Featured Research

from universities, journals, and other organizations

How does body temperature reset the biological clock?

Date:
August 23, 2012
Source:
Université de Genève
Summary:
Scientists have discovered a molecular mechanism by which body temperature rhythms influence the expression of 'clock genes' and synchronize local oscillators. This study also demonstrates how the production of DBP, a protein involved in detoxification and drug metabolism, is modulated by daily variations of temperature.

Numerous processes in our body fluctuate in a regular pattern during the day. These circadian (or daily) variations can be driven by local oscillators present within our cells or by systemic signals controlled by the master pacemaker, located in the brain. Ueli Schibler, profes- sor at the University of Geneva (UNIGE), Switzerland, unveils a mo- lecular mechanism by which body temperature rhythms influence the expression of 'clock genes' and synchronize local oscillators. This study, made in collaboration with a team at the Ecole polytechnique fédérale of Lausanne (EPFL), also demonstrates how the production of DBP, a protein involved in detoxification and drug metabolism, is modulated by daily variations of temperature.

This research has been published in Science.

Many of our physiological functions, such as heart beat frequency, hormone secretion or body temperature, are regulated by internal clocks. Most of our body's cells possess one of them, formed by a group of 'clock genes' displaying a cyclic activity that peaks every twenty-four hours. These local oscillators are synchronized by a central pacemaker, located in the brain which adapts to geophysical time by light-dark cycles.

The master clock also controls coordination signals that are sent to subsidiary oscillators. 'Body temperature variations constitute one of these daily resetting cues, but we did not know how it functioned', explains Ueli Schibler, professor at the Department of Molecular Biology of the UNIGE. To address this issue, the researcher's team has developed a system allowing to expose cells to simulated body temperatures cycles.

A genetic engineering technique to probe living cells

'We have discovered that temperature cycles modulate the rhythmic expression of a protein called CIRP, and that this molecule is required for a robust activation of clock genes on a daily basis', says Jörg Morf, researcher at the NCCR Frontiers in Genetics and first author of the article. In contrast to most regulatory proteins, which control the expression of genes by binding them directly, CIRP acts downstream, by adhering to gene transcripts, the RNAs.

In collaboration with Felix Naef's group at the EPFL, the researchers have then identified virtually all CIRP's target RNAs in living cells, using an ultra sophisticated genetic engineering technique they developed. This achievement allowed probing the transcriptome, that is RNAs from all genes transcribed at a given time. 'CIRP binds transcripts encoding different circadian oscillator proteins in the cell, which increases their stability and allows them to accumulate', comments Ueli Schibler. The sensitivity of their experiments has even enabled the team to localize and count each RNA molecule of a targeted circadian gene named Clock.

Effect on detoxification and drug metabolism

This system functions a bit like that of a clockwork: temperature variations induce a rhythmic production of CIRP, which in turn reinforces cyclic activation of circadian oscillator genes. In humans, the difference of 1°C in body temperature observed between the morning and the evening takes on new significance. 'We have recently demonstrated that such a small fluctuation was sufficient to synchronize cellu- lar oscillators', reports the biologist.

One of these biochemical cogs controlled by CIRP induces cyclic accumulation of DBP, a protein involved in detoxification and drug metabolism. 'Certain antitumor drugs administered to sick mice in the morning lead to a 100% mortality, while the rodents receiving the same dose in the evening all survive. This shows how much internal clocks can influence the efficacy and toxicity of drugs', notes Ueli Schibler.


Story Source:

The above story is based on materials provided by Université de Genève. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jörg Morf, Guillaume Rey, Kim Schneider, Markus Stratmann, Jun Fujita, Felix Naef, and Ueli Schibler. Cold-Inducible RNA-Binding Protein Modulates Circadian Gene Expression Posttranscriptionally. Science, 23 August 2012 DOI: 10.1126/science.1217726

Cite This Page:

Université de Genève. "How does body temperature reset the biological clock?." ScienceDaily. ScienceDaily, 23 August 2012. <www.sciencedaily.com/releases/2012/08/120823143051.htm>.
Université de Genève. (2012, August 23). How does body temperature reset the biological clock?. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2012/08/120823143051.htm
Université de Genève. "How does body temperature reset the biological clock?." ScienceDaily. www.sciencedaily.com/releases/2012/08/120823143051.htm (accessed October 23, 2014).

Share This



More Health & Medicine News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) — Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) — Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) — Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) — Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins