Sperm fucosyltransferase-5 mediates spermatozoa–oviductal epithelial cell interaction to protect human spermatozoa from oxidative damage

Abstract

Oxidative damage by reactive oxygen species (ROS) is a major cause of sperm dysfunction. Excessive ROS generation reduces fertilization and enhances DNA damage of spermatozoa. Interaction between spermatozoa and oviductal epithelial cells improves the fertilizing ability of and reduces chromatin damage in spermatozoa. Our previous data showed that oviductal epithelial cell membrane proteins interact with the human spermatozoa and protect them from ROS-induced reduction in sperm motility, membrane integrity and DNA integrity. Sperm fucosyltransferase-5 (sFUT5) is a membrane carbohydrate-binding protein on human spermatozoa. In this study, we demonstrate for the first time that sFUT5 is involved in human spermatozoa-oviduct interaction and the beneficial effects of such interaction on the fertilizing ability of human spermatozoa. Anti-sFUT5 antibody-treated spermatozoa had reduced binding to oviductal membrane proteins. It is consistent with the result that affinity-purified sFUT5 is bound to the epithelial lining of human oviduct and to the immortalized human oviductal epithelial cell line, OE-E6/E7. Pretreatment of spermatozoa with anti-sFUT5 antibody and oviductal membrane proteins with sFUT5 suppressed the protective action of oviductal membrane proteins against ROS/cryopreservation-induced oxidative damage in spermatozoa. Asialofetuin, a reported sFUT5 substrate, can partly mimic the protective effect of oviductal epithelial cell membrane proteins on sperm motility, membrane and DNA integrity. The results enhance our understanding on the protective mechanism of oviduct on sperm functions.

Sperm selection by the oviduct: perspectives for male fertility and assisted reproductive technologies

“…Similarly, bovine sperm bind sulfated Lewis A (suLe A ) trisaccharide closely related to suLe X [69,70]. In humans, an oviduct glycan related to the glycan on asialofetuin could be responsible for retaining sperm [71]. The sperm membrane proteins responsible for binding to the oviduct epithelium have also been investigated (see review [33]).…”

“…Interestingly, capacitation induced the loss of these proteins, pointing to a possible mechanism of sperm release from the oviduct [72,75]. In humans, the carbohydrate-binding protein fucosyltrans ferase-5 has been identified as a candidate mediating spermoviduct binding [71]. However, sperm from the cauda epididymis that have not been exposed to seminal plasma proteins can still bind OECs [76], which suggests that other sperm receptors may be involved.…”

Roles of AMP-Activated Protein Kinase (AMPK) in Mammalian Reproduction

“…Plasma membrane disorder is most likely to occur at the apical part of the acrosome, where a majority of phosphorylated AMPK protein accumulates, leading to impaired acrosomal integrity (Hurtado de Llera et al, 2013). Male germ cells will encounter various metabolic stresses in the process of transit through the female genital tract or semen cryopreservation (Huang et al, 2015). In this case, the integrity of sperm structure and intracellular adaptive physiological responses, such as AMPK regulating cell metabolism when ATP is limited, are required for successful fertilization.…”

Genomic integrity in the male germ line: evidence in support of the disposable soma hypothesis

“…Notwithstanding such measures, the male germ line is more vulnerable to spontaneous mutations than the female, for the simple reason that male germ cells are constantly replicating, while the female germ line spends most of its post-natal existence in a state of meiotic repose (Crow 2000). Furthermore, the male gamete has to undertake a potentially hazardous journey between the site of insemination and the oocyte, during which the chromatin may be subjected to significant oxidative stress (Huang et al 2015).…”