A new research has brought optimism regarding the potential of regenerative hearing treatments curing traditionally irreversible deafness someday. The inner ear’s non-regenerating sensory hearing cells are a key factor in hearing loss, but this new research offers potential for future medical advancements in treating deafness.
Epigenetic silencing deactivates genes for sensory cells development
In recent research, partially supported by the National Institutes of Health, experts from the University of Southern California’s stem cell department elucidate the intricacy of our fragile auditory sense. Additionally, they propose the potential for novel hearing remedies through the application of these specialized cells.
First study author of one of the papers John Duc Nguyen said the inner ear’s non-sensory supporting cells undergo ‘epigenetic silencing’, deactivating essential genes for sensory cell transformation. Nguyen added that researching this silencing process could provide insights into reactivating these genes, potentially leading to hearing regeneration.
A second study investigated the development of sensory hearing cells in the inner ear, focusing on the timing and process of their formation. The study identified and discussed two specific genes with potential for regenerating adult hearing.
Xizi Wong said that researchers focused on Sox11 and Sox4 since they established that they are necessary for sensory hearing cells formation during development.
Co-author Gage Crump, who also chairs USC’s Department of Stem Cell Biology said that the papers highlight Neil Segil’s lasting impact as a mentor to young stem cell researchers.
Gene silencing involves methyl groups attaching to DNA
The process of gene silencing involves methyl groups binding to DNA, rendering it inaccessible. Nguyen’s paper explores this method, wherein methylated DNA prevents cells from utilizing instructions, such as those directing the development of sensory hearing cells.
Researchers, led by Nguyen, utilized non-sensory supporting cells from mice’s inner ears in experiments. They validated DNA methylation’s role in suppressing genes that encourage transformation into sensory hearing cells. Notably, the gene Atoh1, a key inner ear development regulator, was confirmed to be affected by this process. An enzyme called TET can reverse gene silencing by removing methyl groups from DNA. This restores the ability of supporting cells to transform into sensory hair cells.
