在小鼠肺纤维化成纤维细胞表型转化过程中NF-κB的表达及其意义

Expression and Significance of Nuclear Factor-κB in Transformation of Fibroblast to Myofibroblast in Bleomycin-induced Mice Pulmonary Fibrosis

目的探讨平阳霉素(BLM)致小鼠肺纤维化病理过程中,核因子-κB(NF-κB)在成纤维细胞(FB)向肌成纤维细胞(MF)转化过程中的表达及其意义。方法将12只C57BL/6雌性小鼠随机分成2组,模型组气管内注射平阳霉素A2,对照组注射生理盐水;两组小鼠分别于气管内注射后第1及第3天随机取3只处死,用组织块贴壁法原代培养肺组织成纤维细胞,将第4代培养细胞分别进行P65及α-平滑肌肌动蛋白(α-SMA)免疫细胞化学染色,p65原位杂交染色,行图像分析,以平均光密度(MOD值)表示p65及α-SMA蛋白表达量及p65mRNA表达量。结果模型组、对照组p65免疫细胞化学染色的MOD值分别为(0.1055±0.0443)和(0.0521±0.0121);原位杂交染色的MOD值分别为(0.1659±0.0532)和(0.0753±0.0196);模型组、对照组α-SMA免疫细胞化学染色的MOD值分别为(0.1314±0.0247)和(0.0660±0.0026);模型组P65蛋白和α-SMA蛋白及p65mRNA表达量均较对照组增强(P<0.05);模型组P65蛋白及p65mRNA均与α-SMA蛋白表达呈正相关(r分别为0.764和0.626,P<0.05)。结论在平阳霉素诱导的肺间质纤维化病理过程中,存在着成纤维细胞向肌成纤维的表型转化,这一转化可能对肺间质纤维化的形成具有重要作用;NF-κB活化可能在成纤维细胞向肌成纤维细胞转化中起关键的调节作用,并因此在肺间质纤维化中发挥重要的作用。

OBJECTIVE To investigate the expression and the significance of nuclear factor -κB （NF-κB） in the transformation of fibroblast to rnyofibroblast in pathological process of the bleomycin-induced mice pulmonary fibrosis. METHODS Twelve female C57BL/6 mice were randomly divided into two groups Model group which mice were treated with bleomycin A2 by intratracheal injection and Control group which mice were treated with sterile isotonic saline by intratracheal injection. At the first and the third days after animal model established were selected three mice from each group randomly. Fibroblasts were primarily cultured by using tissue explant culture technique and were subcultured 4 passages, p65 And α-SMA protein expression of Fb in the 4th cultures were detected by immunocytoehemical staining, p65 mRNA expression of Fb in the 4th cultures was detected by in situ hybridization staining. Image analysis, p65 protein and α-SMA protein and p65mRNA amount were expressed by the mean optical density value （MOD value）. RESULTS The MOD values of p65 in the model group and the control group with the immunocytoehemical staining were （0. 1055±0. 0443） and （0. 0521±0. 0121）; the MOD values in situ hybridization staining were （0. 1659±0. 0532） and （0. 0753±0. 0196） ; the MOD values of mSMA in the model group and the control group were （0. 1314±0. 0247） and （0. 0660±0. 0026）. The expression of p65 protein, α-SMA protein and p65 mRNA in the model group was higher than those in the control group （P〈 0.05）. P65 protein and p65 mRNA expression were positively correlated with α-SMA protein in the model group （r=0. 764 and 0. 626, P〈0.05）. CONCLUSIONS In the pathological process of bleomycin-indueed pulmonary fibrosis, the phenotypic transformation of fihroblasts to myofibroblasts is existed. This transformation may play an important role in the formation of pulmonary fibrosis. The activation of nuclear factor-κB may play a key regulatory role in the transformation of fibroblasts to myofibroblasts and, therefore, play an important role in the process of pulmonary fibrosis.