抗KL-6抗体减弱博莱霉素诱导的肺纤维化

Bieomycin-induced pulmonary fibrosis is attenuated by anti-KL-6 antibody

目的探讨抗KL-6抗体对博莱霉素诱导的肺纤维化的预防作用及可能机制。方法用气管内滴注博莱霉素的方法制作小鼠肺纤维化模型，于滴注博莱霉素前2天开始雾化抗KL-6抗体，至滴注博莱霉素后第21天。通过支气管肺泡灌洗液细胞计数及分类评价肺部炎症情况，通过肺组织病理评分、羟脯氨酸含量评价肺纤维化情况。通过肺组织中KL6、转化生长因子β1（TGF—β1）、肝细胞生长因子（HGF）水平、I型和Ⅲ型胶原的表达及上皮细胞凋亡情况探讨其可能机制。结果预防性应用抗KL6抗体可显著降低第21天支气管啼泡灌洗液中的细胞总数及巨噬细胞、淋巴细咆数（P〈O．05）；降低第14、21天时的肺组织病理评分、羟脯氨酸含量及I型、Ⅲ型胶原的表达（P〈0．05）；降低各时间点上肺组织中KL-6、TGF-β1水平（P〈0．05）；升高第14、21天时HGF水平（P〈0．05）；减少各个时间点上的上皮细胞凋亡数（P〈0．05）。结论预防性应用抗KL-6抗体可减弱博莱霉素诱导的炎症和纤维化反应，其治疗效应可能是通过降低I型和Ⅲ型胶原的表达、增加HGF的产生、减少KL6和TGF—β1的产生、降低肺上皮细胞的凋亡而发挥作用。

Objective To assess the effect and mechanisms of antiLKL-6 antibody on bleomycin induced pulmonary fibrosis in mice. Methods Pulmonary fibrosis was induced in C57BL/6 mice by intratracheal instillation of bleomycin. Anti-KL-6 antibody was given from two days before bleomycin instillation to the 21st day after bleomycin instillation. I.ung inflammation was assessed by bronchoalveolar lavage fluid （BAI.F） differential cell count. Changes in tissue remodeling were evaluated by quantified pathological examination, measurement of hydroxyproline content. Collagen type and type II were detected by qRT-PCR, KL-6, transforming growth factor-β1 （TGF-β1）, and hepatocyte growth factor （HGF） in lung tissues were detected by ELISA,and epithelial apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Results Anti-KL 6 antibody significantly reduced the number of alveolar inflammatory cells, macrophages and lymphocytes in BAI.F on the 21st day after bleomycin instillation （ P 〈0.05）. On the 14th and 21st day, the histopathological changes of pulmonary fibrosis were attenuated and the increase of lung hydroxyproline content and collagen （type and type III ） mRNA expression induced by bleomycin were alleviated （ P 〈0.05）. Moreover, anti-KL 6 antibody down regulated the increased production of TGF-β1 and KL-6 and up-regulated the decreased production of HGF induced by bleomycin （ P 〈 0.05）. Epithelial apoptosis was also reduced by anti-KL-6 antibody （ P 〈 0.05 ）. Conclusions Anti KL-6 antibody attenuates bleomycin-induced pulmonary fibrosis, possibly through reducing the expression of collagen type I and type III , increasing HGF level, attenuating the production of KL-6 and TGF-β1 , and alleviating epithelial apoptosis.