Dr. Alysson Muotri

How the Tooth Fairy is helping unlock the secrets of autism

/ Kevin McCormack / Leave a comment

Our 2021-22 Annual Report is now online. It’s filled with information about the work we have done over the last year (we are on a fiscal calendar year from July 1 – June 30), the people who have helped us do that work, and some of the people who have benefited from that work. One of those is Dr. Alysson Muotri, a professor in the Departments of Pediatrics and Cellular & Molecular Medicine at the University of California, San Diego.

Dr. Alysson Muotri, in his lab at UCSD

For Dr. Alysson Muotri, trying to unlock the secrets of the brain isn’t just a matter of scientific curiosity, it’s personal. He has a son with autism and Dr. Muotri is looking for ways to help him, and millions of others like him around the world.

He created the Tooth Fairy project where parents donated more than 3,000 baby teeth from  children with autism and children who are developing normally. Dr. Muotri then turned cells from those teeth into neurons, the kind of brain cell affected by autism. He is using those cells to try and identify how the brain of a child with autism differs from a child who is developing normally.

“We’ve been using cells from this population to see what are the alterations (in the gene) and if we can revert them back to a normal state. If you know the gene that is affected, and autism has a strong genetic component, by genome sequencing you can actually find what are the genes that are affected and in some cases there are good candidates for gene therapy. So, you just put the gene back. And we can see that in the lab where we are correcting the gene that is mutated, the networks start to function in a way that is more neurotypical or normal. We see that as highly promising, there’s a huge potential here to help those individuals.”

He is also creating brain organoids, three-dimensional structures created from stem cells that mimic some of the actions and activities of the brain. Because these are made from human cells, not mice or other animals, they may be better at indicating if new therapies have any potential risks for people.

“We can test drugs in the brain organoids of the person and see if it works, see if there’s any toxicity before you actually give the drug to a person, and it will save us time and money and will increase our knowledge about the human brain.”

He says he still gets excited seeing how these cells work. “It’s amazing, it’s a miracle. Every time I see it, it’s like seeing dolphins in the sea because it’s so beautiful.”

Dr. Muotri is also a big proponent of diversity, equity and inclusion in scientific research. He says in the past it was very much a top-down model with scientists deciding what was important. He says we need to change that and give patients and communities a bigger role in shaping the direction of research.

“I think this is something we scientists have to learn, how to incorporate patients in our research. These communities are the ones we are studying, and we need to know what they want and not assume that what we want is what they want. They should be consulted on our grants, and they should participate in the design of our experiments. That is the future.”

Meet the man who is unlocking the secrets of autism and sending mini-brains into space

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Dr. Alysson Muotri, UC San Diego

Normally if you meet someone who has a mini-fridge filled with brains, your first thought is to call the police. But when that someone is Dr. Alysson Muotri, a professor at U.C. San Diego, your second thought is “do tell me more.”

Alysson is a researcher who is fascinated by the human brain. He is working on many levels to try and unlock its secrets and give us a deeper understanding of how our brains evolved and how they work.

One of the main focuses of his work is autism (he has a son on the autism spectrum) and he has found a way to see what is happening inside the cells affected by autism—work that is already leading to the possibility of new treatments.

As for those mini-brains in his lab? Those are brain organoids, clumps of neurons and other cells that resemble—on a rudimentary level—our brains. They are ideal tools for seeing how our brains are organized, how the different cells signal and interact with each other. He’s already sent some of these brain organoids into space.

Brain in space

Alysson talks about all of this, plus how our brains compare to those of Neanderthals, on the latest episode of our podcast, Talking ‘Bout (re)Generation.

It’s a fascinating conversation. Enjoy.

Scientists use stem cells to create Neanderthal-like “mini-brain”

/ Yimy Villa / 2 Comments
Alysson R. Muotri, Ph.D.

The evolution of modern day humans has always been a topic that has been shrouded in mystery. Some of what is known is that Neanderthals, an archaic human species that lived on this planet up until about 11,700 years ago, interbred with our species (Homo sapiens) at some point in time. Although their brains were about as big as ours, anthropologists think they must have worked differently due to the fact that they never achieved the sophisticated technology and artistry modern humans have.

Since brains do not fossilize, it has been challenging to see how these two early human species have changed over time. To help answer this question, Dr. Alysson Muotri and his team at UC San Diego created so-called “mini-brains” using stem cells and gene editing technology to better understand how the Neanderthal brain might have functioned.

For this study, Dr. Muotri and his team closely evaluated the differences in genes between modern day humans and Neanderthals. They found a total of 61 different genes, but for this study focused on one in particular that plays a role in influencing early brain development.

Brain organoids that carry a Neanderthal gene.
Image courtesy of the Muotri Lab and UCSD

Using gene editing technology, the team introduced the Neanderthal version of the gene into human stem cells. These stem cells, which have the ability to become various cell types, were then used to create brain cells. These cells eventually formed brain organoids or “mini-brains”, 3D models made of cells that can be used to analyze certain features of the human brain. Although they are far from perfect replicas, they can be used to study physical structure and other characteristics. In a previous CIRM funded study, Dr. Muotri had used “mini-brains” to model an autism spectrum disorder and help test treatments.

Dr. Muotri and his team found that the Neanderthal-like brain organoids looked very different than modern human brain organoids, having a distinctly different shape. Upon further analysis, the team found that modern and Neanderthal-like brain organoids also differed in the way their cells grow. Additionally, the way in which connections between neurons formed as well as the proteins involved in forming these connections differed between the two organoids. Finally, electrical impulses displayed higher activity at earlier stages, but didn’t synchronize in networks in Neanderthal-like brain organoids.

According to Muotri, the neural network changes in Neanderthal-like brain organoids mimic the way newborn primates acquire new abilities more rapidly than human newborns.

In a news release from UCSD, Dr. Muotri discusses the next steps in advancing this research.

“This study focused on only one gene that differed between modern humans and our extinct relatives. Next we want to take a look at the other 60 genes, and what happens when each, or a combination of two or more, are altered. We’re looking forward to this new combination of stem cell biology, neuroscience and paleogenomics.”

The full results of this study were published in Science.

Ask the Stem Cell Team About Autism

/ Kevin McCormack / 2 Comments

Do an online search for “autism stem cells” and you quickly come up with numerous websites offering stem cell therapies for autism. They offer encouraging phrases like “new and effective approach” and “a real, lasting treatment.” They even include dense scientific videos featuring people like Dr. Arnold Caplan, a professor at Case Western Reserve University who is known as the “father of the mesenchymal stem” (it would be interesting to know if Dr. Caplan knows he is being used as a marketing tool?)

The problem with these sites is that they are offering “therapies” that have never been proven to be safe, let alone effective. They are also very expensive and are not covered by insurance. Essentially they are preying on hope, the hope that any parent of a child with autism spectrum disorder (ASD) will do anything and everything they can to help their child.

But there is encouraging news about stem cells and autism, about their genuine potential to help children with ASD. That’s why we are holding a special Facebook Live “Ask the Stem Cell Team” about Autism on Thursday, March 19th at noon (PDT).    

The event features Dr. Alysson Muotri from UC San Diego. We have written about his work with stem cells for autism in the past. And CIRM’s own Associate Director for Discovery and Translation, Dr. Kelly Shephard.

We’ll take a look at Dr. Muotri’s work and also discuss the work of other researchers in the field, such as Dr. Joanne Kurtzberg’s work at Duke University.

But we also want you to be a part of this as well. So, join us online for the event. You can post comments and questions during the event, and we’ll do our best to answer them. Or you can send us in questions ahead of time to info@cirm.ca.gov.

If you missed the “broadcast” not to worry, you can watch it here:

Two studies identify a molecule that could be used to block Zika virus and kill cancer cells

/ Yimy Villa / 1 Comment
Dr. Tariq Rana (left) and Dr. Jeremy Rich (right) both lead independent teams at UC San Diego that identified a molecule, αvβ5 integrin, as the Zika virus’ key to getting into brain stem cells

Zika virus is caused by a virus transmitted by Aedes mosquitoes. People usually develop mild symptoms that include fever, rash, and muscle and joint pain. However, Zika virus infection during pregnancy can lead to much more serious problems. The virus causes infants to be born with microcephaly, a condition in which the brain does not develop properly, resulting in an abnormally small head. In 2015-2016, the rapid spread of the virus was observed in Latin America and the Caribbean, increasing the urgency of understanding how the virus affected brain development.

Working independently, Dr. Tariq Rana and Dr. Jeremy Rich from UC San Diego identified the same molecule, αvβ5 integrin, as the Zika virus’ key to entering brain stem cells. The two studies, with the aid of CIRM funding, discovered how to take advantage of the molecule in order to block the Zika virus from infecting cells. In addition to this, they were able to turn it into something useful: a way to destroy brain cancer stem cells.

In the first study, Dr. Rana and his team used CRISPR gene editing on brain cancer stem cells to delete individual genes, which was done to see which genes are required for the Zika virus to enter the cells. They discovered that the gene responsible for αvβ5 integrin also enabled the Zika virus.

In a press release by UC San Diego, Dr. Rana elaborates on the importance of his findings.

“…we found Zika uses αvβ5, which is unique. When we further examined αvβ5 expression in brain, it made perfect sense because αvβ5 is the only integrin member enriched in neural stem cells, which Zika preferentially infects. Therefore, we believe that αvβ5 is the key contributor to Zika’s ability to infect brain cells.”

In the second study, Dr. Rich and his team use an antibody to block αvβ5 integrin and found that it prevented the virus from infecting brain cancer stem cells and normal brain stem cells. The team then went on to block αvβ5 integrin in a mouse model for glioblastoma, an aggressive type of brain tumor, by using an antibody or deactivating the gene responsible for the molecule. Both approaches blocked Zika virus infection and allowed the treated mice to live longer than untreated mice. 

Dr. Rich then partnered with Dr. Alysson Muotri at UC San Diego to transplant glioblastoma tumors into laboratory “mini-brains” that can be used for drug discovery. The researchers discovered that Zika virus selectively eliminates glioblastoma stem cells from the mini-brains. Additionally, blocking αvβ5 integrin reversed that anti-cancer activity, further demonstrating the molecule’s crucial role in Zika virus’ ability to destroy cells.

In the same UC San Diego press release, Dr. Rich talks about how understanding Zika virus could help in treating glioblastoma.

“While we would likely need to modify the normal Zika virus to make it safer to treat brain tumors, we may also be able to take advantage of the mechanisms the virus uses to destroy cells to improve the way we treat glioblastoma.”

Dr. Rana’s full study was published in Cell Reports and Dr. Rich’s full study was published in Cell Stem Cell.