Hypercholesterolemia blocked sevoflurane-induced cardioprotection against ischemia–reperfusion injury by alteration of the MG53/RISK/GSK3β signaling.

Abstract: Background: Recent studies have demonstrated that volatile anesthetic preconditioning confers myocardial protection against ischemia–reperfusion (IR) injury through activation of the reperfusion injury salvage kinase (RISK) pathway. As RISK has been shown to be impaired in hypercholesterolemia, we investigate whether anesthetic-induced cardiac protection was maintained in hypercholesterolemic rats. Methods: Normocholesteolemic or hypercholesterolemic rat hearts were subjected to 30min of ischemia and 2h of reperfusion. Animals received 2.4% sevoflurane during three 5min periods with and without PI3K antagonist wortmannin (10μg/kg, Wort) or the ERK inhibitor PD 98059 (1mg/kg, PD). The infarct size, apoptosis, p-Akt, p-ERK1/2, p-GSK3β were determined. Results: Two hundred and six rats were analyzed in the study. In the healthy rats, sevoflurane significantly reduced infarct size by 42%, a phenomenon completely reversed by wortmannin and PD98059 and increased the phosphorylation of Akt, ERK1/2 and their downstream target of GSK3β. In the hypercholesterolemic rats, sevoflurane failed to reduce infarct size and increase the phosphorylated Akt, ERK1/2 and GSK3β. In contrast, GSK inhibitor SB216763 conferred cardioprotection against IR injury in healthy and hypercholesterolemic hearts. Conclusions: Hyperchoesterolemia abrogated sevoflurane-induced cardioprotection against IR injury by alteration of upstream signaling of GSK3β and acute GSK inhibition may provide a novel therapeutic strategy to protect hypercholesterolemic hearts against IR injury. [Copyright &y& Elsevier]