Researchers discover new tool that may help to reverse hearing loss

A new scientific discovery may some day help millions of people to hear again.

Hearing loss caused by aging, noise and some medications has been irreversible because scientists have not been able to replace specific outer and inner ear sensory cells when they die. But researchers at Northwestern Medicine have identified a single master gene that programs ear hair cells into either outer or inner ones.  

Their work, published in the journal Nature and reported in SciTechDaily, offers hope to people suffering from hearing loss. 

About 15% of American adults suffer from some type of hearing problem, a percentage that worsens as we age. Nearly 25% of adults aged 65 to 74 and 50% who are 75 and older have disabling hearing loss.  

Most hearing loss results from the death of outer hair cells made by the cochlea. These outer hair cells expand and contract in response to pressure from sound waves and amplify sound for the inner hair cells. The inner cells transmit those vibrations to the neurons to create the sounds we hear. 

While scientists can produce an artificial hair cell, they have not found ways to induce it to become an inner or outer cell, each of which provides different essential functions to produce hearing.   

Northwestern scientists found the master gene switch that programs the ear hair cells is TBX2. When it is expressed, the cell becomes an inner hair cell. When blocked, the cell becomes an outer hair cell.  

Jaime García-Añoveros, professor of Anesthesiology, Neurology and Neuroscience at Northwestern and the study’s lead author, said that producing these cells will require a gene cocktail. First, ATOH1 and GF1 are necessary to make a cochlear hair cell from a non-hair cell. Then the TBX2 would be turned on or off to produce the needed inner or outer cell. 

The goal would be to reprogram supporting cells into outer or inner hair cells. These supporting cells are interlaced among the hair cells and provide them with structural support. 

The work being done at Northwestern reflects one of the seven strategies that drive our investments and initiatives: Restock the shelves. This strategy is focused on the need to provide the aging body with the tools needed to rebuild and protect it. In this case, researchers found ways to differentiate ear hair cells, which could lead to restored hearing. 

We believe the seven strategies all play a major role in creating longer, healthier lives. If you’d like to help us achieve our mission, donate.