[HN Gopher] Scientists regenerate hair cells that enable hearing
___________________________________________________________________
Scientists regenerate hair cells that enable hearing
Author : geox
Score : 371 points
Date : 2023-05-11 00:08 UTC (22 hours ago)
(HTM) web link (hms.harvard.edu)
(TXT) w3m dump (hms.harvard.edu)
| xwdv wrote:
| If we can regenerate hair cells, could we generate even more hair
| cells to enable some kind of super hearing?
| Workaccount2 wrote:
| When I was younger I had a very expensive full blown audio system
| in my car. I would drive around blasting music so loud you'd feel
| it shaking your bones and punching your organs (don't worry it
| was a pretty rural area). A totally visceral experience.
|
| I absolutely cannot do that anymore, given the damage it
| eventually did to my ears, but man, If I could heal my ears so I
| could go back and do that again...
| ghastmaster wrote:
| I have been curious lately if red light can cause hair growth
| externally, would it be something to research for internal "hair"
| growth. Getting light to the inner ear, would be difficult since
| it is encased in bone.
| anovikov wrote:
| I hope they will at least figure out how to regenerate normal
| hair as a byproduct of this research...
| sylware wrote:
| Why I feel uncomfortable when I hear: cells not dividing are now
| dividing that thanks to our drug cocktail. You know, if it cannot
| be stopped and they divide a bit to fast...
|
| Wild guess: it is not actually what they managed to do.
| darkwater wrote:
| Read (or skimmed) the article and I'm not an English native
| speaker but... TIL that "hair" can be used also for hearing
| related things? I thought that hair was just "any of the fine
| threadlike strands growing from the skin of humans, mammals, and
| some other animals."
| dsr_ wrote:
| The tiny sensors inside your ear are nerves attached to hair of
| various lengths. It's specialized, but it's recognizably the
| same thing as the kind on the outside of your body.
| HPsquared wrote:
| https://en.wikipedia.org/wiki/Hair_cell
|
| "Hair cells are the sensory receptors of both the auditory
| system and the vestibular system in the ears of all
| vertebrates, and in the lateral line organ of fishes. Through
| mechanotransduction, hair cells detect movement in their
| environment.[1]"
| a2tech wrote:
| We have ultra fine hairs in our ears that wiggle when sound
| waves travel over them and those hairs bases are connected to
| receptors that capture those wiggles and send it to your brain.
| Thats (extremely roughly) how your ears work.
| darkwater wrote:
| OK,I think I need to go through primary school human anatomy
| lessons again :( I completely forgot about those.
| CommanderData wrote:
| We are a long way from a cure.
|
| Hearing is complicated, this is a repost and it's believed many
| components need to be fixed in order to hear again. A drug
| (FX-322) was pulled recently after reaching stage 2 clinical
| trials and had good evidence of regenerating hair cells via
| progenitors in mice and cadaver.
|
| Hair cells are not even considered the first thing to be damaged
| when one notices hearing loss. It's considered neurons connecting
| the audiotry nerve to and from the hair cell via the spiral
| ganglion cell are lost (both neuron and eventually the cell after
| a few months/years).
|
| There is currently no way of reconnecting these or regenerating
| the SG cell.
|
| I also think funding in this area is extremely low (looking at
| DoD and UK govs commitment's). Given the funding available I
| think researchers have done great but more money is needed.
| xtracto wrote:
| I also thought of fx322 and oto313 (from another lab). Hearing
| regeneration and tinnitus healing are those things that seem
| "achievable " but are way more complicated than it seems
| initially.
|
| The subreddit r/tinnitusresearch has good coverage of the
| scientific efforts. Which as you mentioned are not that many.
| CommanderData wrote:
| There's another promising candidate by Sound Pharmaceuticals.
| A synthetic compound, Ebselen
|
| https://clinicaltrials.gov/ct2/show/NCT04677972
|
| The trials have shown some degree of efficacy above controls.
| At this stage I only consider evidence from trials to get
| excited over, though it's important to be optimistic over lab
| results and research.
| ck_one wrote:
| When I first starting doing more research I was surprised by
| the low funding and the fairly big number of affected patients.
| Why is there not more funding? Research is making steady
| progress so the field doesn't appear to be a money sink with
| nothing to show for.
| ck_one wrote:
| Can you point me to some sources that back up your claim that
| neurons are damaged first and only later hair cells are lost as
| well. I always thought it's the other way round.
| CommanderData wrote:
| Of course. There's an good video explaining this and also
| citing / explaining the same research. I made a error in my
| original post, it is the synapse* not neuron between the SG
| and audiotry nerve, and the IHC / OHC.
|
| Hidden Hearing Loss: The Effects of Synaptopathy, Stanford.
|
| https://youtu.be/ZGmPG94Rmr8
| ck_one wrote:
| Thanks for following up.
|
| I think there are different forms of hearing loss (hidden
| hearing loss, noice induced hearing loss, middle ear
| hearing loss, ...). I think noice induced hearing loss is
| most common nowadays and is caused by structural damage to
| hair cells. Regenerating hair cells might cure this
| particular form of hearing loss but not others. I think the
| one you mentioned has a different root cause for which new
| hair cells are only part of the puzzle.
| mdani wrote:
| The article seems to suggest that the SG cell is also getting
| regenerated. See
|
| > The new cells contained transduction channels that relay
| sound signals and the ability to form connections with auditory
| neurons -- processes essential to hearing.
| CommanderData wrote:
| Incredible I think I missed that part. Afaik the only other
| drug shown to regenerate synapse in animals was a
| Bisphosphonates (Zoledronate acid).
|
| There's further questions on the models. Using Guinea pigs
| and mice yeild different outcomes. There's also questions on
| whether adult mice are better suited for hearing research.
| ck_one wrote:
| Are both cell types functional?
| TheRealPomax wrote:
| The web was weird and wonderful. The cure was Facebook and
| Twitter.
|
| Keep your cure for JS as far away from me as possible, thanks.
| BaskCatSayHi wrote:
| anyway, it sounds great.
| unnamed76ri wrote:
| I'm really tired and based on the headline I thought scientists
| had a cure for male pattern baldness and the new hairs increased
| your sense of hearing...
| amelius wrote:
| > I thought scientists had a cure for male pattern baldness
|
| They have:
|
| https://www.thebrighterside.news/post/scientists-reverse-hai...
| unnamed76ri wrote:
| Serious question from the article though...why do Americans
| account for an outsized percentage of hearing loss sufferers?
| aaron695 wrote:
| It's wrong, they are comparing American hearing loss with the
| world wide _disabling_ hearing loss.
|
| 1.5 billion people (nearly 20% of the global population) live
| with hearing loss; 430 million of them have disabling hearing
| loss - https://www.who.int/news-room/fact-
| sheets/detail/deafness-an...
| newyankee wrote:
| Selection bias, more access to hearing tests, solutions,
| awareness. In developing countries like mine, we simply have
| to speak louder.
| hammyhavoc wrote:
| Big country, "louder is better", teens blasting their hearing
| with in-ears, concerts that leave your ears ringing for days,
| inadequate safety in the workplace, heavy use of drugs like
| Viagra (yes, hearing loss and tinnitus are a side effect in
| some users with high blood pressure). Diet-related hearing
| loss too as a lot of people eat crap. Probably other reasons
| too.
| hydrok9 wrote:
| military cases are huge
| colanderman wrote:
| Also, stupidly loud cars and motorcycles on city streets,
| and ineffective vehicle noise laws / enforcement thereof.
| justinclift wrote:
| > heavy use of drugs like Viagra (yes, hearing loss and
| tinnitus are a side effect in some users with high blood
| pressure)
|
| Oh wow. The Manga/Anime trope of male characters
| spontaneously bleeding from the nose when they get er...
| excited might actually have some real world examples.
|
| Pretty sure "bleeding from the nose and ears" would kill
| the mood completely though. For most of the population
| anyway. ;)
| hammyhavoc wrote:
| Anecdote: Sudafed used to actually make my dad's nose
| bleed, but not just internally, from the external pores
| of the nose, and from the backs of his hands in terms of
| pores.
| justinclift wrote:
| Heh Heh Heh
|
| If it wasn't dangerous, that could be useful in some
| situations.
|
| ie. "I really don't feel like working hard today", so
| takes some Sudafed and gets on a Zoom/Teams call with
| work colleagues. ;D
|
| Would probably only work once per employer though...
| hanniabu wrote:
| > Diet-related hearing loss too as a lot of people eat crap
|
| Cases like this where it's caused by another issue are
| theoretically reversible though, right?
| hammyhavoc wrote:
| To a point--potentially, to some extent, maybe.
|
| Depending on what you've lacked, for how long, your age--
| these are all variables. The younger you are, the lower
| the chances of reversing it as kids need a decent diet,
| period. How long you've been subsisting of off crap is
| the important one.
|
| There was one highly publicized case about a kid who had
| gone deaf and blind from bad diet:
| https://edition.cnn.com/2019/09/03/health/poor-diet-
| blindnes...
|
| With all the above said, one of my born-blind friends has
| started going deaf due to bad diet, and whilst changing
| his diet hasn't improved his hearing, it has massively
| improved his overall health and importantly _halted_ the
| hearing loss at the rate it was going, so it 's not been
| a pointless exercise to make a lifestyle change that'll
| benefit him in the years to come.
|
| Wishing anyone reading this good health for them and
| theirs.
| lostmsu wrote:
| I read it as if research showed that scientists regenerate
| their hair cells, and everyone else does not.
| thaumasiotes wrote:
| If you can regenerate hairs that stopped growing in one place,
| that sounds like a step toward regenerating other hairs that
| have stopped growing in other places.
|
| And the market for baldness cures has got to be at least as big
| as the market for hearing recovery, despite the gulf in
| fundamental importance.
| OnlyMortal wrote:
| What's that you say?
| fnord77 wrote:
| in mice
| XorNot wrote:
| This is incidentally one of the low-key issues that happens to a
| lot of soldiers - however attentive you are, ultimately you're
| going to get exposed to some loud bangs even if you're never in
| an actual war zone.
|
| So there's a _big_ demand for an effective way to restore damaged
| hearing.
| seanw444 wrote:
| And shooting enthusiasts. Decent ear pro significantly slows
| down the process, but it doesn't eliminate it. I'd love for my
| eye floaters and gradually-increasing tinnitus to be non-
| invasively curable (or at least treatable) before I die.
| kid64 wrote:
| Could this be parlayed into a general-purpose hair loss
| treatment,?
| glenngillen wrote:
| Not obviously related to the article, but given this might
| attract the hearing-curious or knowledgeable.
|
| For as long as I can remember I've had great difficulty hearing
| in noisy environments. In my younger years it didn't bother me
| too much as I was mostly at noisy events to enjoy the music
| anywhere, and if I wanted to talk we'd move somewhere quieter. If
| I make a concerted effort I can usually hear someone directly
| opposite me fine, though in an especially noisy venue like a
| concert I'm often filling in the blanks with lip reading or other
| visual cues. If I'm standing by something noisy in the house
| (range, operating vacuum cleaner, etc.) I can often tell someone
| is talking to me but usually have no idea what they are saying.
| All this has been on the "minor inconvenience" end of a personal
| impact spectrum. Recently I had a minor traffic accident
| (reversed into a car at very low speed, little damage and no
| injuries) and I realised that in that moment I had such little
| awareness of what was around me that it I was concerned. There
| was a lot of very loud conversation happening around me at the
| time. No screaming or anything, and I wasn't part of the
| conversation, but it was enough to completely destroy my focus at
| the time. I'd had a similar incident a couple of years prior. All
| this meant I decided I should book in to have my hearing checked.
|
| Fast forward to the results: she said the tympanogram results
| show a highly compliant middle ear, but far more aggressively
| responsive than she'd seen before. Usually you'd see little or
| slow response if there was a problem but I'm the complete
| opposite of that. For the audiogram results I can hear into
| negative decibels but with a large enough delta in the results
| between left and right ear that I'll need to do some follow-up
| scans. She also ran two separate types of test to check for
| Auditory Processing Disorder.
|
| Everything game back within range, or at least on the opposite
| side of what you'd call hearing "loss". Which prompted her to
| mention "but, at conferences lately they have been talking about
| a phenomenon that is presenting more frequently and being
| referred to as 'hidden hearing loss'...". So I've been down a
| rabbit hole of reading for the past week trying to filter out the
| things that a pure woo to the stuff that looks like it has some
| rigour to it. Seems like there's also been a trend for people to
| label some of these symptoms as "pub deaf".
|
| I'm curious if any others on HN have had similar experiences
| and/or been down this research path before.
| sebazzz wrote:
| Interesting, I thought this was just a glitch of me. I think I
| have the same issue. Whereas other people seem to hear each
| other well in busy environments, it takes me much effort to
| focus and retrieve the person talking from all the other noise.
| The volume levels are fine, I'm just having trouble focusing
| and extracting the specific person I want to hear.
|
| Now I also have some issue that eustachian tube gets a bit
| clogged up or something, because I react more than usual to
| small air particles. I can usually fix that by blowing while
| keeping my nose and mouth shut - but the issue above still
| remains in some form.
| forrest2 wrote:
| I think I have this:
| https://www.nationwidechildrens.org/conditions/auditory-proc...
|
| Might be the same thing depending on your full set of symptoms.
| glenngillen wrote:
| Yeah, they tested for APD (two different approaches). I found
| it _really_ difficult though enjoyable in terms of being able
| to self analyse what it was that made me struggle. That said,
| my results were apparently normal and everyone finds it
| difficult.
| hoseja wrote:
| Isn't that some autism sensory processing thing?
| glenngillen wrote:
| Yeah, I thought that might be it that too even though I don't
| present any other autism symptoms. Much harder to diagnose in
| that case, which is why they tried to isolate with the APD
| testing.
| clolege wrote:
| Could it be ADHD?
|
| I have both ADHD and "hidden hearing loss" and I chalk both up
| to my brain struggling to filter out noise/distractions.
| darkwater wrote:
| And how good do you hear in a silent environment? I'm asking
| because I feel a bit reflected in your description (always had
| problem following conversations in a noisy environment) but in
| a calm one I can hear very faint noises/voices (while others
| cannot, for example). But TBH I don't know if my noisy envs
| experience is "normal" or it is just me.
| glenngillen wrote:
| I wouldn't have thought I had anything beyond normal hearing
| in quiet environments. Modern life means there's always some
| background hum of a refrigerator or an old light or a whining
| transformer in a wall or in a roof. But apparently I can hear
| negative decibels so maybe most people don't hear these
| things?
|
| If nothing else I'm finding the current journey interesting
| as I'm having to re-evaluate what is "normal" for both myself
| and others, for an experience that is obviously very personal
| and difficult to compare with others.
| sudosysgen wrote:
| I'm in the same situation. I was told that this is a relatively
| common symptom if you have ADHD and it's close to auditory
| processing disorder. Basically you just get deeply distracted
| by loud sounds and can't focus on anything auditory.
| blueyoda wrote:
| This sounds exactly like me. Strangely enough, my hearing test
| was perfect.
|
| Whenever there is background noise, I cannot decipher what
| someone is saying. I've lost count of how many times I've been
| asked, "are you deaf?"
|
| Could it be some form of ADHD?
| glenngillen wrote:
| I had a similar inkling, which is what led me to discovering
| APD. The tests for that were normal though.
|
| This whole "hidden hearing loss" concept seems like such a
| broad term for a huge group of things. Some of them
| potentially related to dysfunction in the inner ear that we
| can't test for but can be treated (in mice) with
| neurotrophin.
|
| The specialist I saw said at the last conference she attended
| the researcher presenting on it said most patients presenting
| were in their 40s. I've not seen any papers that make such a
| claim though. I was only the second patient she'd personally
| encountered that had the symptoms, and we are both in our
| 40s.
| joshu wrote:
| ADHD and APD go hand in hand.
| dghughes wrote:
| My experience has weirdly been the opposite.
|
| I got a job at a crowded and noisy casino. During some big
| events it was so crowded I had to walk sideways through crowds
| in the slot machine area. And very loud due to slot machines
| and people talking, yelling, screaming if they win.
|
| Eventually I realized as I conversed with my co-workers we
| didn't need to yell and I could hear them 10 feet away. Note we
| did also use CB radios too but no mic just open speakers
| blasting which added to the noise.
|
| I found out it is called the Cocktail Party Effect. It seems to
| be a learned skill that comes with time but it isn't something
| you naturally have. Ironically I probably now have hearing
| damage too working in that loud environment.
| vrglvrglvrgl wrote:
| [dead]
| dantheman0207 wrote:
| I have tinnitus, which is pretty annoying. Very excited to see
| the possibility of treatment for this.
| steve_taylor wrote:
| I'd love to know what silence is like.
| amelius wrote:
| Well, actually, true silence (as in an anechoic chamber) can
| be maddening.
| hyperjeff wrote:
| i worked for a company once with a large (10' sided cube)
| and very high-quality anechoic chamber and would go in
| there on lunch breaks to mediate, was fantastic. (never had
| audio hallucinations.) i was young and had no hearing
| issues which probably helped.
| Technotroll wrote:
| Have you ever been in one? I visited the one that Norwegian
| Broadcasting Corporation (NRK) had at Marienlyst in Oslo.
| This is before I knew anything about anechoic chambers and
| the sort.
|
| It was called The Dead Room...
|
| The first thing I noticed is that I had to speak a lot
| louder to be heard. But the most unnerving thing happened
| when we finally stood still in there.
|
| I could hear my blood run through my own veins.......... So
| out of sheer panic I started moving and talking again lol.
|
| This room was in the basement, and was secluded from all
| the other rooms in the building. The control room was even
| two stories up from the studio. They used it to record
| special samples that had to be completely "dead," as in no
| echo or reverberation on it outside the instrument itself.
| By they looks of it they also used it for Foley recordings,
| because there was some surfaces in there and some pans of
| powders and sand.
| brokenkebaby wrote:
| True silence makes people to experience auditory
| hallucinations usually. So like tinnitus, but I guess less
| predictable, and less consistent
| ChrisHyung wrote:
| Same. Doesn't bother me at all, it's just background noise,
| but it's not true silence.
| tmountain wrote:
| I used to play in bands and go to a lot of concerts without
| earplugs (mistakes of youth). I've had tinnitus for almost
| 20 years, and I am so used to it now that it's a non issue.
| That said, it drove me crazy in the beginning.
| 1001101 wrote:
| 30+ years of midwest raves did me in. One sound system
| had 1MW bass bins - have been to some with ~40ft x ~15ft
| of bass bins. Only one ruptured ear drum in all of that
| time (Regis - didn't even seem that loud) - that's the
| ear that is the worst. Doesn't bother me, other than
| anxiety about potential neurological effects.
| bheadmaster wrote:
| I used to play in bands and go to concerts without
| earplugs too, and one of my favorite pastimes is
| listening to music on loud volumes. Yet I've never
| developed tinnitus.
|
| I guess I'm just lucky, or my hearing is just so
| sensitive that what I consider "loud" is actually fairly
| quiet. I know that I've had problems actually _hearing_
| sounds in band practice without using earplugs - I 'd
| just hear a bunch of noise, and often lose the beat
| because of the inability to hear other musicians clearly.
| [deleted]
| Tenoke wrote:
| There is this tapping on your head trick[0] that legitimately
| works for many people (me included) to clear up your tinitius
| but only for a few seconds after it. If you are curious what
| silence sounds you can try it.
|
| 0. https://www.reddit.com/r/videos/comments/3oauru/if_you_hav
| e_...
| lachlan_gray wrote:
| Woah thanks for sharing! it works although the total
| silence is a little unnerving
| senectus1 wrote:
| same.
|
| If I can get rid of the persistent high pitched whine in my
| left ear my QoL will go through the roof.
| dantheman0207 wrote:
| My hearing is not particularly bad, and my tinnitus tends to
| come and go depending on the environment. Still, I would love
| to resolve it once and for all. It's a pretty common
| condition too.
| soyyo wrote:
| tinnitus is not always related to hearing, I got mine after
| my jaw dislocated, I still got my hearing checked just in
| case and it was completely OK.
| wazoox wrote:
| Beta-blockers give me tinnitus. Unfortunately you can't
| choose not to take them when it's convenient...
| thanatos519 wrote:
| Some generators on https://mynoise.net/ have strong anecdotal
| evidence of at least temporary clearing of tinnitus. There's
| even https://mynoise.net/Albums/view.php?album=TinnitusRelief
|
| YMMV.
| tmountain wrote:
| Be careful with these. My friend had to see a specialist
| after extended use of mynoise because it made his tinnitus
| much worse to the extent that it was almost intolerable.
| burnte wrote:
| Yeah, I tried them when they started and for me it didn't
| make my tinnitus worse, it just made me notice much more
| when it's there because suddenly I had breaks from it, and
| THAT was worse. I used them a few times and quit because of
| that.
| ccooffee wrote:
| From the article on PNAS[0]:
|
| > Despite the progress in our approach to achieve HC regeneration
| in the adult cochlea in vitro and in vivo, major challenges
| remain before potential clinical applications. First, regenerated
| HCs need to be terminally differentiated and fully mature, and to
| be located in the sensory epithelial region such that their
| stereocilia contact the tectorial membrane to mediate the
| mechanoelectrical transduction, as well as be able to survive
| long term. The current regenerated HC-like cells are immature and
| the time frame we used is not ideal to determine their long-term
| survival. One potential reason for the lack of terminal
| differentiation is the continuous Atoh1 expression mediated by
| adenovirus, which is known to impact HC maturation and is
| detrimental to HC survival (9, 56). Future studies to express
| Atoh1 transiently in the reprogrammed SCs could address the
| issue. Second, the surgical procedure of "cochleostomy" in the
| adult cochlea severely damages the microenvironment of the
| cochlea including extensive OHC death around the injection site.
| Future studies using an alternative delivery vehicle with a
| minimally invasive surgical procedure such as an AAV with round
| window injection could significantly improve HC regeneration
| efficiency without causing trauma to the inner ear. Third, major
| efforts should be made to identify/create new AAVs or novel
| delivery vehicles such as nanoparticles capable of targeting
| adult cochlear SCs for reprogramming. Finally, the restoration of
| hearing in adult deaf animal models significantly and reliably by
| HC regeneration will elevate the field of HC regeneration to a
| clinically relevant stage.
|
| It sounds like the authors have found a more effective way to
| trigger generation of immature Hair Cells than was already known,
| but they're several large steps away from "restoration of hearing
| in adult deaf animal models".
|
| However, the submitted article (from hms.harvard.edu) summarizes
| the findings as:
|
| > [Authors] reported creating a drug-like cocktail of different
| molecules that successfully regenerated hair cells in a mouse
| model by reprogramming a series of genetic pathways within the
| inner ear.
|
| While it's not outright false, the "successfully regenerated"
| isn't the way I'd interpret the PNAS paper. Perhaps I misread the
| paper.
|
| [0] https://www.pnas.org/doi/10.1073/pnas.2215253120
| technocratius wrote:
| Thanks for adding this context. As someone suffering from SNHL
| with a great wish to have some of my hearing restored,
| headlines & articles like these often give my a sense of hope
| for a near-term solution that turns out to be false. I wish
| (pop)scientific news would be a little bit more
| nuanced/careful..
|
| Anyway, great that another small but significant step is made
| in this terribly complicated problem :)
| FairDune wrote:
| Same here - suffering from Sensorineural hearing loss since I
| was a kid. Lots of hope but not seen a ubiquitous or even an
| experimental solution in sight.
| olejorgenb wrote:
| Is this similar to the abandoned[1] program by Frequency
| Therapeutics?
|
| > The FX 322 gel contains drugs that early studies indicate
| helped to aid new hair cell formation. These are called
| progenitor cells, which are unable to evolve into any body
| tissue. Instead, they are usually more inclined to develop into
| cells near where they are found in the body. > This particular
| drug encourages them to grow into stereocilia, which are hair-
| like cells in your ears that detect sound. Hearing loss is when
| these hair cells are irreversibly damaged, as they cannot repair
| themselves.
|
| [1] https://seekingalpha.com/news/3935169-frequency-
| crashes-75-o...
| p0nce wrote:
| Well, that is a let down.
| everydayentropy wrote:
| If only they could regenerate them for my head :(
| stuaxo wrote:
| Maybe this could fix tinnitus for people one day.
| IG_Semmelweiss wrote:
| I actually suggested a friend to enroll in one sich study when it
| first surfaced in HN, a year ago.
|
| My friend mentioned he didnt meet the criteria for the study (I
| think age was the problem).
|
| I'm happy to see developments on this area of research and I hope
| someone succeeds. Being deaf is very difficult for a specially
| social animal like us, humans
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