Effects of morphine preconditioning on expression of microRNAs during hypoxia-reoxygenation in isolated cardiomyocytes in rats with heart failure / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of morphine preconditioning on the expression of microRNAs (miRNAs) during hypoxia-reoxygenation (H/R) in isolated cardiomyocytes in rats with heart failure.Methods Healthy adult male Sprague Dawley rats,w eighing 200-220 g,were used in this study.Adriamycin 2.0 mg/kg was injected once a week for 6 weeks via the tail vein to induce heart failure.The cardiomyocytes were isolated from the failing hearts of rats and seeded in 24-well plates or in 60 mm diameter dishes.The cells were then randomly divided into 3 groups (n =16 each) using a random number tablecontrol group (group C); group H/R;morphine preconditioning group (group MP).The cells were cultured in normal culture atmosphere in group C.After being exposed to hypoxic air (5％ CO2-95％ N2) for 90 min,the cells were returned to the high-glucose DMEM supplemented with 10％ newborn bovine serum and were then cultured for 120 min in H/R and MP groups.In group M,the cells were cultured in morphine culture medium (final concentration of morphine 0.3 μmol/L) for 10 min and then were returned to the culture medium without morphine and cultured for 30 min immediately before hypoxia.At 120 min of reoxygenation,the cells of 8 wells in each group were chosen to detect the cell viability and lactate dehydrogenase (LDH) activity (by Typan blue staining).All the RNAs were extracted from the cardiomyocytes of the left 8 wells in each group and subjected to miRNA microarray to screen differentially expressed miRNAs.Results The cell viability was significantly lower,the activity of LDH was higher,the expression of miR-6216 and let7e-5p was higher,and the expression of miR-133b-5p was lower in H/R and MP groups than in group C (P ＜ 0.05).Compared with H/R group,the cell viability was significantly increased,the activity of LDH was decreased,the expression of miR-133b-5p was up-regulated,and the expression of miR-6216 and let-7e-5p was down-regulated in MP group (P ＜ 0.05).Conclusion Morphine preconditioning reduces H/R injury to isolated cardiomyocytes in rats with heart failure through regulating the expression of miRNAs such as miR133b-5p,miR-6216 and let-7e-5p.