Exploring potential new drug treatments for age-related macular degeneration and diabetic retinopathy

Why is this research needed?

Age-related macular degeneration (AMD) and diabetic retinopathy are eye diseases that cause the death of nerves in the retina, the part of the eye which senses light. When the nerves in the retina die, they can no longer sense light, which in turn leads to loss of vision.

AMD is the leading cause of vision loss in the UK, affecting more than 700,000 people. Diabetic retinopathy is the most common cause of sight loss in people suffering from diabetes, and the leading cause of visual impairment and blindness in working-age people. Currently, there is no cure for either disease.

One factor that both diseases have in common is inflammation, a normal response of the body to injury. During inflammation, cells release chemical signals that help the body to recognise that there is problem. After time, this signalling stops and healing begins.

In AMD and diabetic retinopathy, however, the inflammatory signals are not switched off. One particular signal, adenosine triphosphate (ATP), is recognised by molecules on the cell surface called P2X7 receptors, causing them to open holes, or channels, in the cell membrane. The continued presence of ATP means that P2X7 receptors stay switched on and the channels stay open in the cell surface, allowing calcium to enter the cell, where it activates processes that can lead to cell death.

Previous research has shown that over-activation of the P2X7 receptor has been directly linked to the death of retinal pigment epithelial (RPE) cells that support photoreceptor cells (which sense light), and retinal ganglion cells, which process the light signal.

What is the aim of the project?

Dr Young’s project aims to determine whether blocking P2X7 receptors will help to prevent cell death, and consequently stop the vision loss experienced by people suffering from AMD or diabetic retinopathy. His team will design and test new small molecules to identify those that are most successful at blocking P2X7. They will also create a disease model of AMD, using specially cultured retinal pigment epithelial cells, to further understand the role of P2X7 in the activation and progression of age-related macular degeneration.

How will this research help to beat sight loss faster?

If Dr Young’s team is successful in identifying a molecule that can block P2X7 receptors on retinal cells, this would enable the team to bid for the larger grants needed to scale up their experiments, allowing them to take the next important step in the process of drug development before ultimately progressing to clinical trials in humans.

Thank you

In 2017, Sight Research UK launched a special appeal in support of Dr Young’s project. His research is being made possible thanks to the generosity of our community of donors. In particular, we would like to thank the Payne-Gallwey Charitable Trust, the Carr-Gregory Trust, the Tula Trust, the Tilehouse Trust, and the Marshall & Viggars Charitable Trust for their significant contributions. We are also deeply grateful to all our individual supporters, whose donations large and small have contributed to fund the development of this research.

Further information

You can find more about the causes and symptoms of AMD and diabetic retinopathy.