JAK2/STAT3信号通路调控急性肺损伤过程中Th17/Treg失衡机制的研究

JAK2/STAT3 signaling pathway regulates the Th17/Treg imbalance in acute lung injury

目的探讨JAK2/STAT3信号通路在急性肺损伤(acute lung injury,ALI)过程中对Th17/Treg失衡的影响及其机制。方法将24只C57BL/6小鼠随机分为4组:对照组、模型组、JAK2抑制剂组和STAT3抑制剂组,每组6只。对照组气道内滴注生理盐水,8 h后腹腔注射等量生理盐水,模型组、JAK2抑制剂组和STAT3抑制剂组气道滴注脂多糖(lipopolysaccharide,LPS)构建ALI模型,8 h后分别腹腔注射等量生理盐水、Fedratinib和NSC74859。LPS滴注24 h后测定小鼠肺湿重/干重(W/D),HE染色观察肺组织病理变化,流式检测肺组织中Treg细胞和Thl7细胞的比例,ELISA检测肺组织匀浆中IL-6、lL-10、IL-17A和TGF-β1水平,Western blot检测肺组织中JAK2、STAT3、p-JAK2和p-STAT3蛋白的表达。结果与对照组相比,模型组W/D升高(P<0.01),肺组织损伤严重,有大量炎性细胞浸润,肺组织中Th17/Treg比值、炎症因子IL-6、IL-17A、TGF-β1水平、p-JAK2和p-STAT3蛋白表达水平均显著升高(P<0.01),IL-10水平显著降低(P<0.01);与模型组相比,JAK2抑制剂组和STAT3抑制剂组W/D降低(P<0.05),肺组织损伤有所减轻,炎性细胞浸润减少,肺组织中Th17/Treg比值、炎症因子IL-6、IL-17A、TGF-β1水平、p-JAK2和p-STAT3蛋白表达水平均显著降低(P<0.01),IL-10水平显著升高(P<0.01)。结论抑制JAK2/STAT3信号通路的激活能够调节LPS诱导的ALI小鼠肺组织中Th17/Treg细胞的失衡,抑制炎症反应,减轻肺损伤。

Objective To investigate the effect of the JAK2/STAT3 signaling pathway on the Th17/Treg imbalance in acute lung injury(ALI)and its mechanism.Methods Twenty-four C57BL/6 mice were randomly divided into control,model,JAK2 inhibitor,and STAT3 inhibitor groups with six mice in each group.The control group was instilled with normal saline in their airway,and the same amount of normal saline was injected intraperitoneally 8 h later.The model,JAK2 inhibitor,and STAT3 inhibitor groups were instilled with lipopolysaccharide(LPS)in their airway to establish the ALI model,and the same amount of normal saline,Fedratinib,and NSC74859 were injected intraperitoneally 8 hours later,respectively.The wet/dry(W/D)lung weight of mice was measured at 24 h after LPS infusion,the pathological changes of lung tissue were observed by HE staining,the proportion of Treg and Th17 cells in lung tissue was measured by flow cytometry,and IL-6,LL-10,IL-17A,and TGF-β1 levels in lung tissue homogenates were measured by ELISA.Protein expression of JAK2,STAT3,p-JAK2,and p-STAT3 in lung tissues was detected by Western blot.Results Compared with the control group,the W/D ratio was increased(P<0.01),lung tissue injury was severe,there was a degree number of inflammatory cell infiltration,the Th17/Treg ratio,the levels of inflammatory factors IL-6,IL-17A,TGF-β1,p-JAK2,and p-STAT3 were significantly increased(P<0.01),and the IL-10 level was significantly decreased in the model group(P<0.01).Compared with the model group,the W/D lung weight of JAK2 inhibitor and STAT3 inhibitor groups was decreased(P<0.05),lung tissue injury was alleviated,inflammatory cell infiltration was reduced,the Th17/Treg ratio,IL-6,IL-17A,and TGF-β1 levels,p-JAK2 and p-STAT3 protein expression levels were significantly decreased in lung tissue(P<0.01),and the IL-10 level was significantly increased(P<0.01).Conclusions Inhibiting activation of the JAK2/STAT3 signaling pathway regulates the imbalance of Th17/Treg cells in lung tissue of ALI mice induced by LPS,inhibits the inflammatory response,and reduces lung injury.