Scientists have alleviated the symptoms of muscular dystrophy in mice with the help of a gene processing tool.
Muscular dystrophy is a crippling hereditary disorder that is caused by mutations in the genes and weakens muscle fibers.
Researchers used CRISPR to change the genomes of mice with muscular dystrophy and to stimulate the expression of certain genes.
This gave the mice crucial instructions that were missing, preventing them from getting the characteristic muscle wastage and paralysis.
Charities said that although a "cure" has not been discovered and human testing is needed, the findings offer a glimmer of hope to people with muscular dystrophy.
Scientists in Canada have alleviated the symptoms of muscular dystrophy in mice with a gene processing tool (stock photo of DNA)
Muscle-wasting disorders such as muscular dystrophy affect 70,000 people in the UK. Most diagnoses are in children and the symptoms get worse over time.
The researchers from the Program in Genetics and Genome Biology, the Hospital for Sick Children Research Institute, Canada, only looked at a subtype of muscular dystrophy, congenital muscular dystrophy type 1A (MDC1A).
Of the 10,000 people in the UK who have some form of muscular dystrophy, around 400 are thought to have congenital muscular dystrophy
People with MDC1A usually have a reduced muscle tension, which means that they cannot walk without help.
This condition is believed to be the most common type of congenital muscular dystrophy, accounting for 30 to 40 percent of all cases.
They can also get epileptic seizures and have difficulty breathing, feeding, arriving and generally growing.
HOW DOES CRISPR DNA PROCESSING WORK?
The CRISPR gene processing technique is increasingly used in health research because it can change the building blocks of the body.
At a basic level, CRISPR works as a process for cutting and pasting DNA.
Called technically CRISPR-Cas9, the process involves sending new DNA strands and enzymes to organisms to process their genes.
In humans, genes act as blueprints for many processes and traits in the body – they dictate everything from the color of your eyes and hair to whether or not you have cancer.
The components of CRISPR-Cas9 – the DNA sequence and the enzymes needed to implant it – are often sent into the body via a harmless virus, so scientists can determine where they are going.
Cas9 enzymes can then cut DNA strands, effectively disable a gene, or remove portions of DNA that need to be replaced by the CRISPR's. These are new parts that are submitted to change the gene and the effect of which is preprogrammed to produce.
But the process is controversial because it can be used to change babies & # 39; s in the womb – initially to treat diseases – but can lead to an increase in & # 39; designer baby & # 39; s & # 39; because doctors offer ways to change the DNA of embryos.
Source: Broad institute
MDC1A is caused by mutations in the Lama2 gene, which helps the body produce a range of proteins, including laminin-α2, needed for muscle strength.
Rodent studies have shown that the expression of a related gene, Lama1, which is linked to a similar protein, laminin-α1, can help alleviate symptoms in mice with the disease.
However, researchers have made an effort to target the gene with standard therapy methods. That is why Dr. Ronald Cohn and his colleague & # 39; s tried CRISPR.
CRISPR gene processing works like a & # 39; molecular scissors & # 39 ;, allowing scientists to enter the DNA of an organism and change, edit, or delete parts.
They focused on the Lama1 gene by introducing an enzyme into the DNA, which increased the expression of the laminin α1.
The researchers published their findings in the journal Nature and discovered that it significantly reduced the clinical symptoms of the disease in mice.
The authors propose that in the future it might be possible to treat muscular dystrophy and other genetic disorders by setting up protective genes & # 39; and harmful genes & # 39; reject & # 39 ;.
Professor Dominic Wells, translational medicine at Royal Veterinary College, said: "The study by Kemaladewi and colleagues is an elegant demonstration in mice of the potential to regulate a compensation gene to treat muscular dystrophy.
"This serves as a proof of concept for the further development of this approach to therapy for patients with congenital muscular dystrophy type 1A (MDC1A) and possibly other muscular dystrophys."
The CRISPR method used is considered safer because instead of breaking the DNA for the desired results, it is only processed.
However, there are still risks that have not been investigated and the strategies used have potential to induce gene expression in other areas.
Dr. Alena Pance, senior scientist at Wellcome Trust Sanger Institute, said: "Enable & # 39; enable & # 39; of the modification gene must take place in specific tissues – in the case of muscular dystrophy, in skeletal muscles and sciatic nerves.
& # 39; But the work does not investigate its expression in other tissues in the mouse, where expression of this gene may be undesirable.
"The most important advance of this approach is the potential to treat complex diseases that are caused by multiple mutations, perhaps even with different genes.
"Instead of trying to repair all defects, an activation gene can overcome the pathology of the disease if a modification gene can be found, as shown in this study.
& # 39; In addition, diseases that escape all treatment options nowadays can finally have a glimmer of hope. & # 39;
The charity Muscular Dystrophy UK said it was an "exciting" investigation.
Dr. Kate Adcock, director of research and innovation, said: "It must give hope to people with congenital muscular dystrophy type 1A and their families.
"Targeting disease-modifying genes in this way can benefit a wider range of patients because the technique is not dependent on an individual mutation.
"We are encouraged that the technique does not seem to cause unwanted gene processing, but there is still a way to go before treatment is brought to the clinic. The next step will be to replicate the study in other animal models before we extend the study to humans.
"This may not be a cure, but it is a step in the right direction to find a treatment for congenital muscular dystrophy type 1A."
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