Assessment of protein modifications in liver of rats under chronic treatment with paracetamol (acetaminophen) using two complementary mass spectrometry-based metabolomic approaches

作者：Mast Carole; Lyan Bernard; Joly Charlotte; Centeno Delphine; Giacomoni Franck; Martin Jean Francois; Mosoni Laurent; Dardevet Dominique; Pujos Guillot Estelle; Papet Isabelle^*

来源：Journal of Proteomics, 2015, 120: 194-203.

DOI：10.1016/j.jprot.2015.03.014

• Chronic treatment
• Mass spectrometry
• Metabolomics
• Paracetamol
• Post-translational modification
• Oxidized residue

Liver protein can be altered under paracetamol (APAP) treatment. APAP-protein adducts and other protein modifications (oxidation/nitration, expression) play a role in hepatotoxicity induced by acute overdoses, but it is unknown whether liver protein modifications occur during long-term treatment with non-toxic doses of APAP. We quantified APAP-protein adducts and assessed other protein modifications in the liver from rats under chronic (17 days) treatment with two APAP doses (0.5% or 1% of APAP in the diet w/w). A targeted metabolomic method was validated and used to quantify APAP-protein adducts as APAP-cysteine adducts following proteolytic hydrolysis. The limit of detection was found to be 7 ng APAP cysteine/mL hydrolysate i.e. an APAP-Cys to tyrosine ratio of 0.016%.. Other protein modifications were assessed on the same protein hydrolysate by untargeted metabolomics including a new strategy to process the data and identify discriminant molecules. These two complementary mass spectrometry (MS)-based metabolic approaches enabled the assessment of a wide range of protein modifications induced by chronic treatment with APAP.
Biological significance
APAP-protein adducts were detected even in the absence of glutathione depletion and hepatotoxicity, i.e. in the 0.5% APAP group, and increased by 218% in the 1% APAP group compared to the 0.5% APAP group. At the same time, the untargeted metabolomic method revealed a decrease in the binding of cysteine, cysteinyl glycine and GSH to thiol groups of protein cysteine residues, an increase in the oxidation of tryptophan and proline residues and a modification in protein expression. This wide range of modifications in liver proteins occurred in rats under chronic treatment with APAP that did not induce hepatotoxicity.

• 出版日期2015-4-29