‘We have overcome a major hurdle’ to restore hearing, investigators say.
- Gene discovery allows the production of inner or outer ear hair cells
- Death of outer hair cells due to aging or noise cause most hearing loss
- Master gene switch turns on ear hair cell development
Hearing loss caused by aging, noise, and some cancer therapy medications and antibiotics has been irreversible because scientists have not been able to reprogram existing cells to develop into the outer and inner ear sensory cells — essential for hearing — once they die.
But Northwestern Medicine scientists have discovered a single master gene that programs ear hair cells into either outer or inner ones, overcoming a major hurdle that had previously prevented the development of these cells to restore hearing, according to new research published today (May 4, 2022) in the journal Nature.
“Our finding gives us the first clear cell switch to make one type versus the other,” said lead study author Jaime García-Añoveros, PhD, professor of Anesthesiology and Neuroscience and in the Ken and Ruth Davee Department of Neurology. “It will provide a previously unavailable tool to make an inner or outer hair cell. We have overcome a major hurdle.”
About 8.5% of adults aged 55 to 64 in the U.S. have disabling hearing loss. That increases to nearly 25% of those aged 65 to 74 and 50% of those who are 75 and older, reports the Centers for Disease Control (CDC).
Currently, scientists can produce an artificial hair cell, but it does not differentiate into an inner or outer cell, each of which provides different essential functions to produce hearing. The discovery is a major step toward developing these specific cells.
‘It’s like a ballet’ as cells crouch and leap
The death of outer hair cells made by the cochlea is most often the cause of deafness and hearing loss. The cells develop in the embryo and do not reproduce. The outer hair cells expand and contract in response to the 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.
“It’s like a ballet, ”García-Añoveros says with awe as he describes the coordinated movement of the inner and outer cells. “The outers crouch and jump and lift the inners further into the ear. The ear is a beautiful organ. There is no other organ in a mammal where the cells are so precisely positioned. (I mean, with micrometric precision). Otherwise, hearing doesn’t occur.”
The master gene switch Northwestern scientists discovered that programs the ear hair cells is TBX2. When the gene is expressed, the cell becomes an inner hair cell. When the gene is blocked, the cell becomes an outer hair cell. The ability to produce one of these cells will require a gene cocktail, García-Añoveros said. The ATOH1 and GF1 genes are needed 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, which are latticed among the hair cells and provide them with structural support, into outer or inner hair cells.
“We can now figure out how to make specifically inner or outer hair cells and identify why the latter are more prone to dying and cause deafness, ”García-Añoveros said. He stressed this research is still in the experimental stage.
Reference: “Tbx2 is a master regulator of inner versus outer hair cell differentiation” by Jaime García-Añoveros, John C. Clancy, Chuan Zhi Foo, Ignacio García-Gómez, Yingjie Zhou, Kazuaki Homma, Mary Ann Cheatham and Anne Duggan, 4 May 2022, Nature.
Other Northwestern authors include co-lead author Anne Duggan, PhD, research assistant professor of Anesthesiology; John C. Clancy, research technician in the García-Añoveros and Duggan laboratory; Chuan Zhi Foo, a graduate student in the Driskill Graduate Program in Life Sciences (DGP); Ignacio García Gómez, PhD, research assistant professor of Anesthesiology; Yingji Zhou, PhD, research assistant professor of Neurology; Kazuaki Homma, PhD, assistant professor of Otolaryngology – Head and Neck Surgery; and Mary Ann Cheatham, PhD, research professor of Communications in the Weinberg College of Arts and Sciences.
The study was funded by the National Institute of Deafness and other Communications Disorders grants R01 DC015903 and R01 DC019834.
I was born without the hairs in my left ear to catch sound particles, would I be a candidate for this new treatment
Is there a clinical trial yet? I want to be in this trial.
I would like to have this done I have been unable to hear well all my life I am 70 years old
How do I sign up? Got a air bone gap
I have 78% hearing loss in my left ear due to some kind of infection. I would love to have it restored.
Will it help if you keep getting ear infections and are not able to wear hearing aid? If trials are still in progress, please let know. Willing to participate!
Are cochlear implantees eligible for this treatment?
Yes, i would like to be it trial
I have hearing loss and tinnitus from working around tools my whole life would like to be in your trial treatment please
Would like to volunteer for trial. I have tinnitus and decreased hearing in left ear.
Bilateral severe hearing loss; aids less effective, words/conversation decreasing,Tinnitus (2 separate sounds) and musical ear syndrome. Would love addn’l info and to join any clinical trials applicable to my issues. Very exciting research!
I have pulsatile and regular tinnitus as well as severe hearing loss in one ear especially. I could live with either deafness or tinnitus but it is really difficult to have both. I would love to be able to hear what my grandchildren are saying.
What I forgot to mention is I’d like to be considered for clinical trials.
Please consider me in a trial if possible. Rried hearing aids without any success! Thanks.
Sign me up
I would be very interested in a clinical trial I currently have hearing aids but these are nowhere as good as my original hears God gave me
When can I sign up for a trial? Age 73
This would be so wonderful.I would love to participate in clinical trials.
I need to be Involved in the program It sounds interesting
I am retired military, and both myself and my husband would love to participate in the clinucal trials!!
How can I get involved with a trial?
Hi I would like if you can provide me more information on this study. I am profoundly deaf in both ears. And would like to know how I can become a part of this study. Thank you Patricia
I have hearing loss and tinnitus and would very much like to participate in a clinical trial.
I am ex army and have severe sensorineural hearing loss in both ears since over 20 years. Am 73 today. Can I be part of your trials? I live in India and am healthy otherwise.
Born without hairs in ears. Left is gone right is about half. Told aids wouldn’t work. Told surgical implants of nerves is 50/50. Hopeful for a cure.
Interested in clinical trial
I’d like to participate. Please send me info! I have 40% loss in one ear, 30% in other, constant tinnitus. Sometimes severe. [email protected]
I have a somewhat different problem that is probably just described differently.
My problem is mostly with inteligibility.I recently started wearing aids, and they increase level ok, but not intelegibility.This has been progressive for a long time.
I am 84, and am used to noise, and don’t have a problem in a quiet environment , or much of a problem with people that enunciate clearly and at moderate speed,at all.
The aids are equalized to take out a lot of the low freq stuff, and expand the mid range, but they sound like i’m always wearing ear plugs.
I suffer from tinnitus and some hearing loss. I would like to participate in a clinical trial.
I am 70 years old and have hearing loss in both ears and tinnitus. I would like to participate in any clinical trials.
I would like to be considered for a trial for hearing loss.
I have severe hearing loss and tinnitus from my job and other foolish things From my youth. Would be cery intrested in these trials
Please signed me up for this program
I would like to be in a trail.
My husband has profound hearing loss. How can he participate in the trails.Where and who can I reach out to get more information.
I had a TORP procedure a still have Tinnitis. Will this procedure help restore my hearing?
I need this badly!
Got cochlear implant on my right ear unfortunately didn’t
Work and can’t go back to HA and got HA on my left ear
I’m ready when you are!!!!
Sounds great. Would like to be a trial candidate.
I have hearing loss in my left ear and a constant ringing please consider me in your trial
I have a hearing loss in my left ear.Started in my 40’s I am seventy five.I would like more information about this treatment.
I am 85. Even with hearing aids, all voices resonate and thus sound like Donald Duck. I also would like to be considered for a trial. Thus far, no comments have been related to if and when there is a trial.
Amazing discoveries like this are when I wonder if there are payoffs to squelch them as big money health care revenues would go down the tubes.
I just turned 70 and I have moderate hearing loss. I would like to volunteer for a clinical trial.
I have recently received a cochlear implant in my left ear due to deafness and have moderate hearing loss in my right ear helped with a hearing aid. I also have tinnitus in both ears as well as musical ear syndrome that developed in the implant ear. While l I am very grateful for the hearing that I do have, this breakthrough is amazing. As others have stated, I too would be so grateful for the opportunity to be involved in a clinical trial like this. What a blessing to regain lost hearing. Thank you so much for your hard work and ongoing efforts to make our lives so much better.
This research done by the Northwestern team is extraordinary; it gives one hope. I have moderate to severe hearing loss in both ears, plus tinnitus, and would love to participate in a clinical trial.
After being exposed to loud noise (intermittently for 18 months I developed tinnitus. After 2 and a half months of tinnitus I experienced “sudden hearing loss” in my left ear. My right ear has some hearing loss and both have tinnitus. I am interested in your study. Thank you.
. I have moderate to severe hearing loss in both ears, plus tinnitus, and would love to participate in a clinical trial.
Having moderate hearing loss, I am very interested in this study. Would be glad to volunteer and learn more.
When this research completed and medicine will available in market..
I have sudden hearing loss caused by virus,
Would. I be able to be in your study? Left ear
1. Benign paroxysmal positional vertigo
2. Sudden sensorineural hearing loss
3. Dizziness and giddiness
4. Otalgia of right ear