牛蒡苷元通过抑制HMGB1/TLR4/NF-κB通路减轻急性脑梗死大鼠的神经元损伤

Arctigenin alleviates neuronal damage of acute cerebral infarction in rats by inhibiting the HMGB1/TLR4/NF-κB pathway

目的探究牛蒡苷元(AG)能否通过抑制高迁移率族蛋白B1(HMGB1)/Toll样受体4(TLR4)/核因子κB(NF-κB)通路的活化,从而减轻急性脑梗死大鼠神经元损伤。方法通过大脑中动脉栓塞(MCAO)建立大鼠急性脑梗死模型后,将50只大鼠随机分为模型组、尼莫地平组(30mg/kg)以及AG低(25mg/kg)、中(50mg/kg)、高(100mg/kg)剂量组,每组10只,另取10只为假手术组(仅麻醉、游离血管,不进行插线操作)。Morris水迷宫实验评估大鼠认知功能;酶联免疫吸附试验(ELISA)检测血清肿瘤坏死因子α(TNF-α)、白细胞介素(IL)-1β、IL-6水平;HE染色与TUNEL染色观察大脑皮层病理学变化与神经元凋亡情况,Western blot检测高迁移率族蛋白B1(HMGB1)、Toll样受体4(TLR4)、核因子κB(NF-κB)、磷酸化NF-κB(p-NF-κB)蛋白表达情况。结果与假手术组比较,模型组认知功能下降,血清TNF-ɑ、IL-1β、IL-6水平升高,神经元凋亡指数及大脑皮层HMGB1、TLR4蛋白表达和p-NF-κB/NF-κB比值升高(P<0.05),大脑皮层神经元排列紊乱,出现严重空泡化和水肿现象,细胞核固缩;与模型组比较,AG各剂量组和尼莫地平组大鼠认知功能部分恢复,血清TNF-ɑ、IL-1β、IL-6水平下降,神经元凋亡指数及大脑皮层HMGB1、TLR4蛋白表达和p-NF-κB/NF-κB比值降低(P<0.05),大脑皮层神经元损伤减轻。结论AG可能通过抑制HMGB1/TLR4/NF-κB通路活化,减轻急性脑梗死大鼠神经元损伤。

Objective To explore whether arctigenin(AG)can reduce neuronal damage of acute cerebral infarction in rats by inhibiting the expression of high mobility group box 1(HMGB1)/Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)pathway.Methods The rat model of acute cerebral infarction was established by middle cerebral artery embolism(MCAO).Fifty model rats were randomly separated into the model group,the nimodipine group(30 mg/kg),the low AG group(25 mg/kg),the medium AG group(50 mg/kg)and the high AG group(100 mg/kg),10 rats in each group.Another 10 rats were used as the sham operation group(only anesthesia,dissociation of blood vessel,no thrombus insertion operation).Morris water maze experiment was used to assess cognitive function in rats.The serum TNF-ɑ,IL-1βand IL-6 contents were tested by ELISA.HE staining and TUNEL staining were performed to observe the pathological changes and neuronal apoptosis of cerebral cortex,and Western blot assay was performed to measure the protein expression of HMGB1,TLR4,p-NF-κB and NF-κB.Results Compared with the sham operation group,the cognitive function was declined in the model group,serum levels of TNF-ɑ,IL-1βand IL-6 were increased,neuronal apoptosis index,cortical HMGB1 and TLR4 protein expression and p-NF-κB/NF-κB ratio were increased(P<0.05).The neuron arrangement of cerebral cortex was disordered,serious vacuolation,edema and nuclear condensation occurred.Compared with the model group,cognitive function was partially restored in the AG groups and the nimodipine group.Serum levels of TNF-ɑ,IL-1βand IL-6 decreased.Neuronal apoptosis index,cortical HMGB1,TLR4 protein expression and p-NF-κB/NF-κB ratio were decreased(P<0.05).Cortical neuron damage was reduced.(P<0.05).Conclusion AG may inhibit the HMGB1/TLR4/NF-κB pathway to reduce neuronal damage in rats with acute cerebral infarction.