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.

klassen

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.”

Paul Bresge

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.

 

 

CIRM’s Randy Mills leaving stem cell agency to take on new challenge

Mills, Randy Union Tribune K.C. Alfred

Some news releases are fun to write. Some less so. The one that CIRM posted today definitely falls into that latter group. It announced that CIRM’s President and CEO, Randy Mills, is leaving us to take up the role of President and CEO at the National Marrow Donor Program – NMPD/Be The Match.

It’s a great opportunity for him but a big loss for us.

Be The Match is a non-profit organization that delivers cures to patients in need of a life-saving marrow or cord blood transplant. The organization operates the national Be The Match Registry®—the world’s largest listing of potential marrow donors and donated umbilical cord blood units—matches patients with their marrow donor, educates healthcare professionals and conducts research so more lives can be saved. The organization also recently created a subsidiary—Be The Match BioTherapiesSM—that supports organizations pursuing new life-saving treatments in cellular therapy.

Randy has been at CIRM since April 2014. In that time he has dramatically re-shaped the agency, and, more importantly, dramatically improved the speed with which we are able to fund research. It’s no exaggeration to say that Randy’s drive to create CIRM 2.0 was a radical overhaul of the way we work. It made it easier for researchers to apply to us for funding, made our funding cycles more consistent and the application process simpler – though no less rigorous.

As our CIRM Board Chair Jonathan Thomas said in the news release:

“CIRM has experienced a remarkable transformation since Randy’s arrival. He has taken the agency to a new level by developing and implementing a bold strategic plan, the results of which include an 82% reduction in approval time for clinical trial projects, a 3-fold increase in the number of clinical trials, and a 65% reduction in the time it takes to enroll those trials. The opportunity for Randy to lead a tremendously important organization such as the NMDP/Be The Match is consistent with the values he demonstrated at CIRM, which put the well-being of patients above all else. We shall miss him but know he will do great things at NMDP/Be The Match.”

From a personal perspective, what most impressed me about Randy was his willingness to involve every person in the agency in changing the way we work. He could easily have come in and simply issued orders and told people what to do. Instead he invited every person at CIRM to sit in on the meetings that were shaping the new direction we took. You didn’t have to go, but if you did you were expected to offer thoughts and ideas. No sitting idly by.

Those meetings not only changed the direction of the agency, they also re-energized the agency. When people feel their voice is being heard, that their opinion has value, they respond by working harder and smarter.

The CIRM of today has the same mission as always – accelerating stem cell treatments to patients with unmet medical needs – but the people working here seem to have a renewed commitment to making that mission a reality.

Randy brought to CIRM energy and a renewed sense of purpose, along with some truly terrible jokes and a strange conviction that he could have been a great rock and roll drummer (suffice to say he made the right career choice when he went into research).

He changed us as an agency, for the better. We shall miss him, but know he will do great things in his new role at NMDP/Be The Match and we wish him success in his new job, and his family great joy in their new home.

MariaM-085-Edit

Maria Millan

Randy will be with us till the end of June and starting July 1st Dr. Maria Millan will take on the role of interim President and CEO.

 

 

 

Stem cell-derived, 3D brain tissue reveals autism insights

Studying human brain disorders is one of the most challenging fields in biomedical research. Besides the fact that the brain is incredibly complex, it’s just plain difficult to peer into it.

It’s neither practical nor ethical to access the cells of the adult brain. Patrick J. Lynch, medical illustrator; C. Carl Jaffe, MD, cardiologist.

For one thing, it’s not practical, let alone ethical, to drill into an affected person’s skull and collect brain cells to learn about their disease. Another issue is that the faulty cellular and molecular events that cause brain disorders are, in many cases, thought to trace back to fetal brain development before a person is even born. So, just like a detective looking for evidence at the scene of a crime, neurobiologists can only piece together clues after the disease has already occurred.

The good news is these limitations are falling away thanks to human induced pluripotent stem cells (iPSCs), which are generated from an individual’s easily accessible skin cells. Last week’s CIRM-funded research report out of Stanford University is a great example of how this method is providing new human brain insights.

Using brain tissue grown from patient-derived iPSCs, Dr. Sergiu Pasca and his team recreated the types of nerve cell circuits that form during the late stages of pregnancy in the fetal cerebral cortex, the outer layer of the brain that is responsible for functions including memory, language and emotion. With this system, they observed irregularities in the assembly of brain circuitry that provide new insights into the cellular and molecular causes of neuropsychiatric disorders like autism.

Recreating interactions between different regions of the development from skin-derived iPSCs
Image: Sergui Pasca Lab, Stanford University

Holy Brain Balls! Recreating the regions of our brain with skin cells
Two years ago, Pasca’s group figured out a way grow iPSCs into tiny, three-dimensional balls of cells that mimic the anatomy of the cerebral cortex. The team showed that these brain spheres contain the expected type of nerve cells, or neurons, as well as other cells that support neuron function.

Still, the complete formation of the cortex’s neuron circuits requires connections with another type of neuron that lies in a separate region of the brain. These other neurons travel large distances in a developing fetus’ brain over several months to reach the cortical cortex. Once in place, these migrating neurons have an inhibitory role and can block the cortical cortex nerve signals. Turning off a nerve signal is just as important as turning one on. In fact, imbalances in these opposing on and off nerve signals are suspected to play a role in epilepsy and autism.

So, in the current Nature study, Pasca’s team devised two different iPSC-derived brain sphere recipes: one that mimics the neurons found in the cortical cortex and another that mimics the region that contains the inhibitory neurons. Then the researchers placed the two types of spheres in the same lab dish and within three days, they spontaneously fused together.

Under video microscopy, the migration of the inhibitory neurons into the cortical cortex was observed. In cells derived from healthy donors, the migration pattern of inhibitory neurons looked like a herky-jerkey car being driven by a student driver: the neurons would move toward the cortical cortex sphere but suddenly stop for a while and then start their migration again.

“We’ve never been able to recapitulate these human-brain developmental events in a dish before,” said Pasca in a press release, “the process happens in the second half of pregnancy, so viewing it live is challenging. Our method lets us see the entire movie, not just snapshots.”

New insights into Timothy Syndrome may also uncover molecular basis of autism
To study the migration of the inhibitory neurons in the context of a neuropsychiatric disease, iPSCs were generated from skin samples of patients with Timothy syndrome, a rare genetic disease which carries a wide-range of symptoms including autism as well as heart defects.

The formation of brain spheres from the patient-derived iPSCs proceeded normally. But the next part of the experiment revealed an abnormal migration pattern of the neurons.  The microscopy movies showed that the start and stop behavior of neurons happened more frequently but the speed of the migration slowed. The fascinating video below shows the differences in the migration patterns of a healthy (top) versus a Timothy sydrome-derived neuron (bottom). The end result was a disruption of the typically well-organized neuron circuitry.

Now, the gene that’s mutated in Timothy Syndrome is responsible for the production of a protein that helps shuttle calcium in and out of neurons. The flow of calcium is critical for many cell functions and adding drugs that slow down this calcium flux restored the migration pattern of the neurons. So, the researchers can now zero in their studies on this direct link between the disease-causing mutation and a specific breakdown in neuron function.

The exciting possibility is that, because this system is generated from a patient’s skin cells, experiments could be run to precisely understand each individual’s neuropsychiatric disorder. Pasca is eager to see what new insights lie ahead:

“Our method of assembling and carefully characterizing neuronal circuits in a dish is opening up new windows through which we can view the normal development of the fetal human brain. More importantly, it will help us see how this goes awry in individual patients.”

Stem cell stories that caught our eye: spinal cord injury trial keeps pace; SMART cells make cartilage and drugs

CIRM-funded spinal cord injury trial keeping a steady pace

Taking an idea for a stem cell treatment and developing it into a Food and Drug Administration-approved cell therapy is like running the Boston Marathon because it requires incremental progress rather than a quick sprint. Asterias Biotherapeutics continues to keep a steady pace and to hit the proper milestones in its race to develop a stem cell-based treatment for acute spinal cord injury.


Just this week in fact, the company announced an important safety milestone for its CIRM-funded SciStar clinical trial. This trial is testing the safety and effectiveness of AST-OPC1, a human embryonic stem cell-derived cell therapy that aims to regenerate some of the lost movement and feeling resulting from spinal cord injuries to the neck.

Periodically, an independent safety review board called the Data Monitoring Committee (DMC) reviews the clinical trial data to make sure the treatment is safe in patients. That’s exactly what the DMC concluded as its latest review. They recommended that treatments with 10 and 20 million cell doses should continue as planned with newly enrolled clinical trial participants.

About a month ago, Asterias reported that six of the six participants who had received a 10 million cell dose – which is transplanted directly into the spinal cord at the site of injury – have shown improvement in arm, hand and finger function nine months after the treatment. These outcomes are better than what would be expected by spontaneous recovery often observed in patients without stem cell treatment. So, we’re hopeful for further good news later this year when Asterias expects to provide more safety and efficacy data on participants given the 10 million cell dose as well as the 20 million cell dose.

It’s a two-fer: SMART cells that make cartilage and release anti-inflammation drug
“It’s a floor wax!”….“No, it’s a dessert topping!”
“Hey, hey calm down you two. New Shimmer is a floor wax and a dessert topping!”

Those are a few lines from the classic Saturday Night Live skit that I was reminded of when reading about research published yesterday in Stem Cell Reports. The clever study generated stem cells that not only specialize into cartilage tissue that could help repair arthritic joints but the cells also act as a drug dispenser that triggers the release of a protein that dampens inflammation.

Using CRISPR technology, a team of researchers led by Farshid Guilak, PhD, at Washington University School of Medicine in St. Louis, rewired stem cells’ genetic circuits to produce an anti-inflammatory arthritis drug when the cells encounter inflammation. The technique eventually could act as a vaccine for arthritis and other chronic conditions. Image: ELLA MARUSHCHENKO

The cells were devised by a research team at Washington University School of Medicine in St. Louis. They started out with skin cells collected from the tails of mice. Using the induced pluripotent stem cell technique, the skin cells were reprogrammed into an embryonic stem cell-like state. Then came the ingenious steps. The team used the CRISPR gene-editing method to create a negative feedback loop in the cells’ inflammation response. They removed a gene that is activated by the potent inflammatory protein, TNF-alpha and replaced it with a gene that blocks TNF-alpha. Analogous experiments were carried out with another protein called IL-1.

Rheumatoid arthritis often affects the small joints causing painful swelling and disfigurement. Image: Wikipedia

Now, TNF-alpha plays a key role in triggering inflammation in arthritic joints. But this engineered cell, in the presence of TNF-alpha, activates the production of a protein that inhibits the actions of TNF-alpha. Then the team converted these stem cells into cartilage tissue and they went on to show that the cartilage was indeed resistant to inflammation. Pretty smart, huh? In fact, the researchers called them SMART cells for “Stem cells Modified for Autonomous Regenerative Therapy.” First author Dr. Jonathan Brunger summed up the approach succinctly in a press release:

“We hijacked an inflammatory pathway to create cells that produced a protective drug.”

This type of targeted treatment of arthritis would have a huge advantage over current anti-TNF-alpha therapies. Arthritis drugs like Enbrel, Humira and Remicade are very effective but they block the immune response throughout the body which carries an increased risk for serious infections and even cancer.

The team is now testing the cells in animal models of rheumatoid arthritis as well as other inflammation disorders. Those results will be important to determine whether or not this approach can work in a living animal. But senior Dr. Farshid Guilak also has an eye on future applications of SMART cells:

“We believe this strategy also may work for other systems that depend on a feedback loop. In diabetes, for example, it’s possible we could make stem cells that would sense glucose and turn on insulin in response. We are using pluripotent stem cells, so we can make them into any cell type, and with CRISPR, we can remove or insert genes that have the potential to treat many types of disorders.”

Capricor reports positive results on CIRM-funded stem cell trial for Duchenne Muscular Dystrophy

Capricor Therapeutics, a Los Angeles-based company, published an update about its CIRM-funded clinical trial for patients with Duchenne muscular dystrophy (DMD), a devastating degenerative muscle disease that significantly reduces life expectancy.

The company reported positive results from their Phase I/II HOPE trial that’s testing the safety of their cardiosphere stem cell-based therapy called CAP-1002. The trial had 25 patients, 13 of which received the cells and 12 who received normal treatment. No serious adverse effects were observed suggesting that the treatment is “generally safe” thus far.

Patients given a single dose of CAP-1002 showed improvements “in certain measures of cardiac and upper limb function” after six months. They also experienced a reduction of cardiac scar tissue and a thickening of the heart’s left ventricle wall, which is typically thinned in DMD patients.

Capricor shared more details on their six-month trial results in a webcast this week, and you can read about them in this blog by Rare Disease Report.

Leading cause of death for DMD patients

DMD is a severe form of muscular dystrophy caused by a recessive genetic mutation in the dystrophin gene on the X chromosome. Consequently, men are much more likely to get the disease than women. Symptoms of DMD start with muscle weakness as early as four years of age, which then leads to deterioration of both skeletal and heart muscle. Heart disease is the leading cause of death in DMD patients – a fact that Capricor hopes to change with its clinical trial.

Capricor’s CEO, Dr. Linda Marbán, commented in a press release that the trial’s results support the findings of other researchers.

“These initial positive clinical results build upon a large body of preclinical data which illustrate CAP-1002’s potential to broadly improve the condition of those afflicted by DMD, as they show that cardiosphere-derived cells exert salutary effects on cardiac and skeletal muscle.”

Also quoted in the press release was Pat Furlong, DMD patient advocate and CEO of Parent Project Muscular Dystrophy.

Pat Furlong

“I’m excited to see these data, especially given the advanced nature of the patients in the HOPE trial. It is also gratifying to see the field of cell therapy making progress after more than two decades in development. It is our hope that CAP-1002 will have broad potential to improve the lives of patients with Duchenne muscular dystrophy.”

Pat recently spoke at the 2nd Annual CIRM Alpha Stem Cell Clinics meeting about her heartbreaking experience of losing two sons to DMD, both at a very young age. You can watch her speech below. We also featured her story and her inspiring efforts to promote DMD awareness in our 2016 Annual Report.

What to HOPE for next?

The trial is a year-long study and Capricor will report 12-month results at the end of 2017. In the meantime, Dr. Marbán and her team have plans to talk with the US Food and Drug Administration (FDA) about the regulatory options for getting CAP-1002 approved and on the market for DMD patients. She explained,

Linda Marban, CEO of Capricor Therapeutics

“We have submitted an FDA meeting request to discuss these results as well as next steps in our development of CAP-1002 for Duchenne muscular dystrophy, which includes our plan to begin a clinical trial of intravenously-administered CAP-1002 in the latter half of this year. We believe the interim HOPE results may enable us to pursue one of the FDA’s Expedited Programs for Serious Conditions, and we will apply for either or both of the Breakthrough Therapy and Regenerative Medicine Advanced Therapy (RMAT) designations for CAP-1002.”


Related Links:

Scientists make stem cell-derived nerve cells damaged in spinal cord injury

The human spinal cord is an information highway that relays movement-related instructions from the brain to the rest of the body and sensory information from the body back to the brain. What keeps this highway flowing is a long tube of nerve cells and support cells bundled together within the spine.

When the spinal cord is injured, the nerve cells are damaged and can die – cutting off the flow of information to and from the brain. As a result, patients experience partial or complete paralysis and loss of sensation depending on the extent of their injury.

Unlike lizards which can grow back lost tails, the spinal cord cannot robustly regenerate damaged nerve cells and recreate lost connections. Because of this, scientists are looking to stem cells for potential solutions that can rebuild injured spines.

Making spinal nerve cells from stem cells

Yesterday, scientists from the Gladstone Institutes reported that they used human pluripotent stem cells to create a type of nerve cell that’s damaged in spinal cord injury. Their findings offer a new potential stem cell-based strategy for restoring movement in patients with spinal cord injury. The study was led by Gladstone Senior Investigator Dr. Todd McDevitt, a CIRM Research Leadership awardee, and was published in the journal Proceedings of the National Academy of Sciences.

The type of nerve cell they generated is called a spinal interneuron. These are specialized nerve cells in the spinal cord that act as middlemen – transporting signals between sensory neurons that connect to the brain to the movement-related, or motor, neurons that connect to muscles. Different types of interneurons exist in the brain and spinal cord, but the Gladstone team specifically created V2a interneurons, which are important for controlling movement.

V2a interneurons extend long distances in the spinal cord. Injuries to the spine can damage these important cells, severing the connection between the brain and the body. In a Gladstone news release, Todd McDevitt explained why his lab is particularly interested in making these cells to treat spinal cord injury.

Todd McDevitt, Gladstone Institutes

“Interneurons can reroute after spinal cord injuries, which makes them a promising therapeutic target. Our goal is to rewire the impaired circuitry by replacing damaged interneurons to create new pathways for signal transmission around the site of the injury.”

 

Transplanting nerve cells into the spines of mice

After creating V2a interneurons from human stem cells using a cocktail of chemicals in the lab, the team tested whether these interneurons could be successfully transplanted into the spinal cords of normal mice. Not only did the interneurons survive, they also set up shop by making connections with other nerve cells in the spinal cord. The mice that received the transplanted cells didn’t show differences in their movement suggesting that the transplanted cells don’t cause abnormalities in motor function.

Co-author on the paper, Dylan McCreedy, described how the transplanted stem cell-derived cells behaved like developing V2a interneurons in the spine.

“We were very encouraged to see that the transplanted cells sprouted long distances in both directions—a key characteristic of V2a interneurons—and that they started to connect with the relevant host neurons.”

Todd McDevitt (right), Jessica Butts (center) and Dylan McCreedy (left) created a special type of neuron from human stem cells that could potentially repair spinal cord injuries. (Photo: Chris Goodfellow, Gladstone)

A new clinical strategy?

Looking forward, the Gladstone team plans to test whether these V2a interneurons can improve movement in mice with spinal cord injury. If results look promising in mice, this strategy of transplanting V2a interneurons could be translated into human clinic trials although much more time and research are needed to get there.

Trials testing stem cell-based treatments for spinal cord injury are already ongoing. Many of them involve transplanting progenitor cells that develop into the different types of cells in the spine, including nerve and support cells. These progenitor cells are also thought to secrete important growth factors that help regenerate damaged tissue in the spine.

CIRM is funding one such clinical trial sponsored by Asterias Biotherapeutics. The company is transplanting oligodendrocyte progenitor cells (which make nerve support cells called oligodendrocytes) into patients with severe spinal cord injuries in their neck. The trial has reported encouraging preliminary results in all six patients that received a dose of 10 million cells. You can read more about this trial here.

What the Gladstone study offers is a different stem cell-based strategy for treating spinal cord injury – one that produces a specific type of spinal nerve cell that can reestablish important connections in the spinal cord essential for movement.

For more on this study, watch the Gladstone’s video abstract “Discovery Offers New Hope to Repair Spinal Cord.


Related Links:

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

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

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

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

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

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

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

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

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

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

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

She said it has to:

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

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

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

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

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

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

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

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

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

Stem cell stories that caught our eye: developing the nervous system, aging stem cells and identical twins not so identical

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

New theory for how the nervous system develops.

There’s a new theory on the block for how the nervous system is formed thanks to a study published yesterday by UCLA stem cell scientists in the journal Neuron.

The theory centers around axons, thin extensions projecting from nerve cells that transmit electrical signals to other cells in the body. In the developing nervous system, nerve cells extend axons into the brain and spinal cord and into our muscles (a process called innervation). Axons are guided to their final destinations by different chemicals that tell axons when to grow, when to not grow, and where to go.

Previously, scientists believed that one of these important chemical signals, a protein called netrin 1, exerted its influence over long distances in a gradient-like fashion from a structure in the developing nervous system called the floor plate. You can think of it like a like a cell phone tower where the signal is strongest the closer you are to the tower but you can still get some signal even when you’re miles away.

The UCLA team, led by senior author and UCLA professor Dr. Samantha Butler, questioned this theory because they knew that neural progenitor cells, which are the precursors to nerve cells, produce netrin1 in the developing spinal cord. They believed that the netrin1 secreted from these progenitor cells also played a role in guiding axon growth in a localized manner.

To test their hypothesis, they studied neural progenitor cells in the developing spines of mouse embryos. When they eliminated netrin1 from the neural progenitor cells, the axons went haywire and there was no rhyme or reason to their growth patterns.

Left: axons (green, pink, blue) form organized patterns in the normal developing mouse spinal cord. Right: removing netrin1 results in highly disorganized axon growth. (UCLA Broad Stem Cell Research Center/Neuron)

A UCLA press release explained what the scientists discovered next,

“They found that neural progenitors organize axon growth by producing a pathway of netrin1 that directs axons only in their local environment and not over long distances. This pathway of netrin1 acts as a sticky surface that encourages axon growth in the directions that form a normal, functioning nervous system.”

Like how ants leave chemical trails for other ants in their colony to follow, neural progenitor cells leave trails of netrin1 in the spinal cord to direct where axons go. The UCLA team believes they can leverage this newfound knowledge about netrin1 to make more effective treatments for patients with nerve damage or severed nerves.

In future studies, the team will tease apart the finer details of how netrin1 impacts axon growth and how it can be potentially translated into the clinic as a new therapeutic for patients. And from the sounds of it, they already have an idea in mind:

“One promising approach is to implant artificial nerve channels into a person with a nerve injury to give regenerating axons a conduit to grow through. Coating such nerve channels with netrin1 could further encourage axon regrowth.”

Age could be written in our stem cells.

The Harvard Gazette is running an interesting series on how Harvard scientists are tackling issues of aging with research. This week, their story focused on stem cells and how they’re partly to blame for aging in humans.

Stem cells are well known for their regenerative properties. Adult stem cells can rejuvenate tissues and organs as we age and in response to damage or injury. However, like most house hold appliances, adult stem cells lose their regenerative abilities or effectiveness over time.

Dr. David Scadden, co-director of the Harvard Stem Cell Institute, explained,

“We do think that stem cells are a key player in at least some of the manifestations of age. The hypothesis is that stem cell function deteriorates with age, driving events we know occur with aging, like our limited ability to fully repair or regenerate healthy tissue following injury.”

Harvard scientists have evidence suggesting that certain tissues, such as nerve cells in the brain, age sooner than others, and they trigger other tissues to start the aging process in a domino-like effect. Instead of treating each tissue individually, the scientists believe that targeting these early-onset tissues and the stem cells within them is a better anti-aging strategy.

David Sadden, co-director of the Harvard Stem Cell Institute.
(Jon Chase/Harvard Staff Photographer)

Dr. Scadden is particularly interested in studying adult stem cell populations in aging tissues and has found that “instead of armies of similarly plastic stem cells, it appears there is diversity within populations, with different stem cells having different capabilities.”

If you lose the stem cell that’s the best at regenerating, that tissue might age more rapidly.  Dr. Scadden compares it to a game of chess, “If we’re graced and happen to have a queen and couple of bishops, we’re doing OK. But if we are left with pawns, we may lose resilience as we age.”

The Harvard Gazette piece also touches on a changing mindset around the potential of stem cells. When stem cell research took off two decades ago, scientists believed stem cells would grow replacement organs. But those days are still far off. In the immediate future, the potential of stem cells seems to be in disease modeling and drug screening.

“Much of stem cell medicine is ultimately going to be ‘medicine,’” Scadden said. “Even here, we thought stem cells would provide mostly replacement parts.  I think that’s clearly changed very dramatically. Now we think of them as contributing to our ability to make disease models for drug discovery.”

I encourage you to read the full feature as I only mentioned a few of the highlights. It’s a nice overview of the current state of aging research and how stem cells play an important role in understanding the biology of aging and in developing treatments for diseases of aging.

Identical twins not so identical (Todd Dubnicoff)

Ever since Takahashi and Yamanaka showed that adult cells could be reprogrammed into an embryonic stem cell-like state, researchers have been wrestling with a key question: exactly how alike are these induced pluripotent stem cells (iPSCs) to embryonic stem cells (ESCs)?

It’s an important question to settle because iPSCs have several advantages over ESCs. Unlike ESCs, iPSCs don’t require the destruction of an embryo so they’re mostly free from ethical concerns. And because they can be derived from a patient’s cells, if iPSC-derived cell therapies were given back to the same patient, they should be less likely to cause immune rejection. Despite these advantages, the fact that iPSCs are artificially generated by the forced activation of specific genes create lingering concerns that for treatments in humans, delivering iPSC-derived therapies may not be as safe as their ESC counterparts.

Careful comparisons of DNA between iPSCs and ESCs have shown that they are indeed differences in chemical tags found on specific spots on the cell’s DNA. These tags, called epigenetic (“epi”, meaning “in addition”) modifications can affect the activity of genes independent of the underlying genetic sequence. These variations in epigenetic tags also show up when you compare two different preparations, or cell lines, of iPSCs. So, it’s been difficult for researchers to tease out the source of these differences. Are these differences due to the small variations in DNA sequence that are naturally seen from one cell line to the other? Or is there some non-genetic reason for the differences in the iPSCs’ epigenetic modifications?

Marian and Vivian Brown, were San Francisco’s most famous identical twins. Photo: Christopher Michel

A recent CIRM-funded study by a Salk Institute team took a clever approach to tackle this question. They compared epigenetic modifications between iPSCs derived from three sets of identical twins. They still found several epigenetic variations between each set of twins. And since the twins have identical DNA sequences, the researchers could conclude that not all differences seen between iPSC cell lines are due to genetics. Athanasia Panopoulos, a co-first author on the Cell Stem Cell article, summed up the results in a press release:

“In the past, researchers had found lots of sites with variations in methylation status [specific term for the epigenetic tag], but it was hard to figure out which of those sites had variation due to genetics. Here, we could focus more specifically on the sites we know have nothing to do with genetics. The twins enabled us to ask questions we couldn’t ask before. You’re able to see what happens when you reprogram cells with identical genomes but divergent epigenomes, and figure out what is happening because of genetics, and what is happening due to other mechanisms.”

With these new insights in hand, the researchers will have a better handle on interpreting differences between individual iPSC cell lines as well as their differences with ESC cell lines. This knowledge will be important for understanding how these variations may affect the development of future iPSC-based cell therapies.

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

retinitis pigmentosas_1

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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Live streaming genes in living cells coming to a computer near you!

Christmas has come early to scientists at the University of Virginia School of Medicine. They’ve developed a technology that allows you to watch how individual genes move and interact in living cells. You can think of it as Facebook’s live streaming meets the adventurous Ms. Frizzle and her Magic School Bus.

Using a gene editing system called CRISPR/Cas9, the team tagged genes of interest with fluorescent proteins that light up under a microscope – allowing them to watch in real time where these genes are in a cell’s nucleus and how they interact with other genes in the genome. This research, which was funded in part by a CIRM Research Leadership award, was published in the journal Nature Communications.

Watching genes in living cells

Traditional methods for observing the locations of genes within cells, such as fluorescent in situ hybridization (FISH), kill the cells – giving scientists only a snapshot of the complex interactions between genes. With this new technology, scientists can track genes in living cells and generate a 3D map of where genes are located within chromatin (the DNA/protein complex that makes up our chromosomes) during the different stages of a cell’s existence. They can also use these maps to understand changes in gene interactions caused by diseases like cancer.

Senior author on the study, Dr. Mazhar Adli, explained in a news release:

Mazhar Adli (Josh Barney, UVA Health System)

“This has been a dream for a long time. We are able to image basically any region in the genome that we want, in real time, in living cells. It works beautifully. With the traditional method, which is the gold standard, basically you will never be able to get this kind of data, because you have to kill the cells to get the imaging. But here we are doing it in live cells and in real time.”

Additionally, this new technique helps scientists conceptualize the position of genes in a 3D rather than in a linear fashion.

“We have two meters of DNA folded into a nucleus that is so tiny that 10,000 of them will fit onto the tip of a needle,” Adli explained. “We know that DNA is not linear but forms these loops, these large, three-dimensional loops. We want to basically image those kind of interactions and get an idea of how the genome is organized in three-dimensional space, because that’s functionally important.”

Not only can this CRISPR technology light up specific genes of interest, but it can also turn their activity on or off, allowing the scientists to observe the effects of one gene’s activity on others. The flexibility of this approach for visualizing genes in live cells is something that the research world currently lacks.

“We were told we would never be able to do this. There are some approaches that let you look at three-dimensional organization. But you do that experiment on hundreds of millions of cells, and you have to kill them to do it. Here, we can look at the single-cell level, and the cell is still alive, and we can take movies of what’s happening inside.”

This is a pretty nifty imaging tool for scientists that allows them to watch where genes are located and how they move as a cell develops and matures. Live-streaming the components of the genetic engine that keeps a cell running could also provide new insights into why certain genetic diseases occur and potentially open doors for developing better treatments.

Scientists tracked specific genomic locations in a living cell over time using their CRISPR/Cas9 technology. (Nature communications)