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T Hasunuma

Publications and source records attributed to T Hasunuma.

At least 37 records · Page 2Linked to original sources
PubMed1998

Induction of apoptosis in the rheumatoid synovium by Fas ligand gene transfer.

We have recently reported that local administration of anti-Fas monoclonal antibody (MAb) in human T cell leukemia virus type 1 (HTLV-1) carrying mice improved arthritis due to the induction of apoptosis. This finding strongly indicated the beneficial therapeutic effect of Fas-mediated apoptosis in rheumatoid arthritis (RA). To establish further the therapeutic effect of Fas-mediated apoptosis on RA taking into consideration safety and practicality, we investigated the effect of cells transfected with human Fas ligand (hFasL) gene on proliferating human rheumatoid synovium engrafted in severe combined immunodeficiency (SCID-RA) mice. The hFasL transfectants exhibited cytotoxic activity against RA synoviocytes via the Fas/FasL system in vitro. Histopathological and immunohistochemical studies showed that local injection of irradiated-hFasL transfectants eliminated synoviocytes and mononuclear cells in engrafted human rheumatoid synovium of SCID-RA mice. Furthermore, in situ nick and labeling analysis confirmed that the cells in engrafted synovium frequently underwent apoptosis by irradiated-hFasL transfectants. Our results clearly demonstrated that hFasL transfectants induced apoptosis by cell-to-cell interaction via the Fas/FasL system. Thus, ex vivo gene transfer of FasL may represent a novel therapeutic strategy for RA.

Animals↗
PubMed1998

Human T cell leukemia virus type-I and rheumatoid arthritis.

HTLV-I is a retrovirus known as an oncogenic virus for human. This virus, initially found as a causative agent for adult T cell leukemia, has been lately focused as a causative virus for several autoimmune disorders. Here we described the characteristics of polyarthritis in HTLV-I careers, which is indistinguishable from idiopathic rheumatoid arthritis (RA). The relationship between arthritis and this virus was clearly proved by epidimiological study. Moreover, we presented transactivating gene of this virus, tax, is responsible for proliferation of synovial cells. This was proved by Tax transgenic mice, which present chronic destructive arthritis resembling human RA. Other autoimmune disorders, such as Sjögren's syndrome and uveitis, are also reviewed.

Adult↗
PubMed1997

T cell receptor of Fas-sensitive T cells in rheumatoid synovium.

Apoptosis is found in synoviocytes and CD3+ T cells in the synovium of patients with rheumatoid arthritis (RA). To analyze the pathogenesis of apoptosis in rheumatoid synovium, we examined the expression of Fas Ag, Fas ligand (Fas-L), and TCR on T cells susceptible to anti-Fas mAbs. Fas Ag is expressed on 40 to 60% of CD3+ T cells in the synovium as measured by immunohistochemical and flow cytometry methods. It was observed by the reverse transcription-PCR method that Fas-L is overexpressed on T cells infiltrating the rheumatoid synovium. These results suggest that apoptosis in RA synovium is mediated by the Fas/Fas-L pathway. PCR-single-strand conformation polymorphism clearly demonstrated that more than 50% of T cells that accumulate in synovium are removed by incubation with anti-Fas mAbs for 24 h in vitro, indicating that these cells are Fas sensitive. Junctional sequence analysis revealed several conserved amino acids motifs (ERxxxSMNTE, IAAEGLLG, QxEGxD, VPD, TLAGxYNEQ, EPSE, LTNxGEL, QGK, NIP, GLL, and KWT) in the CDR3 region of accumulated Fas-sensitive T cell clones, whereas these motifs were not detected in Fas-resistant clones. In conclusion, our findings support the notion that Fas-sensitive T cells in rheumatoid synovium are generated by Ag stimulation and recognize relatively limited T cell epitopes on autoantigens, suggesting that susceptibility to anti-Fas mAbs might be a selection marker for activated autoreactive T cells in RA.

Aged↗
PubMed1997

TCR in Fas-sensitive T cells from labial salivary glands of patients with Sjögren's syndrome.

Apoptosis is found in labial salivary glands of patients with Sjogren's syndrome (SS). To analyze the pathogenesis of apoptosis in labial salivary glands of SS patients, we examined the expression of Fas Ag and Fas ligand (FasL) and TCR on T cells susceptible to anti-Fas mAbs (CH-11). Fas Ag is expressed on epithelial cells and mononuclear cells in the salivary glands as observed by an immunohistochemical method. FasL is over-expressed specifically on T cells infiltrating into the labial salivary glands as seen by an reverse transcription-PCR method. These results suggest that apoptosis in SS lips is mediated by a Fas/FasL pathway. PCR single-strand conformation polymorphism (SSCP) clearly demonstrated that more than 40% of the T cells accumulated in labial salivary glands are deleted by incubation with CH-11 for 24 h in vitro, indicating that these expanded cells are Fas sensitive. junctional sequence analysis showed that the same conserved amino acid motifs (LAGG, RLA, SLG, QGPG, PGG, GGE, RGR, KPG, AGD, and MLG) in complementarity determining region 3 (CDR3) are found in Fas-sensitive T cell clones, whereas they are not detected in Fas-resistant clones, suggesting that Fas-sensitive T cells recognize restricted T cell epitopes on autoantigens. In conclusion, the findings suggest that Fas-sensitive T cells in labial salivary glands of SS patients are generated by Ag stimulation and might function as autoreactive T cells.

Amino Acid Sequence↗
PubMed1997

Accumulation of soluble Fas in inflamed joints of patients with rheumatoid arthritis.

OBJECTIVE: To examine the concentration of the soluble form of the Fas molecule (sFas) in the serum and synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: The concentration of sFas in the serum of 15 normal subjects and in the synovial fluid and serum of 45 RA patients and 13 OA patients was determined. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and the level of several cytokines in serum and synovial fluid were also determined. RESULTS: The synovial fluid concentration of sFas was higher in RA than in OA patients (P < 0.005). The synovial fluid level of sFas correlated weakly with serum levels of CRP (r = 0.541), the ESR (r = 0.499), and with synovial fluid levels of interleukin-2 (IL-2) receptor (r = 0.544), IL-6 (r = -0.529), and intercellular adhesion molecule 1 (r = 0.514). Reverse transcription-polymerase chain reaction analysis revealed that synovial cells and infiltrating mononuclear cells expressed sFas messenger RNA in RA patients. CONCLUSION: Our data suggest that accumulation of sFas in the joint cavity of RA patients may inhibit apoptosis and exacerbate the inflammatory process.

Aged↗
PubMed1997

Tenosynovial nodulosis in a patient infected with human T cell lymphotropic virus I.

We describe a 45-year-old man who presented with multiple nodules along the tendons of the scapular region, the elbows, wrists, forearms, thighs, and ankles. The patient was a carrier of human T cell lymphotropic virus I (HTLV-I), which was probably transmitted from his mother; his mother also had polyarthritis. Histopathologically, the nodules consisted of numerous, small, fibrinoid masses. The synovium adjacent to the tendon sheath was hyperplastic, with fibrinoid necrosis mimicking rheumatoid synovium. However, synovitis was not present inside the adjacent joint. HTLV-I proviral DNA was detected in the cells of the nodule, in tenosynovial cells, and in peripheral blood lymphocytes, but not in skin fibroblasts. In situ reverse transcription assay showed a high quantity of tax/rex messenger RNA in the proliferating lining cells. Based on these features, we classified this case as an atypical manifestation of HTLV-I-associated arthropathy associated with fibrinoid nodules resulting from chronic tenosynovitis.

Carrier State↗
PubMed1997

Direct evidence of high DNA binding activity of transcription factor AP-1 in rheumatoid arthritis synovium.

OBJECTIVE: To investigate the possible activation of transcription factor AP-1 in rheumatoid arthritis (RA) and its involvement in the pathogenesis of RA. METHODS: Synovial tissues and peripheral blood samples were obtained from 25 patients with RA and 5 patients with osteoarthritis (OA) during arthroplasty and synovectomy. The synovial tissue was digested with collagenase and separated into adherent and nonadherent cells by plastic-adhesion methods. Nuclear extracts obtained from each sample were examined by electrophoretic mobility shift assay to determine the DNA binding activity of AP-1. The expression of c-fos and c-jun messenger RNA (mRNA) was examined by in situ reverse transcription assay. RESULTS: A markedly high DNA binding activity of AP-1 was detected in the synovial tissues of RA patients, while virtually no activity or only a little activity was observed in OA patients. Following separation of adherent and nonadherent cells, the AP-1 activity was mainly detected in adherent cells, which consisted of synovial cells and macrophages. However, the activity was significantly higher in the mononuclear cells infiltrating into RA synovium than in RA peripheral blood mononuclear cells. The high DNA binding activity of AP-1 in RA correlated with the expression of c-fos and c-jun mRNA in situ. Furthermore, AP-1 binding activity also correlated with disease activity. CONCLUSION: In RA synovium, AP-1 DNA binding activity was constitutively up-regulated. These findings suggest that AP-1 may play an important role in the pathogenesis of RA, including synovial hyperplasia and abnormal immune responses.

Aged↗
PubMed1997

Selective activation of the JNK/AP-1 pathway in Fas-mediated apoptosis of rheumatoid arthritis synoviocytes.

OBJECTIVE: To evaluate the Fas-dependent signaling pathway, we examined the involvement of protein tyrosine phosphorylation and the DNA binding activity of AP-1 in rheumatoid arthritis (RA) cultured synovial cells. METHODS: The number of dead cells was counted after treatment with anti-Fas antibody in the presence of protein tyrosine kinase or phosphatase inhibitor. Protein tyrosine phosphorylation in synoviocytes after Fas ligation was examined by immunoblot and immunoprecipitation analyses. The DNA binding activity of AP-1 was examined by electrophoretic mobility shift assay. RESULTS: Treatment with the protein tyrosine phosphatase inhibitor, orthovanadate, significantly enhanced the apoptosis of RA synoviocytes after Fas ligation. Ligation of the Fas molecule on RA synoviocytes induced a rapid tyrosine phosphorylation of JNK (c-Jun amino-terminal kinase) and formation of the AP-1 transcription factor. CONCLUSION: Our results strongly suggest that the JNK/AP-1 signaling pathway is activated during the process of Fas-mediated apoptosis of RA synovial cells.

Apoptosis↗
PubMed1997

Transcriptional regulation of the HOX4C gene by basic fibroblast growth factor on rheumatoid synovial fibroblasts.

OBJECTIVE: To examine the expression of genes of the HOX D cluster in the synovial tissue of patients with rheumatoid arthritis (RA), and to determine whether basic fibroblast growth factor (bFGF) influences the expression and transcriptional regulation of the gene. METHODS: The expression of genes of the HOX D cluster, including HOX4C, HOX4D, HOX4H, and HOX4I, was determined in the synovium of 4 patients with RA and 4 with osteoarthritis (OA) by in situ reverse transcription (RT) and RT-polymerase chain reaction (RT-PCR). The induction of HOX4C messenger RNA (mRNA) by bFGF was determined by RT-PCR. The binding activity of a transcriptional regulator of the HOX4C gene, C2, was analyzed by the mobility shift assay. NIH-3T3 cells transfected with a construct containing C2 binding sequence were incubated with bFGF, and the activity of the reporter was measured by luciferase assay. RESULTS: Using an in situ RT assay, specific expression of HOX4C mRNA was detected in 3 of 4 RA synovial samples, whereas none of the OA synovia expressed HOX4C. HOX4D, HOX4H, and HOX4I genes were expressed in all synovial samples from RA and OA patients. The presence of HOX4C mRNA was also confirmed by RT-PCR and Southern blotting. Treatment with bFGF increased the expression of HOX4C mRNA in RA fibroblasts. The mobility shift assay and luciferase assay showed that bFGF enhanced C2 binding activity and significantly increased the transcriptional activity on RA fibroblasts. CONCLUSION: Our findings suggest that HOX4C is involved in synovial hyperplasia, and that the transcriptional regulation of HOX4C genes by bFGF may play a crucial role in the pathogenesis of RA.

Arthritis, Rheumatoid↗
PubMed1997

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.

Aged↗
PubMed1997

In situ expression of protooncogenes and Fas/Fas ligand in rheumatoid arthritis synovium.

OBJECTIVE: To examine the relationship among the expression of protooncogenes such as c-fos and c-myc, Fas antigen, Fas ligand, and apoptosis in the synovial tissue of patients with rheumatoid arthritis (RA). METHODS: The expression of c-fos, c-myc, Fas antigen, and Fas ligand was examined in synovial tissues of 6 patients with RA and 4 with osteoarthritis (OA) using in situ reverse transcriptase (RT) assay and immunohistochemical staining. Apoptosis was detected by TUNEL method in situ. RESULTS: Expression of protooncogenes, c-fos, and c-myc was detected in all samples from patients with RA, but in only a few cells of OA synovium. 30 to 90% of cells in RA synovium positive for these protooncogenes also coexpressed Fas antigen. Fas positive cells in RA synovium underwent apoptosis to a significant degree. Fas ligand mRNA was detected only in mononuclear cells in RA synovium. CONCLUSION: The expression of protooncogenes is closely related to Fas mediated apoptosis in RA synoviocytes.

Aged↗
PubMed1997

[Pathomechanism of HTLV-I associated arthropathy and the role of tax gene].

HTLV-I is known to be a causative agent for adult T cell leukemia. Recent studies revealed this virus is also related to several autoimmune disorders, such as arthropathy, myelopathy and Sjögren's syndrome. We studied etiology of HTLV-I associated arthropathy (HAAP), and found that tax is a causative gene for synovial proliferation and induction of immunogenicity. HTLV-I transgenic mice supported the etiopathological role of tax gene. Our results suggested that HAAP is considered to be a prototype of rheumatoid arthritis, and tax is a best tool for recognizing pathomechanism of rheumatoid arthritis.

Animals↗
PubMed1996

Fas-mediated stimulation induces IL-8 secretion by rheumatoid arthritis synoviocytes independently of CPP32-mediated apoptosis.

In this study, we investigated the IL-1 beta converting enzyme (ICE) family cysteine proteases responsible for the Fas-mediated apoptosis of rheumatoid arthritis (RA) synoviocytes and their involvement in proinflammatory cytokine production. CPP32 inhibitor, but not ICE inhibitor, was capable of inhibiting the Fas-mediated apoptosis of RA synovial cells. CPP32, but not ICE, was activated in response to anti-Fas stimulation. IL-8, but not IL-1 beta, was secreted from the anti-Fas-stimulated RA synoviocytes even in the presence of CPP32 inhibitor. These results demonstrated that CPP32, but not ICE, is the predominant cysteine protease that mediates the Fas-mediated apoptosis of RA synovial cells. We also demonstrated that anti-Fas stimulation of RA synoviocytes leads to IL-8 secretion independently of the CPP32-mediated apoptosis, which would accelerate inflammation.

Apoptosis↗