Sodium-glucose co-transporters (SGLT2) inhibitors prevent lipid droplets formation in vascular inflammation or lipid overload by SGLT2-independent mechanism

Background: The formation of vascular lipid droplets (LDs) induced by vascular inflammation or lipid overload contributes to vascular pathophysiology in diabetes and cardiometabolic diseases, while sodium-glucose co-transporter 2 inhibitors (SGLT2-I) are beneficial in treating these conditions. Thus, we hypothesized that SGLT2-I would directly modify vascular LDs formation during vascular inflammation or lipid overload, and explored underlying mechanisms. Methods: LDs formation in isolated murine aorta from wild-type or SGLT2-KO animals was induced by either treatment with tumour necrosis factor (TNF) to induce vascular inflammation or using oleic acid (OA) to mimic lipid overload. Vascular LDs and markers of vascular inflammation were monitored through fluorescence microscopy. Pharmacological inhibitors of sodium-hydrogen exchanger 1 (NHE1), endothelial sodium channels (EnNaC), sodium-calcium exchanger (NCX), protein kinase C (PKC), and NOX1/4 were used to test their role in empagliflozin’s effects on vascular LDs. Results: Empagliflozin, dapagliflozin or ertugliflozin inhibited LDs formation in aorta exposed to TNF or OA. Empagliflozin reduced vascular inflammation (based on ICAM-1) and TNF/OA-induced LDs formation. These effects persisted in SGLT2-KO mice. Inhibition of NHE1, PKC or NOX1/4 recapitulated empagliflozin’s effects on TNF-induced vascular inflammation, without additional effects of empagliflozin. However, NHE1 inhibition was not involved in the SGLT2-independent reduction of OA-induced LDs formation by empagliflozin. Conclusions: This is the first report demonstrating that SGLT2-I prevent the formation of LDs in the vasculature. Empagliflozin downregulates LDs formation in vascular inflammation or lipid overload via an SGLT2-independent mechanism. Empagliflozin’s protective effects involve the NHE1/PKC/NOX pathway in the TNF response but not in the OA response.