ESSENTIAL FATTY-ACID METABOLISM IN CULTURED HUMAN AIRWAY EPITHELIAL-CELLS
ESSENTIAL FATTY-ACID METABOLISM IN CULTURED HUMAN AIRWAY EPITHELIAL-CELLS
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DOI：
10.1016/0005-2760(92)90317-o
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发表时间：
1992-10-30
期刊：
影响因子：
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通讯作者：
CLANDININ, MT
中科院分区：
文献类型：
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作者：
KANG, JX;MAN, SFP;CLANDININ, MT
为了表征人气道上皮的必需脂肪酸代谢，我们检查了上皮细胞掺入和去饱和/延长18：2（n - 6）的能力以及这些细胞中磷脂脂肪酰基链的周转。将上皮细胞培养5-7天，并用[1-C-14]18：2（n - 6）（1 μ Ci，100 nmol）孵育。通过向培养基中补充18：2（n - 6），细胞的必需脂肪酸谱容易改变。孵育4小时后，每mg培养细胞蛋白质中，32 +/- 5.6 nmol [1 - C-14]18：2（n - 6）掺入磷脂（65 +/-9.5%，其中74%掺入磷脂酰胆碱（PC））和中性脂质（31 +/- 10%）。30 +/- 8%的[1 - C-14]18：2（n - 6）被转化为同源三烯、四烯和五烯，主要产物为20：3（n - 6）和20：4（n - 6）。18：2（n - 6）的转换具有时间依赖性和供体年龄相关性。20：3（n - 6）和20：4（n - 6）的较高比例掺入磷脂酰肌醇（PI）和磷脂酰乙醇胺（PE）中。从18：2（n - 6）形成的总产物的约10-15%从膜释放到培养基中。20：4（n - 6）和20：5（n - 3）均抑制18：2（n - 6）掺入和去饱和。18：2（n - 6）的掺入率高于18：1（n - 9）或16：0。通过脉冲追踪研究，18：2（n - 6）在PC、PI和PE中的半衰期估计分别为5.5、6.0和7.3 h。这些数据表明人体气道上皮细胞中必需脂肪酸的代谢活跃。这种代谢可能在调节这些细胞的膜特性和功能中起关键作用。
To characterize essential fatty acid metabolism of human airway epithelium, we examined the capacity of epithelial cells to incorporate and desaturate/elongate 18:2(n - 6) and the turnover of phospholipid fatty acyl chains in these cells. Epithelial cells were cultured for 5-7 days and incubated with [1-C-14]18:2(n - 6) (1 muCi, 100 nmol). The essential fatty acid profile of the cells was readily modified by 18:2(n - 6) supplementation to culture medium. After 4 h incubation, 32 +/- 5.6 nmol of [1 - C-14]18:2(n - 6) was incorporated into phospholipids (65 +/- 9.5%, of which 74% was incorporated into phosphatidylcholine (PC)) and neutral lipid (31 +/- 10%) per mg protein of cultured cells. 30 +/- 8% of [1 - C-14]18:2(n - 6) incorporated, was converted to homologous trienes, tetraenes and pentaenes, the major products being 20:3(n - 6) and 20:4(n - 6). The conversion of 18:2(n - 6) was time-dependent and donor age-related. A higher proportion of 20:3(n - 6) and 20:4(n - 6) was incorporated into phosphatidylinositol (PI) and phosphatidylethanolamine (PE). About 10-15% of total products formed from 18:2(n - 6) was released from membrane to culture medium. Both 20:4(n - 6) and 20:5(n - 3) inhibited 18:2(n - 6) incorporation and desaturation. Rate of incorporation of 18:2(n - 6) was more than either 18:1(n - 9) or 16:0. With pulse-chase studies, the half-life of 18:2(n - 6) in PC, PI and PE was estimated to be 5.5, 6.0 and 7.3 h, respectively. These data indicate active metabolism of essential fatty acids in human airway epithelial cells. This metabolism may play a key role in the regulation of membrane properties and function in these cells.