UCSD scientists devise tiny sensors that detect forces at cellular level

A big focus of stem cell research is trying to figure how to make a stem cell specialize, or differentiate, into a desired cell type like muscle, liver or bone. When we write about these efforts in the Stem Cellar, it’s usually in terms of researchers identifying proteins that bind to a stem cell’s surface and trigger changes in gene activity inside the cell that ultimately leads to a specific cell fate.

But, that’s not the only game in town. As incredible as it sounds, affecting a cell’s shape through mechanical forces also plays a profound role in gene activity and determining a cell’s fate. In one study, mesenchymal stem cells would specialize into fat cells or bone-forming cells depending on how much the MSCs were stretched out on a petri dish.

An artist’s illustration of nano optical fibers detecting the minuscule forces produced by swimming bacteria. Credit: Rhett S. Miller/UC Regents

Since we’re talking about individual cells, the strength of these mechanical forces is tiny, making measurements nearly impossible. But now, a research team at UC San Diego has engineered a device 100 times thinner than a human hair that can detect these miniscule forces. The study, funded in part by CIRM, was reported yesterday in Nature Photonics.

The device is made of a very thin optical fiber that’s coated with a resin which contains gold particles. The fiber is placed directly into the liquid that cells are grown in and then hit with a beam of light. The light is scattered by the gold particles and measured with a conventional light microscope. Forces and even sound waves caused by cells in the petri dish change the intensity of the light scattering which is detected by the microscope.

Donald Sirbuly,
team lead

In this study, the researchers measured astonishingly small forces (0.0000000000001 pound of force, to be exact!) in a culture of gut bacteria which swim around in the solution with the help of their whip-like flagella. The team also detected the sound of beating heart muscle cells at a level that’s a thousand times below the range of human hearing.

Dr. Donald Sirbuly, the team lead and a professor at UCSD’s Jacobs School of Engineering is excited about the research possibilities with this device:

“This work could open up new doors to track small interactions and changes that couldn’t be tracked before,” he said in a press release.

Bradley Fikes, the biotechnology reporter for the San Diego Union Tribune, reached out to others in the field to get their take on potential applications of this nanofiber device. Dr. John Marohn at Columbia University told Fikes in a news article (subscription is needed to access) that it could help stem cell scientists’ fully understand all of the intricacies of cell fate:

“So one of the cues that cells get, and they listen to these cues to decide how to change how to evolve, are just outside forces. This would give a way to kind of feel the outside forces that the cells feel, in a noninvasive way.”

And Eli Rothenberg at NYU School of Medicine, also not part of the study, summed up the device’s novelty, power and ease of use in an interview with Fikes:

“One of the main challenges in measuring things in biology is forces. We have no idea what’s going on in terms of forces in cells, in term of motion of molecules, the forces they interact with. But these sensors, you can put anywhere. They’re tiny, you can place them on the cells. If a cancer cell’s surface is moving, you can measure the forces…The fabrication of this device is quite straightforward. So, the simplicity of having this device and what you can measure with it, that’s kind of striking.”

 

 

Engineered bone tissue improves stem cell transplants

Bone marrow transplants are currently the only approved stem cell-based therapy in the United States. They involve replacing the hematopoietic, or blood-forming stem cells, found in the bone marrow with healthy stem cells to treat patients with cancers, immune diseases and blood disorders.

For bone marrow transplants to succeed, patients must undergo radiation therapy to wipe out their diseased bone marrow, which creates space for the donor stem cells to repopulate the blood system. Radiation can lead to complications including hair loss, nausea, fatigue and infertility.

Scientists at UC San Diego have a potential solution that could make current bone marrow transplants safer for patients. Their research, which was funded in part by a CIRM grant, was published yesterday in the journal PNAS.

Engineered bone with functional bone marrow in the center. (Varghese Lab)

Led by bioengineering professor Dr. Shyni Varghese, the team engineered artificial bone tissue that contains healthy donor blood stem cells. They implanted the engineered bone under the skin of normal mice and watched as the “accessory bone marrow” functioned like the real thing by creating new blood cells.

The implant lasted more than six months. During that time, the scientists observed that the cells within the engineered bone structure matured into bone tissue that housed the donor bone marrow stem cells and resembled how bones are structured in the human body. The artificial bones also formed connections with the mouse circulatory system, which allowed the host blood cells to populate the implanted bone tissue and the donor blood cells to expand into the host’s bloodstream.

Normal bone structure (left) and engineered bone (middle) are very similar. Bone tissue shown on top right and bone marrow cells on bottom right. (Varghese lab)

The team also implanted these artificial bones into mice that received radiation to mimic the procedures that patients typically undergo before bone marrow transplants. The engineered bone successfully repopulated the blood systems of the irradiated mice, similar to how blood stem cell functions in normal bone.

In a UC San Diego news release, Dr. Varghese explained how their technology could be translated into the clinic,

“We’ve made an accessory bone that can separately accommodate donor cells. This way, we can keep the host cells and bypass irradiation. We’re working on making this a platform to generate more bone marrow stem cells. That would have useful applications for cell transplantations in the clinic.”

The authors concluded that engineered bone tissue would specifically benefit patients who needed bone marrow transplants for non-cancerous bone marrow-related diseases such as sickle cell anemia or thalassemia where there isn’t a need to destroy cancer-causing cells.

Stem Cell Patient Advocates, Scientists and Doctors Unite Around a Common Cause

Some phrases just bring a smile to your face: “It’s a girl/boy”, “Congratulations, you got the job”, and “Another beer sir?” (or maybe that last one is just me). One other phrase that makes me smile is “packed house”. That’s why I was smiling so much at our Patient Advocate Event at UC San Diego last week. The room was jammed with around 150 patients and patient advocates who had come to hear about the progress being made in stem cell research.

Jonathan Thomas, Chair of the CIRM governing Board, kicked off the event with a quick run-through of our research, focusing on our clinical trials. As we have now funded 29 clinical trials, it really was a quick run-through, but JT did focus on a couple of remarkable stories of cures for patients suffering from Severe Combined Immunodeficiency (SCID) and Chronic Granulomatous Disease.

His message was simple. We have come a long way, but we still have a long way to go to fulfill our mission of accelerating stem cell treatments to patients with unmet medical needs. We have a target of 40 new clinical trials by 2020 and JT stressed our determination to do everything we can to reach that goal.

David Higgins, Parkinson’s Disease Advocate and CIRM Board Member (Credit Cory Kozlovich, UCSD)

Next up was David Higgins, who has a unique perspective. David is a renowned scientist, he’s also the Patient Advocate for Parkinson’s disease on the CIRM Board, and he has Parkinson’s disease. David gave a heartfelt presentation on the changing role of the patient and their growing impact on health and science.

In the old days, David said, the patient was merely the recipient of whatever treatment a doctor determined was appropriate. Today, that relationship is much more like a partnership, with physician and patient working together to determine the best approach.

He said CIRM tries to live up to that model by engaging the voice of the patient and patient advocate at every stage of the approval process, from shaping concepts to assessing the scientific merits of a project and deciding whether to fund it, and then doing everything we can to help it succeed.

He said California can serve as the model, but that patients need to make their voices heard at the national level too, particularly in light of the proposed huge budget cuts for the National Institutes of Health.

Dr. Jennifer Braswell. (Credit Cory Kozlovich, UCSD)

U.C. San Diego’s Dr. Jennifer Braswell gave some great advice on clinical trials, focusing on learning how to tell a good trial from a questionable one, and the questions patients need to ask before agreeing to be part of one.

She said it has to:

  • Be at a highly regarded medical center
  • Be based on strong pre-clinical evidence
  • Involved well-informed and compassionate physicians and nurses
  • Acknowledge that it carries some risk.

“You all know that if it sounds too good to be true, it probably is. If someone says a clinical trial carries no risk that’s a red flag, you know that’s not true. There is risk. Good researchers work hard to reduce the risk as much as possible, but you cannot eliminate it completely.”

She said even sites such as www.clinicaltrials.gov – a list of all the clinical trials registered with the National Institutes of Health – have to be approached cautiously and that you should talk to your own physican before signing up for anything.

Finally, UC San Diego’s Dr. Catriona Jamieson talked about her research into blood cancers, and how her work would not have been possible without the support of CIRM. She also highlighted the growing number of trials being carried out at through the CIRM Alpha Stem Cell Clinic Network, which helps scientists and researchers share knowledge and resources, enabling them to improve the quality of the care they provide patients.

The audience asked the panelists some great questions about the need for;

  • A national patient database to make it easier to recruit people for clinical trials
  • For researchers to create a way of letting people know if they didn’t get into a clinical trial so the patients wouldn’t get their hopes up
  • For greater public education about physicians or clinics offering unproven therapies

Adrienne Shapiro, an advocate for sickle cell disease patients, asks a question at Thursday’s stem cell meeting in La Jolla. (Bradley J. Fikes)

The meeting showed the tremendous public interest in stem cell research, and the desire to move it ahead even faster.

This was the first of a series of free public events we are holding around California this year. Next up, Los Angeles. More details of that shortly.

Stem Cell Stories That Caught Our Eye: Free Patient Advocate Event in San Diego, and new clues on how to fix muscular dystrophy and Huntington’s disease

UCSD Patient Advocate mtg instagram

Stem cell research is advancing so fast that it’s sometimes hard to keep up. That’s one of the reasons we have our Friday roundup, to let you know about some fascinating research that came across our desk during the week that you might otherwise have missed.

Of course, another way to keep up with the latest in stem cell research is to join us for our free Patient Advocate Event at UC San Diego next Thursday, April 20th from 12-1pm.  We are going to talk about the progress being made in stem cell research, the problems we still face and need help in overcoming, and the prospects for the future.

We have four great speakers:

  • Catriona Jamieson, Director of the CIRM UC San Diego Alpha Stem Cell Clinic and an expert on cancers of the blood
  • Jonathan Thomas, PhD, JD, Chair of CIRM’s Board
  • Jennifer Briggs Braswell, Executive Director of the Sanford Stem Cell Clinical Center
  • David Higgins, Patient Advocate for Parkinson’s on the CIRM Board

We will give updates on the exciting work taking place at UCSD and the work that CIRM is funding. We have also set aside some time to get your thoughts on how we can improve the way we work and, of course, answer your questions.

What: Stem Cell Therapies and You: A Special Patient Advocate Event

When: Thursday, April 20th 12-1pm

Where: The Sanford Consortium for Regenerative Medicine, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037

Why: Because the people of California have a right to know how their money is helping change the face of regenerative medicine

Who: This event is FREE and open to everyone.

We have set up an EventBrite page for you to RSVP and let us know if you are coming. And, of course, feel free to share this with anyone you think might be interested.

This is the first of a series of similar Patient Advocate Update meetings we plan on holding around California this year. We’ll have news on other locations and dates shortly.

 

Fixing a mutation that causes muscular dystrophy (Karen Ring)

It’s easy to take things for granted. Take your muscles for instance. How often do you think about them? (Don’t answer this if you’re a body builder). Daily? Monthly? I honestly don’t think much about my muscles unless I’ve injured them or if they’re sore from working out.

duchennes-cardiomyocytes-body

Heart muscle cells (green) that don’t have dystrophin protein (Photo; UT Southwestern)

But there are people in this world who think about their muscles or their lack of them every day. They are patients with a muscle wasting disease called Duchenne muscular dystrophy (DMD). It’s the most common type of muscular dystrophy, and it affects mainly young boys – causing their muscles to progressively weaken to the point where they cannot walk or breathe on their own.

DMD is caused by mutations in the dystrophin gene. These mutations prevent muscle cells from making dystrophin protein, which is essential for maintaining muscle structure. Scientists are using gene editing technologies to find and fix these mutations in hopes of curing patients of DMD.

Last year, we blogged about a few of these studies where different teams of scientists corrected dystrophin mutations using CRISPR/Cas9 gene editing technology in human cells and in mice with DMD. One of these teams has recently followed up with a new study that builds upon these earlier findings.

Scientists from UT Southwestern are using an alternative form of the CRISPR gene editing complex to fix dystrophin mutations in both human cells and mice. This alternative CRISPR complex makes use of a different cutting enzyme, Cpf1, in place of the more traditionally used Cas9 protein. It’s a smaller protein that the scientists say can get into muscle cells more easily. Cpf1 also differs from Cas9 in what DNA nucleotide sequences it recognizes and latches onto, making it a new tool in the gene editing toolbox for scientists targeting DMD mutations.

gene-edited-cardiomyocytes-body.jpg

Gene-edited heart muscle cells (green) that now express dystrophin protein (Photo: UT Southwestern)

Using CRISPR/Cpf1, the scientists corrected the most commonly found dystrophin mutation in human induced pluripotent stem cells derived from DMD patients. They matured these corrected stem cells into heart muscle cells in the lab and found that they expressed the dystrophin protein and functioned like normal heart cells in a dish. CRISPR/Cpf1 also corrected mutations in DMD mice, which rescued dystrophin expression in their muscle tissues and some of the muscle wasting symptoms caused by the disease.

Because the dystrophin gene is one of the longest genes in our genome, it has more locations where DMD-causing mutations could occur. The scientists behind this study believe that CRISPR/Cpf1 offers a more flexible tool for targeting different dystrophin mutations and could potentially be used to develop an effective gene therapy for DMD.

Senior author on the study, Dr. Eric Olson, provided this conclusion about their research in a news release by EurekAlert:

“CRISPR-Cpf1 gene-editing can be applied to a vast number of mutations in the dystrophin gene. Our goal is to permanently correct the underlying genetic causes of this terrible disease, and this research brings us closer to realizing that end.”

 

A cellular traffic jam is the culprit behind Huntington’s disease (Todd Dubnicoff)

Back in the 1983, the scientific community cheered the first ever mapping of a genetic disease to a specific area on a human chromosome which led to the isolation of the disease gene in 1993. That disease was Huntington’s, an inherited neurodegenerative disorder that typically strikes in a person’s thirties and leads to death about 10 to 15 years later. Because no effective therapy existed for the disease, this discovery of Huntingtin, as the gene was named, was seen as a critical step toward a better understand of Huntington’s and an eventual cure.

But flash forward to 2017 and researchers are still foggy on how mutations in the Huntingtin gene cause Huntington’s. New research, funded in part by CIRM, promises to clear some things up. The report, published this week in Neuron, establishes a connection between mutant Huntingtin and its impact on the transport of cell components between the nucleus and cytoplasm.

Roundup Picture1

The pores in the nuclear envelope allows proteins and molecules to pass between a cell’s nucleus and it’s cytoplasm. Image: Blausen.com staff (2014).

To function smoothly, a cell must be able to transport proteins and molecules in and out of the nucleus through holes called nuclear pores. The research team – a collaboration of scientists from Johns Hopkins University, the University of Florida and UC Irvine – found that in nerve cells, the mutant Huntingtin protein clumps up and plays havoc on the nuclear pore structure which leads to cell death. The study was performed in fly and mouse models of HD, in human HD brain samples as well as HD patient nerve cells derived with the induced pluripotent stem cell technique – all with this same finding.

Roundup Picture2

Huntington’s disease is caused by the loss of a nerve cells called medium spiny neurons. Image: Wikimedia commons

By artificially producing more of the proteins that make up the nuclear pores, the damaging effects caused by the mutant Huntingtin protein were reduced. Similar results were seen using drugs that help stabilize the nuclear pore structure. The implications of these results did not escape George Yohrling, a senior director at the Huntington’s Disease Society of America, who was not involved in the study. Yohrling told Baltimore Sun reporter Meredith Cohn:

“This is very exciting research because we didn’t know what mutant genes or proteins were doing in the body, and this points to new areas to target research. Scientists, biotech companies and pharmaceutical companies could capitalize on this and maybe develop therapies for this biological process”,

It’s important to temper that excitement with a reality check on how much work is still needed before the thought of clinical trials can begin. Researchers still don’t understand why the mutant protein only affects a specific type of nerve cells and it’s far from clear if these drugs would work or be safe to use in the context of the human brain.

Still, each new insight is one step in the march toward a cure.

A life-threatening childhood disease and the CIRM-funded team seeking a stem cell cure featured in new video

“My hope for Brooke is she can one day look back and we have to remind her of the disease she once had.”

That’s Clay Emerson’s biggest hope for his young daughter Brooke, who has cystinosis, a life-threatening genetic disease that appears by the age of two and over time causes damage to many organs, especially the kidneys and eyes but also the liver, muscle, brain, pancreas and other tissues. The Emersons and other families affected by the disease are featured in a recent video produced by the Cystinosis Research Foundation.

I doubt many can watch the seven-minute piece without getting a lump in their throat or watery eyes. One of many heart wrenching scene shows Brooke’s mother, Jill Emerson, preparing a day’s worth of medicine that she administers through a tube connected to Brook’s stomach.

“Brooke takes about 20 doses of medication a day and that’s throughout the 24hr period in a day. The poor kid hasn’t had a full night’s sleep ever in her entire life because I have to wake her up to take her life-saving medicine.”

Jill Emerson prepares a day’s worth of medicine for her daughter Brooke. Unfortunately, the treatments only slow the progression of cystinosis but don’t cure it. (Video Still: Cystinosis Research Foundation)

But these treatments only slow down the progression of this incurable disease. Even perfect compliance with taking the medicine doesn’t stop severe complications of the disease including kidney failure, diabetes, muscle weakness, and difficulty swallowing just to name a few. Cystinosis also shorten life spans. Natalie, the video’s narrator, a young woman with cystinosis wonders how much time she has left:

“There are people in their 20s who have recently died from cystinosis. I am 25 years old and I often think about how long I have to live. I’m praying for a cure for all of us.”

Her prayers may be answered in the form of a stem cell gene therapy treatment. UCSD researcher Dr. Stephanie Cherqui, who is also featured in the video, received $5 million in CIRM funding to bring her team’s therapy to clinical trials in people.

At a cellular level, cystinosis is caused by mutations in a gene called CTNS which lead to an accumulation of the amino acid cysteine. The excess cysteine eventually forms crystals causing devastating damage to cells throughout the body. Cherqui’s treatment strategy is to take blood stem cells from affected individuals, insert a good copy of the CTNS gene using genome editing into the cells’ DNA, and then transplant the cells back into the patient.

Cystinosis_Cherqui

Dr. Stephanie Cherqui and her team are working hard to bring a stem cell gene therapy treatment for cystinosis to clinical trials. (Video Still: Cystinosis Research Foundation)

Her team has preliminary evidence that the strategy works in mice. Now, they will use the CIRM grant to complete these pre-clinical studies and prepare the genetically engineered blood stem cells for use in patients. These steps are necessary to get the green light from the Food and Drug Administration (FDA) to begin clinical trials, hopefully some time this year.

Cherqui says that if all goes well, the treatment approach may have benefits beyond cystinosis:

“If we can bring this to the finish line, we can then show the way to maybe hundreds, maybe thousands of other genetic diseases. So this could be a real benefit to mankind.”

Stem Cell Stories That Caught Our Eye: Plasticity in the pancreas and two cool stem cell tools added to the research toolbox

There’s more plasticity in the pancreas than we thought. You’re taught a lot of things about the world when you’re young. As you get older, you realize that not everything you’re told holds true and it’s your own responsibility to determine fact from fiction. This evolution in understanding happens in science too. Scientists do research that leads them to believe that biological processes happen a certain way, only to sometimes find, a few years later, that things are different or not exactly what they had originally thought.

There’s a great example of this in a study published this week in Cell Metabolism about the pancreas. Scientists from UC Davis found that the pancreas, which secretes a hormone called insulin that helps regulate the levels of sugar in your blood, has more “plasticity” than was originally believed. In this case, plasticity refers to the ability of a tissue or organ to regenerate itself by replacing lost or damaged cells.

The long-standing belief in this field was that the insulin producing cells, called beta cells, are replenished when beta cells actively divide to create more copies of themselves. In patients with type 1 diabetes, these cells are specifically targeted and killed off by the immune system. As a result, the beta cell population is dramatically reduced, and patients have to go on life-long insulin treatment.

UC Davis researchers have identified another type of insulin-producing cell in the islets, which appears to be an immature beta cell shown in red. (UC Davis)

But it turns out there is another cell type in the pancreas that is capable of making beta cells and they look like a teenage, less mature version of beta cells. The UC Davis team identified these cells in mice and in samples of human pancreas tissue. These cells hangout at the edges of structures called islets, which are clusters of beta cells within the pancreas. Upon further inspection, the scientists found that these immature beta cells can secrete insulin but cannot detect blood glucose like mature beta cells. They also found their point of origin: the immature beta cells developed from another type of pancreatic cell called the alpha cell.

Diagram of immature beta cells from Cell Metabolism.

In coverage by EurekAlert, Dr Andrew Rakeman, the director of discovery research at the Juvenile Diabetes Research Foundation, commented on the importance of this study’s findings and how it could be translated into a new approach for treating type 1 diabetes patients:

“The concept of harnessing the plasticity in the islet to regenerate beta cells has emerged as an intriguing possibility in recent years. The work from Dr. Huising and his team is showing us not only the degree of plasticity in islet cells, but the paths these cells take when changing identity. Adding to that the observations that the same processes appear to be occurring in human islets raises the possibility that these mechanistic insights may be able to be turned into therapeutic approaches for treating diabetes.”

 

Say hello to iPSCORE, new and improved tools for stem cell research. Stem cells are powerful tools to model human disease and their power got a significant boost this week from a new study published in Stem Cell Reports, led by scientists at UC San Diego School of Medicine.

The team developed a collection of over 200 induced pluripotent stem cell (iPS cell) lines derived from people of diverse ethnic backgrounds. They call this stem cell tool kit “iPSCORE”, which stands for iPSC Collection for Omic Research (omics refers to a field of study in biology ending in -omics, such as genomics or proteomics). The goal of iPSCORE is to identify particular genetic variants (unique differences in DNA sequence between people’s genomes) that are associated with specific diseases and to understand why they cause disease at the molecular level.

In an interview with Phys.org, lead scientist on the study, Dr. Kelly Frazer, further explained the power of iPSCORE:

“The iPSCORE collection contains 75 lines from people of non-European ancestry, including East Asian, South Asian, African American, Mexican American, and Multiracial. It includes multigenerational families and monozygotic twins. This collection will enable us to study how genetic variation influences traits, both at a molecular and physiological level, in appropriate human cell types, such as heart muscle cells. It will help researchers investigate not only common but also rare, and even family-specific variations.”

This research is a great example of scientists identifying a limitation in stem cell research and expanding the stem cell tool kit to model diseases in a diverse human population.

A false color scanning electron micrograph of cultured human neuron from induced pluripotent stem cell. Credit: Mark Ellisman and Thomas Deerinck, UC San Diego.

Stem cells that can grow into ANY type of tissue. Embryonic stem cells can develop into any cell type in the body, earning them the classification of pluripotent. But there is one type of tissue that embryonic stem cells can’t make and it’s called extra-embryonic tissue. This tissue forms the supportive tissue like the placenta that allows an embryo to develop into a healthy baby in the womb.

Stem cells that can develop into both extra-embryonic and embryonic tissue are called totipotent, and they are extremely hard to isolate and study in the lab because scientists lack the methods to maintain them in their totipotent state. Having the ability to study these special stem cells will allow scientists to answer questions about early embryonic development and fertility issues in women.

Reporting this week in the journal Cell, scientists from the Salk Institute in San Diego and Peking University in China identified a cocktail of chemicals that can stabilize human stem cells in a totipotent state where they can give rise to either tissue type. They called these more primitive stem cells extended pluripotent stem cells or EPS cells.

Salk Professor Juan Carlos Izpisua Bemonte, co–senior author of the paper, explained the problem their study addressed and the solution it revealed in a Salk news release:

“During embryonic development, both the fertilized egg and its initial cells are considered totipotent, as they can give rise to all embryonic and extra-embryonic lineages. However, the capture of stem cells with such developmental potential in vitro has been a major challenge in stem cell biology. This is the first study reporting the derivation of a stable stem cell type that shows totipotent-like bi-developmental potential towards both embryonic and extra-embryonic lineages.”

Human EPS cells (green) can be detected in both the embryonic part (left) and extra-embryonic parts (placenta and yolk sac, right) of a mouse embryo. (Salk Institute)

Using this new method, the scientists discovered that human EPS stem cells were able to develop chimeric embryos with mouse stem cells more easily than regular embryonic stem cells. First author on the study, Jun Wu, explained why this ability is important:

“The superior chimeric competency of both human and mouse EPS cells is advantageous in applications such as the generation of transgenic animal models and the production of replacement organs. We are now testing to see whether human EPS cells are more efficient in chimeric contribution to pigs, whose organ size and physiology are closer to humans.”

The Salk team reported on advancements in generating interspecies chimeras earlier this year. In one study, they were able to grow rat organs – including the pancreas, heart and eyes – in a mouse. In another study, they grew human tissue in early-stage pig and cattle embryos with the goal of eventually developing ways to generate transplantable organs for humans. You can read more about their research in this Salk news release.

One scientist’s quest to understand autism using stem cells

April is National Autism Awareness Month and people and organizations around the world are raising awareness about a disorder that affects more than 20 million people globally. Autism affects early brain development and causes a wide spectrum of social, mental, physical and emotional symptoms that appear during childhood. Because the symptoms and their severity can vary extremely between people, scientists now use the classification of autism spectrum disorder (ASM).

Alysson Muotri UC San Diego

In celebration of Autism Awareness Month, we’re featuring an interview with a CIRM-funded scientist who is on the forefront of autism and ASD research. Dr. Alysson Muotri is a professor at UC San Diego and his lab is interested in unlocking the secrets to brain development by using molecular tools and stem cell models.

One of his main research projects is on autism. Scientists in his lab are using induced pluripotent stem cells (iPSCs) derived from individuals with ASD to model the disease in a dish. From these stem cell models, his team is identifying genes that are associated with ASD and potential drugs that could be used to treat this disorder. Ultimately, Dr. Muotri’s goal is to pave a path for the development of personalized therapies for people with ASD.

I reached out to Dr. Muotri to ask for an update on his Autism research. His responses are below.

Q: Can you briefly summarize your lab’s work on Autism Spectrum Disorders?

AM: As a neuroscientist studying autism, I was frustrated with the lack of a good experimental model to understand autism. All the previous models (animal, postmortem brain tissues, etc.) have serious experimental limitations. The inaccessibility of the human brain has blocked the progress of research on ASD for a long time. Cellular reprogramming allows us to transform easy-access cell types (such as skin, blood, dental pulp, etc.) into brain cells or even “mini-brains” in the lab. Because we can capture the entire genome of the person, we can recapitulate early stages of neurodevelopment of that same individual. This is crucial to study neurodevelopment disorders, such as ASD, because of the strong genetic factor underlying the pathology [the cause of a disease]. By comparing “mini-brains” between an ASD and neurotypical [non-ASD] groups, we can find anatomical and functional differences that might explain the clinical symptoms.

Q: What types of tools and models are you using to study ASD?

AM: Most of my lab takes advantage of reprogramming stem cells and genome editing techniques to generate 3D organoid models of ASD. We use the stem cells to create brain organoids, also called “mini-brains” in the lab. These mini-brains will develop from single cells and grow and mature in the same way as the fetal brain. Thus, we can learn about their structure and connectivity over time.

A cross section of a cerebral organoid or mini-brain courtesy of Alysson Muotri.

This new model brings something novel to the table: the ability to experimentally test specific hypotheses in a human background.  For example, we can ask if a specific genetic variant is causal for an autistic individual. Thus, we can edit the genome of that autistic individual, fixing target mutations in these mini-brains and check if now the fixed mini-brains will develop any abnormalities seen in ASD.

The ability to combine all these recent technologies to create a human experimental model of ASD in the lab is quite new and very exciting. As with any other model, there are limitations. For example, the mini-brains don’t have all the complexity and cell types seen in the developing human embryo/fetus. We also don’t know exactly if we are giving them the right and necessary environment (nutrients, growth factors, etc.) to mature. Nonetheless, the progress in this field is taking off quickly and it is all very promising.

Two mini-brains grown in a culture dish send out cellular extensions to connect with each other. Neurons are in green and astrocytes are in pink. Image courtesy of Dr. Muotri.

Q: We’ve previously written about your lab’s work on the Tooth Fairy Project and how you identified the TRPC6 gene. Can you share updates on this project and any new insights?

AM: The Tooth Fairy Project was designed to collect dental pulp cells from ASD and control individuals in a non-invasive fashion (no need for skin biopsy or to draw blood). We used social media to connect with families and engage them in our research. It was so successful we have now hundreds of cells in the lab. We use this material to reprogram into stem cells and to sequence their DNA.

One of the first ASD participants had a mutation in one copy of the TRPC6 gene, a novel ASD gene candidate. Everybody has two copies of this gene in the genome, but because of the mutation, this autistic kid has only one functional copy. Using stem cells, we re-created cortical neurons from that individual and confirmed that this mutation inhibits the formation of excitatory synapses (connections required to propagate information).

Interestingly, while studying TRPC6, we realized that a molecule found in Saint John’s Wort, hyperforin, could stimulate the functional TRPC6. Since the individual still has one functional TRPC6 gene copy, it seemed reasonable to test if hyperforin treatment could compensate the mutation on the other copy. It did. A treatment with hyperforin for only two weeks could revert the deficits on the neurons derived from that autistic boy. More exciting is the fact that the family agreed to incorporate St. John’s Wort on his diet. We have anecdotal evidence that this actually improved his social and emotional skills.

To me, this is the first example of personalized treatment for ASD, starting with genome sequencing, detecting potential causative genetic mutations, performing cellular modeling in the lab, and moving into clinic. I believe that there are many other autistic cases where this approach could be used to find better treatments, even with off the counter medications. To me, that is the greatest insight.

Watch Dr. Muotri’s Spotlight presentation about the Tooth Fairy Project and his work on autism.

Q: Is any of the research you are currently doing in autism moving towards clinical trials?

AM: IGF-1, or insulin growth factor-1, a drug we found promising for Rett syndrome and a subgroup of idiopathic [meaning its causes are spontaneous or unknown] ASD is now in clinical trials. Moreover, we just concluded a CIRM award on a large drug screening for ASD. The data is very promising, with several candidates. We have 14 drugs in the pipeline, some are repurposed drugs (initially designed for cancer, but might work for ASD). It will require additional pre-clinical studies before we start clinical trials.

Q: What do you think the future of diagnosis and treatment will be for patients with ASD?

AM: I am a big enthusiastic fan of personalized treatments for ASD. While we continue to search for a treatment that could help a large fraction of ASD people, we also recognized that some cases might be easier than others depending on their genetic profile. The idea of using stem cells to create “brain avatars” of ASD individuals in the lab is very exciting. We are also studying the possibility of using this approach as a future diagnostic tool for ASD. I can imagine every baby having their “brain avatar” analyses done in the lab, eventually pointing out “red flags” on the ones that failed to achieve neurodevelopment milestones. If we could capture these cases, way before the autism symptoms onset, we could initiate early treatments and therapies, increasing the chances for a better prognostic and clinical trajectory. None of these would be possible without stem cell research.

Q: What other types of research is your lab doing?

Mini-brains grown in a dish in Dr. Muotri’s lab.

AM: My lab is also using these human mini-brains to test the impact of environmental factors in neurodevelopment. By exposing the mini-brains to certain agents, such as pollution particles, household chemicals, cosmetics or agrotoxic products [pesticides], we can measure the concentration that is likely to induce brain abnormalities (defects in neuronal migration, synaptogenesis, etc.). This toxicological test can complement or substitute for other commonly used analyses, such as animal models, that are not very humane or predictive of human biology. A nice example from my lab was when we used this approach to confirm the detrimental effect of the Zika virus on brain development. Not only did we show causation between the circulating Brazilian Zika virus and microcephaly [a birth defect that causes an abnormally small head], but our data also pointed towards a potential mechanism (we showed that the virus kills neural progenitor cells, reducing the thickness of the cortical layers in the brain).

You can learn more about Dr. Muotri’s research on his lab’s website.


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You Are Invited: CIRM Patient Advocate Event, San Diego April 20th

Cured_AR_2016_cover

The word “cured” is one of the loveliest words in the English language. Last year we got to use it twice when we talked about stem cell therapies we are funding. Two of our clinical trials are not just helping people, they are curing them (you can read about that in our Annual Report).

But this was just part of the good news about stem cell research. We are making progress on many different fronts, against many different diseases, and we want to tell you all about that.

That’s why we are holding a special Patient Advocate event at UC San Diego on Thursday, April 20th from 12 – 1pm to talk about the progress being made in stem cell research, the problems we still face and need help in overcoming, and the prospects for the future.

We will have four terrific speakers:

  • Catriona Jamieson, Director of the CIRM UC San Diego Alpha Stem Cell Clinic and an expert on cancers of the blood
  • Jonathan Thomas, PhD, JD, Chair of CIRM’s Board
  • Jennifer Briggs Braswell, Executive Director of the Sanford Stem Cell Clinical Center
  • David Higgins, Patient Advocate for Parkinson’s on the CIRM Board

We will give updates on the exciting work taking place at UCSD and the work that CIRM is funding. We have also set aside some time to get your thoughts on how we can improve the way we work and, of course, answer your questions.

So we would love for you to join us, and tell your friends about the event as well. Here are the basic details.

What: Stem Cell Therapies and You: A Special Patient Advocate Event

When: Thursday, April 20th 12-1pm

Where: The Sanford Consortium for Regenerative Medicine, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037

Why: Because the people of California have a right to know how their money is helping change the face of regenerative medicine

Who: This event is FREE and open to the public

We have set up an EventBrite page for people to RSVP and let us know if they are coming.

We hope to see you there.

 

Stem Cell Stories that Caught our Eye: stem cell insights into anorexia, Zika infection and bubble baby disease

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

Stem cell model identifies new culprit for anorexia.

Eating disorders like anorexia nervosa are often thought to be caused by psychological disturbances or societal pressure. However, research into the genes of anorexia patients suggests that what’s written in your DNA can be associated with an increased vulnerability to having this disorder. But identifying individual genes at fault for a disease this complex has remained mostly out of scientists’ reach, until now.

A CIRM-funded team from the UC San Diego (UCSD) School of Medicine reported this week that they’ve developed a stem cell-based model of anorexia and used it to identify a gene called TACR1, which they believe is associated with an increased likelihood of getting anorexia.

They took skin samples from female patients with anorexia and reprogrammed them into induced pluripotent stem cells (iPSCs). These stem cells contained the genetic information potentially responsible for causing their anorexia. The team matured these iPSCs into brain cells, called neurons, in a dish, and then studied what genes got activated. When they looked at the genes activated by anorexia neurons, they found that TACR1, a gene associated with psychiatric disorders, was switched on higher in anorexia neurons than in healthy neurons. These findings suggest that the TACR1 gene could be an identifier for this disease and a potential target for developing new treatments.

In a UCSD press release, Professor and author on the study, Alysson Muotri, said that they will follow up on their findings by studying stem cell lines derived from a larger group of patients.

Alysson Muotri UC San Diego

“But more to the point, this work helps make that possible. It’s a novel technological advance in the field of eating disorders, which impacts millions of people. These findings transform our ability to study how genetic variations alter brain molecular pathways and cellular networks to change risk of anorexia nervosa — and perhaps our ability to create new therapies.”

Anorexia is a disease that affects 1% of the global population and although therapy can be an effective treatment for some, many do not make a full recovery. Stem cell-based models could prove to be a new method for unlocking new clues into what causes anorexia and what can cure it.

Nature versus Zika, who will win?

Zika virus is no longer dominating the news headlines these days compared to 2015 when large outbreaks of the virus in the Southern hemisphere came to a head. However, the threat of Zika-induced birth defects, like microcephaly to pregnant women and their unborn children is no less real or serious two years later. There are still no effective vaccines or antiviral drugs that prevent Zika infection but scientists are working fast to meet this unmet need.

Speaking of which, scientists at UCLA think they might have a new weapon in the war against Zika. Back in 2013, they reported that a natural compound in the body called 25HC was effective at attacking viruses and prevented human cells from being infected by viruses like HIV, Ebola and Hepatitis C.

When the Zika outbreak hit, they thought that this compound could potentially be effective at preventing Zika infection as well. In their new study published in the journal Immunity, they tested a synthetic version of 25HC in animal and primate models, they found that it protected against infection. They also tested the compound on human brain organoids, or mini brains in a dish made from pluripotent stem cells. Brain organoids are typically susceptible to Zika infection, which causes substantial cell damage, but this was prevented by treatment with 25HC.

Left to right: (1) Zika virus (green) infects and destroys the formation of neurons (pink) in human stem cell-derived brain organoids.  (2) 25HC blocks Zika infection and preserves neuron formation in the organoids. (3) Reduced brain size and structure in a Zika-infected mouse brain. (4) 25HC preserves mouse brain size and structure. Image courtesy of UCLA Stem Cell.

A UCLA news release summarized the impact that this research could have on the prevention of Zika infection,

“The new research highlights the potential use of 25HC to combat Zika virus infection and prevent its devastating outcomes, such as microcephaly. The research team will further study whether 25HC can be modified to be even more effective against Zika and other mosquito-borne viruses.”

Harnessing a naturally made weapon already found in the human body to fight Zika could be an alternative strategy to preventing Zika infection.

Gene therapy in stem cells gives hope to bubble-babies.

Last week, an inspiring and touching story was reported by Erin Allday in the San Francisco Chronicle. She featured Ja’Ceon Golden, a young baby not even 6 months old, who was born into a life of isolation because he lacked a properly functioning immune system. Ja’Ceon had a rare disease called severe combined immunodeficiency (SCID), also known as bubble-baby disease.

 

Ja’Ceon Golden is treated by patient care assistant Grace Deng (center) and pediatric oncology nurse Kat Wienskowski. Photo: Santiago Mejia, The Chronicle.

Babies with SCID lack the body’s immune defenses against infectious diseases and are forced to live in a sterile environment. Without early treatment, SCID babies often die within one year due to recurring infections. Bone marrow transplantation is the most common treatment for SCID, but it’s only effective if the patient has a donor that is a perfect genetic match, which is only possible for about one out of five babies with this disease.

Advances in gene therapy are giving SCID babies like Ja’Ceon hope for safer, more effective cures. The SF Chronicle piece highlights two CIRM-funded clinical trials for SCID run by UCLA in collaboration with UCSF and St. Jude Children’s Research Hospital. In these trials, scientists isolate the bone marrow stem cells from SCID babies, correct the genetic mutation causing SCID in their stem cells, and then transplant them back into the patient to give them a healthy new immune system.

The initial results from these clinical trials are promising and support other findings that gene therapy could be an effective treatment for certain genetic diseases. CIRM’s Senior Science Officer, Sohel Talib, was quoted in the Chronicle piece saying,

“Gene therapy has been shown to work, the efficacy has been shown. And it’s safe. The confidence has come. Now we have to follow it up.”

Ja’Ceon was the first baby treated at the UCSF Benioff Children’s Hospital and so far, he is responding well to the treatment. His great aunt Dannie Hawkins said that it was initially hard for her to enroll Ja’Ceon in this trial because she was a partial genetic match and had the option of donating her own bone-marrow to help save his life. In the end, she decided that his involvement in the trial would “open the door for other kids” to receive this treatment if it worked.

Ja’Ceon Golden plays with patient care assistant Grace Deng in a sterile play area at UCSF Benioff Children’s Hospital.Photo: Santiago Mejia, The Chronicle

It’s brave patients and family members like Ja’Ceon and Dannie that make it possible for research to advance from clinical trials into effective treatments for future patients. We at CIRM are eternally grateful for their strength and the sacrifices they make to participate in these trials.

A Clinical Trial Network Focused on Stem Cell Treatments is Expanding

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

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

Get to Know Our Alpha Clinics

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

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

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

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

The Alpha Clinics Network is expanding

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

CIRM’s Chairman Jonathan Thomas explained,

Jonathan Thomas

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

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

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

Apply to be one our new Alpha Clinics!

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

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

City of Hope Medical Center and Alpha Stem Cell Clinic


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