Geneticists from the United States have found another application for the genomic editor CRISPR, using it to remove mutations from stem cells of people suffering from retinal degeneration.
American geneticists have announced the successful completion of experiments in which they "fixed" mutations in genes that cause retinal degeneration and blindness using reprogrammed stem cells and the CRISPR genomic editor, according to an article published in Scientific Reports.
“Our goal is to create a methodology for the personalized fight against eye diseases. We still have a lot to do, but we believe we can be the first to adapt CRISPR to treat congenital diseases. In this work, we have shown that this can in principle be achieved,”said Stephen Tsang of Columbia University in New York, USA.
Tsang and his colleagues have been working for several years to create a gene therapy aimed at treating retinitis pigmentosa, a hereditary disease that leads to destruction of the retina, the death of light-sensitive cells and blindness.
One of the most common forms of retinitis, affecting up to 90% of carriers of this disease, is caused by a single mutation in the RGPR gene, in which there is a "typo" just one "letter" long - a nucleotide.
Tsang and his colleagues propose fighting this type of retinitis by growing stem cells, replacing the wrong version of RGPR, and turning them into retinal cones and rods, which are then inserted into the patient's eye and replace damaged light-sensitive cells.
The authors of the article were able to implement the first step in this therapy - they successfully replaced the damaged RGPR gene without causing damage to other genes surrounding this DNA fragment, and by growing a culture of similar stem cells. This was quite difficult to do, since RGPR contains many repetitive fragments that are present in other regions of the genome and to which CRISPR can mistakenly react.
While scientists have not tried to turn them into cones, rods and other cells of the retina, however, they say that it is quite simple to do this using the appropriate hormones and signaling molecules. In the near future, they will try to do this, and then transplant cells into the eyes of animals suffering from this form of retinitis, and also see if CRISPR / Cas9 can be used to repair other mutations that cause retinal degeneration.
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