Gene transferring methods are being used in a different way to treat blinding diseases by activating a type of dormant stem cell within the retina. Researchers from Mount Sinai are focussed on Muller glial retinal stem cells, and have reported they helped blind mice regain some risual function after reprogramming Muller glial retinal stem cells in 2 steps of gene transfer.
Muller glial retinal stem cells act as a source of stem cells part of retinal self repair systems within zebrafish which can proliferate on their own to replenish retinal neurons, mammal MGs lack the self regenerative capability. Scientists can activate MGs to divide in mammals but the process requires injuring the tissue which is counterproductive; now scientists using gene transfers have made MGs divide in mice without having to injure the retina.
Dormant MG cells were stimulated to re-enter the cell cycle by injecting eyes with genes to turn on beta-catenin proteins; eyes were then injected with 3 transcription factors to ensure newly divided cells developed into rod photoreceptors. Scientists found new rod photoreceptors had been generated in the blind mice looking structurally the same as real rods that communicated with other retinal neurons, and had integrated into visual pathway as evidence showed light response signals were being sent from retina to the brain; 4-6 weeks after reprogramming blind mice were able to sense light and regained their vision according to the scientists.
New pathway has been opened to potentially address vision loss and treatment of blinding disease by manipulating the body’s regenerative capability to self repair, by this first step to finding cures involving self repair over medicine or invasive procedures.
Behavioral studies will be conducted to determine if the animals have regained ability to perform visual tasks and there are plans of testing the technique on cultured human retinal tissue. Findings may help researchers develop regenerative therapies for blinding diseases such as age related macular degeneration, retinitis pigmentosa, and possibly glaucoma and others.
