巨噬细胞移动抑制因子经Rho途径促进人肺成纤维细胞III型胶原合成

目的: 观察重组巨噬细胞移动抑制因子(rMIF)对人胚肺成纤维细胞(MRC-5)的作用,探讨哮喘气道重塑的发生机制。方法: 不同浓度的rMIF (25-100 μg/L)分别作用于MRC-5细胞48 h, RT-PCR法检测III型胶原mRNA表达,Western blotting检测III型胶原蛋白合成; 100 μg/L rMIF刺激MRC-5细胞48 h,刺激前0.5 h加入Rho激酶特异性抑制剂Y27632, RT-PCR法检测III型胶原mRNA表达,Western blotting法检测III型胶原蛋白表达。结果: 刺激MRC-5细胞48 h,rMIF可呈剂量依赖地诱导III型胶原mRNA(P<0.01)和蛋白(P<0.01)表达。Y27632预刺激后,显著抑制rMIF100μg/L诱导的III型胶原mRNA和蛋白表达(均P<0.01)。结论: MIF可能通过Rho途径刺激人肺成纤维细胞III型胶原合成,从而在哮喘气道重塑的发病机制中发挥重要作用。

Recombinant MIF induces synthesis of collagen type III in lung fibroblasts via Rho-kinase

AIM: To investigate the effects of recombinant macrophage migration inhibitory factor (rMIF) on the synthesis of collagen type III in fibroblasts.METHODS: The MRC-5 fibroblasts were divided into 2 groups.The cells in treatment group were exposed to rMIF at the concentrations of 25-100 μg/L for 48 h. The cells without rMIF treatment served as control group. Half an hour before challenging with rMIF (100 μg/L), Y27632 (a Rho-kinase inhibitor) was added to the cells in both 2 groups. After challenged for 48 h, total RNA and protein in the cells were extracted. The expression of collagen type III at mRNA and protein levels was analyzed by RT-PCR and Western blotting, respectively.RESULTS: Different concentrations of rMIF significantly increased the expression of collagen type III at mRNA and protein levels in a dose-dependent manner as compared with the control cells (r=0.862 and r=0.914; all P<0.01). These increases were abolished by Y27632 pretreatment(P<0.01).CONCLUSION: rMIF increases the synthesis of collagen type III in MRC-5 cells and Rho-kinase regulates the MIF-induced synthesis of collagen, suggesting that MIF may play important roles in the pathogenesis of airway remodeling.