Isthmin 对博来霉素诱导肺纤维化小鼠胶原沉积及血管生成的影响

目的探讨Isthmin（ISM）对肺纤维模型小鼠肺部胶原沉积、血管新生的影响，为肺纤维化的防治提供理论依据。方法将昆明小鼠随机分成：对照组、模型组、ISM组3组，每组16只。博来霉素（BLM）气管内滴人制作小鼠肺纤维化模型，对照组（气管内注射0．9％NS＋尾静脉注入0．9％NS）、模型组（气管内注射BLM＋尾静脉注入0．9％NS）、ISM组（气管内注射BLM＋尾静脉注入Isthmin蛋白）。分别于第7天、14天、21天、28天取实验小鼠肺组织，病理切片苏木精-伊红染色（HE）染色观察肺结构变化，Masson染色了解肺部胶原沉积情况，CD31免疫组化观察对血管内皮细胞数目的影响。结果给予ISM蛋白可减轻小鼠肺结构破坏，减少肺部胶原沉积，血管内皮细胞数目增加。肺组织胶原纤维Masson染色经平均光密度比较，模型组与对照组第7、14、21和28天差异具有统计学意义（P〈0．01）；Isthmin组与模型组比较，第21天和28天差异具有统计学意义（P〈0．01）；肺组织CD31蛋白平均光密度比较，模型组与对照组第14天、21天和28天差异显著（P〈0．05）、第7天差异具有统计学意义（P〈0．01），Isthmin组与模型组比较，第21天和28天差异具有统计学意义（P〈0．05）。结论ISM蛋白可减轻肺纤维化程度，但不是通过抑制血管形成实现的。

Influence of Isthmin on collagen deposition and angiogenesis in mouse with bleomycin-induced pulmonary fibrosis

Objective To investigate the effect of Isthmin （ISM） on collagen deposition and angiogenesis in mouse with pulmonary fibrosis, and in order to provide the theory basis for the prevention of pulmonary fibrosis. Methods KM mice were randomly divided into 3 groups （ n = 16） ： control group, model group, ISM group. The pulmonary fibrosis mouse model was produced by intratracheal instillation of bleomycin （BLM）. The experimental mouse were injected recombinant ISM by tail vein. Control group （intratracheal instillation of 0.9% NS ＋ tail vein of 0.9% NS）, model group（ intratracheal instillation of BLM ＋ tail vein of 0.9% NS）, ISM group （intratracheal instillation of BLM ＋ tail vein of ISM）. 7, 14, 21, 28 days after exposure, respectively, lung tissue of mouse were taken out for pathological observation ： hematoxylin and eosin （HE） staining for changes in the structure of the lungs, Masson staining for lung collagen deposition, immunohistochemistry （determination of CD31 protein level ） for endothelial. Results ISM can reduce structural damage to the mouse lungs and lung collagen deposition, number of endothelial was increased. There was very statistically significant difference of the average optical density of lung tissue collagen fiber by Masson staining between model group and control group after 7, 14, 21 and 28 days （ P 〈 0. 01 ） ; Isthmin group compared with model group, it had very statistically significant difference after 21 and 28 days （P 〈 0.01 ）. There was statistically significant difference of average optical density of lung tissue CD31 protein in model group and control group after 14 days, 21 days and 28 days（P 〈 0.05）, very statistically significant difference after 7 days（P 〈 0.01 ） , Isthmin group compared with model group, there was statistically significant difference after 21 and 28 days （P 〈 0.05）. Conclusions ISM can reduce pulmonary fibrosis, but it may not achieved by inhibiting angiogenesis.