Inagaki, Emi



School of Medicine, Department of Ophthalmology (Shinanomachi)


Project Senior Assistant Professor (Non-tenured)/Project Assistant Professor (Non-tenured)/Project Lecturer (Non-tenured)


Papers 【 Display / hide

  • Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men.

    Irie J, Inagaki E, Fujita M, Nakaya H, Mitsuishi M, Yamaguchi S, Yamashita K, Shigaki S, Ono T, Yukioka H, Okano H, Nabeshima YI, Imai SI, Yasui M, Tsubota K, Itoh H

    Endocrine journal  2019.11

    ISSN  0918-8959

  • Immunological Properties of Neural Crest Cells Derived from Human Induced Pluripotent Stem Cells

    Fujii S., Yoshida S., Inagaki E., Hatou S., Tsubota K., Takahashi M., Shimmura S., Sugita S.

    Stem Cells and Development (Stem Cells and Development)  28 ( 1 ) 28 - 43 2019.01

    ISSN  15473287

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    © Shota Fujii et al. 2018; Published by Mary Ann Liebert, Inc. 2018. Collecting sufficient quantities of primary neural crest cells (NCCs) for experiments is difficult, as NCCs are embryonic transient tissue that basically does not proliferate. We successfully induced NCCs from human induced pluripotent stem cells (iPSCs) in accordance with a previously described method with some modifications. The protocol used in this study efficiently produced large amounts of iPSC-derived NCCs (iPSC-NCCs). Many researchers have recently produced large amounts of iPSC-NCCs and used these to examine the physiological properties, such as migratory activity, and the potential for medical uses such as wound healing. Immunological properties of NCCs are yet to be reported. Therefore, the purpose of this study was to assess the immunological properties of human iPSC-NCCs. Our current study showed that iPSC-NCCs were hypoimmunogenic and had immunosuppressive properties in vitro. Expression of HLA class I molecules on iPSC-NCCs was lower than that observed for iPSCs, and there was no expression of HLA class II and costimulatory molecules on the cells. With regard to the immunosuppressive properties, iPSC-NCCs greatly inhibited T cell activation (cell proliferation and production of inflammatory cytokines) after stimulation. iPSC-NCCs constitutively expressed membrane-bound TGF-β, and TGF-β produced by iPSC-NCCs played a critical role in T cell suppression. Thus, cultured human NCCs can fully suppress T cell activation in vitro. This study may contribute to the realization of using stem cell-derived NCCs in cell-based medicine.

  • A Rabbit Corneal Endothelial Dysfunction Model Using Endothelial-Mesenchymal Transformed Cells

    Yamashita K., Hatou S., Inagaki E., Higa K., Tsubota K., Shimmura S.

    Scientific Reports (Scientific Reports)  8 ( 1 )  2018.12

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    © 2018, The Author(s). Unlike humans, rabbit corneal endothelial wounds are known to spontaneously heal. The current study was aimed to develop a new rabbit bullous keratopathy model using corneal endothelial cells that were induced to undergo endothelial-mesenchymal transformation (EMT). EMT was induced in rabbit corneal endothelial cells (RCECs) by culturing with TGFβ and basic FGF Supplemented Medium. The corneal endothelia in recipient rabbits were mechanically scraped from the corneal endothelial surface inside an 8 mm mark. Then, a suspension of EMT-induced RCECs (EMT-RCECs) was injected into the anterior chamber. Eyes injected with freshly isolated RCECs (Fresh RCECs group) and eyes that were scraped without injection of cells (Scrape group) were used as controls. Immediately following operation, subepithelial and stromal edema was observed with increased central corneal thickness and corneal opacity in all groups. In the EMT-RCECs group, bullous keratopathy persisted for 42 days up to the end of the study. In the Fresh-RCECs and Scrape groups, corneal transparency and thickness recovered by 7 days after treatment and was maintained up to 42 days. The activated fibroblast marker, α-SMA, was observed spanning from corneal endothelium to corneal stroma in the EMT-RCECs group. Interestingly, α-SMA was upregulated in the Scrape-group as well. In all groups, there was no damage to other intraocular structures, and intraocular pressure was normal throughout the observation period. Transplanting a fresh donor cornea effectively treated corneal edema due to bullous keratopathy. This model is a promising tool for pre-clinical trials in the development of new therapies against corneal endothelial dysfunction.

  • Corneal Endothelial Regeneration Using Mesenchymal Stem Cells Derived from Human Umbilical Cord

    Yamashita K., Inagaki E., Hatou S., Higa K., Ogawa A., Miyashita H., Tsubota K., Shimmura S.

    Stem Cells and Development (Stem Cells and Development)  27 ( 16 ) 1097 - 1108 2018.08

    ISSN  15473287

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    © Copyright 2018, Mary Ann Liebert, Inc. Corneal blindness is the third leading cause of blindness in the world, and one of the main etiologies is dysfunction of the corneal endothelium. Current treatment of corneal endothelial disease is allogenic corneal transplantation, which is limited by the global shortage of donor corneas and immunological rejection. The corneal endothelium consists of a monolayer of cells derived from the neural crest and mesoderm. Its main function is to prevent corneal edema by tight junctions formed by zonular occludens-1 (ZO-1) and Na, K-ATPase pump function. The human umbilical cord (UC) is a rich source of mesenchymal stem cells (MSCs). UC-MSCs that have multi-lineage potential may be an accessible allogenic source. After inducing differentiation with medium containing glycogen synthase kinase (GSK) 3-β inhibitor, UC-MSCs formed polygonal corneal endothelial-like cells that functioned as tissue-engineered corneal endothelium (UTECE). Expressions of major corneal endothelial markers were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and quantitative RT-PCR (qRT-PCR). Western blotting confirmed the expression of Na,K-ATPase and PITX2, the functional and developmental markers of corneal endothelial cells. Immunohistochemistry revealed the localization of Na,K-ATPase and ZO-1 in cell-cell junctions, suggesting the presence of tight junctions. In vitro functional analysis revealed that UTECE had significantly high pump function compared with UC-MSCs. Moreover, UTECE transplanted into a rabbit model of bullous keratopathy successfully maintained corneal thickness and transparency. Our findings suggest that UTECE may be used as a source of allogenic cells for the treatment of corneal endothelial disease.

  • Ketone body 3-hydroxybutyrate mimics calorie restriction via the Nrf2 activator, fumarate, in the retina

    Izuta Y., Imada T., Hisamura R., Oonishi E., Nakamura S., Inagaki E., Ito M., Soga T., Tsubota K.

    Aging Cell (Aging Cell)  17 ( 1 )  2018.02

    ISSN  14749718

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    © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd. Calorie restriction (CR) being the most robust dietary intervention provides various health benefits. D-3-hydroxybutyrate (3HB), a major physiological ketone, has been proposed as an important endogenous molecule for CR. To investigate the role of 3HB in CR, we investigated potential shared mechanisms underlying increased retinal 3HB induced by CR and exogenously applied 3HB without CR to protect against ischemic retinal degeneration. The repeated elevation of retinal 3HB, with or without CR, suppressed retinal degeneration. Metabolomic analysis showed that the antioxidant pentose phosphate pathway and its limiting enzyme, glucose-6-phosphate dehydrogenase (G6PD), were concomitantly preserved. Importantly, the upregulation of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a regulator of G6PD, and elevation of the tricarboxylic acid cycle's Nrf2 activator, fumarate, were also shared. Together, our findings suggest that CR provides retinal antioxidative defense by 3HB through the antioxidant Nrf2 pathway via modification of a tricarboxylic acid cycle intermediate during 3HB metabolism.

Reviews, Commentaries, etc. 【 Display / hide

  • NMN(nicotinamide mononucleotide)による網膜保護作用

    稲垣 絵海, 中村 滋, 菅井 恵津子, 泉田 祐輔, 今田 敏弘, 結城 賢哉, 榛村 重人, 芝田 晋介, 岡野 栄之, 坪田 一男

    日本緑内障学会抄録集 (日本緑内障学会)  30回   98 - 98 2019.09

Research Projects of Competitive Funds, etc. 【 Display / hide

  • 間葉系幹細胞局所投与による眼表面難治疾患制御法の開発


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists , Principal investigator

  • 前眼部を用いた新規造腫瘍試験モデルの構築と応用


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists , Principal investigator

  • Sirtuinを標的とした眼疾患の新しい予防、治療方法の開発


    Keio University, Grant-in-Aid for Scientific Research (B), No Setting

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    本年度は特にSirtuinの脱アセチル化反応に基質として必要なNAD関連中間代謝産物に着目した。成果の概要としては第一に、動物モデルを用いてNAD関連中間代謝産物を経口投与し、関連する代謝産物の血中濃度を測定することでその体内動態を明らかにした。さらにこれらの代謝産物を二週間にわたり経口投与した結果、複数の臓器においてSirtuin関連遺伝子の変化やミトコンドリア関連分子の変化を認めるなど好ましい変化を予備検討の結果を得た。第二にin vitroモデルにおいてNAD関連分子不含有培地を用いた検討を行い細胞内NAD量の変化による代謝変換の影響を解析し有用な結果を得た。第三に本学倫理委員会の承認を経ておこなっている複数の眼疾患患者における臨床検体の解析についても体内のNAD関連代謝産物の濃度が、複数の眼疾患のバイオマーカーとなる予備知見の結果を得ている。

  • 角膜内皮細胞機能制御におけるNAD+の生理学的重要性と治療標的としての可能性


    Keio University, Grant-in-Aid for JSPS Fellows, No Setting

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    NAD(Nicotinamide adenine dinucleotide)は酸化還元反応において重要な役割を果たす古典的な補酵素として古くから知られていた。近年、哺乳類NAD合成系の律速酵素であるNAMPTがNAD量を調節し、老化・代謝などの様々な局面で重要である事が明らかになっている。代謝臓器内のNADを増強することが、代謝改変に有効な可能性がありヒトでの臨床試験も始まっている。しかしこれらのNAD関連代謝産物のヒトにおける正確な測定系、体内局在、さらに正確前眼部における有用性は不明であった。


Courses Taught 【 Display / hide