Abstract
Androgens are essential for sexual development and reproduction. However, androgen regulation in health and disease is poorly understood. We showed that human adrenocortical H295R cells grown under starvation conditions acquire a hyperandrogenic steroid profile with changes in steroid metabolizing enzymes HSD3B2 and CYP17A1 essential for androgen production. Here we studied the regulatory mechanisms underlying androgen production in starved H295R cells. Microarray expression profiling of normal versus starved H295R cells revealed fourteen differentially expressed genes; HSD3B2, HSD3B1, CYP21A2, RARB, ASS1, CFI, ASCL1 and ENC1 play a role in steroid and energy metabolism and ANGPTL1, PLK2, DUSP6, DUSP10 and FREM2 are involved in signal transduction. We discovered two new gene networks around RARB and ANGPTL1, and show how they regulate androgen biosynthesis. Transcription factor RARB stimulated the promoters of genes involved in androgen production (StAR, CYP17A1 and HSD3B2) and enhanced androstenedione production. For HSD3B2 regulation RARB worked in cooperation with Nur77. Secretory protein ANGPTL1 modulated CYP17A1 and DUSP6 expression by inducing ERK1/2 phosphorylation. By contrast, our studies revealed no evidence for hormones or cell cycle involvement in regulating androgen biosynthesis. In summary, these studies establish a firm role for RARB and ANGPTL1 in the regulation of androgen production in H295R cells.
Highlights
Pregnenolone, which is needed for the production of all steroids
In the Biological General Repository for Interaction Datasets (BioGRID; www.thebiogrid.org), we found evidence that retinoic acid receptor beta (RARB) interacts with the nuclear receptor 4A2 (NR4A2), which belongs to the nuclear receptor 4A family that includes Nur[77] as a member
In search of regulators of human androgen biosynthesis, we explored mechanisms underlying the induction of androgen production in serum starved H295R adrenal cells
Summary
Pregnenolone, which is needed for the production of all steroids. Steroid biosynthesis proceeds further via a series of enzymatic reactions which involves the enzymes cytochrome P450c17 (encoded by CYP17A1) and 3β-hydroxysteroid dehydrogenase II (3βHSDII) (encoded by HSD3B2) that are essential for the production of all sex steroids. Recent studies have demonstrated that in PCOS theca cells reduced levels of activated mitogen-activated protein kinase (MEK1/2) and extracellular signal-regulated kinase 1/2 (ERK1/2) correlate with increased androgen production[26]. These findings implicate alterations in the MAPK pathway in the pathogenesis of excessive ovarian androgen production in PCOS. In this study we investigated the gene expression profiles and specific signaling pathways in androgen producing H295R cells to obtain further insight into androgen regulation in humans. We used the previously described H295R cell starvation model which causes a shift in the steroid profile towards androgen production and produces a differential gene expression profile of a hyperandrogenic state. Among them retinoic acid receptor beta (RARB) and angiopoietin-like protein 1 (ANGPTL1) led us to novel pathways involved in the regulation of androgens
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
