虫草素调节MAPK/AP-1信号通路对慢性阻塞性肺疾病大鼠肺组织损伤的影响

Effects of cordycepin on lung tissue injury in rats with chronic obstructive pulmonary disease by regulating MAPK/AP-1 signal pathway

目的 基于丝裂原活化蛋白激酶(MAPK)/激活蛋白-1(AP-1)信号通路探讨虫草素(Cor)对慢性阻塞性肺疾病大鼠肺组织损伤的改善作用。方法 利用烟熏联合脂多糖滴入气管的方法建立慢性阻塞性肺疾病大鼠模型,将造模大鼠随机分为模型组(COPD)、虫草素低、中、高剂量组(Cor-L、M、H,10、20、50 mg/kg)、阳性对照组(NAC,0.5 g/kg),另设置正常培养的大鼠为对照组(NC)。使用肺功能仪检测大鼠肺功能指标呼气峰流速(PEF)、用力肺活量(FVC);HE染色观察大鼠肺组织病理学变化;对肺泡灌洗液白细胞进行计数分离;ELISA法检测肺泡灌洗液中TNF-α、IL-6和LTB4水平;微量法试剂盒检测肺组织中MDA、SOD、GSH-Px水平;Western Blot检测MAPK/AP-1信号通路蛋白表达。结果 与NC组比较,COPD组大鼠肺组织出现肺泡肿大,炎性细胞浸润等病理学变化,肺功能(PEF、FVC)、巨噬细胞比率、淋巴细胞比率、SOD、GSH-Px活性显著下降,白细胞数目、中性粒细胞比率、TNF-α、IL-6和LTB4水平、MDA含量、p-ERK/ERK、p-JNK/JNK、p-p38/p38、C-jun、C-fos蛋白表达显著上升(P<0.05);与COPD组比较,Cor各剂量组、NAC组大鼠肺组织病理学变化明显好转,肺功能(PEF、FVC)、巨噬细胞比率、淋巴细胞比率、SOD、GSH-Px活性显著上升,白细胞数目、中性粒细胞比率、TNF-α、IL-6和LTB4水平、MDA含量、p-ERK/ERK、p-JNK/JNK、p-p38/p38、C-jun、C-fos蛋白表达显著下降(P<0.05);NAC组与Cor-H组上述指标无显著差异(P>0.05)。结论 虫草素可以抑制MAPK/AP-1信号通路,减轻炎症反应和氧化应激,改善慢性阻塞性肺疾病大鼠肺组织病理损伤。

Objective To investigate the improvement of cordycepin(Cor)on lung tissue injury in rats with chronic obstructive pulmonary disease(COPD)based on the mitogen-activated protein kinase(MAPK)/activator protein-1(AP-1)signal pathway.Methods A rat model of chronic obstructive pulmonary disease was established by smoking combined with lipopolysaccharide dripping into the trachea.The model rats were randomly grouped into a model group(COPD),low,medium,and high dose cordycepin groups(Cor-L,M,H,10,20,50 mg/kg),positive control group(NAC,0.5 g/kg),and normal cultured rats were set as the control group(NC).The lung function indexes peak expiratory flow(PEF),forced vital capacity(FVC)of rats were measured by lung function instrument;HE staining was applied to observe the pathological changes of lung tissue in rats;the white blood cells of alveolar lavage fluid were counted and separated;the levels of TNF-α,IL-6,and LTB4 in alveolar lavage fluid were detected by ELISA;the levels of MDA,SOD,and GSH-Px in lung tissue were detected with the micro-method kit;and Western blot was applied to detect the expression of MAPK/AP-1 signal pathway protein.Results Compared with the NC group,the lung tissue of COPD group showed pathological changes such as alveolar swelling and inflammatory cell infiltration,the lung function(PEF,FVC),macrophage ratio,lymphocyte ratio,SOD and GSH-Px activities were lower,the number of white blood cells,neutrophil ratio,TNF-α,IL-6 and LTB4 levels,MDA content,p-ERK/ERK,p-JNK/JNK,p-p38/p38,C-jun,C-fos protein expression were higher(P<0.05);compared with COPD group, the pathological changes of lung tissue of rats in Cor groups and NAC group were improved, the lung function (PEF, FVC), macrophage ratio, lymphocyte ratio, SOD and GSH-Px activities were higher, the number of white blood cells, neutrophil ratio, TNF-α, IL-6 and LTB4 levels, MDA content, p-ERK/ERK, p-JNK/JNK, p-p38/p38, C-jun, C-fos protein expression were lower ( P <0.05);there was no obvious difference in the above indexes between NAC group and Cor-H group ( P >0.05). Conclusion Cordycepin can inhibit MAPK/AP-1 signal pathway, reduce inflammatory reaction and oxidative stress, and improve lung tissue pathological damage in rats with chronic obstructive pulmonary disease.