Researchers from the United Kingdom and the United States used gene-edited sheep to develop a promising drug treatment for a fatal brain disorder affecting children known as "infantile Batten disease," reports recently revealed.
As specified in an Interesting Engineering report, children affected by the said disease are burdened by a series of symptoms, including "loss of vision, impaired cognition, and mobility problems."
Worse, seizures and early death can occur in the disease's later stages. According to Professor Jonathan Cooper, from Washington University of Medicine in St. Louis, one of the project's leaders, the impact on families "is devastating."
The work started as a collaboration with researchers at Collaborations Pharmaceuticals, which had discovered that mice affected by one form of Batten disease called CLN1 could be cured with a missing enzyme.
The CRISPR-Cas9 Technique
Another project leader, Professor Tom Wishart, from Edinburgh University's Roslin Institute, where Dolly the Sheep was cloned in 1996, said that was encouraging, although there was a need to test the treatment in more massive brains that have structure more like of a child.
The professor also said that one could not extrapolate straight from mouse studies to humans. He added having an intermediate bigger model is essential.
The study investigators used the gene-editing technique called CRISPR-Cas9, described in a ScienceDirect report, to produce a version of the gene that results in CLN1 in sheep.
The disease has no cure.https://t.co/QBWG4HwrgF
— Interesting Engineering (@IntEngineering) October 10, 2022
Describing the method, Wishart explained that sheep ovaries were collected from abattoirs, and eggs were taken out and fertilized.
'Symptomless' Carriers
CRISPR reagents were added to produce the required changes in CLN1, and the eggs were then implanted into surrogate sheep, explained the project leader.
Now, the team has a group of sheep that carry the faulty gene. Such symptomless carriers like the Batten disease children's parents, Wishart said.
From there, he added, they could breed sheep with two faulty copies. These continued developing diseases like those children and turned out to be the subjects of the treatment trials.
Batten disease devastates children as they miss an enzyme produced by healthy CLN1 genes. This causes the lysosomes of the bodies, the parts responsible for recycling waste that builds up in cells, to malfunction.
Unsafe for Human Trials
The experiment in mice discovered that simply injecting the missing enzyme into the brain of these animals significantly improved their condition. Nonetheless, it was still unsafe to move to human trials.
According to Cooper, two crucial issues can be missed. These issues include the manner of delivery of the drug to the right place in a bigger brain "and how to scale up dosing," a similar Citswarangal.com report said.
That is the reason researchers needed to repeat the experiment with sheep. Using the animals, the scientists could approximate an appropriate dose and the route for its delivery to the sheep's brains, which were bigger than mice's brains and closer to that of humans.
The study published in the Journal of Clinical Investigation showed clear improvements in the sheep that suffered from the disease. Nonetheless, the study investigators insist that more years of research are still needed to optimize the treatment and guarantee its safety and viability.
Related information about how gene editing is curing diseases is shown on Real Science's YouTube video below:
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