Inner Ear Hair Cell Regeneration — Maybe We Can Know More

improving the function of the remaining cells may still be worth the effort and restore auditory nerve function.

I think this is a great thing. It's should provide a lot of relief maybe a cure for my T. Though because this hasn't created new neuron I would probably revert to T over the course of life and more neuron death.
 
Another paper using Anc80L65. They show that injection through the semicircular canal in adult mice can reach essentially all areas of the cochlea - inner and outer hair cells along the entire cochlea as well as supporting cells. There was also no measurable damage to hearing from the procedure. Paper is at http://www.nature.com/articles/srep45524

This is something of a follow-on to one of the Anc80L65 papers published a couple of months ago (http://www.nature.com/nbt/journal/v35/n3/full/nbt.3781.html).

Key differences seem to be

1) the use of adult rather than newborn mice (this is important)
2) different injection approach
3) more general exploration of areas reached by virus
4) more detailed safety analysis - they are particularly concerned about potential damage to the cochlea when doing surgery on adults

With 3 papers in two months on Anc80L65, this will be something to keep an eye on.
 
A bit more followup.

First, from http://www.nature.com/articles/srep45524, "the work in the paper was partially supported by Decibel Therapeutics."

Second, from http://www.nature.com/nbt/journal/v35/n3/full/nbt.3801.html, "The Anc80L65 vector is patented by L.H.V., patent #WO/2015/054653 – "Methods of predicting ancestral virus sequence and uses thereof."" I didn't find a granted patent (though I am not a patent attorney), but I did find an application: http://appft.uspto.gov/netacgi/nph-...=Vandenberghe&OS=Vandenberghe&RS=Vandenberghe

Third, from http://www.nature.com/nbt/journal/v35/n3/full/nbt.3781.html, "L.H.V., K.M.S., and J.R.H. have filed a patent on the use of Anc80L65 in the cochlea." I didn't see an application for this, but it is possible that it takes time to show up in the on-line data base - it hasn't been "published" yet.

Fourth, from http://www.nature.com/articles/srep45524, "L.H.V. has filed a patent application on the use of Anc80 in the cochlea." Again, I didn't find the patent application, but this is presumably his application with Stankovic, and Holt. (Vandenberghe does have a patent using AAVs the eye http://patft.uspto.gov/netacgi/nph-...=Vandenberghe&OS=Vandenberghe&RS=Vandenberghe. He's actually published quite a lot on vision, so he seems to be moving to the ear now.)

It's clear that Vandenberghe is the virus guy. He's now worked with senior authors Charles Liberman, Konstantina Stankovic, Jeffrey Holt, and Gwenaëlle S Géléoc. Together this is a serious group. It also will be interesting to see whether Decibel will license Anc80L65.
 
Could it be the motorcycle accident he had? The same affliction that caused him tinnitus? Look under his user name.

@dan26 I admire your strong spirit, for keeping up with this for such a long time. Don't give up hope now! We are entering a new age now where we will be able to restore many types of hearing damage. It was only in 1980s that scientists discovered that birds can regenerate their hair cells.


You don't think it can be repaired? It may be more difficult to repair if it's cut higher up, near the root of the branch. But nothing is impossible! The impossible is what keeps us motivated and going forward.

Hey guys: the tinnitus was definitely from losing all my hearing and like i might have said in the past, the tinnitus started like 6 months after being deafened in the accident. When i went to the ENT way back and told them about the crazy noises they said, "your hearing might be trying to come back!" so i thought to myself, Yeah oh please let that be. But eventually i found out myself what the noises were. I didnt even know they had a name!! Imagine having 5-10 different noises in your head at once and not being able to hear anything except the crazy noises in your head. Thats what i endured for about 8 years till i had the cochlear implant device implanted. I drank a lot. I was near suicide and all that jazz. Doctors lied to me. Maybe they didnt want to tell me what was going on with my ears and brain. Who knows. Not much was known about tinnitus back then in the early '80's.
But i have hung in there all these years and my lil boy is 2 1/2 years old now and what a joy he is. So, i have to fight the good fight and hope and pray something is developed to quiet the noises. Thanks for encouraging words guys.
 
Thats what i endured for about 8 years till i had the cochlear implant device implanted.

I imagine it must have been hell. Props to you for hanging in there.
Did the CI make any difference to your T?

How is your hearing with the CI now? How does it compare with your original (natural) hearing?
 
Have you guys found any evidence that loss of synapse happens at the cochlear nucleus? My understanding is that synapses are lost only at the hair cells. Of course, if the neuron dies, then the synapse at the cochlear nucleus is also lost. But can the nucleus synapse be lost before the neuron dies?

Does anyone have any hard numbers on how long these neurons can survive? I know that the general opinion is that they can survive for a very long time. Here is Liberman saying it can survive up to several years:

"Each missing synapse represents a cochlear nerve fiber that has been disconnected due to retraction of the terminal segment—it will never reconnect," Liberman noted. "It no longer responds to sound, and, within a few months or years, the rest of the neuron will disappear."

http://www.newswise.com/articles/noise-induced-hidden-hearing-loss-mechanism-discovered

I just have not seen any study measuring neuron survival time in particular. This may be important to know to figure out the window of opportunity for treatment.
 
For those that know more I read somewhere a Chinese clinic is planning for viral introduction into the synapses of the NT-3 growth factor. Does that make sense? Are we at the stage were humans have designed a virus like AAV to contain the NT-3 growth factor. Have we been able to design a virus with will only target nerve cells? Are there other planned clinic trials using this method.
 
For those that know more I read somewhere a Chinese clinic is planning for viral introduction into the synapses of the NT-3 growth factor.
Where did you read this? It's not really possible to evaluate any of this without seeing the original.
Are we at the stage were humans have designed a virus like AAV to contain the NT-3 growth factor.
I don't believe there is anything in the published literature. My guess is this is something Decibel is or will be working on.
Have we been able to design a virus with will only target nerve cells?
No, not to my knowledge, but if you look a few posts up, I posted a link to a brand new article that discusses the ability of Anc80L65 to reach spiral ganglion neurons. They specifically mention the possible application of NT-3 as a motivation for the work.
Are there other planned clinic trials using this method.
I know of no trials for NT-3 regardless of method of application. Perhaps you can provide information on this Chinese trial.
 
A little historical perspective. This claim from 2014 was on some very basic science and not that many products available. While there is a ton available currently it seem like there is more companies competing with pipeline products. Almost to the stage of improvement of hearing loss which will be followed by enhancing product efficency. 2024 for a deafness cure maybe accurate and a tinnitus cure for 90% of people will happen earlier than that.

 
@RB2014 is this always the timeline or do some phases get shorten if efficacy is shown. For people on this site I could see a bunch being able to get into a phase 3 for frequency or decibel if they make it that far. Especially decibel because nerve repair/growth isn't as sexy and the general public might not connect it as much with better hearing
 
@RB2014 is this always the timeline or do some phases get shorten if efficacy is shown. For people on this site I could see a bunch being able to get into a phase 3 for frequency or decibel if they make it that far. Especially decibel because nerve repair/growth isn't as sexy and the general public might not connect it as much with better hearing

I am not an expert on this process, but I don't see any of the timelines getting shortened. There is a fast track process for the clinical trials that the fda has, that I have read about, but I don't think it would apply in this case. If you look at Novartis I think their phase 2 trial was even extended to 2019 instead of 2017. Even if efficacy is shown, they still need to evaluate the data especially if different dosages are administered and maybe even look at the different causes of the hearing loss. There could also be long term effects that don't show up immediately. I don't see any of clinical studies getting shortened.
 
I am not an expert on this process, but I don't see any of the timelines getting shortened. There is a fast track process for the clinical trials that the fda has, that I have read about, but I don't think it would apply in this case. If you look at Novartis I think their phase 2 trial was even extended to 2019 instead of 2017. Even if efficacy is shown, they still need to evaluate the data especially if different dosages are administered and maybe even look at the different causes of the hearing loss. There could also be long term effects that don't show up immediately. I don't see any of clinical studies getting shortened.

If I remember correctly, the FDA granted Auris Medical the fast-track thingy for AM-101 (though none of the users of TT who volunteered got any benefit).
 
Yea I think it really depends how well it work and if there are people will major setback. If one of these company has good success early in Phase 1 and Phase 2 and no patient has extreme reactions then you can bet the FDA will relent to the public pressure to accelerate the phasing schedule.
 
For those that know more I read somewhere a Chinese clinic is planning for viral introduction into the synapses of the NT-3 growth factor.
I don't know about that, but Chinese have grown a man's ear on his arm.

A plastic surgeon in China has successfully grown an artificial ear on a man's arm in a pioneering medical procedure.

http://www.dailymail.co.uk/news/peo...ore-hearing-lost-organ-horrific-accident.html

Are we at the stage were humans have designed a virus like AAV to contain the NT-3 growth factor. Have we been able to design a virus with will only target nerve cells?

It may not be necessary. According to Frequency researchers the hair cells they grow in lab form the synaptic components, which should, in theory, release NT-3 and BDNF to attract nerve fibers.
 
How's the hearing through that? ;)
Excellent! You can hear both highs and lows! :D And there is no tinnitus! :eek:

It's crazy the kind of things these doctors are doing. You have this Chinese guy doing ear regeneration on an arm! Then that Italian guy contemplating head transplant!

But no doctor is able to find a cure for tinnitus... What we need perhaps is one of these doctors that's crazy enough to test out some of these new ideas about inner ear regeneration on a human. The Chinese seem to be best suited for that. They are the right kind of crazy! :D It wouldn't surprise me if they came along and beaten the westerners at their own game.
 
So stem cells typically do not survive because of the high potassium concentration.
That's my takeaway too. Not that I didn't know about it. This is a known issue.

This study shows that they are modifying the endolymph to increase the chance of cell survival.

The data demonstrate that conditioning procedures aimed at transiently reducing the concentration of potassium in the SM facilitate survival of hESCs for at least one week.

Does a viral vector survive in this environment?
I have no data on this, but my impression is that viruses are more resilient to endolymph.
 
So stem cells typically do not survive because of the high potassium concentration.
That is my understanding. They do survive in the perilymph but do not migrate to the auditory epithelium.
Does a viral vector survive in this environment?
As far as I can tell, the viruses do not interact with the endolymph. They are injected through the RWM or oval windows (or diffuse across the RWM) into the perilymph. However, unlike the stem cells which do not appear to migrate to the auditory epithelium (at least in large numbers), the virus migrates throughout the inner ear. Thus, it is able to transduce OHC, IHC, SG neurons, etc.
 
According to Frequency researchers the hair cells they grow in lab form the synaptic components, which should, in theory, release NT-3 and BDNF to attract nerve fibers.

I'm of a mixed mind on this. I get that this is a amazing leap forward in terms of hearing restoration but using up your supporting cells in this procedure is risky especially you don't have a lot of hearing loss. My question is if a newly grown hair doesn't get connected up does it die.

Would a safer option be to reestablish a large number of synaptic connections to your existing hair cells and by doing so get rid of your T. Then you could wait until an optimized Frequency process comes out. But it seems like Decibel and neuro stem cell procedures may be years behind Frequency. Which is weird because multiple sources have said neuron regrowth is easier than regrowing stem cells.

Would this Frequency procedure use up the supporting stem cells? Do hair cells die if they don't recieve synaptic connections within a few weeks or do they survive and wait for that connection?
 
You probably meant to say endolymph.
I didn't.

From http://www.nature.com/articles/srep46058

"Following delivery of cells into the scala tympani, a fluid-filled lumen adjacent to the cochlear duct epithelium, transplanted cells can survive but remain in the perilymph in scala tympani and do not reach the auditory epithelium where they need to reside to transduce sound efficiently. Consequently, it is necessary to inject the cells directly into the scala media, the fluid-filled lumen within the cochlear duct epithelium. However, the high concentration of potassium of the endolymph11 in scala media quickly kills the transplanted cells"

See also http://www.cochlea.eu/en/cochlea/cochlear-fluids
 

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