Cyclic AMP efflux through MRP4 regulates actin dynamics signalling pathway and sperm motility in bovines

PLAZA, JESSICA; YANEFF, AGUSTÍN; MIRAGAYA, MARCELO; CHIARANTE, NICOLÁS; LOTTERO-LECONTE, RAQUEL; OSYCKA-SALUT, CLAUDIA E.; PEREZ-MARTINEZ, SILVINA; ALONSO, CARLOS A. I.; ARROYO-SALVO, CAMILA; DAVIO, CARLOS

Scientific Reports

Nature

Lugar: Londres; Año: 2020 vol. 10

2045-2322

Previously we demonstrated that multidrug resistance-associated protein 4 transporter (MRP4)mediates cAMP efflux in bovine spermatozoa and that extracellular cAMP (ecAMP) triggers eventsassociated to capacitation. Here, we deepen the study of the role of MRP4 in bovine sperm functionby using MK571, an MRP4 inhibitor. The incubation of spermatozoa with MK571 during 45 mininhibited capacitation-associated events. MRP4 was localized in post-acrosomal region and mid-pieceat 15 min capacitation, while at 45 min it was mainly located in the acrosome. After 15 min, MK571decreased total sperm motility (TM), progressive motility (PM) and several kinematic parameters.The addition of ecAMP rescued MK571 effect and ecAMP alone increased the percentage of motilesperm and kinematics parameters. Since actin cytoskeleton plays essential roles in the regulationof sperm motility, we investigated if MRP4 activity might affect actin polymerization. After 15 mincapacitation, an increase in F-actin was observed, which was inhibited by MK571. This effect wasreverted by the addition of ecAMP. Furthermore, ecAMP alone increased F-actin levels while no F-actinwas detected with ecAMP in the presence of PKA inhibitors. Our results support the importance ofcAMP efflux through MRP4 in sperm capacitation and suggest its involvement in the regulation ofactin polymerization and motility.