How Your Body Can Turn Back Time
Hearing loss is a growing problem with increased prevalence,
and the reason for this is because
evolutionarily, humans are not designed to withstand the assaults of modern society.
Interestingly, if you look at places like Easter Island,
你会发现那里的人 年老的时候 听力还是正常的
people maintain normal hearing into old age,
but it’s just by living in the modern society
我们周边就有地铁 有车辆 有城市 有音乐
where we have subways and cars and cities and iPods,
that we are overburdening our hearing, and causing a great deal of hearing loss.
The origin of hearing loss is often the loss of
what are called sensory hair cells in the cochlea.
And these hair cells move and response to sound,
and create a signal that gets sent to your brain, and that’s really the origin of hearing.
Now what happens with hearing loss
is those delicate hair cells start to die off over time,
due to external insults from loud noise, or certain types of drugs.
When that happens,
they are not naturally regenerated in mammals.
Interestingly, many species like birds and reptiles,
如果你将它们的毛细胞破坏掉 一段时间后 可能一个月后
if you knock out their hair cells, and wait a period of time, a month,
their hair cells come back naturally, and they can start hearing again.
So this process is hardwired into nature,
but mammals just haven’t found a way to turn on the system.
With many technologies designed to address hearing loss,
they really just treat symptoms rather than the root cause of the disease,
which is the loss of the hair cell.
And the way to think about this is like
if you have a TV screen,
and you start losing the pixels on the TV screen.
Essentially, what these aid devices do is they make the screen brighter,
but they don’t fundamentally replace all the pixels that are lost.
So it does help you pick up some degree of signal,
but it doesn’t in any way replace that native function of hearing,
which is really our goal of re-growing hair cells,
and putting those pixels back in the place, and giving you that natural hearing.
At Frequency, we’re focused on an entirely new mode of medicine,
and the objective of this is to make your body’s natural stem or progenitor cells
regenerate damaged tissue in place.
And this could really transform medicine
across a whole variety of diseases and organs.
And where we’ve learned this from is actually looking at the portions of the human body
that are very regenerative.
And for instance, if you look at the human intestine,
it re-creates itself every five days entirely.
And that will actually last until you’re well over 100 years old,
so your body knows how to re-create certain tissues.
Our objective is to identify what are the local signals
that cells get from their niche environment
that tells them to start to regrow, and start to repair tissue,
so we can start turning on the dormant progenitor and stem cells that exist throughout the body.
In order to make good medicines out of that,
we focus on applications
通过试验 我们可以在短期内 有选择性地
where those cells can be activated very selectively
and very locally for a short period of time.
That gives you tremendous benefits
in terms of the safety and controllability of reactivating these systems.
And our first application is to do this in hearing loss,
where we found that there are dormant progenitors that exist within the cochlea,
that in some species have the capacity to regenerate,
but in mammals are locked in an off position,
and we are simply finding small molecule drugs,
traditional drugs that can go in,
turn on those progenitors and re-create hair cells, in this case in the cochlea,
to restore the hearing function.
We frequently get asked about the difference between between stem cells and progenitor cells
关于如何才能准确区分它们 在医学领域上 这是个有争议的话题
Well there’s debate in the field as how to exactly define them.
I think what’s very important is to recognize the distinction
between your body’s progenitor cells and a pluripotent stem cell.
Now, a pluripotent stem cell can turn into any cell in your body.
It’s really powerful and really flexible.
The advantage of just activating progenitors in your body
is they’re generally most of the way differentiated
from that pluripotent stem cell that can become anything into the final tissue.
’cause they’re really almost locked into their fate.
So when you activate them,
they generally only know how to make cells of one or two types.
So this gives you a highly controlled system
as opposed to if you are working with a pluripotent system.
要考虑到 在医疗试验中 制造出的细胞类型可能不符合你的要求
There’s more concern about creating cell types that you don’t desire in the given application.
Throughout the body, progenitor cells are often controlled by their neighbouring cells.
And what tends to happen is there is a neighboring cell sitting right next to progenitor
which is constantly sending signals over the progenitor.
And this could be saying “continuously divide”
which is commonly going on in the intestine.
or in the cochlea it could be giving a signal that saying “stay asleep”.
Our science is really to understand what are those signals that are being pasted.
What specific pathways are being activated by those signals.
And then we say, how can we go in with chemicals,
找到使用化学药物 抑制剂 催化剂的位置
inhibitors or activators to those pathways
so we can selectively turn on the signals to drive growth where and when we want it.
We’re very focused on advancing our hearing loss therapy,
失聪治疗是“祖细胞激活” 即PCA 这个广阔医疗平台中的一个分支
and this is part of a broader platform we think of as “progenitor cell activation,” or PCA.
And with PCA, we think this can be applied to many tissues,
where you can understand what progenitor needs to be activated,
and define molecules that can activate that progenitor in the right spot.
So you can think of many skin diseases that this could address,
everything from wounding to balding to burns,
other types of skin pathologies where regeneration is needed.
And by being able to control the growth and differentiation in the intestinal environment,
also opens up opportunities to address GI diseases.
We see opportunities, as with the ear, in the eye,
another sensory organ that’s plaguedwith a number of degenerative diseases
where known progenitor cells have been found that could address many of these maladies as well.