Stem cell therapy may help mend a broken heart

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 funds clinical trials targeting heart disease, stroke and childhood brain tumors

Gary Steinberg (Jonathan Sprague)

Heart disease and stroke are two of the leading causes of death and disability and for people who have experienced either their treatment options are very limited. Current therapies focus on dealing with the immediate impact of the attack, but there is nothing to deal with the longer-term impact. The CIRM Board hopes to change that by funding promising work for both conditions.

Dr. Gary Steinberg and his team at Stanford were awarded almost $12 million to conduct a clinical trial to test a therapy for motor disabilities caused by chronic ischemic stroke.  While “clot busting” therapies can treat strokes in their acute phase, immediately after they occur, these treatments can only be given within a few hours of the initial injury.  There are no approved therapies to treat chronic stroke, the disabilities that remain in the months and years after the initial brain attack.

Dr. Steinberg will use embryonic stem cells that have been turned into neural stem cells (NSCs), a kind of stem cell that can form different cell types found in the brain.  In a surgical procedure, the team will inject the NSCs directly into the brains of chronic stroke patients.  While the ultimate goal of the therapy is to restore loss of movement in patients, this is just the first step in clinical trials for the therapy.  This first-in-human trial will evaluate the therapy for safety and feasibility and look for signs that it is helping patients.

Another Stanford researcher, Dr. Crystal Mackall, was also awarded almost $12 million to conduct a clinical trial to test a treatment for children and young adults with glioma, a devastating, aggressive brain tumor that occurs primarily in children and young adults and originates in the brain.  Such tumors are uniformly fatal and are the leading cause of childhood brain tumor-related death. Radiation therapy is a current treatment option, but it only extends survival by a few months.

Dr. Crystal Mackall and her team will modify a patient’s own T cells, an immune system cell that can destroy foreign or abnormal cells.  The T cells will be modified with a protein called chimeric antigen receptor (CAR), which will give the newly created CAR-T cells the ability to identify and destroy the brain tumor cells.  The CAR-T cells will be re-introduced back into patients and the therapy will be evaluated for safety and efficacy.

Joseph Wu Stanford

Stanford made it three in a row with the award of almost $7 million to Dr. Joe Wu to test a therapy for left-sided heart failure resulting from a heart attack.  The major issue with this disease is that after a large number of heart muscle cells are killed or damaged by a heart attack, the adult heart has little ability to repair or replace these cells.  Thus, rather than being able to replenish its supply of muscle cells, the heart forms a scar that can ultimately cause it to fail.  

Dr. Wu will use human embryonic stem cells (hESCs) to generate cardiomyocytes (CM), a type of cell that makes up the heart muscle.  The newly created hESC-CMs will then be administered to patients at the site of the heart muscle damage in a first-in-human trial.  This initial trial will evaluate the safety and feasibility of the therapy, and the effect upon heart function will also be examined.  The ultimate aim of this approach is to improve heart function for patients suffering from heart failure.

“We are pleased to add these clinical trials to CIRM’s portfolio,” says Maria T. Millan, M.D., President and CEO of CIRM.  “Because of the reauthorization of CIRM under Proposition 14, we have now directly funded 75 clinical trials.  The three grants approved bring forward regenerative medicine clinical trials for brain tumors, stroke, and heart failure, debilitating and fatal conditions where there are currently no definitive therapies or cures.”

A new way to evade immune rejection in transplanting cells

Immune fluorescence of HIP cardiomyocytes in a dish; Photo courtesy of UCSF

Transplanting cells or an entire organ from one person to another can be lifesaving but it comes with a cost. To avoid the recipient’s body rejecting the cells or organ the patient has to be given powerful immunosuppressive medications. Those medications weaken the immune system and increase the risk of infections. But now a team at the University of California San Francisco (UCSF) have used a new kind of stem cell to find a way around that problem.

The cells are called HIP cells and they are a specially engineered form of induced pluripotent stem cell (iPSC). Those are cells that can be turned into any kind of cell in the body. These have been gene edited to make them a kind of “universal stem cell” meaning they are not recognized by the immune system and so won’t be rejected by the body.

The UCSF team tested these cells by transplanting them into three different kinds of mice that had a major disease; peripheral artery disease; chronic obstructive pulmonary disease; and heart failure.

The results, published in the journal Proceedings of the National Academy of Science, showed that the cells could help reduce the incidence of peripheral artery disease in the mice’s back legs, prevent the development of a specific form of lung disease, and reduce the risk of heart failure after a heart attack.

In a news release, Dr. Tobias Deuse, the first author of the study, says this has great potential for people. “We showed that immune-engineered HIP cells reliably evade immune rejection in mice with different tissue types, a situation similar to the transplantation between unrelated human individuals. This immune evasion was maintained in diseased tissue and tissue with poor blood supply without the use of any immunosuppressive drugs.”

Deuse says if this does work in people it may not only be of great medical value, it may also come with a decent price tag, which could be particularly important for diseases that affect millions worldwide.

“In order for a therapeutic to have a broad impact, it needs to be affordable. That’s why we focus so much on immune-engineering and the development of universal cells. Once the costs come down, the access for all patients in need increases.”

Meet the people who are changing the future

Kristin MacDonald

Every so often you hear a story and your first reaction is “oh, I have to share this with someone, anyone, everyone.” That’s what happened to me the other day.

I was talking with Kristin MacDonald, an amazing woman, a fierce patient advocate and someone who took part in a CIRM-funded clinical trial to treat retinitis pigmentosa (RP). The disease had destroyed Kristin’s vision and she was hoping the therapy, pioneered by jCyte, would help her. Kristin, being a bit of a pioneer herself, was the first person to test the therapy in the U.S.

Anyway, Kristin was doing a Zoom presentation and wanted to look her best so she asked a friend to come over and do her hair and makeup. The woman she asked, was Rosie Barrero, another patient in that RP clinical trial. Not so very long ago Rosie was legally blind. Now, here she was helping do her friend’s hair and makeup. And doing it beautifully too.

That’s when you know the treatment works. At least for Rosie.

There are many other stories to be heard – from patients and patient advocates, from researchers who develop therapies to the doctors who deliver them. – at our CIRM 2020 Grantee Meeting on next Monday September 14th Tuesday & September 15th.

It’s two full days of presentations and discussions on everything from heart disease and cancer, to COVID-19, Alzheimer’s, Parkinson’s and spina bifida. Here’s a link to the Eventbrite page where you can find out more about the event and also register to be part of it.

Like pretty much everything these days it’s a virtual event so you’ll be able to join in from the comfort of your kitchen, living room, even the backyard.

And it’s free!

You can join us for all two days or just one session on one day. The choice is yours. And feel free to tell your friends or anyone else you think might be interested.

We hope to see you there.

Stem Cell All-Stars, All For You

goldstein-larry

Dr. Larry Goldstein, UC San Diego

It’s not often you get a chance to hear some of the brightest minds around talk about their stem cell research and what it could mean for you, me and everyone else. That’s why we’re delighted to be bringing some of the sharpest tools in the stem cell shed together in one – virtual – place for our CIRM 2020 Grantee Meeting.

The event is Monday September 14th and Tuesday September 15th. It’s open to anyone who wants to attend and, of course, it’s all being held online so you can watch from the comfort of your own living room, or garden, or wherever you like. And, of course, it’s free.

BotaDaniela2261

Dr. Daniela Bota, UC Irvine

The list of speakers is a Who’s Who of researchers that CIRM has funded and who also happen to be among the leaders in the field. Not surprising as California is a global center for regenerative medicine. And you will of course be able to post questions for them to answer.

srivastava-deepak

Dr. Deepak Srivastava, Gladstone Institutes

The key speakers include:

Larry Goldstein: the founder and director of the UCSD Stem Cell Program talking about Alzheimer’s research

Irv Weissman: Stanford University talking about anti-cancer therapies

Daniela Bota: UC Irvine talking about COVID-19 research

Deepak Srivastava: Gladsone Institutes, talking about heart stem cells

Other topics include the latest stem cell approaches to COVID-19, spinal cord injury, blindness, Parkinson’s disease, immune disorders, spina bifida and other pediatric disorders.

You can choose one topic or come both days for all the sessions. To see the agenda for each day click here. Just one side note, this is still a work in progress so some of the sessions have not been finalized yet.

And when you are ready to register go to our Eventbrite page. It’s simple, it’s fast and it will guarantee you’ll be able to be part of this event.

We look forward to seeing you there.

Gladstone scientists respond to coronavirus pandemic

In these uncertain times, we often look to our top scientists for answers as well as potential solutions. But where does one begin to try and solve a problem of this magnitude? The first logical step is building on the supplies currently available, the work already accomplished, and the knowledge acquired.

This is the approach that the Gladstone Institutes in San Francisco is taking. Various scientists at this institution have shifted their current operations towards helping with the current coronavirus pandemic. These efforts have focused on helping with diagnostics, treatment, and prevention of COVID-19.

Diagnostics

Dr. Jennifer Doudna and Dr. Melanie Ott are collaborating in order to develop an effective method to rapidly diagnose those with COVID-19. Dr. Doudna’s work has focused on CRISPR technology, which we have talked about in detail in a previous blog post, while Dr. Ott has focused on studying viruses. By combining their expertises, these two scientists hope to develop a diagnostic tool capable of delivering rapid results and usable in areas such as airports, ports of entry, and remote communities.

Treatment

Dr. Nevan Krogan has discovered all of the human host cell proteins that COVID-19 interacts with to hijack the cell’s machinery. These proteins serve as new targets for potential drug therapies.

Since the high fatality rate of the virus is driven by lung and heart failure, Dr. Ott, Dr. Bruce Conklin, and Dr. Todd McDevitt will test effects of the virus and potential drug therapies in human lung organoids and human heart cells, both developed from human stem cells.

Dr. Warner Greene, who also focuses on the study of viruses, is screening a variety of FDA-approved drugs to identify those that could be rapidly repurposed as a treatment for COVID-19 patients or even as a preventive for high risk-groups.

Prevention

Dr. Leor Weinberger has developed a new approach to fight the spread of viruses. It is called therapeutic interfering particles (TIPs) and could be an alternative to a vaccine. TIPs are defective virus fragments that mimic the virus but are not able to replicate. They combat the virus by hijacking the cell machinery to transform virus-infected cells into factories that produce TIPS, amplifying the effect of TIPs in stopping the spread of virus. TIPs targeting COVID-19 would transmit along the same paths as the virus itself, and thus provide protection to even the most vulnerable populations.

You can read more about these groundbreaking projects in the news release linked here.

Of Mice and Men, and Women Too; Stem cell stories you might have missed

Mice brains can teach us a lot

Last week’s news headlines were dominated by one big story, the use of a stem cell transplant to effectively cure a person of HIV. But there were other stories that, while not quite as striking, did also highlight how the field is advancing.

A new way to boost brain cells (in mice!)

It’s hard to fix something if you don’t really know what’s wrong in the first place. It would be like trying to determine why a car is not working just by looking at the hood and not looking inside at the engine. The human brain is far more complex than a car so trying to determine what’s going wrong is infinitely more challenging. But a new study could help give us a new option.

Researchers in Luxembourg and Germany have developed a new computer model for what’s happening inside the brain, identifying what cells are not operating properly, and fixing them.

Antonio del Sol, one of the lead authors of the study – published in the journal Cell – says their new model allows them to identify which stem cells are active and ready to divide, or dormant. 

“Our results constitute an important step towards the implementation of stem cell-based therapies, for instance for neurodegenerative diseases. We were able to show that, with computational models, it is possible to identify the essential features that are characteristic of a specific state of stem cells.”

The work, done in mice, identified a protein that helped keep brain stem cells inactive in older animals. By blocking this protein they were able to help “wake up” those stem cells so they could divide and proliferate and help regenerate the aging brain.

And if it works in mice it must work in people right? Well, that’s what they hope to see next.

Deeper understanding of fetal development

According to the Mayo Clinic between 10 and 20 percent of known pregnancies end in miscarriage (though they admit the real number may be even higher) and our lack of understanding of fetal development makes it hard to understand why. A new study reveals a previously unknown step in this development that could help provide some answers and, hopefully, lead to ways to prevent miscarriages.

Researchers at the Karolinska Institute in Sweden used genetic sequencing to follow the development stages of mice embryos. By sorting those different sequences into a kind of blueprint for what’s happening at every stage of development they were able to identify a previously unknown phase. It’s the time between when the embryo attaches to the uterus and when it begins to turn these embryonic stem cells into identifiable parts of the body.

Qiaolin Deng, Karolinska Institute

Lead researcher Qiaolin Deng says this finding provides vital new evidence.

“Being able to follow the differentiation process of every cell is the Holy Grail of developmental biology. Knowledge of the events and factors that govern the development of the early embryo is indispensable for understanding miscarriages and congenital disease. Around three in every 100 babies are born with fetal malformation caused by faulty cellular differentiation.”

The study is published in the journal Cell Reports.

Could a new drug discovery reduce damage from a heart attack?

Every 40 seconds someone in the US has a heart attack. For many it is fatal but even for those who survive it can lead to long-term damage to the heart that ultimately leads to heart failure. Now British researchers think they may have found a way to reduce that likelihood.

Using stem cells to create human heart muscle tissue in the lab, they identified a protein that is activated after a heart attack or when exposed to stress chemicals. They then identified a drug that can block that protein and, when tested in mice that had experienced a heart attack, they found it could reduce damage to the heart muscle by around 60 percent.

Prof Michael Schneider, the lead researcher on the study, published in Cell Stem Cell, said this could be a game changer.

“There are no existing therapies that directly address the problem of muscle cell death and this would be a revolution in the treatment of heart attacks. One reason why many heart drugs have failed in clinical trials may be that they have not been tested in human cells before the clinic. Using both human cells and animals allows us to be more confident about the molecules we take forward.”

A new and improved method for making healthy heart tissue is here

Scientists from the Gladstone Institutes have done it again. They’ve made a better and faster way of generating healthy heart tissue in mice with damaged hearts. With further advancements, their findings could potentially be translated into a new way of treating heart failure in patients.

Previously, the Gladstone team discovered that they could transform scar tissue in the damaged hearts of mice into healthy, beating heart muscle cells by a process called direct reprogramming. The team found that turning on three transcription factors, Gata4, Mef2c and Tbx5 (collectively called GMT), in the damaged hearts of mice activated heart genes that turned scar tissue cells, also known as cardiac fibroblasts, into beating heart cells or cardiomyocytes.

Their GMT direct cardiac reprogramming technology was only able to turn 10 percent of cardiac fibroblasts into cardiomyocytes in mice over the period of six to eight week. In their new CIRM-funded study published in Circulation, they improved upon their original reprogramming method by identifying two chemicals that improved the efficiency of making new heart cells. Not only were they able to create eight times the number of beating cardiomyocytes from mouse cardiac fibroblasts, but they were also able to speed up the reprogramming process to a period of just one week.

To find these chemicals, they screened a library of 5,500 small molecules. The chemicals that looked most promising for cardiac reprogramming were inhibitors of the TGF-β and WNT signaling pathways. The importance of these chemicals was explained in a Gladstone news release:

“The first chemical inhibits a growth factor that helps cells grow and divide and is important for repairing tissue after injury. The second chemical inhibits an important pathway that regulates heart development. By combining the two chemicals with GMT, the researchers successfully regenerated heart muscle and greatly improved heart function in mice that had suffered a heart attack.”

Senior author on the study, Deepak Srivastava, further explained:

“While our original process for direct cardiac reprogramming with GMT has been promising, it could be more efficient. With our screen, we discovered that chemically inhibiting two biological pathways active in embryonic formation improves the speed, quantity, and quality of the heart cells produced from our original process.”

Encouraged by their studies in mice, the scientists also tested their new and improved direct reprogramming method on human cells. Previously they found that while the same GMT transcription factors could reprogram human cardiac fibroblasts into cardiomyocytes, a combination of seven factors was required to make quality cardiomyocytes comparable to those seen in mice. But with the addition of the two inhibitors, they were able to reduce the number of reprogramming factors from seven to four, which included the GMT factors and one additional factor called Myocardin. These four factors plus the two chemical inhibitors were capable of reprograming human cardiac fibroblasts into beating heart cells.

With heart failure affecting more than 20 million people globally, the need for new therapies that can regenerate the heart is pressing. The Gladstone team is hoping to advance their research to a point where it could be tested in human patients with heart failure. First author on the study, Tamer Mohamed, concluded:

“Heart failure afflicts many people worldwide, and we still do not have an effective treatment for patients suffering from this disease. With our enhanced method of direct cardiac reprogramming, we hope to combine gene therapy with drugs to create better treatments for patients suffering from this devastating disease.”

Tamer Mohamed and Deepak Srivastava, Gladstone Institutes

Tamer Mohamed and Deepak Srivastava. Photo courtesy of Chris Goodfellow, Gladstone Institutes


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Using skin cells to repair damaged hearts

heart-muscle

Heart muscle  cells derived from skin cells

When someone has a heart attack, getting treatment quickly can mean the difference between life and death. Every minute delay in getting help means more heart cells die, and that can have profound consequences. One study found that heart attack patients who underwent surgery to re-open blocked arteries within 60 minutes of arriving in the emergency room had a six times greater survival rate than people who had to wait more than 90 minutes for the same treatment.

Clearly a quick intervention can be life-saving, which means an approach that uses a patient’s own stem cells to treat a heart attack won’t work. It simply takes too long to harvest the healthy heart cells, grow them in the lab, and re-inject them into the patient. By then the damage is done.

Now a new study shows that an off-the-shelf approach, using donor stem cells, might be the most effective way to go. Scientists at Shinshu University in Japan, used heart muscle stem cells from one monkey, to repair the damaged hearts of five other monkeys.

In the study, published in the journal Nature, the researchers took skin cells from a macaque monkey, turned those cells into induced pluripotent stem cells (iPSCs), and then turned those cells into cardiomyocytes or heart muscle cells. They then transplanted those cardiomyocytes into five other monkeys who had experienced an induced heart attack.

After 3 months the transplanted monkeys showed no signs of rejection and their hearts showed improved ability to contract, meaning they were pumping blood around the body more powerfully and efficiently than before they got the cardiomyocytes.

It’s an encouraging sign but it comes with a few caveats. One is that the monkeys used were all chosen to be as close a genetic match to the donor monkey as possible. This reduced the risk that the animals would reject the transplanted cells. But when it comes to treating people, it may not be feasible to have a wide selection of heart stem cell therapies on hand at every emergency room to make sure they are a good genetic match to the patient.

The second caveat is that all the transplanted monkeys experienced an increase in arrhythmias or irregular heartbeats. However, Yuji Shiba, one of the researchers, told the website ResearchGate that he didn’t think this was a serious issue:

“Ventricular arrhythmia was induced by the transplantation, typically within the first four weeks. However, this post-transplant arrhythmia seems to be transient and non-lethal. All five recipients of [the stem cells] survived without any abnormal behaviour for 12 weeks, even during the arrhythmia. So I think we can manage this side effect in clinic.”

Even with the caveats, this study demonstrates the potential for a donor-based stem cell therapy to treat heart attacks. This supports an approach already being tested by Capricor in a CIRM-funded clinical trial. In this trial the company is using donor cells, derived from heart stem cells, to treat patients who developed heart failure after a heart attack. In early studies the cells appear to reduce scar tissue on the heart, promote blood vessel growth and improve heart function.

The study from Japan shows the possibilities of using a ready-made stem cell approach to helping repair damage caused by a heart attacks. We’re hoping Capricor will take it from a possibility, and turn it into a reality.

If you would like to read some recent blog posts about Capricor go here and here.

Ready, Set, Go: CIRM funded clinical trial for heart disease finishes patient enrollment

Heart disease is the leading cause of death in the United States with over 600,000 deaths occurring per year. Patients with heart disease or heart failure are given treatments that attempt to prevent their condition from getting worse or improve some of their symptoms. However, no treatment exists that can completely restore their heart function except for having a heart transplant – a risky procedure that has significant obstacles associated with it including transplant rejection and limited donor availability.

Regenerative medicine research for heart disease is an up-and-coming field. Scientist and companies are testing stem cell-based therapies to treat patients with heart disease in hopes of improving or restoring heart function.

capricor

CIRM is funding a company called Capricor Therapeutics located in Los Angeles, California, that’s testing a stem cell-based therapy in a Phase II clinical trial for cardiac dysfunction called ALLSTAR (ALLogeneic Heart STem Cells to Achieve Myocardial Regeneration).  The treatment is called  CAP-1002, which is an infusion of allogeneic cardiosphere-derived cells (CDCs). Capricor has shown that CDCs can regenerate tissue in the injured human heart in a previous Phase I clinical trial called CADUCEUS, which treated patients one to three months after they had a heart attack.

This week, Capricor reported that it has passed another milestone in the ALLSTAR trial and finished patient enrollment. Compared to the CADUCEUS trial, the patient population in ALLSTAR was expanded to include individuals that had a heart attack in the past 12 months. The purpose of this expanded patient population is to determine whether CAP-1002 is beneficial to patients with older heart injuries. A total of 142 patients were enrolled in the trial and 134 of those patients received either a single injection of CAP-1002 or a placebo treatment into their coronary artery associated with the heart injury.

In a news release, Capricor President and CEO Linda Marban explained the logic behind the CADUCEUS and ALLSTAR trials for cardiac dysfunction:

Linda Marban, CEO of Capricor Therapeutics

Linda Marban, CEO of Capricor Therapeutics

“As we and others have shown, CAP-1002 possesses the ability to promote therapeutic regeneration in the injured heart, a powerful concept for the treatment of heart disease. In the CADUCEUS clinical trial, CDCs decreased scar size and increased viable tissue in the hearts of patients who had suffered a large heart attack. In ALLSTAR, not only are we studying a population similar to the one that delivered such astounding results in CADUCEUS (30 – 90 days post-MI), but we have also included patients that were 91 – 365 days post-MI to see if we could extend the indication window. We have also moved to an allogeneic platform from autologous cells.”

ALLSTAR patients will be monitored carefully over the next year to make sure the CAP-1002 treatment is safe. After a year, Capricor will assess the potential regenerative capacity of CAP-1002 by measuring the size of the heart injury and looking for a reduction in scar tissue using magnetic resonance imaging (MRI).

“With the last patient in ALLSTAR having been dosed on September 30th, we expect to report top-line 12-month primary efficacy outcome results in the fourth quarter of 2017,” said Marban. “We are very much looking forward to seeing the results of the ALLSTAR trial because they may show, for the first time in a Phase II clinical trial, that cells can reduce scar and potentially improve outcomes.”

CIRM is also funding another clinical trial by Capricor that’s evaluating CAP-1002 in young boys with cardiomyopathy – diseases that affect heart muscle – resulting from Duchenne muscular dystrophy. The Phase I/II trial called HOPE recently completed its patient enrollment and you can read more about it here on the Stem Cellar.


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