Optimal application of biological mass spectrometry (MS) in combination with two-dimensional electrophoresis (2-DE) of liver can lead to the identification of new potential biological markers/products of human Wilson’s disease. To this end, we analyzed a number of 2-DE protein spots in Long-Evans Cinnamon (LEC) rats using matrix-assisted laser desorption/ionization (MALDI)-time of flight mass spectrometry (TOF-MS). LEC rats have been used as an animal model for human Wilson’s disease, since they develop hepatic abnormalities due to accumulation of copper in the liver in the course of the growing period. Livers from LEC and WKAH/Hkm (control) rats of 12 and 16 weeks of age were separately homogenized and performed with 2-DE. Protein spots of 2-DE were analyzed by using image analysis software to compare the changes in protein quantities. Seventeen protein spots were found to be different between the two strains at both ages studied. In detail, four protein spots increased by 1.5 times in LEC rats, compared with control. Two of them were highly increased by approximately 7 times. The two protein spots were determined as fructose-1-6-bisphosphatase and argininosuccinate-synthase. On the other hand, 12 protein spots decreased by 2 times (n=8) and by 1.5 times (n=4) in LEC rats. All identified proteins (10 of 12) were belonging to a group of superoxide dismutase (SOD), such as catalase, glutathione-transferase, peroxisome. Interestingly, a protein spot of 36.5 kDa was completely disappeared in LEC rats, whereas it was positive in control. Finally, either increase or decrease of the 17 protein spots were also identified in the younger LEC rats of 4, 8 and 10 weeks of age. These results suggest that decrease in the expression of SOD proteins may be related with a cause and/or progress of Wilson’s disease, and demonstrate that a technique of MALDI-TOF-MS in combination with 2-DE may be useful for rapid and accurate analysis of biomolecules in liver tissue.
Source: Korean J Physiol Pharmacol.2006 Oct;10(Suppl II):240
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