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Featured researches published by Masashi Narazaki.


Rheumatology | 2010

The skin of patients with systemic sclerosis softened during the treatment with anti-IL-6 receptor antibody tocilizumab

Yoshihito Shima; Yusuke Kuwahara; Hiroyuki Murota; Shun Kitaba; Mari Kawai; Toru Hirano; Junsuke Arimitsu; Masashi Narazaki; Keisuke Hagihara; Atsushi Ogata; Ichiro Katayama; Ichiro Kawase; Tadamitsu Kishimoto; Toshio Tanaka

Objective. SSc is an autoimmune disease characterized by fibrosis of the skin and internal organs. Although the aetiology remains uncertain, many reports have suggested that IL-6 is involved in SSc pathogenesis. Tocilizumab, an anti-IL-6 receptor antibody, is an anti-arthritis medicine that works through the blockade of IL-6 functions. To examine the effect of tocilizumab on SSc, we administered tocilizumab to two SSc patients. Methods. Two dcSSc patients were administered tocilizumab at 8 mg/kg once a month for 6 months. One patient had pulmonary fibrosis assessed by CT and spirometry, and the other had chronic renal failure caused by scleroderma renal crisis. Their skin condition was monitored with a Vesmeter and the modified Rodnan total skin score (mRTSS). Skin biopsies were obtained before and after the tocilizumab treatment to investigate the histological changes. Results. After tocilizumab treatment, both patients showed softening of the skin with reductions of 50.7 and 55.7% in the total z-score of Vesmeter hardness and 51.9 and 23.0% in the mRTSS, respectively. Histological examination showed thinning of the collagen fibre bundles in the dermis. The creatinine clearance in the patient with chronic renal failure improved from 38 to 55 ml/min. However, the fibrotic changes in the lung in the other patient remained unchanged. Conclusions. In the two cases of SSc that we report here, softening of the skin was observed during the treatment with tocilizumab.


Expert Review of Clinical Immunology | 2010

Tocilizumab for the treatment of rheumatoid arthritis

Toshio Tanaka; Atsushi Ogata; Masashi Narazaki

Tocilizumab is a humanized anti-IL-6 receptor monoclonal antibody, which binds to circulating soluble IL-6 receptor and membrane-expressed IL-6 receptor, inhibiting IL-6 binding to both forms of IL-6 receptor. Several Phase III clinical trials demonstrate the clinical efficacy of tocilizumab as monotherapy or with disease-modifying anti-rheumatic drugs for adult patients with moderately to severely active rheumatoid arthritis. Tocilizumab in combination with methotrexate after 24 weeks of treatment could induce disease remission in 30% of patients with rheumatoid arthritis refractory to anti-TNF antagonist therapy. The most common adverse reactions reported in clinical studies are upper respiratory tract infection, nasopharyngitis, headache, hypertension and mild, reversible increases in alanine aminotransferase enzymes. Serious adverse reactions include infections, gastrointestinal perforations and hypersensitivity reactions, including anaphylaxis. The clinical efficacy and safety of tocilizumab has led to the approval of this innovative drug for the treatment of rheumatoid arthritis in more than 70 countries worldwide.


Annals of the Rheumatic Diseases | 2009

Rapid improvement of AA amyloidosis with humanised anti-interleukin 6 receptor antibody treatment

Sumiyuki Nishida; Keisuke Hagihara; Yoshihito Shima; Mari Kawai; Yusuke Kuwahara; Junsuke Arimitsu; Toru Hirano; Masashi Narazaki; Atsushi Ogata; Kazuyuki Yoshizaki; Ichiro Kawase; Tadamitsu Kishimoto; Tetsuaki Tanaka

AA amyloidosis is a serious complication of chronic inflammatory and infectious diseases.1 Amyloid fibril deposition causes progressive deterioration in various organs. In October 2007, a 50-year-old woman was admitted to our hospital with severe diarrhoea and weight loss. She had had rheumatoid arthritis (RA) for 12 years. Despite vigorous treatment with prednisolone and disease-modifying anti-rheumatic drugs (DMARDs), including bucillamine, sulfasalazine, auranofin, leflunomide and methotrexate or tacrolimus, her disease remained active. In January 2007, treatment was started with biological drugs. Subcutaneous injection of 25 mg of etanercept twice weekly for 2 months and, subsequently, intravenous injection of 3 mg/kg infliximab for 5 months combined with 20 mg of prednisolone …


Arthritis Care and Research | 2009

Successful treatment of reactive arthritis with a humanized anti–interleukin‐6 receptor antibody, tocilizumab

Toshio Tanaka; Yusuke Kuwahara; Yoshihito Shima; Toru Hirano; Mari Kawai; Masako Ogawa; Junsuke Arimitsu; Keisuke Hagihara; Masashi Narazaki; Atsushi Ogata; Ichiro Kawase; Tadamitsu Kishimoto

Reactive arthritis is a disease with the clinical triad of arthritis, urethritis, and conjunctivitis (1). The onset of the disease is often preceded by bacterial infections of Campylobacter, Chlamydia, Salmonella, Shigella, or Yersinia, either in the urogenital or gastrointestinal tract (2,3). HLA–B27 is strongly associated with reactive arthritis, so that this disease is considered as one of the HLA–B27positive spondylarthropathies. Although the pathogenesis of reactive arthritis remains imperfectly understood, bacterial infections trigger systemic immunoreactions, and overproduction of proinflammatory cytokines has been shown to contribute to sterile joint inflammation (1–4). Several kinds of drugs are used for the management of reactive arthritis, including nonsteroidal antiinflammatory drugs (NSAIDs); disease-modifying antirheumatic drugs (DMARDs) such as sulfasalazine, methotrexate, and leflunomide; corticosteroids; and immunosuppressive drugs, including azathioprine and cyclosporine, whereas the use of antibiotics remains controversial (1–4). Infliximab, a chimeric anti–tumor necrosis factor (anti-TNF ) antibody, and etanercept, a 75-kd TNF receptor fusion protein, reportedly ameliorated symptoms in patients with reactive arthritis (5–8), as well as other HLA–B27-positive spondylarthropathies (9). However, to our knowledge, there have been no reports regarding the efficacy of the humanized anti–interleukin-6 (IL-6) receptor antibody, tocilizumab (10), for reactive arthritis. Here we report a case of reactive arthritis treated successfully with tocilizumab.


Allergology International | 2009

Preventative Effect of a Flavonoid, Enzymatically Modified Isoquercitrin on Ocular Symptoms of Japanese Cedar Pollinosis

Toru Hirano; Mari Kawai; Junsuke Arimitsu; Masako Ogawa; Yusuke Kuwahara; Keisuke Hagihara; Yoshihito Shima; Masashi Narazaki; Atsushi Ogata; Mihoko Koyanagi; Tomoko Kai; Ryosuke Shimizu; Masamitsu Moriwaki; Yukio Suzuki; Satoshi Ogino; Ichiro Kawase; Toshio Tanaka

BACKGROUND Flavonoids are nutrients that exert anti-allergic effects. We investigated the preventative effect of enzymatically modified isoquercitrin (EMIQ), a flavonoid, to relieve the symptoms of Japanese cedar pollinosis. METHODS In a parallel-group, double-blind placebo-controlled study design, 24 subjects with Japanese cedar pollinosis took 100mg EMIQ or a placebo for 8 weeks, starting 4 weeks prior to the onset of pollen release. Subjective symptoms, ADL scores and the usage of drugs were recorded daily, and the QOL score was obtained every 4 weeks. Blood sampling was performed before and after the study to measure serum levels of IgE and flavonoids. RESULTS During the entire study period, ocular symptom + medication score for the EMIQ group was significantly lower (p < 0.05) than that of the placebo group. When limited to the period, ocular symptom scores (p < 0.05, weeks 5-6), and ocular congestion scores (p < 0.05, weeks 5-6) for the EMIQ group was significantly lower than that for the placebo group while other scores for the EMIQ group, such as ocular itching scores (p = 0.09, weeks 4-5), lacrimation scores (p = 0.07, weeks 5-6), and ocular congestion scores (p = 0.06, weeks 4-5), all tended to be lower. However no significant differences were found in nasal symptoms between the two groups. Serum concentrations of IgE were not significantly downregulated but the serum concentrations of quercetin and its derivatives were elevated significantly by the intake of EMIQ. CONCLUSIONS Intake of the quercetin glycoside EMIQ proved to be effective for the relief of ocular symptoms caused by Japanese cedar pollinosis.


Modern Rheumatology | 2009

Imatinib mesylate inhibited rat adjuvant arthritis and PDGF-dependent growth of synovial fibroblast via interference with the Akt signaling pathway

Fumitaka Terabe; Masayasu Kitano; Mari Kawai; Yusuke Kuwahara; Toru Hirano; Junsuke Arimitsu; Keisuke Hagihara; Yoshihito Shima; Masashi Narazaki; Toshio Tanaka; Ichiro Kawase; Hajime Sano; Atsushi Ogata

Overgrowth of the synovium plays an important role in the pathogenesis of rheumatoid arthritis (RA). Platelet-derived growth factor (PDGF) is one of the most potent mitogenic factors of synovial cells, and imatinib mesylate (imatinib) is a specific inhibitor of the PDGF receptor tyrosine kinase. The aim of this study was to elucidate the anti-rheumatic activity of imatinib. The in vivo effects of imatinib were assessed by evaluating the sequential manifestation of adjuvant-induced arthritis in rats using paw volume and clinical scores. Imatinib was found to inhibit rat adjuvant-induced arthritis, but the inhibitory effects were incomplete. To confirm the mechanism of anti-rheumatic-activity of imatinib, we assessed the in vitro effects of imatinib on the proliferation of RA synovial fibroblast-like cells (RASFs) using a MTT assay. Intracellular signaling of PDGF was evaluated by Western blot analysis. Platelet-derived growth factor was found to induce a significant proliferation of RASFs, while imatinib inhibited PDGF-induced proliferation of RASF. Imatinib also inhibited PDGF-induced phosphorylation of the PDGF receptor and Akt, whereas constitutive activated extracellular signal-regulated kinase was not inhibited by imatinib. In contrast, imatinib did not inhibit transforming growth factor β- and basic fibroblast growth factor-induced proliferation of RASF. Oral administration of imatinib ameliorated adjuvant-induced arthritis in rats, and it inhibited PDGF-induced RASF proliferation through disruption of the PDGF-R to Akt kinase signaling pathway. Because imatinib cannot inhibit the non-PDGF-dependent proliferation of RASFs, the anti-rheumatic effect of imatinib may be incomplete. The development of inhibitors of RASF proliferation may lead to the successful treatment of RA.


International Archives of Allergy and Immunology | 2009

Effect of enzymatically modified isoquercitrin, a flavonoid, on symptoms of Japanese cedar pollinosis: a randomized double-blind placebo-controlled trial.

Mari Kawai; Toru Hirano; Junsuke Arimitsu; Shinji Higa; Yusuke Kuwahara; Keisuke Hagihara; Yoshihito Shima; Masashi Narazaki; Atsushi Ogata; Mihoko Koyanagi; Tomoko Kai; Ryosuke Shimizu; Masamitsu Moriwaki; Yukio Suzuki; Satoshi Ogino; Ichiro Kawase; Toshio Tanaka

Background: Flavonoids exert antiallergic and antioxidant effects. We investigated the efficacy of enzymatically modified isoquercitrin (EMIQ), a flavonoid, to relieve symptoms of pollinosis. Methods: In a parallel-group, double-blind placebo-controlled study design, 20 subjects with Japanese cedar pollinosis took two capsules daily of 100 mg EMIQ or a placebo for 8 weeks during the pollen season. Subjective symptoms and activities of daily living (ADL) scores were recorded every day, and the quality of life (QOL) score was obtained every 4 weeks. Blood sampling was performed before and after the study to measure serum cytokines, chemokines, IgE, quercetin and oxidized biomarkers. Results: During the entire study period, total ocular score and ocular itching score for the EMIQ group were significantly lower (p < 0.05) than for the placebo group. When limited to the individual periods, total symptom score for the EMIQ group was significantly lower (p < 0.05, week 4–5) than that for the placebo group while other scores for the EMIQ group, such as total nasal score (p = 0.06, week 4–5), nasal obstruction score (p = 0.08, week 4–5), lacrimation score (p = 0.06, week 5–6), ocular congestion score (p = 0.08, week 4–7) and ADL score (p = 0.08, week 4–7), all tended to be lower. The levels of serum cytokines such as interleukin (IL)-4, IL-5, IL-12, IL-13, interferon-γ, and eotaxin and IgE were not significantly downregulated by the intake of EMIQ but the serum concentrations of oxidized low-density lipoprotein and thymus and activation-regulated chemokine were reduced. Conclusion: Intake of the quercetin glycoside EMIQ was safe and influenced ocular symptoms caused by pollinosis.


Rheumatology | 2010

Treatment of a patient with remitting seronegative, symmetrical synovitis with pitting oedema with a humanized anti-interleukin-6 receptor antibody, tocilizumab

Toshio Tanaka; Keisuke Hagihara; Yoshihito Shima; Masashi Narazaki; Atsushi Ogata; Ichiro Kawase; Tadamitsu Kishimoto

Puja Mehta, Peter J. Norsworthy, Angela E. Hall, Susan J. Kelly, Mark J. Walport, Marina Botto and Matthew C. Pickering Rheumatology Section, Department of Immunology, Imperial College Healthcare NHS Trust, London, Department of Haematology, Wycombe Hospital, High Wycombe and The Wellcome Trust, London, UK Accepted 19 October 2009 Correspondence to: Matthew C. Pickering, Rheumatology Section, Imperial College Healthcare NHS Trust, Du Cane Road, London, W12 ONN, UK. E-mail: [email protected] References


Journal of the National Cancer Institute | 2008

Neuropilin-2: A New Molecular Target for Antiangiogenic and Antitumor Strategies

Masashi Narazaki; Marta Segarra; Giovanna Tosato

Aggressive cancers grow progressively, invade locally, and metas-tasize through a multistep process that involves a malignant cell and a supportive environment (1). Tumor neovascularization critically contributes to tumor growth (2). Hence, there has been great interest in reducing cancer progression by shutting down the tumor blood supply (3). The antiangiogenic drugs currently approved for cancer treatment include bevacizumab (Avastin), a humanized monoclonal antibody blocking vascular endothelial growth factor (VEGF), and sorafenib (Nexavar) and sunitinib (Sutent), synthetic inhibitors of VEGF receptor signaling (4 , 5). These VEGF-targeted therapies have shown benefi t in certain cancer types, but responses have generally been modest and measured in months of extended cancer survival (6 – 8). This experience raises many questions regarding the appropriate role of current antiangiogenic therapies in cancer treatment (9). In this issue of the Journal, Gray et al. (10) present exciting results that support a potential new strategy, targeting neuropilin-2. Neuropilins are nonsignaling transmembrane receptors that are shared by two distinct ligand families, the class 3 semaphorins, which regulate neuronal guidance, and the VEGF proteins, which regulate angiogenesis (11 , 12). Ligand binding to neuropilins dictates their association with specifi c signal transducers: semaphorins mediate interactions with plexin A receptors, whereas VEGFs mediate interactions with VEGF receptors. VEGF and Sema3A (one of the semaphorins) have overlapping binding domains on the extracellular portion of neuropilin-1 and, for this reason, can compete with one another for binding (13). Two neuropilins are known, neuropilin-1 and neuropilin-2 that have similar structures but differ in their endothelial expression during development. Neuropilin-1 is expressed mainly in the arterial endothelium, whereas neuropi-lin-2 is expressed mainly in the venous and lymphatic endothelium (14 , 15). Neuropilin-1 interacts with heparin-binding isoforms of VEGF-A,-B,-E and placental growth factor; neuropilin-2 interacts with VEGF-A,-C, and-D (11 , 12). Gene-targeting studies have demonstrated that mice lacking functional neuropilin-1 receptors die during embryogenesis with heart and vascular defects, demonstrating a critical role of neuropilin-1 in vascular development (16 – 18); mice lacking both neuropilin-1 and neuropilin-2 are more severely affected than mice lacking only neuropilin-1 (16 – 18). Neuropilin-2 – defi cient mice develop normally, but they are smaller than wild-type mice and display minor abnormalities in the lym-phatic system (15). Interestingly, neuropilin-2 – defi cient mice also display defective retinal neovascularization in response to ischemia (19). Recent studies have shown that administration of neuropilin-1 – neutralizing antibodies to tumor-bearing mice reduced tumor angiogenesis …


Blood | 2010

Oligo-guanosine nucleotide induces neuropilin-1 internalization in endothelial cells and inhibits angiogenesis

Masashi Narazaki; Marta Segarra; Xu Hou; Toshio Tanaka; Xuri Li; Giovanna Tosato

Ligand interaction with cognate cell-surface receptor often promotes receptor internalization, protecting cells from prolonged or excessive signaling from extracellular ligands. Compounds that induce internalization of surface receptors prevent ligand binding to cognate cell-surface receptors serving as inhibitors. Here, we show that synthetic polyriboguanosine (poly G) and oligo-deoxyriboguanosine (oligo G) reduce endothelial levels of surface neuropilin-1 (NRP1), a receptor shared by semaphorin 3A and vascular endothelial growth factor (VEGF), which plays critical roles in angiogenesis. Oligo G also reduces levels of cell-surface scavenger receptor expressed by endothelial cells I (SREC-I), but not levels of NRP2, gp130, CD31, VEGFR-1, or VEGFR-2. Poly or oligo A, T, and C do not promote NRP1 or SREC-I internalization. We find that oligo G binds to NRP1 with high affinity (Kd:1.3 ± 0.16 nM), bridges the extracellular domain of NRP1 to that of SREC-I, and induces coordinate internalization of NRP1 and SREC-I. In vitro, oligo G blocks the binding and function of VEGF(165) in endothelial cells. In vivo, intravitreal administration of oligo G reduces choroidal neovascularization in mice. These results demonstrate that synthetic oligo G is an inhibitor of pathologic angiogenesis that reduces cell-surface levels and function of NRP1 acting as an internalization inducer.

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