Abstract
The recognized association between male hypogonadism and obesity has multifactorial implications on adipose tissue (AT) physiology. The fat solubility of testosterone (T) suggests a sequestration process in fat depots, leading to reduced circulating levels of T in obesity. Several evidence suggest that steroids play a two-sided inhibitory role on adipogenesis by locally decreasing lipid accumulation and by stimulating lipolysis. The current study investigates T trafficking and activity in dysfunctional AT. Samples of subcutaneous AT (SAT) were obtained from explants from lipoaspirate plastic surgery in six obese and six normal weight male patients. Experimental procedures on both SAT explants and insulin-resistant (IR) 3T3-L1 adipocytes were performed, including real-time PCR and mass-spectrometry quantification. A significant deregulation of gene responsiveness to androgens in IR cells and obese SAT was observed (all p < 0.05), together with reduced T release after adrenergic stimulation (-10% compared with -55% in lean SAT, p = 0.021). Higher concentrations of intracellular T and estradiol in obese SAT were also observed (2.4 vs. 1.3 ng/g, p = 0.013 and 0.075 vs. 0.22 ng/g, p = 0.004, respectively). Testosterone accumulation resulted in even lower expression in androgen-responsive genes involved in lipolytic and anti-adipogenic pathways from both in vitro and ex vivo experiments. These results suggest an altered response of dysfunctional fat cells to testosterone stimulation, which normally favors lipolysis and induces an anti-adipogenic effect. The considerable reduction of lipolytic T release after adrenergic stimulation in obese SAT contributes to AT dysfunction, in a feedforward loop further reducing T levels in obese hypogonadal males.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.