leukotriene-b4 and Osteoarthritis

Osteoarthritis is characterized mainly by degenerative changes in joint cartilage, ultimately resulting in loss of cartilage, and alterations in the subchondral bone. Osteoarthritis osteoblasts show a number of metabolic alterations that may interfere with normal cell metabolism and signaling, possibly leading to altered extracellular matrix composition. This review examines the role of eicosanoids in this structural degradation.. Prostaglandins exert diverse modulatory roles in osteoarthritis, with prostaglandin E2 known to play an important role in inflammation. Prostaglandins and leukotriene B4 have been shown to regulate proinflammatory cytokine and interstitial collagenase synthesis in human osteoarthritis synovial membrane explants. Human osteoarthritis osteoblasts produce variable levels of prostaglandin E2 and leukotriene B4 compared with normal osteoblasts. Prostaglandin E2 levels can distinguish two types of patients with osteoarthritis: osteoblasts from one group produce low levels of prostaglandin E2 and interleukin-6, and the other shows an increase in production. In contrast, osteoarthritis osteoblasts that produce high levels of prostaglandin E2 produce low levels of leukotriene B4 and vice versa. This observation could be explained by the selective metabolism of arachidonic acid via the 5-lipoxygenase or cyclooxygenase pathways in osteoarthritis osteoblasts.. Prostaglandins play a significant role not only in joint physiology, but also in the pathogenesis of joint disorders. In addition, it has been identified that osteoarthritis subchondral osteoblasts can synthesize leukotriene B4, indicating a role of leukotrienes in bone remodeling associated with osteoarthritis. A therapeutic intervention that blocks lipoxygenase/cyclooxygenase pathways, thereby inhibiting production of prostaglandins and leukotrienes, may therefore be very attractive for the treatment of osteoarthritis patients.

Topics: Bone Remodeling; Cartilage, Articular; Dinoprostone; Humans; Leukotriene B4; Osteoarthritis; Osteoblasts

Most of the previous studies dealing with the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the synthesis of inflammatory mediators involved in joint damage have been done in cells cultured in vitro or in blood cells from patients treated for short periods of time. In this work we have evaluated the long-term effect of aceclofenac, a new NSAID, and diclofenac on the production of a series of inflammatory mediators by blood cells from 30 patients with severe knee osteoarthritis. Both aceclofenac and diclofenac significantly inhibited prostaglandin E2 (PGE2) synthesis by blood mononuclear and polymorphonuclear cells after 180 days of treatment. However, no clear effect was noted on leukotriene B4 (LTB4) and platelet activating factor (PAF) production. The generation of O-2 by polymorphonuclear cells, stimulated with FMLP, was decreased after 15 days of treatment with both drugs, but reached normal values after 180 days. Interleukin-1 beta (IL-1 beta) production decreased significantly at 180 days with both drugs in the group of high producer patients. In a few (n = 3) patients with high basal mononuclear cell tumor necrosis factor alpha (TNF alpha) production, this also decreased on treatment for 180 days with the NSAIDs. In the remaining low TNF alpha-producing patients, TNF alpha production tended to increase. Interleukin-6 (IL-6) synthesis was not affected by aceclofenac while it was diminished by diclofenac. The decrease in IL-6 in all treated patients was significantly correlated with a worsening of the clinical condition. On the whole, these data could afford a pathogenetic basis for the long-term employment of these drugs in patients with inflammatory conditions.

Topics: Adult; Aged; Aged, 80 and over; Anti-Inflammatory Agents, Non-Steroidal; Cytokines; Diclofenac; Dinoprostone; Double-Blind Method; Female; Humans; Interleukin-1; Interleukin-6; Knee Joint; Leukotriene B4; Male; Middle Aged; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Osteoarthritis; Platelet Activating Factor; Reactive Oxygen Species; Tumor Necrosis Factor-alpha

The role of PGD2 has been recognized in allergy, innate immunity and inflammation. Western blot analysis identified 21 kDa lipocalin (L)-prostaglandin D2 (PGD2) synthase (S) in human osteoarthritis (OA)-affected cartilage, whose expression was increased by IL-1β and TNFα. Similarly, PGD2 was spontaneously released by human OA-affected cartilage (and upregulated by IL-β) in ex vivo conditions and could be inhibited by indomethacin. Addition of PGD2 to human OA-affected cartilage significantly increased accumulation of PGE2, PGF1α, PGF2α, TXB2, but inhibited LTB4 and nitric oxide (NO) accumulation. Similarly, PGD2 (but not 13,14-dihydro-15-keto PGD2) augmented IL-1β induced PGE2 but inhibited IL-β induced nitric oxide (NO) in human chondrocytes. Celecoxib (10 μM) inhibits COX-1 mediated PGD2, and nitric oxide synthase (NOS) mediated NO in human OA-affected cartilage. Furthermore, celecoxib (1 μM) counter balances (IL-1β induced+PGD2 modulated) levels of NO and PGE2 in human OA-affected cartilage and chondrocytes to basal levels. These results show concentration-dependent, pro- and anti-inflammatory activity of PGD2 in human chondrocytes and cartilage, which can be neutralized by celecoxib. In view of the broad prostaglandin dependent and independent mechanism of action of celecoxib, these observations further reaffirm the broader role of celecoxib as a "Disease Modifying Drug" for human Osteoarthritis.

Topics: Celecoxib; Cells, Cultured; Chondrocytes; Dinoprost; Dinoprostone; Humans; Inflammation Mediators; Interleukin-1beta; Knee; Leukotriene B4; Nitric Oxide; Osteoarthritis; Prostaglandin D2; Prostaglandins F; Pyrazoles; Sulfonamides; Thromboxane B2

This study aimed to investigate whether hydroxynonenal (HNE) depletion is responsible for the switch from cyclooxygenase-2 (COX-2) and microsomal prostaglandin E2 synthase-1 (mPGES-1) to 5-lipoxygenase-activating protein (FLAP) and 5-lipoxygenase (5-LOX).. For COX-2 and mPGES-1 studies, human osteoarthritic chondrocytes were stimulated at different incubation times (up to 24 hours) with a single or repetitive addition of 10 muM HNE to the cultures at 2-hour intervals, up to 14 hours. For 5-LOX and FLAP studies, cells were treated with a single addition of 10 muM HNE for 24 hours, 48 hours, and 72 hours in the presence or absence of naproxen (a nonspecific COX-2 inhibitor) or antibody anti-transforming growth factor-beta 1 (TGF-beta1). The protein levels of COX-2, mPGES-1 and early growth response factor-1 (Egr-1) transcription factor were evaluated by western blot, and those of prostaglandin E2 (PGE2), leukotriene B4 (LTB4) and TGF-beta1 were determined with commercial kits. The levels of mPGES-1, FLAP and 5-LOX mRNA were measured by real-time RT-PCR. Transient transfection was performed to determine promoter activities of mPGES-1 and 5-LOX.. Single addition of 10 muM HNE to cultured chondrocytes induced PGE2 release as well as COX-2 and mPGES-1 expression at the protein and mRNA levels, with a plateau reached respectively at 8 and 16 hours of incubation, followed by a subsequent decline. However, repeated treatments with HNE prevented the decline of COX-2 and mPGES-1 expression that occurred with a single aldehyde addition. HNE induced mPGES-1 promoter activity, possibly through transcription factor Egr-1 activation. After 48 hours, when COX-2 expression decreased, the LTB4 level rose through 5-LOX and FLAP upregulation. The addition of naproxen to cultured chondrocytes revealed that FLAP and 5-LOX regulation by HNE required PGE2 production. Furthermore, our data showed that HNE significantly induced TGF-beta1 production. The addition of anti-TGF-beta1 antibody reduced HNE-induced 5-LOX and FLAP expression by 40%, indicating the partial involvement of a TGF-beta1-dependent mechanism.. Our data demonstrate that the shunt to the FLAP and 5-LOX pathway in HNE-induced human osteoarthritic chondrocytes is attributed to COX-2 and mPGES-1 inhibition, probably due to HNE depletion. PGE2 and TGF-beta1 are suggested to be involved in this regulation.

Topics: 5-Lipoxygenase-Activating Proteins; Aged; Aldehydes; Arachidonate 5-Lipoxygenase; Blotting, Western; Carrier Proteins; Cells, Cultured; Chondrocytes; Cyclooxygenase 2; Cysteine Proteinase Inhibitors; Gene Expression; Gene Expression Regulation; Humans; Intramolecular Oxidoreductases; Leukotriene B4; Membrane Proteins; Microsomes; Osteoarthritis; Prostaglandin-E Synthases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta1

To determine the effects of the antioxidant resveratrol on the functions of human chondrocytes in osteoarthritis (OA).. Chondrocytes and cartilage explants were isolated from OA patients undergoing knee replacement surgery. Effects of resveratrol in the presence or absence of interleukin-1beta (IL-1beta) stimulation were assessed by measurement of prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)) synthesis, cyclooxygenase (COX) activity, matrix metalloproteinase (MMP) expression, and proteoglycan production. To explore the mechanisms of action of resveratrol, its effects on mitochondrial function and apoptosis were examined by assessing mitochondrial membrane potential, ATP levels, cytochrome c release, and annexin V staining.. Resveratrol inhibited both spontaneous and IL-1beta-induced PGE(2) production by >20% (P < 0.05) and by 80% (P < 0.001), respectively; similarly, LTB(4) production was reduced by >50% (P < 0.05). The production of PGE(2) was inhibited via a 70-90% suppression of COX-2 expression and enzyme activity (P < 0.05). Resveratrol also promoted anabolic effects in OA explant cultures, by elevating proteoglycan synthesis and decreasing production of MMPs 1, 3, and 13. Pretreatment of OA chondrocytes with resveratrol blocked mitochondrial membrane depolarization, loss of mitochondrial biomass, and IL-1beta-induced ATP depletion. Similarly, IL-1beta-mediated induction of the apoptotic markers cytochrome c and annexin V was also inhibited by resveratrol. Exogenous addition of PGE(2) abolished the protective effects of resveratrol on mitochondrial membrane integrity, ATP levels, expression of apoptotic markers, and DNA fragmentation.. Resveratrol protects against IL-1beta-induced catabolic effects and prevents chondrocyte apoptosis via its inhibition of mitochondrial membrane depolarization and ATP depletion. These beneficial effects of resveratrol are due, in part, to its capacity to inhibit COX-2-derived PGE(2) synthesis. Resveratrol may therefore protect against oxidant injury and apoptosis, which are main features of progressive OA.

Topics: Adenosine Triphosphate; Analysis of Variance; Annexin A5; Antioxidants; Apoptosis; Blotting, Western; Cartilage; Chondrocytes; Cyclooxygenase 2; Cytochromes c; Dinoprostone; DNA Fragmentation; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Humans; Interleukin-1beta; Leukotriene B4; Matrix Metalloproteinases; Membrane Potential, Mitochondrial; Mitochondria; Osteoarthritis; Proteoglycans; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Stilbenes

Serotonin antagonists show impressive analgesic efficacy in rheumatoid arthritis, osteoarthritis (OA) or fibromyalgia; however, this effect is not well understood. We examined the mechanism of serotonin-induced inflammation and its antagonists in OA. Serotonin receptor subtypes and COX-2 were analysed by RT-PCR from synovial tissue. Serum-free cultures were stimulated with 10 muM serotonin and/or the antagonists ketanserin (5-HT(2A)), tropisetron (5-HT(3)) and parecoxib (COX-2). Prostaglandin E(2) (PGE(2)), tumour necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta) and leukotriene B4 (LTB4) were measured by an immunoassay in the supernatants. RT-PCR results showed mRNA for 5-HT(2A) and 5-HT(3) receptors, and COX-2. PGE(2) in the supernatants increased by 261.2% +/- 56.7 (mean +/- SEM; P = 0.007) in response to serotonin. TNF-alpha, IL-1beta and LTB4 levels did not change. Ketanserin, tropisetron and parecoxib suppressed PGE(2). The serotonin-induced PGE(2) overexpression appeared thus to be mediated by 5-HT(2A) and 5-HT(3) receptors. This activation might involve COX-2. The findings may explain the potent benefit of 5-HT(3) antagonists.

Topics: Aged; Cells, Cultured; Culture Media, Serum-Free; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Dinoprostone; Drug Interactions; Humans; Indoles; Interleukin-1beta; Isoxazoles; Ketanserin; Leukotriene B4; Macrophages; Middle Aged; Osteoarthritis; Receptor, Serotonin, 5-HT2A; Receptors, Serotonin, 5-HT3; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Serotonin; Serotonin Agents; Serotonin Antagonists; Synovial Membrane; Tropisetron; Tumor Necrosis Factor-alpha

To compare levels of bradykinin (BK), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), and substance P (SP) between successful and unsuccessful cases of arthrocentesis of temporomandibular joint disorders (TMDs).. A total of 66 joints in 66 patients with TMDs who underwent arthrocentesis were evaluated in this study. Synovial fluid diluted with saline solution was aspirated from the superior joint compartment before arthrocentesis and their concentrations of BK, LTB4, PGE2, and SP were determined by enzyme-linked immunosorbent assay. The differences in the detection rate and concentration of each mediator between successful cases and unsuccessful cases of arthrocentesis were analyzed statistically.. Arthrocentesis was successful for 77% (51/66) of the joints. The mean detection rate of LTB4 was significantly (P < .05) higher in the unsuccessful cases (47%) than in the successful cases (16%). The mean concentration of BK was significantly (P < .0005) higher in the unsuccessful cases (425 pg/mL) than in the successful cases (144 pg/mL). There was also a statistical correlation between the detection of LTB4 and PGE2 (P < .01).. Increased levels of BK and LTB4 in the synovial fluid of patients with TMDs may indicate that arthrocentesis is less likely to be a successful treatment.

Topics: Adolescent; Adult; Aged; Bradykinin; Dinoprostone; Female; Humans; Joint Dislocations; Leukotriene B4; Male; Middle Aged; Osteoarthritis; Pain; Paracentesis; Prognosis; Statistics, Nonparametric; Substance P; Synovial Fluid; Temporomandibular Joint Disorders

The TNF superfamily member LIGHT has a T-cell co-stimulatory role and has previously been associated with inflammation and autoimmunity. To investigate its role in rheumatoid arthritis (RA), a disease where activated T cells contribute in a prominent way, we have analysed the expression of LIGHT and its receptors in RA and analysed its effects on synovial fibroblasts in vitro.. The expression of LIGHT was measured in synovial tissues and fluids and the receptors of LIGHT were detected on synovial fibroblasts derived from patients with RA and osteoarthritis (OA). The effects of recombinant LIGHT on the production of proinflammatory cytokines and proteases and on the apoptosis of synovial fibroblasts was assessed.. LIGHT mRNA was present in synovial tissues of patients with RA but not with OA. Correspondingly, soluble LIGHT protein could be detected in RA synovial fluid samples at much higher levels than in synovial fluid from patients with OA. Immunohistochemical detection of LIGHT and analysis of synovial fluid cells by flow cytometry revealed CD4 T cells as the major source of LIGHT in the rheumatoid joint. Synovial fibroblasts from RA patients were found to express the LIGHT receptors HVEM and LTbetaR. Recombinant LIGHT induced RA synovial fibroblasts to upregulate MMP-9 mRNA, CD54 and IL-6 in an NF-kappaB-dependent fashion. In vitro, exposure of cultured synovial fibroblasts to LIGHT reduced FAS-mediated apoptosis significantly, without affecting the rate of spontaneous apoptosis.. The results provide evidence for a novel T-cell-dependent activation of synovial fibroblasts by LIGHT in joints of patients with RA, contributing to an inflammatory and destructive phenotype.

Topics: Aged; Apoptosis; Arthritis, Rheumatoid; CD4-Positive T-Lymphocytes; Cell Proliferation; Cell Survival; Cells, Cultured; Female; Fibroblasts; Flow Cytometry; Humans; Immunohistochemistry; Intercellular Adhesion Molecule-1; Interleukin-6; Leukotriene B4; Male; Matrix Metalloproteinase 9; Middle Aged; NF-kappa B; Osteoarthritis; Receptors, Tumor Necrosis Factor, Member 14; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Statistics, Nonparametric; Synovial Fluid; Synovial Membrane; Tumor Necrosis Factor Ligand Superfamily Member 14

Osteoarthritis (OA) is characterized by articular cartilage degradation and hypertrophic bone changes with osteophyte formation and abnormal bone remodeling. Two groups of OA patients were identified via the production of variable and opposite levels of prostaglandin E2 (PGE2) or leukotriene B4 (LTB4) by subchondral osteoblasts, PGE2 levels discriminating between low and high subgroups. We studied whether the expression of 5-lipoxygenase (5-LO) or 5-LO-activating protein (FLAP) is responsible for the shunt from prostaglandins to leukotrienes. FLAP mRNA levels varied in low and high OA groups compared with normal, whereas mRNA levels of 5-LO were similar in all osteoblasts. Selective inhibition of cyclooxygenase-2 (COX-2) with NS-398-stimulated FLAP expression in the high OA osteoblasts subgroup, whereas it was without effect in the low OA osteoblasts subgroup. The addition of PGE2 to the low OA osteoblasts subgroup decreased FLAP expression but failed to affect it in the high OA osteoblasts subgroup. LTB4 levels in OA osteoblasts were stimulated about twofold by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plus transforming growth factor-beta (TGF-beta), a situation corresponding to their effect on FLAP mRNA levels. Treatments with 1,25(OH)2D3 and TGF-beta also modulated PGE2 production. TGF-beta stimulated PGE2 production in both OA osteoblast groups, whereas 1,25(OH)2D3 alone had a limited effect but decreased the effect of TGF-beta in the low OA osteoblasts subgroup. This modulation of PGE2 production was mirrored by the synthesis of COX-2. IL-18 levels were only slightly increased in a subgroup of OA osteoblasts compared with normal; however, no relationship was observed overall between IL-18 and PGE2 levels in normal and OA osteoblasts. These results suggest that the shunt from the production of PGE2 to LTB4 is through regulation of the expression of FLAP, not 5-LO, in OA osteoblasts. The expression of FLAP in OA osteoblasts is also modulated differently by 1,25(OH)2D3 and TGF-beta depending on their endogenous low and high PGE2 levels.

Topics: 5-Lipoxygenase-Activating Proteins; Aged; Arachidonate 5-Lipoxygenase; Blotting, Western; Carrier Proteins; Cells, Cultured; Dinoprostone; Female; Gene Expression; Gene Expression Profiling; Humans; Interleukin-10; Interleukin-18; Leukotriene B4; Lipoxygenase; Male; Membrane Proteins; Osteoarthritis; Osteoblasts; Prostaglandin-Endoperoxide Synthases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

To determine if treatment with licofelone, a combined 5-lipoxygenase and cyclo-oxygenase inhibitor, in vivo in experimental dog osteoarthritis can modify bone cell metabolism in long term in vitro subchondral osteoblast cell cultures (Ob).. Group 1 received sectioning of the anterior cruciate ligament (ACL) of the right knee with no active treatment (placebo group). Groups 2 and 3 received sectioning of the ACL of the right knee, and were given licofelone (2.5 or 5.0 mg/kg daily by mouth, respectively) for eight weeks beginning the day after surgery. Primary Ob were prepared from the subchondral bone plate. Levels of phenotypic markers (alkaline phosphatase activity, osteocalcin release), and urokinase plasminogen activator (uPA) and insulin-like growth factor-1 (IGF-I) levels, were evaluated in each group. Lastly, prostaglandin E(2) (PGE(2)) and leucotriene B(4) levels were evaluated.. No significant differences in alkaline phosphatase activity or osteocalcin release from Ob between the three groups, under either basal or 1,25(OH)(2)D(3) induction were seen. In contrast, treatment with licofelone reduced uPA and IGF-I levels in Ob. PGE(2) levels, which were still raised in the placebo group, were decreased sharply by licofelone. A relationship was found between licofelone treatment and either the reduction in the size of lesions on tibial plateaus or the levels of uPA, IGF-I, or PGE(2).. Licofelone treatment prevents and/or delays the abnormal metabolism of subchondral osteoblasts in this model. Licofelone reduced PGE(2) levels after long term Ob, suggesting that the reduction in uPA and IGF-I levels is linked, at least in part, to this reduction.

Topics: Acetates; Animals; Antirheumatic Agents; Arthritis, Experimental; Cells, Cultured; Cyclooxygenase Inhibitors; Dinoprostone; Dogs; Enzyme Inhibitors; Insulin-Like Growth Factor I; Leukotriene B4; Lipoxygenase Inhibitors; Osteoarthritis; Osteoblasts; Pyrroles; Urokinase-Type Plasminogen Activator

To compare the effect of licofelone, NS-398 (an inhibitor of cyclooxygenase 2 [COX-2]), and BayX-1005 (an inhibitor of 5-lipoxygenase activating protein) on the production of leukotriene B(4) (LTB(4)) and prostaglandin E(2) (PGE(2)), and on cell biomarkers by human osteoarthritis (OA) subchondral osteoblasts.. Primary in vitro osteoblasts were prepared from subchondral bone specimens obtained from OA patients and autopsy subjects. LTB(4) and PGE(2) levels were measured by enzyme-linked immunosorbent assay in conditioned media of osteoblasts incubated in the presence or absence of licofelone, NS-398, or BayX-1005. The effect of these drugs or of the addition of LTB(4) on alkaline phosphatase (AP) activity and osteocalcin release by OA and normal osteoblasts was determined. The presence of LTB(4) receptors in normal and OA osteoblasts was evaluated by Western blot analysis.. OA osteoblasts produced variable levels of PGE(2) and LTB(4) compared with normal osteoblasts. Licofelone, at the maximal dose used, inhibited production of PGE(2) and LTB(4) by OA osteoblasts by a mean +/- SEM of 61.2 +/- 6.4% and 67.0 +/- 7.6%, respectively. NS-398 reduced PGE(2) production by 75.8 +/- 5.3%. BayX-1005 inhibited LTB(4) production in OA osteoblasts by 38.7 +/- 14.5% and marginally affected PGE(2) levels (reduction of 14.8 +/- 5.3%). Licofelone dose-dependently stimulated 1,25-dihydroxyvitamin D-induced AP activity while inhibiting osteocalcin release. BayX-1005 partly reproduced these effects, but NS-398 failed to affect them. LTB(4) dose-dependently inhibited AP activity in OA osteoblasts, while its effect on osteocalcin depended on endogenous LTB(4) levels in these cells. In normal osteoblasts, LTB(4) dose-dependently stimulated osteocalcin, whereas it failed to influence AP. LTB(4) receptors BLT1 and BLT2 were present in normal and OA osteoblasts.. Licofelone inhibits the production of PGE(2) and LTB(4). Selective effects of licofelone on AP and osteocalcin occur via its role on LTB(4) production. Because LTB(4) can modify cell biomarkers in OA and normal osteoblasts, our results suggest licofelone could modify abnormal bone remodeling in OA.

Topics: Acetates; Alkaline Phosphatase; Blotting, Western; Cyclooxygenase Inhibitors; Dinoprostone; Female; Humans; In Vitro Techniques; Leukotriene B4; Lipoxygenase Inhibitors; Male; Middle Aged; Nitrobenzenes; Osteoarthritis; Osteoblasts; Osteocalcin; Pyrroles; Quinolines; Sulfonamides

The purpose of this study was to investigate the correlations between the concentrations of pain-related mediators in synovial fluid and the degree of synovitis and between the concentrations of pain-related mediators and the degree of joint pain in patients with internal derangement and osteoarthritis of the temporomandibular joint.. The concentrations of substance P, serotonin, bradykinin, leukotriene B(4) (LTB(4)), and prostaglandin E(2) in SF and the degree of arthroscopic synovitis of 32 joints with internal derangement and osteoarthritis were assessed. The correlations between the concentration of each mediator and the score of arthroscopic synovitis and between the concentration of each mediator and the score of joint pain were analyzed statistically.. The detection rates of substance P, serotonin, bradykinin, LTB(4), and prostaglandin E(2) were 25%, 25%, 91%, 53%, and 16%, respectively. Positive correlations were found between the concentrations of bradykinin and LTB(4) and the score of synovitis.. Bradykinin in SF might be useful as an index of the degree of synovitis.

Topics: Adolescent; Adult; Aged; Arthralgia; Bradykinin; Dinoprostone; Enzyme-Linked Immunosorbent Assay; Facial Pain; Female; Humans; Inflammation Mediators; Joint Dislocations; Leukotriene B4; Male; Middle Aged; Neurotransmitter Agents; Nociceptors; Osteoarthritis; Serotonin; Statistics, Nonparametric; Substance P; Synovial Fluid; Synovitis; Temporomandibular Joint Disorders

To determine the level of leukotriene B4 (LTB4) synthesized and released by synovium of patients with osteoarthritis (OA), and to study the role of lipoxygenase (LO)/cyclooxygenase (COX) products on proinflammatory cytokine and interstitial collagenase (MMP-1) synthesis.. Human OA synovial explants were cultured in the presence of lipopolysaccharide (L) and the ionophores ionomycin (I) and thapsigargin (T) (LIT) for 72 h at 37 degrees C, and LTB4 released into the culture medium was measured in the absence or presence of a COX-2-specific inhibitor, NS-398, or the 5-LO activating protein inhibitor Bay-x-1005. Increasing concentrations of LTB4 (10(-9) to 10(-6) M) were incubated with explants for 24 h at 37 degrees C, and interleukin 1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in the conditioned medium were quantitated by ELISA. The effect of endogenous eicosanoids on basal and induced levels of IL-1beta, TNF-alpha, and MMP-1 synthesis was examined by incubating explants in the presence of NS-398 and Bay-x-1005. The effect of antiinflammatory cytokines rhIL-4, IL-10, and IL-13 on basal and LTB4 dependent stimulation of IL-1beta/TNF-alpha synthesis was studied under titration conditions.. Physiologically relevant concentrations (10(-10) to 10(-9) mol/l) of LTB4 were produced in the presence of LIT. Bay-x-1005 abrogated LTB4 release, while NS-398 was without effect. LTB4 stimulated IL-1beta and TNF-alpha synthesis with an EC50 of 190 +/- 35 and 45 +/- 9 nmol/l, respectively. Significant concentrations of IL-1beta and TNF-alpha were released (100-200 and 500-600 pg/ml, respectively). Basal and LIT induced IL-1beta and TNF-alpha production were inhibited by Bay-x-1005 in a dose dependent manner, while the addition of NS-398 caused a potent stimulatory effect. The preferential COX-2 inhibitor also induced MMP-1 synthesis in a manner essentially identical to the proinflammatory cytokines. The antiinflammatory cytokine IL-4 blocked LTB4 dependent stimulation of IL-1beta and TNF-alpha synthesis. In contrast, IL-10 markedly stimulated both cytokines when incubated alone or in the presence of LTB4 where the effect was additive.. Endogenous and locally produced eicosanoids regulate proinflammatory cytokine and MMP-1 synthesis under basal and stimulated conditions in vitro, with leukotrienes and prostaglandins having opposite effects in general. The clinical use of antiinflammatory drugs that inhibit eicosanoid synthesis requires an appreciation of their relative capacity to inhibit LO/COX in order to predict their effect on the synthesis of proinflammatory cytokines and matrix metalloproteases. IL-10 stimulated proinflammatory cytokine synthesis in our ex vivo culture system.

Topics: Aged; Cells, Cultured; Dinoprostone; Eicosanoids; Fibroblasts; Humans; Interleukin-1; Leukotriene B4; Lipoxygenase Inhibitors; Matrix Metalloproteinase 1; Middle Aged; Osteoarthritis; Quinolines; Synovial Membrane; Tumor Necrosis Factor-alpha

Mud pack therapy (MPT) influences the serum levels of several cytokines involved in chondrocyte metabolism and in the pathogenesis of osteoarthrosis. In fact, we have observed decreases of IL-1 and TNF-alpha, involved in cartilage inflammation and destruction, and increases of IGF-1 that have a protective influence on the cartilage. It is known that in osteoarthrosis MPT is also able to decrease pain, largely attributable to the inflammatory response.. We enrolled 31 subjects undergoing MPT and collected blood samples before and after the therapy to assay serum levels of prostaglandin (PGE2) and leukotriene (LTB4) compounds with potent inflammatory and algesic properties.. The study shows a decrease in PGE2 and LTB4 serum levels in all the samples after MPT with no correlation between the PGE2 and LTB4 decreases.. Mud pack therapy exerts a protective effect on the cartilage and is able to induce pain relief by reducing the inflammatory reaction.

Topics: Aged; Anti-Inflammatory Agents, Non-Steroidal; Dinoprostone; Female; Hot Temperature; Humans; Leukotriene B4; Male; Middle Aged; Osteoarthritis

Lipids in the synovial fluid of patients with active rheumatoid arthritis are elevated compared to normal synovial fluid and that of other inflammatory arthropathies. Various assumptions about the role of these lipids have been made. This study offers evidence that these lipids may contribute to the synovitis in rheumatoid arthritis through participation in the arachidonic pathway within the joint space. Phospholipase A2 activity, phospholipids, prostaglandin E2, and leukotriene B4 have been correlated in the synovial fluid and plasma of untreated rheumatoid patients and compared with that of patients with osteoarthritis.

Topics: Arthritis, Rheumatoid; Case-Control Studies; Dinoprostone; Humans; Leukotriene B4; Lipoproteins; Male; Middle Aged; Osteoarthritis; Phospholipases A; Phospholipases A2; Phospholipids; Synovial Fluid; Synovitis

Enzyme immunoassay for prostaglandin E2 (PGE2), and radioimmunoassays for prostaglandin F2 alpha (PGF2 alpha), 6-keto-PGF1 alpha, and leukotriene B4 (LTB4) were performed on synovial fluid from normal middle carpal joints of 10 horses, and from 30 middle carpal or antebrachiocarpal joints of horses affected by degenerative joint disease and chip fractures to compare the concentrations of inflammatory mediators. Significantly greater concentrations of PGE2 were detected in fluid from affected than from control joints, but there were no significant differences in the mean concentrations of PGF2 alpha, 6-keto-PGF1 alpha, and LTB4.

Topics: Animals; Carpus, Animal; Eicosanoids; Fractures, Bone; Horse Diseases; Horses; Leukotriene B4; Osteoarthritis; Prostaglandins E; Prostaglandins F; Synovial Fluid

The effects of recombinant human IL-1 beta on the production of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), N-acetyl-beta-D-glucosaminidase (NAG), and superoxide by synovial cells and chondrocytes derived from osteoarthritis patients were determined. IL-1 beta markedly enhanced PGE2 production in chondrocytes and, to the lesser extent, in synovial cells. Synovial cells and chondrocytes spontaneously released LTB4 into culture medium and IL-1 beta significantly inhibited LTB4 production by these cells. IL-1 beta significantly suppressed the release of NAG and superoxide by synovial cells, whereas it significantly enhanced the production of NAG and superoxide by chondrocytes. Production of intracellular superoxide dismutase by synovial cells was significantly enhanced on incubation with IL-1 beta, but that of chondrocytes was not altered. IL-6, unlike IL-1 beta, significantly suppressed the production of NAG and superoxide by synovial cells and chondrocytes. These results suggest that IL-1 has differing effects on the release of mediators by synovial cells and chondrocytes and that these cells also vary in their responses to IL-1 beta and IL-6.

Topics: Acetylglucosaminidase; Cartilage, Articular; Cells, Cultured; Dinoprostone; Humans; Interleukin-1; Interleukin-6; Leukotriene B4; Osteoarthritis; Recombinant Proteins; Superoxide Dismutase; Superoxides; Synovial Membrane

Leukotriene B4 (LTB4) was measured in synovial fluid from 20 patients with rheumatoid arthritis and 15 patients with osteoarthritis. The level of LTB4 was significantly higher in synovial fluid from rheumatoid arthritis patients as compared with synovial fluid from osteoarthritis patients. LTB4 levels also significantly correlated with cell numbers, rheumatoid factor, and immune complexes in synovial fluid from rheumatoid arthritis patients. There was an inverse correlation between LTB4 levels and complement components. The high-pressure liquid chromatography peak of immunoreactivity extracted from the synovial fluid occurred at a retention volume identical to that of authentic LTB4. These results suggest that the increased level of this mediator in synovial fluid may contribute to perpetuation of inflammation and tissue destruction in rheumatoid arthritis.

Topics: Adult; Aged; Antigen-Antibody Complex; Arthritis, Rheumatoid; Complement System Proteins; Female; Humans; Leukotriene B4; Male; Middle Aged; Osteoarthritis; Synovial Fluid

The effects of sulfasalazine (SASP) and its metabolites sulfapyridine (SP) and 5-aminosalicylic acid (5-ASA) were investigated on release of prostaglandins (PG) and leukotrienes (LT) from synovial tissue of 37 patients with osteoarthritis, chondrocalcinosis and rheumatoid arthritis. Calcium ionophore A23187 significantly increased the release of PGE2, 6-keto-PGF1 alpha, LTB4, and LTC4 from human synovial tissue irrespective of the underlying joint disease. SASP inhibited release of LTC4 and increased release of PGE2. On the other hand, 5-ASA and SP inhibited the release of all eicosanoids measured. The effective concentrations of SASP and SP were found to be in the range which can be reached during SASP therapy. On the other hand, blood and synovial fluid levels of 5-ASA are considerably lower than those which inhibit eicosanoid synthesis in vitro. While nonsteroidal anti-inflammatory drugs, which are used for symptomatic therapy of rheumatoid arthritis, inhibit cyclooxygenase only, SP, the active metabolite of the second line anti-rheumatic drug SASP, inhibits both PG and LT release. Inhibition of LT synthesis by SASP and SP could contribute to the second line efficacy of SASP therapy in rheumatoid arthritis.

Topics: 6-Ketoprostaglandin F1 alpha; Aminosalicylic Acids; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Rheumatoid; Chondrocalcinosis; Culture Techniques; Dinoprostone; Humans; Knee Joint; Leukotriene B4; Leukotrienes; Mesalamine; Osteoarthritis; Prostaglandins; SRS-A; Sulfapyridine; Sulfasalazine; Synovial Membrane

LTB4 and PGE2-like activity in synovial fluid samples from patients with osteoarthritis of the knee joint were determined and found to be significantly higher than in samples obtained from normal patients. The results suggest that leukotrienes and prostaglandins may have a role in the pathogenesis of osteoarthritis.

Topics: Adult; Aged; Dinoprostone; Humans; Leukotriene B4; Middle Aged; Osteoarthritis; Synovial Fluid

A procedure for the quantification of leukotriene B4 (LTB4) in synovial fluid has been developed using gas chromatography/tandem mass spectrometry based on selected reaction monitoring of the elimination of t-butyldimethylsilanol from the ions of m/z 431 and 438 in the negative ion chemical ionization mass spectra of the di-t-butyldimethylsilyl/pentafluorobenzyl derivatives of leukotriene B4 and the internal standard (2H8)leukotriene B4. The detection limit (approximately 10 pg ml-1) is sufficiently low to permit determination of LTB4 concentration in the synovial fluid of patients with various arthropathies. Single-stage mass spectrometry was found not to be selective enough to permit quantification of LTB4 in synovial fluid.

Topics: Arthritis, Rheumatoid; Gas Chromatography-Mass Spectrometry; Humans; Leukotriene B4; Osteoarthritis; Synovial Fluid

The metabolism in vitro of synthetic leukotriene B4 (LTB4) in synovial fluid from rheumatoid arthritis and osteoarthritis patients and in whole blood from these same patient groups and from normal volunteers has been studied. A linear relationship existed between a plot of the time of incubation of samples with LTB4 and the percentage of the initial concentration of LTB4 at each time point. The slope of this line, the rate constant for metabolism, has been used to compare different samples. LTB4 was metabolised more rapidly in the synovial fluid of rheumatoid arthritis patients than osteoarthritis patients. Furthermore, LTB4 was metabolised more rapidly in the blood of rheumatoid arthritis patients than either osteoarthritis patients or normal volunteers. These differences in metabolism correlate with the polymorphonuclear leukocyte (PMN) and albumin content of samples. It is suggested that binding of LTB4 to albumin in vivo will in part determine the available concentration of LTB4 in inflammatory lesions.

Topics: Arthritis, Rheumatoid; Humans; In Vitro Techniques; Kinetics; Leukotriene B4; Neutrophils; Osteoarthritis; Reference Values; Synovial Fluid

Non-steroidal antirheumatic drugs permit a nonspecific, symptomatic therapy of inflammatory rheumatic processes and may also be given for a limited period of time in patients with so-called activated osteoarthrosis. Their mode of action is a complex one. More recent knowledge on mediators in inflammation such as prostaglandins, leukotriens and oxygen radicals have brought new insights on the mode of action of non-steroidal antirheumatic drugs.

Topics: Analgesia; Anti-Inflammatory Agents; Enzyme Inhibitors; Fever; Free Radicals; Humans; Immunosuppression Therapy; Leukotriene B4; Osteoarthritis; Oxygen; Platelet Aggregation; Prostaglandins; Rheumatic Diseases