芝麻素通过AMPK/NLRP3信号通路缓解哮喘小鼠气道炎症的作用机制

Sesamin alleviates airway inflammation in asthma through AMPK/NLRP3 signaling pathway

目的探讨芝麻素通过AMPK/NLRP3信号通路缓解卵清蛋白(ovalbumin,OVA)诱导的哮喘小鼠模型的气道炎症。方法将40只雄性清洁级Balb/c小鼠,随机分为5组,分别为正常组(control)、OVA模型组、芝麻素低剂量组(50 mg/kg)、芝麻素高剂量组(100 mg/kg)、阳性对照地塞米松(dexamethasone,DEX)治疗组(1 mg/kg),每组8只。使用Diff-Quick染色法对每组小鼠肺泡灌洗液(BALF)中的各种炎症细胞进行分类、计数;小鼠BALF中IL-4、IL-5、IL-13、IFN-γ的含量使用ELISA法进行检测;流式细胞术测定小鼠肺组织CD4阳性细胞群中细胞因子的阳性百分率;对各组小鼠的肺组织进行HE、PAS染色,并观察其病理学改变;对小鼠肺组织进行免疫组织化学染色,观察NLRP3蛋白的表达分布情况;Western blot方法检测AMPK、p-AMPK、NLRP3、Caspase-1、ASC和IL-1β蛋白表达水平。结果芝麻素能够减少OVA引起的哮喘小鼠BALF中各种炎症细胞数量,降低小鼠BALF中IL-4、IL-5、IL-13的含量,提高IFN-γ的表达水平。通过芝麻素治疗后可抑制哮喘小鼠肺组织中炎性细胞浸润和气道上皮杯状细胞产生和黏液分泌,增加肺组织中p-AMPK的表达,降低NLRP3、Caspase-1、ASC和IL-1β蛋白表达,在哮喘小鼠肺组织中,Th2细胞因子IL-4水平降低,Th1细胞因子IFN-γ水平升高,恢复Th1/Th2平衡。结论芝麻素可以减轻哮喘小鼠气道炎症反应,其机制可能与AMPK/NLRP3信号通路有关。

This study was designed to investigate the effect of sesamin on airway inflammation in allergic asthmatic mice and the role of AMPK/NLRP3 signaling pathway in this process.Total of 40 female Balb/c mice were recruited and randomly divided into control group,OVA model group,sesamin low-dose(50 mg/kg)group,sesamiin high-dose(100 mg/kg)group and dexamethasone(DEX)positive control group(1 mg/kg).Diff-Quick staining was used to count inflammatory cells in bronchoalveolar lavage fluid(BALF)of mice in each group;ELISA was used to detect the contents of IL-4,IL-5,IL-13,and IFN-γin BALF of mice;flow cytometry was used to determine the positive proportion of cytokines in the CD4+cell population of mouse lung tissues;HE and PAS staining were used to observe the histopathological changes in the lungs of mice;immunohistochemical staining was used to observe the expression and distribution of NLRP3 protein in the lungs;and Western blot assay was used to detect the expression levels of AMPK,p-AMPK,NLRP3,caspase-1,ASC,and IL-1βproteins.Data showed that sesamin could reduce the number of inflammatory cells,decrease the contents of IL-4,IL-5 and IL-13,and increase the expression of IFN-γin BALF of OVA-induced asthmatic mice.Sesamin treatment inhibited inflammatory cell infiltration and airway epithelial goblet cell production and mucus secretion,increased the expression of p-AMPK,and decreased NLRP3,caspase-1,ASC,and IL-1βprotein expression in lung tissue of asthmatic mice.After sesamin treatment,the level of Th2 cytokine IL-4 was decreased,the level of Th1 cytokine IFN-γwas increased,and the Th1/Th2 balance was restored.In summary,sesamin can alleviate airway inflammation in asthmatic mice,and the mechanism may be related to the AMPK/NLRP3 signaling pathway.