Common and distinct effects of sodium-glucose cotransporter-2 inhibitors on in vitro platelet activation

Recent studies have demonstrated antiplatelet activity of sodium-glucose cotransporter-2 (SGLT2) inhibitors, particularly at high micromolar concentrations (10-30 µM). However, the effects of clinically relevant nanomolar concentrations on platelet function have not been reported. This study investigated the roles of empagliflozin and dapagliflozin, primarily at 0.625 µM, on platelet functions. In vitro assays were performed to assess platelet activation and aggregation in the presence of SGLT2 inhibitors using human platelet-rich plasma (PRP). The results demonstrated that empagliflozin and dapagliflozin produced a modest but significant (approximately 20 %) inhibition of collagen-induced platelet aggregation. In response to adenosine diphosphate (ADP), SGLT2 inhibitors increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP), which may contribute to platelet inhibition. However, dapagliflozin, but not empagliflozin, elevated tumor necrosis factor alpha (TNF-α) secretion from activated platelets and enhanced endothelial nitric oxide synthase (eNOS) expression following stimulation with ADP. Molecular docking suggested binding of both SGLT2 inhibitors to the catalytic subunit of protein kinase A, yet only empagliflozin directly enhanced PKA catalytic activity. The effects of cariporide, a selective sodium-hydrogen exchanger 1 (NHE-1) inhibitor, were contradictory to those of SGLT2 inhibitors, particularly on TNF-α secretion, suggesting that SGLT2 inhibitors might not target platelet NHE-1. In conclusion, this study highlights both shared and distinct effects of SGLT2 inhibitors on platelet function. Differences in PKA function, eNOS expression, and TNF-α secretion may underlie the divergent activities between empagliflozin and dapagliflozin in platelets. These findings may contribute to a better understanding of the cardiovascular benefits of SGLT2 inhibitors.