MUC1抑制COPD中烟草烟雾诱导的黏液高分泌

MUC1 inhibits cigarette smoke-induced mucus hypersecretion in COPD

目的:探究黏蛋白1(MUC1)对烟草烟雾(CS)暴露诱导的慢性阻塞性肺疾病(COPD)中MUC5AC和MUC5B的表达影响。方法:(1)动物实验:健康SPF级雄性C57BL/6小鼠20只,随机分为空白对照组(n=10)和CS暴露组(n=10),采用CS暴露24周的方法建立COPD小鼠模型。建模结束后,检测小鼠肺功能;肺组织切片进行HE和PAS染色评估肺组织病理改变及气道杯状细胞增生情况;Western blot法检测肺组织MUC1蛋白水平;ELISA法检测支气管肺泡灌洗液中白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、MUC5AC和MUC5B的表达水平,以评估小鼠肺部炎症及黏液分泌情况。(2)细胞实验:用烟草烟雾提取物(CSE)处理人支气管上皮细胞系16HBE,通过Western blot、RT-qPCR和免疫荧光染色检测MUC1、MUC5AC和MUC5B的表达。用MUC1小干扰RNA(siRNA)和MUC1过表达质粒转染16HBE细胞以沉默和过表达MUC1,确定MUC1对MUC5AC和MUC5B表达的影响。结果:(1)CS组小鼠表现为类似COPD的病变,包括肺气肿、肺功能下降及气道炎症(P<0.05);(2)CS组小鼠气道杯状细胞增生显著增加(P<0.01),肺组织中MUC1及支气管肺泡灌洗液中MUC5AC和MUC5B的水平显著升高(P<0.05);(3)与对照组相比,CSE处理组的16HBE细胞中MUC1、MUC5AC和MUC5B表达水平显著升高(P<0.01);(4)通过siRNA沉默MUC1显著促进了CSE诱导的MUC5AC和MUC5B表达水平升高(P<0.05);而过表达MUC1则显著降低了CSE诱导的MUC5AC和MUC5B表达水平升高(P<0.05)。结论:CS诱导小鼠COPD发病过程中,MUC1表达增加并可抑制CSE诱导的黏液高分泌。

AIM:To investigate the effects of mucin 1(MUC1)on the expression levels of MUC5AC and MUC5B in chronic obstructive pulmonary disease(COPD)induced by cigarette smoke(CS)exposure.METHODS:Twenty healthy SPF male C57BL/6 mice were randomly divided into control group(n=10)and CS exposure group(n=10).A COPD mouse model was established by exposure to CS for 24 weeks.After model establishment,lung functions were tested.Lung sections were subjected to HE and PAS staining to evaluate the pathological changes of lung tissue and goblet cell hyperplasia in bronchi.The expression of MUC1 in lung tissue was detected by Western blot.The levels of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),MUC5AC and MUC5B in bronchoalveolar lavage fluid(BALF)were assayed by ELISA to evaluate the lung inflammation and mucus secretion.Furthermore,human bronchial epithelial cell line 16HBE was treated with cigarette smoke extract(CSE),and the expression levels of MUC1,MUC5AC and MUC5B were determined by Western blot,RT-qPCR and immunofluorescence.Small interfering RNA(siRNA)targeting MUC1 and MUC1-overexpressing plasmid were transfected into 16HBE cells to determine the effects of MUC1 on the expression levels of MUC5AC and MUC5B.RESULTS:The mice exposed to CS developed COPD-like abnormalities manifested by emphysema,lung function decline and lung inflammation(P<0.05).The hyperplasic airway goblet cells was significantly increased in CS group(P<0.01).The expression of MUC1 in lung tissue and the levels of MUC5AC and MUC5B in bronchoalveolar lavage fluid were significantly increased in CS group(P<0.05).In 16HBE cells,CSE treatment significantly increased the expression levels of MUC1,MUC5AC and MUC5B(P<0.01).Furthermore,knockdown of MUC1 expression by siRNA significantly increased the expression of MUC5AC and MUC5B upon CSE stimulation(P<0.05),while overexpression of MUC1 significantly reduced the overexpression of MUC5AC and MUC5B induced by CSE(P<0.05).CONCLUSION:Increased expression of MUC1 induced by CS exposure along with COPD development in mice can prevent CSE-induced mucus hypersecretion in bronchial epithelial cells.