研究者データベース

大久保 直登(オオクボ ナオト)
薬学研究院 医療薬学部門 医療薬学分野
講師

基本情報

所属

  • 薬学研究院 医療薬学部門 医療薬学分野

職名

  • 講師

学位

  • 歯学博士(北海道大学)

ホームページURL

J-Global ID

プロフィール

  • 歯根膜幹細胞を用いた組織再生をテーマに

    日々研究を続けております。

    現在の目標は、この幹細胞の歯科臨床現場での

    臨床応用の実現です。

研究キーワード

  • 歯根膜幹細胞   脱灰象牙質基質   幹細胞スキャホールド   再生医療   間葉系幹細胞   

研究分野

  • ライフサイエンス / 口腔再生医学、歯科医用工学
  • ライフサイエンス / 常態系口腔科学

職歴

  • 2022年04月 - 現在 北海道大学大学院薬学研究院 分子細胞医薬学 講師
  • 2021年04月 - 2022年03月 北海道大学大学院薬学研究院 分子細胞医薬学 助教
  • 2019年04月 - 2021年03月 北海道大学大学院薬学研究院 臨床病態解析学 助教
  • 2012年12月 - 2019年03月 北海道大学大学院薬学研究院 臨床病態解析学 博士研究員
  • 2010年 - 2012年 岩手医科大学 歯学部 博士研究員

学歴

  • 2005年04月 - 2009年03月   国立大学法人 北海道大学   大学院歯学研究科   博士課程口腔医学専攻

研究活動情報

論文

  • Primary Teeth-Derived Demineralized Dentin Matrix Autograft for Unilateral Maxillary Alveolar Cleft during Mixed Dentition
    Yusuke Matsuzawa, Naoto Okubo, Soichi Tanaka, Haruhiko Kashiwazaki, Yoshimasa Kitagawa, Yoichi Ohiro, Tadashi Mikoya, Toshiyuki Akazawa, Masaru Murata
    J. Funct. Biomater. 2022 13 2022年09月 [査読有り]
  • Naoto Okubo, Masahiro Ishikawa, Mamata Shakya, Hidetaka Hosono, Osamu Maehara, Tatsuya Ohkawara, Shunsuke Ohnishi, Toshiyuki Akazawa, Masaru Murata
    Journal of Hard Tissue Biology 31 1 47 - 54 2022年01月 [査読有り]
  • Osamu Maehara, Goki Suda, Mitsuteru Natsuizaka, Taku Shigesawa, Gouki Kanbe, Megumi Kimura, Masaya Sugiyama, Masashi Mizokami, Masato Nakai, Takuya Sho, Kenichi Morikawa, Koji Ogawa, Shinya Ohashi, Shingo Kagawa, Hideaki Kinugasa, Seiji Naganuma, Naoto Okubo, Shunsuke Ohnishi, Hiroshi Takeda, Naoya Sakamoto
    Cancer biology & therapy 22 5-6 372 - 380 2021年06月03日 
    Fibroblast growth factors (FGFs) and their receptors (FGFRs) are important for signaling to maintain cancer stem-like cells (CSCs) in esophageal squamous cell carcinoma (ESCC). However, which FGF receptor, 1, 2, 3, 4, and L1, is essential or whether FGFRs have distinct different roles in ESCC-CSCs is still in question. This study shows that FGFR2, particularly the IIIb isoform, is highly expressed in non-CSCs. Non-CSCs have an epithelial phenotype, and such cells are more differentiated in ESCC. Further, FGFR2 induces keratinocyte differentiation through AKT but not MAPK signaling and diminishes CSC populations. Conversely, knockdown of FGFR2 induces epithelial-mesenchymal transition (EMT) and enriches CSC populations in ESCC. Finally, data analysis using The Cancer Genome Atlas (TCGA) dataset shows that expression of FGFR2 significantly correlated with cancer cell differentiation in clinical ESCC samples. The present study shows that each FGFR has a distinct role and FGFR2-AKT signaling is a key driver of keratinocyte differentiation in ESCC. Activation of FGFR2-AKT signaling could be a future therapeutic option targeting CSC in ESCC.
  • Tatsuya Ohkawara, Naoto Okubo, Osamu Maehara, Jun Nishihira, Hiroshi Takeda
    Toxicology letters 339 51 - 59 2021年03月15日 
    Overdose use of acetaminophen (APAP) often occurs a severe liver injury, and its liver injury is lethal in some cases. Macrophage migration inhibitory factor (MIF) is expressed in a variety of cells and has multifunctional roles. However, the role of MIF in APAP-induced liver injury has not been fully investigated. In this study, we investigated whether treatment with (S,R)-3-(4-hydroxyphenil)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), a MIF inhibitor, protected mice from acute APAP-induced liver injury. Acute liver injury was induced by injection of APAP (300 mg/kg body weight). Mice were treated with a single injection of ISO-1(15 mg/kg body weight) 1 h (h) before APAP administration. Histological, biochemical and molecular analyses were performed in liver of mice 12 h after APAP administration. ISO-1 remarkably improved the histological findings of APAP-induced liver injury in mice. The increases in serum levels of alanine aminotransferase (ALT), and macrophage inflammatory protein-2 (MIP-2) by APAP were inhibited by ISO-1. In addition, ISO-1 reduced the increased number of the myeloperoxidase-staining cells and that of TUNEL-positive staining cells in the liver of mice with APAP-induced liver injury. Up-regulation of hepatic receptor interacting protein kinase (RIPK)3 and heat shock protein70 by APAP was suppressed in the liver of mice given ISO-1. These results provide the additional evidence that inhibition of MIF activity may be clinically effective for treatment of acute APAP-induced liver injury.
  • 武田 宏司, 大久保 直登, 中川 宏治, 大西 俊介, 藤塚 直樹, 服部 智久
    臨床消化器内科 33 11 1349 - 1356 (株)日本メディカルセンター 2018年09月 
    <文献概要>六君子湯は上部消化管症状や食欲不振に対して使用されている漢方薬であるが,近年その作用機序が明らかになりつつある.六君子湯は5-HT2B/5-HT2C受容体の阻害によるグレリン分泌亢進あるいは分解阻害により血中グレリン濃度を上昇させる.また,ホスホジエステラーゼ3阻害およびグレリン受容体の感受性亢進などを介してグレリン抵抗性を解除する.さらに,5-HT2Cなど複数の受容体の阻害により抗ストレス作用を示す.最近の研究で,六君子湯がサーチュイン1活性化などを介してマウスの寿命延長をもたらすことが明らかになった.六君子湯は,脳腸軸を構成する複数の標的に作用し,グレリンシステムを増強して生体の機能異常を改善する薬剤と考えられる.
  • Maiko Ohta, Naoyuki Chosa, Seiko Kyakumoto, Seiji Yokota, Naoto Okubo, Akira Nemoto, Masaharu Kamo, Shigeharu Joh, Kenichi Satoh, Akira Ishisaki
    International Journal of Molecular Medicine 42 3 1484 - 1494 Spandidos Publications 2018年06月 [査読有り][通常論文]
     
    Mechanosensitive (MS) neurons in the periodontal ligament (PDL) pass information to the trigeminal ganglion when excited by mechanical stimulation of the tooth. During occlusal tooth trauma of PDL tissues, MS neurons are injured, resulting in atrophic neurites and eventual degeneration of MS neurons. Nerve growth factor (NGF), a neurotrophic factor, serves important roles in the regeneration of injured sensory neurons. In the present study, the effect of pro‑inflammatory cytokines, including interleukin 1β (IL‑1β) and tumor necrosis factor α (TNF‑α), on transforming growth factor β1 (TGF‑β1)‑induced NGF expression was evaluated in rat PDL‑derived SCDC2 cells. It was observed that TGF‑β1 promoted NGF expression via Smad2/3 and p38 mitogen‑activated protein kinase (MAPK) activation. IL‑1β and TNF‑α suppressed the TGF‑β1‑induced activation of Smad2/3 and p38 MAPK, resulting in the abrogation of NGF expression. NGF secreted by TGF‑β1‑treated SCDC2 cells promoted neurite extension and the expression of tyrosine hydroxylase, a rate‑limiting enzyme in dopamine synthesis in rat pheochromocytoma PC12 cells. These results suggested that pro‑inflammatory cytokines suppressed the TGF‑β‑mediated expression of NGF in PDL‑derived fibroblasts through the inactivation of TGF‑β‑induced Smad2/3 and p38 MAPK signaling, possibly resulting in the disturbance of the regeneration of injured PDL neurons.
  • 加島 裕基, 大久保 直登, 中川 宏治, 武田 宏司, 北川 善政
    北海道歯学雑誌 38 2 158 - 168 北海道歯学会 2018年03月 
    インターフェロン-β(IFN-β)はウイルス感染における免疫、炎症反応において重要だが、その発現制御機構は不明点が多い。過去にフォークヘッド転写因子FOXO3aがその産生を負に制御することが報告されたが、詳細な機序に関する報告は少ない。そこで我々はFOXO3aによるIFN-βの発現制御の分子機構の解明を目的に本研究を行った。まず、293T細胞、293-TLR3細胞にFOXO3aを過剰発現させた後にpolyICを導入し、IFN-βmRNA発現量を定量的RT-PCRにより測定した。次に293T細胞にMAVS、TBK1、IRF3-5DをFOXO3と共発現させ、IFN-βプロモーター活性をルシフェラーゼアッセイにより測定した。その結果、FOXO3aはpolyICにより誘導されるIFN-βmRNAの発現、MAVS、TBK1で誘導されるIFN-βプロモーター活性を抑制した。続いて293T細胞にTBK1、FOXO3a、IRF3を導入後、免疫沈降、ウエスタンブロットによりFOXO3aとTBK1、IRF3の相互作用について検討した。その結果、TBK1とFOXO3aの結合を認め、FOXO3aの共発現によりIRF3のリン酸化が減弱したが、TBK1のリン酸化は変化しなかった。最後に、PI3K阻害剤LY294002処理によるFOXO3aの細胞内局在を免疫蛍光染色により検討した。また、LY294002処理下で、B型DNAであるpolydAdT(B-DNA)により誘導されるIFN-βmRNAの発現量を定量的RT-PCRにて解析した。その結果、LY294002処理によりFOXO3aの核への局在が観察され、同処理下ではB-DNA導入によるIFN-βmRNAの発現が増強した。以上より、FOXO3aはTBK1と相互作用し、IRF3リン酸化を減弱させてIFN-β発現を負に制御する可能性が考えられた。(著者抄録)
  • Takizawa N, Okubo N, Kamo M, Chosa N, Mikami T, Suzuki K, Yokota S, Ibi M, Ohtsuka M, Taira M, Yaegashi T, Ishisaki A, Kyakumoto S
    Experimental cell research 358 2 411 - 420 2017年09月 [査読有り][通常論文]
     
    Immunosuppressive/anti-inflammatory macrophage (Mφ), M2-Mφ that expressed the typical M2-Mφs marker, CD206, and anti-inflammatory cytokine, interleukin (IL)-10, is beneficial and expected tool for the cytotherapy against inflammatory diseases. Here, we demonstrated that bone marrow-derived lineage-positive (Lin+) blood cells proliferated and differentiated into M2-Mφs by cooperation with the bone marrow-derived mesenchymal stem cells (MSCs) under hypoxic condition: MSCs not only promoted proliferation of undifferentiated M2-Mφs, pre-M2-Mφs, in the Lin+ fraction via a proliferative effect of the MSCs-secreted macrophage colony-stimulating factor, but also promoted M2-Mφ polarization of the pre-M2-Mφs through cell-to-cell contact with the pre-M2-Mφs. Intriguingly, an inhibitor for intercellular adhesion molecule (ICAM)-1 receptor/lymphocyte function-associated antigen (LFA)-1, Rwj50271, partially suppressed expression of CD206 in the Lin+ blood cells but an inhibitor for VCAM-1 receptor/VLA-4, BIO5192, did not, suggesting that the cell-to-cell adhesion through LFA-1 on pre-M2-Mφs and ICAM-1 on MSCs was supposed to promoted the M2-Mφ polarization. Thus, the co-culture system consisting of bone marrow-derived Lin+ blood cells and MSCs under hypoxic condition was a beneficial supplier of a number of M2-Mφs, which could be clinically applicable to inflammatory diseases.
  • N Fujitsuka, A Asakawa, A Morinaga, M S Amitani, H Amitani, G Katsuura, Y Sawada, Y Sudo, Y Uezono, E Mochiki, I Sakata, T Sakai, K Hanazaki, T Yada, K Yakabi, E Sakuma, T Ueki, A Niijima, K Nakagawa, N Okubo, H Takeda, M Asaka, A Inui
    Molecular psychiatry 21 11 1613 - 1623 2016年11月 
    Caloric restriction (CR) is known to retard aging and delay functional decline as well as the onset of diseases in most organisms. Ghrelin is secreted from the stomach in response to CR and regulates energy metabolism. We hypothesized that in CR ghrelin has a role in protecting aging-related diseases. We examined the physiological mechanisms underlying the ghrelin system during the aging process in three mouse strains with different genetic and biochemical backgrounds as animal models of accelerated or normal human aging. The elevated plasma ghrelin concentration was observed in both klotho-deficient and senescence-accelerated mouse prone/8 (SAMP8) mice. Ghrelin treatment failed to stimulate appetite and prolong survival in klotho-deficient mice, suggesting the existence of ghrelin resistance in the process of aging. However, ghrelin antagonist hastened death and ghrelin signaling potentiators rikkunshito and atractylodin ameliorated several age-related diseases with decreased microglial activation in the brain and prolonged survival in klotho-deficient, SAMP8 and aged ICR mice. In vitro experiments, the elevated sirtuin1 (SIRT1) activity and protein expression through the cAMP-CREB pathway was observed after ghrelin and ghrelin potentiator treatment in ghrelin receptor 1a-expressing cells and human umbilical vein endothelial cells. Furthermore, rikkunshito increased hypothalamic SIRT1 activity and SIRT1 protein expression of the heart in the all three mouse models of aging. Pericarditis, myocardial calcification and atrophy of myocardial and muscle fiber were improved by treatment with rikkunshito. Ghrelin signaling may represent one of the mechanisms activated by CR, and potentiating ghrelin signaling may be useful to extend health and lifespan.
  • Reo Nozaki, Toru Kono, Hiroki Bochimoto, Tsuyoshi Watanabe, Kaori Oketani, Yuichi Sakamaki, Naoto Okubo, Koji Nakagawa, Hiroshi Takeda
    Oncotarget 7 43 70437 - 70446 2016年10月25日 
    Zanthoxylum fruit, obtained from the Japanese pepper plant (Zanthoxylum piperitum De Candolle), and its extract (Zanthoxylum fruit extract, ZFE) have multiple physiological activities (e.g., antiviral activity). However, the potential anticancer activity of ZFE has not been fully examined. In this study, we investigated the ability of ZFE to induce autophagic cell death (ACD). ZFE caused remarkable autophagy-like cytoplasmic vacuolization, inhibited cell proliferation, and ultimately induced cell death in the human cancer cell lines DLD-1, HepG2, and Caco-2, but not in A549, MCF-7, or WiDr cells. ZFE increased the level of LC3-II protein, a marker of autophagy. Knockdown of ATG5 using siRNA inhibited ZFE-induced cytoplasmic vacuolization and cell death. Moreover, in cancer cells that could be induced to undergo cell death by ZFE, the extract increased the phosphorylation of c-Jun N-terminal kinase (JNK), and the JNK inhibitor SP600125 attenuated both vacuolization and cell death. Based on morphology and expression of marker proteins, ZFE-induced cell death was neither apoptosis nor necrosis. Normal intestinal cells were not affected by ZFE. Taken together, our findings show that ZFE induces JNK-dependent ACD, which appears to be the main mechanism underlying its anticancer activity, suggesting a promising starting point for anticancer drug development.
  • Koji Nakagawa, Toshihisa Kohara, Yasuko Uehata, Yui Miyakawa, Maremi Sato-Ueshima, Naoto Okubo, Masahiro Asaka, Hiroshi Takeda, Masanobu Kobayashi
    Biochemical and biophysical research communications 469 3 470 - 6 2016年01月15日 
    The transcription factor hypoxia-inducible factor-1 (HIF-1) functions as a master regulator of hypoxic response by inducing the transcription of various genes responsible for cellular adaptation to hypoxia. In this study, we investigated the effects of protein inhibitor of activated STAT3 (PIAS3), a small ubiquitin-related modifier (SUMO) E3 ligase, on HIF-1-mediated transcriptional activation. We found that PIAS3 physically associated with HIF-1α. Moreover, PIAS3 overexpression enhanced the transcriptional activity of HIF-1α independently of its SUMO E3 ligase activity. Conversely, quantitative RT-PCR analysis showed that RNAi-mediated PIAS3 knockdown reduced the expression of HIF-1 target genes under hypoxia. In addition, PIAS3 knockdown induced the destabilization of HIF-1α protein, and the destabilization was reversed by the proteasome inhibitor MG132. Taken together, these results suggest that PIAS3 functions as a positive regulator of HIF-1α-mediated transcription by increasing its protein stability.
  • Hiroshi Takeda, Shunsuke Ohnishi, Koji Nakagawa, Naoto Okubo, Chihiro Yamada, Chiharu Sadakane, Yayoi Saegusa, Miwa Nahata, Tomohisa Hattori
    Methods in Pharmacology and Toxicology 135 - 163 2016年 [査読有り][通常論文]
     
    Rikkunshito is a kampo herbal medicine which is widely used in Japan for the treatment of the upper gastrointestinal symptoms of patients with functional dyspepsia (FD), gastroesophageal reflux disease (GERD), dyspeptic symptoms of postgastrointestinal surgery patients, and chemotherapy-induced dyspepsia in cancer patients. Recently, very unique characteristics of rikkunshito have been unveiled oral administration of rikkunshito potentiates orexigenic action of ghrelin through several different mechanisms. In addition, several lines of evidence obtained from both animal and human studies indicate that rikkunshito can be an attractive and promising therapeutic option for the anorectic conditions including cisplatin-induced dyspepsia, anorexia of aging, stress-induced hypophagia, cancer cachexia-anorexia syndrome, and drug-related anorexia. We will highlight what is known about the orexigenic effect of rikkunshito with a special focus on an interaction with ghrelin signaling system.
  • Chihiro Yamada, Chiharu Sadakane, Miwa Nahata, Yayoi Saegusa, Koji Nakagawa, Naoto Okubo, Shunsuke Ohnishi, Tomohisa Hattori, Hiroshi Takeda
    Psychoneuroendocrinology 55 81 - 93 2015年05月 
    The combination of depression and anorexia may influence morbidity and progressive physical disability in the elderly. Gender differences exist in hypothalamic-pituitary-adrenal axis activation following stress exposure. The objective of this study was to investigate gender differences in feeding behavior under novelty stress in aged mice. Food intake measurement, immunohistochemical assessment, and mRNA expression analysis were conducted to investigate the role of serotonin 2C receptor (5-HT(2C)R) and its relationship with ghrelin in stress-induced suppression of feeding behavior in aged mice. After exposure to novelty stress, a 21-fold increase in plasma corticosterone and remarkable suppression of food intake were observed in aged male mice. Furthermore, a 5-HT(2C)R agonist suppressed food intake in aged male mice. Novelty stress induced a 7-fold increase in 5-HT(2C)R and c-Fos co-expressing cells in the paraventricular nucleus of the hypothalamus in aged male mice but caused no change in aged female mice. Plasma acylated ghrelin levels decreased in stressed aged male mice and administration of the 5-HT(2C)R antagonist inhibited this decrease. The 5-HT(2C)R antagonist also reversed the suppression of food intake in estrogen receptor α agonist-treated aged male mice. Therefore, conspicuously suppressed feeding behavior in novelty stress-exposed aged male mice may be mediated by 5-HT(2C)R hypersensitivity, leading to hypoghrelinemia. The hypersensitivity may partly be due to estrogen receptor activation in aged male mice.
  • Onishi Reizo, Ohnishi Shunsuke, Higashi Ryosuke, Watari Michiko, Yamahara Kenichi, Okubo Naoto, Nakagawa Koji, Katsurada Takehiko, Suda Goki, Natsuizaka Mitsuteru, Takeda Hiroshi, Sakamoto Naoya
    CELL TRANSPLANTATION 24 12 2601 - 2614 2015年 [査読有り][通常論文]
     
    Mesenchymal stem cells (MSCs) are a valuable cell source in regenerative medicine. Recently, several studies have shown that MSCs can be easily isolated from human amnion. In this study, we investigated the therapeutic effect of human amnion-derived MSCs (AMSCs) in rats with severe colitis. Colitis was induced by the administration of 8% dextran sulfate sodium (DSS) from day 0 to day 5, and AMSCs (1 × 10(6) cells) were transplanted intravenously on day 1. Rats were sacrificed on day 5, and the colon length and histological colitis score were evaluated. The extent of inflammation was evaluated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry. The effect of AMSCs on the inflammatory signals was investigated in vitro. AMSC transplantation significantly ameliorated the disease activity index score, weight loss, colon shortening, and the histological colitis score. mRNA expression levels of proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and migration inhibitory factor (MIF) were significantly decreased in the rectums of AMSC-treated rats. In addition, the infiltration of monocytes/macrophages was significantly decreased in AMSC-treated rats. In vitro experiments demonstrated that activation of proinflammatory signals induced by TNF-α or lipopolysaccharide (LPS) in immortalized murine macrophage cells (RAW264.7) was significantly attenuated by coculturing with AMSCs or by culturing with a conditioned medium obtained from AMSCs. Although the phosphorylation of IκB induced by TNF-α or LPS was not inhibited by the conditioned medium, nuclear translocation of NF-κB was significantly inhibited by the conditioned medium. Taken together, AMSC transplantation provided significant improvement in rats with severe colitis, possibly through the inhibition of monocyte/macrophage activity and through inhibition of NF-κB activation. AMSCs could be considered as a new cell source for the treatment of severe colitis.
  • M Nahata, Y Saegusa, C Sadakane, C Yamada, K Nakagawa, N Okubo, S Ohnishi, T Hattori, N Sakamoto, H Takeda
    Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society 26 6 821 - 31 2014年06月 
    BACKGROUND: Physical or psychological stress causes functional disorders in the upper gastrointestinal tract. This study aims to elucidate the ameliorating effect of exogenous acylated ghrelin or rikkunshito, a Kampo medicine which acts as a ghrelin enhancer, on gastric dysfunction during acute restraint stress in mice. METHODS: Fasted and postprandial motor function of the gastric antrum was wirelessly measured using a strain gauge force transducer and solid gastric emptying was detected in mice exposed to restraint stress. Plasma corticosterone and ghrelin levels were also measured. To clarify the role of ghrelin on gastrointestinal dysfunction in mice exposed to stress, exogenous acylated ghrelin or rikkunshito was administered, then the mice were subjected to restraint stress. KEY RESULTS: Mice exposed to restraint stress for 60 min exhibited delayed gastric emptying and increased plasma corticosterone levels. Gastric motility was decreased in mice exposed to restraint stress in both fasting and postprandial states. Restraint stress did not cause any change in plasma acylated ghrelin levels, but it significantly increased the plasma des-acyl ghrelin levels. Administration of acylated ghrelin or rikkunshito improved the restraint stress-induced delayed gastric emptying and decreased antral motility. Ameliorating effects of rikkunshito on stress-induced gastric dysfunction were abolished by simultaneous administration of a ghrelin receptor antagonist. CONCLUSIONS & INFERENCES: Plasma acylated/des-acyl ghrelin imbalance was observed in acute restraint stress. Supplementation of exogenous acylated ghrelin or enhancement of endogenous ghrelin signaling may be useful in the treatment of decreased gastric function caused by stress.
  • Yokota J, Chosa N, Sawada S, Okubo N, Takahashi N, Hasegawa T, Kondo H, Ishisaki, A.
    Int. J. Mol. Med. 33 3 534 - 542 2014年03月 [査読有り][通常論文]
     
    Transforming growth factor-beta (TGF-beta) is a critical regulator of osteogenic differentiation and the platelet-derived growth factor (PDGF) is a chemoattractant or mitogen of osteogenic mesenchymal cells. However, the combined effects of these regulators on the osteogenic differentiation of mesenchymal cells remains unknown. In this study, we investigated the effects of TGF-beta and/or PDGF on the osteogenic differentiation of human mesenchymal stem cells (hMSCs). The TGF-beta-induced osteogenic differentiation of UE7T-13 cells, a bone marrow-derived hMSC line, was markedly enhanced by PDGF, although PDGF alone did not induce differentiation. TGF-beta induced extracellular signal-regulated kinase (ERK) phosphorylation and PDGF induced Akt phosphorylation. In addition, the mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) inhibitor, U0126, suppressed the osteogenic differentiation induced by TGF-beta alone. Moreover, U0126 completely suppressed the osteogenic differentiation synergistically induced by TGF-beta and PDGF, whereas the phosphoinositide-3-kinase (PI3K) inhibitor, LY294002, only partially suppressed this effect. These results suggest that the enhancement of TGF-beta-induced osteogenic differentiation by PDGF-induced PI3K/Akt-mediated signaling depends on TGF-beta-induced MEK activity. Thus, PDGF positively modulates the TGF-beta-induced osteogenic differentiation of hMSCs through synergistic crosstalk between MEK- and PI3K/Akt-mediated signaling.
  • 吉田 茉莉子, 大久保 直登, 石崎 明
    岩手医科大学歯学雑誌 38 3 125 - 126 岩手医科大学歯学会 2014年
  • Emiko Aomatsu, Noriko Takahashi, Shunsuke Sawada, Naoto Okubo, Tomokazu Hasegawa, Masayuki Taira, Hiroyuki Miura, Akira Ishisaki, Naoyuki Chosa
    SCIENTIFIC REPORTS 4 3652  2014年01月 [査読有り][通常論文]
     
    Human mesenchymal stem cells (hMSCs) remodel or regenerate various tissues through several mechanisms. Here, we identified the hMSC-secreted protein SCRG1 and its receptor BST1 as a positive regulator of self-renewal, migration, and osteogenic differentiation. SCRG1 and BST1 gene expression decreased during osteogenic differentiation of hMSCs. Intriguingly, SCRG1 maintained stem cell marker expression (Oct-4 and CD271/LNGFR) and the potentials of self-renewal, migration, and osteogenic differentiation, even at high passage numbers. Thus, the novel SCRG1/BST1 axis determines the fate of hMSCs by regulating their kinetic and differentiation potentials. Our findings provide a new perspective on methods for ex vivo expansion of hMSCs that maintain native stem cell potentials for bone-forming cell therapy.
  • Saito D, Kyakumoto S, Chosa N, Ibi M, Takahashi N, Okubo N, Sawada S, Ishisaki A, Kamo M
    Journal of biochemistry 153 3 303 - 315 3 2013年03月 [査読有り][通常論文]
     
    We investigated whether transforming growth factor (TGF)-beta 1 promoted epithelial-mesenchymal transition (EMT) and migration of human oral squamous cell carcinoma (hOSCC) cells. Among 6 hOSCC cell lines investigated, Smad2 phosphorylation and TGF-beta target genes expression were most clearly upregulated following TGF-beta 1 stimulation in HSC-4 cells, indicating that HSC-4 cells were the most responsive to TGF-beta 1. In addition, the expression levels of the mesenchymal markers N-cadherin and vimentin were most clearly induced in HSC-4 cells among the hOSCC cell lines by TGF-beta 1 stimulation. Interestingly, E-cadherin and beta-catenin at the cell surface were internalized in HSC-4 cells stimulated with TGF-beta 1. In addition, the expression levels of the EMT-related transcription factor Slug was significantly upregulated on TGF-beta 1 stimulation. Moreover, the downregulation of Slug by RNA interference clearly inhibited the TGF-beta 1-induced expression of mesenchymal marker and the migration of HSC-4 cells. Proteomics analysis also revealed that the expression levels of integrin alpha 3 beta 1-targeted proteins were upregulated in TGF-beta 1-stimulated HSC-4 cells. Neutral antibodies against integrin alpha 3 and beta 1, as well as a focal adhesion kinase (FAK) inhibitor, clearly suppressed TGF-beta 1-induced cell migration. These results suggest that the EMT and integrin alpha 3 beta 1/FAK pathway-mediated migration of TGF-beta 1-stimulated HSC-4 hOSCC cells is positively controlled by Slug.
  • Hiroshi Takeda, Koji Nakagawa, Naoto Okubo, Mie Nishimura, Shuichi Muto, Shunsuke Ohnishi, Naoya Sakamoto, Hidetaka Hosono, Masahiro Asaka
    Biological & pharmaceutical bulletin 36 9 1401 - 5 2013年 
    Anorexia is an important issue in the management of elderly patients with cancer because it contributes to the development of malnutrition, increases morbidity and mortality, and negatively affects patients' quality of life. This review summarizes the potential mechanisms of the development of anorexia in three animal models that mimic the situations commonly seen in elderly patients receiving chemotherapy. Cisplatin-induced anorexia is attributable to a decrease in peripheral and central ghrelin secretion caused by the stimulation of serotonin (5-hydroxytryptamine; 5-HT)2B and 5-HT2C receptors via 5-HT secretion. Age-associated anorexia is caused by an increase in plasma leptin, which results from disturbed reactivity of ghrelin in the hypothalamus and regulation of ghrelin secretion. Environmental change causes the activation of central 5-HT1B and 5-HT2C receptors and the melanocortin-4 receptor system, resulting in a decrease in circulating ghrelin levels which lowers food intake. New therapeutic approaches based on these pathophysiological mechanisms are warranted for the treatment of anorexia in cancer patients, especially elderly ones.
  • Kimura H, Okubo N, Chosa N, Kyakumoto S, Kamo M, Miura H, Ishisaki A
    Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology 32 4 899 - 914 2013年 [査読有り][通常論文]
     
    Background/Aims: Remodeling of fibrous and vascular tissues in the periodontal ligament (PDL) around the tooth root was observed during tooth movement by orthodontic force application. We previously demonstrated that a single cell-derived culture (SCDC) of primarily cultured PDL fibroblasts, called SCDC2, has an endothelial progenitor cell (EPC)-like character and can form endothelial cell (EC) marker-positive blood vessel-like structures. However, the types of molecular mechanisms that control the in vivo kinetic properties and the differentiation of the PDL-derived EPC-like cells into myofibroblasts (MFs), which are known to expand fibrous tissues, require clarification. Methods: Using specific mitogen activated protein kinase (MAPK) inhibitors, we examined how epidermal growth factor (EGF)-mediated MAPK signals affected the proliferation, migration, and MF differentiation of these cells. Results: EGF induced SCDC2 cell proliferation in MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)- and c-Jun N-terminal kinase (JNK)-dependent manners. In addition, EGF suppressed the expression of MF differentiation markers in these cells in a MEK/ERK-dependent manner, and, moreover, stimulated the cell migration in a MEK/ERK-dependent manner. Conclusion: EGF regulates fibrous tissue remodeling in PDLs through MEK/ERK- and JNK-mediated signals by affecting the proliferation, migration, and MF differentiation of the PDL-derived EPC-like cells. © 2013 S. Karger AG, Basel.
  • Mikako Takahashi, Naoto Okubo, Naoyuki Chosa, Noriko Takahashi, Miho Ibi, Masaharu Kamo, Harumi Mizuki, Akira Ishisaki, Seiko Kyakumoto
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 29 3 357 - 364 2012年03月 [査読有り][通常論文]
     
    The periodontal ligament (PDL) is a fibrous connective tissue located between the tooth root and the alveolar bone. We previously demonstrated that a single cell-derived culture of primarily cultured PDL fibroblasts has the potential to construct an endothelial cell (EC) marker-positive blood vessel-like structure, suggesting that the fibroblastic lineage cells in ligament tissue could act as the endothelial progenitor cells (EPCs), which regenerate to construct a vascular system around the damaged ligament tissue. Moreover, we showed that EPC-like fibroblasts expressed not only EC markers but also smooth muscle cell (SMC) markers. Generally, an interaction between ECs and SMCs regulates blood vessel development and remodeling, and is required for the formation of a mature and functional vascular network. However, the mechanism underlying the SMC differentiation of the ligament-derived EPC-like fibroblasts remains to be clarified. In this study, we showed that suppression of fibroblast growth factor 1 (FGF-1)-induced extracellular signal-regulated kinase 1/2 (ERK 1/2) signaling with the MAPK/ERK kinase (MEK) inhibitor U0126 completely abolished the FGF-1-induced proliferation of the ligament-derived EPC-like fibroblasts. In addition, U0126 treatment of FGF-1-stimulated ligament-derived EPC-like fibroblasts significantly induced the SMC differentiation of the cells. Thus, FGF-1-induced ERK1/2 signaling not only promoted the proliferation of the ligament-derived EPC-like fibroblasts, but also suppressed the SMC differentiation of the cells, suggesting that FGF-1 controls the construction of a vascular network around the ligament tissue by regulating the proliferation and SMC differentiation of the EPC-like cells through ER K-mediated signaling.
  • Noriko Takahashi, Naoyuki Chosa, Tomokazu Hasegawa, Soko Nishihira, Naoto Okubo, Mamoru Takahashi, Yoshiki Sugiyama, Mitsuro Tanaka, Akira Ishisaki
    ARCHIVES OF ORAL BIOLOGY 57 1 44 - 51 2012年01月 [査読有り][通常論文]
     
    Objectives: The aim of this study was to characterize the expression status of cadherins in dental pulp-derived mesenchymal progenitor/stem cells from deciduous and permanent teeth, and to determine how cadherins affect the multipotency of the progenitor/stem cells. Materials and methods: We evaluated and compared the expression status of cadherins in dental pulp-derived cells from deciduous teeth and in cells from permanent teeth by using an array of primers for amplification of RNA encoding human cell adhesion molecules and a real time PCR system. In order to elucidate how cadherins (which are differentially expressed in deciduous and permanent teeth) affect the multipotency of the dental pulp-derived progenitor/stem cells, the ability of the dental pulp cells to differentiate into adipocytes and osteoblasts was evaluated. Results: R-cadherin was found to be vigorously expressed in the dental pulp cells derived from permanent teeth but not in the dental pulp cells derived from deciduous teeth. N-cadherin was found to be expressed essentially equally in both types of cells. The ability of the dental pulp cells of deciduous teeth to differentiate into adipocytes and osteoblasts was found to be much higher than that of cells obtained from permanent teeth. Conclusion: R-cadherin maybe a key molecule for providing control over the multipotency of the dental pulp-derived mesenchymal stem cells. (C) 2011 Elsevier Ltd. All rights reserved.
  • Yoshida M, Okubo N, Chosa N, Hasegawa T, Ibi M, Kamo M, Kyakumoto S, Ishisaki A
    International journal of biological sciences 8 7 1062 - 1074 7 2012年 [査読有り][通常論文]
     
    The periodontal ligament (PDL) is a fibrous connective tissue that attaches the tooth to the alveolar bone. We previously demonstrated the ability of PDL fibroblast-like cells to construct an endothelial cell (EC) marker-positive blood vessel-like structure, indicating the potential of fibroblastic lineage cells in PDL tissue as precursors of endothelial progenitor cells (EPCs) to facilitate the construction of a vascular system around damaged PDL tissue. A vascular regeneration around PDL tissue needs proliferation of vascular progenitor cells and the subsequent differentiation of the cells. Transforming growth factor-beta (TGF-beta) is known as an inducer of endothelial-mesenchymal transition (EndMT), however, it remains to be clarified what kinds of TGF-beta signals affect growth and mesenchymal differentiation of PDL-derived EPC-like fibroblastic cells. Here, we demonstrated that TGF-beta 1 not only suppressed the proliferation of the PDL-derived EPC-like fibroblastic cells, but also induced smooth muscle cell (SMC) markers expression in the cells. On the other hand, TGF-beta 1 stimulation suppressed EC marker expression. Intriguingly, overexpression of Smad7, an inhibitor for TGF-beta 1-induced Smad-dependent signaling, suppressed the TGF-beta 1-induced growth inhibition and SMC markers expression, but did not the TGF-beta 1-induced downregulation of EC marker expression. In contrast, p38 mitogen-activated protein kinase (MAPK) inhibitor SB 203580 suppressed the TGF-beta 1-induced downregulation of EC marker expression. In addition, the TGF-beta 1-induced SMC markers expression of the PDL-derived cells was reversed upon stimulation with fibroblast growth factor (FGF), suggesting that the TGF-beta 1 might not induce terminal SMC differentiation of the EPC-like fibroblastic cells. Thus, TGF-beta 1 not only negatively controls the growth of PDL-derived EPC-like fibroblastic cells via a Smad-dependent manner but also positively controls the SMC-differentiation of the cells possibly at the early stage of the translineage commitment via Smad-and p38 MAPK-dependent manners.
  • Soko Nishihira, Naoto Okubo, Noriko Takahashi, Akira Ishisaki, Yoshiki Sugiyama, Naoyuki Chosa
    CELL BIOLOGY INTERNATIONAL 35 5 475 - 481 2011年05月 [査読有り][通常論文]
     
    MSCs (mesenchymal stem cells) migrate into damaged tissue and then proliferate and differentiate into various cell lineages to regenerate bone, cartilage, fat and muscle. Cell-cell adhesion of MSCs is essential for the MSC-dependent tissue regeneration after their homing into a damaged tissue. However, it remains to be elucidated what kinds of adhesion molecules play important roles in the cell-cell communication between MSCs. In order to identify adhesion molecules that facilitate mutual contact between MSCs, a comprehensive analysis of mRNA expression in adhesion molecules was performed by comparing profiles of expression status of adhesion molecules in MSCs at low- and high-cell density. We found that the expression level of VCAM1 (vascular cell adhesion molecule-1)/CD106 was clearly up-regulated in the human bone marrow-derived MSCs-UE7T-13 cells - under a condition of high cell density. Intriguingly, the migratory ability of the cells was clearly accelerated by a knockdown of VCAM1. Furthermore, the migratory ability of UE7T-13 cells was decreased by the over expression of exogenous VCAM1. In addition, the high cell density-induced expression of VCAM1 was clearly suppressed by NF-kappa B (nuclear factor-kappa B) signalling-related protein kinase inhibitors such as an IKK-2 (I kappa B kinase-2) inhibitor VI. In conclusion, the high cell density-induced VCAM1 expression through the NF-kappa B pathway inhibits the migratory ability of human bone marrow-derived MSCs.
  • 高橋美香子, 大久保直登, 帖佐直幸, 高橋典子, 加茂政晴, 水城春美, 石崎明, 客本斉子
    口腔組織培養学会誌 20 1 23 - 24 2011年02月 [査読無し][通常論文]
  • 大久保直登, 帖佐直幸, 客本斉子, 高橋典子, 加茂政晴, 石崎明
    口腔組織培養学会誌 19 1 29 - 30 2010年02月 [査読無し][通常論文]
  • Naoto Okubo, Akira Ishisaki, Tadashi Iizuka, Masato Tamura, Yoshimasa Kitagawa
    JOURNAL OF VASCULAR RESEARCH 47 5 369 - 383 2010年 [査読有り][通常論文]
     
    Objective: To evaluate whether fibroblasts derived from periodontal ligament retain the ability to differentiate into putative vascular cells and construct vascular cell-specific marker-positive blood vessel structures. We also evaluated the morphological features of the structure and investigated the intracellular molecular mechanism underlying the angiogenic activity of these cells. Methods: Single cell-derived cultures (SCDCs) were established from primary rat ligament fibroblast cultures, and their expression of ligament cell-, mesenchymal stem cell-and vascular cell-specific markers was evaluated by RT-PCR and immunocytochemistry. The ability of the cells to construct a blood vessel structure was evaluated in a three-dimensional type I collagen scaffold. The morphological and immunohistological characteristics of the structure were then evaluated. Results: Each SCDC expressed endothelial cell (EC)-specific and smooth muscle cell-specific markers, in addition to mesenchymal stem cell- and ligament cell-specific markers. SCDC2 cells, which abundantly expressed the EC markers Flk-1 and Tie-2, vigorously constructed a blood vessel structure in a phosphoinositide 3-kinase activation-dependent manner. Conclusion: Periodontal ligament fibroblasts have the potential to construct an EC marker-positive blood vessel-like structure. Consequently, the fibroblastic lineage in ligament tissue could be a candidate precursor for construction of a vascular system around damaged ligament tissue to facilitate its regeneration. Copyright (C) 2010 S. Karger AG, Basel
  • 歯根膜由来幹細胞による血管内皮細胞マーカー陽性血管構造の形成
    大久保 直登, 田村 正人, 飯塚 正, 加茂 政晴, 客本 斉子, 帖佐 直幸, 高橋 典子, 北川 善政, 石崎 明
    Journal of Oral Biosciences 51 Suppl. 68 - 68 (一社)歯科基礎医学会 2009年08月
  • ラット歯周靱帯由来間葉系幹細胞が有する血管構築能力の詳細について
    大久保 直登, 山崎 裕, 北川 善政
    日本口腔外科学会雑誌 54 Suppl. 94 - 94 (公社)日本口腔外科学会 2008年09月
  • 塩酸プロピトカイン・フェリプレシンにて術中メトヘモグロビン血症を発症した左上顎歯肉癌の1例
    大久保 直登, 阿部 貴洋, 佐藤 淳, 佐藤 明, 野谷 健一, 北川 善政
    日本口腔外科学会雑誌 52 12 772 - 772 (公社)日本口腔外科学会 2006年12月

その他活動・業績

受賞

  • 2021年02月 北海道経済部産業振興局 令和2年度北海道科学技術奨励賞
  • 2011年05月 平成23年度北海道歯学会: 北海道歯学会賞
  • 2010年07月 第70回岩手科大学歯学会: 岩手歯学会賞
  • 2009年09月 第18回硬組織再生生物学会 最優秀ポスター賞

共同研究・競争的資金等の研究課題

  • 動物の歯を利用した脱灰象牙質由来コラーゲン顆粒骨再生材料の研究開発
    国立研究開発法人日本医療研究開発機構:医療研究開発推進事業費補助金・橋渡し研究プログラム・シーズB
    研究期間 : 2021年04月 -2024年03月
  • 健康長寿社会実現のための疾患罹患リスク予知関連「新規指標」 の探索
    ノーステック財団:札幌ライフサイエンス産業活性化事業 (事業化支援補助金)
    研究期間 : 2022年04月 -2023年03月
  • 歯根膜幹細胞・脱灰象牙質ハイブリッド移植材による新規骨再生治療法の確立
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2018年04月 -2022年03月 
    代表者 : 大久保 直登, 北川 善政, 村田 勝
  • 疾患罹患リスクの予知につながる非侵襲性光感受型医療用デバイスの開発
    国立研究開発法人日本医療研究開発機構:医療研究開発推進事業費補助金・橋渡し研究プログラム・シーズA
    研究期間 : 2021年04月 -2022年02月
  • 光感受性を応⽤した疾患罹患リスクを数値化できる次世代⾮侵襲型デバイスの開発
    国立大学法人 北海道大学:北海道ダイバーシティ研究環境推進ネットワーク事務局(Knit) 補助金
    研究期間 : 2020年04月 -2021年03月
  • 北海道資源を活用した生体移植材の新規加工形態開発とその機能評価
    ノーステック財団:イノベーション創出研究支援事業・発展・橋渡し研究補助金
    研究期間 : 2019年07月 -2020年02月
  • 象牙質の特性を活用した細胞シート基材への応用可能な医療用膜移植材の開発
    国立研究開発法人日本医療研究開発機構:医療研究開発推進事業費補助金・橋渡し研究プログラム・シーズA
    研究期間 : 2019年04月 -2020年02月
  • 北海道資源を活用した新開発医療用バイオマテリアルの機能評価
    ノーステック財団:イノベーション創出研究支援事業・発展・橋渡し研究補助金
    研究期間 : 2018年07月 -2019年02月
  • 2種類の新規歯根膜幹細胞の同定およびその特異的マーカー遺伝子候補の厳選による出願中特許の強化
    国立研究開発法人日本医療研究開発機構:医療研究開発推進事業費補助金・橋渡し研究プログラム・シーズA
    研究期間 : 2018年04月 -2019年02月
  • 日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 大久保 直登, 北川 善政
     
    我々はこれまでに、歯根膜組織中に再生医療に応用可能な多分化能力を有した歯根膜幹細胞が存在し、この幹細胞が3次元的な構造を有した血管を構築する能力や創傷治癒にとって必要不可欠な筋線維芽細胞への分化能力を有していることを報告してきた。今回の研究課題において、この歯根膜幹細胞を筋線維芽細胞へ分化させた際に生じる物理的な組織収縮力を利用することで、三次元的な靭帯様構造を作成することに成功した。作成した靭帯様構造は組織学的な靭帯構造と類似した、並行して整列したコラーゲン線維束を形成し、物理的な強度を有していた。本研究の成果により、将来的に歯根膜幹細胞が靭帯再生治療に応用できる可能性が示唆された。
  • 北海道資源を利用した新規バイオマテリアルの開発
    ノーステック財団:イノベーション創出研究支援事業・スタートアップ研究補助金
    研究期間 : 2017年07月 -2018年02月
  • 培養条件検討による歯根膜幹細胞特異的マーカーの同定と,そのマーカーを指標にした新規歯根膜幹細胞 抽出法の開発
    国立研究開発法人日本医療研究開発機構:医療研究開発推進事業費補助金・橋渡し研究プログラム・シーズA
    研究期間 : 2017年04月 -2018年02月
  • 日本学術振興会:科学研究費助成事業 若手研究(B)
    研究期間 : 2012年04月 -2015年03月 
    代表者 : 大久保 直登
     
    我々は以前に歯根膜組織由来の血管構築能を有する幹細胞を樹立し報告した。この幹細胞が複数の造血幹細胞マーカーを発現し三次元培養によって構築した血管管腔内においてエオジン好染の血球様細胞を誘導することを見出した。そこで、このヘマンジオブラスト様の幹細胞の誘導に関わるキー遺伝子を特定するためにマイクロアレイ解析を行い、一つの転写因子を選定した。その転写因子のアデノウィルスベクターを作成し歯根膜細胞に投与した所、血管新生能および血球細胞誘導能の顕著な増加を認めた。さらに造血幹細胞マーカー遺伝子の発現上昇も確認した。これにより、ヘマンジオブラスト様幹細胞誘導に関わるキー遺伝子の特定に成功した。
  • 歯根膜幹細胞を応用した食感再現型次世代人工歯の開発
    ノーステック財団:イノベーション創出研究支援事業・発展・橋渡し研究補助金
    研究期間 : 2014年07月 -2015年02月
  • 噛みごたえを求め歯根膜幹細胞を組み込んだ次世代型人工歯の開発
    ノーステック財団:イノベーション創出研究支援事業・スタートアップ研究補助金
    研究期間 : 2013年07月 -2014年02月
  • 日本学術振興会:科学研究費助成事業 若手研究(B)
    研究期間 : 2010年 -2011年 
    代表者 : 大久保 直登
     
    我々は歯根膜組織中に存在する歯根膜幹細胞が血管を構築する能力を有することを初めて明らかとした。その際、同一組織由来の血管構築能力の高い細胞と低い細胞の2種類の細胞を樹立した。今回我々はこの2種類の細胞の網羅的遺伝子発現を解析・比較することで、血管新生を制御する可能性のある複数の遺伝子を選定することに成功した。さらに、血管構築能力の高い細胞による詳細な血管新生解析の結果、この細胞が血管を構築する際に同時に血液細胞も誘導している可能性を見出した。
  • 歯根膜由来幹細胞による血管構造形成メカニズムの解明
    日本学術振興会:科学研究費助成事業 研究活動スタート支援
    研究期間 : 2009年 -2010年 
    代表者 : 大久保 直登
     
    研究実施計画に示していたように、自身で樹立した単一の歯根膜細胞初代培養系から派生した2種類の細胞、1)血管形成能の高い細胞群と2)低い細胞群の血管形成能力の違いに着目し、この2種類の細胞間での遺伝子発現様式についてcDNAマイクロアレイを用いて網羅的に調査を行った。その結果、血管形成能力の高いもののみに優位に発現する遺伝子を"血管形成誘導能力の発現を制御すると思われる候補遺伝子"として選定を行うことに成功した。 その後、マイクロアレイの結果より見出した複数の遺伝子を指標に、1)の細胞群において血管形成にかかわると思われるさまざまな刺激を行った際の各遺伝子の発現を調べた結果、特徴的な発現パターンを示す遺伝子群を見出した。興味深いことに、この遺伝子群の中には、その発現に正または負の相関関係を示すものがあり、現在ウェスタンブロットやリアルタイムPCR法などを用いて確認中である。 さらに、上記においてピックアップしたモデル遺伝子の中から真の血管新生誘導遺伝子をin vitroにおいて絞り込むため、候補とした遺伝子に対するsi RNAを作成し、該当候補遺伝子のノックアウトを行うことにより血管形成が起こらなくなりうるかも現在調査中である。 また、in vitro三次元血管形成誘導モデルにおいても、Tie-2遺伝子の強発現部位(血管形成性細胞)と弱発現部位(非血管形成性細胞)を見出しているが(Okubo.et.alJ.Vasc.Res.2010)、この歯根膜幹細胞による上記の2部位に対するレーザーマイクロダイセクションによる組織サンプルからのmRNAを抽出する作業を進め、さまざまな方法により、"歯根膜由来細胞の血管形成能力を制御する遺伝子"の同定を目指している。

教育活動情報

主要な担当授業

  • 生化学実習Ⅰ
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 薬学部
    キーワード : タンパク質、アフィニティー精製、SDS-PAGE、クマシー染色、ELISA、抗体、抗原、タンパク質分子量、構造解析
  • 生化学実習Ⅱ
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 薬学部
    キーワード : 酵素反応速度論、ミカエリス定数、最大速度、代謝回転数、阻害剤、阻害定数


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