Linking systemic angiogenic factors (VEGF, angiogenin, TIMP-2) and Doppler ultrasound to anti-inflammatory treatment in rheumatoid arthritis

MMP-13, VEGF, and Disease Activity in a Cohort of Rheumatoid Arthritis Patients

Identifying certain serum biomarkers associated with the degree of rheumatoid arthritis (RA) activity can provide us with a more accurate view of the evolution, prognosis, and future quality of life for these patients. Our aim was to analyze the presence and clinical use of matrix metalloproteinase-13 (MMP-13), along with vascular endothelial growth factor (VEGF) and well-known cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) for patients with RA. We also wanted to identify the possible correlations between MMP-13 and these serological markers, as well as their relationship with disease activity indices, quality of life, and ultrasonographic evaluation. For this purpose, we analyzed serum samples of 34 RA patients and 12 controls. In order to assess serum concentrations for MMP-13, VEGF, TNF-α, and IL-6, we used the enzyme-linked immunosorbent assay (ELISA) technique. Our results concluded that higher levels of MMP-13, VEGF, TNF-α, and IL-6 were present in the serum of RA patients compared to controls, with statistical significance. We furthermore identified moderately positive correlations between VEGF, MMP-13, and disease activity indices, as well as with the ultrasound findings. We also observed that VEGF had the best accuracy (97.80%), for differentiating patients with moderate disease activity. According to the data obtained in our study, that although MMP-13, TNF-α and C-reactive protein (CRP) have the same sensitivity (55.56%), MMP-13 has a better specificity (86.67%) in the diagnosis of patients with DAS28_(4v) CRP values corresponding to moderate disease activity. Thus, MMP-13 can be used as a biomarker that can differentiate patients with moderate or low disease activity. VEGF and MMP-13 can be used as additional parameters, along with TNF-α and IL-6, that can provide the clinician a better picture of the inflammatory process, disease activity, and structural damage in patients with RA. Our data can certainly constitute a start point for future research and extended studies with multicenter involvement, to support the selection of individualized and accurate therapeutic management strategies for our patients.

Targeting matrix metalloproteases: A promising strategy for herbal medicines to treat rheumatoid arthritis

As a type of metalloproteinase, matrix metalloproteinases (MMPs) can be divided into collagenase, gelatinase, stromelysins, membrane-type (MT)-MMPs and heterogeneous subgroups according to their structure and function. MMP contents in the human body are strictly regulated, and their synthesis, activation and inhibition processes should be kept in a certain balance; otherwise, this would result in the occurrence of various diseases. Rheumatoid arthritis (RA) is a known immune-mediated systemic inflammatory disease that is affected by a variety of endogenous and exogenous factors. In RA development, MMPs act as important mediators of inflammation and participate in the degradation of extracellular matrix substrates and digestion of fibrillar collagens, leading to the destruction of joint structures. Interestingly, increasing evidence has suggested that herbal medicines have many advantages in RA due to their multitarget properties. In this paper, literature was obtained through electronic databases, including the Web of Science, PubMed, Google Scholar, Springer, and CNKI (Chinese). After classification and analysis, herbal medicines were found to inhibit the inflammatory process of RA by regulating MMPs and protecting joint structures. However, further preclinical and clinical studies are needed to support this view before these herbal medicines can be developed into drugs with actual application to the disease.

TXNDC5 protects synovial fibroblasts of rheumatoid arthritis from the detrimental effects of endoplasmic reticulum stress

TXNDC5 is an endoplasmic reticulum (ER)-resident chaperone that protects the endothelium from secondary effects of ER stress. Previous studies by the current authors identified TXNDC5 as a key pathological factor in promoting the inflammatory phenotype of fibroblast-like synoviocytes (FLSs) from rheumatoid arthritis (RA). However, its activity in RA FLSs under ER stress remains unclear. The current study found that TXNDC5 is responsive to ER stress in RA FLSs since its expression was induced by ER stress at both the endogenous and secretory level. A functional study indicated that silencing TXNDC5 reduced the viability of RA FLSs more markedly in the presence of ER stressors. In contrast, rhTXNDC5 attenuated a decrease in cell viability as a result of ER stress. Moreover, silencing TXNDC5 attenuated the induction of IL-6 and IL-8 from RA FLSs in response to ER stress. In addition, rhTXNDC5 induced a greater increase in VEGF production during ER stress. These findings confirm the pro-survival and pro-inflammation roles of TXNDC5 under ER stress in RA FLSs. TXNDC5 appears to act as a mediator linking ER stress and inflammation of RA.

Linking systemic angiogenic markers to synovial vascularization in rheumatoid arthritis

Background

Neoangiogenesis is a crucial event to promote the development of the hyperplasic proliferative pathologic synovium in Rheumatoid arthritis (RA). Ultrasound (US) is sensitive for detection of power Doppler (PD) vascularization.

Objective

To explore the associations between a set of complementary circulating angiogenic markers and a comprehensive US assessment in patients with RA.

Patients and methods

Serum levels of eight angiogenic markers were measured by quantitative ELISAs in a total of 125 patients with RA, who were all systematically assessed in parallel by PDUS, performed on 32 joints.

Results

Serum levels of soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) and Tie-2 were more likely to be increased in patients with synovial hyperemia detected on at least one joint (Power Doppler grade ≥1). sVCAM-1, Tie-2 and Angiostatin concentrations gradually increased together with the grade of the semiquantitative PDUS scale and concentrations of these three markers were markedly increased in patients with moderate to marked hyperemia (Power Doppler grade 2 and 3). Levels of sVCAM-1, Tie-2, and Angiostatin correlated with a global arthritis sum score, defined by the sum of the semiquantitative PDUS scores for all joints examined. Levels of Tie-2 and Placenta Growth Factor (PlGF) were associated with PDUS features indicating residual disease activity.

Conclusion

Our results support the relevance of measuring serum levels of vascular markers to evaluate the intensity and extent of synovial vascularization. Angiogenic markers, and particularly Tie-2, could be a valuable surrogate of active synovitis and their place in relation to PDUS in clinical practice deserve further investigation.

What is the added value of ultrasound joint examination for monitoring synovitis in rheumatoid arthritis and can it be used to guide treatment decisions? A systematic review and cost-effectiveness analysis

BACKGROUND

Synovitis (inflamed joint synovial lining) in rheumatoid arthritis (RA) can be assessed by clinical examination (CE) or ultrasound (US).

OBJECTIVE

To investigate the added value of US, compared with CE alone, in RA synovitis in terms of clinical effectiveness and cost-effectiveness.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE and the Cochrane databases were searched from inception to October 2015.

REVIEW METHODS

A systematic review sought RA studies that compared additional US with CE. Heterogeneity of the studies with regard to interventions, comparators and outcomes precluded meta-analyses. Systematic searches for studies of cost-effectiveness and US and treatment-tapering studies (not necessarily including US) were undertaken.

MATHEMATICAL MODEL

A model was constructed that estimated, for patients in whom drug tapering was considered, the reduction in costs of disease-modifying anti-rheumatic drugs (DMARDs) and serious infections at which the addition of US had a cost per quality-adjusted life-year (QALY) gained of £20,000 and £30,000. Furthermore, the reduction in the costs of DMARDs at which US becomes cost neutral was also estimated. For patients in whom dose escalation was being considered, the reduction in number of patients escalating treatment and in serious infections at which the addition of US had a cost per QALY gained of £20,000 and £30,000 was estimated. The reduction in number of patients escalating treatment for US to become cost neutral was also estimated.

RESULTS

Fifty-eight studies were included. Two randomised controlled trials compared adding US to a Disease Activity Score (DAS)-based treat-to-target strategy for early RA patients. The addition of power Doppler ultrasound (PDUS) to a Disease Activity Score 28 joints-based treat-to-target strategy in the Targeting Synovitis in Early Rheumatoid Arthritis (TaSER) trial resulted in no significant between-group difference for change in Disease Activity Score 44 joints (DAS44). This study found that significantly more patients in the PDUS group attained DAS44 remission (p = 0.03). The Aiming for Remission in Rheumatoid Arthritis (ARCTIC) trial found that the addition of PDUS and grey-scale ultrasound (GSUS) to a DAS-based strategy did not produce a significant between-group difference in the primary end point: composite DAS of < 1.6, no swollen joints and no progression in van der Heijde-modified total Sharp score (vdHSS). The ARCTIC trial did find that the erosion score of the vdHS had a significant advantage for the US group (p = 0.04). In the TaSER trial there was no significant group difference for erosion. Other studies suggested that PDUS was significantly associated with radiographic progression and that US had added value for wrist and hand joints rather than foot and ankle joints. Heterogeneity between trials made conclusions uncertain. No studies were identified that reported the cost-effectiveness of US in monitoring synovitis. The model estimated that an average reduction of 2.5% in the costs of biological DMARDs would be sufficient to offset the costs of 3-monthly US. The money could not be recouped if oral methotrexate was the only drug used.

LIMITATIONS

Heterogeneity of the trials precluded meta-analysis. Therefore, no summary estimates of effect were available. Additional costs and health-related quality of life decrements, relating to a flare following tapering or disease progression, have not been included. The feasibility of increased US monitoring has not been assessed.

CONCLUSION

Limited evidence suggests that US monitoring of synovitis could provide a cost-effective approach to selecting RA patients for treatment tapering or escalation avoidance. Considerable uncertainty exists for all conclusions. Future research priorities include evaluating US monitoring of RA synovitis in longitudinal clinical studies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015017216.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

SIRT1 promotes tumor-like invasion of fibroblast-like synoviocytes in rheumatoid arthritis via targeting TIMP1

Suppression of tissue inhibitor of matrix metalloproteinase (TIMP) is associated with the tumor-like invasion of fibroblast-like synoviocytes (FLSs) that occurs during rheumatoid arthritis-related cartilage destruction. Silent information regulator 2 homolog1 (SIRT1), a histone deacetylase, is widely involved in transcriptional regulation, genomic stability, metabolism and DNA repair. Recent studies suggest that SIRT1 may also impact inflammatory response and the proliferation of FLSs in rheumatoid arthritis (RA). However, it is unknown whether SIRT1 has a role in the tumor-like invasion of FLSs in rheumatoid arthritis. Herein we report that SIRT1 contributes to FLS invasion and cartilage destruction via a TIMP1-dependent mechanism. Elevated SIRT1 in RA synovia suppresses TIMP1 expression via deacetylation of TIMP1-associated histones, thereby disrupting the binding of the transcription factor specificity protein 1 (Sp1) to the TIMP1 promoter. In rats with collagen-induced arthritis, depletion of SIRT1 remarkably promoted TIMP1 expression in synovial tissues and ameliorated cartilage destruction. These results describe a new role for SIRT1 and demonstrate its potential value as a therapeutic target for rheumatoid arthritis.

Calprotectin (S100A8/A9) has the strongest association with ultrasound-detected synovitis and predicts response to biologic treatment: results from a longitudinal study of patients with established rheumatoid arthritis

BACKGROUND

Calprotectin (S100A8/A9 or MRP8/14) and S100A12 (leukocyte-derived proteins), interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF) are markers of inflammation and angiogenesis. Ultrasound (US) is sensitive for detection of greyscale synovitis and power Doppler (PD) vascularization. The objective of the present study was to explore the associations between calprotectin, S100A12, IL-6, VEGF, erythrocyte sedimentation rate, C-reactive protein and a comprehensive US assessment in patients with rheumatoid arthritis (RA) starting biologic disease-modifying anti-rheumatic drug (bDMARD) treatment.

METHODS

A total of 141 patients with RA were assessed by US, clinical examination and biomarker levels at baseline and at 1, 2, 3, 6 and 12 months after initiation of bDMARDs. US assessment of 36 joints and 4 tendon sheaths were scored semi-quantitatively (0-3 scale). European League Against Rheumatism (EULAR) response was calculated. Statistical assessments performed to explore the associations between biomarkers and US sum scores included Spearman's rank correlation analysis as well as linear and linear mixed model regression analyses.

RESULTS

Calprotectin showed the overall strongest correlations with both US sum scores (r _s = 0.25-0.62) and swollen joint counts (of 32) (r _s = 0.24-0.47) (p < 0.05 at all examinations). An association with US sum scores remained after we adjusted for age, sex, disease duration and all the other markers in a regression analysis at baseline. Decreased calprotectin at the first month was predictive of both EULAR response (p ≤ 0.001) and decreased sum PD scores at 3, 6 and 12 months (p ≤ 0.05).

CONCLUSIONS

Calprotectin had the highest association with US synovitis and predicted treatment response. It may thus be considered as a marker for evaluating inflammation and responsiveness in patients with RA on bDMARD treatment.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) identifier: ACTRN12610000284066 . Registered on 8 April 2010 (retrospectively registered).