Akira Ito

Kyushu University, Hukuoka, Fukuoka, Japan

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Publications (137)321.81 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We constructed a DNA damage-responsive transgene expression system mediated by the p53 promoter. We incorporated a transactivation system to generate transcriptional amplification via a positive feedback loop. Higher levels of DNA damage-responsive transgene expression were observed when transactivation was active. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
    Journal of Bioscience and Bioengineering 03/2015; DOI:10.1016/j.jbiosc.2015.02.009 · 1.79 Impact Factor
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    ABSTRACT: Genetic engineering of cellular genomes has provided useful tools for biomedical and pharmaceutical studies such as the generation of transgenic animals and producer cells of biopharmaceutical proteins. Gene integration using site-specific recombinases enables precise transgene insertion into predetermined genomic sites if the target site sequence is introduced into a specific chromosomal locus. We previously developed an accumulative site-specific gene integration system (AGIS) using Cre and mutated loxPs. The system enabled the repeated integration of multiple transgenes into a predetermined locus of a genome. In this study, we explored applicable mutated loxP pairs for AGIS to improve the integration efficiency. The integration efficiencies of 52 mutated loxP sequences, including novel sequences, were measured using an in vitro evaluation system. Among mutated loxP pairs that exhibited a high integration efficiency, the applicability of the selected pairs to AGIS was confirmed for transgene integration into the Chinese hamster ovary cell genome. The newly found mutated loxP pairs should be useful for Cre-mediated integration of transgenes and AGIS. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
    Journal of Bioscience and Bioengineering 01/2015; DOI:10.1016/j.jbiosc.2014.11.019 · 1.79 Impact Factor
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    ABSTRACT: Skeletal muscle regeneration requires migration, proliferation and fusion of myoblasts to form multinucleated myotubes. In our previous study, we showed that insulin-like growth factor (IGF)-I gene delivery stimulates the proliferation and differentiation of mouse myoblast C2C12 cells and promotes the contractile force generated by tissue-engineered skeletal muscles. The aim of this study was to investigate the effects of the extracellular matrix on IGF-I gene-engineered C2C12 cells in vitro. Retroviral vectors for doxycycline (Dox)-inducible expression of the IGF-I gene were transduced into C2C12 cells. When cultured on a type IV collagen-coated surface, we observed significant increases in the migration speed and number of IGF-I gene-engineered C2C12 cells with Dox addition, designated as C2C12/IGF (+) cells. Co-culture of C2C12/IGF (+) cells and parental C2C12 cells, which had been cultured in differentiation medium for 3 days, greatly enhanced myotube formation. Moreover, type IV collagen supplementation promoted the fusion of C2C12/IGF (+) cells with differentiated C2C12 cells and increased the number of myotubes with striations. Myotubes formed by C2C12/IGF (+) cells cultured on type IV collagen showed a dynamic contractile activity in response to electrical pulse stimulation. These findings indicate that type IV collagen promotes skeletal muscle regeneration mediated by IGF-I-expressing myoblasts, which may have important clinical implications in the design of myoblast-based therapies. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
    Journal of Bioscience and Bioengineering 11/2014; 119(5). DOI:10.1016/j.jbiosc.2014.10.008 · 1.79 Impact Factor
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    ABSTRACT: We report here a magnetically labeled feeder system for mouse embryonic stem/induced pluripotent stem (ES/iPS) cells. Magnetic attraction of feeder cells labeled with magnetite nanoparticles significantly increased ES/iPS colony-forming efficiency. Magnetic labeling of feeder cells also facilitated separation of ES/iPS cells from feeder cells.
    Journal of Bioscience and Bioengineering 11/2014; 119(5). DOI:10.1016/j.jbiosc.2014.10.020 · 1.79 Impact Factor
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    ABSTRACT: Background: Adipose-derived regenerative cells (ADRCs) are a promising source of autologous stem cells for regeneration and repair of damaged tissue. Herein, we investigated the therapeutic potential of ADRC sheets created by a magnetite tissue engineering technology (Mag-TE) for myocardial infarction. Methods and results: Adipose tissue was obtained from wild-type (WT) mice and ADRCs were isolated. ADRCs incubated with magnetic nanoparticle-containing liposomes (MCLs) were cultured. MCL-labeled ADRCs were mixed with a diluted extracellular matrix (ECM) precursor, and a magnet was placed on the reverse side. Magnetized ADRCs formed multilayered cell sheets after a 24-h incubation. WT mice were subjected to myocardial infarction by permanent ligation of the left anterior descending artery. We then transplanted the constructed ADRC sheet or a cell-free collagen gel sheet, as a control, onto the infarcted myocardium using an Alnico magnet before skin closure. Cardiac parameters were measured by echocardiogram, and angiogenesis was determined by tissue capillary density. ADRC sheet-treated mice showed significant improvements in systolic function, infarct wall thinning, and fibrotic length after myocardial infarction. ADRC sheet implantation also promoted angiogenesis in both the infarct area and the border zone in WT mice after myocardial infarction. The angiogenic effects of ADRC sheets were attributed to an increased expression of VEGF and bFGF mRNA in ischemic hearts. Conclusions: ADRC sheets created by this Mag-TE method protect the heart against pathological cardiac remodeling. Our ADRC sheets have the potential to be a novel regenerative strategy for ischemic heart disease.
    International Journal of Cardiology 07/2014; 175(3). DOI:10.1016/j.ijcard.2014.06.034 · 6.18 Impact Factor
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    ABSTRACT: Electrical impulses are necessary for proper in vivo skeletal muscle development. To fabricate functional skeletal muscle tissues in vitro, recapitulation of the in vivo niche, including physical stimuli, is crucial. Here, we report a technique to engineer skeletal muscle tissues in vitro by electrical pulse stimulation (EPS). Electrically excitable tissue-engineered skeletal muscle constructs were stimulated with continuous electrical pulses of 0.3 V/mm amplitude, 4 ms width, and 1 Hz frequency, resulting in a 4.5-fold increase in force at day 14. In myogenic differentiation culture, the percentage of peak twitch force (%Pt) was determined as the load on the tissue constructs during the artificial exercise induced by continuous EPS. We optimized the stimulation protocol, wherein the tissues were first subjected to 24.5%Pt, which was increased to 50-60%Pt as the tissues developed. This technique may be a useful approach to fabricate tissue-engineered functional skeletal muscle constructs.
    Scientific Reports 04/2014; 4:4781. DOI:10.1038/srep04781 · 5.08 Impact Factor
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    ABSTRACT: Artificial skeletal muscle tissues composed of cells are expected to be used for applications of regenerative medicine and drug screening. Generally, however, the physical forces generated by tissue-engineered skeletal muscle are lower than those of skeletal muscle tissues found in the body. Local hyperthermia is used for many diseases including muscle injuries. It was recently reported that mild heat treatment improved skeletal muscle functions. In this study, we investigated the effects of mild heat treatment on the tissue-engineered skeletal muscle tissues in vitro. We used magnetite cationic liposomes to label C2C12 myoblast cells magnetically, and constructed densely packed artificial skeletal muscle tissues by using magnetic force. Cell culture at 39°C promoted the differentiation of myoblast cells into myotubes. Moreover, the mild and transient heat treatment improved the contractile properties of artificial skeletal muscle tissue constructs. These findings indicate that the culture method using heat treatment is a useful approach to enhance functions of artificial skeletal muscle tissue.
    Current pharmaceutical biotechnology 04/2014; DOI:10.2174/1389201015666140408125231 · 2.51 Impact Factor
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    ABSTRACT: N-propionyl cysteaminylphenol-maleimide-dextran (NPCMD) is a toxic tyrosinase substrate developed to treat melanoma. We investigated the effect of NPCMD on innate immune responses in monocytes. CD14(+) monocytes and a monocytic cell line, THP-1, were stimulated with NPCMD in vitro. Cytokines in the culture supernatants were determined by ELISA and flow cytometry. NPCMD stimulated CD14(+) monocytes and THP-1 cells to secrete TNFα, IL-6 and IL-8, but not IL-10 or IL-12. TNFα secretion from THP-1 cells stimulated with NPCMD was inhibited by addition of an anti-TLR4 mAb in culture. Moreover, NPCMD stimulated production of pro-IL-1β in CD14(+) monocytes and monocytic cell line THP-1 cells and activated the NLRP3-inflammasome, resulting in production of mature IL-1β. Use of ASC and NLRP3-deficient THP-1 cell lines established involvement of the NLRP3 inflammasome in an IL-1β secretion in treatment with NPCMD. Inhibition of IL-1β secretion by an endocytosis inhibitor, cytochalasin B, and a lysosomal enzyme cathepsin B inhibitor, CA-074 Me, suggested the involvement of lysosomal rupture and leakage of cathepsin B into the cytosol in NLRP3 activation by NPCMD. The immunopotentiating effect of NPCMD mediated by TLR4 and NLRP3 inflammasome activation could be useful for eliciting effective adaptive immune responses against melanoma and other tumors.
    Journal of dermatological science 11/2013; DOI:10.1016/j.jdermsci.2013.11.006 · 3.34 Impact Factor
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    ABSTRACT: By combining synthetic biology with nanotechnology, we demonstrate remote controlled gene expression using a magnetic field. Magnetite nanoparticles, which generate heat under an alternating magnetic field, have been developed to label cells. Magnetite nanoparticles and heat-induced therapeutic genes were introduced into tumor xenografts. The magnetically triggered gene expression resulted in tumor growth inhibition. This system shows great potential for controlling target gene expression in a space and time selective manner and may be used for remote control of cell functions via gene expression.
    ACS Synthetic Biology 10/2013; 3(5). DOI:10.1021/sb4000838 · 3.95 Impact Factor
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    ABSTRACT: Exploitation of biological properties unique to cancer cells may provide a novel approach to overcome difficult challenges to the treatment of advanced melanoma. In order to develop melanoma-targeted chemothermoimmunotherapy, a melanogenesis substrate, N-propionyl-4-S-cysteaminylphenol (NPrCAP), sulfur-amine analogue of tyrosine, was conjugated with magnetite nanoparticles. NPrCAP was exploited from melanogenesis substrates, which are expected to be selectively incorporated into melanoma cells and produce highly reactive free radicals through reacting with tyrosinase, resulting in chemotherapeutic and immunotherapeutic effects by oxidative stress and apoptotic cell death. Magnetite nanoparticles were conjugated with NPrCAP to introduce thermotherapeutic and immunotherapeutic effects through nonapoptotic cell death and generation of heat shock protein (HSP) upon exposure to alternating magnetic field (AMF). During these therapeutic processes, NPrCAP was also expected to provide melanoma-targeted drug delivery system.
    02/2013; 2013:742925. DOI:10.1155/2013/742925
  • Journal of Dermatological Science 02/2013; 69(2):e90. DOI:10.1016/j.jdermsci.2012.11.575 · 3.34 Impact Factor
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    ABSTRACT: We previously reported the production of human erythropoietin (hEpo) using genetically manipulated (GM) chickens. The recombinant hEpo was produced in the serum and egg white of the GM chickens, and the oligosaccharide chain structures of the serum-derived hEpo were more favorable than those of the egg white-derived hEpo. In the present study, a retroviral vector encoding an expression cassette for a fusion protein of hEpo and the Fc region of human immunoglobulin G (hEpo/Fc) was injected into developing chicken embryos, with the aim of recovering the serum-derived hEpo from egg yolk through the yolk accumulation mechanism of maternal antibodies. The GM chickens that hatched stably produced the hEpo/Fc fusion protein not only in their serum and egg white, but also in the egg yolk as expected. Lectin blot analyses revealed that significant amounts of the oligosaccharide chains of hEpo/Fc produced in the serum and eggs of GM chickens terminated with galactose, and that the oligosaccharide chains of the serum- and yolk-derived hEpo/Fc incorporated sialic acid residues. Moreover, biological activity assessment using Epo-dependent cells revealed that the yolk-derived hEpo/Fc exhibited a comparable performance to the serum- and CHO-derived hEpo/Fc. These results indicate that transport of Fc fusion proteins from the blood circulation to the yolk in chickens represents an effective strategy for the production of pharmaceutical glycoproteins using transgenic chicken bioreactors.
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    ABSTRACT: Purpose: Control of therapeutic gene expression in tumours is a major goal of gene therapy research, as it can restrict cytotoxic gene expression in cancer cells. In addition, the combination of hyperthermia with gene therapy through the application of heat-inducible vectors can result in considerable improvements in therapeutic efficiency. In this study, to combine heat-inducibility with high-level transgene expression, we developed a heat-inducible transgene expression system with transcriptional amplification mediated by a tetracycline-responsive transactivator. Materials and methods: A hybrid promoter was generated by placing the heat shock protein (HSP) 70B' promoter under the tetracycline-repressor responsive element sequence, and a reporter/therapeutic gene expression plasmid was constructed by placing a reporter/therapeutic gene under the control of this hybrid promoter. Results: When the transactivator expression plasmid harbouring an expression cassette of the tetracycline-responsive transactivator gene was co-transfected with a reporter gene expression plasmid, the reporter gene expression was controlled by heat treatment. With this system, high levels of heat-induced transgene expression were observed compared to that from the HSP promoter alone without the transactivator. Evaluation of in vitro therapeutic effects using cancer cell lines revealed that therapeutic gene expression effectively caused cell death in a greater percentage of the cells. Conclusion: These findings indicate that this strategy improves the efficacy of cancer gene therapy.
    International Journal of Hyperthermia 12/2012; 28(8):788-98. DOI:10.3109/02656736.2012.738847 · 2.77 Impact Factor
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    ABSTRACT: Peptide immunotherapy using T-cell epitopes is expected to be an effective treatment for allergic diseases such as Japanese cedar (Cryptomeria japonica; Cj) pollinosis. To develop a treatment for pollen allergy by inducing oral tolerance, we generated genetically manipulated (GM) chickens by retroviral gene transduction, to produce a fusion protein of chicken egg white lysozyme and a peptide derived from seven dominant human T-cell epitopes of Japanese cedar pollen allergens (cLys-7crp). The transgene sequence was detected in all chickens transduced with the retroviral vector. Transduction efficiency in blood cells correlated to transgene expression. Western blot analysis revealed that cLys-7crp was expressed in the egg white of GM hens. Mice induced to develop allergic rhinitis by Cj pollinosis were fed with cLys-7crp-containing egg white produced by GM chickens. Total and Cj allergen (Cry j 1)-specific IgE levels were significantly decreased in allergic mice fed with cLys-7crp-containing egg white compared with allergic mice fed with normal egg white. These results suggest that oral administration of T-cell epitope-containing egg white derived from GM chickens is effective for the induction of immune tolerance as an allergy therapy.
    PLoS ONE 10/2012; 7(10):e48512. DOI:10.1371/journal.pone.0048512 · 3.53 Impact Factor
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    ABSTRACT: Tissue engineered skeletal muscle should possess a high cell-dense structure with unidirectional cell alignment. However, limited nutrient and/or oxygen supply within the artificial tissue constructs might restrict cell viability and muscular functions. In this study, we genetically modified myoblast cells with the anti-apoptotic Bcl-2 gene and evaluated their function in artificial skeletal muscle tissue constructs. Magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of skeletal muscle bundles by applying a magnetic force. Bcl-2-overexpressing muscle bundles formed highly cell-dense and viable tissue constructs, while muscle bundles without Bcl-2 overexpression exhibited substantial necrosis/apoptosis at the central region of the bundle. Bcl-2-overexpressing muscle bundles contracted in response to electrical pulses and generated a significantly higher physical force. These findings indicate that the incorporation of anti-apoptotic gene-transduced myoblast cells into tissue constructs significantly enhances skeletal muscle formation and function.
    Tissue Engineering Part A 10/2012; 19(1-2). DOI:10.1089/ten.TEA.2011.0728 · 4.64 Impact Factor
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    ABSTRACT: Aim: Accumulating evidence has indicated that hyperthermia using magnetite nanoparticles induces anti-tumor immunity. This study investigated the diversity of T-cell receptors (TCRs) in tumor-infiltrating lymphocytes after hyperthermia using magnetite nanoparticles. Materials & methods: Functionalized magnetite nanoparticles, N-propionyl-4-S-cysteaminylphenol (NPrCAP)/magnetite, were synthesized by conjugating the melanogenesis substrate NPrCAP with magnetite nanoparticles. NPrCAP/magnetite nanoparticles were injected into B16 melanomas in C57BL/6 mice, which were subjected to an alternating magnetic field for hyperthermia treatment. Results: Enlargement of the tumor-draining lymph nodes was observed after hyperthermia. The TCR repertoire was restricted in tumor-infiltrating lymphocytes, and expansion of Vβ11(+) T cells was preferentially found. DNA sequences of the third complementarity-determining regions revealed the presence of clonally expanded T cells. Conclusion: These results indicate that the T-cell response in B16 melanomas after hyperthermia is dominated by T cells directed toward a limited number of epitopes and that epitope-specific T cells frequently use a restricted TCR repertoire. Original submitted 14 May 2012; Revised submitted 30 July 2012.
    Nanomedicine 10/2012; DOI:10.2217/nnm.12.142 · 5.82 Impact Factor
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    ABSTRACT: Metastatic melanoma is resistant to conventional therapies. N-propionyl-4-S-cysteaminylphenol (NPrCAP), an N-protected sulfur-amine analog of tyrosine, is a good substrate for tyrosinase and is selectively incorporated into melanoma cells, causing cytotoxicity in vitro and in vivo. We have recently shown that intratumoral injections of NPrCAP suppress not only the growth of primary B16F1 melanoma tumors but also of secondary, re-challenged tumors. The participation of CD8(+) T cells has been suggested for the NPrCAP-mediated anti-B16 melanoma immunity. In this study, the molecular mechanism of the NPrCAP cytotoxicity and immunogenicity was examined. The phenol NPrCAP was shown to be activated by mushroom tyrosinase to the ortho-quinone N-propionyl-4-S-cysteaminyl-1,2-benzoquinone (NPrCAQ), and the structure was confirmed by reducing it to the corresponding catechol. NPrCAQ reacted rapidly with biologically relevant sulfhydryl compounds such as cysteine, glutathione and bovine serum albumin. The NPrCAQ-thiol adduct formation was proven with a model thiol N-acetylcysteine by spectroscopic methods. The production and release of NPrCAQ-protein adducts was verified in B16F1 melanoma cells in vitro and in B16F1 melanoma-bearing mice in vivo through the detection of 5-S-cysteaminyl-3-S-cysteinylcatechol after acid hydrolysis of the protein fraction. These results suggest that the phenol NPrCAP, acting as a prohapten, can be activated in melanoma cells by tyrosinase to the quinone-hapten NPrCAQ, which binds to melanosomal proteins through their cysteine residues to form possible neo-antigens, thus triggering the immunological response. NPrCAP thus represents a potential new approach to immunotherapy against metastatic melanoma.
    Biochemical pharmacology 06/2012; 84(5):646-53. DOI:10.1016/j.bcp.2012.06.015 · 4.65 Impact Factor
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    ABSTRACT: One of the major goals of gene therapy is to regulate the expression of therapeutic genes in desired cells or tissues. For this purpose, heat-inducible vectors have been exploited for cancer gene therapy combined with hyperthermia, which can result in considerable improvement of therapeutic effects. In the present study, we constructed a novel heat-inducible gene expression system incorporating a transactivation system with a positive feedback loop of transcriptional amplification. The target gene expression mediated by the transactivator under the control of a heat shock protein 70B' promoter is enhanced by self-promoted transactivator gene expression. This expression system showed tight control of target gene expression together with high-level expression; enhanced expression of the reporter gene was observed in transfected cells upon heat treatment, while negligible gene expression was detected in non-heated cells. When a therapeutic gene was used as the target gene, a considerable cytotoxic effect was observed after heat treatment of cancer cells transfected with the plasmids. The heat-induced transgene expression system is a promising new approach for the development of both a safe and effective vector for hyperthermia-based cancer gene therapy.
    Journal of Bioscience and Bioengineering 05/2012; 114(4):460-5. DOI:10.1016/j.jbiosc.2012.05.006 · 1.79 Impact Factor
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    ABSTRACT: N-propionyl-4-S-cysteaminylphenol (NPr-4-S-CAP) is selectively incorporated into melanoma cells and degrades them. However, it remains unclear whether NPr-4-S-CAP can induce cell death associated with the induction of host immune responses and tumor suppression in vivo. To examine the molecular mechanism of NPr-4-S-CAP-mediated cytotoxicity toward melanoma cells and to test whether NPr-4-S-CAP can suppress transplanted primary and secondary B16F1 melanomas. Cytotoxicity and apoptosis of melanoma cells were assessed by cell counting, flow cytometry, and detection of reactive oxygen species (ROS) and apoptotic molecules. NPr-4-S-CAP-associated host immunity was studied using a B16F1 mouse melanoma model through the application of CD4- and CD8-specific antibodies and tetramer assay. NPr-4-S-CAP suppressed growth of pigmented melanoma cells associated with an increase of intracellular ROS, activation of caspase 3 and DNA fragmentation, suggesting that NPr-4-S-CAP mediated ROS production, eliciting apoptosis of melanoma cells. Growth of transplanted B16F1 melanomas was inhibited after the consecutive intratumoral injections of NPr-4-S-CAP, and the tumor growth after rechallenge of B16F1 was significantly suppressed in the treated mice. This suppression occurred when the treated mice were given the anti-CD4 antibody, but not the anti-CD8 antibody. Tetramer assay demonstrated increased TYRP-2-specific CD8(+) T cells in the lymph node and spleen cells prepared from NPr-4-S-CAP-treated B16F1-bearing mice. These suggest that NPr-4-S-CAP induces apoptosis in melanoma cells through ROS production and generates CD8(+) cell immunity resulting in the suppression of rechallenged B16F1 melanoma.
    Journal of dermatological science 05/2012; 67(1):51-60. DOI:10.1016/j.jdermsci.2012.04.009 · 3.34 Impact Factor
  • Journal of chemical engineering of Japan 01/2012; 45(5):348-354. DOI:10.1252/jcej.11we237 · 0.61 Impact Factor

Publication Stats

3k Citations
321.81 Total Impact Points

Institutions

  • 2007–2015
    • Kyushu University
      • Department of Chemical Engineering
      Hukuoka, Fukuoka, Japan
    • Meteorological Research Institute, Japan Meteorological Agency
      Ibaragi, Ōsaka, Japan
  • 2010–2013
    • Fukuoka University
      • Department of Chemical Engineering
      Hukuoka, Fukuoka, Japan
    • Pasteur Institute of Iran (IPI)
      Teheran, Tehrān, Iran
  • 2008
    • Nagoya City University
      • Medical School
      Nagoya, Aichi, Japan
  • 2000–2008
    • Nagoya University
      • Graduate School of Engineering
      Nagoya, Aichi, Japan
  • 2004
    • The University of Tokyo
      • Department of Chemistry and Biotechnology
      Tokyo, Tokyo-to, Japan
  • 2000–2001
    • Yokohama City University
      • Department of Medicine
      Yokohama, Kanagawa, Japan
  • 1993–1998
    • Kanagawa Prefectural Institute Of Public Health
      Yokohama, Kanagawa, Japan