桥尾蛋白磷酸化参与大鼠螺旋神经节神经元GABA_A受体内化

Phosphorylation of Gephyrin Is Involved in GABA_A Receptors Internalization in Rat Spiral Ganglion Neurons

林晓宇;韦芳玉;覃江圆;叶莞丽;易健启;陈慧英;刘金兰;覃继新;苏纪平;

1:广西医科大学第一附属医院耳鼻咽喉头颈外科

2:广西右江民族医学院附属医院耳鼻咽喉头颈外科

摘要
目的 探讨桥尾蛋白(gephyrin)丝氨酸S270位点磷酸化在水杨酸钠(sodium salicylate, SS)介导的GABA_A受体(GABA type A receptors, GABA_ARs)内化的作用。方法 将12只SD大鼠分成4组,分别为SS处理组、LiCl处理组、SS+LiCl处理组和对照组,每组3只,急性分离各组耳蜗螺旋神经节神经元(spiral ganglion neurons, SGNs),SGNs原代培养48 h后分别用5 mM SS、1 mM LiCl、5 mM SS联合1 mM LiCl处理1 h,对照组不予处理;采用实时荧光定量PCR(RT-qPCR)检测GABA_ARsα2亚基、桥尾蛋白基因表达的改变;采用Western blot技术检测各组GABA_ARsα2膜蛋白和总蛋白表达的改变、桥尾蛋白及其S270位点磷酸化的改变。结果 RT-qPCR结果显示,各组GABA_ARsα2亚基mRNA、桥尾蛋白mRNA与对照组比较均无明显变化(P>0.05),Western blot结果显示,SS处理组GABA_ARsα2亚基膜蛋白(0.08±0.02)较对照组(0.18±0.04)表达显著下调(P<0.01),LiCl处理组(0.14±0.03)有效逆转SS诱导的GABA_ARsα2亚基膜蛋白下调(SS组为0.08±0.02)(P<0.05),LiCL组膜蛋白、各组总蛋白与对照组比较无明显变化(P>0.05);SS处理组桥尾蛋白S270磷酸化(0.84±0.02)较对照组(0.35±0.14)显著增强(P<0.001)。LiCl处理组(0.66±0.10)有效逆转SS诱导的桥尾蛋白S270磷酸化增强(SS组为0.84±0.02,P<0.05),LiCl处理组桥尾蛋白磷酸化、各处理组桥尾蛋白与对照组比较无明显变化。结论 桥尾蛋白S270位点磷酸化可增强参与SS诱导的SGNs GABA_ARs内化。
关键词
桥尾蛋白;磷酸化;GABA_A受体;内化;螺旋神经节神经元
基金项目(Foundation):
国家自然科学基金项目(81560174,81360157);; 广西自然科学基金(2014GXNSFAA118137)资助
作者
林晓宇;韦芳玉;覃江圆;叶莞丽;易健启;陈慧英;刘金兰;覃继新;苏纪平;
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