(dramatic music)
(bright music)
- [Narrator] These
scientists work in the lab of
Juan Carlos Izpisua Belmonte.
They want to find ways to turn genes on
in living organisms, to fight disease.
It is not gene editing,
although it involves a gene editing tool.
This is your DNA.
This is your DNA on CRISPR.
The gene editing tool CRISPR-Cas9
can be directed to cut
DNA in specific places.
It combines a GPS feature, Guide RNA,
with a cutting feature, Cas9 enzyme.
The two can be packaged inside a virus
to be delivered into cells.
But this genetic cut and paste
risks causing permanent DNA damage.
So another approach is epigenetic.
Epi, meaning above.
It is a way to turn genes on
or off without altering DNA.
It is not permanent.
Salk scientists wanted
to modify CRISPR-Cas9
and use it to make epigenetic changes.
The team used modified Guide RNA
to keep the GPS feature of CRISPR,
but without a cutting property.
At the same time, they
attached gene switches
to the CRISPR system so it could genes on.
However, this made the
whole package too big
to fit inside a single virus
for efficiently delivering
into living organisms.
So the Salk team had the idea
to split the components into two packages.
One virus package
containing the Cas9 enzyme,
the other virus package containing
the GPS system and gene switches.
In theory, the packages
would work together
after being injected into a patient.
The team tested the system on mice
with a form of muscular dystrophy.
It's a disease that causes muscle weakness
due to a faulty dystrophin gene.
But instead of trying to repair
the faulty dystrophin gene,
the Salk team used their technology
to turn on a similar gene called utrophin.
Results showed that
mice with the treatment
increased in strength and muscle mass.
Their health improved.
The team also tested
elements of the system
to turn on genes that
help relieve kidney damage
and to convert ordinary liver cells
into insulin-producing
cells in a diabetic model.
There were promising results
in mice in both cases.
The Salk research shows that CRISPR-Cas9
can be modified to activate
genes in living organisms
without changing their DNA.
It is an alternative to gene editing,
but can be ideally targeted to any gene
without causing permanent
changes or damage.
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