K Kimata

Aichi Medical University, Koromo, Aichi, Japan

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Publications (152)674.71 Total impact

  • Clinical and Experimental Nephrology 09/2014; DOI:10.1007/s10157-014-1025-7 · 1.71 Impact Factor
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    ABSTRACT: Hyaluronan (HA), a large anionic polysaccharide (glycosaminoglycan), is a major constituent of the extracellular matrix of the adult brain. To address its function, we examined the neurophysiology of knock-out mice deficient in hyaluronan synthase (Has) genes. Here we report that these Has mutant mice are prone to epileptic seizures, and that in Has3(-/-) mice, this phenotype is likely derived from a reduction in the size of the brain extracellular space (ECS). Among the three Has knock-out models, namely Has3(-/-), Has1(-/-), and Has2(CKO), the seizures were most prevalent in Has3(-/-) mice, which also showed the greatest HA reduction in the hippocampus. Electrophysiology in Has3(-/-) brain slices demonstrated spontaneous epileptiform activity in CA1 pyramidal neurons, while histological analysis revealed an increase in cell packing in the CA1 stratum pyramidale. Imaging of the diffusion of a fluorescent marker revealed that the transit of molecules through the ECS of this layer was reduced. Quantitative analysis of ECS by the real-time iontophoretic method demonstrated that ECS volume was selectively reduced in the stratum pyramidale by ∼40% in Has3(-/-) mice. Finally, osmotic manipulation experiments in brain slices from Has3(-/-) and wild-type mice provided evidence for a causal link between ECS volume and epileptiform activity. Our results provide the first direct evidence for the physiological role of HA in the regulation of ECS volume, and suggest that HA-based preservation of ECS volume may offer a novel avenue for development of antiepileptogenic treatments.
    The Journal of Neuroscience : The Official Journal of the Society for Neuroscience 04/2014; 34(18):6164-6176. DOI:10.1523/JNEUROSCI.3458-13.2014 · 6.75 Impact Factor
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    ABSTRACT: Hyaluronan (HA) is a primary component of the extracellular matrix of cells, and it is involved in the pathogenesis of atherosclerosis. The purpose of this study was to investigate the role of HA in neointimal formation after vascular injury and determine its tissue-specific role in vascular smooth muscle cells (VSMCs) by using a cre-lox conditional transgenic (cTg) strategy. HA was found to be expressed in neointimal lesions in humans with atherosclerosis and after wire-mediated vascular injury in mice. Inhibition of HA synthesis using 4-methylumbelliferone markedly inhibited neointimal formation after injury. In vitro experiments revealed that low-molecular-weight HA (LMW-HA) induced VSMC activation, including migration, proliferation, and production of inflammatory cytokines, and reactive oxygen species (ROS). The migration and proliferation of VSMCs were mediated by the CD44/RhoA and CD44/ERK1/2 pathways, respectively. Because HA synthase 2 (HAS2) is predominantly expressed in injured arteries, we generated cTg mice that overexpress the murine HAS2 gene specifically in VSMCs (cHAS2/CreSM22α mice) and showed that HA overexpression markedly enhanced neointimal formation after cuff-mediated vascular injury. Further, HA-overexpressing VSMCs isolated from cHAS2/CreSM22α mice showed augmented migration, proliferation, and production of inflammatory cytokines and ROS. VSMC-derived HA promotes neointimal formation after vascular injury, and HA may be a potential therapeutic target for cardiovascular disease.
    PLoS ONE 03/2013; 8(3):e58760. DOI:10.1371/journal.pone.0058760 · 3.53 Impact Factor
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    ABSTRACT: Neuronal axons and their growth cones recognize molecular guidance cues within the local environment, forming axonal pathways to produce precise neuronal networks during nervous system development. Chondroitin sulfates (CS), carbohydrate chains on chondroitin sulfate proteoglycans, exhibit great structural diversity and exert various influences on axons and growth cones as guidance cues or their modulators; however, the relationship between their structural diversity and function in axonal guidance is not well known. To uncover the roles of CS in axonal guidance, artificially modified hybrid molecules: CS derivatives of biotinylated CS and lipid-derivatized CS, were used. The experiments with biotinylated CS suggest that the growing axons act on their environment, modifying CS, and rendering it more favorable for their growth. The experiments with lipid-derivatized CS demonstrated that growth cones distinguish types of CS with different unit contents and are likely to discriminate the structural diversity of CS. The application of CS derivatives is useful in uncovering axon–environment interaction and structure–function relationship of CS directly.
    Polymers 02/2013; 5(1):254-268. DOI:10.3390/polym5010254 · 2.51 Impact Factor
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    ABSTRACT: Chondroitin sulfate (CS), the carbohydrate chain of chondroitin sulfate proteoglycans, is involved in neuronal circuit formation during development. CS shows great structural diversity with combination of disaccharide units of different structure (A-, C-, D-, or E-unit). However, whether its structural diversity contributes to pathway formation remains unclear. We chemically coupled the reducing end of various types of CS to the amino group of phosphatidylethanolamine (lipid-derivatized CS, CS-PE) and established an in vitro time-lapse assay to observe the behaviors of growth cones of retinal ganglion cells from embryonic day 6 chick retina on exposure to beads coated with lipid-derivatized CS (CS-PE beads). Among CS-PEs with different content of the structural units, the beads coated with E-unit-containing CS-PE [E-unit: GlcAβ1-3GalNAc(4,6-O-disulfate)] (CSE-PE beads) significantly caused the growth cones to retract and to turn away from the beads, but the beads coated with CSA-, CSC- or CSD-PE beads did not. Importantly, not all the growth cones retracted equally from the CSE-PE beads, but they showed continuum of the repulsive behaviors; some behaved moderately and others remarkably. The growth cones distinguished different samples of CS: CSE and the others. Moreover, the continuum of the repulsive behaviors suggests that CS might be involved with the fine regulation of growth cones' behavior through its characteristic structure.
    Brain research 11/2012; 1491. DOI:10.1016/j.brainres.2012.11.011 · 2.83 Impact Factor
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    ABSTRACT: Cell surface heparan sulfate proteoglycans (HSPGs) are involved in the binding and entry of human T-cell leukemia virus type 1 (HTLV-1) into host cells, while sulfated polysaccharides such as heparin inhibit HTLV-1 infection. Chondroitin sulfate proteoglycans (CSPGs) are classified as another major type of proteoglycans. Here, we examined the effect of four types of chondroitin sulfate (CS) on HTLV-1 infection. Accordingly, a human T-cell line, MOLT-4, was inoculated with cell-free HTLV-1 in the presence or absence of soluble CS, and the synthesis of reverse-transcribed HTLV-1 DNA within cells 20 hours after inoculation was detected using polymerase chain reaction (PCR). Among the four types of CS (A, C, D, and E), the E type (CSE), which was derived from the squid cartilage, exhibited anti-HTLV-1 activity. Furthermore, we observed that CSE directly interacted with recombinant HTLV-1 envelope (Env) proteins and inhibited the binding of HTLV-1 virions to MOLT-4 cells, indicating that the interaction between Env and CSE plays a significant role in its anti-HTLV-1 activity. In addition, CSE inhibited syncytium formation that was induced by HTLV-1-producing cells. When CSE was mixed with the synthetic fusion inhibitor peptide corresponding to the ectodomain of the Env transmembrane subunit (TM) gp21, the HTLV-1 infection was further inhibited when compared with the inhibitory effect of each compound alone. Thus, further elucidation of the in vitro antiviral mechanism of CSE shown in this study will lead to the development of CSE-like molecules for the entry inhibition of HTLV-1.
    AIDS research and human retroviruses 10/2012; DOI:10.1089/AID.2012.0156 · 2.46 Impact Factor
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    ABSTRACT: The contribution of hyaluronan (HA) to the regulatory network of the hematopoietic microenvironment was studied using knock-out mice of three hyaluronan synthase genes (Has1, Has2, and Has3). The number of hematopoietic progenitors was decreased in bone marrow and increased in extramedullary sites of Prx1-Cre;Has2(flox/flox);Has1(-/-);Has3(-/-) triple knock-out (tKO) mice as compared with wild type (WT) and Has1(-/-);Has3(-/-) double knock-out (dKO) mice. In line with this observation, decreased hematopoietic activity was observed in long term bone marrow cultures (LTBMC) from tKO mice, whereas the formation of the adherent layer and generation of hematopoietic cells in WT and dKO cultures was not different. 4-Methylumbelliferone (4MU) was used to pharmacologically inhibit the production of HA in LTBMC. Treatment with 4MU inhibited HA synthesis, decreased expression of HAS2 and HAS3, and eliminated hematopoiesis in LTBMC, and this effect was alleviated by the addition of exogenous HA. Exogenous HA also augmented the cell motility in LTBMC, which correlated with the HA-stimulated production of chemokines and growth factors. Conditioned media from HA-induced LTBMC enhanced the chemotaxis of hematopoietic stem/progenitor cells (HSPC) in response to SDF-1. Exposure of endothelial cells to 4MU decreased their ability to support HSPC rolling and adhesion. In addition, migration of transplanted HSPC into the marrow of 4MU-pretreated mice was lower than in untreated mice. Collectively, the results suggest that HA depletion reduces the ability of the microenvironment to support HSPC, and confirm a role for HA as a necessary regulatory element in the structure of the hematopoietic microenvironment.
    Journal of Biological Chemistry 05/2012; 287(30):25419-33. DOI:10.1074/jbc.M112.376699 · 4.60 Impact Factor
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    ABSTRACT: Hyaluronan (HA) plays crucial roles in the tumourigenicity of many types of malignant tumours. 4-Methylumbelliferone (MU) is an inhibitor of HA synthesis. Several studies have shown its inhibitory effects on malignant tumours; however, none have focused on its effects on osteosarcoma. We investigated the effects of MU on HA accumulation and tumourigenicity of highly metastatic murine osteosarcoma cells (LM8) that have HA-rich cell-associated matrix, and human osteosarcoma cell lines (MG-63 and HOS). In vitro, MU inhibited HA retention, thereby reducing the formation of functional cell-associated matrices, and also inhibited cell proliferation, migration, and invasion. Akt phosphorylation was suppressed by MU (1.0 mM). In vivo, although MU showed only a mild inhibitory effect on the growth of the primary tumour, it markedly inhibited (75% reduction) the development of lung metastasis. Hyaluronan retention in the periphery of the primary tumour was markedly suppressed by MU. These findings suggested that MU suppressed HA retention and cell-associated matrix formation in osteosarcoma cells, resulting in a reduction of tumourigenicity, including lung metastasis. 4-Methylumbelliferone is a promising therapeutic agent targeting both primary tumours and distant metastasis of osteosarcoma, possibly via suppression of HA retention.
    British Journal of Cancer 11/2011; 105(12):1839-49. DOI:10.1038/bjc.2011.459 · 4.82 Impact Factor
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    ABSTRACT: Neuronal development is the result of a multitude of neural migrations, which require extensive cell-cell communication. These processes are modulated by extracellular matrix components, such as heparan sulfate (HS) polysaccharides. HS is molecularly complex as a result of nonrandom modifications of the sugar moieties, including sulfations in specific positions. We report here mutations in HS 6-O-sulfotransferase 1 (HS6ST1) in families with idiopathic hypogonadotropic hypogonadism (IHH). IHH manifests as incomplete or absent puberty and infertility as a result of defects in gonadotropin-releasing hormone neuron development or function. IHH-associated HS6ST1 mutations display reduced activity in vitro and in vivo, suggesting that HS6ST1 and the complex modifications of extracellular sugars are critical for normal development in humans. Genetic experiments in Caenorhabditis elegans reveal that HS cell-specifically regulates neural branching in vivo in concert with other IHH-associated genes, including kal-1, the FGF receptor, and FGF. These findings are consistent with a model in which KAL1 can act as a modulatory coligand with FGF to activate the FGF receptor in an HS-dependent manner.
    Proceedings of the National Academy of Sciences 06/2011; 108(28):11524-9. DOI:10.1073/pnas.1102284108 · 9.81 Impact Factor
  • N Sugiura, K Kimata
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    Methods in Enzymology 09/2010; 247(36):362-73. DOI:10.1002/chin.199536324 · 2.19 Impact Factor
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    ABSTRACT: Although chondroitin sulfate (CS) is known to act as an inhibitory axon guidance cue, retinal axons show substantial growth on a culture substrate containing CS. Thus, the question arises as to how retinal axons elongate on CS-containing culture substrates. To elucidate the effects of retinal axons on a substrate containing CS, we synthesized biotinylated CS (biotin-CS) and developed a culture substrate with streptavidin-conjugated biotin-CS (complex between streptavidin and biotin-CS) to culture retinal axons. The effects of retinal axons on the streptavidin-biotin-CS complex were analyzed immunocytochemically using antibodies against CS and streptavidin, which recognize the carbohydrate and protein portions of the complex, respectively. After the axons were cultured on the substrate, areas that were CS-immunonegative but streptavidin-immunopositive were observed on the surface, corresponding to areas with or without axons, respectively. Absence of CS immunostaining was considered to be caused by structural alterations in the carbohydrate chains of the CS under the influence of the axons.
    03/2010; 85(4):189-93. DOI:10.1007/s12565-010-0076-4
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    ABSTRACT: We established a clonal chondrocyte-like cell line (TC6, TC stands for large T immortalized chondrocyte-like cell line) derived from articular cartilage of transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. TC6 cells exhibited spindle-like or polygonal morphology and grew well at 33 degrees C in alpha-minimal essential medium supplemented with 0.5% fetal bovine serum. After confluence, these cells formed nodules that were positive for staining with alcian blue. Northern blot analysis demonstrated that these cells expressed messenger RNAs (mRNA) of the genes encoding cartilage-specific proteins such as type II procollagen, link protein, and aggrecan. Furthermore, the expression of type II procollagen and link protein genes in TC6 cells was regulated by parathyroid hormone and basic fibroblast growth factor, suggesting the presence of the receptors for the hormone and cytokine. The expression of link protein mRNA in TC6 cells was regulated in a time-dependent manner and was enhanced in culture within a week and increased continuously up to 10-fold by the end of 4 weeks. Expression of mRNAs encoding type II procollagen and versican/PG-M also increased moderately during the culture period. TC6 cells expressed type I procollagen mRNA, however, its level declined along with time in culture in contrast to the enhancement of the genes encoding cartilage-specific molecules in these cells. Interestingly, alkaline phosphatase mRNA expression was barely detectable in the TC6 cells in their growing phase while it was enhanced dramatically more than 7-fold by day 14 in culture. These results indicate that the TC6 cells could serve as an excellent model for the studies on chondrocyte physiology.
    Journal of Bone and Mineral Research 11/2009; 11(11):1646-54. DOI:10.1002/jbmr.5650111108 · 6.59 Impact Factor
  • H Morita, A Yoshimura, K Kimata
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    ABSTRACT: Recent studies, including those by van den Hoven and colleagues, have challenged the classic negative-charge theory of glomerular filtration. However, the possibility remains that heparan sulfate in the glomerular basement membrane plays a role in maintaining the glomerular filtration barrier.
    Kidney International 03/2008; 73(3):247-8. DOI:10.1038/sj.ki.5002659 · 8.52 Impact Factor
  • Journal of Allergy and Clinical Immunology 01/2007; 119(1). DOI:10.1016/j.jaci.2006.11.213 · 11.25 Impact Factor
  • Osteoarthritis and Cartilage 12/2006; 14. DOI:10.1016/S1063-4584(07)60549-4 · 4.66 Impact Factor
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    ABSTRACT: Human lactoferrin is a component of the non-specific immune system with distinct antiviral properties. We used alphaviruses, adapted to interaction with heparan sulfate (HS), as a tool to investigate the mechanism of lactoferrin's antiviral activity. Lactoferrin inhibited infection of BHK-21 cells by HS-adapted, but not by non-adapted, Sindbis virus (SIN) or Semliki Forest virus (SFV). Lactoferrin also inhibited binding of radiolabeled HS-adapted viruses to BHK-21 cells or liposomes containing lipid-conjugated heparin as a receptor analog. On the other hand, low-pH-induced fusion of the viruses with liposomes, which occurs independently of virus-receptor interaction, was unaffected. Studies involving preincubation of virus or cells with lactoferrin suggested that the protein does not bind to the virus, but rather blocks HS-moieties on the cell surface. Charge-modified human serum albumin, with a net positive charge, had a similar antiviral effect against HS-adapted SIN and SFV, suggesting that the antiviral activity of lactoferrin is related to its positive charge. It is concluded that human lactoferrin inhibits viral infection by interfering with virus-receptor interaction rather than by affecting subsequent steps in the viral cell entry or replication processes.
    Virology 04/2005; 333(2):284-92. DOI:10.1016/j.virol.2005.01.010 · 3.28 Impact Factor
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    ABSTRACT: Hyaluronan is a major molecule in joint fluid and plays a crucial role in joint motion and the maintenance of joint homeostasis. The concentration and average molecular weight of hyaluronan in the joint fluids are reduced in osteoarthritis and rheumatoid arthritis. To elucidate the underlying mechanism, we analyzed the message expression of three isoforms of hyaluronan synthase and hyaluronidase from knee synovium, using real-time reverse transcriptase polymerase chain reaction. Synovia were obtained from 17 patients with osteoarthritis, 14 patients with rheumatoid arthritis, and 20 healthy control donors. The message expression of hyaluronan synthase-1 and -2 in the synovium of both types of arthritis was significantly less than in the control synovium, whereas that of hyaluronidase-2 in the synovium of both arthritides was significantly greater than in the control synovium. The decreased expression of the messages for hyaluronan synthase-1 and -2 and/or the increased expression of the message for hyaluronidase-2 may be reflected in the reduced concentration and decreased average molecular weight of hyaluronan in the joint fluids of patients with osteoarthritis and rheumatoid arthritis.
    Arthritis research & therapy 09/2004; 6(6):R514-20. DOI:10.1186/ar1223 · 4.12 Impact Factor
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    ABSTRACT: To dissect the role of the globular domains of PGM/versican--a large hyaluronan binding proteoglycan (PG) enriched in tumor lesions--we have stably transduced a human leiomyosarcoma cell line with either the G1 or G3 domain of the PG and subsequently assayed the effect of this manipulation on several cellular processes in vitro and in vivo. G1- and G3-overexpressing cells were found to exhibit an enhanced growth that was more accentuated in the absence of serum components and was seen both when cells were cultured on ECM substrates and in the absence of ECM anchorage. Accordingly, if inoculated subcutaneously into nude mice, G1 transfectants formed larger tumor masses than control cells at the site of implantation, albeit after a certain latency period. Upon binding to cell surface CD44, proliferation of G1-, but not G3-, overexpressing cells were dose dependently inhibited by exogenous hyaluronan (HA) or HA fragments. G1- and G3-transduced cells did not differ in their intrinsic ability to adhere and migrate on various purified ECM components, whereas G1-overproducing sarcoma cells were more invasive than the corresponding G3 mutants, and their locomotion was perturbed by exogenous HA. The augmented anchorage-independent growth exhibited solely by G1-transduced was largely ascribable to a reduced apoptotic rate, thereby indicating a shift in the proliferation--apoptosis equilibrium of the cells toward the former. In fact, G1-overexpressing cells appeared resistant to both cytotoxic drug-induced and Fas-dependent programmed cell death, and this resistance implicated mitochondrial apoptotic genes. The results indicate that the terminal domains of versican may differentially control propagation of tumor cells and diversely modulate their responses to environmental HA.
    The FASEB Journal 05/2004; 18(6):779-81. DOI:10.1096/fj.03-0660fje · 5.48 Impact Factor
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    ABSTRACT: Liposarcoma is common soft tissue sarcoma that is sometimes difficult to treat, besides its good prognosis. The inter-alpha-trypsin inhibitor heavy chains (HCs) has been reported to be linked to hyaluronan, which play important roles in tumour progression and metastasis. In this study, clinical significance of HCs in patients with liposarcoma was investigated. HC expression was studied by immunohistochemistry on resected specimens of 33 liposarcoma patients and 10 lipoma patients. The expression of HC mRNA was analyzed by reverse transcription polymerase chain reaction (RT-PCR). Serum concentration of HC was determined with enzyme-linked immunosorbent assay (ELISA). Prominent positive staining of HC was observed in extracellular matrix of pleomorphic and myxoid liposarcoma. In well-differentiated liposarcoma and lipoma, faint staining was seen with HC. No products of HC could be detected by RT-PCR. Serum concentration of HC was not up-regulated in any subtypes of liposarcoma. HC expression was not significantly correlated with tumour subtypes and prognosis. HC was strongly accumulated in pleomorphic and myxoid liposarcoma, however, was not locally synthesized in liposarcoma. HC might play roles in stabilizing extracellular matrix, such as hyaluronan (HA), in liposarcoma.
    European Journal of Surgical Oncology 11/2003; 29(8):665-9. DOI:10.1016/S0748-7983(03)00135-5 · 2.89 Impact Factor
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    ABSTRACT: The importance of proteoglycans for secretion of proteolytic enzymes was studied in the murine macrophage cell line J774. Untreated or 4beta-phorbol 12-myristate 13-acetate (PMA)-stimulated macrophages were treated with hexyl-beta-d-thioxyloside to interfere with the attachment of glycosaminoglycan chains to their respective protein cores. Activation of the J774 macrophages with PMA resulted in increased secretion of trypsin-like serine proteinase activity. This activity was completely inhibited by plasminogen activator inhibitor 1 and by amiloride, identifying the activity as urokinase plasminogen activator (uPA). Treatment of both the unstimulated or PMA-stimulated macrophages with xyloside resulted in decreased uPA activity and Western blotting analysis revealed an almost complete absence of secreted uPA protein after xyloside treatment of either control- or PMA-treated cells. Zymography analyses with gels containing both gelatin and plasminogen confirmed these findings. The xyloside treatment did not reduce the mRNA levels for uPA, indicating that the effect was at the post-translational level. Treatment of the macrophages with xylosides did also reduce the levels of secreted matrix metalloproteinase 9. Taken together, these findings indicate a role for proteoglycans in the secretion of uPA and MMP-9.
    European Journal of Biochemistry 11/2003; 270(19):3971-80. DOI:10.1046/j.1432-1033.2003.03785.x · 3.58 Impact Factor

Publication Stats

6k Citations
674.71 Total Impact Points


  • 1989–2014
    • Aichi Medical University
      • • Institute for Molecular Science of Medicine
      • • Department of Orthopaedic Surgery
      Koromo, Aichi, Japan
  • 2011
    • Columbia University
      New York City, New York, United States
  • 2000
    • Seikagaku Corporation
      Edo, Tōkyō, Japan
  • 1984–2000
    • Nagoya University
      • • Division of Surgery
      • • Division of General Medicine
      • • Department of Chemistry
      Nagoya-shi, Aichi-ken, Japan
  • 1999
    • University of California, Davis
      • Area of Chemical Biology
      Davis, California, United States
  • 1995–1998
    • National Institutes of Health
      • Laboratory of Cell and Developmental Biology
      Bethesda, MD, United States
  • 1997
    • Kyoto Prefectural University
      Kioto, Kyōto, Japan
    • Kanazawa University
      Kanazawa, Ishikawa, Japan
    • Osaka University
      • Division of Pediatric Surgery
      Suika, Ōsaka, Japan
  • 1996
    • Nippon Veterinary and Animal Science University
      • Department of Veterinary Anatomy
      Edo, Tōkyō, Japan
  • 1989–1995
    • University of Washington Seattle
      • Department of Pathology
      Seattle, WA, United States
  • 1994
    • University of South Florida
      • Morsani College of Medicine
      Tampa, Florida, United States
  • 1990
    • National Institute for Basic Biology
      Okazaki, Aichi, Japan