Huang Han-Chang, Hong Liang, Chang Ping, Zhang Jiao, Lu Shu-Yan, Zheng Bo-Wen, Jiang Zhao-Feng
Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, 197#, Beitucheng West Road, Haidian District, Beijing, 100191, China,
Neurotox Res. 2015 May;27(4):411-20. doi: 10.1007/s12640-014-9512-x. Epub 2014 Dec 27.
Alzheimer's disease (AD) is one of the common neurodegenerative diseases. Increase of labile copper pool plays an important role in the pathogenesis of AD. Nrf2(NF-E2-related factor-2)-ARE (antioxidant response element) signaling is an important intracellular manner to defend against oxidative stress. In this study, we used SH-SY5Y cells as a model of neuron to test the effect of chitooligosaccharides (COSs) on Cu(2+)-induced oxidative damage. SH-SY5Y cells were treated with different concentrations of COSs (100-800 mg/L) before incubated with Cu(2+). Cell viability and cell damage and apoptosis were assessed. Both extracellular H(2)O(2) and intracellular ROS were measured and the relative levels of Nrf2, phosphorylated Nrf2, and HO-1 were analyzed by Western blotting, and further HO-1 mRNA was relatively quantified by real-time quantitative PCR. The results indicated that Cu(2+)-induced decrease of cell viability and increase of LDH release. In cell-free solution, COSs alone or with Cu(2+) cannot scavenge O(2)(-); however, COSs downregulate the levels of cellular oxidative stress and activated Caspase-3 induced by Cu(2+). Further, the levels of pSer40-Nrf2 protein and both the transcription and the translation of HO-1 gene are dramatically increased in COSs-protective group compared with Cu(2+) damage group. Therefore, these results indicate that Nrf2 activation might be involved in the protection of COSs against Cu(2+)-induced cellular oxidative damage. COSs contribute to the attenuation of oxidative damage and could be used as a nutritional agent for AD treatment.
阿尔茨海默病（AD）是常见的神经退行性疾病之一。不稳定铜池的增加在AD发病机制中起重要作用。Nrf2（核因子E2相关因子2）-ARE（抗氧化反应元件）信号通路是细胞内抵御氧化应激的重要方式。在本研究中，我们以SH-SY5Y细胞作为神经元模型，检测壳寡糖（COSs）对铜离子（Cu(2+)）诱导的氧化损伤的影响。在与Cu(2+)孵育前，用不同浓度（100 - 800 mg/L）的COSs处理SH-SY5Y细胞。评估细胞活力、细胞损伤和凋亡情况。检测细胞外过氧化氢（H(2)O(2)）和细胞内活性氧（ROS）水平，并通过蛋白质免疫印迹法分析Nrf2、磷酸化Nrf2和血红素加氧酶-1（HO-1）的相对水平，进一步通过实时定量PCR对HO-1 mRNA进行相对定量分析。结果表明，Cu(2+)诱导细胞活力降低和乳酸脱氢酶（LDH）释放增加。在无细胞溶液中，单独的COSs或与Cu(2+)一起都不能清除超氧阴离子（O(2)(-)）；然而，COSs可下调细胞氧化应激水平，并抑制Cu(2+)诱导的半胱天冬酶-3（Caspase-3）激活。此外，与Cu(2+)损伤组相比，COSs保护组中pSer40-Nrf2蛋白水平以及HO-1基因的转录和翻译水平均显著升高。因此，这些结果表明Nrf2激活可能参与了COSs对Cu(2+)诱导的细胞氧化损伤的保护作用。COSs有助于减轻氧化损伤，可作为AD治疗的营养剂。
