Science Translational Medicine

Stem cell therapy may help mend a broken heart

/ Kevin McCormack / 1 Comment
Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014

Dilated cardiomyopathy (DCM), a condition where the muscles of the heart are weak and can lead to heart failure, is considered rare in children. However, because the symptoms are not always easy to recognize the condition can go unnoticed for many years, and in severe cases can damage the heart irreparably. In that case the child’s only option is a heart transplant, and a lack of organ donors means that is not always available.

Now, new research out of Japan – published in the journal Science Translation Medicine – could lead the way to new treatments to help children avoid the need for a transplant.

In the study, researchers at Okayama University used heart stem cells called cardiosphere-derived cells (CDCs) to try and repair the damage caused by DCM.  

In a news release, lead researcher Professor Hidemasa Oh, says previous work has shown that because CDCs have the ability to turn into heart tissue they have the potential of reversing damage, but it’s not clear if this would work in children.

“I have been working on cardiac regeneration therapy since 2001. In this study, my team and I assessed the safety and efficacy of using CDCs to treat DCM in children.”

Tests in animal models with DCM showed that the CDCs resulted in a thickening of the heart muscle leading to increased blood flow around the body. This increased blood supply helped repair damaged tissue. Based on this trial the researcher determined what might be a suitable dose of CDCs for children with DCM and were granted permission to carry out a Phase 1 clinical trial.

Five young patients were treated and the results were cautiously encouraging. After a year none of the patients had experienced any severe side effects, but all had indications of improved heart function.

The study also gave the researchers some strong clues as to how the therapy seem to work. They found that when the CDCs were transplanted into the patient they secreted exosomes, which play an important role in cells communicating with one another. These exosomes then helped create a series of actions within the body; they blocked further damage to the heart tissue and they also helped kickstart the repair process.

The Okayama team are now hoping to carry out a Phase 2 clinical trial with more patients. Ultimately, they hope to be able to see if this approach could help prevent the need for a heart transplant in children, and even adults.

CIRM funded stem cell therapy could one day help stroke and dementia patients

/ Yimy Villa / 3 Comments
Image Description: Microscope images showing brain tissue that has been damaged by white matter stroke (left) and then repaired by the new glial cell therapy (right). Myelin (seen in red), is a substance that protects the connections between neurons and is lost due to white matter stroke. As seen at right, the glial cell therapy (green) restores lost myelin and improves connections in the brain. | Credit: UCLA Broad Stem Cell Research Center/Science Translational Medicine

Dementia is a general term that describes problems with memory, attention, communication, and physical coordination. One of the major causes of dementia is white matter strokes, which occurs when multiple strokes (i.e. a lack of blood supply to the brain) gradually damages the connecting areas of the brain (i.e. white matter).

Currently, there are no therapies capable of stopping the progression of white matter strokes or enhancing the brain’s limited ability to repair itself after they occur.

However, a CIRM-funded study ($2.09 million) conducted by S. Thomas Carmichael, M.D., Ph.D. and his team at UCLA showed that a one-time injection of an experimental stem cell therapy can repair brain damage and improve memory function in mice with conditions that mimic human strokes and dementia.

The therapy consists of glial cells, which are a special type of cell present in the central nervous system that surround and protect neurons. The glial cells are derived from induced pluripotent stem cells (iPSCS), stem cells that are derived from skin or blood cells through the process of reprogramming and have the ability to become virtually any type of cell.

Dr. Carmichael and his team injected the newly developed glial cells into the brains of mice that had damage similar to humans in the early to middle stages of dementia. The team found that the cell therapy traveled to the damaged areas of the brain and secreted chemicals that stimulated the brain’s own stem cells to start repairing the damage. This not only limited the progression of damage, but also enhanced the formation of new neural connections and increased the production of myelin, a fatty substance that covers and protects neurons.

In a press release from UCLA, Francesca Bosetti, Ph.D., Pharm.D., Program Director at the National Institute of Neurological Disorders and Strokes, was optimistic about what these findings could mean for patients with strokes or dementia.

“These preliminary results suggest that glial cell-based therapies may one day help combat the white matter damage that many stroke and vascular dementia patients suffer every year.”

Another interesting finding from this study is that even if the injected cells were eliminated a few months after they had been transplanted, the mice’s recovery was unaffected. The researchers believe that this indicates that the therapy primarily serves as a way to stimulate the brain’s own repair process.

In the same press release, Dr. Carmichael elaborates on this concept.

“Because the cell therapy is not directly repairing the brain, you don’t need to rely on the transplanted cells to persist in order for the treatment to be successful.”

The team is now conducting the additional studies necessary to apply to the Food and Drug Administration (FDA) for permission to test the therapy in a clinical trial in humans. If the therapy is shown to be safe and effective through clinical trials in humans, the team envisions that it could be used at hospitals as a one-time treatment for people with early signs of white matter stroke.

The full results of this study were published in Science Translational Medicine.

New hydrogel developed could aid in therapies to generate bones in head and neck

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Taking a cue from mussels’ natural ability to adhere to surfaces underwater, the UCLA researchers incorporated an alginate-based solution in their hydrogel.
Photo taken by D. Jude, Univ. of Michigan

When most people think of mussels, what immediately comes to mind might be a savory seafood dish or favorite seafood restaurant. But to Dr. Alireza Moshaverinia and his team of researchers at the UCLA School of Dentistry, it’s the ability that mussels have to stick to wet surfaces that is of particular interest.

Partially inspired by this concept and with support from CIRM, the team of researchers developed the first adhesive hydrogel specifically to regenerate bone and tissue defects following head and neck injuries.

Over the past few years, surgeons and clinicians have began to use hydrogels to administer stem cells to help regenerate lost tissues and for bone defects. Hydrogels are beneficial because they can be effective at carrying stem cells to targeted areas inside the body. However, when used in surgeries of the mouth, they tend to become less effective because blood and saliva prevent them from properly adhering to the targeted site. As a result of this, the stem cells don’t stay in place long enough to deliver their regenerative properties.

To help with this problem, the researchers at UCLA developed a new hydrogel by adding alginate into the mix. Alginates are found in the cells of algae and form a sticky, gum-like substance when wet.

The scientists then tested their new hydrogel by loading it with bone building stem cells and applying it to the mouths of rats with an infectious disease that affects the bone structure. They then sealed the hydrogel in place and applied a light treatment, similar to what dentists use in humans to solidify dental fillings.

The results showed that the bone around the implants in all of the rats had completely regenerated.

In a news release from UCLA, Dr. Moshaverinia elaborates on what this study means for potential future treatments.

“The light treatment helped harden the hydrogel, providing a more stable vehicle for delivery of the stem cells. We believe that our new tissue engineering application could be an optimal option for patients who have lost their hard and soft craniofacial tissues due to trauma, infection or tumors.”

The full study was published in Science Translational Medicine.

Stem cell transplant in utero offers potential treatment for congenital diseases

/ Yimy Villa / 2 Comments
Dr. Tippi Mackenzie, UCSF
Image Credit: UCSF

Each year, around 24,000 women in the US lose a pregnancy. One reason for this unfortunate occurrence are metabolic disorders, one of which is known as Sly syndrome and is caused by a single genetic mutation. In Sly syndrome, the body’s cells lack an enzyme necessary for proper cell function. Many fetuses with this condition die before birth but those that survive are treated with regular injections of the lacking enzyme. Unfortunately, patients can eventually develop an immune response to these injections and it cannot enter the brain after birth.

However, a team of researchers at UCSF are looking at exploring a potential treatment that could be delivered in-utero. In a CIRM supported study, Dr. Tippi Mackenzie and Dr. Quoc-Hung Nguyen transplanted blood-forming stem cells from normal mice into fetal mice carrying the genetic mutation for Sly syndrome. The researchers were most interested to see whether these cells could reach the brain, and whether they would change into cells called microglia, immune cells that originate from blood-forming stem cells. In a normally developing fetus, once matured, microglia produce and store the necessary enzyme, as well as regulate the immune environment of the brain.

Stem cells transplanted in utero (green) engrafted into fetal mouse brain tissue. 
Image credit: Q-H Nguyen/MacKenzie lab.

The researchers found that the stem cells were able to engraft in the brain, liver, kidney, and other organs. Furthermore, these stem cells were able to eventually turn into the appropriate cell type needed to produce the enzyme in each of the organs.

In a press release, Dr. Mackenzie talks about the impact that this potential treatment could have.

“This group of vulnerable patients has been relatively ignored in the fetal surgery world. We know these patients could potentially benefit from a number of medical therapies. So this is our first foray into treating one of those diseases.”

In the same press release, Dr. Nguyen talks about the impact of the results from this study.

“These exciting findings are just the tip of the iceberg. They open up a whole new approach to treating a range of diseases. At the same time, there’s also a lot of work to do to optimize the treatment for humans.”

The next step for Dr. Mackenzie is to apply to the U.S. Food and Drug Administration to launch a clinical trial of enzyme replacement therapy that will ultimately enroll patients with Sly syndrome and related metabolic disorders.

This approach is similar to a CIRM funded trial conducted by Dr. Mackenzie that involves a blood stem cell transplant in utero.

The full results to this study were published in Science Translational Medicine.

Drug used to treat multiple sclerosis may improve glioblastoma outcomes

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Dr. Jeremy Rich, UC San Diego

Glioblastoma is an aggressive form of cancer that invades brain tissue, making it extremely difficult to treat. Current therapies involving radiation and chemotherapy are effective in destroying the bulk of brain cancer cells, but they are not able to reach the brain cancer stem cells, which have the ability to grow and multiply indefinitely. These cancer stem cells enable the glioblastoma to continuously grow even after treatment, which leads to recurring tumor formation.

Dr. Jeremy Rich and his team at UC San Diego examined glioblastomas further by obtaining glioblastoma tumor samples donated by patients that underwent surgery and implanting these into mice. Dr. Rich and his team tested a combinational treatment that included a targeted cancer therapy alongside a drug named teriflunomide, which is used to treatment patients with multiple sclerosis. The research team found that this approach successfully halted the growth of glioblastoma stem cells, shrank the tumor size, and improved survival in the mice.

In order to continue replicating, glioblastoma stem cells make pyrimidine, one of the compounds that make up DNA. Dr. Rich and his team noticed that higher rates of pyrimidine were associated with poor survival rates in glioblastoma patients. Teriflunomide works by blocking an enzyme that is necessary to make pyrmidine, therefore inhibiting glioblastoma stem cell replication.

In a press release, Dr. Rich talks about the potential these findings hold by stating that,

“We’re excited about these results, especially because we’re talking about a drug that’s already known to be safe in humans.”

However, he comments on the need to evaluate this approach further by saying that,

“This laboratory model isn’t perfect — yes it uses human patient samples, yet it still lacks the context a glioblastoma would have in the human body, such as interaction with the immune system, which we know plays an important role in determining tumor growth and survival. Before this drug could become available to patients with glioblastoma, human clinical trials would be necessary to support its safety and efficacy.”

The full results to this study were published in Science Translational Medicine.

Encouraging news about CIRM-funded clinical trial targeting vision loss

/ Kevin McCormack / 3 Comments

dry AMD

An eye affected by dry age-related macular degeneration

Dry age-related macular degeneration (AMD) is the leading cause of vision loss in the U.S. By 2020 it’s estimated that as many as three million Americans will be affected by the disease. Right now, there is no effective therapy. But that could change. A new CIRM-funded clinical trial is showing promise in helping people battling the disease not just in stabilizing their vision loss, but even reversing it.

In AMD, cells in the retina, the light-sensitive tissue at the back of the eye, are slowly destroyed affecting a person’s central vision. It can make it difficult to do everyday activities such as reading or watching TV and make it impossible for a person to drive.

Researchers at the University of Southern California (USC) Roski Eye Institute at the Keck School of Medicine, and Regenerative Patch Technologies, have developed a therapy using embryonic stem cells that they turned into retinal pigment epithelium (RPE) cells – the kind of cell destroyed by AMD. These cells were then placed on a synthetic scaffold which was surgically implanted in the back of the eye.

Imaging studies showed that the RPE cells appeared to integrate well into the eye and remained in place during follow-up tests 120 to 365 days after implantation.

Encouraging results

Of the five patients enrolled in the Phase 1/2a trial, four maintained their vision in the treated eye, two showed improvement in the stability of their vision, and one patient had a 17-letter improvement in their vision on a reading chart. In addition, there were no serious side effects or unanticipated problems.

There were other indications the implants were proving beneficial.  People with normal vision have the ability to focus their gaze on a single location. People with advanced AMD lose that ability. In this trial, two of the patients recovered stable fixation. These improvements were maintained in follow-up tests.

Abla-8

Abla Creasey, Ph.D., CIRM’S Vice President of Therapeutics and Strategic Infrastructure says even these small benefits are important:

“Having a therapy with a favorable safety profile, that could slow down the progression, or even reverse the vision loss would benefit millions of Americans. That’s why these results, while still in an early stage are encouraging, because the people treated in the trial are ones most severely affected by the disease who have the least potential for visual recovery.”

This study reflects CIRM’s long-term commitment to supporting the most promising stem cell research. The Stem Cell Agency began supporting USC’s Dr. Mark Humayun, the lead inventor of the implant, in 2010 and has been a partner with him and his team since then.

Dr.MarkHumayun2 copy

In a news release Dr. Humayun said they plan to recruit another 15 patients to see if these results hold up:

“Our study shows that this unique stem cell–based retinal implant thus far is well-tolerated, and preliminary results suggest it may help people with advanced dry age-related macular degeneration.”

While the results, published in the journal Science Translational Medicine, are encouraging the researchers caution that this was a very early stage clinical trial, with a small number of patients. They say the next step is to continue to follow the four patients treated in this trial to see if there are any further changes to their vision, and to conduct a larger trial.

 

 

Stories that caught our eye: How dying cells could help save lives; could modified blood stem cells reverse diabetes?; and FDA has good news for patients, bad news for rogue clinics

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Gunsmoke

Growing up I loved watching old cowboy movies. Invariably the hero, even though mortally wounded, would manage to save the day and rescue the heroine and/or the town.

Now it seems some stem cells perform the same function, dying in order to save the lives of others.

Researchers at Kings College in London were trying to better understand Graft vs Host Disease (GvHD), a potentially fatal complication that can occur when a patient receives a blood stem cell transplant. In cases of GvHD, the transplanted donor cells turn on the patient and attack their healthy cells and tissues.

Some previous research had found that using bone marrow cells called mesenchymal stem cells (MSCs) had some success in combating GvHD. But it was unpredictable who it helped and why.

Working with mice, the Kings College team found that the MSCs were only effective if they died after being transplanted. It appears that it is only as they are dying that the MSCs engage with the individual’s immune system, telling it to stop attacking healthy tissues. The team also found that if they kill the MSCs just before transplanting them into mice, they were just as effective.

In a news article on HealthCanal, lead researcher Professor Francesco Dazzi, said the next step is to see if this will apply to, and help, people:

“The side effects of a stem cell transplant can be fatal and this factor is a serious consideration in deciding whether some people are suitable to undergo one. If we can be more confident that we can control these lethal complications in all patients, more people will be able to receive this life saving procedure. The next step will be to introduce clinical trials for patients with GvHD, either using the procedure only in patients with immune systems capable of killing mesenchymal stem cells, or killing these cells before they are infused into the patient, to see if this does indeed improve the success of treatment.”

The study is published in Science Translational Medicine.

Genetically modified blood stem cells reverse diabetes in mice (Todd Dubnicoff)

When functioning properly, the T cells of our immune system keep us healthy by detecting and killing off infected, damaged or cancerous cells in our body. But in the case of type 1 diabetes, a person’s own T cells turn against the body by mistakenly targeting and destroying perfectly normal islet cells in the pancreas, which are responsible for producing insulin. As a result, the insulin-dependent delivery of blood sugar to the energy-hungry organs is disrupted leading to many serious complications. Blood stem cell transplants have been performed to treat the disease by attempting to restart the immune system. The results have failed to provide a cure.

Now a new study, published in Science Translational Medicine, appears to explain why those previous attempts failed and how some genetic rejiggering could lead to a successful treatment for type 1 diabetes.

An analysis of the gene activity inside the blood stem cells of diabetic mice and humans reveals that these cells lack a protein called PD-L1. This protein is known to play an important role in putting the brakes on T cell activity. Because T cells are potent cell killers, it’s important for proteins like PD-L1 to keep the activated T cells in check.

Cell based image for t 1 diabetes

Credit: Andrea Panigada/Nancy Fliesler

Researchers from Boston Children’s Hospital hypothesized that adding back PD-L1 may prevent T cells from the indiscriminate killing of the body’s own insulin-producing cells. To test this idea, the research team genetically engineered mouse blood stem cells to produce the PD-L1 protein. Experiments with the cells in a petri dish showed that the addition of PD-L1 did indeed block the attack-on-self activity. And when these blood stem cells were transplanted into a diabetic mouse strain, the disease was reversed in most of the animals over the short term while a third of the mice had long-lasting benefits.

The researchers hope this targeting of PD-L1 production – which the researchers could also stimulate with pharmacological drugs – will contribute to a cure for type 1 diabetes.

FDA’s new guidelines for stem cell treatments

Gottlieb

FDA Commissioner Scott Gottlieb

Yesterday Scott Gottlieb, the Commissioner at the US Food and Drug Administration (FDA), laid out some new guidelines for the way the agency regulates stem cells and regenerative medicine. The news was good for patients, not so good for clinics offering unproven treatments.

First the good. Gottlieb announced new guidelines encouraging innovation in the development of stem cell therapies, and faster pathways for therapies, that show they are both safe and effective, to reach the patient.

At the same time, he detailed new rules that provide greater clarity about what clinics can do with stem cells without incurring the wrath of the FDA. Those guidelines detail the limits on the kinds of procedures clinics can offer and what ways they can “manipulate” those cells. Clinics that go beyond those limits could be in trouble.

In making the announcement Gottlieb said:

“To be clear, we remain committed to ensuring that patients have access to safe and effective regenerative medicine products as efficiently as possible. We are also committed to making sure we take action against products being unlawfully marketed that pose a potential significant risk to their safety. The framework we’re announcing today gives us the solid platform we need to continue to take enforcement action against a small number of clearly unscrupulous actors.”

Many of the details in the announcement match what CIRM has been pushing for some years. Randy Mills, our previous President and CEO, called for many of these changes in an Op Ed he co-wrote with former US Senator Bill Frist.

Our hope now is that the FDA continues to follow this promising path and turns these draft proposals into hard policy.

 

Surprise findings about bone marrow transplants could lead to more effective stem cell therapies

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Surgery_0

Bone marrow transplant: Photo courtesy FierceBiotech

Some medical therapies have been around for so long that we naturally assume we understand how they work. That’s not always the case. Take aspirin for example. It’s been used for more than 4,000 years to treat pain and inflammation but it was only in the 1970’s that we really learned how it works.

The same is now true for bone marrow transplants. Thanks to some skilled research at the Fred Hutchinson Cancer Research Center in Seattle.

Bone marrow transplants have been used for decades to help treat deadly blood cancers such as leukemia and lymphoma. The first successful bone marrow transplant was in the late 1950’s, involving identical twins, one of whom had leukemia. Because the twins shared the same genetic make-up the transplant avoided potentially fatal problems like graft-vs-host-disease, where the transplanted cells attack the person getting them. It wasn’t until the 1970’s that doctors were able to perform transplants involving people who were not related or who did not share the same genetic make-up.

In a bone marrow or blood stem cell transplant, doctors use radiation or chemotherapy to destroy the bone marrow in a patient with, say, leukemia. Then cancer-free donor blood stem cells are transplanted into the patient to help create a new blood system, and rebuild their immune system.

Surprise findings

In the study, published in the journal Science Translational Medicine, the researchers were able to isolate a specific kind of stem cell that helps repair and rebuild the blood and immune system.

The team found that a small subset of blood stem cells, characterized by having one of three different kinds of protein on their surface – CD34 positive, CD45RA negative and CD90 positive – did all the work.

In a news release Dr. Hans-Peter Kiem, a senior author on the study, says some of their initial assumptions about how bone marrow transplants work were wrong:

“These findings came as a surprise; we had thought that there were multiple types of blood stem cells that take on different roles in rebuilding a blood and immune system. This population does it all.”

Tracking the cells

The team performed bone-marrow transplants on monkeys and then followed those animals over the next seven years, observing what happened as the donor cells grew and multiplied.

They tracked hundreds of thousands of cells in the blood and found that, even though the cells with those three proteins on the surface made up just five percent of the total blood supply, they were responsible for rebuilding the entire blood and immune system.

Study co-author Dr. Jennifer Adair said they saw evidence of this rebuilding within 10 days of the transplant:

“Our ability to track individual blood cells that developed after transplant was critical to demonstrating that these really are stem cells.”

Hope for the future

It’s an important finding because it could help researchers develop new ways of delivering bone marrow transplants that are both safer and more effective. Every year some 3,000 people die because they cannot find a matching donor. Knowing which stem cells are specifically responsible for an effective transplant could help researchers come up with ways to get around that problem.

Although this work was done in monkeys, the scientists say humans have similar kinds of stem cells that appear to act in the same way. Proving that’s the case will obviously be the next step in this research.