Random versus selective membrane phospholipid oxidation in apoptosis: Role of phosphatidylserine
Random versus selective membrane phospholipid oxidation in apoptosis: Role of phosphatidylserine
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DOI：
10.1021/bi9808262
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发表时间：
1998-09-29
期刊：
影响因子：
2.9
通讯作者：
Kagan, VE
中科院分区：
文献类型：
--
作者：
Fabisiak, JP;Tyurina, YY;Kagan, VE
活性氧的形成与细胞凋亡有关。为了探讨脂质过氧化在细胞凋亡中的作用，我们用2，2 ′-偶氮二（2，4-二甲基异戊腈）（AMVN）在HL-60细胞膜上产生过氧化自由基，以代谢整合到HL-60细胞磷脂中的顺式-帕里那酸（cis-PnA）为探针，检测特定磷脂类的脂质过氧化程度。在2小时内，AMVN（500 μ M）随机氧化超过85%的cis-PnA含有ic。所有主要类别的磷脂。AMVN诱导的脂质过氧化反应后，细胞凋亡所确定的核凝聚，DNA片段化，和膜联蛋白V结合到外部化的磷脂酰丝氨酸（PS）。外部氨基磷脂的丁胺衍生化显示，PS，而不是磷脂酰乙醇胺，被外部化。维生素E类似物，6-羟基-2，2，5，7，8-五甲基苯并二氢吡喃（PMC），抑制磷脂中的顺式-PnA的总氧化超过85%。然而，并非所有磷脂都受到同等保护。磷脂酰胆碱，磷脂酰乙醇胺，磷脂酰肌醇，鞘磷脂几乎完全保护PMC，而氧化的PS在整个活细胞中不受影响。PS对PMC的不敏感性不是固有性质，因为PMC在AMVN氧化由顺式PnA标记的细胞制备的脂质体期间同等地保护所有脂质。PS氧化在细胞凋亡中的潜在作用进一步表明，细胞共暴露于AMVN和PMC后，细胞凋亡的忠实执行。
The formation of reactive oxygen species has been associated with apoptosis. To assess the role of lipid peroxidation in apoptosis, we used 2,2'-azobis(2,4-dimethylisovaleronitrile) (AMVN) to generate peroxyl radicals within cellular membranes of HL-60 cells, cis-Parinaric acid (cis-PnA) metabolically integrated into phospholipids of HL-60 cells was used as a probe to assess the extent of lipid peroxidation within specific phospholipid classes. Within 2 h, AMVN (500 mu M) randomly oxidized more than 85% of cis-PnA contained ic. all major classes of phospholipids. AMVN-induced lipid peroxidation was followed by apoptosis as determined by nuclear condensation, DNA fragmentation, and annexin V binding to externalized phosphatidylserine (PS). Fluorescamine derivatization of external aminophospholipids revealed that PS, but not phosphatidylethanolamine, was externalized. The vitamin E analogue, 6-hydroxy-2,2,5,7,8-pentamethylchromane (PMC), inhibited overall oxidation of cis-PnA in phospholipids by more than 85%. Not all, phospholipids, however, were equally protected. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and sphingomyelin were nearly completely protected by PMC, while oxidation of PS was unaffected in whole living cells. The insensitivity of PS to PMC was not an intrinsic property because PMC protected all lipids equally during AMVN oxidation of liposomes prepared from cis-PnA-labeled cells. The potential role for PS oxidation in apoptosis was further suggested by the faithful execution of apoptosis following coexposure of cells to AMVN and PMC.