AMD: a protein responsible for age-related vision loss?

A degenerative disease attacking sight, age-related macular degeneration is responsible for nearly 90% of all vision loss in the elderly. The results of an American study revealed that a protein is involved in the degeneration of vision as well as other age-related pathologies.

AMD: what is age-related macular degeneration?

Age-related macular degeneration (AMD) corresponds to a disease causing the progressive degradation of a part of the retina, called the macula. This is located behind the eye. In the long term, this degradation can lead to loss of central vision. AMD is the leading cause of visual impairment in people over 50. About 20 to 30% of people over the age of 75 are affected.

AMD begins with an early age-related maculopathy phase. It is without degeneration and most of the time it is asymptomatic. However, it happens that some people perceive distortions of straight lines or blurry spots. In short, this phase is characterized by the presence of small whitish deposits inside and around the macula.

In short, the disease can evolve into late degenerative, atrophic or wet forms. They cause irreversible damage to the macula and loss of central vision in one or both eyes.

Vitronectin, the protein responsible for AMD

Led by Professor Francesca Marassi of the Sanford Burnham Prebys Medical Discovery Institute, the study looks at the link between a protein found in the human body and AMD. According to the results of this work published in the Biophysical Journal, vitronectin plays a key role in age-related vision loss. Moreover, the latter would also be involved in the appearance of other pathologies such as Alzheimer’s disease or atherosclerosis.

In order to reach these conclusions, Professor Francesca Marassi – accompanied by a team of researchers, took a closer look at this protein. To do this, scientists needed to know the changes in its structure at many degrees of temperature and under different levels of pressure while approaching the effects produced in the human body.

To determine its function, the researchers needed to determine the structure of vitronectin. The team of scientists therefore carried out a detailed biochemical analysis. Thus, they discovered that the protein can change shape when under pressure. These modifications would allow the protein to bind more easily to calcium ions in the blood which, according to the team of scientists, subsequently leads to the accumulation of calcified plaque deposits (one of the hallmarks of macular degeneration and other age-related diseases).

A possible treatment within a few years

Thanks to this major discovery, the researchers hope to achieve a treatment for macular degeneration. With the help of their partners in the biotech industry, their goal is to design antibodies that selectively block the protein’s calcium binding, without disrupting its other important functions in the body.