Navigation Links
Study finds linchpin of skin response to UVA light
Date:1/21/2013

PROVIDENCE, R.I. [Brown University] Last year, a team of researchers at Brown University discovered that certain skin cells use a light-sensitive receptor found outside of the eye to sense ultraviolet light and quickly begin pumping out melanin to protect against DNA damage. In a new study, lab members identify a key player in that biomolecular chain of events that could someday become a pharmacological target for improving this protective response.

The new discovery, published the week of Jan. 21 in the Proceedings of the National Academy of Sciences, is that human melaoncyte skin cells rely on an ion channel called TRPA1 to allow a flood of calcium ions into the cells when they are exposed to UVA light. The resulting abundance of calcium ions signals the cell to begin making melanin, the pigment responsible for the tanning response in people.

Several experiments described in the paper show that TRPA1, which is known from a number of other appearances elsewhere in the body, is an essential step in the skin's response to UVA light, said senior author Elena Oancea, assistant professor of medical science in the Department of Molecular Pharmacology, Physiology, and Biotechnology at Brown.

As a matter of basic science, the finding strengthens the evidence of a striking parallel between the skin's response to UVA light and the way the eye detects light.

"Its exciting because it confirms this phototransduction pathway is similar to those found in the eye. It consists of a light-sensitive receptor, molecular signaling cascade, and an ion channel," Oancea said. "The involvement of an ion channel makes this pathway a lot more like other phototransduction pathways."

In other parts of the body, TRPA1 has been shown to help detect pungent but benign chemicals, such as those in intensely flavorful foods. Oancea and lead author Nicholas Bellono said the chemical sensitivity of TRPA1 offers the intriguing possibility that it could become a target for experiments to boost melanin production.

"TRPA1 ion channels are involved in the detection of pungent chemicals such as cinnamaldehyde, wasabi, and mustard oil, and we've now found it's important for this melanin response," Bellono said. "There is a possibility that we can pharmacologically alter pigmentation through regulation of this ion channel."

Oancea and Bellono emphasized, however, that people who go out in the sun should always take widely recommended precautions to protect their skin, such as using high-SPF commercial sunscreens or wearing protective hats and clothing.

Finding the channel

From the prior research in Oancea's lab, Bellono knew he was looking for some kind of molecular pathway that would start with a light sensitive receptor and trigger an elevated level of calcium ions in the melanocytes.

It seemed possible that a TRP ion channel would be involved because TRPs are involved in phototransduction elsewhere in the body that lead to an increase in intracellular calcium. There are, however, many types of TRP channels, and the molecular identity of the UVA-activated channel in melanocytes was not apparent. Oancea confessed that she even suspected another as the culprit. But many experiments later, the team hit on TRPA1 and amassed considerable evidence to confirm its vital role.

In one experiment, for example, they treated melanocytes with "antagonist" chemicals known to block TRPA1 activity. They then exposed the cells to UVA light and measured the resulting electrical response. The cells blocked with the antagonists had 80 to 90 percent reduction in current compared to the unhindered cells.

They used a similar technique of specifically blocking TRPA1 activity to show that the ion channel contributes greatly to the presence of calcium ions after UVA exposure compared to unhindered melanocyte cells. They also found melanocytes produce little or no melanin following exposure to UVA when TRPA1 is blocked.

They did not, however, do experiments to see whether adding TRPA1 stimulating substances could increase melanin production.


'/>"/>
Contact: David Orenstein
david_orenstein@brown.edu
401-863-1862
Brown University
Source:Eurekalert  

Related biology news :

1. Penn Vet study reveals a promising new target for Parkinsons disease therapies
2. Abortions are safe when performed by advanced practice nurses and physician assistants, study shows
3. Study offers new insights into the mechanics of muscle fatigue
4. Recent study suggests bats are reservoir for ebola virus in Bangladesh
5. Privacy a problem for mothers of newborns in neonatal intensive care units, CWRU study finds
6. Study finds a new culprit for epileptic seizures
7. Researcher awarded $5.08 million to study oilseed camelina as biofuel feedstock
8. International study: Where theres smoke or smog, theres climate change
9. Born to lead? Leadership can be an inherited trait, study finds
10. CU-led study shows pine beetle outbreak buffers watersheds from nitrate pollution
11. UCI study reveals why Down syndrome boosts susceptibility to other conditions
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study finds linchpin of skin response to UVA light
(Date:6/22/2016)... WASHINGTON , June 22, 2016 On ... highly-anticipated call to industry to share solutions for the ... by U.S. Customs and Border Protection (CBP), explains that ... nationals are departing the United States ... criminals, and to defeat imposters. Logo - ...
(Date:6/15/2016)... June 15, 2016 Transparency ... titled "Gesture Recognition Market by Application Market - Global Industry Analysis ... 2024". According to the report, the  global gesture recognition ... 2015 and is estimated to grow at a ... by 2024.  Increasing application of gesture ...
(Date:6/3/2016)... , June 3, 2016 ... Management) von Nepal ... und Lieferung hochsicherer geprägter Kennzeichen, einschließlich Personalisierung, ... führend in der Produktion und Implementierung von ... der Ausschreibung im Januar teilgenommen, aber Decatur ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... 27, 2016 , ... Cancer experts from Austria, Hungary, Switzerland, ... a new and helpful biomarker for malignant pleural mesothelioma. Surviving Mesothelioma has just ... now. , Biomarkers are components in the blood, tissue or body fluids ...
(Date:6/27/2016)... , June 27, 2016   Ginkgo Bioworks , ... industrial engineering, was today awarded as one of ... of the world,s most innovative companies. Ginkgo Bioworks ... for the real world in the nutrition, health ... work directly with customers including Fortune 500 companies ...
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, a leader in ... Trials Patient Recruitment and Retention Tips.” Partnering with experienced clinical research professionals, Mosio ... practical tips, tools, and strategies for clinical researchers. , “The landscape of how ...
(Date:6/23/2016)... June 23, 2016 Houston Methodist Willowbrook ... Cy-Fair Sports Association to serve as their official ... Houston Methodist Willowbrook will provide sponsorship support, athletic ... with association coaches, volunteers, athletes and families. ... Cy-Fair Sports Association and to bring Houston Methodist ...
Breaking Biology Technology: