Role of JAK2-STAT3 signaling pathway in sevoflurane postconditioning-induced inhibition of mPTP opening during myocardial ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of Janus kinase 2-signal transducer and activator of transcription 3 (JAK2-STAT3) signaling pathway in sevoflurane postconditioning-induced inhibition of mitochondrial permeability transition pore (mPTP) opening during myocardial ischemia-reperfusion (I/R)in rats.Methods Sixty pathogen-free healthy male Sprague-Dawley rats,weighing 250-300 g,were divided into 4 groups (n=15 each) using a random number tableI/R group,sevoflurane postconditioning group (group SP),AG-490 group (group AG) and sevoflurane postconditioning plus AG-490 group (group SP+AG).Myocardial I/R was induced by 30 min ligation of the left anterior descending branch of coronary artery followed by 120 min reperfusion.In group SP,2.8％ sevoflurane was inhaled for 15 min starting from 2 min before reperfusion.JAK2 inhibitor AG-490 3 mg/kg was intravenously injected at 10 min before reperfusion in group AG.In group SP+AG,AG-490 3 mg/kg was intravenously injected at 10 min before reperfusion,and 2.8％ sevoflurane was inhaled for 15 min starting from 2 min before reperfusion.At 15 min of reperfusion,5 rats were sacrificed and myocardial specimens were obtained for determination of the expression of JAK2,phosphorylated JAK2 (p-JAK2),STAT3 and phosphorylated STAT3 (p-STAT3)in myocardial tissues by Western blot.The ratios of p-JAK2 to JAK2 expression (p-JAK2/JAK2) and pSTAT3 to STAT3 expression (p-STAT3/STAT3) were calculated.Five rats were sacrificed at the end of reperfusion for measurement of myocardial infarct size.The left 5 rats were selected and sacrificed,myocardial specimens were obtained,and the opening of mPTP was detected by a calcein-cobalt quenching method.Results Compared with group I/R,the myocardial infarct size and mPTP opening were significantly decreased,and JAK2/p-JAK2 and STAT3/p-STAT3 were increased in group SP (P＜0.05),and no significant change was found in the parameters mentioned above in SP+AG and AG groups (P＞0.05).Compared with group SP,the myocardial infarct size was significantly enlarged,the extent of mnPTP opening was aggravated,and JAK2/p-JAK2 and STAT3/p-STAT3 were decreased in SP+AG and AG groups (P＜0.05).Conclusion The mechanism by which sevoflurane postconditioning inhibits the opening of mPTP during myocardial I/R is related to activation of JAK2-STAT3 signaling pathway in rats.