Empagliflozin Reduces Inflammation and Bioenergetics in Proinflammatory Human Macrophages: Clues to Mechanisms of Blood Vessel Protection?

SGLT-2 inhibitors (SGLT2i) reduce cardiovascular (CV) risk in people with type 2 diabetes and atherosclerotic CV diseases. The inflammatory function of macrophages (Mφ) - which play a pivotal role in atherosclerosis - is strictly dependent on their metabolism. Aim: To determine whether empagliflozin (EMPA) reduces inflammation and modifies bioenergetic metabolism in proinflammatory human Mφ (M1). Methods: M1 were differentiated from healthy donors’ monocytes and incubated with/without EMPA 100 µM for 16h. Biomarkers of inflammation and oxidative stress were quantified by qPCR. Steady-state energetic metabolism (fluxes: pmol/min for 5x104 cells) was measured by indirect microcalorimetry [oxidations of lipids (LipOX,) glucose and amino acids; anaerobic glycolysis (AnaerGlyc); tricarboxylic acid cycle (TCA); energy expenditure (EPR); maximum estimate of ATP production (ATPflux)] which is based on the integration of measured O2 and H+ (Agilent Seahorse), lactate and NH4 (enzymatic method) fluxes with the stoichiometric equations of metabolic pathways. Results: In M1, EMPA reduces (≈50%) inflammation (IL1β, IL8, TNFα and MCP1; p<0.05-0.001) and oxidative stress (GPX and HO-1; p <0.05). EMPA lowers OCR (133±9.7 vs. 153±10.3, p<0.001), LipOX (1.15±0.1 vs. 1.33±0.1; p<0.005), TCA (45±3 vs. 52±4; p<0.001), AnaerGlyc (210±23 vs. 268±24; p<0.01), ATPflux (1097±94 vs. 1313±94; p<0.005) and EPR (83±7 vs. 98±7 µJ/min; p<0.001). After dissipating mitochondrial membrane potential and forcing maximal OCR with FCCP, TCA (77±11 vs. 97±12, p=0.001), LipOX (1.7±0.3 vs. 2.2±0.4, p<0.005) and EPR (125±17 vs. 153±17; p<0.005), but not AnaerGlyc, remain inhibited by EMPA. Conclusions: EMPA alters M1 inflammation along with cytosolic (AnaerGlyc) and - to a greater extent - mitochondrial (TCA) bioenergetics. EMPA-induced metabolic dysfunction of M1 in vivo might result into reduced metaflammation and contribute to SGLT2i-dependent CV protection. Disclosure V. Spigoni: None. G. Cinquegrani: None. F. Fantuzzi: None. S. Lorusso: None. A. Dei cas: Other Relationship; Self; Novo Nordisk. R. C. Bonadonna: Advisory Panel; Self; Sanofi, Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company. Funding Italian Diabete Ricerca Foundation; Eli Lilly Italy