Cell membrane proteins from oviductal epithelial cell line protect human spermatozoa from oxidative damage.

OBJECTIVE To study the potential protective action in vitro of oviductal epithelial cell membrane proteins against oxidative damage in human spermatozoa. DESIGN Prospective in vitro study. SETTING University research laboratory and infertility clinic. PATIENT(S) Semen from men attending the infertility clinic at the Queen Mary Hospital with normal semen parameters (World Health Organization, 2010). INTERVENTION(S) We studied the effect of oviductal epithelial cell membrane proteins on the sperm functions and endogenous antioxidant enzyme activities. MAIN OUTCOME MEASURE(S) Sperm motility, lipid peroxidation, DNA fragmentation, intracellular reactive oxygen species (ROS) level, superoxide dismutase, and glutathione peroxidase activities. RESULT(S) Oviductal epithelial cell membrane proteins bind to the human spermatozoa and protect them from ROS-induced damages in terms of sperm motility, membrane integrity, DNA integrity, and intracellular ROS level. Spermatozoa-oviduct epithelial cell interaction also enhances the antioxidant defenses in spermatozoa. CONCLUSION(S) Our results demonstrated the protective effects of spermatozoon-oviductal epithelial cell interaction against oxidative stress in human spermatozoa. The results enhance our understanding of the protective mechanism of oviduct on sperm functions.