Building a better brain (model) in the lab

Leica Picture of a brain organoid: courtesy National Institute of Allergy and Infectious Diseases, NIH

One of the biggest problems with trying to understand what is happening in a disease that affects the brain is that it’s really difficult to see what is going on inside someone’s head. People tend to object to you trying to open their noggin while they are still using it.

New technologies can help, devices such as MRI’s – which chart activity and function by measuring blood flow – or brain scans using electroencephalograms (EEGs), which measure activity by tracking electrical signaling and brain waves. But these are still limited in what they can tell us.

Enter brain organoids. These are three dimensional models made from clusters of human stem cells grown in the lab. They aren’t “brains in a dish” – they can’t function or think independently – but they can help us develop a deeper understanding of how the brain works and even why it doesn’t always work as well as we’d like.

Now researchers at UCLA’s Broad Center of Regenerative Medicine have created brain organoids that demonstrate brain wave activity similar to that found in humans, and even brain waves found in particular neurological disease.

The team – with CIRM funding – took skin tissue from healthy individuals and, using the iPSC method – which enables you to turn these cells into any other kind of cell in the body – they created brain organoids. They then studied both the physical structure of the organoids by examining them under a microscope, and how they were functioning by using a probe to measure brain wave activity.

In a news release Dr. Ranmal Samarasinghe, the first author of the study in the journal Nature Neuroscience, says they wanted to do this double test for a very good reason: “With many neurological diseases, you can have terrible symptoms but the brain physically looks fine. So, to be able to seek answers to questions about these diseases, it’s very important that with organoids we can model not just the structure of the brain but the function as well.”

Next, they took skin cells from people with a condition called Rhett syndrome. This is a rare genetic disorder that affects mostly girls and strikes in the first 18 months of life, having a severe impact on the individual’s ability to speak, walk, eat or even breathe easily. When the researchers created brain organoids with these cells the structure of the organoids looked similar to the non-Rhett syndrome ones, but the brain wave activity was very different. The Rhett syndrome organoids showed very erratic, disorganized brain waves.

When the team tested an experimental medication called Pifithrin-alpha on the Rhett organoids, the brain waves became less erratic and more like the brain waves from the normal organoids.

“This is one of the first tangible examples of drug testing in action in a brain organoid,” said Samarasinghe. “We hope it serves as a stepping stone toward a better understanding of human brain biology and brain disease.”

Celebrating a young life that almost wasn’t

Often on the Stem Cellar we feature CIRM-funded work that is helping advance the field, unlocking some of the secrets of stem cells and how best to use them to develop promising therapies. But every once in a while it’s good to remind ourselves that this work, while it may often seem slow, is already saving lives.

Meet Ja’Ceon Golden. He was one of the first patients treated at U.C. San Francisco, in partnership with St. Jude Children’s Hospital in Memphis, as part of a CIRM-funded study to treat a rare but fatal disorder called Severe Combined Immunodeficiency (SCID). Ja’Ceon was born without a functioning immune system, so even a simple cold could have been fatal.

At UCSF a team led by Dr. Mort Cowan, took blood stem cells from Ja’Ceon and sent them to St. Jude where another team corrected the genetic mutation that causes SCID. The cells were then returned to UCSF and re-infused into Ja’Ceon.  

Over the next few months those blood stem cells grew in number and eventually helped heal his immune system.

He recently came back to UCSF for more tests, just to make sure everything is OK. With him, as she has been since his birth, was his aunt and guardian Dannie Hawkins. She says Ja’Ceon is doing just fine, that he has just started pre-K, is about to turn five years old and in January will be five years post-therapy. Effectively, Ja’Ceon is cured.

SCID is a rare disease, there are only around 70 cases in the US every year, but CIRM funding has helped produce cures for around 60 kids so far. A recent study in the New England Journal of Medicine showed that a UCLA approach cured 95 percent of the children treated.

The numbers are impressive. But not nearly as impressive, or as persuasive of the power of regenerative medicine, as Ja’Ceon and Dannie’s smiles.

Ja’Ceon on his first day at pre-K. He loved it.

Latest CIRM TRAN1 awards focus on CAR-based cell therapy to treat cancer

Earlier this week the CIRM ICOC Board awarded $14.5 million to fund three translational stage research projects (TRAN1), whose goal is to support early development activities necessary for advancement to a clinical study or broad end use of a potential therapy. Although all three projects have their distinct area of focus, they all utilize CAR-based cell therapy to treat a certain type of cancer. This approach involves obtaining T cells, which are an immune system cell that can destroy foreign or abnormal cells, and modifying them with a chimeric antigen receptor (CAR). This enables the newly created CAR-engineered cells to identify specific tumor signals and destroy the cancer. In the sections below we will take a deeper look at each one of these recently approved projects.

TRAN1-12245

Image Description: Hideho Okada, M.D., Ph.D.

$2,663,144 was awarded to the University of California, San Francisco (UCSF) to develop specialized CAR-T cells that are able to recognize and destroy tumor cells in glioblastoma, an aggressive type of cancer that occurs in the brain and spinal cord. The specialized CAR-T cells have been created such that they are able to detect two specific signals expressed in glioblastoma. Hideho Okada, M.D., Ph.D. and his team at UCSF will test the therapy in mice with human glioblastoma grafts. They will be looking at preclinical safety and if the CAR-T cell therapy is able to produce a desired or intended result.

TRAN1-12250

Image Description: Lili Yang, Ph.D.

$5,949,651 was awarded to the University of California, Los Angeles (UCLA) to develop specialized CAR-engineered cells from human blood stem cells to treat multiple myeloma, a type of blood cancer. Lili Yang, Ph.D. and her team have developed a method using human blood stem cells to create invariant natural killer T (iNKT) cells, a special kind of T cell with unique features that can more effectively attack tumor cells using multiple mechanisms and migrate to and infiltrate tumor sites. After being modified with CAR, the newly created CAR-iNKT cells are able to target a specific signal present in multiple myeloma. The team will test the therapy in mice with human multiple myeloma. They will be looking at preclinical safety and if the CAR-iNKT cells are able to produce a desired or intended result.

TRAN1-12258

Image Description: Cristina Puig-Saus, Ph.D.

Another $5,904,462 was awarded to UCLA to develop specialized CAR-T cells to treat melanoma, a form of skin cancer. Cristina Puig-Saus, Ph.D. and her team will use naïve/memory progenitor T cells (TNM), a subset of T cells enriched with stem cells and memory T cells, an immune cell that remains long after an infection has been eliminated. After modification with CAR, the newly created CAR-TNM cells will target a specific signal present in melanoma. The team will test the therapy in mice with human melanoma. They will be looking at preclinical safety and if the CAR-TNM cells are able to produce a desired or intended result.

CIRM Board Approves Continued Funding for SPARK and Alpha Stem Cell Clinics

Yesterday the governing Board of the California Institute for Regenerative Medicine (CIRM) approved $8.5 million to continue funding of the Summer Program to Accelerate Regenerative Medicine Knowledge (SPARK) and Alpha Stem Cell Clinics (ASCC).

This past February, the Board approved continued funding for stem cell focused educational programs geared towards undergraduate, masters, pre/postdoctoral, and medical students. The SPARK program is an existing CIRM educational program that provides for a summer internship for high school students.

To continue support for SPARK, the Board has approved $5.1 million to be allocated to ten new awards ($509,000 each) with up to a five-year duration to support 500 trainees.  The funds will enable high school students all across California to directly take part in summer research at various institutions with a stem cell, gene therapy, or regenerative medicine focus.  The goal of these programs is to prepare and inspire the next generation of scientists and provide opportunities for California’s diverse population, including those who might not have the opportunity to take part in summer research internships due to socioeconomic constraints.

CIRM’s ASCC Network is a unique regenerative medicine-focused clinical trial network that currently consists of five medical centers across California who specialize in accelerating stem cell and gene-therapy clinical trials by leveraging of resources to promote efficiency, sharing expertise, and enhancing chances of success for the patients. To date, over 105 trials in various disease indications have been supported by the ASCC Network.  While there are plans being developed for a significant ASCC Network expansion by some time next year, funding for all five sites has ended or are approaching the end of their current award period. To maintain the level of activity of the ASCC Network until expansion funding is available next year, the Board approved $3.4 million to be allocated to five supplemental awards (up to $680,000 each) in order to provide continued funding to all five sites; the host institutions will be required to match the CIRM award.  These funds will support talent retention and program key activities such as the coordination of clinical research, management of patient and public inquiries, and other operational activities vital to the ASCC Network.

“Education and infrastructure are two funding pillars critical for creating the next generation of researchers and conducting stem cell based clinical trials” says Maria T. Millan, M.D., President and CEO of CIRM.  “The importance of these programs was acknowledged in Proposition 14 and we expect that they will continue to be important components of CIRM’s programs and strategic direction in the years to come.”

The Board also awarded $14.5 million to fund three translational stage research projects (TRAN1), whose goal is to support early development activities necessary for advancement to a clinical study or broad end use of a potential therapy.

The awards are summarized in the table below:

ApplicationTitleInstitution Award
TRAN1-12245  Development of novel synNotch CART cell therapy in patients with recurrent EGFRvIII+ glioblastoma    UCSF    $2,663,144
TRAN1-12258  CAR-Tnm cell therapy for melanoma targeting TYRP-1    UCLA  $5,904,462  
TRAN1-12250HSC-Engineered Off-The-Shelf CAR-iNKT Cell Therapy for Multiple Myeloma  UCLA  $5,949,651

New Study Shows CIRM-Supported Therapy Cures More than 95% of Children Born with a Fatal Immune Disorder

Dr. Donald B. Kohn; Photo courtesy UCLA

A study published in the New England Journal of Medicine shows that an experimental form of stem cell and gene therapy has cured 48 of 50 children born with a deadly condition called ADA-SCID.

Children with ADA-SCID, (severe combined immunodeficiency due to adenosine deaminase deficiency) lack a key enzyme that is essential for a healthy, functioning immune system. As a result, even a simple infection could prove fatal to these children and, left untreated, most will die within the first two years of life.

In the study, part of which was supported by CIRM, researchers at the University of California Los Angeles (UCLA) and Great Ormond Street Hospital (GOSH) in London took some of the children’s own blood-forming stem cells and, in the lab, corrected the genetic mutation that causes ADA-SCID. They then returned those cells to the children. The hope was that over time the corrected stem cells would create a new blood supply and repair the immune system.

In the NEJM study the researchers reported outcomes for the children two and three years post treatment.

“Between all three clinical trials, 50 patients were treated, and the overall results were very encouraging,” said Dr. Don Kohn, a distinguished professor of microbiology, immunology and molecular genetics at the David Geffen School of Medicine at UCLA and a member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA. “All the patients are alive and well, and in more than 95% of them, the therapy appears to have corrected their underlying immune system problems.”

Two of the children did not respond to the therapy and both were returned to the current standard-of-care therapy. One subsequently underwent a bone marrow transplant. None of the children in the study experienced serious side-effects.

“This is encouraging news for all families affected by this rare but deadly condition,” says Maria T. Millan, MD, President and CEO of CIRM. “It’s also a testament to the power of persistence. Don Kohn has been working on developing this kind of therapy for 35 years. To see it paying off like this is a remarkable testament to his skill as a researcher and determination to help these patients.”

Hitting our Goals: Accelerating to the finish line

Way, way back in 2015 – seems like a lifetime ago doesn’t it – the team at CIRM sat down and planned out our Big 6 goals for the next five years. The end result was a Strategic Plan that was bold, ambitious and set us on course to do great things or kill ourselves trying. Well, looking back we can take some pride in saying we did a really fine job, hitting almost every goal and exceeding them in some cases. So, as we plan our next five-year Strategic Plan we thought it worthwhile to look back at where we started and what we achieved. Goal #6 was Accelerate.

Ever wonder how long it takes for a drug or therapy to go from basic research to approval by the US Food and Drug Administration (FDA)? Around 12 years on average is the answer. That’s a long time. And it can take even longer for stem cell therapies to go that same distance.

There are a lot of reasons why it takes so long (safety being a hugely important element) but when we were sitting down in 2015 to put together our Strategic Plan we wanted to find a way to speed up that process, to go faster, without in any way reducing the focus on safety.

So, we set a goal of reducing the time it takes from identifying a stem cell therapy candidate to getting an Investigational New Drug (IND) approval from the FDA, which means it can be tested in a clinical trial. At the time it was taking us around eight years, so we decided to go big and try to reduce that time in half, to four years.

Then the question was how were we going to do that? Well, before we set the goal we did a tour of the major biomedical research institutions in California – you know, University of California Los Angeles (UCLA) UC San Francisco, Stanford etc. – and asked the researchers what would help them most. Almost without exception said “a clearing house”, a way to pair early stage investigators with later stage partners who possess the appropriate expertise and interest to advance the project to the next stage of development, e.g., helping a successful basic science investigator find a qualified partner for the project’s translational research phase.

So we set out to do that. But we didn’t stop there. We also created what we called Clinical Advisory Panels or CAPs. These consisted of a CIRM Science Officer with expertise on a particular area of research, an expert on the kind of research being done, and a Patient Representative. The idea was that CAPs would help guide and advise the research team, helping them overcome specific obstacles and get ready for a clinical trial. The Patient Representative could help the researchers understand what the needs of the patient community was, so that a trial could take those into account and be more likely to succeed. For us it wasn’t enough just to fund promising research, we were determined to do all we could to support the team behind the project to advance their work.

How did we do. Pretty good I would have to say. For our Translational stage projects, the average amount of time it took for them to move to the CLIN1 stage, the last stage before a clinical trial, was 4.18 years. For our CLIN1 programs, 73 percent of those achieved their IND within 2 years, meaning they were then ready to actually start an FDA-sanctioned clinical trial.

Of course moving fast doesn’t guarantee that the therapy will ultimately prove effective. But for an agency whose mission is “to accelerate stem cell therapies to patients with unmet medical needs”, going slow is not an option.

CIRM funded stem cell therapy could one day help stroke and dementia patients

Image Description: Microscope images showing brain tissue that has been damaged by white matter stroke (left) and then repaired by the new glial cell therapy (right). Myelin (seen in red), is a substance that protects the connections between neurons and is lost due to white matter stroke. As seen at right, the glial cell therapy (green) restores lost myelin and improves connections in the brain. | Credit: UCLA Broad Stem Cell Research Center/Science Translational Medicine

Dementia is a general term that describes problems with memory, attention, communication, and physical coordination. One of the major causes of dementia is white matter strokes, which occurs when multiple strokes (i.e. a lack of blood supply to the brain) gradually damages the connecting areas of the brain (i.e. white matter).

Currently, there are no therapies capable of stopping the progression of white matter strokes or enhancing the brain’s limited ability to repair itself after they occur.

However, a CIRM-funded study ($2.09 million) conducted by S. Thomas Carmichael, M.D., Ph.D. and his team at UCLA showed that a one-time injection of an experimental stem cell therapy can repair brain damage and improve memory function in mice with conditions that mimic human strokes and dementia.

The therapy consists of glial cells, which are a special type of cell present in the central nervous system that surround and protect neurons. The glial cells are derived from induced pluripotent stem cells (iPSCS), stem cells that are derived from skin or blood cells through the process of reprogramming and have the ability to become virtually any type of cell.

Dr. Carmichael and his team injected the newly developed glial cells into the brains of mice that had damage similar to humans in the early to middle stages of dementia. The team found that the cell therapy traveled to the damaged areas of the brain and secreted chemicals that stimulated the brain’s own stem cells to start repairing the damage. This not only limited the progression of damage, but also enhanced the formation of new neural connections and increased the production of myelin, a fatty substance that covers and protects neurons.

In a press release from UCLA, Francesca Bosetti, Ph.D., Pharm.D., Program Director at the National Institute of Neurological Disorders and Strokes, was optimistic about what these findings could mean for patients with strokes or dementia.

“These preliminary results suggest that glial cell-based therapies may one day help combat the white matter damage that many stroke and vascular dementia patients suffer every year.”

Another interesting finding from this study is that even if the injected cells were eliminated a few months after they had been transplanted, the mice’s recovery was unaffected. The researchers believe that this indicates that the therapy primarily serves as a way to stimulate the brain’s own repair process.

In the same press release, Dr. Carmichael elaborates on this concept.

“Because the cell therapy is not directly repairing the brain, you don’t need to rely on the transplanted cells to persist in order for the treatment to be successful.”

The team is now conducting the additional studies necessary to apply to the Food and Drug Administration (FDA) for permission to test the therapy in a clinical trial in humans. If the therapy is shown to be safe and effective through clinical trials in humans, the team envisions that it could be used at hospitals as a one-time treatment for people with early signs of white matter stroke.

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

CIRM funding helps improve immune cell therapy to combat HIV

Image description: T cell infected with HIV.
Image Credit: National Institute of Allergy and Infectious Diseases (NIAID)

In June of last year we wrote about how Dr. Scott Kitchen and his team at UCLA are engineering blood forming stem cells in order to fight HIV, a potentially deadly virus that attacks the immune system and can worsen into AIDS if left untreated. HIV causes havoc in the body by attacking T cells, a vital part of the body’s immune system that helps fight off infections and diseases.

Dr. Kitchen’s approach uses what is called Chimeric Antigen Receptor (CAR) T gene therapy. This is a type of immune therapy that involves genetically modifying the body’s own blood forming stem cells to create T cells that have the ability to fight HIV. These newly formed immune cells have the potential to not only destroy HIV-infected cells but to create “memory cells” that could provide lifelong protection from HIV infection.

Flash forward to April of this year and the results of the CIRM funded study ($1.7M) have been published in PLOS Pathogens.

Unfortunately, although the previously designed CAR T gene therapy was still able to create HIV fighting immune cells, the way the CAR T gene therapy was designed still had the potential to allow for HIV infection.

For this new study, the team modified the CAR T gene therapy such that the cells would be resistant to infection and allow for a more efficient and longer-lasting cell response against HIV than before.

While the previous approach allowed for the continuous production of new HIV-fighting T cells that persisted for more than two years, these cells are inactivated until they come across the HIV virus. The improved CAR T gene therapy engineers the body’s immune response to HIV rather than waiting for the virus to induce a response. This is similar in concept to how a vaccine prepares the immune system to respond against a virus. The new approach also creates a significant number of “memory” T cells that are capable of quickly responding to reactivated HIV. 

The hope is that these findings can influence the development of T cells that are able carry “immune system” memory with the ability to recognize and kill virus-infected or cancerous cells. 

To date, CIRM has also funded four separate clinical trials related to the treatment of HIV/AIDS totaling over $31 million.

Unlocking a key behind why our bones get weaker as we age

Magnified image of a bone with osteoporosis. Photo Courtesy Sciencephoto.com

Getting older brings with it a mixed bag of items. If you are lucky you can get wiser. If you are not so lucky you can get osteoporosis. But while scientists don’t know how to make you wiser, they have gained some new insights into what makes bones weak and so they might be able to help with the osteoporosis.

Around 200 million people worldwide suffer from osteoporosis, a disease that causes bones to become so brittle that in extreme cases even coughing can lead to a fracture.

Scientists have known for some time that the cells that form the building blocks of our skeletons are found in the bone marrow. They are called mesenchymal stem cells (MSCs) and they have the ability to turn into a number of different kinds of cells, including bone or fat. The keys to deciding which direction the MSCs take are things called epigenetic factors, these basically control which genes are switched on or off and in what order. Now researchers from the UCLA School of Dentistry have identified an enzyme that plays a critical role in that process.

The team found that when the enzyme KDM4B is missing in MSCs those cells are more likely to become fat cells rather than bone cells. Over time that leads to weaker bones and more fractures.

In a news release Dr. Cun-Yu Wang, the lead researcher, said: “We know that bone loss comes with age, but the mechanisms behind extreme cases such as osteoporosis have, up until recently, been very vague.”

To see if they were on the right track the team created a mouse model that lacked KDM4B. Just as they predicted the MSCs in the mouse created more fat than bone, leading to weaker skeletons.

They also looked at mice who were placed on a high fat diet – something known to increase bone loss and weaker bones in people – and found that the diet seemed to reduce KDM4B which in turn produced weaker bones.

In the news release Dr. Paul Krebsbach, Dean of the UCLA School of Dentistry, said the implications for the research are enormous. “The work of Dr. Wang, his lab members and collaborators provides new molecular insight into the changes associated with skeletal aging. These findings are an important step towards what may lead to more effective treatment for the millions of people who suffer from bone loss and osteoporosis.”

The study is published in the journal Cell Stem Cell.

UCLA scientists discover how SARS-CoV-2 causes multiple organ failure in mice

Heart muscle cells in an uninfected mouse (left) and a mouse infected with SARS-CoV-2 (right) with mitochondria seen in pink. The disorganization of the cells and mitochondria in the image at right is associated with irregular heartbeat and death.
Image credit: UCLA Broad Stem Cell Center

As the worldwide coronavirus pandemic rages on, scientists are trying to better understand SARS-CoV-2, the virus that causes COVID-19, and the effects that it may have beyond those most commonly observed in the lungs. A CIRM-funded project at UCLA, co-led by Vaithilingaraja Arumugaswami, Ph.D. and Arjun Deb, M.D. discovered that SARS-CoV-2 can cause organ failure in the heart, kidney, spleen, and other vital organs of mice.

Mouse models are used to better understand the effects that a disease can have on humans. SARS-CoV-2 relies on a protein named ACE2 to infect humans. However, the virus doesn’t recognize the mouse version of the ACE2 protein, so healthy mice exposed to the SARS-CoV-2 virus don’t get sick.

To address this, past experiments by other research teams have genetically engineered mice to have the human version of the ACE2 protein in their lungs. These teams then infected the mice, through the nose, with the SARS-CoV-2 virus. Although this process led to viral infection in the mice and caused pneumonia, they don’t get as broad a range of other symptoms as humans do.

Previous research in humans has suggested that SARS-CoV-2 can circulate through the bloodstream to reach multiple organs. To evaluate this further, the UCLA researchers genetically engineered mice to have the human version of the ACE2 protein in the heart and other vital organs. They then infected half of the mice by injecting SARS-CoV-2 into their bloodstreams and compared them to mice that were not infected. The UCLA team tracked overall health and analyzed how levels of certain genes and proteins in the mice changed.

Within seven days, all of the mice infected with the virus had stopped eating, were completely inactive, and had lost an average of about 20% of their body weight. The genetically engineered mice that had not been infected with the virus did not lose a significant amount of weight. Furthermore, the infected mice had altered levels of immune cells, swelling of the heart tissue, and deterioration of the spleen. All of these are symptoms that have been observed in people who are critically ill with COVID-19.

What’s even more surprising is that the UCLA team also found that genes that help cells generate energy were shut off in the heart, kidney, spleen and lungs of the infected mice. The study also revealed that some changes were long-lasting throughout the organs in mice with SARS-CoV-2. Not only were genes turned off in some cells, the virus made epigenetic changes, which are chemical alterations to the structure of DNA that can cause more lasting effects. This might help explain why some people that have contracted COVID-19 have symptoms for weeks or months after they no longer have traces of the virus in their body.

In a UCLA press release, Dr. Deb discusses the importance and significance of their findings.

“This mouse model is a really powerful tool for studying SARS-CoV-2 in a living system. Understanding how this virus can hijack our cells might eventually lead to new ways to prevent or treat the organ failure that can accompany COVID-19 in humans.”

The full results of this study were published in JCI Insight.