cardiomyocytes

Using stem cells and smart machines to warn of heart problems

/ Kevin McCormack / 1 Comment

Despite advances in treatments in recent years heart disease remains the leading cause of death in the US. It accounts for one in three deaths in this country, and many people are not even aware they have a problem until they have a heart attack.

One of the early warning signs of danger is a heart arrhythmia; that’s when electrical signals that control the hearts beating don’t work properly and can result in the heart beating too fast, too slow, or irregularly. However, predicting who is at risk of these arrhythmias is difficult. Now new research may have found a way to change that.

A research team at the Institute of Molecular and Cell Biology in Singapore combined stem cells with machine learning, and developed a way to predict arrhythmias, with a high degree of accuracy.

The team used stem cells to create different batches of cardiomyocytes or heart muscle cells. Some of these batches were healthy heart cells, but some had arrhythmias caused by different problems such as a genetic disorder or drug induced.

They then trained a machine learning program to use videos to scan the 3,000 different groups of cells. By studying the different beating patterns of the cells, and then using the levels of calcium in the cells, the machine was able to predict, with 90 percent accuracy, which cells were most likely to experience arrhythmias.

The researchers say their approach is faster, simpler and more accurate than current methods of trying to predict who is at risk for arrhythmias and could have a big impact on our ability to intervene before the individual suffers a fatal heart attack.

The research was published in the journal Stem Cell Reports.

The California Institute for Regenerative Medicine has invested more than $180 million in more than 80 different projects, including four clinical trials, targeting heart disease.

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

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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.”

CIRM funded study uses drug development in a dish for treatment of heart arrhythmias

/ Yimy Villa / 1 Comment
Image Credit: Center for Disease Control and Prevention (CDC)

Cardiac (heart) arrhythmias occur when electrical impulses that coordinate your heartbeats don’t work properly, causing your heart to beat too fast, too slow, or in an irregular manner. In the U.S. alone, almost one million individuals are hospitalized every year for heart arrhythmias. Close to 300,000 individuals die of sudden arrhythmic death syndrome every year, which occurs when there is a sudden loss of blood flow resulting from the failure of the heart to pump effectively. Unfortunately, drugs to treat arrhythmias have liabilities and several drugs have been pulled from the market due to serious side effects. Mexiletine is one potential drug for heart arrhythmias that has liabilities and potential side effects.

That is why a CIRM funded study ($6.3 million) conducted by John Cashman, Ph.D. at the Human BioMolecular Research Institute in San Diego looked at re-engineering mexiletine in a way that the drug could still produce a desired result and not be as toxic.

The study used induced pluripotent stem cells (iPSCs), a type of stem cell “reprogrammed” from the skin or blood of patients that can be used to make virtually any kind of cell. iPSCs obtained for the study were from a healthy patient and from one with a type of heart arrhythmia. The healthy and arrhythmia iPSCs were then converted into cardiomyocytes, a type of cell that makes up the heart muscle.

By using their newly created healthy cardiomyocytes and those with the arrhythmia defect, Cashman and his team were able to carry out drug development in a dish. This enabled them to attempt to lessen drug toxicity while still potentially treating heart arrhythmias. The team was able to modify mexiletine such that is was less toxic and found that it could potentially decrease a patient’s risk of developing ventricular tachycardia (a fast, abnormal heart rate) and ventricular fibrillation (an abnormal heart rhythm), both of which are types of heart arrhythmias.

“The new compounds may lead to treatment applications in a whole host of cardiovascular conditions that may prove efficacious in clinical trials,” said Cashman in a press release. “As antiarrhythmic drug candidate drug development progresses, we expect the new analogs to be less toxic than current therapeutics for arrhythmia in congenital heart disease, and patients will benefit from improved safety, less side effects and possibly with significant cost-savings.”

The team hopes that their study can pave the way for future research in which cells in a dish can be used to lessen the toxicity of a potential drug candidate while still producing a desired result for different diseases and conditions.

The full study was published in ACS Publications.

An Atlas of the Human Heart that May Guide Development of New Therapies

/ Kevin McCormack / Leave a comment

By Lisa Kadyk, PhD. CIRM Senior Science Officer

Illustration of a man’s heart – Courtesy Science Photo

I love maps; I still have auto club maps of various parts of the country in my car.  But, to tell the truth, those maps just don’t have as much information as I can get by typing in an address on my cell phone.  Technological advances in global positioning systems, cellular service, data gathering and storage, etc. have made my beloved paper maps a bit of a relic.  

Similarly, technological advances have enabled scientists to begin making maps of human tissues and organs at a level of detail that was previously unimaginable.  Hundreds of thousands of single cells can be profiled in parallel, examining expression of RNA and proteins.  These data, in combination with new three-dimensional spatial analysis techniques and sophisticated computational algorithms, allow high resolution mapping of all the cells in a given tissue or organ.

Given these new capabilities, an international “Human Cell Atlas Consortium” published a white paper in 2017 outlining plans and strategies to build comprehensive reference maps of all human cells, organ by organ.  The intent of building such an atlas is to give a much better understanding of the biology and physiology of normal human tissues, as well as to give new insights into the nature of diseases affecting those tissues and to point the way to developing new therapies. 

One example of this new breed of cartography was published September 24 in the journal Nature, in a paper called simply “Cells of the Human Heart”.   This tour-de-force effort was led by scientists from Harvard Medical School, the Wellcome Sanger Institute, the Max Delbruck Center for Molecular Medicine in Berlin and Imperial College, London.  These teams and their collaborators analyzed about 500,000 cells from six different regions of the healthy adult human heart, using post-mortem organs from 14 donors.  They examined RNA and protein expression and mapped the distribution of different types of cells in each region of the heart.  In addition, they made comparisons of male and female hearts, and identified cells expressing genes known to be associated with different types of heart disease.  

One of the take-home messages from this study is that there is a lot of cellular complexity in the heart – with 11 major cell types (examples include atrial and ventricular cardiomyocytes, fibroblasts and smooth muscle cells), as well as multiple subpopulations within each of those types.  Also notable is the different distribution of cells between the atria (which are at the top of the heart and receive the blood) and ventricles (which are on the bottom of the heart and pump blood out): on average, close to half of the cells in the ventricles are cardiomyocytes, whereas only a third of the cells in the atria are cardiomyocytes.  Finally, there is a significantly higher percentage of cardiomyocytes in the ventricles of women (56%) than in the ventricles of men (47%).    The authors speculate that this latter difference might explain the higher volume of blood pumped per beat in women and lower rates of cardiovascular disease.  

The authors gave a few examples of how their data can be used for a better understanding of heart disease.  For example, they identified a specific subpopulation of cardiomyocytes that expresses genes associated with atrial fibrillation, suggesting that the defect may be associated with those cells.   Similarly, they found that a specific neuronal cell type expresses genes that are associated with a particular ventricular dysfunction associated with heart failure.    In addition, the authors identified which cells in the heart express the highest levels of the SARS-CoV-2 receptor, ACE2, including pericytes, fibroblasts and cardiomyocytes.  

Now that these data are accessible for exploration at www.heartcellatlas.org, I have no doubt that many scientific explorers will begin to navigate to a more complete understanding of both the healthy and diseased heart, and ultimately to new treatments for heart disease.

Precision guided therapy from a patient’s own cells

/ Kevin McCormack / 1 Comment

Dr. Wesley McKeithan, Stanford

Imagine having a tool you could use to quickly test lots of different drugs against a disease to see which one works best. That’s been a goal of stem cell researchers for many years but turning that idea into a reality hasn’t been easy. That may be about to change.

A team of CIRM-funded researchers at the Stanford Cardiovascular Institute and the Human BioMolecular Research Institute in San Diego found a way to use stem cells from patients with a life-threatening heart disease, to refine an existing therapy to make it more effective, with fewer side effects.

The disease in question is called long QT syndrome (LQTS). This is a heart rhythm condition that can cause fast, chaotic heartbeats. Some people with the condition have seizures. In some severe cases, particularly in younger people, LQTS can cause sudden death.

There are a number of medications that can help keep LQTS under control. One of these is mexiletine. It’s effective at stabilizing the heart’s rhythm, but it also comes with some side effects such as stomach pain, chest discomfort, drowsiness, headache, and nausea.

The team wanted to find a way to test different forms of that medication to see if they could find one that worked better and was safer to take. So they used induced pluripotent stem cells (iPSCs) from patients with LQTS to do just that.

iPSCs are cells that are made from human tissue – usually skin – that can then be turned into any other cell in the body. In this case, they took tissue from people with LQTS and then turned them into heart cells called cardiomyocytes, the kind affected by the disease. The beauty of this technique is that even though these cells came from another source, they now look and act like cardiomyocytes affected by LQTS.

Dr. Mark Mercola, Stanford

In a news release Stanford’s Dr. Mark Mercola, the senior author of the study, said using these kinds of cells gave them a powerful tool.

“Drugs for heart disease are typically developed using overly simplified models, like tumor cells engineered in a specific way to mimic a biochemical event. Consequently, drugs like this one, mexiletine, have undesirable properties of concern in treating patients. Here, we used cells from a patient to generate that person’s heart muscle cells in a dish so we could visualize both the good and bad effects of the drug.”

The researchers then used these man-made cardiomyocytes to test various drugs that were very similar in structure to mexiletine. They were looking for ones that could help stabilize the heart arrhythmia but didn’t produce the unpleasant side effects. And they found some promising candidates.

Study first author, Dr. Wesley McKeithan, says the bigger impact of the study is that they were able to show how this kind of cell from patients with a particular disease can be used to “guide drug development and identify better drug improvement and optimization in a large-scale manner.”

 “Our approach shows the feasibility of introducing human disease models early in the drug development pipeline and opens the door for precision drug design to improve therapies for patients.”

The study is published in the journal Cell Stem Cell.

Scientists at UC Davis discover a way to help stem cells repair heart tissue

/ Yimy Villa / Leave a comment
Researchers Phung Thai (left) and Padmini Sirish were part of a research team seeking stem cell solutions to heart failure care.  Image Credit: UC Davis

Repairing the permanent damage associated with a heart attack or long-term heart disease has been a challenge that scientists have been trying to tackle for a long time. Heart failure affects approximately 5.7 million people in the U.S and it is estimated that this number will increase to 9 million by the year 2030. At a biological level, the biggest challenge to overcome is cell death and thickening of muscles around the heart.

Recently, using stem cells to treat heart disease has shown some promise. However, little progress has been made in this area because the inflammation associated with heart disease decreases the chances of stem cell survival. Fortunately, Dr. Nipavan Chiamvimonvat and her team of researchers at UC Davis have found an enzyme inhibitor that may help stem cells repair damaged heart tissue.

Dr. Nipavan Chiamvimonvat
 Image Credit: UC Davis

The enzyme the team is looking at, known as soluble epoxide hydrolase (or sEH for short), is a known factor in joint and lung disease and is associated with inflammation. The inhibitor Dr. Chiamvimonvat and her team are studying closely is called TPPU and it is meant to block sEH.

In their study, the UC Davis team used human-induced pluripotent stem cells (hiPSCs), a kind of stem cell made by reprogramming skin or blood cells that then has the ability to form all cell types. In this case, the hiPSCs were turned into heart muscle cells.

To evaluate the effectiveness of TPPU, the team then induced heart attacks in six groups of mice. A group of these mice was treated with a combination of TPPU and the newly created heart muscle cells.  The team found that the mice treated with this combination approach had the best outcomes in terms of increased engraftment and survival of transplanted stem cells. Additionally, this group also had less heart muscle thickening and improved heart function. 

The next step for Dr. Chiamvimonvat and her team is to conduct more animal testing in order to obtain the data necessary to test this therapy in clinical trials.

In a press release, Dr. Chiamvimonvat discusses the importance of research and its impact on patients.

““It is my dream as a clinician and scientist to take the problems I see in the clinic to the lab for solutions that benefit our patients.”

The full study was published in Stem Cells Translational Medicine.

 

Stem Cell Roundup: watching brain cells in real time, building better heart cells, and the plot thickens on the adult neurogenesis debate

/ Karen Ring / 2 Comments

Here are the stem cell stories that caught our eye this week.

Watching brain cells in real time

This illustration depicts a new method that enables scientists to see an astrocyte (green) physically interacting with a neuronal synapse (red) in real time, and producing an optical signal (yellow). (Khakh Lab, UCLA Health)

Our stem cell photo of the week is brought to you by the Khakh lab at UCLA Health. The lab developed a new method that allows scientists to watch brain cells interact in real time. Using a technique called fluorescence resonance energy-transfer (FRET) microscopy, the team can visualize how astrocytes (key support cells in our central nervous system) and brain cells called neurons form connections in the mouse brain and how these connections are affected by diseases like Alzheimer’s and ALS.

Baljit Khakh, the study’s first author, explained the importance of their findings in a news release:

“This new tool makes possible experiments that we have been wanting to perform for many years. For example, we can now observe how brain damage alters the way that astrocytes interact with neurons and develop strategies to address these changes.”

The study was published this week in the journal Neuron.

Turn up the power: How to build a better heart cell (Todd Dubnicoff)

For years now, researchers have had the know-how to reprogram a donor’s skin cells into induced pluripotent stem cells (iPSCs) and then specialize them into heart muscle cells called cardiomyocytes. The intervening years have focused on optimizing this method to accurately model the biology of the adult human heart as a means to test drug toxicity and ultimately develop therapies for heart disease. Reporting this week in Nature, scientists at Columbia University report an important step toward those goals.

The muscle contractions of a beating heart occur through natural electrical impulses generated by pacemaker cells. In the case of lab-grown cardiomyocytes, introducing mechanical and electrical stimulation is required to reliably generate these cells. In the current study, the research team showed that the timing and amount of stimulation is a critical aspect to the procedure.

The iPS-derived cardiomyocytes have formed heart tissue that closely mimics human heart functionality at over four weeks of maturation. Credit: Gordana Vunjak-Novakovic/Columbia University.

The team tested three scenarios on iPSC-derived cardiomyocytes (iPSC-CMs): no electrical stimulation for 3 weeks, constant stimulation for 3 weeks, and finally, two weeks of increasingly higher stimulation followed by a week of constant stimulation. This third setup mimics the changes that occur in a baby’s heart just before and just after birth.

These scenarios were tested in 12 day-old and 28 day-old iPSC-CMs. The results show that only the 12 day-old cells subjected to the increasing amounts of stimulation gave rise to fully mature heart muscle cells. On top of that, it only took four weeks to make those cells. Seila Selimovic, Ph.D., an expert at the National Institutes of Health who was not involved in the study, explained the importance of these findings in a press release:

“The resulting engineered tissue is truly unprecedented in its similarity to functioning human tissue. The ability to develop mature cardiac tissue in such a short time is an important step in moving us closer to having reliable human tissue models for drug testing.”

Read more at: https://phys.org/news/2018-04-early-bioengineered-human-heart-cells.html#jCp

Yes we do, no we don’t. More confusion over growing new brain cells as we grow older (Kevin McCormack)

First we didn’t, then we did, then we didn’t again, now we do again. Or maybe we do again.

The debate over whether we are able to continue making new neurons as we get older took another twist this week. Scientists at Columbia University said their research shows we do make new neurons in our brain, even as we age.

This image shows what scientists say is a new neuron in the brain of an older human. A new study suggests that humans continue to make new neurons throughout their lives. (Columbia University Irving Medical Center)

In the study, published in the journal Cell Stem Cell, the researchers examined the brains of 28 deceased donors aged 14 to 79. They found similar numbers of precursor and immature neurons in all the brains, suggesting we continue to develop new brain cells as we age.

This contrasts with a UCSF study published just last month which came to the opposite conclusion, that there was no evidence we make new brain cells as we age.

In an interview in the LA Times, Dr. Maura Boldrini, the lead author on the new study, says they looked at a whole section of the brain rather than the thin tissues slices the UCSF team used:

“In science, the absence of evidence is not evidence of absence. If you can’t find something it doesn’t mean that it is not there 100%.”

Well, that resolves that debate. At least until the next study.

Gladstone scientists tackle heart failure by repairing the heart from within

/ Karen Ring / Leave a comment

Modern medicine often involves the development of a drug or treatment outside the body, which is then given to a patient to fix, improve or even prevent their condition. But what if you could regenerate or heal the body using the cells and tissue already inside a patient?

Scientists at the Gladstone Institutes are pursuing such a strategy for heart disease. In a CIRM-funded study published today in the journal Cell, the team identified four genes that can stimulate adult heart muscle cells, called cardiomyocytes, to divide and proliferate within the hearts of living mice. This discovery could be further developed as a strategy to repair cardiac tissue damage caused by heart disease and heart attacks.

Regenerating the Heart

Heart disease is the leading cause of death in the US and affects over 24 million people around the world. When patients experience a heart attack, blood flow is restricted to the heart, and parts of the heart muscle are damaged or die due to the lack of oxygen. The heart is unable to regenerate new healthy heart muscle, and instead, cardiac fibroblasts generate fibrous scar tissue to heal the injury. This scar tissue impairs the heart’s ability to pump blood, causing it to work harder and putting patients at risk for future heart failure.

Deepak Srivastava, President of the Gladstone Institutes and a senior investigator there, has dedicated his life’s research to finding new ways to regenerate heart tissue. Previously, his team developed methods to reprogram mouse and human cardiac fibroblasts into beating cardiomyocytes in hopes of one day restoring heart function in patients. The team is advancing this research with the help of a CIRM Discovery Stage research grant, which will aid them in developing a gene therapy product that delivers reprogramming factors into scar tissue cells to regenerate new heart muscle.

In this new study, Srivastava took a slightly different approach and attempted to coax cardiomyocytes, rather than cardiac fibroblasts, to divide and regenerate the heart. During development, fetal cardiomyocytes rapidly divide to create heart tissue. This regenerative ability is lost in adult cardiomyocytes, which are unable to divide because they’ve already exited the cell cycle (a series of phases that a cell goes through that ultimately results in its division).

Deepak Srivastava (left) and first author Tamer Mohamed (right). Photo credits: Diana Rothery.

Unlocking proliferative potential

Srivastava had a hunch that genes specifically involved in the cell division could be used to jump-start an adult cardiomyocyte’s re-entry into the cell cycle. After some research, they identified four genes (referred to as 4F) involved in controlling cell division. When these genes were turned on in adult cardiomyocytes, the cells started to divide and create new heart tissue.

This 4F strategy worked in mouse and rat cardiomyocytes and also was successful in stimulating cell division in 15%-20% of human cardiomyocytes. When they injected 4F into the hearts of mice that had suffered heart attacks, they observed an improvement in their heart function after three months and a reduction in the size of the scar tissue compared to mice that did not receive the injection.

The team was able to further refine their method by replacing two of the four genes with chemical inhibitors that had similar functions. Throughout the process, the team did not observe the development of heart tumors caused by the 4F treatment. They attributed this fact to the short-term expression of 4F in the cardiomyocytes. However, Srivastava expressed caution towards using this method in a Gladstone news release:

“In human organs, the delivery of genes would have to be controlled carefully, since excessive or unwanted cell division could cause tumors.”

First stop heart, next stop …

This study suggests that it’s possible to regenerate our tissues and organs from within by triggering adult cells to re-enter the cell cycle. While more research is needed to ensure this method is safe and worthy of clinical development, it could lead to a regenerative treatment strategy for heart failure.

Srivastava will continue to unravel the secrets to the proliferative potential of cardiomyocytes but predicts that other labs will pursue similar methods to test the regenerative potential of adult cells in other tissues and organs.

“Heart cells were particularly challenging because when they exit the cell cycle after birth, their state is really locked down—which might explain why we don’t get heart tumors. Now that we know our method is successful with this difficult cell type, we think it could be used to unlock other cells’ potential to divide, including nerve cells, pancreatic cells, hair cells in the ear, and retinal cells.”

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Stem Cell Roundup: Improving muscle function in muscular dystrophy; Building a better brain; Boosting efficiency in making iPSC’s

/ Kevin McCormack / Leave a comment

Here are the stem cell stories that caught our eye this week.

Photos of the week

TGIF! We’re so excited that the weekend is here that we are sharing not one but TWO amazing stem cell photos of the week.

RMI IntestinalChip

Image caption: Cells of a human intestinal lining, after being placed in an Intestine-Chip, form intestinal folds as they do in the human body. (Photo credit: Cedars-Sinai Board of Governors Regenerative Medicine Institute)

Photo #1 is borrowed from a blog we wrote earlier this week about a new stem cell-based path to personalized medicine. Scientists at Cedars-Sinai are collaborating with a company called Emulate to create intestines-on-a-chip using human stem cells. Their goal is to create 3D-organoids that represent the human gut, grow them on chips, and use these gut-chips to screen for precision medicines that could help patients with intestinal diseases. You can read more about this gut-tastic research here.

Young mouse heart 800x533

Image caption: UCLA scientists used four different fluorescent-colored proteins to determine the origin of cardiomyocytes in mice. (Image credit: UCLA Broad Stem Cell Research Center/Nature Communications)

Photo #2 is another beautiful fluorescent image, this time of a cross-section of a mouse heart. CIRM-funded scientists from UCLA Broad Stem Cell Research Center are tracking the fate of stem cells in the developing mouse heart in hopes of finding new insights that could lead to stem cell-based therapies for heart attack victims. Their research was published this week in the journal Nature Communications and you can read more about it in a UCLA news release.

Stem cell injection improves muscle function in muscular dystrophy mice

Another study by CIRM-funded Cedars-Sinai scientists came out this week in Stem Cell Reports. They discovered that they could improve muscle function in mice with muscular dystrophy by injecting cardiac progenitor cells into their hearts. The injected cells not only improved heart function in these mice, but also improved muscle function throughout their bodies. The effects were due to the release of microscopic vesicles called exosomes by the injected cells. These cells are currently being used in a CIRM-funded clinical trial by Capricor therapeutics for patients with Duchenne muscular dystrophy.

How to build a better brain (blob)

For years stem cell researchers have been looking for ways to create “mini brains”, to better understand how our own brains work and develop new ways to repair damage. So far, the best they have done is to create blobs, clusters of cells that resemble some parts of the brain. But now researchers at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA have come up with a new method they think can advance the field.

Their approach is explained in a fascinating article in the journal Science News, where lead researcher Bennet Novitch says finding the right method is like being a chef:

“It’s like making a cake: You have many different ways in which you can do it. There are all sorts of little tricks that people have come up with to overcome some of the common challenges.”

Brain cake. Yum.

A more efficient way to make iPS cells

17yamanaka-master768

Shinya Yamanaka. (Image source: Ko Sasaki, New York Times)

In 2006 Shinya Yamanaka discovered a way to take ordinary adult cells and reprogram them into embryonic-like stem cells that have the ability to turn into any other cell in the body. He called these cells induced pluripotent stem cells or iPSC’s. Since then researchers have been using these iPSC’s to try and develop new treatments for deadly diseases.

There’s been a big problem, however. Making these cells is really tricky and current methods are really inefficient. Out of a batch of, say, 1,000 cells sometimes only one or two are turned into iPSCs. Obviously, this slows down the pace of research.

Now researchers in Colorado have found a way they say dramatically improves on that. The team says it has to do with controlling the precise levels of reprogramming factors and microRNA and…. Well, you can read how they did it in a news release on Eurekalert.

 

 

 

Making beating heart cells from stem cells just got easier

/ Karen Ring / 2 Comments

Here’s a heartwarming story for the holidays. Scientists from the Salk Institute in La Jolla, California have figured out a simple, easy way to make beating heart cells from human stem cells that will aid research and therapy development for heart disease. Their study, which received funding support from CIRM, was published last week in the journal Genes & Development.

The Salk team discovered that making beating heart tissue from human stem cells is as simple as turning off a single gene called YAP. You might be wondering how the team settled on this gene and no, it doesn’t involve pulling a random gene name out of a hat.

In previous studies, the researchers found that two cell signaling pathways, Wnt and Activin, are crucial for the development of embryonic stem cells into specialized cells like cardiomyocytes (beating heart cells). This research led to the discovery of a third pathway, controlled by YAP, which sets up a road block for cell specialization and keeps stem cells in their undifferentiated state.

Only hESCs without YAP (right panel) make heart cells (green) in one step. Blue dye marks cell nuclei. (Salk Institute)

The team deleted YAP from these stem cells using CRISPR gene editing technology, and then treated the stem cells to the Activin signaling molecule. Without YAP, exposure to Activin prompted the stem cells to develop immediately into beating cardiomyocytes that you can see beating away in the Salk video below.

Dr. Kathy Jones, Salk professor and senior author on the study, explained why this discovery is important to the field in a news release:

“This discovery is really exciting because it means we can potentially create a reliable protocol for taking normal cells and moving them very efficiently from stem cells to heart cells. Researchers and commercial companies want to easily generate cardiomyocytes to study their capacity for repair in heart attacks and disease—this brings us one step closer to being able to do that.”

First author, Conchi Estarás, emphasized how their new method for making cardiomyocytes is attractive not only for its simplicity, but also for its cost-effectiveness in enabling large-scale manufacturing of these cells for treatment.

“Instead of requiring two steps to achieve specialization, removing YAP cut it to just one step. That would mean a huge savings for industry in terms of reagent materials and expense.”

Looking ahead, Jones and her team do not plan on deleting the YAP gene from stem cells because of the potential side effects cause by the loss of YAP’s other cellular functions. Instead, they will be using commercially available molecules that can temporarily inhibit the function of YAP in hopes that this less permanent action will still readily produce beating heart cells from stem cells.

Kathy Jones and Conchi Estarás. (Image courtesy of Salk Institute)