Influence of sodium-glucose cotransporter protein type 2 inhibition on cardiac remodeling in rats with aortic stenosis: functional assessment and assessment and of cellular pathways of inflammation and autophagy

Abstract

Cardiovascular diseases have high morbidity and mortality rates, with heart failure (HF) being one of the main causes of death in the world. A 46% increase in the prevalence of HF is expected for the year 2030 in relation to 2012. HF is characterized by decreased capacity for daily activities and physical exercise due to the early occurrence of fatigue or dyspnea resulting from ventricular dysfunction, congestion pulmonary or low output. After the initial cardiac injury, molecular, genetic, cellular and interstitial changes occur that manifest clinically as changes in the size, shape and function of the heart, called cardiac remodeling. It is considered that inflammatory activation and changes in the autophagy process are important factors in the progression of cardiac remodeling and the development of HF. Studies have shown that the NLRP3 inflammasome acts as a relevant mediator in cardiac remodeling, promoting inflammation and activating profibrotic signaling pathways. Dysregulation of autophagy has been reported as an important link between inflammation and the development of HF, where interest in autophagic processes has grown considerably due to their better understanding of their relevance in cardiovascular diseases. Autophagy is a catabolic process that involves the elimination of damaged cellular proteins and organelles. The most studied autophagic regulators in the heart are serine/threonine kinase, mammalian/mechanistic target of rapamycin (mTOR), and AMP-activated protein kinase (AMPK). Few studies have evaluated the interaction between autophagy and inflammatory activation in situations of cardiac injury. The pharmacological treatment of HF has made great progress in the last decade with the advent of inhibition of the sodium-glucose cotransporter protein type 2 (SGLT2). Currently, dapagliflozin (DAPA) and empagliflozin are recommended for the treatment of HF, regardless of the presence of diabetes and ejection fraction. The mechanisms of action of SGLT2 inhibitors are not yet completely understood. SGLT2 inhibition was accompanied by activation of autophagy markers and is associated with reduced inflammation in different experimental models. Valve disease is a frequent cause of HF, with aortic stenosis standing out due to its high prevalence and the fact that its incidence is estimated to increase considerably with the aging of the population. Few studies have evaluated the effects of SGLT2 inhibition in an experimental model of HF induced by aortic stenosis. The objective of the study is to evaluate the influence of SGLT2 inhibition on cardiac remodeling, myocardial inflammation, and the autophagic process in rats with aortic stenosis. Methods: Eighteen weeks after induction of aortic stenosis, four experimental groups of male Wistar rats will be formed: sham (n=15); sham + dapagliflozin (DAPA, n=15); aortic stenosis (ASO, n=18); aortic stenosis + dapagliflozin (EAO+ DAPA, n=18). Rats belonging to the DAPA and EAO+ DAPA groups will receive dapagliflozin at a concentration of 10 mg/kg/day added to their diet daily for 8 weeks. In vivo structural and functional assessment of the heart will be performed using echocardiography. Myocardial function will be evaluated in preparations with papillary muscles isolated from the left ventricle (LV). The expression of the NLRP3 inflammasome and proteins from the AMPK and mTOR cellular signaling pathways will be evaluated by Western blot. The serum and myocardial concentration of pro-inflammatory cytokines will be assessed by Elisa. The gene expression of genes involved in the activation of myocardial inflammation and autophagy will be evaluated by real-time RT-PCR. Comparisons between groups will be carried out by analysis of variance (ANOVA) complemented by the Bonferroni test (normal distribution), or by the Kruskal-Wallis test complemented by the Dunn test (non-normal distribution). The results will be discussed at a 5% significance level. (AU)