Androgen and Estrogen Receptor Activation Impacts Cardiac Function in a PCOS-Prone Rodent Model

Abstract

Abstract Introduction: The global risk and incidence of cardiovascular disease (CVD) is increased in polycystic ovary syndrome (PCOS). Early risk factors and subclinical CVD includes atherogenic dyslipidemia, obesity, insulin resistance, blood pressure, atherosclerosis and impaired cardiac function. Androgen exposure is associated with onset of adiposity, impaired insulin-glucose and lipid metabolism, and cardiac dysfunction. The mechanisms of increased risk of CVD and cardiac dysfunction in PCOS related to hyperandrogenemia, AR and estrogen receptor (ER) activation remain unclear. Aim: The aim of this study was to investigate the effect of androgen treatment on cardiac AR and ER activation, fatty acid metabolism and cardiac function in a PCOS-prone rodent model. Methods: A PCOS-prone rodent model at 6 wks of age with obesity, apoB-remnant lipemia and insulin resistance, and controls were treated with testosterone for 12 weeks. Cardiac function was assessed using transthoracic doppler echocardiography (M-Mode 2D-imaging), lipogenic, AR, ER and other metabolic gene and protein expression were assessed using RTPCR and SDS-PAGE western blot. Results: PCOS-prone animals exhibited left ventricular (LV) hypertrophy, with increased LV mass to body weight (551.6 ± 38.85 mg vs 999 ± 96.17 mg, p<0.05), LV posterior wall diastolic diameter and LV internal diastolic diameter compared to controls. Isovolumetric relaxation time (IVRT) was prolonged (15.91 ± 1.591 msec vs 23.75 ± 0.722 msec, p<0.05). Mild systolic dysfunction was evidenced by increased isovolumetric contraction time (IVCT; 22.5 ± 1.348 msec vs 28.96 ± 1.248 msec, p<0.05) and decreased % ejection fraction and % fractional shortening in PCOS-prone compared to controls. T treatment increased LV mass, IVCT and IVRT in controls but did not exacerbate cardiac function in PCOS-prone animals. T treatment increased cardiac protein expression of PPAR-⍺ in PCOS-prone and controls, and T increased ACC in controls. AR protein expression tended to be reduced, and ER-⍺ was reduced in both T treated control and PCOS-prone animals. Conclusions: The PCOS-prone rodent model demonstrates early cardiac LV hypertrophy and diastolic-systolic dysfunction and T treatment alters fatty acid metabolism, and AR and ER activation are associated with altered cardiac morphology and function in the PCOS-prone and control conditions.