PI3K-Akt signaling pathway effect in oocyte maturation and early embryo development in cattle

Abstract

The PI3K-Akt signaling pathway plays a key role in oocyte development by regulating important cellular functions such as cell proliferation, apoptosis, DNA repair, glucose metabolism and protein synthesis. In follicular environment the PI3K-Akt pathway has already been described as important for early development, maturation, granulosa cells proliferation and, recently by our research group, described as being strongly regulated by follicular cell miRNAs and positively related to oocyte competence. This project aims to better understand PI3K-Akt signaling pathway function and the cellular functions regulated by it in cumulus-oocyte complexes during maturation process. Three approaches will be used to understand the consequences of PI3K-Akt activation/inhibition during in vitro maturation step of the bovine embryos production. The first approach will be to evaluate the influence of in vitro maturation on PI3K-Akt signaling pathway activity using cumulus cell samples from immature and matured in vivo and in vitro COCs. The genes of the pathway itself and also genes related to different cellular functions regulated by this pathway will be evaluated. The second and third approaches will consist of PI3K-Akt pathway stimulation or inhibition through drugs and biomolecules (miRNAs) in cumulus-oocyte complexes during maturation. Will be evaluated the cellular effects (apoptosis, metabolism, protein synthesis and cell proliferation) of PI3K-Akt signaling pathway activation or inhibition in COCs and the influence of this pathway modulation in maturation (MII), cleavage and blastocyst production rates. Functional knowledge of signaling pathways such as PI3K-Akt within the cumulus-oocyte complex and how these pathways influence the ability of oocytes to develop to the blastocyst stage is essential to improve the outcomes of assisted reproductive technologies in addition to improving the quality of the embryos produced in vitro.