Gene therapy could help restore vision lost to degenerative disease
Scientists in Canada have developed a new technique that may one day help restore some sight to patients with inherited vision impairment. The regenerative therapy works by expressing genes that convert dormant cells into new light-sensing cells in the retina to replace those lost to disease.
Genetic diseases such as retinitis pigmentosa occur when the light-sensing cells in the retina begin to degrade. This impairs a patient’s vision over time, often reducing their ability to detect detail and color, creating a 'tunnel vision' effect, and in severe cases can eventually lead to complete blindness.
In a new study, scientists at the University of Montreal have developed a technique that shows promise in reversing vision loss. The team found a way to activate 'dormant' cells in the retina to reprogram them into what are called induced neuron cells, which could then be converted into new light-sensing cells to restore lost vision.
Müller cells are a type of glia that provide structural support for the neurons in the retina. Intriguingly, in fish these Müller cells can also be reactivated to regenerate the retina after it’s damaged by injury or disease, but sadly that’s an ability we mammals lack. The new study screened a series of genes for any that might help unlock this regeneration.
In doing so, the team identified a pair of transcription factors called Ikzf1 and Ikzf4, which can be expressed in Müller cells to convert them into retinal neurons. These could in turn be coaxed to replace key light-sensing cells. Other studies have found promising results doing similar things with other transcription factors.
While it’s still very early days, the team says this research offers new hope for eventually being able to regenerate the retina and restore vision to patients in advanced stages of degenerative diseases. Other gene therapies have shown promise in slowing the progression or preventing disease, or implanting artificial retinas to restore lost vision.
“We may one day be able to take advantage of the cells that are normally present in the retina and stimulate them to regenerate retinal cells lost to pathological conditions and to restore vision,” said Ajay David, co-author of the study.
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: University of Montreal