Research activity information

• Heterogeneity of perivascular astrocyte endfeet depending on vascular regions in the mouse brain.

  Takeshi Kameyama, Muneaki Miyata, Hajime Shiotani, Jun Adachi, Soichiro Kakuta, Yasuo Uchiyama, Kiyohito Mizutani, Yoshimi Takai

  Astrocytes interact with not only synapses but also brain blood vessels through perivascular astrocyte endfeet (PV-AEF) to form the neurovascular unit (NVU). However, PV-AEF components have not been fully identified. Here, we biochemically isolated blood vessels from mouse brain homogenates and purified PV-AEF. The purified PV-AEF were observed in different sizes, similar to PV-AEF on brain blood vessels. Mass spectrometry analysis identified 9,762 proteins in the purified PV-AEF, including cell adhesion molecules, nectin-2δ, Kirrel2, and podoplanin. Immunofluorescence microscopic analysis revealed that nectin-2δ and podoplanin were concentrated mainly in arteries/arterioles and veins/venules of the mouse brain, whereas Kirrel2 was mainly in arteries/arterioles. Nectin-2α/δ, Kirrel2, and podoplanin were preferentially observed in large sizes of the purified PV-AEF. Furthermore, Kirrel2 potentially has cell adhesion activity of cultured astrocytes. Collectively, these results indicate that PV-AEF have heterogeneity in sizes and molecular components, implying different roles of PV-AEF in NVU function depending on vascular regions.

  Lead, Oct. 2023, iScience, 26(10) (10), 108010 - 108010, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Necl2/3-mediated mechanism for tripartite synapse formation.

  Osamu Nozawa, Muneaki Miyata, Hajime Shiotani, Takeshi Kameyama, Ryouhei Komaki, Tatsuhiro Shimizu, Toshihiko Kuriu, Yutaro Kashiwagi, Yuka Sato, Michinori Koebisu, Atsu Aiba, Shigeo Okabe, Kiyohito Mizutani, Yoshimi Takai

  Ramified, polarized protoplasmic astrocytes interact with synapses via perisynaptic astrocyte processes (PAPs) to form tripartite synapses. These astrocyte-synapse interactions mutually regulate their structures and functions. However, molecular mechanisms for tripartite synapse formation remain elusive. We developed an in vitro co-culture system for mouse astrocytes and neurons that induced astrocyte ramifications and PAP formation. Co-cultured neurons were required for astrocyte ramifications in a neuronal activity-dependent manner and synaptically released glutamate and activation of astrocytic mGluR5 metabotropic glutamate receptor were likely involved in astrocyte ramifications. Astrocytic Necl-2/CADM1 trans-interacted with axonal Necl-3/CADM2, inducing astrocyte-synapse interactions and astrocyte functional polarization by recruiting EAAT1/2 glutamate transporters and Kir4.1 K+ channel to the PAPs, without affecting astrocyte ramifications. This Necl-2/3 trans-interaction increased functional synapse number. Thus, astrocytic Necl-2, synaptically released glutamate, and axonal Necl-3 cooperatively formed tripartite glutamatergic synapses in vitro. Studies on hippocampal mossy fiber synapses in Necl-3 knockout and Necl-2/3 double knockout mice confirmed these novel mechanisms for astrocyte-synapse interactions and astrocyte functional polarization in vivo.

  Feb. 2023, Development (Cambridge, England), 150(4) (4), English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Stimulatory role of nectin-4 and p95-ErbB2 in multilayered T47D cell proliferation.

  Shin Kedashiro, Takeshi Kameyama, Kiyohito Mizutani, Yoshimi Takai

  Multilayered proliferation in an adherent culture as well as proliferation in a suspension culture is a characteristic feature of cancer cells. We previously showed using T47D human mammary cancer cells that nectin-4, upregulated in many cancer cells, cis-interacts with ErbB2 and its trastuzumab-resistant splice variants, p95-ErbB2 and ErbB2ΔEx16, and enhances DNA synthesis mainly through the PI3K-AKT pathway in an adherent culture. We showed here that only the combination of nectin-4 and p95-ErbB2, but not that of nectin-4 and ErbB2 or that of nectin-4 and ErbB2ΔEx16, cooperatively enhanced multilayered T47D cell proliferation through the Hippo pathway-mediated SOX2 gene expression in an adherent culture. T47D cells expressed the components of the apical junctional complex (AJC) consisting of adherens junctions (AJs) and tight junctions and cell polarity molecules, but not the AJ component afadin. The AJC and apicobasal polarity were disorganized in T47D cells in a monolayer and T47D cells stably expressing both nectin-4 and p95-ErbB2 in multilayers. These results indicate that nectin-4 and p95-ErbB2 play a stimulatory role in multilayered proliferation in an adherent culture.

  Apr. 2022, Genes to cells : devoted to molecular & cellular mechanisms, English, International magazine

  [Refereed]

  Scientific journal


• Nectin-2 in general and in the brain

  Kiyohito Mizutani, Muneaki Miyata, Hajime Shiotani, Takeshi Kameyama, Yoshimi Takai

  Springer Science and Business Media LLC, Oct. 2021, Molecular and Cellular Biochemistry

  [Refereed]

  Scientific journal


• Nectins and Nectin-like molecules in synapse formation and involvement in neurological diseases

  Kiyohito Mizutani, Muneaki Miyata, Hajime Shiotani, Takeshi Kameyama, Yoshimi Takai

  Elsevier BV, Sep. 2021, Molecular and Cellular Neuroscience, 115, 103653 - 103653

  [Refereed]

  Scientific journal


• Nectin-4 and p95-ErbB2 cooperatively regulate Hippo signaling-dependent SOX2 gene expression, enhancing anchorage-independent T47D cell proliferation.

  Shin Kedashiro, Takeshi Kameyama, Kiyohito Mizutani, Yoshimi Takai

  Nectin-4, upregulated in various cancer cells, cis-interacts with ErbB2 and its trastuzumab-resistant splice variants, p95-ErbB2 and ErbB2∆Ex16, enhancing DNA synthesis through the PI3K-AKT signaling in human breast cancer T47D cells in an adherent culture. We found here that nectin-4 and p95-ErbB2, but not nectin-4 and either ErbB2 or ErbB2∆Ex16, cooperatively enhanced SOX2 gene expression and cell proliferation in a suspension culture. This enhancement of T47D cell proliferation in a suspension culture by nectin-4 and p95-ErbB2 was dependent on the SOX2 gene expression. In T47D cells, nectin-4 and any one of p95-ErbB2, ErbB2, or ErbB2∆Ex16 cooperatively activated the PI3K-AKT signaling, known to induce the SOX2 gene expression, to similar extents. However, only a combination of nectin-4 and p95-ErbB2, but not that of nectin-4 and either ErbB2 or ErbB2∆Ex16, cooperatively enhanced the SOX2 gene expression. Detailed studies revealed that only nectin-4 and p95-ErbB2 cooperatively activated the Hippo signaling. YAP inhibited the SOX2 gene expression in this cell line and thus the MST1/2-LATS1/2 signaling-mediated YAP inactivation increased the SOX2 gene expression. These results indicate that only the combination of nectin-4 and p95-ErbB2, but not that of nectin-4 and either ErbB2 or ErbB2∆Ex16, cooperatively regulates the Hippo signaling-dependent SOX2 gene expression, enhancing anchorage-independent T47D cell proliferation.

  Apr. 2021, Scientific reports, 11(1) (1), 7344 - 7344, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Identification of Sox2 and NeuN Double-Positive Cells in the Mouse Hypothalamic Arcuate Nucleus and Their Reduction in Number With Aging

  Ayumu Sugiura, Tatsuhiro Shimizu, Takeshi Kameyama, Tomohiko Maruo, Shin Kedashiro, Muneaki Miyata, Kiyohito Mizutani, Yoshimi Takai

  Mar. 2021, FRONTIERS IN AGING NEUROSCIENCE, 12, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Nectin-2α is localized at cholinergic neuron dendrites and regulates synapse formation in the medial habenula.

  Hajime Shiotani, Muneaki Miyata, Takeshi Kameyama, Kenji Mandai, Miwako Yamasaki, Masahiko Watanabe, Kiyohito Mizutani, Yoshimi Takai

  The medial habenula (MHb) receives afferents from the triangular septum and the medial septal complex, projects efferents to the interpeduncular nucleus (IPN) in the midbrain to regulate dopamine and serotonin levels, and is implicated in stress, depression, memory, and nicotine withdrawal syndrome. We previously showed that the cell adhesion molecule nectin-2α is localized at the boundary between adjacent somata of clustered cholinergic neurons and regulates the voltage-gated A-type K+ channel Kv4.2 localization at membrane specializations in the MHb. This adhesion apparatus, named nectin-2α spots, is not associated with the nectin-binding protein afadin or any classic cadherins and their binding proteins p120-catenin and β-catenin. We showed here that nectin-2α was additionally localized at cholinergic neuron dendrites in synaptic regions of the MHb. The genetic ablation of nectin-2 reduced the number of synapses in the MHb without affecting their morphology. Nectin-2α was associated with afadin, cadherin-8, p120-catenin, β-catenin, and αN-catenin, forming puncta adherentia junctions (PAJs). Nectin-2α was observed in the IPN, but not in the triangular septum or the medial septal complex. The genetic ablation of nectin-2 did not affect synapse formation in the IPN. These results indicate that nectin-2α forms two types of adhesion apparatus in the MHb, namely nectin-2α spots at neighboring somata and PAJs at neighboring dendrites, and that dendritic PAJs regulate synapse formation in the MHb. This article is protected by copyright. All rights reserved.

  May 2020, The Journal of comparative neurology, 529(2) (2), 450 - 477, English, International magazine

  [Refereed]

  Scientific journal


• BinCARD2 as a positive regulator of interferon response in innate immunity.

  Suzuki H, Kameyama T, Takaoka A

  Apr. 2019, Biochemical and biophysical research communications, 511(2) (2), 287 - 293

  [Refereed]


• Constitutive aryl hydrocarbon receptor signaling constrains type I interferon-mediated antiviral innate defense

  Taisho Yamada, Hiromasa Horimoto, Takeshi Kameyama, Sumio Hayakawa, Hiroaki Yamato, Masayoshi Dazai, Ayato Takada, Hiroshi Kida, Debbie Bott, Angela C. Zhou, David Hutin, Tania H. Watts, Masahiro Asaka, Jason Matthews, Akinori Takaoka

  Jun. 2016, NATURE IMMUNOLOGY, 17(6) (6), 687 - +, English

  [Refereed]

  Scientific journal


• A role of the sphingosine-1-phosphate (S1P)-S1P receptor 2 pathway in epithelial defense against cancer (EDAC).

  Sayaka Yamamoto, Yuta Yako, Yoichiro Fujioka, Mihoko Kajita, Takeshi Kameyama, Shunsuke Kon, Susumu Ishikawa, Yusuke Ohba, Yusuke Ohno, Akio Kihara, Yasuyuki Fujita

  At the initial step of carcinogenesis, transformation occurs in single cells within epithelia, where the newly emerging transformed cells are surrounded by normal epithelial cells. A recent study revealed that normal epithelial cells have an ability to sense and actively eliminate the neighboring transformed cells, a process named epithelial defense against cancer (EDAC). However, the molecular mechanism of this tumor-suppressive activity is largely unknown. In this study, we investigated a role for the sphingosine-1-phosphate (S1P)-S1P receptor 2 (S1PR2) pathway in EDAC. First, we show that addition of the S1PR2 inhibitor significantly suppresses apical extrusion of RasV12-transformed cells that are surrounded by normal cells. In addition, knockdown of S1PR2 in normal cells induces the same effect, indicating that S1PR2 in the surrounding normal cells plays a positive role in the apical elimination of the transformed cells. Of importance, not endogenous S1P but exogenous S1P is involved in this process. By using FRET analyses, we demonstrate that S1PR2 mediates Rho activation in normal cells neighboring RasV12-transformed cells, thereby promoting accumulation of filamin, a crucial regulator of EDAC. Collectively these data indicate that S1P is a key extrinsic factor that affects the outcome of cell competition between normal and transformed epithelial cells.

  Feb. 2016, Molecular biology of the cell, 27(3) (3), 491 - 9, English, International magazine

  [Refereed]

  Scientific journal


• Helicobacter pylori induces IL-1 beta protein through the inflammasome activation in differentiated macrophagic cells

  Shoichiro Kameoka, Takeshi Kameyama, Takaya Hayashi, Seiichi Sato, Naomi Ohnishi, Takeru Hayashi, Naoko Murata-Kamiya, Hideaki Higashi, Masanori Hatakeyama, Akinori Takaoka

  Lead, 2016, BIOMEDICAL RESEARCH-TOKYO, 37(1) (1), 21 - 27, English

  [Refereed]

  Scientific journal


• The microRNA miR-485 targets host and influenza virus transcripts to regulate antiviral immunity and restrict viral replication

  Harshad Ingle, Sushil Kumar, Ashwin Ashok Raut, Anamika Mishra, Diwakar Dattatraya Kulkarni, Takeshi Kameyama, Akinori Takaoka, Shizuo Akira, Himanshu Kumar

  Dec. 2015, SCIENCE SIGNALING, 8(406) (406), ra126, English

  [Refereed]

  Scientific journal


• The RNA Sensor RIG-I Dually Functions as an Innate Sensor and Direct Antiviral Factor for Hepatitis B Virus

  Seiichi Sato, Kai Li, Takeshi Kameyama, Takaya Hayashi, Yuji Ishida, Shuko Murakami, Tsunamasa Watanabe, Sayuki Iijima, Yu Sakurai, Koichi Watashi, Susumu Tsutsumi, Yusuke Sato, Hidetaka Akita, Takaji Wakita, Charles M. Rice, Hideyoshi Harashima, Michinori Kohara, Yasuhito Tanaka, Akinori Takaoka

  Lead, Jan. 2015, IMMUNITY, 42(1) (1), 123 - 132, English

  [Refereed]

  Scientific journal


• Characterization of innate immune signalings stimulated by ligands for pattern recognition receptors.

  Kameyama T, Takaoka A

  Lead, 2014, Methods in molecular biology (Clifton, N.J.), 1142, 19 - 32

  [Refereed]


• Targeted Induction of Interferon-lambda in Humanized Chimeric Mouse Liver Abrogates Hepatotropic Virus Infection

  Shin-ichiro Nakagawa, Yuichi Hirata, Takeshi Kameyama, Yuko Tokunaga, Yasumasa Nishito, Kazuko Hirabayashi, Junichi Yano, Takahiro Ochiya, Chise Tateno, Yasuhito Tanaka, Masashi Mizokami, Kyoko Tsukiyama-Kohara, Kazuaki Inoue, Makoto Yoshiba, Akinori Takaoka, Michinori Kohara

  Mar. 2013, PLOS ONE, 8(3) (3), e59611, English

  [Refereed]

  Scientific journal


• R248Q変異p53によるH1299細胞の浸潤能増強(p53 dominant-negative mutant R248Q promotes invasion of H1299 cells)

  吉川 和人, 浜田 淳一, 亀山 武志, 鈴木 友希子, 伊川 真弓, 多田 光宏, 中川 宏治, 北川 善政, 守内 哲也

  (一社)日本癌学会, Aug. 2009, 日本癌学会総会記事, 68回, 143 - 143, English

• B型肝炎ウイルス感染に対するRNAセンサーRIG‐Iのデュアル機能による生体防御機構

  佐藤精一, 亀山武志, 高岡晃教, 佐藤精一, 亀山武志, 高岡晃教

  15 Jan. 2016, 感染・炎症・免疫, 45(4) (4), 270‐277, Japanese


• B型肝炎ウイルス感染におけるRIG‐Iのウイルスセンサーおよび抗ウイルス因子としてのデュアル機能

  亀山武志, 亀山武志, 佐藤精一, 佐藤精一, 高岡晃教, 高岡晃教

  科学評論社, 25 Jul. 2015, 月刊臨床免疫・アレルギー科, 64(1) (1), 78 - 84, Japanese


• ピロリ菌の病原因子CagAはNLRP3inflammasomeを活性化し,IL‐1βを産生する

  亀岡章一郎, 亀山武志, 佐藤精一, 林剛瑠, 大西なおみ, 紙谷尚子, 東秀明, 畠山昌則, 高岡晃教

  2015, 日本生化学会大会(Web), 88th, 3TTOKUP-07(3P1168) (WEB ONLY), Japanese


• B型肝炎ウイルスの持続感染を再現する効率的な培養細胞評価系の開発に関する研究 自然免疫認識機構の制御によるHBV複製への影響

  高岡晃教, 佐藤精一, LI Kai, 亀山武志, 林隆也, 原島秀吉, 秋田英万, 櫻井遊, 小原道法, 脇田隆字, 渡士幸一

  2015, B型肝炎ウイルスの持続感染を再現する効率的な培養細胞評価系の開発に関する研究 平成26年度 総括・分担研究報告書, 56‐61, Japanese


• 核酸を用いた自然免疫経路活性化による抗腫瘍効果の検討

  亀山武志, 木口舞美, 佐藤精一, 石川浩三, 高岡晃教

  30 Jun. 2014, 日本がん免疫学会総会プログラム・抄録集, 18th, 110, Japanese


• B型肝炎ウイルスの持続感染を再現する効率的な培養細胞評価系の開発に関する研究 自然免疫認識機構の制御によるHBV複製への影響

  高岡晃教, 佐藤精一, LI Kai, 亀山武志, 林隆也, 原島秀吉, 秋田英万, 櫻井遊

  2014, B型肝炎ウイルスの持続感染を再現する効率的な培養細胞評価系の開発に関する研究 平成25年度 総括・分担研究報告書, 55‐59, Japanese


• 抗ウイルス応答において活性化されるRIG-Iの強力な調節因子ZAPSの同定

  白鳥 聡一, 早川 清雄, 大和 弘明, 亀山 武志, 北辻 千展, 樫木 芙美, 後藤 翔平, 亀岡 章一郎, 藤倉 大輔, 山田 大翔, 水谷 龍明, 数馬田 美香, 佐藤 麻衣子, 田中 淳司, 浅香 正博, 大場 雄介, 宮崎 忠昭, 今村 雅寛, 高岡 晃教

  01 Aug. 2012, 北海道醫學雜誌 = Acta medica Hokkaidonensia, 87(4) (4), 194 - 194, Japanese


• チロシン脱リン酸化酵素であるPRL‐3は癌抑制遺伝子p53の転写活性を制御する

  亀山武志, 亀山武志, 中川宏治, 浜田淳一, 多田光宏, 柏崎晴彦, 守内哲也, 井上農夫男

  2008, 生化学, 1P-1154, Japanese

• がん生物学イラストレイテッド

  渋谷 正史, 湯浅 保仁

  Contributor, Chapter 5 2.上皮間葉転換, 羊土社, 2019, Japanese, ISBN: 9784758120968


• 免疫疾患 : 疾患モデルの作製と利用

  岩倉 洋一郎

  Contributor, 第3節 第2項 IRFファミリー, エル・アイ・シー, 2011, Japanese, ISBN: 9784900487499

• Research on the immune system in uninfected cells that defines the immune response during viral infection

  Kameyama Takeshi

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kobe University, Apr. 2018 - Mar. 2021

  Interferons (IFNs) are the main cytokines for the innate immune response against viral infection. It is known that IFNs are constitutively induced at very low levels in the absence of viral infection. These constitutively induced IFNs and their signals are essential for the rapid and robust induction of IFN induction after viral infection and for the suppression of carcinogenesis. However, the mechanism of this constitutive IFN induction and its regulation remains unclear. In this study, we found that the constitutive IFNs are induced through an intracellular RNA sensor-dependent recognition of endogenous RNAs and the downstream signaling pathway. Furthermore, we found several regulatory factors that regulate cytosolic nucleic acid-mediated innate immune responses. These results identified a novel regulatory mechanism that controls constitutively induced IFNs, which may provide a novel prophylactic target for viral control and suppression of carcinogenesis.


• Activation of innate immune response by DNA from food

  HAYAKAWA Sumio

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, Tokyo Medical and Dental University, 01 Apr. 2014 - 31 Mar. 2017

  Food is recognized as one of the important factors which regulate human health such as immune response. It is known that vitamins, minerals and proteins are essential nutrients to build a healthy body. However, the role of food DNA on health is not clearly understood. So, we focused on the effect of food DNA on activation of innate immune signaling pathway mediated by PRRs. Here we show that a complex with the food DNA and short peptide, the only cathelicidin-derived antimicrobial peptide, activated innate immune response and functioned as a ligand of RIG-I in macrophage. We suggest that DNA from food could provide an application in therapy aimed at maintaining good health.


• Establishment of local and switchable innate immune activation by novel nucleic acid adjuvant

  TAKAOKA Akinori, SATO Seiichi, KAMEYAMA Takeshi

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 01 Apr. 2013 - 31 Mar. 2015

  Adjuvant is an important component for effective vaccination and antitumor therapy. Establishment of local and switchable adjuvant is considered to be an efficient strategy to reduce side effects and efficiently activate innate immune responses. The purpose of this study is the establishment of a novel nucleic acid adjuvant that can trigger the activation of innate immune system in response to X-ray irradiation. In this study, type-C CpG ligands contained with cystamine-modified cytosine were used and showed its structural change by X-ray irradiation, albeit their low efficiency. These results showed these ligands could be a switchable activator and further investigation will be needed to improve their efficiency.


• The study of activation of innate immune response by dietary nucleic acids via oral mucosa

  KAMEYAMA Takeshi, HAYAKAWA Sumio, ADACHI Yoshihiro Christopher, TAKAOKA Akinori, OKADA Kanako, TODA Haruka

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Hokkaido University, 2011 - 2013, Principal investigator

  Diet contains various kinds of nutrient,, which keep us healthy. However the nutritional role of nucleic acids derived from diets is not clearly understood. The innate immunity system is an essential step as the front line of host defense. Although oral mucosa acts as powerful barriers, the importance of oral mucosa in innate immunity remains unclear. In this study, we demonstrate that DNA derived from vegetable activated innate immune response both in vitro and in vivo, which may provide the nutritional immunological role of dietary nucleic acids.

  Competitive research funding


• Analysis of the innate immune response to nucleic acids in tumor cells.

  HAYAKAWA Sumio, KAMEYAMA Takeshi, ADACHI Yoshihiro Christopher

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 2011 - 2012

  Pattern recognition receptors (PRRs)-mediated activation of the innate immune response is triggered by recognition of pathogen-associated molecular patterns (PAMPs), such as a various bacterial cell wall components, peptidoglycan and lipoprotein, as well as bacterial and viral nucleic acids. In this study, we demonstrate that nucleic acids are recognized by PRRs in some tumor types, and promoted the activation of IRF and NF-kB pathway. However, some types of tumor cells are not activated. Furthermore, we are able to find the relationship between the tissue specificity of innate immune response and apoptosis induction. In in vivo experiment, nucleic acids inhibit growth of transplantation tumor in nude mice. Thus, these finding indicate that nucleic acids may contribute to the progress of material for therapeutic cancer. We consider clarifying the detail mechanism of nucleic acids recognition on innate immune response from the molecular, biochemical and cell biology viewpoints.