MON-108 Dihydrotestosterone Lowers Cytosolic Sterol Regulatory Element-Binding Protein-1 in Adipose Tissue from Female Mice

Abstract

: Hyperandrogenemia (HA) and insulin resistance (IR) are hallmarks of polycystic ovary syndrome (PCOS), a common endocrine disorder that affects roughly 1 in 5 women, according to the Rotterdam criteria. These hallmarks are also integral elements of non-alcoholic fatty liver disease (NALFD), a disorder that is common in women with PCOS. In lean female mouse models of dihydrotestosterone (DHT)-induced PCOS, a low dose of DHT promotes IR and hepatic lipogenesis via the androgen receptor (AR), thus resulting in NAFLD (1). However, the molecular mechanism of HA-induced NAFLD has not been determined. We hypothesized that a low dose of DHT would interrupt hepatic lipid metabolism leading to NAFLD. To investigate the role of androgen and AR on a master regulator of lipogenesis, sterol regulatory element-binding protein 1 (SREBP-1), we extracted white adipose tissue (WAT) from lean, female wild-type mice and lean PCOS female mice, aka "DHT mice." Then we analyzed the effect of low-dose DHT on lipogenic protein and gene expression as a control to low-dose DHT's impact on the liver. We accomplished this by performing Western blots and real-time quantitative polymerase chain reaction (qRT-PCR) analysis of the cytosolic lipogenic proteins and gene expression of WAT. A low dose of DHT lowered the active form of SREBP-1 in DHT mice in comparison to the control mice, but there was no significant change in fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), phosphorylated ACC (p-ACC), and the active and inactive forms of SREBP-2. We speculate that the low-dose DHT promotes the translocation of SREBP-1 from the cytosol to the nucleus to influence lipogenic gene expression leading to increased lipogenesis contributing to NAFLD. (1) Andrisse et al., Endocrinology. 2017 Mar 1;158(3):531-544.