Effects of morphine preconditioning on expression of microRNAs during hypoxia-reoxygenation in H9 c2 myocardial cells / 中国药理学通报

ABSTRACT

Aim To evaluate the effects of morphine preconditioning ( MPC ) on the expression of microR-NAs ( miRNAs ) induced by hypoxia-reoxygenation (H/R) in H9c2 myocardial cells. Methods H9c2 cells were randomly divided into 3 groups ( n=4 each) as followscontrol group ( CON) , hypoxia/ reoxygen-ation group ( H/R ) and morphine preconditioning group ( MPC+H/R) . The cells were cultured in nor-mal condition in CON group. The cells were subjected to 5 h hypoxia followed by 1 h reoxygenation in H/R group and MPC+H/R group. Specifically, the cells in MPC+H/R group were preconditioned with morphine with the final concentration of 1 μmol·L-1 for 10 min before H/R. After the treatment, CCK-8 was used to detect cell viability and chemical colorimetry was used to detect lactate dehydrogenase ( LDH ) activity in the culture medium. Cell apoptosis was assessed by An-nexin-V-FITC/PI flow cytometry. Relative expression of Fas protein was detected by Western blot. The ex-pression of miRNA in myocardial cells was analyzed by quantitative reverse transcription polymerase chain re-action ( qRT-PCR ) . Results Compared with CON group, the cell viability was significantly decreased, while the LDH activity, apoptotic rate and Fas protein expression were dramatically increased in group H/R (P<0. 01). However, MPC significantly increased the cell viability, whereas it decreased the LDH activity, apoptotic rate and Fas protein expression induced by H/R injury ( P < 0. 01 ) . The expressions of miR-133a-5p, miR-133b-5p, miR-664-1-5p, miR-6216 and let-7 e-5 p were markedly down-regulated by H/R as compared to CON group ( P <0. 05 ) , while MPC inhibited these miRNAs which were significantly down-regulated by H/R group ( P <0. 01 ) . Conclusion Morphine preconditioning might protect H9 c2 myocar-dial cells against H/R injury by regulating the expres-sion of miRNAs such as miR-133a-5p, miR-133b-5p, miR-664-1-5p, miR-6216 and let-7e-5p.