丹酚酸B通过抑制IL-13/STAT6通路和恢复Th17/Treg平衡阻滞大鼠慢性阻塞性肺病研究

Salvianolic acid B blocks the progression of COPD in rats by inhibiting IL-13/STAT6 path⁃way and restoring Th17/Treg balance

目的:探究丹酚酸B对慢性阻塞性肺病的作用及其可能的机制。方法:将40只SD大鼠随机分为对照组、模型组、丹酚酸B组和阳性对照组,每组10只。除对照组外,其余组大鼠采用烟熏联合气管内滴注脂多糖法建立慢阻肺大鼠模型。丹酚酸B组和阳性对照组腹腔注射丹酚酸B(50 mg/kg)和地塞米松(0.2 mg/kg),其余组注射生理盐水。AniRes2005动物肺功能分析系统检测各大鼠肺功能改变;大鼠肺水肿情况使用大鼠肺组织湿/干重比(W/D)检测;HE染色检测大鼠肺组织病理学变化;AB-PAS染色检测各组大鼠肺组织杯状细胞增生;免疫组化检测大鼠肺组织MUC5AC表达;Western blotting检测大鼠肺组织MUC5AC、RORγt、Foxp3和IL-13/STAT6通路中IL-13蛋白和STAT6(p-STAT6/STAT6)磷酸化水平;ELISA检测肺泡灌洗液(BALF)中TNF-α、TGF-β、IL-6、IL-10和IL-17A水平。结果:与对照组相比,模型组、丹酚酸B组和阳性对照组大鼠肺功能明显降低(P<0.05),W/D比值、肺组织病理学评分、AB/PAS阳性率明显升高(P<0.05),MUC5AC、RORγt、IL-13和p-STAT6/STAT6表达明显升高(P<0.05),肺泡灌洗液(BALF)中TNF-α、TGF-β、IL-6和IL-17A水平明显升高(P<0.05),Foxp3表达和IL-10水平明显降低(P<0.05);而与模型组相比,丹酚酸B组和阳性对照组大鼠肺功能明显改善(P<0.05),W/D比值、肺组织病理学评分、AB/PAS阳性率显著下降(P<0.05),MUC5AC、RORγt、IL-13和p-STAT6/STAT6表达明显降低(P<0.05),TNF-α、TGF-β、IL-6和IL-17A水平明显降低,Foxp3表达和IL-10水平明显升高(P<0.05)。结论:丹酚酸B可能通过抑制IL-13/STAT6通路和恢复Th17/Treg平衡对慢阻肺大鼠发挥保护作用。

Objective:To explore the effect of salvianolic acid B on chronic obstructive pulmonary disease(COPD)and its possible mechanism.Methods:Forty SD rats were randomly divided into control group,model group,salvianolic acid B group and positive control group,with 10 rats in each group.Except for the control group,the COPD models were established in other groups by exposure to cigarette smoke and intratracheal instillation of lipopolysaccharide.Rats in salvianolic acid B group and positive control group were intraperitoneally injected with salvianolic acid B(50 mg/kg)and dexamethasone(0.2 mg/kg),respectively.The control group and model group rats were injected with normal saline.The lung function was detected.The wet/dry weight ratio(W/D)was used to detect the pulmonary edema.The pathological changes of lung tissue were detected by HE staining.The proliferation of goblet cells was detected by AB-PAS staining.The expression of MUC5AC was detected by immunohistochemistry.The protein levels of IL-13,Foxp3,MUC5AC,RORγt and the phosphorylation level of STAT6(p-STAT6/STAT6)were detected by Western blotting.The levels of TNF-α,TGF-β,IL-6,IL-10 and IL-17A in alveolar lavage fluid(BALF)were determined by ELISA.Results:Compared with the control group,the lung function and the expressions of Foxp3 and IL-10 in model group,salvianolic acid B group and positive control group were significantly decreased,while the W/D ratio,lung histopathological score,AB/PAS positive rate,MUC5AC,RORγt,the expressions of IL-13 and p-STAT6,and the levels of TNF-α,TGF-β,IL-6 and IL-17A in BALF were significantly increased(P<0.05).Compared with the model group,the lung function in salvianolic acid B group and positive control group were significantly improved,the W/D ratio,lung histopathological score,AB/PAS positive rate,MUC5AC,RORγt,the expression of IL-13 and p-STAT6,and the expression of TNF-α,TGF-β,IL-6 and IL-17A were significantly decreased,while the expression of Foxp3 and IL-10 were significantly increased(P<0.05).Conclusion:Salvianolic acid B may exert a protective effect in COPD rats by inhibiting IL-13/STAT6 pathway and restoring the balance of Th17/Treg.