Ask the Stem Cell Team About Autism

On March 19th we held a special Facebook Live “Ask the Stem Cell Team About Autism” event. We were fortunate enough to have two great experts – Dr. Alysson Muotri from UC San Diego, and CIRM’s own Dr. Kelly Shepard. As always there is a lot of ground to cover in under one hour and there are inevitably questions we didn’t get a chance to respond to. So, Dr. Shepard has kindly agreed to provide answers to all the key questions we got on the day.

If you didn’t get a chance to see the event you can watch the video here. And feel free to share the link, and this blog, with anyone you think might be interested in the material.

Dr. Kelly Shepard

Can umbilical cord blood stem cells help reduce some of the symptoms?

This question was addressed by Dr. Muotri in the live presentation. To recap, a couple of clinical studies have been reported from scientists at Duke University and Sutter Health, but the results are not universally viewed as conclusive.  The Duke study, which focused on very young children, reported some improvements in behavior for some of the children after treatment, but it is important to note that this trial had no placebo control, so it is not clear that those patients would not have improved on their own. The Duke team has moved forward with larger trial and placebo control.

Does it have to be the child’s own cord blood or could donated blood work too?

In theory, a donated cord product could be used for similar purposes as a child’s own cord, but there is a caveat- the donated cord tissues must have some level of immune matching with the host in order to not be rejected or lead to other complications, which under certain circumstances, could be serious.

Some clinics claim that the use of fetal stem cells can help stimulate improved blood and oxygen flow to the brain. Could that help children with autism?

Fetal stem cells have been tested in FDA approved/sanctioned clinical trials for certain brain conditions such as stroke and Parkinson Disease, where there is clearer understanding of how and which parts of the brains are affected, which nerve cells have been lost or damaged, and where there is a compelling biological rationale for how certain properties the transplanted cells, such as their anti-inflammatory properties, could provide benefit.

Alysson Muotri in his lab and office at Sanford Consortium in La Jolla, California; Photograph by David Ahntholz http://www.twopointpictures.com http://www.davidahntholz.com

In his presentation, Dr. Muotri noted that neurons are not lost in autistic brains, so there is nothing that would be “replaced” by such a treatment. And although some forms of autism might include inflammation that could potentially be mitigated, it is unlikely that  the degree of benefit that might come from reducing inflammation would be worth the risks of the treatment, which includes intracranial injection of donated material.  Unfortunately, we still do not know enough about the specific causes and features of autism to determine if and to what extent stem cell treatments could prove helpful. But we are learning more every day, especially with some of the new technologies and discoveries that have been enabled by stem cell technology. 

Some therapies even use tissue from sheep claiming that a pill containing sheep pancreas can migrate to and cure a human pancreas, pills containing sheep brains can help heal human brains. What are your thoughts on those?

For some conditions, there may be a scientific rationale for how a specific drug or treatment could be delivered orally, but this really depends on the underlying biology of the condition, the means by which the drug exerts its effect, and how quickly that drug or substance will be digested, metabolized, or cleared from the body’s circulation. Many drugs that are delivered orally do not reach the brain because of the blood-brain barrier, which serves to isolate and protect the brain from potentially harmful substances in the blood circulation. For such a drug to be effective, it would have to be stable within the body for a period of time, and be something that could exert its effects on the brain either directly or indirectly.

Sheep brain or pancreas (or any other animal tissue consumed) in a pill form would be broken down into basic components immediately by digestion, i.e. amino acids, sugars, much like any other meat or food. Often complex treatments designed to be specifically targeted to the brain are delivered by intra-cranial/intrathecal injection, or by developing special strategies to evade the blood brain barrier, a challenge that is easier said than done. For autism, there is still a lot to be learned regarding how a therapeutic intervention might work to help people, so for now, I would caution against the use of dietary supplements or pills that are not prescribed or recommended by your doctor. 

What are the questions parents should ask before signing up for any stem cell therapy

There is some very good advice about this on the both the CIRM and ISSCR websites, including a handbook for patients that includes questions to ask anyone offering you a stem cell treatment, and also some fundamental facts that everyone should know about stem cells. https://www.closerlookatstemcells.org/patient-resources/

What kinds of techniques do we have now that we didn’t have in the past that can help us better understand what is happening in the brain of a child with autism.

We covered this in the online presentation. Some of the technologies discussed include:

– “disease in a dish” models from patient derived stem cells for studying causes of autism

–  new ways to make human neurons and other cell types for study

– organoid technology, to create more realistic brain tissues for studying autism

– advances in genomics and sequencing technologies to identify “signatures” of autism to help identify the underlying differences that could lead to a diagnosis

Alysson, you work with things called “brain organoids” explain what those are and could they help us in uncovering clues to the cause of autism and even possible therapies?

We blogged about this work when it was first published and you can read about it on our blog here.

Gladstone scientists respond to coronavirus pandemic

In these uncertain times, we often look to our top scientists for answers as well as potential solutions. But where does one begin to try and solve a problem of this magnitude? The first logical step is building on the supplies currently available, the work already accomplished, and the knowledge acquired.

This is the approach that the Gladstone Institutes in San Francisco is taking. Various scientists at this institution have shifted their current operations towards helping with the current coronavirus pandemic. These efforts have focused on helping with diagnostics, treatment, and prevention of COVID-19.

Diagnostics

Dr. Jennifer Doudna and Dr. Melanie Ott are collaborating in order to develop an effective method to rapidly diagnose those with COVID-19. Dr. Doudna’s work has focused on CRISPR technology, which we have talked about in detail in a previous blog post, while Dr. Ott has focused on studying viruses. By combining their expertises, these two scientists hope to develop a diagnostic tool capable of delivering rapid results and usable in areas such as airports, ports of entry, and remote communities.

Treatment

Dr. Nevan Krogan has discovered all of the human host cell proteins that COVID-19 interacts with to hijack the cell’s machinery. These proteins serve as new targets for potential drug therapies.

Since the high fatality rate of the virus is driven by lung and heart failure, Dr. Ott, Dr. Bruce Conklin, and Dr. Todd McDevitt will test effects of the virus and potential drug therapies in human lung organoids and human heart cells, both developed from human stem cells.

Dr. Warner Greene, who also focuses on the study of viruses, is screening a variety of FDA-approved drugs to identify those that could be rapidly repurposed as a treatment for COVID-19 patients or even as a preventive for high risk-groups.

Prevention

Dr. Leor Weinberger has developed a new approach to fight the spread of viruses. It is called therapeutic interfering particles (TIPs) and could be an alternative to a vaccine. TIPs are defective virus fragments that mimic the virus but are not able to replicate. They combat the virus by hijacking the cell machinery to transform virus-infected cells into factories that produce TIPS, amplifying the effect of TIPs in stopping the spread of virus. TIPs targeting COVID-19 would transmit along the same paths as the virus itself, and thus provide protection to even the most vulnerable populations.

You can read more about these groundbreaking projects in the news release linked here.

New hydrogel developed could aid in therapies to generate bones in head and neck

Taking a cue from mussels’ natural ability to adhere to surfaces underwater, the UCLA researchers incorporated an alginate-based solution in their hydrogel.
Photo taken by D. Jude, Univ. of Michigan

When most people think of mussels, what immediately comes to mind might be a savory seafood dish or favorite seafood restaurant. But to Dr. Alireza Moshaverinia and his team of researchers at the UCLA School of Dentistry, it’s the ability that mussels have to stick to wet surfaces that is of particular interest.

Partially inspired by this concept and with support from CIRM, the team of researchers developed the first adhesive hydrogel specifically to regenerate bone and tissue defects following head and neck injuries.

Over the past few years, surgeons and clinicians have began to use hydrogels to administer stem cells to help regenerate lost tissues and for bone defects. Hydrogels are beneficial because they can be effective at carrying stem cells to targeted areas inside the body. However, when used in surgeries of the mouth, they tend to become less effective because blood and saliva prevent them from properly adhering to the targeted site. As a result of this, the stem cells don’t stay in place long enough to deliver their regenerative properties.

To help with this problem, the researchers at UCLA developed a new hydrogel by adding alginate into the mix. Alginates are found in the cells of algae and form a sticky, gum-like substance when wet.

The scientists then tested their new hydrogel by loading it with bone building stem cells and applying it to the mouths of rats with an infectious disease that affects the bone structure. They then sealed the hydrogel in place and applied a light treatment, similar to what dentists use in humans to solidify dental fillings.

The results showed that the bone around the implants in all of the rats had completely regenerated.

In a news release from UCLA, Dr. Moshaverinia elaborates on what this study means for potential future treatments.

“The light treatment helped harden the hydrogel, providing a more stable vehicle for delivery of the stem cells. We believe that our new tissue engineering application could be an optimal option for patients who have lost their hard and soft craniofacial tissues due to trauma, infection or tumors.”

The full study was published in Science Translational Medicine.

CIRM-funded treatment for Cystinosis receives orphan drug designation

Dr. Stephanie Cherqui, UC San Diego

Orphan drug designation is a special status given by the Food and Drug Administration (FDA) for potential treatments of rare diseases that affect fewer than 200,000 in the U.S. This type of status can significantly help advance treatments for rare diseases by providing financial incentives in the form of tax credits towards the cost of clinical trials and prescription drug user fee waivers.

Fortunately for us, a stem cell-gene therapy approach used in a CIRM-funded clinical trial for Cystinosis has just received orphan drug designation. The trial is being conducted by Dr. Stephanie Cherqui at UC San Diego, which is an academic collaborator for AVROBIO, Inc.

Cystinosis is a rare disease that primarily affects children and young adults, and leads to premature death, usually in early adulthood.  Patients inherit defective copies of a gene called CTNS, which results in abnormal accumulation of an amino acid called cystine in all cells of the body.  This buildup of cystine can lead to multi-organ failure, with some of earliest and most pronounced effects on the kidneys, eyes, thyroid, muscle, and pancreas.  Many patients suffer end-stage kidney failure and severe vision defects in childhood, and as they get older, they are at increased risk for heart disease, diabetes, bone defects, and neuromuscular defects. 

Dr. Cherqui’s clinical trial uses a gene therapy approach to modify a patient’s own blood stem cells with a functional version of the defective CTNS gene. The goal of this treatment is to reintroduce the corrected stem cells into the patient to give rise to blood cells that will reduce cystine buildup in affected tissues.  

In an earlier blog, we shared a story by UCSD news that featured Jordan Janz, the first patient to participate in this trial, as well as the challenges promising approaches like this one face in terms of getting financial support. Our hope is that in addition to the funding we have provided, this special designation gives additional support to what appears to be a very promising treatment for a very rare disease.

You can read the official press release from AVROBIO, Inc. related to the orphan drug designation status here.

New CAR-T cell therapy using scorpion venom developed to treat brain tumors

Contributed by Wikimedia Commons (Public Domain)

Glioblastoma (GBM) is an aggressive form of cancer that begins in the brain and results in tumors that can be very difficult to treat. This condition has claimed the lives of Beau Biden, former Vice President Joe Biden’s son, and John McCain, former Senator of Arizona. However, a new approach to combat this condition is being developed at City of Hope and has just received approval from the FDA to conduct clinical trials. The innovative approach involves using a combination of chimeric antigen receptor (CAR)-T cell therapy and specific components of scorpion venom!

Before we dive into how the scorpion venom is being used, what exactly is CAR-T cell therapy?

Diagram of CAR-T Cell Therapy
Image Source: National Cancer Institute

This approach consists of using T cells, which are an immune system cell that can destroy foreign or abnormal cells, and modifying them with a protein called a chimeric antigen receptor (CAR). These newly designed CAR-T cells are able to identify and destroy cancer cells by detecting a specific protein on these cells. What makes CAR-T cell even more promising is that the specific protein detected can be set to virtually anything.

This is where the scorpion venom comes into play. One of the components of this venom is called chlorotoxin (CLTX), which has the ability to specifically bind to brain tumor cells.

Michael Barish, Ph.D. (Left), Christine Brown, Ph.D. (Center), Dongrui Wang (Right)
Photo Credit: Business Wire

For this study, Dr. Christine Brown, Dr. Michael Barish, and a team of researchers at City of Hope designed CAR-T cells using chlorotoxin in order to specifically detect and destory brain tumor cells. Now referred to as CLTX-CAR-T cells, they found that these newly engineered cells were highly effective at selectively killing brain tumor cells in animal models. What’s more remarkable is that the CLTX-CAR-T cells ignored non-tumor cells in the brain and other organs.

In a press release, Dr. Barish describes the CLTX-CAR-T cell approach in more detail.

“Much like a scorpion uses toxin components of its venom to target and kill its prey, we’re using chlorotoxin to direct the T cells to target the tumor cells with the added advantage that the CLTX-CAR T cells are mobile and actively surveilling the brain looking for appropriate target. We are not actually injecting a toxin, but exploiting CLTX’s binding properties in the design of the CAR. The idea was to develop a CAR that would target T cells to a wider variety of GBM tumor cells than the other antibody-based CARs.”

In the same press release, Dr. Brown talks about the promise of this newly developed therapy.

“Our chlorotoxin-incorporating CAR expands the populations of solid tumors potentially targeted by CAR T cell therapy, which is particularly needed for patients with cancers that are difficult to treat such as glioblastoma. This is a completely new targeting strategy for CAR T therapy with CARs incorporating a recognition structure different from other CARs.”

The first-in-human clinical trial using the CLTX-CAR T cells is now screening potential patients.

CIRM has funded a separate clinical trial conducted by Dr. Brown that also involves CAR-T cell therapy for brain tumors.

The full results of this study was published in Science Translational Medicine.

A video talking about this approach can also be found here.

Overcoming obstacles in blood stem cell therapies

Photo Credit: OHSU Knight Cancer Institute

Today, we here at CIRM wanted to provide an update on the fascinating world of hematopoietic (blood) stem cell-based therapies.  What is the current status of this promising field and what are some of the challenges that need to be overcome? Dr. Kelly Shepard, Associate Director of Discovery and Translation here at CIRM, answers these questions and many more in the blog entry below.

There have been a number of exciting advances in regenerative medicine over the past few years, especially in the use of gene therapy and hematopoietic (blood) stem cell transplantation to treat and even cure various diseases of the blood and immune system. These studies built off groundbreaking research by Till and McCulloch in the 1950-60’s, who identified a rare and special stem cell in the bone marrow of mice that gives rise to all cells of the blood and immune system for the lifetime of the animal, the “hematopoietic stem cell”, or HSC. It wasn’t long before scientists and doctors realized the therapeutic implications of this discovery, and the journey to identify the human counterpart began. Fast forward to the present, and HSC transplantation (HSCT) has become a standard medical procedure for treating various cancers and genetic disorders of the blood. The basic premise is this: a patient with a diseased or defective blood/immune system receives an infusion of healthy HSCs, which are typically procured from donated bone marrow or umbilical cords, but in certain situations, might come from the patient him/herself. Once established in the recipient, these healthy cells will divide and regenerate a new blood and immune system over the course of the patient’s lifetime.

For HSCT to be successful, the donor cells must “engraft”, or take up permanent residence in their new environment. This usually necessitates “conditioning” the recipient with some form of chemotherapy or radiation, which eliminates some of the patient’s own cells to create room for the new arrivals. Unfortunately, conditioning creates a situation where the patient is extremely vulnerable to infections and other complications during the period of recovery, as it will take weeks for his/her blood and immune systems to be reestablished. These inherent risks mean HSC transplants can only be offered to patients with life threatening diseases such as leukemia, or to those with significant blood/immune disorders who are sufficiently healthy to tolerate the toxic conditioning regimen and to weather the extended period of recovery.

A second major issue preventing a more widespread use of HSCT is the shortage of healthy donor HSCs that are available for transplant, which must be immune matched to the recipient to prevent rejection. Immune matching is also critical to avoid a dangerous complication called graft vs. host disease, where the transplanted cells or their progeny launch an immune attack against the recipient’s organs, often leading to chronic disease and sometimes, death. Unfortunately, there are many people who have no compatible donors and for whom the risk of even a partially matched transplant is unacceptable.

Scientists and clinicians have long sought means to overcome the technical challenges of HSCT in order to “unleash” its true potential to cure and treat a wider variety of diseases, and to  make it feasible (and affordable) for a much larger number of patients. CIRM has endeavored to support novel approaches that could hopefully produce game changing advances for the field. Some of these approaches were recently highlighted in a Perspective article, published in Stem Cells Translational Medicine in early 2020, along with a discussion of other important advances in related areas, listed below. More information can be found in that article or referring to our website to learn more about the individual projects.

Approaches that could increase the availability of healthy HSCs for transplant include development of non-toxic conditioning regimens to facilitate a patient’s acceptance and recovery from the transplant procedure; novel technologies for expanding HSCs for transplant; and gene modification technologies to correct inherited mutations in HSCs.
Illustration Credit: Dr. Kelly Shepard, CIRM

Developing New Sources of Healthy and Immune Compatible HSCs for transplant

  • Exploring ways to produce HSCs from pluripotent stem cells in the lab
  • Expanding populations of HSCs that are already present in donated tissues such as cord blood
  • Using genetic engineering to “repair” defects in the DNA of HSCs from patients with inherited blood and/or immune disorders
  • Using genetic engineering to create “immune invisible” or “universal donor” HSCs that will not be rejected after transplantation

Developing Safer and More Tolerable Conditioning Regimens

  • Exploring reduced intensity forms of conditioning with drugs or radiation
  • Using antibodies rather than chemicals to free up space in the bone marrow for incoming, donor HSCs
  • Using dietary methods to free up space in the bone marrow for incoming, donor HSCs

Accelerating Reovery of Immune Function Lost Through Conditioning

  • Adding back key populations of immune cells to protect the host during regeneration of their immune system
  • Discovering new drugs and treatments to accelerate the pace of regeneration after transplant, or to prevent the death of HSCs that survived conditioning

Overcoming these scientific and technical challenges could create a paradigm shift in the way HSCT is applied and used and consequently, reduce the costs and risks associated with the procedure. In this way, the true potential of HSCT could be unleashed for the greatest good.

CIRM supported study finds that a gene associated with autism influences brain stem cells

Dr. Bennett Novitch, UCLA Broad Stem Cell Research Center
Image Credit: UCLA Broad Stem Cell Research Center

In a previous blog post, we discussed new findings in a CIRM supported study at the Salk Institute for Autism Spectrum Disorder (ASD), a developmental disorder that comes in broad ranges and primarily affects communication and behavior.

This week, a new study, also supported by CIRM, finds that a gene associated with ASD, intellectual disability, and language impairment can affect brain stem cells, which in turn, influence early brain development. Dr. Bennett Novitch and his team at UCLA evaluated a gene, called Foxp1, which has been previously studied for its function in the neurons in the developing brain.

Image showing brain cells with lower levels of Foxp1 function (left) and higher levels (right). neural stem cells are stained in green; secondary progenitors and neurons in red.
Image Credit: UCLA Broad Stem Cell Research Center

In this study, Dr. Novitch and his team looked at Foxp1 levels in the brains of developing mouse embryos. What they discovered is that, in normal developing mice the gene was active much earlier than previous studies had indicated. It turns out that the gene was active during the period when neural stem cells are just beginning to expand in numbers and generate a subset of brain cells found deep within the developing brain.

When mice lacked the gene entirely, there were fewer neural stem cells at early stages of brain development, as well as fewer brain cells deep within the developing brain. Alternatively, when the levels of the gene were above normal, the researchers found significantly more neural stem cells and brain cells deep within the developing brain. Additionally, higher levels of the neural stem cells were observed in mice with high levels of the gene even after they were born.

In a press release from UCLA, Dr. Novitch explains how the different levels of the gene can be tied to the variation of Foxp1 levels seen in ASD patients.

“What we saw was that both too much and too little Foxp1 affects the ability of neural stem cells to replicate and form certain neurons in a specific sequence in mice. And this fits with the structural and behavioral abnormalities that have been seen in human patients.”

The full study was published in Cell Reports.

Dashed Dreams and New Hope: A Quest to Cure Thymic Deficiency

By Kelly Shepard, PhD., CIRM’s Associate Director, Discovery & Translation

CIRM has previously blogged about advances in treating certain forms of  “bubble baby” disease”, where a person is born with a defect in their blood forming stem cells that results in a deficient immune system, rendering them vulnerable to lethal infections by all manner of bacteria, virus or germ.

If a suitable donor can be found, or if the patient’s own defective cells can be corrected through gene therapy approaches, it is now possible to treat or cure such disorders through a bone marrow transplant. In this procedure, healthy blood stem cells are infused into the patient, taking up residence in his or her bone marrow and dividing to give rise to functioning immune cells such as T cells and B cells.

Unfortunately, there is another type of “bubble baby” disease that cannot be treated by providing healthy blood stem cells, because the defective immune system is caused by a different culprit altogether- a missing or dysfunctional thymus.

Created for the National Cancer Institute, http://www.cancer.gov

T Cells Go to School

What is a thymus?  Most of us give little thought to this leaf-shaped organ, which is large and important in our early childhoods, but becomes small and inconspicuous as we age. This transformation belies the critical role a thymus plays in the development of our adaptive immune systems, which takes place in our youth: to prepare our bodies to fight infections for the rest of our lives.

One might think of the thymus as a “school”, where immature T cells go to “learn” how to recognize and attack foreign antigens (surface markers), such as those found on microorganisms or tissues from other individuals. The thymus also “teaches” our immune system to distinguish “self” from “other” by eliminating any T cells that attack our own tissues. Without this critical function, our immune system could inadvertently turn against us, causing serious autoimmune disorders such as ulcerative colitis and myasthenia gravis.

Many children with a severely deficient or absent thymus, referred to as athymia, have inherited a chromosome that is missing a key stretch of genes on a region called 22q11. Doctors believe perhaps 1/2000-1/4000 babies are born with some type of deletion in this region, which leads to a variable spectrum of disorders called 22q11 syndrome that can affect just about any part of the body, and can even cause learning disabilities and mental illness.

Individuals with one form of 22q11, called DiGeorge Syndrome, are particularly affected in the heart, thymus, and parathyroid glands. In the United States, about 20 infants are born per year with the “complete” and most severe form of DiGeorge Syndrome, who lack a thymus altogether, and have severely depressed numbers of T cells for fighting infections. Without medical intervention, this condition is usually fatal by 24 months of age.

Optimism and Setback                                                                  

Although there are no therapies approved by the Food and Drug Administration (FDA) for pediatric athymia, Dr. Mary Louise Markert at Duke University and Enzyvant, Inc. have been pioneering an experimental approach to treat children with complete DiGeorge syndrome.

In this procedure, discarded thymic tissues are collected from infants undergoing cardiac surgery, where some of the thymus needs to be removed in order for the surgeon to gain access to the heart. These tissues are processed to remove potentially harmful donor T cells and then transplanted into the thigh of an athymic DiGeorge patient.

Results from early clinical trials seemed promising, with more than 70% of patients surviving, including several who are now ten years post-transplant. Based on those results, in June of 2019 Enzyvant applied to the FDA for a Biologics License Application (BLA), which is needed to be able to sell the therapy in the US. Unfortunately, only a few months later, Enzyvant announced that the FDA had declined to approve the BLA due to manufacturing concerns.

While it may be possible to address these issues in time, the need to step back to the drawing board was a devastating blow to the DiGeorge Community, who have waited decades for a promising treatment to emerge on the horizon.

New Opportunities

Despite the setback, there is reason to hope. In early 2019, CIRM granted a “Quest” Award to team of investigators at Stanford University to develop a novel stem cell based approach for treating thymic deficiency. Co-led by Katja Weinacht, a pediatric hematologist/oncologist, and Vittorio Sebastiano, a stem cell expert and developmental biologist, the team’s strategy is to coax induced pluripotent stem cells (iPS) in the laboratory to differentiate into thymic tissue, which could then be transplanted into patients using the route pioneered by Duke and Enzyvant.

Katja Weinacht: Photo courtesy Stanford Children’s Health

The beauty of this new approach is that pluripotent stem cells are essentially immortal in culture, providing an inexhaustible supply of fresh thymic cells for transplant, thereby allowing greater control over the quality and consistency of donor tissues. A second major advantage is the possibility of using pluripotent cells from the patient him/herself as the source, which should be perfectly immune-matched and alleviate the risk of rejection and autoimmunity that comes with use of donated tissues.

Vittorio Sebastiano: Photo courtesy Stanford

Sounds easy, so what are the challenges? As with many regenerative medicine approaches, the key is getting a pluripotent stem cell to differentiate into the right type of cells in the lab, which is a very different environment than what cells experience naturally when they develop in the context of an embryo and womb, where many cells are interacting and providing complex, instructive cues to one another. The precise factors and timing all need to be worked out and in most cases, this is done with an incomplete knowledge of human development.

A second challenge relates to using cells from DiGeorge patients to produce thymic tissue, which are missing several genes on their 22nd chromosome and will likely require sophisticated genetic engineering to restore this ability.

Fortunately, Drs. Weinacht and Sebastiano are up to the challenge, and have already made progress in differentiating human induced pluripotent stem cells (iPS) into thymic lineage intermediates that appear to be expressing the right proteins at the right time. They plan to combine these cells with engineered materials to create a three-dimensional (3D) tissue that more closely resembles an authentic organ, and which can be tested for functionality in athymic mice.

There is more work to be done, but these advances, along with continued technological improvements and renewed efforts from Enzyvant, could forge a path to the clinic and  lead to a brighter future for patients suffering from congenital athymia and other forms of thymic dysfunction.

 

CIRM supported study of gene silencer blocks ALS degeneration, saves motor function

Dr. Martin Marsala, UC San Diego

Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease, is a neurodegenerative disease that destroys the nerve cells in the brain and spinal cord. As a result of ALS, the motor neurons that enable bodily movement and muscle control are harmed, which can make it difficult to move, speak, eat, and breathe. This condition usually affects people from age 40 to 70, but individuals in their 20s and 30s have also been known to develop ALS. Unfortunately there is no cure for this condition.

However, a study supported by CIRM and conducted by Dr. Martin Marsala at UC San Diego is using a mouse model to look at an approach that uses a gene silencer to protect motor neurons before or shortly after ALS symptoms start to develop.

The gene silencer works by turning off a targeted gene and is delivered via injection. In the case of ALS, previous research suggests that mutations in a gene called SOD1 may cause motor neuronal cell death, resulting in ALS. For this study, Dr. Marsala and his team injected the gene silencer at two sites in the spinal cord in adult mice expressing an ALS-causing mutation of the SOD1 gene. The mice injected did not yet display symptoms of ALS or had only begun showing symptoms.

In mice not yet showing ALS symptoms, they displayed normal neurological function with no onset ALS symptoms after treatment. Additionally, near complete protection of motor neurons and other cells was observed. In mice that had just began showing ALS symptoms, the injection blocked further disease progression as well as further harm to remaining motor neurons. Both of these groups of mice lived without negative side effects for the duration of the study.

In a news release, Dr. Marsala talks about what these results mean for the study of ALS.

“At present, this therapeutic approach provides the most potent therapy ever demonstrated in mouse models of mutated SOD1 gene-linked ALS.”

The next steps for this research would be to conduct additional safety studies with a larger animal model in order to determine an optimal, safe dose for the treatment.

The full results of this study were published in Nature Medicine.

In addition to supporting this research for ALS, CIRM has funded two clinical trials in the field as well. One of these trials is being conducted by BrainStorm Cell Therapeutics and the other trial is being by Cedars-Sinai Medical Center.

Brain wave of an idea is picked as one of the top science stories of the year

Dr. Alysson Muotri: Photo courtesy UC San Diego

It’s always gratifying when one of the projects you have funded starts to show promising results. It says your faith in the research and the researcher were well founded. But it’s also fun when the project you fund turns up some really cool findings and is picked as a top science story of the year.

That’s what happened with UC San Diego researcher Alysson Muotri’s work on growing brain organoids (tiny clumps of brain cells, created in a dish, that can mimic some of the properties of a real brain). His work, funded by yours truly, was chosen by Discover Magazine as one of the Top Ten Science stories of 2019.

You can read about that here.

Or you can watch a video about the work.

Alysson has done some extraordinary work in the past and we look forward to seeing even more extraordinary science from him in 2020.