We all know that traveling to different time zones or working the night shift shakes up our body clocks. A new URMC study also shows that tobacco smoke can harm circadian rhythms, by changing gene expression patterns in lung tissue.
The study, led by Irfan Rahman, Ph.D., professor of Environmental Medicine, was published online today by The FASEB Journal, and reports for the first time that chronic exposure to cigarette smoke caused mice to act sluggish – as if they just took a red-eye flight -- an effect that persisted for up to 30 days even after the exposure stopped.
Circadian rhythms are centralized in a specific region of the brain called the suprachiasmatic nucleus (SCN), but circadian clocks also exist in peripheral tissues including the liver, heart, and lungs. The latest research confirms that in addition to daylight, other environmental cues can put stress on the peripheral clocks. Rahman’s lab found the mechanism by which tobacco smoke changes the core clock gene in the lung – BMAL1 – boosting lung inflammation.
Patients with chronic obstructive pulmonary disease (COPD/asthma) and other lung ailments usually have daily respiratory symptoms that run in cycles, such as nighttime breathlessness followed by severe early-morning coughing. In collaboration with circadian biologist Michael T. Sellix, Ph.D., assistant professor in the Division of Endocrinology and Metabolism, Paige B. Lawrence, Ph.D., professor of Environmental Medicine, and Patricia J. Sime, M.D., professor of Medicine, Rahman’s group is also studying whether the flu virus similarly alters daily sleep cycles and lung function.
The National Heart, Lung and Blood Institute funded the study.
To see the full paper: http://www.fasebj.org/content/early/2013/09/10/fj.13-232629.abstract