Gene Discovery Allows the Production of Inner or Outer Ear Hair Cells (Northwestern University)

Interesting discovery discussed here:

Restoring Hearing: New Tool To Create Ear Hair Cells Lost Due to Aging or Noise

• 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.”​

The study paper:

Tbx2 is a master regulator of inner versus outer hair cell differentiation​

/G

 

Feels like we've been getting a lot of new hearing research developments lately. This is cool.

 

This is good!

 

We will watch your research with much anticipation.

 

Biotech PhDs are getting into en-masse this because its a major problem and beneficial to all of humanity.

Tinnitus and hearing loss are horrible, and on the one hand it's sad it's common, on the other hand that's motivating a lot of researchers to figure out a solution for it.

 

Fuck yeah I was thinking the same thing.

 

You can modify my genes until I'm a pile of sludge. Just make the tinnitus go away.

 

Well hot damn!

 

I’m just curious, if there’s no way currently to diagnose if one has lost inner or outer hair cells, how would they determine which ones an individual need? I guess they are still quite far from understanding how to apply this in clinical trials.

 

As treatment protocols start being formulated for tinnitus, they will likely approach it from as many angles at the same time as possible. I can imagine down the road a drug may exist for hearing loss using several of these compounds that are being tested + perhaps some form of modulation therapy to allow the neuronal signals causing tinnitus to recede back to a baseline.

 

In terms of Audiology I've seen the inner hair cells being responsible for the sharpness of noises. In word recognition it's like differentiating between Elephant and Olyphant. Outer hair cells are more for general hearing frequencies like not being able to hear crickets or birds chirping but hearing a car engine. With this framework a barrage test of different noises with modifications like muffling some and not others can make differentiating between them a sign of improvement.

There's also brain scanning that has been focused around the cochlea itself which might be able to pick up neural signals from replaced hair cells that were not there before the treatment.

 

Will this cure also have to go through the various 1-2-3 clinical trial steps and be FDA approved before eventually being marketed?

 

No.

It needs to finish preclinical first before even going into Phase 1-2-3 . This will take many years to come to market. But no worries, plenty of other alternatives are in Phase 2-3 already!

 

This sounds very promising! Hope it can lead to good treatments for both tinnitus and hearing loss.

 

"Ablation of Tbx2 in postnatal, largely differentiated IHCs makes them transdifferentiate directly into OHCs, replacing IHC features with those of mature and not embryonic OHCs."​

I don't get it. Can someone explain to me? Do we keep this TBX2 in our body (postnatal)? Because nothing happens once our hear cells die (no regrowth, neither OHC nor IHC).