2021/05/06 更新

写真a

イシダ ヨウコ
石田 陽子
ISHIDA Yoko
所属
教育研究院 医歯学系 特任講師
医歯学総合研究科 特任講師
職名
特任講師
通称等の別名
Ishida-Okumura Yoko
外部リンク

学位

  • 博士(歯学) ( 2004年3月   新潟大学 )

研究分野

  • ライフサイエンス / 常態系口腔科学

経歴(researchmap)

  • 新潟大学   医歯学総合研究科   特任助教

    2011年6月 - 現在

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  • 医療法人社団 羽尾歯科医院   歯科医師

    2010年6月 - 2011年5月

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  • 医療法人フルーツ アップル歯科クリニック   歯科医師

    2007年5月 - 2010年5月

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  • 新潟大学   歯学部 歯学科   助教

    2004年4月 - 2006年9月

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経歴

  • 新潟大学   医歯学総合研究科   特任講師

    2019年4月 - 現在

  • 新潟大学   医歯学総合研究科   特任助教

    2011年6月 - 2019年3月

  • 新潟大学   歯学部 歯学科   助教

    2004年4月 - 2006年9月

学歴

  • 新潟大学   Graduate School, Division of Dental Research  

    - 2004年3月

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    国名: 日本国

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  • 新潟大学   歯学部   歯学科

    - 2000年3月

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    国名: 日本国

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論文

  • Perceptions of dental students in Japanese national universities about studying abroad 査読

    H. Oka, Y. Ishida, G. Hong, P. T.T. Nguyen

    European Journal of Dental Education22 ( 1 ) e1 - e6   2018年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Blackwell Publishing Ltd  

    Purpose: Dental faculties in Japan have organised many short-term international exchange programs to enable their undergraduates to study abroad. However, not many students apply for those programs. In this present study, we attempted to clarify the factors that discourage undergraduate dental students from studying abroad. Methods: We administered a questionnaire survey to 512 undergraduate dental students in three national universities located in different areas in Japan. Results: Although 61.7% of the participants expressed interest in studying abroad, only 19.1% of them had prior experiences of study abroad or plans to do so. Their main worries were about lack of sufficient language ability in academic fields. Comparing those who were interested in studying abroad with those who were not revealed significant differences regarding their concern about lack of language ability and lack of specialised knowledge in dentistry. Participants who did not want to study abroad indicated that they did not perceive a purpose in doing so and cited not having foreign friends as a problem. Household income was significantly correlated with concerns about overall expenses. Conclusion: Overall, language ability and academic knowledge appeared to be the two strongest factors affecting dental students’ consideration of studying abroad. Dental schools in Japan can use the findings of this study to improve their undergraduate exchange programs in such a way as to stimulate greater interest amongst their students.

    DOI: 10.1111/eje.12212

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  • Molecular phenotype of tissue-nonspecific alkaline phosphatase with a proline (108) to leucine substitution associated with dominant odontohypophosphatasia 査読

    Natsuko Numa-Kinjoh, Keiichi Komaru, Yoko Ishida, Miwa Sohda, Kimimitsu Oda

    MOLECULAR GENETICS AND METABOLISM115 ( 4 ) 180 - 185   2015年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Hypophosphatasia (HPP) is a genetic disease characterized by defective calcification of hard tissues such as bone and teeth accompanying deficiency of serum alkaline phosphatase (ALP) activity. Its development results from various mutations in the ALPL gene encoding tissue-nonspecific ALP (TNSALP). HPP is known to be transmitted in an autosomal recessive or autosomal dominant manner. A point mutation (c.323C>T) in the ALPL gene leading to a proline to leucine substitution at position 108 of TNSALP was first reported in a patient diagnosed with odonto-HPP (M Herasse et al., J Med Genet 2003;40:605-609), although the effects of this mutation on the TNSALP molecule have not been elucidated. To understand the molecular basis of this dominantly transmitted HPP, we first characterized TNSALP (P108L) by expressing it in COS-1 cells transiently. In contrast to wild-type TNSALP (WT), TNSALP (P108L) showed virtually no ALP activity. When coexpressed with TNSALP (WT), TNSALP (P108L) significantly inhibited the enzyme activity of TNSALP (WT), confirming that this mutant TNSALP exerts a dominant negative effect on TNSALP (WT). Using immunofluorescence and digestion with phosphatidylinositol-specific phospholipase C, we demonstrated that TNSALP (P108L) was anchored to the cell surface via glycosylphosphatidylinositol-like TNSALP (WT) in a Tet-On CHO cell expression system. Consistent with this, TNSALP (P108L) acquired endo-beta-N-acetylglucosaminidase H resistance and sialic acids, as evidenced by glycosidase treatments. Importantly, TNSALP (WT) largely formed a functional dimeric structure, while TNSALP (P108L) was found to be present as a monomer in the cell. This indicates that the molecular structure of TNSALP is affected by a missense mutation at position 108, which is in contact with the active site, such that it no longer assembles into the functional dimeric form. Collectively, these results may explain why TNSALP (P108L) loses its ALP activity, even though it is able to gain access to the cell surface. (C) 2015 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.ymgme.2015.05.006

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  • Molecular characterization of tissue-nonspecific alkaline phosphatase with an Ala to Thr substitution at position 116 associated with dominantly inherited hypophosphatasia. 査読

    Ishida Y, Komaru K, Oda K

    Biochimica et biophysica acta1812 ( 3 ) 326 - 32   2011年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.bbadis.2010.12.002

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  • Molecular basis of perinatal hypophosphatasia with tissue-nonspecific alkaline phosphatase bearing a conservative replacement of valine by alanine at position 406 査読

    Natsuko Numa, Yoko Ishida, Makiko Nasu, Miwa Sohda, Yoshio Misumi, Tadashi Noda, Kimimitsu Oda

    FEBS JOURNAL275 ( 11 ) 2727 - 2737   2008年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    Hypophosphatasia, a congenital metabolic disease related to the tissue-nonspecific alkaline phosphatase gene (TNSALP), is characterized by reduced serum alkaline phosphatase levels and defective mineralization of hard tissues. A replacement of valine with alanine at position 406, located in the crown domain of TNSALP, was reported in a perinatal form of hypophosphatasia. To understand the molecular defect of the TNSALP (V406A) molecule, we examined this missense mutant protein in transiently transfected COS-1 cells and in stable CHO-K1 Tet-On cells. Compared with the wild-type enzyme, the mutant protein showed a markedly reduced alkaline phosphatase activity. This was not the result of defective transport and resultant degradation of TNSALP (V406A) in the endoplasmic reticulum, as the majority of newly synthesized TNSALP (V406A) was conveyed to the Golgi apparatus and incorporated into a cold detergent insoluble fraction (raft) at a rate similar to that of the wild-type TNSALP. TNSALP (V406A) consisted of a dimer, as judged by sucrose gradient centrifugation, suggestive of its proper folding and correct assembly, although this mutant showed increased susceptibility to digestion by trypsin or proteinase K. When purified as a glycosylphosphatidylinositol-anchorless soluble form, the mutant protein exhibited a remarkably lower K(cat)/K(m) value compared with that of the wild-type TNSALP. Interestingly, leucine and isoleucine, but not phenylalanine, were able to substitute for valine, pointing to the indispensable role of residues with a longer aliphatic side chain at position 406 of TNSALP. Taken together, this particular mutation highlights the structural importance of the crown domain with respect to the catalytic function of TNSALP.

    DOI: 10.1111/j.1742-4658.2008.06414.x

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  • Aberrant interchain disulfide bridge of tissue-nonspecific alkaline phosphatase with an Arg433 -> Cys substitution associated with severe hypophosphatasia 査読

    Makiko Nasu, Masahiro Ito, Yoko Ishida, Natsuko Numa, Keiichi Komaru, Shuichi Nomura, Kimimitsu Oda

    FEBS JOURNAL273 ( 24 ) 5612 - 5624   2006年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BLACKWELL PUBLISHING  

    Various mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene are responsible for hypophosphatasia characterized by defective bone and tooth mineralization; however, the underlying molecular mechanisms remain largely to be elucidated. Substitution of an arginine at position 433 with a histidine [TNSALP(R433H)] or a cysteine [TNSALP(R433C)] was reported in patients diagnosed with the mild or severe form of hypophosphatasia, respectively. To define the molecular phenotype of the two TNSALP mutants, we sought to examine them in transient (COS-1) and conditional (CHO-K1 Tet-On) heterologous expression systems. In contrast to an 80 kDa mature form of the wild-type and TNSALP(R433H), a unique disulfide-bonded 160 kDa molecular species appeared on the cell surface of the cells expressing TNSALP(R433C). Sucrose density gradient centrifugation demonstrated that TNSALP(R433C) forms a disulfide-bonded dimer, instead of being noncovalently assembled like the wild-type. Of the five cysteine residues per subunit of the wild-type, only Cys102 is thought to be present in a free form. Replacement of Cys102 with serine did not affect the dimerization state of TNSALP(R433C), implying that TNSALP(R433C) forms a disulfide bridge between the cysteine residues at position 433 on each subunit. Although the cross-linking did not significantly interfere with the intracellular transport and cell surface expression of TNSALP(R433C), it strongly inhibited its alkaline phosphatase activity. This is in contrast to TNSALP(R433H), which shows enzyme activity comparable to that of the wild-type. Importantly, addition of dithiothreitol to the culture medium was found to partially reduce the amount of the cross-linked form in the cells expressing TNSALP(R433C), concomitantly with a significant increase in enzyme activity, suggesting that the cross-link between two subunits distorts the overall structure of the enzyme such that it no longer efficiently carries out its catalytic function. Increased susceptibility to proteases confirmed a gross conformational change of TNSALP(R433C) compared with the wild-type. Thus, loss of function resulting from the interchain disulfide bridge is the molecular basis for the lethal hypophosphatasia associated with TNSALP(R433C).

    DOI: 10.1111/j.1742-4658.2006.05550.x

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  • Novel aggregate formation of a frame-shift mutant protein of tissue-nonspecific alkaline phosphatase is ascribed to three cysteine residues in the C-terminal extension - Retarded secretion and proteasomal degradation 査読

    K Komaru, Y Ishida, Y Amaya, M Goseki-Sone, H Orimo, K Oda

    FEBS JOURNAL272 ( 7 ) 1704 - 1717   2005年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BLACKWELL PUBLISHING LTD  

    In the majority of hypophosphatasia patients, reductions in the serum levels of alkaline phosphatase activity are caused by various missense mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene. A unique frame-shift mutation due to a deletion of T at cDNA number 1559 [TNSALP (1559delT)] has been reported only in Japanese patients with high allele frequency. In this study, we examined the molecular phenotype of TNSALP (1559delT) using in vitro translation/translocation system and COS-1 cells transiently expressing this mutant protein. We showed that the mutant protein not only has a larger molecular size than the wild type enzyme by approximate to 12 kDa, reflecting an 80 amino acid-long extension at its C-terminus, but that it also lacks a glycosylphosphatidylinositol anchor. In support of this, alkaline phosphatase activity of the cells expressing TNSALP (1559delT) was localized at the juxtanucleus position, but not on the cell surface. However, only a limited amount of the newly synthesized protein was released into the medium and the rest was polyubiquitinated, followed by degradation in the proteasome. SDS/PAGE and analysis by sucrose-density-gradient analysis indicated that TNSALP (1559delT) forms a disulfide-bonded high-molecular-mass aggregate. Interestingly, the aggregate form of TNSALP (1559delT) exhibited a significant enzyme activity. When all three cysteines at positions of 506, 521 and 577 of TNSALP (1559delT) were replaced with serines, the aggregation disappeared and instead this modified mutant protein formed a noncovalently associated dimer, strongly indicating that these cysteine residues in the C-terminal region are solely responsible for aggregate formation by cross-linking the catalytically active dimers. Thus, complete absence of TNSALP on cell surfaces provides a plausible explanation for a severe lethal phenotype of a homozygote hypophosphatasia patient carrying TNSALP (1559delT).

    DOI: 10.1111/j.1742-4658.2005.04597.x

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  • Tissue-nonspecific alkaline phosphatase with an Asp(289)-> Val mutation fails to reach the cell surface and undergoes proteasome-mediated degradation 査読

    Y Ishida, K Komaru, M Ito, Y Amaya, S Kohno, K Oda

    JOURNAL OF BIOCHEMISTRY134 ( 1 ) 63 - 70   2003年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPANESE BIOCHEMICAL SOC  

    A missense mutation in the gene of tissue-nonspecific alkaline phosphatase, which replaces aspartic acid at position 289 with valine [TNSALP (D289V)], was reported in a lethal hypophosphatasia patient [Taillandier, A. et al. (1999) Hum. Mut. 13, 171-172]. To define the molecular defects of TNSALP (D289V), this mutant protein in transiently transfected COS-1 cells was analyzed biochemically and morphologically. TNSALP (D289V) exhibited no alkaline phosphatase activity and mainly formed a disulfide-linked high molecular mass aggregate. Cell-surface biotinylation, digestion with phosphatidylinositol-specific phospholipase C and an immunofluorescence study showed that the mutant protein failed to appear on the cell surface and was accumulated intracellularly. In agreement with this, pulse/chase experiments demonstrated that TNSALP (D289V) remained endo-beta-N-acetyl-glucosaminidase H-sensitive throughout the chase and was eventually degraded, indicating that the mutant protein is unable to reach the medial-Golgi. Proteasome inhibitors strongly blocked the degradation of TNSALP (D289V), and furthermore the mutant protein was found to be ubiquitinated. Besides, another naturally occurring TNSALP with a Glu(218)-->Gly mutation was also found to be polyubiquitinated and degraded in the proteasome. Since the acidic amino acids at positions 218 and 289 of TNSALP are thought to be directly involved in the Ca2+ coordination, these results suggest the critical importance of calcium binding in post-translational folding and assembly of the TNSALP molecule.

    DOI: 10.1093/jb/mvg114

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▶ 全件表示

MISC

  • アルカリホスファターゼの構造と機能 招待

    織田公光, 小丸圭一

    臨床化学33 ( 1 ) 36 - 44   2004年

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    記述言語:日本語   掲載種別:記事・総説・解説・論説等(学術雑誌)  

    DOI: 10.14921/jscc1971b.33.1_36

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共同研究・競争的資金等の研究

  • 口蓋裂発症へのエピジェネティクスの関与の解明(石田陽子)

    2017年04月 - 現在

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    資金種別:競争的資金

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