脂多糖对人类风湿性关节炎滑膜细胞白介素-6表达的影响脂多糖对人类风湿性关节炎滑膜细胞白介素-6表达的影响

目的研究脂多糖（LPS）及其刺激的U937细胞培养上清液和地塞米松对人类风湿性关节炎（RA）成纤维状滑膜细胞(FLS)白介素-6（IL-6）表达的影响。方法用放免分析法检测IL-6蛋白的表达；RT-PCR法测定IL-6 mRNA的表达。结果LPS处理对FLS中IL-6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IL-6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刺激的U937细胞上清液使FLS中IL-6表达增加；而地塞米松能抑制上述IL-6的变化。

Effect of lipopolysaccharide on expression of interleukin-6 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 interleukin-6 (IL-6) expression in the synoviocyte from patients with rheumatoid arthritis (RA). METHODS: Fibroblast-like synoviocytes (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 expression of IL-6 protein was detected by radioimmunoassay. The mRNA expression of IL-6 was accessed by RT-PCR. RESULTS: The growth of FLS was not markedly affected by LPS, and the protein secretion and mRNA expression of IL-6 were not markedly changed in FLS treated with LPS. The IL-6 secretion and IL-6 mRNA expression were significantly increased in FLS cultured with the supernatant from U937 cell treated with LPS. Dexamethasone markedly inhibited the protein secretion and mRNA expression of IL-6 in FLS cultured with the supernatant from U937 cell stimulated with LPS. The inhibitory effects were increased as the concentration of dexamethasone increased. CONCLUSION: LPS was not shown to directly affect the expression of IL-6 in FLS, but it indirectly causes the increase of the IL-6 expression in FLS by stimulating U937 cell. Dexamethasone can inhibit this increase of the IL-6 expression.