Epididymal antimicrobial peptides: the role in sperm function (review)

Abstract

The significant worldwide decline in male fertility requires a comprehensive study of molecular regulatory mechanisms of gametogenesis and post-testicular sperm maturation. Improving ways to influence these processes as well as searching for substances that increase the resistance of gametes to the action of various damaging factors open up prospects for development of new approaches to treat male infertility. In this regard, current emphasis is on the study of a role of endogenous antimicrobial peptides (AMPs) and their physiological activity during the maturation and functioning of male germ cells. AMPs are unique components of the innate immune system. They not only provide protection against bacteria, viruses, and fungi, but also have relatively diverse biological effects. These effects are closely related to the ability of AMPs to be directly involved in the physiological processes of post-testicular maturation of germ cells, in modification of the plasma membranes of sperms in the epididymis, and their capacitation in the female reproductive tract. This review focuses on the current understanding of the role of epididymal AMPs with regard to the functioning of sperm in normal and pathological conditions.