A Clinical Trial Network Focused on Stem Cell Treatments is Expanding

Geoff Lomax is a Senior Officer of CIRM’s Strategic Initiatives.

California is one of the world-leaders in advancing stem cell research towards treatments and cures for patients with unmet medical needs. California has scientists at top universities and companies conducting cutting edge research in regenerative medicine. It also has CIRM, California’s Stem Cell Agency, which funds promising stem cell research and is advancing stem cell therapies into clinical trials. But the real clincher is that California has something that no one else has: a network of medical centers dedicated to stem cell-based clinical trials for patients. This first-of-its-kind system is called the CIRM Alpha Stem Cell Clinics Network.

Get to Know Our Alpha Clinics

In 2014, CIRM launched its Alpha Stem Cell Clinics Network to accelerate the development and delivery of stem cell treatments to patients. The network consists of three Alpha Clinic sites at UC San Diego, City of Hope in Duarte, and a joint clinic between UC Los Angeles and UC Irvine. Less than three years since its inception, the Alpha Clinics are conducting 34 stem cell clinical trials for a diverse range of diseases such as cancer, heart disease and sickle cell anemia. You can find a complete list of these clinical trials on our Alpha Clinics website. Below is an informational video about our Alpha Clinics Network.

So far, hundreds of patients have been treated at our Alpha Clinics. These top-notch medical centers use CIRM-funding to build teams specialized in overseeing stem cell trials. These teams include patient navigators who provided in-depth information about clinical trials to prospective patients and support them during their treatment. They also include pharmacists who work with patients’ cells or manufactured stem cell-products before the therapies are given to patients. And lastly, let’s not forget the doctors and nurses that are specially trained in the delivery of stem cell therapies to patients.

The Alpha Clinics Network also offers resources and tools for clinical trial sponsors, the people responsible for conducting the trials. These include patient education and recruitment tools and access to over 20 million patients in California to support successful recruitment. And because the different clinical trial sites are in the same network, sponsors can benefit from sharing the same approval measures for a single trial at multiple sites.

Looking at the big picture, our Alpha Clinics Network provides a platform where patients can access the latest stem cell treatments, and sponsors can access expert teams at multiple medical centers to increase the likelihood that their trial succeeds.

The Alpha Clinics Network is expanding

This collective expertise has resulted in a 3-fold (from 12 to 36 – two trials are being conducted at two sites) increase in the number of stem cell clinical trials at the Alpha Clinic sites since the Network’s inception. And the number continues to rise every quarter. Given this impressive track record, CIRM’s Board voted in February to expand our Alpha Clinics Network. The Board approved up to $16 million to be awarded to two additional medical centers ($8 million each) to create new Alpha Clinic sites and work with the current Network to accelerate patient access to stem cell treatments.

CIRM’s Chairman Jonathan Thomas explained,

Jonathan Thomas

“We laid down the foundation for conducting high quality stem cell trials when we started this network in 2014. The success of these clinics in less than three years has prompted the CIRM Board to expand the Network to include two new trial sites. With this expansion, CIRM is building on the current network’s momentum to establish new and better ways of treating patients with stem cell-based therapies.”

The Alpha Clinics Network plays a vital role in CIRM’s five-year strategic plan to fund 50 new clinical trials by 2020. In fact, the Alpha Clinic Network supports clinical trials funded by CIRM, industry sponsors and other sources. Thus, the Network is on track to becoming a sustainable resource to deliver stem cell treatments indefinitely.

In addition to expanding CIRM’s Network, the new sites will develop specialized programs to train doctors in the design and conduct of stem cell clinical trials. This training will help drive the development of new stem cell therapies at California medical centers.

Apply to be one our new Alpha Clinics!

For the medical centers interested in joining the CIRM Alpha Stem Cell Clinics Network, the deadline for applications is May 15th, 2017. Details on this funding opportunity can be found on our funding page.

The CIRM Team looks forward to working with prospective applicants to address any questions. The Alpha Stem Cell Clinics Network will also be showcasing it achievement at its Second Annual Symposium, details may be found on the City of Hope Alpha Clinics website.

City of Hope Medical Center and Alpha Stem Cell Clinic


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Funding stem cell research targeting a rare and life-threatening disease in children

cystinosis

Photo courtesy Cystinosis Research Network

If you have never heard of cystinosis you should consider yourself fortunate. It’s a rare condition caused by an inherited genetic mutation. It hits early and it hits hard. Children with cystinosis are usually diagnosed before age 2 and are in end-stage kidney failure by the time they are 9. If that’s not bad enough they also experience damage to their eyes, liver, muscles, pancreas and brain.

The genetic mutation behind the condition results in an amino acid, cystine, accumulating at toxic levels in the body. There’s no cure. There is one approved treatment but it only delays progression of the disease, has some serious side effects of its own, and doesn’t prevent the need for a  kidney transplant.

Researchers at UC San Diego, led by Stephanie Cherqui, think they might have a better approach, one that could offer a single, life-long treatment for the problem. Yesterday the CIRM Board agreed and approved more than $5.2 million for Cherqui and her team to do the pre-clinical testing and work needed to get this potential treatment ready for a clinical trial.

Their goal is to take blood stem cells from people with cystinosis, genetically-modify them and return them to the patient, effectively delivering a healthy, functional gene to the body. The hope is that these genetically-modified blood stem cells will integrate with various body organs and not only replace diseased cells but also rescue them from the disease, making them healthy once again.

In a news release Randy Mills, CIRM’s President and CEO, said orphan diseases like cystinosis may not affect large numbers of people but are no less deserving of research in finding an effective therapy:

“Current treatments are expensive and limited. We want to push beyond and help find a life-long treatment, one that could prevent kidney failure and the need for kidney transplant. In this case, both the need and the science were compelling.”

The beauty of work like this is that, if successful, a one-time treatment could last a lifetime, eliminating or reducing kidney disease and the need for kidney transplantation. But it doesn’t stop there. The lessons learned through research like this might also apply to other inherited multi-organ degenerative disorders.

Salk Scientists Unlock New Secrets of Autism Using Human Stem Cells

Autism is a complex neurodevelopmental disorder whose mental, physical, social and emotional symptoms are highly variable from person to person. Because individuals exhibit different combinations and severities of symptoms, the concept of autism spectrum disorder (ASD) is now used to define the range of conditions.

There are many hypotheses for why autism occurs in humans (which some estimates suggest now affects around 3.5 million people in the US). Some of the disorders are thought to be at the cellular level, where nerve cells do not develop normally and organize properly in the brain, and some are thought to be at the molecular level where the building blocks in cells don’t function properly. Scientists have found these clues by using tools such as studying human genetics and animal models, imaging the brains of ASD patients, and looking at the pathology of ASD brains to see what has gone wrong to cause the disease.

Unfortunately, these tools alone are not sufficient to recreate all aspects of ASD. This is where cellular models have stepped in to help. Scientists are now developing human stem cell derived models of ASD to create “autism in a dish” and are finding that the nerve cells in these models show characteristics of these disorders.

Stem cell models of autism and ASD

We’ve reported on some of these studies in previous blogs. A group from UCSD lead by CIRM grantee Alysson Muotri used induced pluripotent stem cells or iPS cells to model non-syndromic autism (where autism is the primary diagnosis). The work has been dubbed the “Tooth Fairy Project” – parents can send in their children’s recently lost baby teeth which contain cells that can be reprogrammed into iPS cells that can then be turned into brain cells that exhibit symptoms of autism. By studying iPS cells from individuals with non-syndromic autism, the team found a mutation in the TRPC6 gene that was linked to abnormal brain cell development and function and is also linked to Rett syndrome – a rare form of autism predominantly seen in females.

Another group from Yale generated “mini-brains” or organoids derived from the iPS cells of ASD patients. They specifically found that ASD mini-brains had an increased number of a type of nerve cell called inhibitory neurons and that blocking the production of a protein called FOXG1 returned these nerve cells back to their normal population count.

Last week, a group from the Salk Institute in collaboration with scientists at UC San Diego published findings about another stem cell model for ASD that offers new clues into the early neurodevelopmental defects seen in ASD patients.  This CIRM-funded study was led by senior author Rusty Gage and was published last week in the Nature journal Molecular Psychiatry.

Unlocking clues to autism using patient stem cells

Gage and his team were fascinated by the fact that as many as 30 percent of people with ASD experience excessive brain growth during early in development. The brains of these patients have more nerve cells than healthy individuals of the same age, and these extra nerve cells fail to organize properly and in some cases form too many nerve connections that impairs their overall function.

To understand what is going wrong in early stages of ASD, Gage generated iPS cells from ASD individuals who experienced abnormal brain growth at an early age (their brains had grown up to 23 percent faster when they were toddlers compared to normal toddlers). They closely studied how these ASD iPS cells developed into brain stem cells and then into nerve cells in a dish and compared their developmental progression to that of healthy iPS cells from normal individuals.

Neurons derived from people with ASD (bottom) form fewer inhibitory connections (red) compared to those derived from healthy individuals (top panel). (Salk Institute)

Neurons derived from people with ASD (bottom) form fewer inhibitory connections (red) compared to those derived from healthy individuals (top panel). (Salk Institute)

They quickly observed a problem with neurogenesis – a term used to describe how brain stem cells multiply and create new nerve cells in the brain. Brain stem cells derived from ASD iPS cells displayed more neurogenesis than normal brain stem cells, and thus were creating an excess amount of nerve cells. The scientists also found that the extra nerve cells failed to form as many synaptic connections with each other, an essential process that allows nerve cells to send signals and form a functional network of communication, and also behaved abnormally and overall had less activity compared to healthy neurons. Interestingly, they saw fewer inhibitory neuron connections in ASD neurons which is contrary to what the Yale study found.

The abnormal activity observed in ASD neurons was partially corrected when they treated the nerve cells with a drug called IGF-1, which is currently being tested in clinical trials as a possible treatment for autism. According to a Salk news release, “the group plans to use the patient cells to investigate the molecular mechanisms behind IGF-1’s effects, in particular probing for changes in gene expression with treatment.”

Will stem cells be the key to understanding autism?

It’s clear that human iPS cell models of ASD are valuable in helping tease apart some of the mechanisms behind this very complicated group of disorders. Gage’s opinion is that:

“This technology allows us to generate views of neuron development that have historically been intractable. We’re excited by the possibility of using stem cell methods to unravel the biology of autism and to possibly screen for new drug treatments for this debilitating disorder.”

However, to me it’s also clear that different autism stem cell models yield different results, but these differences are likely due to which populations the iPS cells are derived from. Creating more cell lines from different ASD subpopulations will surely answer more questions about the developmental differences and differences in brain function seen in adults.

Lastly, one of the co-authors on the study, Carolina Marchetto, made a great point in the Salk news release by acknowledging that their findings are based on studying cells in a dish, not actual patient’s brains. However, Marchetto believes that these cells are useful tools for studying autism:

“It never fails to amaze me when we can see similarities between the characteristics of the cells in the dish and the human disease.”

Rusty Gage and Carolina Marchetto. (Salk Institute)

Rusty Gage and Carolina Marchetto. (Salk Institute)


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Multi-Talented Stem Cells: The Many Ways to Use Them in the Clinic

CIRM kicked off the 2016 International Society for Stem Cell Research (ISSCR) Conference in San Francisco with a public stem cell event yesterday that brought scientists, patients, patient advocates and members of the general public together to discuss the many ways stem cells are being used in the clinic to develop treatments for patients with unmet medical needs.

Bruce Conklin, Gladstone Institutes & UCSF

Bruce Conklin, Gladstone Institutes & UCSF

Bruce Conklin, an Investigator at the Gladstone Institutes and UCSF Professor, moderated the panel of four scientists and three patient advocates. He immediately captured the audience’s attention by showing a stunning video of human heart cells, beating in synchrony in a petri dish. Conklin explained that scientists now have the skills and technology to generate human stem cell models of cardiomyopathy (heart disease) and many other diseases in a dish.

Conklin went on to highlight four main ways that stem cells are contributing to human therapy. First is using stem cells to model diseases whose causes are still largely unknown (like with Parkinson’s disease). Second, genome editing of stem cells is a new technology that has the potential to offer cures to patients with genetic disorders like sickle cell anemia. Third, stem cells are known to secrete healing factors, and transplanting them into humans could be beneficial. Lastly, stem cells can be engineered to attack cancer cells and overcome cancer’s normal way of evading the immune system.

Before introducing the other panelists, Conklin made the final point that stem cell models are powerful because scientists can use them to screen and develop new drugs for diseases that have no treatments or cures. His lab is already working on identifying new drugs for heart disease using human induced pluripotent stem cells derived from patients with cardiomyopathy.

Scientists and Patient Advocates Speak Out

Malin Parmar, Lund University

Malin Parmar, Lund University

The first scientist to speak was Malin Parmar, a Professor at Lund University. She discussed the history of stem cell development for clinical trials in Parkinson’s disease (PD). Her team is launching the first in-human trial for Parkinson’s using cells derived from human pluripotent stem cells in 2016. After Parmar’s talk, John Lipp, a PD patient advocate. He explained that while he might look normal standing in front of the crowd, his PD symptoms vary wildly throughout the day and make it hard for him to live a normal life. He believes in the work that scientists like Parmar are doing and confidently said, “In my lifetime, we will find a stem cell cure for Parkinson’s disease.”

Adrienne Shapiro, Patient Advocate

Adrienne Shapiro, Patient Advocate

The next scientist to speak was UCLA Professor Donald Kohn. He discussed his lab’s latest efforts to develop stem cell treatments for different blood disorder diseases. His team is using gene therapy to modify blood stem cells in bone marrow to treat and cure babies with SCID, also known as “bubble-boy disease”. Kohn also mentioned their work in sickle cell disease (SCD) and in chronic granulomatous disease, both of which are now in CIRM-funded clinical trials. He was followed by Adrienne Shapiro, a patient advocate and mother of a child with SCD. Adrienne gave a passionate and moving speech about her family history of SCD and her battle to help find a cure for her daughter. She said “nobody plans to be a patient advocate. It is a calling born of necessity and pain. I just wanted my daughter to outlive me.”

Henry Klassen (UC Irvine)

Henry Klassen, UC Irvine

Henry Klassen, a professor at UC Irvine, next spoke about blinding eye diseases, specifically retinitis pigmentosa (RP). This disease damages the photo receptors in the back of the eye and eventually causes blindness. There is no cure for RP, but Klassen and his team are testing the safety of transplanting human retinal progenitor cells in to the eyes of RP patients in a CIRM-funded Phase 1/2 clinical trial.

Kristen MacDonald, RP patient

Kristen MacDonald, RP patient

RP patient, Kristen MacDonald, was the trial’s first patient to be treated. She bravely spoke about her experience with losing her vision. She didn’t realize she was going blind until she had a series of accidents that left her with two broken arms. She had to reinvent herself both physically and emotionally, but now has hope that she might see again after participating in this clinical trial. She said that after the transplant she can now finally see light in her bad eye and her hope is that in her lifetime she can say, “One day, people used to go blind.”

Lastly, Catriona Jamieson, a professor and Alpha Stem Cell Clinic director at UCSD, discussed how she is trying to develop new treatments for blood cancers by eradicating cancer stem cells. Her team is conducting a Phase 1 CIRM-funded clinical trial that’s testing the safety of an antibody drug called Cirmtuzumab in patients with chronic lymphocytic leukemia (CLL).

Scientists and Patients need to work together

Don Kohn, Catriona Jamieson, Malin Parmar

Don Kohn, Catriona Jamieson, Malin Parmar

At the end of the night, the scientists and patient advocates took the stage to answer questions from the audience. A patient advocate in the audience asked, “How can we help scientists develop treatments for patients more quickly?”

The scientists responded that stem cell research needs more funding and that agencies like CIRM are making this possible. However, we need to keep the momentum going and to do that both the physicians, scientists and patient advocates need to work together to advocate for more support. The patient advocates in the panel couldn’t have agreed more and voiced their enthusiasm for working together with scientists and clinicians to make their hopes for cures a reality.

The CIRM public event was a huge success and brought in more than 150 people, many of whom stayed after the event to ask the panelists more questions. It was a great kick off for the ISSCR conference, which starts today. For coverage, you can follow the Stem Cellar Blog for updates on interesting stem cell stories that catch our eye.

CIRM Public Stem Cell Event

CIRM Public Stem Cell Event

Stem cell stories that caught our eye: a surprising benefit of fasting, faster way to make iPSCs, unlocking the secret of leukemia cancer cells

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Fasting

Is fasting the fountain of youth?

Among the many insults our bodies endure in old age is a weakened immune system which leaves the elderly more susceptible to infection. Chemotherapy patients also face the same predicament due to the immune suppressing effects of their toxic anticancer treatments. While many researchers aim to develop drugs or cell therapies to protect the immune system, a University of Southern California research report this week suggests an effective alternative intervention that’s startlingly straightforward: fasting for 72 hours.

The study published in Cell Stem Cell showed that cycles of prolonged fasting in older mice led to a decrease in white blood cells which in turn set off a regenerative burst of blood stem cells. This restart of the blood stem cells replenished the immune system with new white blood cells. In a pilot Phase 1 clinical trial, cancer patients who fasted 72 hours before receiving chemotherapy maintained normal levels of white blood cells.

A look at the molecular level of the process pointed to a decrease in the levels of a protein called PKA in stem cells during the fasting period. In a university press release carried by Science Daily, the study leader, Valter Longo, explained the significance of this finding:

“PKA is the key gene that needs to shut down in order for these stem cells to switch into regenerative mode. It gives the ‘okay’ for stem cells to go ahead and begin proliferating and rebuild the entire system. And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting. Now, if you start with a system heavily damaged by chemotherapy or aging, fasting cycles can generate, literally, a new immune system.”

In additional to necessary follow up studies, the team is looking into whether fasting could benefit other organ systems besides the immune system. If the data holds up, it could be that regular fasting or direct targeting of PKA could put us on the road to a much more graceful and healthier aging process.

4955224186_31f969e6fd_m

Faster, cheaper, safer way to use iPS cells

Science, like traffic in any major city, never moves quite as quickly as you would like, but now Japanese researchers are teaming up to develop a faster, and cheaper way of using iPSC’s , pluripotent stem cells that are reprogrammed from adult cells, for transplants.

Part of the beauty of iPSCs is that because those cells came from the patient themselves, there is less risk of rejection. But there are problems with this method. Taking adult cells and turning them into enough cells to treat someone can take a long time. It’s expensive too.

But now researchers at Kyoto University and three other institutions in Japan have announced they are teaming up to change that. They want to create a stockpile of iPSCs that are resistant to immunological rejection, and are ready to be shipped out to researchers.

Having a stockpile of ready-to-use iPSCs on hand means researchers won’t have to wait months to develop their own, so they can speed up their work.

Shinya Yamanaka, who developed the technique to create iPSCs and won the Nobel prize for his efforts, say there’s another advantage with this collaboration. In a news article on Nikkei’s Asian Review he said these cells will have been screened to make sure they don’t carry any potentially cancer-causing mutations.

“We will take all possible measures to look into the safety in each case, and we’ll give the green light once we’ve determined they are sound scientifically. If there is any concern at all, we will put a stop to it.”

CIRM is already working towards a similar goal with our iPSC Initiative.

Unlocking the secrets of leukemia stem cells

the-walking-dead-season-6-zombies

Zombies: courtesy “The Walking Dead”

Any article that has an opening sentence that says “Cancer stem cells are like zombies” has to be worth reading. And a report in ScienceMag  that explains how pre-leukemia white blood cell precursors become leukemia cancer stem cells is definitely worth reading.

The article is about a study in the journal Cell Stem Cell by researchers at UC San Diego. The senior author is Catriona Jamieson:

“In this study, we showed that cancer stem cells co-opt an RNA editing system to clone themselves. What’s more, we found a method to dial it down.”

An enzyme called ADAR1 is known to spur cancer growth by manipulating small pieces of genetic material known as microRNA. Jamieson and her team wanted to track how that was done. They discovered it is a cascade of events, and that once the first step is taken a series of others quickly followed on.

They found that when white blood cells have a genetic mutation that is linked to leukemia, they are prone to inflammation. That inflammation then activates ADAR1, which in turn slows down a segment of microRNA called let-7 resulting in increased cell growth. The end result is that the white blood cells that began this cascade become leukemia stem cells and spread an aggressive and frequently treatment-resistant form of the blood cancer.

Having uncovered how ADAR1 works Jamieson and her team then tried to find a way to stop it. They discovered that by blocking the white blood cells susceptibility to inflammation, they could prevent the cascade from even starting. They also found that by using a compound called 8-Aza they could impede ADAR1’s ability to stimulate cell growth by around 40 percent.

Jamieson

Catriona Jamieson – definitely not a zombie

Jamieson says the findings open up all sorts of possibilities:

“Based on this research, we believe that detecting ADAR1 activity will be important for predicting cancer progression. In addition, inhibiting this enzyme represents a unique therapeutic vulnerability in cancer stem cells with active inflammatory signaling that may respond to pharmacologic inhibitors of inflammation sensitivity or selective ADAR1 inhibitors that are currently being developed.”

This wasn’t a CIRM-funded study but we have supported other projects by Dr. Jamieson that have led to clinical trials.

 

 

 

 

UCSD scientists find new clue into how Zika virus impairs brain development

In April of this year, the Centers for Disease Control and Prevention (CDC) announced their conclusion that Zika virus causes microcephaly, a birth defect that results in abnormal brain development and a smaller sized head in infants. Rather than a single study being responsible for their conclusion, the CDC argued that “mounting evidence” from multiple recent reports has made the link between Zika infection in pregnant women and microcephaly undeniable.

Now that the general consensus is that Zika virus impairs brain development, scientists are making fast progress to develop appropriate models of brain development to understand exactly how the virus causes microcephaly. We recently blogged about one study from UC San Francisco, which found a molecular link between Zika infection and the function of brain stem cells. They used a brain organoid model, derived from human stem cells, to identify a protein receptor called AXL that is expressed on the surface of brain stem cells and is a major entry point for Zika virus infection.

The power of mini-brains

Cross section of a brain organoid. (MIT Tech Review)

Cross section of a brain organoid. (MIT Tech Review)

So called “mini-brains”, or 3D brain organoids, have proven to be a very useful model for brain development and Zika virus infection. With rapid advances in stem cell technologies, mini-brains now develop the appropriate cell types and brain structures representative of the first trimester of fetal brain development. They also can be derived from both embryonic stem cells and induced pluripotent stem cells, making them a versatile technology that can model patient specific diseases.

Speaking of mini-brains, a study was published just last week in the journal Cell Stem Cell from UC San Diego that used mini-brains to identify an immune system molecule that gets hijacked by the Zika virus. They found that Toll-like-Receptor 3 (TLR3) negatively impacts the ability of brain stem cells to differentiate or specialize into the mature cells of the brain.

When the organoids were exposed to a strain of the Zika virus, MR766, their size five days later was smaller than organoids that weren’t exposed to the virus. The growth rate for normal organoids in the time period was 22.6% while the rate for Zika-treated organoids was only 16%. Dissection of the Zika-treated organoids revealed that the virus was successful in infecting brain stem cells specifically and somehow impaired their ability to differentiate. They also noticed that a specific immune molecule called TLR3 was abnormally activated in the organoids after Zika infection.

TLR3: too much of a good thing

In an attempt to put the puzzle pieces together, the authors focused on TLR3 and its potential role in causing brain development defects caused by Zika virus. TLR3 is a sentinel of the innate immune system, the body’s first line defense against infection. It’s a receptor on the surface of cells that can recognize foreign viruses and mount an immune response by activating infection fighting genes.

Brain organoids were used to model Zika virus infection. (Cell Stem Cell)

Brain organoids were used to model Zika virus infection. (Cell Stem Cell)

TLR3 sounds like a good guy when it comes to defending the immune system, but there are cases where too much TLR3 is not a good thing. Activation of TLR3 in Zika-infected brain organoids turned on a group of 41 genes that blocked the differentiation of brain stem cells, causing brain organoid shrinkage, and also caused the stem cells to commit apoptosis, a cellular form of programmed suicide.

Logically, the authors tested whether blocking the activity of TLR3 in Zika-infected organoids alleviated these negative effects. A TLR3 inhibitor was effective at preventing brain stem cell apoptosis and also organoid shrinkage in Zika-treated organoids. However, the treatment wasn’t perfect, the Zika-infected organoids did not grow to the same size as untreated organoids after TLR3 inhibition and still experienced more cell death.

Senior author on the study Dr. Tariq Rana explained:

“We all have an innate immune system that evolved specifically to fight off viruses, but here the virus turns that very same defense mechanism against us. By activating TLR3, the Zika virus blocks genes that tell stem cells to develop into the various parts of the brain. The good news is that we have TLR3 inhibitors that can stop this from happening.”

The size of brain organoids is reduced with Zika infection but partly rescued with a TLR3 inhibitor. Normal (left), Zika infected (middle), Zika infected with TLR3 inhibitor treatment. (Cell Stem Cell)

The size of brain organoids is reduced with Zika infection but partly rescued with a TLR3 inhibitor. Normal (left), Zika infected (middle), Zika infected with TLR3 inhibitor treatment. (Cell Stem Cell)

Next Steps

In a UCSD press release, the authors admit that this work is still in its early stages. The experiments they conducted used both mouse and human cells and further work is needed to determine whether TLR3 is an appropriate target for blocking Zika infection in humans.

They also note that this study tests only one strain of the Zika virus, one that originated in Uganda, and that other strains prevalent in countries like Latin America and Asia should be tested as well. Other strains could have different mechanisms of infection and different effects on the function of brain stem cells.

Rana acknowledged this and commented:

Dr. Tariq Rana, UCSD

Dr. Tariq Rana, UCSD

“We used this 3D model of early human brain development to help find one mechanism by which Zika virus causes microcephaly in developing fetuses, but we anticipate that other researchers will now also use this same scalable, reproducible system to study other aspects of the infection and test potential therapeutics.”


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Brain Stem Cells in a Dish to the Rescue

braindish

Image credit: CureCDKL5.org

The best way to impress your friends at the next party you attend might be to casually mention that scientists can grow miniature brain models in a dish using human stem cells. Sure, that might scare away some people, but when you explain how these tiny brain models can be used to study many different neurological diseases and could help identify new therapies to treat these diseases, your social status could sky rocket.

Recently, a group at UC San Diego used human stem cells to model a rare neurological disorder and identified a drug molecule that might be able to fix it. This work was funded in part by CIRM, and it was published today in the journal Molecular Psychiatry.

The disorder is called MECP2 duplication syndrome. It’s caused by a duplication of the MECP2 gene located in the X chromosome, and is genetically inherited as an X-linked disorder, meaning the disease is much more common in males. Having extra copies of this gene causes a number of unfortunate symptoms including reduced muscle tone (hypotonia), intellectual disabilities, impaired speech, seizures, and developmental delays, to name a few. So far, treatments for this disorder only help ease the symptoms and do not cure the disease.

The group from UCSD decided to model this disease using induced pluripotent stem cells (iPSCs) derived from patients with MECP2 duplication syndrome. iPSCs can form any cell type in the body, and the group used this to their advantage by coaxing the iPSCs into the specific type of nerve cell affected by the disorder. Their hard work was rewarded when they observed that the diseased nerve cells acted differently than normal nerve cells without the disease.

In fact, the diseased nerve cells generated more connections with other nearby nerve cells, and this altered their ability to talk to each other and perform their normal functions. The senior author Alysson Muotri described the difference as an “over-synchronization of the neuronal networks”, meaning that they were more active and tended to fire their signals in unison.

After establishing a relevant nerve cell model of MECP2 duplication disorder, the group tested out a library of drug molecules and identified a new drug candidate that was able to rescue the diseased nerve cells from their “over-synchronized” activity.

The senior author Alysson Muotri commented on the study in a press release:

Alysson Muotri (Photo by David Ahntholz)  

This work is encouraging for several reasons. First, this compound had never before been considered a therapeutic alternative for neurological disorders. Second, the speed in which we were able to do this. With mouse models, this work would likely have taken years and results would not necessarily be useful for humans.

 

The press release goes on to describe how Muotri and his team plan to push their preclinical studies using human stem-cell based models forward in hopes of entering clinical trials in the near future.


 

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