• PMID: 29378615
• Gene Name: CST3
• Condition: Human sperm capacitation and acrosome reaction, Male infertility
• Association: Associated
• Sex: Male
• Infertility type: Male infertility
• Other associated phenotypes: Human sperm capacitation and acrosome reaction, Male infertility

Expression of cystatin C in the female reproductive tract and its effect on human sperm capacitation

Lee RK, Tseng HC, Hwu YM, Fan CC, Lin MH, Yu JJ, Yeh LY, Li SH.

BACKGROUND: Cystatin C (CST3), a cysteine protease inhibitor in seminal plasma, is expressed in animal uteri. However, its expression in the human female reproductive tract and its effect on human sperm capacitation are unclear. METHODS: The cellular localization of CST3 was observed using immunohistochemistry. The binding of CST3 to sperm was examined using immunocytochemistry. Sperm motility parameters were analyzed using computer-assisted sperm analysis. Sperm capacitation was evaluated by analyzing cholesterol content, protein tyrosine phosphorylation levels, and the acrosome reaction. RESULTS: Immunohistochemical staining demonstrated that CST3 is prominently expressed in the female reproductive tract, including the epithelial lining and cervix and endometrium fluids, particularly at times near ovulation. It can bind to human sperm on the post-acrosomal head region and the mid and principal piece of the tail. CST3 enhances sperm motility and inhibits the signal initiating sperm capacitation, i.e., efflux of cholesterol from the sperm plasma membrane and a late sperm capacitation event, i.e., the increase in the sperm protein tyrosine phosphorylation. The suppressive trend on sperm acrosome reaction further supports CST3's ability to inhibit sperm capacitation. CONCLUSIONS: These findings suggest that cervical CST3 may prevent precocious capacitation and acrosome reaction, thus preserving sperm fertilizing ability before it reaches the fallopian tube. Additionally, CST3 may help sperm enter the upper reproductive tract by enhancing sperm motility. FAU - Lee, Robert Kuo-Kuang AU - Lee RK AD - Department of Medical Research, Mackay Memorial Hospital, Tamsui District, New Taipei City, 251, Taiwan. AD - Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei City, 104, Taiwan. AD - Department of Obstetrics and Gynecology, Taipei Medical University, Taipei City, 110, Taiwan. FAU - Tseng, Huan-Chin AU - Tseng HC AD - Department of Medical Research, Mackay Memorial Hospital, Tamsui District, New Taipei City, 251, Taiwan. FAU - Hwu, Yuh-Ming AU - Hwu YM AD - Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei City, 104, Taiwan. AD - Mackay Medical College, Sanzhi District, New Taipei City, 252, Taiwan. AD - Mackay Junior College of Medicine, Nursing, and Management, Beitou District, Taipei City, 112, Taiwan. FAU - Fan, Chi-Chen AU - Fan CC AD - Office of Superintendent, Mackay Memorial Hospital, Taipei City, Taiwan. AD - Department of Medical Laboratory Science and Biotechnology, Yuanpei University, Hsinchu, 300, Taiwan. FAU - Lin, Ming-Huei AU - Lin MH AD - Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei City, 104, Taiwan. AD - Mackay Junior College of Medicine, Nursing, and Management, Beitou District, Taipei City, 112, Taiwan. FAU - Yu, Jhih-Jie AU - Yu JJ AD - Department of Medical Research, Mackay Memorial Hospital, Tamsui District, New Taipei City, 251, Taiwan. FAU - Yeh, Ling-Yu AU - Yeh LY AD - Department of Medical Research, Mackay Memorial Hospital, Tamsui District, New Taipei City, 251, Taiwan.