真核起始因子(eIF6)对M2型巨噬细胞炎性介质表达的影响

Effects of e IF6 on the expression of pro-inflammatory mediators derived from M2 macrophages

目的探讨真核细胞起始因子(e IF6)基因对M2型巨噬细胞纤维化相关因子分泌及重要蛋白酶表达的影响。方法采用e IF6野生型(e IF6+/+)及敲降型(e IF6+/-)C57BL/6雄性小鼠,腹腔灌洗获得巨噬细胞,通过白介素4(IL-4)诱导形成M2型巨噬细胞。应用基因芯片比较e IF6+/+与e IF6+/-小鼠M2型巨噬细胞基因表达谱的差异,并通过RT-PCR及ELISA对芯片检测结果进行验证。结果基因芯片检测结果显示,与e IF6+/-小鼠组比,e IF6+/+小鼠M2型巨噬细胞中血管内皮生长因子(VEGF)及金属蛋白酶抑制剂2(TIMP-2)基因表达显著下调,基质金属蛋白酶2(MMP-2)基因表达显著上调。RT-PCR及ELISA检测结果显示,与e IF6+/-小鼠相比,e IF6+/+小鼠M2型巨噬细胞中VEGF、TIMP-2 m RNA及蛋白表达水平明显下降(P<0.05),而MMP-2 m RNA及蛋白表达水平明显上升(P<0.05)。结论 e IF6可能通过抑制VEGF生成而防止血管及肉芽组织过度增生,同时通过调节MMP-2/TIMP-2的比例以平衡细胞外基质的降解与沉积,从而缓解瘢痕形成。

Objective To explore the effects of eukaryotic translation initiation factor 6 （eIF6） on the expression of fibrotic cytokines and metabolic enzymes derived from M2 macrophages. Methods eIF6 wild type mice （eIF6＋/＋） and eIF6 knock out mice （eIF6＋/-） were used. Macrophages were collected from peritoneal lavage fluid, and they were stimulated with IL-4 for enrichment of M2 macrophages. The differential gene expressions of eIF6＋/＋ and eIF6＋/ M2 macrophages were studied with gene chip. The differential expression of genes was further confirmed with both RT-PCR and ELISA. Results The gene chip showed that the expressions of VEGF and TIMP-2 were down-regulated in eIF6＋/＋ macrophages compared with those in eIF6＋/ M2 macrophages, while the expression of MMP-2 was up-regulated in eIF6＋/＊ M2 macrophages （P〈0.05）. The result of RT-PCR and ELISA had confirmed that the RNA and protein expressions of VEGF and TIMP-2 were decreased in eIF6＋/＋ macrophages compared with those in eIF6＋/ M2 macrophages, while the RNA and protein expressions of MMP-2 were up-regulated in eIF6＋/＋ M2 macrophages （P〈0.05）. Conclusion eIF6 not only inhibits the expression of VEGE reduces angiogenesis and granulation tissue formation, but also enhances the extracellular matrix degradation and deposition by regulating the balance of MMPZ/TIMP2, and thus attenuating the degree of fibrosis （scar formation）.