Characterization of Steroid Metabolic Pathways in Established Human and Mouse Cell Models

Immortalized adrenal, placental and gonadal cell models are often termed steroidogenic based on steroid hormone production and steroidogenic enzymes. Profiling of 'classic' steroid metabolites is common; however, downstream untargeted metabolites remain unidentified. This study characterized steroidogenesis in human adrenal H295R and H295A; placental BeWo and JEG-3; mouse Leydig MA-10; and mouse adrenal Y-1 and OS-3 cells. Steroids were determined under basal, stimulated and serum-free conditions using liquid chromatography-mass spectrometry. This study identified distinct differences in mineralocorticoid and glucocorticoid production in the two human adrenal models and between the human and mouse adrenal models; unconventional hydroxylated progesterone steroid metabolites in all models which were most abundant in MA-10 cells; glucocorticoids and abundant classical androgens in MA-10 cells; 11-oxy androgens in H295R, H295A and MA-10 cells; comparable levels of the classical androgens in H295R and MA-10 cells, while 11-oxy androgen were more abundant in H295R and H295A cells; and high pregnenolone and progesterone in placental models with limited hydroxylated progesterone metabolites. Our detailed protocols and comprehensive steroid profiles provide an invaluable guide to researchers for in vitro investigations into steroidogenesis.