Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC 27834, USA.
J Nutr. 2011 Jun;141(6):1041-8. doi: 10.3945/jn.111.138750. Epub 2011 Apr 27.
Model membrane and cellular detergent extraction studies show (n-3) PUFA predominately incorporate into nonrafts; thus, we hypothesized (n-3) PUFA could disrupt nonraft organization. The first objective of this study was to determine whether (n-3) PUFA disrupted nonrafts of EL4 cells, an extension of our previous work in which we discovered an (n-3) PUFA diminished raft clustering. EPA or DHA treatment of EL4 cells increased plasma membrane accumulation of the nonraft probe 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate by ~50-70% relative to a BSA control. Förster resonance energy transfer imaging showed EPA and DHA also disrupted EL4 nanometer scale nonraft organization by increasing the distance between nonraft molecules by ~25% compared with BSA. However, changes in nonrafts were due to an increase in cell size; under conditions where EPA or DHA did not increase cell size, nonraft organization was unaffected. We next translated findings on EL4 cells by testing if (n-3) PUFA administered to mice disrupted nonrafts and rafts. Imaging of B cells isolated from mice fed low- or high-fat (HF) (n-3) PUFA diets showed no change in nonraft organization compared with a control diet (CD). However, confocal microscopy revealed the HF (n-3) PUFA diet disrupted lipid raft clustering and size by ~40% relative to CD. Taken together, our data from 2 different model systems suggest (n-3) PUFA have limited effects on nonrafts. The ex vivo data, which confirm previous studies with EL4 cells, provide evidence that (n-3) PUFA consumed through the diet disrupt B cell lipid raft clustering.
模型膜和细胞去污剂提取研究表明，（n-3）多不饱和脂肪酸主要掺入非筏区；因此，我们假设（n-3）多不饱和脂肪酸可能破坏非筏区的组织。本研究的首要目标是确定（n-3）多不饱和脂肪酸是否破坏了 EL4 细胞的非筏区，这是我们之前研究的延伸，我们发现（n-3）多不饱和脂肪酸减少了筏区的聚集。EPA 或 DHA 处理 EL4 细胞使非筏探针 1,1'-二亚油酰基-3,3,3',3'-四甲基吲哚碳菁高氯酸盐在质膜上的积累相对于 BSA 对照增加了约 50-70%。Förster 共振能量转移成像显示，EPA 和 DHA 还通过增加非筏区分子之间的距离约 25%，破坏了 EL4 纳米级非筏区组织，与 BSA 相比。然而，非筏区的变化是由于细胞尺寸的增加；在 EPA 或 DHA 不增加细胞尺寸的情况下，非筏区组织不受影响。我们接下来通过测试给予小鼠的（n-3）多不饱和脂肪酸是否破坏非筏区和筏区来验证 EL4 细胞的发现。对从喂食低脂或高脂（n-3）多不饱和脂肪酸饮食的小鼠中分离的 B 细胞进行成像，与对照饮食（CD）相比，非筏区组织没有变化。然而，共聚焦显微镜显示，高脂（n-3）多不饱和脂肪酸饮食使脂质筏聚集和大小破坏约 40%，与 CD 相比。综上所述，我们从两个不同的模型系统获得的数据表明，（n-3）多不饱和脂肪酸对非筏区的影响有限。体外数据证实了之前在 EL4 细胞上的研究，提供了证据表明，通过饮食摄入的（n-3）多不饱和脂肪酸破坏了 B 细胞的脂质筏聚集。
