CCK-8 prevents glutamate-induced apoptosis in cultured cortical neurons via up-regulation of bcl-2/bax ratio and down-regulation of caspase-3 / 重庆医科大学学报

ABSTRACT

Objective: To investigate the mechanisms responsible for the neuroprotection by cholecystokinin octapeptide against glutamate-induced apoptosis in vitro cultured cortical neurons. Methods: Primary cultured corticaI neurons from SD rats of 0～24 hold were incubated for 8 days. The cultured cells were divided randomly into three groups control group,glutamate group and CCK group. In the controI group,cells were not treated with glutamate orCCK;Neurons in glutamate group were incubated with 50?mol/Lglutamate for 30 min;In CCK group,CCK-8 was added to the Neurons 24 h prior to incubation with glutamate. After injuried by glutamate,cells in all the groups were incubated with normal medium for 0,6,12,24 h and 48 h. At the five time points,cells were fixed respectively for experiment. Cell viability were determined by the colorimetric MTT assay;The protein expression of Bcl-2,Bax and Caspase-3 were determined by immunocytochemistry techniques. Results:Pretreatment with CCK for 24 h significantly improved glutamate-induced suppression of cell viability. Pretreatment with CCK also completely reversed the suppression of Bcl-2 expression,and significantly inhibited Bax overexpression and Caspase-3 activition induced by glutamate. Conclusion:Theneuroprotective mechanisms of CCK against glutamate-induced apoptosis in cultured cortical neurons may be associated with up-regulation of Bcl-2/Bax ratio and down-regulation of Caspase-3.