Featured Research

from universities, journals, and other organizations

Discovery may help stop age-related macular degeneration at the molecular level

Date:
January 6, 2010
Source:
American Society for Biochemistry and Molecular Biology
Summary:
Researchers have gleaned a key insight into the molecular beginnings of age-related macular degeneration, the No. 1 cause of vision loss in the elderly, by determining how two key proteins interact to naturally prevent the onset of the condition.

Researchers at University College London say they have gleaned a key insight into the molecular beginnings of age-related macular degeneration, the No. 1 cause of vision loss in the elderly, by determining how two key proteins interact to naturally prevent the onset of the condition.

Related Articles


In a paper to be published in a forthcoming issue of the Journal of Biological Chemistry, the team reports for the first time how a common blood protein linked to the eye condition reins in another protein that, when produced in vastly increased amounts in the presence of inflammation or infection, can damage the eye.

"By starting to understand these interactions in greater detail, we can begin to devise methods that will ultimately prevent the development of blindness in the elderly," said Zuby Okemefuna, the lead author of the paper to be published Jan. 8.

Age-related macular degeneration, or AMD, is painless but affects the macula, the part of the retina that allows one to see fine detail. One form of the debilitating condition, known as "wet" AMD, occurs when abnormal and fragile blood vessels grow under the macula, leaking blood and fluid and displacing and damaging the macula itself. The second form, "dry" AMD, occurs when light-sensitive cells in the macula slowly break down.

It is believed that both forms start on a common molecular route and then deviate into dry or wet AMD, explained the research leader, Steve Perkins.

"The earliest hallmark of AMD is the appearance of protein, lipid and zinc deposits under the retinal pigment epithelial cells," he said, adding that the yellowish deposits, usually discovered by an ophthalmologist, are commonly known as "drusen."

The researchers studied two proteins involved in drusen formation -- blood protein Factor H and a second blood protein known as C-reactive protein -- and showed that Factor H binds to C-reactive protein when C-reactive protein is present in large amounts, as in the case of infection, to reduce the potentially damaging effects of an overactive immune system.

"In the eye, during the normal processes of aging, cells will die naturally for all sorts of reasons," Okemefuna said. "The blood supply to the eye will bring C-reactive protein with it, and a low level of C-reactive protein activity will enable the normal processes of clearance of dead cells at the retina through mild inflammation. In conditions of high inflammation, the levels of C-reactive protein in the retina will increase dramatically."

Uncontrolled C-reactive protein activity causes damage to the retina, which is followed by more inflammation and then even more damage to the retina, and so forth.

"It's the debris of broken up retinal cells, some of which is caused by this cycle, that is deposited as drusen," Okemefuna said.

The team also found that a genetically different form of Factor H does not bind to the C-reactive protein quite as well as the normal one, making people who carry the modified protein more vulnerable to an immune system attack in the eye and, thus, drusen buildup.

"In normal individuals, further damage to the retina by prolonged exposure to high levels of C-reactive protein is prevented by Factor H. C-reactive protein also prevents Factor H from clumping together and initiating the processes that lead to drusen formation," Perkins said. "Both these 'good' activities of Factor H are much reduced in the genetically different form of Factor H."

While there is no known cure for AMD, existing therapies aim to treat the symptoms and delay progression.

"It is interesting how the interaction of these two blood proteins protects the eye during crisis," Perkins said. "The two proteins also can be involved in a rare and often fatal cause of kidney failure in children. We now are better positioned to begin to work out preventative strategies for these diseases."

Ruodan Nan, Ami Miller and Jayesh Gor also were co-authors on the study, which was funded over the past three years by University College London, the Biotechnology and Biological Sciences Research Council, the Mercer Fund of the Fight for Sight Charity and the Henry Smith Charity.


Story Source:

The above story is based on materials provided by American Society for Biochemistry and Molecular Biology. Note: Materials may be edited for content and length.


Cite This Page:

American Society for Biochemistry and Molecular Biology. "Discovery may help stop age-related macular degeneration at the molecular level." ScienceDaily. ScienceDaily, 6 January 2010. <www.sciencedaily.com/releases/2010/01/100104114549.htm>.
American Society for Biochemistry and Molecular Biology. (2010, January 6). Discovery may help stop age-related macular degeneration at the molecular level. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2010/01/100104114549.htm
American Society for Biochemistry and Molecular Biology. "Discovery may help stop age-related macular degeneration at the molecular level." ScienceDaily. www.sciencedaily.com/releases/2010/01/100104114549.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
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