Stem cell stories that caught our eye: two studies of the heart and cool stem cell art

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Image from Scope Blog.

Image from Scope Blog.

Understanding Heart Defects. Healthy heart tissue is made up of smooth, solid muscle, which is essential for normal heart function. Patients with a heart defect called left ventricular non-compaction (LVNC), lack normal heart tissue in their left ventricle – the largest, strongest blood-pumping chamber – and instead have spongy-looking tissue.

LVNC occurs during early heart development where pieces of heart muscle fail to condense (compact) and instead form an airy, sponge-like network that can leave patients at risk for heart failure and other complications.

A team at Stanford is interested in learning how LVNC occurs in humans, and they’re using human stem cells for the answer. Led by CIRM grantee Joe Wu, the scientists generated induced pluripotent stem cells (iPSCs) from four patients with LVNC. iPSCs are cells that can be turned into any other cell in the body, so Wu turned these cells into iPSC-derived heart muscle in a dish.

Wu’s team was particularly interested in determining why some LVNC patients have symptoms of disease while others seem perfectly normal. After studying the heart muscle cells derived from the four LVNC patients, they identified a genetic mutation in a gene called TBX20. This gene produces a type of protein called a cardiac transcription factor, which controls the expression of other heart related genes.

Upon further exploration, the scientists found that the genetic mutation in TBX20 prevented LVNC heart muscle cells from dividing at their normal rate. If they blocked the signal of mutant TBX20, the heart cells went back to their normal activity and created healthy looking heart tissue.

This study was published in Nature Cell Biology and covered by the Stanford Medicine Scope blog. In an interview with Scope, Joe Wu highlighted the big picture of their work:

Joseph Wu Stanford

Joseph Wu Stanford

“This study shows the feasibility of modeling such developmental defects using human tissue-specific cells, rather than relying on animal cells or animal models. It opens up an exciting new avenue for research into congenital heart disease that could help literally the youngest — in utero — patients.”

Stem Cell Heart Patch. Scientists from the University of Wisconsin, Madison are creating stem cell-based heart patches that they hope one day could be used to treat heart disease.

In a collaboration with Duke and the University of Alabama at Birmingham, they’re developing 3D stem cell-derived patches that contain the three main cell types found in the heart: cardiomyocytes (heart muscle cells), fibroblasts (support cells), and endothelial cells (cells that line the insides of blood vessels). These patches would be transplanted into heart disease patients to replace damaged heart tissue and improve heart function.

As with all research that has the potential for reaching human patients, the scientists must first determine whether the heart patches are safe in animal models. They plan to transplant the heart patches into a pig model – chosen because pigs have similar sized hearts compared to humans.

In a UW-Madison News release, the director of the UW-Madison Stem Cell and Regenerative Medicine Center Timothy Kamp, hinted at the potential for this technology to reach the clinic.

“The excitement here is we’re moving closer to patient applications. We’re at a stage when we need to see how these cells do in a large animal heart attack model. We’ll be making patches of heart muscle that can be applied to these injured areas.”

Kamp and his team still have a lot of work to do to perfect their heart patch technology, but they are thinking ahead. Two issues that they are trying to address are how to prevent a patient’s immune system from rejecting the heart patch transplant, and how to make sure the heart patches beat in sync with the heart they are transplanted into.

Check out the heart patches in action in this video:

(Video courtesy of Xiaojun Lian)

Cool Stem Cell Art! When I was a scientist, I worked with stem cells all the time. I grew them in cell culture dishes, coaxed them to differentiate into brain cells, and used a technique called immunostaining to take really beautiful, colorful pictures of my final cell products. I took probably thousands of pictures over my PhD and postdoc, but sadly, only a handful of these photos ever made it into journal publications. The rest collected dust either on my hard drive or in my lab notebook.

It’s really too bad that at the time I didn’t know about this awesome stem cell art contest called Cells I See run by the Centre for Commercialization of Regenerative Medicine (CCRM) in Ontario Canada and sponsored by the Stem Cell Network.

The contest “is about the beauty of stem cells and biomaterials, seen directly through the microscope or through the interpretive lens of the artist.” Scientists can submit their most prized stem cell images or art, and the winner receives a cash prize and major science-art street cred.

The submission deadline for this year’s contest was earlier this month, and you can check out the contenders on CCRM’s Facebook page. Even better, you can vote for your favorite image or art by liking the photo. The last date to vote is October 15th and the scientist whose image has the most likes will be the People’s Choice winner. CCRM will also crown a Grand Prize winner at the Till & McCulloch Stem Cell Meeting in October.

I’ll leave you with a few of my favorite photos, but please don’t let this bias your vote =)!

"Icy Astrocytes" by Samantha Yammine

“Icy Astrocytes” by Samantha Yammine (Vote here!)

"Reaching for organoids" by Amy Wong

“Reaching for organoids” by Amy Wong (Vote here!)

"Iris" by Sabiha Hacibekiroglu

“Iris” by Sabiha Hacibekiroglu (Vote here!)

Out of the mouths, or in this case hearts, of babes comes a hopeful therapy for heart attack patients

Pediatric-Congenital-Heart-Disease-patient-300x200

Lessons learned from babies with heart failure could now help adults

Inspiration can sometimes come from the most unexpected of places. For English researcher Stephen Westaby it came from seeing babies who had heart attacks bounce back and recover. It led Westaby to a new line of research that could offer hope to people who have had a heart attack.

Westaby, a researcher at the John Radcliffe hospital in Oxford, England, found that implanting a novel kind of stem cell in the hearts of people undergoing surgery following a heart attack had a surprisingly significant impact on their recovery.

Westaby got his inspiration from studies showing babies who had a heart attack and experienced scarring on their heart, were able to bounce back and, by the time they reached adolescence, had no scarring. He wondered if it was because the babies’ own heart stem cells were able to repair the damage.

Scarring is a common side effect of a heart attack and affects the ability of the heart to be able to pump blood efficiently around the body. As a result of that diminished pumping ability people have less energy, and are at increased risk of further heart problems. For years it was believed this scarring was irreversible. This study, published in the Journal of Cardiovascular Translational Research, suggests it may not be.

Westaby and his team implanted what they describe as a “novel mesenchymal precursor (iMP)” type of stem cell in the hearts of patients who were undergoing heart bypass surgery following a heart attack. The cells were placed in parts of the heart that showed sizeable scarring and poor blood flow.

Two years later the patients showed a 30 percent improvement in heart function, a 40 percent reduction in scar size, and a 70 percent improvement in quality of life.

In an interview with the UK Guardian newspaper, Westaby admitted he was not expecting such a clear cut benefit:

“Quite frankly it was a big surprise to find the area of scar in the damaged heart got smaller,”

Of course it has to be noted that the trial was small, only involving 11 patients. Nonetheless the findings are important and impressive. Westaby and his team now hope to do a much larger study.

CIRM is funding a clinical trial with Capricor that is taking a similar approach, using stem cells to rejuvenate the hearts of patients who have had heart attacks.

Fred Lesikar, one of the patient’s in the first phase of that trial, experienced a similar benefit to those in the English trial and told us about it in our Stories of Hope.

Spotlight on CIRM Grantee Joe Wu: Clinical Trials for Heart Disease in a Dish?

It’s always exciting to read a science article featuring a talented scientist who is breaking boundaries in the field of regenerative medicine. It’s especially exciting to us at CIRM when the scientist is a CIRM grantee.

Last week, OZY published a fun and inspiring piece on Stanford scientist Joe Wu. Dr. Wu is the Director of the Stanford Cardiovascular Institute and his lab studies how stem cells (both adult and pluripotent) function and how they can be used to model heart diseases and screen for new drug therapies. He also is a CIRM grantee and has a Disease Team Therapy Development grant that aims to clinically test human embryonic stem cell-derived cardiomyocytes (heart cells) in end stage heart failure patients.

Dr. Joe Wu. (Image Source: Sean Culligan/OZY)

Dr. Joe Wu. (Image Source: Sean Culligan/OZY)

The OZY piece does a great job of highlighting Dr. Wu’s recent efforts to use human induced pluripotent stem cells (iPS cells) to make heart tissue in a dish and model cardiovascular disease. And without getting too technical, the article explains Dr. Wu’s larger mission to combine precision medicine and stem cell research to identify drugs that would be best suited for specific patient populations.

The article commented,

“He envisions treatments based on an individual’s own iPS cells. For example, a popular breast cancer drug has an 8 percent chance of giving patients heart failure. In Wu’s world, we’d test the drug on stem cells first, and if a patient lands in that 8 percent, begin treatment for the side effects preemptively or avoiding the drug totally and avoiding heart failure, too.”

Basically, Dr. Wu sees the future of clinical trials in a dish using human stem cells. “His goal is to take these stem cells from thousands of patients to create a genetically diverse enough bank that will allow for “clinical trials in a dish” — Wu’s go-to phrase.”

Instead of following the traditional drug development paradigm that takes more than 10 years, billions of dollars, and unfortunately usually ends in failure, Dr. Wu wants to follow an accelerated path where stem cells are used for drug toxicity and efficacy testing.

This alternative path could improve overall drug development and approval by the FDA. The article explained,

“Testing drugs on stem cells will give big pharma and the FDA vastly improved heads up for toxic complications. Stem cells are “absolutely” the best avenue going forward, says Norman Stockbridge, director of the division of cardiovascular and renal products at the FDA’s Center for Drug Evaluation and Research.”

Not everyone is on the same page with Dr. Wu’s bold vision of the future of precision medicine, stem cells, and treatments for heart disease. Some believe he is overly ambitious, however top scientists in the stem cell field have praised Dr. Wu’s “systematic approach” to research and how he doesn’t stop at data discovery, he focuses on the big picture and how his work can ultimately help patients.

You can read more about Dr. Wu’s research on his lab website and I highly encourage you to check out the OZY article which is a great example of science communication for the general public.


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Rare disease underdogs come out on top at CIRM Board meeting

 

It seems like an oxymoron but one in ten Americans has a rare disease. With more than 7,000 known rare diseases it’s easy to see how each one could affect thousands of individuals and still be considered a rare or orphan condition.

Only 5% of rare diseases have FDA approved therapies

rare disease

(Source: Sermo)

People with rare diseases, and their families, consider themselves the underdogs of the medical world because they often have difficulty getting a proper diagnosis (most physicians have never come across many of these diseases and so don’t know how to identify them), and even when they do get a diagnosis they have limited treatment options, and those options they do have are often very expensive.  It’s no wonder these patients and their families feel isolated and alone.

Rare diseases affect more people than HIV and Cancer combined

Hopefully some will feel less isolated after yesterday’s CIRM Board meeting when several rare diseases were among the big winners, getting funding to tackle conditions such as ALS or Lou Gehrig’s disease, Severe Combined Immunodeficiency or SCID, Canavan disease, Tay-Sachs and Sandhoff disease. These all won awards under our Translation Research Program except for the SCID program which is a pre-clinical stage project.

As CIRM Board Chair Jonathan Thomas said in our news release, these awards have one purpose:

“The goal of our Translation program is to support the most promising stem cell-based projects and to help them accelerate that research out of the lab and into the real world, such as a clinical trial where they can be tested in people. The projects that our Board approved today are a great example of work that takes innovative approaches to developing new therapies for a wide variety of diseases.”

These awards are all for early-stage research projects, ones we hope will be successful and eventually move into clinical trials. One project approved yesterday is already in a clinical trial. Capricor Therapeutics was awarded $3.4 million to complete a combined Phase 1/2 clinical trial treating heart failure associated with Duchenne muscular dystrophy with its cardiosphere stem cell technology.  This same Capricor technology is being used in an ongoing CIRM-funded trial which aims to heal the scarring that occurs after a heart attack.

Duchenne muscular dystrophy (DMD) is a genetic disorder that is marked by progressive muscle degeneration and weakness. The symptoms usually start in early childhood, between ages 3 and 5, and the vast majority of cases are in boys. As the disease progresses it leads to heart failure, which typically leads to death before age 40.

The Capricor clinical trial hopes to treat that aspect of DMD, one that currently has no effective treatment.

As our President and CEO Randy Mills said in our news release:

Randy Mills, Stem Cell Agency President & CEO

Randy Mills, Stem Cell Agency President & CEO

“There can be nothing worse than for a parent to watch their child slowly lose a fight against a deadly disease. Many of the programs we are funding today are focused on helping find treatments for diseases that affect children, often in infancy. Because many of these diseases are rare there are limited treatment options for them, which makes it all the more important for CIRM to focus on targeting these unmet medical needs.”

Speaking on Rare Disease Day (you can read our blog about that here) Massachusetts Senator Karen Spilka said that “Rare diseases impact over 30 Million patients and caregivers in the United States alone.”

Hopefully the steps that the CIRM Board took yesterday will ultimately help ease the struggles of some of those families.

A cardiac love triangle: how transcription factors interact to make a heart

 Here’s a heartfelt science story for all those Valentine’s day fans out there. Scientists from the Gladstone Institutes have identified how a group of transcription factors interact during embryonic development to make a healthy heart. Their work will increase our biological understanding of how the heart is formed and could produce new methods for treating cardiovascular disease.

The study, published today in the journal Cell, describes a tumultuous love story between cardiac transcription factors. Transcription factors are proteins that orchestrate gene expression. They have the power to turn genes on or off by binding to specific DNA sequences and recruiting other proteins that will eventually turn the information encoded in that gene into a functional protein.

Every organ has its own special group of transcription factors that coordinate the gene expression required for that organ’s development. Often times, transcription factors within a group directly interact with each other and work together to conduct a specific sequence of events. These interactions are essential for making healthy tissues and organs, but scientists don’t always understand how these interactions work.

For the heart, scientists have already identified a group of transcription factors essential for cardiac development, and genetic mutations in any of these factors can impair heart formation and cause heart defects in newborns. What’s not known, however, are the details on how some of these cardiac transcription factors interact to get their job done.

A cardiac love triangle

In the Gladstone study, the scientists focused on how three key cardiac transcription factors – NKX2.5, TBX5, and GATA4 – interact during heart development. They first proved that these transcription factors are essential for the formation of the heart in mouse embryos. When they eliminated the presence of one of the three factors from the developing mouse embryo, they observed abnormal heart development and heart defects. When they removed two factors (NKX2.5 and TBX5), the results were even worse – the heart wasn’t able to form and none of the embryos survived.

Normal heart muscle cells, courtesy Kyoto University

Normal cardiomyocytes or heart cells, courtesy Kyoto University

Next, they studied how these transcription factors interact to coordinate gene expression in heart cells called cardiomyocytes made from mouse embryonic stem cells that lacked either NKX2.5, TBX5, or both of these factors. Compared to normal heart cells, cardiomyocytes that lacked one or both of these two transcription factors started beating at inappropriate times – either earlier or later than the normal heart cells.

Taking a closer look, the scientists discovered that TBX5, NKX2.5 and GATA4 all hangout in the same areas of the genome in embryonic stem cells that are transitioning into cardiomyocytes. In fact, each individual transcription factor required the presence of the others to bind their DNA targets. If one of these factors was missing and the love triangle was broken, the remaining transcription factors became confused and bound random DNA sequences in the genome, causing a mess by turning on genes that shouldn’t be on.

First author on the study, Luis Luna-Zurita, explained the importance of maintaining this cardiac love triangle in a Gladstone Press Release:

Luis Luna-Zurita, Gladstone Institute

Luis Luna-Zurita, Gladstone Institute

“Transcription factors have to stick together, or else the other one goes and gets into trouble. Not only are these transcription factors vital for turning on certain genes, but their interaction is important to keep each other from going to the wrong place and turning on a set of genes that doesn’t belong in a heart cell.”

Crystal structure tells all

Protein crystal structure of NKX2.5 and TBX5 bound to DNA.

Protein crystal structure of NKX2.5 and TBX5 bound to DNA. (Luna-Zurita et al. 2016)

The last part of the study proved that two of these factors, NKX2.5 and TBX5, directly interact and physically touch each other when they bind their DNA targets. In collaboration with a group from the European Molecular Biology Laboratory (EMBL) in Germany, they developed protein crystal structures to model the molecular structure of these transcription factors when they bind DNA.

Co-author and EMBL scientist Christoph Muller explained his findings:

“The crystal structure critically shows the interaction between two of the transcription factors and how they influence one another’s binding to a specific stretch of DNA. Our detailed structural analysis revealed a direct physical connection between TBX5 and NKX2-5 and demonstrated that DNA plays an active role in mediating the interaction between the two proteins.”

Big picture

While this study falls in the discovery research category, its findings increase our understanding of the steps required to make a healthy heart and sheds light on what goes wrong in patients or newborns with heart disease.

Senior author on the paper and Gladstone Professor Benoit Bruneau explained the biomedical applications of their study for treating human disease:

DSC_0281_2

Benoit Bruneau, Gladstone Institute

“Gene mutations that cause congenital heart disease lower the levels of these transcription factors by half, and we’ve shown that the dosage of these factors determines which genes are turned on or off in a cell. Other genetic variants that cause heart defects like arrhythmias also affect the function of these factors. Therefore, the better we understand these transcription factors, the closer we’ll come to a treatment for heart disease. Our colleagues at Gladstone are using this knowledge to search for small molecules that can affect gene regulation and reverse some of the problems caused by the loss of these transcription factors.”

 

I think it’s worth mentioning that these studies were done using mouse embryos and mouse embryonic stem cells. Future work should be done to determine whether this cardiac love triangle and the same transcription factor interactions exist in human heart cells.


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CIRM Scholar Jessica Gluck on using stem cells to make biological pacemakers for the heart

As part of our CIRM scholar series, we feature the research accomplishments of students and postdocs that have received CIRM funding.

Jessica Gluck, CIRM Scholar

Jessica Gluck, CIRM Scholar

I’d like to introduce you to one of our CIRM Scholars, Jessica Gluck. She’s currently a Postdoctoral Fellow at UC Davis working on human stem cell models of heart development. Jessica began her education in textiles and materials science at North Carolina State University, but that developed into a passion for biomedical engineering and stem cell research, which she pursued during her PhD at UC Los Angeles. During her graduate research, Jessica developed 3D bio-scaffolds that help human stem cells differentiate into functioning heart cells.

We asked Jessica to discuss her latest foray in the fields of stem cells and heart development.


Q: What are you currently working on in the lab?

JG: I work as a postdoc at UC Davis in the lab of Deborah Lieu. She’s working on developing pacemaking cardiomyocytes (heart cells) from human induced pluripotent stem cells (iPS cells). Pacemaking cells are the cells of the heart that are in charge of rhythm and synchronicity. Currently, we’re able to take iPS cells and get them to a cardiomyocyte state, but we want to further develop them into a pacemaking cell.

So ultimately, we’re trying to make a biological pacemaker. We can figure out how we can make a cell become the cell that tells your heart to beat, and there’s two things we can get out of that. First, if we understand how we get these beating cells, the ones that are telling the other heart cells to beat, we might be able to understand how different heart diseases progress, and we might be able to come up with a new way to prevent or treat that disease. Second, if we understand how we’re getting these pacemaking cells, we could hopefully bioengineer a biological pacemaker so you wouldn’t necessarily need an electronic pacemaker. With a biological one, a patient wouldn’t have to go back to the doctor to have their battery replaced. And they wouldn’t have to have multiple follow up surgeries throughout their life.

Q: What models are you using to study these pacemaking cells?

JG: I’m looking at my project from two different directions. On one side, we’re using a pig model, and we’re isolating cells from the sinoatrial (SA) node, which is where the pacemaking cells actually reside in your heart. And there’s really not that many of these cells. You probably have about a billion cells in your heart, but there’s maybe 100,000 of these pacemaking cells that are actually controlling the uniform beating of the heart. So we’re looking at the native SA node in the pig heart to see if it’s structurally any different than ventrical or atrial heart tissue.

Diagram of the heart depicting the Sinoatrial Node. (Image from Texas Heart Institute.

Diagram of the heart depicting the Sinoatrial Node. (Image from Texas Heart Institute)

We’ve found that the SA node is definitely different. So we’re de-cellularizing that tissue (removing the cells but not the matrix, or support structure, that keeps them in place) thinking that we could use the native matrix as a scaffold to help guide these heart cells to become the pacemaking phenotype. On the other side, we’re taking dishes with a known elasticity and we’re coating them with different proteins to see if we can tease out if there’s something that an individual protein does or a certain stiffness that actually is part of the driving force of making a pacemaking cell. We’ve gotten some pretty good preliminary results. So hopefully the next phase will be seeing how functional the cells are after they’ve been on these de-cellularized matrices.

Q: Why does your lab work with pig models?

JG: Pig hearts are pretty close to the human heart – their anatomy is pretty similar. To give you context, a pig heart is slightly larger than the size of your two hands clasped together. But the SA node, when you isolate it out, is only a couple of millimeters squared. It’s a lot smaller than we originally thought, and if we had gone with a smaller animal model, we wouldn’t be able to tangibly study or manipulate the SA node area. Because we are at UC Davis, we have a Meat Lab on campus, and we are able to get the pig hearts from them.

Q: Have you run into any road blocks with your research?

JG: For anybody that’s working with cardiomyocytes, the biggest problem is getting stem cells to become mature cardiomyocytes. Some labs have shown that you can get cells to a more mature cardiomyocyte after it’s been in culture for almost 100 days, but that’s not exactly feasible or that helpful.

We’ve been able to isolate out a small population of cells that we’re pretty sure are pacemaking cells. Over the last year, we’ve realized that a lot of the information that we thought we knew about pacemaking cells isn’t necessarily specific to pacemaking cells. Many of the biological markers that people have published in the literature are present in pacemaking cells, but we realized that they are also present in other heart cells like atrial cells, just in a lower amount. So we haven’t really been able to pick one specific biomarker that we’ve been able to say, yes this is actually a pacemaking cell. Instead, we have a small percentage of cells that we’re able to study. But we’re trying to figure out if there’s a way that we could increase our yield, or if there’s something fundamentally different about the environment that would also increase the yield of these pacemaking cells. So we’ve had a lot of trouble shooting along the way.

Q: What was your experience like as a CIRM scholar?

JG: I became a CIRM scholar in the spring of 2014. It was through the UC Davis Stem Cell Training Program. The opportunity was very helpful for me because it was in my first year as a postdoc at Davis. I earned my PhD at UCLA, so I was dealing with being on a new campus, trying to figure out whose lab I could go to to borrow random things and where to find equipment that I needed to use. So it was helpful to be around a group of other people that were also doing stem cell projects. Even though a lot of us were focused on different areas, it was still helpful to talk to other people, especially if you get somebody’s perspective that isn’t necessarily in your field. They might come up with a random idea that you haven’t thought of before.

Over the course of the year, we had a journal club, which was always interesting to see what’s going on in the field. I also went to the annual International Society for Stem Cell Research meeting in Vancouver using CIRM funding. And as part of the program, we also worked with the CIRM Bridges program between UC Davis and Cal State Sacramento. There were Bridges master’s students that were there with us. It was interesting to hear their take on everything, and they were very enthusiastic. We have had two master’s students work in our lab. I think it was very beneficial to them because they got a lot of hands on training and both have gone on to jobs in the regenerative medicine field.

Q: What is the future of stem cell research?

JG: If you’re looking at heart disease and stem cell treatments, there’s been some interesting clinical trials that have come out that have some promising results. I think that for a couple of those studies, people might have jumped the gun a little getting the treatments into the clinic. There’s still a lot that people should study in the lab before we move on to clinical trials. But I do think that we will see something in the next 20 years where stem cell research is going to have a huge therapeutic benefit. The field is just moving so quickly, and I think it will be really interesting to see what advances are made.

For our research, I’ve always been fairly realistic, and unfortunately, I don’t think we will see this biological pacemaker any time soon. But I think that the research that we produce along the way will be very beneficial to the field and our work will hopefully improve the foundation of what is known about pacemaking cells. What I think is really interesting about our lab’s work, is that we are moving into a 3D culture environment. Cells behave very differently in the body as opposed to on a plastic petri dish. So I think it’s very encouraging that we are seeing a lot more labs moving towards a more physiologically relevant model.

Q: What are your future goals?

I’ve been lucky that I’ve been able to work with very well established professors and also brand new faculty. But I’ve seen how difficult the funding climate is – it’s very daunting. So I’m really not sure what will happen next, and I’m keeping my options open.

I’ve really enjoyed working with our undergraduate and graduate students. I’ve gotten involved with outreach programs in Sacramento that promote science to young kids. It’s something that I’ve really enjoyed, and it’s very interesting telling people that I work in stem cells. Middle school kids seem to think that stem cells are magic. It’s fun to explain the very basics of stem cells and to see the light bulb moment where they understand it. I’m hoping to end up in a career that is still within the stem cell field but more towards teaching or outreach programs.

Q: What is your favorite thing about being a scientist?

JG: The thing I really like is having a puzzle that you’re trying to figure out the answer to. It’s great because every time you answer one question, that answer is going to lead you to at least three or four more new questions. I think that that’s really interesting especially trying to figure out how all the puzzle pieces fit together, and I’ve really enjoyed getting to work with people in very different fields. My parents think its funny because they said even as a little kid, I hated not knowing the answers to questions – and still do! They were completely understanding as to why I stayed in school as long as I did.

You can learn more about Jessica’s research by following her on Twitter: @JessicaGluckPhD

Regenerating damaged muscle after a heart attack

Cardio cells image

Images of clusters of heart muscle cells (in red and green) derived from human embryonic stem cells 40 days after transplantation. Courtesy UCLA

Every year more than 735,000 Americans have a heart attack. Many of those who survive often have lasting damage to their heart muscle and are at increased risk for future attacks and heart failure. Now CIRM-funded researchers at UCLA have identified a way that could help regenerate heart muscle after a heart attack, potentially not only saving lives but also increasing the quality of life.

The researchers used human embryonic stem cells to create a kind of cell, called a cardiac mesoderm cell, which has the ability to turn into cardiomyocytes, fibroblasts, smooth muscle, and endothelial cells. All these types of cells play an important role in helping repair a damaged heart.

As those embryonic cells were in the process of changing into cardiac mesoderms, the team was able to identify two key markers on the cell surface. The markers, called CD13 and ROR2 – which makes them sound like extras in the latest Star Wars movie – pinpointed the cells that were likely to be the most efficient at changing into the kind of cells needed to repair damaged heart tissue.

The researchers then transplanted those cells into an animal model and found that not only did many of the cells survive but they also produced the cells needed to regenerate heart muscle and vessels.

Big step forward

The research was published in the journal Stem Cell Reports. Dr. Reza Ardehali, the senior author of the CIRM-funded study, says this is a big step forward in the use of embryonic stem cells to help treat heart attacks:

“In a major heart attack, a person loses an estimated 1 billion heart cells, which results in permanent scar tissue in the heart muscle. Our findings seek to unlock some of the mysteries of heart regeneration in order to move the possibility of cardiovascular cell therapies forward. We have now found a way to identify the right type of stem cells that create heart cells that successfully engraft when transplanted and generate muscle tissue in the heart, which means we’re one step closer to developing cell-based therapies for people living with heart disease.”

More good news

But wait, as they say in cheesy TV infomercials, there’s more. Ardehali and his team not only found the markers to help them identify the right kinds of cell to use in regenerating damaged heart muscle, they also found a way to track the transplanted cells so they could make sure they were going where they wanted them to, and doing what they needed them to.

In a study published in Stem Cells Translational Medicine,  Ardehali and his team used special particles that can be tracked using MRI. They used those particles to label the cardiac mesoderm cells. Once transplanted into the animal model the team was able to follow the cells for up to 40 days.

Ardehali says knowing how to identify the best cells to repair a damaged heart, and then being able to track them over a long period, gives us valuable tools to use as we work to develop better, more effective treatments for people who have had a heart attack.

CIRM is already funding a Phase 2 clinical trial, run by a company called Capricor, using stem cells to treat heart attack patients.

 

Patching up a Broken Heart with FSTL1

Get-Over-Heartbreak-Step-08How do you mend a broken heart? It’s a subject that songwriters have pondered for generations, without success. But if you pose the same question to a heart doctor, they would give you a number of practical options that focus on the prevention or management of the physical symptoms you are dealing with.

That’s because heart disease is complicated. There are many different types of diseases that affect the health and function of the heart. And once damage happens to your heart, say from a heart attack, it’s really hard to fix.

New regenerative factor for heart disease

Scientists from Stanford University, the University of California, San Diego, and the Sanford-Burnham-Prebys Medical Discovery Institute have teamed up to figure out how to fix a broken heart. In a CIRM-funded study published today in the journal Nature, the group reported that the gene follistatin-like 1 (FSTl1) has the ability to regenerate heart tissue when it’s delivered within a patch to the injured heart.

2004_Heart_Wall

The different layers of the heart.

The wall of the heart is made up of three different layers: the endocardium (inner), myocardium (middle), and epicardium (outer). The epicardium not only protects the inner two layers of the heart, but also supports the growth of the fetal heart.

The group decided to study epicardial cells to determine whether these cells produced specific factors that protect or even regenerate adult heart tissue. They took epicardial cells from rodents and cultured them with heart cells (called cardiomyocytes), and found that the heart cells divided and reproduced much more quickly when cultured with the epicardial cells. This suggested that the epicardial cells might secrete factors that promote the expansion of the heart cells.

Patching up a broken heart

They next asked whether factors secreted from epicardial cells could improve heart function in mice after heart injury. They designed and engineered tiny patches that contained a cocktail of special epicardial factors and sewed them onto the heart tissue of mice that had just experienced the equivalent of a human heart attack. When they monitored these mice two weeks later, they saw an improvement in heart function in mice with the patch compared to mice without.

When they analyzed the cocktail of epicardial factors in the patch, they identified one factor that had potential for regenerating heart tissue. It was FSTL1. To test its regenerative abilities, they cultured rodent heart cells in a dish and treated them with FSTL1 protein. This treatment caused the heart cells to divide like crazy, thus proving that FSTL1 had regenerative qualities.

Moving from the dish into animal models, the scientists explored which layers of the heart FSTL1 was expressed in after heart injury. In healthy hearts, FSTL1 is expressed in the epicardium. However, in injured hearts, they found that FSTL1 expression was missing in the epicardium and was instead present in the middle layer of the heart, the myocardium.

FSTL1 to the rescue

patch

Cross sections of a healthy (control) or injured mouse heart. Injured hearts treated with patches containing FSTL1 show the most recovery of healthy heart tissue (red). Image adapted from Wei et al. 2015)

In a eureka moment, the scientists decided to add a FSTL1 protein back to the epicardial layer of the heart, post heart injury, using the same patch system they used earlier in mice, to see whether this would promote heart tissue regeneration. Their guess was correct. FSTL1 delivery through the engineered epicardium patch system resulted in a number of beneficial effects to the heart including better function and survival, reduced scar tissue build up (a consequence of heart injury), and increased blood flow to the area of the patch.

Upon further inspection, they found that the FSTL1 epicardial patch caused heart cells to divide and proliferate. The same effect did not happen when FSTL1 is expressed in the myocardium layer of the injured heart.

To make sure their findings translated to other animal models, they studied the regenerative effects of FSTL1 in a pig model of heart injury. They applied patches infused with FSTL1 to the injured heart and as expected, observed that FSTL1 delivery improved symptoms and caused heart cells to divide.

No more heartbreak?

The authors concluded that heart injury turns off the activity of an important factor, FSTL1, in specific heart cells needed for heart regeneration. By turning on FSTL1 back on in the epicardium after injury, heart cells will receive the signal to divide and regenerate heart tissue.

Co-first author and CIRM postdoctoral scholar Ke Wei spoke to CIRM about the next steps for this study and its relevance:

Ke Wei

Co-first author, Ke Wei

In the future, we hope that our engineered epicardium patch technology can be used as a clinical platform to deliver drugs or cells to the injured heart. This strategy differs from conventional tools to treat heart attack, and may provide a novel approach in our repertoire battling heart diseases.

Thus it seems that scientists have found a potential way to patch-up a broken heart and to extend a lifeline for those suffering from heart disease. It’s comforting to know that the regenerative abilities of FSTl1 will be explored in human models and will hopefully reach clinical trials.

Ke Wei (UCSD, Sanford-Burnham-Prebys) and Vahid Serpooshan (Stanford) were co-first authors on this study. The senior authors were Daniel Bernstein (Stanford), Mark Mercola (UCSD, Sanford-Burnham-Prebys), and Pilar Ruiz-Lozano (Stanford). Both Ke Wei and Mark Mercola received CIRM funding for this study.


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10 Years/10 Therapies: 10 Years after its Founding CIRM will have 10 Therapies Approved for Clinical Trials

In 2004, when 59 percent of California voters approved the creation of CIRM, our state embarked on an unprecedented experiment: providing concentrated funding to a new, promising area of research. The goal: accelerate the process of getting therapies to patients, especially those with unmet medical needs.

Having 10 potential treatments expected to be approved for clinical trials by the end of this year is no small feat. Indeed, it is viewed by many in the industry as a clear acceleration of the normal pace of discovery. Here are our first 10 treatments to be approved for testing in patients.

HIV/AIDS. The company Calimmune is genetically modifying patients’ own blood-forming stem cells so that they can produce immune cells—the ones normally destroyed by the virus—that cannot be infected by the virus. It is hoped this will allow the patients to clear their systems of the virus, effectively curing the disease.

Spinal cord injury patient advocate Katie Sharify is optimistic about the latest clinical trial led by Asterias Biotherapeutics.

Spinal cord injury patient advocate Katie Sharify is optimistic about the clinical trial led by Asterias Biotherapeutics.

Spinal Cord Injury. The company Asterias Biotherapeutics uses cells derived from embryonic stem cells to heal the spinal cord at the site of injury. They mature the stem cells into cells called oligodendrocyte precursor cells that are injected at the site of injury where it is hoped they can repair the insulating layer, called myelin, that normally protects the nerves in the spinal cord.

Heart Disease. The company Capricor is using donor cells derived from heart stem cells to treat patients developing heart failure after a heart attack. In early studies the cells appear to reduce scar tissue, promote blood vessel growth and improve heart function.

Solid Tumors. A team at the University of California, Los Angeles, has developed a drug that seeks out and destroys cancer stem cells, which are considered by many to be the reason cancers resist treatment and recur. It is believed that eliminating the cancer stem cells may lead to long-term cures.

Leukemia. A team at the University of California, San Diego, is using a protein called an antibody to target cancer stem cells. The antibody senses and attaches to a protein on the surface of cancer stem cells. That disables the protein, which slows the growth of the leukemia and makes it more vulnerable to other anti-cancer drugs.

Sickle Cell Anemia. A team at the University of California, Los Angeles, is genetically modifying a patient’s own blood stem cells so they will produce a correct version of hemoglobin, the oxygen carrying protein that is mutated in these patients, which causes an abnormal sickle-like shape to the red blood cells. These misshapen cells lead to dangerous blood clots and debilitating pain The genetically modified stem cells will be given back to the patient to create a new sickle cell-free blood supply.

Solid Tumors. A team at Stanford University is using a molecule known as an antibody to target cancer stem cells. This antibody can recognize a protein the cancer stem cells carry on their cell surface. The cancer cells use that protein to evade the component of our immune system that routinely destroys tumors. By disabling this protein the team hopes to empower the body’s own immune system to attack and destroy the cancer stem cells.

Diabetes. The company Viacyte is growing cells in a permeable pouch that when implanted under the skin can sense blood sugar and produce the levels of insulin needed to eliminate the symptoms of diabetes. They start with embryonic stem cells, mature them part way to becoming pancreas tissues and insert them into the permeable pouch. When transplanted in the patient, the cells fully develop into the cells needed for proper metabolism of sugar and restore it to a healthy level.

HIV/AIDS. A team at The City of Hope is genetically modifying patients’ own blood-forming stem cells so that they can produce immune cells—the ones normally destroyed by the virus—that cannot be infected by the virus. It is hoped this will allow the patients to clear their systems of the virus, effectively curing the disease

Blindness. A team at the University of Southern California is using cells derived from embryonic stem cell and a scaffold to replace cells damaged in Age-related Macular Degeneration (AMD), the leading cause of blindness in the elderly. The therapy starts with embryonic stem cells that have been matured into a type of cell lost in AMD and places them on a single layer synthetic scaffold. This sheet of cells is inserted surgically into the back of the eye to replace the damaged cells that are needed to maintain healthy photoreceptors in the retina.

Cells’ Knack for Hoarding Proteins Inadvertently Kickstarts the Aging Process

Even cells need to take out the trash in order to maintain a healthy clean environment. And scientists are now uncovering the harmful effects when cells instead begin to hoard their garbage.

Cells' penchant for hoarding proteins may spur the cellular aging process, according to new research.

Cells’ penchant for hoarding proteins may spur the cellular aging process, according to new research. [Labyrinth (1986)]

Aging, on the cellular level is—at its core—the increasing inability for cells to repair themselves over time. As cells begin to break down faster than they can be repaired, the risk of age-related diseases escalates. Cancer, heart disease and neurological conditions such as Alzheimer’s disease are some of aging’s most deadly effects.

As a result, scientists have long searched for ways to give our cells a little help and improve our quality of life as we age. For example, recent research has pointed to a connection between fasting (restricting calories) and a longer lifespan, though the molecular mechanisms behind this connection remain somewhat cryptic.

But now Dr. Daniel Gottschling, a scientist at the Fred Hutchinson Cancer Research Center and an aging expert, has made extraordinary progress toward solving some of the mysteries of aging.

In two studies published this month in the Proceedings of the National Academy of Sciences and eLife, Gottschling and colleagues discover that a particular long-lasting protein builds up over time in certain cell types, causing the buildup of a protein hoard that damages the cell beyond repair.

Clearing out the Cobwebs

Some cells, such as those that make up the skin or that reside in the gut, are continually replenished by a stockpile of adult stem cells. But other cells, such as those found in the eye and brain, last for years, decades and—in some cases—our entire lifetimes.

Within and surrounding these long-lived cells are similarly long-lived proteins which help the cell perform essential functions. For example, the lens of the human eye, which helps focus light, is made up of these proteins that arise during embryonic development and last for a lifetime.

Dr. Daniel Gottschling is looking to unlock the mysteries behind cellular aging.

Dr. Daniel Gottschling is looking to unlock the mysteries behind cellular aging. [Image courtesy of the Fred Hutchinson Cancer Research Center]

“Shortly after you’re born, that’s it, you get no more of that protein and it lives with you the rest of your life,” explained Gottschling.

As a result, if those proteins degrade and die, new ones don’t replace them—the result is the age-related disease called cataracts.

But scientists weren’t exactly sure of the relationship between these dying proteins and the onset of conditions such as cataracts, and other disease related to aging. Did these conditions occur because the proteins were dying? Or rather because the proteins were building up to toxic levels?

So Gottschling and his team set up a series of experiments to find out.

Stashing Trash

They developed a laboratory model by using yeast cells. Interestingly, yeast cells share several key properties with human stem cells, and are often the focus of early-stage research into basic, fundamental concepts of biology.

Like stem cells, yeast cells grow and divide asymmetrically. In other words, a ‘mother’ cell will produce many ‘daughter’ cells, but will itself remain intact. In general, yeast mother cells produce up to 35 daughter cells before dying—which usually takes just a few days.

 Yeast “mother” cells budding and giving birth to newborn “daughter” cells.  [Image courtesy of Dr. Kiersten Henderson / Gottschling Lab]

Yeast “mother” cells budding and giving birth to newborn “daughter” cells.
[Image courtesy of Dr. Kiersten Henderson / Gottschling Lab]

Here, the research team used a special labeling technique that marked individual proteins that exist within and surrounding these mother cells. These microscopic tracking devices then told researchers how these proteins behaved over the entire lifespan of the mother cell as it aged.

The team found a total of 135 long-lived proteins within the mother cell. But what really surprised them was what they found upon closer examination: all but 21 of these 135 proteins appeared to have no function. They appeared to be trash.

“No one’s ever seen proteins like this before [in aging],” said Nathanial Thayer, a graduate student in the Gottschling Lab and lead author of one of the studies.

Added Gottschling, “With the number of different fragments [in the mother cell], we think they’re going to cause trouble. As the daughter yeast cells grow and split off, somehow mom retains all these protein bits.”

This startling discovery opened up an entirely new set of questions, explained Gottschling.

“It’s not clear whether the mother’s trash keeper function is a selfless act designed to give her daughters the best start possible, or if she’s hanging on to them for another reason.”

Hungry, Hoarding Mother Cells

So Gottschling and his team took a closer look at one of these proteins, known as Pma1.

Recent work by the Gottschling Lab found that cells lose their acidity over time, which itself leads to the deterioration of the cells’ primary energy source. The team hypothesized that Pma1 was somehow intricately tied to corresponding levels of pH (high pH levels indicate an acidic environment, while lower pH levels signify a more basic environment).

In the second study published in eLife, led by Postdoctoral Fellow Dr. Kiersten Henderson, the team made several intriguing discoveries about the role of Pma1.

First, they uncovered a key difference between mother and daughter cells: daughter cells are born with no Pma1. As a result, they are far more acidic than their mothers. But when they ramped up Pma1 in the mother cells, the acidity levels in subsequent generations of daughter cells changed accordingly.

“When we boosted levels of the protein, daughter cells were born with Pma1 and became more basic (they had a lower pH), just like their mothers.”

Further examination uncovered the true relationship between Pma1 and these cells. At its most fundamental, Pma1 helps the mother cells eat.

“Pma1 plays a key role in cellular feeding,” said Gottschling. “The protein sits on the surface of cells and helps them take in nutrients from their environment.”

Pma1 gives the mother cell the ability to gorge herself. The more access to food she has, the easier it is for her to produce more daughter cells. By hoarding Pma1, the mother cell can churn out more offspring. Unfortunately, she is also signing her own death certificate—she’s creating a more basic environment that, in the end, proves toxic and contributes to her death.

The hoarding, it turns out, may not all be due to the mother cells’ failure to ‘take out the trash.’ Instead, she wants to keep eating and producing daughters—and hoarding Pma1 allows her to do just that.

“There’s this whole trade off of being able to divide quickly and the negative side is that the individual, the mother, does not get to live as long.”

Together, the results from these two studies provide a huge boost for researchers like Gottschling who are trying to unravel the molecular mysteries of aging. But the process is incredibly intricate, and there will likely be no one simple solution to improving quality of life as we get older.

“The whole issue of aging is so complex that we’re still laying the groundwork of possibilities of how things can go awry,” said Gottschling. “And so we’re still learning what is going on. We’re defining the aging process.”