[关键词]
[摘要]
目的 观察芍甘木瓜汤对脑卒中偏瘫痉挛状态大鼠神经行为学的影响,并探讨对脑源性神经营养因子(BDNF)/酪氨酸蛋白激酶B(TrkB)/环磷腺苷效应元件结合蛋白(CREB)信号通路的调控机制。方法 取50只SD大鼠采用改良线栓法制作大脑中动脉梗死模型,选取建模成功大鼠随机分为模型组、巴氯芬(0.008 g/kg)组和芍甘木瓜汤低、中、高剂量(0.05、0.10、0.15 g/kg)组。另取10只SD大鼠不栓塞大脑中动脉作为假手术组,于再灌注2 h后ig给药,每天1次,连续2周,假手术组和模型组ig等量生理盐水。干预前后分别采用Zea Longa量表、改良Ashworth量表评价神经行为学、肌张力变化,采用大鼠多导生理记录仪测定上肢伸直幅度;酶联免疫法检测大鼠干预前后血清BDNF、TrkB水平;苏木素-伊红(HE)染色观察缺血半暗带脑组织病理变化,透射电镜下观察缺血半暗带脑组织神经元超微结构;实时荧光定量PCR(qRT-PCR)检测缺血半暗带脑组织BDNF、TrkB-FL、TrkB-T1、CREB mRNA表达;Western blotting检测BDNF、TrkB-FL、TrkB-T1、CREB蛋白表达及p-CREB水平。结果 干预后巴氯芬组和芍甘木瓜汤各剂量组的Zea Longa量表、改良Ashworth量表分级均较干预前和模型组(干预后)显著改善(P<0.05),上肢伸直幅度均较干预前和模型组(干预后)均显著增加(P<0.05),血清BDNF、TrkB水平均较干预前和模型组(干预后)显著升高(P<0.05),缺血半暗带脑组织病理变化和神经元超微结构均较模型组明显改善。模型组缺血半暗带脑组织BDNF、TrkB-FL mRNA与蛋白表达,p-CREB蛋白水平均显著低于假手术组(P<0.05),巴氯芬组和芍甘木瓜汤各剂量组均较模型组显著升高(P<0.05);模型组缺血半暗带脑组织TrkB-T1 mRNA与蛋白表达显著高于假手术组(P<0.05),巴氯芬组和芍甘木瓜汤各剂量组均较模型组显著下降(P<0.05)。各组缺血半暗带脑组织CREB mRNA表达差异无统计学意义。结论 对脑卒中偏瘫痉挛状态大鼠ig予以芍甘木瓜汤可改善其神经行为学,降低肌张力,增加血清BDNF、TrkB水平,减轻缺血半暗带脑组织病理和神经元超微结构变化,推测与激活BDNF/TrkB/CREB通路,上调BDNF、TrkB-FL mRNA与蛋白表达,下调TrkB-T1 mRNA与蛋白表达,增加p-CREB水平有关。
[Key word]
[Abstract]
Objective To observe the effect of Shaogan Mugua Decoction on neuroethology in rats with hemiplegia spasticity after stroke, and to explore the regulation mechanism of brain-derived neurotrophic factor (BDNF)/tyrosine protein kinase B (TrkB)/camp effector element binding protein (CREB) signal pathway. Methods Totally 50 SD rats were randomly divided into model group, baclofen group, low, medium and high concentration groups of Shaogan Mugua decoction. Another 10 SD rats were taken without middle cerebral artery embolization, which were recorded as sham group. The baclofen group was given 0.008 g/kg baclofen by gavage, and the low, medium and high concentration groups of Shaogan Mugua Decoction were given 0.05, 0.1 and 0.15 g/kg Shaogan Mugua Decoction respectively, and the sham group and the model group were given the same amount of normal saline, lasted for two weeks. Before and after intervention, Zea longa scale and modified Ashworth scale were used to evaluate neurobehavior and muscle tension. The range of upper limb extension was measured by multi-channel physiological recorder. The serum levels of BDNF and TrkB were detected by enzyme-linked immunosorbent assay (ELISA). Hematoxylin eosin (HE) staining was used to observe the histopathology of ischemic penumbra brain tissues. The ultrastructure of neurons of histopathology of ischemic penumbra brain tissues was observed under transmission electron microscope. Real time reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expressions of BDNF, TrkB-FL, TrkB-T1 and CREB mRNA. The expressions of BDNF, TrkB-FL, TrkB-T1, CREB and p-CREB were detected by Western blotting. Results After intervention, the scores of Zea longa scale and modified Ashworth scale in baclofen group and three dose groups of Shaogan Mugua Decoction were improved compared with those before intervention and model group (P<0.05), the extents of upper limb extension were increased compared with those before intervention and model group (P<0.05), serum BDNF and TrkB levels were increased compared with those before intervention and model group (P<0.05), the pathological changes of ischemic penumbra tissues and ultrastructure of neurons in infarcted area were improved compared with those in the model group. The expressions of BDNF, TrkB-FL mRNA and proteins, and the level of p-CREB in the model group were lower than those in the sham operation group (P<0.05), while those in the baclofen group and three dose groups of Shaogan Mugua Decoction were increased compared with those in model group (P<0.05). The expression of TrkB-T1 mRNA and protein in the model group was higher than that in the sham group (P<0.05), while those in the baclofen group and three dose groups of Shaogan Mugua Decoction were decreased compared with that in the model group (P<0.05). There was no significant difference in the expression of CREB mRNA in the ischemic penumbra tissues among the three groups. Conclusion Shaogan Mugua Decoction can improve neurobehavior, decrease muscle tension, and increase serum BDNF and TrkB levels in rats with hemiplegic spasticity after stroke. It is speculated that it is related to activating BDNF/TrkB/CREB pathway, up regulating the mRNA and protein expressions of BDNF and TrkB-FL, down regulating the mRNA and protein expressions of TkrB-T1, and increasing the level of p-CREB.
[中图分类号]
R285.5
[基金项目]
湖北省教育厅科学研究计划指导性项目(B2018098)