Nrf2—a protein involved in protecting against oxidative stress—is critical in the protection of the lungs in mice against the inflammation and destruction typical of emphysema, a team of researchers at Johns Hopkins University Bloomberg School of Public Health report in the November 1 issue of the Journal of Clinical Investigation. The finding could explain why only a tiny fraction of heavy cigarette smokers develop severe forms of the disease, according to Shyam Biswal and colleagues, since while all humans have Nrf2, the genetically determined responsiveness of the Nrf2 pathway may act as a major determinant of susceptibility to tobacco smoke–induced emphysema.

Biswal and colleagues subjected Nrf2-deficient mice as well as wildtype ICR strain mice to chronic cigarette smoke by burning cigarettes using a smoking machine. The authors found a dramatic increase in alveolar destruction in the lungs of Nrf2-deficient mice when compared with wildtype mice after...