What to be thankful for this Thanksgiving: scientists hard at work

Biomedical technician Louis Pinedo feeds stem cells their special diet. Photo by Cedars-Sinai.

With Thanksgiving and Black Friday approaching in the next couple of days, we wanted to give thanks to all the scientists hard at work during this holiday weekend. Science does not sleep–the groundbreaking research and experiments that are being conducted do not take days off. There are tasks in the laboratory that need to be done daily otherwise months, even years, of important work can be lost in an instant.

Below is a story from Cedars-Sinai Medical Center that talks about one of these scientists, Louis Pinedo, that will be working during this holiday weekend.

Stem Cells Don’t Take the Day Off on Thanksgiving

Inside a Cedars-Sinai Laboratory, Where a Scientist Will be Busy Feeding Stem Cells During the Holiday

While most of us are stuffing ourselves with turkey and pumpkin pie at home on Thanksgiving Day, the staff at one Cedars-Sinai laboratory will be on the job, feeding stem cells.

“Stem cells do not observe national holidays,” says Loren Ornelas-Menendez, the manager of a lab that converts samples of adult skin and blood cells into stem cells—the amazing “factories” our bodies use to make our cells. These special cells help medical scientists learn how diseases develop and how they might be cured.

Stem cells are living creatures that must be hand-fed a special formula each day, monitored for defects and maintained at just the right temperature. And that means the cell lab is staffed every day, 52 weeks a year.

These cells are so needy that Ornelas-Menendez jokes: “Many people have dogs. We have stem cells.”

Millions of living stem cells are stored in the David and Janet Polak Foundation Stem Cell Core Laboratory at the Cedars-Sinai Board of Governors Regenerative Medicine Institute. Derived from hundreds of healthy donors and patients, they represent a catalogue of human ills, including diabetes, breast cancer, Alzheimer’s disease, Parkinson’s disease and Crohn’s disease.

Cedars-Sinai scientists rely on stem cells for many tasks: to make important discoveries about how our brains develop; to grow tiny versions of human tissues for research; and to create experimental treatments for blindness and neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) that they are testing in clinical trials.

The lab’s main collection consists of induced pluripotent stem cells, or iPSCs, which mimic the all-powerful stem cells we all had as embryos. These ingenious cells, which Cedars-Sinai scientists genetically engineer from adult cells, can make any type of cell in the body—each one matching the DNA of the donor. Other types of stem cells in the lab make only one or two kinds of cells, such as brain or intestinal cells.

Handy and versatile as they are, stem cells are high-maintenance. A few types, such as those that make connective tissue cells for wound healing, can be fed as infrequently as every few days. But iPSCs require a daily meal to stay alive, plus daily culling to weed out cells that have started to turn into cells of the gut, brain, breast or other unwanted tissues.

So each day, lab staff suit up and remove trays of stem cells from incubators that are set at a cozy 98.6 degrees. Peering through microscopes, they carefully remove the “bad” cells to ensure the purity of the iPSCs they will provide to researchers at Cedars-Sinai and around the world.

While the cells get sorted, a special feeding formula is defrosting in a dozen bottles spread around a lab bench. The formula incudes sodium, glucose, vitamins and proteins. Using pipettes, employees squeeze the liquid into food wells inside little compartments that contain the iPSCs. Afterward, they return the cells to their incubators.

The lab’s 10 employees are on a rotating schedule that ensures the lab is staffed on weekends and holidays, not just weekdays. On Thanksgiving Day this year, biomedical technician Louis Pinedo expects to make a 100-mile round trip from his home in Oxnard, California, to spend several hours at work, filling nearly 600 feeding wells. On both Christmas and New Year’s Day, two employees are expected to staff the lab.

All this ceaseless effort helps make Cedars-Sinai one of the world’s top providers of iPSCs, renowned for consistency and quality. Among the lab’s many clients are major universities and the global Answer ALS project, which is using the cells in its search for a cure for this devastating disease.

That’s why the lab’s director, Dhruv Sareen, PhD, suggests that before you sit down to your Thanksgiving feast, why not lift a glass to these hard-working lab employees?

“One day the cells they tend could lead to treatments for diseases that have plagued humankind for centuries,” he says. “And that’s something to be truly thankful for.”

Machine learning used to pattern stem cells – a vital step in organ modeling

Gladstone researchers discovered a method to control the patterns stem cells form in a dish. The work was led by Senior Investigator Todd McDevitt (left) and his team, including (pictured) David Joy and Ashley Libby.

When someone thinks of machine learning, the first thing that comes to mind might be the technology used by Netflix or Hulu to suggest new shows based on their viewing history. But what if this technology could be applied towards advancing the field of regenerative medicine?

Thanks to a CIRM funded study, a team of scientists lead by Dr. Todd McDevitt at the Gladstone Institutes have found a way to to use machine learning to control the spacial organization of stem cells, a key process that plays a vital role in organ development. This new understanding of how stem cells organize themselves in 3D is an important step towards being able to create functional and/or personalized organs for research or organ transplants.

“We’ve shown how we can leverage the intrinsic ability of stem cells to organize,” said Dr. McDevitt in a news release from Gladstone Institutes. “This gives us a new way of engineering tissues, rather than a printing approach where you try to physically force cells into a specific configuration.”

In their normal environment, stem cells are able to form patterns as they mature and over time morph into the tissues seen in an adult organism. One type of stem cell, called an induced pluripotent stem cell (iPSC), can become nearly every cell type of the body. In fact, researchers have already found ways to direct iPSCs to become various cell types such as those in the heart or brain.

Unfortunately, attempting to replicate the pattern formation of stem cells as they mature has been challenging. Some have used 3D printing to lay out stem cells in a desired shape, but the cells often migrated away from their initial locations.

In the same news release mentioned above, Ashley Libby, a graduate student at Gladstone and co-first author of this study, said that,

“Despite the importance of organization for functioning tissues, we as scientists have had difficulty creating tissues in a dish with stem cells. Instead of an organized tissue, we often get a disorganized mix of different cell types.”

To solve this problem, the scientists used a computational model to learn how to influence stem cells into forming new arrangements, such as those that might be useful in generating personalized organs.

Previous studies conducted by Dr. McDevitt showed that blocking the expression of two genes, called ROCK1 and CDH1, affected the layout of iPS cells grown in a petri dish.

In this current study, the scientists used CRISPR/Cas9 gene editing (you can read about this technology in more detail here) to block expression of ROCK1 and CDH1 at any time by adding a drug to the iPSCs. This was done to see if they could predict stem cell arrangement based on the alterations made to ROCK1 and CDH1 at different drug doses and time periods.

The team carried out various experiments with different doses and timing. Then, the data was input into a machine-learning program designed to identify patterns, something that could take a human months to identify.

(Left) video showing simulated interactions between different stem cell populations. (Right) image of stem cells grown in conditions dictated by the machine-learning program generate a colony that forms a bull’s-eye pattern, as predicted.

The machine-learning program used the data to predict ways that ROCK1 and CDH1 affect iPSC organization. The scientists then began to see whether the program could compute how to make entirely new patterns, like a bull’s-eye or an island of cells. The team says the results were little short of astounding. Machine learning was able to accurately predict conditions that will cause stem cell colonies to form desired patterns.

The full study was published in the journal Cell Systems.

Rare Disease, Type 1 Diabetes, and Heart Function: Breakthroughs for Three CIRM-Funded Studies

This past week, there has been a lot of mention of CIRM funded studies that really highlight the importance of the work we support and the different disease areas we make an impact on. This includes important research related to rare disease, Type 1 Diabetes (T1D), and heart function. Below is a summary of the promising CIRM-funded studies released this past week for each one of these areas.

Rare Disease

Comparison of normal (left) and Pelizaeus-Merzbacher disease (PMD) brains (right) at age 2. 

Pelizaeus-Merzbacher disease (PMD) is a rare genetic condition affecting boys. It can be fatal before 10 years of age and symptoms of the disease include weakness and breathing difficulties. PMD is caused by a disruption in the formation of myelin, a type of insulation around nerve fibers that allows electrical signals in the brain to travel quickly. Without proper signaling, the brain has difficulty communicating with the rest of the body. Despite knowing what causes PMD, it has been difficult to understand why there is a disruption of myelin formation in the first place.

However, in a CIRM-funded study, Dr. David Rowitch, alongside a team of researchers at UCSF, Stanford, and the University of Cambridge, has been developing potential stem cell therapies to reverse or prevent myelin loss in PMD patients.

Two new studies, of which Dr. Rowitch is the primary author, published in Cell Stem Cell, and Stem Cell Reports, respectively report promising progress in using stem cells derived from patients to identify novel PMD drugs and in efforts to treat the disease by directly transplanting neural stem cells into patients’ brains. 

In a UCSF press release, Dr. Rowitch talks about the implications of his findings, stating that,

“Together these studies advance the field of stem cell medicine by showing how a drug therapy could benefit myelination and also that neural stem cell transplantation directly into the brains of boys with PMD is safe.”

Type 1 Diabetes

Viacyte, a company that is developing a treatment for Type 1 Diabetes (T1D), announced in a press release that the company presented preliminary data from a CIRM-funded clinical trial that shows promising results. T1D is an autoimmune disease in which the body’s own immune system destroys the cells in the pancreas that make insulin, a hormone that enables our bodies to break down sugar in the blood. CIRM has been funding ViaCyte from it’s very earliest days, investing more than $72 million into the company.

The study uses pancreatic precursor cells, which are derived from stem cells, and implants them into patients in an encapsulation device. The preliminary data showed that the implanted cells, when effectively engrafted, are capable of producing circulating C-peptide, a biomarker for insulin, in patients with T1D. Optimization of the procedure needs to be explored further.

“This is encouraging news,” said Dr. Maria Millan, President and CEO of CIRM. “We are very aware of the major biologic and technical challenges of an implantable cell therapy for Type 1 Diabetes, so this early biologic signal in patients is an important step for the Viacyte program.”

Heart Function

Although various genome studies have uncovered over 500 genetic variants linked to heart function, such as irregular heart rhythms and heart rate, it has been unclear exactly how they influence heart function.

In a CIRM-funded study, Dr. Kelly Frazer and her team at UCSD studied this link further by deriving heart cells from induced pluripotent stem cells. These stem cells were in turn derived from skin samples of seven family members. After conducting extensive genome-wide analysis, the team discovered that many of these genetic variations influence heart function because they affect the binding of a protein called NKX2-5.

In a press release by UCSD, Dr. Frazer elaborated on the important role this protein plays by stating that,

“NKX2-5 binds to many different places in the genome near heart genes, so it makes sense that variation in the factor itself or the DNA to which it binds would affect that function. As a result, we are finding that multiple heart-related traits can share a common mechanism — in this case, differential binding of NKX2-5 due to DNA variants.”

The full results of this study were published in Nature Genetics.

CIRM funded study identifies potential drug target for deadly heart condition

Joseph Wu is co-senior author of a study that demonstrates how patient-derived heart cells can help scientists better study the heart and screen potential therapies. Photo courtesy of Steve Fisch

Heart disease continues to be the number one cause of death in the United States. An estimated 375,000 people have a genetic form of heart disease known as familial dilated cardiomyopathy. This occurs when the heart muscle becomes weakened in one chamber in the heart, causing the open area of the chamber to become enlarged or dilated. As a result of this, the heart can no longer beat regularly, causing shortness of breath, chest pain and, in severe cases, sudden and deadly cardiac arrest.

A diagram of a normal heart compared to one with the dilated cardiomyopathy

A CIRM funded study by a team of researchers at Stanford University looked further into this form of genetic heart disease by taking a patient’s skin cells and converting them into stem cells known as induced pluripotent stem cells (iPSCs), which can become any type of cell in the body. These iPSCs were then converted into heart muscle cells that pulse just as they do in the body. These newly made heart muscle cells beat irregularly, similar to what is observed in the genetic heart condition.

Upon further analysis, the researchers linked a receptor called PGDF to cause various genes to be more highly activated in the mutated heart cells compared to normal ones. Two drugs, crenolanib and sunitinib, interfere with the PGDF receptor. After treating the abnormal heart cells, they began beating more regularly, and their gene-activation patterns more closely matched those of cells from healthy donors.

These two drugs are already FDA-approved for treating various cancers, but previous work shows that the drugs may damage the heart at high doses. The next step would be determining the right dose of the drug. The current study is part of a broader effort by the researchers to use these patient-derived cells-in-a-dish to screen for and discover new drugs.

Dr. Joseph Wu, co-senior author of this study, and his team have generated heart muscle cells from over 1,000 patients, including those of Dr. Wu, his son, and his daughter. In addition to using skin cells, the same technique to create heart cells from patients can also be done with 10 milliliters of blood — roughly two teaspoons.

In a news release, Dr. Wu is quoted as saying,

“With 10 milliliters of blood, we can make clinically usable amounts of your beating heart cells in a dish…Our postdocs have taken my blood and differentiated my pluripotent stem cells into my brain cells, heart cells and liver cells. I’m asking them to test some of the medications that I might need to take in the future.”

The full results of this study were published in Nature.

Blood-brain barrier chip created with stem cells expands potential for personalized medicine

An Organ-Chip used in the study to create a blood-brain barrier (BBB).

The brain is a complex part of the human body that allows for the formation of thoughts and consciousness. In many ways it is the essence of who we are as individuals. Because of its importance, our bodies have developed various layers of protection around this vital organ, one of which is called the blood-brain barrier (BBB).

The BBB is a thin border of various cell types around the brain that regulate what can enter the brain tissue through the bloodstream. Its primary purpose is to prevent toxins and other unwanted substances from entering the brain and damaging it. Unfortunately this barrier can also prevent helpful medications, designed to fix problems, from reaching the brain.

Several brain disorders, such as Amyotrophic Lateral Sclerosis (ALS – also known as Lou Gehrig’s disease), Parkinson’s Disease (PD), and Huntington’s Disease (HD) have been linked to defective BBBs that keep out critical biomolecules needed for healthy brain activity.

In a CIRM-funded study, a team at Cedars-Sinai Medical Center created a BBB through the use of stem cells and an Organ-Chip made from induced pluripotent stem cells (iPSCs). These are a specific type of stem cells that can turn into any type of cell in the body and can be generated from a person’s own cells. In this study, iPSCs were created from adult blood samples and used to make the neurons and other supporting cells that make up the BBB. These cells were then placed inside an Organ-Chip which recreates the environment that cells normally experience within the human body.

Inside the 3-D Organ-Chip, the cells were able to form a BBB that functions as it does in the body, with the ability to block entry of certain drugs. Most notably, when the BBB was generated from cell samples of patients with HD, the BBB malfunctioned in the same way that it does in patients with the disease.

These findings expand the potential for personalized medicine for various brain disorders linked to problems in the BBB. In a press release, Dr. Clive Svendsen, director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute and senior author of the study, was quoted as saying,

“The study’s findings open a promising pathway for precision medicine. The possibility of using a patient-specific, multicellular model of a blood barrier on a chip represents a new standard for developing predictive, personalized medicine.”

The full results of the study were published in the scientific journal Cell Stem Cell.

First patient treated for colon cancer using reprogrammed adult cells

Dr. Sandip Patel (left) and Dr. Dan Kaufman (center) of UC San Diego School of Medicine enjoy a light-hearted moment before Derek Ruff (right) receives the first treatment for cancer using human-induced pluripotent stem cells (hiPSCs). Photo courtesy of UC San Diego Health.

For patients battling cancer for the first time, it can be quite a draining and grueling process. Many treatments are successful and patients go into remission. However, there are instances where the cancer returns in a much more aggressive form. Unfortunately, this was the case for Derek Ruff.

After being in remission for ten years, Derek’s cancer returned as Stage IV colon cancer, meaning that the cancer has spread from the colon to distant organs and tissues. According to statistics from Fight Colorectal Cancer, colorectal cancer is the 2nd leading cause of cancer death among men and women combined in the United States. 1 in 20 people will be diagnosed with colorectal cancer in their lifetime and it is estimated that there will be 140,250 new cases in 2019 alone. Fortunately, Derek was able to enroll in a groundbreaking clinical trial to combat his cancer.

In February 2019, as part of a clinical trial at the Moores Cancer Center at UC San Diego Health in collaboration with Fate Therapeutics, Derek became the first patient in the world to be treated for cancer with human-induced pluripotent stem cells (hiPSCs). hiPSCs are human adult cells, such as those found on the skin, that are reprogrammed into stem cells with the ability to turn into virtually any kind of cell. In this trial, hiPSCs were reprogrammed into natural killer (NK) cells, which are specialized immune cells that are very effective at killing cancer cells, and are aimed at treating Derek’s colon cancer.

A video clip from ABC 10 News San Diego features an interview with Derek and the groundbreaking work being done.

In a public release, Dr. Dan Kaufman, one of the lead investigators of this trial at UC San Diego School of Medicine, was quoted as saying,

“This is a landmark accomplishment for the field of stem cell-based medicine and cancer immunotherapy. This clinical trial represents the first use of cells produced from human induced pluripotent stem cells to better treat and fight cancer.”

In the past, CIRM has given Dr. Kaufman funding related to the development of NK cells. One was a $1.9 million grant for developing a different type of NK cell from hiPSCs, which could also potentially treat patients with lethal cancers. The second grant was a $4.7 million grant for developing NK cells from human embryonic stem cells (hESCs) to potentially treat patients with acute myelogenous leukemia (AML).

In the public release, Dr. Kaufman is also quoted as saying,

“This is a culmination of 15 years of work. My lab was the first to produce natural killer cells from human pluripotent stem cells. Together with Fate Therapeutics, we’ve been able to show in preclinical research that this new strategy to produce pluripotent stem cell-derived natural killer cells can effectively kill cancer cells in cell culture and in mouse models.”

Midwest universities are making important tools to advance stem cell research

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iPSCs are not just pretty, they’re also pretty remarkable

Two Midwest universities are making headlines for their contributions to stem cell research. Both are developing important tools to advance this field of study, but in two unique ways.

Scientists at the University of Michigan (UM), have compiled an impressive repository of disease-specific stem cell lines. Cell lines are crucial tools for scientists to study the mechanics of different diseases and allows them to do so without animal models. While animal models have important benefits, such as the ability to study a disease within the context of a living mammal, insights gained from such models can be difficult to translate to humans and many diseases do not even have good models to use.

The stem cell lines generated at the Reproductive Sciences Program at UM, are thanks to numerous individuals who donated extra embryos they did not use for in vitro fertilization (IVF). Researchers at UM then screened these embryos for abnormalities associated with different types of disease and generated some 36 different stem cell lines. These have been donated to the National Institute of Health’s (NIH) Human Embryonic Stem Cell Registry, and include cell lines for diseases such as cystic fibrosis, Huntington’s Disease and hemophilia.

Using one such cell line, Dr. Peter Todd at UM, found that the genetic abnormality associated with Fragile X Syndrome, a genetic mutation that results in developmental delays and learning disabilities, can be corrected by using a novel biological tool. Because Fragile X Syndrome does not have a good animal model, this stem cell line was critical for improving our understanding of this disease.

In the next state over, at the University of Wisconsin-Madison (UWM), researchers are doing similar work but using induced pluripotent stem cells (iPSCs) for their work.

The Human Stem Cell Gene Editing Service has proved to be an important resource in expediting research projects across campus. They use CRISPR-Cas9 technology (an efficient method to mutate or edit the DNA of any organism), to generate human stem cell lines that contain disease specific mutations. Researchers use these cell lines to determine how the mutation affects cells and/or how to correct the cellular abnormality the mutation causes. Unlike the work at UM, these stem cell lines are derived from iPSCs  which can be generated from easy to obtain human samples, such as skin cells.

The gene editing services at UWM have already proved to be so popular in their short existence that they are considering expanding to be able to accommodate off-campus requests. This highlights the extent to which both CRISPR technology and stem cell research are being used to answer important scientific questions to advance our understanding of disease.

CIRM also created an iPSC bank that researchers can use to study different diseases. The  Induced Pluripotent Stem Cell (iPSC) Repository is  the largest repository of its kind in the world and is used by researchers across the globe.

The iPSC Repository was created by CIRM to house a collection of stem cells from thousands of individuals, some healthy, but some with diseases such as heart, lung or liver disease, or disorders such as autism. The goal is for scientists to use these cells to better understand diseases and develop and test new therapies to combat them. This provides an unprecedented opportunity to study the cell types from patients that are affected in disease, but for which cells cannot otherwise be easily obtained in large quantities.

Hey, what’s the big idea? CIRM Board is putting up more than $16.4 million to find out

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David Higgins, CIRM Board member and Patient Advocate for Parkinson’s disease; Photo courtesy San Diego Union Tribune

When you have a life-changing, life-threatening disease, medical research never moves as quickly as you want to find a new treatment. Sometimes, as in the case of Parkinson’s disease, it doesn’t seem to move at all.

At our Board meeting last week David Higgins, our Board member and Patient Advocate for Parkinson’s disease, made that point as he championed one project that is taking a new approach to finding treatments for the condition. As he said in a news release:

“I’m a fourth generation Parkinson’s patient and I’m taking the same medicines that my grandmother took. They work but not for everyone and not for long. People with Parkinson’s need new treatment options and we need them now. That’s why this project is worth supporting. It has the potential to identify some promising candidates that might one day lead to new treatments.”

The project is from Zenobia Therapeutics. They were awarded $150,000 as part of our Discovery Inception program, which targets great new ideas that could have a big impact on the field of stem cell research but need some funding to help test those ideas and see if they work.

Zenobia’s idea is to generate induced pluripotent stem cells (iPSCs) that have been turned into dopaminergic neurons – the kind of brain cell that is dysfunctional in Parkinson’s disease. These iPSCs will then be used to screen hundreds of different compounds to see if any hold potential as a therapy for Parkinson’s disease. Being able to test compounds against real human brain cells, as opposed to animal models, could increase the odds of finding something effective.

Discovering a new way

The Zenobia project was one of 14 programs approved for the Discovery Inception award. You can see the others on our news release. They cover a broad array of ideas targeting a wide range of diseases from generating human airway stem cells for new approaches to respiratory disease treatments, to developing a novel drug that targets cancer stem cells.

Dr. Maria Millan, CIRM’s President and CEO, said the Stem Cell Agency supports this kind of work because we never know where the next great idea is going to come from:

“This research is critically important in advancing our knowledge of stem cells and are the foundation for future therapeutic candidates and treatments. Exploring and testing new ideas increases the chances of finding treatments for patients with unmet medical needs. Without CIRM’s support many of these projects might never get off the ground. That’s why our ability to fund research, particularly at the earliest stage, is so important to the field as a whole.”

The CIRM Board also agreed to invest $13.4 million in three projects at the Translation stage. These are programs that have shown promise in early stage research and need funding to do the work to advance to the next level of development.

  • $5.56 million to Anthony Oro at Stanford to test a stem cell therapy to help people with a form of Epidermolysis bullosa, a painful, blistering skin disease that leaves patients with wounds that won’t heal.
  • $5.15 million to Dan Kaufman at UC San Diego to produce natural killer (NK) cells from embryonic stem cells and see if they can help people with acute myelogenous leukemia (AML) who are not responding to treatment.
  • $2.7 million to Catriona Jamieson at UC San Diego to test a novel therapeutic approach targeting cancer stem cells in AML. These cells are believed to be the cause of the high relapse rate in AML and other cancers.

At CIRM we are trying to create a pipeline of projects, ones that hold out the promise of one day being able to help patients in need. That’s why we fund research from the earliest Discovery level, through Translation and ultimately, we hope into clinical trials.

The writer Victor Hugo once said:

“There is one thing stronger than all the armies in the world, and that is an idea whose time has come.”

We are in the business of finding those ideas whose time has come, and then doing all we can to help them get there.

 

 

 

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.

New study says stem cells derived from older people may have more problems than we thought.

heart muscle from iPS

iPS-generated heart muscle cells

Ever since 2006 when Japanese researcher Shinya Yamanaka showed that you could take an adult cell, such as those in your skin, and reprogram it to act like an embryonic stem cell, the scientific world has looked at these induced pluripotent stem (iPS) cells as a potential game changer. They had the ability to convert a person’s own cells into any other kind of cell in the body, potentially offering a way of creating personalized treatments for a wide variety of diseases.

Fears that this reprogramming method might create some cancer-causing genetic mutations seemed to have been eased when two recent studies suggested this approach is relatively safe and unlikely to lead to any tumors in patients. We funded one of those studies and blogged about it.

Reason for caution

But now a new study in the journal Cell Stem Cell  says “not so fast”. The study says the older the person is, the greater the chance that any iPS cells derived from their tissue could contain potentially harmful mutations, but not in the places you would normally think.

A team at Oregon Health and Science University, led by renowned scientist Shoukhrat Mitalipov, took skin and blood samples from a 72-year-old man. The scientists examined the DNA from those samples, then reprogrammed those cells into iPS cells, and examined the DNA from the new stem cells.

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Shoukhrat Mitalipov: photo courtesy Oregon Health and Science University

When they looked at the cells collectively the levels of mutations in the new iPS cells appeared to be quite low. But when they looked at individual cells, they noticed a wide variety of mutations in the mitochondria in those cells.

Now, mitochondria play an important role in the life of a cell. They act as a kind of battery, providing the power a cell needs to perform a variety of functions such as signaling and cell growth. But while they are part of the cell, mitochondria have their own genomes. It was here that the researchers found the mutations that raised questions.

Older cells have more problems

Next they repeated the experiment but this time took skin and blood samples from 14 people between the ages of 24 and 72. They found that  older people had more genetic mutations in their mitochondrial DNA that were then transferred to the iPS cells derived from those people. In some cases up to 80 percent of the iPS cell lines generated showed mitochondrial mutations. That’s really important because the greater the amount of mutated mitochondrial DNA in a cell, the more its ability to function is compromised.

In a news release, Mitalipov says this should cause people to pause before using iPS cells derived from an older person for therapeutic purposes:

“Pathogenic mutations in our mitochondrial DNA have long been thought to be a driving force in aging and age-related diseases, though clear evidence was missing. Now with that evidence at hand, we know that we must screen stem cells for mutations or collect them at younger age to ensure their mitochondrial genes are healthy. This foundational knowledge of how cells are damaged in the natural process of aging may help to illuminate the role of mutated mitochondria in degenerative disease.”

To be clear, the researchers are not saying these iPS cells from older people should never be used, only that they need to be carefully screened to ensure they are not seriously damaged before being transplanted into a patient.

A possible solution

Mitalipov suggests a simple way around the problem would be to identify the iPS cell with the best mitochondria, and then use that as the basis for a new cell line that could then be used to create a new therapy.

Taosheng Huang, a researcher at the Mitochondrial Disorders Program at Cincinnati Children’s Hospital Medical Center, is quoted in the news release saying the lesson is clear:

“If you want to use iPS cells in a human, you must check for mutations in the mitochondrial genome. Every single cell can be different. Two cells next to each other could have different mutations or different percentages of mutations.”