Deaf mice regained their hearing with gene therapy
A gene therapy delivery method has been created to treat congenital deafness in adult mice. Researchers believe the method will be suitable for humans as well.An international team of researchers has demonstrated the possibility of treating congenital deafness in mice with gene therapy. The drug, injected into the cerebrospinal fluid, penetrates the inner ear and restores hair cell function.
Previous studies have shown that gene therapy can restore hearing in newborn mice. The difficulty with adults is that the inner ear is closed by the temporal bone with age and injecting the drug in the same way is fraught with the risk of damage. Geneticists have found an alternative way to deliver the drug.
They used the connection that exists between the inner ear fluid and the cerebrospinal fluid. They used computer design to build a model that shows how fluid from other parts of the brain gets into the inner ear and chose a target for treatment.
The geneticists injected adenoviruses carrying the drug's dissolved active ingredient into a large reservoir of cerebrospinal fluid located at the base of the skull. Moving through the channels, the viruses reached the inner ear and activated genes that express the vesicular glutamate transporter protein 3, which is essential for hair cells.
The study showed that the mice gradually recovered their hearing after the therapy, with the researchers recording minimal expression of the activated gene in other parts of the brain and its absence in the liver. This means that most of the therapy reached its goal and had no significant effect on other systems. The researchers believe that a similar method, if proven safe, could be used to treat congenital genetically induced deafness in adults as well.