Tooth-enamel protein found in eyes with dry AMD

tooth enamel protein

A protein that normally deposits mineralised calcium in tooth enamel may also be responsible for calcium deposits in the back of the eye in people with dry age-related macular degeneration (AMD), according to a US study. 

This protein, amelotin, may turn out to be a therapeutic target for the blinding disease. 

The findings—by researchers at the National Eye Institute (NEI) in Maryland—are published in the journal Translational Research. NEI is part of the National Institutes of Health.

“Using a simple cell culture model of retinal pigment epithelial cells, we were able to show that amelotin gets turned on by a certain kind of stress and causes formation of a particular kind of calcium deposit also seen in bones and teeth,” senior author of the study Graeme Wistow said.

“When we looked in human donor eyes with dry AMD, we saw the same thing.”

There are two forms of AMD—wet and dry. While there are treatments that can slow the progression of wet AMD, there are currently no treatments for dry AMD, also called geographic atrophy. In dry AMD, deposits of cholesterol, lipids, proteins, and minerals accumulate at the back of the eye. Some of these deposits are called soft drusen and have a specific composition, different from deposits found in wet AMD. 

Recently, researchers found a calcium-containing mineral compound called hydroxyapatite (HAP) in dry AMD deposits. HAP is a key component of tooth enamel and bone. 

“Prior to this study, nobody really knew how the hydroxyapatite was accumulating in the dry AMD drusen,” co-author Dinusha Rajapakse said.

“Finding this tooth-specific protein in the eye, this protein that’s linked to hydroxyapatite deposition—that was really unexpected. Mechanistically, amelotin looks like a key player for the formation of these very specific hydroxyapatite spherules.

“Conceptually, you could see coming up with drugs that specifically block the function of amelotin in eye, and this might delay the progression of the disease,” Rajapakse added. “But we won’t know until we try it.”

Previous articleChronic back pain
Next articleGovernment $10,000 grants to help your business during the pandemic


Please enter your comment!
Please enter your name here