Dapagliflozin Regulates Cardiac Metabolic Remodeling Partially via Uncoupling Protein 3 in a Nondiabetic Thoracic Aortic Constriction-Induced Mouse Model

Objectives: We aimed to examine the protective effects of dapagliflozin (dapa) on thoracic aortic constriction (TAC)-induced heart failure in a nondiabetic mouse model. More specifically, we determined the effects of dapa on uncoupling protein 3 (UCP3) activation and subsequent metabolic remodeling. Methods: Sixty C57BL/6J mice were divided into six groups for TAC surgery and received different doses of dapa via gavage for 4 weeks. Echocardiography was performed to evaluate cardiac structure and function. Histological and molecular markers of cardiac remodeling and metabolic changes were assessed through staining assays, RT-PCR, western blot, and ELISA. HL-1 cells were used to explore the role of UCP3 in metabolic remodeling through transfection with UCP3 siRNA. Results: Mice that received TAC exhibited elevated heart weight/body weight ratios (HW/BW), left ventricular (LV) hypertrophy, impaired LV ejection fraction, and increased rates of fibrosis and apoptosis, unlike mice that received sham operation. Treatment with dapa after TAC restored HW/BW, improved LV parameters, and reduced fibrosis and apoptosis. dapa changed the expression levels of enzymes involved in glucose and fatty acid (FA) metabolism, such as pyruvate dehydrogenase lipoamide kinase isozyme 4, glucose transporter 4, carnitine palmitoyltransferase-1α, carnitine O-acetyltransferase, carnitine O-octanoyltransferase, acyl-CoA thioesterase 1, acyl-CoA thioesterase 2, peroxisome proliferator-activated receptors α and β, proliferator-activated receptor-gamma coactivator-1α, and UCP3, relative to the levels in mice in the TAC group. UCP3 siRNA reduced the expression of AMP-activated protein kinase and of factors involved in FA oxidation in vitro. Conclusions: Dapa exhibits cardioprotective effects in the model and augments expression of UCP3, which may be involved in metabolic remodeling in the failing heart.