Ringeissen Stephanie, Connor Susan C, Brown H Roger, Sweatman Brian C, Hodson Mark P, Kenny Steve P, Haworth Richard I, McGill Paul, Price Mark A, Aylott Mike C, Nunez Derek J, Haselden John N, Waterfield Catherine J
Safety Assessment, GlaxoSmithKline, Park Road, Ware, Herts, SG12 ODP, UK.
Biomarkers. 2003 May-Aug;8(3-4):240-71. doi: 10.1080/1354750031000149124.
This study identified two potential novel biomarkers of peroxisome proliferation in the rat. Three peroxisome proliferator-activated receptor (PPAR) ligands, chosen for their high selectivity towards the PPARalpha, -delta and -gamma subtypes, were given to rats twice daily for 7 days at doses known to cause a pharmacological effect or peroxisome proliferation. Fenofibrate was used as a positive control. Daily treatment with the PPARalpha and -delta agonists produced peroxisome proliferation and liver hypertrophy. 1H nuclear magnetic resonance spectroscopy and multivariate statistical data analysis of urinary spectra from animals given the PPARalpha and -delta agonists identified two new potential biomarkers of peroxisome proliferation--N-methylnicotinamide (NMN) and N-methyl-4-pyridone-3-carboxamide (4PY)--both endproducts of the tryptophan-nicotinamide adenine dinucleotide (NAD+) pathway. After 7 days, excretion of NMN and 4PY increased 24- and three-fold, respectively, following high doses of fenofibrate. The correlation between total NMN excretion over 7 days and the peroxisome count was r=0.87 (r2=0.76). Plasma NMN, measured using a sensitive high performance liquid chromatography method, was increased up to 61-fold after 7 days' treatment with high doses of fenofibrate. Hepatic gene expression of aminocarboxymuconate-semialdehyde decarboxylase (EC 4.1.1.45) was downregulated following treatment with the PPARalpha and -delta agonists. The decrease was up to 11-fold compared with controls in the groups treated with high doses of fenofibrate. This supports the link between increased NMN and 4PY excretion and regulation of the tryptophan-NAD+ pathway in the liver. In conclusion, NMN, and possibly other metabolites in the pathway, are potential non-invasive surrogate biomarkers of peroxisome proliferation in the rat.
本研究在大鼠中鉴定出两种潜在的过氧化物酶体增殖新生物标志物。选择了三种对过氧化物酶体增殖激活受体（PPAR）α、δ和γ亚型具有高选择性的PPAR配体，以已知会产生药理作用或过氧化物酶体增殖的剂量，每日两次给予大鼠，持续7天。非诺贝特用作阳性对照。每日用PPARα和δ激动剂治疗会导致过氧化物酶体增殖和肝脏肥大。对给予PPARα和δ激动剂的动物尿液光谱进行的1H核磁共振光谱分析和多变量统计数据分析，鉴定出两种新的潜在过氧化物酶体增殖生物标志物——N-甲基烟酰胺（NMN）和N-甲基-4-吡啶酮-3-甲酰胺（4PY），二者均为色氨酸-烟酰胺腺嘌呤二核苷酸（NAD+）途径的终产物。7天后，高剂量非诺贝特给药后，NMN和4PY的排泄分别增加了24倍和3倍。7天内NMN总排泄量与过氧化物酶体计数之间的相关性为r=0.87（r2=0.76）。使用灵敏的高效液相色谱法测定，高剂量非诺贝特治疗7天后，血浆NMN增加了61倍。用PPARα和δ激动剂治疗后，氨基羧基粘康酸半醛脱羧酶（EC 4.1.1.45）的肝脏基因表达下调。与高剂量非诺贝特治疗组的对照组相比，下调幅度高达11倍。这支持了NMN和4PY排泄增加与肝脏中色氨酸-NAD+途径调节之间的联系。总之，NMN以及该途径中的其他可能代谢物，是大鼠过氧化物酶体增殖的潜在非侵入性替代生物标志物。
