What destroys the joint in rheumatoid arthritis?

Site of invasion revisited: epigenetic drivers of joint destruction in RA

New analytical methods and the increasing availability of synovial biopsies have recently provided unprecedented insights into synovial activation in general and synovial fibroblast (SF) biology in particular. In the course of this development, SFs have become one of the most rapidly evolving and exciting fields of rheumatoid arthritis (RA) research. While their active role in the invasion of RA synovium into cartilage has long been studied, recent studies have brought new aspects of their heterogeneity and propagation in RA. This review integrates old and new evidence to give an overview picture of the processes active at the sites of invasive synovial tissue growth in RA.

Experimental and clinical reports on anti-inflammatory, antioxidant, and immunomodulatory effects of Curcuma longa and curcumin, an updated and comprehensive review

Curcuma longa (C. longa) or turmeric is a plant with a long history of use in traditional medicine, especially for treating inflammatory conditions C. longa and its main constituent, curcumin (CUR), showed various pharmacological effects such as antioxidant and anti-microbial properties. The updated knowledge of anti-inflammatory, antioxidant, and immunomodulatory effects of C. longa and CUR is provided in this review article. Pharmacological effects of C. longa, and CUR, including anti-inflammatory, antioxidant, and immunomodulatory properties, were searched using various databases and appropriate keywords until September 2020. Various studies showed anti-inflammatory effects of C. longa and CUR, including decreased white blood cell, neutrophil, and eosinophil numbers, and its protective effects on serum levels of inflammatory mediators such as phospholipase A2 and total protein in different inflammatory disorders. The antioxidant effects of C. longa and CUR were also reported in several studies. The plant extracts and CUR decreased malondialdehyde and nitric oxide levels but increased thiol, superoxide dismutase, and catalase levels in oxidative stress conditions. Treatment with C. longa and CUR also improved immunoglobulin E (Ig)E, pro-inflammatory cytokine interleukin 4 (IL)-4, transforming growth factor-beta, IL-17, interferon-gamma levels, and type 1/type 2 helper cells (Th1)/(Th2) ratio in conditions with disturbance in the immune system. Therefore C. longa and CUR showed anti-inflammatory, antioxidant, and immunomodulatory effects, indicating a potential therapeutic effect of the plant and its constituent, CUR, for treating of inflammatory, oxidative, and immune dysregulation disorders.

Arthroscopy of the Temporomandibular Joint in Patients With Juvenile Idiopathic Arthritis

PURPOSE

The early diagnosis of temporomandibular joint (TMJ) involvement in patients with juvenile idiopathic arthritis (JIA) before joint destruction and growth disturbances could allow for interceptive treatment. The purpose of this article is to report early TMJ arthroscopic findings in patients with JIA.

PATIENTS AND METHODS

This was a case series of 3 patients with JIA treated at the Emory University Division of Oral and Maxillofacial Surgery from July 2011 through December 2012. Patients were included if they had a confirmed diagnosis of JIA, did not respond to anti-rheumatologic medication, and had TMJ pain or limited mouth opening. All patients underwent TMJ arthroscopy with an injection of triamcinolone hexacetonide. Demographics, medical history, magnetic resonance imaging findings, arthroscopic findings, and postoperative course were reported.

RESULTS

Three female patients (mean age, 12.5 yr; 5 joints) underwent arthroscopy. Arthroscopic findings consisted of mild to moderate synovitis and grade 2 to 4 chondromalacia with or without fibrosis. Postoperatively, all patients had improvement in pain and mouth opening.

CONCLUSIONS

There was a positive correlation between duration of JIA activity in the TMJ and severity of arthroscopic findings. Arthroscopic lysis and lavage combined with triamcinolone hexacetonide injection resulted in improvement in pain and range of motion.

Arthroscopic synovectomy of the ankle in rheumatoid arthritis

PURPOSE

To evaluate the outcome of arthroscopic synovectomy of the ankle joint in patients with early-stage rheumatoid arthritis (RA).

METHODS

Between 2005 and 2009, 18 consecutive patients with RA involving the ankle underwent arthroscopic synovectomy. Pain was measured using a visual analog scale (VAS), and clinical outcome was determined by calculating the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score with a mean follow-up of 5 years (60 months). Assessments were performed preoperatively, at 6 and 12 months postoperatively, and then yearly thereafter. Clinical success was defined as the absence of synovitis symptoms or when patients demonstrated good or excellent outcomes (AOFAS Ankle-Hindfoot Scale score ≥80) with >50% improvement in VAS score for pain. Demographic, laboratory, and radiological variables were evaluated to determine possible factors predicting clinical outcome.

RESULTS

VAS and AOFAS scores were significantly improved at the final follow-up (60 months; P < .0001). The greatest improvements in clinical scores were observed after 12 months; thereafter, they steadily declined. Of the 18 patients examined, 14 (77.8%) were considered to have had clinical success with no reintervention. Variables predictive of clinical success were short duration of symptoms (P = .042) and minimal radiographic changes based on the Larsen grading system (P = .030).

CONCLUSIONS

Arthroscopic synovectomy is a safe and successful procedure in ankle joints affected by RA. The best clinical outcomes are achieved when the procedure is performed early in the disease course and when there is no evidence of cartilage degeneration.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

Signal transduction pathways in chronic inflammatory autoimmune disease: small GTPases

Ras superfamily small GTPases represent a wide and diverse class of intracellular signaling proteins that are highly conserved during evolution. These enzymes serve as key checkpoints in coupling antigen receptor, growth factor, cytokine and chemokine stimulation to cellular responses. Once activated, via their ability to regulate multiple downstream signaling pathways, small GTPases amplify and diversify signaling cascades which regulate cellular proliferation, survival, cytokine expression, trafficking and retention. Small GTPases, particularly members of the Ras, Rap, and Rho family, critically coordinate the function and interplay of immune and stromal cells during inflammatory respones, and increasing evidence indicates that alterations in small GTPase signaling contribute to the pathological behavior of these cell populations in human chronic inflammatory diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Here, we review how Ras, Rap, and Rho family GTPases contribute to the biology of cell populations relevant to human chronic inflammatory disease, highlight recent advances in understanding how alterations in these pathways contribute to pathology in RA and SLE, and discuss new therapeutic strategies that may allow specific targeting of small GTPases in the clinic.

A comprehensive molecular interaction map for rheumatoid arthritis

Background

Computational biology contributes to a variety of areas related to life sciences and, due to the growing impact of translational medicine - the scientific approach to medicine in tight relation with basic science -, it is becoming an important player in clinical-related areas. In this study, we use computation methods in order to improve our understanding of the complex interactions that occur between molecules related to Rheumatoid Arthritis (RA).

Methodology

Due to the complexity of the disease and the numerous molecular players involved, we devised a method to construct a systemic network of interactions of the processes ongoing in patients affected by RA. The network is based on high-throughput data, refined semi-automatically with carefully curated literature-based information. This global network has then been topologically analysed, as a whole and tissue-specifically, in order to translate the experimental molecular connections into topological motifs meaningful in the identification of tissue-specific markers and targets in the diagnosis, and possibly in the therapy, of RA.

Significance

We find that some nodes in the network that prove to be topologically important, in particular AKT2, IL6, MAPK1 and TP53, are also known to be associated with drugs used for the treatment of RA. Importantly, based on topological consideration, we are also able to suggest CRKL as a novel potentially relevant molecule for the diagnosis or treatment of RA. This type of finding proves the potential of in silico analyses able to produce highly refined hypotheses, based on vast experimental data, to be tested further and more efficiently. As research on RA is ongoing, the present map is in fieri, despite being -at the moment- a reflection of the state of the art. For this reason we make the network freely available in the standardised and easily exportable .xml CellDesigner format at ‘www.picb.ac.cn/ClinicalGenomicNTW/temp.html’ and ‘www.celldesigner.org’.

The role of resident synovial cells in destructive arthritis

Infiltration by inflammatory cells, thickening of the lining layer, and destructive invasion into cartilage and bone are pathognomic features of the synovium in rheumatoid arthritis (RA). However, the most common cell types at the sites of invasion are resident cells of the joint, in particular synovial fibroblasts. These cells differ from healthy synovial fibroblasts in their morphology, their expression of proto-oncogenes and antiapoptotic molecules, and in their lack of certain tumor suppressor genes. Through their production of proinflammatory cytokines and chemokines mediated by signaling via Toll-like receptors, they are not only effector cells but also active parts of the innate immune system attracting inflammatory immune cells to the synovium. Most importantly, by producing matrix-degrading molecules they contribute strongly to the destructive mechanisms operative in RA.

The effects of sulfasalazine treatment on enthesal abnormalities of inflammatory rheumatic diseases

The aim of this study was to evaluate the effects of a 1-year course of sulfasalazine monotherapy on enthesal abnormalities of inflammatory rheumatic diseases (IRDs) using ultrasonography. Thirty-six patients with IRD including 20 patients with rheumatoid arthritis (RA) and 16 patients with ankylosing spondylitis (AS) (22 women, 14 men, mean ages 43.3 +/- 8.8 years), and 18 healthy controls (10 women, 8 men, mean ages 42.5 +/- 9.9 years) matched by age and body mass index were enrolled in this study. For the evaluation of enthesal structures, all patients and controls underwent ultrasonographic (USG) examinations of five enthesal sites of both lower limbs using high-resolution and Doppler USG. An ultrasonographic score of lower limb enthesitis was calculated using Glasgow ultrasound enthesitis scoring system (GUESS). Clinical and laboratory activities of IRD patients were also evaluated. Patient group was made to undergo 2 g/day sulfasalazine monotherapy for 1 year. All evaluations were made at the beginning of the treatment and repeated after 1 year follow-up. Results showed that the frequency of enthesal abnormalities of the IRD group was significantly higher than controls. On USG examination, 301/1,296 (23.2%) enthesal structures were abnormal in IRD patients, and 19/648 (2.93%) structures were abnormal in controls. Mean GUESS score of the IRD group (6.40 +/- 2.41) was also significantly higher than controls (1.79 +/- 1.60) (p < 0.001). Although there was a significant improvement in clinical and laboratory activity parameters of the IRD patients, significant decrease was not observed in enthesal abnormalities (295/1,296 enthesal structures-22.7%) and mean GUESS score (6.20 +/- 2.38) after 1 year sulfasalazine trial. Additionally, there was no significant improvement in enthesal abnormalities and mean GUESS scores of AS and RA subgroups separately. Sulfasalazine treatment was not found effective on enthesal abnormalities of IRD patients. Further studies with larger groups including other IRDs are required to validate our results.

Ultrasonographic evaluation of tendons and enthesal sites in rheumatoid arthritis: comparison with ankylosing spondylitis and healthy subjects

The objective of this study was to determine tendon involvements and enthesal abnormalities in patients with rheumatoid arthritis (RA) using high-resolution ultrasonographic images and to compare the findings with those seen in patients with ankylosing spondylitis (AS) and healthy controls. A total of 24 patients with RA, 18 with AS, and 20 healthy controls matched by age and body mass index (BMI) were included in the study. All of the patients and controls underwent clinical and ultrasonographic examinations of both lower limbs at five enthesal sites (superior and inferior pole of the patella, tibial tuberosity, Achilles tendon, and plantar aponeurosis) and both upper limbs at two tendon sites (tendons of m. biceps brachii and supraspinatus at the shoulder). High-resolution ultrasonographic examinations were performed to detect bursitis, structure thickness, bony erosion, and enthesophyte. An ultrasonographic score of lower limb enthesitis was calculated using the Glasgow Ultrasound Enthesitis Scoring System (GUESS) in all patients. Tendon involvements and enthesal abnormalities were found significantly more often in the RA group than in controls (p<0.05 to <0.001), but were not found to be different from the AS group (p>0.05). On clinical examination 67 of 336 (19.9%) tendon and enthesal sites were abnormal and on ultrasonographic examination 130 of 336 (38.2%) sites were abnormal in RA patients. The most frequently affected enthesal sites in the lower limbs were suprapatellar, infrapatellar, and Achilles tendon in both the RA and AS groups. The tibial tuberosity was less affected in both groups, and involvement of the plantar aponeurosis was not different from the controls. A statistically significant correlation was found between the Ritchie articular index and GUESS (r=0.578, p=0.008). Tendon involvements and enthesal abnormalities in RA patients were found more often than had been estimated. Further studies are required to validate our results.

Human wee1 kinase is directly transactivated by and increased in association with c-Fos/AP-1: rheumatoid synovial cells overexpressing these genes go into aberrant mitosis

Wee1 kinase downregulates the M-phase promoting factor, a complex of cdc2 and cyclin B kinase, that controls mitotic cell division. We isolated human wee1 kinase gene promoter and found that it contained one AP-1-binding motif in its promoter region (5'-CGAGTCA-3'; -823/-817), through which wee1 kinase gene was directly transactivated by c-Fos/AP-1. In rheumatoid synovial cells, wee1 kinase was increased in conjunction with the increase of c-Fos/AP-1 and the substrate of wee1, cdc2, was phosphorylated. The amount of wee1 and c-Fos and the phosphorylation of cdc2 were decreased after treatment of the cells with an inhibitor of AP-1, curcumin. A significant proportion of cultured synovial cells of the patients with rheumatoid arthritis, but not those of osteoarthritis, shifted to a tetraploid (4C) state upon long-term culture. Thus, human wee1 kinase gene is directly transactivated by and increased in association with c-Fos/AP-1, and rheumatoid synovial cells overexpressing these genes go into aberrant mitosis.

The in?uence of?1-acid glycoprotein on collagenase-3 activity in early rheumatoid arthritis

The concentration and glycosylation of alpha(1)-acid glycoprotein (AGP) alter significantly during inflammation. A definitive physiological role for AGP remains elusive and is the subject of extensive investigation. This study investigated the influence of AGP on the activity of collagenase-3, an important mediator of cartilage destruction in rheumatoid arthritis. AGP was isolated from normal and rheumatoid plasma. Fucosylation was determined by high pH anion-exchange chromatography; sialylation was assessed following enzymatic digest. Rheumatoid AGP displayed elevated fucosylation and sialylation compared with normal. The influence of each sample on collagenase-3 activity was measured fluorometrically. AGP influenced collagenase-3 catalysis and collagen binding, with catalytic activity correlating with fucosylation. Rheumatoid AGP exhibited less efficient inhibition than normal plasma AGP. It is hypothesized that AGP within rheumatoid synovial fluid may be inadequate to prevent excessive cartilage destruction and hence may exacerbate the disease process.

Synovial tissue of the hip at power Doppler US: correlation between vascularity and power Doppler US signal

PURPOSE

To correlate power Doppler ultrasonographic (US) findings of the vascularity of synovial tissue of the hip joint with the results of histopathologic examination of the same tissue to assess the value of power Doppler US in the visualization of synovitis.

MATERIALS AND METHODS

The hip joints of 24 patients with osteoarthritis (n = 15) or rheumatoid arthritis (n = 9) of the hip joint were examined with US before arthroplasty. The vascularity of the synovial membrane was classified qualitatively by using power Doppler US. During surgery, a section of the synovial tissue examined at power Doppler US preoperatively was resected. The vascularity of the tissue specimen was investigated and graded qualitatively by a pathologist who was not aware of the US findings. Visual qualitative grading was controlled by means of analysis of the US images and histopathologic specimens with a digital image evaluation system. Correlations between power Doppler US and histopathologic examination findings were calculated by using Spearman rank correlation and Pearson correlation tests.

RESULTS

The correlation between the qualitative power Doppler US results and the qualitative vascularity grades was 0.92 (P <.01, Spearman rho). The correlation between quantitative and qualitative results was 0.93 (P <.01, Spearman rho) for US imaging and 0.97 (P <.01, Spearman rho) for histopathologic examination.

CONCLUSION

Study results showed power Doppler US to be reliable for qualitative grading of the vascularity of synovial tissue of the hip.

p53, proto-oncogene and rheumatoid arthritis

OBJECTIVE

To review the literature published in the past 6 years concerning the role of p53 tumor-suppressor protein in rheumatoid arthritis (RA).

METHODS

A MEDLINE search was performed to identify all publications that covered the role of p53 in RA. In addition, selected articles related to proto-oncogenes and matrix metalloproteinases were included in this review.

RESULTS

p53 protein is expressed in RA fibroblast-like synoviocytes (FLSs), and its overexpression is a characteristic feature of RA. The overexpression of p53 is probably induced by DNA strand breaks caused by the genotoxic environment of RA joints, in some cases because of p53 mutations. Independent studies from 3 groups indicated that p53 mutations can and do occur in RA synovial tissue samples derived from a subset of RA patients. Inactivation of p53 may contribute to the invasiveness of FLSs and to the high-level expression of cartilage degradation enzymes as well. Gene transfer or gene knockout studies using a collagen-II-induced RA animal model to examine the role of p53 in RA have been reported. Initial results are positive and indicate that gene transfer of p53 may be clinically useful for the management of RA.

CONCLUSIONS

p53 protein is expressed in RA FLSs, and its overexpression is a characteristic feature of RA. p53 mutations occur in the synovial tissues derived from a subset of RA patients. The clinical implications of p53 expression and the functional importance of somatic mutations in RA, however, are still unclear. Further research is needed to fully understand the implications of these findings and develop corresponding new therapeutic strategies.

Correlation of power Doppler sonography with vascularity of the synovial tissue of the knee joint in patients with osteoarthritis and rheumatoid arthritis

OBJECTIVE

To examine the significance of power Doppler sonography (PDS) in the diagnosis of synovial hypertrophy of the knee joint by verifying and comparing the PDS findings with histopathologic findings of synovial membrane vascularity.

METHODS

The knee joints of 23 patients who were undergoing arthroplasty of the knee joint because of osteoarthritis or rheumatoid arthritis were examined with ultrasound before arthroplasty. The vascularity of the synovial membrane was classified semiquantitatively using PDS. A sample of synovial tissue was obtained during the arthroplasty, and the vascularity of the synovial tissue was evaluated by immunohistochemistry (factor VIII) and was graded qualitatively by a pathologist who was unaware of the PDS findings. The visual qualitative grading by the examiner was controlled by analyzing PDS images and histologic samples using a digital image evaluation system.

RESULTS

The correlation between the qualitative PDS results and the qualitative grading of the vascularity by the pathologist was 0.89 by Spearman's rho (P < 0.01). The Pearson correlation coefficient between the digital analysis of the PDS images and the digital analysis of the tissue sections was 0.81 (P < 0.01). Digital image analysis and qualitative grading by the examiner had a correlation of 0.89 by Spearman's p (P < 0.01) for the PDS images. The correlation between the qualitative estimation of vascularity by the pathologist and the digital image analysis was 0.88 by Spearman's rho (P < 0.01).

CONCLUSION

In the present study, PDS proved to be a reliable diagnostic method for qualitative grading of the vascularity of the synovial tissue. In clinical practice, PDS allows further differentiation of the hypertrophic synovium.

Grafting of fibroblasts isolated from the synovial membrane of rheumatoid arthritis (RA) patients induces chronic arthritis in SCID mice-A novel model for studying the arthritogenic role of RA fibroblasts in vivo

The objective of this study was to verify whether isolated rheumatoid arthritis (RA) synovial fibroblasts induce chronic arthritis in SCID mice, in analogy to whole tissue pieces. Fibroblasts were isolated from the synovial membrane of four RA patients (or controls) by out-growth and repeated-passage culture. Following flow-cytometry characterization, 2x10(6)cells were transferred into the left knee joint of SCID mice. The development of arthritis was assessed by joint swelling and histological changes. Human and murine cytokines were measured in vitro in co-cultures (or Transwelltrade mark systems) of human and murine cells. Purified RA synovial fibroblasts, but not healthy synovial or skin fibroblasts, induced hu/mu arthritis within 6 weeks. In-vitro secretion of murine and human interleukin(IL)-6, as well as murine tumour necrosis factor (TNF)-alpha, indicated cross-activation between murine macrophages and human RA fibroblasts. Soluble-factor mechanisms proved more effective than cell-contact mechanisms. Purified RA fibroblasts can, alone, induce hu/mu SCID arthritis. The cytokine profile suggests that xenogeneic interaction between human fibroblasts and murine macrophages may determine the sequence of events leading to hu/mu arthritis.