CB 1 cannabinoid receptor drives oocyte maturation and embryo development via PI3K/Akt and MAPK pathways.

Endocannabinoids have been recognized as mediators of practically all reproductive events in mammals. However, little is known about the role of this system in oocyte maturation. In a mouse model, we observed that activation of cannabinoid receptor 1 (CB1 ) during in vitro oocyte maturation modulated the phosphorylation status of Akt and ERK1/2 and enhanced the subsequent embryo production. In the absence of CB1 , in vivo oocyte maturation was impaired and embryo development delayed. Cannabinoid receptor 2 (CB2 ) was unable to rescue these effects. Finally, we confirmed abnormal oocyte maturation rather than impaired embryonic transport through the oviduct in CB1 knockouts. Our data suggest that cannabinoid agonists may be useful in vitro maturation supplements. For in vitro fertilization patients intolerant to gonadotropins, this could be a promising and only option.-López-Cardona, A. P., Pérez-Cerezales, S., Fernández-González, R., Laguna-Barraza, R., Pericuesta, E., Agirregoitia, N., Gutiérrez-Adán, A., Agirregoitia, E. CB1 cannabinoid receptor drives oocyte maturation and embryo development via PI3K/Akt and MAPK pathways.