The present investigation aimed to outline the effects of PNP on Amphiregulin (AREG)- induced oocytes maturation. Bovine COCs were aspirated from small antral follicles (2–6 mm in diameter) and incubated in IVM medium contained 1 μl /ml Amphiregulin of human origin supplemented with PNP at 0 (control), 10(-7) M (LD), 10(-6) M (MD), 10(-5) M (HD) and 10(-4) M (VHD) at 38.5°C in a humidified atmosphere of 5% CO2 in air for 22 h. Oocytes were evaluated for cumulus cells' expansion, nuclear maturation and the expression of the expansion-related genes (HAS2, TNFIPA6, StAR, CYP11A1 and PTGS2). Progesterone and prostaglandin-E2 concentrations were measured in the in vitro maturation media after 22 h using EIA. Data showed that the
presence of VHD of PNP, decreased the cumulus expansion. An exposure to PNP was found to alter the expansion-related gene expression in the bovine cumulus cell expansion, specifically PTGS2 (up-regulated with MD) and CYP11A1 (down-regulated with HD). The expression of HAS2, TNFIP6 and StAR genes,
hormonal excretory activity and nuclear maturation did not show significant differences in PNP groups as compared with control. Concluding that the exposure to PNP during oocyte maturation may impair the epidermal growth factor-stimulated cumulus cell expansion mediated by altering of PTGS2 and/or CYP11A1genes
and this presents risk on acquisition of oocyte competence in mammals. |
