Long-term culture of human spermatogonial stem cells

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H02935
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 56030:Urology-related
• Research Institution: Kyoto University
• Principal Investigator: Shinohara Mito 京都大学, 医学研究科, 助教 (10372591)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 精子 / 幹細胞 / 生殖 / 不妊症

Outline of Final Research Achievements

Spermatogonial stem cells (SSCs) continuously proliferate by self-renewal division and produce sperm after injection into the seminifelous tubules of testes. This study aimed at the development of new infertility treatment, and tried to develop a method to manipulate human SSCs. CXCR4 was identified as a marker of human SSCs, through screening of cell surface antigens. Factors which promote proliferation of spermatogonia were examined by screening of small molecule chemical libraries and ARTN, NRTN, PSPN, the family molecules of GDNF, the self-renewal factor of SSCs, as well as FGF family molecules, and BMP family molecules, which are considered to be involved in survival of spermatogonia. Using culture conditions modified from the conventional culture condition of mouse SSCs by adding ARTN, a ligand for GFRA3, human testes cells produced colonies in vitro, which were maintained for > 2 months period.

Free Research Field

生殖医学

Academic Significance and Societal Importance of the Research Achievements

小児悪性腫瘍患者の生存率は近年向上したが、放射線治療や薬物療法の副作用として不妊になるケースが多い。精子凍結ができない小児患者の妊孕性を担保する方法として、あらかじめ精子幹細胞を凍結保存し治療後に精細管内へ移植する試みが海外にて進められている。しかし小児精巣から採取できる精子幹細胞は極めて少なく、試験管内にて増幅する技術が必要とされている。また培養を行うことで悪性腫瘍細胞の混入を防ぐことができるという利点もある。本研究の成果はヒト精子幹細胞の試験管内増幅技術の確立のために不可欠であるヒト精子幹細胞のマーカー分子や増殖を促す因子を同定した点で、学術的・社会的意義がある。