Shimadzu Corporation, Mass Spectrometry Business Unit, Manchester, United Kingdom.
J Proteome Res. 2011 Feb 4;10(2):705-13. doi: 10.1021/pr100885w. Epub 2010 Dec 9.
Alcoholism is a complex disorder that, in man, appears to be genetically influenced, although the underlying genes and molecular pathways are not completely known. Here, the intragastric alcohol feeding model in rodents was used together with high mass accuracy LC-MS(n) analysis to assess the metabonomic changes in nonpolar metabolite profiles for livers from control and alcohol-treated rats and mice. Ion signals with a peak area variance of less than 30% (based on repeat analysis of a pooled quality control sample analyzed throughout the batch) were submitted to multivariate statistical analysis (using principal components analysis, PCA). PCA revealed robust differences between profiles from control and alcohol-treated animals from both species. The major metabolites seen to differ between control and alcohol-treated animals were identified using high accuracy MS(n) data and verified using external search engines ( http://www.lipidmaps.org ; http://www.hmdb.ca; http://www.genome.jp/kegg/ ) and authentic standards. The main metabolite classes to show major changes in the alcoholic liver-derived samples were fatty acyls, fatty acid ethyl esters, glycerolipids, and phosphatidylethanol homologues. Significant metabolites that were up-regulated by alcohol treatment in both rat and mouse livers included fatty acyls, metabolites such as octadecatrienoic acid and eicosapentaenoic acid, a number of fatty acid ethyl esters such as ethyl arachidonate, ethyl docosahexaenoic acid, ethyl linoleate, and ethyl oleate and phosphatidylethanol (PEth) homologues (predominantly PEth 18:0/18:2 and PEth 16:0/18:2; PEth homologues are currently considered as potential biomarkers for harmful and prolonged alcohol consumption in man). A number of glycerophospholipids resulted in both up-regulation (m/z 903.7436 M + H corresponding to a triglyceride) and down-regulation (m/z 667.5296 M + H corresponding to a diglyceride). Metabolite profiles were broadly similar in both mouse and rat models. However, there were a number of significant differences in the alcohol-treated group particularly in the marked down-regulation of retinol and free cholesterol in the mouse compared to the rat. Unique markers for alcohol treatment included ethyl docosahexaenoic acid. Metabolites were identified with high confidence using predominantly negative ion MS(n) data for the fatty acyl components to match to www.lipidmaps.org MS and MS/MS databases; interpreting positive ion data needed to take into account possible adduct ions which may confound the identification of other lipid classes. The observed changes in lipid profiles were consistent with alcohol-induced liver injury in humans.
酒精中毒是一种复杂的疾病，在男性中似乎受到遗传影响，尽管其潜在的基因和分子途径尚不完全清楚。在这里，我们使用了灌胃酒精喂养模型，结合高质量准确度 LC-MS(n) 分析，评估了来自对照和酒精处理的大鼠和小鼠肝脏中非极性代谢产物谱的代谢组学变化。基于对整个批次中分析的混合质量控制样品的重复分析，峰面积方差小于 30%的离子信号被提交给多变量统计分析（使用主成分分析，PCA）。PCA 显示出来自两种物种的对照和酒精处理动物之间的特征图谱存在明显差异。使用高精度 MS(n) 数据鉴定出与对照和酒精处理动物之间存在差异的主要代谢物，并使用外部搜索引擎（http://www.lipidmaps.org；http://www.hmdb.ca；http://www.genome.jp/kegg/）和真实标准进行验证。在酒精性肝衍生样本中显示出主要变化的主要代谢物类是脂肪酸酰基、脂肪酸乙酯、甘油磷脂和磷脂乙醇同系物。在大鼠和小鼠肝脏中，酒精处理上调的显著代谢物包括脂肪酸酰基、十八碳三烯酸和二十碳五烯酸等代谢物、花生四烯酸乙酯、二十二碳六烯酸乙酯、亚油酸乙酯、油酸乙酯和磷脂乙醇同系物（主要是磷脂乙醇 18:0/18:2 和磷脂乙醇 16:0/18:2；目前，磷脂乙醇同系物被认为是人类有害和长期饮酒的潜在生物标志物）。一些甘油磷脂既上调（m/z 903.7436 M + H 对应三酰基甘油）又下调（m/z 667.5296 M + H 对应二酰基甘油）。在两种小鼠和大鼠模型中，代谢物图谱均相似。然而，在酒精处理组中存在许多显著差异，特别是在小鼠中视黄醇和游离胆固醇的明显下调与大鼠相比。酒精处理的独特标志物包括二十二碳六烯酸乙酯。使用主要的负离子 MS(n) 数据鉴定脂肪酸酰基成分的代谢物，以匹配 www.lipidmaps.org MS 和 MS/MS 数据库；解释正离子数据需要考虑可能混淆其他脂质类别的加合物离子。所观察到的脂质谱变化与人类酒精性肝损伤一致。
