Hearing loss is one of the most common disabilities in the United States. It can be caused by the effects of aging, genetic mutations, environmental stress, or exposure to drugs such as platinum-based chemotherapy drugs. Researchers have been focusing their attention on several pathways with implications in development and regeneration. Now, researchers from the USC stem cell laboratory of Neil Segil, PhD, have discovered a natural barrier to the regeneration of the inner ear’s sensory cells, which are lost in hearing and balance disorders. Their mouse study may lead to new gene engineering approaches for regenerating the inner ear.
For the first few days of life, lab mice retain an ability for supporting cells to transform into hair cells through the process of transdifferentiation, which allows for regeneration. By one week of age, mice lose this regenerative capacity, and humans probably lose this ability before birth.
“Our study raises the possibility of using therapeutic drugs, gene editing, or other strategies to make epigenetic modifications that tap into the latent regenerative capacity of inner ear cells as a way to restore hearing,” said Segil. “Similar epigenetic modifications may also prove useful in other non-regenerating tissues, such as the retina, kidney, lung, and heart.”