Role of Nrf2-ARE signaling pathway in mitigation of anoxia/reoxygenation-induced damage to rat cardiomyocytes by emulsified isoflurane postconditioning / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of nuclear factor E2-related factor 2 (Nrf2)-antioxidant response element (ARE) signaling pathway in mitigation of anoxia/reoxygenation (A/R)-induced damage to rat cardiomyocytes by emulsified isoflurane postconditioning.Methods Primarily cultured cardiomyocytes obtained from Sprague-Dawley rats,aged 16-20 weeks,were seeded into the laminin pre-treated 6-well plates at a density of 104/cm2 and cultured for 20 h.The cells were randomly divided into 3 groups (n =12 each) using a random number tablecontrol group (group C),group A/R,and emulsified isoflurane postconditioning group (group EI).The cells were cultured for 110 min without any treatment in group C.The cells were exposed to 45 min anoxia followed by 60 min reoxygenation in A/R and EI groups.After 45 min of hypoxia,the cells were cultured with emulsified isoflurane 1.68 mmol/L for 5 min before onset of reoxygenation in group EI.At the end of reoxygenation,transmission electron microscope was used to observe the ultrastructure of myocardial cells,and mitochondrial function was scored.The mRNA and protein expression of Nrf2,heme oxygenase-1 (HO-1),superoxide dismutase 1 (SOD1),and quinone oxidoreductase 1 (NQO1) was detected by real-time PCR and Western blot.Laser scanning confocal microscopy was used to detect Nrf2 nuclear translocation at the end of incubation,and Nrf2 activity was recorded in the nucleus of myocardial cells.Results Compared with group C,the mitochondrial function score was significantly increased,the mRNA and protein expression of Nrf2,HO-1,SOD1 and NQO1 was down-regulated,and Nrf2 activity in the nucleus was enhanced in A/R and EI groups.Compared with group A/R,the mitochondrial function score was significantly decreased,the mRNA and protein expression of Nrf2,HO-1,SOD1 and NQO1 was up-regulated,and Nrf2 activity in the nucleus was enhanced in group EI.Conclusion The mechanism by which emulsified isoflurane postconditioning mitigates A/R-induced damage to rat cardiomyocytes is related to induced nuclear translocation of Nrf2 and activated Nrf2-ARE signaling pathway.