interleukin-8 and Sarcoma--Synovial

Benzoylaconitine (BAC), the main hydrolysate of aconitine, is a lower toxic monoester type alkaloid considered as the pharmacodynamic constituent in Aconitum species. In this study, the effects and mechanisms of BAC on production of inflammatory cytokines interleukin (IL)-6 and IL-8 were investigated in IL-1β-stimulated human synovial SW982 cells. The SW982 cells were incubated with BAC (0, 5 and 10 µM) before stimulating with IL-1β (10 ng/mL). The results revealed that BAC suppressed gene and protein expression of IL-6 and IL-8 induced by IL-1β. BAC decreased activation of mitogen-activated protein kinase (MAPK) and phosphorylation of Akt. BAC also inhibited degradation of inhibitor of kappaB (IκB)-α, phosphorylation and nuclear transposition of p65 protein. The results demonstrate that BAC exerts an anti-inflammatory effect dependent on MAPK, Akt and nuclear factor-κB (NF-κB) pathways in human synovial cells stimulated with IL-1β, suggesting that BAC may be exploited as a potential therapeutic agent for rheumatoid arthritis (RA) treatment.

Topics: Aconitine; Arthritis, Rheumatoid; Cell Line; Cell Survival; eIF-2 Kinase; Humans; Interleukin-1beta; Interleukin-6; Interleukin-8; Mitogen-Activated Protein Kinases; NF-kappa B; Phosphorylation; Sarcoma, Synovial; Signal Transduction

Familial Mediterranean fever (FMF) is a recessive inherited autoinflammatory syndrome. Patients with FMF have symptoms such as recurrent fever and abdominal pain, sometimes accompanied by arthralgia. Biopsy specimens have revealed substantial neutrophil infiltration into synovia. FMF patients have a mutation in the Mediterranean fever gene, encoding pyrin, which is known to regulate the inflammasome, a platform for processing interleukin (IL)-1β. FMF patients heterozygous for E148Q mutation, heterozygous for M694I mutation, or combined heterozygous for E148Q and M694I mutations, which were found to be major mutations in an FMF study group in Japan, suffer from arthritis, the severity of which is likely to be lower than in FMF patients with M694V mutations. Expression plasmids of wild-type (WT) pyrin and mutated pyrin, such as E148Q, M694I, M694V, and E148Q+M694I, were constructed, and SW982 synovial sarcoma cells were transfected with these expression plasmids. IL-8 and IL-6 were spontaneously secreted from the culture supernatant of SW982 cells without any stimulation, whereas IL-1β and TNF-α could not be detected even when stimulated with lipopolysaccharide. Notably, two inflammasome components, ASC and caspase-1, could not be detected in SW982 cells by Western blotting. IL-8 but not IL-6 secretion from SW982 cells was largely suppressed by WT pyrin, but less suppressed by mutated pyrin, which appeared to become weaker in the order of E148Q, M694I, E148Q+M694I, and M694V mutations. As for IL-8 and IL-6, similar results were obtained using stable THP-1 cells expressing the WT pyrin or mutated pyrins, such as M694V or E148Q, when stimulated by LPS. In addition, IL-8 secretion from mononuclear cells of FMF patients was significantly higher than that of healthy volunteers when incubated on a culture plate. Thus, our results suggest that IL-8 secretion from SW982 synovial sarcoma cells suppressed by pyrin independently of inflammasome is affected by pyrin mutations, which may reflect the activity in FMF arthritis.

Topics: CARD Signaling Adaptor Proteins; Caspase 1; Cell Line, Tumor; Cytokines; Cytoskeletal Proteins; Down-Regulation; Extracellular Signal-Regulated MAP Kinases; Familial Mediterranean Fever; Genetic Association Studies; HEK293 Cells; Humans; Inflammasomes; Interleukin-8; Leukocytes, Mononuclear; Mutation, Missense; Phosphorylation; Protein Processing, Post-Translational; Pyrin; Sarcoma, Synovial; Solubility

Synovial hyperplasia is a hallmark of rheumatoid arthritis (RA) and is regarded as a major destructive element of articular bone and cartilage. This pathological process is accompanied by the production of proinflammatory cytokines, prostaglandin E(2) (PGE(2)), and matrix metalloproteinases (MMPs) in synoviocytes. We studied the spontaneous production of these substances in RA synoviocytes in spheroid culture. Synovial sarcoma cell line SW 982 formed a single spheroid in non-adherent culture plates. It produced interleukin (IL)-1beta, IL-6, IL-8, PGE(2), MMP-2 and MMP-13. Neither the addition of integrin antagonizing oligopeptide (GRGDSP) nor that of vitronectin receptor inhibitor SB-265123 to the culture inhibited any production. Phosphorylation of p38 mitogen-activated protein (MAP) kinase was observed during the culture. A novel p38 MAP kinase inhibitor, R-130823, inhibited the release of IL-6, IL-8 and MMP-13 in a concentration-dependent manner, but not that of IL-1beta or MMP-2. Real-time RT-PCR analysis demonstrated that IL-6, IL-8 and MMP-13 were inhibited at the transcriptional level. R-130823 did not affect the production of PGE(2) in spheroid culture, while the addition of R-130823 suppressed IL-1beta-induced PGE(2) synthesis in monolayer culture of SW 982 cells. The results suggest that spheroid culture induced proinflammatory factors and MMPs in signaling pathways both dependent and independent of p38 MAP kinase.

Topics: Cell Adhesion; Cell Culture Techniques; Cell Line, Tumor; Dinoprostone; Humans; Interleukin-6; Interleukin-8; Matrix Metalloproteinase 13; Matrix Metalloproteinase Inhibitors; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Pyridines; Pyrroles; Sarcoma, Synovial; Spheroids, Cellular