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Plasma HDL Reduces Nonesterified Fatty Acid Hydroperoxides Originating from Oxidized LDL: a Mechanism for Its Antioxidant Ability
Author(s) -
Kotosai Mari,
Shimada Sachiko,
Kanda Mai,
Matsuda Namiko,
Sekido Keiko,
Shimizu Yoshibumi,
Tokumura Akira,
Nakamura Toshiyuki,
Murota Kaeko,
Kawai Yoshichika,
Terao Junji
Publication year - 2013
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-013-3779-1
Subject(s) - chemistry , antioxidant , lipidology , lysophosphatidylcholine , low density lipoprotein , phosphatidylcholine , clinical chemistry , cholesteryl ester , fatty acid , high density lipoprotein , lipoprotein , biochemistry , cholesterol , phospholipid , membrane
The antioxidant property of plasma high‐density lipoprotein (HDL) is thought to be involved in potential anti‐atherogenic effects but the exact mechanism is not known. We aimed to reveal the contribution of HDL on the elimination of lipid hydroperoxides (LOOH) derived from oxidized low‐density lipoprotein (LDL). Oxidized LDL prepared by copper ion‐induced oxidation contained nonesterified fatty acid hydroperoxides (FFA‐OOH) and lysophosphatidylcholine (lysoPtdCho), in addition to cholesteryl ester hydroperoxides (CE‐OOH) and phosphatidylcholine hydroperoxides (PtdCho‐OOH). A platelet‐activating factor‐acetylhydrolase (PAF‐AH) inhibitor suppressed formation of FFA‐OOH and lysoPtdCho in oxidized LDL. Among LOOH species, FFA‐OOH was preferentially reduced by incubating oxidized LDL with HDL. HDL exhibited selective FFA‐OOH reducing ability if it was mixed with a liposomal solution containing FFA‐OOH, CE‐OOH and PtdCho‐OOH. Two‐electron reduction of the hydroperoxy group to the hydroxy group was confirmed by the formation of 13‐hydroxyoctadecadienoic acid from 13‐hydroperoxyoctadecadienoic acid in HPLC analyses. This reducing effect was also found in apolipoprotein A‐1 (apoA‐1). FFA‐OOH released from PtdCho‐OOH due to PAF‐AH activity in oxidized LDL undergo two‐electron reduction by the reducing ability of apoA1 in HDL. This preferential reduction of FFA‐OOH may participate in the mechanism of the antioxidant property of HDL.