乌参醒脑汤对帕金森病大鼠行为学及内质网应激PERK/ATF4通路的影响

Effects of Wushen Xingnao Decoction on behavior and endoplasmic reticulum stress PERK/ATF4 pathway in rat models of Parkinson's disease

摘要:

目的 探究乌参醒脑汤对帕金森病大鼠行为学及内质网应激PERK/ATF4通路的影响。方法 将48只大鼠随机分为对照组、模型组、低剂量组、高剂量组，每组12只。除对照组外，另3组在大脑纹状体内注射0.2% 6-羟基多巴胺（6-OHDA）复制帕金森病模型。模型复制成功后，低剂量组和高剂量组（5.4 g/kg和10.8 g/kg）乌参醒脑汤连续灌胃给药21 d，给药结束后，通过旋转实验和旷场实验观察各组大鼠行为学表现；取大鼠纹状体，通过苏木精-伊红（HE）染色，观察其组织病理变化；采用实时荧光定量聚合酶链反应和Western blotting检测大鼠纹状体蛋白激酶R样内质网激酶（PERK）、转录活化因子4（ATF4）、C/EBP同源蛋白（CHOP）和B淋巴细胞瘤-2基因（Bax） mRNA和蛋白的表达。结果 与对照组比较，模型组大鼠旋转频率、水平运动频率降低（P <0.05）；与模型组比较，低剂量组和高剂量组大鼠旋转频率降低（P <0.05），水平运动频率升高（P <0.05）；与低剂量组比较，高剂量组大鼠旋转频率降低（P <0.05），水平运动频率升高（P <0.05）。HE染色结果显示，对照组大鼠纹状体多巴胺能神经细胞元形态正常，结构和轮廓清晰，且数量多。模型组大鼠纹状体多巴胺能神经元细胞数量很少，形态破损严重，多成角状。低剂量组和高剂量组大鼠纹状体多巴胺能神经元细胞数量较多，结构比较完整，轮廓清晰。与对照组比较，模型组PERK、ATF4、CHOP、Bax mRNA和蛋白相对表达量升高（P <0.05）；与模型组比较，低剂量组和高剂量组PERK、ATF4、CHOP、Bax mRNA和蛋白相对表达量降低（P <0.05）；与低剂量组比较，高剂量组PERK、ATF4、CHOP、Bax mRNA和蛋白相对表达量降低（P <0.05）。结论 乌参醒脑汤可以改善帕金森病大鼠的运动失调，修复损伤的多巴胺能神经元，其作用机制可能与抑制内质网应激PERK/ATF4通路有关。

Abstract:

Objective To investigate the effects of Wushen Xingnao Decoction on behavior and endoplasmic reticulum stress PERK/ATF4 pathway in rat models with Parkinson's disease.Methods Forty-eight rats were divided into control group, model group, low-dose group and the high-dose group, with twelve rats in each group. Except for the control group, the other three groups were injected with 0.2% 6-hydroxydopamine (6-OHDA) into the striatum to establish the models of Parkinson's disease. Three days after the model establishment, Wushen Xingnao Decoction was continuously administered by gavage for twenty-one days in the low-dose group (5.4 g/kg) and the high-dose group (10.8 g/kg). Following the administration, the behavioral performance of rats in each group was observed via rotation test and open field test. The histopathological changes of the rat striatum were observed by H&E staining. The relative mRNA and protein expressions of PERK, ATF4, CHOP and Bax were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting, respectively.Results The rotational speed and horizontal movement speed of rats were lower in the model group than those in the control group (P < 0.05). Compared with the model group, the rotational speed of rats was decreased and the horizontal movement speed was increased in low-dose group and high-dose group (P < 0.05). The rotational speed of rats was decreased and the horizontal movement speed was increased in the high-dose group relative to those in the low-dose group (P < 0.05). The morphology of striatal dopaminergic neurons was normal and the number of striatal dopaminergic neurons was high in the control group as revealed via H&E staining. In the model group, the number of dopaminergic neurons in the striatum was low, and they were severely damaged and were mostly angular in shape. In contrast, the number of dopaminergic neurons in the striatum of rats was relatively high and the neurons were well-defined in low-dose group and high-dose group. Compared with the control group, the mRNA and protein expression levels of PERK, ATF4, CHOP and Bax in the striatum of rats were higher in the model group (P < 0.05). The mRNA and protein expression levels of PERK, ATF4, CHOP and Bax in the striatum of rats in the low-dose group and high-dose group were lower than those in the model group (P < 0.05), while they were even lower in the high-dose group than those in the low-dose group (P < 0.05).Conclusions Wushen Xingnao Decoction can improve the motor function of rat models of Parkinson's disease and repair the damaged dopaminergic neurons, which may be related to the inhibition of endoplasmic reticulum stress PERK/ATF4 pathway.