Hidden inner ear cells may hold key to restoring hearing
Baku, July 6, AZERTAC
Researchers at Tel Aviv University have identified a rare population of cells in the inner ear with a natural ability to regenerate sensory hair cells, a discovery that could help pave the way for biological treatments for irreversible hearing loss, TPS-IL reported.
Hearing loss affects more than 1.5 billion people worldwide, including about 430 million people with disabling hearing loss requiring rehabilitation, according to the World Health Organization. Many cases result from irreversible damage to sensory hair cells in the cochlea, the spiral-shaped structure of the inner ear that converts sound vibrations into electrical signals sent to the brain.
While previous research showed that blocking a key cellular signaling pathway could trigger limited hair cell regeneration in animal models, the new study identifies the specific cells capable of responding and the molecular characteristics that give them this regenerative potential.
“The research highlights the nature of cells that can participate in the regeneration process,” Prof. David Sprinzak, one of the study’s authors, told The Press Service of Israel. “Identifying these cells and understanding the mechanisms by which these cells can transform to become new hair cells can potentially guide us to developing treatments that promote hair cell regeneration and restore hearing.”
The research was led by Prof. Karen Avraham, dean of Tel Aviv University’s Gray Faculty of Medical and Health Sciences, and spearheaded by doctoral student Lama Khalaily. It was conducted in collaboration with Sprinzak of the Wise Faculty of Life Sciences, Shahar Kasirer, Dr. Litao Tao of Creighton University in Nebraska and additional researchers.
The cochlea contains sensory hair cells as well as surrounding supporting cells that maintain their function. In mammals, damaged hair cells cannot naturally regenerate, making most forms of hearing loss permanent.
Using live tissue imaging and single-cell multi-omics techniques, which analyze gene activity in individual cells, researchers examined supporting cells after inhibiting the Notch signaling pathway, a cellular communication system involved in development and previously linked to hair cell regeneration.
Rather than responding uniformly, only a rare subset of supporting cells began transforming into hair cells. The researchers identified these as “transdifferentiating Deiters’ cells,” or tDCs, and found they possess distinct genetic and epigenetic characteristics enabling them to respond.
The findings suggest the main obstacle to regeneration is not a complete lack of regenerative ability but that only a small subset of supporting cells is naturally primed to become hair cells.
“Our study shows that even in tissues long considered incapable of regeneration, such as the cochlea of the inner ear, there is in fact a hidden regenerative capacity, though it is very limited and appears only in a rare subpopulation of cells,” Avraham said.
“The major challenge now is to understand how this ability can be expanded and activated in additional cells. If we succeed, we may lay the foundation for innovative biological treatments that restore hearing, rather than merely compensate for its loss.”
Sprinzak cautioned that any clinical application remains years away. “A potential first clinical application will be to improve or restore hearing for people who have lost their hair cells due to trauma or ototoxic treatments,” he said.
He added that researchers are now studying “the genetic and epigenetic nature of regeneration processes, and the impact of potential treatments on regenerative capacity in adults.”
Although the approach remains experimental, Sprinzak said future treatment could involve “a local injection in the cochlea that targets the supporting cells, providing local pharmacological and genetic treatments that promote hair cell regeneration.”
The findings were published in the peer-reviewed journal Science Advances.
Other news in this section
