电针干预对缺血再灌注模型大鼠的神经保护与神经调节蛋白1/表皮生长因子受体4信号通路的关系

背景:电针干预曲池、足三里穴位能够起到神经保护作用,改善患者的运动功能,然而针对其作用机制的深入研究则相对较少。目的:基于神经调节蛋白1/表皮生长因子受体4信号通路观察电针干预对脑缺血再灌注损伤模型大鼠的神经保护作用。方法:取90只SPF级雄性Wistar大鼠,采用改良线栓法制备脑缺血再灌注损伤大鼠模型,并随机分为模型组、非穴位组和穴位组;另取30只大鼠只予以左侧颈部血管的分离作为假手术组。造模后3 h,非穴位组用电针刺激右侧肢体腋横纹下和尾骨尖下3 mm的非穴位处,穴位组用电针刺激曲池和足三里,共治疗7 d;假手术组和模型组不予任何治疗,只进行与治疗组相同条件的抓取与固定。造模完成后,以神经功能缺损评分进行模型评价;治疗结束后评价各组大鼠的神经功能缺损评分;检测缺血侧局部脑血流量和血流速度;TTC染色观察并计算脑梗死体积;电镜观察神经元的超微结构;TUNEL染色观察神经细胞凋亡情况;Western blotting检测神经调节蛋白1/表皮生长因子受体4通路蛋白表达水平。结果与结论:①与假手术组相比,模型组和非穴位组大鼠的神经功能缺损评分、脑梗死体积、神经细胞凋亡率、神经调节蛋白1、表皮生长因子受体4蛋白表达水平明显升高,脑血流量、脑血流速度明显下降(P<0.05),神经元超微结构异常,模型组与非穴位组间差异无显著性意义(P>0.05);②与模型组相比,穴位组大鼠的神经功能缺损评分、脑梗死体积、神经细胞凋亡率明显下降,脑血流量、脑血流速度、神经调节蛋白1、表皮生长因子受体4蛋白表达水平明显上升(P<0.05),神经元超微结构明显改善;③说明电针刺激曲池、足三里穴位能够明显改善脑缺血再灌注损伤大鼠的神经功能缺损状态和脑神经元超微结构,抑制神经细胞凋亡,起到神经保护作用,其机制可能与神经调节蛋白1/表皮生长因子受体4信号通路的调控有关。

Relationship between electroacupuncture-induced neuroprotection and neuregulin-1/epidermal growth factor receptor 4 signaling pathway in ischemia-reperfusion model rats

BACKGROUND: Electroacupuncture intervention at Quchi (LI11) and Zusanli (ST36) acupoints can play a neuroprotective effect and improve motor function in patients. However, there are relatively few in-depth studies on its mechanism of action. OBJECTIVE: To investigate the neuroprotective effect of electroacupuncture intervention in a rat model of cerebral ischemia-reperfusion injury based on the neuregulin-1/epidermal growth factor receptor 4 signaling pathway. METHODS: Ninety specific pathogen-free male Wistar rats were randomly divided into three groups (n=30 per group): A model group, a non-acupoint group, and an acupoint group. Another 30 rats were selected as a sham operation group with the separation of blood vessels in the left side of the neck. At 3 hours after modeling, in the non-acupuncture group, electroacupuncture was performed atthe non-acupoints under the axillary transverse striae of the right limb and 3 mm below the tip of the coccyx by using electroacupuncture, while in the acupuncture group, electroacupuncture was performed at Quchi (LI11) and Zusanli (ST36) acupoints for 7 days. Rats in the sham operation and model groups were not given any treatment, only grasped and fixed under the same conditions as the non-acupoint and acupoint groups. After modeling, the neurological deficit scores were used for model evaluation. The neurological deficit scores were evaluated in each group after treatment; and the regional cerebral blood flow and blood flow velocity on the ischemic side were measured. 2,3,5-Triphenyltetrazolium chloride staining was used to detect the volume of cerebral infarction. Electron microscope was used to observe the ultrastructure of neurons. TUNEL staining was used to detect the apoptosis of neurocytes. Western blot was used to detect the pathway protein expression of neuregulin 1/ epidermal growth factor receptor 4. RESULTS AND CONCLUSION: Compared with the sham operation group, the neurological deficit score, cerebral infarction volume, neuronal apoptosis rate, neuregulin-1 protein level, and epidermal growth factor receptor 4 protein level were significantly increased, cerebral blood flow and cerebral blood flow velocity were significantly decreased in the model and non-acupoint groups (P < 0.05). The ultrastructure of neurons was abnormal in the model group and the non-acupoint group. However, there was no significant difference between the model group and the non-acupoint group (P > 0.05). Compared with the model group, the neurological deficit score, cerebral infarction volume, neuronal apoptosis rate were significantly decreased, and cerebral blood flow, cerebral blood flow velocity, neuregulin 1 protein level, and epidermal growth factor receptor 4 protein level were significantly increased in the acupoint group (P < 0.05). The ultrastructure of neurons was also significantly improved in the acupoint group. These results indicate that electroacupuncture at Quchi (LI11) and Zusanli (ST36) acupoints can significantly improve the state of neurological deficit and the ultrastructure of brain neurons, inhibit neuronal apoptosis, and play a neuroprotective effect in rats with cerebral ischemia-reperfusion injury. Its mechanism may be related to the regulation of neuregulin-1/epidermal growth factor receptor 4 signaling pathway. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.