醉茄素A对金黄色葡萄球菌肺炎小鼠的抗炎作用

Anti-inflammatory effects of withaferin A in mice with staphylococcus aureus pneumonia

目的探究醉茄素A(withaferin A,WFA)对金黄色葡萄球菌肺炎小鼠的治疗作用及相关机制。方法将30只小鼠随机平均分为对照组、模型组和WFA治疗组。经鼻孔滴注金黄色葡萄球菌法构建金黄色葡萄球菌肺炎小鼠模型。WFA治疗组在造模后,每日腹腔注射5 mg/kg WFA,连续7 d。收集支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF),计数BALF中细胞,ELISA法检测BALF中IFN-γ、IL-6、TNF-α和IL-1β水平;收集肺组织,采用肺湿重/干重法评估肺水肿程度;HE染色法观察肺组织病理形态学表现;免疫组织化学染色观察CD177标记的中性粒细胞浸润情况和NLRP3表达,Western blot检测NLRP3炎症小体的主要成员NLRP3、ASC和cleaved caspase-1的表达水平。结果与模型组比较,WFA治疗组BALF中细胞总数减少且IFN-γ、IL-6、TNF-α和IL-1β水平降低,肺水肿减轻、肺组织中中性粒细胞浸润程度减轻、NLRP3、ASC和cleaved caspase-1的表达水平降低。结论WFA可改善金黄色葡萄球菌肺炎小鼠症状、降低炎症并减弱NLRP3炎症小体通路活性。

Objective To investigate the therapeutic effect of withaferin A(WFA)in Staphylococcus aureus pneumonia mice and its related mechanism.Methods 30 mice were randomly divided into the control,model,and WFA treatment groups.The mouse model of Staphylococcus aureus pneumonia was established by nostril instillation.The WFA treatment group was intraperitoneally injected with 5 mg/kg WFA for 7 consecutive days after modeling.Bronchoalveolar lavage fluid(BALF)was collected and cells in it were counted.The level of IFN-γ,IL-6,TNF-αand IL-1βin BALF was detected by ELISA.Lung tissue was collected.The degree of pulmonary edema was assessed by the lung wet weight/dry weight method.The pathological morphology of lung tissue was observed by HE staining.The infiltration of CD177 labeled neutrophils and the expression of NLRP3 was observed by immunohistochemical staining.The expression of NLRP3,ASC and Cleaved caspase-1,major members of the NLRP3 inflammasome,was detected by Western blot.Results Compared with the model group,the number of cells and the level of IFN-γ,IL-6,TNF-α,and IL-1βin BALF were decreased in the WFA group.The pulmonary edema and neutrophil infiltration in lung tissue,as well as the NLRP3,ASC,and cleaved caspase-1 expression,were also reduced in the WFA group.Conclusion WFA can attenuate symptoms,reduce inflammation,and inhibit the NLRP3 inflammasome pathway in mice with Staphylococcus aureus pneumonia.