脂多糖对人类风湿性关节炎滑膜细胞基质金属蛋白酶-9表达的影响

目的 研究脂多糖（LPS）对人类风湿性关节炎（RA）成纤维状滑膜细胞(FLS)基质金属蛋白酶-9（MMP-9）表达的影响。方法 明胶酶谱法测定MMP-9酶活性；Western blot法测定MMP-9蛋白的表达；RT-PCR法测定MMP-9 mRNA的表达。结果 LPS处理对FLS中MMP-9表达无显著影响；LPS刺激的U937细胞培养上清液可明显增强FLS 中MMP-9酶活性、蛋白分泌及mRNA表达；地塞米松可显著抑制上述变化，且其抑制作用随浓度的增加而增强。结论 LPS对FLS中MMP-9表达无直接影响，LPS刺激的U937细胞上清液使FLS中MMP-9表达增加，而地塞米松能抑制MMP-9的变化。

Effect of lipopolysaccharide on expression of matrix metalloproteinase-9 in human synoviocyte from patients with rheumatoid arthritis

AIM: To study the effects of lipopolysaccharide (LPS), the supernatant of U937 cells stimulated with LPS and dexamethasone on matrix metalloproteinase-9 (MMP-9) expression in the synoviocyte from patients with rheumatoid arthritis(RA). METHODS: Fibroblast-like cells (FLS) from the joint tissue of patients with rheumatoid arthritis were cultured and incubated for 24 h with LPS (1 mg.L-1) or the supernatant of U937 cells stimulated with LPS (1 mg.L-1) for 24 h. Dexamethasone was added to the supernatant of U937 cells and FLS was incubated for 24 h. The activity of MMP-9 was analyzed by gelatin zymography. Protein expression of MMP-9 was detected by Western blot using special polyclonal antibodies. The mRNA expression of MMP-9 was detected by RT-PCR. RESULTS: The expression of MMP-9 was not markedly changed in FLS treated with LPS. The MMP-9 activity, MMP-9 secretion and MMP-9 mRNA expression were significantly increased in FLS cultured with the supernatant from U937 cell treated with LPS. Dexamethasone markedly inhibited the activity, protein secretion and mRNA expression of MMP-9 in FLS cultured with the supernatant from U937 cell stimulated with LPS, and the inhibitory effects were increased as the concentration of dexamethasone increased. CONCLUSION: LPS did not directly affect the expression of MMP-9 in FLS, but it was found to indirectly cause the increase of MMP-9 expression in FLS by stimulating U937 cell. Dexamethasone was found to inhibit this increase of MMP-9 expression.