博莱霉素致肺间质成纤维细胞MMP-2/TIMP-1表达失衡

观察博莱霉素对肺间质成纤维细胞中基质金属蛋白酶-2（MMP-2）及组织金属蛋白酶抑制剂-1（TIMP-1）表达的影响，探讨博莱霉素引起肺纤维化的机制。体外培养肺间质成纤维细胞，并向培养基中加入博莱霉素，在作用不同时间后收集样本，采用酶谱图测定细胞培养上清液中MMP-2酶活性、ELISA测定TIMP-1量，免疫组织化学法检测细胞中MMP-2、TIMP-1的原位表达，RT-PCR法检测MMP-2和TIMP-1的mRNA水平。结果发现，博莱霉素在2h、12h促进MMP-2的分泌，24h后无促分泌作用；而2-48h，MMP-2的原位表达及mRNA均不受博莱霉素的影响；博莱霉素从12h开始促进TIMP-1及mRNA的表达，并持续至48h。结果表明博莱霉素可引起肺间质戍纤维细胞MMP-2／TIMP-1表达失衡，并可能参与肺纤维化的发生。

Bleomycin Induced Imbalance of MMP-2/TIMP-1 in Pulmonary Interstitial Fibroblasts

To investigate the effect of bleomycin on the expression of matrix metalloproteinase-2 (MMP- 2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in pulmonary interstitial fibroblasts. Pulmonary interstitial fibroblasts were primary cultured, then treated with bleomycin-A5. MMP-2 activity in medium was determined by gelatin zymography. Protein content of TIMP-1 in medium was detected by ELISA. Intracellular protein content of MMP-2 and TIMP-1 were detected by immunocytochemistry. Expression of MMP-2 and TIMP-1 mRNA were determined by RT-PCR. The results showed BLM-A5 induced secreting of MMP-2 from pulmonary interstitial fibroblasts at 2 h and 12 h, and there was no effect after 24 h. Intracellular proteins and mRNA of MMP-2 were not influenced by BLM-A5 from 2 h to 48 h. BLM-A5 up-regulated the expression of protein and mRNA of TIMP-1 after 12 h. The results demonstrated that BLM-A5 induced secreting of MMP-2 in early stage in pulmonary intersti- tial fibroblasts, and then up-regulate the expression of TIMP-1. These maybe contributed to the mechanism of MMP-2/TIMP-1 imbalance in pulmonary fibrosis.