TY - JOUR
T1 - Activation of NADPH oxidase is required for macrophage-mediated oxidation of low-density lipoprotein
AU - Aviram, Michael
AU - Rosenblat, Mira
AU - Etzioni, Amos
AU - Levy, Rachel
N1 - Funding Information:
From the Lipid Research Laboratory and the Department of Pediatrics A, Rambam Medical Center, The Bruce Rappaport Faculty of Medicine, Technion; the Rappaport Family lnstitute for Research in the Medical Sciences, Haifa; and the Infectious Disease Laboratory, Clinical Biochemistry Unit, Faculty of Health Sciences, Ben Gurion University, Beer Sheva, Israel. Submitted September5, 1995; accepted April 3, 1996. Supported by a grant from the Rappaport Family Institute for Research in the Medical Sciences. Address reprint requests to Michael Aviram, DSc, Head, Lipid Research Laboratory, Rambam Medical Center, Haifa, Israel. Copyright © 1996 by W..B. Saunders Company 0026-0495/96/4509-0006503.00/0
PY - 1996/1/1
Y1 - 1996/1/1
N2 - Low-density lipoprotein (LDL) oxidation by arterial wall cells, a key event during early atherogenesis, was suggested to involve the activation of 15-lipoxygenase and/or nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. We sought to analyze the role of these oxygenases in macrophage- mediated oxidation of LDL under oxidative stress. Upon incubation of LDL with the J-774 A.1 macrophage-like cell line or with human monocyte-derived macrophages (HMDM) in the presence of 1 μmol/L CuSO4, the release of superoxide anions to the medium was demonstrated. Under these conditions, the cytosolic protein components of the NADPH oxidase complex, P-47 and P-67, translocated to the plasma membrane, indicating LDL-mediated activation of the NADPH oxidase complex. Under the above-mentioned experimental conditions, the macrophage 15-lipoxygenase was also activated, as determined by the release of 15-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE) and 13- hydroxyoctadecadienoic acid (13-HODE) to the medium. Inhibition of the macrophage NADPH oxidase with apocynin or dismutation of superoxide anions, the product of NADPH oxidase activation, with superoxide dismutase (SOD) significantly inhibited macrophage-mediated oxidation of LDL (by 61% to 89%) under these conditions. Phorbol myristate acetate (PMA), which causes NADPH oxidase activation in J-774 A.1 macrophages, had no significant effect on 15- lipoxygenase activity, but still resulted in cell-mediated oxidation of LDL. Finally, HMDM from two patients with chronic granulomatous disease (CGD) that were shown to lack active NADPH oxidase, but to possess almost normal 15- lipoxygenase activity failed to oxidize LDL. We thus conclude that LDL- induced NADPH oxidase activation (under oxidative stress) is required for macrophage-mediated oxidation of LDL, whereas activation of 15-lipoxygenase may not be sufficient for LDL oxidation under these conditions.
AB - Low-density lipoprotein (LDL) oxidation by arterial wall cells, a key event during early atherogenesis, was suggested to involve the activation of 15-lipoxygenase and/or nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. We sought to analyze the role of these oxygenases in macrophage- mediated oxidation of LDL under oxidative stress. Upon incubation of LDL with the J-774 A.1 macrophage-like cell line or with human monocyte-derived macrophages (HMDM) in the presence of 1 μmol/L CuSO4, the release of superoxide anions to the medium was demonstrated. Under these conditions, the cytosolic protein components of the NADPH oxidase complex, P-47 and P-67, translocated to the plasma membrane, indicating LDL-mediated activation of the NADPH oxidase complex. Under the above-mentioned experimental conditions, the macrophage 15-lipoxygenase was also activated, as determined by the release of 15-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE) and 13- hydroxyoctadecadienoic acid (13-HODE) to the medium. Inhibition of the macrophage NADPH oxidase with apocynin or dismutation of superoxide anions, the product of NADPH oxidase activation, with superoxide dismutase (SOD) significantly inhibited macrophage-mediated oxidation of LDL (by 61% to 89%) under these conditions. Phorbol myristate acetate (PMA), which causes NADPH oxidase activation in J-774 A.1 macrophages, had no significant effect on 15- lipoxygenase activity, but still resulted in cell-mediated oxidation of LDL. Finally, HMDM from two patients with chronic granulomatous disease (CGD) that were shown to lack active NADPH oxidase, but to possess almost normal 15- lipoxygenase activity failed to oxidize LDL. We thus conclude that LDL- induced NADPH oxidase activation (under oxidative stress) is required for macrophage-mediated oxidation of LDL, whereas activation of 15-lipoxygenase may not be sufficient for LDL oxidation under these conditions.
UR - http://www.scopus.com/inward/record.url?scp=0029783343&partnerID=8YFLogxK
U2 - 10.1016/S0026-0495(96)90005-0
DO - 10.1016/S0026-0495(96)90005-0
M3 - Article
AN - SCOPUS:0029783343
SN - 0026-0495
VL - 45
SP - 1069
EP - 1079
JO - Metabolism: Clinical and Experimental
JF - Metabolism: Clinical and Experimental
IS - 9
ER -