Abstract: Objective To investigate the possible mechanism of high mobility group box 1 (HMGB1) involved in the regulation of asthma-related inflammatory cytokines in bronchial epithelial cells. Methods Twenty female mice (BALB/c strain) were randomly divided into control and asthma group.An asthmatic mouse model was established by intraperitoneal injection and aerosol inhalation of ovalbumin.16-HBE cells with different treatments were divided into six groups:control group,HMGB1 group (100 ng/mL,200 ng/mL,500 ng/mL),500 ng/mL HMGB1+AG490 group,500 ng/mL HMGB1+ Rapamycin group.The hematoxylin-eosin staining was used to observe the mice airway structural changes.The mRNA and protein expression of HMGB1 in lung tissue of mice was measured by RT-PCR and immunohistochemistry,respectively.The level of HMGB1 in the supernatants of the BALF and the levels of TNF-α,IL-6 and IL-1α in all cells were measured by ELISA,while the protein expressions of p-JAK2 and p-STAT3 were measured by Western blot. Results Compared with normal control group,the expression of HMGB1 in BALF and in the lung tissue of asthma group were significantly increased.HMGB1 increased the levels of TNF-α,IL-6 and IL-1α,upregulated the protein levels of p-JAK2 and p-STAT3 in a dose-dependent manner.Pretreatment with AG490 and Rapamycin significantly inhibited the expressions of p-JAK2 and p-STAT3,decreased the levels of TNF-α,IL-6 and IL-1α. Conclusion HMGB1 could regulate the inflammatory response in asthma,which may be related to the promotion of asthma-related inflammatory cytokines in bronchial epithelial cells via activating JAK2/STAT3 pathways.

Key words: high mobility group box 1, bronchial epithelial cells, JAK2/STAT3, asthma, inflammatory cytokines

摘要： 目的 探讨高迁移率族蛋白B1(HMGB1)参与调节支气管上皮细胞分泌哮喘相关炎症因子的机制。方法 20只雌性BALB/c小鼠随机分对照组和哮喘组,采用卵清蛋白腹腔注射致敏联合雾化吸入激发建立哮喘小鼠模型。支气管上皮细胞16-HBE分组处理:空白对照组,HMGB1组(浓度分别为100、200、500 ng/mL),500 ng/mL HMGB1+AG490组,500 ng/mL HMGB1+雷帕霉素组。HE染色观察小鼠气道结构;qRT-PCR和免疫组化法检测两组小鼠肺部组织HMGB1的表达;ELISA法测定两组小鼠支气管肺泡灌洗液(BALF)上清中HMGB1的含量和各组细胞上清液中肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和白细胞介素-1α(IL-1α)水平。Western blot检测各组细胞中p-JAK2和p-STAT3的蛋白水平。结果 哮喘组小鼠HMBG1的表达比正常小鼠明显升高。HMGB1升高细胞中TNF-α、IL-6和IL-1α水平,上调p-JAK2和p-STAT3水平,并且呈现浓度依赖性关系。AG490和雷帕霉素处理抑制细胞中p-JAK2和p-STAT3表达,同时降低TNF-α、IL-6和IL-1α水平。结论 HMGB1参与调控哮喘慢性炎症反应,可能与活化JAK2/STAT3信号通路促进支气管上皮细胞分泌炎症因子有关。

关键词: 高迁移率族蛋白B1, 支气管上皮细胞, JAK2/STAT3, 哮喘, 炎症因子