Irvine, Calif., March 19, 2012 By analyzing the hundreds of metabolic products present in the liver, researchers with the UC Irvine Center for Epigenetics & Metabolism have discovered that circadian rhythms our own body clock greatly control the production of such key building blocks as amino acids, carbohydrates and lipids.
They identified more than 600 liver-originated metabolites, which are the chemical substances created by metabolism that sustain and promote cell health and growth. Approximately 60 percent of these metabolites were found to be dependent on the endogenous circadian clock many more than expected, as only about 15 percent of the body's genes are regulated by it.
Circadian rhythms over 24 hours govern fundamental biological and physiological processes in almost all organisms. They anticipate environmental changes and adapt certain bodily functions to the appropriate time of day. Disruption of these cycles can seriously affect human health.
Center for Epigenetics & Metabolism director Paolo Sassone-Corsi, lead author on the study and one of the world's preeminent researchers on circadian rhythms, said the liver metabolites reveal how the body clock through the main circadian gene, CLOCK orchestrates the interplay between metabolites and signaling proteins in much the same way a conductor leads a symphony.
"Metabolites and signaling proteins like the horns and strings in an orchestra need to be perfectly coordinated, and we've found that CLOCK provides that direction," he said.
Since external cues such as day-night lighting patterns and nutrition influence the circadian machinery, metabolites and their relationship to signaling proteins in cells seem to be acutely tied to circadian disruptions. This may help explain, Sassone-Corsi added, some of the primary physiological factors underlying obesity, high cholesterol and metabolic-based diseases like diabetes.
"This interplay has far-rea
|Contact: Tom Vasich|
University of California - Irvine