Influence of empagliflozin on the myocardium of rats with heart failure induced by aortic stenosis

Abstract

Heart Failure (HF) is clinically characterized by reduced capacity for physical exercise and daily activities. HF is caused by diseases such as arterial hypertension, myocardial infarction, valvulopathies, and cardiomyopathies. Chronic hemodynamic overloads produced by these diseases induce genetic, molecular, cellular and interstitial changes that manifest clinically as alterations in the size, shape, and function of the heart, a process called cardiac remodeling. These hemodynamic overloads can generate changes in the collagen architecture, induce fibrosis and cause imbalance between the production of reactive oxygen species and the antioxidant capacity. Alterations of these pathways contribute to the process of cardiac remodeling, leading to worsening of the clinical picture of HF. Due to the high morbidity and mortality associated with HF, there is great interest in the development of new drugs to attenuate the cardiac remodeling resulting from the progression of the disease. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, prescribed in the treatment of diabetes mellitus, have shown cardioprotective effect, but the underlying mechanisms are still unclear. Thus, the aim of this study is to evaluate the influence of empagliflozin on structural and molecular changes in the myocardium of rats with heart failure induced by aortic stenosis. Methods: Eighteen weeks after aortic stenosis induction surgery, four experimental groups of male Wistar rats will be constituted: sham (Sham, n=15); sham + empagliflozin (S+EMPA, n=15); aortic stenosis (EAO, n=25); aortic stenosis + empagliflozin (EAO+EMPA, n=25). The rats of groups S+EMPA and EAO+EMPA will receive empagliflozin (10 mg/kg/day) added to their diet, for 8 weeks. In vivo cardiac structural and functional evaluation will be performed by echocardiography. Left ventricular tissue samples will be obtained for biochemical, histological, and molecular analysis. In vitro, H9C2 cells will be induced by oxidative stress by H2O2 and treated with emplaglifozine. After treatment, they will undergo immunofluorescence (Nfr2) and Western blotting (antioxidant enzymes, MAPKs, NF-kB, TNF-±, IL-6). Comparisons between groups will be performed by two factors Analysis of Variance (ANOVA), complemented with the Bonferroni multiple comparison test (normal distribution) or Kruskal-Wallis test complemented with Dunn multiple comparison test (non-normal distribution). Significance level will be set at 5%. (AU)