SIN-1-induced cytotoxicity in cultured endothelial cells involves reactive oxygen species and nitric oxide: Protective effect of sepiapterin
SIN-1-induced cytotoxicity in cultured endothelial cells involves reactive oxygen species and nitric oxide: Protective effect of sepiapterin
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DOI：
10.1097/00005344-199902000-00018
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发表时间：
1999-02-01
影响因子：
3
通讯作者：
Yamamoto, T
中科院分区：
文献类型：
--
作者：
Ishii, M;Shimizu, S;Yamamoto, T
本研究的目的是研究是否四氢生物蝶呤（BH 4），一氧化氮（NO）合酶的辅因子之一，减弱内皮细胞死亡诱导的3-morpholinosydnonimine-N-乙基脲（SIN-1），这是已知的生产超氧化物和NO。内皮细胞死亡的细胞内乳酸脱氢酶（LDH）的释放进行了评估。向内皮细胞中加入SIN-1（500，1，000 μ M）从加入后6小时起诱导细胞死亡。SIN-1诱导的内皮细胞死亡强烈减少治疗与羧基PTIO，一氧化氮清除剂，或超氧化物歧化酶（SOD）。铁螯合剂和羟基自由基清除剂也减少SIN-1诱导的内皮细胞死亡。有趣的是，SIN-1诱导的内皮细胞死亡也减少了处理过氧化氢酶。因此，NO、超氧化物、羟基自由基和过氧化氢可能与SIN-1诱导的内皮细胞死亡有关。此外，预处理与sepiapterin，BH 4合成的前体，减少SIN-1诱导的内皮细胞死亡，并增加细胞内BH 4含量。与N-乙酰血清素（NAS），一种BH 4合成的抑制剂共同预处理，防止sepiapterin的保护作用和细胞内BH 4含量的增加。当台盼蓝的摄取被用作细胞死亡的另一个标志物时，也观察到了sepiapterin的保护作用。这些结果表明，BH_4对NO和超氧化物引起的内皮细胞死亡具有保护作用。BH 4的保护作用可能至少部分涉及清除超氧化物或过氧化氢或两者，因为我们和其他小组先前发现BH 4具有清除活性氧的活性。
The purpose of this study was to examine whether tetrahydrobiopterin (BH4), one of the cofactors of nitric oxide (NO) synthase, attenuates endothelial cell death induced by 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1), which is known to produce both superoxide and NO. Endothelial cell death was assessed by the release of intracellular lactate dehydrogenase (LDH). Addition of SIN-1 (500, 1,000 mu M) to endothelial cells induced cell death from 6 h after its addition. The SIN-1-induced endothelial cell death was strongly reduced by treatment with carboxy-PTIO, a NO scavenger, or superoxide dismutase (SOD). Iron chelators and hydroxyl radical scavengers also reduced the SIN-1-induced endothelial cell death. Interestingly, the SIN-1-induced endothelial cell death was also reduced by treatment with catalase. Thus NO, superoxide, hydroxyl radical, and hydrogen peroxide are likely to be implicated in SIN-1-induced endothelial cell death. Moreover, pretreatment with sepiapterin, a precursor of BH4 synthesis, reduced the SIN-1-induced endothelial cell death and increased the intracellular BH4 content. Both the protective effect of sepiapterin and the increase in intracellular BH4 content were prevented by co-pretreatment with N-acetylserotonin (NAS), an inhibitor of BH4 synthesis. The protective effect of sepiapterin also was observed when uptake of trypan blue was used as another marker of cell death. These findings suggest that BH4 has a protective effect against endothelial cen death caused by the presence of NO and superoxide. The protective effect of BH4 may at least partly involve scavenging of superoxide or hydrogen peroxide or both, because we and other groups previously found that BH4 has a scavenging activity for reactive oxygen species.