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ID PMID Title PublicationDate abstract
16699049 Differential drug resistance to anti-tumour necrosis factor agents in rheumatoid arthritis 2006 Jun A significant number of patients receiving infliximab require dosing adjustments while some patients may indeed develop drug resistance
18203325 High concentration simvastatin induces apoptosis in fibroblast-like synoviocytes from pati 2008 Feb OBJECTIVE: We previously reported that 10 mg/day of simvastatin significantly reduced clinical scores of rheumatoid arthritis (RA) in patients with active RA with hypercholesterolemia. We have also reported that a certain pharmacological concentration of simvastatin, i.e., 0.05-0.1 microM, inhibits the production of interleukin 6 (IL-6) and IL-8 and the cell proliferation induced by tumor necrosis factor-alpha (TNF-alpha) in fibroblast-like synoviocytes (FLS) derived from patients with RA in vitro. We investigated other effects of simvastatin on FLS from the standpoint of cell viability and apoptosis. METHODS: RA FLS were cultured with or without 0.05-50 microM simvastatin for 48 h. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured by flow cytometric analysis using propidium iodide and annexin-V. Caspase-3 and -9 activities were analyzed by colorimetric assays. RESULTS: High concentrations of simvastatin, i.e., 1.0-50 microM, reduced cell viability and induced prominent apoptosis in FLS in a dose-dependent manner. The apoptosis induced by simvastatin was caspase-3- and caspase-9-dependent. These effects were completely reversed in the presence of mevalonic acid or geranylgeranyl-pyrophosphate, but not in the presence of farnesyl-pyrophosphate. Further, a geranylgeranyl transferase inhibitor and a RhoA kinase inhibitor mimicked the effect of simvastatin. CONCLUSION: These data, together with our previous report, suggest that low (pharmacological range) and high concentrations of simvastatin affect FLS differently: (1) at a low concentration, it inhibits IL-6 and IL-8 production and the cell proliferation of FLS induced by TNF-alpha (2) at high concentrations, it induces apoptosis in FLS. Understanding this dose-dependent biphasic effect of simvastatin may prove important for its clinical applications in the treatment of RA.
17015762 Interaction of vascular endothelial growth factor 165 with neuropilin-1 protects rheumatoi 2006 Oct 15 Rheumatoid arthritis (RA) synoviocytes are resistant to apoptosis and exhibit a transformed phenotype, which might be caused by chronic exposure to genotoxic stimuli including reactive oxygen species and growth factors. In this study, we investigated the role of vascular endothelial growth factor165 (VEGF165), a potent angiogenic factor, and its receptor in the apoptosis of synoviocytes. We demonstrated here that neuropilin-1, rather than fms-like tyrosine kinase-1 and kinase insert domain-containing receptor, is the major VEGF165 receptor in the fibroblast-like synoviocytes. Neuropilin-1 was highly expressed in the lining layer, infiltrating leukocytes, and endothelial cells of rheumatoid synovium. The production of VEGF165, a ligand for neuropilin, was significantly higher in the RA synoviocytes than in the osteoarthritis synoviocytes. The ligation of recombinant VEGF165 to its receptor prevented the apoptosis of synoviocytes induced by serum starvation or sodium nitroprusside (SNP). VEGF165 rapidly triggered phospho-Akt and phospho-ERK activity and then induced Bcl-2 expression in the rheumatoid synoviocytes. The Akt or ERK inhibitor cancelled the protective effect of VEGF165 on SNP-induced synoviocyte apoptosis. Moreover, VEGF165 blocks SNP-induced Bcl-2 down-regulation as well as SNP-induced Bax translocation from the cytosol to the mitochondria. The down-regulation of the neuropilin-1 transcripts by short interfering RNA caused spontaneous synoviocyte apoptosis, which was associated with both the decrease in Bcl-2 expression and the increase in Bax translocation to mitochondria. Collectively, our data suggest that the interaction of VEGF165 with neuropilin-1 is crucial to the survival of rheumatoid synoviocytes and provide important implications for the abnormal growth of synoviocytes and therapeutic intervention in RA.
18545980 Human rheumatoid synoviocytes express functional P2X7 receptors. 2008 Aug Human type B synoviocytes are involved in joint injury during rheumatic diseases by producing inflammatory mediators such as interleukin-6 (IL-6). The increased level of purine and pirimidine nucleotides in the synovial fluid of rheumatoid arthritis (RA) patients could activate the large family of P2 receptors. Thus, we investigated the presence of P2 receptors in human type B synoviocytes from rheumatoid joints, also evaluating whether the P2X7 receptor is involved in IL-6 release. Reverse transcriptase polymerase chain reaction analysis revealed messenger ribonucleic acid (mRNA) expression for the P2X1, P2X2, P2X4, P2X5, P2X6, P2X7, P2Y1, P2Y4, P2Y11, P2Y12, P2Y13, and P2Y14 but not the P2X3, P2Y2, and P2Y6 receptors. The expression of the P2X7 receptor was confirmed by Western blot analysis. Adenosine triphosphate (ATP) and the P2X7 receptor agonist 2'-3'-O-(4-benzoylbenzoyl)ATP (BzATP) triggered an increase in intracellular calcium, thereby suggesting the expression of functional P2 receptors, including the P2X7 receptor. Moreover, BzATP treatment upregulated both IL-6 mRNA and protein expression. Synoviocytes spontaneously released low quantities of IL-6; the incubation with BzATP induced the release of larger amounts of the cytokine, and such a release was blunted by the P2X7 antagonist oxidized ATP. The selective P2X1 and P2X3 receptor agonist alpha,beta-methylene ATP did not affect IL-6 release. Finally, BzATP failed to induce a significant uptake of the large-molecule YO-PRO, thus suggesting the lack of pore formation after P2X7 receptor stimulation. In conclusion, among the different P2 receptors expressed on human RA type B synoviocytes, the P2X7 receptor may modulate IL-6 release but not inducing changes in cell membrane permeability.
18576291 Functional outcome after stroke in patients with rheumatoid arthritis and systemic lupus e 2008 Jul 15 OBJECTIVE: To compare outcomes following stroke rehabilitation among patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) versus patients with neither RA nor SLE (non-RA/SLE). METHODS: We conducted a retrospective analysis using a national database of patients with stroke admitted to inpatient rehabilitation between 1994 and 2001. Primary outcomes were discharge disposition and functional status, rated by the Functional Independence Measure (FIM) Instrument, at discharge and at followup. The independent variable was RA or SLE. Covariates were age, sex, race/ethnicity, admission FIM ratings, additional comorbidities (none, 1-3, and >3), type of stroke, and length of stay. RESULTS: We studied 47,853 patients with stroke, 368 with RA, and 119 with SLE. Discharge dispositions were similar for patients with RA and non-RA/SLE (81% discharged home). At discharge, the average FIM rating for patients with RA was 85.8, compared with 87.8 for non-RA/SLE patients. At followup, the average FIM rating for patients with RA was 95.9, compared with 99.6 for non-RA/SLE patients. RA was associated with lower FIM ratings at discharge and followup in multivariate analyses. SLE was associated with younger age (17.5 years). However, patients with SLE had similar discharge dispositions and FIM ratings to non-RA/SLE patients. CONCLUSION: RA was associated with lower functional status ratings at discharge and followup. Outpatient therapy for patients with RA may reduce long-term assistance. Patients with SLE were younger, but had similar functional outcomes to patients without RA/SLE, suggesting early morbidity from stroke among patients with SLE.
19033869 Biologic therapy (TNF-alpha antagonists)-induced psoriasis: a cytokine imbalance between T 2008 Dec We report 3 patients with psoriatic arthritis and 2 with rheumatoid arthritis who developed worsening, and/or de novo psoriasis, and/or psoriasiform rash, while on tumor necrosis factor antagonist therapy. All 5 patients initially presented with active skin, and/or joint inflammatory involvement, and exhibited significant clinical response to tumor necrosis factor antagonist therapy. Within approximately 6 months, however, psoriatic and/or psoriasiform rash developed de novo in 2 rheumatoid arthritis patient and exacerbated in the other 3 patients. Biopsy findings revealed histologic and immunohistochemical changes indistinguishable from psoriasis.Psoriatic rash improved after discontinuation of biologic therapy and/or initiation of a short course of oral prednisone. One patient with psoriatic arthritis was rechallenged with infliximab due to exacerbation of both psoriasis and psoriatic arthritis, and this was followed by prompt improvement of both conditions. At 6 months follow-up, this patient remains under excellent control. To date, there have been over 50 cases of this type of dermatologic complication described. Interferon alpha seems to play an important role in the pathogenesis of this complication. This type of complication has been described with all 3 available tumor necrosis factor inhibitors, and most patients improve after discontinuation of biologic therapy.
18221087 Fibroblast growth factors, fibroblast growth factor receptors, diseases, and drugs. 2006 Jun Maintenance of endothelial cells (ECs), the building blocks of the vascular tree, is a presumed function of fibroblast growth factors (FGFs). In particular, the two prototypic members of FGF family, namely FGF1 and FGF2, due to their potent mitogenic and pro-migratory activities, have the ability to induce metabolic and phenotypic changes in ECs that are required to stimulate angiogenesis. In addition to FGF1 and FGF2, 23 other members of the FGF family have since been identified and characterized and they are reviewed in relation to their disease pathology. Particular emphasis is given to the biology of the FGFs and FGFRs on how they mediate the onset of angiogenesis. The focus of the present review is to survey what is known about the role of the currently identified FGFs and their four high affinity tyrosine kinase receptors in diseases and the angiogenesis-targeted drugs currently in clinical trials. Some new and promising patented drugs that target the angiogenic pathway are discussed. Examination of the currently patented drugs may identify more potent and specific regulators of FGF/FGFR signaling system for treatment of tumor angiogenesis in clinical settings. Additionally, novel drug development strategies are highlighted and reviewed.
16430744 Oral tuberculosis associated with a treatment with anti-rheumatic drugs. 2006 Feb BACKGROUND: The use of immunosuppressive medication is a dominant risk factor for infection in patients with rheumatoid arthritis (RA). Methotrexate (MTX) is one of the traditional disease-modifying antirheumatic drugs. Adalimumab [a human anti-tumor necrosis factor-alpha (anti-TNF-alpha) monoclonal antibody] represent an important advance in the treatment of RA and has been recently come in use. TNF-alpha plays a role in the host defense against Mycobacterium tuberculosis and notably in granuloma formation. Infections occur at a high rate among those who use one or the combination of the two medications. METHOD: We examined a female patient that was referred to our department for evaluation and treatment of a granular lesion on the soft palate and uvula, complaining of mild dysphagia. The patient was treated for 4 months with MTX and adalimumab for RA before the oral lesion appeared. RESULTS: The histopathological examination of a specimen of the oral lesion, taken by biopsy, showed a chronic inflammation characterized by tuberculous granulomas. Polymerase chain reaction test and culture of a new specimen was positive for M. tuberculosis. CONCLUSIONS: The therapeutic use of MTX or/and adalimumab for the treatment of RA or few others diseases, can cause oral tuberculosis.
17195359 [Inhibition of cardiolipin binding antibodies from synovial fluids of patients with arthri 2006 May In the presented study was prooven that aCl antibodies cross-reacting with LPS (endotoxin) from arthritic synovial fluids are part of the aPL antibodies pool and correlated with presence in joints bacterial cell wall components like LPS-showing endotoxin presence in synovial fluids and they may be usefull in differential diagnosis of the different kind of arthritis and also in explanation of their aetiology at all--especially in cases of early, undifferentiated arthritis.
16469081 Adult variant of self-healing papular mucinosis in a patient with rheumatoid arthritis: pr 2006 Jan According to a recent classification, self-healing papular mucinosis (SHPM) is a subtype of papular mucinosis (also known as lichen myxedematosus), which is in turn a type of idiopathic localized cutaneous mucinosis. SHPM tends to occur in children, but there have been a few reports of an adult type. We report a 70-year-old Japanese woman who presented with reddish, rice-kernel-sized papules of a few days' duration on her right arm. She had a 25-year history of rheumatoid arthritis, which had been well treated with a low dose of corticosteroid as well as some other medications. No paraproteinemia or thyroid dysfunction were observed. The eruptions spontaneously resolved within 2.5 months of onset. Histological findings showed a well-circumscribed mucinous stroma surrounded by dermal mesenchymal cells, such as fibroblast-like cells in the middle of the dermis. Immunohistochemically, these cells were positive only for vimentin on the mucinous lesion. On the circumference of the mucinous lesion, these cells expressed either CD34 or factor XIIIa (FXIIIa). Because vimentin was common to dermal mesenchymal cells, we defined the cells expressing CD34 or FXIIIa, except for vimentin+ cells lacking CD34 or FXIIIa, as dermal dendritic cells (DDC). The findings of the present case suggest that CD34+ or FXIIIa+ DDC and tryptase-positive mast cells on the perilesional area in combination with vimentin+ cells on the mucinous lesion might have given rise to the dermal deposition of mucin in our case. These cells, which are possibly activated in an autoimmune manner associated with rheumatoid arthritis, might play important roles in the development of dermal deposition of mucin in SHPM.
17376315 Lectin-like oxidized low-density lipoprotein receptor-1: protein, ligands, expression and 2007 Mar 5 OBJECTIVE: To review the recent research progress in lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) including its protein, ligands, expression and pathophysiological significance. Data sources Information included in this article was identified by searching of PUBMED (1997 - 2006) online resources using the key term LOX-1. STUDY SELECTION: Mainly original milestone articles and critical reviews written by major pioneer investigators of the field were selected. RESULTS: The key issues related to the LOX-1 protein as well as ligands for LOX-1. Factors regulating the expression of LOX-1 were summarized. The pathophysiological functions of LOX-1 in several diseases were discussed. CONCLUSIONS: Identification of LOX-1 and a definition of its biological role in pathophysiologic states provide deeper insight into the pathogenesis of some cardiovascular diseases especially in atherosclerosis and provide a potential selective therapeutic approach. LOX-1 is unlocking and drugs targeting LOX-1 might be a promising direction to explore.
18070636 Results of revision metacarpophalangeal joint surgery in rheumatoid patients following pre 2007 Dec PURPOSE: Primary silicone metacarpophalangeal (MCP) joint arthroplasties have good results that deteriorate with time. The purpose of this study was to assess indications, patient satisfaction, and clinical and radiographic results following revision surgery in rheumatoid patients who had previously undergone silicone MCP arthroplasty. METHODS: Twenty hands in 18 patients (62 implants) had revision silicone MCP arthroplasties between 1986 and 2005 and had a greater than 1-year follow-up period (mean 5 y). A retrospective chart review was performed to collect preoperative and intraoperative data. Patients were then re-examined and administered a questionnaire addressing subjective outcome and satisfaction. RESULTS: Intraoperatively, 76% of the implants were fractured. Thirteen of 17 synovial biopsies revealed giant cell foreign body reaction. Preoperatively, the average arc of motion was from 16 degrees to 50 degrees , and ulnar drift was 24 degrees . Postoperatively, the average arc of motion was from 20 degrees to 54 degrees , and ulnar drift was 13 degrees . X-rays of 14 hands revealed that 15 of 44 revised implants had fractured. Sixteen patients (18 hands) were available to complete questionnaires. Twelve patients (14 hands) were satisfied and 3 were dissatisfied. Five of 16 patients would not have the revision again. These patients had worse average postoperative ulnar drift (30 degrees vs 9 degrees ) than the other 11 patients. All patients except one who had preoperative pain had at least moderate pain relief, and of the 6 patients who had revision surgery because of pain, 5 were satisfied. CONCLUSIONS: Revision silicone arthroplasty provides excellent pain relief, and the majority of patients were pleased with their results. Objective results, however, were generally poor. Soft tissue reconstruction is more difficult to achieve than the primary procedure, as evidenced by minimal improvement in ulnar drift, a high rate of implant fracture, and no change in arc of motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
18945303 Effect of folic or folinic acid supplementation on methotrexate-associated safety and effi 2009 Mar BACKGROUND: Methotrexate is a folic acid antagonist widely used for the treatment of inflammatory disorders for more than 50 years. Methotrexate is a standard systemic therapy for severe psoriasis and rheumatoid arthritis. Folic acid supplementation has been advocated to limit the toxicity of methotrexate on blood cells, gastrointestinal tract and liver. However, there is still controversy regarding the usefulness of folic acid supplementation. OBJECTIVES: We sought to assess the evidence for the efficacy of folic acid supplementation in patients treated with methotrexate for inflammatory diseases. We also investigated whether folic acid supplementation may decrease the efficacy of methotrexate. METHODS: Cochrane and MEDLINE databases were systematically searched. Randomized controlled trials in patients treated with methotrexate for rheumatoid arthritis or psoriasis with or without arthritis were included. Study selection, assessment of methodological quality, data extraction and analysis were carried out by two independent researchers. We selected double-blind randomized placebo-controlled trials. Analysis was performed for each subgroup of side-effects: gastrointestinal, mucocutaneous, haematological and hepatic. RESULTS: Six randomized controlled trials met the inclusion criteria, with a total sample of 648 patients. There were 257 patients in the placebo group, 198 patients treated with folic acid, and 193 patients treated with folinic acid. The statistical analysis showed a significant reduction of 35.8% of hepatic side-effects induced by methotrexate for patients with supplementation with folic or folinic acid (95% confidence interval -0.467 to -0.248). There was no statistical difference for mucocutaneous and gastrointestinal side-effects although there was a trend in favour of supplementation. The effect of supplementation on haematological side-effects could not be assessed accurately due to a low incidence of these events in the population studied. We were unable to analyse the effect of supplementation on the effectiveness of methotrexate, as markers of activity used in each study were not comparable. CONCLUSIONS: Supplementation with folic acid is an effective measure to reduce hepatic adverse effects associated with methotrexate treatment. There is no difference between folinic acid and folic acid, but the lower cost of the latter promotes its use.
18719928 Outcome of stemmed shoulder hemi-arthroplasty revision. 2009 Jun INTRODUCTION: We report our experience of revision of failed stemmed shoulder hemi-arthroplasty for causes other than infection. MATERIAL/METHOD: Seventeen revisions were followed for a minimum of 2 years. Fifteen cases were revised for symptomatic glenoid erosion. Sixteen were revised to a total shoulder arthroplasty and one to a cuff tear arthropathy head. RESULT: The mean visual analogue pain score following revision surgery was reduced from 6.7 to 3.2 (P = 0.008). However the Constant-Murley and the Association of Shoulder and Elbow Surgeons scores failed to improve significantly. CONCLUSION: We conclude that revision surgery for failed stemmed shoulder hemi-arthroplasty improves pain but not function.
18160419 Discrepancies between the EULAR response criteria and the NICE guidelines for continuation 2008 Feb OBJECTIVES: A discrepancy exists between the National Institute for Health and Clinical Excellence (NICE) guidelines for continuation of TNF therapy in RA and EULAR response criteria. We performed a retrospective study of patients starting anti-TNF therapy to establish how many NICE non-responders would have met EULAR response criteria, and whether this may increase. METHOD: We calculated the percentage of NICE non-responders who would have met EULAR moderate response criteria. We then compared the mean decrease in disease activity score (DAS28) for patients with low and high baseline scores. We analysed trends for treating RA in Derby with anti-TNF to address whether we were treating less active disease over time. RESULTS: At 3 months (n = 271 patients), 7.7% of NICE non-responders would have met EULAR moderate response criteria. At 6 months (n = 240 patients) this was 23.7%. Patients starting with a higher DAS28 had a significantly greater absolute drop in score. The mean decrease between the 1st and 3rd tertiles of patients divided by baseline DAS28 was significant at 3 and 6 months (P < 0.001). Derby rheumatologists were treating less active RA over time. Comparing the mean DAS28 baseline between the 1st and 3rd tertiles of patients divided by anti-TNF commencement date was significant (P < 0.001). CONCLUSIONS: A significant minority of NICE non-responders would fall within the moderate EULAR response criteria. This is likely to increase in future due to the increasing tendency to initiate anti-TNF in patients with less active disease. Consequently, NICE guidelines should be brought in line with EULAR response criteria.
17133579 Rheumatoid arthritis association with the FCRL3 -169C polymorphism is restricted to PTPN22 2006 Dec OBJECTIVE: Variants in genes encoding the Fc receptor-like 3 (FcRL-3) and the class II major histocompatibility complex (MHC) transactivator proteins have been associated with an increased risk of rheumatoid arthritis (RA) in Japanese and Nordic populations, respectively. The aim of this study was to investigate these associations in a Canadian Caucasian cohort of RA cases and healthy controls. METHODS: A total of 1,187 RA patients and 462 healthy controls were genotyped for FCRL3 and MHC2TA gene variants associated with RA. Epistasis between the FCRL3 -169C and the PTPN22 1858T variants was also examined. RESULTS: An association was detected between RA and both the FCRL3 -169C allele (OR 1.19, P = 0.023) and the homozygous genotype (OR 1.41, P = 0.027), but association of the MHC2TA promoter region variant (-168G) with RA was not replicated. Stratification of the RA cohort by PTPN22 genotypes revealed the FCRL3 risk variant and RA association was stronger in the patient subgroup lacking PTPN22 1858T variants (P = 0.004) and was not detectable in the subgroup with PTPN22 1858T variants (P = 0.52). The PTPN22 association with RA was greater in the absence than in the presence of the FCRL3 -169C allele (P = 0.0008 versus P = 0.001). The PTPN22 1858T variant also increased the risk of autoimmune thyroid disease (AITD) in the RA patients, whereas the FCRL3 risk variant was protective against AITD. CONCLUSION: Our findings support an association of RA with an FCRL3 functional polymorphism and reveal that this association is stronger in the absence of PTPN22 risk genotypes. These findings support a genetic heterogeneity across RA populations, suggesting that both the FCRL3 and PTPN22 genes play roles in RA susceptibility, but in different individuals.
16802342 Direct modulation of rheumatoid inflammatory mediator expression in retinoblastoma protein 2006 Jul OBJECTIVE: It is known that the cyclin-dependent kinase inhibitor (CDKI) gene p21(Cip1) suppresses rheumatoid inflammation by down-modulating type I interleukin-1 receptor (IL-1RI) expression and inhibiting JNK activity. The purpose of this study was to determine whether CDK activity directly modulates the production of inflammatory molecules in patients with rheumatoid arthritis (RA). METHODS: Genes for the CDKIs p16(INK4a) and p18(INK4c), a constitutively active form of retinoblastoma (RB) gene product, cyclin D1, and CDK-4, were transferred into RA synovial fibroblasts (RASFs). RASFs were also treated with a synthetic CDK-4/6 inhibitor (CDK4I). Levels of matrix metalloproteinase 3 (MMP-3), monocyte chemoattractant protein 1 (MCP-1), and IL-1RI expression were determined by Northern blotting, real-time polymerase chain reaction analysis, and enzyme-linked immunosorbent assay. CDKIs were immunoprecipitated to reveal their association with JNK. RESULTS: Transfer of the p16(INK4a) and p18(INK4c) genes and CDK4I suppressed the production of MMP-3 and MCP-1. Unlike p21(Cip1), neither CDKI gene inhibited IL-1RI or JNK. The expression of MMP-3 was up-regulated when CDK-4 activity was augmented. This regulation functioned at the messenger RNA (mRNA) level in MMP-3, but not in MCP-1. Transfer of active RB suppressed the production of MMP-3 and MCP-1 without changing their mRNA levels. CONCLUSION: CDK-4/6 modulated the production of MMP-3 and MCP-1. MMP-3 production was regulated primarily at the mRNA level in an RB-independent manner, whereas MCP-1 production was controlled posttranscriptionally by RB. These results show that cell cycle proteins are associated with control of mediators of inflammation through multiple pathways.
18341615 The tumour suppressor gene p53 modulates the severity of antigen-induced arthritis and the 2008 May p53 is a transcription factor with a well-described role in the induction of apoptosis and cell cycle arrest as part of a protective response to a variety of stressful stimuli. Expansion of inflamed tissue in rheumatoid arthritis has been related to the loss of functioning p53, and the severity of collagen-induced arthritis is increased in p53-/- mice. Our objective was to assess the role of p53 in a model of adaptive immunity, antigen-induced arthritis (AIA). AIA was induced in p53-/- and wild-type mice by priming with methylated bovine serum albumin followed by intra-articular challenge. Severity of arthritis was assessed using a standardized scoring system and synovial apoptosis was detected by TdT-mediated biotin-dUTP nick-end labelling. Splenocyte proliferation was measured by [H(3)] incorporation and interferon (IFN)-gamma release. Splenocyte viability was assessed using Titreglow. Splenic T cell activation status was assessed by flow cytometry. Serum cytokines were measured using enzyme-linked immunosorbent assay. Increased severity of AIA in p53-/- mice was associated with decreased synovial apoptosis and with increased delayed-type hypersensitivity response, increased mitogen and antigen-induced splenocyte proliferation and increased IFN-gamma release in p53-/- mice compared with wild-type mice. Antigen-specific immunoglobulin responses were equivalent in both groups. Splenocyte viability was increased in p53-/- mice but T cell apoptosis was equivalent. T cell activation markers were increased in p53-/- mice compared with wild-type mice. Lipopolysaccharide-induced tumour necrosis factor release was increased in p53-/- mice with a trend to increased interleukin-6 in p53-/- mice compared with littermates. p53 is involved in the modulation of adaptive and innate immune responses relevant to arthritis models and is also involved in the modulation of severity of AIA by both cell-cycle dependent and cell-cycle-independent mechanisms.
17896809 Increased nuclear factor-kappaB activation in peripheral blood monocytes of patients with 2007 Oct OBJECTIVE: Rheumatoid arthritis (RA) is a disease characterized by prolonged production of tumor necrosis factor-alpha (TNF-alpha), which is regulated by the Rel/nuclear factor-kappaB (NF-kappaB) transcription factors. We assessed NF-kappaB activation in peripheral blood mononuclear cells (PBMC), peripheral blood lymphocytes (PBL), and monocytes from patients with RA, patients with ankylosing spondylitis (AS), and healthy subjects. METHODS: NF-kappaB activation was determined by electrophoretic mobility shift assays and by Western blotting in PBMC, monocytes, and PBL isolated from peripheral blood of patients with RA, patients with AS, and healthy subjects and determined after ex vivo pretreatment of PBMC, PBL, and monocytes of patients with RA and healthy subjects with infliximab and with etanercept. RESULTS: Enhanced NF-kappaB activation was observed in monocytes, PBL, and PBMC isolated from patients with RA, but not in PBMC, PBL, and monocytes of patients with AS and healthy subjects. The NF-kappaB complex was composed of p50 and p65 subunits and its activation required inhibitor of NF-kappaBalpha degradation. We observed a positive correlation between the NF-kappaB activation in monocytes, PBL, and PBMC, and TNF-alpha levels in peripheral blood of patients with RA. Ex vivo treatment with infliximab and etanercept decreased NF-kappaB activation in monocytes of patients with RA, but not in PBL and PBMC, and not in healthy subjects. CONCLUSION: Our results indicate a role for NF-kappaB activation and TNF-alpha in the activation of monocytes of patients with RA, and suggest an important role of circulating monocytes in RA pathogenesis.
16879057 Optimization of an enzymatic method for the determination of lysosomal N-acetyl-beta-D-hex 2006 BACKGROUND: Our goal was to develop a suitably sensitive assay for N-acetyl-beta-D-hexosaminidase (HEX) and beta-glucuronidase to allow their use as markers of joint diseases. METHODS: We optimized a spectrophotometric method for the determination of lysosomally derived HEX and beta-glucuronidase in synovial fluid on a microplate reader to improve its utility. HEX and beta-glucuronidase act on the 4-nitrophenyl derivatives N-acetyl-beta-glucosamine and beta-D-glucuronide, respectively, to produce 4-nitrophenol, which can be measured at 405 nm on a microplate reader. RESULTS: Maximum enzyme activity was observed at pH 4.7 in a citrate-phosphate buffer for HEX and at pH 4.5 in an acetate buffer for beta-glucuronidase. A 10-microL sample with 30 microL of substrate solution and 40 microL of appropriate buffer produced measurable amounts of 4-nitrophenol after incubation for 60 min at 37 degrees Celsius. Reactions were terminated by the addition of 200 microL of 200 mM borate buffer (pH 9.8). CONCLUSIONS: The assay is sufficiently sensitive for small volumes of synovial fluid, and is useful for the clinical diagnosis of joint diseases.