迷走神经刺激对急性呼吸窘迫综合征大鼠Th17和Treg相关蛋白及炎症因子的影响

Effects of vagus nerve stimulation on Th17-and Treg-related proteins and inflammatory factors in rats with acute respiratory distress syndrome

目的在脂多糖(LPS)诱导的急性呼吸窘迫综合征(ARDS)模型大鼠中,探讨迷走神经刺激(VNS)对辅助性T细胞17(Th17)和调节性T细胞(Treg)相关蛋白及炎症因子的调控作用。方法将30只SD大鼠随机分为对照组、LPS组和LPS+VNS组,每组10只。LPS组和LPS+VNS组大鼠通过鼻腔滴注2 mg/kg LPS构建ARDS模型。LPS+VNS组于鼻腔滴注LPS 6 h后暴露左侧颈部迷走神经,给予电压5 V、频率5 Hz、脉冲宽度2 ms的电刺激,持续10 min。电刺激2 h后取双肺及脾组织进行检测。检测指标包括肺部病理学变化、肺湿干比、支气管肺泡灌洗液(BALF)总蛋白含量、BALF中炎症因子水平、肺及脾组织中Treg转录蛋白叉头框蛋白P3(Foxp3)和Th17转录蛋白维甲酸受体相关孤儿受体γt(Rorγt)表达。结果与对照组相比,LPS组大鼠肺泡壁明显变厚、炎症细胞浸润到肺泡腔,BALF总蛋白含量增高(P<0.01),肺湿干比增高(P<0.01),BALF中IL-1β、IL-6、IL-17、IL-10表达升高(均P<0.01),肺和脾组织中Foxp3和Rorγt蛋白表达上调;与LPS组相比,LPS+VNS组大鼠肺组织病理表现减轻,肺湿干比下降(P<0.05),BALF总蛋白含量降低(P<0.05),BALF中IL-6和IL-17降低(均P<0.05)、IL-10升高(P<0.01),肺及脾组织中Foxp3蛋白表达上调、Rorγt蛋白表达下调。结论VNS可能通过调控大鼠肺和脾组织Th17和Treg相关蛋白表达进而调控炎症因子水平,减轻LPS诱导的ARDS病理改变。

Objective To investigate the effects of vagus nerve stimulation(VNS)on T helper cell 17(Th17)-and regulatory T cell(Treg)-related proteins and inflammatory factors in lipopolysaccharide(LPS)-induced acute respiratory distress syndrome(ARDS)rats.Methods Thirty SD rats were randomly divided into control group,LPS group and LPS+VNS group,with 10 rats in each group.The ARDS model was established by nasal instillation of 2 mg/kg LPS into SD rats in LPS group and LPS+VNS group.In LPS+VNS group,after LPS nasal instillation for 6 h,the left cervical vagus nerve was exposed and stimulated under 5 V,5 Hz,2 ms for 10 min.Tissues of lung and spleen were examined after 2 h.The indicators included lung pathological changes,lung wet to dry ratio,total protein content in bronchoalveolar lavage fluid(BALF),inflammatory factor levels in BALF,and expression of forkhead box protein P3(Foxp3,a transcription protein of Treg)and retinoic acid-related orphan receptorγt(Rorγt,a transcription protein of Th17)in the lung and spleen.Results Compared with the control group,the alveolar wall of rats in LPS group was significantly thickened,inflammatory cells infiltrated into the alveolar space;the total protein content of BALF was significantly increased(P<0.01);lung wet to dry ratio was significantly increased(P<0.01);the expression of IL-1β,IL-6,IL-17 and IL-10 was significantly increased in BALF(all P<0.01);and the expression of Foxp3 and Rorγt was up-regulated in the lung and spleen.Compared with LPS group,the pathological manifestations of rats were alleviated in LPS+VNS group;the lung wet to dry ratio,the total protein content of BALF,and the levels of IL-6 and IL-17 in BALF were significantly decreased(all P<0.05);the level of IL-10 in BALF was significantly increased(P<0.01);and the expression of Foxp3 was up-regulated,while the expression of Rorγt was down-regulated in the lung and spleen.Conclusion VNS may regulate the expression of inflammatory factors by regulating Th17-and Treg-related proteins in the tissues of lung and spleen in rats,thereby alleviating the pathological changes of LPS-induced ARDS.