Synergistic cooperation between the β-catenin and SF1 regulates progesterone synthesis in laying hen ovarian granulosa cells

The development of ovarian follicles in poultry is a key factor affecting the performance of egg production. Ovarian follicle development is regulated via the Wnt/β-catenin signaling pathway, and β-catenin, encoded by CTNNB1, is a core component of this pathway. In this study, using ovary GCs from laying hens, we investigated the regulatory role of CTNNB1 in steroid synthesis. We found that CTNNB1 significantly regulates the expression of StAR and CYP11A1 (key genes related to progesterone synthesis) and the secretion of progesterone (P4). Furthermore, simultaneous overexpression of CTNNB1 and SF1 resulted in significantly higher levels of CYP11A1 and secretion of P4 than in cells overexpressing CTNNB1 or SF1 alone. We also found that in GCs overexpressing SF1, levels of CYP11A1 and secreted P4 were significantly greater than in controls. Silencing of CYP11A1 resulted in the inhibition of P4 secretion while overexpression of SF1 in CYP11A1-silenced cells restored P4 secretion to normal levels. Together, these results indicate that synergistic cooperation between the β-catenin and SF1 regulates progesterone synthesis in laying hen ovarian hierarchical granulosa cells to promote CYP11A1 expression.