Increased levels of stromelysin-1 and tissue inhibitor of metalloproteinases-1 in sera from patients with rheumatoid arthritis

Use of some bone-related cytokines as predictors for rheumatoid arthritis severity by neural network analysis

Background. Rheumatoid arthritis (RA) is characterized by synovial membrane inflammation that results in joint damage. Many earlier studies have measured cytokines for a better diagnosis of RA. In the present study, three bone biomarkers (osteopontin, Stromelysin-1 (MMP3), and vascular endothelial growth factor-A (VEGF)) are examined for their ability to estimate the severity of disease by using artificial neural network (NN) analysis and regression analysis. Methods: The study enrolled 87 RA patients and 44 healthy control subjects. The biomarkers were measured by the enzyme-linked immunosorbent assay (ELISA) technique. Disease Activity Score (28 joints) and C-reactive protein (CRP) (DAS28-CRP) was calculated by using (DAS28-CRP) calculator. The patients with DAS28-CRP5.1 are considered as having high disease activity (HDA). While patients group with DAS28-CRP5.1 are considered as moderate disease activity (MDA). The neural network (NN) analysis was used for the differentiation between groups. Results. Results showed that the most sensitive predictor for high disease activity (HDA) of RA is MMP3, followed by osteopontin and VEGF. These three biomarkers can differentiate significantly between HDA and moderate disease activity (MDA) with a relatively high size effect (Partial 2=0.323, p0.001). HDA group has a significantly higher MMP3, CRP, RF, and anti-citrullinated protein antibodies (ACPA) than the MDA group. Conclusions. The use of the NN analysis indicated that the measured biomarkers help predict the HDA state in RA patients. MMP3 and osteopontin are diagnostic biomarkers for the severity of RA disease and related to many disease-related characteristics with a sensitivity of 88.9% and specificity of 68.4%.

Concentration of Selected Metalloproteinases and Osteocalcin in the Serum and Synovial Fluid of Obese Women with Advanced Knee Osteoarthritis

The aim of the study was to evaluate the levels of selected MMPs (matrix metalloproteinases) and osteocalcin in the serum and synovial fluid of obese women with osteoarthritis and their correlations with clinical status. The studied group consisted of 39 overweight females undergoing primary total knee arthroplasty due to osteoarthritis (OA). The staging of knee OA was evaluated according to the Ahlbӓck and Kellgren–Lawrence scores. Synovial fluid and peripheral blood samples were obtained. The levels of selected MMPs and osteocalcin were assessed using commercial ELISA kits. The mean value of MMP3 was significantly higher in patients with more advanced disease in both serum (p = 0.0067) and synovial fluid (p = 0.0328). The pro-MMP13 level tended to be higher in synovial fluid in the case of more advanced stages (p = 0.0882), with no tendency regarding the serum level (p = 0.9595). The synovial level of pro-MMP1 was significantly correlated with the synovial concentration of MMP9 and MMP3. The synovial level of MMP9 also showed a significant correlation with the synovial level of MMP3 and pro-MMP13. Furthermore, it was found that the serum level of MMP3 was significantly correlated with the synovial pro-MMP13 level. A correlation between the osteocalcin level in serum and its synovial level was determined. The serum MMP9 level showed a significant correlation with BMI, whereas the synovial MMP9 level was notably correlated with age. Our results showed that the levels of MMP3, MMP9, and pro-MMP13 increased in more advanced radiological stages of OA, indicating the underlying inflammatory process of OA.

Progressive Bone Destruction in Rapidly Destructive Coxopathy Is Characterized by Elevated Serum Levels of Matrix Metalloprotease-3 and C-Reactive Protein

OBJECTIVE

Rapidly destructive coxopathy (RDC) is a rare condition characterized by rapid joint space narrowing; however, its pathology remains unclear. This study aimed to clarify the association of laboratory biomarkers with the radiological progression of RDC.

METHODS

We examined 34 female and 4 male patients with RDC between October 2010 and April 2018. Patients were divided into 3 groups according to the progressive radiographic staging of RDC. Group 1 patients had progressive obliteration of the joint space without subchondral destruction (n = 11), group 2 had progressed subchondral destruction (n = 18), and group 3 had cessation of bone destruction observed for more than 6 months (n = 9). Clinical evaluation results were assessed using the Japanese Orthopedic Association hip score. Blood test results, including serum matrix metalloproteinase-3 (MMP-3), and C-reactive protein (CRP), were also evaluated.

RESULTS

There were no significant differences in patient background or Japanese Orthopedic Association hip scores among the groups. However, there were significant differences in MMP-3 levels among groups, with MMP-3 levels in group 2 being significantly higher than those in group 3 (group 2, 118.4 ± 81.2 ng/mL; group 3, 42.5 ± 15.1 ng/mL, p < 0.001). The CRP levels in group 2 were also significantly higher than those in group 3 (group 2, 0.77 ± 0.92 mg/dL; group 3, 0.13 ± 0.07 mg/dL, p = 0.019), but elevated CRP levels in group 2 decreased back to the reference range.

CONCLUSIONS

Matrix metalloproteinase-3 and CRP are the biomarkers of RDC progression but not of its occurrence. Severe inflammatory response may be associated with bone destruction in RDC.

Simultaneous determination of CXCL7 chemokine and MMP3 metalloproteinase as biomarkers for rheumatoid arthritis

This paper reports the preparation of the first dual electrochemical immunosensor for the simultaneous determination of the CXCL7 chemokine and the MMP3 metalloproteinase as relevant biomarkers for the better diagnosis and monitoring of rheumatoid arthritis derived from the multiple biomarkers measurement. The developed immunosensor involves the use of carboxylated magnetic beads (MBs) and dual screen-printed carbon electrodes (SPdCEs). Sandwich-type configurations implied the covalent immobilization of specific anti-CXCL7 (cAb1) or anti-MMP3 (cAb2) capture antibodies onto MBs and the use of biotinylated detection antibodies with further labelling with HRP-Strept conjugates. The resulting MBS bioconjugates were magnetically captured on the respective working electrode of the SPdCE and the determination of the antigens was accomplished by measuring the amperometric responses of H₂O₂ mediated by hydroquinone (HQ) at a potential value of -0.20 V. The dual immunosensor provided calibration plots with linear ranges between 1 and 75 ng mL^-1 (CXCL7) (R² = 0.997) and from 2.0 to 2000 pg mL^-1 (MMP3) (R² = 0.998) with detection limits of 0.8 ng mL^-1 and 1.2 pg mL^-1, respectively. The assay took 2 h 20 min for the simultaneous determination of both biomarkers. The dual immunosensor was successfully applied to the analysis of human serum from positive and negative RA patients.

Comparison of efficacy between anti-IL-6 receptor antibody and other biological disease-modifying antirheumatic drugs in the patients with rheumatoid arthritis who have knee joint involvement: the ANSWER cohort, retrospective study

OBJECTIVE

We aimed to investigate the efficacy of anti-IL-6 receptor antibody (aIL-6) and other biologic disease-modifying antirheumatic drugs (bDMARDs), such as TNF inhibitor and CTLA4-Ig in the treatment of rheumatoid arthritis (RA) in patients with knee joint involvement.

METHODS

We retrospectively analyzed 1059 treatment courses of patients with RA who visited our hospitals and were treated with bDMARDs. We categorized them into two groups, with or without knee joint involvement. We investigated the clinical disease activity index (CDAI) at baseline and 12 weeks after the initiation of bDMARDs. We compared the improvement of the markers between aIL-6 and other bDMARDs.

RESULTS

Treatment with aIL-6 significantly increased ΔCDAI (n = 91, 15.4 ± 1.1; mean ± SEM) in patients with knee joint involvement, compared to other bDMARDs (n = 232, 11.0 ± 0.7) at 12 weeks (P = 0.006). Following the multivariate analysis adjusted by the CDAI levels at baseline, age, gender, concomitant use of methotrexate, and the first use of bDMARDs, ΔCDAI levels were significantly higher in aIL-6, compared to other bDMARDs (P = 0.02). However, there was no significant difference in ΔCDAI improvement between aIL-6 (n = 162, 5.9 ± 0.6) and other bDMARDs (n = 573, 6.2 ± 0.4) in patients without swollen knee joints. ΔCDAI levels were equally increased in patients with shoulder and elbow joint involvement.

CONCLUSION

aIL-6 was more effective in the patients with RA and knee joint involvement, compared to other bDMARDs.

Cartilage oligomeric matrix protein, C-terminal cross-linking telopeptide of type II collagen, and matrix metalloproteinase-3 as biomarkers for knee and hip osteoarthritis (OA) diagnosis: a systematic review and meta-analysis

OBJECTIVE

This study was design to examine the diagnostic performance of cartilage oligomeric matrix protein (COMP), C-terminal cross-linking telopeptide of type II collagen (CTX-II), and matrix metalloproteinase-3 (MMP-3) as biomarker for knee and hip OA.

METHODS

Systematic search on multiple databases was completed in January 2018 using certain keywords. COMP, CTX-II, MMP-3 levels in knee and hip OA patients and healthy individuals were collected and calculated. Differences between subgroups were expressed as standardized mean differences (SMD). Subgroup analyses were performed to compare COMP, CTX-II, and MMP-3 performance between measuring sources, genders, large and small sample size and diagnostic criteria for OA patients.

RESULTS

A moderate performance of COMP in distinguishing between knee (SMD: 0.68; 95% confidence intervals (CI): 0.43-0.93; P < 0.0001) or hip (SMD: 0.25; 95% CI, 0.10, 0.40; P = 0.0008) OA patients and controls were found. CTX-II showed a moderated standardised mean differences (SMD) of 0.48 (95% CI, 0.32, 0.64; P < 0.0001) in the detection of knee OA and a large SMD of 0.76 (95% CI, 0.09, 1.42; P = 0.03) in diagnosing hip OA. A small SMD of 0.32 (95% CI, -0.03, 0.67; P = 0.07) was found for MMP-3 performance and the results did not reach statistic significance. Progression study revealed potential effectiveness of serum COMP in predicting OA progression. Subgroup analysis showed that serum COMP and urinary CTX-II performed better in male than female. Study size and diagnostic criteria did not significantly influence the pooled SMD, but they might be the sources of heterogeneity among studies.

CONCLUSION

The overall results indicates that serum COMP and urinary CTX-II can distinguish between knee or hip OA patients and control subjects. Serum COMP is effective in predicting OA progression.Further researches with rigorous study design and a larger sample size are required to validate our findings.

Methodology and Applications of Disease Biomarker Identification in Human Serum

Biomarkers are biomolecules that serve as indicators of biological and pathological processes, or physiological and pharmacological responses to a drug treatment. Because of the high abundance of albumin and heterogeneity of plasma lipoproteins and glycoproteins, biomarkers are difficult to identify in human serum. Due to the clinical significance the identification of disease biomarkers in serum holds great promise for personalized medicine, especially for disease diagnosis and prognosis. This review summarizes some common and emerging proteomics techniques utilized in the separation of serum samples and identification of disease signatures. The practical application of each protein separation or identification technique is analyzed using specific examples. Biomarkers of cancers of prostate, breast, ovary, and lung in human serum have been reviewed, as well as those of heart disease, arthritis, asthma, and cystic fibrosis. Despite the advancement of technology few biomarkers have been approved by the Food and Drug Administration for disease diagnosis and prognosis due to the complexity of structure and function of protein biomarkers and lack of high sensitivity, specificity, and reproducibility for those putative biomarkers. The combination of different types of technologies and statistical analysis may provide more effective methods to identify and validate new disease biomarkers in blood.

Weighting with the Lansbury articular index improves the correlation of ultrasound score with serum matrix metalloproteinase-3 level in rheumatoid arthritis patients

OBJECTIVE

To determine whether weighting improves the correlation of ultrasound (US) score with serum matrix metalloproteinase-3 (MMP-3) level in rheumatoid arthritis (RA).

METHODS

As ultrasound examination was performed on 100 RA patients, and the severity of synovial effusion and synovial hypertrophy and the blood flow were semi-quantitatively graded from 0 to 3 by using the gray-scale (GS) and power Doppler (PD) modes. We then calculated the sums of the scores of the 28 joints of each patient in the 2 modes, that is, the GS28 and PD28 scores, as well as the respective scores weighted using the Lansbury articular index (LAI, shoulder and elbow, × 12; wrist, × 8; and knee, × 24)-Lans GS28 and Lans PD28 scores.

RESULT

The Lans PD28 score showed a higher correlation with MMP-3 (r = 0.591; 95% confidence interval, 0.446-0.705, p < 0.0001) than the existing measures. The scores of the large joints-the knee, shoulder, and elbow-correlated well with the serum MMP-3 level.

CONCLUSION

Weighting with the LAI can improve the correlation of US findings with serum MMP-3 level. Bidirectional approach based on both serum MMP-3 level and US scores can further improve the assessment of disease activity in RA patients.

Acute-phase serum amyloid A regulates tumor necrosis factor α and matrix turnover and predicts disease progression in patients with inflammatory arthritis before and after biologic therapy

OBJECTIVE

To investigate the relationship between acute-phase serum amyloid A (A-SAA) and joint destruction in inflammatory arthritis.

METHODS

Serum A-SAA and C-reactive protein (CRP) levels, the erythrocyte sedimentation rate (ESR), and levels of matrix metalloproteinase 1 (MMP-1), MMP-2, MMP-3, MMP-9, MMP-13, tissue inhibitor of metalloproteinases 1 (TIMP-1), vascular endothelial growth factor (VEGF), and type I and type II collagen-generated biomarkers C2C and C1,2C were measured at 0-3 months in patients with inflammatory arthritis commencing anti-tumor necrosis factor α (anti-TNFα) therapy and were correlated with 1-year radiographic progression. The effects of A-SAA on MMP/TIMP expression on RA fibroblast-like synoviocytes (FLS), primary human chondrocytes, and RA/psoriatic arthritis synovial explant cultures were assessed using real-time polymerase chain reaction, enzyme-linked immunosorbent assay, antibody protein arrays, and gelatin zymography.

RESULTS

Serum A-SAA levels were significantly (P < 0.05) correlated with MMP-3, the MMP-3:TIMP-1 ratio, C1,2C, C2C, and VEGF. The baseline A-SAA level but not the ESR or the CRP level correlated with the 28-joint swollen joint count and was independently associated with 1-year radiographic progression (P = 0.038). A-SAA increased MMP-1, MMP-3, MMP-13, and MMP/TIMP expression in RA FLS and synovial explants (P < 0.05). In chondrocytes, A-SAA induced MMP-1, MMP-3, and MMP-13 messenger RNA and protein expression (all P < 0.01), resulting in a significant shift in MMP:TIMP ratios (P < 0.05). Gelatin zymography revealed that A-SAA induced MMP-2 and MMP-9 activity. Blockade of the A-SAA receptor SR-B1 (A-SAA receptor scavenger receptor-class B type 1) inhibited MMP-3, MMP-2, and MMP-9 expression in synovial explant cultures ex vivo. Importantly, we demonstrated that A-SAA has the ability to induce TNFα expression in RA synovial explant cultures (P < 0.05).

CONCLUSION

A-SAA may be involved in joint destruction though MMP induction and collagen cleavage in vivo. The ability of A-SAA to regulate TNFα suggests that A-SAA signaling pathways may provide new therapeutic strategies for the treatment of inflammatory arthritis.

Levels of serum matrix metalloproteinase-3 correlate with disease activity in the enthesitis-related arthritis category of juvenile idiopathic arthritis

OBJECTIVE

Serum matrix metalloproteinase-3 (MMP-3) has been shown to reflect disease activity in ankylosing spondylitis (AS) and rheumatoid arthritis. Elevated levels have been found in juvenile idiopathic arthritis (JIA). In the enthesitis-related arthritis category of JIA (JIA-ERA), we studied whether serum MMP-3 levels and ratios of MMP-3/tissue inhibitor of metalloproteinase (TIMP-1) are correlated with disease activity and whether they are sensitive to change in disease activity.

METHODS

A total of 54 patients with JIA-ERA (International League of Associations for Rheumatology criteria) were enrolled for study. Baseline disease activity measures included tender and swollen joint counts, Maastricht AS Enthesitis Score, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), patient assessment of pain and global disease activity, physician assessment of global disease activity, and erythrocyte sedimentation rate (ESR). Serum MMP-3 and TIMP-1 levels were measured using ELISA. A group of 24 patients were followed up for longitudinal study.

RESULTS

The mean age of 54 patients (48 males) at disease onset was 11.8 ± 4.19 years and duration of disease was 5.2 ± 4.3 years. Median ESR was 65 mm/h (range 46.5-97) and median BASDAI was 3.4 (range 2.5-4.7). Median MMP-3, TIMP-1, and MMP-3/TIMP-1 ratio were 50.4 ng/ml (IQR 13.0-193.8), 228.9 ng/ml (IQR 108.2-290.4), and 0.3 (IQR 0.07-1.13), respectively. At inclusion MMP-3 levels correlated directly with various disease activity measures: tender joint count (TJC; r = 0.60), swollen joint count (SJC; r = 0.45), BASFI (r = 0.29), BASDAI (r = 0.32), ESR (r = 0.49), physician global assessment (r = 0.40), patient visual analog scale for pain (r = 0.28), and patient global assessment (r = 0.38; all p < 0.05). MMP-3/TIMP-1 ratio correlated only with TJC (r = 0.51), SJC (r = 0.39), and ESR (r = 0.34; p < 0.05). At followup, change in MMP-3 correlated with changes in TJC (r = 0.42) and SJC (r = 0.44; p < 0.05), while change in ESR did not correlate with change in any disease activity measure.

CONCLUSION

MMP-3 levels are a good marker for disease activity in JIA-ERA.

Aryl hydrocarbon receptor deficiency in T cells suppresses the development of collagen-induced arthritis

The contributions of aryl hydrocarbon receptor (Ahr) to the pathogenesis of rheumatoid arthritis have not been elucidated. Here, we show that Ahr deficiency ameliorated collagen-induced arthritis, a mouse model of RA. Collagen-immunized Ahr KO mice showed decreased serum levels of such proinflammatory cytokines as IL-1β and IL-6. The Th17 and Th1 cell populations in lymph nodes from these mice decreased and increased, respectively, whereas the percentage of regulatory T cells was unchanged. Interestingly, a lack of Ahr specifically in T cells significantly suppressed collagen-induced arthritis development, whereas Ahr deficiency in macrophages had no effect. These finding indicate that the development of experimental autoimmune arthritis depends on the presence of Ahr in T cells, and that Th1/Th17 balance may be particularly important for this process.

Matrix metalloproteinase-3 inhibitor retards treadmill running-induced cartilage degradation in rats

INTRODUCTION

The effect of intra-articular injection of matrix metalloproteinase (MMP)-3 inhibitor was investigated in a rat model to understand the role of MMP-3 in cartilage degradation induced by excessive loading from running.

METHODS

A total of 24 male Wistar rats were randomly assigned into groups of sedentary control (SED), high-intensity running (HIR), HIR + low dosage of MMP-3 Inhibitor I (HIRI1), and HIR + high dosage of MMP-3 Inhibitor I (HIRI2). Rats in the HIR, HIRI1 and HIRI2 groups were intensively trained for six weeks on the treadmill. Those in HIRI1 and HIRI2 groups were provided bilateral intra-articular injections of 80 μL of 0.2 mM and 2 mM MMP-3 Inhibitor I in knee joints once a week, respectively. Blood samples were collected to measure serum MMP-3 level using ELISA. Femoral condyles were collected to observe cartilage characteristics by histochemistry, and MMP-3 as well as collagen II was measured by immunohistochemistry. In addition, cartilage samples were obtained to assess MMP-3 mRNA expression by RT-PCR.

RESULTS

Histological examination showed osteoarthritic changes in rats after six weeks of high intensity running. In comparison to the SED group, significant decreases in glycosaminoglycans (GAG) and collagen content were found in the HIR group, which corresponded to significant increase in serum MMP-3 level, cartilage MMP-3 activity and gene expression. However, such a degradative process was considerably retarded by intra-articular injection of MMP-3 inhibitor at higher dosage. Statistical differences were found between the HIR and HIRI2 groups with regard to GAG and collagen II content, serum MMP-3 level, cartilage MMP-3 activity and gene expression.

CONCLUSIONS

High-intensity running for six weeks may lead to cartilage degradation in a rat model. It was shown that the chrondroprotective effect was offered by the use of intra-articular injection of MMP-3 inhibitor. MMP-3 acts as the key mediator of this catabolic change under such mechanical condition. The results also showed that MMP-3 selective inhibitor may be an effective option for retarding such osteoarthritic changes.

Soluble biomarkers of cartilage and bone metabolism in early proof of concept trials in psoriatic arthritis: effects of adalimumab versus placebo

BACKGROUND

There is growing interest in soluble biomarkers that could be used on the group level for screening purposes in small proof of principle studies during early drug development. We investigated early changes in serum levels of several candidate biomarkers involved in cartilage and bone metabolism following the initiation of adalimumab as a prototypic active treatment in psoriatic arthritis (PsA) compared to placebo.

MATERIALS AND METHODS

Twenty-four PsA patients were randomized to receive either adalimumab 40 mg s.c. every other week or placebo for 4 weeks, followed by an open label extension phase. Serum samples were obtained at baseline and after 4 and 12 weeks of treatment and analyzed for levels of CPII and PINP (synthesis of type II and type I procollagen), melanoma inhibitory activity (MIA) (chondrocyte anabolism), matrix metalloproteinase (MMP)-3, C2C and cartilage oligomeric matrix protein (COMP) (type II collagen degradation), osteocalcin (OC) (bone formation), NTX-I and ICTP (both type I collagen degradation).

RESULTS

After 4 weeks, there was a significant decrease in serum MMP-3 levels in adalimumab-treated patients (P<0.005), while no change was observed in the placebo group. A significant increase in serum MIA was noted after adalimumab therapy (P<0.005) but not after placebo treatment. After 12 weeks, there was a marked reduction in serum MMP-3 in both groups (P<0.005), whereas other markers did not show significant changes compared to baseline.

CONCLUSION

MMP-3 and MIA could serve as soluble biomarkers associated with inflammation as well as joint remodelling and destruction and may, together with clinical evaluation and in combination with other biomarkers, assist in distinguishing between effective and ineffective therapy in small, proof-of-principle studies of short duration in PsA.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN23328456.

A multiparameter approach to monitor disease activity in collagen-induced arthritis

Introduction

Disease severity in collagen-induced arthritis (CIA) is commonly assessed by clinical scoring of paw swelling and histological examination of joints. Although this is an accurate approach, it is also labour-intensive and the application of less invasive and less time-consuming methods is of great interest. However, it is still unclear which of these methods represents the most discriminating measure of disease activity.

Methods

We undertook a comparative analysis in which different measurements of inflammation and tissue damage in CIA were studied on an individual mouse level. We compared the current gold standard methods - clinical scoring and histological examination - with alternative methods based on scoring of X-ray or micro-computed tomography (CT) images and investigated the significance of systemically expressed proteins, involved in CIA pathogenesis, that have potential as biomarkers.

Results

Linear regression analysis revealed a marked association of serum matrix metalloproteinase (MMP)-3 levels with all features of CIA including inflammation, cartilage destruction and bone erosions. This association was improved by combined detection of MMP-3 and anti-collagen IgG2a antibody concentrations. In addition, combined analysis of both X-ray and micro-CT images was found to be predictive for cartilage and bone damage. Most remarkably, validation analysis using an independent data set proved that variations in disease severity, induced by different therapies, could be accurately represented by predicted values based on the proposed parameters.

Conclusions

Our analyses revealed that clinical scoring, combined with serum MMP-3, anti-collagen IgG2a measurement and scoring of X-ray and micro-CT images, yields a comprehensive insight into the different aspects of disease activity in CIA.

FK506 inhibition of gliostatin/thymidine phosphorylase production induced by tumor necrosis factor-α in rheumatoid fibroblast-like synoviocytes

Gliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities. The purpose of this study was to determine the inhibitory effects of FK506 (tacrolimus) on GLS production in rheumatoid arthritis (RA). We investigated the modulation of serum GLS by FK506 therapy and the effect of FK506 on the production of GLS in fibroblast-like synoviocytes (FLSs). Serum samples were collected from 11 RA patients with active disease at baseline and after 12 weeks of FK506 treatment. Serum concentrations of GLS and matrix metalloproteinase (MMP)-3 were measured by ELISA and found to be down-regulated in responders evaluated with a disease activity score. Patient FLSs were cultured and stimulated by tumor necrosis factor (TNF)-α with or without FK506. The expression levels of GLS were determined using reverse transcription-polymerase chain reaction (RT-PCR) and enzyme immunoassay and shown to be significantly increased. GLS levels in TNF-α-stimulated FLSs were reduced by FK506 treatment. Our data show a novel mechanism for the action of physiological concentrations of FK506 in RA that regulates the production of GLS in FLSs.

Gene expression profiles of disc tissues and peripheral blood mononuclear cells from patients with degenerative discs

The objective of this study was to analyze gene expression profiles of intervertebral disc samples and peripheral blood mononuclear cells (PBMCs) from patients with degenerative discs using Agilent's Human 1A Oligo microarray. RNA samples from disc tissue and PBMCs were obtained from patients with degenerative discs and from subjects in a control group. RNA samples were reverse-transcribed into Cy5-labeled cRNA, combined with a Cy3-labeled reference and hybridized to oligonucleotide microarrays. Microarrays were scanned by Gene-Pix 4000B and data were analyzed using GenePixPro 3.0 software. The microarray data were validated in the same RNA samples by qRT-PCR analysis of selected genes. For the disc tissue, the mRNA expressions of 522 genes changed obviously in the degeneration group, accounting for approximately 2.64% of all analyzed transcripts. These included transcription-related, ion channel and transport protein, receptor, protein synthesis and modifying, growth factor, etc. For PBMCs, the expressions of 62 genes changed obviously in the patients in the degeneration group. These changes included ion channel, transport protein, transcription-related, DNA synthesis and repair, metalloprotease, immune globulin-related, growth factor-related, extracellular matrix-related, adhesion molecule, etc. Analyzed on the association of the differential expression of genes between disc tissue and PBMCs, some genes were not compatible. The course of intervertebral disc denegation is a complicated dynamic process, however, and may mainly be local pathogenesis. These findings furnish new data for the mechanistic investigation of degenerative discs.

Testing of the OMERACT 8 Draft Validation Criteria for a Soluble Biomarker Reflecting Structural Damage in Rheumatoid Arthritis: A Systematic Literature Search on 5 Candidate Biomarkers

Objective.

To test the OMERACT 8 draft validation criteria for soluble biomarkers by assessing the strength of literature evidence in support of 5 candidate biomarkers.

Methods.

A systematic literature search was conducted on the 5 soluble biomarkers RANKL, osteoprotegerin (OPG), matrix metalloprotease (MMP-3), urine C-telopeptide of types I and II collagen (U-CTX-I and U CTX-II), focusing on the 14 OMERACT 8 criteria. Two electronic voting exercises were conducted to address: (1) strength of evidence for each biomarker as reflecting structural damage according to each individual criterion and the importance of each individual criterion; (2) overall strength of evidence in support of each of the 5 candidate biomarkers as reflecting structural damage endpoints in rheumatoid arthritis (RA) and identification of omissions to the criteria set.

Results.

The search identified 111 articles. The strength of evidence in support of these biomarkers reflecting structural damage was low for all biomarkers and was rated highest for U-CTX-II [score of 6.5 (numerical rating scale 0–10)]. The lowest scores for retention of specific criteria in the draft set went to criteria that refer to the importance of animal studies, correlations with other biomarkers reflecting damage, and an understanding of the metabolism of the biomarker.

Conclusion.

Evidence in support of any of the 5 tested biomarkers (MMP-3, CTX-I, CTX-II, OPG, RANKL) was inadequate to allow their substitution for radiographic endpoints in RA. Three of the criteria in the draft criteria set might not be required, but few omissions were identified.

Matrix metalloproteinase-3 on ligamentum flavum in degenerative lumbar spondylolisthesis

STUDY DESIGN

Human ligamentum flavum (LF) was examined for the activity level of matrix metalloproteinase-3 (MMP-3) in degenerative spondylolithesis (DS) patients using immunohistochemistry, Western blot, reverse transcriptase-polymerase chain reaction (RT-PCR), and quantitative real-time PCR.

OBJECTIVE

To investigate the hypothesis that the activity of MMP-3 is elevated in LF of DS patients, which might contribute to DS pathogenesis.

SUMMARY OF BACKGROUND DATA

MMP-3 is a proteinase produced by connective tissue cells and is responsible for the degradation and modification of extracellular matrix molecules. MMP-3 activity has been established in articular cartilage, synovial membrane, and intervertebral discs, but not in the LF.

METHODS

The experimental group consisted of 18 patients with DS and the control group consisted of 18 patients with spinal stenosis (SS) without any instabilities. MMP-3 expression was measured with in situ using immunohistochemistry and both for mRNA and protein levels.

RESULTS

The MMP-3 positive cell ratio in the LF observed in DS patients was substantially higher than in SS patients (P = 0.030). In Western blot, the average optical density (OD) of MMP-3 was higher in LF of DS than of SS (P = 0.028). There was greater MMP-3 expression in DS patients as quantified by RT-PCR (P = 0.004).

CONCLUSION

Our study shows that MMP-3 expression in the LF of DS patients was significantly higher than in SS patients. Increased MMP-3 expression may be associated with the degenerative changes of LF in DS patients comprising one of the mechanisms of pathogenesis in DS.

Relationship between radiological knee osteoarthritis and biochemical markers of cartilage and bone degradation (urine CTX-II and NTX-I): the Matsudai Knee Osteoarthritis Survey

Biochemical markers of cartilage and bone degradation are becoming increasingly important in the evaluation of knee osteoarthritis (OA). To clarify the correlation between radiological knee OA and urine CTX-II (C-terminal crosslinking telopeptide of collagen type II) or urine NTX-I (N-terminal crosslinking telopeptide of type I collagen), we conducted a cross-sectional study in the cohorts of the epidemiological knee survey at the Matsudai district in Niigata Prefecture, Japan. Urine specimens were collected from 296 subjects, and CTX-II and NTX-I were measured using ELISA. Standing knee AP X-rays were obtained and graded according to the Kellgren-Lawrence classification. The subjects were then divided by gender, age (40- to 59-year-old group and 60- to 79-year-old group), and the X-ray grade (Grade 0, 1, Grade 2, and Grade 3, 4). In non-OA (Grade 0, 1) subjects, the 60- to 79-year-old group had significantly higher CTX-II values than the younger group only in females. The subjects of both genders aged over 60 years of age with OA Grade 3, 4 had significantly higher CTX-II values than the Grade 0, 1 group or the Grade 2 group. For NTX-I, there were no significant differences between each OA grade although the Grade 3, 4 group females from 60 to 79 years of age had higher values than the Grade 2 group. In addition, in the 60- to 79-year-old subjects of both genders, a positive correlation was observed between the urine CTX-II and urine NTX-I. For the subjects ranging from 60 to 79 years of age in both genders, the urine CTX-II values indicate the progression of OA. In addition, the weak but positive correlation between urine CTX-II and urine NTX-I in the subjects ranging from 60 to 79 years of age in both genders suggests that bone resorption and cartilage degradation appear to develop in parallel.

Comparison of renal and vascular protective effects between telmisartan and amlodipine in hypertensive patients with chronic kidney disease with mild renal insufficiency

The present study was conducted to compare the renal and vascular protective effects of telmisartan and amlodipine in untreated hypertensive chronic kidney disease (CKD) patients with moderate renal insufficiency. Thirty hypertensive CKD patients were randomly assigned to receive telmisartan 40 mg (n = 15) or amlodipine 5 mg (n = 15) once daily for 12 months. Changes in blood pressure, serum creatinine, 24-h creatinine clearance (Ccr), proteinuria, brachial-ankle pulse wave velocity (baPWV), intima-media thickness (IMT), plasma interleukin-6 (IL-6), plasma matrix metalloproteinase (MMP)-9 and lipid profiles were monitored in all patients. Before treatment, there were no significant differences in these parameters between the telmisartan and amlodipine groups. Over the 12 month observation period, blood pressure decreased equally in both groups. However, serum creatinine, proteinuria, baPWV, IMT, plasma levels of IL-6 and MMP-9 and total cholesterol decreased and 24-h Ccr increased more strikingly in the telmisartan group than the amlodipine group. These data suggest that telmisartan is more effective than amlodipine for protecting renovascular functions, and potentially for ameliorating atherosclerosis, in hypertensive CKD patients with moderate renal insufficiency.

Oral and Maxillofacial Pathology: Interleukin-1 β, interleukin-6, and tissue inhibitor of metalloproteinase-1 in the synovial fluid of the temporomandibular joint with respect to cartilage destruction

OBJECTIVE

The distribution and biological roles of interleukin (IL)-1 beta, IL-6, and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the synovial fluid of patients with non-inflammatory chronic temporomandibular joint (TMJ) disorders were evaluated in relation to pain upon joint movements and X-ray and magnetic resonance imaging (MRI) findings.

MATERIALS AND METHODS

TMJ aspirates were obtained from 48 patients (48 joints) with chronic TMJ disorders and from 18 controls (18 joints). The IL-1 beta and IL-6 levels in the aspirates were determined by using an enzyme-linked immunosorbent assay and the TIMP-1 level was measured by an enzyme immunoassay. Following examinations for pain upon joint movements and X-ray and MRI observations, the IL-1 beta, IL-6, and TIMP-1 levels and frequencies of their detection were compared.

RESULTS

The IL-1 beta level and frequency of detection showed no correlation with pain upon joint movements or with the X-ray and MRI findings. In the frequency of detection of IL-6, there were significant differences between control (no detection) and all chronic TMJ disorder groups that were classified by imaging diagnosis (P < 0.001). A correlation was also noted between the presence of IL-6 and pain upon joint movements. The IL-6 level was correlated with the TIMP-1 level and with pain upon joint movements. TIMP-1 level was correlated with pain upon joint movements. The TIMP-1 was present in higher level from patients with chronic TMJ disorders who exhibited osseous changes on the X-ray images.

CONCLUSION

The results indicated that the IL-6 and TIMP-1 levels in the TMJ aspirates of patients with chronic TMJ disorders have been raised. The former was not detected in the TMJ aspirates of the control. These findings suggest that IL-6 and TIMP-1 might play a role in the etiology of chronic TMJ disorders, but further studies are needed to validate this.

Autoimmunity and oxidatively modified autoantigens

Oxidative damage mediated by reactive oxygen species results in the generation of deleterious by-products. The oxidation process itself and the proteins modified by these molecules are important mediators of cell toxicity and disease pathogenesis. Aldehydic products, mainly the 4-hydroxy-2-alkenals, form adducts with proteins and make them highly immunogenic. Proteins modified in this manner have been shown to induce pathogenic antibodies in a variety of diseases including systemic lupus erythematosus (SLE), alcoholic liver disease, diabetes mellitus (DM) and rheumatoid arthritis (RA). 8-oxodeoxyguanine (oxidatively modified DNA) and oxidized low-density lipoproteins (LDL) occur in SLE, a disease in which premature atherosclerosis is a serious problem. In addition, immunization with 4-hydroxy-2-nonenal (HNE) modified 60 kD Ro autoantigen induces an accelerated epitope spreading in an animal model of SLE. Advanced glycation end product (AGE) pentosidine and AGE modified IgG have been shown to correlate with RA disease activity. Oxidatively modified glutamic acid decarboxylase is important in type 1 DM, while autoantibodies against oxidized LDL are prevalent in Behcet's disease. The fragmentation of scleroderma specific autoantigens occurs as a result of oxidative modification and is thought to be responsible for the production of autoantibodies through the release of cryptic epitopes. The administration of antioxidants is a viable untried alternative for preventing or ameliorating autoimmune disease, particularly on account of the overwhelming evidence for the involvement of oxidative damage in autoimmunity. However, this should be viewed in the light of disappointing results obtained with the use of antioxidants in cardiovascular disease.

Association of the 5A/6A promoter polymorphism of the MMP-3 gene with the radiographic progression of rheumatoid arthritis

Matrix metalloproteinases (MMPs) as a family of zinc-dependent endopeptidases have been involved in remodeling the extracellular matrix (ECM) in rheumatoid arthritis (RA). In RA patients synovial fluid and serum include enhanced levels of MMP-3. The 5A/6A polymorphism in the MMP-3 gene promoter can contribute to the severity of RA on account of a higher promoter activity of the 5A allele in vitro. The aim of the study was to associate the 5A/6A polymorphism of the MMP-3 gene with radiographic progression of RA. A total of 128 RA patients according to the ACR criteria were available for the study. Radiographs of both hands, obtained from all RA patients, were scored using the modified Sharp/van der Heijde method and the Steinbrocker method. The total Sharp score (TSS) and the annual radiographic progression rate (TSS/year) were calculated. Significant association with the 5A/6A polymorphism was found between patients with TSS/year <or= 1.00 and those with TSS/year > 1.00 in allelic frequencies (Pa = 0.046) and also in genotype distribution (Pg = 0.04). Compared to other genotypes the prevalence of 5A/5A genotype was lower within patients with TSS/year <or= 1.00 (odds ratio [OR] = 0.2; 95% confidence interval [CI] 0.04-0.85; P = 0.01). Also, in comparison to genotypes 5A/6A and 5A/5A, the prevalence of 6A/6A genotype was higher within patients with nonerosive RA (OR = 2.65; 95% CI 1.03-6.83, P = 0.02). Results obtained in this study provide the evidence of an association of the 5A/6A promoter polymorphism of the MMP-3 gene to the radiographic progression of RA.

Serum levels of matrix metalloproteinase 3 (stromelysin 1) for monitoring synovitis in rheumatoid arthritis

CONTEXT

Matrix metalloproteinase 3 (MMP-3) is expressed in synovial tissues and involved in cartilage destruction in rheumatoid arthritis and osteoarthritis.

OBJECTIVE

To study whether measurement of MMP-3 serum concentrations is useful to monitor the activity of rheumatoid synovitis.

DESIGN

Levels of MMP-3 in serum and synovial tissue samples obtained from 29 rheumatoid arthritis patients and 20 osteoarthritis patients were measured by the 1-step sandwich enzyme immunoassay system.

RESULTS

Levels of MMP-3 in the serum and synovial samples were significantly higher in rheumatoid arthritis than in osteoarthritis (P < .001), and the levels correlated directly with each other (r = 0.712, P < .001; N = 49). Immunohistochemistry demonstrated almost exclusive localization of MMP-3 to the lining cells in rheumatoid synovium. The immunoreactivity correlated directly with the scores of synovial inflammatory cell infiltration (r = 0.606, P < .001; n = 29) and the MMP-3 levels in the synovial tissues (r = 0.564, P = .001; n = 29) and those in the serum samples (r = 0.529, P = .003; n = 29) in rheumatoid arthritis. Levels of MMP-3 in rheumatoid serum samples dropped to low values at 1 and 2 weeks after total knee arthroplasty, while the levels of C-reactive protein increased at 1 week and the erythrocyte sedimentation rate and counts of white blood cells and platelets were unchanged at 1 and 2 weeks postoperative.

CONCLUSIONS

Our results demonstrate that MMP-3 levels in the serum of rheumatoid arthritis patients correlate with the levels produced by the synovial lining cells and suggest that the activity of rheumatoid synovitis can be monitored by measuring serum levels of MMP-3.

Serum pro-matrix metalloproteinase-3 as an indicator of disease activity and severity in rheumatoid arthritis: comparison with traditional markers

Matrix metalloproteinase-3 (MMP-3) production increases in rheumatoid arthritis (RA) and has been proposed as a marker of disease activity and joint damage. The aim of this cross-sectional study is to examine the usefulness of serum proMMP-3 as an indicator of disease activity and severity in comparison with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Serum proMMP-3 was measured by a quantitative ELISA in 85 RA patients and 70 healthy subjects. Clinical and laboratory measures of disease activity and severity were obtained. Radiological joint damage was assessed by the method of Larsen. Serum proMMP-3 was significantly higher in RA patients than that in the healthy subjects. The active RA patients had significantly higher serum proMMP-3 than the inactive patients. Serum proMMP-3 was significantly correlated with some parameters of disease activity including swollen joints count, proximal interphalangeal joint score, morning stiffness, and Health Assessment Questionnaire; however, ESR and serum CRP were better correlated with all indicators of the disease activity than proMMP-3. The analysis of receiver operating characteristic supported that ESR and CRP had higher performance for reflection of activity compared to proMMP-3. There were no significant associations among Larsen score and proMMP-3, ESR, and CRP. Our results suggest that the cross-sectional measurement of serum proMMP-3 could not give additional information about RA disease activity compared to ESR and CRP, and could not give any information about joint damage.

Generation of neoantigenic epitopes after posttranslational modification of type II collagen by factors present within the inflamed joint

OBJECTIVE

Collagen-induced arthritis is a commonly accepted model of rheumatoid arthritis (RA). However, it has been difficult to substantiate the involvement of autoimmunity to type II collagen (CII) in the pathogenesis of RA. The aim of this investigation was to determine if CII, modified by reactive oxidant species present within the inflamed joint, could generate neoantigenic epitopes.

METHODS

Oxidants that play a role in acute and chronic inflammation and are present in the rheumatoid joint (hydroxyl radical, hypochlorous acid, and peroxynitrite) were used for modification of native CII. In addition, CII was glycated with ribose, since nonenzymatic oxidative reactions by glycation are evident in RA. Modifications were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 3-dimensional fluorescence followed by enzyme-linked immunosorbent assay (ELISA) and Western blotting, using, as probes, sera from patients with RA and from patients with other inflammatory and noninflammatory joint diseases.

RESULTS

Only 1 RA serum sample showed strong binding to native CII. In contrast, binding to modified CII was increased in 14 of 31 RA sera, of which 7 were strong binders and 7 were moderate binders. Among the non-RA serum samples, only 1 yielded a strong reaction to modified CII and 5 of 41 were moderate binders. Samples that showed the strongest binding to modified CII in ELISA also showed strong binding to various fragmented or aggregated forms of CII in Western blots, as well as strong binding to fragmented CII present in RA synovial fluid.

CONCLUSION

When modified by conditions found within the inflamed joint, CII acts as an autoantigen in RA.

The diagnostic utility of anti-cyclic citrullinated peptide antibodies, matrix metalloproteinase-3, rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein in patients with erosive and non-erosive rheumatoid arthritis

Objective: To compare the diagnostic utility of laboratory variables, including matrix metalloproteinase-3 (MMP-3), anti-cyclic citrullinated peptide (CCP) antibodies, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) in patients with erosive and non-erosive rheumatoid arthritis (RA).

Methods: We assembled a training set, consisting of 60 patients with RA, all fulfilling the revised criteria of the American College of Rheumatology. A commercial enzyme linked immunosorbent assay (ELISA) was used both to test for anti-CCP antibodies (second generation ELISA kit) and MMP; RF were detected by latex-enhanced immunonephelometric assay. CRP was measured by latex turbidimetric immunoassay.

Results: The levels of anti-CCP antibody titers and ESR were significantly higher in patients with erosive disease than those in non-erosive RA patients (p < 0.001 and 0.0341) respectively. Moreover, a higher frequency of elevated titers of anti-CCP antibodies was found in RA patients with erosions compared to patients with non-erosive RA (78.3% vs. 43.2% respectively). The ROC curves of anti-CCP passed closer to the upper left corner than those other markers and area under the curve (AUC) of anti-CCP was significantly larger than AUC of other markers (0.755 for anti-CCP, 0.660 for ESR, 0.611 for CRP, 0.577 for RF, and 0.484 for MMP-3 female).

A positive predictive value was higher for anti-CCP antibodies in comparison to other markers. We did not find significant statistical correlation between anti-CCP antibody titers and inflammatory markers such as ESR or CRP. However, we confirmed the correlation of elevated titers of anti-CCP antibodies and RF in both groups of patients whereas the degree of correlation was more significant in non-erosive patients.

Conclusion: The results of our study suggest that the presence of elevated anti-CCP antibody titers have better diagnostic performance than MMP-3, RF, CRP and ESR in patients with erosive RA.

Comparison of modern marker proteins in serum and synovial fluid in patients with advanced osteoarthrosis and rheumatoid arthritis

Numerous studies have focused on the significance of modern marker proteins in the synovial fluid of the knee joint and in the serum both, for osteoarthritis (OA) and rheumatoid arthritis (RA). The relationship between the serum concentrations and the concentrations in the synovial fluid is still unclear. Synovial fluid and serum samples were obtained from 13 patients with advanced OA and from 8 patients with severe RA and concentrations of MMP-1, MMP-3, MMP-13, TIMP-1, COMP and MIA/CD-RAP were determined. All values were normalized against the total protein concentrations. Serum concentrations of MMP-13 in the RA-group were statistically higher than the synovial values (P<0.05). MMP-13 was the only marker protein that revealed distinct higher levels in the serum than in the synovial fluid. The study design allows only conclusions about advanced stages of RA and OA. Longitudinal investigations may provide further information about the value of MMP-13 as a potential marker to monitor the course of RA and OA.

Lectin-like oxidized low-density lipoprotein receptor 1 mediates matrix metalloproteinase 3 synthesis enhanced by oxidized low-density lipoprotein in rheumatoid arthritis cartilage

OBJECTIVE

To investigate for the presence of oxidized low-density lipoprotein (ox-LDL) and lectin-like oxidized LDL receptor 1 (LOX-1) in cartilage specimens from rheumatoid arthritis (RA) joints and to determine whether the interaction of ox-LDL with LOX-1 can induce matrix metalloproteinase 3 (MMP-3) in articular cartilage explant culture.

METHODS

Human articular cartilage specimens obtained from patients with RA, osteoarthritis (OA), and femoral neck fractures were examined for LOX-1 and ox-LDL by confocal fluorescence microscopy. The association between ox-LDL and LOX-1 was evaluated by immunofluorescence analysis. Articular cartilage specimens from patients with femoral neck fractures were incubated with ox-LDL, with or without preincubation with neutralizing anti-LOX-1 antibody. MMP-3 synthesis by chondrocytes in explant cartilage was evaluated by immunofluorescence, and protein secretion into conditioned medium was monitored by immunoblotting and enzyme-linked immunosorbent assay.

RESULTS

The majority of the RA chondrocytes stained positively with both anti-LOX-1 and anti-ox-LDL antibodies; however, no positive cells were found in OA and normal cartilage specimens. Anti-LOX-1 antibody suppressed the binding of DiI-labeled ox-LDL to chondrocytes in explant culture, suggesting that the interaction was mediated by LOX-1. In contrast to native LDL, ox-LDL induced MMP-3 synthesis by articular chondrocytes in association with the induction of LOX-1, which resulted in enhanced secretion of MMP-3 into the culture medium. Anti-LOX-1 antibody reversed ox-LDL-stimulated MMP-3 synthesis to control levels.

CONCLUSION

Ox-LDL, principally mediated by LOX-1, enhanced MMP-3 production in articular chondrocytes. Increased accumulation of ox-LDL with elevated expression of LOX-1 in RA cartilage indicates a specific role of the receptor-ligand interaction in cartilage pathology in RA.

Involvement of matrix metalloproteinases and their inhibitors in peripheral synovitis and down-regulation by tumor necrosis factor ? blockade in spondylarthropathy

OBJECTIVE

To investigate the role of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in spondylarthropathy (SpA) synovitis.

METHODS

Paired samples of synovial biopsy tissue as well as serum and synovial fluid (SF) from 41 patients with SpA and 20 patients with rheumatoid arthritis (RA) and serum samples from 20 healthy controls were analyzed by immunohistochemistry and enzyme-linked immunosorbent assay for the presence of MMPs 1, 2, 3, and 9 and TIMPs 1 and 2. In addition, sera from 16 patients with ankylosing spondylitis (AS) and peripheral synovitis and 17 patients with AS and exclusively axial involvement were analyzed. An additional cohort of SpA patients was analyzed at baseline and after 12 weeks of infliximab treatment.

RESULTS

Staining for MMPs and TIMPs showed a cellular and interstitial pattern in the synovial lining and sublining layers that was similar between the RA and SpA patients. Involvement of MMPs and TIMPs in SpA synovitis was suggested by the correlation with cellular infiltration, vascularization, and cartilage degradation. Higher serum levels of MMPs 3 and 9 were revealed in SpA and RA patients as compared with healthy controls. Production of MMP-3, but not MMP-9, in the serum reflected the presence of peripheral synovitis, as indicated by 1) the correlation between serum levels, SF levels (which were 1,000-fold higher than the serum levels), and synovial expression of MMP-3, 2) the increased levels of MMP-3 in AS patients with peripheral disease and not exclusively axial involvement, and 3) the correlation of serum and SF MMP-3 with parameters of synovial, but not systemic, inflammation. The modulation of the MMP/TIMP system by tumor necrosis factor alpha (TNFalpha) blockade was confirmed by the down-regulation of all MMPs and TIMPs in the synovium and a pronounced and rapid decrease of serum MMP-3.

CONCLUSION

MMPs and TIMPs are highly expressed in SpA synovitis and mirror both the inflammatory and tissue-remodeling aspects of the local disease process. Serum MMP-3, originating from the inflamed joint, represents a valuable biomarker for peripheral synovitis. Modulation of the MMP/TIMP system by infliximab could contribute to the antiinflammatory and tissue-remodeling effects of TNFalpha blockade in SpA.

High diagnostic performance of ELISA detection of antibodies to citrullinated antigens in rheumatoid arthritis

OBJECTIVE

We investigated the rheumatoid arthritis (RA) diagnostic performances of anti-cyclic citrullinated peptide antibody (anti-CCP) and antifilaggrin antibody (AFA) in comparison with RF and matrix metalloproteinase-3 (MMP-3).

METHODS

We used a second generation enzyme-linked immunosorbent assay (ELISA) kit for the detection of anti-CCP. We constructed recombinant human filaggrin, which was citrullinated in vitro by human peptidylarginine deiminase, and subsequently used it as the coating antigen for AFA-ELISA. A total of 549 RA patients and 208 other rheumatic disease patients were included in the study.

RESULTS

The specificities of anti-CCP (88.9%) and AFA (94.7%) were superior to those of RF (81.7%) and MMP-3 (49.5%). The sensitivity of anti-CCP (87.6%) was superior to all others. However, the sensitivity of AFA (68.7%) was inferior to those of RF (69.8%) and MMP-3 (75.7%). Furthermore, receiver operating characteristic curves of anti-CCP and AFA passed closer to the upper left corner than those of RF and MMP-3, and the areas under the curves (AUC) of AFA and anti-CCP were significantly larger. In addition, the AUC of anti-CCP was significantly larger than that of AFA.

CONCLUSION

ELISA detection of antibodies to citrullinated antigens, especially a second generation anti-CCP, showed higher discriminative ability than other assays, including RF, and would be useful to aid the diagnosis of RA in clinical practice.

Turnover of type II collagen and aggrecan in cartilage matrix at the onset of inflammatory arthritis in humans: Relationship to mediators of systemic and local inflammation

OBJECTIVE

To determine in vivo the extent of damage to, and changes in turnover of, articular cartilage type II collagen (CII) and the proteoglycan aggrecan following the onset of inflammatory arthritis in humans, and to examine the hypothesis that there are direct relationships between cartilage biomarkers of damage/turnover and clinical, histologic, and molecular markers of inflammation.

METHODS

Synovial fluid (SF) and synovial membrane (SM) were obtained by arthroscopy, and a synovitis score was determined, in 32 patients with rheumatoid arthritis (RA) (13 with early untreated disease, 19 with established disease), 18 with psoriatic arthritis (PsA), and 10 with osteoarthritis (OA). Systemic disease activity markers were recorded, and SM CD3+ T cells, CD4+ T cells, CD68+ macrophages, and lining layer hyperplasia were quantified. SF levels of tumor necrosis factor alpha (TNFalpha), interleukin-10 (IL-10), matrix metalloproteinase 1 (MMP-1), MMP-3, Col2-3/4C(Long mono) neoepitope (C2C) (reflecting collagenase cleavage of cartilage CII), C-propeptide of type II procollagen (PIICP) (a biosynthesis marker), keratan sulfate (KS), and the 846 epitope of aggrecan (turnover) were measured by enzyme-linked immunosorbent assay or radioimmunoassay.

RESULTS

Levels of cartilage degradation products in early RA or early PsA were not elevated above levels in OA, although in early inflammatory arthritis, TNFalpha and MMP-1 levels were similar to those observed in late inflammatory disease and higher than those in OA. PIICP was reduced in early RA. Correlations were observed between the SF C2C neoepitope level and the Health Assessment Questionnaire score, C-reactive protein level, plasma viscosity, synovitis score, and SF TNFalpha and MMP-1 levels. KS epitope content was reduced in direct relation to SM macrophage infiltration in the sublining and lining layers and in the presence of elevated SF MMP-3. Both SF MMP-1 and SF MMP-3 levels correlated with CD4+ T cell infiltration and lining layer hyperplasia in the SM, and MMP-1 levels correlated with lining layer CD68 levels, but TNFalpha and IL-10 levels did not.

CONCLUSION

Except for CII synthesis, there were no significant changes in extracellular matrix turnover of aggrecan or CII in the early stages of human inflammatory arthritis. However, the direct correlation between the increases in TNFalpha and MMP-1 production and collagen degradation suggests that collagenase cleavage of cartilage collagen is related to the activities of TNFalpha and MMP-1. The reduction in CII synthesis in early RA may contribute to the developing pathology, since a lack of synthesis of this molecule would inhibit maintenance of cartilage matrix.

Gene transfer of the catabolic inhibitor TIMP-1 increases measured proteoglycans in cells from degenerated human intervertebral discs

STUDY DESIGN

Cells from degenerated intervertebral discs were transduced with an adenoviral vector delivering cDNA of the catabolic inhibitor, TIMP-1, and alterations in the measured proteoglycan were assessed.

OBJECTIVES

To assess the potential of TIMP-1 to favorably modify the proteoglycan content of degenerated intervertebral disc cells.

SUMMARY OF BACKGROUND DATA

Gene therapy with anabolic factors has resulted in increased proteoglycan synthesis in intervertebral disc cells. Biochemical analysis of degenerated discs has revealed elevated levels of the catabolic enzymes, matrix metalloproteinase, suggesting an intimate role of these factors in the degenerative process. The use of TIMP-1, an endogenous inhibitor of matrix metalloproteinase, via gene therapy may provide an additional method to alter the degenerative processes occurring in the intervertebral disc.

MATERIALS AND METHODS

Degenerated intervertebral disc were isolated from eight patients undergoing elective surgical procedures. Cells were cultured in monolayer and transduced with different concentrations of either an adenoviral-tissue inhibitor of metalloproteinase-1 (Ad-TIMP-1) or adenoviral-bone morphogenic protein-2 (Ad-BMP-2) construct. Cells were cultured in a three-dimensional pellet and proteoglycan synthesis was assessed via 35S-sulfur incorporation.

RESULTS

Gene delivery of TIMP-1 and BMP-2 increased measured proteoglycan synthesis at each concentration assessed. IVD cells treated with Ad-TIMP-1 demonstrated an optimal response at a multiplicity of infection (MOI) of 100. Cells treated with Ad-BMP-2 demonstrated a progressive increase in proteoglycan synthesis with increasing viral concentrations.

CONCLUSIONS

Successful delivery of the anticatabolic gene, TIMP-1, results in increased measured proteoglycan in cultured degenerated disc cells. This finding supports catabolic inhibition as a promising avenue of research for the treatment of degenerative disc disease via gene therapy.

The effects of mechanical strain on synovial fibroblasts

PURPOSE

Arthritic diseases of the temporomandibular joint, such as rheumatoid arthritis and osteoarthritis, suggest that inflammatory mediators and metalloproteinases may play a role in their pathogenesis. Recent clinical evidence from physical therapy and other modalities has shown a significant decrease in temporomandibular joint symptoms in patients with early disease. This project examines the effect of mechanical strain on synovial fibroblasts' production of inflammatory mediators including prostaglandin E(2) (PGE(2)) and proteinases.

MATERIALS AND METHODS

An established synovial fibroblast cell line (HIG-82) was grown to confluency in modified Eagle's medium supplemented with 10% fetal calf serum. The monolayer of fibroblasts was then subjected to mechanical strain using the Flexercell Strain Unit (Flexcell International Corporation, McKeesport, PA) at 3 cycles per minute, with 10 seconds' elongation of up to 24% and 10 seconds of relaxation. Levels of PGE(2) were determined by radioimmunoassay using commercially available product and measured in nanograms per milliliter of supernatant. Proteinases collagenase, gelatinase, and stromelysin were measured by H(3) radioactive labeling of acidic anhydride to the specific substrate. Enzymatic proteolysis of the radiolabeled substrate was then measured in supernate as units per milliliter. Statistical analysis of all results was performed using Student's t test in triplicate.

RESULTS

PGE(2) levels of mechanically activated cells was 18.1 +/- 13.4 ng/mL, with control levels being 58.0 +/- 9.2 ng/mL. This is a statistically significant decrease, between strained and unstrained cells with P <.05. In control cells, proteinase activity that degrades collagen, gelatin, or casein was 4.27 +/- 1.5, 4.62 +/- 0.11, or 0.11 +/- 0.01 U/mL, respectively. Levels for mechanically strained cells were 3.99 +/- 1.90, 4.02 +/- 0.90, and 0.12 +/- 0.01 U/mL, respectively. These results show that there is a significant decrease in PGE(2) levels of synovial fibroblasts undergoing mechanical strain. Proteinases examined show no difference in levels between mechanically activated fibroblasts and their controls.

CONCLUSION

This decrease in PGE(2) production in synovial fibroblasts could help elucidate the mechanism by which physical therapy, and in particular continuous passive motion, may decrease inflammatory mediators of the temporomandibular joint.

Inhibition of cartilage degradation: a combined tissue engineering and gene therapy approach

OBJECTIVE

To determine if tissue-engineered cartilage can be protected from cytokine-induced degradation using a gene therapy approach.

METHODS

Chemical and pantropic retroviral gene transfer methodologies were compared for their ability to introduce a luciferase reporter gene into adult bovine cartilage chondrocytes grown in monolayer. Pantropic retrovirus was then used to transduce these cells with human tissue inhibitor of metalloproteinases 1 (TIMP-1), and the stability of expression in monolayer or pellet culture was monitored for 6 weeks. Untransduced and TIMP-1-transduced cells were also used to tissue engineer 3-dimensional cartilage constructs that were then challenged with interleukin-1 (IL-1) for 4 weeks. Conditioned media and residual cartilage were collected for analysis of matrix components, including type II collagen and proteoglycans, and for TIMP-1 production and matrix metalloproteinase (MMP) activity.

RESULTS

Chemical transfection of adult bovine chondrocytes gave rise to short-lived reporter expression that was virtually undetectable after 4 weeks of culture. In contrast, pantropic retroviral transduction gave rise to stable expression that persisted at a high level for at least 6 weeks. Pantropic transduction of the cells with TIMP-1 gave rise to similar long-term expression, both in monolayer and pellet cultures. TIMP-1-transduced tissue-engineered cartilage also retained TIMP-1 expression for an additional 4 weeks of culture in the presence of IL-1. Compared with control samples, TIMP-1-transgenic cartilage resisted the catabolic effects of IL-1, with MMP activity reduced to basal levels and a decreased loss of type II collagen.

CONCLUSION

Pantropic retroviral transduction permits long-term expression of potentially therapeutic transgenes in adult tissue-engineered cartilage. While TIMP-1 transduction could be used to prevent collagen breakdown, alternative transgenes may be necessary to protect cartilage proteoglycans.

Significant increases in serum and plasma concentrations of matrix metalloproteinases 3 and 9 in patients with rapidly destructive osteoarthritis of the hip

OBJECTIVE

Rapidly destructive osteoarthritis (OA) of the hip is an uncommon subset of OA that affects mainly elderly women. Previous studies indicate that elevated levels of matrix metalloproteinases (MMPs) are produced within the tissue of patients with the condition. In the present study, we sought to determine whether serum and plasma levels of MMPs and tissue inhibitors of metalloproteinases (TIMPs) are also elevated.

METHODS

Blood samples were obtained from 16 patients with rapidly destructive hip OA and from 20 patients with OA before total hip arthroplasty was performed. Synovial specimens were obtained during surgery. Synovial fibroblasts that had migrated sufficiently from explants were subcultured in vitro for 72 hours after confluency, and harvested supernatants were collected. Blood, tissue samples, and fibroblasts were assayed for MMPs 1, 2, 3, and 9, and TIMPs 1 and 2 by sandwich enzyme immunoassay.

RESULTS

In blood samples, the levels of MMP-3 and MMP-9 in the group with rapidly destructive hip OA were significantly higher than the normal range and were also significantly higher than those in the OA group. In tissue samples, the levels of MMP-1, MMP-3, MMP-9, and TIMP-1 in the group with rapidly destructive hip OA were significantly higher than those in the OA group.

CONCLUSION

The results of this study show that serum and plasma levels of MMP-3 and MMP-9 are significantly increased in patients with rapidly destructive hip OA. Significantly large amounts of these MMPs produced in synovial tissues within the hip joint could contribute in part to elevation of blood levels. Detection of increased levels of MMP-3 and MMP-9 in patients with painful, disabling hip OA may be of diagnostic value for rapidly destructive hip OA.

Increased matrix metalloproteinase-3 serum levels in rheumatic diseases: relationship with synovitis and steroid treatment

OBJECTIVE

To determine matrix metalloproteinase-3 (MMP-3) serum levels in patients with rheumatic diseases and to study the relation between MMP-3 and C reactive protein (CRP) levels.

METHODS

MMP-3 serum levels were determined by enzyme linked immunosorbent assay (ELISA) in (a) patients with active inflammatory rheumatic diseases: rheumatoid arthritis (RA), psoriatic arthritis, polymyalgia rheumatica, acute crystal arthritis, and ankylosing spondylitis; (b) patients with active inflammatory systemic diseases: cutaneo-articular or renal systemic lupus erythematosus (SLE), systemic sclerosis, and vasculitides; (c) patients with non-inflammatory rheumatic diseases: osteoarthritis and fibromyalgia; (d) critically ill patients without rheumatic diseases, representing an acute inflammatory control group; (e) healthy controls.

RESULTS

MMP-3 serum levels were significantly increased in patients with active RA, psoriatic arthritis, and polymyalgia rheumatica, whether treated or not by corticosteroids, and in female patients with acute crystal arthritis. MMP-3 serum levels were normal in steroid-free patients with active cutaneo-articular or renal SLE, systemic sclerosis, and vasculitides but were significantly increased in steroid treated patients. MMP-3 levels were normal in fibromyalgia, osteoarthritis, ankylosing spondylitis, and acute inflammatory controls. MMP-3 was significantly correlated with CRP in RA (r=0.5, p=0.0004) but not in any of the other disease groups.

CONCLUSIONS

MMP-3 serum levels are increased in inflammatory rheumatic diseases characterised by joint synovitis, such as RA, polymyalgia rheumatica, psoriatic arthritis, and acute crystal arthritis-that is, whether the diseases are acute or chronic, erosive or not. They are normal in SLE, systemic sclerosis, and vasculitides as well as in non-rheumatic inflammatory controls, but are significantly increased by steroids. These data strongly suggest that serum MMP-3 reflects synovial inflammation.

Increased levels of serum tissue inhibitor of metalloproteinase-1 but not metalloproteinase-3 in atopic dermatitis

Matrix metalloproteinases and their specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs), contribute to inflammation-induced tissue destruction and subsequent remodeling for maintenance of tissue homeostasis. Since the production of these enzymes and their inhibitors is regulated by mediators such as proinflammatory cytokines and growth factors, elevated levels of serum TIMPs and/or MMPs have been documented in patients with several inflammatory disorders. In this study, we examined the role of TIMPs and MMPs in the pathogenesis of atopic dermatitis (AD) by evaluating the serum levels of TIMP-1 and MMP-3 in 40 patients with AD and 20 control subjects by ELISA. The serum TIMP-1 levels were significantly higher in AD patients in exacerbation status than in nonatopic subjects, whereas serum MMP-3 levels were not significantly different between them. As a result, AD patients revealed significantly elevated TIMP-1/MMP-3 ratios. The levels of serum TIMP-1 were significantly reduced in AD patients following conventional treatments. Significantly higher values of peripheral eosinophil counts, serum levels of IgE and lactate dehydrogenase, eruption score, and eruption area were noted in the AD patients with elevated TIMP-1 levels when compared with those with normal values. Moreover, the points of chronic eruptions such as lichenification and prurigo were significantly higher in the patients with elevated TIMP-1 levels than those with normal TIMP-1, while those of acute lesions such as oozy/microvesicles and oedema were not different between these groups. Serum TIMP-1 level may be a useful marker to estimate the long-term disease activity of AD.

Tissue inhibitor of metalloproteinases-4 (TIMP-4) gene expression is increased in human osteoarthritic femoral head cartilage

Tissue inhibitor of metalloproteinases-4 (TIMP-4), the newest member of the TIMP family, blocks the activities of several matrix metalloproteinases (MMPs) implicated in the arthritic cartilage erosion. By utilizing semi-quantitative RT-PCR, immunoblotting, and immunohistochemistry, we investigated whether the TIMP-4 gene is expressed in human non-arthritic and osteoarthritic (OA) cartilage. Directly analyzed femoral head cartilage showed TIMP-4 RNA expression in 2 of 9 non-arthritic and 12 of 14 OA patients. Femoral head cartilage from 6 of 9 OA patients had elevated TIMP-4 protein compared to the low-level expression in 3 of 8 non-arthritic controls. In most patients, there was correlation between TIMP-4 RNA and protein expression. TIMP-4 protein was also detected immunohistochemically in the upper zone of OA cartilage. The widespread TIMP-4 RNA and protein expression and augmentation in femoral OA cartilage suggests its important role in joint tissue remodeling and pathogenesis of OA. Increased TIMP levels in arthritic cartilage may not be a sufficiently effective defense against cartilage resorption by excessive multiple MMPs and aggrecanases.

Engineering of tissue inhibitor of metalloproteinases mutants as potential therapeutics

Matrix metalloproteinases (MMPs) play a central role in many biological processes such as development, morphogenesis and wound healing, but their unbalanced activities are implicated in numerous disease processes such as arthritis, cancer metastasis, atherosclerosis, nephritis and fibrosis. One of the key mechanisms to control MMP activities is inhibition by endogenous inhibitors called tissue inhibitors of metalloproteinases (TIMPs). This review highlights the structures and inhibition mechanism of TIMPs, the biological activities of TIMPs, the unique properties of TIMP-3, and the altered specificity towards MMPs achieved by mutagenesis. A potential therapeutic use of TIMP variants is discussed.