Targeting High Glucose-Induced Epigenetic Modifications at Cardiac Levels: The Role of SGLT2 and SGLT2 Inhibitors

Background: Sodium-glucose co-transporters inhibitors showed many beneficial effects at the cardiovascular level. Several mechanisms of action have been identified. However, no data are reported on their capability to act via epigenetic mechanisms. Therefore, this study aimed to investigate the ability of SGLT2 inhibitors to induce protective effects at the cardiovascular level by acting on DNA methylation. Methods: To better clarify this issue, the effects of empagliflozin on hyperglycemia-induced epigenetic modifications were evaluated in human ventricular cardiac myoblasts AC16 exposed to hyperglycemia for 7 days. Therefore, effects of EMPA on DNA methylation of NF-κB, SOD2, and IL-6 genes in AC16 exposed to high glucose were analyzed by pyrosequencing-based methylation analysis. Modifications of gene expression and DNA methylation of NF-κB and SOD2 were confirmed in response to a transient SGLT2 gene silencing in the same cellular model. Moreover, chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR) was performed to evaluate the occupancy of TET2 across the investigated regions of NF-κB and SOD2 promoters. Results: Seven days of high glucose treatment induced a significant demethylation in the promoter regions of NF-kB and SOD2 with a consequently high level in mRNA expression of both genes. The observed DNA demethylation was mediated by increased TET2 expression and binding to the CpGs island in promoter regions of analyzed genes. Indeed, empagliflozin prevented the HG-induced demethylation changes by reducing TET2 binding to the investigated promoter region and counteracts the altered gene expression. The transient SGLT2 gene silencing prevents the DNA demethylation observed in promoter regions, thus suggesting a role of SGLT2 as a potential target of the anti-inflammatory and anti-oxidant effect of empagliflozin in cardiomyocytes. Conclusions: In conclusion, our results demonstrated that empagliflozin, mainly acting on SGLT2, prevented DNA methylation changes induced by high glucose and provided evidence of a new mechanism by which SGLT2i can exert cardio-beneficial effects.