Functional analysis and culture of human spermatogonial stem cells

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22512
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 48:Biomedical structure and function and related fields
• Research Institution: Kyoto University
• Principal Investigator: Shinohara Takashi 京都大学, 医学研究科, 教授 (30322770)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: 精子形成

Outline of Final Research Achievements

To set up a culture system for human spermatogonial stem cells (SSCs), we established a method for enzymatic digestion of human testis cells. Based on the gene expression patterns in mouse SSCs, we screened monoclonal antibodies that can react with human SSCs. Through this screening, we found that human spermatogonial stem cells express Epha2 on their surface. The frequency of cells expressing Epha2 in the testis is significantly lower than those previously reported for human SSCs. This purification protocol was useful for starting human SSC cultures without the contamination of testicular somatic cells. By adjusting the culture conditions, we were able to derive two candidate SSC cultures. However, we still have not been able to collect these cells for functional analysis because they died upon dissociation into single cells by trypsin. We are currently taking different approaches to determine their SSC activity.

Free Research Field

生殖生物学

Academic Significance and Societal Importance of the Research Achievements

癌治療成績の向上に伴い、小児の約7-8割の患者が生存し、20代の若者250人に一人が癌治療の生存者である。ところが、治療の副作用として半分程度の患者が不妊となっている。ヒト精子幹細胞の培養が成功すれば、この細胞をがん治療前の患者さんの精巣から回収し、試験管内で増幅したのちに治療後の精巣に移植するすることで妊孕性を回復することができると期待されている。今回の研究によりヒト精子幹細胞の培養条件が改善し、近い将来ヒトへの応用も可能になると期待できる。