CIRM Board Approves $19.7 Million in Awards for Translational Research Program

In addition to approving funding for breast cancer related brain metastases last week, the CIRM Board also approved an additional $19.7 million geared towards our translational research program. The goal of this program is to help promising projects complete the testing needed to begin talking to the US Food and Drug Administration (FDA) about holding a clinical trial.

Before getting into the details of each project, here is a table with a brief synopsis of the awards:

TRAN1 – 11532

Illustration of a healthy eye vs eye with AMD

$3.73 million was awarded to Dr. Mark Humayun at USC to develop a novel therapeutic product capable of slowing the progression of age-related macular degeneration (AMD).

AMD is an eye disease that causes severe vision impairment, resulting in the inability to read, drive, recognize faces, and blindness if left untreated.  It is the leading cause of vision loss in the U.S. and currently affects over 2 million Americans.  By the year 2050, it is projected that the number of affected individuals will more than double to over 5 million.  A layer of cells in the back of the eye called the retinal pigment epithelium (RPE) provide support to photoreceptors (PRs), specialized cells that play an important role in our ability to process images.  The dysfunction and/or loss of RPE cells plays a critical role in the loss of PRs and hence the vision problems observed in AMD.  One form of AMD is known as dry AMD (dAMD) and accounts for about 90% of all AMD cases.

The approach that Dr. Humayun is developing will use a biologic product produced by human embryonic stem cells (hESCs). This material will be injected into the eye of patients with early development of dAMD, supporting the survival of photoreceptors in the affected retina.

TRAN1 – 11579

Illustration depicting the role neuronal relays play in muscle sensation

$6.23 million was awarded to Dr. Mark Tuszynski at UCSD to develop a neural stem cell therapy for spinal cord injury (SCI).

According to data from the National Spinal Cord Injury Statistical Center, as of 2018, SCI affects an estimated 288,000 people in the United States alone, with about 17,700 new cases each year. There are currently no effective therapies for SCI. Many people suffer SCI in early adulthood, leading to life-long disability and suffering, extensive treatment needs and extremely high lifetime costs of health care.

The approach that Dr. Tuszynski is developing will use hESCs to create neural stem cells (NSCs).  These newly created NSCs would then be grafted at the site of injury of those with SCI.  In preclinical studies, the NSCs have been shown to support the formation of neuronal relays at the site of SCI.  The neuronal relays allow the sensory neurons in the brain to communicate with the motor neurons in the spinal cord to re-establish muscle control and movement.

TRAN1 – 11548

Graphic depicting the challenges of traumatic brain injury (TBI)

$4.83 million was awarded to Dr. Brian Cummings at UC Irvine to develop a neural stem cell therapy for traumatic brain injury (TBI).

TBI is caused by a bump, blow, or jolt to the head that disrupts the normal function of the brain, resulting in emotional, mental, movement, and memory problems. There are 1.7 million people in the United States experiencing a TBI that leads to hospitalization each year. Since there are no effective treatments, TBI is one of the most critical unmet medical needs based on the total number of those affected and on a cost basis.

The approach that Dr. Cummings is developing will also use hESCs to create NSCs.  These newly created NSCs would be integrated with injured tissue in patients and have the ability to turn into the three main cell types in the brain; neurons, astrocytes, and oligodendrocytes.  This would allow for TBI patients to potentially see improvements in issues related to memory, movement, and anxiety, increasing independence and lessening patient care needs.

TRAN1 – 11628

Illustration depicting the brain damage that occurs under hypoxic-ischemic conditions

$4.96 million was awarded to Dr. Evan Snyder at Sanford Burnham Prebys to develop a neural stem cell therapy for perinatal hypoxic-ischemic brain injury (HII).

HII occurs when there is a lack of oxygen flow to the brain.  A newborn infant’s body can compensate for brief periods of depleted oxygen, but if this lasts too long, brain tissue is destroyed, which can cause many issues such as developmental delay and motor impairment.  Current treatment for this condition is whole-body hypothermia (HT), which consists of significantly reducing body temperature to interrupt brain injury.  However, this is not very effective in severe cases of HII. 

The approach that Dr. Snyder is developing will use an established neural stem cell (NSC) line.   These NSCs would be injected and potentially used alongside HT treatment to increase protection from brain injury.

Stem cell byproducts provide insight into cure for spina bifida

A diagram of an infant born with spina bifida, a birth defect where there is an incomplete closing of the backbone portion of the spinal cord. Photo courtesy of the Texas Children’s Hospital website.

Some of you might remember a movie in the early 2000s by the name of “Miracle in Lane 2”. The film is based on an inspirational true story and revolves around a boy named Justin Yoder entering a soapbox derby competition. In the movie, Justin achieves success as a soapbox derby driver while adapting to the challenges of being in a wheelchair.

Scene from “Miracle in Lane 2”

The reason that Justin is unable to walk is due to a birth defect known as spina bifida, which causes an incomplete closing of the backbone portion of the spinal cord, exposing tissue and nerves. In addition to difficulties with walking, other problems associated with this condition are problems with bladder or bowel control and accumulation of fluid in the brain.

According to the Center for Disease Control (CDC) , each year about 1,645 babies in the US are born with spina bifida, with Hispanic women having the highest rate of children born with the condition. There is currently no cure for this condition, but researchers at UC Davis are one step closer to changing that.

Dr. Aijun Wang examining cells under a microscope. He has identified stem cell byproducts that protect neurons. Photo courtesy of UC Regents/UC Davis Health

Dr. Aijun Wang, Dr. Diana Farmer, and their research team have identified crucial byproducts produced by stem cells that play an important role in protecting neurons. These byproducts could assist with improving lower-limb motion in patients with spina bifida.

Prior to this discovery, Dr. Farmer and Dr. Wang demonstrated that prenatal surgery combined with connective tissue (e.g. stromal cells) derived from stem cells improved hind limb control in dogs with spina bifida. Below you can see a clip of two English bulldogs with spina bifida who are now able to walk.

Their findings were published in the Journal of the Federation of American Societies for Experimental Biology on February 12, 2019.

The team will use their findings to perfect the neuroprotective qualities of a stem cell treatment developed to improve locomotive problems associated with spina bifida.

In a public release posted by EurekaAlert!, Dr. Wang is quoted as saying, “We are excited about what we see so far and are anxious to further explore the clinical applications of this research.”

The discovery and development of a treatment for spina bifida was funded by a $5.66 million grant from CIRM. You can read more about that award and spina bifida on a previous blog post linked here.

Performance, Passion and Progress: and that’s just page one of our 2018 Annual Report

2018_ar_webimage

It’s hard to sum up the activities and achievements of a year in a single document, let alone one that’s just 24 pages. But that’s what we have done in putting together our 2018 Annual Report.

It’s a look back at the year just gone, the highlights, the low lights (spoiler alert – there weren’t any) and the impact we had on the field of stem cell research. But it’s far more than that. It’s also a look ahead. A look at the challenges we face, and profiles of the people who are going to help us overcome those challenges and maintain our progress.

And people are truly at the heart of this report, from UC San Francisco’s Dr. Tippi MacKenzie who is on the front cover for her work in developing an in-utero treatment for the almost always fatal disorder alpha thalassemia major (and the photo of the baby and mom whose lives were changed by that therapy) to Rich Lajara on the back cover, the first person ever treated in a CIRM-funded clinical trial.

Inside are an array of simple images designed to reflect how we as a state agency have performed this year. The numbers themselves tell a powerful story:

  • 50 clinical trials funded to date, 7 this year alone
  • $2.6 billion in CIRM grants has been leveraged to bring in an additional $3.2 billion in matching funds and investments from other sources.
  • 1,180 patients have been involved in CIRM clinical trials

We know people don’t have a lot of time to read Annual Reports so we have made this as visually engaging and informative as possible. We want you to get a real sense of who we are, what we have done and who has helped us do that without you having to wade through a document the size of War and Peace (great book by the way – the Russians beat Napoleon).

We think we have a great story to tell. This Annual Report is one chapter in that story. We hope you like it.

 

Scientists say they’re one step closer to being able to build a new you, using your own stem cells.

Organ transplant

One of the biggest obstacles to transplanting organs from one person to another is that the immune system of the person getting the new life-saving organ often tries to reject it. The immune cells see the new material as “foreign” and attacks it, sometimes destroying it.

Right now, the only way to prevent that is by using powerful immunosuppressive drugs to keep the patient’s immune system at bay and protect the new organ. It’s effective, but it also comes with some long-term health consequences.

But now researchers at Tel Aviv University in Israel say they may have found a way around that, using the patient’s own stem cells.

The team says it was able to take fatty tissue from patients and, using the iPSC procedure, turn them into other kinds of cells to help repair different kinds of tissue.

In a story in the “Times of Israel”, Prof Tal Dvir, the lead researcher, said this new approach could theoretically be used to engineer any tissue type in the body.

“We were able to create a personalized hydrogel from the materials of the biopsy, to differentiate fatty tissue cells into different cell types and to engineer cardiac, spinal cord, cortical and other tissue implants to treat different diseases. Since both the cells and the material used derive from the patient, the implant does not provoke an immune response, ensuring proper regeneration of the defected organ.”

Dvir says the research, published in the journal Advanced Materials, has only been tested in animals so far but has shown great promise, helping regenerate damaged tissues in mice and rats. Their next goal is to see if they can replicate this in people.

“Theoretically we can work in every disease or disorder that cells are involved in, where tissue is dying. We can create the tissue to fix that injury by a simple injection of materials and cells at the injury site,”

While this has long been a goal of many stem cell researchers around the world, problems translating what looks good in animals into what works in people has invariably slowed down the progress of even the most promising approach. At least so far.

New hope for stem cell therapy in patients with leukemia

LeukemiaWhiteBloodCell

Leukemia white blood cell

Of the many different kinds of cancer that affect humans, leukemia is the most common in young people. As with many types cancer, doctors mostly turn to chemotherapy to treat patients. Chemotherapy, however, comes with its own share of issues, primarily severe side effects and the constant threat of disease recurrence.

Stem cell therapy treatment has emerged as a potential cure for some types of cancer, with leukemia patients being among the first groups of patients to receive this type of treatment. While exciting because of the possibility of a complete cure, stem cell therapy comes with its own challenges. Let’s take a closer look.

Leukemia is characterized by abnormal white blood cells (also known as the many different types of cells that make up our immune system) that are produced at high levels. Stem cell therapy is such an appealing treatment option because it involves replacing the patient’s aberrant blood stem cells with healthy ones from a donor, which provides the possibility of complete and permanent remission for the patient.

Unfortunately, in approximately half of patients who receive this therapy, the donor cells (which turn into immune cells), can also destroy the patients healthy tissue (i.e. liver, skin etc…), because the transplanted blood stem cells recognize patient’s tissue as foreign. While doctors try to lessen this type of response (also known as graft versus host disease (GVHD)), by suppressing the patient’s immune system, this procedure lessens the effectiveness of the stem cell therapy itself.

Now scientists at the University of Zurich have made an important discovery – published in the journal Science Translational Medicine – that could mitigate this potentially fatal response in patients. They found that a molecule called GM-CSF, is a critical mediator of the severity of GVHD. Using a mouse model, they showed that if the donor cells were unable to produce GM-CSF, then mice fared significantly better both in terms of less damage to tissues normally affected by GVHD, such as the skin, and overall survival.

While exciting, the scientists were concerned about narrowing in on this molecule as a potential target to lessen GVHD, because GM-CSF, an important molecule in the immune system, might also be important for ensuring that the donor immune cells do their jobs properly. Reassuringly, the researchers found that blocking GM-CSF’s function had no effect on the ability of the donor cells to exert their anti-cancer effect. This was surprising because previously the ability of donor cells to cause GVHD, versus protect patients from the development of cancer was thought to occur via the same biological mechanisms.

Most excitingly, however, was that finding that high levels of GM-CSF are also observed in patient samples, and that the levels of GM-CSF correlate to the severity of GVHD. Dr. Burkhard Becher and his colleagues, the authors of this study, now want to run a clinical trial to determine whether blocking GM-CSF blocks GVHD in humans like it does in mice. In a press release, Dr. Becher states the importance of these findings:

“If we can stop the graft-versus-host response while preserving the anti-cancer effect, this procedure can be employed much more successfully and with fewer risks to the patient. This therapeutic strategy holds particular promise for patients with the poorest prognosis and highest risk of fatality.”

CIRM invests in stem cell clinical trial targeting lung cancer and promising research into osteoporosis and incontinence

Lung cancer

Lung cancer: Photo courtesy Verywell

The five-year survival rate for people diagnosed with the most advanced stage of non-small cell lung cancer (NSCLC) is pretty grim, only between one and 10 percent. To address this devastating condition, the Board of the California Institute for Regenerative Medicine (CIRM) today voted to invest almost $12 million in a team from UCLA that is pioneering a combination therapy for NSCLC.

The team is using the patient’s own immune system where their dendritic cells – key cells in our immune system – are genetically modified to boost their ability to stimulate their native T cells – a type of white blood cell – to destroy cancer cells.  The investigators will combine this cell therapy with the FDA-approved therapy pembrolizumab (better known as Keytruda) a therapeutic that renders cancer cells more susceptible to clearance by the immune system.

“Lung cancer is a leading cause of cancer death for men and women, leading to 150,000 deaths each year and there is clearly a need for new and more effective treatments,” says Maria T. Millan, M.D., the President and CEO of CIRM. “We are pleased to support this program that is exploring a combination immunotherapy with gene modified cell and antibody for one of the most extreme forms of lung cancer.”

Translation Awards

The CIRM Board also approved investing $14.15 million in four projects under its Translation Research Program. The goal of these awards is to support promising stem cell research and help it move out of the laboratory and into clinical trials in people.

Researchers at Stanford were awarded almost $6 million to help develop a treatment for urinary incontinence (UI). Despite being one of the most common indications for surgery in women, one third of elderly women continue to suffer from debilitating urinary incontinence because they are not candidates for surgery or because surgery fails to address their condition.

The Stanford team is developing an approach using the patient’s own cells to create smooth muscle cells that can replace those lost in UI. If this approach is successful, it provides a proof of concept for replacement of smooth muscle cells that could potentially address other conditions in the urinary tract and in the digestive tract.

Max BioPharma Inc. was awarded almost $1.7 million to test a therapy that targets stem cells in the skeleton, creating new bone forming cells and blocking the destruction of bone cells caused by osteoporosis.

In its application the company stressed the benefit this could have for California’s diverse population stating: “Our program has the potential to have a significant positive impact on the lives of patients with osteoporosis, especially in California where its unique demographics make it particularly vulnerable. Latinos are 31% more likely to have osteoporosis than Caucasians, and California has the largest Latino population in the US, accounting for 39% of its population.”

Application Title Institution CIRM funding
TRAN1-10958 Autologous iPSC-derived smooth muscle cell therapy for treatment of urinary incontinence

 

 

Stanford University

 

$5,977,155

 

TRAN2-10990 Development of a noninvasive prenatal test for beta-hemoglobinopathies for earlier stem cell therapeutic interventions

 

 

Children’s Hospital Oakland Research Institute

 

$1,721,606

 

TRAN1-10937 Therapeutic development of an oxysterol with bone anabolic and anti-resorptive properties for intervention in osteoporosis  

MAX BioPharma Inc.

 

$1,689,855

 

TRAN1-10995 Morphological and functional integration of stem cell derived retina organoid sheets into degenerating retina models

 

 

UC Irvine

 

$4,769,039

 

Say Hello to CIRM’s New Active Awards Portfolio Dashboard (Video Included!)

It takes a lot of time, money and effort to develop a promising stem cell research idea into an effective treatment that can help patients. Oftentimes, you don’t hear about the early-stage research that goes into developing a particular treatment until it reaches the clinic.

CIRM recognizes the importance of investing in all stages of stem cell research and has an impressive portfolio of over 160 active projects spanning discovery, translation, and clinical-stage research.

To help you understand the breadth of our funding efforts, and to highlight our expanding research pipeline, we’ve created the Active Awards Portfolio Dashboard on our website. This interactive tool makes it easy to search through the active research projects that we’re currently funding, and filter these projects by disease focus, technology type or stage of research.

Watch the short video below to learn more about our new Dashboard and how to use it.

The Active Awards Dashboard reflects our Agency’s commitment to investing in the full range of stem cell research and to helping the most promising research projects advance to the next level.

For those of you interested in learning more about the 45 active clinical trials we’re funding, be sure to check out the companion Clinical Trials Dashboard on our website, featured previously on the Stem Cellar blog.

Harnessing the body’s immune system to tackle cancer

Often on the Stem Cellar we write about work that is in a clinical trial. But getting research to that stage takes years and years of dedicated work. Over the next few months, we are profiling some of the scientists we fund who are doing Discovery (early stage) and Translational (pre-clinical) research, to highlight the importance of this work in developing the treatments that could ultimately save lives. 

This second profile in the series is by Ross Okamura, Ph.D., a science officer in CIRM’s Discovery & Translation Program.

Your immune system is your body’s main protection against disease; harnessing this powerful defense system to target a given disorder is known as immunotherapy.  There are different types of immunotherapies that have been developed over the years. These include vaccines to help generate antibodies against viruses, drugs to direct immune cell function and most recently, the engineering of immune cells to fight cancer.

Understanding How Immunotherapies Work

One of the more recent immunotherapy approaches to fight cancer that has seen rapid development is equipping a subset of immune cells (T cells) with a chimeric antigen receptor (CAR). In brief, CAR T ceIls are first removed from the patient and then engineered to recognize a specific feature of the targeted cancer cells.  This direct targeting of T cells to the cancer allows for an effective anti-cancer therapy made from your own immune system.

Simplified explanation of how CAR T cell therapies fight cancer. (Memorial Sloan Kettering)

For the first time this fall, two therapeutics employing CAR T cells targeting different types of blood cancers were approved for use by the US Food and Drug Administration (FDA) based on remarkable results found during the clinical trials. Specifically, Kymriah (developed by Novartis) was approved for treatment of acute lymphoblastic leukemia and Yescarta (developed by Kite Pharma) was approved for treatment of non-Hodgkin lymphoma.

There are drawbacks to the CAR T approach, however. Revving up the immune system to attack tumors can cause dangerous side effects. When CAR T cells enter the body, they trigger the release of proteins called cytokines, which join in the attack on the tumors. But this can also create what’s referred to as a cytokine storm or cytokine release syndrome (CRS), which can lead to a range of responses, from a mild fever to multi-organ failure and death. Balancing treatments to resolve CRS after it’s detected while still maintaining the treatment’s cancer-killing abilities is a significant challenge that remains to be overcome.  A second issue is that cancer cells can evade the immune system by no longer producing the target that the CAR-T therapy was designed to recognize. When this happens, the patient subsequently experiences a cancer relapse that is no longer treatable by the same cell therapy.

Natural Killer (NK) T cells represent another type of anti-cancer immunotherapy that is also being tested in clinical trials. NK cells are part of the innate immune system responsible for defending your body against both infection and tumor formation.  NK cells target stressed cells by releasing cell-penetrating proteins that poke holes in the cells leading to induced cell death.  As an immunotherapy, NK cells have the potential to avoid both the issues of CRS and cancer cell immune evasion as they release a more limited array of cytokines and do not rely on a specific single target to recognize tumors.  NK cells instead selectively target tumor cells due to the presence of stress-induced proteins on the cancer cells. In addition, the cancer cells lack other proteins that would normally send out a “I’m a healthy cell you can ignore me” message to NK cells. Without that message, NK cells target and kill those cancer cells.

Developing new immunotherapies against cancer

Dan Kaufman, UCSD

Dr. Dan Kaufman of the University of California at San Diego is a physician-scientist whose research group developed a method to produce functional NK cells from human pluripotent stem cells (PSC).  In order to overcome a major hurdle in the use of NK cells as an anti-cancer therapeutic, Dr. Kaufman is exploring using stem cells as a limitless source to produce a scalable, standardized, off-the-shelf product that could treat thousands of patients.  CIRM is currently funding Dr. Kaufman’s work under both a Discovery Quest award and a just recently funded Translational research award in order to try to advance this candidate approach.

In the CIRM Translational award, Dr. Kaufman is looking to cure acute myelogenous leukemia (AML) which in the US has a 5-year survival rate of 27% (National Cancer Institute, 2017) and is estimated to kill over 10,000 individuals this year (American Cancer Society, 2017).  He has previously shown that his stem cell-derived NK cells can kill human cancer cells in a dish and in mouse models, and his goals are to perform preliminary safety studies and to develop a process to scale his production of NK cells to support a clinical trial in people.  Since NK cells don’t require the patient and the donor to be a genetic match to be effective, a bank of PSC-derived NK cells derived from a single donor could potentially treat thousands of patients.

Looking forward, CIRM is also providing Discovery funding to Dr. Kaufman to explore ways to improve his existing approach against leukemia as well as expand the potential of his stem cell-derived NK cell therapeutic by engineering his cells to directly target solid tumors like ovarian cancer.

The field of pluripotent stem cell-based immunotherapies is full of game-changing potential and important innovations like Dr. Kaufman’s are still in the early stages.  CIRM recognizes the importance of supporting early stage research and is currently investing $27.9 million to fund 8 active Discovery and Translation awards in the cancer immunotherapy area.

Budgeting for the future of the stem cell agency

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The CIRM Board discusses the future of the Stem Cell Agency

Budgets are very rarely exciting things; but they are important. For example, it’s useful for a family to know when they go shopping exactly how much money they have so they know how much they can afford to spend. Stem cell agencies face the same constraints; you can’t spend more than you have. Last week the CIRM Board looked at what we have in the bank, and set us on a course to be able to do as many of the things we want to, with the money we have left.

First some context. Last year CIRM spent a shade over $306 million on a wide range of research from Discovery, the earliest stage, through Translational and into Clinical trials. We estimate that is going to leave us with approximately $335 million to spend in the coming years.

A couple of years ago our Board approved a 5 year Strategic Plan that laid out some pretty ambitious goals for us to achieve – such as funding 50 new clinical trials. At the time, that many clinical trials definitely felt like a stretch and we questioned if it would be possible. We’re proving that it is. In just two years we have funded 26 new clinical trials, so we are halfway to our goal, which is terrific. But it also means we are in danger of using up all our money faster than anticipated, and not having the time to meet all our goals.

Doing the math

So, for the last couple of months our Leadership Team has been crunching the numbers and looking for ways to use the money in the most effective and efficient way. Last week they presented their plan to the Board.

It boiled down to a few options.

  • Keep funding at the current rate and run out of money by 2019
  • Limit funding just to clinical trials, which would mean we could hit our 50 clinical trial goal by 2020 but would not have enough to fund Discovery and Translational level research
  • Place caps on how much we fund each clinical trial, enabling us to fund more clinical trials while having enough left over for Discovery and Translational awards

The Board went for the third option for some good reasons. The plan is consistent with the goals laid out in our Strategic Plan and it supports Discovery and Translational research, which are important elements in our drive to develop new therapies for patients.

Finding the right size cap

Here’s a look at the size of the caps on clinical trial funding. You’ll see that in the case of late stage pre-clinical work and Phase 1 clinical trials, the caps are still larger than the average amount we funded those stages last year. For Phase 2 the cap is almost the same as the average. For Phase 3 the cap is half the amount from last year, but we think at this stage Phase 3 trials should be better able to attract funding from other sources, such as industry or private investors.

cap awards

Another important reason why the Board chose option three – and here you’ll have to forgive me for being rather selfish – is that it means the Administration Budget (which pays the salaries of the CIRM team, including yours truly) will be enough to cover the cost of running this research plan until 2020.

The bottom line is that for 2018 we’ll be able to spend $130 million on clinical stage research, $30 million for Translational stage, and $10 million for Discovery. The impact the new funding caps will have on clinical stage projects is likely to be small (you can see the whole presentation and details of our plan here) but the freedom it gives us to support the broad range of our work is huge.

And here is where to go if you are interested in seeing the different funding opportunities at CIRM.

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.


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