New strategy of infertility treatment by regulating sperm functions

• Project/Area Number: 20K07015
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 47030:Pharmaceutical hygiene and biochemistry-related
• Research Institution: Kumamoto University
• Principal Investigator: Takeo Toru 熊本大学, 生命資源研究・支援センター, 教授 (10517014)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2022: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2021: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 不妊症 / 受精阻害因子 / マイクロ流体デバイス / 精子選別 / 体外受精 / 受精適期 / リン脂質 / シクロデキストリン / 受精 / 精子 / 卵子 / 生殖工学 / 不妊 / 人工授精 / 不妊症モデルマウス

Outline of Research at the Start

不妊症は、妊娠を望むカップルが１年以上の不妊期間がある状態と定義され、急速な人口減少が進む日本において解決すべき課題となっている。不妊症と診断される方の中には、精子や卵子の機能には問題がないにも関わらず不妊となる場合がある。この原因不明不妊症を解決するためには、不妊症となる原因の解明が必要不可欠である。そこで本研究では、実験用マウスを用いて精子の機能解析および体内受精における精子や卵子の挙動を観察することで、in vitro および in vivoにおける受精阻害因子を解明し、受精成功率を向上させる新規不妊治療技術の開発に有用な基礎的知見の収集を行う。

Outline of Final Research Achievements

The research aims to elucidate the fertilization inhibitory factors and develop new technology to enhance fertilization function. We found that sperm sorting using a microfluidic device enhances the fertilization rate. Furthermore, analysis of the in vivo fertilization environment revealed that there is an optimal time for fertilization in the fallopian tubes, and that fertilization efficiency is increased by synchronizing the time when sperm and egg encounter each other. This year, we demonstrated that the removal of phospholipids is effective in improving sperm fertilization efficiency, and that phospholipid-directed cyclic oligosaccharides (cyclodextrins) are effective in improving the fertilization rate in IVF. In summary, we developed a sperm sorting technique to improve fertilization efficiency, improved in vivo fertilization efficiency, and discovered new compounds that increase the fertilization rate in in vitro fertilization.

Academic Significance and Societal Importance of the Research Achievements

本研究では、受精効率を高める精子の選別技術の開発、生体内における受精効率の改善、体外受精における受精率を高める新規化合物を発見し、生殖科学の進展に資する知見が得られた。また、本研究の知見を応用することで、生殖医療、家畜や産業動物の繁殖、絶滅危惧動物の保護に有用な基礎的知見が得られた。

Research Products

• [Journal Article] Synchronization of the ovulation and copulation timings increased the number of in vivo fertilized oocytes in superovulated female mice (2023)
  • Author(s): Nakao Satohiro、Ito Kotono、Sugahara Chihiro、Watanabe Hitomi、Kondoh Gen、Nakagata Naomi、Takeo Toru
  • Journal Title: PLOS ONE Volume: 18 Issue: 2 Pages: e0281330-e0281330
  • DOI: 10.1371/journal.pone.0281330
  • Peer Reviewed / Open Access
• [Journal Article] Dimethyl-α-cyclodextrin induces capacitation by removing phospholipids from the plasma membrane of mouse sperm (2023)
  • Author(s): Nakao Satohiro、Ito Kotono、Sakoh Kazuhito、Takemoto Kenji、Watanabe Hitomi、Kondoh Gen、Irie Tetsumi、Nakagata Naomi、Takeo Toru
  • Journal Title: Biology of Reproduction Volume: 108 Issue: 4 Pages: 671-681
  • DOI: 10.1093/biolre/ioad013
  • Peer Reviewed
• [Journal Article] Asian Mouse Mutagenesis Resource Association (AMMRA): mouse genetics and laboratory animal resources in the Asia Pacific (2021)
  • Author(s): Hsian-Jean Chin, Michael S. Dobbie, Xiang Gao, James E. Hennessy, Ki-Hoan Nam, Je Kyung Seong, Toshihiko Shiroishi, Toru Takeo, Atsushi Yoshiki, Jing Zao, Chi-Kuang Leo Wang
  • Journal Title: Mammalian Genome Volume: 33 Issue: 1 Pages: 192-202
  • DOI: 10.1007/s00335-021-09912-1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Successful selection of mouse sperm with high viability and fertility using microfluidics chip cell sorter (2020)
  • Author(s): Satohiro Nakao, Toru Takeo, Hitomi Watanabe, Gen Kondoh, Naomi Nakagata
  • Journal Title: Scientific Reports Volume: 10 Issue: 1 Pages: 8862-8862
  • DOI: 10.1038/s41598-020-65931-z
  • Peer Reviewed / Open Access
• [Presentation] Recent challenges of the Center for Animal Resources and Development at Kumamoto University (2023)
  • Author(s): Toru Takeo, Satohiro Nakao, Katsuma Yamaga, Ryusei Maeda, Ryo Kubota, Kotono Ito, Nobuyuki Mikoda, Naomi Nakagata
  • Organizer: 36th International Mammalian Genome Conference
  • Int'l Joint Research
• [Presentation] Efficient production of in vivo fertilized oocytes from female mice by treating inhibin antiserum and gonadotropins (2023)
  • Author(s): Satohiro Nakao, Kotono Ito, Chihiro Sugahara, Yoshino Wakasugi, Naomi Nakagata, Toru Takeo
  • Organizer: 36th International Mammalian Genome Conference
  • Int'l Joint Research
• [Presentation] Recent progress of CARD reproductive technology (2022)
  • Author(s): Toru Takeo, Satohiro Nakao, Katsuma Yamaga, Ryusei Maeda, Ryo Kubota, Kotono Ito, Nobuyuki Mikoda, Naomi Nakagata
  • Organizer: The 17th Transgenic Technology Meeting
  • Int'l Joint Research
• [Presentation] 生殖工学技術を活用した国際マウスバンクネットワークの構築 (2022)
  • Author(s): 竹尾透
  • Organizer: 第69回日本実験動物学会
  • Invited
• [Presentation] Application of the optimised protocol of in vitro fertilisation in mouse repository (2021)
  • Author(s): Toru Takeo
  • Organizer: Cryopreservation and Assisted Reproductive Technologies in Genetically Altered Animals Best practice, tips and tools
  • Int'l Joint Research / Invited
• [Presentation] Annual Report of Mouse Resource and Reproductive Technology at CARD (2021)
  • Author(s): Toru Takeo
  • Organizer: 2021 AMMRA Meeting
  • Int'l Joint Research / Invited
• [Presentation] Use of in-vitro fertilization in developing genetically modified mouse models (2021)
  • Author(s): Toru Takeo, Satohiro Nakao, Katsuma Yamaga, Reiri Koga, Yoshino Wakasugi, Yuka Deshimaru, Maki Sakaguchi
  • Organizer: Workshop on genetically modified mouse models, in-vitro fertilization and therapeutic approaches to genetic diseases
  • Int'l Joint Research / Invited
• [Presentation] Sharing bioresource and reproductive technology of mice (2021)
  • Author(s): Toru Takeo
  • Organizer: Sri Lanka Association for Laboratory Animal Science
  • Int'l Joint Research / Invited
• [Book] 月刊「細胞」 (2023)
  • Author(s): 中尾聡宏, 山鹿優真, 中潟直己, 竹尾 透
  • Total Pages: 3
  • Publisher: 北隆館
• [Book] BIO Clinica 2021年 2月号 不妊診療UPDATE (2021)
  • Author(s): 竹尾透、中尾聡宏
  • Total Pages: 4
  • Publisher: 北隆館
• [Remarks] 熊本大学生命資源研究・支援センター資源開発分野
  • URL: http://irda.kuma-u.jp/divisions/reproductive_engineer/reproductive_engineer.html
• [Remarks] マウス生殖工学オンラインマニュアル
  • URL: http://card.medic.kumamoto-u.ac.jp/card/japanese/manual/index.html
• [Remarks] Twitter：Toru Takeo
  • URL: https://twitter.com/ToruTakeo