亚低温对体外缺氧缺糖损伤后神经元的保护作用及其对谷氨酸转运体、亲代谢型谷氨酸受体表达的影响

Neuroprotection afforded by mild hypothermia after oxygen-glucose deprivation in vitro:effects on expression of glutamate transporter and metabotropic glutamate receptor

目的通过研究亚低温对体外缺氧缺糖损伤的神经细胞谷氨酸转运体(GLT-1)、亲代谢型谷氨酸受体(mGluR2/3)表达的影响,探讨亚低温的神经保护途径。方法分组培养大鼠大脑皮层细胞,亚低温组在33 C条件、常温组在37 C条件,缺氧缺糖培养2h后,复氧复糖37 C培养,经时(6h、12h、24h、3d)检测LDH释放量、GLT-1和mGluR2/3蛋白表达量。结果在复氧复糖后,两组LDH释放均呈现上升趋势,其中24h和3d亚低温组的LDH上升水平显著降低(P<0.05);两组GLT-1表达均呈现先下降后上升的趋势,其中6h和12h亚低温组的GLT-1下降水平显著降低(P<0.05);两组mGluR2/3表达均呈现上升趋势,其中12h和24h亚低温组的mGluR2/3升高水平显著增加(P<0.05)。结论亚低温能够在体外水平,通过抑制GLT-1蛋白的表达下调,促进mGluR2/3的表达上调,抑制神经元兴奋性损伤。

Objective To investigate whether neuroprotection can be afforded by mild hypothermia after oxygen-glucose deprivation in vitro through the effects on expression of glutamate transporter （GLT-1） and metabotropic glutamate receptor （mGluR2/3）. Methods Rat cultured cortical cells were exposed to oxygen-glucost deprivation （OGD） either in 37 C （normothermia group） or in 33 C （hypothcrmia group） for 2h before the cells were put into normal culture medium of 37 C. 6h,12h,24h,3d after OGI）, LDH release was measured with UV spcctrophotometer and protein expression of GLT-1 and mGluR2/3 was determined by western blot. Results LDH release of normothermia group and hypothermia group was increased after OGD and there was significant difference between the two groups at 24h and 3d（P〈0.05）. The protein expression of GLT-1 of two groups was decreased before recovered. 6h. 12h after OGD,GLT-1 of hypothermia group was significantly higher than that of normothermia group （P%0. 05）. mGluR2/3 of normothermia group and hypothermia group was increased after OGD. 12h,24h after OGD,the expression of mGluR2/3 in hypothermia group was much more than that of normothermia group（P〈0.05）. Conclusions Neuroprotection can be afforded by mild hypothermia after oxygen-glucose deprivation in vitro through relieving the injury of GLT-1 protein and enhancing the expression of mGluR2/3.