清肺口服液黄酮类成分改善RSV感染小鼠肺上皮屏障损伤的机制研究

  目的  探讨清肺口服液黄酮类成分(Fla)对呼吸道合胞病毒(RSV)感染小鼠肺上皮屏障损伤的保护机制。  方法  将BALB/c小鼠随机分为正常组，模型组，Fla低、高剂量组(30、60 mg·kg-1·d-1)，阳性药利巴韦林组(46 mg·kg-1·d-1)。建立RSV感染的小鼠模型, 持续给药4 d后, HE染色观察肺组织病理学变化; ELISA检测肺泡灌洗液(BALF)中白介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的含量; 以BALF蛋白含量和BALF/血清荧光比评估肺上皮通透性; Western blot检测肺组织紧密连接蛋白-1(Claudin-1)、闭合蛋白(Occludin)、闭锁小带蛋白-1(ZO-1)、p38丝裂原活化蛋白激酶(p38 MAPK)、p-p38 MAPK、Toll样受体4(TLR4)、髓样分化因子88(MyD88)的蛋白表达。  结果  与模型组相比, Fla高、低剂量组小鼠肺组织病理损伤减轻(P < 0.05, P < 0.01), BALF中IL-1β、TNF-α含量下降(P < 0.05, P < 0.01), BALF蛋白含量和BALF/血清荧光比降低(P < 0.05, P < 0.01), 肺组织中Claudin-1、Occludin、ZO-1蛋白表达升高(P < 0.05, P < 0.01), p-p38 MAPK/p38 MAPK、TLR4、MyD88蛋白表达下降(P < 0.05, P < 0.01)。  结论  Fla可能通过抑制TLR4/MyD88/p38 MAPK通路, 促进紧密连接蛋白表达, 减轻肺部炎症, 从而改善RSV导致的肺上皮屏障损伤。 

Mechanism of Qingfei Oral Liquid Flavonoids in Improving Lung Epithelial Barrier Damage in RSV-Infected Mice

  OBJECTIVE  To investigate the protective mechanism of flavonoids in Qingfei Oral Liquid(Fla) on pulmonary epithelial barrier damage in respiratory syncytial virus (RSV)-infected mice.  METHODS  BALB/c mice were randomly divided into normal group, model group, low- and high-dose groups of flavonoids in Fla(30, 60 mg·kg-1·d-1), positive drug ribavirin group (46 mg·kg-1·d-1). RSV-infected mice model was established. After continuous administration for 4 d, the pathological changes of lung tissue were observed by HE staining; ELISA was used to detect the contents of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α); Protein content in BALF and BALF/serum fluorescence ratio were used to evaluate lung epithelial permeability; Western blot was used to detect the protein expression of Claudin-1, Occludin, ZO-1, p38 mitogen-activated protein kinase (p38 MAPK), p-p38 MAPK, TLR4 and Myd88 in lung tissue.  RESULTS  Compared with the model group, the lung pathological damage in Fla group was alleviated (P < 0.05, P < 0.01), the contents of IL-1β and TNF-α in BALF decreased (P < 0.05, P < 0.01), the protein content in BALF and the ratio of BALF/serum fluorescence decreased (P < 0.05, P < 0.01), the levels of Claudin-1, Occludin and ZO-1 in the lung tissue increased (P < 0.05, P < 0.01), the protein expression of p-p38 MAPK/p38 MAPK, TLR4 and Myd88 decreased (P < 0.05, P < 0.01).  CONCLUSION  Fla might inhibit the TLR4/MyD88/p38 MAPK pathway, increase the tight junction protein, and reduce lung inflammation, thereby improving the lung epithelial barrier damage caused by RSV.