Education 【 display / non-display 】

Education 【 display / non-display 】

• 1978

  -

  1984

  Sapporo Medical College   School of Medicine  

• 　

  -

  1988

  Sapporo Medical University  

Research Experience 【 display / non-display 】

Research Experience 【 display / non-display 】

• 2024.04

  -

  Now

  Japan Healthcare University   School of Health Sciences   Specially Appointed Professor

  M.D., Ph.D

  　View Summary

  Professor Emeritus, Sapporo Medical University

• 2023.11

  -

  2024.03

  Sapporo Medical University School of Medicine, Institute of Regenerative Medicine   Department of Tissue Development and Regeneration   Full Professor

  M.D., Ph.D

• 2011.04

  -

  2023.10

  Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine   Department of Tissue Development and Regeneration   Full Professor

• 2002.09

  -

  2011.03

  Cancer Research Institute, Sapporo Medical University School of Medicine   Department of Pathophysiology   Full Professor

  Full Professor

• 1998.07

  -

  2002.08

  Cancer Research Institute, Sapporo Medical College   Department of Pathology   Associate Professor

  Associate Professor

display all >>

Professional Memberships 【 display / non-display 】

Professional Memberships 【 display / non-display 】

• 　

  　

  　

  Japanese Society for Artificial Organs

• 　

  　

  　

  American Association for Cancer Research

• 　

  　

  　

  米国実験病理学会

• 　

  　

  　

  Japanese Society of Pathology

• 　

  　

  　

  American Society for Investigative Pathology

display all >>

Research Areas 【 display / non-display 】

Research Areas 【 display / non-display 】

• Life sciences   Biomedical engineering  

• Life sciences   General surgery, pediatric surgery  

• Life sciences   Experimental pathology  

• Life sciences   Biomaterials  

• Life sciences   Human pathology  

display all >>

Affiliation 【 display / non-display 】

Affiliation 【 display / non-display 】

• Sapporo Medical University   医学部   Professor  

Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

• CD44

• Nicotinamide

• ヒト

• 肝前駆細胞

• Hepatic stem/progenitor cells

display all >>

Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Generation of functional liver organoids on combining hepatocytes and cholangiocytes with hepatobiliary connections ex vivo.

  Naoki Tanimizu, Norihisa Ichinohe, Yasushi Sasaki, Tohru Itoh, Ryo Sudo, Tomoko Yamaguchi, Takeshi Katsuda, Takafumi Ninomiya, Takashi Tokino, Takahiro Ochiya, Atsushi Miyajima, Toshihiro Mitaka

  Nature communications   12 ( 1 ) 3390 - 3390  2021.06  [Refereed]  [International journal]

  　View Summary

  In the liver, the bile canaliculi of hepatocytes are connected to intrahepatic bile ducts lined with cholangiocytes, which remove cytotoxic bile from the liver tissue. Although liver organoids have been reported, it is not clear whether the functional connection between hepatocytes and cholangiocytes is recapitulated in those organoids. Here, we report the generation of a hepatobiliary tubular organoid (HBTO) using mouse hepatocyte progenitors and cholangiocytes. Hepatocytes form the bile canalicular network and secrete metabolites into the canaliculi, which are then transported into the biliary tubular structure. Hepatocytes in HBTO acquire and maintain metabolic functions including albumin secretion and cytochrome P450 activities, over the long term. In this study, we establish functional liver tissue incorporating a bile drainage system ex vivo. HBTO enable us to reproduce the transport of hepatocyte metabolites in liver tissue, and to investigate the way in which the two types of epithelial cells establish functional connections.

  DOI PubMed

• Epithelial Morphogenesis during Liver Development

  Naoki Tanimizu, Toshihiro Mitaka

  COLD SPRING HARBOR PERSPECTIVES IN BIOLOGY ( COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT )  9 ( 8 )  2017.08  [Refereed]

  　View Summary

  Tissue stem/progenitor cells supply multiple types of epithelial cells that eventually acquire specialized functions during organ development. In addition, three-dimensional (3D) tissue structures need to be established for organs to perform their physiological functions. The liver contains two types of epithelial cells, namely, hepatocytes and cholangiocytes, which are derived from hepatoblasts, fetal liver stem/progenitor cells (LPCs), in mid-gestation. Hepatocytes performing many metabolic reactions form cord-like structures, whereas cholangiocytes, biliary epithelial cells, form tubular structures called intrahepatic bile ducts. Analyses for human genetic diseases and mutant mice have identified crucial molecules for liver organogenesis. Functions of those molecules can be examined in in vitro culture systems where LPCs are induced to differentiate into hepatocytes or cholangiocytes. Recent technical advances have revealed 3D epithelial morphogenesis during liver organogenesis. Therefore, the liver is a good model to understand how tissue stem/progenitor cells differentiate and establish 3D tissue architectures during organ development.

  DOI

• Re-evaluation of liver stem/progenitor cells

  Naoki Tanimizu, Toshihiro Mitaka

  ORGANOGENESIS ( LANDES BIOSCIENCE )  10 ( 2 ) 208 - 215  2014.04  [Refereed]

  　View Summary

  Liver stem/progenitor cells (LPCs) are defined as cells that supply two types of liver epithelial cells, hepatocytes and cholangiocytes, during development, cellular turnover, and regeneration. Hepatoblasts, which are fetal LPCs derived from endoderm stem cells, robustly proliferate and differentiate into hepatocytes and cholangiocytes during fetal life. Between mid-gestation and the neonatal period, some cholangiocytes function as LPCs. Although LPCs in adult livers can be enriched in cells positive for cholangiocyte markers, their tissue localization and functions in cellular turnover remain obscure. On the other hand, it is well known that liver regeneration under conditions suppressing hepatocyte proliferation is supported by LPCs, though their origin has not been clearly identified. Recently many groups took advantage of new techniques including prospective isolation of LPCs by fluorescence-activated cell sorting and genetic lineage tracing to facilitate our understanding of epithelial supply in normal and injured livers. Those works suggest that, in normal livers, the turnover of hepatocytes mostly depends on duplication of hepatocytes. It is also demonstrated that liver epithelial cells as well as LPCs have great plasticity and flexible differentiation capability to respond to various types of injuries by protecting or repairing liver tissues.

  DOI PubMed

• CINC-2 and miR-199a-5p in exosomes secreted by transplanted Thy1+ cells activate hepatocytic progenitor cell growth in rat liver regeneration

  Norihisa Ichinohe, Naoki Tanimizu, Keisuke Ishigami, Yusuke Yoshioka, Naoki Fujitani, Takahiro Ochiya, Motoko Takahashi, Toshihiro Mitaka

  ( Research Square Platform LLC )   2023.01

  　View Summary

  Abstract Background Small hepatocyte-like progenitor cells (SHPCs) are hepatocytic progenitor cells that transiently form clusters in rat livers treated with retrorsine and with 70% partial hepatectomy (PH). We previously reported that transplantation of Thy1⁺ cells derived from d-galactosamine-treated livers promotes SHPC expansion, resulting in the acceleration of liver regeneration. Extracellular vesicles (EVs) produced by Thy1⁺ cells act on sinusoidal endothelial cells (SECs) and Kupffer cells to secrete IL17B and IL25, respectively, resulting in SHPC activation through IL17 receptor B (RB) signaling. Our aim is to identify factors in Thy1-EVs that activate IL17RB signaling.Methods Thy1⁺ cells isolated from rats with d-galactosamine-induced liver injury were cultured for one week. Although some liver stem/progenitor cells proliferated into colonies, others maintained as mesenchymal cells (MCs). Thy1-MCs or Thy1-liver stem/progenitor cells were transplanted into retrorsine/PH-treated livers to examine their effects on SHPCs. SHs isolated from adult rat livers were used to validate factors regulating growth induction.Results The number and size of SHPCs remarkably increased in livers transplanted with Thy1-MCs. Comprehensive analysis of Thy1-MC-EVs revealed that miR-199a-5p, CINC-2, and MCP-1 are candidates for stimulating SHPC growth. Administration of the miR-199a-5p mimic, and not CINC-2, promoted SH growth. SECs treated with CINC-2 induced IL17b expression and their conditioned medium promoted SH growth.Conclusion Thy1-MC transplantation may accelerate liver regeneration due to SHPCs expansion, which is stimulated by CINC-2/IL17RB signaling and miR-199a-5p.

  DOI

• Extracellular vesicles containing miR-146a-5p secreted by bone marrow mesenchymal cells activate hepatocytic progenitors in regenerating rat livers.

  Norihisa Ichinohe, Masayuki Ishii, Naoki Tanimizu, Toru Mizuguchi, Yusuke Yoshioka, Takahiro Ochiya, Hiromu Suzuki, Toshihiro Mitaka

  Stem cell research & therapy   12 ( 1 ) 312 - 312  2021.05  [Refereed]  [International journal]

  　View Summary

  BACKGROUND: Small hepatocyte-like progenitor cells (SHPCs) appear to form transient clusters in rat livers treated with retrorsine (Ret) and 70% partial hepatectomy (PH). We previously reported that the expansion of SHPCs was amplified in Ret/PH-treated rat livers transplanted with Thy1+ cells derived from D-galactosamine-treated injured livers. Extracellular vesicles (EVs) produced by hepatic Thy1+ donor cells activated SHPCs via interleukin (IL)-17 receptor B signaling. As bone marrow-derived mesenchymal cells (BM-MCs) also express Thy1, we aimed to determine whether BM-MCs could also promote the growth of SHPCs. METHODS: BM-MCs were isolated from dipeptidyl-peptidase IV (DPPIV)-positive rats. BM-MCs or BM-MC-derived EVs were administered to DPPIV-negative Ret/PH rat livers, and the growth and the characteristics of SHPC clusters were evaluated 14 days post-treatment. miRNA microarrays and cytokine arrays examined soluble factors within EVs. Small hepatocytes (SHs) isolated from an adult rat liver were used to identify factors enhancing hepatocytic progenitor cells growth. RESULTS: The recipient's livers were enlarged at 2 weeks post-BM-MC transplantation. The number and the size of SHPCs increased remarkably in livers transplanted with BM-MCs. BM-MC-derived EVs also stimulated SHPC growth. Comprehensive analyses revealed that BM-MC-derived EVs contained miR-146a-5p, interleukin-6, and stem cell factor, which could enhance SHs' proliferation. Administration of EVs derived from the miR-146a-5p-transfected BM-MCs to Ret/PH rat livers remarkably enhanced the expansion of SHPCs. CONCLUSIONS: miR-146a-5p involved in EVs produced by BM-MCs may play a major role in accelerating liver regeneration by activating the intrinsic hepatocytic progenitor cells.

  DOI PubMed

display all >>

Books and Other Publications 【 display / non-display 】

Books and Other Publications 【 display / non-display 】

• 肝繊維化と肝細胞癌におけるラミニンα5鎖とその受容体の役割

  吉川 大和, 三高 俊広

  [吉川大和]  2008

Misc 【 display / non-display 】

Misc 【 display / non-display 】

• 肝細胞癌における細胞接着分子ルテランの放出メカニズムの解明

  小川 貴穂, 三輪 隆博, 谷水 直樹, 門谷 裕一, 水口 徹, 平田 公一, 野水 基義, 三高 俊広, 吉川 大和

  日本結合組織学会学術大会・マトリックス研究会大会合同学術集会プログラム・抄録集 ( 日本結合組織学会・マトリックス研究会 )  45回・60回   125 - 125  2013.06

• PD-6-1 肝細胞癌における細胞外マトリックスの分子環境 : ラミニンα鎖と受容体ルテランによる分子機序(PD パネルディスカッション,第113回日本外科学会定期学術集会)

  水口 徹, 吉川 大和, 谷水 直樹, 一戸 義久, 中村 幸雄, 川本 雅樹, 目黒 誠, 野水 基義, 三高 俊広, 平田 公一

  日本外科学会雑誌 ( 一般社団法人日本外科学会 )  114 ( 2 ) 242 - 242  2013.03

  CiNii

• 分子生物学的手法を用いた肝細胞癌治療戦略 肝細胞癌における細胞外マトリックスの分子環境 ラミニンα鎖と受容体ルテランによる分子機序

  水口 徹, 吉川 大和, 谷水 直樹, 一戸 義久, 中村 幸雄, 川本 雅樹, 目黒 誠, 野水 基義, 三高 俊広, 平田 公一

  日本外科学会雑誌 ( (一社)日本外科学会 )  114 ( 臨増2 ) 242 - 242  2013.03

• Construction of functional ex-vivo liver tissues with pericyte-incorporated microvessels using microporous membranes

  J. Kasuya, R. Sudo, T. Mitaka, M. Ikeda, K. Tanishita

  JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE ( WILEY-BLACKWELL )  6   306 - 306  2012.09

  Research paper, summary (international conference)  

• 肝細胞癌における細胞接着分子Lutheran/B-CAMの発現とシェディング(Shedding of Luthern/basal cell adhesion molecule (Lu/B-CAM) from hepatocellular carcinoma)

  吉川 大和, 水口 徹, 平田 公一, 野水 基義, 三高 俊広

  日本癌学会総会記事 ( 日本癌学会 )  71回   484 - 484  2012.08

display all >>

Awards 【 display / non-display 】

Awards 【 display / non-display 】

• 北海道医師会賞・北海道知事賞

  2020.10   北海道医師会   肝臓の幹・前駆細胞の研究

• 寿原記念財団研究助成金

  2006.12   寿原記念財団   ヒト肝前駆細胞を用いた肝不全治療法確立のための基礎的研究

• 武田研究奨励賞優秀賞

  2001  

Research Projects 【 display / non-display 】

Research Projects 【 display / non-display 】

• Development of designer cells for severe liver diseases treatment and analysis of their regeneration mechanism by focusing on tisse stem cells.

  Grant-in-Aid for Scientific Research (C)

  Project Year :

  2023.04

  -

  2026.03

   

  市戸 義久, 三高 俊広

• Establishment of hepatobiliary connection ex vivo

  Grant-in-Aid for Scientific Research (C)

  Project Year :

  2020.04

  -

  2023.03

   

  谷水 直樹, 三高 俊広

  　View Summary

  我々は、マウス肝前駆細胞と胆管上皮細胞の共培養を行うことで、胆管接続型の肝臓オルガノイド(Hepatobiliary tubular organoid; HBTO)の作製に成功した。肝細胞機能の長期維持が可能であること、組織内の代謝産物輸送の再現などを可能にした。また。HBTO作成にあたり、肝前駆細胞と胆管上皮細胞の間のECADを介した細胞間結合が重要であることを示すデータを得た。以上の結果を、Research articleとしてNature Communications誌に発表した。 肝病態モデル構築については、マウスの初代星細胞とクッパー細胞をHBTOに導入し、脂肪酸添加による変化を検討した。肝細胞障害は認められなったが、脂肪滴の蓄積が観察された。今後、脂肪酸添加群において星細胞が活性化していることを確認する予定である。 新規薬物動態実験系の確立のために、HBTOから肝細胞代謝産物を回収する方法の確立を試みている。タイト結合の阻害を行うために、クローディン阻害ペプチドの使用を試みが、培地への速やかなCLF（胆汁酸アナログ）の放出が検出されなかった。次に、タイト結合に局在する分子のノックダウンを行うことにした。Ezrinに対するguide RNAを設計し、GFPを発現するベクターに導入した。細胞株にプラスミドをトランスフェクションした後、GFP(+)細胞を分取し、培養を行った。Western blottingでEzrinタンパク質の減少、免疫染色でEzrinの消失を確認した。続いて、初代胆管上皮細胞への遺伝子導入を試みたが、効率やトランスフェクション後の培養に問題があった。今後、ウイルスによるプラスミド導入、あるいは上皮細胞特性を維持したままの胆管上皮細胞株の樹立などを行い、バリア機能阻害の系を確立する予定である。

• 血管相互作用を基軸にした三次元コンプレックス組織工学の創生

  基盤研究(B)

  Project Year :

  2019.04

  -

  2023.03

   

  須藤 亮, 山下 忠紘, 谷下 一夫, 三高 俊広

  　View Summary

  三次元組織工学において血管組織と実質組織、および血管組織と腫瘍組織の相互作用（血管相互作用）を解明することは極めて重要な課題であり、立体臓器の再生手法や新たながん治療戦略の立案につながる。そこで、本研究は、血管相互作用を基軸として、血管と三次元肝組織（実質組織）、および血管と胆管がんオルガノイド（腫瘍組織）の関係を明らかにすることによって、複数の組織が複合化した高次の三次元組織を構築する組織工学（三次元コンプレックス組織工学）の学術基盤を創生することを目的としている。 研究実施計画の1年目となる2019年度は、本研究の基軸となる血管相互作用を調べるうえで重要な血管組織の構築と高機能化について中心的に取り組んだ。具体的には、マイクロ流体デバイスを用いてヒト血管内皮細胞とヒト間葉系幹細胞の共培養を行い、壁細胞（ペリサイト）に被覆されて安定化した毛細血管網を構築した。さらに、階層性を有する血管網を構築するために、血管径を拡大させる力学的因子および生化学的因子を検討した。まず、血管径を拡張させる力学的因子としてせん断応力を検討した。すなわち、本研究で構築した微小血管の内腔に培養液を灌流する実験を行い、微小血管が拡大リモデリングを行うことを立証した。次に、血管径を拡張させる生化学的因子としてApelinを検討し、Apelinを添加することによって培養血管の直径が拡大することを示した。 以上の研究により血管構築手法の基盤を確立し、三次元肝組織（実質組織）および胆管癌オルガノイド（腫瘍組織）との相互作用の検討に着手した。具体的には、マイクロ流体デバイスを用いてヒトiPS細胞由来肝細胞様細胞の培養法を検討した。また、マイクロ流体デバイスで胆管がんオルガノイドを形成する手法を検討し、マイクロ流体デバイスにおいても従来研究と同様にオルガノイドを形成する手法を確立した。

• Renewal of severely damaged livers by activating hepatic progenitor cells

  Grant-in-Aid for Scientific Research (B)

  Project Year :

  2018.04

  -

  2021.03

   

  MITAKA Toshihiro

  　View Summary

  Small hepatocytes (SHs) are a subpopulation of mature hepatocytes that can act as hepatocytic progenitor cells. Hepatocytic parental progenitor cells (HPPCs) exist among SHs. In this study we demonstrated that the self-renewal ability of HPPCs depended on laminin111 through integrin beta1 signaling. In addition, we succeeded in generating a hepatobiliary tubular organoid using mouse hepatocytic progenitor cells and cholangiocytes. Hepatocytes form the bile canalicular network and secret metabolites into the canaliculi, which are then transported into the biliary tubular structure. Transplantation of bone marrow-derived mesenchymal cells (BM-MCs) enhanced the regeneration of retrorsine/PH (Ret/PH) model rat livers. Small hepatocyte-like progenitor cells (SHPCs) are intrinsic hepatic progenitor cells appeared in Ret/PH-treated livers. Administration of BM-MC-derived extracellular vesicles containing miR-146a-5p, interleukin 6, and stem cell factor could enhance the growth of SHPCs.

• In vitro reconstruction of hepatic tissue

  Grant-in-Aid for Challenging Research (Exploratory)

  Project Year :

  2017.06

  -

  2019.03

   

  Mitaka Toshihiro

  　View Summary

  We developed the method to reconstruct hepatic organoids consisting of mouse hepatocytes and cholangiocytes, which could drain bile juice into bile ducts from bile canaliculi formed by hepatocytes. Cholangiocytes are cultured on collagen gel and then hepatocytes are added. After collagen gel containing Matrigel is overlaid on the cells, hepatic organoids with the connections between bile canaliculi and bile ducts are formed within 2 weeks. Hepatocytic parental progenitor cells (HPPCs) with self-renewal capability exist in a population of small hepatocytes, which is a subpopulation of mature hepatocytes. HPPCs could be passaged several times with maintaining their abilities of basic hepatic functions and production of progeny. Self-renewal capability of HPPCs is maintained when they are cultured on laminin 111, which transduces the signal via integrin beta1.

display all >>