New gene-editing technique reverses vision loss

Researchers in China have successfully restored the vision of mice with retinitis pigmentosa, one of the major causes of blindness in humans. The study, that was published in the Journal of Experimental Medicine, uses a new, highly versatile form of CRISPR-based genome editing with the potential to correct a wide variety of disease-causing genetic mutations.

Retinitis pigmentosa can be caused by mutations in over 100 different genes and is estimated to impair the vision of 1 in 4,000 people. It begins with the dysfunction and death of dim light-sensing rod cells, before spreading to the cone cells required for color vision, eventually leading to severe, irreversible vision loss.

The researchers attempted to rescue the vision of mice with retinitis pigmentosa caused by a mutation in the gene encoding a critical enzyme called PDE6β. To do this, the team developed a new, more versatile CRISPR system called PESpRY, which can be programmed to correct many different types of genetic mutation, regardless of where they occur within the genome.

When programmed to target the mutant PDE6β gene, the PESpRY system was able to efficiently correct the mutation and restore the enzyme’s activity in the retinas of mice. This prevented the death of rod and cone photoreceptors and restored their normal electrical responses to light.

Hence, the authors concluded that the study provides substantial evidence for the in vivo applicability of this new genome-editing strategy and its potential in diverse research and therapeutic contexts, in particular for inherited retinal diseases such as retinitis pigmentosa.

Reference:

New gene-editing technique reverses vision loss in mice; Journal of Experimental Medicine, DOI: 10.1084/jem.20220776