Gene therapy restores vision lost due to degenerative diseases

In a study published earlier this month in the Proceedings of the National Academy of Sciences, scientists at the University of Montreal in Canada report a promising new technique for reversing vision loss in patients with hereditary visual impairment.

Therapy is based on expression. genes that transform dormant cells into new light-sensitive units in the retina. The degradation of these light-sensitive cells, which occurs in certain genetic diseases such as retinitis pigmentosa, is caused by certain genetic mutations that directly affect the production of certain key proteins for retinal function.

The result is a long-term vision loss for the patient due to loss of the ability to perceive colors (dyschromatopsia) and reduced peripheral vision (tunnel effect). Up to total blindness in more severe cases.

How does gene therapy that restores vision work?

To test your theories, researchers focused their research on so-called Müller cells, a form of glia (nervous system units) that provide structural support for neurons in the retina. Although these neuroglia can regenerate naturally in fish, mammals do not.

While the study’s first author, Camille Boudreau-Pinsonnault, examined a set of DNA sequences capable of resolving this regeneration in humans, “We identified two genes that, when expressed in these inactive cells, called Müller cells, can turn them into neurons of the retina”: Ikzf1 and Ikzf4.

The screening test for Müller glial reprogramming factors shows that the combined expression of the Ikzf1 and Ikzf4 genes “reprogram mouse embryonic fibroblasts into culture-derived neuronsIt rapidly remodels chromatin and activates a neuronal gene expression program,” says the study.

What are the effects of the new gene therapy?

While some current approaches, such as gene therapy, offer some hope for slowing or blocking the loss of photoreceptor cells in the retina, the proposed treatment breaks new ground. suggesting the restoration of already lost cellsIt can be especially useful for patients in advanced stages of degenerative disease.

Encouraged by the success of the study, the scientists now plan to improve the technique and develop a way to achieve full maturation of cells in cone photoreceptors (retinal cells) in order to restore vision with “normally present” cells. present in the retina,” says study co-author Ajay David.