Effect of Cholecystokinin Octapeptide on Expression of GLT-1 in Glutamate-induced Hippocampal Astrocytes / 华中科技大学学报(医学版)

ABSTRACT

Objective To investigate the effect of cholecystokinin octapeptide(CCK-8)on glutamate transporter 1(GLT-1)expression in hippocampal astrocytes induced by glutamate(Glu).Methods The mouse hippocampal astrocytes were isolated and the toxicity of CCK-8 at different concentrations on the mouse hippocampal astrocytes was detected.The cells were divided into control group,Glu group,Glu+0.1 μmol/L CCK-8 group,Glu+0.5 μmol/L CCK-8 group and Glu+1.0 μmol/L CCK-8 group.MTT assay was used to detect cell proliferation.Flow cytometry was used to detect cell apoptosis.Biochemical kit was used to detect Glu content in the extracellular supernatant,and qRT-PCR was used to detect the mRNA expression of GLT-1 and glutamate/aspartate transporter(GLAST).The protein expressions of Caspase-3,Bcl-2,GLT-1 and GLAST were detected by Western blotting,and the expression of TNF-α in the cell supernatant was detected by ELISA.Results CCK-8 at different concentrations had no significant effect on the proliferation of mouse hippocampal astrocytes.Compared with the control group,the cell proliferation ability and the expression levels of Bcl-2 protein,GLT-1 and GLAST mRNA and protein in Glu group were significantly decreased(all P＜0.01),the apoptosis rate,extracellular Glu content,Caspase-3 protein expression level in cells and TNF-α level in cell supernatant were significantly increased(all P＜0.01);Compared with the Glu group,the cell proliferation a-bility and the expression levels of Bcl-2 protein,GLT-1 and GLAST mRNA and protein in the Glu+0.5 μmol/L CCK-8 group and Glu+1.0 μmol/L CCK-8 group were significantly increased(all P＜0.05),the apoptosis rate,extracellular Glu content,Caspase-3 protein expression level in cells and TNF-α level in cell supernatant were significantly decreased(all P＜0.01).Con-clusion CCK-8 can inhibit Glu-induced inflammatory response of astrocytes,promote the expression of GLT-1,reduce the con-centration of extracellular Glu,promote cell proliferation and inhibit apoptosis.