Hypothermic inhibition of apoptotic pathways for combined neurotoxicity of iron and ascorbic acid in differentiated PC12 cells: Reduction of oxidative stress and maintenance of the glutathione redox state
Hypothermic inhibition of apoptotic pathways for combined neurotoxicity of iron and ascorbic acid in differentiated PC12 cells: Reduction of oxidative stress and maintenance of the glutathione redox state
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DOI：
10.1016/j.brainres.2009.06.016
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发表时间：
2009-08-04
期刊：
影响因子：
2.9
通讯作者：
Hiroi, Mayo
中科院分区：
文献类型：
--
作者：
Hasegawa, Masashi;Ogihara, Tohru;Hiroi, Mayo
近年来的临床试验证实了低温治疗新生儿缺氧缺血性脑病（HIE）的有效性和安全性。我们以前曾报道，非蛋白结合铁和抗坏血酸（AA）的水平增加，在CSF中的新生儿缺氧缺血性脑病。在这项研究中，我们研究了低温对铁和AA的联合细胞毒作用的分化的PC 12细胞的影响。低温治疗的最佳设置是温度30-32 ℃，抢救时间窗小于6小时，最短持续时间至少为24小时。低温有效地防止了损失的线粒体跨膜电位从6小时至72小时（研究期结束），并衰减释放的凋亡蛋白（细胞色素c和凋亡诱导因子）在6小时暴露于Fe-AA。caspase-3的激活也延迟至24 h。Akt被瞬时激活，但没有观察到温度的影响。当温度降低5 ℃时，氧化应激标志物的升高，包括邻-、Meta-和二-酪氨酸（蛋白质氧化的标志物）和4-羟基壬烯醛（脂质过氧化）显著减弱。GSSG/2GSH氧化还原电对的半细胞还原电位（Ehc）在未应激的分化的PC 12细胞中为-220 ~-180 mV，当Ehc超过-180 mV时，细胞发生凋亡。在暴露于Fe-AA的24小时内，低温可防止Ehc升高至-180 mV以上。总之，低温可通过维持细胞环境降低以及减轻氧化应激来抑制细胞凋亡途径，从而防止Fe-AA毒性引起的细胞死亡。(C)2009爱思唯尔有限公司版权所有。
Recent clinical trials have demonstrated the efficacy and safety of therapeutic hypothermia for neonatal hypoxic ischemic encephalopathy (HIE). We previously reported that the levels of non-protein-bound iron and ascorbic acid (AA) are increased in the CSF of infants with HIE. In this study, we investigated the effect of hypothermia on the combined cytotoxicity of Fe and AA for differentiated PC12 cells. The optimal settings for hypothermic treatment were a temperature of 30-32 degrees C, rescue time window of less than 6 h, and minimum duration of at least 24 h. Hypothermia effectively prevented the loss of the mitochondrial transmembrane potential from 6 h to 72 h (end of the study period) and attenuated the release of apoptotic proteins (cytochrome c and apoptosis-inducing factor) at 6 h of exposure to Fe-AA. Activation of caspase-3 was also delayed until 24 h. Akt was transiently activated, although no influence of temperature was observed. Elevation of oxidative stress markers, including ortho-, meta-, and di-tyrosine (markers of protein oxidation) and 4-hydroxynonenal (lipid peroxidation) was significantly attenuated when the temperature was reduced by 5 degrees C. The half-cell reduction potential (Ehc) of GSSG/2GSH redox couple ranged from -220 to -180 mV in unstressed differentiated PC12 cells, and apoptosis was triggered when Ehc exceeded -180 mV. Hypothermia prevented Ehc from rising above -180 mV within 24 h of exposure to Fe-AA. In conclusion, hypothermia prevented cell death due to Fe-AA toxicity by inhibiting apoptotic pathways through maintenance of a reduced cellular environment, as well as by alleviating oxidative stress. (C) 2009 Elsevier B.V. All rights reserved.