proteins involved in autophagosome formation: Beclin-1 and microtubule-associated protein light chain 3-II. To investigate whether the efficacy of CAPS was maintained with "delayed" treatment, additional pigs received CAPS (20 mg/kg) at 30 minutes after occlusion. Expression of Beclin-1 and microtubule-associated protein light chain 3-II, as well as infarct size, were assessed at end-reperfusion. CAPS was cardioprotective: infarct size was 25±5 and 41±4%, respectively, in the CAPS-pretreated and CAPS-delayed treatment groups versus 56±5% in saline controls (P<0.01 and P<0.05 versus control). Moreover, administration of CAPS was associated with increased expression of both proteins. Conclusion-: Our results demonstrate attenuation of ischemia-reperfusion injury with CAPS and are consistent with the concept that induction of autophagy may provide a novel strategy to confer cardioprotection.
AB - Background-: Emerging evidence suggests that "adaptive" induction of autophagy (the cellular process responsible for the degradation and recycling of proteins and organelles) may confer a cardioprotective phenotype and represent a novel strategy to limit ischemia-reperfusion injury. Our aim was to test this paradigm in a clinically relevant, large animal model of acute myocardial infarction. Methods and results-: Anesthetized pigs underwent 45 minutes of coronary artery occlusion and 3 hours of reperfusion. In the first component of the study, pigs received chloramphenicol succinate (CAPS) (an agent that purportedly upregulates autophagy; 20 mg/kg) or saline at 10 minutes before ischemia. Infarct size was delineated by tetrazolium staining and expressed as a % of the at-risk myocardium. In separate animals, myocardial samples were harvested at baseline and 10 minutes following CAPS treatment and assayed (by immunoblotting) for 2 proteins involved in autophagosome formation: Beclin-1 and microtubule-associated protein light chain 3-II. To investigate whether the efficacy of CAPS was maintained with "delayed" treatment, additional pigs received CAPS (20 mg/kg) at 30 minutes after occlusion. Expression of Beclin-1 and microtubule-associated protein light chain 3-II, as well as infarct size, were assessed at end-reperfusion. CAPS was cardioprotective: infarct size was 25±5 and 41±4%, respectively, in the CAPS-pretreated and CAPS-delayed treatment groups versus 56±5% in saline controls (P<0.01 and P<0.05 versus control). Moreover, administration of CAPS was associated with increased expression of both proteins. Conclusion-: Our results demonstrate attenuation of ischemia-reperfusion injury with CAPS and are consistent with the concept that induction of autophagy may provide a novel strategy to confer cardioprotection.
KW - autophagy
KW - ischemia
KW - myocardial infarction
KW - reperfusion
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UR - http://www.scopus.com/inward/citedby.url?scp=77957221783&partnerID=8YFLogxK
U2 - 10.1161/CIRCULATIONAHA.109.928242
DO - 10.1161/CIRCULATIONAHA.109.928242
M3 - Article
C2 - 20837911
AN - SCOPUS:77957221783
SN - 0009-7322
VL - 122
SP - S179-S184
JO - Circulation
JF - Circulation
IS - 11 SUPPL. 1
ER -