Effects of dexmedetomidine on oxygen-glucose deprivation/reperfusion-induced neuronal apoptosis / 临床麻醉学杂志

ABSTRACT

Objective To investigate protective effects of dexmedetomidine on oxygen-glucose deprivation/reperfusion(OGD/R)-induced neuronal apoptosis.Methods SH-SY5Y cells were differentiated to neurons with ATRA and followed by TPA.According to the results of preliminary experiment, OGD/R modle was constructed by oxygen-glucose deprivation(OGD) for 12 h and reperfusion(R) for another 12 h.During the start of the OGD, neurons were immediately divided into six groups: group D0(0 μmol/L dexmedetomidine), group D1(0.1 μmol/L dexmedetomidine), group D2 (1 μmol/L dexmedetomidine), group D3 (10 μmol/L dexmedetomidine), group D4(100 μmol/L dexmedetomidine), group D5 (1 000 μmol/L dexmedetomidine).After reperfusion 12 h, the cell viability was evaluated by the method of MTT.The cellular apoptosis was observed by flow cytometry method.The protective effects of different concentration dexmedetomidine on OGD/R-induced neuronal apoptosis were investigated.Then in chosen the exact group having protective effects, endoplasmic reticulum stress specific protein mesencephalic astrocyte-derived neurotrophic factor (MANF) and pro-apoptotic protein Caspase-3 and CHOP were detected by Westernblot method.Results Compared with group D0, there was no difference on the cell viability and cellular apoptosis induced by OGD/R in groups D1 and D2, but a significant decrease and increase in groups D4 and D5 (P<0.01 or P<0.05).And only group D3 had a neuroprotective effect, significantly increased the cell viability and inhibited the apoptosis (P<0.01).Further studys found that group D3 significantly up-regulated ER stress specific protein MANF (P<0.01) and inhibited up-regulation of Caspase-3 and CHOP (P<0.01).Conclusion These data suggest that 10 μmol/L dexmedetomidine had neuroprotective effect on OGD/R-induced neuronal apoptosis and significantly increased cell viability.Our results also indicate that up-regulation of ER stress specific protein MANF and inhibition of CHOP and Caspase-3 by MANF are involved in the neuroprotective effects of Dexmedetomidine.