Synergistic effect of schizandrin A and DNaseⅠknockdown on high glucose induced beta cell apoptosis by decreasing intracellular calcium concentration

OBJECTIVE:To explore the synergistic effect of deoxyribonucleaseⅠ(DNaseⅠ)knockdown combined with Schizandrin A(Sch A)in protecting islet beta-cells(β-cells)from apoptosis under high-glucose(HG)conditions.METHODS:The concentration of Sch A was detected by Cell Counting Kit-8(CCK-8).High glucose-cultured rat insulinoma beta cell line(RIN-M5F)cells were treated with Sch A and transfected with DNaseⅠsmall interfering RNA(siRNA).Cell apoptosis rate and apoptosis-related protein level were examined by flow cytometry and Western blot method respectively.In addition,Na^(+)-K^(+)-adenosine triphosphatease(Na^(+)-K^(+)-ATPase)and Ca^(2+)-Mg^(2+)-ATPase activity,cell membrane potential,and intracellular Ca^(2+)concentration was also examined respectively.RESULTS:Our study revealed that HG stimulation can cause a significant increase in DNaseⅠlevel and cell apoptosis rate.However,Sch A combined with DNaseⅠknockdown can significantly decrease the cell apoptosis rate and apoptosis-related protein levels such as BAX(P<0.05)and Caspase-3(P<0.01).In addition,we also found that the combination of Sch A and DNaseⅠknockdown can dramatically increase cell membrane potential level,Na+-K+-ATPase,and Ca^(2+)-Mg^(2+)-ATPase activity.Meanwhile,intracellular Ca^(2+)concentration was also found to be significantly decreased by the synergistic effect of Sch A and DNaseⅠknockdown.CONCLUSION:Overall,our study reveals a synergistic effect of Sch A and DNaseⅠknockdown in protectingβ-cells from HG-induced apoptosis.