N-t-butyl hydroxylamine, a hydrolysis product of α-phenyl-N-t-butyl nitrone, is more potent in delaying senescence in human lung fibroblasts
N-t-butyl hydroxylamine, a hydrolysis product of α-phenyl-N-t-butyl nitrone, is more potent in delaying senescence in human lung fibroblasts
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DOI：
10.1074/jbc.275.10.6741
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发表时间：
2000-03-10
影响因子：
4.8
通讯作者：
Ames, BN
中科院分区：
文献类型：
--
作者：
Atamna, H;Paler-Martínez, A;Ames, BN
α-苯基-N-叔丁基硝酮（PBN）是一种自旋捕获剂，可清除羟基自由基，保护组织免受氧化损伤，并延缓正常人肺成纤维细胞（IMR 90）和加速衰老小鼠的衰老。N-叔丁基羟胺和苯甲醛是PEN的分解产物。与200 μ M PEN相比，N-叔丁基羟胺在低至10 μ M的浓度下延迟IMR 90细胞的衰老，产生类似的效果，这表明N-叔丁基羟胺是PEN的活性形式。与PEN无关的N-苄基羟胺和N-甲基羟胺化合物也有效地延缓衰老，表明活性官能团是N-羟胺。所有测试的N-羟胺显著降低氧化剂的内源性产生，如通过2 '，7'-二氯二氢荧光素的氧化和GSH/GSSG比率的增加所测量的。过氧化氢诱导的衰老加速被N-羟胺逆转。DNA损伤，确定的脱嘌呤/脱嘧啶位点的水平，也显着降低治疗后与N-羟胺。N-羟胺似乎是有效的，通过线粒体，他们延迟线粒体中的年龄依赖性的变化，如测定的罗丹明-123的积累，他们防止减少细胞色素C-FeIII的超氧自由基，他们逆转年龄依赖性的线粒体顺乌头酸酶的衰变，这表明他们与超氧自由基反应。
alpha-Phenyl-N-t-butyl nitrone (PBN), a spin trap, scavenges hydroxyl radicals, protects tissues from oxidative injury, and delays senescence of both normal human lung fibroblasts (IMR90) and senescence-accelerated mice. N-t-butyl hydroxylamine and benzaldehyde are the breakdown products of PEN. N-t-Butyl hydroxylamine delays senescence of IMR90 cells at concentrations as low as 10 mu M compared with 200 mu M PEN to produce a similar effect, suggesting that N-t-butyl hydroxylamine is the active form of PEN. N-Benzyl hydroxylamine and N-methyl hydroxylamine compounds unrelated to PEN were also effective in delaying senescence, suggesting the active functional group is the N-hydroxylamine. All the N-hydroxylamines tested significantly decreased the endogenous production of oxidants, as measured by the oxidation of 2',7'-dichlorodihydrofluorescin and the increase in the GSH/GSSG ratio. The acceleration of senescence induced by hydrogen peroxide is reversed by the N-hydroxylamines. DNA damage, as determined by the level of apurinic/apyrimidinic sites, also decreased significantly following treatment with N-hydroxylamines. The N-hydroxylamines appear to be effective through mitochondria; they delay age-dependent changes in mitochondria as measured by accumulation of rhodamine-123, they prevent reduction of cytochrome C-FeIII by superoxide radical, and they reverse an age dependent decay of mitochondrial aconitase, suggesting they react with the superoxide radical.