Role of PPARgamma and its gonadotrophic regulation in rat ovarian granulosa cells in vitro.

The peroxisome proliferator-activated receptors (PPARs), including PPARalpha, PPARbeta/delta, and PPARgamma, are a family of transcription factors belonging to the steroid receptor superfamily. In rat ovary, PPARgamma is mainly expressed in granulosa cells of developing follicles, implying a possible role of PPARgamma in ovarian functions. In the present study, the role of PPARgamma and its gonadotrophic regulation in granulosa cells collected from diethylstilbestrol-treated immature rats were studied. The results showed that PPARgamma could inhibit proliferation and induce apoptosis in primarily cultured granulosa cells. PPARgamma could also stimulate the biosynthesis of estradiol and progesterone after FSH pretreatment, and FSH could regulate the functions of PPARgamma through PKA, ERK1/2, and p38 MAPK signaling pathways. These data suggested that PPARgamma may be involved in follicular atresia and FSH-stimulated steroidogenesis during follicle development.