Shinichi Yoshino

Functional haplotypes of PADI4, encoding citrullinating enzyme peptidylarginine deiminase 4, are associated with rheumatoid arthritis.

Individuals with rheumatoid arthritis frequently have autoantibodies to citrullinated peptides, suggesting the involvement of the peptidylarginine deiminases citrullinating enzymes (encoded by PADI genes) in rheumatoid arthritis. Previous linkage studies have shown that a susceptibility locus for rheumatoid arthritis includes four PADI genes but did not establish which PADI gene confers susceptibility to rheumatoid arthritis. We used a case-control linkage disequilibrium study to show that PADI type 4 is a susceptibility locus for rheumatoid arthritis (P = 0.000008). PADI4 was expressed in hematological and rheumatoid arthritis synovial tissues. We also identified a haplotype of PADI4 associated with susceptibility to rheumatoid arthritis that affected stability of transcripts and was associated with levels of antibody to citrullinated peptide in sera from individuals with rheumatoid arthritis. Our results imply that the PADI4 haplotype associated with susceptibility to rheumatoid arthritis increases production of citrullinated peptides acting as autoantigens, resulting in heightened risk of developing the disease.

An intronic SNP in a RUNX1 binding site of SLC22A4 , encoding an organic cation transporter, is associated with rheumatoid arthritis

Rheumatoid arthritis is a common inflammatory disease with complex genetic components. We investigated the genetic contribution of the cytokine gene cluster in chromosome 5q31 to susceptibility to rheumatoid arthritis in the Japanese population by case-control linkage disequilibrium (LD) mapping using single nucleotide polymorphisms (SNPs). Here we report that there is significant association between rheumatoid arthritis and the organic cation transporter gene SLC22A4 (P = 0.000034). We show that expression of SLC22A4 is specific to hematological and immunological tissues and that SLC22A4 is also highly expressed in the inflammatory joints of mice with collagen-induced arthritis. A SNP affects the transcriptional efficiency of SLC22A4 in vitro, owing to an allelic difference in affinity to Runt-related transcription factor 1 (RUNX1), a transcriptional regulator in the hematopoietic system. A SNP in RUNX1 is also strongly associated with rheumatoid arthritis (P = 0.00035). Our data indicate that the regulation of SLC22A4 expression by RUNX1 is associated with susceptibility to rheumatoid arthritis, which may represent an example of an epistatic effect of two genes on this disorder.

Involvement of CD70-CD27 interactions in the induction of experimental autoimmune encephalomyelitis

CD70/CD27 are cell surface molecules belonging to the TNF/TNF-receptor families. Ligation of CD27 by its ligand CD70 is thought to be important in T cell activation and T cell-B cell interaction. However, the in vivo function of these molecules during the establishment of cell-mediated immunity remains unclear. In this study, we examined the contribution of CD70-CD27 interactions to cell-mediated immunity by investigating the effect of anti-CD70 mAb on the development of experimental autoimmune encephalomyelitis (EAE). Treatment of SJL/J mice with anti-CD70 mAb prevented EAE induced by immunization with PLP(139-151). The preventive effect of anti-CD70 mAb was not due to the inhibition of T cell priming and antibody production from B cells, or immune deviation. However, TNF-alpha production was suppressed by treatment with anti-CD70 mAb, indicating that the ameliorating effect of anti-CD70 mAb appeared, at least in part, to be mediated by the inhibition of TNF-alpha production. These results indicate that the CD70-CD27 interaction plays a pivotal role in the development of cell-mediated autoimmune disease.

ABNORMAL ECHOGENIC FINDINGS DETECTED BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY AND CARDIORESPIRATORY IMPAIRMENT DURING TOTAL KNEE ARTHROPLASTY WITH TOURNIQUET

Background In patients undergoing total knee arthroplasty, intraoperative pulmonary embolic events are rare, and most occur following tourniquet deflation. This embolization can be observed using transesophageal echocardiography. However, the authors have encountered sudden decreases in arterial oxygen partial pressure while a tourniquet is still inflated. Therefore, the current investigation was designed to detect emboli during the tourniquet inflation phase and to identify the composition of the echogenic material. Methods Forty-six patients were randomly assigned to undergo total knee arthroplasty without (control, n = 24) or with a tourniquet (n = 22). Hemodynamic monitoring, blood gas analysis, and continuous transesophageal echocardiography were performed during the total knee arthroplasty procedure. Right jugular blood specimens were collected whenever echogenic material was seen in the atrium. Results In the tourniquet group, embolic events occurred in 27% of patients during femoral reaming and in 100% after tourniquet deflation. In the control group, emboli were detected in 54% of patients during femoral reaming. Most of the patients exhibited cardiopulmonary impairment after severe echogenic embolism, even while the tourniquet was inflated (two patients). None of the blood samples aspirated from the central catheters contained detectable material. Conclusions This prospective study showed that embolic events occurred during total knee arthroplasty, even while a tourniquet was inflated. An inflated tourniquet does not completely prevent pulmonary emboli.

Type II collagen is a target antigen of clonally expanded T cells in the synovium of patients with rheumatoid arthritis

OBJECTIVE To investigate whether type II collagen (CII) is recognised by oligoclonally expanded synovial T cells of patients with rheumatoid arthritis (RA). METHODS Peripheral blood mononuclear cells (PBMC) from 15 RA patients were stimulated with CII in vitro. T cell clones expanded by such stimulation were compared with the clonally expanded synovial T cells by using T cell receptor (TCR) B chain gene specific reverse transcription-polymerase chain reaction and subsequent single strand conformation polymorphism analyses. RESULTS Stimulation of the heterogeneous peripheral T cells with CII induced clonal expansion of T cells. In three of 15 patients, a proportion of these clones (approximately 17% to 25%) was found to be identical to expanded T cell clones in the synovium in vivo. CONCLUSION T cell clones that had TCR CDR3 sequences identical to those induced by purified CII were found in a proportion of RA patients. This finding suggests that CII is recognised by T cells that accumulate clonally in RA joints. Oligoclonal T cell expansion in RA joints is probably driven, at least in part, by intra-articular components such as CII.

Changes in coagulation-fibrinolysis marker and neutrophil elastase following the use of tourniquet during total knee arthroplasty and the influence of neutrophil elastase on thromboembolism

Background:  To clarify in detail the mechanism underlying the development and exacerbation of deep venous thrombosis (DVT) and/or pulmonary thromboembolism (PTE), we focused on the following factors: the thrombin‐antithrombin III complex (TAT), D‐dimer and neutrophil elastase (NE). We basically investigated whether NE played an important role in the development of PTE I a mice model.

Inhibitory effects of anti-rheumatic drugs on vascular endothelial growth factor in cultured rheumatoid synovial cells

Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis and is constitutively expressed in the synovium of rheumatoid arthritis (RA). Over‐expression of VEGF may play an important role in pathogenic vascularization and synovial hyperplasia of RA. In the present study, we examined whether disease‐modifying anti‐rheumatic drugs (DMARDs), including bucillamine (BUC), gold sodium thiomalate (GST), methotrexate (MTX) and salazosulfapiridine (SASP), act by inhibiting the production of VEGF by cultured synovial cells of patients with RA. Treatment of cultured synoviocytes with lipopolysaccharide (LPS) significantly increased VEGF production by cultured synovial cells. BUC significantly inhibited LPS‐induced VEGF production, while GST tended to inhibit the production of VEGF. The inhibitory effects on VEGF production were dose‐dependent. In contrast, MTX and SASP did not affect VEGF production. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis showed that BUC also inhibited LPS‐induced VEGF mRNA expression in RA synovial cells. The present study provides the first evidence that BUC inhibits VEGF production and the expression of its mRNA in synovial cells of RA patients. Our results indicate that the anti‐rheumatic effects of BUC are mediated by suppression of angiogenesis and synovial proliferation in the RA synovium through the inhibition of VEGF production by synovial cells.

Characterisation of fibroblast-like cells in pannus lesions of patients with rheumatoid arthritis sharing properties of fibroblasts and chondrocytes

OBJECTIVE To better understand the characteristics of synoviocytes located in the rheumatoid arthritis (RA) pannus. METHODS One cell line, termed PSC, was cloned from RA pannus lesions. Phenotypic analysis was done by contrast microscopy, indirect immunostaining, and safranin O staining. Transcription of several protooncogenes and matrix degrading enzymes was evaluated. The expression of mRNA for collagen II was detected by in situ hybridisation. The ability of anchorage independent growth was assessed by soft agarose culture. RESULTS PSCs showed a high transcription of protooncogenes c-fos, c-myc and c-jun. They also expressed mRNA for matrix degrading enzymes, such as collagenase, cathepsin B, and cathepsin L. Anchorage independent growth assay demonstrated that PSCs formed colonies in soft agar culture. Phenotypic analysis showed that this fibroblast-like PSC was stained intensely with anti-vimentin and anti-fibroblast antibody. In situ reverse transcriptase assay showed that the cell line expressed type II collagen mRNA. CONCLUSION Alternative fibroblast-like cells were identified in the pannus lesion of RA sharing properties of fibroblasts and chondrocytes. These findings suggest that this fibroblast-like cell derived from pannus lesions may contribute to the destruction of the cartilage in RA.

Comparative study between thromboembolism and total knee arthroplasty with or without tourniquet in rheumatoid arthritis patients.

Abstract Introduction. To investigate whether the occurrence of pulmonary embolism (PE) and/or deep vein thrombosis (DVT) are influenced by use of a tourniquet or not in the patients who underwent total knee arthroplasty for rheumatoid arthritis (RA). Patients and methods. The patients were randomly divided into a with-tourniquet group (19 patients) and a without-tourniquet group (18 patients). In the first group, snowstorm-like echogenic particles were observed after deflation of the tourniquet in all patients according to the transesophageal echocardiography. Results. In addition, the PaO2 level was significantly decreased. Also, one had a PE, and DVT was confirmed in two patients. In the without-tourniquet group, none of these conditions was noted. Conclusion. These results suggest that the use of a tourniquet will promote the risk of developing postoperative PE and/or DVT after total knee arthroplasty.

Ankle Arthrodesis in Rheumatoid Arthritis Using an Intramedullary Nail with Fins

We describe an intramedullary nail with fin-like longitudinal ridges that we have developed for arthrodesis of the ankle in rheumatoid arthritis. Four fins with sharp tips were attached to the distal part of a cylindrical nail to stabilize the tibiotalar and subtalar joints. We used this nail in 15 feet of 15 patients with rheumatoid arthritis who were followed for an average of 34.9 months. Postsurgery, 13 patients were allowed to bear weight immediately, as tolerated, without immobilization. By 3 weeks, these patients were able to bear weight fully. Solid fusion of the ankle joint in an acceptable position and good clinical results were obtained in all patients. The only complications were two cases of delayed wound-healing.