Research progress on serine proteases in the field of male reproduction: a narrative review.

Background and Objective: Male infertility is a growing global reproductive health issue with complex, poorly understood mechanisms. Serine proteases are critical proteins that play important roles in male reproduction. Although some research progress has been made, their specific mechanisms in human male infertility remain unclear, and clinical applications are still exploratory. This narrative review summarizes current advances on serine proteases in male reproduction, identifies knowledge gaps, and provides a reference for future research. Methods: This review employed a systematic literature search to comprehensively synthesize evidence on the functions of SPs in male reproduction, with a focus on their multidimensional regulatory mechanisms, exploring their association with male infertility and analyzing current research progress and clinical application prospects. Databases searched included PubMed and Web of Science. Search strategies utilized keywords such as "serine proteases", "spermatogenesis", "sperm function" and "male infertility". Key Content and Findings: The search initially identified and evaluated 475 full-text articles, ultimately yielding 66 key references incorporated into this review. SPs, as an important class of proteases, play a key role in male reproduction, involving multiple processes such as spermatogenesis, maturation, migration, and fertilization. In recent years, with the rapid development of molecular biology and genetics technologies, researchers have gradually revealed the core functions of SPs in male reproductive health and their close relationship with male infertility. SPs show broad application potential in clinical diagnosis and treatment of male infertility, providing theoretical support and reference for basic research and medical intervention in male reproductive health. Conclusions: The multidimensional regulatory functions of SPs in male reproduction have garnered significant attention. Their active participation is evident in key steps from the differentiation of spermatogonia in the testes to sperm maturation in the epididymis and ultimately to the fusion of sperm and eggs. By balancing and integrating different perspectives and findings from research, it is expected that a more solid bridge will be built between basic research and clinical practice in the future, promoting continuous progress and innovation in the field of male reproductive health.