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

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.

 

Magnetized stem cells used to treat lung disease in mice

Magnetic targeting technique has emerged as a new strategy to aid delivery, increase retention, and enhance the effects of mesenchymal stromal cells (MSCs) but, so far, has not been performed in lung diseases. With the aid of magnets, magnetized MSCs remained longer in the lungs, and this was associated with increased beneficial effects for the treatment of silicosis in mice. Image Credit: AlphaMed Press

Certain jobs, such as construction work and sand blasting, are quite labor intensive but can also lead to some unexpected health complications down the road. One of these is called silicosis, a serious lung disease that affects millions of workers worldwide. It is the result of years of breathing in silica, a type of dust particle most commonly found in sand. The particles can cause inflammation and scarring of the lung tissue, which can lead to trouble breathing and death in the most severe cases. There is currently no cure for this condition and once the damage is done it cannot be reversed.

However, Dr. Patricia Rocco and Dr. Fernanda Cruz from the Laboratory of Pulmonary Investigation at Universidade Federal do Rio de Janeiro, Brazil have found a promising approach to treat silicosis that involves the use of stem cells and magnetization.

In this study, mesenchymal stromal cells (MSCs), a type of stem cell that has anti-inflammatory properties, were magnetized using specialized nanoparticles. The effects of the newly magnetized MSCs were then studied in mice in which silicosis was induced to see if magnetization could aid in delivery to the lungs. One group of mice was injected with saline (as a control study) while another group was injected with the magnetized MSCs. A third group of mice was injected with magnetized MSCs with a pair of magnets attached to their chest for 2 days. The results showed that using the magnetized MSCs alongside the magnets proved to be most effective in migrating the cells towards the lungs.

In a news release, Dr. Cruz elaborated on their findings for this portion of the study.

“Upon removal of the magnets, we examined all the animals in all the groups and found that those implanted with magnets had a significantly larger amount of magnetized MSCs in their lungs.”

For the next portion of the study, the team compared treatments in mice using magnetized MSCs with magnets vs non-magnetized MSCs. After 7 days, the magnets were removed from the mice with magnetized MSCs and their lungs were evaluated. It was found that those treated with magnetized MSCs and magnets showed significant signs of lung improvement while the other mice did not.

In the same news release, Dr. Rocco discusses the implications that these results have in terms of developing a potential treatment.

“This tells us that magnetic targeting may be a promising strategy for enhancing the beneficial effects of MSC-based cell therapies for silicosis and other chronic lung diseases.”

The full results of this study were published in Stem Cells Translational Medicine (SCTM).

CIRM has recently funded a clinical trial that uses MSCs to treat patients with acute respiratory distress syndrome (ARDS), a life-threatening lung injury that occurs when fluid leaks into the lungs, in both COVID-19 positive and COVID-19 negative patients.

Stem cell study holds out promise for kidney disease

Kidney failure

Image via youtube.com

Kidney failure is the Rodney Dangerfield of diseases, it really doesn’t get the respect it deserves. An estimated 660,000 Americans suffer from kidney failure and around 47,000 people die from it every year. That’s more than die from breast or prostate cancer. But now a new study has identified a promising stem cell candidate that could help in finding a way to help repair damaged kidneys.

Kidneys are the body’s waste disposal system, filtering our blood and cleaning out all the waste products. Our kidneys have a limited ability to help repair themselves but if someone suffers from chronic kidney disease then their kidneys are slowly overwhelmed and that leads to end stage renal disease. At that point the patient’s options are limited to dialysis or an organ transplant.

Survivors hold out hope

Italian researchers had identified some cells in the kidneys that showed a regenerative ability. These cells, which were characterized by the expression of a molecule called CD133, were able to survive injury and create different types of kidney cells.

Researchers at the University of Torino in Italy decided to take these findings further and explore precisely how CD133 worked and if they could take advantage of that and use it to help repair damaged kidneys.

In their findings, published in the journal Stem Cells Translational Medicine, the researchers began by working with a chemotherapy drug called cisplatin, which is used against a broad range of cancers but is also known to cause damage to kidneys in around one third of all patients. The team found that CD133 was an important factor in helping those damaged kidneys recover. They also found that CD133 prevents aging of kidney progenitor cells, the kind of cell needed to help create new cells to repair the kidneys in future.

Hope for further research

The finding opens up a number of possible lines of research, including exploring whether infusions of CD133 could help patients whose kidneys are no longer able to produce enough of the molecule to help repair damage.

In an interview in DD News, Dr. Anthony Atala, Director of the Wake Forest Institute for Regenerative Medicine – praised the research:

“This is an interesting and novel finding. Because the work identifies mechanisms potentially involved in the repair of tissue after injury, it suggests the possibility of new therapies for tissue repair and regeneration.”

CIRM is funding several projects targeting kidney disease including four clinical trials for kidney failure. These are all late-stage kidney failure problems so if the CD133 research lives up to its promise it might be able to help people at an earlier stage of disease.

Finally a possible use for your excess fat; using it to fix your arthritic knee

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One of the most common questions we get asked at CIRM, almost every other day to be honest, is “are there any stem cell treatments for people with arthritis in their knees?” It’s not surprising. This is a problem that plagues millions of Americans and is one of the leading causes of disability in the US.

Sadly, we have to tell people that there are no stem cell treatments for osteoarthritis (OA) in the knee that have been approved by the Food and Drug Administration (FDA). There’s also a lack of solid evidence from clinical trials that the various approaches are effective.

But that could be changing. There’s a growing number of clinical trials underway looking at different approaches to treating OA in the knee using various forms of stem cells. Sixteen of those are listed at clinicaltrials.gov. And one new study suggests that just one injection of stem cells may be able to help reduce pain and inflammation in arthritic knees, at least for six months. The operative word here being may.

The study, published in the journal Stem Cells Translational Medicine,  used adipose-derived stromal cells, a kind of stem cell taken from the patient’s own fat. Previous studies have shown that these cells can have immune boosting and anti-scarring properties.

The cells were removed by liposuction, so not only did the patient’s get a boost for their knees they also got a little fat reduction. A nice bonus if desired.

The study was quite small. It involved 18 patients, between the ages of 50 and 75, all of whom had suffered from osteoarthritis (OA) in the knee for at least a year before the treatment. This condition is caused by the cartilage in the knee breaking down, allowing bones to rub against each other, leading to pain, stiffness and swelling.

One group of patients were given a low dose of the cells (23,000) injected directly into the knee, one a medium dose (103,000) and one a high dose (503,000).

Over the next six months, the patients were closely followed to see if there were any side effects and, of course, any improvement in their condition. In a news release, Christian Jorgensen, of University Hospital of Montpellier, the director of the study, said the results were encouraging:

“Although this phase I study included a limited number of patients without a placebo arm we were able to show that this innovative treatment was well tolerated in patients with knee OA and it provided encouraging preliminary evidence of efficacy. Interestingly, patients treated with low-dose ASCs significantly improved in pain and function compared with the baseline.”

The researchers caution that the treatment doesn’t halt the progression of OA and does not restore the damaged cartilage, instead it seems to help patients by reducing inflammation.

In a news article about the study Tony Atala, director of the Wake Forest Institute for Regenerative Medicine, in Winston-Salem, N.C. and the editor of Stem Cells Translational Medicine said the study offered the patients involved another benefit:

“In fact, most of the patients (in the study group) who had previously scheduled total knee replacement surgery decided to cancel the surgery. It will be interesting to see if these improvements are seen in larger groups of study participants.”

Interesting is an understatement.

But while this is encouraging it’s important to remember it was done in a small group of patients and needs to be replicated in a much larger group before we can draw any solid conclusions. It will also be important to see if the benefits last longer than six months.

We might not have to wait too long for some answers. The researchers are already running a 2-year trial involving 150 people in Europe.

We’ll let you know what they find.

 

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.