Zhen Yueying, Krausz Kristopher W, Chen Chi, Idle Jeffrey R, Gonzalez Frank J
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Mol Endocrinol. 2007 Sep;21(9):2136-51. doi: 10.1210/me.2007-0150. Epub 2007 Jun 5.
Peroxisome proliferator-activated receptor alpha (PPARalpha) is a nuclear receptor with manifold effects on intermediary metabolism. To define a set of urinary biomarkers that could be used to determine the efficacy of PPARalpha agonists, a metabolomic investigation was undertaken in wild-type and Pparalpha-null mice fed for 2 wk either a regular diet or a diet containing the PPARalpha ligand Wy-14,643 ([4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio] acetic acid), and their urine was analyzed by ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry. Principal components analysis of 6393 accurate mass positive ions revealed clustering as a single phenotype of the treated and untreated Pparalpha (-/-) mice plus two additional discrete phenotypes for the treated and untreated Pparalpha (+/+) mice. Biomarkers of PPARalpha activation were identified from their accurate masses and confirmed by tandem mass spectrometry of authentic compounds. Biomarkers were quantitated from raw chromatographic data using appropriate calibration curves. PPARalpha urinary biomarkers highly statistically significantly elevated by Wy-14,643 treatment included 11beta-hydroxy-3,20-dioxopregn-4-en-21-oic acid (>3700-fold), 11beta,20-dihydroxy-3-oxopregn-4-en-21-oic acid (50-fold), nicotinamide (>2-fold), nicotinamide 1-oxide (5-fold), 1-methylnicotinamide (1.5-fold), hippuric acid (2-fold), and 2,8-dihydroxyquinoline-beta-d-glucuronide (3-fold). PPARalpha urinary biomarkers highly statistically significantly attenuated by Wy-14,643 treatment included xanthurenic acid (1.3-fold), hexanoylglycine (20-fold), phenylpropionylglycine (4-fold), and cinnamoylglycine (9-fold). These biomarkers arise from PPARalpha effects on tryptophan, corticosterone, and fatty acid metabolism and on glucuronidation. This study underscores the power of mass spectrometry-based metabolomics combined with genetically modified mice in the definition of monogenic metabolic phenotypes.
过氧化物酶体增殖物激活受体α（PPARα）是一种对中间代谢有多种作用的核受体。为了确定一组可用于评估PPARα激动剂疗效的尿液生物标志物，对野生型和Pparα基因敲除小鼠进行了代谢组学研究，这些小鼠分别喂食常规饮食或含有PPARα配体Wy-14,643（[4-氯-6-(2,3-二甲基苯胺基)-2-嘧啶硫基]乙酸）的饮食2周，然后通过超高效液相色谱与飞行时间质谱联用分析它们的尿液。对6393个精确质量的正离子进行主成分分析显示，经处理和未经处理的Pparα（-/-）小鼠聚类为单一表型，而经处理和未经处理的Pparα（+/+）小鼠则聚类为另外两种离散表型。从其精确质量中鉴定出PPARα激活的生物标志物，并通过对真实化合物的串联质谱进行确认。使用适当的校准曲线从原始色谱数据中对生物标志物进行定量。经Wy-14,643处理后高度统计学显著升高的PPARα尿液生物标志物包括11β-羟基-3,20-二氧代孕-4-烯-21-酸（>3700倍）、11β,20-二羟基-3-氧代孕-4-烯-21-酸（50倍）、烟酰胺（>2倍）、烟酰胺1-氧化物（5倍）、1-甲基烟酰胺（1.5倍）、马尿酸（2倍）和2,8-二羟基喹啉-β-D-葡萄糖醛酸（3倍）。经Wy-14,643处理后高度统计学显著降低的PPARα尿液生物标志物包括黄尿酸（1.3倍）、己酰甘氨酸（20倍）、苯丙酰甘氨酸（4倍）和肉桂酰甘氨酸（9倍）。这些生物标志物源自PPARα对色氨酸、皮质酮和脂肪酸代谢以及葡萄糖醛酸化的影响。本研究强调了基于质谱的代谢组学与基因修饰小鼠相结合在单基因代谢表型定义中的作用。
