Inhibiting microglia activation through gene therapy could prevent cone degenerationPublished: May 2, 2019
Harvard researchers have identified inhibiting microglial activation as a promising approach to prevent retinal degeneration in retinitis pigmentosa.
Retinitis pigmentosa (RP) is a group of inherited retinal degenerative diseases characterized by progressive degeneration of rod photoreceptors leading to night-blindness, followed by the degeneration of cone photoreceptors, resulting in a total loss of vision. With a prevalence of approximately 1 in 3500, it is one of the most common visual impairments worldwide and currently there is no treatment available.
The mechanism behind cone degeneration is still unknown and microglial cells, the immune cells of the central nervous system, were shown to be activated in retinas of RP patients and RP mouse models. Therefore, Dr Constance Cepko and team of Harvard Medical School hypothesized that they would be able to stop cone degeneration by inhibiting microglial activation.
To test this, the team used adeno-associated vectors (AAV) to deliver genes encoding microglial regulatory signals and this led to the identification of soluble CX3CL1 (sCX3CL1) as a promising candidate to target microglia. Injecting AAV8-sCX3CL1 into RP mice retina significantly prolonged cone survival and improved visual function. Rod survival was not affected.
These findings demonstrate gene therapy with sCX3CL1 as a promising approach to maintain vision in retinal degenerative diseases.
Source: Soluble CX3CL1 gene therapy improves cone survival and function in mouse models of retinitis pigmentosa. Wang SK et al., PNAS, April 2019. DOI