RF03 | PMON296 Insulin-induced AKR1C3 Metabolizes Classical and 11-oxygenated Androgens in a Model of PCOS Adipocytes

Abstract Polycystic ovary syndrome (PCOS) is the most prevalent endocrinopathy in women. These patients commonly develop hyperandrogenism and this androgen excess (AE) is believed to drive the syndrome. PCOS women also characteristically develop insulin resistance (IR), which correlates with AE in PCOS women. Aldo-keto reductase family 1 member C3 (AKR1C3) catalyzes the conversion of peripheral androgens and is induced by insulin in adipocytes. Classically, AKR1C3 converts Δ4-androstene-3,17-dione (4AD) to testosterone (T) and 5α-androstane-3,17-dione (5AD) to 5α-dihydrotestosterone (DHT). As a result, androgen conversion in adipocytes may contribute to the AE of PCOS women. Additionally, the 11-oxygenated androgens of adrenal origin were reported as the dominant androgens of PCOS and may be an alternative source of AE. AKR1C3 can also convert 11-ketoandrostene-3,17-dione (11K-4AD) to 11-ketotestosterone (11K-T) and 11-ketoandrostane-3,17-dione (11K-5AD) to 11-ketodihydrotestosterone (11K-DHT). T, DHT, 11K-T and 11K-DHT are potent agonists for the androgen receptor (AR). Therefore, overexpression of AKR1C3 by insulin could increase AR activation through production of both classical and 11-keto potent androgens. We hypothesize that AKR1C3 induced by insulin will produce 11K-T and 11K-DHT in a model of PCOS adipocytes. We developed a stable-isotope-dilution liquid chromatography high resolution mass spectrometric assay (SID-LC-HRMS) for the quantification of both classical and 11-oxygenated androgens in differentiated Simpson-Golabi-Behmel Syndrome adipocytes. Cells were treated with 4AD, 11K-4AD, or 11β-hydroxy-androstene-3,17-dione (11β-OH-4AD), the adrenal precursor to 11K-4AD. Androgens were derivatized with Girard P to enhance sensitivity and specificity. Analyte peaks were quantified using calibration curves of analyte to internal standard ratios versus pg of authentic standard. Our data suggests that 11β-OH-4AD is converted to 11K-4AD, which is then converted by insulin-induced AKR1C3 to 11K-T. The conversion of 11K-4AD to 11K-T was AKR1C3 dependent since a panel of AKR1C3 inhibitors blocked 11K-T formation. We found that 11K-T is deactivated to 11β-hydroxy-testosterone (11β-OH-T) and 11K-4AD can be back converted to 11β-OH-4AD by 11β-hydroxy steroid dehydrogenase type 1 (HSD11B1). This suggests that HSD11B1 protects the AR from overactivation by converting potent 11-keto androgens to their less potent 11β-hydroxy counterparts. Both classical and 11-oxygenated androgens may be sources of AE in PCOS by their intracrine formation in adipocytes. Our work elucidates the role of AKR1C3 in the formation of both classical and 11-keto potent androgens in a model of PCOS adipocytes and supports AKR1C3 as a potential therapeutic target in mitigating the AE of PCOS. Presentation: Saturday, June 11, 2022 1:00 p.m. - 1:05 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.