C/EBP? regulates Vegf gene expression in granulosa cells undergoing luteinization during ovulation in female rats.

ABSTRACT: The ovulatory LH-surge increases Vegf gene expression in granulosa cells (GCs) undergoing luteinization during ovulation. To understand the factors involved in this increase, we examined the roles of two transcription factors and epigenetic mechanisms in rat GCs. GCs were obtained from rats treated with eCG before, 4?h, 8?h, 12?h and 24?h after hCG injection. Vegf mRNA levels gradually increased after hCG injection and reached a peak at 12?h. To investigate the mechanism by which Vegf is up-regulated after hCG injection, we focused on C/EBP? and HIF1?. Their protein expression levels were increased at 12?h. The binding activity of C/EBP? to the Vegf promoter region increased after hCG injection whereas that of HIF1? did not at this time point. The C/EBP? binding site had transcriptional activities whereas the HIF1? binding sites did not have transcriptional activities under cAMP stimulation. The levels of H3K9me3 and H3K27me3, which are transcriptional repression markers, decreased in the C/EBP? binding region after hCG injection. The chromatin structure of this region becomes looser after hCG injection. These results show that C/EBP? regulates Vegf gene expression with changes in histone modifications and chromatin structure of the promoter region in GCs undergoing luteinization during ovulation.

SUBMITTER: Shinagawa M 

PROVIDER: S-EPMC6345775 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature