Transcriber: 09. Nguyễn Minh Hương Reviewer: David DeRuwe
Let me ask you something.
What’s the most amazing building project on earth?
Take a guess.
Maybe it’s ITER,
the French fusion reactor that’s costing 25 billion USD,
tens of thousands of expert workers, and has been built over 25 years.
But actually no.
What is it?
Look in the mirror.
It’s you.
Building a person is more complex
than any human-made engineering project anywhere,
and it’s incredibly efficient, quick, and almost always perfect,
even if you don’t think that about yourself.
And what about the price?
The average price of a house in the United States now is $375,000.
The cost of building you, in terms of raw materials - $1000.
So how does this amazing construction industry of life work?
Well, I’m a university professor, and I get to ask questions like this,
and my favorite way of answering them is to teach.
So I designed a course called Building with Cells.
We compared building a person and building a house.
It was a fantastic experience for professor and students alike.
Let me tell you what we learned.
And with no science training needed,
you will appreciate the extraordinary process that built you
and the possibilities for improving human health from these processes.
All right, let’s start.
To build a house, you need bricks.
To build a person, you need something analogous.
You’ve probably heard of cells.
A brick is a certain size.
A cell is 10,000 times smaller -
the bricks of life.
When you build a house, you order some bricks,
you get this huge pile of bricks, and you start.
And here’s a big difference:
When you were built, there was one really powerful starter cell,
and that starter cell made more cells and more cells,
and they made more cells and more cells,
until there were 100 trillion cells that are you.
There was no purchase necessary.
When I'm having a bad day,
I sometimes think about how I came from this one tiny cell,
and the magic, the miraculous thing involved in building me,
always improves my day.
You can try it next time.
All right, bricks join. You’ve got to build walls.
You buy yourself some cement, you make yourself a nice wall,
and then, whoops, you realize that actually you’ve put it in the wrong place.
So what do you do?
You demolish it, you cart away the debris, and you start again,
building your wall where you actually want it.
Cells have to build walls, too.
In fact, much of your body is made of beautiful walls of cells,
put together in sheets and various constructs.
The bricks are cemented together, and you purchase the cement.
The cells are cemented together too.
But unlike cement, the cells make their own glues and clamps
that hold themselves together.
And unlike walls, when cells need to reorganize,
when your body needs a new wall somewhere else,
it doesn’t destroy the old one.
The wall breaks apart into single cells,
and those can be reused in an amazingly efficient process.
So how does this work?
How do the cells know to make glues and clamps
and do these various rebuilding processes?
Well, unlike a brick, which is pretty much the same all the way through,
inside every tiny cell, there are production lines and machines.
In fact, each of your cells is a factory.
It is packed with stuff that are making the glues and the clamps
and other chemicals and the whole machinery to make more cells.
Here’s a thought for you:
While you’re sitting here,
each of your 100 trillion cells is buzzing away making stuff,
very busy, extremely productive.
You don’t know it, do you, because it’s kind of quiet?
But that is true. You are a buzz of activity and supply chain.
A brick is a brick.
You get red bricks, get brown bricks, yellow bricks, maybe,
but they’re pretty much the same.
Inside your body,
there are 500 different kinds of cells,
and they look totally different,
and they carry out totally different functions.
They are your red blood cells that carry oxygen around your body,
your muscle cells that allow you to move,
your skin cells that make a nice barrier so that pathogens can’t get inside.
And all of them came from that one powerful starter cell.
It really is mind-boggling.
When you build a house, you put the rooms in the right places for function.
You know, the bedroom is next to the bathroom,
and the kitchen is next to the dining room.
The rooms of your body are your organs,
and they’re also arranged in really good places for function,
and they also, like your house, have different functions.
In fact, your organs are laid out so beautifully,
if you look inside a person, it’s packed like a nice box of chocolates.
If you need an extra bathroom in your house,
you call up a contractor, and within a month ,
you can have your bedroom converted into an extra bathroom.
How about your organs? Nope.
Your heart and your kidney are not the same at all,
and you can’t get any contractor to turn one into another.
Why is that?
Because there are different kinds of cells that make up your heart and your kidney,
and they are really different.
And here’s a conundrum.
Your kidneys are made of at least 10 different kinds of cells.
All of those cells have to get to the right place
at the right time to build your kidney.
How did they know to do that?
Two ways.
Firstly, they move. Cells are on the go.
They move because they’re told to towards a target,
so your kidney cells moved to where your kidney was going to form.
They also have conversations. Cells are very noisy.
They are constantly talking to each other, and they are influencers.
They tell each other what to do.
So one cell will tell another cell what to do.
That cell will hear it and change completely into something else.
Those processes,
the combination of cells moving and cells becoming something else
is what made those 10 kinds of cells
that make your kidney in the right place at the right time
so that the structure could be built.
Very efficient.
You know, in a house, things always need fixing.
The drain gets clogged; the roof is leaking.
You call a repair person, and they come and fix things.
Your body needs fixing all the time, too.
But actually it’s different again.
Your repair and maintenance system is built-in,
and it’s largely carried out by this powerful set of cells called stem cells.
Stem cells have the capacity to make lots of different kinds of cells,
and stem cells will make extra red blood cells where they’re needed,
extra bone cells where they’re needed, extra muscle cells where they’re needed.
Every minute we have been talking ...
every minute, 300 million of your cells have died,
but I bet you haven’t noticed
because 300 million new cells were made in exactly that same time.
It’s like a wall.
You pull out a brick and you quickly put in another one and you don’t notice.
There is so much cell repair and replacement in your body
that, apart from your brain,
you are pretty much new every two or three years.
Quite extraordinary, and it gives a huge opportunity to repair damage,
as you can imagine.
Oh, right.
You build a house, there are architectural plans, there are pages;
you can put out the pages that say how to build a kitchen.
There are plans to build a person to be different.
They’re called the genetic code, and you’ve probably heard of DNA.
The genetic code is not a book of plans.
Rather, it is long strings of code of four chemicals: A, G, C, and T.
And there are long, long strands of these.
And in every cell of your body,
there are 3 billion pieces of code arranged in chunks called genes.
Every one of your cells has the entire book of plans to build a person.
How does it work?
Well, we know and we don’t know.
It is not completely understood
how the genes are used as plans to build a person.
They work together over time and over space,
and somehow this working together
is what gives you the blueprint to make a heart or a kidney.
We know enough that if someone has a genetic disorder,
scientists and doctors can go in and can find the bit of the code
that has been changed, that isn’t working optimally.
And sometimes that knowledge
can lead to very precise and useful treatments for that disorder -
not all the time, but more and more.
It’s really an extraordinary power of genetic medicine.
In our course, the students learned the principles of how life was built.
We also explored what you could do with those principles;
how cells could be engineered
to move towards cures for disease or organ repair.
We talked about cancer immunotherapy,
where cells can be changed to target and kill a tumor.
We talked about how scientists have painstakingly been able
to build cells in the lab that produce insulin, pancreatic beta cells,
and how these are in pre-clinical trials
and will go ahead to help people with certain types of diabetes.
We talked about how you can’t in the lab build a full kidney,
but scientists can build little bits of kidneys,
and those little bits are being really useful
to understand how kidney disease works.
Maybe someday they can be put together to make something like a functional kidney
that can help with the enormous need for organ transplants.
And we talked about crazy things like 3-D printing with cells
that can build tiny blood vessels someday
that can be used to help people with vascular disease.
Along the way, we realized something
that although the raw materials to build a person really run not very much,
the value of the built product - the person - is enormous.
It’s inestimable.
It’s the value of life.
I told the students that I think anything is possible
in the great Construction Industry of Life!
We are bounded only by our creativity and our determination.
Thank you.
(Applause)