ABSTRACT
<p><b>AIM</b>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).</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>
Subject(s)
Humans , Anti-Inflammatory Agents , Pharmacology , Arthritis, Rheumatoid , Pathology , Cell Division , Cells, Cultured , Dexamethasone , Pharmacology , Fibroblasts , Pathology , Gene Expression , Lipopolysaccharides , Pharmacology , Matrix Metalloproteinase 9 , Genetics , Metabolism , RNA, Messenger , Genetics , Synovial Membrane , Pathology , U937 CellsABSTRACT
<p><b>AIM</b>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).</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>
Subject(s)
Humans , Arthritis, Rheumatoid , Pathology , Cell Division , Cells, Cultured , Dexamethasone , Pharmacology , Fibroblasts , Metabolism , Gene Expression , Interleukin-6 , Genetics , Lipopolysaccharides , Pharmacology , RNA, Messenger , Genetics , Synovial Membrane , Metabolism , U937 CellsABSTRACT
<p><b>AIM</b>To investigate the expression of matrix metalloproteinase-9 (MMP-9) in mouse ears induced with croton oil and the inhibitory effect of dexamethasone, indomethacin and resveratrol on MMP-9 expression, and further explore the relationship between anti-inflammation and MMP-9 inhibition of these three medicines.</p><p><b>METHODS</b>Immuno-histochemistry was used to detect the expression of MMP-9 in mouse ears. Expression of MMP-9 in U937 cells was analyzed by gelatin zymography.</p><p><b>RESULTS</b>Mouse ear edema induced with croton oil was inhibited significantly by dexamethasone and indomethacin at the dose of 10 mg.kg-1 and resveratrol at 50 mg.kg-1 administered subcutaneously. The inhibitory rate was 76.2% (P < 0.001), 56.7% (P < 0.001) and 36.9% (P < 0.001) respectively. The MMP-9 expression increased in mouse ears induced with croton oil and inhibited by dexamethasone, indomethacin and resveratrol at above doses. Gelatin zymography results showed that MMP-9 expression in U937 cells increased significantly after exposed to PMA at 1 x 10(-8) mol.L-1 (P < 0.001); MMP-9 expression induced with phorbol myristate acetate(PMA) was inhibited by dexamethasone at 1 x 10(-9), 1 x 10(-7) and 1 x 10(-5) mol.L-1, indomethacin at 1 x 10(-6) and 1 x 10(-5) mol.L-1 and resveratrol at 1 x 10(-6) and 1 x 10(-5) mol.L-1.</p><p><b>CONCLUSION</b>The inhibition of MMP-9 expression may be one of the anti-inflammatory mechanisms of dexamethasone, indomethacin and resveratrol.</p>