Stem Cell Stories that Caught our Eye: CRISPRing Human Embryos, brain stem cells slow aging & BrainStorm ALS trial joins CIRM Alpha Clinics

Here are the stem cell stories that caught our eye this week. Enjoy!

Scientists claim first CRISPR editing of human embryos in the US.

Here’s the big story this week. Scientists from Portland, Oregon claim they genetically modified human embryos using the CRISPR/Cas9 gene editing technology. While their results have yet to be published in a peer review journal (though the team say they are going to be published in a prominent journal next month), if they prove true, the study will be the first successful attempt to modify human embryos in the US.

A representation of an embryo being fertilized. Scientists can inject CRISPR during fertilization to correct genetic disorders. (Getty Images).

Steve Connor from MIT Technology Review broke the story earlier this week noting that the only reports of human embryo modification were published by Chinese scientists. The China studies revealed troubling findings. CRISPR caused “off-target” effects, a situation where the CRISPR machinery randomly introduces genetic errors in a cell’s DNA, in the embryos. It also caused mosaicism, a condition where the desired DNA sequences aren’t genetically corrected in all the cells of an embryo producing an individual with cells that have different genomes. Putting aside the ethical conundrum of modifying human embryos, these studies suggested that current gene editing technologies weren’t accurate enough to safely modify human embryos.

But a new chapter in human embryo modification is beginning. Shoukhrat Mitalipov (who is a member of CIRM’s Grants Working Group, the panel of scientific experts that reviews our funding applications) and his team from the Oregon Health and Science University said that they have developed a method to successfully modify donated human embryos that avoids the problems experienced by the Chinese scientists. The team found that introducing CRISPR at the same time an embryo was being fertilized led to successful correction of disease-causing mutations while avoiding mosaicism and “off-target” effects. They grew these embryos for a few days to confirm that the genetic modifications had worked before destroying them.

The MIT piece quoted a scientist who knows of Mitalipov’s work,

“It is proof of principle that it can work. They significantly reduced mosaicism. I don’t think it’s the start of clinical trials yet, but it does take it further than anyone has before.”

Does this discovery, if it’s true, open the door further for the creation of designer babies? For discussions about the future scientific and ethical implications of this research, I recommend reading Paul Knoepfler’s blog, this piece by Megan Molteni in Wired Magazine and Jessica Berg’s article in The Conversation.

Brain stem cells slow aging in mice

The quest for eternal youth might be one step closer thanks to a new study published this week in the journal Nature. Scientists from the Albert Einstein College of Medicine in New York discovered that stem cells found in an area of the brain called the hypothalamus can slow the aging process in mice.

The hypothalamus is located smack in the center of your brain near the brain stem. It’s responsible for essential metabolic functions such as making and secreting hormones, managing body temperature and controlling feelings of hunger and thirst. Because the body’s metabolic functions decline with age, scientists have suspected that the hypothalamus plays a role in aging.

The mouse hypothalamus. (NIH, Wikimedia).

In the current study, the team found that stem cells in the hypothalamus gradually disappear as mice age. They were curious whether the disappearance of these stem cells could jump start the aging process. When they removed these stem cells, the mice showed more advanced mental and physical signs of aging compared to untreated mice.

They also conducted the opposite experiment where they transplanted hypothalamic stem cells taken from baby mice (the idea being that these stem cells would exhibit more “youthful” qualities) into the brains of middle-aged mice and saw improvements in mental and physical functions and a 10% increase in lifespan.

So what is it about these specific stem cells that slows down aging? Do they replenish the aging brain with new healthy cells or do they secrete factors that keep the brain healthy? Interestingly, the scientists found that these stem cells secreted vesicles that contained microRNAs, which are molecules that regulate gene expression by turning genes on or off.

They injected these microRNAs into the brains of middle-aged mice and found that they reversed symptoms of aging including cognitive decline and muscle degeneration. Furthermore, when they removed hypothalamic stem cells from middle-aged mice and treated them with the microRNAs, they saw the same anti-aging effects.

In an interview with Nature News, senior author on the study, Dongsheng Cai, commented that hypothalamic stem cells could have multiple ways of regulating aging and that microRNAs are just one of their tools. For this research to translate into an anti-aging therapy, “Cai suspects that anti-ageing therapies targeting the hypothalamus would need to be administered in middle age, before a person’s muscles and metabolism have degenerated beyond a point that could be reversed.”

This study and its “Fountain of Youth” implications has received ample attention from the media. You can read more coverage from The Scientist, GenBio, and the original Albert Einstein press release.

BrainStorm ALS trial joins the CIRM Alpha Clinics

Last month, the CIRM Board approved $15.9 million in funding for BrainStorm Cell Therapeutic’s Phase 3 trial that’s testing a stem cell therapy to treat patients with a devastating neurodegenerative disease called amyotrophic lateral sclerosis or ALS (also known as Lou Gehrig’s disease).

The stem cell therapy, called NurOwn®, is made of mesenchymal stem cells extracted from a patient’s bone marrow. The stem cells are genetically modified to secrete neurotrophic factors that keep neurons in the brain healthy and prevent their destruction by diseases like ALS.

BrainStorm has tested NurOwn in early stage clinical trials in Israel and in a Phase 2 study in the US. These trials revealed that the treatment was “safe and well tolerated” and that “NurOwn also achieved multiple secondary efficacy endpoints, showing clear evidence of a clinically meaningful benefit.  Notably, response rates were higher for NurOwn-treated subjects compared to placebo at all time points in the study out to 24 weeks.”

This week, BrainStorm announced that it will launch its Phase 3 CIRM-funded trial at the UC Irvine (UCI) CIRM Alpha Stem Cell Clinic. The Alpha Clinics are a network of top medical centers in California that specialize in delivering high quality stem cell clinical trials to patients. UCI is one of four medical centers including UCLA, City of Hope, and UCSD, that make up three Alpha Clinics currently supporting 38 stem cell trials in the state.

Along with UCI, BrainStorm’s Phase 3 trial will also be conducted at two other sites in the US: Mass General Hospital in Boston and California Pacific Medical Center in San Francisco. Chaim Lebovits, President and CEO, commented,

“We are privileged to have UCI and Dr. Namita Goyal join our pivotal Phase 3 study of NurOwn. Adding UCI as an enrolling center with Dr. Goyal as Principal Investigator will make the treatment more accessible to patients in California, and we welcome the opportunity to work with this prestigious institution.”

Before the Phase 3 trial can launch at UCI, it needs to be approved by our federal regulatory agency, the Food and Drug Administration (FDA), and an Institutional Review Board (IRB), which is an independent ethics committee that reviews biomedical research on human subjects. Both these steps are required to ensure that a therapy is safe to test in patients.

With promising data from their Phase 1 and 2 trials, BrainStorm’s Phase 3 trial will likely get the green light to move forward. Dr. Goyal, who will lead the trial at the UCI Alpha Clinic, concluded:

“NurOwn is a very promising treatment with compelling Phase 2 data in patients with ALS; we look forward to further advancing it in clinical development and confirming the therapeutic benefit with Brainstorm.”

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UC Irvine scientists engineer stem cells to “feel” cancer and destroy it

By blocking cell division, chemotherapy drugs take advantage of the fact that cancer cells multiply rapidly in the body. Though this treatment can extend and even save the lives of cancer patients, it’s somewhat like destroying an ant hill with an atomic bomb: there’s a lot of collateral damage. The treatment is infused through the blood so healthy cells that also divide frequently – like those in hair follicles, the intestines and bone marrow – succumb to the chemotherapy. To add insult to injury, cancers often become resistant to these drugs and metastasize, or invade, other parts of the body. Sadly, this spreading of a cancer is responsible for 90% of cancer deaths.

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UCI doctoral students Shirley Zhang, left, and Linan Liu are co-leading authors of the study. Photo: UC Irvine

Developing more specific, effective anti-cancer therapies is the focus of many research institutes and companies. While some new strategies target cell surface proteins that are unique to cancer cells, a UC Irvine (UCI) team has devised a stem cell-based technique that can seek out and destroy breast cancer cells that have metastasized in the lungs of mice by sensing the stiffness of the surrounding tissue. The CIRM-funded study was published this week in Science Translational Medicine.

While cells make up the tissues and organs of our bodies, they also secrete proteins and molecules that form a scaffold between cells called the extracellular matrix. This cell scaffolding is not just structural, it also plays a key role in regulating cell growth and other functions. And previous studies have shown that at sites of tumors, accumulation of collagen and other proteins in the matrix increases tissue stiffness and promotes metastasis.

Based on this knowledge, the UCI team aimed to create a cell system that would release chemotherapy drugs in response to increased stiffness. It turns out that mesenchymal stem cells – which give rise to bone, muscle, cartilage and fat – not only migrate to tumors in the body but also activate particular genes in response to the stiffness of their local cellular environment.  The researchers engineered mesenchymal stem cells to carry a gene that codes for a protein involved in the activation of a chemotherapy drug which is given by mouth. They also designed the gene to turn on only when it encounters stiff, cancerous tissue. They called the method a mechanoresponsive cell system (MRCS).

To test the MRCS, mice were infused with human breast cancer cells, which metastasized or spread to the lung. The MRCS-engineered mesenchymal stem cells were infused through the blood and homed to the lungs where they activated the chemotherapy drug which caused localized killing of the tumor cells with minimal damage to lung tissue. When the MRSC stem cells were given to mice without tumors, no increase in tissue damage was seen, proving that the MRSC-induced chemotherapy drug is only activated in the presence of cancerous tissue and has few side effects.

In a press release, team leader Weian Zhao, explained that these promising results could have wide application:

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Weian Zhao
Photo: UC Irvine

“This published work is focused on breast cancer metastases in the lungs. However, the technology will be applicable to other metastases as well, because many solid tumors have the hallmark of being stiffer than normal tissue. This is why our system is innovative and powerful, as we don’t have to spend the time to identify and develop a new genetic or protein marker for every kind of cancer.”

 

The team envisions even more applications. The MRCS could be engineered to carry genes that would enable detection with imaging technologies like PET scans. In this scenario, the MRCS could act as a highly sensitive detection system for finding areas of very early metastases when current techniques would miss them. They could also design the MRCS to activate genes that code for proteins that can break down and soften the stiff cancerous tissues which may inhibit the ability for a tumor to spread.

Stories that caught our eye: An antibody that could make stem cell research safer; scientists prepare for clinical trial for Parkinson’s disease; and the stem cell scientist running for Congress

Antibody to make stem cells safer:

There is an old Chinese proverb that states: ‘What seems like a blessing could be a curse’. In some ways that proverb could apply to stem cells. For example, pluripotent stem cells have the extraordinary ability to turn into many other kinds of cells, giving researchers a tool to repair damaged organs and tissues. But that same ability to turn into other kinds of cells means that a pluripotent stem cell could also turn into a cancerous one, endangering someone’s life.

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Researchers at the A*STAR Bioprocessing Technology Institute: Photo courtesy A*STAR

Now researchers at the Agency for Science, Technology and Research (A*STAR) in Singapore may have found a way to stop that happening.

When you change, or differentiate, stem cells into other kinds of cells there will always be some of the original material that didn’t make the transformation. Those cells could turn into tumors called teratomas. Scientists have long sought for a way to identify pluripotent cells that haven’t differentiated, without harming the ones that have.

The team at A*STAR injected mice with embryonic stem cells to generate antibodies. They then tested the ability of the different antibodies to destroy pluripotent stem cells. They found one, they called A1, that did just that; killing pluripotent cells but leaving other cells unharmed.

Further study showed that A1 worked by attaching itself to specific molecules that are only found on the surface of pluripotent cells.

In an article on Phys.Org Andre Choo, the leader of the team, says this gives them a tool to get rid of the undifferentiated cells that could potentially cause problems:

“That was quite exciting because it now gives us a view of the mechanism that is responsible for the cell-killing effect.”

Reviving hope for Parkinson’s patients:

In the 1980’s and 1990’s scientists transplanted fetal tissue into the brains of people with Parkinson’s disease. They hoped the cells in the tissue would replace the dopamine-producing cells destroyed by Parkinson’s, and stop the progression of the disease.

For some patients the transplants worked well. For some they produced unwanted side effects. But for most they had little discernible effect. The disappointing results pretty much brought the field to a halt for more than a decade.

But now researchers are getting ready to try again, and a news story on NPR explained why they think things could turn out differently this time.

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Viviane Tabar, MD; Photo courtesy Memorial Sloan Kettering Cancer Center

Viviane Tabar, a stem cell researcher at Memorial Sloan Kettering Cancer Center in New York, says in the past the transplanted tissue contained a mixture of cells:

“What you were placing in the patient was just a soup of brain. It did not have only the dopamine neurons, which exist in the tissue, but also several different types of cells.”

This time Tabar and her husband, Lorenz Studer, are using only cells that have been turned into the kind of cell destroyed by the disease. She says that will, hopefully, make all the difference:

“So you are confident that everything you are putting in the patient’s brain will consist of  the right type of cell.”

Tabar and Studer are now ready to apply to the Food and Drug Administration (FDA) for permission to try their approach out in a clinical trial. They hope that could start as early as next year.

Hans runs for Congress:

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Hans Keirstead: Photo courtesy Orange County Register

Hans Keirstead is a name familiar to many in the stem cell field. Now it could become familiar to a lot of people in the political arena too, because Keirstead has announced he’s planning to run for Congress.

Keirstead is considered by some to be a pioneer in stem cell research. A CIRM grant helped him develop a treatment for spinal cord injury.  That work is now in a clinical trial being run by Asterias. We reported on encouraging results from that trial earlier this week.

Over the years the companies he has founded – focused on ovarian, skin and brain cancer – have made him millions of dollars.

Now he says it’s time to turn his sights to a different stage, Congress. Keirstead has announced he is going to challenge 18-term Orange County Republican Dana Rohrabacher.

In an article in the Los Angeles Times, Keirstead says his science and business acumen will prove important assets in his bid for the seat:

“I’ve come to realize more acutely than ever before the deficits in Congress and how my profile can actually benefit Congress. I’d like to do what I’m doing but on a larger stage — and I think Congress provides that, provides a forum for doing the greater good.”

Stem cell-derived blood-brain barrier gives more complete picture of Huntington’s disease

Like a sophisticated security fence, our bodies have evolved a barrier that protects the brain from potentially harmful substances in the blood but still allows the entry of essential molecules like blood sugar and oxygen. Just like in other parts of the body, the blood vessels and capillaries in the brain are lined with endothelial cells. But in the brain, these cells form extremely tight connections with each other making it nearly impossible for most things to passively squeeze through the blood vessel wall and into the brain fluid.

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Compared to blood vessels in other parts of the body, brain blood vessels form a much tighter seal to protect the brain.
Image source: Dana and Chris Reeve Foundation

Recent studies have shown defects in the brain-blood barrier are associated with neurodegenerative disorders like Huntington’s disease and as a result becomes leakier. Although the debilitating symptoms of Huntington’s disease – which include involuntary movements, severe mood swings and difficulty swallowing – are primarily due to the gradual death of specific nerve cells, this breakdown in the blood-brain barrier most likely contributes to the deterioration of the Huntington’s brain.

What hasn’t been clear is if mutations in Huntingtin, the gene that is linked to Huntington’s disease, directly impact the specialized endothelial cells within the blood-brain barrier or if these specialized cells are just innocent bystanders of the destruction that occurs as Huntington’s progresses. It’s an important question to answer. If the mutations in Huntingtin directly affect the blood-brain barrier then it could provide a bigger picture of how this incurable, fatal disease works. More importantly, it may provide new avenues for therapy development.

A UC Irvine research team got to the bottom of this question with the help of induced pluripotent stem cells (iPSCs) derived from the skin cells of individuals with Huntington’s disease. Their CIRM-funded study was published this week in Cell Reports.

In a first for a neurodegenerative disease, the researchers coaxed the Huntington’s disease iPSCs in a lab dish to become brain microvascular endothelial cells (BMECs), the specialized cells responsible for forming the blood-brain barrier. The researchers found that the Huntington’s BMECs themselves were indeed dysfunctional. Compared to BMECs derived from unaffected individuals, the Huntington’s BMECs weren’t as good at making new blood vessels, and the vessels they did make were leakier. So the Huntingtin mutation in these BMECs appears to be directly responsible for the faulty blood-brain barrier.

The team dug deeper into this new insight by looking for possible differences in gene activity between the healthy and Huntington’s BMECs. They found that the Wnt group of genes, which plays an important role in the development of the blood-brain barrier, are over active in the Huntington’s BMECs. This altered Wnt activity can explain the leaky defects. In fact, the use of a drug inhibitor of Wnt fixed the defects. Dr. Leslie Thompson, the team lead, described the significance of this finding in a press release:

“Now we know there are internal problems with blood vessels in the brain. This discovery can be used for possible future treatments to seal the leaky blood vessels themselves and to evaluate drug delivery to patients with HD.”

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Study leader, Leslie Thompson. Steve Zylius / UCI

A companion Cell Stem Cell report, also published this week, used the same iPSC-derived blood-brain barrier system. In that study, researchers at Cedars-Sinai pinpointed BMEC defects as the underlying cause of Allan-Herndon-Dudley syndrome, another neurologic condition that causes mental deficits and movement problems. Together these results really drive home the importance of studying the blood-brain barrier function in neurodegenerative disease.

Dr. Ryan Lim, the first author on the UC Irvine study, also points to a larger perspective on the implications of this work:

“These studies together demonstrate the incredible power of iPSCs to help us more fully understand human disease and identify the underlying causes of cellular processes that are altered.”

jCyte gets FDA go-ahead for Fast Track review process of Retinitis Pigmentosa stem cell therapy

21 century cures

When the US Congress approved, and President Obama signed into law, the 21st Century Cures Act last year there was guarded optimism that this would help create a more efficient and streamlined, but no less safe, approval process for the most promising stem cell therapies.

Even so many people took a wait and see approach, wanting a sign that the Food and Drug Administration (FDA) would follow the recommendations of the Act rather than just pay lip service to it.

This week we saw encouraging signs that the FDA is serious when it granted Regenerative Medicine Advanced Therapy (RMAT) status to the CIRM-funded jCyte clinical trial for a rare form of blindness. This is a big deal because RMAT seeks to accelerate approval for stem cell therapies that demonstrate they can help patients with unmet medical needs.

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jCyte co-founder Dr. Henry Klassen

jCyte’s work is targeting retinitis pigmentosa (RP), a genetic disease that slowly destroys the cells in the retina, the part of the eye that converts light into electrical signals which the brain then interprets as vision. At first people with RP lose their night and peripheral vision, then the cells that help us see faces and distinguish colors are damaged. RP usually strikes people in their teens and, by the time they are 40, many people are legally blind.

jCyte’s jCell therapy uses what are called retinal progenitor cells, injected into the eye, which then release protective factors to help repair and rescue diseased retinal cells. The hope is this will stop the disease’s progression and even restore some vision to people with RP.

Dr. Henry Klassen, jCyte’s co-founder and a professor at UC Irvine, was understandably delighted by the designation. In a news release, he said:

“This is uplifting news for patients with RP. At this point, there are no therapies that can help them avoid blindness. We look forward to working with the FDA to speed up the clinical development of jCell.”

FDA

On the FDA’s blog – yes they do have one – it says researchers:

“May obtain the RMAT designation for their drug product if the drug is intended to treat serious or life-threatening diseases or conditions and if there is preliminary clinical evidence indicating that the drug has the potential to address unmet medical needs for that disease or condition. Sponsors of RMAT-designated products are eligible for increased and earlier interactions with the FDA, similar to those interactions available to sponsors of breakthrough-designated therapies. In addition, they may be eligible for priority review and accelerated approval.”

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jCyte CEO Paul Bresge

jCyte is one of the first to get this designation, a clear testimony to the quality of the work done by Dr. Klassen and his team. jCyte CEO Paul Bresge says it may help speed up their ability to get this treatment to patients.

 

“We are gratified by the FDA’s interest in the therapeutic potential of jCell and greatly appreciate their decision to provide extra support. We are seeing a lot of momentum with this therapy. Because it is well-tolerated and easy to administer, progress has been rapid. I feel a growing sense of excitement among patients and clinicians. We look forward to getting this critical therapy over the finish line as quickly as possible.”

Regular readers of this blog will already be familiar with the story of Rosie Barrero, one of the first group of people with RP who got the jCell therapy. Rosie says it has helped restore some vision to the point where she is now able to read notes she wrote ten years ago, distinguish colors and, best of all, see the faces of her children.

RMAT is no guarantee the therapy will be successful. But if the treatment continues to show promise, and is safe, it could mean faster access to a potentially life-changing therapy, one that could ultimately rescue many people from a lifetime of living in the dark.

 

 

jCyte starts second phase of stem cell clinical trial targeting vision loss

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How retinitis pigmentosa destroys vision

Studies show that Americans fear losing their vision more than any other sense, such as hearing or speech, and almost as much as they fear cancer, Alzheimer’s and HIV/AIDS. That’s not too surprising. Our eyes are our connection to the world around us. Sever that connection, and the world is a very different place.

For people with retinitis pigmentosa (RP), the leading cause of inherited blindness in the world, that connection is slowly destroyed over many years. The disease eats away at the cells in the eye that sense light, so the world of people with RP steadily becomes darker and darker, until the light goes out completely. It often strikes people in their teens, and many are blind by the time they are 40.

There are no treatments. No cures. At least not yet. But now there is a glimmer of hope as a new clinical trial using stem cells – and funded by CIRM – gets underway.

klassenWe have talked about this project before. It’s run by UC Irvine’s Dr. Henry Klassen and his team at jCyte. In the first phase of their clinical trial they tested their treatment on a small group of patients with RP, to try and ensure that their approach was safe. It was. But it was a lot more than that. For people like Rosie Barrero, the treatment seems to have helped restore some of their vision. You can hear Rosie talk about that in our recent video.

Now the same treatment that helped Rosie, is going to be tested in a much larger group of people, as jCyte starts recruiting 70 patients for this new study.

In a news release announcing the start of the Phase 2 trial, Henry Klassen said this was an exciting moment:

“We are encouraged by the therapy’s excellent safety track record in early trials and hope to build on those results. Right now, there are no effective treatments for retinitis pigmentosa. People must find ways to adapt to their vision loss. With CIRM’s support, we hope to change that.”

The treatment involves using retinal progenitor cells, the kind destroyed by the disease. These are injected into the back of the eye where they release factors which the researchers hope will help rescue some of the diseased cells and regenerate some replacement ones.

Paul Bresge, CEO of jCyte, says one of the lovely things about this approach, is its simplicity:

“Because no surgery is required, the therapy can be easily administered. The entire procedure takes minutes.”

Not everyone will get the retinal progenitor cells, at least not to begin with. One group of patients will get an injection of the cells into their worst-sighted eye. The other group will get a sham injection with no cells. This will allow researchers to compare the two groups and determine if any improvements in vision are due to the treatment or a placebo effect.

The good news is that after one year of follow-up, the group that got the sham injection will also be able to get an injection of the real cells, so that if the therapy is effective they too may be able to benefit from it.

Rosie BarreroWhen we talked to Rosie Barrero about the impact the treatment had on her, she said it was like watching the world slowly come into focus after years of not being able to see anything.

“My dream was to see my kids. I always saw them with my heart, but now I can see them with my eyes. Seeing their faces, it’s truly a miracle.”

We are hoping this Phase 2 clinical trial gives others a chance to experience similar miracles.


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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

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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.

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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.

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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.

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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.

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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 stem cell clinical trial for blindness: watch Rosie’s story

Everything we do at CIRM is laser-focused on our mission: to accelerate stem cell treatments for patients with unmet medical needs. So, you might imagine what a thrill it is to meet the people who could be helped by the stem cell research we fund. People like Rosie Barrero who suffers from Retinitis Pigmentosa (RP), an inherited, incurable form of blindness, which she describes as “an impressionist painting in a foggy room”.

The CIRM team first met Rosie Barrero back in 2012 at one of our governing Board meetings. She and her husband, German, attended the meeting to advocate for a research grant application submitted by UC Irvine’s Henry Klassen. The research project aimed to bring a stem cell-based therapy for RP to clinical trials. The Board approved the project giving a glimmer of hope to Rosie and many others stricken with RP.

Now, that hope has become a reality in the form of a Food and Drug Administration (FDA)-approved clinical trial which Rosie participated in last year. Sponsored by jCyte, a company Klassen founded, the CIRM-funded trial is testing the safety and effectiveness of a non-surgical treatment for RP that involves injecting stem cells into the eye to help save or even restore the light-sensing cells in the back of the eye. The small trial has shown no negative side effects and a larger, follow-up trial, also funded by CIRM, is now recruiting patients.

Almost five years after her first visit, Rosie returned to the governing Board in February and sprinkled in some of her witty humor to describe her preliminary yet encouraging results.

“It has made a difference. I’m still afraid of public speaking but early on [before the clinical trial] it was much easier because I couldn’t see any of you. But, hello everybody! I can see you guys. I can see this room. I can see a lot of things.”

After the meeting, she sat down for an interview with the Stem Cellar team to talk about her RP story and her experience as a clinical trial participant. The three-minute video above is based on that interview. Watch it and be inspired!

Stem cells reveal developmental defects in Huntington’s disease

Three letters, C-A-G, can make the difference between being healthy and having a genetic brain disorder called Huntington’s disease (HD). HD is a progressive neurodegenerative disease that affects movement, cognition and personality. Currently more than 30,000 Americans have HD and there is no cure or treatment to stop the disease from progressing.

A genetic mutation in the huntingtin gene. caused by an expanded repeat of CAG nucleotides, the building blocks of DNA that make our genes, is responsible for causing HD. Normal people have less than 26 CAG repeats while those with 40 or more repeats will get HD. The reasons are still unknown why this trinucleotide expansion causes the disease, but scientists hypothesize that the extra CAG copies in the huntingtin gene produce a mutant version of the Huntingtin protein, one that doesn’t function the way the normal protein should.

The HD mutation causes neurodegeneration.

As with many diseases, things start to go wrong in the body long before symptoms of the disease reveal themselves. This is the case for HD, where symptoms typically manifest in patients between the ages of 30 and 50 but problems at the molecular and cellular level occur decades before. Because of this, scientists are generating new models of HD to unravel the mechanisms that cause this disease early on in development.

Induced pluripotent stem cells (iPSCs) derived from HD patients with expanded CAG repeats are an example of a cell-based model that scientists are using to understand how HD affects brain development. In a CIRM-funded study published today in the journal Nature Neuroscience, scientists from the HD iPSC Consortium used HD iPSCs to study how the HD mutation causes problems with neurodevelopment.

They analyzed neural cells made from HD patient iPSCs and looked at what genes displayed abnormal activity compared to healthy neural cells. Using a technique called RNA-seq analysis, they found that many of these “altered” genes in HD cells played important roles in the development and maturation of neurons, the nerve cells in the brain. They also observed differences in the structure of HD neurons compared to healthy neurons when grown in a lab. These findings suggest that HD patients likely have problems with neurodevelopment and adult neurogenesis, the process where the adult stem cells in your brain generate new neurons and other brain cells.

After pinpointing the gene networks that were altered in HD neurons, they identified a small molecule drug called isoxazole-9 (Isx-9) that specifically targets these networks and rescues some of the HD-related symptoms they observed in these neurons. They also tested Isx-9 in a mouse model of HD and found that the drug improved their cognition and other symptoms related to impaired neurogenesis.

The authors conclude from their findings that the HD mutation disrupts gene networks that affect neurodevelopment and neurogenesis. These networks can be targeted by Isx-9, which rescues HD symptoms and improves the mental capacity of HD mice, suggesting that future treatments for HD should focus on targeting these early stage events.

I reached out to the leading authors of this study to gain more insights into their work. Below is a short interview with Dr. Leslie Thompson from UC Irvine, Dr. Clive Svendsen from Cedars-Sinai, and Dr. Steven Finkbeiner from the Gladstone Institutes. The responses were mutually contributed.

Leslie Thompson

Steven Finkbeiner

Clive Svendsen

 

 

 

 

 

 Q: What is the mission of the HD iPSC Consortium?

To create a resource for the HD community of HD derived stem cell lines as well as tackling problems that would be difficult to do by any lab on its own.  Through the diverse expertise represented by the consortium members, we have been able to carry out deep and broad analyses of HD-associated phenotypes [observable characteristics derived from your genome].  The authorship of the paper  – the HD iPSC consortium (and of the previous consortium paper in 2012) – reflects this goal of enabling a consortium and giving recognition to the individuals who are part of it.

Q: What is the significance of the findings in your study and what novel insights does it bring to the HD field?

 Our data revealed a surprising neurodevelopmental effect of highly expanded repeats on the HD neural cells.  A third of the changes reflected changes in networks that regulate development and maturation of neurons and when compared to neurodevelopment pathways in mice, showed that maturation appeared to be impacted.  We think that the significance is that there may be very early changes in HD brain that may contribute to later vulnerability of the brain due to the HD mutation.  This is compounded by the inability to mount normal adult neurogenesis or formation of new neurons which could compensate for the effects of mutant HTT.  The genetic mutation is present from birth and with differentiated iPSCs, we are picking up signals earlier than we expected that may reflect alterations that create increased susceptibility or limited homeostatic reserves, so with the passage of time, symptoms do result.

What we find encouraging is that using a small molecule that targets the pathways that came out of the analysis, we protected against the impact of the HD mutation, even after differentiation of the cells or in an adult mouse that had had the mutation present throughout its development.

Q: There’s a lot of evidence suggesting defects in neurodevelopment and neurogenesis cause HD. How does your study add to this idea?

Agree completely that there are a number of cell, mouse and human studies that suggest that there are problems with neurodevelopment and neurogenesis in HD.  Our study adds to this by defining some of the specific networks that may be regulating these effects so that drugs can be developed around them.  Isx9, which was used to target these pathways specifically, shows that even with these early changes, one can potentially alleviate the effects. In many of the assays, the cells were already through the early neurodevelopmental stages and therefore would have the deficits present.  But they could still be rescued.

Q: Has Isx-9 been used previously in cell or animal models of HD or other neurodegenerative diseases? Could it help HD patients who already are symptomatic?

The compound has not been used that we know of in animal models to treat neurodegeneration, although was shown to affect neurogenesis and memory in mice. Isx9 was used in a study by Stuart Lipton in Parkinson’s iPSC-derived neurons in one study and it had a protective effect on apoptosis [cell death] in a study by Ryan SD et al., 2013, Cell.

We think this type of compound could help patients who are symptomatic.  Isx-9 itself is a fairly pleiotropic drug [having multiple effects] and more research would be needed [to test its safety and efficacy].

Q: Have you treated HD mice with Isx-9 during early development to see whether the molecule improves HD symptoms?

Not yet, but we would like to.

Q: What are your next steps following this study and do you have plans to translate this research into humans?

We are following up on the research in more mature HD neurons and to determine at what stages one can rescue the HD phenotypes in mice.  Also, we would need to do pharmacodynamics and other types of assays in preclinical models to assess efficacy and then could envision going into human trials with a better characterized drug.  Our goal is to ultimately translate this to human treatments in general and specifically by targeting these altered pathways.

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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