Biological cross-talk between bodys circadian rhythm and metabolism identifiedNovember 17th, 2007 - 1:56 pm ICT by admin
Washington, Nov 17 (ANI): Researchers have identified a protein that explains the biological co-ordination between bodys 24-hour, or circadian schedule, and metabolism.
Its well known that the bodys energy levels cycle on a 24-hour, or circadian, schedule, and that this metabolic process is fuelled by oxygen. Now, researchers at the University of Pennsylvania School of Medicine have found that a protein called Rev-erb coordinates the daily cycles of oxygen-carrying heme molecules to maintain the bodys correct metabolism.
Many studies, including this one, point to a link between the human internal clock and such metabolic disorders as obesity and diabetes. Proteins such as Rev-erb are the gears of the clock and understanding their role is important for fighting these diseases, the researchers said.
This is the next chapter on Rev-erb, a member of a family of cell-nucleus proteins that includes receptors for anti-diabetic drugs, explains senior author Mitchell A. Lazar, MD, PhD, Director of the Institute for Diabetes, Obesity, and Metabolism at Penn.
About two years ago Lazars group discovered that Rev-erb was a critical component of the circadian clock. In this paper, they found that the activity of Rev-erb is controlled by heme.
Heme represents the body’s most important way of transporting and using oxygen, which would simply bubble away in the body without being bound to heme.
In a molecular baton hand-off, oxygen is transferred from heme in the bloodstream to the heme molecules found inside a cell, says Lazar, of how oxygen reaches cells to run their metabolic needs.
One of the most important roles of heme inside cells is to facilitate the use of oxygen to generate energy in the process known as cellular respiration.
The findings further tie together the 24-hour cycle of the body with metabolic function.
Circadian rhythms are our sleep-wake cycle and metabolism is how we process food, so it makes sense that there would be biological cross-talk between the bodys 24-hour rhythm and metabolic function, says Lazar.
He added that the newly discovered circadian/metabolic link could be the focus of a new generation of diabetes treatments.
The Penn group worked with scientists at GlaxoSmithKline, who demonstrated that the Rev-erb protein can physically bind to heme in the test tube. They found that heme, by regulating the activity of Rev-erb, reduces the amount of glucose produced by liver cells.
Whats exciting about this is that it puts heme in a central role in the metabolic regulation of the cell. Not only is it a key component in making energy, but also in the pathway for turning off glucose production. Excessive glucose production by the liver is a major cause of high blood sugar in diabetes, Lazar said.
The study is published in Science Express in advance of print publication in Science. (ANI)
- Molecules act as 'shift workers' to protect liver from accumulating fat - Mar 11, 2011
- Scientists discover better drugs for sleep problems - Apr 09, 2012
- Circadian clock found in pancreas linked to diabetes - Jun 19, 2010
- New mechanism regulating body's 24-hour clock identified - Nov 12, 2010
- A rhythm awry means rolls of fat - Aug 30, 2012
- Our body clocks determine how much fat we burn - Nov 16, 2010
- Intense light reduces heart attack risks - Apr 26, 2012
- Mechanism that controls 24-hour clock of all forms of life discovered - Jan 27, 2011
- Liver's role vital in regulating body clock - May 04, 2012
- Disruption in body clock genes could lead to diabetes - Jul 14, 2010
- Our body clock unchanged for millions of years - Jan 28, 2011
- Clock gene prepares plants for spring bloom - Mar 12, 2012
- Round-the-clock lifestyle affects metabolism, behaviour - Feb 28, 2011
- Indian-American identifies 'wake-up' gene - Sep 30, 2011
- Tweaking plants' bio-clock can revolutionise food output - Sep 04, 2011
Tags: 24 hour, bodys, cell nucleus, cells, cellular respiration, circadian clock, circadian rhythm, circadian rhythms, diabetes, diabetic drugs, heme, lazar, metabolism, molecules, obesity, oxygen, phd director, protein, proteins, university of pennsylvania school of medicine