Some sleep disorders may become a thing of the past, according to a study published in the journal Neuron. Researchers from McGill University and Concordia University say they have found how protein synthesis is controlled within the body’s circadian clock – an internal mechanism that controls our daily rhythms.
Many of us are robbed of a good night’s sleep because of stress-induced insomnia, graveyard shifts and long-haul flights. In this latest study, the investigators believe they may have found how to eventually put these common sleep disturbances to bed.
All living beings, including humans, live through daily rhythms that have adapted to the rotation of the earth that generates day and night. In mammals, the “circadian clock” in the brain drives the daily rhythms in wakefulness and sleep, metabolism and feeding, and some other vital processes. MIT scientists recently found a gene linked to longevity which also regulates our circadian clock.
Scientists have failed to fully understand the complex molecular processes behind the inner workings of this brain clock – until now, the researchers say.
Co-author, Dr. Shimon Amir, says his research team has identified how a fundamental biological process known as protein synthesis is controlled within our circadian clock.
He believes their findings may pave the way for future treatments for disorders caused by circadian clock dysfunction, including shift work disorders, jet lag, and even chronic conditions such as Parkinson’s disease and depression.
Dr. Amir said:
“To understand and treat the causes and symptoms of circadian abnormalities, we have to take a closer look at the fundamental biological mechanisms that control our internal clocks.”
Circadian rhythm affects the daily cycles of several physiological processes. This diagram shows the circadian patterns of somebody who gets up early, lunches around noon, and sleeps at night. Circadian rhythms are mainly synchronized with light-dark cycles, and also ambient temperature, stress, exercise, and meal times.
Dr. Amir and Dr. Nahum Sonenberg set out to determine how protein synthesis is controlled in the brain clock.
Dr. Sonenberg explained “We identified a repressor protein in the clock and found that by removing this protein, the brain clock function was surprisingly improved.”
They studied mice that lacked 4E-BP1, a protein that blocks the vital function of protein synthesis. They found that mice that lacked 4E-BP1 recovered from circadian clock disruptions much more rapidly than mice with the protein.
Dr.Ruifeng Cao, who works with the two other doctors said “In modern society, with the frequency of trans-time zone travel, we often deal with annoying jet lag problems, which usually require a couple of weeks of transition. However, by inducing a state like jet lag in the mice lacking that protein, we found they were able to adapt to time zones changes in about half of the time required by regular mice.”
They also found that the mice lacking 4E-BP1 had higher levels of VIP (vasoactive intestinal peptide). VIP is a small protein that is vital for proper brain clock function.
The scientists believe that with genetic manipulations the functioning of the circadian clock could be improved, which would lead to new treatments for circadian clock-related disorders.
Dr. Cao said “A stronger clock function may help improve many physiological processes, such as aging. In addition, understanding the molecular mechanisms of biological clocks may contribute to the development of time-managing drugs.” Dr. Amir agreed, noting that “the more we know about these mechanisms, the better able we will be to solve problems associated with disruptions to our bodies’ internal clocks”.
Researchers from the Karolinska Institute in Sweden found that circadian rhythm disruptions may affect the growth of blood vessels, raising the risk of cancer, obesity and diabetes.