探讨“天麻-红景天”药对调控TNF-α/NF-κB保护低灌注-脑小血管病模型小鼠内皮细胞屏障的作用机制

Mechanism of tall gastrodia tuber-rose root medicinal pair on the regulation of TNF-α/NF-κB to protect the endothelial cell barrier in mice with hypoperfused-cerebral small vessel disease model

目的 探讨“天麻-红景天”药对通过调控肿瘤坏死因子-α(TNF-α)/核因子κB(NF-κB),保护低灌注-脑小血管病小鼠内皮细胞屏障的作用机制。方法 将70只雄性C57BL/6小鼠分为假手术组、模型组、天麻-红景天1~3组(天麻与红景天质量比分别为1∶1、2∶1、1∶2),每组14只。采用单侧颈总动脉闭塞法制备脑小血管病小鼠模型。术后6 h灌胃1次,之后每24 h灌胃1次,天麻-红景天1~3组小鼠给药剂量分别为1.30、1.95、1.95 g/(kg·d),假手术组、模型组小鼠灌胃等体积生理盐水。在实验第3天(急性期)、第7天(亚急性期)进行脑血流量和行为学检测后取材。激光散斑衬比成像观察脑血流量的变化;步态分析仪评价运动协调能力;HE染色观察脑组织病理形态学变化;蛋白质印迹法检测白蛋白的表达水平;免疫荧光法和蛋白质印迹法检测咬合蛋白(Occludin)和闭锁连接蛋白-1(ZO-1)的表达水平;实时荧光PCR和蛋白质印迹法检测TNF-α、NF-κB、白细胞介素-β(IL-β)、白细胞介素-6(IL-6)的表达水平。结果 与假手术组比较,第3、7天模型组小鼠脑血流量降低(P<0.05);出现摆动时长延长、步频减少、步态平衡性降低(P<0.05)的步态异常情况;脑组织病理损伤严重,白蛋白表达水平升高,Occludin和ZO-1蛋白表达水平下降(P<0.05);TNF-α、NF-κB、IL-β、IL-6 mRNA及蛋白表达升高(P<0.05)。与模型组比较,第3、7天天麻-红景天各组小鼠脑血流量升高(P<0.05);摆动时长缩短、步频增加、步态平衡性升高(P<0.05);脑组织病理损伤减轻,白蛋白表达水平降低(P<0.05),Occludin和ZO-1蛋白表达水平升高(P<0.05);TNF-α、NF-κB、IL-β、IL-6的mRNA及蛋白表达降低(P<0.05)。其中,天麻-红景天2组在第3天综合疗效较好,天麻-红景天3组在第7天综合疗效更佳。结论 “天麻-红景天”药对能提高低灌注-脑小血管病小鼠脑血流量,改善步态异常,减轻脑组织病理损伤,保护内皮细胞屏障的功能和结构,其机制可能与降低炎症因子表达有关。

Objective We aimed to investigate the mechanism of Tianma(tall gastrodia tuber)-Hongjingtian(rose root)medicinal pair in regulating tumor necrosis factor-α(TNF-α)/nuclear factor-κB(NF-κB)to protect the endothelial cell barrier in mice with hypoperfused-cerebral small vessel disease.Methods Seventy male C57BL/6 mice were assigned to the sham operation group,model group,Tianma-Hongjingtian groupⅠ,Ⅱ,andⅢ(the mass ratio of Tianma to Hongjingtian were 1:1,2:1,and 1:2),with 14 mice in each group.A unilateral common carotid artery occlusion mouse model was established.The mice of each group were gavaged once at six hours after the surgery then once every 24 h thereafter.The doses of Tianma-Hongjingtian groupⅠ,Ⅱ,andⅢwere 1.30,1.95,and 1.95 g/(kg·d),and the sham operation and model groups were administered with the same volume of saline.Cerebral blood flow detection and behavioral post and sampling were performed on the 3rd day(acute phase)and 7th day(subacute phase)of the experiment.Laser diffuse linear ratio imaging was used to observe changes in cerebral blood flow.A gait analyzer was used to evaluate motor coordination.Hematoxylin-eosin staining combined with light microscopy was used to observe pathological and morphological changes in brain tissue.Western blotting was used to detect the expression level of albumin.Immunofluorescence and Western blotting were used to detect the expression levels of tight junction proteins(Occludin and ZO-1).The expression levels of TNF-α,NF-κB,IL-β,and IL-6 were detected through RT-PCR and Western blotting.Results Compared with the sham operation group,cerebral blood flow was reduced on the 3rd day and 7th day in the model group(P<0.05);gait abnormalities of prolonged swing duration,reduced stride frequency,and reduced gait equilibrium(P<0.05)were observed;severe pathological damage was observed in brain tissues,with increased level of albumin expression,decreased protein expression levels of Occludin and ZO-1(P<0.05);mRNA and protein expression levels of TNF-α,NF-κB,IL-β,and IL-6 increased(P<0.05).Compared with the model group,the cerebral blood flow of mice on the 3rd and 7th day in the three Tianma-Hongjingtian groups was elevated(P<0.05);swinging duration was shortened,step frequency increased,gait equilibrium was elevated(P<0.05);brain histopathological damage was reduced,albumin expression level decreased(P<0.05),and the expression levels of Occludin and ZO-1 proteins were elevated(P<0.05);the mRNA and protein expression levels of TNF-α,NF-κB,IL-β,and IL-6 were decreased(P<0.05).Among them,the combined efficacy was better on the 3rd day of Tianma-Hongjingtian groupⅡ;the combined efficacy was better on the 7th day of Tianma-Hongjingtian groupⅢ.Conclusion Tianma-Hongjingtian can increase cerebral blood flow,improve gait abnormalities,reduce pathological damage to brain tissue,and protecte the function and structure of the endothelial barrier in mice with hypoperfused cerebral small vessel disease,and the mechanism may be related to decreasing the expression of inflammatory factors.