Statins are largely used in clinics in the treatment of patients with cardiovascular diseases for their effect on lowering circulating cholesterol. Lectin-like oxidized low-density lipoprotein (LOX-1), the primary receptor for ox-LDL, plays a central role in the pathogenesis of atherosclerosis and cardiovascular disorders. We have recently shown that chronic exposure of cells to lovastatin disrupts LOX-1 receptor cluster distribution in plasma membranes, leading to a marked loss of LOX-1 function. Here we investigated the molecular mechanism of statin-mediated LOX-1 inhibition and we demonstrate that all tested statins are able to displace the binding of fluorescent ox-LDL to LOX-1 by a direct interaction with LOX-1 receptors in a cell-based binding assay. Molecular docking simulations confirm the interaction and indicate that statins completely fill the hydrophobic tunnel that crosses the C-type lectin-like (CTLD) recognition domain of LOX-1. Classical molecular dynamics simulation technique applied to the LOX-1 CTLD, considered in the entire receptor structure with or without a statin ligand inside the tunnel, indicates that the presence of a ligand largely increases the dimer stability. Electrophoretic separation and western blot confirm that different statins binding stabilize the dimer assembly of LOX-1 receptors in vivo. The simulative and experimental results allow us to propose a CTLD clamp motion, which enables the receptor-substrate coupling. These findings reveal a novel and significant functional effect of statins.
Keywords: Ato, atorvastatin; CTLD, C-type lectin-like domain; Cav-1, caveolin-1; DMEM, Dulbecco's modified Eagle's medium; DiI, 1,1′-dioctadecyl-3,3,3′,3′-tetramethyllindocarbocyanine perchlorate; Flu, fluvastatin; HEK, human embryonic kidney; HMG-CoA, 3-hydroxy-3-methylglutaryl coenzyme A; LDL, low-density lipoprotein; LDL-C, low-density lipoprotein-cholesterol; LOX-1 receptor; LOX-1, lectin-like oxidized low-density lipoprotein receptor-1; Lov, lovastatin; Mab, monoclonal antibody; Pra, pravastatin; molecular docking; molecular dynamics simulation; monomer-dimer ratio; ox-LDL, oxidized low-density lipoprotein; statin; substrate recognition.