CD4⁺CD25⁺/highCD127low/⁻ regulatory T cells are enriched in rheumatoid arthritis and osteoarthritis joints--analysis of frequency and phenotype in synovial membrane, synovial fluid and peripheral blood

INTRODUCTION

CD4⁺CD25⁺/highCD127low/⁻ regulatory T cells (Tregs) play a crucial role in maintaining peripheral tolerance. Data about the frequency of Tregs in rheumatoid arthritis (RA) are contradictory and based on the analysis of peripheral blood (PB) and synovial fluid (SF). Because Tregs exert their anti-inflammatory activity in a contact-dependent manner, the analysis of synovial membrane (SM) is crucial. Published reports regarding this matter are lacking, so we investigated the distribution and phenotype of Tregs in concurrent samples of SM, SF and PB of RA patients in comparison to those of osteoarthritis (OA) patients.

METHODS

Treg frequency in a total of 40 patients (18 RA and 22 OA) matched for age and sex was assessed by flow cytometry. Functional status was assessed by analysis of cell surface markers representative of activation, memory and regulation.

RESULTS

CD4⁺ T cells infiltrate the SM to higher frequencies in RA joints than in OA joints (P = 0.0336). In both groups, Tregs accumulate more within the SF and SM than concurrently in PB (P < 0.0001). Relative Treg frequencies were comparable in all compartments of RA and OA, but Treg concentration was significantly higher in the SM of RA patients (P = 0.025). Both PB and SM Tregs displayed a memory phenotype (CD45RO⁺RA⁻), but significantly differed in activation status (CD69 and CD62L) and markers associated with Treg function (CD152, CD154, CD274, CD279 and GITR) with only minor differences between RA and OA.

CONCLUSIONS

Treg enrichment into the joint compartment is not specific to inflammatory arthritis, as we found that it was similarly enriched in OA. RA pathophysiology might not be due to a Treg deficiency, because Treg concentration in SM was significantly higher in RA. Synovial Tregs represent a distinct phenotype and are activated effector memory cells (CD62L⁻CD69⁺), whereas peripheral Tregs are resting central memory cells (CD62L⁺CD69⁻).

Identification of autoantibodies against transthyretin for the screening and diagnosis of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, autoimmune, systemic and inflammatory rheumatic disease that leads to inflammation of the joints and surrounding tissues. Identification of novel protein(s) associated with severity of RA is a prerequisite for better understanding of pathogenesis of this disease that may also have potential to serve as novel biomarkers in the diagnosis of RA. Present study was undertaken to compare the amount of autoantigens and autoantibodies in the plasma of RA patients in comparison to healthy controls. Plasma samples were collected from the patients suffering from RA, Osteoarthritis (OA), Systemic lupus erythematosus (SLE) and healthy volunteers. The screening of plasma proteins were carried out using 2-dimensional gel electrophoresis followed by identification of differentially expressed protein by MALDI-TOF MS/MS. Among several differentially expressed proteins, transthyretin (TTR) has been identified as one of the protein that showed significantly up regulated expression in the plasma of RA patients. The results were further validated by Western blot analysis and ELISA. In comparison to OA synovium, an exclusive significantly high expression of TTR in RA has been validated through IHC, Western blotting and IEM studies. Most importantly, the increase in expression of TTR with the progression of severity of RA condition has been observed. The autoantibodies against TTR present in the RA plasma were identified using immunoprecipitation-Western methods. The significant production of autoantibodies was validated by ELISA and Western blot analysis using recombinant pure protein of TTR. Hence, these novel observations on increase in TTR expression with the increase in severity of RA conditions and significant production of autoantibodies against TTR clearly suggest that a systematic studies on the role TTR in the pathogenesis of RA is immediately required and TTR may be used as a serum diagnostic marker together with other biochemical parameters and clinical symptoms for RA screening and diagnosis.

[The pathogenetic substantiation of new therapeutic approach to the treatment of secondary osteoarthritis in patients with rheumatoid arthritis with basis therapy]

The article concerns the efficacy of the use of new therapeutic approach in the therapy of secondary osteoarthritis in patients with rheumatoid arthritis. The dynamic of Cartilage Oligomeric Matrix Protein, activity of the disease on DAS28, cytokine profile was estimated. The analysis of the results showed the advantages of the use of inhibitor of IL-1 combined with laser therapy in the treatment of secondary osteoarthritis in patients with rheumatoid arthritis.

Lentiviral small hairpin RNA knockdown of macrophage inflammatory protein-1γ ameliorates experimentally induced osteoarthritis in mice

Immune cells are involved in the pathogenesis of osteoarthritis (OA). CD4(+) T cells were activated during the onset of OA and induced macrophage inflammatory protein (MIP)-1γ expression and subsequent osteoclast formation. We evaluated the effects of local knockdown of MIP-1γ in a mouse OA model induced by anterior cruciate ligament transection. The mouse macrophage cell lines and osteoclast-like cells generated from immature hematopoietic monocyte/macrophage progenitors of murine bone marrow were cocultured with either receptor activator of NFκB ligand (RANKL) or CD4(+) T cells. The levels of MIP-1γ and RANKL in cells and mice were examined by enzyme-linked immunosorbent assay (ELISA). The osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase and cathepsin K staining. OA was induced in one hind-leg knee joint of B6 mice. Lentiviral vector encoding MIP-1γ small hairpin RNA (shRNA) and control vector were individually injected intra-articularly into the knee joints, which were histologically assessed for manifestations of OA. The expression of MIP-1γ and matrix metalloproteinase (MMP)-13 and the infiltration of CD4(+) T cells, macrophages, and osteoclastogenesis in tissues were examined using immunohistochemistry. CD4(+) T cells were involved in OA by inducing MIP-1γ expression in osteoclast progenitors and the subsequent osteoclast formation. Neutralizing MIP-1γ with a specific antibody abolishes RANKL-stimulated and CD4(+) T-cell-stimulated osteoclast formation. MIP-1γ levels were significantly higher in synovium and the chondro-osseous junction of joints 90 days postsurgery. The number of infiltrated CD4(+) T cells and macrophages and IL-1β expression were reduced in the synovial tissues of mice treated with MIP-1γ shRNA. Histopathological examinations revealed that mice treated with MIP-1γ shRNA had less severe OA than control mice had, as well as decreased osteoclast formation and MMP-13 expression. Locally inhibiting MIP-1γ expression may ameliorate disease progression and provide a new OA therapy.

Vorinostat, a HDAC inhibitor, showed anti-osteoarthritic activities through inhibition of iNOS and MMP expression, p38 and ERK phosphorylation and blocking NF-κB nuclear translocation

Overproduction of nitric oxide (NO) and matrix metalloproteinases (MMPs) plays an important role in the pathogenesis of osteoarthritis (OA). In present study, we investigated whether vorinostat can inhibit the catabolic effects of IL-1β in vitro, especially the inhibition of MMPs and inducible nitric oxide synthase (iNOS) through the attenuation of nuclear factor kappa-B (NF-κB) and mitogen activated protein kinase (MAPK) pathways in human chondrocytes. Human OA chondrocytes were either left untreated or treated with various concentrations of vorinostat followed by incubation with IL-1β (5ng/mL). Effects of vorinostat on IL-1β-induced gene and protein expression of iNOS, MMP-1, MMP-13 and tissue inhibitors of metalloproteinase-1 (TIMP-1) were verified by quantitative real time-PCR and Western blot analysis. Production of NO, MMP-1, MMP-13 and TIMP-1 released in culture supernatant was estimated using commercially available kits. The roles of NF-κB and MAPK pathways in the regulation of targeted genes and the mechanism involved in vorinostat mediated modulation of these genes were determined by Western blot using specific antibodies. We found that vorinostat down-regulated iNOS, MMP-1 and MMP-13 expression and up-regulated TIMP-1 expression in human OA chondrocytes. In addition, the release of NO, MMP-1 and MMP-13 secreted from IL-1β stimulated chondrocytes was also suppressed by vorinostat. Interestingly, vorinostat selectively inhibited IL-1β-induced p38 and ERK1/2 activation without affecting JNK activation. Furthermore, we observed that vorinostat inhibited NF-κB pathway by suppressing the degradation of I-κBα and attenuating NF-κB p65 translocation to the nucleus. These results suggest that vorinostat may be a promising therapeutic agent for the prevention and treatment of OA.

Anti-inflammatory response of dietary vitamin E and its effects on pain and joint structures during early stages of surgically induced osteoarthritis in dogs

There is evidence that vitamin E (VE) has anti-inflammatory and analgesic properties in human osteoarthritis (OA). This double-blinded and randomized pilot study used a broad spectrum of clinical and laboratory parameters to investigate whether such beneficial effects could be detected in a canine experimental OA model. Dogs were divided into 2 groups: control (n = 8), which received a placebo, and test group (n = 7), which received 400 IU/animal per day of VE for 55 d, starting the day after transection of the cranial cruciate ligament. Lameness and pain were assessed using a visual analogue scale (VAS), numerical rating scale (NRS), and electrodermal activity (EDA) at day 0, day 28, and day 55. Cartilage and synovial inflammation lesions were assessed. One-side comparison was conducted at an alpha-threshold of 10%. At day 56, dogs were euthanized and concentrations of prostaglandin E2 (PGE2), nitrogen oxides (NOx), and interleukin-1 beta (IL-1β) were measured in synovial fluid. Concentrations of NOx and PGE2 in synovial fluid were lower in the test group (P < 0.0001 and P = 0.03, respectively). Values of VAS, NRS, and EDA showed a consistent trend to be lower in the test group than in the control, while statistical significance was reached for VAS at day 55 and for EDA at day 28 (adjusted P = 0.07 in both cases). Histological analyses of cartilage showed a significant reduction in the scores of lesions in the test group. This is the first time that a study in dogs with OA using a supplement with a high dose of vitamin E showed a reduction in inflammation joint markers and histological expression, as well as a trend to improving signs of pain.

Profiling the secretion of soluble mediators by end stage osteoarthritis synovial tissue explants reveals a reduced responsiveness to an inflammatory trigger

Objective

Evidence is accumulating that synovial tissue plays an active role in osteoarthritis (OA), however, exact understanding of its contribution is lacking. In order to further elucidate its role in the OA process, we aimed to identify the secretion pattern of soluble mediators by synovial tissue and to assess its ability to initiate cartilage degeneration.

Methods

Synovial tissue explants (STEs) obtained from donors without history of OA (n = 8) or from end stage OA patients (n = 16) were cultured alone or together with bovine cartilage explants in the absence or presence of IL-1α. The secretion of 48 soluble mediators was measured and the effect on glycosaminoglycan (GAG) release and matrix metalloproteinase (MMP) activity was determined.

Results

Normal and OA STEs secreted comparable levels of almost all measured soluble mediators. However, in the presence of IL-1α these mediators were less secreted by OA than by normal STEs of which 15 differed significantly (p<0.01). No effect of normal or OA STEs on GAG release from the cartilage explants was observed, and no differences in MMP activity between OA and normal STEs were detected.

Conclusions

Unexpectedly, a comparable secretion profile of soluble mediators was found for OA and normal STEs while the reduced responsiveness of OA STEs to an inflammatory trigger indicates a different state of this tissue in OA patients. The effects could be the result of prolonged exposure to an inflammatory environment in OA development. Further understanding of the pro-inflammatory and inflammation resolving mechanisms during disease progression in synovial tissue may provide valuable targets for therapy in the future.

[The dynamics of indices of immune and cytokine status for patients with essential hypertension in combination with osteoarthritis]

In the article the results of estimation of basic indexes of cellular and humoral link of immune system and cytokine status are resulted for patients with essential hypertension in combination with osteoarthritis and also influences of complex therapy of essential hypertension and osteoarthritis on these indexes are resulted.

Identification of novel autoantigen in the synovial fluid of rheumatoid arthritis patients using an immunoproteomics approach

Rheumatoid arthritis (RA) is a chronic, autoimmune and inflammatory joint disease with a poorly understood etiology. Despite widespread diagnostic use of anti-citrullinated protein antibodies and rheumatoid factor proteins there is a strong demand for novel serological biomarkers to improve the diagnosis this disease. The present study was aimed to identify novel autoantigens involved in rheumatoid arthritis (RA) pathogenesis through immune-proteomic strategy. Synovial fluid samples from clinically diagnosed RA patients were separated on two-dimensional gel electrophoresis (2-DE). Samples from patients with non-RA rheumatisms (osteoarthritis and trauma) were used as controls. Immunoreactive proteins were spotted by Western blotting followed by identification through Q-TOF mass spectrometer analysis. Forty Western blots were generated using plasma from ten individual RA patients and 33 reactive spots were identified, 20 from the high molecular weight (HMW) gel and 13 from the low molecular weight (LMW) gel. Among the 33 common immunogenic spots, 18 distinct autoantigens were identified, out of which 14 are novel proteins in this context. Expression analysis of five important proteins, vimentin, gelsolin, alpha 2 HS glycoprotein (AHSG), glial fibrillary acidic protein (GFAP), and α1B-glycoprotein (A1BG) by Western blot analysis using their specific antibodies revealed their higher expression in RA synovial fluid as compared to non-RA samples. Recombinantly expressed GFAP and A1BG protein were used to develop an in-house ELISA to quantify the amount of autoantibodies in the RA patients. RA patients revealed an increase in the expression of GFAP and A1BG in the plasma as compared to osteoarthritis patients. Therefore, GFAP and A1BG can be proposed as potential new autoantigens of diagnostic importance for RA subjects. Further characterization of these proteins in rheumatoid arthritis will be helpful in understanding the role of these proteins in the disease pathogenesis providing new diagnostic tool with better specificity and accurate detection of the disease.

Immunopathogenesis of osteoarthritis

Even though osteoarthritis (OA) is mainly considered as a degradative condition of the articular cartilage, there is increasing body of data demonstrating the involvement of all branches of the immune system. Genetic, metabolic or mechanical factors cause an initial injury to the cartilage resulting in release of several cartilage specific auto-antigens, which trigger the activation of immune response. Immune cells including T cells, B cells and macrophages infiltrate the joint tissues, cytokines and chemokines are released from different kinds of cells present in the joint, complement system is activated, and cartilage degrading factors such as matrix metalloproteinases (MMPs) and prostaglandin E2 (PGE2) are released, resulting in further damage to the articular cartilage. There is considerable success in the treatment of rheumatoid arthritis using anti-cytokine therapies. In OA, however, these therapies did not show much effect, highlighting more complex nature of pathogenesis of OA. This needs the development of more novel approaches to treat OA, which may include therapies that act on multiple targets. Plant natural products have this kind of property and may be considered for future drug development efforts. Here we reviewed the studies implicating different components of the immune system in the pathogenesis of OA.

A seroimmunological profile of erosive hand osteoarthritis

OBJECTIVES

erosive hand osteoarthritis (EHOA) is an inflammatory disorder involving joints of the hands, which may be accompanied by acute phase reactants. The relationship between EHOA and classical osteoarthritis (OA) is still controversial, since some authors consider EHOA as a distinct disease, other as a subset of OA, and some as a border entity between OA and rheumatoid arthritis (RA). Scarce data are available about the seroimmunological profile of the disease, which could aid to identify a possible role of the immune system in EHOA pathogenesis, and could also allow to better differentiate EHOA both from OA and RA.

MATERIAL AND METHODS

blood was drawn from the following patients: 37 with EHOA, 35 with OA and 45 with RA. All sera were tested for rheumatoid factor, anti-cyclic citrullinated peptide antibodies (anti-CCP), antinuclear antibodies (ANA), anti-extractable nuclear antigens (anti-ENA) and anti-neutrophil cytoplasmic antibodies (ANCA).

RESULTS

ANCA were never detected in OA, whereas they were found in 7 (19%) EHOA and 8 (18%) RA patients; the difference between EHOA and OA was statistically significant (p<0.01). Anti-CCP antibodies, which were consistently negative in OA, were positive in 2 EHOA (5%) at a low titre and in 23 (51%) RA patients, usually at a very high titre. The difference between EHOA and OA was not statistically significant, while the number of RA positive patients was significantly higher (p<0.001).

CONCLUSIONS

our findings suggest that the seroimmunological profile of EHOA is different from that of OA. In EHOA patients ANCA and anti-CCP antibodies might be either markers of inflammation involving neutrophils and/or markers of an underlying autoimmune process.

Levels of lectin pathway proteins in plasma and synovial fluid of rheumatoid arthritis and osteoarthritis

The innate immune system contributes to the development of rheumatoid arthritis (RA). A potent contributor to such processes is the complement system. The complement system is known to be activated in the inflammatory phases of osteoarthritis (OA). The lectin pathway of the complement system is activated through the recognition of pathogens or altered self-structures by mannan-binding lectin (MBL) or one of the three ficolins in collaboration with MBL-associated serine proteases (MASPs). We assessed the lectin pathway in plasma and synovial fluid (SF) of 27 RA patients and 30 OA patients by measuring MBL, MASP-2, MASP-3, M-ficolin, and H-ficolin. The concentration for all 5 proteins was significantly higher in plasma than in SF (P < 0.001) and the concentration in paired plasma and SF samples correlated in both RA and OA (significance levels between <0.001 and 0.02). The ratio of SF/plasma concentration was for all proteins significantly elevated in RA compared with OA patients (all P < 0.001). The M-ficolin concentration correlated with the neutrophils in both plasma (P = 0.01) and SF (P < 0.001) of RA, and in plasma of 78 controls (P = 0.03). To our knowledge, this is the first report on these proteins in SF, except for MBL where our results are in contrast to the one previous publication. The results support an important physiological role of the neutrophils in determining the M-ficolin levels in both RA and healthy adults. We suggest that quantifications of white blood cells should be included in future clinical investigations of M-ficolin.

Functional role of IL-22 in psoriatic arthritis

INTRODUCTION

Interleukin-22 (IL-22) is a cytokine of IL-10 family with significant proliferative effect on different cell lines. Immunopathological role of IL-22 has been studied in rheumatoid arthritis (RA) and psoriasis. Here we are reporting the functional role of IL-22 in the inflammatory and proliferative cascades of psoriatic arthritis (PsA).

METHOD

From peripheral blood and synovial fluid (SF) of PsA (n = 15), RA (n = 15) and osteoarthritis (OA, n = 15) patients, mononuclear cells were obtained and magnetically sorted for CD3+ T cells. Fibroblast like synoviocytes (FLS) were isolated from the synovial tissue of PsA (n = 5), RA (n = 5) and OA (n = 5) patients. IL-22 levels in SF and serum were measured by enzyme linked immunosorbent assay (ELISA). Proliferative effect of human recombinant IL-22 (rIL-22) on FLS was assessed by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole) and CFSE dilution (Carboxyfluorescein succinimidyl ester) assays. Expression of IL-22Rα1 in FLS was determined by western blot.

RESULTS

IL-22 levels were significantly elevated in SF of PsA patients (17.75 ± 3.46 pg/ml) compared to SF of OA (5.03 ± 0.39 pg/ml), p < 0.001. In MTT and CFSE dilution assays, rIL-22 (MTT, OD: 1.27 ± 0.06) induced significant proliferation of FLS derived from PsA patients compared to media (OD: 0.53 ± 0.02), p < 0.001. In addition, rIL-22 induced significantly more proliferation of FLS in presence of TNF-α. IL-22Rα1 was expressed in FLS of PsA, RA and OA patients. Anti IL-22R antibody significantly inhibited the proliferative effect of rIL-22. Further we demonstrated that activated synovial T cells of PsA and RA patients produced significantly more IL-22 than those of OA patients.

CONCLUSION

SF of PsA patients have higher concentration of IL-22 and rIL-22 induced marked proliferation of PsA derived FLS. Moreover combination of rIL-22 and TNF-α showed significantly more proliferative effect on FLS. IL-22Rα1 was expressed in FLS. Successful inhibition of IL-22 induced FLS proliferation by anti IL-22R antibody suggests that blocking of IL-22/IL-22R interaction may be considered as a novel therapeutic target for PsA.

Overexpression of decoy receptor 3 in synovial tissues of inflammatory arthritis

OBJECTIVES

Decoy receptor 3 (DCR3) was a newly identified soluble receptor which was reported to modulate the function of T cells, dendritic cells and macrophages. The aim of this study was to investigate DCR3 expression on the synovial tissue in different types of arthritis.

METHODS

We obtained synovial tissues from 17 rheumatoid arthritis (RA), 17 ankylosing spondylitis (AS) and 17 osteoarthritis (OA) patients. Synovial specimens were stained with hematoxylin and eosin. The amount of lymphocytes and mononuclear cells infiltration and vascularity during light microscopic examination was scored from 0-4. The expression of CD3, CD4, CD8, CD68 and DCR3 in lining layer (LL) and sublining layer (SL) cells was stained using the immunohistochemical method and analysed by microscopic examination (score from 0-4, 0=absent, 1=slight, 2=moderate, 3=large, 4=extreme).

RESULTS

OA patients were older than the RA and AS patients (65.9±10.3 years for OA, 58.4±17.7 for RA, and 43.2±16.4 for AS). Synovial tissues in RA patients had significantly increased mononuclear cells infiltration when compared to AS and OA patients (2.3±0.6, 1.9±0.5, 1.6±0.5, respectively, p<0.05). There was no striking difference in DCR3 expression in the synovial LL between RA, AS, and OA patients. CD4+ T cells and CD68+ monocytes/macrophages in the SL were more prominent in RA and AS than in OA (p<0.05). Similarly, DCR3 in the SL was more overexpressed in RA and AS than in OA (1.83±0.21, 1.71±0.36, 1.39±0.31, respectively, p<0.01).

CONCLUSIONS

The increased synovial inflammatory cells infiltration in RA and AS was associated with the elevated DCR3 expression.

[Research progression of interleukin-1 in the pathogenesis of osteoarthritis]

Osteoarthritis is a common joint disease, which seriously affects the patient's health and quality of life. It results in substantial social and economic costs. Etiology and pathogenesis of OA is still not completely clear, but people paid more attention on Cytokines, especially IL-1, which is considered as core factor in the development of OA. In recent years, many clinical trials considered IL-1 as a target treatment for OA. It provided a new treatment method. This article is to overview the mechanism of IL-1 in OA cartilage damage.

Usefulness of anti-cyclic citrullinate peptide antibody determination in synovial fluid analysis of patients with rheumatoid arthritis

OBJECTIVE

To assess the role of anti-cyclic citrullinated peptide (CCP) antibody detection in synovial fluid (SF) of RA patients compared to OA patients.

METHODS

We evaluated in 25 RA subjects and 14 OA patients, presenting a knee-joint effusion, the main clinical and laboratory parameters including the number of painful and/or swollen joints, Ritchie index, morning stiffness, ESR, CRP and analysis of SF obtained by therapeutic arthrocentesis. IgG anti-CCP (ELISA), rheumatoid factor (RF) and total IgG (nephelometry method) were measured in SF and paired serum samples.

RESULTS

We found anti-CCP antibodies and RF in 64% (16/25) and 60% (15/25) of RA sera, respectively; 72% (18/25) of RA patients were positive for anti-CCP antibodies or RF. We found a higher SF/serum ratio for anti-CCP (p<0.004) compared to that for total IgG. The calculation of anti-CCP concentration as IgG anti-CCP (units)/total IgG (g L-1) revealed higher values in SF than in serum (p<0.046) in RA patients. Among these, correlation analysis showed that anti-CCP/total IgG values in SF correlated with the relative concentration of serum anti-CCP/total IgG (rs=0.842; p<0.00001) and serum anti-CCP antibody levels (rs=0.799; p<0.0001). We did not find any correlation between SF anti-CCP levels and the main characteristics of SF as well as the clinical or laboratory parameters.

CONCLUSION

Our study give evidence for a preferential production of anti-CCP antibodies at RA joint level, confirming the pathogenetic role of these autoantibodies. Moreover, SF determination of anti-CCP, corrected for the total amount of the corresponding immunoglobulin, may be helpful as diagnostic tool in selected cases.

A benzamide-linked small molecule HS-Cf inhibits TNF-α-induced interferon regulatory factor-1 in porcine chondrocytes: a potential disease-modifying drug for osteoarthritis therapeutics

BACKGROUND

Using tumor necrosis factor-alpha (TNF-α)-activated porcine chondrocytes as a screening tool, we aim to synthesize and identify small-molecule inhibitors preserving immunomodulatory effects as therapeutics for osteoarthritis (OA).

METHODS

Chondrocytes were isolated from pig joints. A minilibrary of 300 benzamide-linked small molecules was established. The levels of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) were measured by Western blot and Griess reaction, respectively. Proteoglycan degradation in cartilage explants was determined by histochemistry analysis. The activation of transcription factors and protein kinases was determined by electrophoretic mobility shift assays or Western blots. Zymography and real-time reverse transcriptase-polymerase chain reaction were used to determine enzyme activity and expression of matrix metalloproteinases (MMPs) and aggrecanases, respectively.

RESULTS

Bioassay screening of benzamide-linked small molecules revealed that 2-hydroxy-N-[3-(trifluoromethyl)phenyl]benzamide (HS-Cf) was a potent inhibitor of NO production and iNOS expression in TNF-α-stimulated porcine chondrocytes. HS-Cf suppressed TNF-α-induced activity of MMP-13 and expressions of several aggrecanases and prevented TNF-α-mediated reduction of collagen II. Histochemistry analysis confirmed that HS-Cf could prevent TNF-α-induced degradation and release of proteoglycan/aggrecan in cartilage explants. Such effects by HS-Cf were likely through suppressing TNF-α-induced interferon regulatory factor-1 (IRF-1) but not nuclear factor-kappaB signaling. The significance of IRF-1 was further confirmed by short hairpin knockdown studies.

CONCLUSIONS

In a minilibrary containing 300 small molecules, we identified a benzamide-linked small molecule, HS-Cf, that through down-regulating TNF-α-induced IRF-1 activity suppressed chondrocyte activation and prevented cartilage destruction. HS-Cf might be a potential disease-modifying drug for OA therapeutics.

Elevated Th22 cells correlated with Th17 cells in patients with rheumatoid arthritis

BACKGROUND

T-helper (Th) 22 and Th17 cells are implicated in the pathogenesis of autoimmune diseases. The roles of Th22 cells in the pathophysiology of rheumatoid arthritis (RA) remain unsettled.

MATERIALS AND METHODS

CD4(+)IFNγ(-)IL17(-)IL-22(+) T cells (Th22 cells), CD4(+)IFNγ(-)IL-22(-)IL17(+) T cells (pure Th17 cells), CD4(+)IL17(+) T cells (Th17 cells), and CD4(+)IFNγ(+) T cells (Th1 cells) in RA, osteoarthritis patients, and healthy controls were examined by flow cytometry. Plasma IL-22 and IL-17 levels were examined by enzyme-linked immunosorbent assay.

RESULTS

Th22 cells, pure Th17 cells, Th17 cells, and interleukin-22 were significantly elevated in RA patients compared with osteoarthritis and healthy controls, but there were no significant differences regarding Th1 cells and interleukin-17. Th22 cells showed a positive correlation with interleukin-22 as well as pure Th17 cells or Th17 cells in RA patients. Additionally, the percentages of Th22 cells, pure Th17 cells as well as Th17 cells correlated positively with both C-reactive protein levels and 28-joints disease activity score.

CONCLUSION

Together, our results indicated a possible role of Th22 pure Th17 cells and Th17 cells in RA, and blockade of the interleukin-22 may be a reasonable therapeutic strategy for RA.

Soluble macrophage-derived CD163 is a marker of disease activity and progression in early rheumatoid arthritis

OBJECTIVES

To investigate the expression of the soluble form of the resident macrophage marker CD163 (sCD163) and its association with core parameters for disease activity, including radiographic progression in early rheumatoid arthritis (RA).

METHODS

In a longitudinal sample set from early RA patients (n=34) we measured plasma levels of sCD163 at initiation of treatment and after 9 months of treatment and correlated levels with disease activity in 28 joints (DAS28), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and total Sharp score (TSS). We also measured plasma levels of sCD163 in 55 healthy volunteers (HV) and in a transverse sample set of chronic (>8 years of disease) RA patients (n=24) and OA patients (n=24) with paired plasma and joint fluid.

RESULTS

Early RA patients had significantly higher plasma levels of sCD163 (1.69mg/l (1.42-2.10)) (median (IQR)) at baseline than after 9 months of treatment (1.28mg/l (0.963-1.66), p=0.001), but not significantly changed compared with HV (1.66mg/l (1.22-2.02)). In early RA patients, baseline levels of sCD163, correlated with DAS28, CRP and ESR. Interestingly, sCD163 at 9 months was associated with radiographic progression (TSS) between year 0 and 5 (r=0.468, p=0.02). Levels of sCD163 were higher in RA patients, than in OA patients and higher in SF than in plasma.

CONCLUSIONS

Plasma levels of macrophage derived sCD163 are associated with disease activity and predict radiographic progression in early RA patients, supporting that sCD163 may have a role as a biomarker of disease activity and that resident macrophages are important for joint destruction.

Proliferation of the synovial lining cell layer in suggested metal hypersensitivity

Synovial tissues in joints with prostheses display characteristic morphological changes in cases with aseptic failure, particularly macrophage infiltration. Since proliferation of the synovial lining cell layer represents a feature characteristic of autoimmune joint diseases, the possibility of morphological changes of the synovial lining cell layer in periprosthetic tissues was investigated. Synovial biopsies from five groups of morphologically well-defined lesions (osteoarthritis, rheumatoid arthritis, aseptic loosened metal-on-polyethylene and metal-on-metal arthroplasty and suggested metal hypersensitivity) were compared using a conventional staining method and immunohistochemistry. The synovial lining cell layer was substantially enlarged in both rheumatoid arthritis and cases suggestive of metal hypersensitivity. Macrophage infiltrates were apparent in rheumatoid arthritis and all specimens from retrieved hip arthroplasties. Although both synovial and subsynovial macrophages were positive for CD163 (indicating synovial M2 macrophages), the remaining fibroblast-like synoviocytes and scattered stromal fibroblasts showed a positive reaction with the D2-40 antibody (indicating fibroblast-like synoviocytes). Furthermore, in contrast to CD163-positive macrophages, the enlarged D2-40-positive fibroblast-like synoviocytes displayed cytoplasmatic tubular projections. Proliferation of the periprosthetic synovial lining cell layer occurred in cases with unexplained groin pain following metal-on-metal hip resurfacing arthroplasty, suggestive of hypersensitivity. Despite some important study limitations, the present observation adds to the evidence that metal hypersensitivity shares characteristic morphological features with autoimmune diseases of the joints.

Abnormal networks of immune response-related molecules in bone marrow cells from patients with rheumatoid arthritis as revealed by DNA microarray analysis

INTRODUCTION

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic synovitis that progresses to destruction of cartilage and bone. Bone marrow (BM) cells have been shown to contribute to this pathogenesis. In this study, we compared differentially expressed molecules in BM cells from RA and osteoarthritis (OA) patients and analyzed abnormal regulatory networks to identify the role of BM cells in RA.

METHODS

Gene expression profiles (GEPs) in BM-derived mononuclear cells from 9 RA and 10 OA patients were obtained by DNA microarray. Up- and down-regulated genes were identified by comparing the GEPs from the two patient groups. Bioinformatics was performed by Expression Analysis Systemic Explorer (EASE) 2.0 based on gene ontology, followed by network pathway analysis with Ingenuity Pathways Analysis (IPA) 7.5.

RESULTS

The BM mononuclear cells showed 764 up-regulated and 1,910 down-regulated genes in RA patients relative to the OA group. EASE revealed that the gene category response to external stimulus, which included the gene category immune response, was overrepresented by the up-regulated genes. So too were the gene categories signal transduction and phosphate metabolism. Down-regulated genes were dominantly classified in three gene categories: cell proliferation, which included mitotic cell cycle, DNA replication and chromosome cycle, and DNA metabolism. Most genes in these categories overlapped with each other. IPA analysis showed that the up-regulated genes in immune response were highly relevant to the antigen presentation pathway and to interferon signaling. The major histocompatibility complex (MHC) class I molecules, human leukocyte antigen (HLA)-E, HLA-F, and HLA-G, tapasin (TAP) and TAP binding protein, both of which are involved in peptide antigen binding and presentation via MHC class I molecules, are depicted in the immune response molecule networks. Interferon gamma and interleukin 8 were overexpressed and found to play central roles in these networks.

CONCLUSIONS

Abnormal regulatory networks in the immune response and cell cycle categories were identified in BM mononuclear cells from RA patients, indicating that the BM is pathologically involved in RA.

[Comparison of the status of STAT4 tyrosine phosphorylation in peripheral T-lymphocytes induced by IL-12 in rheumatoid arthritis and osteoarthritis]

OBJECTIVE

To compare the levels of STAT4 tyrosine phosphorylation in peripheral T-lymphocytes induced by IL-12 in rheumatoid arthritis (RA) and osteoarthritis (OA).

METHODS

From May 2007 to August 2009, peripheral blood mononuclear cells (PBMCs) were isolated from RA patients [RA group, all the cases were female, the age was from 28 to 55 years with an average of (45.0 +/- 13.0) years] and OA patients [OA group, all the cases also were female; the age was from 55 to 75 years with an average of (67.0 +/- 9.6) years]. The purity of T-lymphocytes from PBMCs was accredited by flow cytometry. The IL-12 of 50 ng/ml added in T-lymphocytes, the levels of STAT4 tyrosine phosphorylation were detected by western blot after different time intervals (0, 10, 30, 60 min).

RESULTS

The purity of T-lymphocytes were above 91% through diremption and depuration for peripheral blood monouclear cells. The levels of STAT4 tyrosine phosphorylation in T-lymphocytes from RA induced by IL-12 were higher than that from OA in the different times (10, 30, 60 min); after 30 min, its levels from RA and OA achieved to crest value.

CONCLUSION

STAT4 in peripheral T-lymphocytes of rheumatoid arthritis was more easily to be activated than osteoarthritis.

[Circumannular features of non-specific resistance in patients with osteoarthrosis in mid-lattitudes]

Modified cosinor-analysis was used to calculate biorhythmologic characteristics (period, amplitude, phase, mesor) of the circumannual rhythm of neuroendocrine regulation parameters, the state of bioradical hemostasis, and protein components of non-specific resistance in patients with osteoarthrosis living in moderate climates. Near-annual rhythms of these parameters are described. The chronological analysis indicates that strenuouos activity of the regulatory systems responsible for adaptive reactions of the organism falls within the periods from March to May and from August to October. Variability of the above parameters is shown to be related to the efficacy of osteoarthrosis therapy in different phases of the near-annual rhythm.