Publishing type：Research paper (scientific journal)   Publisher：Zoological Society of Japan  

DOI： 10.2108/zs210107

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Publishing type：Research paper (scientific journal)   Publisher：Japanese Society for Biological Sciences in Space  

DOI： 10.2187/bss.36.9

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/biof.1774

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/biof.1774

Language：English   Publishing type：Research paper (scientific journal)  

Extracellular vesicles (EVs) have been recognized as a universal method of cellular communications and are reportedly produced in bacteria, archaea, and eukaryotes. Bacterial EVs are often called "Outer Membrane Vesicles" (OMVs) as they were the result of a controlled blebbing of the outer membrane of gram-negative bacteria such as Porphyromonas gingivalis (P. gingivalis). Bacterial EVs are natural messengers, implicated in intra- and inter-species cell-to-cell communication among microorganism populations present in microbiota. Bacteria can incorporate their pathogens into OMVs; the content of OMVs differs, depending on the type of bacteria. The production of distinct types of OMVs can be mediated by different factors and routes. A recent study highlighted OMVs ability to carry crucial molecules implicated in immune modulation, and, nowadays, they are considered as a way to communicate and transfer messages from the bacteria to the host and vice versa. This review article focuses on the current understanding of OMVs produced from major oral bacteria, P. gingivalis: generation, characteristics, and contents as well as the involvement in signal transduction of host cells and systemic diseases. Our recent study regarding the action of P. gingivalis OMVs in the living body is also summarized.

DOI： 10.1016/j.jdsr.2021.07.003

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publishing type：Research paper (scientific journal)  

Periodontal diseases are common inflammatory diseases that are induced by infection with periodontal bacteria such as Porphyromonas gingivalis (Pg). The association between periodontal diseases and many types of systemic diseases has been demonstrated; the term "periodontal medicine" is used to describe how periodontal infection/inflammation may impact extraoral health. However, the molecular mechanisms by which the factors produced in the oral cavity reach multiple distant organs and impact general health have not been elucidated. Extracellular vesicles (EVs) are nano-sized spherical structures secreted by various types of cells into the tissue microenvironment, and influence pathophysiological conditions by delivering their cargo. However, a detailed understanding of the effect of EVs on periodontal medicine is lacking. In this study, we investigated whether EVs derived from Pg-infected macrophages reach distant organs in mice and influence the pathophysiological status. EVs were isolated from human macrophages, THP-1 cells, infected with Pg. We observed that EVs from Pg-infected THP-1 cells (Pg-inf EVs) contained abundant core histone proteins such as histone H3 and translocated to the lungs, liver, and kidneys of mice. Pg-inf EVs also induced pulmonary injury, including edema, vascular congestion, inflammation, and collagen deposition causing alveoli destruction. The Pg-inf EVs or the recombinant histone H3 activated the NF-κB pathway, leading to increase in the levels of pro-inflammatory cytokines in human lung epithelial A549 cells. Our results suggest a possible mechanism by which EVs produced in periodontal diseases contribute to the progression of periodontal medicine.

DOI： 10.1016/j.bbadis.2021.166236

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© 2020, The Author(s). Differentiation of osteoclasts (OCs) from hematopoietic cells requires cellular interaction with osteoblasts (OBs). Due to the difficulty of live-imaging in the bone, however, the cellular and molecular mechanisms underlying intercellular communication involved in OC differentiation are still elusive. Here, we develop a fracture healing model using the scale of trap:GFP; osterix:mCherry transgenic zebrafish to visualize the interaction between OCs and OBs. Transplantation assays followed by flow cytometric analysis reveal that most trap:GFPhigh OCs in the fractured scale are detected in the osterix:mCherry+ fraction because of uptake of OB-derived extracellular vesicles (EVs). In vivo live-imaging shows that immature OCs actively interact with osterix:mCherry+ OBs and engulf EVs prior to convergence at the fracture site. In vitro cell culture assays show that OB-derived EVs promote OC differentiation via Rankl signaling. Collectively, these data suggest that EV-mediated intercellular communication with OBs plays an important role in the differentiation of OCs in bone tissue.

DOI： 10.1038/s42003-020-0925-1

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Osteocytes, osteoblasts (bone-forming cells), and osteoclasts (bone-resorbing cells) are the primary types of cells that regulate bone metabolism in mammals. Sclerostin produced in bone cells activates osteoclasts, inhibiting bone formation; excess production of sclerostin, therefore, leads to the loss of bone mass. Fish scales have been reported to have morphological and functional similarities to mammalian bones, making them a useful experimental system for analyzing vertebrate bone metabolism in vitro. However, whether fish scales contain cells producing sclerostin and/or osteocytes has not been determined. The current study demonstrated, for the first time, that sclerostin-containing cells exist in goldfish scales. Analysis of the distribution and shape of sclerostin-expressing cells provided evidence that osteoblasts produce sclerostin in goldfish scales. Furthermore, our results found that osteocyte-like cells exist in goldfish scales, which also produce sclerostin. Finally, we demonstrated that microgravity in outer space increased the level of sclerostin in the scales of goldfish, a finding suggesting that the induction of sclerostin is the mechanism underlying the activation of osteoclasts under microgravity.

DOI： 10.2220/biomedres.41.279

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publisher：(一社)日本骨代謝学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

Outer membrane vesicles (OMVs) are nanosized particles derived from the outer membrane of gram-negative bacteria. Oral bacterium Porphyromonas gingivalis (Pg) is known to be a major pathogen of periodontitis that contributes to the progression of periodontal disease by releasing OMVs. The effect of Pg OMVs on systemic diseases is still unknown. To verify whether Pg OMVs affect the progress of diabetes mellitus, we analyzed the cargo proteins of vesicles and evaluated their effect on hepatic glucose metabolism. Here, we show that Pg OMVs were equipped with Pg-derived proteases gingipains and translocated to the liver in mice. In these mice, the hepatic glycogen synthesis in response to insulin was decreased, and thus high blood glucose levels were maintained. Pg OMVs also attenuated the insulin-induced Akt/glycogen synthase kinase-3 β (GSK-3β) signaling in a gingipain-dependent fashion in hepatic HepG2 cells. These results suggest that the delivery of gingipains mediated by Pg OMV elicits changes in glucose metabolisms in the liver and contributes to the progression of diabetes mellitus.

DOI： 10.1016/j.bbadis.2020.165731

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

© 2020 Japanese Association for Oral Biology Background: Bacteria exhibit multi-cellular social behavior, such as biofilm formation, virulence generation, bioluminescence, or sporulation, through cell-to-cell communication involving a quorum sensing (QS) system capable of sensing species density. Pseudomonas aeruginosa (P. aeruginosa) is a ubiquitous gram-negative opportunistic pathogen that is frequently isolated from immunocompromised patients. It is particularly detected in patients with severe periodontitis and persistent endodontic infections, forcing a rethink of the role of this opportunistic pathogen in oral lesions. Highlight: N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) is a pivotal QS molecule, which regulates numerous virulence genes in P. aeruginosa and exhibits broad biological modulation effects in mammalian cells. In this review, we highlight the diverse OdDHL-mediated apoptosis and immunomodulatory effects on host cells. The structural properties, signaling pathways, targeted genes and proteins, and intracellular metabolism of OdDHL are also discussed to clarify the interactions between P. aeruginosa and the host. Conclusion: The purpose of this review is to identify a valid target for quenching OdDHL, which could potentially eliminate the pathogenic effect of P. aeruginosa.

DOI： 10.1016/j.job.2020.01.001

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1038/s41467-019-11373-9

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Other Link： http://www.nature.com/articles/s41467-019-11373-9

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/jpi.12594

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jpi.12594

Language：English   Publisher：(一社)日本骨代謝学会  

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Many studies have investigated the actions of melatonin on osteoblasts and osteoclasts. However, the underlying mechanisms, especially regarding osteocyte function, remain largely unknown. Therefore, this study aimed to clarify the underlying mechanisms of melatonin action on bone tissue via osteocyte function. Chick calvariae were employed as a model. In ovo injection of melatonin (5, 50 and 500 µg) dose-dependently decreased the mRNA expression levels of cathepsin K and matrix metalloproteinase 9 (MMP9) in chick calvariae without affecting the expression levels of receptor activator of NF-κB ligand or osteoprotegerin. Surprisingly enough, the expression of calcitonin mRNA in chick calvariae was significantly raised. After 3 days of in vitro treatment of melatonin (10-7 and 10-5 M) on newly hatched chick calvariae, both calcitonin mRNA expression in calvariae and the concentration of calcitonin in cultured medium were augmented in a dose-dependent manner, coincident with the decreased mRNA expression levels of cathepsin K and MMP9. Immunohistochemical analyses revealed expression of melatonin receptors and calcitonin by osteocytes buried in bone matrix. Moreover, the mRNA expression levels of melatonin receptors, calcitonin and sclerostin (a marker of osteocyte), were strongly and positively correlated. In conclusion, we demonstrated the expression of melatonin receptors and calcitonin expression in osteocytes for the first time and suggest a new mechanism underlying the suppressive effect of melatonin on osteoclasts via upregulation of calcitonin secretion by osteocytes.

DOI： 10.1530/JOE-18-0707

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Bioscientifica  

Endochondral ossification, including bone growth and other metabolic events, is regulated by circadian rhythms. Herein, we provide evidence that melatonin has a direct effect on the circadian rhythm of chondrocytes. We detected mRNA expression of the genes which encode the melatonin-synthesizing enzymes AANAT (arylalkylamine N-acetyltransferase) and HIOMT (hydroxyindole O-methyltransferase), as well as the melatonin receptors MT1 and MT2 in mouse primary chondrocytes and cartilage. Production of melatonin was confirmed by mass spectrometric analysis of primary rat and chick chondrocytes. Addition of melatonin to primary BALB/c mouse chondrocytes caused enhanced cell growth and increased expression of <italic>Col2a1</italic>, <italic>Aggrecan</italic> and <italic>Sox9</italic>, but inhibited <italic>Col10a1</italic> expression. Addition of luzindole, an MT1 and MT2 antagonist, abolished these effects. These data indicate that chondrocytes produce melatonin, which regulates cartilage growth and maturation via the MT1 and MT2 receptors. Kinetic analysis showed that melatonin caused rapid upregulation of <italic>Aanat</italic>, <italic>Mt1</italic>, <italic>Mt2</italic> and <italic>Pthrp</italic> expression, followed by <italic>Sox9</italic> and <italic>Ihh</italic>. Furthermore, expression of the clock gene <italic>Bmal1</italic> was induced, while that of <italic>Per1</italic> was downregulated. Chronobiological analysis of synchronized C3H mouse chondrocytes revealed that melatonin induced the cyclic expression of <italic>Aanat</italic> and modified the cyclic rhythm of <italic>Bmal1</italic>, <italic>Mt1</italic> and <italic>Mt2</italic>. In contrast, <italic>Mt1</italic> and <italic>Mt2</italic> showed different rhythms from <italic>Bmal1</italic> and <italic>Aanat</italic>, indicating the existence of different regulatory genes. Our results indicate that exogenous and endogenous melatonin work in synergy in chondrocytes to adjust rhythmic expression to the central suprachiasmatic nucleus clock.

DOI： 10.1530/JOE-19-0022

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1369/0022155418793588

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Increased risk of fracture associated with type 2 diabetes has been a topic of recent concern. Fracture rislc is related to a decrease in bone strength, which can be affected by bone metabolism and the quality of the bone. To investigate the cause of the increased fracture rate in patients with diabetes through analyses of bone metabolism and bone matrix protein properties, we used goldfish scales as a bone model for hyperglycemia. Using the scales of seven alloxan-treated and seven vehicle-treated control goldfish, we assessed bone metabolism by analyzing the activity of marker enzymes and mRNA expression of marker genes, and we measured the change in molecular weight of scale matrix proteins with SDS-PAGE. After only a 2-week exposure to hyperglycemia, the molecular weight of alpha- and beta-fractions of bone matrix collagen proteins changed incrementally in the regenerating scales of hyperglycemic goldfish compared with those of euglycemic goldfish. In addition, the relative ratio of the gamma-fraction significantly increased, and a delta-fraction appeared after adding glyceraldehyde a candidate for the formation of advanced glycation end products in diabetes to isolated type 1 collagen in vitro. The enzymatic activity and mRNA expression of osteoblast and osteoclast markers were not significantly different between hyperglycemic and euglycemic goldfish scales. These results indicate that hyperglycemia is likely to affect bone quality through glycation of matrix collagen from an early stage of hyperglycemia. Therefore, non-enzymatic glycation of collagen fibers in bone matrix may lead to the deterioration of bone quality from the onset of diabetes. (C) 2016 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.cbpa.2016.09.010

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMEDICAL RESEARCH PRESS LTD  

The effects of low-intensity pulsed ultrasound (LIPUS) on osteoclastogenesis were examined using fish scales that had both osteoclasts and osteoblasts. The binding of the receptor activator of NF-kappa B ligand (RANKL) in osteoblasts to the receptor activator of NF-kappa B (RANK) in osteoclasts induced osteoclastogenesis. Therefore, we focused on RANK/RANKL signaling. After 6 h of incubation following LIPUS treatment, mRNA expression of RANKL increased significantly. Resulting from the increased RANKL mRNA level, the expression of transcription-regulating factors significantly increased after 6 h of incubation, and then the mRNA expression of functional genes was significantly up-regulated after 12 h of incubation. However, the mRNA expression of osteoprotegerin (OPG), which is known as an osteoclastogenesis inhibitory factor, also significantly increased after 6 h of incubation and tended to further increase after 12 h of incubation. At 24 h of incubation, osteoclastic functional genes' mRNA expression decreased to the level of the control. Furthermore, we performed an in vivo experiment with goldfish. Two weeks after daily LIPUS exposure, osteoclastic marker enzymes tended to decrease while osteoblastic marker enzymes were activated. The regeneration rate of the LIPUS-treated scales was significantly higher than that of the control scales. Thus, LIPUS moderately activates osteoclasts and induces bone formation.

DOI： 10.2220/biomedres.38.71

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PAGEPRESS PUBL  

We previously developed a novel method for gene transfer, which combined a non-viral gene expression vector with transcutaneous in vivo electroporation. We applied this method to transfer the bone morphogenetic protein (BMP) gene and induce ectopic bone formation in rat skeletal muscles. At present, it remains unclear which types of cells can differentiate into osteogenic cells after BMP gene transfer by in vivo electroporation. Two types of stem cells in skeletal muscle can differentiate into osteogenic cells: muscle-derived stem cells, and bone marrow-derived stem cells in the blood. In the present study, we transferred the BMP gene into rat skeletal muscles. We then stained tissues for several muscle-derived stem cell markers (e.g., Pax7, M-cadherin), muscle regeneration-related markers (e.g., Myod1, myogenin), and an inflammatory cell marker (CD68) to follow cell differentiation over time. Our results indicate that, in the absence of BMP, the cell population undergoes muscle regeneration, whereas in its presence, it can differentiate into osteogenic cells. Commitment towards either muscle regeneration or induction of ectopic bone formation appears to occur five to seven days after BMP gene transfer.

DOI： 10.4081/ejh.2017.2772

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOC HISTOCHEMISTRY & CYTOCHEMISTRY  

Tight junction (TJ) is one of the cell-cell junctions and known to have the barrier and fence functions between adjacent cells in both simple and stratified epithelia. We examined the distribution pattern, constitutive proteins, and permeability of TJ in the stratified squamous epithelium of the palatal mucosa of mice. Ultrastructural observations based on the ultrathin section and freeze-fracture methods revealed that poorly developed TJs are located at the upper layer of the stratum granulosum. The positive immunofluorescence of occludin (OCD), claudin (CLD)-1 and -4 were localized among the upper layer of the stratum granulosum showing a dot-like distribution pattern. And CLD-1 and -4 were localized among the stratum spinosum and the lower part of stratum granulosum additionally showed a positive reaction along the cell profiles. Western blotting of TJ constitutive proteins showed OCD, CLD-1, -2, -4, and -5 bands. The permeability test using biotin as a tracer revealed both the areas where biotin passed through beyond OCD positive points and the areas where biotin stopped at OCD positive points. These results show that poor TJs localize at the upper layer of the stratum granulosum of the palatal epithelium, and the TJs are leaky and include at least CLD-1 and -4.

DOI： 10.1267/ahc.17006

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Using fish scales in which osteoclasts and osteoblasts coexist on the calcified bone matrix, we examined the effects of low-intensity pulsed ultrasound (LIPUS) on both osteoclasts and osteoblasts. At 3 h of incubation after LIPUS treatment, osteoclastic markers such as tartrate-resistant acid phosphatase (TRAP) and cathepsin K mRNA expressions decreased significantly while mRNA expressions of osteoblastic markers, osteocalcin, distal less homeobox 5, runt-related transcription factor 2a, and runt-related transcription factor 2b, increased significantly. At 6 and 18 h of incubation, however, both osteoclastic and osteoblastic marker mRNA expression did not change at least present conditions. Using GeneChip analysis of zebrafish scales treated with LIPUS, we found that cell death-related genes were upregulated with LIPUS treatment. Real-time PCR analysis indicated that the expression of apoptosis-related genes also increased significantly. To confirm the involvement of apoptosis in osteoclasts with LIPUS, osteoclasts were induced by autotransplanting scales in goldfish. Thereafter, the DNA fragmentation associated with apoptosis was detected in osteoclasts using the TUNEL (TdT-mediated dUTP nick end labeling) method. The multi-nuclei of TRAP-stained osteoclasts in the scales were labeled with TUNEL. TUNEL staining showed that the number of apoptotic osteoclasts in goldfish scales was significantly elevated by treatment with LIPUS at 3 h of incubation. Thus, we are the first to demonstrate that LIPUS directly functions to osteoclasts and to conclude that LIPUS directly causes apoptosis in osteoclasts shortly after exposure. (C) 2016 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.cbpa.2016.01.022

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

Metal-binding proteins, metallothioneins (MTs), may play important roles in bone metabolism. However, the contribution of MTs to bone metabolism remains obscure. In the present study, we investigated the expression of MT isoforms in bone cells and mRNA for MT isoforms in the tibiae following ovariectomy (OVX). The results obtained showed that MT-I/II and MT-III were expressed in osteoblasts, osteoclasts, and osteocytes 4 weeks after OVX. Peaks in the mRNA expression ratios (OVX/Sham) of MT-I/II and MT-III changed following OVX. The expression ratio of MT-I/II increased after 1 week, whereas that of MT-III increased 4 weeks after OVX. These results suggest that the contribution of MTs to bone metabolism may depend on the isoforms in the cell types and the stage after OVX.

DOI： 10.2485/jhtb.25.21

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMEDICAL RESEARCH PRESS LTD  

Mechanical stress promotes osteoblast proliferation and differentiation from mesenchymal stem cells (MSCs). Although numerous growth factors and cytokines are known to regulate this process, information regarding the differentiation of mechanically stimulated osteoblasts from MSCs in in vivo microenvironment is limited. To determine the significant factors involved in this process, we performed a global analysis of differentially expressed genes, in response to tensile stress, in the mouse cranial suture wherein osteoblasts differentiate from MSCs. We found that the gene expression levels of several components involved in bone morphogenetic protein, Wnt, and epithelial growth factor signalings were elevated with tensile stress. Moreover gene expression of some extracellular matrices (ECMs), such as cysteine rich protein 61 (Cyr61)/CCN1 and galectin-9, were upregulated. These ECMs have the ability to modulate the activities of cytokines and are known as matricellular proteins. Cyr61/CCN1 expression was prominently increased in the fibroblastic cells and preosteoblasts in the suture. Thus, for the first time we demonstrated the mechanical stimulation of Cyr61/CCN1 expression in osteogenic cells in an ex vivo system. These results suggest the importance of matricellular proteins along with the cytokine-mediated signaling for the mechanical regulation of MSC proliferation and differentiation into osteoblastic cell lineage in vivo.

DOI： 10.2220/biomedres.37.117

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publisher：(一社)歯科基礎医学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：INT PRESS EDITING CENTRE INC  

We have developed an immortalized oral epithelial cell line, ROE2, from fetal transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen gene. The cells grew continuously at either a permissive temperature of 33 degrees C or an intermediate temperature of 37 degrees C. At the nonpermissive temperature of 39 degrees C, on the other hand, growth decreased significantly, and the Sub-G1 phase of the cell cycle increased, indicating that the cells undergo apoptosis at a nonpermissive temperature. Histological and immunocytochennical analyses revealed that ROE2 cells at 37 degrees C had a stratified epithelial-like morphology and expressed cytokeratins Krt4 and Krt13, marker proteins for oral nonkeratinized epithelial cells. Global-scale comprehensive nnicroarray analysis, coupled with bioinformatics tools, demonstrated a significant gene network that was obtained from the upregulated genes. The gene network contained 16 genes, including Cdkn1a, Fos, Krt13, and Prdm1, and was associated mainly with the biological process of skin development in the category of biological functions, organ development. These four genes were validated by quantitative real-time polymerase chain reaction, and the results were nearly consistent with the microarray data. It is therefore anticipated that this cell line will be useful as an in vitro model for studies such as physiological functions, as well as for gene expression in oral epithelial cells.

DOI： 10.1538/expanim.63.31

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Although low-intensity pulsed ultrasound (LIPUS) has been shown to enhance bone fracture healing, the underlying mechanism of LIPUS remains to be fully elucidated. Here, to better understand the molecular mechanism underlying cellular responses to LIPUS, we investigated gene expression profiles in mouse MC3T3-E1 preosteoblast cells exposed to LIPUS using high-density oligonucleotide microarrays and computational gene expression analysis tools. Although treatment of the cells with a single 20-min LIPUS (1.5 MHz, 30 mW/cm2) did not affect the cell growth or alkaline phosphatase activity, the treatment significantly increased the mRNA level of Bglap. Microarray analysis demonstrated that 38 genes were upregulated and 37 genes were downregulated by 1.5-fold or more in the cells at 24-h post-treatment. Ingenuity pathway analysis demonstrated that the gene network U (up) contained many upregulated genes that were mainly associated with bone morphology in the category of biological functions of skeletal and muscular system development and function. Moreover, the biological function of the gene network D (down), which contained downregulated genes, was associated with gene expression, the cell cycle and connective tissue development and function. These results should help to further clarify the molecular basis of the mechanisms of the LIPUS response in osteoblast cells. © 2013 by the authors
licensee MDPI, Basel, Switzerland.

DOI： 10.3390/ijms141122721

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ZOOLOGICAL SOC JAPAN  

Fish scales are a form of calcified tissue similar to that found in human bone. In medaka scales, we detected both osteoblasts and osteoclasts and subsequently developed a new scale assay system. Using this system, we analyzed the osteoblastic and osteoclastic responses under 2-, 3-, and 4-gravity (G) loading by both centrifugation and vibration. After loading for 10 min, the scales from centrifugal and vibration loading were incubated for 6 and 24 hrs, respectively, after which the osteoblastic and osteoclastic activities were measured. Osteoblastic activity significantly increased under 2- to 4-G loading by both centrifugation and vibration. In contrast, we found that osteoclastic activity significantly decreased under 2- and 3-G loading in response to both centrifugation and vibration. Under 4-G loading, osteoclastic activity also decreased on centrifugation, but significantly increased under 4-G loading by vibration, concomitant with markedly increased osteoblastic activity. Expression of the receptor activator of the NF-kappa B ligand (RANKL), an activation factor of osteoclasts expressed in osteoblasts, increased significantly under 4-G loading by vibration but was unchanged by centrifugal loading. A protein sequence similar to osteoprotegerin (OPG), which is known as an osteoclastogenesis inhibitory factor, was found in medaka using our sequence analysis. The ratio of RANKL/OPG-like mRNAs in the vibration-loaded scales was significantly higher than that in the control scales, although there was no difference between centrifugal loaded scales and the control scales. Accordingly, medaka scales provide a useful model by which to analyze bone metabolism in response to physical strain.

DOI： 10.2108/zsj.30.217

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier Ltd  

In our previous study, wesuccessfully induced bone formation in rat skeletal muscle using a gene-transfer system, in which a non-viral BMP-2 expression vector was applied to the muscle by in vivo electroporation at 100 V. With the ultimate goal of applying this method to maxillofacial bone regeneration therapy, we sought to establish a safer system in which the gene is transferred into the target area with a lower voltage, but with the same efficiency. The LacZ or BMP-2 gene was transferred using in vivo electroporation under various conditions: 25-100 V, 50-200-ms loading time, and 8-128 pulses. The gene-transfer efficiency or bone induction was quantified by measuring β-galactosidase or alkaline phosphatase (ALP) activity and calcium content. Histological, immunohistochemical, and X-ray analyses were also used to examine the effect of the gene transfer. When the voltage for in vivo electroporation was lowered, the gene transfer efficiency was also reduced. However, by increasing the loading time or number of pulses, it was possible to improve the gene-transfer efficiency to the same level attained at 100 V, and in vivo electroporation under the lower voltage conditions successfully induced new bone. We have established a safe and efficient gene-transfer system for bone regeneration therapy using a non-viral BMP gene expression vector and in vivo electroporation. © 2011 Asian Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd.

DOI： 10.1016/j.ajoms.2011.10.006

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

The effect of fugu parathyroid hormone 1 (fugu PTH1) on osteoblasts and osteoclasts in teleosts was examined with an assay system using teleost scale and the following markers: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Synthetic fugu PTH1 (1-34) (100 pg/m1-10 ng/ml) significantly increased ALP activity at 6 h of incubation. High-dose (10 ng/ml) fugu PTH1 significantly increased ALP activity even after 18 h of incubation. In the case of TRAP activity, fugu PTH1 did not change at 6 h of incubation, but fugu PTH1 (100 pg/m1-10 ng/ml) significantly increased TRAP activity at 18 h. Similar results were obtained for human PTH (1-34), but there was an even greater response with fugu PTH1 than with human PTH. In vitro, we demonstrated that both the receptor activator of the NF-kappa B ligand in osteoblasts and the receptor activator NF-kappa B mRNA expression in osteoclasts increased significantly by fugu PTH1 treatment. In an in vivo experiment, fugu PTH1 induced hypercalcemia resulted from the increase of both osteoblastic and osteoclastic activities in the scale as well as the decrease of scale calcium contents after fugu PTH1 injection. In addition, an in vitro experiment with intramuscular autotransplanted scale indicated that the ratio of multinucleated osteoclasts/mononucleated osteoclasts in PTH-treated scales was significantly higher than that in the control scales. Thus, we concluded that PTH acts on osteoblasts and osteoclasts in the scales and regulates calcium metabolism in goldfish. (C) 2011 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bone.2011.02.004

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

The adaptive response of bone to mechanical loading in teleosts is not well understood. We recently developed a new assay system using teleost scales, which consists of osteoblasts, osteoclasts, and bone matrix protein. In this system, alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) were used as markers of osteoblasts and osteoclasts, respectively. Using this assay system, we examined the effects of mechanical loading on ALP and TRAP activity in goldfish scales. ALP activity in the scales was significantly elevated (p&lt;0.01) by ultrasound stimuli (1 MHz, 50% duty factor, 0.5 Hz pulse repetition frequency, 60 mW/cm(2) [I(SATA)] and 6 min) after both 18 h and 24 h of incubation while TRAP activity remained unchanged. In addition, mRNA expression of both insulin-like growth factor-I (IGF-I) and estrogen receptors (ER) increased significantly, as did ALP activity. After the goldfish had been swimming for 3 days (speed: 2 body lengths/second, duration: 3 h/day), the scales&apos; ALP activity increased significantly (p&lt;0.01) but TRAP activity did not change. These in vitro and in vivo results strongly suggest that osteoblasts in the goldfish scale respond sensitively to mechanical stress and may be important in promoting bone formation. (C) 2010 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.cbpa.2010.03.002

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

The periodontal ligament (PDL), a connective tissue located between the cementum of teeth and the alveolar bone of mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. The PDL contains fibroblastic cells of a heterogeneous cell population, from which we have established several cell lines previously. To analyze characteristics unique for PDL at a molecular level, we performed cDNA microarray analysis of the PDL cells versus MC3T3-E1 osteoblastic cells. The analysis followed by validation by reverse transcription-polymerase chain reaction and immunochemical staining revealed that endoglin, which had been shown to associate with transforming growth factor (TGF)-beta and bone morphogenetic proteins (BMPs) as signaling modulators, was abundantly expressed in PDL cells but absent in osteoblastic cells. The knockdown of endoglin greatly suppressed the BMP-2-induced osteoblastic differentiation of PDL cells and subsequent mineralization. Interestingly, the endoglin knockdown did not alter the level of Smad-1/5/8 phosphorylation induced by BMP-2, while it suppressed the BMP-2-induced expression of IdI, a representative BMP-responsive gene. Therefore, it is conceivable that endoglin regulates the expression of BMP-2-responsive genes in PDL cells at some site downstream of Smad-1/5/8 phosphorylation. Alternatively, we found that Smad-2 as well as Smad-1/5/8 was phosphorylated by BMP-2 in the PDL cells, and that the BMP-2-induced Smad-2 phosphorylation was suppressed by the endoglin knockdown. These results, taken together, raise a possibility that PDL cells respond to BMP2 via a unique signaling pathway dependent on endoglin, which is involved in the osteoblastic differentiation and mineralization of the cells. J. Cell. Physiol. 222: 465-473, 2010. (C) 2009 Wiley-Liss, Inc.

DOI： 10.1002/jcp.21968

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Language：Japanese   Publisher：岡山歯学会  

2004年に岡山大学歯学部に設置された「歯学部将来構想検討ワーキング」(ワーキング)が歯科系の全教職員に対して将来像を提案し、2008年開催の教職員・学生の全体集会で提案項目の重要性・達成度・緊急度について参加者が評価を行った。その後、今後実施を開始または前向きに検討する項目をワーキングが選択、実施する場合の方法などについて検討した。その結果、歯科界の発展の可能性や社会の要求について探り、歯科治療が全身健康に寄与できることを広報することで、歯学部を受検する高校生や歯学部学生に対して卒業後の種々の方向性を示し、基礎分野と臨床分野の教育における関連、チームワーク医療、チュートリアルなどのカリキュラムの充実が求められていた。また教育や診療における活動度を評価できるシステム作成により教員の意識を高め、教育と診療を公平に評価することも重要であり、研究組織の再編と研究内容の充実、患者の満足度調査なども課題として挙げられた。

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ZOOLOGICAL SOC JAPAN  

In teleosts, prolactin is involved in calcium regulation, but its role in scale/bone metabolism is unclear. Using the in-vitro system with goldfish scales developed recently, we explored the effects of teleost prolactin, growth hormone, and somatolactin on osteoclasts and osteoblasts. Addition of prolactin at concentrations of 0.01-100 ng/ml reduced osteoclastic activity, partly via osteoclast apoptosis, after 6-18 h incubation. Conversely, growth hormone and somatolactin at a concentration of 100 ng/ml increased osteoclastic activity after 18 h incubation, indicating the specificity of the inhibitory effect of prolactin on osteoclastic activity. On the other hand, these three hormones promoted osteoblastic activity at concentrations of 10-100 ng/ml. The results from this study are the first demonstration of direct effects of prolactin on scale/bone metabolism and osteoclastic activity in a teleost.

DOI： 10.2108/zsj.25.739

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DOI： 10.2187/bss.22.3

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

Complementary DNAs encoding two major osteoclastic markers, tartrate-resistant acid phosphatase (TRAP) and cathepsin K (Cath K) were cloned from the scales of a teleost, the goldfish. This is the first report of the full coding sequence of TRAP and Cath K molecules in fish. In the goldfish scale both TRAP and Cath K mRNAs were expressed in the multinucleate osteoclasts, which showed large numbers of mitochondria and lysosomes, and a well developed ruffled border. These characteristic features of osteoclasts in the scales are similar to those in mammals. Most teleosts use the scale as an internal calcium reservoir during the reproductive season. The expression of TRAP and Cath K mRNAs in the scale significantly increased in April, which is a reproductive season, compared with that in October, a non-reproductive season. Thus, both of these molecular markers should be useful for the study of osteoclasts in the teleost scale. (c) 2007 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2007.08.010

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：COMPANY OF BIOLOGISTS LTD  

We recently reported that tensile stress induces osteoblast differentiation and osteogenesis in the mouse calvarial suture in vitro. Using this experimental system, we identified PIASx beta, a splice isoform of Pias2, as one of the genes most highly upregulated by tensile stress. Further study using cell culture revealed that this upregulation was transient and was accompanied by upregulation of other differentiation markers, including osterix, whereas expression of Runx2 was unaffected. Runx2 and osterix are the two master proteins controlling osteoblast differentiation, with Runx2 being upstream of osterix. Targeted knockdown of PIASx beta by small interfering RNA (siRNA) markedly suppressed osteoblastic differentiation and matrix mineralization, whereas transient overexpression of PIASx beta caused the exact opposite effects. Regardless of PIASx beta expression level, Runx2 expression remained constant. Reporter assays demonstrated that osterix enhanced its own promoter activity, which was further stimulated by PIASx beta but not by its sumoylation-defective mutant. NFATc1 and NFATc3 additionally increased osterix transcriptional activity when co-transfected with PIASx beta. Because osterix has no consensus motif for sumoylation, other proteins are probably involved in the PIASx beta-mediated activation and NFAT proteins may be among such targets. This study provides the first line of evidence that PIASx beta is indispensable for osteoblast differentiation and matrix mineralization, and that this signaling molecule is located between Runx2 and osterix.

DOI： 10.1242/jcs.005090

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SAGE PUBLICATIONS INC  

Epidemiological studies have shown that postmenopausal women who do not use an estrogen supplement have fewer teeth than those who do. We hypothesized that changes in the dentition of post-menopausal women might be due to alveolar bone alterations by estrogen deficiency. To clarify this, we analyzed the microstructural alveolar bone changes in ovariectomized monkeys and compared these with their lumbar bone mineral density. The % of baseline bone mineral density showed a significant decrease in the ovariectomized group as compared with the controls. The second-molar interradicular septa in ovariectomized monkeys showed a significantly decreased nodes number, cortices number, and an increased structural model index value. More pores were seen in the ovariectomized group at the top of the septa. This study demonstrated that, in such monkeys, estrogen deficiency led to fragility of the trabecular structure of the molar alveolar bone, and such fragility was inversely correlated with lumbar bone mineral density.

DOI： 10.1177/154405910708600108

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Language：Japanese   Publisher：岡山歯学会  

岡山大学における歯学部の将来と日本の歯科界の将来を素晴らしいものにすることを期待して、歯学部に設置された「将来を考えるワーキンググループ」(ワーキンググループ)が種々の観点から将来像の検討を行い、岡山大学歯科系の全教員・職員に対して、提案を行った。その提案に対して集まった意見をまとめ、岡山大学歯学部の将来像を設定するための対策を検討した。今回は教育関連項目をまとめた。岡山大学歯学部学生の動機付けを行い、就学中に、歯学へ興味を持つような授業カリキュラムを作成、調整することが望まれた。教育カリキュラムの一つとしてチュートリアル教育が様々な大学に広まりつつあり、自ら考え、成長して行く歯科医師を作ることが期待された。学生評価の厳格化、評価方法の見直し、さらには教育・教員に対する評価も求められていた。

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Dental pulp is assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. This study was undertaken to clarify the mechanism inducing bone formation in the dental pulp by investigating the pulpal healing process, after tooth replantation, by micro-computed tomography (mu-CT), immunocytochemistry for heat-shock protein (HSP)-25 and cathepsin K (CK), and histochemistry for both alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). Under deep anesthesia, the upper right first molar of 4-week-old Wistar rats was extracted and immediately repositioned in the original socket. In control teeth at this age, the periphery of the coronal dental pulp showed intense ALP-positive and HSP-25-positive reactions, whereas there were no TRAP-positive or CK-positive cells. Tooth replantation weakened or terminated ALP-positive and HSP-25-positive reactions in the pulp tissue at the initial stages. At 3-7 days after operation, the ALP-positive region recovered from the root apex to the coronal pulp followed by HSP-25-positive reactions in successful cases showing tertiary dentin formation. In other cases, TRAP-positive and CK-positive cells appeared in the pulp tissue of the replanted tooth at postoperative days 5-10 and remained associated with the bone tissue after 12-60 days. Immunoelectron microscopy clearly demonstrated that CK-positive osteoclast-lineage cells made contact with mesenchymal cells with prominent nucleoli and well-developed cell organelles. These data suggest that the appearance of TRAP-positive and CK-positive cells is involved in the induction of bone tissue formation in dental pulp.

DOI： 10.1007/s00441-005-0138-4

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

Histochemical, immunohistochemical and electron energy-loss spectroscopic studies were performed to examine the relationship between sulphated glycosaminoglycans and medullary bone calcification using oestrogen-injected male Japanese quail. Sulphated glycosaminoglycans, detected by high iron diamine (HID) or HID-thiocarbohydrazide-silver protein (HID-TCH-SP) methods, were distributed throughout the matrix of medullary bone, some periphery and extending tips of the trabeculae stained weakly, and the globular structures at osteoid areas were exclusively positive for HID-TCH-SP stain. Immunohistochemistry identified keratan sulphate located in the globular structures at osteoid areas and calcified matrix, but chondroitin-4 sulphate and chondroitin-6 sulphate were not detected in the matrix. Using electron spectroscopic imaging, sulphur was determined to be localized in the globular structures. These results demonstrate that medullary bone matrix accumulates keratan sulphate in the globular structures, which are the foci for calcification, and eventually in the calcified areas. This suggests that keratan sulphate containing sulphur is maintained in the calcified matrix. These results indicate a unique process of calcification exists in medullary bone.

DOI： 10.1093/jmicro/dfh097

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

It has been shown that, in live subjects, the ability of calcitonin (CT) to decrease serum calcium (Ca) levels can be lost in response to its continued or repeated administration. The present study investigated the relationship between such changes of in vivo serum Ca levels and the response of osteoclasts to CT administration, including the downregulation of their CT receptors (CTRs). Rats were either given a single injection of CT or repeated injections at either 6- or 24-h intervals, after which their serum Ca levels were evaluated. Their parietal holies were dissected, and the amount of I-125-labeled elcatonin (I-125-eCT) binding to their osteoclasts measured using autoradiography. Ultrastructural changes in the osteoclasts were also examined. Twenty-four hours after a single CT administration, serum Ca levels had dropped, and there was an absence of ruffled borders on the osteoclasts. Less I-125-eCT binding to the osteoclast was found than in the control group. Forty-eight and 72 h after CT administration, serum Ca levels had almost returned to control levels, and the osteoclasts showed ruffled borders once again. The amount of I-125-eCT binding to the osteoclast also recovered to control levels. When these osteoclasts were then incubated in CT, their ruffled borders once again disappeared. In the 6-h interval multiple CT administration schedule subjects, upon inspection 72 h after their first administration (6 h following the final one), serum Ca levels were found to have almost returned to control levels with the presence of osteoclast ruffled borders. The amount of I-125-eCT binding to these osteoclasts was remarkably limited, and no disappearance of the ruffled borders occurred in response to additional CT incubation. In the 24-h interval multiple administration schedule subjects, upon inspection 72 h after their first CT administration (24 h following the final one), there was less I-125-eCT binding than in the single-dose subjects tested 24 h after their injection, and the ability of CT to lower their serum Ca levels was reduced. The ability of CT to lower serum Ca levels was therefore related to the response of osteoclasts to the CT (the disappearance of the ruffled borders), and this response was related to the amount of CTRs available for binding with CT on the osteoclast surface. Furthermore, the reduced effectiveness of CT in response to repeated CT administration was found to be related to the downregulation of the CTRs on the osteoclast surface. (C) 2004 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bone.2004.03.018

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：KARGER  

Osteopontin (OPN) is considered as a key protein in cell regeneration. OPN is thought to have many functions in cell-cell binding and cell-matrix binding via OPN receptors in various organs. But there is little information on the precise role of OPN. To clarify the functional role of OPN in tubular injury, we performed in situ hybridization and immunohistochemical analysis of the expression of OPN in a renal cortical necrosis model induced by cisplatin from the acute injury to late recovery phases. In the acute injury phase, both mRNA and protein of OPN were markedly induced in damaged tubular lumens with cell debris. In the late recovery phase, on the other hand, OPN protein and mRNA were observed in dilated and flattened tubular epithelial cells showing a regenerative appearance. Most of these cells were also immunostained with CD44, a receptor of OPN. PCNA staining was also co-localized with these expressions. In light of the CD44 function regulating cell proliferation, these findings suggest that OPN may contribute to regeneration of tubular epithelial cells during the acute to late recovery phases of cortical tubular damage induced by cisplatin. Copyright (C) 2004 S. Karger AG, Basel.

DOI： 10.1159/000078643

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

We previously demonstrated that tensile stress (TS)-induced osteoblast differentiation eventually led to osteogenesis in an organ culture of mouse calvaria I sutures. In the present study, we employed RNA-fingerprinting using an arbitrarily primed polymerase chain reaction (RAP-PCR)to identify alpha-adaptin C, a component of the endocytosis machinery AP2, as a TS-inducible gene. Protein production, as well as the gene expression of alpha-adaptin C, was induced by TS as early as 3 h following the initiation of loading. In situ hybridization and immunohistochemical analysis revealed that the induction of alpha-adaptin C mostly occurred in fibroblastic cells in the sutures, suggesting that it precedes TS-induced osteoblast differentiation. Consistent with this result, TS significantly increased the number of coated pits (CPs) and coated vesicles (CVs) in the undifferentiated fibroblastic cells but not in the osteoblastic cells around calvarial bones. Further, TS-induced osteoblast differentiation was suppressed when endocytosis was inhibited by potassium depletion. These results, taken together, suggest that TS accelerates osteoblast differentiation and osteogenesis, possibly through the induction of the alpha-adaptin C expression and consequent activation of receptor-mediated endocytosis. (C) 2003 Wiley-Liss, Inc.

DOI： 10.1002/jcp.10269

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：COMPANY OF BIOLOGISTS LTD  

The periodontal ligament (PDL) is a connective tissue located between the cementum of teeth and the alveolar bone of the mandibula. It plays an integral role in the maintenance and regeneration of periodontal tissue. The cells responsible for maintaining this tissue are thought to be fibroblasts, which can be either multipotent or composed of heterogenous cell populations. However, as no established cell lines from the PDL are available, it is difficult to assess what type of cell promotes all of these functions. As a first step to circumvent this problem, we have cloned and characterized cell lines from the PDL from mice harboring a temperature-sensitive SV 40 large T-antigen gene. RT-PCR and in situ hybridization studies demonstrated that a cell line, designated PDL-L2, mimics the gene expression of the PDL in vivo: it expresses genes such as alkaline phosphatase, type I collagen, periostin, runt-related transcription factor-2 (Runx2) and EGF receptor, but does not express genes such as bone sialoprotein and osteocalcin. Unlike osteoblastic cells and a mixed cell population from the PDL, PDL-L2 cells do not produce mineralized nodules in the minearlization medium. When PDL-L2 cells were incubated in the presence of recombinant human bone morphogenetic protein-2 alkaline phosphatase activity increased and mineralized nodules were eventually produced, although the extent of mineralization is much less than that in osteoblastic MC3T3-E1 cells. Furthermore, PDL-L2 cells appeared to have a regulatory mechanism by which the function of Runx2 is normally suppressed.

DOI： 10.1242/jcs.00098

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL SCIENCE INC  

Background. There is controversy regarding the exact localization and roles of osteopontin (OPN), a multipotential chemokine, in renal injury. There is little information on the expression and role of OPN in gentamicin-induced acute tubular necrosis (ATN) and its recovery process.
Methods. A severe ATN model was made using male Wistar rats by injecting gentamicin (150 mg/kg/day) for five days and limiting the provision of water. The expression and localization of OPN mRNA and protein, ED1 as a macrophage marker, proliferating cellular nuclear antigen (PCNA), CD44 as an OPN receptor, megalin as a proximal tubule marker, and their relationships to each other were examined from the early tubular necrotic period to the late recovery period by Northern blotting, in situ hybridization, and double immunohistochemical staining.
Results. In the gentamicin group, OPN mRNA and protein were expressed in only the PCNA-positive proliferating cortical distal tubules, not in the necrotic proximal tubules, until day 6 after the first administration, but were found markedly in PCNA-positive regenerative proximal and distal tubules on days 10, 15, and 30. The localization of PCNA-positive cells was almost always accompanied with the up-regulated expression of OPN using quantitative analysis (P &lt; 0.01). CD44 expression was markedly up-regulated in the renal cortical tubular epithelium from days 6 to 30. In the control group, no expression of OPN and CD44 in the cortical area was found throughout the experimental period.
Conclusions. These results suggested that OPN is related to the proliferation and regeneration of tubular epithelial cells after tubular damage.

DOI： 10.1046/j.1523-1755.2001.059003959.x

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The objective of this study was to investigate the role of osteopontin (OPN) secreted by cementocytes in root resorption. The localization of OPN immunoreaction and mRNA in cellular cementum of rat molars during physiological distal drift were investigated. Furthermore, tartaric acid-resistant acid phosphatase activity was detected as a marker of odontoclasts and its precursor cells. At the distal side of the buccal roots of maxillary molars, many of cementocytes in cellular cementum facing actively resorbed alveolar bone were positive for OPN immunoreaction and OPN mRNA. Immunoreaction for OPN was also demonstrated at the cementocyte lacunae and canaliculi. Odontoclast precursors appeared on the cementum surface where OPN-positive cementocytes were localized. Odontoclasts were found in the vicinity of OPN-positive cementocytes. At the mesial side where no resorption was observed, OPN immunoreaction and mRNA were observed in few of cementocytes. Ultrastructural findings revealed that cell processes of cementocytes were in close contact with odontoclasts which were resorbing cementum. These results suggest that OPN secreted by cementocytes plays an important role in the induction of odontoclasts to the cementum surface.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER-VERLAG TOKYO  

Bone marrow stromal cells have been considered to play an important role in osteoclast differentiation. However, the interaction of these cells in vivo has not been clearly demonstrated. To clarify this, we examined the distribution of alkaline phosphatase (ALPase) and tartrate-resistant acid phosphatase (TRAPase) activities as markers of osteoblastic and osteoclastic cells, respectively. Rat tibiae were fixed and embedded in Technovit 8100 or paraffin. ALPase and TRAPase activities were detected simultaneously on a plastic section by the azo-dye method. ALPase activity was detected on the plasma membranes of osteoblasts and some bone marrow fibroblastic stromal cells. These ALPase-positive cells were connected to each other by cytoplasmic processes, forming a cellular network in bone marrow. The ALPase activity of fibroblastic stromal cells tended to be stronger in those cells close to the bone surface than in the cells in the center of bone marrow. Reticular fibers in bone marrow were found to form a network. The ALPase-positive fibroblastic stromal cells may be reticular cells, because the localization of those cells was in accord with the localization of reticular fibers. The TRAPase-positive mononuclear cells and osteoclasts were mostly observed to be associated with the intensely ALPase-positive fibroblastic stromal cells. Immunoreactivity of osteoclast differentiation factor (ODF) was found in the fibroblastic stromal cells. These findings suggest that the network of ALPase-positive fibroblastic stromal cells in bone marrow serves as a guide for the migration of osteoclast precursor cells toward the bone surface, and may control the differentiation and activity of osteoclasts.

DOI： 10.1007/s007740170004

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Mechanical stress is one of the most potent inducer of bone formation. The mechanism by which cells receive and transduce the signal into osteogenesis, however, remains unknown. Previous studies have demonstrated that mechanical stress causes changes in expression levels of many genes in osteoblasts and osteocytes both in vivo and in vitro. However, none of these changes are specific to bone cells. Moreover it is not clear which types of cells contributed to the increased osteoblasts induced by mechanical stress. The purpose of this study, therefore, was to identify which cells differentiate into osteoblasts and to examine how the expression of genes that are specific to osteogenic cells changes.

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Pseudomonas aeruginosa (P. aeruginosa) is associated with periapical periodontitis. The lesions are characterized by a disorder in osteoblast metabolism. Quorum sensing molecular N-(3-oxododecanoyl)-homoserine lactone (AHL) is secreted by P. aeruginosa and governs the expression of numerous virulence factors. AHL can trigger intracellular calcium ([Ca2+]i) fluctuations in many host cells. However, it is unclear whether AHL can regulate osteoblast metabolism by affecting [Ca2+]i changes or its spatial correlation. We explored AHL-induced apoptosis and differentiation in pre-osteoblastic MC3T3-E1 cells and evaluated [Ca2+]i mobilization using several extraction methods. The spatial distribution pattern of [Ca2+]i among cells was investigated by Moran's I, an index of spatial autocorrelation. We found that 30 μM and 50 μM AHL triggered opposing osteoblast fates. At 50 μM, AHL inhibited osteoblast differentiation by promoting mitochondrial-dependent apoptosis and negatively regulating osteogenic marker genes, including Runx2, Osterix, bone sialoprotein (Bsp), and osteocalcin (OCN). In contrast, prolonged treatment with 30 μM AHL promoted osteoblast differentiation concomitantly with cell apoptosis. The elevation of [Ca2+]i levels in osteoblasts treated with 50 μM AHL was spatially autocorrelated, while no such phenomenon was observed in 30 μM AHL-treated osteoblasts. The blocking of cell-to-cell spatial autocorrelation in the osteoblasts provoked by 50 μM AHL significantly inhibited apoptosis and partially restored differentiation. Our observations suggest that AHL affects the fate of osteoblasts (apoptosis and differentiation) by affecting the spatial correlation of [Ca2+]i changes. Thus, AHL acts as a double-edged sword for osteoblast function.

DOI： 10.1016/j.cellsig.2020.109740

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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OBJECTIVE: Low-intensity pulsed ultrasound (LIPUS) provides noninvasive therapeutic treatment to accelerate fracture repair and distraction osteogenesis. However, most studies concerning the influence of LIPUS on bone metabolism have been conducted in vivo systems using osteoblastic cells. Therefore, details of the direct effect of LIPUS on osteoclasts are not yet fully understood. Teleost scale is a calcified tissue that contains osteoclasts and osteoblasts. Its bone matrix consists of type I collagen and hydroxyapatite, and is similar to that of mammalian bone. Therefore, we examined the effect of LIPUS on the osteoclasts and osteoblasts of zebrafish and goldfish scales, as a model of the bone matrix simplified to its bare bones. METHODS: Ultrasound was generated with the Sonic Accelerated Fracture Healing System (SAFHS 4000J; Teijin Pharma, Ltd). Scales were collected from zebrafish under anesthesia; they were then treated with LIPUS for 20 minutes, incubated at 15°C for 3, 6, and 18 hours in L-15 medium, and subjected to measurement of the mRNA expression. Following the osteoclast induction by the autotransplantation of goldfish scales, we further examined the number of apoptotic osteoclasts after LIPUS treatment. RESULTS AND DISCUSSION: At 3 hours of incubation after LIPUS treatment, osteoclastic marker expression decreased while osteoblastic markers increased. Using GeneChip analysis of zebrafish scales treated by LIPUS, we found that cell death-related genes were up-regulated by LIPUS treatment. TUNEL staining showed that the number of apoptotic osteoclasts in goldfish scales was elevated by treatment with LIPUS at 3 hours of incubation. Thus, we conclude that LIPUS promotes apoptosis in osteoclasts shortly after exposure.

DOI： 10.1097/01.bot.0000489982.40329.52

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DOI： 10.11223/jard.13.2

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DOI： 10.11223/jard.12.11

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DOI： 10.5983/nl2008jsce.37.194

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Language：English   Publishing type：Book review, literature introduction, etc.   Publisher：SPRINGER JAPAN KK  

Estrogen deficiency-induced postmenopausal osteoporosis has become a worldwide problem, inducing low bone mass and microarchitectural deterioration of the bone scaffolding in the vertebrae and long bones. With the prevalence of such osteoporosis on the increase, the influence of this estrogen deficiency on the jaw bones has drawn the attention of researchers and clinicians in the field of dentistry. The aim of this article is therefore to review the microstructural changes occurring after ovariectomy in the jaw bones of animal subjects. Induced estrogen deficiency clearly led to structural changes in the jaw bones and alveolar bone of animal subjects (rats and monkeys). Severe bone loss in the rat alveolar bone was principally caused by high bone resorptive activity. This activity accelerated greatly immediately after ovariectomy, and was then followed by more moderate resorptive activity, which continued over an extended period. Additionally, occlusal hypofunction further greatly accelerated the fragility of the alveolar bone structure in ovariectomized rats. Microstructural damage also seen in the alveolar bone of ovariectomized monkeys was found to be directly connected to their systemic osteoporosis. Recent investigations of the relationship in humans between systemic osteoporosis and jaw bone loss have also suggested that a connection may exist between these two. However, more research is required to confirm this connection in humans as well.

DOI： 10.1007/s00774-008-0870-4

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Language：Japanese  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：ZOOLOGICAL SOC JAPAN  

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Language：Japanese   Publisher：医歯薬出版(株)  

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Language：Japanese   Publisher：(一社)日本顎関節学会  

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Language：Japanese   Publisher：(一社)日本解剖学会  

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Language：Japanese   Publisher：(株)メディカルレビュー社  

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Language：Japanese   Publisher：新潟歯学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：(一社)日本骨代謝学会  

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Language：Japanese   Publisher：(公社)日本歯科医師会  

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Language：Japanese   Publisher：日本骨形態計測学会  

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Language：Japanese   Publisher：(一社)日本解剖学会  

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Language：Japanese   Publisher：新潟歯学会  

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J-GLOBAL

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER SOC BONE & MINERAL RES  

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Language：Japanese   Publisher：日本骨形態計測学会  

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Language：Japanese   Publisher：(一社)日本骨代謝学会  

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Language：Japanese   Publisher：(一社)日本骨代謝学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：ELSEVIER SCIENCE INC  

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Authorship：Lead author   Language：English   Publisher：AMER SOC BONE & MINERAL RES  

Mechanical stress is an important factor controlling bone remodeling, which maintains proper bone morphology and functions. However, the mechanism by which mechanical stress is transduced into biological stimuli remains unclear. Therefore, the purpose of this study is to examine how gene expression changes with osteoblast differentiation and which cells differentiate into osteoblasts, Tensile stress was applied to the cranial suture of neonatal mouse calvaria In a culture by means of helical springs. The suture was extended gradually, displaying a marked increase in cell number including osteoblasts, A histochemical study showed that this osteoblast differentiation began in the neighborhood of the existing osteoblasts, which can be seen by 3 h, The site of osteoblast differentiation moved with time toward the center of the suture, which resulted in an extension of osteoid, Scattered areas of the extended osteoid were calcified by 48 h, Reverse-transcription polymerase chain reaction (RT-PCR) revealed that tensile stress increased bone morphogenetic protein 4 (BMP-4) gene expression by 6 h and it remained elevated thereafter, This was caused by the induction of the gene in preosteoblastic cells in the neighborhood of osteoblasts and adjacent spindle-shaped fibroblastic cells. These changes were evident as early as 3 h and continued moving toward the center of the suture, The expression of Cbfa1/Osf-2, an osteoblast-specific transcription factor, followed that of BMP-4 and those cells positive with these genes appeared to differentiate into osteoblasts, These results suggest that BMP-4 may play a pivotal role by acting as an autocrine and a paracrine factor for recruiting osteoblasts in tensile stress-induced osteogenesis.

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Language：Japanese   Publisher：新潟歯学会  

J-GLOBAL

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)日本骨代謝学会  

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Language：English   Publisher：(一社)日本解剖学会  

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DOI： 10.11477/mf.2425902496

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER SOC BONE & MINERAL RES  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER SOC BONE & MINERAL RES  

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Language：Japanese   Publisher：歯科基礎医学会  

CiNii Article

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Language：Japanese   Publisher：歯科基礎医学会  

CiNii Article

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Language：Japanese  

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Language：Japanese   Publisher：(一社)日本骨代謝学会  

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Language：English   Publisher：Elsevier Ltd  

DOI： 10.1016/S0959-8049(97)10131-9

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PubMed

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Language：English   Publisher：Elsevier Ltd  

DOI： 10.1016/S0959-8049(97)10131-9

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PubMed

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Language：English   Publisher：Elsevier Ltd  

DOI： 10.1016/S0959-8049(97)10131-9

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PubMed

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：BLACKWELL SCIENCE INC  

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Language：Japanese  

CiNii Article

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Authorship：Lead author   Language：English   Publisher：BLACKWELL SCIENCE INC  

Continuous treatment with calcitonin (CT) to inhibit osteoclastic bone resorption results in acquired resistance, The mechanisms of this ''escape'' phenomenon are not yet established. The aim of this study was to examine the effects of continuous treatment with CT on the generation of osteoclasts and calcitonin receptor (CTR) expression in mouse bone marrow cultures, This was done by daily CT treatment of mouse bone marrow cultures from day 0, when only undifferentiated mononuclear precursors of osteoclast-like cells were present, or commencing from day 6, when differentiated osteoclast-like cells were abundant, The response to CT treatment was determined by quantitation of cells positive for tartrate-resistant acid phosphatase (TRAP) and binding of I-125-salmon CT, Calcitonin receptor and TRAP mRNA levels were determined using semi-quantitative reverse transcription/polymerase chain reaction, When cultures were treated with CT from day 0, TRAP-positive multinucleated cells appeared, These cells expressed only very low levels of CTR or CTR mRNA and were morphologically indistinguishable from osteoclast-like cells formed in control cultures, They also displayed the ability to resorb bone, Continuous CT treatment of cultures from day 6 rapidly reduced the CTR mRNA levels, with a t(1/2) of 6 to 12 h, and these levels remained low thereafter, I-125-salmon CT binding capacity, as determined by autoradiography, was lost in parallel, These effects were specific for the CTR since there was no consistent effect on TRAP mRNA levels, Based on these data, we suggest that the ''escape'' phenomenon mag result from a prolonged CT-induced loss of CT responsiveness due, at least in part, both to reduced synthesis of CTR, and to the appearance in bone of CTR-deficient osteoclasts.

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Authorship：Lead author   Language：English   Publisher：BLACKWELL SCIENCE INC  

The binding sites and chronologic localization of elcatonin (eCT) in osteoclasts were examined by autoradiography using [I-125]elcatonin (I-125-eCT). In addition to the structural changes induced by calcitonin (CT) reported so far, changes were also observed in the structure of Golgi apparatus. These changes continued until 48-72 h after incubation with eCT. Developed silver grains of I-125-eCT were localized into multinucleated osteoclasts and mononuclear cells that were ultrastructurally defined as ''preosteoclasts.'' The silver grains located on plasma membranes of those cells and were then internalized; they accumulated, especially in the Golgi apparatus, and remained for 48-72 h. A few silver grains were also detected in lysosomes and small vesicles. The decrease in the number of silver grains in the Golgi apparatus accompanied the recovery of osteoclast structures-Golgi apparatus and then ruffled borders. These findings suggest that (1) CT especially inhibits the sorting function of Golgi apparatus in osteoclasts, resulting in prolonged retention of CT in this organelle. (2) The CT in Golgi apparatus may keep its activity and cause the prolonged effect of CT on osteoclast activity.

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Language：English   Publisher：SPRINGER VERLAG  

Bone labeling, histochemical, and fine structural studies were performed in order to clarify the effects of ipriflavone (IP) on rat bone tissue in vivo and in vitro. Labeling experiments showed a slight increase in bone formation during 3 days' administration. It was also noted that many osteoclasts detached from the bone surface at 1, 2, and 6 hours after administration in vivo. In addition, irregular localization of tartrate-resistant acid phosphatase (TRACPase) activity was observed in osteoclasts. Fine structurally, IP-treated osteoclasts exhibited irregularity in their ruffled borders, as reported in calcitonin administration, and many enlarged rough endoplasmic reticuli and vacuoles were observed. However, osteoclasts at 12 hours after administration, as well as the control, indicated recovery features from the effect of IP. Osteoblast proliferation and differentiation led to increasing alkaline phosphatase activity (ALPase) with time as well as the development of rough endoplasmic reticuli and Golgi apparatus with well-developed fine structure. These findings imply active synthesis of bone matrix. In our in vitro experiment, osteoclasts and osteoblasts displayed histochemical and fine structural characteristics similar to those observed in our in vivo experiment. Moreover, fewer TRACP-positive mononuclear cells were observed after 24-hour culture with IP than with the control. These results suggest that IP inhibits directly and/or indirectly differentiation and activity of osteoclasts and also promotes differentiation of osteoblast-lineage cells and their bone-forming activity.

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Event date： 2023.11.17 - 2023.11.18

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2023.10.21 - 2023.10.22

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Event date： 2023.10.14 - 2023.10.15

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Event date： 2023.9.23 - 2023.9.24

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Event date： 2023.9.16 - 2023.9.18

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Event date： 2023.3.28 - 2023.3.31

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Event date： 2023.3.18 - 2023.3.20

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Event date： 2022.11.26 - 2022.11.27

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Event date： 2022.10.28 - 2022.10.30

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.9.16 - 2022.9.18

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Event date： 2022.7.22 - 2022.7.23

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Event date： 2022.7.8 - 2022.7.9

Language：English   Presentation type：Poster presentation  

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Event date： 2022.7.8 - 2022.7.9

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Event date： 2022.6.30 - 2022.7.2

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2021.10.9 - 2021.10.11

Presentation type：Oral presentation (general)  

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Event date： 2021.3.26 - 2021.3.27

Language：English   Presentation type：Oral presentation (general)  

Venue：長良川 岐阜  

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Event date： 2020.9.4 - 2020.9.5

Language：Japanese   Presentation type：Poster presentation  

Venue：オンライン開催  

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Event date： 2020.3.25 - 2020.3.27

Language：English  

Venue：山口（誌面開催）  

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Event date： 2020.3.25 - 2020.3.27

Language：Japanese  

Venue：山口（誌面開催）  

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Event date： 2019.12.7 - 2019.12.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢  

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Event date： 2019.12.7 - 2019.12.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢  

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Event date： 2019.11.21 - 2019.11.22

Language：English   Presentation type：Poster presentation  

Venue：岡山  

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Event date： 2019.10.26 - 2019.10.27

Language：English   Presentation type：Oral presentation (general)  

Venue：島根  

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Event date： 2019.10.26 - 2019.10.27

Language：English   Presentation type：Oral presentation (general)  

Venue：島根  

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Event date： 2019.10.26 - 2019.10.27

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：島根  

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Event date： 2019.10.12 - 2019.10.14

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2019.10.12 - 2019.10.14

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2019.10.12 - 2019.10.14

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2019.9.21 - 2019.9.22

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉  

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Event date： 2019.7.19 - 2019.7.20

Language：English   Presentation type：Oral presentation (general)  

Venue：淡路  

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Event date： 2019.7.19 - 2019.7.20

Language：English   Presentation type：Poster presentation  

Venue：淡路  

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Event date： 2019.7.19 - 2019.7.20

Language：English   Presentation type：Poster presentation  

Venue：淡路  

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Event date： 2019.3.27 - 2019.3.29

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Event date： 2019.3.27 - 2019.3.29

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Event date： 2019.3.27 - 2019.3.29

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Event date： 2018.11.24 - 2018.11.25

Language：English   Presentation type：Oral presentation (general)  

Venue：徳島  

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Event date： 2018.11.24 - 2018.11.25

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島  

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Event date： 2018.10.20 - 2018.10.21

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島  

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Event date： 2018.10.20 - 2018.10.21

Language：English   Presentation type：Oral presentation (general)  

Venue：徳島  

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Event date： 2018.10.20 - 2018.10.21

Language：English   Presentation type：Oral presentation (general)  

Venue：徳島  

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Event date： 2018.10.20 - 2018.10.21

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島  

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Event date： 2018.9.29 - 2018.9.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎  

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Event date： 2018.9.24 - 2018.9.26

Language：English   Presentation type：Oral presentation (general)  

Venue：京都  

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Event date： 2018.9.5 - 2018.9.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

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Event date： 2018.9.5 - 2018.9.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

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Event date： 2018.3.28 - 2018.3.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2018.3.28 - 2018.3.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2017.12.9 - 2017.12.10

Language：Japanese   Presentation type：Poster presentation  

Venue：岐阜  

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Event date： 2017.12.2 - 2017.12.3

Presentation type：Oral presentation (general)  

Venue：高知  

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Event date： 2017.10.28 - 2017.10.29

Presentation type：Oral presentation (general)  

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Event date： 2017.10.28 - 2017.10.29

Presentation type：Oral presentation (general)  

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Event date： 2017.10.13 - 2017.10.14

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山国際交流センター、岡山  

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Event date： 2017.10.9 - 2017.10.13

Language：English   Presentation type：Poster presentation  

Venue：Tsukuba, Japan  

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Event date： 2017.9.16 - 2017.9.18

Language：Japanese   Presentation type：Poster presentation  

Venue：松本市，長野  

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Event date： 2017.9.16 - 2017.9.18

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：松本市，長野  

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Event date： 2017.9.16 - 2017.9.18

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：松本市，長野  

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Event date： 2017.8.26

Presentation type：Symposium, workshop panel (nominated)  

Venue：岡山  

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Event date： 2017.7.21 - 2017.7.22

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎県・宮崎市  

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Event date： 2017.6.3 - 2017.6.4

Presentation type：Oral presentation (general)  

Venue：福井県勝山市  

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Event date： 2016.11.14 - 2016.11.19

Language：English   Presentation type：Poster presentation  

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Event date： 2016.11.14 - 2016.11.19

Language：English   Presentation type：Poster presentation  

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Event date： 2016.10.22 - 2016.10.23

Presentation type：Oral presentation (general)  

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Event date： 2016.7.20 - 2016.7.23

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2016.7.20 - 2016.7.23

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2016.6.23 - 2016.6.25

Language：English   Presentation type：Symposium, workshop panel (nominated)  

Venue：新潟  

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Event date： 2016.3.28 - 2016.3.30

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2016.1.23

Presentation type：Oral presentation (general)  

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Event date： 2015.12.11 - 2015.12.13

Language：English   Presentation type：Oral presentation (general)  

Venue：広島  

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Event date： 2015.12.6

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2015.9.16 - 2015.9.19

Language：English   Presentation type：Poster presentation  

Venue：Spain  

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Event date： 2015.9.11 - 2015.9.13

Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Event date： 2015.9.11 - 2015.9.13

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Event date： 2015.9.11 - 2015.9.13

Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Event date： 2015.9.11 - 2015.9.13

Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Event date： 2015.4.27 - 2015.4.29

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo  

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Event date： 2015.3.21 - 2015.3.23

Language：English   Presentation type：Symposium, workshop panel (nominated)  

Venue：Hyogo, Kobe  

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Event date： 2015.3.21 - 2015.3.23

Language：English   Presentation type：Poster presentation  

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Event date： 2015.1.24 - 2015.1.25

Language：Japanese  

Venue：宇宙航空研究開発機構 相模原キャンパス  

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Event date： 2015.1.6 - 2015.1.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙航空研究開発機構宇宙科学研究所 相模原キャンパス  

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Event date： 2014.9.25 - 2014.9.27

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2014.9.23 - 2014.9.24

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2014.9.11 - 2014.9.13

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2014.6.6 - 2014.6.8

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2014.5.20 - 2014.5.23

Language：English   Presentation type：Symposium, workshop panel (nominated)  

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Event date： 2014.5.20 - 2014.5.23

Language：English   Presentation type：Poster presentation  

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Event date： 2014.3.8 - 2014.3.9

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2014.1.25

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2013.11.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：帝京大学板橋キャンパス  

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Event date： 2013.10.24 - 2014.10.26

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎市民プラザ、宮崎  

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Event date： 2013.10.24 - 2014.10.26

Language：Japanese   Presentation type：Poster presentation  

Venue：宮崎市民プラザ、宮崎  

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Event date： 2013.10.22 - 2013.10.23

Language：English   Presentation type：Oral presentation (general)  

Venue：Taipei, Taiwan  

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Event date： 2013.9.26 - 2013.9.28

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山  

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Event date： 2013.9.26 - 2013.9.28

Language：Japanese   Presentation type：Poster presentation  

Venue：岡山  

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Event date： 2013.9.20 - 2013.9.22

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山  

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Event date： 2013.8.19

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：能登、石川  

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Event date： 2013.6.28 - 2013.6.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：パシフィコ横浜会議センター  

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Event date： 2013.5.28 - 2013.6.1

Language：English   Presentation type：Poster presentation  

Venue：Kobe, Japan  

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Event date： 2013.3.28 - 2013.3.30

Language：Japanese   Presentation type：Poster presentation  

Venue：高松 香川  

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Event date： 2012.11.17 - 2012.11.18

Language：Japanese   Presentation type：Poster presentation  

Venue：松本  

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Event date： 2012.11.17 - 2012.11.18

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：松本  

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Event date： 2012.6.22 - 2012.6.24

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Venue：横浜  

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Event date： 2012.3.26 - 2012.3.28

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山梨  

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Event date： 2012.1.23 - 2012.1.24

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：東京  

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Event date： 2012.1.21

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2011.9.30 - 2011.10.2

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Venue：岐阜  

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Event date： 2011.9.13

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学  

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Event date： 2011.9.4

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：鶴見大学会館、神奈川  

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Event date： 2011.7.30 - 2011.7.31

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福井  

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Event date： 2011.7.28 - 2011.7.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪  

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Event date： 2011.5.20 - 2011.5.21

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜  

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Event date： 2011.3.28 - 2011.3.30

Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

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Event date： 2011.1.24 - 2011.1.25

Presentation type：Oral presentation (general)  

Venue：神奈川  

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Event date： 2010.9.20 - 2010.9.23

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2010.7.21 - 2010.7.23

Language：Japanese   Presentation type：Poster presentation  

Venue：東京  

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Event date： 2010.3.28 - 2010.3.30

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手  

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Event date： 2009.3.28 - 2009.3.30

Language：Japanese   Presentation type：Poster presentation  

Venue：岡山  

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Event date： 2009.3.28 - 2009.3.30

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Venue：岡山  

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Event date： 2009.3.21 - 2009.3.25

Language：English   Presentation type：Poster presentation  

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Event date： 2009.1.14 - 2009.1.15

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：神奈川  

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Event date： 2008.10.29 - 2008.10.31

Presentation type：Poster presentation  

Venue：大阪  

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Event date： 2008.10.29 - 2008.10.31

Presentation type：Poster presentation  

Venue：大阪  

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Event date： 2008.9.26 - 2008.9.27

Presentation type：Oral presentation (general)  

Venue：奈良  

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Event date： 2008.9.5 - 2008.9.7

Presentation type：Oral presentation (general)  

Venue：福岡  

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Event date： 2008.6.30 - 2008.7.2

Presentation type：Oral presentation (general)  

Venue：札幌  

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Event date： 2008.1.17 - 2008.1.18

Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2007.9

Presentation type：Oral presentation (general)  

Venue：弘前  

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Event date： 2007.3.9

Venue：東京  

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Event date： 2007.1.15 - 2007.1.17

Presentation type：Oral presentation (general)  

Venue：東京  

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Event date： 2006.9.22 - 2006.9.23

Venue：神奈川県 鶴見  

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Event date： 2006.7.27 - 2006.7.29

Venue：新潟  

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Event date： 2005.12.10

Venue：東京  

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Event date： 2005.10.6 - 2005.10.8

Venue：茨城県つくば市