Bmal1 promotes prostaglandin E₂ synthesis by upregulating Ptgs2 transcription in response to increasing estradiol levels in day 4 pregnant mice

Rhythmic expression of Bmal1 and Ptgs2 was observed in the uterus isolated from D3.5–4.5 of pregnant mice. E 2 increased the expression of Bmal1 and Ptg2 in UESCs isolated from mice on D4. The expression of Ptgs2 was significantly decreased in Bmal1-siRNA treated UESCs. Bmal1 knockdown also inhibited PGE 2 synthesis. Thus, these data suggest that Bmal1 in mice promotes PGE 2 synthesis by upregulating Ptgs2 in response to increases in E 2 on D4 of pregnancy.