Featured Research

from universities, journals, and other organizations

Lack of VEGF can cause defects similar to dry macular degeneration

Date:
November 13, 2009
Source:
Schepens Eye Research Institute
Summary:
Scientists have found that when the eye is missing a diffusible form of vascular endothelial growth factor (VEGF), i.e. one that when secreted can reach other cells at a distance, the retina shows defects similar to "dry" macular degeneration.

Scientists at Schepens Eye Research Institute have found that when the eye is missing a diffusible form of vascular endothelial growth factor (VEGF), i.e. one that when secreted can reach other cells at a distance, the retina shows defects similar to "dry" macular degeneration, also called geographic atrophy (GA).

This finding, published in the November 3, 2009 print edition of PNAS (Proceedings of the National Academy of Sciences), not only increases the understanding of the causes of this blinding disease, but it may also impact the use of anti-VEGF drugs, such as Lucentis, which are designed to neutralize VEGF in eyes with "wet" macular degeneration.

"These results are significant for several reasons. We know little about what causes GA or how to treat it. Our discovery may be an important piece of the puzzle. It shows that reduced VEGF from the retinal pigment epithelium (RPE), RPE, the bottommost layer of the retina, to the choriocapillaris (CC) -- the small blood vessels beneath retina-- leads to degeneration of the CC. Therefore, the continuous blockage of VEGF may contribute to the development of or a worsening of GA," says Patricia D'Amore, principal investigator of the study and senior scientist at Schepens.

VEGF is a protein that stimulates the growth of new blood vessels. The eye produces several different forms of VEGF that differ in their size and their ability to move away from the producing cell.

Age-related macular degeneration (AMD) is a disease that destroys the macula, the central part of the retina responsible for detailed vision needed for reading, driving and face recognition. It comes in two types -- "wet" and "dry." In wet AMD, a pathological overproduction of VEGF leads to the development of abnormal blood vessels, which leak and damage the retina. Wet AMD can be treated with some success with anti-VEGF drugs that block abnormal blood vessel growth and leakage. Dry macular degeneration develops less rapidly, and is related to an accumulation of debris under the retina that can advance to GA where RPE and underlying vessels are lost.

Knowing that the RPE in the adult produced VEGF, the Schepens team hypothesized that in a healthy individual ,the RPE produces forms of VEGF that, when secreted, can move away from the RPE and reach the underlying CC to support its function and survival. The CC vessels are extremely important as they supply the photoreceptors (the light- and color-sensitive cells in the macula) with oxygen and nutrients necessary for vision.

In the PNAS study, the researchers tested their hypothesis using a genetic mouse model in which the RPE produced a form of VEGF that was unable to diffuse. As the mice aged, they began to display an age-dependent degeneration of both the CC and RPE, culminating with the death of photoreceptors and vision loss, similar to that observed in GA,.

The next step in the research, according to the first author Dr. Magali Saint-Geniez, is to determine if this model can be used to investigate the role of RPE-CC interaction in AMD and to design new therapies.


Story Source:

The above story is based on materials provided by Schepens Eye Research Institute. Note: Materials may be edited for content and length.


Cite This Page:

Schepens Eye Research Institute. "Lack of VEGF can cause defects similar to dry macular degeneration." ScienceDaily. ScienceDaily, 13 November 2009. <www.sciencedaily.com/releases/2009/11/091102121506.htm>.
Schepens Eye Research Institute. (2009, November 13). Lack of VEGF can cause defects similar to dry macular degeneration. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2009/11/091102121506.htm
Schepens Eye Research Institute. "Lack of VEGF can cause defects similar to dry macular degeneration." ScienceDaily. www.sciencedaily.com/releases/2009/11/091102121506.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com
Tooth Plaque Provides Insight Into Diets Of Ancient People

Tooth Plaque Provides Insight Into Diets Of Ancient People

Newsy (July 19, 2014) Research on plaque from ancient teeth shows that our prehistoric ancestor's had a detailed understanding of plants long before developing agriculture. Video provided by Newsy
Powered by NewsLook.com
Contaminated Water Kills 3 Babies in South African Town

Contaminated Water Kills 3 Babies in South African Town

AFP (July 18, 2014) Contaminated water in South Africa's northwestern town of Bloemhof kills three babies and hospitalises over 500 people. The incident highlights growing fears over water safety in South Africa. Duration: 02:22 Video provided by AFP
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:
from the past week

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