基于TLR-2/MyD88/NF-κB通路探讨养阴清肺汤加味对肺炎支原体感染小鼠炎症的影响

Effect of Modified Yangyin Qingfei Decoction(养阴清肺汤加味)on Inflammation in Mice Infected with Mycoplasma Pneumoniae and TLR-2/MyD88/NF-κB Signaling Pathway

目的探讨养阴清肺汤加味(Yangyin Qingfei decoction plus,YQDP)对肺炎支原体(Mycoplasma pneumoniae,MP)感染小鼠炎症反应及Toll样受体2(Toll-like receptor 2,TLR-2)/髓样分化因子88(Myeloid differentiation factor 88,MyD88)/核转录因子-κB(Nuclear factor-κB,NF-κB)信号通路的影响。方法选取BALB/c小鼠60只,随机分为正常组、模型组、阿奇霉素组、YQDP低、中、高剂量组,每组10只,除正常组外均建立MP感染小鼠模型,模型建立成功后开始给药治疗并于第7天取材。采用HE染色法观察小鼠的肺部病理改变情况,ELISA法检测血清中白介素-6(Interleukin-6,IL-6)、IL-8(Interleukin-8)、IL-17(Interleukin-17)水平,RT-PCR法、Western blot法检测TLR-2、MyD88、NF-κB mRNA及蛋白表达水平。结果与正常组比较,模型组小鼠大部分肺泡结构破坏严重,完整肺泡较少,肺泡间隔明显增厚并可见大量炎性细胞,血清中IL-6、IL-8、IL-17含量明显升高(P<0.05),肺组织中TLR-2、MyD88、NF-κB mRNA及蛋白表达量升高(P<0.05)。与模型组比较,给予阿奇霉素、YQDP治疗后,小鼠肺组织病理显示肺泡结构有明显恢复,肺泡周围存在的炎性细胞浸润均有不同程度减少,血清中IL-6、IL-8、IL-17含量明显降低(P<0.05),肺组织中TLR-2、MyD88、NF-κB mRNA及蛋白表达量降低(P<0.05),并且YQDP治疗组的降低趋势与其低、中、高剂量呈现依赖性。结论YQDP可能通过调控TLR-2/MyD88/NF-κB信号通路,起到减轻MP感染小鼠肺部炎症作用。

Objective To investigate the effect of Modified Yangyin Qingfei Decoction(养阴清肺汤加味,YQDP)on the inflammatory response and Toll-like receptor 2(TLR-2)/myeloid differentiation factor 88(MyD88)/nuclear factor-κB(NF-κB)signaling pathwayin in mice infected with mycoplasma pneumoniae(MP).Methods BALB/c mice(n=60)were randomly divided into normal group,MP model group,azithromycin group,and low,medium and high dose groups of YQDP,models of MP infection were established except for the normal group.After successful modeling,all mice were treated for 7 days.The lung tissue and serum of mice was collected at the last administration.The lung pathological changes of lung tissue were observed by HE staining,the levels of interleukin-6(IL-6),interleukin-8(IL-8)and interleukin-17(IL-17)in serum were detected by ELISA,TLR-2,MyD88 and NF-κB mRNA and protein expression levels were detected by RT-PCR and Western blot.Results Compared with those of the normal group,the lung tissue of the model group was less intact,the most of the alveolar structures were seriously damaged,the alveolar septum was significantly thickened,and a large number of inflammatory cells were visible.The contents of IL-6,IL-8 and IL-17 in serum were significantly increased(P<0.05).The expressions of TLR-2,MyD88,NF-κB mRNA and protein in lung tissues were increased(P<0.05).Compared with those of the model group,after treatment,lung histopathology showed that the alveolar structure was significantly restored,and the inflammatory cell infiltration around the alveoli was reduced to varying degrees.The contents of IL-6,IL-8 and IL-17 in serum were significantly reduced(P<0.05).The expressions of TLR-2,MyD88,NF-κB mRNA and protein in lung tissues were decreased(P<0.05).The reduction trend of YQDP treatment group was dependent on its low,medium and high doses.Conclusions YQDP may reduce lung inflammation in MP-infected mice by regulating the TLR-2/MyD88/NF-κB signaling pathway.