The effects of irisin and leptin on steroidogenic enzyme gene expression in human granulosa cells: In vitro studies

Reproduction and energy metabolism are closely related, and fertility can be directly affected by either obesity or malnutrition. In this study, we investigated the in vitro effects of irisin and leptin, two hormones primarily involved in energy metabolism, on the expression of genes encoding key steroidogenic enzymes in primary cultures of human granulosa cells. Granulosa cells were purified from follicular fluid samples obtained during in vitro fertilization (IVF) procedure, cultured, and treated with irisin (125-2000 ng/ml) or leptin (25-400 ng/ml) for 1-3 days. mRNA expression levels of cytochrome P450 enzymes [CYP11A1, CYP19A1, CYP21A2], hydroxy-delta-5-steroid dehydrogenase, 3 beta and steroid delta-isomerase 1 (HSD3B1), and hydroxysteroid 17-beta dehydrogenase 3 (HSD17B3) were measured using qRT-PCR analysis. Irisin significantly upregulated CYP19A1 mRNA levels, while leptin upregulated CYP19A1 and HSD3B1 mRNA levels. These preliminary results show that irisin and leptin may directly affect the expression of the genes important for ovarian steroidogenesis and female reproduction.