Blind Man’s Vision Partially Recovered With Optogenetic Gene Therapy

 

Image Credit: Natali_Mis, et al. “Natali_Mis/Istockphoto.” DallasInnovates.com, Dallas Innovates, 22 June 2021, dallasinnovates.com/bedford-biotech-restores-meaningful-vision-in-blind-patients-with-gene-therapy-and-may-soon-go-public/.

Researchers found with a particular type of gene-based therapy, a man with retinitis pigmentosa gained limited vision. Retinitis pigmentosa is a genetic disease that causes the death of light-gathering cells in the retina of the eyes. The fifty-eight-year-old man was treated with optogenetic therapy, which utilizes a protein sensitive to light and forces the nerve cells to fire off signals when they are struck with a particular light wavelength. Optogenetic therapy is different from conventional gene therapies, which can help to either stop or slow the progression of degenerative eye diseases but do not help those who have already gone blind. 

The researchers, Sahel, Roska, and other team members, used a light protein sensitive to amber light for their clinical trial. The team then used an adeno-associated virus to insert the instructions for making the protein into the ganglion nerve cell layer, which fires messages to the visual parts of the brain. After this treatment, the man was given a pair of goggles that produced amber light pulses to his eyes. With these goggles and the treatment, the man was able to identify objects and count them compared to before the treatment, where he was unable to identify motion or objects. The study team emphasizes that the man needs the goggles to see still as the pulses produced by the goggles make the nerve cells fire off and therefore enables the man to see. While there is only one patient who has shown improvement so far, this progress lays down the foundation for more research on the treatment of degenerative eye diseases. It will help to guide scientists to even better results in the future.

Article Credit: https://www.sciencenews.org/article/blindness-retinitis-pigmentosa-gene-therapy-vision-optogenetics

Link to study: https://www.nature.com/articles/s41591-021-01351-4

The Holy Grail of DNA, HITI

Adult body cells in tissues cannot divide. With this, DNA does not change or develop especially DNA found in the heart, brain and liver. Scientists have discovered a way to enter the cell and modify the DNA to prevent previously incurable diseases. The technique, known as HITI, was based on the famous CRISPR gene-editing technique. With this, they can insert DNA at a target location into the non-dividing cells that make up the majority of adult organs and tissues.

 The researchers used the technique on rats born with a genetic disease called retinitis pigmentosa, which affects about one in 4,000 people in the UK. Researchers are now using this mechanism to correct gene defects. Clinical trials are a long way off because the CRISPR proteins may cut DNA at other sites that may have untoward effects.'

http://www.independent.co.uk/news/science/gene-editing-breakthrough-fix-broken-genes-delay-ageing-cure-incurable-diseases-a7421596.html

https://www.thesun.co.uk/living/2205506/what-is-dna-editing-and-how-could-fixing-broken-genes-make-us-live-longer/

Breakthrough Genome Editing Technique for Nondividing Cells

A new genome editing technique called HITI has been developed. It combines the CRISPR-Cas9 genome editing tool with the ability to now target nondividing cells. The CRISPR method targets dividing cells, such as those found in the skin or gut. Until now, however, researchers struggled to use CRISPR on nondividing cells, which accounts for the majority of adult organs and tissues. Nondividing cells are found in the eye, brain, pancreas, heart, liver and numerous other organs. According to the study published in the journal Nature, this new method is 10 times more efficient on dividing cells and can modify nondividing cells.

“The new Salk technology is ten times more efficient than other methods at incorporating new DNA into cultures of dividing cells, making it a promising tool for both research and medicine. But, more importantly, the Salk technique represents the first time scientists have managed to insert a new gene into a precise DNA location in adult cells that no longer divide, such as those of the eye, brain, pancreas or heart, offering new possibilities for therapeutic applications in these cells.”-Salk News release.

In order to insert genes into nondividing cells, the researchers from Salk Institute targeted a natural repair pathway in cells called NHEJ (non-homologous end-joining) that re-joins strands of broken DNA and paired the process with existing gene-editing technology to swap out a section of DNA in the eyes of rats affected by retinitis pigmentosa. In humans, the condition is also a heritable disease that causes progressive retinal degeneration, and in those with retinitis pigmentosa, one of the genes that is damaged is called Mertk. The HITI gene-editing technique replaced the defunct Mertk gene with a functional copy, and after five weeks, the rats’ vision improved and some of their retinal cells were healed too.

If you want to learn more about the science behind their new CRISPR genome editing technology, check out the Salk news release, or you can also watch this short three minute youtube video made by the Salk Institute about the study.

This new gene-editing technique is remarkable, considering it hasn't been done before. It’s likely this new gene-editing technique can provide new avenues of research for various conditions, including retinal, heart, and even neurological diseases. It can pave the way to revolutionary new treatments that can alter DNA of damaged essential organs for which cells seldom divide, such as heart and brain cells. HITI could possibly replace CRISPR and change the genomics game.  HITI has huge potential for various useful applications, and I'm sure we'll keep hearing more about it in the near future.