Effect of propofol postconditioning on necroptosis during hypoxia-reoxygenation injury in diabetic cardiomyocytes

Abstract

Objective To evaluate the effect of propofol postconditioning on necroptosis during hypoxia-reoxygenation (H/R) injury in diabetic cardiomyocytes. Methods Normally cultured H9C2 cardiomyocytes were divided into 5 groups (n=19 each) using a random number table: control group (group C), high glucose group (group HG), H/R group, propofol postconditioning (group P) and solvent dimethyl sulfoxide (DMSO) control group (group DMSO). H9C2 cells were incubated for 48 h in DMEM culture medium containing 5.5 and 25 mmol/L glucose in group C and group HG, respectively.In group H/R, H9C2 cells were incubated for 48 h in DMEM culture medium containing 25 mmol/L glucose and then underwent H/R.H9C2 cells were incubated for 48 h in DMEM culture medium containing 25 mmol/L glucose and then underwent H/R, and propofol at the final concentration of 50 μmol/L was added at the onset of reoxygenation in group P. In group DMSO, H9C2 cells were incubated for 48 h in DMEM culture medium containing 25 mmol/L glucose and then underwent H/R, and DMSO at the final concentration of 150 μmol/L was added at the onset of reoxygenation.The model of cardiomyocyte H/R injury was established by subjecting cardiomyocytes to 6 h of hypoxia followed by 12 h of reoxygenation.At 12 h of reoxygenation, the cell viability was measured by CCK8 assay, the product of lactate dehydrogenase (LDH) in culture medium was measured, the level of reactive oxygen species (ROS) was determined by flow cytometry, cardiomyocyte apoptosis was detected by TUNEL, and the expression of receptor-interacting protein 1 (RIP1), RIP3, Bax, Bcl-2, activated caspase-3 and caspase-3 was determined by Western blot.The apoptotic rate and ratio of activated caspase-3/caspase-3 were calculated. Results Compared with group C, the cell viability was significantly decreased, the product of LDH was increased, the level of ROS and apoptotic rate were increased, the expression of RIP1, RIP3 and Bax was up-regulated, the expression of Bcl-2 was down-regulated, and the ratio of activated caspase-3/caspase-3 was increased in group HG (P 0.05). Conclusion The mechanism by which propofol postconditioning ameliorates H/R injury in diabetic cardiomyocytes may be related to inhibiting necroptosis. Key words: Propofol; Ischemic postconditioning; Diabetes mellitus; Myocytes, cardiac; Reperfusion injury; Necroptosis