It has been known for years that certain fish and lizards have the ability to regenerate their own hearing cells. A recent publication by a team from the Keck School of Medicine at USC (University of Southern California) advances in explaining the mechanism.
In zebrafish (pictured above, confocal microscope image) and certain lizards endowed with these regenerative capacities, the cells supporting the sensory cells have the capacity to respecialize, to replace damaged auditory cells. The researchers wondered how genes usually present in sensory cells could become activated in support cells. They discovered a mechanism, which is triggered after sound trauma or an accident that destroys hearing cells. Substances called DNA “activators” – they intervene during the development of the embryo but only remain present in animals capable of regeneration – trigger the production of a protein (ATOH1), which induces the activation of genes essential for creating sensory cells in the inner ear. “In the future, targeted strategies to open these activators in the human inner ear could be used to stimulate our natural regenerative abilities and reverse deafness”said one of the co-authors of the study.
Long-range Atoh1 enhancers maintain competency for hair cell regeneration in the inner earTuo Shi, Yeeun Kim, Juan Llamas, Xizi Wang, Peter Fabian, Thomas P. Lozito, Neil Segil, Ksenia Gnedeva, J. Gage Crump, Proceedings of the National Academy of Sciences (PNAS).
Photo credit: Daniel Castranova, NICHD/NIH
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