染矽小鼠体内KL-6含量与肺纤维化关系

Correlation between pulmonary fibrosis and KL-6 level in silica-treated mice

目的 探讨染矽小鼠血液及支气管肺泡灌洗液（BALF）中涎液化糖链抗原-6（KL-6）含量与肺纤维化关系。方法 雌雄各半的60只C57BL/6小鼠,随机分为染矽组和对照组,染矽组经气管滴入二氧化硅,对照组滴入生理盐水;各组小鼠于染硒后30、45、60、75、90 d分批处死,收集血液和BALF检测KL-6含量;肺组织切片行Masson胶原染色,显微镜评估肺纤维化程度。结果 染矽组小鼠染硒45~90 d肺组织出现胶原沉积;与染矽45 d小鼠比较,染矽60、75、90 d小鼠肺纤维化评分值均显著增加（P〈0.01）;染矽60、75、90 d小鼠血液KL-6含量明显高于对照组和染矽45 d小鼠（P〈0.01）;染矽75、90 d小鼠BALF中KL-6含量明显高于对照组和染矽60 d小鼠（P〈0.01）;小鼠血液及BALF中KL-6含量与纤维化评分值呈正相关（r=0.866、0.737,P〈0.01）。结论 小鼠染矽45~90 d出现肺纤维化,血液及BALF中KL-6含量与肺纤维化程度呈正相关。

Objective To investigate the correlation between pulmonary fibrosis and Krebs yon den lungen-6 （KL-6） level in serum and bronchoalveolar lavage fluid （BALF） in mice exposed to silica. Methods Sixty C57BL/6 mice（ half male and half female）were divided randomly into silica-treated group and control group. The mice in silicatreated group were injected with silica suspension and those in the control with normal saline through trachea. The mice were sacrificed at 30th,45th,60th ,75th, and 90th day after the silica exposure. KL-6 in the serum and BALF was determined with enzyme-linked immunosorbent assay（ELISA）. The lung tissues were fixed and stained with Masson stain for the evaluation of pulmonary fibrosis. Results Collagen deposition in lung tissue was observed as early as 45 days after the silica exposure. Compared with the mice 45 days after the silica-treatement,the scores of pulmonary fibrosis were all significantly increased for the silica-treated mice at 60th ,75th, and 90th day after the exposure（ P 〈 0. 01 for all）. For the mice of 60,75 and 90 days after the silica-treatment,the serum KL-6 levels were obviously higher than that of the control and the mice of 45 days after the silica-exposure （P 〈 0. 01 ）. For the mice of 75 and 90 days after the silica-treatment, the KL-6 levels in BALF were obviously higher than those of the control and silica-treated mice 60 days after the exposure （P 〈0. 01 for all） and serum and BALF KL-6 levels were positively correlated with the scores of pulmonary fibrosis （r = 0. 866 or 0. 737 ,P 〈 0. 01 ）. Conclusion Pulmonary fibrosis occurs 45 days after silica exposure and serum and BALF KL-6 level is positively correlated with the severity of pulmonary fibrosis in mice.