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To get started with the Braving Anxiety journey,
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[♩INTRO]
In 2020, researchers did something that sounds straight out of a sci-fi movie.
In experiments on mice, they took a type of cell called a glia cell,
and they transformed it into a neuron.
In a sense, they took one kind of body part and turned it into another one.
And apart from being amazing, this technology could potentially
reverse symptoms of Parkinson’s Disease.
Parkinson’s is characterized by the death of a population of neurons that produce
dopamine — a neurotransmitter that regulates movement, among other things.
That’s why the disease causes symptoms such as tremors
and difficulty with motion.
Today, we have medications that keep Parkinson’s at bay.
But they eventually stop working as the dopamine-producing cells die off,
since drugs can’t work if there’s no target cell to act on.
One solution scientists have talked about here is stem cell therapy.
Stem cells are sort of a blank canvas. They’re undifferentiated,
which means they can turn into a variety of cell types.
So, if stem cells were used in a treatment,
some of them could transform into neurons to replace the dead ones.
But accessing stem cells is difficult.
It can require a bone marrow transplant or harvesting cells from fetal tissue,
both of which come with their own challenges.
So, a much more appealing approach would be to reprogram
a patient’s existing cells to start making dopamine again… somehow.
It’s a tall order, but scientists have actually figured out how to do that using,
of all things, viruses and bacteria.
One technique they’ve used utilizes AAV technology.
The AAV stands for adeno-associated virus.
These viruses don’t cause human diseases, so they make great lab tools.
Like any virus, they insert their genes into a host cell,
and the host cell follows those genetic instructions.
Normally, the instructions tell the cell to start assembling more copies
of the virus, so the virus can replicate and continue infecting something.
But in this case, researchers can edit the genes carried by the AAV,
and provide new instructions to tell the cell what to make or how to behave.
The second technique is a newer gene-editing technology called CRISPR-Cas9.
With CRISPR, scientists program a bacterial enzyme
to act like a pair of very precise scissors that snip out specific genes.
The trouble is, there isn’t just one gene behind Parkinson’s Disease.
And we don’t understand the disease well enough to go in
and somehow rescue those dying dopamine cells with AAVs.
But we may be able to use these techniques to replace the neurons.
And that brings us back to 2020.
In papers published that year, two research groups did just that by using AAV
or CRISPR to make a simple genetic edit in glia cells.
Glia are support cells for neurons.
Among other things, they provide electrical insulation, clear up excess
neurotransmitters, respond to brain injuries, and form the blood-brain barrier.
In fact, there are probably almost as many glia in your brain
and nervous system as there are neurons!
And in their study, scientists were able to convert glia into neurons
by decreasing, or knocking down, the activity of just one small gene family,
called Ptbp.
Depending on the study, they did this by either using AAV
to inhibit their target gene, or CRISPR to cut it out completely.
Now, the fascinating thing is,
Ptbp isn’t actually related to Parkinson’s or dopamine.
Instead, this group seems to be involved at an early developmental stage
in determining which cells become neurons and which don’t.
And when one of these genes is blocked or edited out,
that stops a cell from producing a specific protein — and changes its destiny.
In these studies, scientists transformed glia cells into neurons
that had all the typical features you’d expect:
They produced neuron-like electrical signals,
expressed neuron-specific genes, and even made dopamine.
That part is especially cool, because not all neurons produce dopamine.
But in this case, the former-glia cells got the memo to fill that specific role
maybe from signals in the neighboring brain region.
The coolest thing of all, though, is that this didn’t just happen in a petri dish.
The scientists used this technique on live mice with Parkinson’s-like symptoms.
And over time, the treatment returned the mice’s dopamine levels
and movement ability to normal.
Which is incredible.
Now, if glia are so important, it might seem unwise to transform
some of them into neurons.
But luckily, new glia are reliably produced throughout adulthood,
so swapping a few of them shouldn’t pose a long-term problem.
And in other cases, scientists can also change
other kinds of cells into neurons, too — including cancer cells.
Other researchers have converted a carcinoma cell line into neurons,
using a similar editing technique to tweak this same gene.
So this kind of technology may have applications even far beyond Parkinson’s.
That said, clinical applications will still have to be developed and tested
Before this could become a viable therapy in humans.
We are talking about some pretty serious brain surgery here.
Drilling a hole into someone’s skull is no simple feat.
And injecting gene-editing vectors into the brain is a delicate procedure!
Still, this is a big step in our understanding of how brain cells develop.
And it’s a huge leap towards curing Parkinson’s and similar diseases.
The human brain is complex, but it’s also something we can understand.
And that’s true for the feelings we experience as well, including anxiety.
Feeling anxiety is completely normal,
but can be a lot more useful in some situations than in others.
And if you want to learn more about that,
you can check out the “Braving Anxiety” journey on the Sanvello app.
It’s hosted by none other than John Green,
who takes you through an expert-designed program to help you
recognize triggers and thinking traps, plus help you reduce stress and anxiety.
The app is ranked #1 for stress, anxiety, and depression, and you can download
it for free in your app store or by clicking the link in the description.
[♩OUTRO]