Could new research uncover the cause of age-related macular degeneration?

Written by Hannah Makin

A recent study published in the journal Experimental Eye Research has demonstrated that the accumulation of proteins associated with Alzheimer’s disease may be the cause of age-related macular degeneration (AMD). These new findings, from a team of researchers at the University of Southampton (Southampton, UK), could aid the development of novel treatments against AMD.
AMD is a major cause of vision loss among elderly individuals and can lead to permanent blindness if left untreated. This complex condition is thought to have both environmental and genetic risk factors and affects approximately 50 million individuals worldwide, yet there is currently no cure.

In the past, studies have demonstrated that a group of peptides associated with Alzheimer’s disease neurodegeneration (amyloid beta (Aβ) proteins) accumulate in both aged and AMD retinas.

To investigate these findings further, researchers aimed to uncover the exact mechanisms of this suggested Aβ-mediated damage. Both cell cultures and mouse models were studied to determine how long it took for these proteins to be internalized by neuroretinal cells, and how the resulting damage was caused.

The study demonstrated that the internalisation of these proteins into the retina took as little as 24 hours. After this occurred, it was also observed that these proteins start to disrupt the function of key cell scaffolding proteins in the retina.

One of the researchers in this study, J Arjuna Ratnayaka (University of Southampton), commented on these findings: “The speed in which these proteins entered the retinal cells was unexpected. These findings have given some insights into how a normal healthy retina can switch to a diseased AMD retina. We hope that this could lead to designing better treatments for patients in the future.”

Following these latest findings, the next steps will be to determine exactly how Aβ proteins are internalized by the retina, and ultimately how this process can be targeted in order to prevent AMD.

Sources: Taylor-Walker G, Lynn SA, Keeling A et al. The Alzheimer’s-related amyloid beta peptide is internalised by R28 neuroretinal cells and disrupts the microtubule associated protein 2 (MAP-2). Exp. Eye Res. 153, 110–121 (2016); www.southampton.ac.uk/news/2016/11/alzheimers-retina.page