Proteomics and biomarker identification in improved sperm motility parameters after 4 h of ejaculatory abstinence

Dale M. Goss, Bashir Ayad, Maré Vlok, Suzél M. Hattingh, Gerhard van der Horst, Stefan S. du Plessis

Division of Medical Physiology, Stellenbosch University, Tygerberg, South Africa; Department of Biochemistry and LCMS-Central Analytical Facility, Stellenbosch University, Tygerberg, South Africa; Department of Basic Medical Sciences, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, UAE

Abstract: Various studies have sought to determine the optimal abstinence period after which semen samples should be collected, with many contradictory results reported. Several factors influence the semen microenvironment, and thus potentially sperm parameters. In this study, we focused on the secretions of the prostate, seminal vesicles and the epididymis. Semen samples were obtained from healthy normozoospermic males (n = 16) after 4 day and 4 h periods of ejaculatory abstinence (EA), and standard semen analysis was performed using computer-aided sperm analysis, whereas seminal plasma citric acid, neutral alpha-glucosidase and fructose concentrations were measured using assay kits. Proteomic analyses of seminal plasma proteins were performed using LC-MS/MS. There were significant decreases in total sperm count (P < 0.001), sperm concentration (P < 0.05) and semen volume (P < 0.05) after 4 h compared with 4 days ejaculatory abstinence. Furthermore, increases were observed in total sperm motility (P < 0.05), sperm progressive motility (P < 0.01), average path velocity (P < 0.001) and curvilinear velocity (P < 0.05) after a 4 h abstinence period, accompanied by significant reductions in citric acid (P < 0.05), neutral alpha-glucosidase (P < 0.01) and fructose (P < 0.01) concentrations. In addition, due to the decreased number of spermatozoa, these concentrations translated to a significant decrease in fructose (P < 0.05) per spermatozoon. A total of 2889 proteins were identified, with 24 proteins differentially expressed. These proteins have various roles in cellular processes and may influence the improvement of sperm motility after 4 h of EA. All these factors present in the seminal plasma indicate towards an intrinsic mechanism capitalising on alternative sources of energy for increased metabolic function and subsequent sperm motility.

Goss D.M., Ayad B., Vlok M., Hattingh S.M., van der Horst G., du Plessis S.S. (2021) Proteomics and Biomarker Identification in Improved Sperm Motility Parameters After 4 h of Ejaculatory Abstinence. In: Björndahl L., Flanagan J., Holmberg R., Kvist U. (eds) XIIIth International Symposium on Spermatology. Springer, Cham. https://doi.org/10.1007/978-3-030-66292-9_48
First Online: 23 July 2021