Circadian Rhythms Protect Our Skin from Harmful UV Radiations

Human skin cells protect themselves from recurring problems like UV radiations, harsh weather conditions and other environmental issues at different times of the day with the help of a biological process called the circadian rhythm. This process activates various genes, which help in shielding our skin.

This ability of the cells can help in finding new ways of combating cancer and premature aging.

The study was carried out by Salvador Aznar Benitah an ICREA Research Professor, along with Luis Serrano and Ben Lehner of the Centre for Genomic Regulation.

"Our study shows that human skin 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," study author Salvador Aznar Benitah stated in a press release.

"This is important because it seems that tissues need an accurate internal clock to remain healthy," Benitah added.

Various cells present in our body have got a biochemical mechanism called circadian clock or circadian oscillator, which executes various functions throughout the day. This clock resets itself depending on the transformations in environment, such as change in the frequency of light.

The researchers found the absence of this mechanism in animals, which leads to early aging of skin stem cells in them. These biological clocks predict cellular damage, which can be used in protecting the skin from cellular damage. The researchers were still analyzing the circadian rhythms and how exactly they affect the skin stem cells.

They found out that a specific group of genes play a very active role in shielding our skin from the harmful effects of the UV rays at different times of the day. These genes multiply during the day time as our skin is more vulnerable to UV radiation during this time.

"We know that the clock is gradually disrupted in aged mice and humans, and we know that preventing stem cells from accurately knowing the time of the day reduces their regenerative capacity," Benitah said.

"Our current efforts lie in trying to identify the causes underlying the disruption of the clock of human skin stem cells and hopefully find means to prevent or delay it," Benitah concluded.