Peptidome profiles in melamine diet-induced bladder stones in C57BL/6 mice

The aim of this research was to detect potential serum biomarkers of melamine diet-induced bladder stones in C57BL/6 mice. Magnetic bead-based weak cationexchange chromatography (MB-WCX) and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) were employed to detect serum biomarkers in 10 mice fed a melamine diet and 10 control mice. Seventeen peaks (fold change>1.5) with a mass to charge (m/z) value of 1000-10,000 Da were detected in the two groups. Among the significant peaks, five were upregulated and the other 12 were downregulated in the model group. Among the upregulated peaks, 2954.49 and 1710.49 were found to correspond to the peptide regions of NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 8(Ndufα8) and basigin, respectively, by liquid chromatography with electrospray ionization and tandem triple quadrupole mass spectrometry(LC-ESI-MS/MS). Western blot analysis was used to detect the expression of Ndufα8 and basigin in another 10 model mice and 10 control mice. The western blot results confirmed the LC-ESI-MS/MS data. The expression of serum basigin and Ndufα8 was partly dependent the concentration of melamine, but no time dependence. In conclusion, Ndufα8 and basigin may be potential serum biomarkers for the detection of melamine diet-induced bladder stones in C57BL/6 mice.