Overexpression of G6PD and HSP90 Beta in Mice with Benzene Exposure Revealed by Serum Peptidome Analysis

Abstract

The small peptides representation of the original proteins are a valuable source of information that can be used as biomarkers involved in toxicity mechanism for chemical exposure. The aim of this study is to investigate serum peptide biomarkers of benzene exposure. C57BL/6 mice were enrolled into control group and benzene groups of 150 and 300 mg/kg/d Serum peptides were identified by mass spectrometry using an assisted laser desorption ionization/time of flight mass spectrometry (MS). Differential peptide spectra were obtained by tandem mass spectrometry and analyzed by searching the International Protein Index using the Sequest program. Forty-one peptide peaks were found in the range of 1000–10,000 Da molecular weight. Among them, seven peaks showed significantly different expression between exposure groups and control group. Two peptide peaks (1231.2 and 1241.8), which showed a two-fold increase in expression, were sequenced and confirmed as glucose 6-phosphate dehydrogenase (G6PD) and heat shock protein 90 Beta (HSP90 Beta), respectively. Furthermore, the expression of the two proteins in liver cells showed the same trend as in serum. In conclusion, G6PD and HSP90 beta might be the candidate serum biomarkers of benzene exposure. It also provided possible clues for the molecular mechanism of benzene-induced oxidative stress.

Inhibition of Glucose‐6‐Phosphate Dehydrogenase Could Enhance 1,4‐Benzoquinone‐Induced Oxidative Damage in K562 Cells

“…We previously performed serum peptidome analysis and found that G6PD is overexpressed in benzene-exposed mice exhibiting hematopoietic toxicities compared with that in normal control mice [ 8 ].…”

“…G6PD is overexpressed in the plasma of mice exposed to benzene [ 8 ] and implicated in the maintenance of GSH in providing protection from oxidative damage. Considering these phenomena, we hypothesized that G6PD overexpression in benzene-exposed mice is a protective mechanism activated in response to oxidative stress induced by benzene exposure.…”