胰岛素增加培养的星形胶质细胞中谷氨酸转运体GLT1的表达

Insulin increases glutamate transporter GLT1 in cultured astrocytes

目的研究胰岛素对GLT1表达的影响。方法对原代星形胶质细胞培养后加入胰岛素刺激,再采用免疫印迹法、细胞表面生物素酰化、实时定量PCR、免疫染色、电生理学等方法,检测GLT1的表达变化。结果研究结果发现用胰岛素短期刺激会导致总的和细胞膜表面的GLT1表达均增加。胰岛素处理后会增加Akt磷酸化,而Akt磷酸化的抑制剂triciribine具有明显抑制胰岛素的作用。研究还发现GLT1表达上调与KBBP表达增加和GLT1mRNA水平增加相关。结论胰岛素会调控星形胶质细胞GLT1的表达,这可能在中枢神经系统损伤后的星形胶质细胞反应中起着重要作用。

Objective In the present study, we aimed to evaluate the effects of insulin on GLT1 expression. Methods We added insulin stimulation after culturing primary astrocytes. GLT1 expression was detected with Western blotting, cell surface biotinylated, real-time quantitative PCR, immunohistochemistry and electrophysiology. Results We found that shortterm stimulation of insulin led to the upregulation of both total and surface expressions of GLT1. Akt phosphorylation increased after insulin treatment, and triciribine, the inhibitor of Akt phosphorylation, significantly inhibited the effects of insulin. We also found that the upregulation of GLT1 expression correlated with increased kappa B motif-binding phos-phoprotein （KBBP） and GLT1 mRNA levels. Conclusions Our results suggest that insulin may modulate the expression of astrocytic GLT1, which might play a role in reactive astrocytes after CNS injuries.