The Salk researchers may have found a way around these side effects by discovering a new function for cryptochromes 1 and 2, proteins that were previously known for their function in the biological clock.
The cryptochromes serve as breaks to slow the clock's activity, signaling our biological systems to wind down each evening. In the morning, they stop inhibiting the clock's activity, helping our physiology ramp up for the coming day.
In their new study on mouse cells, Evans and his colleagues made the surprising discovery that cryptochromes also interact with glucocorticoid receptors, helping to regulate how the body stores and uses sugar.
"We found that not only are the crytopchromes essential to the functioning of the circadian clock, they regulate glucocorticoid action, and thus are central to how the clock interacts with our daily metabolism of nutrients," says Katja A. Lamia, an assistant professor at The Scripps Research Institute and former post-doctoral researcher in Evan's laboratory at Salk.
Mouse cells function much like human cells, so the findings could have important implications for treatment of autoimmune diseases and cancer. By taking into account the daily rise and fall of cryptochrome levels, the scientists say, doctors might be able to better time administration of glucocorticoid drugs to avoid certain side effects related to sugar metabolism.
The discovery also raises the possibility of developing new anti-inflammatory drugs that avoid some side effects by targeting cryptochromes instead of directly targeting the glucocorticoid switches.
More broadly, Evans says, the study may help explain the connection between sleep and nutrient metabolism in our bodies, including why people with jobs that require night work or erratic hours are at higher risk for obesity and diabe
|Contact: Andy Hoang|