Intriguing small molecule directs activity of key ‘clock proteins’

In research published in Nature Communications, Thomas Burris, Ph.D., chair of pharmacological and physiological science at Saint Louis University, reports intriguing findings about a small molecule that directs the activity of key "clock proteins," offering the potential to manage circadian rhythm and treat problems that are associated with its dysfunction, like sleep and anxiety disorders.

 

Circadian rhythm refers to biological processes that cycle every 24 hours. In mammals, the internal clock that maintains circadian rhythm is essential for normal physiological functions. The rhythms can, however, be disrupted, and dysregulation of circadian rhythm is associated with many disorders, including metabolic disease and neuropsychiatric disorders including bipolar disorder, anxiety, depression, schizophrenia and sleep disorders.

Burris and his colleagues examined compounds that target a protein called REV-ERB, which appears to play a key role in regulating mammals' internal clocks.

"It has been suggested that REV-ERB is a core component of our clock," said Burris. "Mice without it are arrhythmic. This study demonstrated that when we give mice a synthetic compound that turns REV-ERB on, it altered their circadian rhythm."

The team examined effects of the REV-ERB drug on patterns of sleep and wakefulness and found that the compound increases wakefulness, reduces REM and slow-wave sleep, and, notably, decreases anxiety.

This is an interesting finding because it is unusual. Frequently, drugs that increase arousal (wakefulness) also increase anxiety (ex. cocaine, amphetamines). And, vice versa: Drugs that decrease anxiety also decrease arousal (ex. benzodiazepines and ethanol). An exception to this common pattern is nicotine.

Intriguing small molecule directs activity of key ‘clock proteins’