Cirelli C, Pfister-Genskow M, McCarthy D, Woodbury R, Tononi G
Dept. of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd. Madison, WI 53719, USA.
Arch Ital Biol. 2009 Sep;147(3):59-68.
Transcriptomic studies have shown that hundreds of genes change their expression levels across the sleep/waking cycle, and found that waking-related and sleep-related mRNAs belong to different functional categories. Proteins, however, rather than DNA or RNA, carry out most of the cellular functions, and direct measurements of protein levels and activity are required to assess the effects of behavioral states on the overall functional state of the cell. Here we used surface-enhanced laser desorption-ionization (SELDI), followed by time-of-flight mass spectrometry, to obtain a large-scale profiling of the proteins in the rat cerebral cortex whose expression is affected by sleep, spontaneous waking, short (6 hours) and long (7 days) sleep deprivation. Each of the 94 cortical samples was profiled in duplicate on 4 different ProteinChip Array surfaces using 2 different matrix molecules. Overall, 1055 protein peaks were consistently detected in cortical samples and 15 candidate biomarkers were selected for identification based on significant changes in multiple conditions (conjunction analysis): 8 "sleep" peaks, 4 "waking" peaks, and 4 "long sleep deprivation" peaks. Four candidate biomarkers were purified and positively identified. The 3353 Da candidate sleep marker was identified as the 30 amino acid C-terminal fragment of rat histone H4. This region encompasses the osteogenic growth peptide, but a possible link between sleep and this peptide remains highly speculative. Two peaks associated with short and long sleep deprivation were identified as hemoglobin alpha1/2 and beta, respectively, while another peak associated with long sleep deprivation was identified as cytochrome C. The upregulation of hemoglobins and cytochrome C may be part of a cellular stress response triggered by even short periods of sleep loss.
转录组学研究表明，数百个基因在睡眠/清醒周期中会改变其表达水平，并且发现与清醒相关和与睡眠相关的信使核糖核酸（mRNA）属于不同的功能类别。然而，执行大多数细胞功能的是蛋白质，而非DNA或RNA，因此需要直接测量蛋白质水平和活性，以评估行为状态对细胞整体功能状态的影响。在此，我们使用表面增强激光解吸电离（SELDI），随后进行飞行时间质谱分析，以大规模分析大鼠大脑皮层中那些表达受睡眠、自发清醒、短期（6小时）和长期（7天）睡眠剥夺影响的蛋白质。94个皮层样本中的每一个都在4种不同的蛋白质芯片阵列表面上使用2种不同的基质分子进行了重复分析。总体而言，在皮层样本中一致检测到1055个蛋白质峰，并基于多种条件下的显著变化（联合分析）选择了15个候选生物标志物进行鉴定：8个“睡眠”峰、4个“清醒”峰和4个“长期睡眠剥夺”峰。4个候选生物标志物被纯化并得到了明确鉴定。分子量为3353道尔顿的候选睡眠标志物被鉴定为大鼠组蛋白H4的30个氨基酸的C末端片段。该区域包含成骨生长肽，但睡眠与该肽之间的可能联系仍极具推测性。与短期和长期睡眠剥夺相关的两个峰分别被鉴定为血红蛋白α1/2和β，而另一个与长期睡眠剥夺相关的峰被鉴定为细胞色素C。血红蛋白和细胞色素C的上调可能是即使短期睡眠不足引发的细胞应激反应的一部分。
