Scientists at the Université de Montréal may have found the answer to restoring vision loss in those suffering from degenerative retinal diseases, such as retinitis pigmentosa (1). Rather than using stem cell therapy, which requires transplantation of independently generated photoreceptors into the patient’s eye, the researchers devised a technique allowing them to circumnavigate the need for transplantation. The novel gene therapy method uses two genes - Ikzf1 and Ikzf4 - that convert dormant glial cells (Müller cells) found in the retina into light-sensing cells that share similar properties to cone photoreceptors. The study found that the technique, while still in its early research stages, helps to replace those light-sensitive cells lost through inherited retinal diseases.
Interestingly, the study authors note that while these Müller cells are already known to help with retinal regeneration in fish (2), they don't usually automatically regenerate in humans after injury or disease. So far, the reasons for this discrepancy between mammals and fish remain unknown.
The research team proposes that this new treatment might unlock the ability to regenerate the retina and restore vision in those patients suffering in the advanced stages of degenerative retinal diseases. They now plan to expand the technique, with the ultimate aim of promoting full maturation of Müller cells into fully functioning, long-term cone photoreceptors.
References
- C Boudreau-Pinsonneault et al., “Direct neuronal reprogramming by temporal identity factors,” PNAS, [Online ahead of print] (2023). PMID: 37126716.
- A Hamon et al., “Müller glial cell-dependent regeneration of the neural retina: An overview across vertebrate model systems,” Developmental Dynamics, 245, 727 (2016). PMID: 26661417.
