Rev-erbα regulates circadian rhythms and StAR expression in rat granulosa cells as identified by the agonist GSK4112

► Rev-erbα links the steroid biosynthesis as well as the cellular clock in ovaries. ► The agonist of Rev-erbα, GSK4112, suppresses Bmal1 mRNA expression. ► GSK4112 enhances StAR expression, but not Lhr expression. ► GSK4112 also induces the Per2-dLuc oscillation phase advance shift. The Rev-erbα gene is regarded as a circadian clock gene and clock-regulated gene which regulates the circadian transcriptional/translational loop in a subtle way. Here, we first detected the circadian oscillation in mature granulosa cells from antral follicles using a real-time monitoring system of Per2 promoter activity with the addition of FSH. Then we used GSK4112, an agonist ligand of Rev-erbα, to investigate the function of Rev-erbα. GSK4112 treatment significantly reduced the Per2-dLuc amplitude and induced the Per2 oscillation phase advance shift. GSK4112 significantly inhibited Bmal1 mRNA expression, whereas it did clearly stimulate expression of StAR mRNA in a dose-dependent manner. Our data are the first to show the Rev-erbα function in the steroid biosynthesis of rat granulosa cells, and to suggest that Rev-erbα may coordinate circadian rhythm and metabolism in rat ovaries.