Arita Kayo, Yamamoto Yorihiro, Takehara Yoshiki, Utsumi Toshihiko, Kanno Tomoko, Miyaguchi Chosei, Akiyama Jitsuo, Yoshioka Tamotsu, Utsumi Kozo
Institute of Medical Science, Kurashiki Medical Center, Kurashiki, Japan.
Free Radic Biol Med. 2003 Jul 15;35(2):189-99. doi: 10.1016/s0891-5849(03)00310-1.
We examined the effects of arachidonic acid (AA), eicosapentaenoic acid (EPA), and their ultraviolet (UV)-irradiated products on HL-60 cells and isolated mitochondria to explore the following four obscure points in the mechanism of polyunsaturated fatty acids (PUFAs)-induced apoptosis: (i). the role of reactive oxygen species, (ii). the interaction of PUFAs and their metabolites with mitochondria in situ, (iii). the cyclosporine A (CsA)-sensitivity in PUFA-induced membrane permeability transition, (iv). the specificity of oxidized n-3 PUFAs in the induction of apoptosis in cancer cells. UV-oxidized PUFAs contained conjugated dienes and thiobarbituric acid reactive substances (TBARS). The apoptotic effects of PUFAs on HL-60 cells were increased by UV-irradiation whereas the swelling effect of PUFAs on isolated mitochondria was decreased. Both oxidized n-3 and n-6 PUFAs induced increased depolarization, ferricytochrome c release, the activation of various caspases, and DNA-fragmentation in a CsA-insensitive mechanism concomitant with a slight increase in the value of TBARS in cells. Furthermore, there were no significant differences in the mechanism of apoptosis induced by either oxidized AA or oxidized EPA. On the basis of these results, it was concluded that both oxidized n-3 or n-6 PUFAs induced apoptosis in HL-60 cells by a similar mechanism in a CsA-insensitive manner and also that oxidized products of PUFAs, but not the cellular oxidation process itself, play an important role in the mechanism of apoptosis in HL-60 cells.
我们研究了花生四烯酸（AA）、二十碳五烯酸（EPA）及其紫外线（UV）照射产物对HL-60细胞和分离的线粒体的影响，以探究多不饱和脂肪酸（PUFAs）诱导细胞凋亡机制中以下四个尚不明确的问题：（i）活性氧的作用；（ii）PUFAs及其代谢产物与原位线粒体的相互作用；（iii）环孢素A（CsA）对PUFAs诱导的膜通透性转变的敏感性；（iv）氧化型n-3 PUFAs在癌细胞凋亡诱导中的特异性。UV氧化的PUFAs含有共轭二烯和硫代巴比妥酸反应性物质（TBARS）。UV照射增强了PUFAs对HL-60细胞的凋亡作用，而PUFAs对分离线粒体的肿胀作用则减弱。氧化型n-3和n-6 PUFAs均通过一种CsA不敏感的机制诱导去极化增加、高铁细胞色素c释放、各种半胱天冬酶激活以及DNA片段化，同时细胞中TBARS值略有增加。此外，氧化型AA或氧化型EPA诱导细胞凋亡的机制没有显著差异。基于这些结果，得出以下结论：氧化型n-3或n-6 PUFAs均通过类似机制以CsA不敏感的方式诱导HL-60细胞凋亡，并且PUFAs的氧化产物而非细胞氧化过程本身在HL-60细胞凋亡机制中起重要作用。
