Genetics key to how ozone damages lungs.

Jan 21, 2009

Vancza EM, K Galdanes, A Gunnison, G Hatch and T Gordon.  2008.  Age, strain and gender as factors for increased sensitivity of the mouse lung to inhaled ozone. Toxicological Sciences doi:10.1093/toxsci/kfn253.

Genetics, age and gender determine what kind and how badly lungs are harmed in mice that breath ozone, a dangerous type of air pollution.

This study is the first to report which differences influence health effects of ozone exposure in various strains of mice. These data suggest that genetic makeup plays a strong role in how young and adult mice respond to ozone.

While not directly applicable to humans, the findings could help explain why certain people have more severe reactions to ozone and air pollution than others.

Genetics -- the DNA and RNA passed from generation to generation -- programs development and guides life processes in all living things. Although every species shares a similar set of genes (called a genome), subtle differences in how and which genes are matched and triggered give individuals different traits, such as brown hair, dark skin color or different responses to toxins at the molecular level.

In this study, certain mouse strains were very susceptible to ozone-induced lung injury, while other strains were hardly affected. Also, in particular strains, female mice suffered more injury than did male mice.  Young mice had overall greater lung injury due to the ozone exposure than did the older mice.

Ozone is a type of oxygen that is formed both naturally high in the atmosphere and as a pollutant close to the ground, usually from human activity. Government agencies regulate its levels, but it remains a large and dangerous part of urban air pollution, emanating from sources such as industrial generators that are used to manufacture some pharmaceuticals, synthetic lubricants or other useful industrial chemicals. Commercially, ozone is a bleaching agent and a water sterilizer.

Ozone injures the lungs and respiratory system. It is considered especially harmful for children, particularly those with allergies and asthma.

Generally, children are more susceptible to toxic effects of environmental pollutants than adults.  However, the exact reasons remain a mystery. Some experts believe their smaller bodies, faster breathing and less developed organs mean children have more toxic exposure than adults.

Researchers had eight different strains of mice with different genetic backgrounds breath ozone for a short time. They measured and compared lung injury and lung inflammation in young (2 weeks old) and adult mice (15 weeks).

The next step will be to identify the key genes that govern the different ozone-induced lung injury and inflammation found in the different mouse strains.