How young blood might help reverse aging. Yes, really
-
0:01 - 0:06This is a painting from the 16th century
from Lucas Cranach the Elder. -
0:06 - 0:09It shows the famous Fountain of Youth.
-
0:09 - 0:15If you drink its water or you bathe in it,
you will get health and youth. -
0:16 - 0:21Every culture, every civilization
has dreamed of finding eternal youth. -
0:22 - 0:27There are people like Alexander the Great
or Ponce De León, the explorer, -
0:27 - 0:30who spent much of their life
chasing the Fountain of Youth. -
0:31 - 0:32They didn't find it.
-
0:33 - 0:36But what if there was something to it?
-
0:36 - 0:39What if there was something
to this Fountain of Youth? -
0:39 - 0:44I will share an absolutely amazing
development in aging research -
0:44 - 0:48that could revolutionize
the way we think about aging -
0:48 - 0:51and how we may treat age-related
diseases in the future. -
0:52 - 0:55It started with experiments that showed,
-
0:55 - 0:58in a recent number
of studies about growing, -
0:58 - 1:04that animals -- old mice --
that share a blood supply with young mice -
1:04 - 1:06can get rejuvenated.
-
1:06 - 1:11This is similar to what you might see
in humans, in Siamese twins, -
1:11 - 1:13and I know this sounds a bit creepy.
-
1:13 - 1:19But what Tom Rando, a stem-cell
researcher, reported in 2007, -
1:19 - 1:23was that old muscle from a mouse
can be rejuvenated -
1:23 - 1:27if it's exposed to young blood
through common circulation. -
1:28 - 1:33This was reproduced by Amy Wagers
at Harvard a few years later, -
1:33 - 1:37and others then showed that similar
rejuvenating effects could be observed -
1:37 - 1:40in the pancreas, the liver and the heart.
-
1:41 - 1:45But what I'm most excited about,
and several other labs as well, -
1:45 - 1:48is that this may even apply to the brain.
-
1:49 - 1:54So, what we found is that an old mouse
exposed to a young environment -
1:54 - 1:57in this model called parabiosis,
-
1:57 - 1:59shows a younger brain --
-
1:59 - 2:01and a brain that functions better.
-
2:02 - 2:04And I repeat:
-
2:04 - 2:10an old mouse that gets young blood
through shared circulation -
2:10 - 2:13looks younger and functions
younger in its brain. -
2:14 - 2:16So when we get older --
-
2:16 - 2:18we can look at different aspects
of human cognition, -
2:18 - 2:20and you can see on this slide here,
-
2:20 - 2:23we can look at reasoning,
verbal ability and so forth. -
2:24 - 2:29And up to around age 50 or 60,
these functions are all intact, -
2:29 - 2:34and as I look at the young audience
here in the room, we're all still fine. -
2:34 - 2:35(Laughter)
-
2:35 - 2:39But it's scary to see
how all these curves go south. -
2:39 - 2:40And as we get older,
-
2:40 - 2:44diseases such as Alzheimer's
and others may develop. -
2:45 - 2:49We know that with age,
the connections between neurons -- -
2:49 - 2:53the way neurons talk to each other,
the synapses -- they start to deteriorate; -
2:53 - 2:57neurons die, the brain starts to shrink,
-
2:57 - 3:01and there's an increased susceptibility
for these neurodegenerative diseases. -
3:02 - 3:06One big problem we have -- to try
to understand how this really works -
3:07 - 3:09at a very molecular mechanistic level --
-
3:09 - 3:13is that we can't study the brains
in detail, in living people. -
3:14 - 3:17We can do cognitive tests,
we can do imaging -- -
3:17 - 3:20all kinds of sophisticated testing.
-
3:20 - 3:23But we usually have to wait
until the person dies -
3:23 - 3:28to get the brain and look at how it really
changed through age or in a disease. -
3:29 - 3:32This is what neuropathologists
do, for example. -
3:32 - 3:38So, how about we think of the brain
as being part of the larger organism. -
3:38 - 3:41Could we potentially understand more
-
3:41 - 3:43about what happens in the brain
at the molecular level -
3:43 - 3:47if we see the brain
as part of the entire body? -
3:47 - 3:52So if the body ages or gets sick,
does that affect the brain? -
3:52 - 3:56And vice versa: as the brain gets older,
does that influence the rest of the body? -
3:57 - 4:01And what connects all the different
tissues in the body -
4:01 - 4:02is blood.
-
4:02 - 4:08Blood is the tissue that not only carries
cells that transport oxygen, for example, -
4:08 - 4:09the red blood cells,
-
4:09 - 4:12or fights infectious diseases,
-
4:12 - 4:16but it also carries messenger molecules,
-
4:16 - 4:20hormone-like factors
that transport information -
4:20 - 4:24from one cell to another,
from one tissue to another, -
4:24 - 4:26including the brain.
-
4:26 - 4:31So if we look at how the blood
changes in disease or age, -
4:31 - 4:33can we learn something about the brain?
-
4:34 - 4:38We know that as we get older,
the blood changes as well, -
4:39 - 4:41so these hormone-like factors
change as we get older. -
4:41 - 4:46And by and large,
factors that we know are required -
4:46 - 4:49for the development of tissues,
for the maintenance of tissues -- -
4:49 - 4:52they start to decrease as we get older,
-
4:52 - 4:57while factors involved in repair,
in injury and in inflammation -- -
4:57 - 4:59they increase as we get older.
-
4:59 - 5:04So there's this unbalance of good
and bad factors, if you will. -
5:05 - 5:08And to illustrate what we can do
potentially with that, -
5:08 - 5:11I want to talk you through
an experiment that we did. -
5:11 - 5:14We had almost 300 blood samples
from healthy human beings -
5:14 - 5:1720 to 89 years of age,
-
5:17 - 5:21and we measured over 100
of these communication factors, -
5:21 - 5:25these hormone-like proteins that
transport information between tissues. -
5:25 - 5:27And what we noticed first
-
5:27 - 5:30is that between the youngest
and the oldest group, -
5:30 - 5:33about half the factors
changed significantly. -
5:33 - 5:36So our body lives in a very
different environment as we get older, -
5:36 - 5:38when it comes to these factors.
-
5:38 - 5:42And using statistical
or bioinformatics programs, -
5:42 - 5:46we could try to discover
those factors that best predict age -- -
5:46 - 5:50in a way, back-calculate
the relative age of a person. -
5:50 - 5:53And the way this looks
is shown in this graph. -
5:54 - 5:59So, on the one axis you see
the actual age a person lived, -
5:59 - 6:00the chronological age.
-
6:00 - 6:02So, how many years they lived.
-
6:02 - 6:05And then we take these top factors
that I showed you, -
6:05 - 6:10and we calculate their relative age,
their biological age. -
6:11 - 6:14And what you see is that
there is a pretty good correlation, -
6:14 - 6:18so we can pretty well predict
the relative age of a person. -
6:18 - 6:22But what's really exciting
are the outliers, -
6:22 - 6:23as they so often are in life.
-
6:24 - 6:28You can see here, the person
I highlighted with the green dot -
6:29 - 6:31is about 70 years of age
-
6:31 - 6:36but seems to have a biological age,
if what we're doing here is really true, -
6:36 - 6:38of only about 45.
-
6:38 - 6:42So is this a person that actually
looks much younger than their age? -
6:42 - 6:47But more importantly: Is this a person
who is maybe at a reduced risk -
6:47 - 6:50to develop an age-related disease
and will have a long life -- -
6:50 - 6:52will live to 100 or more?
-
6:52 - 6:57On the other hand, the person here,
highlighted with the red dot, -
6:57 - 7:02is not even 40,
but has a biological age of 65. -
7:02 - 7:06Is this a person at an increased risk
of developing an age-related disease? -
7:06 - 7:10So in our lab, we're trying
to understand these factors better, -
7:10 - 7:12and many other groups
are trying to understand, -
7:12 - 7:14what are the true aging factors,
-
7:14 - 7:19and can we learn something about them
to possibly predict age-related diseases? -
7:20 - 7:24So what I've shown you so far
is simply correlational, right? -
7:24 - 7:28You can just say,
"Well, these factors change with age," -
7:28 - 7:32but you don't really know
if they do something about aging. -
7:33 - 7:36So what I'm going to show you now
is very remarkable -
7:36 - 7:41and it suggests that these factors
can actually modulate the age of a tissue. -
7:42 - 7:45And that's where we come back
to this model called parabiosis. -
7:45 - 7:48So, parabiosis is done in mice
-
7:48 - 7:53by surgically connecting
the two mice together, -
7:53 - 7:55and that leads then
to a shared blood system, -
7:55 - 8:00where we can now ask,
"How does the old brain get influenced -
8:00 - 8:02by exposure to the young blood?"
-
8:02 - 8:04And for this purpose, we use young mice
-
8:04 - 8:08that are an equivalency
of 20-year-old people, -
8:08 - 8:12and old mice that are roughly
65 years old in human years. -
8:13 - 8:16What we found is quite remarkable.
-
8:16 - 8:20We find there are more neural stem cells
that make new neurons -
8:20 - 8:21in these old brains.
-
8:21 - 8:24There's an increased
activity of the synapses, -
8:24 - 8:26the connections between neurons.
-
8:26 - 8:29There are more genes expressed
that are known to be involved -
8:29 - 8:31in the formation of new memories.
-
8:32 - 8:34And there's less of this bad inflammation.
-
8:35 - 8:42But we observed that there are no cells
entering the brains of these animals. -
8:42 - 8:43So when we connect them,
-
8:43 - 8:49there are actually no cells
going into the old brain, in this model. -
8:49 - 8:53Instead, we've reasoned, then,
that it must be the soluble factors, -
8:53 - 8:58so we could collect simply the soluble
fraction of blood which is called plasma, -
8:58 - 9:02and inject either young plasma
or old plasma into these mice, -
9:02 - 9:04and we could reproduce
these rejuvenating effects, -
9:04 - 9:06but what we could also do now
-
9:06 - 9:08is we could do memory tests with mice.
-
9:08 - 9:12As mice get older, like us humans,
they have memory problems. -
9:13 - 9:14It's just harder to detect them,
-
9:14 - 9:17but I'll show you in a minute
how we do that. -
9:17 - 9:19But we wanted to take this
one step further, -
9:20 - 9:24one step closer to potentially
being relevant to humans. -
9:24 - 9:27What I'm showing you now
are unpublished studies, -
9:27 - 9:31where we used human plasma,
young human plasma, -
9:31 - 9:33and as a control, saline,
-
9:33 - 9:35and injected it into old mice,
-
9:35 - 9:40and asked, can we again
rejuvenate these old mice? -
9:40 - 9:42Can we make them smarter?
-
9:42 - 9:45And to do this, we used a test.
It's called a Barnes maze. -
9:45 - 9:49This is a big table
that has lots of holes in it, -
9:49 - 9:52and there are guide marks around it,
-
9:52 - 9:55and there's a bright light,
as on this stage here. -
9:55 - 9:58The mice hate this and they try to escape,
-
9:58 - 10:02and find the single hole that you see
pointed at with an arrow, -
10:02 - 10:04where a tube is mounted underneath
-
10:04 - 10:07where they can escape
and feel comfortable in a dark hole. -
10:08 - 10:10So we teach them, over several days,
-
10:10 - 10:13to find this space
on these cues in the space, -
10:13 - 10:16and you can compare this for humans,
-
10:16 - 10:20to finding your car in a parking lot
after a busy day of shopping. -
10:20 - 10:21(Laughter)
-
10:21 - 10:25Many of us have probably had
some problems with that. -
10:25 - 10:27So, let's look at an old mouse here.
-
10:27 - 10:29This is an old mouse
that has memory problems, -
10:29 - 10:31as you'll notice in a moment.
-
10:31 - 10:36It just looks into every hole,
but it didn't form this spacial map -
10:36 - 10:41that would remind it where it was
in the previous trial or the last day. -
10:42 - 10:47In stark contrast, this mouse here
is a sibling of the same age, -
10:47 - 10:53but it was treated with young
human plasma for three weeks, -
10:53 - 10:55with small injections every three days.
-
10:56 - 11:00And as you noticed, it almost
looks around, "Where am I?" -- -
11:00 - 11:03and then walks straight
to that hole and escapes. -
11:03 - 11:06So, it could remember where that hole was.
-
11:07 - 11:10So by all means, this old mouse
seems to be rejuvenated -- -
11:10 - 11:13it functions more like a younger mouse.
-
11:13 - 11:16And it also suggests
that there is something -
11:16 - 11:21not only in young mouse plasma,
but in young human plasma -
11:21 - 11:24that has the capacity
to help this old brain. -
11:25 - 11:26So to summarize,
-
11:26 - 11:30we find the old mouse, and its brain
in particular, are malleable. -
11:30 - 11:34They're not set in stone;
we can actually change them. -
11:34 - 11:35It can be rejuvenated.
-
11:36 - 11:38Young blood factors can reverse aging,
-
11:38 - 11:40and what I didn't show you --
-
11:40 - 11:45in this model, the young mouse actually
suffers from exposure to the old. -
11:45 - 11:49So there are old-blood factors
that can accelerate aging. -
11:50 - 11:54And most importantly,
humans may have similar factors, -
11:54 - 11:58because we can take young human
blood and have a similar effect. -
11:59 - 12:02Old human blood, I didn't show you,
does not have this effect; -
12:02 - 12:04it does not make the mice younger.
-
12:05 - 12:09So, is this magic transferable to humans?
-
12:09 - 12:12We're running a small
clinical study at Stanford, -
12:12 - 12:16where we treat Alzheimer's patients
with mild disease -
12:16 - 12:23with a pint of plasma
from young volunteers, 20-year-olds, -
12:23 - 12:26and do this once a week for four weeks,
-
12:26 - 12:29and then we look
at their brains with imaging. -
12:29 - 12:31We test them cognitively,
-
12:31 - 12:35and we ask their caregivers
for daily activities of living. -
12:35 - 12:39What we hope is that there are
some signs of improvement -
12:39 - 12:40from this treatment.
-
12:41 - 12:43And if that's the case,
that could give us hope -
12:43 - 12:46that what I showed you works in mice
-
12:46 - 12:48might also work in humans.
-
12:48 - 12:51Now, I don't think we will live forever.
-
12:52 - 12:54But maybe we discovered
-
12:54 - 12:57that the Fountain of Youth
is actually within us, -
12:57 - 12:59and it has just dried out.
-
13:00 - 13:02And if we can turn it
back on a little bit, -
13:02 - 13:07maybe we can find the factors
that are mediating these effects, -
13:07 - 13:10we can produce these factors synthetically
-
13:10 - 13:14and we can treat diseases of aging,
such as Alzheimer's disease -
13:14 - 13:15or other dementias.
-
13:15 - 13:16Thank you very much.
-
13:16 - 13:20(Applause)
- Title:
- How young blood might help reverse aging. Yes, really
- Speaker:
- Tony Wyss-Coray
- Description:
-
Tony Wyss-Coray studies the impact of aging on the human body and brain. In this eye-opening talk, he shares new research from his Stanford lab and other teams which shows that a solution for some of the less great aspects of old age might actually lie within us all.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 13:35
Brian Greene commented on English subtitles for How young blood might help reverse aging. Yes, really | ||
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Cynthia Betubiza edited English subtitles for How young blood might help reverse aging. Yes, really | ||
Brian Greene edited English subtitles for How young blood might help reverse aging. Yes, really | ||
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Krystian Aparta edited English subtitles for How young blood might help reverse aging. Yes, really | ||
Krystian Aparta edited English subtitles for How young blood might help reverse aging. Yes, really |
Brian Greene
A correction was made to this transcript on 1/15/16.
At 3:06, the subtitle now reads: "molecular, mechanistic level"