Can Stem Cell Therapies Help ALS Patients?

A scientist’s fifteen-year journey to develop a stem cell-based therapy that could one day help ALS patients.

Jan Kaufman

Photo of Clive Svendsen (top left) and Jan & Jeff Kaufman

“Can stem cells help me Clive?”

The sentence appeared slowly on a computer screen, each character separated by a pause while its author searched for the next character using a device controlled by his eye muscle.

The person asking the question was Jeff Kaufman, a Wisconsin man in his 40s completely paralyzed by amyotrophic lateral sclerosis (ALS). On the receiving end was Clive Svendsen, PhD, then a scientist at the University of Wisconsin-Madison, determined to understand how stem cells could help patients like Jeff.

Also known as Lou Gehrig’s disease, ALS is a rapid, aggressive neurodegenerative disease with a two to four-year life expectancy. ALS destroys the nerve cells that send signals from the brain and spinal cord to the muscles that control movement. Denervation, or loss of nerves, causes muscle weakness and atrophy, leaving patients unable to control their own bodies. Currently there are two FDA-approved ALS drugs in the US – riluzole and a new drug called edaravone (Radicava). However, they only slow disease progression in some ALS patients by a few months and there are no effective treatments that stop or cure the disease.

Given this poor prognosis, making ALS the focus of his research career was an easy decision. However, developing a therapeutic strategy was challenging to Svendsen. “The problem with ALS is we don’t know the cause,” he said. “Around 10% of ALS cases are genetic, and we know some of the genes involved, but 90% of cases are sporadic.” He explained that this black box makes it difficult for scientists to know where to start when trying to develop treatments for sporadic ALS cases that have no drug targets.

From Parkinson’s disease to ALS

Svendsen, who moved to Cedars-Sinai in Los Angeles to head the Cedars-Sinai Board of Governors Regenerative Medicine Institute in 2010, has worked on ALS for the past 15 years. Before that, he studied Parkinson’s disease, a long-term neurodegenerative disorder that affects movement, balance and speech. Unlike ALS, Parkinson’s patients have a longer life expectancy and more treatment options that alleviate symptoms of the disease, making their quality of life far better than ALS patients.

Clive Svendsen, PhD, Director, Regenerative Medicine Institute. (Image courtesy of Cedars-Sinai)

“I chose to work on ALS mainly because of the effects it has on ALS families,” explained Svendsen. “Being normal one day, and then becoming rapidly paralyzed was hard to see.”

The transition from Parkinson’s to ALS was not without a scientific reason however. Svendsen was studying how an important growth factor in the brain called Glial Cell Line-Derived Neurotrophic Factor or GDNF could be used to protect dopamine neurons in order to treat Parkinson’s patients. However other research suggested that GDNF was even more effective at protecting motor neurons, the nerve cells destroyed by ALS.

Armed with the knowledge of GDNF’s ability to protect motor neurons, Svendsen and his team developed an experimental stem cell-based therapy that they hoped would treat patients with the sporadic form of ALS. Instead of using stem cells to replace the motor neurons lost to ALS, Svendsen placed his bets on making another cell type in the brain, the astrocyte.

Rooting for the underdog

Astrocytes are the underdog cells of the brain, often overshadowed by neurons that send and receive information from the central nervous system to our bodies. Astrocytes have many important roles, one of the most critical being to support the functions of neurons. In ALS, astrocytes are also affected but in a different way than motor neurons. Instead of dying, ALS astrocytes become dysfunctional and thereby create a toxic environment inhospitable to the motors neurons they are supposed to assist.

Fluorescent microscopy of astrocytes (red) and cell nuclei (blue). Image: Wikipedia.

“While the motor neurons clearly die in ALS, the astrocytes surrounding the motor neurons are also sick,” said Svendsen. “It’s a huge challenge to replace a motor neuron and make it grow a cable all the way to the muscle in an adult human. We couldn’t even get this to work in mice. So, I knew a more realistic strategy would be to replace the sick astrocytes in an ALS patients with fresh, healthy astrocytes. This potentially would have a regenerative effect on the environment around the existing motor neurons.”

The big idea was to combine both GDNF and astrocyte replacement. Svendsen set out to make healthy astrocytes from human brain stem cells that also produce therapeutic doses of GDNF and transplant these cells into the ALS patient spinal cord. Simply giving patients GDNF via pill wouldn’t work because the growth factor is unable to enter the brain or spinal cord tissue where it is needed. The hope, instead, was that the astrocytes would secrete the protective factor that would keep the patients’ motor neurons healthy and alive.

With critical funding from a CIRM Disease Team grant, Svendsen and his colleagues at Cedars-Sinai tested the feasibility of transplanting human brain stem cells (also referred to as neural progenitor cells) that secreted GDNF into a rat model of ALS. Their results were encouraging – the neural progenitor cells successfully developed into astrocytes and secreted GDNF, which collectively protected the rat motor neurons.

Svendsen describes the strategy as “a double whammy”: adding both healthy astrocytes and GDNF secretion to protect the motor neurons. “Replacing astrocytes has the potential to rejuvenate the niche where the motor neurons are. I think that’s a very powerful experimental approach to ALS.”

A fifteen year journey from bench to bedside

With promising preclinical data under his belt, Svendsen and his colleagues, including Robert Baloh, MD, PhD, director of neuromuscular medicine at the Cedars-Sinai Department of Neurology, and neurosurgeon J. Patrick Johnson, MD, designed a clinical trial that would test this experimental therapy in ALS patients. In October 2016, CIRM approved funding for a Phase I/IIa clinical trial assessing the safety of this novel human neural progenitor cell and gene therapy.

Clive Svendsen, PhD, director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute, and Robert Baloh, MD, PhD, director of neuromuscular medicine in the Cedars-Sinai Department of Neurology, in the lab. Svendsen is the sponsor of a current ALS clinical trial at Cedars-Sinai and the overall director of the program. Baloh is the principal investigator for the clinical trial. (Image courtesy of Cedars-Sinai)

This is a first-in-human study, and as such, the U.S. Food and Drug Administration (FDA) required the team to transplant the cells into only one side of the lumbar spinal cord, which effectively means that only one of the patient’s legs will get the treatment. This will allow for a comparison of the function and progression of ALS in the leg on the treated side of the spinal cord compared with the leg on the untreated side.

The trial was approved to treat a total of 18 patients and started in May 2017.

 Svendsen, who first started working on ALS back in 2002, describes his path to the clinic as a “very long and windy road.” He emphasized that this journey wouldn’t be possible without the hard work of his team, Cedars-Sinai and financial support from CIRM.

“It took ten years of preclinical studies and an enormous amount of work from many different people. Just producing the cells that we’re going to use took three years and a lot of trials and tribulations to make it a clinically viable product. It was really thanks to CIRM’s funding and the support of Cedars-Sinai that we got through it all. Without that kind of infrastructure, I can safely say we wouldn’t be here today.”

This “behind-the-scenes” view of how much time and effort it takes to translate a stem cell therapy from basic research into the clinic isn’t something that the public is often exposed to or aware of. Just as “Rome wasn’t built in a day,” Svendsen stressed that good quality stem cell trials take time, and that it’s important for people know how complicated these trials are.

It’s all about the patients

So, what motivates Svendsen to continue this long and harrowing journey to develop a treatment for ALS? He said the answer is easy. “I’m doing it for the patients,” he explained. “I’m not doing this for the money or glory. I just want to develop something that works for ALS, so we can help these patients.”

Svendsen revisited his story about Jeff Kaufman, a man he befriended at the Wisconsin ALS Chapter in 2003. Jeff had three daughters and a son, a wonderful wife, and was a successful lawyer when he was diagnosed with ALS.

“Jeff had basically everything, and then he was stricken with ALS. I still remember going to his house and he could only move his eyes at that point. He tapped out the words ‘Can stem cells help me Clive?’ on his computer screen. And my heart sank because I knew how much and how long it was going to take. I was very realistic so I said, ‘Yes Jeff, but it’s going to take time and money. And even then, it’s a long shot.’ And he told me to go for it, and that stuck in my brain.”

It’s people like Jeff that make Svendsen get out of bed every morning and doggedly pursue a treatment for ALS. Sadly, Jeff passed away due to complications from ALS in 2010. Svendsen says what Jeff and other patients go through is tragic and unfair.

“There’s a gene that goes along with ALS and it’s called the ‘nice person gene,’” he said. “People with ALS are nice. I can’t explain it, but neurologists would say the same thing. You feel like it’s just not fair that it happens to those people.”

The future of stem cell therapies for ALS

It’s clear from speaking with Svendsen, that he is optimistic about the future of stem cell-based therapies for ALS. Scientists still need to unravel the actual causes of ALS. But the experimental stem cell treatments currently in development, including Svendsen’s, will hopefully prove effective at delaying disease progression and give ALS patients more quality years to live.

In the meantime, what concerns Svendsen is how vulnerable ALS patients are to being misled by unapproved stem cell clinics that claim to have cures. “Unfortunately, there are a lot of charlatans out there, and there are a lot of false claims being made. People feed off the desperation that you have in ALS. It’s not fair, and it’s completely wrong. They’ll mislead patients by saying ‘For $40,000 you can get a cure!’”

Compelling stories of patients cured of knee pain or diseases like ALS with injections of their own adult stem cells pop up in the news daily. Many of these stories refer to unapproved treatments from clinics that don’t provide scientific evidence that these treatments are safe and effective. Svendsen said there are reasonable, research-backed trials that are attempting to use adult stem cells to treat ALS. He commented, “I think it’s hard for the public to wade through all of these options and understand what’s real and what’s not real.”

Svendsen’s advice for ALS patients interested in enrolling in a stem cell trial or trying a new stem cell treatment is to be cautious. If a therapy sounds too good to be true, it probably is, and if it costs a lot of money, it probably isn’t legitimate, he explained.

He also wants patients to understand the reality of the current state of ALS stem cell trials. The approved stem cell trials he is aware of are not at the treatment stage yet.

“If you’re enrolled in a stem cell trial that is funded and reputable, then they will tell you honestly that it’s not a treatment. There is currently no approved treatment using stem cells for ALS,” Svendsen said.

This might seem like discouraging news to patients who don’t have time to wait for these trials to develop into treatments, but Svendsen pointed out that the when he started his research 15 years ago, the field of stem cell research was still in its infancy. A lot has been accomplished in the past decade-and-a-half and with talented scientists dedicated to ALS research like Svendsen, the next 15 years will likely offer new insights into ALS and hopefully stem cell-based treatments for a devastating disease that has no cure.

Svendsen hopes that one day, when someone like Jeff Kaufman asks him “Can stem cells help me Clive?” He’ll be able to say, yes they can, yes they can.

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CIRM-Funded Clinical Trials Targeting the Heart, Pancreas, and Kidneys

This blog is part of our Month of CIRM series, which features our Agency’s progress towards achieving our mission to accelerate stem cell treatments to patients with unmet medical needs.

This week, we’re highlighting CIRM-funded clinical trials to address the growing interest in our rapidly expanding clinical portfolio. Today we are featuring trials in our organ systems portfolio, specifically focusing on diseases of the heart/vasculature system, the pancreas and the kidneys.

CIRM has funded a total of nine trials targeting these disease areas, and eight of these trials are currently active. Check out the infographic below for a list of our currently active trials.

For more details about all CIRM-funded clinical trials, visit our clinical trials page and read our clinical trials brochure which provides brief overviews of each trial.

CIRM-Funded Clinical Trials Targeting Brain and Eye Disorders

This blog is part of our Month of CIRM series, which features our Agency’s progress towards achieving our mission to accelerate stem cell treatments to patients with unmet medical needs.

 This week, we’re highlighting CIRM-funded clinical trials to address the growing interest in our rapidly expanding clinical portfolio. Our Agency has funded a total of 40 trials since its inception. 23 of these trials were funded after the launch of our Strategic Plan in 2016, bringing us close to the half way point of our goal to fund 50 new clinical trials by 2020.

Today we are featuring CIRM-funded trials in our neurological and eye disorders portfolio.  CIRM has funded a total of nine trials targeting these disease areas, and seven of these trials are currently active. Check out the infographic below for a list of our currently active trials.

For more details about all CIRM-funded clinical trials, visit our clinical trials page and read our clinical trials brochure which provides brief overviews of each trial.

Treatments, cures and clinical trials: an in-person update on CIRM’s progress

Patients and Patient Advocates are at the heart of everything we do at CIRM. That’s why we are holding three free public events in the next few months focused on updating you on the stem cell research we are funding, and our plans for the future.

Right now we have 33 projects that we have funded in clinical trials. Those range from heart disease and stroke, to cancer, diabetes, ALS (Lou Gehrig’s disease), two different forms of vision loss, spinal cord injury and HIV/AIDS. We have also helped cure dozens of children battling deadly immune disorders. But as far as we are concerned we are only just getting started.

Over the course of the next few years, we have a goal of adding dozens more clinical trials to that list, and creating a pipeline of promising therapies for a wide range of diseases and disorders.

That’s why we are holding these free public events – something we try and do every year. We want to let you know what we are doing, what we are funding, how that research is progressing, and to get your thoughts on how we can improve, what else we can do to help meet the needs of the Patient Advocate community. Your voice is important in helping shape everything we do.

The first event is at the Gladstone Institutes in San Francisco on Wednesday, September 6th from noon till 1pm. The doors open at 11am for registration and a light lunch.

Gladstone Institutes

Here’s a link to an Eventbrite page that has all the information about the event, including how you can RSVP to let us know you are coming.

We are fortunate to be joined by two great scientists, and speakers – as well as being CIRM grantees-  from the Gladstone Institutes, Dr. Deepak Srivastava and Dr. Steve Finkbeiner.

Dr. Srivastava is working on regenerating heart muscle after it has been damaged. This research could not only help people recover from a heart attack, but the same principles might also enable us to regenerate other organs damaged by disease. Dr. Finkbeiner is a pioneer in diseases of the brain and has done ground breaking work in both Alzheimer’s and Huntington’s disease.

We have two other free public events coming up in October. The first is at UC Davis in Sacramento on October 10th (noon till 1pm) and the second at Cedars-Sinai in Los Angeles on October 30th (noon till 1pm). We will have more details on these events in the coming weeks.

We look forward to seeing you at one of these events and please feel free to share this information with anyone you think might be interested in attending.

Family, faith and funding from CIRM inspire one patient to plan for his future

Caleb Sizemore speaks to the CIRM Board at the June 2017 ICOC meeting.

Having been to many conferences and meetings over the years I have found there is a really simple way to gauge if someone is a good speaker, if they have the attention of people in the room. You just look around and see how many people are on their phones or laptops, checking their email or the latest sports scores.

By that standard Caleb Sizemore is a spellbinding speaker.

Last month Caleb spoke to the CIRM Board about his experiences in a CIRM-funded clinical trial for Duchenne Muscular Dystrophy. As he talked no one in the room was on their phone. Laptops were closed. All eyes and ears were on him.

To say his talk was both deeply moving and inspiring is an understatement. I could go into more detail but it’s so much more powerful to hear it from  Caleb himself. His words are a reminder to everyone at CIRM why we do this work, and why we have to continue to do all that we can to live up to our mission statement and accelerate stem cell treatments to patients with unmet medical needs.

Video produced by Todd Dubnicoff/CIRM


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Stem cell agency funds Phase 3 clinical trial for Lou Gehrig’s disease

ALS

At CIRM we don’t have a disease hierarchy list that we use to guide where our funding goes. We don’t rank a disease by how many people suffer from it, if it affects children or adults, or how painful it is. But if we did have that kind of hierarchy you can be sure that Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease, would be high on that list.

ALS is a truly nasty disease. It attacks the neurons, the cells in our brain and spinal cord that tell our muscles what to do. As those cells are destroyed we lose our ability to walk, to swallow, to talk, and ultimately to breathe.

As Dr. Maria Millan, CIRM’s interim President and CEO, said in a news release, it’s a fast-moving disease:

“ALS is a devastating disease with an average life expectancy of less than five years, and individuals afflicted with this condition suffer an extreme loss in quality of life. CIRM’s mission is to accelerate stem cell treatments to patients with unmet medical needs and, in keeping with this mission, our objective is to find a treatment for patients ravaged by this neurological condition for which there is currently no cure.”

Having given several talks to ALS support groups around the state, I have had the privilege of meeting many people with ALS and their families. I have seen how quickly the disease works and the devastation it brings. I’m always left in awe by the courage and dignity with which people bear it.

BrainStorm

I thought of those people, those families, today, when our governing Board voted to invest $15.9 million in a Phase 3 clinical trial for ALS run by BrainStorm Cell Therapeutics. BrainStorm is using mesenchymal stem cells (MSCs) that are taken from the patient’s own bone marrow. This reduces the risk of the patient’s immune system fighting the therapy.

After being removed, the MSCs are then modified in the laboratory to  boost their production of neurotrophic factors, proteins which are known to help support and protect the cells destroyed by ALS. The therapy, called NurOwn, is then re-infused back into the patient.

In an earlier Phase 2 clinical trial, NurOwn showed that it was safe and well tolerated by patients. It also showed evidence that it can help stop, or even reverse  the progression of the disease over a six month period, compared to a placebo.

CIRM is already funding one clinical trial program focused on treating ALS – that’s the work of Dr. Clive Svendsen and his team at Cedars Sinai, you can read about that here. Being able to add a second project, one that is in a Phase 3 clinical trial – the last stage before, hopefully, getting approval from the Food and Drug Administration (FDA) for wider use – means we are one step closer to being able to offer people with ALS a treatment that can help them.

Diane Winokur, the CIRM Board Patient Advocate member for ALS, says this is something that has been a long time coming:

CIRM Board member and ALS Patient Advocate Diane Winokur

“I lost two sons to ALS.  When my youngest son was diagnosed, he was confident that I would find something to save him.  There was very little research being done for ALS and most of that was very limited in scope.  There was one drug that had been developed.  It was being released for compassionate use and was scheduled to be reviewed by the FDA in the near future.  I was able to get the drug for Douglas.  It didn’t really help him and it was ultimately not approved by the FDA.

When my older son was diagnosed five years later, he too was convinced I would find a therapy.  Again, I talked to everyone in the field, searched every related study, but could find nothing promising.

I am tenacious by nature, and after Hugh’s death, though tempted to give up, I renewed my search.  There were more people, labs, companies looking at neurodegenerative diseases.

These two trials that CIRM is now funding represent breakthrough moments for me and for everyone touched by ALS.  I feel that they are a promising beginning.  I wish it had happened sooner.  In a way, though, they have validated Douglas and Hugh’s faith in me.”

These therapies are not a cure for ALS. At least not yet. But what they will do is hopefully help buy people time, and give them a sense of hope. For a disease that leaves people desperately short of both time and hope, that would be a precious gift. And for people like Diane Winokur, who have fought so hard to find something to help their loved ones, it’s a vindication that those efforts have not been in vain.

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.

BloodBrainBarrier

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.”

151117_lesliethompson_05_sz-1080x720

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.”

Bridging the Gap: Regenerating Injured Bones with Stem Cells and Gene Therapy

Scientists from Cedars-Sinai Medical Center have developed a new stem cell-based technology in animals that mends broken bones that can’t regenerate on their own. Their research was published today in the journal Science Translational Medicine and was funded in part by a CIRM Early Translational Award.

Over two million bone grafts are conducted every year to treat bone fractures caused by accidents, trauma, cancer and disease. In cases where the fractures are small, bone can repair itself and heal the injury. In other cases, the fractures are too wide and grafts are required to replace the missing bone.

It sounds simple, but the bone grafting procedure is far from it and can cause serious problems including graft failure and infection. People that opt to use their own bone (usually from their pelvis) to repair a bone injury can experience intense pain, prolonged recovery time and are at risk for nerve injury and bone instability.

The Cedars-Sinai team is attempting to “bridge the gap” for people with severe bone injuries with an alternative technology that could replace the need for bone grafts. Their strategy combines “an engineering approach with a biological approach to advance regenerative engineering” explained co-senior author Dr. Dan Gazit in a news release.

Gazit’s team developed a biological scaffold composed of a protein called collagen, which is a major component of bone. They implanted these scaffolds into pigs with fractured leg bones by inserting the collagen into the gap created by the bone fracture. Over a two-week period, mesenchymal stem cells from the animal were recruited into the collagen scaffolds.

To ensure that these stem cells generated new bone, the team used a combination of ultrasound and gene therapy to stimulate the stem cells in the collagen scaffolds to repair the bone fractures. Ultrasound pulses, or high frequency sound waves undetectable by the human ear, temporarily created small holes in the cell membranes allowing the delivery of the gene therapy-containing microbubbles into the stem cells.

Image courtesy of Gazit Group/Cedars-Sinai.

Animals that received the collagen transplant and ultrasound gene therapy repaired their fractured leg bones within two months. The strength of the newly regenerated bone was comparable to successfully transplanted bone grafts.

Dr. Gadi Pelled, the other senior author on this study, explained the significance of their research findings for treating bone injuries in humans,

“This study is the first to demonstrate that ultrasound-mediated gene delivery to an animal’s own stem cells can effectively be used to treat non-healing bone fractures. It addresses a major orthopedic unmet need and offers new possibilities for clinical translation.”

You can learn more about this study by watching this research video provided by the Gazit Group at Cedars-Sinai.


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Stem cell stories that caught our eye: update on Capricor’s heart attack trial; lithium on the brain; and how stem cells do math

Capricor ALLSTARToday our partners Capricor Therapeutics announced that its stem cell therapy for patients who have experienced a large heart attack is unlikely to meet one of its key goals, namely reducing the scar size in the heart 12 months after treatment.

The news came after analyzing results from patients at the halfway point of the trial, six months after their treatment in the Phase 2 ALLSTAR clinical trial which CIRM was funding. They found that there was no significant difference in the reduction in scarring on the heart for patients treated with donor heart-derived stem cells, compared to patients given a placebo.

Obviously this is disappointing news for everyone involved, but we know that not all clinical trials are going to be successful. CIRM supported this research because it clearly addressed an unmet medical need and because an earlier Phase 1 study had showed promise in helping prevent decline in heart function after a heart attack.

Yet even with this failure to repeat that promise in this trial,  we learned valuable lessons.

In a news release, Dr. Tim Henry, Director of the Division of Interventional Technologies in the Heart Institute at Cedars-Sinai Medical Center and a Co-Principal Investigator on the trial said:

“We are encouraged to see reductions in left ventricular volume measures in the CAP-1002 treated patients, an important indicator of reverse remodeling of the heart. These findings support the biological activity of CAP-1002.”

Capricor still has a clinical trial using CAP-1002 to treat boys and young men developing heart failure due to Duchenne Muscular Dystrophy (DMD).

Lithium gives up its mood stabilizing secrets

As far back as the late 1800s, doctors have recognized that lithium can help people with mood disorders. For decades, this inexpensive drug has been an effective first line of treatment for bipolar disorder, a condition that causes extreme mood swings. And yet, scientists have never had a good handle on how it works. That is, until this week.

evan snyder

Evan Snyder

Reporting in the Proceedings of the National Academy of Sciences (PNAS), a research team at Sanford Burnham Prebys Medical Discovery Institute have identified the molecular basis of the lithium’s benefit to bipolar patients.  Team lead Dr. Evan Snyder explained in a press release why his group’s discovery is so important for patients:

“Lithium has been used to treat bipolar disorder for generations, but up until now our lack of knowledge about why the therapy does or does not work for a particular patient led to unnecessary dosing and delayed finding an effective treatment. Further, its side effects are intolerable for many patients, limiting its use and creating an urgent need for more targeted drugs with minimal risks.”

The study, funded in part by CIRM, attempted to understand lithium’s beneficial effects by comparing cells from patient who respond to those who don’t (only about a third of patients are responders). Induced pluripotent stem cells (iPSCs) were generated from both groups of patients and then the cells were specialized into nerve cells that play a role in bipolar disorder. The team took an unbiased approach by looking for differences in proteins between the two sets of cells.

The team zeroed in on a protein called CRMP2 that was much less functional in the cells from the lithium-responsive patients. When lithium was added to these cells the disruption in CRMP2’s activity was fixed. Now that the team has identified the molecular location of lithium’s effects, they can now search for new drugs that do the same thing more effectively and with fewer side effects.

The stem cell: a biological calculator?

math

Can stem cells do math?

Stem cells are pretty amazing critters but can they do math? The answer appears to be yes according to a fascinating study published this week in PNAS Proceedings of the National Academy of Sciences.

Stem cells, like all cells, process information from the outside through different receptors that stick out from the cells’ outer membranes like a satellite TV dish. Protein growth factors bind those receptors which trigger a domino effect of protein activity inside the cell, called cell signaling, that transfers the initial receptor signal from one protein to another. Ultimately that cascade leads to the accumulation of specific proteins in the nucleus where they either turn on or off specific genes.

Intuition would tell you that the amount of gene activity in response to the cell signaling should correspond to the amount of protein that gets into the nucleus. And that’s been the prevailing view of scientists. But the current study by a Caltech research team debunks this idea. Using real-time video microscopy filming, the team captured cell signaling in individual cells; in this case they used an immature muscle cell called a myoblast.

goentoro20170508

Behavior of cells over time after they have received a Tgf-beta signal. The brightness of the nuclei (circled in red) indicates how much Smad protein is present. This brightness varies from cell to cell, but the ratio of brightness after the signal to before the signal is about the same. Image: Goentoro lab, CalTech.

To their surprise the same amount of growth factor given to different myoblasts cells led to the accumulation of very different amounts of a protein called Smad3 in the cells’ nuclei, as much as a 40-fold difference across the cells. But after some number crunching, they discovered that dividing the amount of Smad3 after growth factor stimulation by the Smad3 amount before growth stimulation was similar in all the cells.

As team lead Dr. Lea Goentoro mentions in a press release, this result has some very important implications for studying human disease:

“Prior to this work, researchers trying to characterize the properties of a tumor might take a slice from it and measure the total amount of Smad in cells. Our results show that to understand these cells one must instead measure the change in Smad over time.”

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.