Regulatory mechanisms of mitochondrial electron transport system involved in male infertility based on a molecular pathology approach.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K09391
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56030:Urology-related
• Research Institution: Yokohama National University
• Principal Investigator: Kurihara Yasuyuki 横浜国立大学, 大学院工学研究院, 教授 (80202050)
• Co-Investigator(Kenkyū-buntansha): 湯村 寧 横浜市立大学, 附属市民総合医療センター, 准教授 (30522023)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 男性不妊症 / 精子 / ミトコンドリア / 治療法

Outline of Final Research Achievements

In this research project, the expression of mitochondrial proteins and their localisation in sperm from male infertility patients were analysed using monoclonal antibodies. The semen evaluation of the patients was also assessed using the SMAS system and MiOXSYS. Furthermore, we aimed to establish novel prognostic indicators for staged male infertility treatment by correlating these results with the efficacy of infertility treatment in each patient.
COXFA4L3 is not expressed in somatic cell-derived components of semen samples, so only the mitochondrial proteins of sperm in semen can be detected. Therefore, expression level and localisation by using an anti-human COXFA4L3 monoclonal antibody were performed. And the COXFA4L3 protein expression level was determined relative to the expression level of the sperm cell-specific glycolytic system protein GAPDS.

Free Research Field

泌尿器科学

Academic Significance and Societal Importance of the Research Achievements

今回の研究では、新たにミトコンドリア電子伝達系複合体4のサブユニットタンパク質が男性不妊症患者の精子先体にも異所的に発現していることを明らかにした。また、この異所的発現している精子を異常精子と判定すると、正常精子が精液試料中に26％以上持つ男性では自然妊娠や人工授精で妊娠が成立することがわかった。この評価法を使うと、不妊症外来に訪れた患者さんに対し、人工授精法と体外受精法や顕微授精法の診療方法の切り分けに有効である事が示唆される。これにより、より体への負担が少なく、安価で短期間に妊娠転帰できる可能性を示唆するものとして社会的意義が深い。