Liver fatty acid-binding protein expression in transfected fibroblasts stimulates fatty acid uptake and metabolism
Liver fatty acid-binding protein expression in transfected fibroblasts stimulates fatty acid uptake and metabolism
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DOI：
10.1016/0005-2760(96)00024-0
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发表时间：
1996-06-11
期刊：
影响因子：
--
通讯作者：
Schroeder, F
中科院分区：
文献类型：
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作者：
Murphy, EJ;Prows, DR;Schroeder, F
利用转染L-FABP编码cDNA的培养l细胞成纤维细胞，研究了胞质肝脂肪酸结合蛋白（L-FABP）在脂肪酸摄取和代谢中的作用。[H-3]油酸被用来确定细胞内酯化对脂肪酸摄取的影响，并确定酯化脂肪酸在特定脂类中的定位。顺式parinaric酸是一种酯化程度较差的脂肪酸，在没有明显酯化的情况下测定摄取。与低表达的l细胞相比，高表达的l细胞对[H-3]油酸和顺式parinaric酸的初始摄取率分别高出80%和50%。由于细胞内酯化作用，[H-3]油酸的最大摄取没有达到平台。在高表达细胞中，最大顺式parinaric酸摄取迅速达到稳定水平，比低表达细胞高34%。孵育1 min后，大部分细胞[H-3]油酸未酯化，大部分酯化部分优先定位于磷脂。在5分钟和30分钟后，与低表达细胞相比，表达L-FABP的细胞将更多的[H-3]油酸酯化成中性脂质和磷脂组分。L-FABP的表达也选择性地刺激[H-3]油酸并入胆碱甘油磷脂。因此，L-FABP的表达不仅在所有时间点刺激脂肪酸摄取，而且还刺激细胞内酯化成特定的脂质池。这些结果首次在完整的细胞培养系统中详细表明，L-FABP表达不仅刺激脂肪酸摄取，而且增加了外源脂肪酸的细胞内酯化反应。
The role of cytosolic liver fatty acid binding protein (L-FABP) in fatty acid uptake and metabolism was examined using cultured L-cell fibroblasts transfected with the cDNA encoding for L-FABP. [H-3]oleic acid was used to determine the effects of intracellular esterification on fatty acid uptake and to determine esterified fatty acid localization to specific lipid classes. cis-Parinaric acid, a poorly esterified fatty acid, was used to determine uptake in the absence of any appreciable esterification. High-expression L-cells had a 80% and 50% greater initial uptake rate for both [H-3]oleic acid and cis-parinaric acid, respectively compared to low-expression L-cells. Maximal uptake of [H-3]oleic acid did not plateau because of intracellular esterification. In high-expressing cells, maximal cis-parinaric acid uptake rapidly plateaued at a level 34% higher than in low-expression cells. After 1 min of incubation, the majority of cellular [H-3]oleic acid was unesterified, with the bulk of the esterified portion preferentially localized to phospholipids. After 5 and 30 min, cells expressing L-FABP esterified a significantly greater amount of [H-3]oleic acid into both the neutral lipid and phospholipid fractions than did low-expression cells. L-FABP expression also selectively stimulated [H-3]oleic acid incorporation into choline glycerophospholipids. Thus, L-FABP expression not only stimulated fatty acid uptake at all time points, but also stimulated intracellular esterification into specific lipid pools. These results show in detail for the first time using an intact cell culture system that L-FABP expression not only stimulated fatty acid uptake, but also increased intracellular esterification of exogenously supplied fatty acids.