Study could help fix eye conditions

By By Deborah Rafferty

By Deborah Rafferty

A new international study could eventually provide medications for diseases caused by leaky blood vessels, such as age-related macular degeneration and diabetes-related damage to the retina, known as retinopathy.

In the study led by Dean Li, professor of the internal medicine and director of molecular medicine program at the U School of Medicine, along with the University of California San Diego and the University of Bonn, Germany, researchers identified a drug-like compound that could strengthen the blood vessels to prevent leaking. The study was published Oct. 25 in Nature Cell Biology’s online edition and will be published in the journal in November.

“The central issue is these are major causes of significant blindness in developed countries,” Li said. “Essentially, our study is trying to understand how to keep blood vessels from leaking.”

In AMD and diabetic retinopathy, genetic defects do not directly affect the structure of the blood vessels in the eye, Li said. However, those genetic defects have been identified as the source of inflammation, which in turn cause the blood vessel to become weaker and leak. When the blood vessels in the eye leak, the retina becomes soggy, distorting the vision. With the possibility of a new drug, the effects from these diseases could be reversed, Li said.

The study focused on pathways in the eye that affect the stability of blood vessels. Researchers were able to manipulate certain genes related to the cause of weak blood vessels in mouse models. The drug-like compound they developed would be able to trick cells that receptors have activated, which leads to stronger vessels, Li said.

This drug would be easier to develop than manipulating the genes themselves and provides proof of concept that the process is understood well enough that it could be made into a drug for humans, Li said.

“There is the hope that we can do the same thing in humans,” Li said. “This opens up the possibility of new ways of making medicines that haven’t really been tried.”

Although this drug-like compound has worked in animals, it is far from ready to distribute to humans, Li said.

The National Institutes of Heath, Juvenile Diabetes Resource Fund, the Department of Defense, and the American Heart Association funded the research.

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