title: Inhibition of LOX-1 by statins may relate to upregulation of eNOS.
abstract: LOX-1, a receptor for oxidized low-density lipoprotein (ox-LDL), plays a critical role in endothelial dysfunction and atherosclerosis; both of these conditions are associated with diminished expression of constitutive endothelial nitric oxide synthase (eNOS). Recent studies show that HMG CoA reductase inhibitors (statins) exert cardioprotective effect. We examined the role of LOX-1 in eNOS expression and modulation of this relationship by two different statins, simvastatin and atorvastatin in human coronary artery endothelial cells (HCAECs). Ox-LDL (40 microg/ml) upregulated the expression of LOX-1; simultaneously, there was a reduction in eNOS expression. Pretreatment of HCAECs with simvastatin or atorvastatin (1 and 10 microM) reduced ox-LDL-induced upregulation of LOX-1 and downregulation of eNOS (both P < 0.05). High concentration of statins (10 microM) was more potent than the low concentration (1 microM) (P < 0.05). Both statins also attenuated ox-LDL-mediated activation of MAP kinase. These observations indicate that statins attenuate the effect of ox-LDL on eNOS expression. Inhibitory effect on LOX-1 and subsequently MAP kinase activity provides a potential mechanism of beneficial effects of statins beyond lowering cholesterol.
authors.affiliation: Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. mehtajl@uams.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Mehta
authors.forename: D Y
authors.initials: DY
authors.lastname: Li
authors.forename: H J
authors.initials: HJ
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Joseph
authors.forename: F
authors.initials: F
authors.lastname: Romeo
mesh_terms: D000069059:Atorvastatin; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D006538:Heptanoic Acids / Q000494:pharmacology; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D008077:Lipoproteins, LDL / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011973:Receptors, LDL / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; D019821:Simvastatin / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL; C495137:OLR1 protein, human; D011758:Pyrroles; D012333:RNA, Messenger; D011973:Receptors, LDL; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; C099252:oxidized low density lipoprotein; D000069059:Atorvastatin; D019821:Simvastatin; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D020928:Mitogen-Activated Protein Kinases