Modulation of sperm movement by protein phosphatase inhibitors

• Autor(a) principal: Ferreira, Ana Filipa Pereira
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/37836
• topic: Male fertility; Sperm motility; Protein phosphatase type 1; Protein phosphatase type 2A; Protein phosphatase type 2B; Cantharidin; Tautomycin; Cypermethrin; Computer-aided sperm analysis

Male fertility relies on the ability of spermatozoa to fertilize the egg in the female reproductive tract. It is known that three protein phosphatases (PPs) are crucial in sperm motility acquisition and regulation, the sperm-specific PP type 1 isoform gamma 2 (PP1γ2), protein phosphatase type 2A (PP2A) and protein phosphatase type 2B (PP2B). An interplay between these PPs has been extensively investigated, with the contribution of some PP inhibitors, however, several were never reported to be tested in spermatozoa. This study aimed to assess the motility pattern alterations following incubation with cantharidin (CAN) and tautomycin (TAU), which inhibit PP1 and PP2A, as well as cypermethrin (CYP), a PP2B inhibitor. Besides, a machine learning-based method of analysis (alternative analysis) was used along with the Computer-Aided Sperm Analysis (CASA) system. CASA results showed that PP inhibitors caused an increase in immotility paired with decreased rapidly-progressive (RP) motility and velocity of the kinematic parameters. The alternative analysis also revealed an increase in hyperactivated spermatozoa and circular trajectories and, contrarily, an increase in RP spermatozoa. CAN affected more significantly RP spermatozoa, whereas TAU most impacted slowly-progressive (SP). CYP caused a significant impact in both RP and SP, being the inhibitor that caused more significant decreases in sperm motility and kinematic parameters. Results from both analyses, CASA and alternative analysis, were often divergent, which could be explained by the differences between the methods, such as video frame rate and height of the analysis chambers. In conclusion, contrarily to the literature, CAN, TAU and CYP consistently decreased spermatozoa motility and kinematic parameters, without affecting cell viability. Hence, additional studies are required to further understand PPs role in activated and hyperactivated motility regulation.