Time course-changes in phosphatidylcholine profile during oxidative modification of low-density lipoprotein.
Time course-changes in phosphatidylcholine profile during oxidative modification of low-density lipoprotein.
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DOI：
10.1186/1476-511x-13-48
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发表时间：
2014-03-14
影响因子：
4.5
通讯作者：
Itabe H
中科院分区：
文献类型：
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作者：
Sasabe N;Keyamura Y;Obama T;Inoue N;Masuko Y;Igarashi Y;Aiuchi T;Kato R;Yamaguchi T;Kuwata H;Iwamoto S;Miyazaki A;Hara S;Yoshikawa T;Itabe H
氧化低密度脂蛋白（oxLDL）形成过程中产生的氧化磷脂酰胆碱（oxPC）和溶血磷脂酰胆碱（lysoPC）参与了动脉粥样硬化病变的发展。我们研究了低密度脂蛋白氧化过程中磷脂酰胆碱（PC）分子种类的时间变化，以确定这些致动脉粥样硬化PC是如何产生的。使用或不使用选择性血小板活化因子乙酰水解酶（PAF-AH）抑制剂对人和兔ldl进行预处理。用硫酸铜孵育法氧化LDL，用液相色谱-串联质谱法分析PC谱。当人体LDL被氧化时，含有多不饱和脂肪酸（PUFA）的PC种的峰面积在短滞后期后急剧下降，同时lysoPC种的峰面积急剧增加。虽然在LDL氧化过程中会形成多种含有氧化脂肪酰基或裂解酰基链的oxPC，但在oxLDL中积累的oxPC产物只有少数：1-棕榈酰-2-（9-氧-壬烷基）PC和具有两个双键的长链oxPC。用PAF-AH抑制剂预处理LDL可大大减少lysoPC的产生，但对脂质过氧化反应和oxPC谱没有影响。兔LDL具有不同的PC分子种类组成，达到完全氧化需要比人LDL更长的时间，在氧化过程中也积累了lysoPC。PAF-AH抑制剂预处理可抑制兔oxLDL中lysoPC的升高。兔oxLDL中形成的主要oxPC种与人oxLDL基本相同。这些结果表明，在LDL氧化过程中，lysoPC是主要产物，PAF-AH活性对lysoPC的生成至关重要。在体外铜离子氧化LDL时，积累的oxPC种类有限。
Oxidized phosphatidylcholines (oxPC) and lysophosphatidylcholine (lysoPC) generated during the formation of oxidized low-density lipoprotein (oxLDL) are involved in atherosclerotic lesion development. We investigated the time course-changes in phosphatidylcholine (PC) molecular species during oxidation of LDL to determine how those atherogenic PCs are produced. Human and rabbit LDLs were pretreated with or without a selective platelet-activating factor acetylhydrolase (PAF-AH) inhibitor. LDL was oxidized by incubation with copper sulfate, and PC profiles were analyzed by liquid chromatography-tandem mass spectrometry. When human LDL was oxidized, the peak areas for polyunsaturated fatty acid (PUFA)-containing PC species dramatically decreased after a short lag period, concomitantly lysoPC species increased sharply. Although a variety of oxPC species containing oxidized fatty acyl groups or cleaved acyl chains are formed during LDL oxidation, only a few oxPC products accumulated in oxLDL: 1-palmitoyl-2-(9-oxo-nonanoyl) PC and long-chain oxPC with two double bonds. Pretreatment of LDL with the PAF-AH inhibitor greatly reduced lysoPC production while it had no effect on lipid peroxidation reactions and oxPC profiles. Rabbit LDL, which has a different composition of PC molecular species and needs a longer time to reach achieve full oxidation than human LDL, also accumulated lysoPC during oxidation. The increase in lysoPC in rabbit oxLDL was suppressed by pretreatment with the PAF-AH inhibitor. The major oxPC species formed in rabbit oxLDL were almost the same as human oxLDL. These results suggest that lysoPC species are the major products and PAF-AH activity is crucial for lysoPC generation during oxidation of LDL. The oxPC species accumulated are limited when LDL is oxidized with copper ion in vitro.