Reduced hepatic expression of glutathione S-transferases in burned mice

Background: Glutathione S-transferases (GSTs) contribute to liver homeostasis and are released into plasma after liver injury. This study investigates the hepatic expression of key GST enzyme subtypes after burn injury. Methods: Mice were subjected to an 18% total body surface area burn. Expression of mGSTα3 and mGSTμ1 was analyzed by reverse-transcriptase polymerase chain reaction and Western blots on liver preparations from burned and control mice. GST catalytic activity was measured by conjugation assays. Results: In burned animals, mGSTα3 mRNA was only reduced at 1 day, whereas mGSTμ1 mRNA decreased at 1 day and at 3 days after injury. Total mGSTμ, protein levels decreased at the same time points, whereas total mGSTα protein levels did not change. Also, by 3 days, total GST conjugation activity was reduced by 25% (p = 0.05). Conclusion: Reduced expression of specific α and μ GST enzymes after burns correlates functionally with reduced GST activity. Altered GST expression may contribute to liver damage after systemic injury.