"Our key contribution to the project was to manipulate the SIK1 protein pharmacologically, and we revealed that such blockage of the protein's activity in combination with exposure to a natural clock resetting agent, such as light, enhanced the clock shifting response," Duffield said. "For example, a one hour shift of the clock became two hours. We also showed this effect in both peripheral tissues as well as in the clock in the brain.
"It would appear that SIK1 plays a common role in our circadian clocks found throughout our body, and working as a hand-brake on our ability to shift our biorhythms and adjust to new time zones, whether these are real or artificial, such as those produced during shift work schedules."
In addition to the inconvenience of jet lag, disruptions in the circadian system, such as produced during shift work, have been linked to many diseases including diabetes, heart disease and cancer. Disturbances of the circadian clock have even been linked to mental disorders, such as schizophrenia, bipolar disease and seasonal affective disorder, also known as winter depression. It is important to note that approximately 16 percent of the U.S. and European workforces undertake some form of shift work.
"Having such a hand-break on the circadian clock systems makes sense so as to prevent excessive responses to environmental change, and that it is only in our modern 24-h
|Contact: Giles Duffield|
University of Notre Dame