Effects of asprosin on estradiol and progesterone secretion and proliferation of bovine granulosa cells.

Asprosin is an adipokine synthesized by the white adipose tissue that regulates glucose homeostasis and that has been reported to affect bovine theca cell function and follicular growth, but its role on granulosa cell functions remains to be unveiled. Hence, the objective of this study was to investigate asprosin impacts on granulosa cell steroidogenesis. Bovine granulosa cells from small ovarian follicles were cultured in vitro to investigate the effects of asprosin on cell proliferation, production of steroids, mRNA abundance of genes that encode steroidogenic enzymes and cell cycle regulators, and protein relative abundance of steroidogenic signaling pathways. Asprosin was shown to affect granulosa cell functions in a dose-dependent manner. In the presence of FSH, asprosin enhanced estradiol production and stimulated an increase in mRNA expression of FSHR and CYP19A1 in a dose-dependent manner. In the presence of IGF1, asprosin decreased estradiol production, increased progesterone production, altered PKA relative protein expression, and tended to alter the ratio of p-ERK1/2/total ERK1/2 protein expression in a dose-dependent manner. Furthermore, asprosin increased p-53 gene expression in basal culture conditions and with or without FSH and IGF1. Taken together, findings of this study show that asprosin is a regulator of granulosa cell functions and the effects of asprosin depend on dose and cell culture conditions.