Dunming Guo

High adiponectin and adiponectin receptor 1 expression in synovial fluids and synovial tissues of patients with rheumatoid arthritis.

OBJECTIVES The major objectives of this article are first to measure the levels of expression of adiponectin and its 2 receptors (adipoR1 and adipoR2) in the peripheral blood mononuclear cells and in the synovial compartment of rheumatoid arthritis (RA) patients, and second, to assess their pro-inflammatory potential. Osteoarthritis patients and healthy subjects served as controls. METHODS Expression of adiponectin, adipoR1, and adipoR2 were assayed by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistology. The potential pro-inflammatory activity of adiponectin was studied by adding recombinant adiponectin to cultures of synovial fibroblasts. RESULTS Immunohistology showed that numerous cells in the synovial biopsies of RA expressed adiponectin, adipoR1, and adipoR2. The synovial fibroblasts were distinctly rich in adiponectin. As expected, high adiponectin levels were present in the synovial fluids. In contrast to the synovial compartment, in peripheral blood mononuclear cells, only adipoR1 exceeded those of osteoarthritis and healthy subjects. When recombinant adiponectin was added to cultures of synovial fibroblasts, it induced up to 8.1- and 11.4-fold increase in the release of monocyte chemoattractant protein-1 and interleukin-6. CONCLUSIONS The adiponectin adipokine axis might play a role in RA.

Proteomic analysis of human articular cartilage : Identification of differentially expressed proteins in knee osteoarthritis

OBJECTIVES The mechanisms underlying the development of age related osteoarthritis (OA) remain unclear. To better understand the pathogenesis of OA and the molecular basis of progressive destruction of articular cartilage in OA, we compared the proteome of OA cartilage with that of normal cartilage. METHODS After removal of proteoglycans and collagens, proteins extracted from either normal or OA knee joint cartilage were separated by two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins in OA cartilage were chosen to be further identified by linear ion trap-Fourier transform ion cyclotron resonance mass spectrometry (LTQ-FT/MS). RESULTS A total of 1436+/-49 or 1472+/-7 protein spots were resolved by 2-DE of normal or OA cartilage extractions, respectively. Sixteen spots from OA cartilage samples were found to have statistically significant changes in the amount of protein compared with normal samples. Of 16 spots, the identities of 14 proteins were unambiguously determined by LTQ-FT/MS. These OA associated proteins fell into five groups, including glycolysis and energy production (ADH, ADK, ENOA, KPYM and FR), signaling (ANNX-I, PEBP and TUB), Redox (PRDX3 and SODM), and cartilage matrix (COLL-I and COLL-VI). Interestingly, two novel RING (Really Interesting New Gene) domain-containing proteins, RF, Zn-RF, were identified, suggesting novel pathways of cartilage protein regulation. CONCLUSIONS This study shows that 2-DE followed by LTQ-FT/MS can be successfully used to characterize the proteome of cartilage without in vitro culturing which could obfuscate physiological differences. The definition of unique OA-associated proteins described here provides significant mechanistic insights into OA by corroborating previously suggested mechanisms and by defining unique players with roles yet to be defined in disease pathogenesis.

IL-29 enhances Toll-like receptor-mediated IL-6 and IL-8 production by the synovial fibroblasts from rheumatoid arthritis patients

IntroductionWe previously reported that IL-29, a newly described member of interferon (IFN) family, was overexpressed in blood and synovium of rheumatoid arthritis (RA) patients and triggered proinflammatory cytokine IL-6 and IL-8 mRNA expression in RA synovial fibroblasts (RA-FLS). This suggests that IL-29 has an important role in synovial inflammation. Toll-like receptors (TLRs) also activate RA-FLS to produce inflammatory mediators including tumor necrosis factor α (TNF-α) and IL-1β in RA-FLS. Since the TLR family plays an early role in the innate immune response and the subsequent induction of the adaptive immune response, we hypothesize that IL-29 interacts with TLRs in RA inflammation. This study aimed to investigate the effect of IL-29 on TLR-mediated proinflammatory cytokine production in RA-FLS.MethodsThe mRNA level of IL-29 receptors (IL-28Rα and IL-10R2) in RA-FLS was determined by semi-quantitative RT- PCR. IL-6 and IL-8 mRNA expressions in RA-FLS were evaluated by real-time PCR after pre-incubation with IL-29 and subsequent stimulation with peptidoglycan (PGN, TLR2 ligand), or polycytidylic acid (poly(I:C), TLR3 ligand), or lipopolysaccharide (LPS, TLR4 ligand) . The production of TLR2, 3, and 4 in RA-FLS after IL-29 stimulation was also assessed by real-time PCR and flow cytometry. IL-29 mRNA and protein expression in RA-FLS after stimulation with PGN, poly(I:C), or LPS were measured by real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively.ResultsThe IL-29 receptor complex (IL-28Rα and IL-10R2) was identified in RA-FLS. IL-29 enhanced TLR-mediated IL-6 and IL-8 expression in RA-FLS. IL-29 upregulated expression of TLR2, 3 and 4 in RA-FLS. Exposure to PGN, poly(I:C) or LPS triggered IL-29 production by RA-FLS.ConclusionsWe show for the first time that IL-29 enhances TLR-induced proinflammatory cytokine production in RA-FLS via upregulation of TLRs.

Interleukin-29 modulates proinflammatory cytokine production in synovial inflammation of rheumatoid arthritis

IntroductionThe immunoregulatory function of interleukin (IL)-29 has recently been recognized. However, little is known about the involvement of IL-29 in the pathogenesis of rheumatoid arthritis (RA). This study aimed to examine the expression profiles of IL-29 in blood, synovial fluid (SF) and synovium in RA patients and investigate the effect of IL-29 on cytokines production in RA synovial fibroblasts.MethodsThe transcript levels of IL-29 and its specific receptor IL-28Rα in peripheral blood mononuclear cells (PBMC) and synovium were determined by real-time reverse transcription-polymerase chain reaction (real-time PCR). The concentrations of IL-29 in serum and synovial fluid (SF) were quantified by enzyme-linked immunoassay (ELISA), and the correlation of serum IL-29 levels with disease activity in RA patients was investigated. Furthermore, the expression of IL-29 in RA synovium was examined by immunohistochemistry and double immunofluorescence analysis. Finally, the expression of IL-6, IL-8, IL-10, IL-17 and matrix metalloproteinase-3 (MMP-3) in synovial fibroblasts upon IL-29 stimulation was determined by real-time PCR.ResultsIL-29 and IL-28Rα mRNA expression in PBMC was significantly increased in patients with RA compared with healthy controls (HC). The serum levels of circulating IL-29 were higher in RA than those in HC. Increased IL-29 levels were detected in RA SF when compared with osteoarthritis (OA) SF. However, serum IL-29 levels showed no significant correlation with RA disease activity. IL-29 was mostly expressed in the lining region of RA synovium. Moreover, IL-29 was expressed predominately in synovial macrophages and fibroblasts. RA synovial fibroblasts exposed to IL-29 specifically upregulated IL-6, -8 and MMP-3 but downregulated IL-10.ConclusionsThe findings in the present study indicate, for the first time, that IL-29 is dysregulated in patients with RA, which may contribute to the RA pathogenesis via inducing the production of proinflammatory cytokines, chemokines or matrix metalloproteinases in synovial fibroblasts.

Altered Expression of Signaling Genes in Jurkat Cells upon FTY720 Induced Apoptosis

FTY720, a novel immunosuppressant, has a marked activity in decreasing peripheral blood T lymphocytes upon oral administration. Recent investigations suggest that the action of FTY720 on lymphocytes may result from its ability to induce cell apoptosis. However, the cell signaling mechanism involved in the FTY720-induced cell apoptosis remains unclear. Here we examined the apoptotic signal pathways mediated by FTY720 in Jurkat cells using microarray analysis. The results showed that FTY720 can induce Jurkat cell apoptosis in a dose and time dependent manner as assessed by cell viability, Hoechst 33258 staining, Annexin V binding and DNA fragmentation tests. cDNA microarray analysis showed that 10 μM of FTY720 up-regulated 54 and down-regulated 10 genes in Jurkat cells among the 458 apoptotic genes examined following the 6 h incubation period. At least five-fold increased expression of modulator of apoptosis-1 (MOAP-1), vascular endothelial growth factor (VEGF), tumor necrosis factor receptor-associated factors (TRAF 6), Caspase 2 (CASP 2), E2F transcription factor 1 (E2F 1) and Casapse 5 (CASP 5) genes was observed in microarray analyses; these results were confirmed with reverse transcription polymerase chain reaction (RT-PCR) examination. Our findings suggest that the mitochondria related signaling pathways are the key pathways involved in the FTY720-induced apoptosis in Jurkat cells. And our results provide a new insight into the mechanism of FTY720, which allows us to draw the first simple diagram showing the potential pathways mediated by FTY720.

High serum level of haptoglobin is associated with the response of 12 weeks methotrexate therapy in recent-onset rheumatoid arthritis patients

We previously found, using microarray, haptoglobin (HP) expression signal was 5.1‐fold increased in peripheral blood mononuclear cells (PBMCs) from methotrexate (MTX)‐resistant rheumatoid arthritis (RA) patients.

The clinical comparison of simultaneous bilateral total knee arthroplasty in treatment of osteoarthritis

Abstract Objective To evaluate the risk and efficacy of simultaneous bilateral total knee arthroplasty(TKA) in treatment of osteoarthritis when compared with sequential bilateral TKA and unilateral TKA. Methods A retrospective analysis was performed on 162 patients who underwent TKA from 2003 to 2006. The analyses were adjusted for demographics, preexisting medical conditions, and osteoar-thritis diagnosis. Results Patients undergoing simultaneous bilateral TKA had significantly lower amounts of blood loss, shorter surgical time, shorter hospitalization time, less hospital charges and lower rates of perioperative complications compared with patients undergoing sequential bilateral TKA. No significant difference was found with regard to postoperative complications between the simultaneous bilateral and the unilateral TKA groups. Patients knee range of motion and the postoperative Hospital for Special Surgery scores(HSS) were similar for the three groups. Conclusion When there are adequate indications for bilateral TKA, simultaneous bilateral TKA is beneficial to patients compared with sequential bilateral or unilateral TKA.