Role In Inflammatory Arthritis Research Articles

Epigenetic and transcriptional regulation of CCL17 production by glucocorticoids in arthritis

Glucocorticoids (GCs) are potent anti-inflammatory agents and are broadly used in treating rheumatoid arthritis (RA) patients, albeit with adverse side effects associated with long-term usage. The negative consequences of GC therapy provide an impetus for research into gaining insights into the molecular mechanisms of GC action. We have previously reported that granulocyte-macrophage colony-stimulating factor (GM-CSF)-induced CCL17 has a non-redundant role in inflammatory arthritis. Here, we provide molecular evidence that GCs can suppress GM-CSF-mediated upregulation of IRF4 and CCL17 expression via downregulating JMJD3 expression and activity. In mouse models of inflammatory arthritis, GC treatment inhibited CCL17 expression and ameliorated arthritic pain-like behavior and disease. Significantly, GC treatment of RA patient peripheral blood mononuclear cells exvivo resulted in decreased CCL17 production. This delineated pathway potentially provides new therapeutic options for the treatment of many inflammatory conditions, where GCs are used as an anti-inflammatory drug but without the associated adverse side effects.

Psoriatic and rheumatoid arthritis joints differ in the composition of CD8+ tissue-resident memory T cell subsets

CD69+CD103+ tissue-resident memory T (TRM) cells are important drivers of inflammation. To decipher their role in inflammatory arthritis, we apply single-cell, high-dimensional profiling to Tcells from the joints of patients with psoriatic arthritis (PsA) or rheumatoid arthritis (RA). We identify three groups of synovial CD8+CD69+CD103+ TRM cells: cytotoxic and regulatory T (Treg)-like TRM cells are present in both PsA and RA, while CD161+CCR6+ type 17-like TRM cells with a pro-inflammatory cytokine profile (IL-17A+TNFα+IFNγ+) are specifically enriched in PsA. In contrast, only one population of CD4+CD69+CD103+ TRM cells is detected and at similarly low frequencies in both diseases. Type 17-like CD8+ TRM cells have a distinct transcriptomic signature and a polyclonal, but distinct, TCR repertoire. Type 17-like cells are also enriched in CD8+CD103- Tcells in PsA compared with RA. These findings illustrate differences in the immunopathology of PsA and RA, with a particular enrichment for type 17 CD8+ Tcells in the PsA joint.

Overproduced bone marrow neutrophils in collagen-induced arthritis are primed for NETosis: An ignored pathological cell involving inflammatory arthritis.

ObjectivesBone marrow edema is a universal manifestation of rheumatoid arthritis (RA), and its pathological essence is a bone marrow lesion (BML) formed by various bone marrow (BM) immune cells. Neutrophils play an important role in inflammatory arthritis, but the role and mechanism of neutrophils in BML are not clear.Materials and methodsGranulocyte colony‐stimulating factor (G‐CSF) −/− mice and wild type (WT) C57BL/6 mice were immunized for collagen‐induced arthritis (CIA). Histological scores of arthritis were evaluated. Immunohistochemistry staining with anti‐Ly6G was conducted. Neutrophil extracellular traps (NETs) in joint sections were determined by immunofluorescence staining. BM neutrophils were isolated for flow cytometry and NETosis induction in vitro.ResultsHistological study showed significant neutrophil infiltrations in BML of CIA mice. Inhibition of BM neutrophil production by G‐CSF knock out can obstruct the induction of BML and CIA. In addition to abundant infiltrated NETs intra‐articular, remarkable NETosis primed BM neutrophils were infiltrated in BML of CIA mice, which was positively related to bone erosion. Neutrophils derived from G‐CSF−/− mice have diminished ability of NETs formation in vitro, while G‐CSF induction can enhance its capacity of NETs formation.ConclusionsWe propose for the first time that the overproduced BM neutrophils in CIA mice are primed for NETosis in a G‐CSF dependent manner, and these pathogenic cells may have an important role in inflammatory arthritis. Blocking this pathological process could be a potential strategy for the treatment of RA.

Decoy Receptor 3 Promotes Preosteoclast Cell Death via Reactive Oxygen Species-Induced Fas Ligand Expression and the IL-1α/IL-1 Receptor Antagonist Pathway.

Purpose Interleukin-1α (IL-1α) is a potent cytokine that plays a role in inflammatory arthritis and bone loss. Decoy receptor 3 (DCR3) is an immune modulator of monocytes and macrophages. The aim of this study was to investigate the mechanism of DCR3 in IL-1α-induced osteoclastogenesis. Methods We treated murine macrophages with DCR3 during receptor activator of nuclear factor kappa Β ligand- (RANKL-) plus IL-1α-induced osteoclastogenesis to monitor osteoclast formation by tartrate-resistant acid phosphatase (TRAP) staining. Osteoclast activity was assessed using a pit formation assay. The mechanisms of inhibition were studied by biochemical analyses, including RT-PCR, immunofluorescent staining, flow cytometry, an apoptosis assay, immunoblotting, and ELISA. Results DCR3 suppresses IL-1α-induced osteoclastogenesis in both primary murine bone marrow-derived macrophages (BMM) and RAW264.7 cells as it inhibits bone resorption. DCR3 induces RANKL-treated osteoclast precursor cells to express IL-1α, secretory IL-1ra (sIL-1ra), intracellular IL-1ra (icIL-1ra), reactive oxygen species (ROS), and Fas ligand and to activate IL-1α-induced interleukin-1 receptor-associated kinase 4 (IRAK4). The suppression of DCR3 during RANKL- or IL-1α-induced osteoclastogenesis may be due to the abundant secretion of IL-1ra, accumulation of ROS, and expression of Fas ligand in apoptotic osteoclast precursor cells. Conclusions We concluded that there is an inhibitory effect of DCR3 on osteoclastogenesis via ROS accumulation and ROS-induced Fas ligand, IL-1α, and IL-1ra expression. Our results suggested that the upregulation of DCR3 in preosteoclasts might be a therapeutic target in inflammatory IL-1α-induced bone resorption.

Downregulation of Transcription Factor T-Bet as a Protective Strategy in Monosodium Urate-Induced Gouty Inflammation.

Gout is sterile joint inflammation triggered by the damaging effects of monosodium urate (MSU) crystals accumulation. Previous studies suggest transcription factor T-bet plays an important role in inflammatory arthritis. Notably, mice lacking T-bet markedly reduced joint inflammation of rheumatoid arthritis models, however, the involvement of T-bet in gouty inflammation has yet to be clarified. Here, we took advantage of T-bet knockout (KO) mice to investigate the role of T-bet in the pathogenesis of MSU-induced gout inflammation. T-bet KO and wild type (WT) mice were used for models of acute inflammation induced with MSU crystals, including footpad, air pouch and peritonitis models. Inflammatory cytokines and phagocytosis were detected in bone-marrow-derived macrophages (BMDMs) from T-bet KO and WT mice treated with MSU crystals in vitro. In addition, T-bet expression in peripheral blood mononuclear cells (PBMCs) from gout patients was measured, as well as plasma inflammatory cytokines. We found that the levels of interleukin (IL)-17, IL-23, and interferon-γ were reduced, but tumor necrosis factor-α was not, in BMDMs from T-bet KO compared with WT mice after MSU challenge in vitro, as well as MSU phagocytosis. In comparison with WT mice in vivo, the swelling index of T-bet KO mice was significantly decreased in the footpad model. T-bet deficiency also dramatically relieved MSU-induced inflammatory cell infiltration in peritonitis and air pouch models in vivo, and as well as the IL-1β levels of air pouch lavage fluid (APLF). In addition, plasma IL-17 and IL-23 levels were elevated in acute gout, whereas protein levels of T-bet were downregulated in PBMCs from acute gout patients and intercritical gout treated with MSU crystals in vitro as well. Transcription factor T-bet deficiency protects against MSU-induced gouty inflammation, suggesting that downregulation of T-bet could be a protective strategy and contribute to spontaneous remission of inflammation in acute gout.

\u03b3\u03b4TCR regulates production of interleukin-27 by neutrophils and attenuates inflammatory arthritis

γδ T cells have been implicated in inflammatory diseases as an important link between the innate and adaptive immune responses, however, their role in inflammatory arthritis remain unclear. To define the contribution of γδ T cells in the pathogenesis of inflammatory arthritis, we performed gene transfer of IL-23 in B10.RIII mice to establish joint inflammation in the presence or absence of γδ T cells. We demonstrated that γδ T cell blockade has a protective effect on arthritis incidence and severity by preventing neutrophil accumulation in the blood, spleen and bone marrow as well as by reducing neutrophil infiltration into the joints. Furthermore, our data demonstrate that absence of γδ T cells was associated with an increase of IL-27 levels produced by neutrophils and dendritic cells, and systemic IL-27 expression also prevents IL-23-induced inflammatory arthritis and limits neutrophil expansion. Collectively our findings reveal an immunomodulatory effect of γδ T cells on neutrophils associated with IL-27 synthesis and secretion and indicate a novel link between IL-27 and the modulation of γδ T cells and neutrophils that can be targeted in the treatment of inflammatory arthritis.

Protein Kinase D1 deletion ameliorates collage-induced arthritis

Abstract Although the etiology of Rheumatoid arthritis (RA) is unknown, it is thought that TLR signaling may be involved in the initiation and progression of the disease. Disruption of the TLR signaling at early stages of RA could be a possible therapeutic strategy. We have previously identified protein kinase D1 (PKD1) as an indispensable component in the MyD88-dependent TLR signaling pathway that plays a critical role in acute and chronic inflammation. Although it is currently not known whether PKD1 plays a pathogenic role in RA in humans, we have previously found that daily treatments of a PKC/PKD inhibitor Gö6976 significantly ameliorated arthritic symptoms in collagen-induced arthritis (CIA). Here, we further investigated the role of PKD1 in pathogenesis of CIA in humanized HLA-DR1 transgenic mice using a tamoxifen-inducible PKD1-gene deletion system. We have found that PKD1 deletion resulted in reduced incidence and severity of arthritis in HLA-DR1 mice immunized with type II collagen. In addition, Gr-1+ myeloid lineage cell infiltration into the joint space was significantly reduced and joint destruction (assessed by joint histopathology study and mCT scanning) was ameliorated in the PKD1-deleted mice compared to wild-type. Our results provide evidences that PKD1 might play an important pathogenic role in inflammatory arthritis and that PKD1 could be a new therapeutic molecular target for arthritis.

Heat shock proteins and their immunomodulatory role in inflammatory arthritis

Autoimmune diseases, including inflammatory arthritis, are characterized by a loss of self-tolerance, leading to an excessive immune responses and subsequent ongoing inflammation. Current therapies are focused on dampening this inflammation, but a permanent state of tolerance is seldom achieved. Therefore, novel therapies that restore and maintain tolerance are needed. Tregs could be a potential target to achieve permanent immunotolerance. Activation of Tregs can be accomplished when they recognize and bind their specific antigens. HSPs are proteins present in all cells and are upregulated during inflammation. These proteins are immunogenic and can be recognized by Tregs. Several studies in animal models and in human clinical trials have shown the immunoregulatory effects of HSPs and their protective effects in inflammatory arthritis. In this review, an overview is presented of the immunomodulatory effects of several members of the HSP family in general and in inflammatory arthritis. These effects can be attributed to the activation of Tregs through cellular interactions within the immune system. The effect of HSP-specific therapies in patients with inflammatory arthritis should be explored further, especially with regard to long-term efficacy and safety and their use in combination with current therapeutic approaches.

Dysregulation of micro-RNAs involved in TLR pathway in peripheral blood mononuclear cells and synovial fluid mononuclear cells of patients with enthesitis related arthritis form of juvenile idiopathic arthritis (HUM3P.254)

Abstract Toll like receptor (TLR) pathway plays a major role in inflammatory arthritis. MicroRNA (miR)-146a, miR-155, miR-21 regulate downstream molecules of TLR signaling like IRAK-1 and TRAF-6. TLR pathway genes are generally upregulated in ERA-JIA. We studied expression of miR-146a, miR-155, miR-21, miR-210 and miR-26a in PBMC and SFMC of patients with ERA. RNA was isolated from PBMC (n=21) & SFMC (n=11) of ERA patients and PBMC of controls (n=11). The miRNA and target gene expressions were analysed by TaqMan qRT-PCR assays. Among 21 patients, 20 were boys. Mean disease onset age was 10.3Y & disease duration was 6Y. All had arthritis, 14 had enthesitis, 4 had uveitis, 7 had IBP and 2 had family history of HLAB27 related disease. No expression difference was seen in miR-146a, miR-155, miR-210 and miR-26a in PBMC of patients and controls but miR-21 was increased in patients. To check inflammatory site specific expression, comparison of SFMC and PBMC was done showing downregulation of miR146a and upregulation of miR-155, miR-21 and miR-210 in SFMC. Expression of miR-26a did not show any change. MiR-146a target genes i.e. IRAK-1 and TRAF-6 were upregulated in SFMC compared to PBMC. There is dysregulation of miRNAs regulating TLR pathway in mononuclear cells of patients with ERA-JIA especially at the chronic inflammation site. Down regulation of miR-146a, a key regulator may lead to over-expression of TLR downstream molecules like IRAK-1 and TRAF-6 thus perpetuating inflammation in ERA.

FRI0338 Therapeutic Effect of A New Histone Deacetylase 6 Inhibitor, Ckd-L, on Collagen Induced Arthritis and Peripheral Blood Mononuclear Cells from Patients with Rheumatoid Arthritis in Vitro

BackgroundEpigenetic regulation plays an important role in inflammatory arthritis, including rheumatoid arthritis (RA). Histone deacetylase inhibitor (HDACi) has been recently reported to have therapeutic effect in collagen induced arthritis (CIA)....

Glycosylation as a marker for inflammatory arthritis

Changes in serum protein glycosylation play an important role in inflammatory arthritis. Altered galactosylation of immunoglobulin G (IgG) in rheumatoid arthritis attracts special attention due to the devastating nature of the disease. Studying glycosylation changes of serum proteins has been recognized as a potential strategy to provide added value regarding diagnostics, aetiopathology and therapy of inflammatory arthritic diseases. Key questions, which are approached in these fields of research, are whether or not glycosylation can be used as a complementary pre-clinical and clinical marker for disease differentiation, diagnosis, the prediction of disease course and severity as well as for the evaluation of disease therapies. These studies mainly focus on TNF antagonists, which present a new and promising way of treating inflammatory arthritis. The recent availability of new high-throughput glycoanalytical tools enables a more profound and efficient investigation in large patient cohorts and helps to gain new insights in the complex mechanism of the underlying disease pathways.

AB0081 Cd11c+ dendritic cells play an important proinflammatory role in inflammatory arthritis

BackgroundDendritic cells (DCs) play an important role in bridging the innate and the adaptive immune response by serving as antigen presenting cells and are therefore implicated in the initiation of...

Interleukin‐22 Reduces the Severity of Collagen‐Induced Arthritis in Association With Increased Levels of Interleukin‐10

The mechanism of action of interleukin- 22 (IL-22) in inflammatory arthritis remains unknown. IL-22-deficient mice exhibit an intact humoral and cellular immune response to collagen and yet have a reduced incidence of collagen-induced arthritis (CIA). Further, administration of anti-IL-22 does not reduce the severity of clinical arthritis but rather improves only certain aspects of joint inflammation as assessed histologically. This study was undertaken to investigate the mechanism of action and role of systemic IL-22 in modulating target organ inflammation. CIA was induced in DBA mice by immunization with collagen and Freund's complete adjuvant. Expression of IL-22 and its receptor (IL-22R) in lymphoid organ and target tissues was determined during various phases of arthritis. The effector functions of IL-22 on induction/regulation of various cytokines in in vitro restimulation cultures were analyzed by enzyme-linked immunosorbent assay (ELISA). Recombinant IL-22 with or without anti-IL-10 antibody was administered to mice following immunization with collagen and prior to the onset of arthritis, and the severity of arthritis was evaluated by clinical scoring and histopathologic assessment. Anticollagen antibodies in mouse sera were analyzed by ELISA. IL-22 and IL-22R were up-regulated in lymphoid organs and joints during the course of arthritis. IL-22 augmented IL-10, IL-17, and IL-6 in lymphoid tissues in vitro. Administration of recombinant IL-22 was associated with an increase in IL-10 levels in vivo and a significant reduction in the progression of arthritis severity. Anti-IL-10 antibody treatment was associated with the abrogation of this protective effect of IL-22. Our data demonstrate, for the first time, that IL-22 has a protective role in inflammatory arthritis.

Simvastatin inhibits cysteine‐rich protein 61 expression in rheumatoid arthritis synovial fibroblasts through the regulation of sirtuin‐1/FoxO3a signaling

To examine the role of sirtuin-1 (SIRT-1)/FoxO3a in the expression of cysteine-rich protein 61 (CYR-61) in rheumatoid arthritis synovial fibroblasts (RASFs) and the influence of simvastatin on this pathway, and to determine the relationship between disease progression and FoxO3a/CYR-61 signaling in synovial fibroblasts in vivo using a rat model of collagen-induced arthritis (CIA). In RASFs, the expression of CYR-61 and SIRT-1, the localization of FoxO3a in the nucleus/cytoplasm, and the phosphorylation/acetylation of FoxO3a were examined by Western blotting. Secretion of CCL20 was assessed by enzyme-linked immunosorbent assay. Promoter activity of the Cyr61 gene was evaluated by luciferase assay, with or without forced expression of FoxO3a and SIRT-1 by lentiviral transduction. FoxO3a-Cyr61 promoter interaction was examined by chromatin immunoprecipitation. In rats with CIA, the expression of CYR-61 and phosphorylated FoxO3a in synovial fibroblasts was examined by immunohistochemistry. In RASFs, simvastatin suppressed the tumor necrosis factor α (TNFα)-induced production of CYR-61 and CCL20. Nuclear levels of FoxO3a were decreased after TNFα stimulation of RASFs, and forced expression of FoxO3a reversed the inductive effects of TNFα on CYR-61. Simvastatin inhibited the nuclear export, phosphorylation, and acetylation of FoxO3a and maintained its binding to the Cyr61 promoter. Forced expression of SIRT-1 in RASFs led to decreased levels of CYR-61 and deacetylation of FoxO3a. Following treatment with simvastatin, the expression of SIRT-1 was up-regulated and SIRT-1/FoxO3a binding was enhanced in RASFs. In rats with CIA, intraarticular injection of simvastatin alleviated arthritis and suppressed CYR-61 expression and FoxO3a phosphorylation in synovial fibroblasts. CYR-61 is important in the pathogenesis of RA, and SIRT-1/FoxO3a signaling is crucial to induction of CYR-61 in RASFs. Simvastatin plays a beneficial role in inflammatory arthritis through its up-regulation of SIRT-1/FoxO3a signaling in synovial fibroblasts. Continued study of the pathways linking sirtuins, FoxO proteins, and the inflammatory responses of RASFs may provide new insights into the pathophysiology of RA.

IRHOM2 is a critical pathogenic mediator of inflammatory arthritis

iRHOM2, encoded by the gene Rhbdf2, regulates the maturation of the TNF-α convertase (TACE), which controls shedding of TNF-α and its biological activity in vivo. TACE is a potential target to treat TNF-α-dependent diseases, such as rheumatoid arthritis, but there are concerns about potential side effects, because TACE also protects the skin and intestinal barrier by activating EGFR signaling. Here we report that inactivation of Rhbdf2 allows tissue-specific regulation of TACE by selectively preventing its maturation in immune cells, without affecting its homeostatic functions in other tissues. The related iRHOM1, which is widely expressed, except in hematopoietic cells, supported TACE maturation and shedding of the EGFR ligand TGF-α in Rhbdf2-deficient cells. Remarkably, mice lacking Rhbdf2 were protected from K/BxN inflammatory arthritis to the same extent as mice lacking TACE in myeloid cells or Tnfa-deficient mice. In probing the underlying mechanism, we found that two main drivers of K/BxN arthritis, complement C5a and immune complexes, stimulated iRHOM2/TACE-dependent shedding of TNF-α in mouse and human cells. These data demonstrate that iRHOM2 and myeloid-expressed TACE play a critical role in inflammatory arthritis and indicate that iRHOM2 is a potential therapeutic target for selective inactivation of TACE in myeloid cells.

GDF15, a distinct TGFβ family member, is differentially regulated in spondyloarthritides compared to other rheumatic diseases

IntroductionThe transforming growth factor β (TGFβ) superfamily consists of a number of cytokines that regulate a variety of cellular processes. Growth differentiation factor 15 (GDF15) is a distant member of...

Role of placenta growth factor in cancer and inflammation

Accumulating evidences have documented that angiogenesis is closely linked to inflammation and regulators of angiogenesis play key roles in various inflammatory conditions. PlGF is an angiogenic protein belonging to the VEGF family and is upregulated mainly in pathologic conditions. Recently, PlGF was discovered having a proinflammatory role in inflammatory arthritis and its serum level drew attention not only as a useful surrogate biomarker but also a potential therapeutic target in atherosclerosis and various cancers. Particularly, PlGF has attractive clinical values because endogenous PlGF is redundant for vascular development and physiological vessel maintenance in healthy adults. However, there have been conflicting results about the efficacy of PlGF inhibition depending on the experimental and clinical settings. Further close investigations for resolving the puzzle of PlGF biology are required.

Tumor necrosis factor α-induced adipose-related protein expression in experimental arthritis and in rheumatoid arthritis

IntroductionTumor necrosis factor-alpha (TNFα) plays a pivotal role in rheumatoid arthritis (RA); however, the mechanism of action of TNFα antagonists in RA is poorly defined. Immunization of DBA/1 mice with glucose-6-phosphate isomerase (GPI) induces severe acute arthritis. This arthritis can be controlled by TNFα antagonists, suggesting similar etiology to RA. In this study, we explored TNFα-related mechanisms of arthritis.MethodsFirst, we performed GeneChip analysis using splenocytes of mice with GPI-induced arthritis. Expression of TNFα-induced adipose-related protein (TIARP) mRNA and protein in spleens, joints and lymph nodes was evaluated, and fluctuation of TIARP mRNA was analyzed after administration of anti-TNFα monoclonal antibody (mAb). Localization of TIARP in spleen and joints was also explored. Six-transmembrane epithelial antigen of the prostate (STEAP) families of proteins, the human ortholog of TIARP gene, were also evaluated in human peripheral blood mononucleocytes and synovium.ResultsAmong the arrayed TNFα-related genes, the expression of TIARP mRNA was the highest (more than 20 times the control). TIARP mRNA was detected specifically in joints and spleens of arthritic mice, and their levels in the synovia correlated with severity of joint swelling. Treatment with anti-TNF mAb significantly reduced TIARP mRNA expression in splenocytes. Among the splenocytes, CD11b+ cells were the main source of TIARP mRNA. Immunohistochemistry showed that TIARP protein was mainly localized in hyperplastic synovium. Among the STEAP family of proteins, STEAP4 was highly upregulated in joints of patients with RA and especially co-localized with CD68+ macrophages.ConclusionsThe results shed light on the new mechanism of action of TNFα antagonists in autoimmune arthritis, suggesting that TIARP plays an important role in inflammatory arthritis, through the regulation of inflammatory cytokines.

Calcineurin을 억제하는 Cabin-1 유전자의 과발현을 통한 류마티스 관절염에 대한 잠재적인 치료 효과

류마티스 관절염은 활액막 내의 염증성 세포와 cytokine의 침적으로 인한 만성적인 염증이 계속 진행되어 연골과 뼈의 파괴 등이 발생하는 특징을 가진 심각한 자가면역질환의 일종이다. Calcineurin은 면역 세포의 활성화를 책임지는 대표적인 세포 내 신호전달 단백질이다. Calcineurin의 억제제로 알려진 Cabin-1을 과발현시키는 유전자 치료를 통해 류마티스 관절염의 새로운 치료법을 시도하게 되었다. 본 연구에서는 EL-4 세포에 calcineurin 저해제인 Cabin-1을 과발현시켜 배양된 세포에서 유전자의 발현정도와 발현의 지속성을 측정하고자 하였다. 또한 형질전환된 류마티스 모델 동물의 간, 림프절, 비장 등의 조직에서 Cabin-1 단백질 발현여부를 조사하고자 하였다. 그 결과 calcineurin이 EL-4 세포에서 발현함을 확인하였으며 calcineurin의 생리학적 억제제인 Cabin-1유전자를 transfection했을 경우 calcineurin phophatase activity가 감소됨을 확인하였다. 또한 Cabin-1의 생체 내 기능을 해석하기 위한 형질전환 생쥐를 생산하였으며 간, 비장, 폐, 말초혈액단핵세포 및 림프절에서 Cabin-1의 발현을 검증하였다. 그러나 Cabin-1 유전자가 T 세포의 발생과 활성에 영향을 끼쳐 심한 면역결핍증상으로 인해 Cabin-1 형질전환 생쥐의 계통을 유지할 수가 없었다. 결론적으로 calcineurin을 억제하는 Cabin-1유전자의 발현 벡터를 구축하였으며 이는 in vivo에서 Cabin-1유전자와 calcineuirn사이의 기작 및 Cabin-1의 기능을 해석하는데 중요한 매개가 될 수 있다. 또한 류마티스 관절염을 포함하여 루푸스, 다발성 경화증, 당뇨병 등과 같은 다양한 면역질환의 발병 원인을 밝혀내고 치료에 응용될 수 있다. Rheumatoid arthritis (RA) is characterized by a tumor-like expansion of the synovium, which is composed of proliferation, infiltrating leukocytes and angiogenesis. Calcineurin is expressed and plays a critical role in inflammatory arthritis. Calcineruin binding protein (Cabin)-l associates with calcineurin, leading to a non-competitive inhibitor of calcineurin activity. We investigated the expression pattern of calcineurin in inflammatory arthritis. The overexpression of Cabin-1 inhibited calcineurin phosphatase activity in in vitro. Moreover, we produced the T cell-specific Cabin-I transgenic mice but they died without transmitting the transgene to offspring. The Cabin-1 transgenic mice have a dominant lymph node expression and a wide tissue distribution. It is postulated that transgenic mice died from the critical effects of the transgene on T cell development or activation. Data suggests that the inhibition of calcineurin by the overexpression of Cabin-1 may be an effective strategy for the suppression of inflammatory arthritis.

Association between serum vitamin D metabolite levels and disease activity in patients with early inflammatory polyarthritis

Previous in vitro and animal studies have suggested that vitamin D, in particular, its metabolite 25-hydroxyvitamin D (25[OH]D), may have immunomodulatory effects. To study further the potential immunomodulatory effects of vitamin D in humans, we explored the hypothesis that serum vitamin D metabolites may be inversely associated with current disease activity, severity, and functional disability in patients with early inflammatory polyarthritis (IP). We studied 206 consecutive patients with IP who were enrolled in the Norfolk Arthritis Register between January 2000 and November 2003 inclusive. Patients were studied within 6 months of symptom onset. None of the patients was taking steroids, and all had received <6 weeks of disease-modifying therapy. Associations between serum levels of 25(OH)D and 1,25-dihydroxyvitamin D (1,25[OH](2)D) at baseline and the swollen and tender joint counts, Health Assessment Questionnaire (HAQ) scores, C-reactive protein (CRP) levels, and the Disease Activity Score 28-joint assessment (DAS28) scores at baseline and 1 year were assessed. The median age at symptom onset was 59 years (range 20-88 years), with a median disease duration of 4 months. At baseline, there was an inverse relationship between 25(OH)D levels and the tender joint count, DAS28 score, and HAQ score. The only inverse relationship with 1,25(OH)(2)D was with the HAQ score. Each 10-ng/ml increase in the level of 25(OH)D was associated with a decrease in the DAS28 score of 0.3 and in the CRP level of approximately 25%. At 1 year, the only significant result was an inverse association between baseline vitamin D metabolite levels and the HAQ score; that is, those with higher metabolite levels had lower HAQ scores. These data provide further support that vitamin D plays an immunomodulatory role in inflammatory arthritis. This association needs to be examined in other cohorts of patients with early IP, as well as in longitudinal studies. If confirmed, the clinical response to vitamin D supplementation should be examined in early IP.