Effects of empagliflozin on myocardial transcriptome in rats with aortic stenosis-induced heart failure
Authors: Urbano Pagan L , Gatto M , Ferreira M R , Gomes M J , Oliveira J P G , Mota G A F , Damatto F C , Souza L M , Santos A C C , Rodrigues E A , Borim P A , Campos D H S , Okoshi M P , Okoshi K 
Published: October 2024

Abstract

Introduction
Aortic stenosis (AS) represents one of the most prevalent valvular heart diseases and an important cause of heart failure. Currently, no medical therapies influence the natural history of aortic stenosis. Although sodium glucose co-transporter 2 inhibitors (SGLT2i) have improved cardiovascular outcomes in heart failure patients with both reduced and preserved ejection fraction, their action mechanisms are not clear. Transcriptome analysis present great potential to identify biomarkers of disease and to gain insight into disease pathophysiology. In this study, we analyzed myocardial mRNA profile in aortic stenosis rats treated with empagliflozin.

Methods
Eighteen weeks after supra-aortic banding surgery, male Wistar rats were divided into 3 groups: Sham (n=15); aortic stenosis (AS, n=27); AS+empagliflozin (AS-EMP, n=27). Empagliflozin (10 mg/kg/day) was added to rat chow for 8 weeks. Transcriptome of left ventricle (LV) myocardium was studied by RNA-sequencing (sample size: 5 per group). Differential gene expression was analyzed in R environment using the DESeq2 package. Genes were considered differentially expressed (DEG) when they exhibited a log2 fold change (log2FC) higher than 1 (upregulated) or lower than -1 (downregulated), coupled with an adjusted p-value below 0.05. Functional enrichment analysis using gene ontology was performed by the online tool Enrich. Statistical analysis: ANOVA and Tukey.

Results
AS-EMP had lower LV diastolic diameter (Sham 8.39±0.57; AS 9.80±0.53*; AS-EMP 9.08±0.87# mm; p&lt;0.05: * vs Sham; # vs AS), left atrium diameter (Sham 5.68±0.40; AS 9.67±1.00*; AS-EMP 8.97±1.36*# mm; p&lt;0.05: * vs Sham; # vs AS), and LV mass (Sham 0.85±0.11; AS 2.19±0.27*; AS-EMP 1.76±0.34*# g; p&lt;0.05: * vs Sham; # vs AS) than AS. A total of 1246 differentially expressed genes were identified, comprising 663 upregulated genes (70 genes in AS vs SHAM; 593 in AS-EMP vs AS) and 583 downregulated genes (35 genes in AS vs SHAM; 548 in AS-EMP vs AS). Most of the differentially expressed genes were enriched in processes such as extracellular matrix and structure organization, signal transduction regulation, and substrate-dependent cell migration (AS vs SHAM), as well as myocardial contraction, negative regulation of programmed cell death, and mitochondrial membrane organization (AS-EMP vs AS). The main upregulated genes were Loxl1, Mfap4, Postn, Col8a1, Pi16, and Nppa in AS vs SHAM; and Mxra8, Zfta, Pnisr, Thoc1, and Ralbp1 in AS-EMP vs AS comparison. The main downregulated genes were Mxra8, Ralbp1, and Tubgcp6 in AS vs SHAM; and Itgb5, Ltbp2, Tmem109, Plec, and Rorc in AS-EMP vs AS comparison.

Conclusion
We identified myocardial genes and biological processes that are potentially involved in aortic stenosis-induced heart failure. Empagliflozin attenuates cardiac remodeling and modulates myocardial genes involved with myocyte contraction, apoptosis, and mitochondrial organization in aortic stenosis rats.