Using RNA base editing techniques, scientists have successfully reversed a genetic form of hearing loss in a mouse model.
The study, published in Science Translational Medicine, proposed that treatment could be administered easily via injections into the cochlea.
Researchers from Fudan University found that this approach safeguarded hair cells essential to hearing and improved auditory function for as long as 3 months after treatment.
Benefits of RNA base editing
The results offer a proof-of-concept that RNA base editing tools could be developed into therapies for inherited hearing loss and potentially other genetic conditions. Unlike DNA editing approaches such as CRISPR, which can cause unintended and permanent changes in genes, RNA editing causes only transient and reversible changes.
Scientists are currently developing RNA-targeting tools as potentially safer alternatives to gene editing, or as complementary tools for use in concert with other techniques, but whether these tools can directly treat genetic conditions has remained largely unexplored.
Treating inherited deafness
The mouse represents an excellent model system for the study of genetic deafness in humans. Many mouse deafness mutants have been identified and the anatomy of the mouse and human ear is similar. Mutations in the unconventional myosin VI gene, Myo6, are associated with deafness and vestibular dysfunction in the Snell’s waltzer mouse. The corresponding human gene, MYO6, is located on chromosome 6q13.
The team applied RNA base editing tools to try to correct hearing loss in a Myo6-mutated mouse model of human inherited deafness.
Screening several base editing tools related to CRISPR, the team found that one tool called mxABE showed both efficient editing of RNA and a low likelihood of unintended edits.
When injected into the cochlea via a viral vector, the treatment resulted in the correction of the mutant Myo6 RNA, slowed the degeneration of sound-sensing hair cells, and improved the rodents’ hearing capabilities for as long as 3 months.
However, the authors caution that more work is needed to improve the editing efficiency of the technique and to further evaluate its safety in longer trials.
Written by Poppy Jayne Morgan, Front Line Genomics
Image Credit: Canva