High-density lipoprotein remodeling by phospholipid nanoparticles improves cholesterol efflux capacity and protects from atherosclerosis

The efficiency of cholesterol efflux from cells promoted by high-density lipoproteins (HDLs) depends on HDL concentration and functional properties. The term "dysfunctional HDL" describes HDLs with impaired protective properties. Cholesterol efflux capacity (CEC) of HDL is reduced in patients with atherosclerosis, but the exact mechanisms underlying this impairment are not well characterized. Enriching HDLs with phospholipids (PLs) improves CEC. Herein, we assessed the potential of PL nanoparticles in improving HDL functionality. We lipidated HDL subfractions by incubating with PL nanoparticles containing soybean polyunsaturated phosphatidylcholine. Incubating blood plasma with PL nanoparticles resulted in the dose-dependent lipidation of all HDL subfractions. Changes in apolipoprotein A1 (apoA-1) and PL concentrations were the most prominent in the HDL2 fraction. Concentrations of PL in the HDL3 fraction and the fraction with a density > 1.21 g/mL increased by 30-50%, whereas apoA-1 levels decreased. We hypothesized that PL nanoparticles may cause HDL remodeling that can improve their functions. The CECs of lipidated HDLs were analyzed by incubating apolipoprotein B (apoB)-depleted plasma with H-3-cholesterol-labeled THP-1 macrophages. The findings revealed a two-fold increase in cholesterol efflux compared with native apoB-depleted plasma. Moreover, intravenous administration of PL nanoparticles restored lipid profiles and effectively protected blood vessels from atherosclerosis progression in cholesterol-fed rabbits compared with that of fenofibrate and atorvastatin. PL nanoparticles also protected against atherosclerosis and decreased the atherogenic index. Altogether, these results indicate that PL nanoparticles can be used to correct the lipid composition and CEC of HDLs.