From Northwestern University in the United States, hope comes for those who have lost hearing, thanks to the discovery of a “switch” in the DNA that makes it possible to produce the two types of sensory hair cells of the ear.
Until now, hearing loss due to old age, certain anti-cancer therapies and even antibiotics, was considered irreversible because science was unable to synthesize the sensory hair cells of the inner and outer ear – essential for hearing – once they were dead.
The gene discovered in mice is called TBX2 and, depending on whether it is on or off, allows the development of hair cells in both the inner ear and the outer ear (the most vulnerable). The research result is published in the journal Nature.
“We have discovered a switch that was not known before, it is the first tool we have at our disposal to cultivate these two types of cells (which do not divide). We have overcome a huge obstacle,” he explained. Jaime Garcia-Yoveros, study author, Northwestern University professor of Anesthesiology and Neuroscience. It is currently possible to produce an artificial hair cell (from stem or other ear cells) but it is not known how to differentiate between internal and external.
How the switch works
The researchers found that when TBX2 is “turned on” a common cell can become an internal hair cell, while when the gene is blocked, the cell produced is the external one. “To arrive at the synthesis of the different cells we will first need a cocktail of genes capable of transforming a non-hair cell into a hair cell; then TBX2 will be switched on or off as needed”. The research, García-Añoveros points out, is still in its experimental phase but is very promising.
“A coordinated ballet”
It is the death of external cells that causes hearing loss and deafness. The outer cells expand and contract in response to the pressure of the sound waves and amplify the sound for the inner cells, which transmit these vibrations to the neurons to create the noises and sounds we hear.
“It is like a coordinated ballet between the two types of cells – continues the scientist – Hearing is a beautiful organ, there are no other organs in mammals in which the cells are positioned so precisely with respect to each other. If this ballet gets stuck, hearing is compromised “.
World Hearing Day: Taking care of hearing is good for the mind
February 28, 2022
The hearing of Italians worsens
According to Censis, about 12% of the Italian population has hearing problems, that is 7 million people (of which 50% among the over 80). But hearing loss also increases among young people, often due to exposure to excessive noise sources, such as headphone music. Worldwide, 1.5 billion people are feeling unwell and it will become 2.5 billion by 2050.
Hearing day, guys turn the volume down. A few decibels are enough to risk
by Viola Rita
01 April 2022
