Grant: Project Grant

Infertility is rising in Canada and worldwide. The percentage of couples that struggle with infertility increased from 8% in the 1980s to almost 16% today in our country, and male infertility accounts for half of the cases of infertile couples. Additionally, the causes of male infertility are unknown in 30% of cases, presenting normal semen evaluation results. We are studying male infertility and its causes. Here, we focus on the role of the lipid sphingosine 1-phosphate (S1P) during human sperm capacitation. The spermatozoon must undergo sperm capacitation to fertilize the oocyte and create the zygote (embryo of one cell), from which a new individual organism will develop. This complex process involves biochemical and morphological changes in the spermatozoon, including lipid metabolism changes and free radical production. The link between lipids and free radical production during capacitation is unknown. In the testis, S1P prevents the death of the germ cell line. S1P is needed for the capacitation process, but the underlying reasons and the mechanism of action of S1P (i.e., how it accomplishes its functions) are unknown. The objective of our research, using mouse models and human spermatozoa from infertile and fertile individuals, is to understand the molecular mechanisms involved in sperm capacitation and whether these mechanisms are failing in infertile spermatozoa. This knowledge is essential to identify possible causes of male infertility and allows us to conduct personalized reproductive medicine to diagnose, treat, and counsel infertile males. Additionally, it will help improve the efficiency of the artificial insemination technique to allow infertile couples to conceive a baby.