Turnover of eicosanoid precursor fatty acids among phospholipid classes and subclasses of cultured human umbilical vein endothelial cells.
Turnover of eicosanoid precursor fatty acids among phospholipid classes and subclasses of cultured human umbilical vein endothelial cells.
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培养的人脐静脉内皮细胞的磷脂类和亚类中类二十烷酸前体脂肪酸的周转。
DOI：
10.1042/bj2580427
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Schafer,AI
中科院分区：
文献类型：
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作者：
Takayama,H;Kroll,MH;GimbroneJr,MA;Schafer,AI
使用培养的人脐静脉内皮细胞，其中磷脂酰胆碱（PC）被各种类二十烷酸前体脂肪酸（EPFA）同等地脉冲标记，我们研究了在活化和未活化的情况下磷脂类和亚类中EPFA的重塑，以及该重塑过程与磷脂酶A2介导的细胞刺激选择性释放花生四烯酸（AA）的关系。当内皮细胞与放射性标记的 EPFA 脉冲孵育 15 分钟时，大于 80% 的细胞相关放射性存在于磷脂中，其中大于 60% 存在于 1,2-二酰基-sn-甘油-3-磷酸胆碱（二酰基 PC）中。去除未掺入的放射性后，将脉冲标记的细胞重新孵育长达 6 小时，导致 EPFA 标记的二酰基 PC 逐渐减少，AA 或二十碳五烯酸 (EPA) 标记的 1-O-alk-1-烯基-2-酰基-sn-甘油-3-磷酸乙醇胺（缩醛磷脂 PE）增加，仅 AA 标记的增加1-O-烷基-2-酰基-sn-甘油-3-磷酸胆碱（烷基PC）。放射性标记磷脂的这种重新分布不会因过量非放射性标记 EPFA 的存在而改变。当阿司匹林处理的 EPFA 标记的内皮细胞用离子载体 A23187 刺激时，与二十碳三烯酸 (ETA) 或 EPA 相比，AA 的选择性释放非常明显，同时 AA 标记的二酰基 PC 相应减少，而 AA 标记的缩醛磷脂 PE 和烷基 PC 特异性增加。通过用佛波醇 12-肉豆蔻酸酯 13-乙酸酯预处理 AA 标记的细胞，A23187 诱导的 AA 放射性选择性变化增强了 2 倍，佛波醇 12-肉豆蔻酸酯 13-乙酸酯本身不引起任何变化。在释放的 AA、二酰基 PC 和缩醛磷脂 PE 中，不含和含有佛波酯的 A23187 诱导的放射性变化彼此显着相关。这些结果表明，人内皮细胞将EPFA（AA、ETA、EPA）均等地掺入二酰基PC中，但选择性地释放酯化成二酰基PC的AA，并特异性重塑为缩醛磷脂PE和烷基PC。
Using cultured human umbilical vein endothelial cells, in which phosphatidylcholine (PC) is equally pulse-labelled by various eicosanoid precursor fatty acids (EPFAs), we have studied the remodelling of EPFAs among the phospholipid classes and subclasses with and without activation, and the relationship of this remodelling process to the selective release of arachidonic acid (AA) by phospholipase A2-mediated cell stimulation. When endothelial cells are pulse-incubated with radiolabelled EPFA for 15 min, greater than 80% of cell-associated radioactivity is present in phospholipids, among which greater than 60% is found in 1,2-diacyl-sn-glycero-3-phosphocholine (diacyl PC). After removing unincorporated radioactivity, reincubation of the pulse-labelled cells for up to 6 h results in progressive decrease in EPFA-labelled diacyl PC, increase in AA- or eicosapentaenoic acid (EPA)-labelled 1-O-alk-1-enyl-2-acyl-sn-glycero-3-phosphoethanolamine (plasmalogen PE) and increase only in AA-labelled 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine (alkyl PC). This redistribution of radiolabelled phospholipids is not altered by the presence of excess non-radiolabelled EPFAs. When aspirin-treated EPFA-labelled endothelial cells are stimulated with ionophore A23187, a very selective release of AA is noted in comparison with eicosatrienoate (ETA) or EPA, accompanied by an equivalent decrease in AA-labelled diacyl PC and specific increase in AA-labelled plasmalogen PE and alkyl PC. These selective changes in AA radioactivity induced by A23187 are enhanced 2-fold by pretreating the AA-labelled cells with phorbol 12-myristate 13-acetate, which by itself induces no changes. The changes in radioactivity induced by A23187 without and with phorbol ester among the released AA, the diacyl PC and the plasmalogen PE are significantly correlated with each other. These results indicate that human endothelial cells incorporate EPFAs (AA, ETA, EPA) equally into diacyl PC but selectively release AA esterified into diacyl PC with specific remodelling into plasmalogen PE and alkyl PC.