EMMPRIN基因沉默对巨噬/泡沫细胞中MMP-9表达及单核细胞迁移能力的影响

目的:观察细胞外基质金属蛋白酶诱导因子(EMMPRIN)基因沉默对巨噬/泡沫细胞中基质金属蛋白酶9(MMP-9)表达以及单核细胞迁移能力的影响。方法:根据RNA干扰原理,设计合成EMMPRIN-siR-NA。通过荧光定量PCR和Western blotting观察巨噬、泡沫细胞中EMMPRIN基因和蛋白被抑制情况。采用West-ern blotting观察特异性抑制EMMPRIN表达对巨噬、泡沫细胞中MMP-9蛋白表达的影响,通过迁移实验观察特异性抑制EMMPRIN表达对单核细胞迁移能力的影响。结果:采用EMMPRIN-siRNA转染巨噬、泡沫细胞,抑制细胞内EMMPRIN的基因和蛋白表达(P0.01)后使巨噬、泡沫细胞中MMP-9的蛋白表达减少了50%和40%。此外特异性抑制EMMPRIN表达使单核细胞在趋化因子MCP-1、VEGF趋化诱导下迁移能力明显减弱(P0.05)。结论:EMMPRIN基因沉默使巨噬、泡沫细胞中MMP-9的蛋白表达明显减少、活性明显减弱同时使单核细胞的趋化迁移能力降低。由此可见EMMPRIN在MMP的表达、活化及单核细胞迁移中扮演重要角色,可能成为防治动脉粥样硬化新的治疗靶点。

EMMPRIN mediates matrix metalloproteinase 9 expression and monocyte migration:evidence from EMMPRIN knockdown by RNA interference

AIM: Although the evidence indicates that extracellular matrix metalloproteinase inducer (EMMPRIN) is closely associated with matrix metalloproteinase (MMP) expression in tumor cells, tumor invasion and metastasis, no direct proof that EMMPRIN regulates MMPs in monocytes, especially in the atherogenic milieu is observed. Here we tested this hypothesis by examining MMP-9 expression in macrophages/foam cells and monocyte migration through EMMPRIN knockdown by siRNA. METHODS: The methods of qPCR and Western blotting were used to detect the suppressions of EMMPRIN mRNA and protein expression in macrophages and foam cells transfected with EMMPRIN-specific siRNA. The protein expression of MMP-9 in macrophages and foam cells was also determined. Monocyte migration after EMMPRIN knockdown was observed by a Transwell assay. RESULTS: EMMPRIN knockdown by siRNA markedly abolished the MMP-9 expression by 50% and 40% in macrophages and foam cells, respectively. Migration induced by chemotactic factor MCP-1 and VEGF was significantly attenuated (P<0.05) in monocytes treated with EMMPRIN-siRNA. CONCLUSION: The protein expression and secretion of MMP-9 are down-regulated by EMMPRIN knockdown during monocyte differentiation into macrophages and foam cells. Moreover, EMMPRIN siRNA treatment also prevents monocyte migration. Thus, EMMPRIN plays a key regulatory role for MMP activity and monocyte migration, making it a potential target for pharmacological intervention of atherosclerosis.