Affiliation: | 1. Tennessee Valley Health System, Veterans Affairs, Nashville, TN, USA
Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
Division of Cardiovascular Medicine, Stanford University Medical Center, Stanford, CA, USA;2. Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, 2213 Garland Ave., Nashville, TN, 37232 USA;3. Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA;4. Tennessee Valley Health System, Veterans Affairs, Nashville, TN, USA
Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, 2213 Garland Ave., Nashville, TN, 37232 USA;5. Tennessee Valley Health System, Veterans Affairs, Nashville, TN, USA |
Abstract: | Elevated postprandial triacylglycerols (TAG) are an important risk factor for cardiovascular disease. Men have higher plasma TAG and impaired TAG clearance compared to women, which may contribute to sex differences in risk of cardiovascular disease. Understanding mechanisms of sex differences in TAG metabolism may yield novel therapeutic targets to prevent cardiovascular disease. Cholesteryl ester transfer protein (CETP) is a lipid shuttling protein known for its effects on high-density lipoprotein (HDL) cholesterol levels. Although mice lack CETP, we previously demonstrated that transgenic CETP expression in female mice alters TAG metabolism. The impact of CETP on TAG metabolism in males, however, is not well understood. Here, we demonstrate that CETP expression increases plasma TAG in males, especially in very-low density lipoprotein (VLDL), by impairing postprandial plasma TAG clearance compared to wild-type (WT) males. Gonadal hormones were required for CETP to impair TAG clearance, suggesting a role for sex hormones for this effect. Testosterone replacement in the setting of gonadectomy was sufficient to restore the effect of CETP on TAG. Lastly, liver androgen receptor (AR) was required for CETP to increase plasma TAG. Thus, expression of CETP in males raises plasma TAG by impairing TAG clearance via testosterone signaling to AR. Further understanding of how CETP and androgen signaling impair TAG clearance may lead to novel approaches to reduce TAG and mitigate risk of cardiovascular disease. |