Animals ; Arthritis, Experimental ; metabolism ; pathology ; Breast Neoplasms ; pathology ; Cadherins ; metabolism ; physiology ; Cell Movement ; Female ; Fibroblasts ; cytology ; pathology ; Humans ; Macrophages ; cytology ; pathology ; Neoplasm Invasiveness ; Synovial Membrane ; cytology ; metabolism ; pathology

OBJECTIVETo explore the expression of interleukin 18 (IL-18) and prostaglandin E2 (PGE2) and their relationship in the synoviocytes of patients with osteoarthritis (OA).

METHODSThe synovial tissues were obtained from 30 OA patients to isolate the synoviocytes for primary culture. The concentrations of IL-18 and PGE2 in the supernatants of synoviocyte culture were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe concentration of IL-18 averaged 51.559-/+27.614 pg/ml and PGE2 327.036-/+333.561 pg/ml in the supernatant of the synoviocytes. A significant positive correlation was noted between their expressions (r=0.863, P<0.01).

CONCLUSIONIL-18 may induce the production of PGE2, and their interactions they may play an important role in the pathogenesis of OA.

Adult ; Aged ; Aged, 80 and over ; Cells, Cultured ; Dinoprostone ; metabolism ; Female ; Humans ; Interleukin-18 ; metabolism ; Male ; Middle Aged ; Osteoarthritis ; metabolism ; pathology ; Synovial Membrane ; metabolism ; pathology

OBJECTIVETo detect the expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in patients with osteoarthritis and investigate their roles in the synovial lesions of osteoarthritis.

METHODSThe expressions of HIF-1α and VEGF in the synovium were detected by immunohistochemical staining in 30 osteoarthritis cases, 20 acute traumatic arthritis cases and 10 normal synovial biopsy samples. The correlation between HIF-1α and VEGF, and their relationships with osteoarthritis were analyzed.

RESULTSThe rates of positive expression of HIF-1α and VEGF in osteoarthritis cases were significantly higher than those in acute traumatic arthritis (86.7% vs 60% and 80% vs 48%, P<0.05). Normal human synovium showed no positive expressions of HIF-1α and VEGF. HIF-1α expression was positively correlated to VEGF expression in acute traumatic synovitis and osteoarthritis cases, with correlation coefficients of 0.666 and 0.678, respectively.

CONCLUSIONThe expressions of HIF-1α and VEGF in the synovial tissue are significantly higher in osteoarthritis cases than in cases of acute traumatic arthritis. They have close relationship in the synovial lesions of osteoarthritis and both contribute to the development of osteoarthritis.

Adult ; Female ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Male ; Middle Aged ; Osteoarthritis ; metabolism ; Synovial Membrane ; metabolism ; pathology ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo examine the expression of FLICE-inhibitory protein (FLIP) in juvenile idiopathic arthritis (JIA) and analyze its correlation with synovial inflammation.

METHODSThe expression of FLIP was assessed in 11 JIA and 3 normal synovial tissue samples by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. The cell types expressing FLIP were further characterized, and the correlation of FLIP expression with the degree of synovial inflammation, as well as the activity of caspase 8 was then analyzed.

RESULTSRT-PCR revealed the expression of FLIP mRNA in all 11 JIA samples, but not in 3 normal synovial tissues. In JIA, FLIP expression could be found in both the lining and sublining layers, mainly in the macrophage-like cells. Moreover, the expression of FLIP in JIA synovial tissues was positively correlated with the degree of synovial inflammation (r = 0.563, P < 0.05).

CONCLUSIONThe expression of antiapoptotic FLIP in JIA synovial tissue and its correlation to accumulation of inflammatory cells in synovial tissue suggests that FLIP potentially extends the lifespan of synovial cells and thus contributes to the progression of joint destruction.

Adolescent ; Arthritis, Juvenile ; metabolism ; pathology ; CASP8 and FADD-Like Apoptosis Regulating Protein ; genetics ; metabolism ; Caspase 8 ; metabolism ; Child ; Female ; Humans ; Inflammation ; metabolism ; pathology ; Male ; Protein Isoforms ; genetics ; metabolism ; Synovial Membrane ; cytology ; metabolism ; pathology

In temporomandibular disorders (TMD), pain takes place when neuropeptides stimulate synovial tissue to produce several cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, which activate neurons and glia of synovial membrane at the bilaminar regions of temporomandibular joint (TMJ). It has been reported that, after neurogenic differentiation, the synovial mesenchymal stem cells (SMSCs), deriving from TMJ, possess the same cytological features as the neuronal cells. This study examined the ability of substance P (SP) and calcitonin gene-related peptide (CGRP) to stimulate SMSCs and neurogenic SMSCs secreting inflammatory cytokines during TMD, evaluated the mutual effects of inflammatory cytokines and neuropeptides and tested the analgesic effect of hyaluronic acid (HA). The levels of IL-1β, IL-6 and TNF-α in SMSCs and neurogenic SMSCs in the presence of neuropeptides were measured by ELISA. SP and CGRP produced by SMSCs and neurogenic SMSCs were determined by RT-PCR and Western blotting. The results showed that the expression of SP and CGRP was significantly enhanced in the neurogenic SMSCs in response to IL-1β, IL-6 and TNF-α, and the effect was remarkably inhibited by HA. IL-1β, IL-6 and TNF-α, in return, could be enhanced in the neurogenic SMSCs upon stimulation by SP and CGRP. Neuropeptides and inflammatory cytokines might work mutually on the TMD pain. The HA-mediated analgesic effect may be implicated in the inhibition of SP and CGRP expression in neurogenic SMSCs.
Calcitonin Gene-Related Peptide ; biosynthesis ; Cells, Cultured ; Cytokines ; biosynthesis ; Female ; Humans ; Male ; Mesenchymal Stromal Cells ; metabolism ; pathology ; Substance P ; biosynthesis ; Synovial Membrane ; metabolism ; pathology ; Temporomandibular Joint ; metabolism ; pathology ; Temporomandibular Joint Disorders ; metabolism ; pathology

Myeloid-related protein (MRP)8/MRP14 is an endogenous Toll-like receptor 4 (TLR4) ligand and is abundant in synovial fluid (SF) of rheumatoid arthritis (RA) patients. Belonging to damage-associated molecular patterns, it amplifies proinflammatory mediators and facilitates a wide range of inflammatory and autoimmune diseases. Interleukin (IL)-17-producing T-helper (Th)17 cells have a crucial role in RA pathogenesis, and IL-6 is the key factor promoting Th17 differentiation. We investigated whether the level of MRP8/MRP14 is positively associated with IL-6 and IL-17 levels in RA SF and found that MRP8/MRP14 level had a significant correlation with IL-6 and IL-17 levels in RA SF. We also observed that MRP8-induced IL-17 production by peripheral blood mononuclear cells but MRP14 did not. Upon stimulation with MRP8, IL-6 production was enhanced by RA fibroblast-like synoviocytes (FLS) and was further elevated by coculturing RA FLS with activated CD4+ T cells. Moreover, we demonstrated that MRP8-activated IL-6 production by RA FLS promoted differentiation of Th17 cells using the coculture system consisting of CD4+ T cells and RA FLS. In addition, IL-6 blockade attenuated Th17 polarization of CD4+ T cells in the cocultures. Inhibitor studies revealed that MRP8 increased IL-6 production in RA FLS via TLR4/phosphoinositide 3-kinase/nuclear factor-kappaB and mitogen-activated protein kinase signaling pathways. Our results show that MRP8 has a crucial role in stimulating IL-6 expression by RA FLS, and subsequently promotes Th17 differentiation in RA, suggesting that neutralizing MRP8 level in RA synovium may be an effective therapeutic strategy in RA treatment.
ATP-Binding Cassette Transporters/*metabolism ; Adult ; Aged ; Arthritis, Rheumatoid/*pathology ; CD4-Positive T-Lymphocytes/metabolism ; Calgranulin B/metabolism ; Cell Differentiation/*immunology ; Fibroblasts/*metabolism/pathology ; Humans ; Inflammation Mediators/metabolism ; Interleukin-17/metabolism ; Interleukin-6/*biosynthesis ; Middle Aged ; Signal Transduction/immunology ; Synovial Fluid/cytology ; Synovial Membrane/metabolism/pathology ; Th17 Cells/*pathology ; Toll-Like Receptor 4/metabolism ; *Up-Regulation

Oxidative stress such as reactive oxygen species (ROS) within the inflamed joint have been indicated as being involved as inflammatory mediators in the induction of arthritis. Correlations between extracellular-superoxide dismutase (EC-SOD) and inflammatory arthritis have been shown in several animal models of RA. However, there is a question whether the over-expression of EC-SOD on arthritic joint also could suppress the progression of disease or not. In the present study, the effect on the synovial tissue of experimental arthritis was investigated using EC-SOD over-expressing transgenic mice. The over-expression of EC-SOD in joint tissue was confirmed by RT-PCR and immunohistochemistry. The degree of the inflammation in EC-SOD transgenic mice was suppressed in the collagen-induced arthritis model. In a cytokine assay, the production of pro-inflammatory cytokines such as, IL-1beta, TNFalpha, and matrix metalloproteinases (MMPs) was decreased in fibroblast-like synoviocyte (FLS) but not in peripheral blood. Histological examination also showed repressed cartilage destruction and bone in EC-SOD transgenic mice. In conclusion, these data suggest that the over-expression of EC-SOD in FLS contributes to the activation of FLS and protection from joint destruction by depressing the production of the pro-inflammatory cytokines and MMPs. These results provide EC-SOD transgenic mice with a useful animal model for inflammatory arthritis research.
Animals ; Arthritis, Experimental/blood/*enzymology/metabolism ; *Arthritis, Rheumatoid/enzymology/pathology ; Fibroblasts/metabolism ; Gene Expression Regulation ; Inflammation/pathology ; Interleukin-1beta/blood/metabolism ; Joints/enzymology/pathology ; Matrix Metalloproteinases/blood/metabolism ; Mice ; Mice, Transgenic ; Reactive Oxygen Species/metabolism ; *Superoxide Dismutase/genetics/metabolism ; Synovial Fluid/*enzymology ; Synovial Membrane/pathology

The aim of this study was to investigate the expression and localization of cyclooxygenase-1 and -2 (COX-1 and COX-2) in synovial tissues from patients with rheumatoid arthritis (RA). Synovial tissues from 9 patients with RA and 5 patients with osteoarthritis (OA) were examined for COX-1 and COX-2 expressions by immunohistochemical staining using 2 polydonal COX-1 and COX-2 antibodies. In RA synovia, synovial lining cells showed intense immunostaining for COX-1, whereas slight to moderate staining was observed in inflammatory cells, stromal fibroblast-like cells and vascular endothelial cells. There was no significant difference in COX-1 expression between RA and OA synovia. The localization of COX-2 expression dearly differed from that of COX-1 expression, being most intense in inflammatory cells. However, there was no difference in COX-1 and COX-2 expressions between RA and OA synovial tissues. Our observations support that inflammatory mechanisms modulated by COX-1 and COX-2 in chronic RA synovium might be similar to those in chronic OA synovium.
Adult ; Aged ; Arthritis, Rheumatoid/pathology ; Arthritis, Rheumatoid/enzymology* ; Cell Division ; Female ; Fibrin/metabolism ; Human ; Isoenzymes/metabolism ; Isoenzymes/biosynthesis* ; Male ; Middle Age ; Neutrophil Infiltration ; Osteoarthritis/enzymology ; Prostaglandin-Endoperoxide Synthase/metabolism ; Prostaglandin-Endoperoxide Synthase/biosynthesis* ; Stromal Cells/pathology ; Stromal Cells/enzymology ; Synovial Membrane/pathology ; Synovial Membrane/enzymology*

AIMTo study the effects of indomethacin on interleukin-6 (IL-6) expression stimulated with lipopolysaccharide (LPS) in rheumatoid arthritic patients' synoviocyte.

METHODSFibroblast-like cells (FLS) from rheumatoid arthritic patients' joint tissue were cultured for 24 h and incubated 24 h with LPS (1 mg.L-1) or the supernatant of U937 cells stimulated by LPS (1 mg.L-1). After indomethacin or dexamethasone added into the supernatant of U937 cells, FLS was incubated with the super natant for 24 h. The expression of IL-6 protein was detected by radioimmunoassay. The mRNA expression of IL-6 was accessed by RT-PCR.

RESULTSLPS did not obviously affect the growth of FLS, and the protein secretion and mRNA expression of IL-6 were not 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. Indomethacin at concentrations of 1 x 10(-7)-1 x 10(-5) mol.L-1 obviously inhibited the protein secretion and mRNA expression of IL-6 in FLS cultured with the supernatant from U937 cell stimulated with LPS, and the inhibitory effects increased as the concentrations of indomethacin increased.

CONCLUSIONIndomethacin can inhibit the increase of IL-6 expression caused by supernatant of U937 cells stimulated with LPS in FLS.

Anti-Inflammatory Agents, Non-Steroidal ; pharmacology ; Arthritis, Rheumatoid ; metabolism ; pathology ; Cells, Cultured ; Fibroblasts ; metabolism ; pathology ; Humans ; Indomethacin ; pharmacology ; Interleukin-6 ; biosynthesis ; genetics ; Lipopolysaccharides ; pharmacology ; RNA, Messenger ; genetics ; Synovial Membrane ; metabolism ; pathology ; U937 Cells

OBJECTIVETo isolate and characterize human rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs).

METHODSThe synovial membrane tissues were obtained from 4 RA patients, 1 chondroma patient and 1 healthy subject and FLS were isolated by means of tissue culture. The cell morphology was observed by phase-contrast microscope and the cell surface markers were detected by flow cytometry.

RESULTSThe FLSs were successfully cultured from the synovial membrane tissues with good cell homogeneity after the third passage. The FLSs of the 3rd to 7th passages were stable and proliferated actively, followed by slow proliferation and aging since the 8th passage. Flow cytometry showed that the 4th-passage FLSs from the RA patients contained 99.04% CD90(+) cells, 2.73% CD3(+) cells, 0.29% CD3(-)CD19(+) cells, 2.81% CD3(-)CD16(+)CD56(+) cells, 5.89% CD14(+) cells, and 54.17% CD55(+) cells. The presence of interleukin-1 receptor type I (IL-1RI, 158.63-/+20.32 pg/ml) and IL-1beta (4.67-/+0.82 pg/ml) were detected in the cell culture supernatant of the 4th-passage FLSs from the RA patients by enzyme-linked immunosorbent assay ELISA.

CONCLUSIONFLSs from RA patients can be effectively culture by means of tissue culture, and the cultured FLSs show high expressions of CD90, IL-1RI and IL-1beta.

Adult ; Aged ; Arthritis, Rheumatoid ; pathology ; Cell Proliferation ; Cell Separation ; Cells, Cultured ; Female ; Fibroblasts ; pathology ; Humans ; Interleukin-1beta ; metabolism ; Male ; Middle Aged ; Receptors, Interleukin-1 Type I ; metabolism ; Synovial Membrane ; cytology ; pathology ; Thy-1 Antigens ; metabolism