Ozone inhalation modifies the rat liver proteome

Area of Science:

• Environmental Health
• Toxicology
• Proteomics

Background:

• Ozone (O3) is a significant air pollutant with known systemic health effects.
• Emerging evidence suggests O3 exposure impacts multiple organ systems beyond the respiratory tract.
• The specific effects of O3 on liver function and protein expression remain largely unexplored.

Purpose of the Study:

• To investigate the hypothesis that inhaled ozone causes downstream alterations in hepatic protein expression.
• To identify specific proteins in the liver that are differentially expressed following short-term ozone exposure.
• To assess the impact of ozone inhalation on indicators of liver cell damage.

Main Methods:

• Male Sprague-Dawley rats were exposed to 0.5 parts per million (ppm) ozone for 8 hours daily over 5 days.
• Plasma liver enzymes were measured to assess for hepatocellular injury.
• Proteomic and mass spectrometry analyses were employed to identify changes in liver protein abundance.

Main Results:

• Ozone exposure did not result in significant elevations in plasma liver enzymes, indicating no acute liver cell death.
• Proteomic analysis identified 10 proteins in the liver with significantly altered abundance post-ozone exposure.
• Key altered proteins included increased Glucose-regulated protein 78 and protein disulfide isomerase, and decreased glutathione S-transferase M1.

Conclusions:

• Environmentally relevant ozone inhalation can modulate the expression of specific proteins within the liver.
• Ozone exposure alters the abundance of stress-responsive proteins in the liver.
• These findings suggest inhaled ozone may be an unrecognized factor influencing hepatic metabolic functions.