AIM:To investigate the role of microRNA-486-5p (miR-486-5p) in the apoptosis of human bone marrow mesenchymal stem cells (hMSCs) induced by hydrogen peroxide (H2O2).METHODS: The hMSCs were cul-tured in vitro and exposed to serum-free medium and H2O2(10 mmol/L).The changes of miR-486-5p expression in oxida-tive stress-related apoptosis of hMSCs were measured by real-time PCR.The hMSCs were transfected with miR-486-5p mimic or inhibitor at concentration of 30 nmol/L by Lipofectamine RNAiMAX.The effect of miR-486-5p on H2 O2-induced decrease in cell viability was evaluated by MTT assay.Hoechst 33342 staining and flow cytometry were applied to determine the role of miR-486-5p in the apoptosis of hMSCs.The protein expression was evaluated by Western blotting.Caspase-3 ac-tivity was determined using a caspase-3 activity kit.RESULTS:Compared with control group, the expression of miR-486-5p significantly decreased after treated with H2O2(P<0.05).In addition, over-expression of miR-486-5p in the hMSCs reduced the cell viability, accelerated apoptosis, down-regulated Bcl-2/Bax ratio, caspase-3 enzyme precursor content and phosphorylation of Akt, and activated caspase-3 activity.Conversely, down-regulation of miR-486-5p significantly inhibited H2 O2-induced cell apoptosis and the caspase-3 activity, increased cell viability and up-regulated Bcl-2/Bax ratio and phos-phorylation level of Akt.CONCLUSION:Over-expression of miR-486-5p promotes H2 O2-induced hMSCs apoptosis, and repression of miR-486-5p protects hMSCs from H2 O2-induced cellular apoptosis, which may be mediated by regulating Akt signaling pathway.