机械性损伤诱导体外培养皮层神经元Homer1蛋白表达及其意义

Mechanical injury induced Homer1 expression in cortical neuron of rat in vitro

目的探讨体外培养皮层神经元机械性损伤后Homer1蛋白各亚型表达变化规律,阐明神经元损伤与Homer1基因表达的关系及意义。方法大鼠皮层神经元体外培养7d,以细小的微量移液器塑料滴头划割培养之神经元,造成机械性损伤。伤后不同时间点(10、30min、1、3、6、12、24、72h),裂解细胞,SDS聚丙烯酰胺凝胶电泳,Westernblot法检测Homer1蛋白各亚型表达变化情况。对照组不进行机械性划割,其他处理同损伤组。结果Homer1a蛋白相对分子质量为28×103,对照组无Homer1a表达,机械性损伤后10min,Homer1a少量表达,伤后30min起,Homer1a表达明显增加,一直持续至伤后72h。Homer1b/c蛋白相对分子质量为47×103,损伤前后Homer1b/c表达量无明显变化。结论微量移液器塑料滴头划割造成培养之皮层神经元机械性损伤,创伤刺激诱导神经元Homer1a表达量迅速增加,而损伤前后Homer1b/c表达量无明显变化。Homer1a表达呈动态变化,与Homer1b/c共同调节第I组代谢型谷氨酸受体的功能。

Objective To study the expression and significance of Homerl in mechanically injured cortical neuron in vitro, elucidate the relationship between mechanical injury and Homerl expression. Methods The rat fetus cortical neurons were divid .ed into injury and control groups after 7 days in vitro cultivation. After that, mechanical injury was performed by plastic tip on cortical neuronal culture in injury group. The expression of Homerl was detected by using Western blot at different time points after injury （ 10 and 30 min, 1,3, 6, 12, 24 and 72 h）. The control group underwent all the same managements except for the tip-caused mechanical injury. Results There was no expression of Homerl-a in control group, but it was increased quickly after injury. Significant expression of Homerl-a was found from 30 min to 72 h post injury. Homerl-b/c was obviously observed in control group, but it did not change significantly after mechanical injury. Conclusion Mechanical injury can be performed on cortical neuronal culture with plastic tip. Traumatic stimulation can induce the expression of Homerl-a quickly, but that of Homerl-b/c did not. Dynamically expressed Homerl-a and constitutively expressed Homerl-b/c modulate the distribution and function of group I metabotropic glutamate receptor （mGluRs）.