Pigment epithelium-derived factor (PEDF) expression and role during follicle development

Abstract

Research QuestionFolliculogenesis is the process of follicles assembly and growth. The process requires a tight dialogue between the oocyte and its supporting granulosa cells (GCs) and is mediated by endocrine and paracrine factors. Pigment epithelium-derived factor (PEDF), an important player in the female reproductive tract, is highly expressed in the GCs and in various ovarian components. Our aim was to characterize the involvement of PEDF in CGs during folliculogenesis. DesignWe examined mRNA expression of PEDF and other key factors, (Cyp19, anti-Müllerian hormone receptor (AMHR), and VEGF), in mice follicles to typify the expression of PEDF in growing follicles and in human primary GCs (hpGCs); and to follow the interplay between PEDF and other folliculogenesis leading players, follicle-stimulating hormone (FSH) and AMH. ResultsPEDF expression increases through folliculogenesis (≥9 follicles/group), though, different than other examined genes, affecting the follicular angiogenic balance. In hpGCs, FSH stimulates the upregulation of PEDF mRNA. Furthermore, a negative correlation between AMH and PEDF was observed, as AMH stimulation reduced the level of PEDF mRNA and PEDF stimulation reduced AMHR level. ConclusionsOur findings suggest that PEDF participates in folliculogenesis and places it as a pro-folliculogenesis player that interacts with the main participants in the process of follicle growth; however, the mechanism of this process is yet to be determined.