Circadian rhythms in skin stem cells protect us against UV rays

October 10, 2013, Cell Press

Human skin must cope with UV radiation from the sun and other harmful environmental factors that fluctuate in a circadian manner. A study published by Cell Press on October 10th in the journal Cell Stem Cell has revealed that human skin stem cells deal with these cyclical threats by carrying out different functions depending on the time of day. By activating genes involved in UV protection during the day, these cells protect themselves against radiation-induced DNA damage. The findings could pave the way for new strategies to prevent premature aging and cancer in humans.

"Our study shows that stem cells posses an internal clock that allows them to very accurately know the time of day and helps them know when it is best to perform the correct function," says study author Salvador Aznar Benitah an ICREA Research Professor who developed this project at the Centre for Genomic Regulation (CRG, Barcelona), and who has recently moved his lab to the Institute for Research in Biomedicine (IRB Barcelona). "This is important because it seems that tissues need an accurate internal clock to remain healthy."

A variety of cells in our body have internal clocks that help them perform certain functions depending on the time of day, and skin cells as well as some stem cells exhibit circadian behaviors. Benitah and his collaborators previously found that animals lacking normal circadian rhythms in skin stem cells age prematurely, suggesting that these cyclical patterns can protect against cellular damage. But until now, it has not been clear how affect the functions of human skin stem cells.

To address this question, Benitah teamed up with his collaborators Luis Serrano and Ben Lehner of the Centre for Genomic Regulation. They found that distinct sets of genes in human skin stem cells show peak activity at different times of day. Genes involved in UV protection become most active during the daytime to guard these cells while they proliferate—that is, when they duplicate their DNA and are more susceptible to radiation-induced damage.

"We know that the clock is gradually disrupted in aged mice and humans, and we know that preventing from accurately knowing the time of the day reduces their regenerative capacity," Benitah says. "Our current efforts lie in trying to identify the causes underlying the disruption of the clock of human and hopefully find means to prevent or delay it."

Explore further: Scientists identify key regulator controlling formation of blood-forming stem cells

More information: Cell Stem Cell, Janich et al.: "Human epidermal stem cell function is regulated by circadian oscillations." dx.doi.org/10.1016/j.stem.2013.09.004

Related Stories

Scientists identify key regulator controlling formation of blood-forming stem cells

September 26, 2013
Stem cell scientists have moved one step closer to producing blood-forming stem cells in a Petri dish by identifying a key regulator controlling their formation in the early embryo, shows research published online today in ...

Recommended for you

LincRNAs identified in human fat tissue

June 21, 2018
A large team of researchers from the U.S. and China has succeeded in identifying a number of RNA fragments found in human fat tissue. In their paper published in the journal Science Translational Medicine the group describes ...

Scientists solve the case of the missing subplate, with wide implications for brain science

June 21, 2018
The disappearance of an entire brain region should be cause for concern. Yet, for decades scientists have calmly maintained that one brain area, the subplate, simply vanishes during the course of human development. Recently, ...

Key molecule of aging discovered

June 21, 2018
Every cell and every organism ages sooner or later. But why is this so? Scientists at the German Cancer Research Center in Heidelberg have now discovered for the first time a protein that represents a central switching point ...

Compound made inside human body stops viruses from replicating

June 20, 2018
The newest antiviral drugs could take advantage of a compound made not by humans, but inside them. A team of researchers has identified the mode of action of viperin, a naturally occurring enzyme in humans and other mammals ...

Research reveals zero proof probiotics can ease your anxiety

June 20, 2018
If you're expecting probiotics to reduce your anxiety, it might be time to put down that yogurt spoon—or supplement bottle—and call a professional instead.

Long-term estrogen therapy changes microbial activity in the gut, study finds

June 20, 2018
Long-term therapy with estrogen and bazedoxifene alters the microbial composition and activity in the gut, affecting how estrogen is metabolized, a new study in mice found.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.