【摘要】 目的:通过构建二氧化硅诱导动物矽肺模型,探讨中性粒细胞胞外诱捕网（neutrophil nxtracellular traps,NETs）在矽肺中可能的作用。方法:将C57BL/6J雄性小鼠完全随机分为磷酸盐缓冲液（phosphate buffered solution,PBS）组、脱氧核糖核酸酶Ⅰ（deoxyribonuclease Ⅰ, DNase Ⅰ）组、二氧化硅+PBS组、二氧化硅+DNase Ⅰ组。通过气管内滴注二氧化硅（0.2 g/kg）混悬液构建小鼠矽肺模型,PBS组与DNase Ⅰ组注入等体积的PBS。在二氧化硅（silicon dioxide,SiO₂）混悬液注入后的第0小时、10小时小鼠气管内注入DNase Ⅰ（5 mg/kg）,以后DNase Ⅰ持续给药:5 mg/kg/day,直到SiO₂混悬液注入后的28天。二氧化硅（SiO₂）干预28天后,取各组小鼠肺组织与肺泡灌洗液,通过PicoGreen荧光染料检测支气管肺泡灌洗液（bronchoalveolar lavage fluid,BALF）中NETs水平,酶联免疫吸附实验（enzyme-linked immunosorbent assay, ELISA）检测BALF中转化生长因子β1 （transforming growth factor-β1,TGF-β1）与炎症因子白细胞介素6（interleukin-6,IL-6）、白细胞介素1β（interleukin-1β,IL-1β）、肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）水平,HE染色和Masson染色观察肺组织的病理学变化,Western Blot检测肺组织中NETs特异性组分瓜氨酸化组蛋白3（citrullinated-histone3,Cit-H3）表达。结果:SiO₂干预28天后,与PBS组相比,二氧化硅+PBS组小鼠肺组织炎症损伤加重,BALF中促炎介质IL-1β、IL-6、TNF-α水平上升;肺组织发生纤维化,大量硅结节形成;肺组织中Cit-H3蛋白表达量增加,BALF中NETs水平显著升高。予以NETs抑制剂DNase Ⅰ进行干预后,肺组织NETs水平显著下降,二氧化硅诱导的肺部炎症损伤、纤维化显著减轻。结论:NETs水平升高可能介导了二氧化硅诱导的小鼠矽肺模型肺部炎症损伤与纤维化。更多还原

【Abstract】 Objective: To explore the possible roles of NETs in the silicosis via constructing silica-induced silicosis animal models. Method（s）: Male C57 BL/6 mice were randomly assigned to four groups: 1) PBS group（PBS, n=20）; 2) DNase Ⅰ group（DNase Ⅰ,n=20）; 3) silica + PBS group（SiO₂+PBS, n=20）; 4) silica + DNase Ⅰ group（SiO₂+ DNase Ⅰ, n=20）. After anesthesia, mice were instilled with a single intratracheal dose of SiO₂ at 0.2 g/kg. The same dose of PBS was served as vehicle control. After SiO₂ treatment, mice was treated with DNase Ⅰ（5 mg/kg, once per day）. Lung tissue samples and bronchoalveolar lavage fluid（BALF）were collected at 28 day after SiO₂ treatment. Part of the left lung were collected for hemotoxylin and eosin（HE） staining, Mason staining. The IL-1β, IL-6 and TGF-β1 in BALF were measured by ELISA. The free DNA（cf-DNA/NETs） level in BALF was detected by PicoGreen fluorescent dye.The expression of Cit-H3 in lung tissue were measured by Western blot. Result（s）: Compared with the PBS group, after 28 days of SiO₂ intervention, the lung tissue of silica group showed severe inflammation injury and fibrosis, a large number of silica nodules were formed,and the levels of NETs, IL-1β, IL-6 and TGF-β1 in the lung tissue were significantly increased. After intervention with DNase Ⅰ, the levels of NETs in lung tissue were significantly decreased, and silica-induced lung inflammation injury and fibrosis were significantly reduced. Conclusion（s）: The increase of NETs may mediate the lung inflammation and fibrosis in silica-induced silicosis.更多还原