多巴胺能神经细胞慢性损伤过程中RET的表达变化

Expression of RET in Mice Substantia Nigra during Dopaminergic Neuron Cells Damage

目的:为了检测RET在多巴胺能神经细胞损伤过程中中脑黑质部位的表达变化,并探索其在多巴胺能神经细胞损伤中的可能作用。方法:本实验将C57BL/6小鼠分为三组:MPTP组、NS组和空白对照组,采用MPTP腹腔注射建立小鼠中脑黑质多巴胺能神经细胞慢性损伤模型,设立第一周到第六周六个时间点(1w-6w),检测小鼠行为学变化,并采用免疫荧光染色和western blotting等方法检测中脑黑质部酪氨酸羟化酶(TH)和RET的表达情况。结果:行为学结果显示,随给药次数及时间延长,悬挂实验中,MPTP组悬挂评分逐渐下降,MPTP组第三周给药以后与NS组比较差异有统计学意义(P<0.05);跳台实验中,小鼠受电击后跳上跳台的时间逐渐延长,错误次数逐渐增多。免疫荧光双标结果显示,在检测的各时间点,在小鼠中脑黑质一直有RET阳性细胞存在,且与TH阳性细胞共表达;western blotting结果显示,TH在给予MPTP后第三周表达开始降低,RET在给予MPTP后第一周和第二周持续高表达,并且也从第三周开始,其表达量明显降低。结论:这种表达变化提示RET的表达与多巴胺能神经细胞损伤有关。

Objective：In orderto detect the expression of RET in the mesencephalic substantia nigra（SN） and explore the possible roles during the dopaminergic（DA） neuron cells damage.Methods：We divided C57BL/6 mice into three groups：MPTP group, NS group and Control group and used MPTP（i.p）to establish DA neuron cells chronic injury model.We set six time points ：the first week to the sixth week （1w-6w）and tested the mice behavioral changes after MPTP injection.Then we applied the methods of immunofluorescence and western blotting to detect the expression of tyrosine hydroxylase （TH） and RET in the mice SN.Results：The behavioral results showed that the scores of the suspension test decreased from the third week compared to the NS group（P0.05）.In the step-down test, the time of the mice jumpped onto the platform extended gradually and the errors were increased gradually after elctric shock.The immunofluorescence double-labeled results showed that RET positive cells were obviously presence in mice substantia nigra at all of the time points and co-expressed with TH in the same neurons.Western blotting showed that TH protein began to decrease from the third week after MPTP injection and RET kept high expression from the first week to the second week but decreased from the third week.Conclusions：This expression suggest that the expression of RET was associated with the DA neurons damage.