Overexpression of CD38 Decreases Cellular NAD Levels and Alters the Expression of Proteins Involved in Energy Metabolism and Antioxidant Defense
Overexpression of CD38 Decreases Cellular NAD Levels and Alters the Expression of Proteins Involved in Energy Metabolism and Antioxidant Defense
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CD38 的过度表达会降低细胞 NAD 水平并改变参与能量代谢和抗氧化防御的蛋白质的表达
DOI：
10.1021/pr4010597
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发表时间：
2014-02-01
影响因子：
4.4
通讯作者：
Deng, Haiteng
中科院分区：
文献类型：
--
作者：
Hu, Yadong;Wang, Helin;Deng, Haiteng
烟酰胺腺嘌呤二核苷酸（Nicotinamide adenine dinucleotide， NAD）是存在于所有活细胞中的辅酶，介导多种细胞信号通路。在本研究中，通过稳定表达n端截断的CD38（一种NAD水解酶），可以使细胞NAD水平降低35%。CD38表达（CD38(+)）细胞比野生型细胞和空载体转染（CD38(-)）细胞生长速率更低，对氧化应激更敏感。定量蛋白质组学分析显示，CD38（+）细胞中有178种蛋白下调，这些蛋白涉及糖酵解、RNA加工和蛋白质合成、抗氧化和DNA修复等多种细胞过程。Western blotting证实了6个选定蛋白的下调。然而，与糖酵解、抗氧化和DNA修复相关基因mRNA表达的下调不如蛋白质表达的相应变化显著，这表明低NAD水平损害了CD38（+）细胞中的蛋白质翻译机制。抗氧化蛋白和dna修复蛋白表达的下调有助于CD38（+）细胞对氧化应激的易感性。综上所述，这些结果表明CD38（+）细胞是研究细胞NAD水平对细胞过程影响的有用模型，并在细胞NAD水平和氧化应激之间建立了新的联系。
Nicotinamide adenine dinucleotide (NAD) is a coenzyme found in all living cells and mediates multiple cellular signaling pathways. In the present study, a 35% decrease of cellular NAD level is achieved by stable expression of the N-terminal truncated CD38, a NAD hydrolase. CD38-expressing (CD38(+)) cells have the lower growth rate and are more susceptive to oxidative stress than the wild type cells and empty vector-transfected (CD38(-)) cells. Quantitative proteomic analysis shows that 178 proteins are down-regulated in CD38(+) cells, which involve in diverse cellular processes including glycolysis, RNA processing and protein synthesis, antioxidant, and DNA repair. Down regulation of six selected proteins is confirmed by Western blotting. However, down-regulation of mRNA expressions of genes associated with glycolysis, antioxidant, and DNA repair is less significant than the corresponding change in protein expression, suggesting the low NAD level impairs the protein translational machinery in CD38(+) cells. Down-regulation of antioxidant protein and DNA-repair protein expression contributes to the susceptibility of CD38(+) cells to oxidative stress. Taken together, these results demonstrate that CD38(+) cells are a useful model to study effects of the cellular NAD levels on cellular processes and establish a new linker between cellular NAD levels and oxidative stress.