A sense of balance is important for a wide range of activities, from simple ones such as walking, running, and driving, to more intricate ones such as dancing, rock climbing, and tight-rope walking. A lack of physical balance in the body can lead to an inbalance in trying to live a normal everyday life.
One primary cause of balance disorders is a problem with hair cells located inside the inner ear, which play a role in maintaining balance, spatial orientation, and regulating eye movement. Damage to these cells can occur as a result from infections, genetic disorders, or aging. Unfortunately, in humans, hair cells in the inner ear regenerate on their own very minimally. In the United States alone, 69 million people experience balance disorders. Symptoms of this disorder include a “spinning” feeling, lack of balance, nausea, and difficulty tracking objects using the eyes.
However, a CIRM funded study has showed promising results for helping treat this disorder. Researchers at Stanford University have discovered a way to regenerate hair cells in the inner ear of mice, giving them a better sense of balance. To do this, the researchers impaired the hair cells in the inner ear of mice and measured how well they regenerated on their own to obtain a baseline measurement. They found that about a third of the cells regenerated on their own.
Next, the researchers manipulated Atoh1, a transcription factor that regulates hair cell formation in mice. By overexpressing Atoh1, the researchers found that as much as 70% of hair cells regenerated in the mice. Additionally, 70% of these mice also recovered their sense of balance. This simple proof of concept could potentially be applied in humans to treat similar disorders related to the loss of hair cells in the inner ear.
In a press release, Dr. Alan Cheng, senior author of this study, is quoted as saying,
“This is very exciting. It’s an important first step to find treatment for vestibular disorders. We couldn’t get sufficient regeneration to recover function before.”
Blood stem cells offer promise for a variety of immune and blood related disorders such as sickle cell disease and leukemia. Like other stem cells, blood stem cells have the ability to generate additional blood stem cells in a process called self-renewal. Additionally, they are able to generate blood cells in a process called differentiation. These newly generated blood cells have the potential to be utilized for transplantations and gene therapies.
However, two limitations have hindered the progress made in this field. One problem relates to the amount of blood stem cells needed to make a potential transplantation or gene therapy viable. Unfortunately, it has been challenging to isolate and grow blood stem cells in large quantity needed for these approaches. A part of this reason relates to getting the blood stem cells to self-renew rather than differentiate.
The second problem involves the existing blood stem cells in the patient’s body prior to transplantation. In order for the procedure to work, the patient’s own blood stem cells must be eliminated to make space for the transplanted blood stem cells. This is done through a process known as conditioning, which typically involves chemotherapy and/or radiation. Unfortunately, chemotherapy and radiation can cause life-threatening side effects due to its toxicity, particularly in pediatric patients, such as growth retardation, infertility and secondary cancer in later life. Very sick or elderly patients are unable to tolerate this conditioning process, making them ineligible for transplants.
A CIRM funded study by a team at Stanford and the University of Tokyo has unlocked the code related to the generation of blood stem cells.
The collaborative team was able to modify the components used to grow blood stem cells. By making these modifications, which effects the growth and physical conditions of blood stem cells, the researchers have shown for the first time that it’s possible to get blood stem cells from mice to renew themselves hundreds or even thousands of times within a period of just 28 days.
Furthermore, the team showed that when they transplanted the newly grown cells into mice that had not undergone conditioning, the donor cells had engrafted and remained functional.
The team also found that gene editing technology such as CRISPR could be used while growing an adequate supply of blood stem cells for transplantation. This opens the possibility of obtaining a patient’s own blood stem cells, correcting the problematic gene, and reintroducing these back to the patient.
In a news release, Dr. Hiromitsu Nakauchi, a senior author of the study, is quoted as saying,
“For 50 years, researchers from laboratories around the world have been seeking ways to grow these cells to large numbers. Now we’ve identified a set of conditions that allows these cells to expand in number as much as 900-fold in just one month. We believe this approach could transform how [blood] stem cell transplants and gene therapy are performed in humans.”
A baby’s time in the womb is one of the most crucial periods in terms of its development. The average length of gestation, which is defined as the amount of time in the womb from conception to birth, is approximately 40 weeks. Unfortunately, for reasons not yet fully understood, there are times that babies are born prematurely, which can lead to problems.
These infants can have underdeveloped portions of the brain, such as the cerebral cortex, which is responsible for advanced brain functions, including cognition, speech, and the processing of sensory and motor information. The brains of premature infants can be so underdeveloped that they are unable to control breathing. This, in combination with underdeveloped lungs, can lower oxygen levels in the blood, which can lead to hypoxic, or low oxygen related, brain injuries.
In a previous study, doctors Anca and Sergiu Pasca and their colleagues at Stanford developed a technique to create a 3D brain that mimics structural and functional aspects of the developing human brain.
Using this same technique, in a new study with the aid of CIRM funding, the team grew a 3D brain that contained cells and genes similar to the human brain midway through the gestational period. They then exposed this 3D brain to low oxygen levels for 48 hours, restored the oxygen level after this time period, and observed any changes.
It was found that progenitor cells in a region known as the subventricular zone, a region that is critical in the growth of the human cortex, are affected. Progenitor cells are “stem cell like” cells that give rise to mature brain cells such as neurons. They also found that the progenitor cells transitioned from “growth” mode to “survival” mode, causing them to turn into neurons sooner than normal, which leads to fewer neurons in the brain and underdevelopment.
“In the past 20 years, we’ve made a lot of progress in keeping extremely premature babies alive, but 70% to 80% of them have poor neurodevelopmental outcomes.”
The team then tested a small molecule to see if it could potentially reverse this response to low oxygen levels by keeping the progenitor cells in “growth” mode. The results of this are promising and Dr. Sergiu Pasca is quoted as saying,
“It’s exciting because our findings tell us that pharmacologically manipulating this pathway could interfere with hypoxic injury to the brain, and potentially help with preventing damage.”
The complete findings of this study were published in Nature.
From Day One CIRM’s goal has been to advance stem cell research in California. We don’t do that just by funding the most promising research -though the 51 clinical trials we have funded to date clearly shows we do that rather well – but also by trying to bring the best minds in the field together to overcome problems.
Over the years we
have held conferences, workshops and symposiums on everything from Parkinson’s
palsy and tissue
engineering. Each one attracted the key players and stakeholders in the
field, brainstorming ideas to get past obstacles and to explore new ways of
developing therapies. It’s an attempt to get scientists, who would normally be
rivals or competitors, to collaborate and partner together in finding the best
It’s not easy to do,
and the results are not always obvious right away, but it is essential if we
hope to live up to our mission of accelerating stem cell therapies to patients
with unmet medical needs.
For example. This
past week we helped organize two big events and were participants in another.
The first event we
pulled together, in partnership with Cedars-Sinai Medical Center, was a
workshop called “Brainstorm Neurodegeneration”. It brought together leaders in stem
cell research, genomics, big data, patient advocacy and the Food and Drug
Administration (FDA) to tackle some of the issues that have hampered progress
in finding treatments for things like Parkinson’s, Alzheimer’s, ALS and
ambitiously subtitled the workshop “a cutting-edge meeting to disrupt the field”
and while the two days of discussions didn’t resolve all the problems facing us
it did produce some fascinating ideas and some tantalizing glimpses at ways to
advance the field.
Two days later we partnered with UC San Francisco to host the Fourth Annual CIRM Alpha Stem Cell Clinics Network Symposium. This brought together the scientists who develop therapies, the doctors and nurses who deliver them, and the patients who are in need of them. The theme was “The Past, Present & Future of Regenerative Medicine” and included both a look at the initial discoveries in gene therapy that led us to where we are now as well as a look to the future when cellular therapies, we believe, will become a routine option for patients.
different groups together is important for us. We feel each has a key role to
play in moving these projects and out of the lab and into clinical trials and
that it is only by working together that they can succeed in producing the
treatments and cures patients so desperately need.
As always it was the patients who surprised us. One, Cierra Danielle Jackson, talked about what it was like to be cured of her sickle cell disease. I think it’s fair to say that most in the audience expected Cierra to talk about her delight at no longer having the crippling and life-threatening condition. And she did. But she also talked about how hard it was adjusting to this new reality.
Cierra said sickle
cell disease had been a part of her life for all her life, it shaped her daily
life and her relationships with her family and many others. So, to suddenly
have that no longer be a part of her caused a kind of identity crisis. Who was
she now that she was no longer someone with sickle cell disease?
She talked about how
people with most diseases were normal before they got sick, and will be normal
after they are cured. But for people with sickle cell, being sick is all they
have known. That was their normal. And now they have to adjust to a new normal.
It was a powerful
reminder to everyone that in developing new treatments we have to consider the
whole person, their psychological and emotional sides as well as the physical.
And so on to the third event we were part of, the Stanford Drug Discovery Symposium. This was a high level, invitation-only scientific meeting that included some heavy hitters – such as Nobel Prize winners Paul Berg and Randy Schekman, former FDA Commissioner Robert Califf. Over the course of two days they examined the role that philanthropy plays in advancing research, the increasingly important role of immunotherapy in battling diseases like cancer and how tools such as artificial intelligence and big data are shaping the future.
CIRM’s President and CEO, Dr. Maria Millan, was one of those invited to speak and she talked about how California’s investment in stem cell research is delivering Something Better than Hope – which by a happy coincidence is the title of our 2018 Annual Report. She highlighted some of the 51 clinical trials we have funded, and the lives that have been changed and saved by this research.
The presentations at
these conferences and workshops are important, but so too are the conversations
that happen outside the auditorium, over lunch or at coffee. Many great
collaborations have happened when scientists get a chance to share ideas, or
when researchers talk to patients about their ideas for a successful clinical
It’s amazing what happens when you bring people together who might otherwise never have met. The ideas they come up with can change the world.
Our immune system is an important and essential part of everyday life. It is crucial for fighting off colds and, with the help of vaccinations, gives us immunity to potentially lethal diseases. Unfortunately, for some infants, this innate bodily defense mechanism is not present or is severely lacking in function.
This condition is known as severe combined immunodeficiency (SCID), commonly nicknamed “bubble baby” disease because of the sterile plastic bubble these infants used to be placed in to prevent exposure to bacteria, viruses, and fungi that can cause infection. There are several forms of SCID, one of which involves a single genetic mutation on the X chromosome and is known as SCID-X1
Many infants with SCID-X1 develop chronic diarrhea, a fungal infection called thrush, and skin rashes. Additionally, these infants grow slowly in comparison to other children. Without treatment, many infants with SCID-X1 do not live beyond infancy.
SCID-X1 occurs almost predominantly in males since they only carry one X chromosome, with at least 1 in 50,000 baby boys born with this condition. Since females carry two X chromosomes, one inherited from each parent, they are unlikely to inherit two X chromosomes with the mutation present since it would require the father to have SCID-X1.
What if there was a way to address this condition by correcting the single gene mutation? Dr. Matthew Porteus at Stanford University is leading a study that has developed an approach to treat SCID-X1 that utilizes this concept.
By using CRISPR-Cas9 technology, which we have discussed in detail in a previous blog post, it is possible to delete a problematic gene and insert a corrected gene. Dr. Porteus and his team are using CRISPR-Cas9 to edit blood stem cells, which give rise to immune cells, which are the foundation of the body’s defense mechanism. In a study published in Nature, Dr. Porteus and his team have demonstrated proof of concept of this approach in an animal model.
The Stanford team was able to take blood stem cells from six infants with SCID-X1 and corrected them with CRISPR-Cas9. These corrected stem cells were then introduced into mice modeled to have SCID-X1. It was found that these mice were not only able to make immune cells, but many of the edited stem cells maintained their ability to continuously create new blood cells.
In a press release, Dr. Mara Pavel-Dinu, a member of the research team, said:
“To our knowledge, it’s the first time that human SCID-X1 cells edited with CRISPR-Cas9 have been successfully used to make human immune cells in an animal model.”
CIRM has previously awarded Dr. Porteus with a preclinical development award aimed at developing gene correction therapy for blood stem cells for SCID-X1. In addition to this, CIRM has funded two other projects conducted by Dr. Porteus related to CRISPR-Cas9. One of these projects used CRISPR-Cas 9 to develop a treatment for chronic sinusitis due to cystic fibrosis and the second project used the technology to develop an approach for treating sickle cell disease.
CIRM has also funded four clinical trials related to SCID. Two of these trials are related to SCID-X1, one being conducted at St. Jude Children’s Research Hospital and the other at Stanford University. The third trial is related to a different form of SCID known as ADA-SCID and is being conducted at UCLA in partnership with Orchard Therapeutics. Finally, the last of the four trials is related to an additional form of SCID known as ART-SCID and is being conducted at UCSF.
A variety of diseases can be traced to a simple root cause: problems in the bone marrow. The bone marrow contains specialized stem cells known as hematopoietic stem cells (HSCs) that give rise to different types of blood cells. As mentioned in a previous blog about Sickle Cell Disease (SCD), one problem that can occur is the production of “sickle like” red blood cells. In blood cancers like leukemia, there is an uncontrollable production of abnormal white blood cells. Another condition, known as myelodysplastic syndromes (MDS), are a group of cancers in which immature blood cells in the bone marrow do not mature and therefore do not become healthy blood cells.
For diseases that originate in the bone marrow, one treatment involves introducing healthy HSCs from a donor or gene therapy. However, before this type of treatment can take place, all of the problematic HSCs must be eliminated from the patient’s body. This process, known as pre-treatment, involves a combination of chemotherapy and radiation, which can be extremely toxic and life threatening. There are some patients whose condition has progressed to the point where their bodies are not strong enough to withstand pre-treatment. Additionally, there are long-term side effects that chemotherapy and radiation can have on infant children that are discussed in a previous blog about pediatric brain cancer.
Could there be a targeted, non-toxic approach to eliminating unwanted HSCs that can be used in combination with stem cell therapies? Researchers at Stanford say yes and have very promising results to back up their claim.
Dr. Judith Shizuru and her team at Stanford University have developed an antibody that can eliminate problematic blood forming stem cells safely and efficiently. The antibody is able to identify a protein on HSCs and bind to it. Once it is bound, the protein is unable to function, effectively removing the problematic blood forming stem cells.
Dr. Shizuru is the senior author of a study published online on February 11th, 2019 in Blood that was conducted in mice and focused on MDS. The results were very promising, demonstrating that the antibody successfully depleted human MDS cells and aided transplantation of normal human HSCs in the MDS mouse model.
This proof of concept holds promise for MDS as well as other disease conditions. In a public release from Stanford Medicine, Dr. Shizuru is quoted as saying, “A treatment that specifically targets only blood-forming stem cells would allow us to potentially cure people with diseases as varied as sickle cell disease, thalassemia, autoimmune disorders and other blood disorders…We are very hopeful that this body of research is going to have a positive impact on patients by allowing better depletion of diseased cells and engraftment of healthy cells.”
The research mentioned was partially funded by us at CIRM. Additionally, we recently awarded a $3.7 million dollar grant to use the same antibody in a human clinical trial for the so-called “bubble baby disease”, which is also known as severe combined immunodeficiency (SCID). You can read more about that award on a previous blog post linked here.
Imagine being told that your seemingly healthy newborn baby has a life-threatening disease. In a moment your whole world is turned upside down. That’s the reality for families with a child diagnosed with severe combined immunodeficiency (SCID). Children with SCID lack a functioning immune system so even a simple cold can prove fatal. Today the governing Board of the California Institute for Regenerative Medicine (CIRM) awarded $3.7 million to develop a new approach that could help these children.
The funding will enable Stanford’s Dr. Judith Shizuru to complete
an earlier CIRM-funded Phase 1 clinical trial using a chemotherapy-free
transplant procedure for SCID.
The goal of the project is to replace SCID patients’ dysfunctional immune cells with healthy ones using a safer form of bone marrow transplant (BMT). Current BMT procedures use toxic chemotherapy to make space in the bone marrow for the healthy transplanted stem cells to take root and multiply. The Stanford team is testing a safe, non-toxic monoclonal antibody that targets and removes the defective blood forming stem cellsin order to promote the engraftment of the transplanted stem cells in the patient.
The funding is contingent on Dr. Shizuru raising $1.7
million in co-funding by May 1 of this year.
“This research highlights two of the things CIRM was
created to do,” says Maria T. Millan, MD, President & CEO of CIRM. “We fund
projects affecting small numbers of patients, something many organizations or
companies aren’t willing to do, and we follow those projects from the bench to
the bedside, supporting them every step along the way.”
Early testing has shown promise in helping patients and
it’s hoped that if this approach is successful in children with SCID it may
also open up similar BMT therapies for patients with other auto-immune diseases
such as multiple sclerosis, lupus or diabetes.
Neurological diseases are among the most daunting diagnoses for a patient to receive, because they impact how the individual interacts with their surroundings. Central to our ability to provide better treatment options for these patients, is scientists’ capability to understand the biological factors that influence disease development and progression. Researchers at the Stanford University School of Medicine have made an important step in providing neuroscientists a better tool to understand the brain.
While animal models are excellent systems to study the intricacies of different diseases, the ability to translate any findings to humans is relatively limited. The next best option is to study human stem cell derived tissues in the laboratory. The problem with the currently available laboratory-derived systems for studying the brain, however, is the limited longevity and diversity of neuronal cell types. Dr. Sergiu Pasca’s team was able to overcome these hurdles, as detailed in their study, published in the journal Nature Neuroscience.
A new approach
Specifically, Dr. Pasca’s group developed a method to differentiate or transform skin derived human induced pluripotent stem cells (iPSCs – which are capable of becoming any cell type) into brain-like structures that mimic how oligodendrocytes mature during brain development. Oligodendrocytes are most well known for their role in myelinating neurons, in effect creating a protective sheath around the cell to protect its ability to communicate with other brain cells. Studying oligodendrocytes in culture systems is challenging because they arise later in brain development, and it is difficult to generate and maintain them with other cell types found in the brain.
These scientists circumvented this problem by using a unique combination of growth factors and nutrients to culture the oligodendrocytes, and found that they behaved very similarly to oligodendrocytes isolated from humans. Most excitingly, they observed that the stem cell-derived oligodendrocytes were able to myelinate other neurons in the culture system. Therefore they were both physically and functionally similar to human oligodendrocytes.
Importantly, the scientists were also able to generate astrocytes alongside the oligodendrocytes. Astrocytes perform many important functions such as providing essential nutrients and directing the electrical signals that help cells in the brain communicate with each other. In a press release, Dr. Pasca explains the importance of generating multiple cell types in this in vitro system:
“We now have multiple cell types interacting in one single
culture. This permits us to look close-up at how the main cellular players in
the human brain are talking to each other.”
This in vitro or laboratory-developed system has the potential to help scientists better understand oligodendrocytes in the context of diseases such as multiple sclerosis and cerebral palsy, both of which stem from improper myelination of brain nerve cells.
This work was partially supported by a CIRM grant.
If you were looking for a poster child for an unmet medical need Huntington’s disease (HD) would be high on the list. It’s a devastating disease that attacks the brain, steadily destroying the ability to control body movement and speech. It impairs thinking and often leads to dementia. It’s always fatal and there are no treatments that can stop or reverse the course of the disease. Today the Board of the California Institute for Regenerative Medicine (CIRM) voted to support a project that shows promise in changing that.
The Board voted to approve $6 million to enable Dr. Leslie Thompson and her team at the University of California, Irvine to do the late stage testing needed to apply to the US Food and Drug Administration for permission to start a clinical trial in people. The therapy involves transplanting stem cells that have been turned into neural stem cells which secrete a molecule called brain-derived neurotrophic factor (BDNF), which has been shown to promote the growth and improve the function of brain cells. The goal is to slow down the progression of this debilitating disease.
“Huntington’s disease affects around 30,000 people in the US and children born to parents with HD have a 50/50 chance of getting the disease themselves,” says Dr. Maria T. Millan, the President and CEO of CIRM. “We have supported Dr. Thompson’s work for a number of years, reflecting our commitment to helping the best science advance, and are hopeful today’s vote will take it a crucial step closer to a clinical trial.”
Another project supported by CIRM at an earlier stage of research was also given funding for a clinical trial.
The Board approved almost $12 million to support a clinical trial to help people undergoing a kidney transplant. Right now, there are around 100,000 people in the US waiting to get a kidney transplant. Even those fortunate enough to get one face a lifetime on immunosuppressive drugs to stop the body rejecting the new organ, drugs that increase the risk for infection, heart disease and diabetes.
Dr. Everett Meyer, and his team at Stanford University, will use a combination of healthy donor stem cells and the patient’s own regulatory T cells (Tregs), to train the patient’s immune system to accept the transplanted kidney and eliminate the need for immunosuppressive drugs.
The initial group targeted in this clinical trial are people with what are called HLA-mismatched kidneys. This is where the donor and recipient do not share the same human leukocyte antigens (HLAs), proteins located on the surface of immune cells and other cells in the body. Around 50 percent of patients with HLA-mismatched transplants experience rejection of the organ.
In his application Dr. Meyer said they have a simple goal: “The goal is “one kidney for life” off drugs with safety for all patients. The overall health status of patients off immunosuppressive drugs will improve due to reduction in side effects associated with these drugs, and due to reduced graft loss afforded by tolerance induction that will prevent chronic rejection.”
The context was the recent initial public offering (IPO) of Forty Seven Inc.. a company co-founded by Dr. Weissman. That IPO followed news that two Phase 2 clinical trials being run by Forty Seven Inc. were demonstrating promising results against hard-to-treat cancers.
Dr. Weissman says the therapies used a combination of two monoclonal antibodies, 5F9 from Forty Seven Inc. and Rituximab (an already FDA-approved treatment for cancer and rheumatoid arthritis) which:
“Led to about a 50% overall remission rate when used on patients who had relapsed, multi-site disease refractory to rituximab-plus-chemotherapy. Most of those patients have shown a complete remission, although it’s too early to tell if this is complete for life.”
5F9 attacks a molecule called CD47 that appears on the surface of cancer cells. Dr. Weissman calls CD47 a “don’t eat me signal” that protects the cancer against the body’s own immune system. By blocking the action of CD47, 5F9 strips away that “don’t eat me signal” leaving the cancer vulnerable to the patient’s immune system. We have blogged about this work here and here.
The news from these trials is encouraging. But what was gratifying about Dr. Weissman’s statement is his generosity in sharing credit for the work with CIRM.
Here is what he wrote:
“What is unusual about Forty Seven is that not only the discovery, but its entire preclinical development and testing of toxicity, etc. as well as filing two Investigational New Drug [IND] applications to the Food and Drug Administration (FDA) in the US and to the MHRA in the UK, as well as much of the Phase 1 trials were carried out by a Stanford team led by two of the discoverers, Ravi Majeti and Irving Weissman at Stanford, and not at a company.
The major support came from the California Institute of Regenerative Medicine [CIRM], funded by Proposition 71, as well as the Ludwig Cancer Research Foundation at the Ludwig Center for Cancer Stem Cell Research at Stanford. CIRM will share in downstream royalties coming to Stanford as part of the agreement for funding this development.
This part of the state initiative, Proposition 71, is highly innovative and allows the discoverers of a field to guide its early phases rather than licensing it to a biotech or a pharmaceutical company before the value and safety of the discovery are sufficiently mature to be known. Most therapies at early-stage biotechs are lost in what is called the ‘valley of death’, wherein funding is very difficult to raise; many times the failure can be attributed to losing the expertise of the discoverers of the field.”
Dr. Weissman also had praise for CIRM’s funding model which requires companies that produce successful, profitable therapies – thanks to CIRM support – to return a portion of those profits to California. Most other funding agencies don’t have those requirements.
“US federal funds, from agencies such as the National Institutes of Health (NIH) similarly support discovery but cannot fund more than a few projects to, and through, early phase clinical trials. And, under the Bayh-Dole Act, the universities keep all of the equity and royalties derived from licensing discoveries. In that model no money flows back to the agency (or the public), and nearly a decade of level or less than level funding (at the national level) has severely reduced academic research. So this experiment of funding (the NIH or the CIRM model) is now entering into the phase that the public will find out which model is best for bringing new discoveries and new companies to the US and its research and clinical trials community.”
We have been funding Dr. Weissman’s work since 2006. In fact, he was one of the first recipients of CIRM funding. It’s starting to look like a very good investment indeed.