Repeated gonadotropin stimulation modulates the expression of specific proteins in mouse oviduct.

Objective: Superovulation protocol modifies the oviductal site-specific expression of some proteins regulating cell cycle and oxidative stress response.

Methods: Swiss CD1 female mice (n=24) were sorted into 2 groups: one was used as control (Ctr, n=10), the other consisted of mice undergoing 8 Rounds (8R) of repeated gonadotropin stimulation (n=14). After their removal, oviducts were cut into two portions: one including Infundibulum and Ampulla (If-Am), and the rest including Isthmus (Is). Both portions were separately used to assess the expression levels of oviductal proteins regulating cell cycle and oxidative stress response. Statistical analysis employed t-test with significance at p<0.05.

Results: In Ctr mice, superoxide dismutases 1 and 2 were significantly more expressed in the If-Am, while phospho-p53, glutathione peroxidase 1 and estrogen receptor beta mainly in the Is. Conversely, catalase, cleaved-caspase 3, estrogen alpha and progesterone receptors were similarly distributed across the oviduct. After 8R, glutathione peroxidase 1 and superoxide dismutase 1 increased in both segments, superoxide dismutase 2 and cleaved-caspase 3 increased mainly in If-Am, while catalase and phosphorylated p53 mainly in Is. Estrogen alpha/beta and progesterone receptors levels remained unchanged.

Conclusions: Altogether, these results demonstrated that in the mouse oviduct many proteins were expressed in a site-specific manner and that repeated gonadotropin stimulation could modulate their expression levels. These data suggest that different localization of proteins between Infundibulum-Ampulla and Isthmus regions is fundamental for creating a suitable microenvironment for embryo development.