Yahefu Reyila, Abudureyimu Mairemugu, Wang Qin, Li Ruisheng, Mu Qingshuang
The Second Affiliated Hospital of Xinjiang Medical University Geriatrics (cadre ward), Urumqi 830063, China.
The Second Affiliated Hospital of Xinjiang Medical University Geriatrics (cadre ward), Urumqi 830063, China. *Corresponding author, E-mail:
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2022 Aug;38(8):685-691.
Objective To explore the effect of down-regulation of high mobility group box 1 (HMGB1) expression on inflammatory response and epithelial mesenchymal transition (EMT) in the lung tissue of mice with chronic obstructive pulmonary disease (COPD) and its related mechanism. Methods The COPD model was induced by cigarette smoking, and HMGB1 expression in lung tissue of mice was down-regulated by small interfering RNA (siRNA). The mice were divided into negative control group (NC group), COPD group, si-NC intervention COPD group, si-HMGB1 intervention COPD group, and tiotropium bromide intervention COPD group (positive control group). After 4 weeks of cigarette smoking induction, the general condition of mice were observed, and the body mass changes of each group were recorded every week. HE staining was used to observe the pathological changes of lung tissue in each group. The expression of HMGB1 mRNA and protein in lung tissues of mice weredetected by real time quantitative PCR and Western blot analysis. The BALF of mice in each group was collected, and the levels of IL-6, TNF-α, IL-1β and TGF-β1 in BALF were detected by ELISA. The expressions of E-cadherin and α-SMA in lung tissues of mice were observed by immunohistochemical staining. The expression of RAGE, TLR4, TGF-β1 and the phosphorylation of NF-κB p65 in lung tissues were detected by Western blot analysis. Results COPD mouse model induced by cigarette smoking was successfully established. Compared with COPD group, down-regulation of HMGB1 expression in lung tissue significantly improved the general vital signs of mice, promoted the increase of body mass, and improved the pathological damage of lung tissue in mice. Compared with the control group, HMGB1 mRNA and protein expression levels increased significantly in COPD group, COPD combined with si-NC group and COPD combined with tiotropium group, while no significant HMGB1 expression was detected in COPD combined with si-HMGB1 group. Compared with the control group, the secretion levels of IL-6, TNF-α, IL-1β, TGF-β1 in BALF, the expression levels of α-SMA, RAGE, TLR4, TGF-β1 and the phosphorylation level of NF-κB p65 in lung tissues were significantly increased in COPD model group, while the expression level of E-cadherin significantly decreased. Compared with the COPD group or the COPD combined with si-NC group, the changes of the above indexes in the lung tissue of mice in the COPD combined with si-HMGB1 group and the COPD combined with tiotropium group dropped markedly, and no significant difference between the latter two groups was found. Conclusion Downregulation of HMGB1 expression in lung tissue of mice can reduce pulmonary inflammatory response and EMT by inhibiting NF-κB pathway, thus ameliorating the progression of cigarette smoke-induced COPD disease.
目的 探讨下调高迁移率族蛋白B1（HMGB1）表达对慢性阻塞性肺疾病（COPD）小鼠肺组织炎症反应及上皮-间质转化（EMT）的影响及其相关机制。方法 采用香烟烟雾诱导建立COPD模型，通过小干扰RNA（siRNA）下调小鼠肺组织中HMGB1表达。将小鼠分为阴性对照组（NC组）、COPD组、si-NC干预COPD组、si-HMGB1干预COPD组和噻托溴铵干预COPD组（阳性对照组）。香烟烟雾诱导4周后，观察小鼠一般情况，每周记录各组小鼠体质量变化。采用苏木精-伊红（HE）染色观察各组肺组织病理变化。采用实时定量PCR和蛋白质印迹法检测小鼠肺组织中HMGB1 mRNA和蛋白表达。收集各组小鼠支气管肺泡灌洗液（BALF），采用酶联免疫吸附测定（ELISA）法检测BALF中白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和转化生长因子-β1（TGF-β1）水平。采用免疫组织化学染色观察小鼠肺组织中E-钙黏蛋白和α-平滑肌肌动蛋白（α-SMA）表达。采用蛋白质印迹法检测肺组织中晚期糖基化终末产物受体（RAGE）、Toll样受体4（TLR4）、TGF-β1表达及核因子-κB p65（NF-κB p65）磷酸化水平。结果 成功建立香烟烟雾诱导的COPD小鼠模型。与COPD组比较，下调肺组织中HMGB1表达可显著改善小鼠一般生命体征，促进体质量增加，减轻小鼠肺组织病理损伤。与对照组比较，COPD组、COPD联合si-NC组及COPD联合噻托溴铵组小鼠肺组织中HMGB1 mRNA及蛋白表达水平显著升高，而COPD联合si-HMGB1组未检测到明显的HMGB1表达。与对照组比较，COPD模型组小鼠BALF中IL-6、TNF-α、IL-1β、TGF-β1分泌水平，肺组织中α-SMA、RAGE、TLR4、TGF-β1表达水平及NF-κB p65磷酸化水平显著升高，而E-钙黏蛋白表达水平显著降低。与COPD组或COPD联合si-NC组比较，COPD联合si-HMGBl组和COPD联合噻托溴铵组小鼠肺组织上述指标变化明显下降，且后两组间差异无统计学意义。结论 下调小鼠肺组织中HMGB1表达可通过抑制NF-κB信号通路减轻肺部炎症反应及EMT进程，从而改善香烟烟雾诱导的COPD病情进展。
