Tobin K A R, Johnsen G M, Staff A C, Duttaroy A K
Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, and Department of Obstetrics and Gynecology, Ulleval University Hospital, Oslo, Norway.
Placenta. 2009 Jan;30(1):41-7. doi: 10.1016/j.placenta.2008.10.007. Epub 2008 Nov 17.
Long-chain polyunsaturated fatty acids (LCPUFAs) such as docosahexaenoic acid (DHA) and arachidonic acid (AA) are essential for proper development of fetal brain and retina. These LCPUFAs are selectively enriched in the fetal circulation compared with the maternal circulation. In the current study we investigated the transfer of LCPUFAs and a non-essential fatty acid (oleic acid, OA) in a transwell monolayer system of placental choriocarcinoma (BeWo) cells. We show that incubation with OA results in increased triglyceride accumulation and lipid droplet formation compared with that of DHA. The relative amount of transfer of DHA across the cell monolayer was approximately 4-fold greater compared with that of OA when these fatty acids were added individually at 100 muM. This reflects the different fates of these two fatty acids in their metabolism and subsequent transport across the placental trophoblasts to the fetus. When using a mixture of fatty acids mimicking the composition of plasma non-esterified fatty acids during the last trimester of pregnancy, the transfer of OA and the LCPUFAs (DHA and AA) into the basolateral reservoir was not significantly different, whereas the transfer of palmitic acid (PA) was approximately 3.5-fold higher than OA transfer. However, since the concentration of OA compared to LCPUFAs was 10-fold higher in the donor chamber, the relative transport of the LCPUFAs was higher compared with that of OA. In addition, we show that inhibiting esterification of fatty acids into acyl-CoA can modulate, in part, the degree of transport through the cells. In conclusion, the transwell model system closely mimics the mechanisms of differential fatty acid transport as observed in vivo. LCPUFAs were transported through the cells more efficiently than shorter fatty acids such as OA.
长链多不饱和脂肪酸（LCPUFAs），如二十二碳六烯酸（DHA）和花生四烯酸（AA），对胎儿大脑和视网膜的正常发育至关重要。与母体循环相比，这些LCPUFAs在胎儿循环中被选择性富集。在本研究中，我们在胎盘绒毛膜癌细胞（BeWo）的Transwell单层系统中研究了LCPUFAs和一种非必需脂肪酸（油酸，OA）的转运。我们发现，与DHA相比，用OA孵育会导致甘油三酯积累增加和脂滴形成。当以100μM单独添加这些脂肪酸时，DHA跨细胞单层的相对转运量比OA大约高4倍。这反映了这两种脂肪酸在其代谢以及随后跨胎盘滋养层向胎儿转运过程中的不同命运。当使用模拟妊娠晚期血浆非酯化脂肪酸组成的脂肪酸混合物时，OA和LCPUFAs（DHA和AA）向基底外侧储库的转运没有显著差异，而棕榈酸（PA）的转运比OA高约3.5倍。然而，由于供体室中OA与LCPUFAs的浓度相比高10倍，LCPUFAs的相对转运量比OA更高。此外，我们表明抑制脂肪酸酯化生成酰基辅酶A可部分调节通过细胞的转运程度。总之，Transwell模型系统紧密模拟了体内观察到的脂肪酸差异转运机制。LCPUFAs比短链脂肪酸如OA更有效地通过细胞转运。
