Docosahexaenoic acid enrichment can reduce L929 cell necrosis induced by tumor necrosis factor
Docosahexaenoic acid enrichment can reduce L929 cell necrosis induced by tumor necrosis factor
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DOI：
10.1016/j.bbalip.2006.03.023
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发表时间：
2006-04-01
影响因子：
4.8
通讯作者：
Masuzawa, Yasuo
中科院分区：
文献类型：
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作者：
Kishida, Etsu;Tajiri, Michiko;Masuzawa, Yasuo
我们以前报道过二十二碳六烯酸（DHA）减弱肿瘤坏死因子（TNF）诱导的人单核细胞U937细胞凋亡。Nutr. 130：1095-1101，2000）。在本研究中，我们研究了DHA和其他多不饱和脂肪酸（PUFA）对TNF诱导的坏死，另一种细胞死亡模式，使用L929小鼠纤维肉瘤细胞的影响。在与缀合有BSA的PUFA预孵育24小时后，用TNF或TNF+放线菌素D（Act D）处理细胞。用DHA预孵育细胞可使磷脂中的多不饱和酸富集，并减弱TNF或TNF+Act D诱导的细胞死亡。当单独用TNF处理细胞时，未检测到DNA梯状化，并且细胞同时用膜联蛋白V-FITC和碘化丙啶染色，表明死亡模式是坏死的。TNF+Act D主要诱导坏死，尽管在这种情况下也观察到同时的凋亡细胞死亡。用油酸、亚油酸或20：3（n-3）预孵育不影响TNF诱导的坏死。相反，补充n-3二十二碳五烯酸（DPAn-3）或二十碳五烯酸（EPA）减少了坏死细胞死亡，但与DHA相比程度较低。与U937细胞凋亡的情况不同，花生四烯酸（AA）显著减弱L929细胞坏死，并且20：3（n-6）或22：4（n-6）分别显示类似或更少的活性。统计分析表明，PUFA的有效活性大小顺序为DHA > DPAn-3 >= EPA > AA（约20：3（n-6）>= 22：4（n-6））。在L929细胞中，n-6或n-3脂肪酸组内的一步去饱和、C2延伸或C2裂解可能非常活跃，因为由20：3（n-6）或22：4（n-6）合成的AA和由AA或EPA合成的C22脂肪酸优先保留在细胞磷脂中。这些观察结果表明，通过补充各种C20或C22多不饱和脂肪酸来减弱TNF诱导的坏死主要归因于三种多不饱和脂肪酸的富集，即，DHA、DPAn-3或AA，磷脂。在这些脂肪酸中，DHA在减少L929坏死方面最有效，如在U937细胞凋亡的情况下所观察到的。这表明富含DHA的膜可以保护细胞免受TNF的影响，而不管死亡模式如何，并且膜DHA可以消除坏死和凋亡常见的死亡信号。(c)2006 Elsevier B. V.保留所有权利。
We previously reported that docosahexaenoic acid (DHA) attenuated tumor necrosis factor (TNF)-induced apoptosis in human monocytic, U937 cells Q. Nutr. 130: 1095-1101, 2000). In the present study, we examined the effects of DHA and other polyunsaturated fatty acids (PUFA) on TNF-induced necrosis, another mode of cell death, using L929 murine fibrosarcoma cells. After preincubation with PUFA conjugated with BSA for 24 h, cells were treated with TNF or TNF+actinomycin D (Act D). Preincubation of cells with DHA enriched this polyunsaturated acid in the phospholipids and attenuated cell death induced by either TNF or TNF+Act D. When cells were treated with TNF alone, DNA laddering was not detected, and cells were coincidently stained with both annexin V-FITC and propidium iodide, indicating that the death mode was necrotic. TNF+Act D predominantly induced necrosis, although concurrent apoptotic cell death was also observed in this case. Preincubation with oleic acid, linoleic acid or 20:3(n-3) did not affect TNF-induced necrosis. Conversely, supplementation with n-3 docosapentaenoic acid (DPAn-3) or eicosapentaenoic acid (EPA) reduced necrotic cell death, but to a lesser extent in comparison with DHA. Unlike the case of U937 cell apoptosis, arachidonic acid (AA) significantly attenuated L929 cell necrosis, and 20:3(n-6) or 22:4(n-6) showed similar or less activity, respectively. Statistical evaluation indicated that the order of effective PUFA activity was DHA > DPAn-3 >= EPA > AA approximate to 20:3(n-6) >= 22:4(n-6). One step desaturation, C2 elongation or C2 cleavage within the n-6 or n-3 fatty acid group was probably very active in L929 cells, because AA, synthesized from 20:3(n-6) or 22:4(n-6), and C22 fatty acids, synthesized from AA or EPA, were preferentially retained in cellular phospholipids. These observations suggested that attenuation of TNF-induced necrosis by the supplementation of various C20 or C22 polyunsaturated fatty acids is mainly attributable to the enrichment of three kinds of polyunsaturated fatty acids, i.e., DHA, DPAn-3 or AA, in phospholipids. Among these fatty acids, DHA was the most effective in the reduction of L929 necrosis as observed in the case of U937 apoptosis. This suggests that DHA-enriched membranes can protect cell against TNF irrespective of death modes and that membranous DHA may abrogate the death signaling common to necrosis and apoptosis. (c) 2006 Elsevier B.V. All rights reserved.