Ozone inhalation modifies the rat liver proteome()

Ozone (O(3)) is a serious public health concern. Recent findings indicate that the damaging health effects of O(3) extend to multiple systemic organ systems. Herein, we hypothesize that O(3) inhalation will cause downstream alterations to the liver. To test this, male Sprague-Dawley rats were exposed to 0.5 ppm O(3) for 8 h/day for 5 days. Plasma liver enzyme measurements showed that 5 day O(3) exposure did not cause liver cell death. Proteomic and mass spectrometry analysis identified 10 proteins in the liver that were significantly altered in abundance following short-term O(3) exposure and these included several stress responsive proteins. Glucose-regulated protein 78 and protein disulfide isomerase increased, whereas glutathione S-transferase M1 was significantly decreased by O(3) inhalation. In contrast, no significant changes were detected for the stress response protein heme oxygenase-1 or cytochrome P450 2E1 and 2B in liver of O(3) exposed rats compared to controls. In summary, these results show that an environmentally-relevant exposure to inhaled O(3) can alter the expression of select proteins in the liver. We propose that O(3) inhalation may represent an important unrecognized factor that can modulate hepatic metabolic functions.