Masaki Watanabe

Kagoshima University, Kagosima, Kagoshima, Japan

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Publications (20)91.1 Total impact

  • The Journal of Immunology 12/2008; 181(9):6670. · 5.52 Impact Factor
  • The Journal of Immunology 12/2008; 181(9):6671. · 5.52 Impact Factor
  • The Journal of Immunology 12/2008; 181(9):6672. · 5.52 Impact Factor
  • Blood 11/2008; 112(8):3529. · 9.06 Impact Factor
  • Arthritis & Rheumatology 10/2008; 58(9):2924. · 7.48 Impact Factor
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    ABSTRACT: The chemokine receptor CXCR4, which binds the chemokine stromal cell-derived factor 1, has been reported to be involved in the chemotaxis of inflammatory cells. In addition, AMD3100, an antagonist of CXCR4, has been reported to be an attractive drug candidate for therapeutic intervention in several disorders in which CXCR4 is critically involved. However, little is known about the therapeutic value of AMD3100 in the treatment of pulmonary fibrosis. In this study, we examined the effects of AMD3100 on a murine bleomycin-induced pulmonary fibrosis model. Concurrent administration of AMD3100 and bleomycin apparently attenuated bleomycin-induced pulmonary inflammation. In this process, an inhibition of neutrophil recruitment at early stage followed by the decrease of other inflammatory cell recruitment in the lung were observed. In addition, it also inhibited the expression of cytokines, including MCP-1, MIP-2, MIP-1alpha, and TGF-beta. In contrast, when AMD3100 was administered following bleomycin treatment, the bleomycin-induced lung inflammation progressed and resulted in severe pulmonary fibrosis. In this process, an increase of inflammatory cell recruitment, an up-regulation of lung MCP-1 and TGF-beta, and a remarkable activation of p44/42 MAPK in neutrophils were observed. U0126, an inhibitor of p44/42 MAPK, significantly abolished these effects. Thus, AMD3100 has dual effect on bleomycin-induced pulmonary fibrosis. Difference of inflammatory cell recruitment and activation might be associated with the dual effect of AMD3100 on bleomycin-induced pulmonary fibrosis.
    The Journal of Immunology 06/2007; 178(9):5888-98. · 5.52 Impact Factor
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    ABSTRACT: Prolonged survival of eosinophils plays an important role in the pathogenesis of Churg-Strauss syndrome (CSS); however, its detailed molecular mechanism is still unclear. TRAIL and its receptors are expressed on a variety of cells, including eosinophils. In this study, we examined the expression of TRAIL receptors on eosinophils from patients with CSS. TRAIL receptor expression was assessed on eosinophils from healthy volunteers, patients with CSS, patients with asthma, and patients with hypereosinophilia due to parasitic infection. TRAIL-induced apoptosis of eosinophils was compared between the patients with CSS and patients with asthma. RNA interference was used to assess the effects of suppression of TRAIL receptor 3. Expression of TRAIL receptor 3, a decoy receptor that acts as an antiapoptotic receptor, on eosinophils from patients with CSS was significantly higher than that in the other subjects. Moreover, in CSS, serum TRAIL receptor 3 levels showed a significant positive correlation with peripheral eosinophil counts, tissue-infiltrating eosinophils stained positive for this receptor, and peripheral T cells expressed TRAIL on their surface. Compared with asthma patients, eosinophils from CSS patients showed a significantly lower percentage of recombinant TRAIL, less autologous T cell-induced apoptosis, and decreased level of active caspase 3. Suppression of TRAIL receptor 3 through RNA interference significantly increased the recombinant TRAIL-induced apoptosis of eosinophils from CSS patients. Increased expression of TRAIL receptor 3 on eosinophils from patients with CSS was observed. These alterations in TRAIL receptor 3 expression might be involved in the molecular pathogenesis of CSS eosinophilia.
    Arthritis & Rheumatology 03/2007; 56(2):662-73. · 7.48 Impact Factor
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    ABSTRACT: Microscopic polyangiitis (MPA) is a systemic necrotizing vasculitis that affects small vessels, resulting in a wide spectrum of organ involvement including the lungs. However, there are little serological markers that predict its prognosis or severity of pulmonary involvement. Vascular endothelial growth factor (VEGF) is an angiogenic mediator, which has been reported to be elevated in systemic vasculitis. In this study, we measured serum VEGF levels in 22 MPA patients with pulmonary involvement. We also investigated VEGF expression in pulmonary cells using flow cytometry analysis. We found that serum VEGF levels in MPA patients were significantly higher than those in respiratory or urinary tract infection. The serum VEGF levels decreased in parallel with the improvement of MPA symptoms. The serum VEGF levels in MPA patients who died within 5 years were significantly higher than those who survived more than 5 years. The sensitivity of VEGF levels to distinguish MPA patient with poor prognosis from those with good prognosis was 90.9%, and specificity was 81.8% (cutoff value = 802.5 pg/ml). The serum VEGF levels showed significant positive correlation with the composite physiological index, which indicates the severity of pulmonary lesion. In flow cytometry analysis, CD11b positive bronchoalveolar lavage fluid cells expressed VEGF. Immunohistochemically, alveolar macrophages, tissue infiltrating inflammatory cells and alveolar epithelial cells stained positive for VEGF. Measurement of serum VEGF levels in MPA might become one of the markers for prognosis and the severity of pulmonary involvement in MPA. VEGF might contribute to the development of pulmonary lesion of MPA.
    Respiratory Medicine 11/2006; 100(10):1724-33. · 2.59 Impact Factor
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    ABSTRACT: Case 1 is a 78-year-old woman in whom lung adenocarcinoma with multiple brain metastasis (cT2N3M1, stage IV) was diagnosed. She was treated with Gefitinib alone. Her lung tumor and metastatic brain lesions decreased 6 months after the start of therapy. She has no recurrence and is still alive with a good performance status after 25 months. Case 2 is an 80-year-old woman in whom lung adenocarcinoma with multiple brain (cT2N3M1, stage IV) was diagnosed. She was also treated with Gefitinib alone and her lung tumor and metastatic brain becomes improved 6 months after the start of therapy. She maintained a good performance status for more than 2 years (29 months). However, 29 months after beginning treatment, she had recurrence in bone and died 2 months later, 31 months after the start of therapy. The prognosis of non-small cell lung cancer with multiple brain metastasis is very poor and the efficacy of chemotherapy for the treatment of multiple brain metastases is limited, and longterm survival remains disappointing. We report two lung adenocarcinoma patients with multiple brain metastasis who survived more than 2 years by treatment with Gefitinib alone.
    Nihon Kokyūki Gakkai zasshi = the journal of the Japanese Respiratory Society. 10/2006; 44(9):653-8.
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    ABSTRACT: A 48-year-old woman was admitted with dyspnea on effort. She suffered from adult T-cell leukemia and received peripheral blood stem cell transplantation (PBSCT). Eight months after the PBSCT, she developed dyspnea on effort and was treated with bronchodilator, inhaled corticosteroid, anti-leukotriene drug, theophylline and oxytropium bromide. However her symptoms progressed and she was admitted. We diagnosed bronchiolitis obliterans syndrome (BOS) because of obstructive pulmonary dysfunction, diffuse patchy high density of the lung field on chest computed tomography and decreased ventilation with peripheral patchy accumulation on ventilation scintigraphy. She was treated with corticosteroid and cyclosporine A and her symptoms and her pulmonary function were improved. However, in parallel with corticosteroid tapering, her symptoms and pulmonary functions worsened. Treatment with Tiotropium bromide was started and her pulmonary function improved significantly. Her pulmonary function did not worsen and tapering steroid dose was successfully achieved. PBSCT was reported to up-regulate the muscarinic receptor activity in lung. Tiotropium bromide might become one additional option for the treatment of BOS.
    Nihon Kokyūki Gakkai zasshi = the journal of the Japanese Respiratory Society. 06/2006; 44(5):404-9.
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    ABSTRACT: Idiopathic pulmonary fibrosis (IPF), characterized by fibroblast proliferation and accumulation of extracellular matrix, including collagen, is a chronic progressive disorder that results in lung remodeling and fibrosis. However, the cellular mechanisms that may make fibroblasts resistant to apoptosis have not been completely elucidated. Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase whose ligand is collagen, is expressed in vivo and contributes in vitro to leukocyte differentiation and nuclear factor (NF)-kappaB activation, which may play an important role in fibroblast survival. In this study, we examined in vivo and in vitro DDR1 expression and its role in cell survival using fibroblasts obtained from IPF and non-IPF patients. Immunohistochemically, fibroblasts present in fibroblastic foci expressed endogenous DDR1. The DDR1 expression level was significantly higher in fibroblasts from IPF patients, and the predominant isoform was DDR1b. In IPF patients, DDR1 activation in fibroblasts inhibited Fas ligand-induced apoptosis and resulted in NF-kappaB nuclear translocation. Suppression of DDR1 expression in fibroblasts by siRNA abolished these effects, and an NF-kappaB inhibitor abrogated the anti-apoptotic effect of DDR1 activation. We propose that DDR1 contributes to fibroblast survival in the tissue microenvironment of IPF and that DDR1 up-regulation may occur in other fibroproliferative lung diseases as well.
    American Journal Of Pathology 04/2006; 168(3):866-77. · 4.52 Impact Factor
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    ABSTRACT: Churg-Strauss syndrome (CSS) is a rare form of systemic vasculitis occurring in patients with asthma and hypereosinophilia. For optimal treatment, prompt distinction of CSS from asthma is necessary; however, there are few serologic screening markers for this purpose. Vascular endothelial growth factor (VEGF), a vascular permeability factor, has been associated with other systemic vasculitis such as Wegener granulomatosis and giant-cell arteritis. The aim of this study was to clarify the clinical value of the measurement of serum VEGF for the distinction of CSS from asthma. We investigated serum VEGF levels in 18 CSS patients, 19 asthma patients, and 12 acute bronchitis patients. We also performed immunohistochemical analysis for VEGF. The serum VEGF levels of CSS patients were significantly higher than those of asthma patients and acute bronchitis patients. The sensitivity and specificity to distinguish CSS from asthma were 93.3% and 81.8%, respectively (cutoff, 600 pg/mL). Infiltrating eosinophils stained intensely positive for VEGF, and serum VEGF levels showed a significant correlation with peripheral eosinophil counts. Serum VEGF levels decreased significantly after therapy (p < 0.001). The infiltrating eosinophils in the CSS lesion stained positive for VEGF in the immunohistochemical analysis. VEGF is one of the useful screening markers for the distinction of CSS from asthma. We suggest that VEGF might be associated with the pathogenesis of CSS.
    Chest 03/2006; 129(2):407-11. · 5.85 Impact Factor
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    ABSTRACT: Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase whose ligand is collagen. Recently, we have reported the association of DDR1 in the cytokine production of human leukocytes in in vitro and in vivo expression in idiopathic pulmonary fibrosis. However, its role in in vivo inflammation has not been fully elucidated. Small interference RNA (siRNA) can induce specific suppression of in vitro and in vivo gene expression. In this study, using a bleomycin-induced pulmonary fibrosis mouse model, we administered siRNA against DDR1 transnasally and evaluated histological changes, cytokine expression, and signaling molecule activation in the lungs. Histologically, siRNA against DDR1 successfully reduced in vivo DDR1 expression and attenuated bleomycin-induced infiltration of inflammatory cells. Furthermore, it significantly reduced inflammatory cell counts and concentrations of cytokines such as MCP-1, MIP-1alpha, and MIP-2 in bronchoalveolar lavage fluid. Subsequently, bleomycin-induced up-regulation of TGF-beta in bronchoalveolar lavage fluid was significantly inhibited, and collagen deposition in the lungs was reduced. Furthermore, siRNA against DDR1 significantly inhibited bleomycin-induced P38 MAPK activation in the lungs. Considered together, we propose that DDR1 contributes to the development of bleomycin-induced pulmonary inflammation and fibrosis.
    The Journal of Immunology 03/2006; 176(3):1928-36. · 5.52 Impact Factor
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    ABSTRACT: COPD, the fifth-leading cause of death worldwide, is characterized by chronic inflammation. However, no available agent can effectively cure this inflammation. A dietary supplement containing omega-3 polyunsaturated fatty acids (PUFAs) has anti-inflammatory effects. In this study, we hypothesized that nutritional support with omega-3 PUFA-rich diets may be useful for treating COPD, and we compared the clinical features and inflammatory mediator levels between the COPD patients who received an omega-3 PUFA-rich supplement and those who received a nonrich supplement. Sixty-four COPD patients received 400 kilocalories per day of an omega-3 PUFA-rich supplement (n-3 group) or an omega-3 PUFA-nonrich supplement (n-6 group) for 2 years. We prospectively investigated the clinical features of these patients and measured the levels of inflammatory mediators. In 6-min walk testing, the dyspnea Borg scale and decrease of arterial oxygen saturation measured by pulse oximetry significantly improved in the n-3 group. Leukotriene B4 levels in serum and sputum and tumor necrosis factor-alpha and interleukin-8 levels in sputum decreased significantly in the n-3 group, while there was no significant change in the n-6 group. Two patients in the n-3 group and three patients in the n-6 group had mild diarrhea, and three patients in the n-3 group and three patients in the n-6 group had nausea; however, their symptoms were controllable and they improved with treatment. With multiple regression analysis, it was proved that the omega-3 PUFA-rich diet significantly contributed to the change in cytokine levels in this study. We suggest nutritional support with an omega-3 PUFA-rich diet as a safe and practical method for treating COPD.
    Chest 01/2006; 128(6):3817-27. · 5.85 Impact Factor
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    ABSTRACT: The prognosis of sarcoidosis with pulmonary infiltrates differs in each case, and several cytokines are reported to contribute to its deterioration. However, the detailed mechanism has not been fully elucidated. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase activated by collagen and associated with cytokine production from inflammatory cells. We previously reported the functional expression of DDR1 on CD14-positive bronchoalveolar lavage fluid (BALF) cells in vivo. In this study, we hypothesized that DDR1 might be associated with the deterioration of pulmonary sarcoidosis (PS), and investigated 33 patients with sarcoidosis with pulmonary infiltrates, prospectively. We found that patients with deteriorated PS showed significantly higher DDR1 expression in CD14-positive BALF cells predominant with DDR1b isoforms. Activation of DDR1 induced monocyte chemoattractant protein-1 (MCP-1) and matrix metalloproteinase-9 (MMP-9) production in a p38 mitogen-activated protein kinase-dependent manner from CD14-positive BALF cells of patients with deteriorated sarcoidosis. DDR1 activation also induced NF-kappaB nuclear translocation in CD14-positive BALF cells of patients with deteriorated PS. The inhibitor of NF-kappaB inhibited the production of MCP-1 and MMP-9. We propose that DDR1 is associated with the deterioration of pulmonary sarcoidosis.
    American Journal of Respiratory Cell and Molecular Biology 01/2006; 33(6):565-73. · 4.15 Impact Factor
  • Internal Medicine 11/2005; 44(10):1103-4. · 0.97 Impact Factor
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    ABSTRACT: We report a case of Hermansky-Pudlak syndrome (HPS) with a novel mutation in the HPS1 gene. This case showed oculocutaneous albinism and lysosomal ceroid accumulation, however platelet dysfunction was not observed. Histopathological findings of the biopsied lung tissue were compatible with HPS. Sequencing analysis showed the insertion of C in the codon 178 (739 bp) of the HPS1 gene forming a stop codon at codon 181. To the best of our knowledge, this is a novel HPS1 gene mutation.
    Internal Medicine 08/2005; 44(7):733-8. · 0.97 Impact Factor
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    ABSTRACT: Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase activated by collagen. We previously reported the functional expression of DDR1 on human monocyte-derived macrophages in vitro; however, information regarding its role in diseases is limited. Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease, and the lesions contain an abundance of collagen. In this study, we examined DDR1 expression on bronchoalveolar lavage fluid (BALF) cells and investigated its functionality using samples obtained from 28 IPF patients, 13 chronic obstructive pulmonary disease patients, and 14 healthy volunteers. The DDR1 expression level in CD14-positive BALF cells was higher in IPF patients than in chronic obstructive pulmonary disease patients or healthy volunteers. The predominant isoform was DDR1b in the IPF group, while DDR1a was predominant in the other two groups. Using immunohistochemical analysis, we also detected DDR1 expression on infiltrating inflammatory cells in the IPF lesion. In IPF patients, DDR1 activation induced the production of MCP-1, IL-8, MIP-1 alpha, and matrix metalloproteinase-9 (MMP-9) from CD14-positive BALF cells in a p38 MAPK-dependent manner. In contrast, DDR1 activation of CD14-positive BALF cells in the other groups did not induce the production of these chemokines or MMP-9. These chemokines and MMP-9 contribute to the development of IPF and, therefore, we suggest that DDR1 might be associated with the pathogenesis of IPF in the tissue microenvironment.
    The Journal of Immunology 06/2005; 174(10):6490-8. · 5.52 Impact Factor
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    ABSTRACT: A 70-year-old woman was admitted to our hospital for the evaluation of a pulmonary nodule in the left S5 segment. On 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET), the nodule showed substantial uptake of 18F-fluorodeoxyglucose. Bronchoscopy was performed, but the cytology was negative. For a pathological diagnosis, a lung biopsy was carried out using video-associated thoracoscopy. The biopsy specimen showed granuloma formation with multinuclear giant cells. An acid-fast bacteria culture of the specimen was positive for Mycobacterium intracellulare. An atypical mycobacterium infection should be considered as a possibility when the 18FDG-PET of patients with pulmonary nodules is interpreted.
    Nihon Kokyūki Gakkai zasshi = the journal of the Japanese Respiratory Society. 12/2004; 42(11):970-4.
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    ABSTRACT: Neutropenia is a common laboratory finding in systemic lupus erythematosus (SLE). However, the molecular mechanism of SLE neutropenia has not been fully explained. In this study, we examined whether TNF-related apoptosis-inducing ligand (TRAIL) is involved in the pathogenesis of SLE neutropenia using samples from SLE patients. Serum TRAIL levels in SLE patients with neutropenia were significantly higher than those of SLE patients without neutropenia and healthy volunteers. Serum TRAIL levels showed a significant negative correlation with neutrophil counts in SLE patients. The expression of TRAIL receptor 3 was significantly lower in SLE patients with neutropenia than in patients without neutropenia or in healthy volunteers. Treatment with glucocorticoids negated the decrease of TRAIL receptor 3 expression on neutrophils of SLE patients. TRAIL may accelerate neutrophil apoptosis of neutrophils from SLE patients, and autologous T cells of SLE patients, which express TRAIL on surface, may kill autologous neutrophils. Interferon gamma and glucocorticoid modulated the expression of TRAIL on T cells of SLE patients and also modulated the expression of cellular Fas-associating protein with death domain-like interleukin-1 beta-converting enzyme (FLICE)-inhibitory protein (cFLIP), an inhibitor of death receptor signaling, in neutrophils. Thus, our results provide a novel insight into the molecular pathogenesis of SLE neutropenia.
    Blood 08/2004; 104(1):184-91. · 9.06 Impact Factor