Lü Lanhai, Li Jicheng, Yew David T, Rudd John A, Mak Ying T
Institute of Cell Biology, Medical School of Zhejiang University, Hangzhou, China.
Neurochem Int. 2008 Jan;52(1-2):282-9. doi: 10.1016/j.neuint.2007.06.016. Epub 2007 Jun 27.
Astrocytes are one of the predominant glial cell types in the adult central nervous system functioning as both supportive and metabolic cells for the brain. Our objective in this experiment is to study the direct effects of hydrogen peroxide induced oxidative stress on astrocytes in culture. These astrocytes were derived from both an aged mouse strain (P8) and a matched control strain (R1). The astrocytes for both the P8 and R1 strains were treated with increasing concentrations of hydrogen peroxide. Our results showed that the oxidative stress had a similar effect in both strains of astrocytes; decreases in 3-(4,5-dimethylthiazol-2-yl)-2,2-diphenyltetrazolium bromide (MTT) and glial fibrillary acidic protein (GFAP) levels, and increases in terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) staining, lactate dehydrogenase (LDH) staining, and superoxide dismutase (SOD), caspase-3 and B-cell lymphoma 2-associated protein X (bax) levels. At a hydrogen peroxide concentration of 400 microM , the differences of the above parameters between P8 cultures and R1 cultures were statistically significant (p<0.05). This strongly suggested that astrocytes derived from P8 and R1 strains reacted to oxidative stress with similar mechanisms and consequences. However, the mechanisms were not able to compensate for the oxidative stress in the P8 strain at a hydrogen peroxide concentration of 400 microM. The inability of the P8 astrocytes to counteract the oxidative stress might lead to inadequate protection from neuronal loss possibly resulting in significantly more astrocytic death. Our results suggested that the changes of astrocytes in peroxide detoxification may play a role in aging of the central nervous system, and further aging studies should examine the oxidative status of the samples.
星形胶质细胞是成体中枢神经系统中主要的胶质细胞类型之一，对大脑起到支持和代谢细胞的作用。本实验的目的是研究过氧化氢诱导的氧化应激对培养的星形胶质细胞的直接影响。这些星形胶质细胞来源于老年小鼠品系（P8）和匹配的对照品系（R1）。对P8和R1品系的星形胶质细胞均用浓度递增的过氧化氢进行处理。我们的结果表明，氧化应激对两个品系的星形胶质细胞产生了相似的影响；3-(4,5-二甲基噻唑-2-基)-2,2-二苯基四氮唑溴盐（MTT）和胶质纤维酸性蛋白（GFAP）水平降低，而末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）染色、乳酸脱氢酶（LDH）染色以及超氧化物歧化酶（SOD）、半胱天冬酶-3和B细胞淋巴瘤2相关蛋白X（bax）水平升高。在过氧化氢浓度为400微摩尔时，P8培养物和R1培养物之间上述参数的差异具有统计学意义（p<0.05）。这有力地表明，来自P8和R1品系的星形胶质细胞对氧化应激的反应机制和后果相似。然而，在过氧化氢浓度为400微摩尔时，这些机制无法补偿P8品系中的氧化应激。P8星形胶质细胞无法抵抗氧化应激可能导致对神经元损失的保护不足，可能导致更多的星形胶质细胞死亡。我们的结果表明，星形胶质细胞在过氧化物解毒方面的变化可能在中枢神经系统衰老中起作用，进一步的衰老研究应检查样本的氧化状态。
