C/EBP Transcription Factors in Ovarian Biology: Orchestrating Follicle Development, Ovulation and Luteinization.

The mammalian ovary is a structurally and functionally dynamic tissue that undergoes cyclical changes involved in folliculogenesis, ovulation, and luteal function. Each process depends on the coordination of complex cell biology such as steroidogenesis, inflammation and vascular remodeling that are regulated at transcriptional and post-translational levels. CCAAT/enhancer-binding proteins (C/EBPs) are a family of transcription factors emerging as key regulators of these processes, in particular C/EBPα and C/EBPβ. The upstream regulation and downstream biological effects of C/EBPα and C/EBPβ are context-dependent and vary depending on the state of ovarian follicles and corpus luteum. These factors integrate local ovarian and endocrine signals to orchestrate ovarian function, and genetic disruption of their expression leads to obstructed primordial follicle formation, impaired ovulation, defective luteinization, and reduced fertility. This narrative review synthesizes current knowledge on the expression, regulation, and function of C/EBP transcription factors, particularly C/EBPα and C/EBPβ, in ovarian biology. It highlights the current knowledge gap and future directions in further defining the role of C/EBP transcription factors in ovarian function and dysfunction.