Human skin begins tanning in seconds, and here's how
We all know that human skin tans after days spent in the sun. That relatively slow process has known links to ultraviolet (and specifically UVB) exposure, which leads to tanning only after it damages the DNA of skin cells. Now, researchers reporting online on November 3 in Current Biology, a Cell Press publication, have uncovered a much speedier path to pigmentation.
The newly discovered response is likely to provide rapid protection against UV damage, the researchers say, and understanding how it works might impact the design of sunscreens in the future.
"Our work shows that a dedicated UV receptor allows skin cells to immediately detect and respond to UV light," said Elena Oancea of Brown University. "We found that human skin detects light using a mechanism similar to that used by the retina, on a timescale significantly faster than was previously known."
That immediate response occurs within a matter of seconds in response to UVA light. UVA accounts for about 95 percent of the ultraviolet radiation at the Earth's surface. UVB makes up the other 5 percent. Scientists did know that UVA causes oxidative damage to cells and leads to pigment darkening in a matter of minutes. The question was how.
Oancea's team found that exposure of pigment-producing cells from human skin to UVA leads to the early synthesis of melanin pigment in a process involving calcium release. What's more, the skin's UVA response depends on rhodopsin, a light-sensitive ingredient also found in the retina of the eye.
"Our findings show that both the eye and skinthe only two organs constantly exposed to solar radiationuse similar molecular mechanisms to decode light," Oancea said.
The studies show that melanin production can be measured in human skin cells within an hour of UV exposure. That's key because melanin doesn't just make the skin darker. It also protects the skin by absorbing ultraviolet radiation and converting it to a less harmful energy in the form of heat.
"We hypothesize that the early melanin production triggered by rhodopsin activation provides a first line of defense against ultraviolet light-induced damage," Oancea says. "If this is the case, then this pathway and its protective capacity should be taken into consideration in the design and use of broad-spectrum sunscreens."
Provided by
Cell Press
-
Sunburn alert: UVB does more damage to DNA than UVA
Jul 01, 2008 |
not rated yet |
0
-
Gene required for radiation-induced protective pigmentation also promotes survival of melanoma cells
Nov 20, 2008 |
not rated yet |
0
-
Researchers find melanoma not caused by early UVA light exposure
May 04, 2010 |
not rated yet |
0
-
UVA radiation damages DNA in human melanocyte skin cells and can lead to melanoma
Jul 01, 2010 |
not rated yet |
0
-
Tanning beds could provide a greater risk than originally thought: new study
Oct 10, 2011 |
not rated yet |
0
-
Motion perception revisited: High Phi effect challenges established motion perception assumptions
Apr 23, 2013 |
3 / 5 (2) |
2
-
Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update)
Apr 02, 2013 |
4.5 / 5 (11) |
5
-
The visual system as economist: Neural resource allocation in visual adaptation
Mar 30, 2013 |
5 / 5 (2) |
9
-
Separate lives: Neuronal and organismal lifespans decoupled
Mar 27, 2013 |
4.9 / 5 (8) |
0
-
Sizing things up: The evolutionary neurobiology of scale invariance
Feb 28, 2013 |
4.8 / 5 (10) |
14
-
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013
-
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013
-
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013
-
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013
-
If you became brain-dead, would you want them to pull the plug?
May 17, 2013
-
MRI bill question
May 15, 2013
- More from Physics Forums - Medical Sciences
More news stories
New fluorescent tools for cancer diagnosis
In recent years, microRNAs (miRNAs) and other non-coding RNAs are small molecules that help control the expression of specific proteins. In recent years they have emerged as disease biomarkers. miRNA profiles have been used ...
Cancer
1 hour ago |
not rated yet |
0
Modulating the immune system to combat metastatic cancer
Cancer cells spread and grow by avoiding detection and destruction by the immune system. Stimulation of the immune system can help to eliminate cancer cells; however, there are many factors that cause the immune system to ...
Cancer
1 hour ago |
not rated yet |
0
Scientists put bowel cancer under the microscope
Researchers from London's Kingston University have begun a two-year study which could help prolong the lives of people with colorectal tumours.
Cancer
4 hours ago |
5 / 5 (1) |
0
Researcher identifies breast cancer fighting hormone
Transformative research from Western University has identified new hormones in the body which may suppress breast cancer and stimulate the regression of breast tumors.
Cancer
5 hours ago |
5 / 5 (1) |
0
Ground breaking cancer research finds immune system link
(Medical Xpress)—Curtin University researchers have found evidence that targeting specific cells in the body can reverse the effects of cancer on the immune system.
Cancer
5 hours ago |
5 / 5 (3) |
0
Storm chasers: born to be wild?
(HealthDay)—We've all seen them: the surfers who race to the beach when a hurricane hits, the guy who decides to ride out the storm in his overmatched boat, the tornado chasers who fearlessly steer their ...
Bulletin provides guidelines for second-trimester abortion
(HealthDay)—New evidence-based guidelines provide guidance on medical and surgical methods for second-trimester abortion and management of associated complications, according to a practice bulletin published ...
About one in four uninsured could be excluded from ACA
(HealthDay)—More than one in four of those eligible for new premium assistance tax credits under the Affordable Care Act (ACA) do not have a checking account and will not be able to receive premiums from ...
Comorbidities common with alopecia areata
(HealthDay)—Comorbid conditions often accompany alopecia areata, according to a study published online May 22 in JAMA Dermatology.
Top-ranked golfer beats scoliosis
(HealthDay)—As a world-class golfer, Stacy Lewis' accomplishments are remarkable. But it was a physical challenge in her childhood that defined her ascent to the top of her sport.
Hormone levels may provide key to understanding psychological disorders in women
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
Nov 04, 2011
Rank: not rated yet