APR 23, 2018 12:37 PM PDT

Damaged Heart Cells Can Regenerate Using Innovative Technique

WRITTEN BY: Kara Marker

There is no definitive “treatment” for the damage that results from a heart attack because the heart cells cannot regenerate themselves after such an attack. But scientists from Columbia University present a new approach that involves using heart cells’ own molecular messages to improve regeneration after a heart attack.

Immunofluorescent staining for F-actin filaments (green) and nuclei (blue) in neonatal cardiomyocytes. Credit: Ps1415

After the death of heart muscle cells, called cardiomyocytes, in the wake of a heart attack, the heart is unable to adequately pump blood. Essentially, the heart is forced to do the same job but with less cells.

The response by scientists from all over the world has recently been stem cell transplantation to replace dead and damaged cardiomyocytes with new cells to improve heart function after a heart attack. However, there are several problems associated with this approach. First, implanted stem cells don’t always survive or successfully transform into cardiomyocytes as intended. Additionally, implanted cardiomyocytes often fail to beat synchronously with the heart, increasing the risk of dangerous abnormal heart rhythms called arrhythmias.

The new approach designed by the team from Columbia University involves applying extracellular vesicles secreted by the cardiomyocytes themselves. These vesicles are secreted by virtually all cell types, and cells use the genetic information the vesicles contain to communicate with other cells.

“We postulated that the benefits of cell therapy of the heart could be coming from the secreted bioactive molecules (such as microRNAs), rather than the cells themselves," explained senior author Vunjak-Novakovic. "So we explored whether the benefits of cell therapy of the injured heart could be achieved without using the cells. This way, we would largely simplify the translation into the clinic, and avoid the burden of arrhythmia associated with implantation of contractile cells."

Developing a therapeutic approach to heart attack using these vesicles has several advantages over a more traditional cell-based therapy. First, the vesicles are easily to isolate and store, so they can either be used immediately in an “acute-care setting” or be saved for later use. As opposed to implanted stem cells, extracellular vesicles do not raise the risk of arrhythmia, and their regulatory path towards clinical application is simpler than the path for cell-based therapies.

Researchers evaluated the effectiveness of this approach first by isolated cardiomyocytes from adult human stem cells and collected their secreted extracellular vesicles. Next, they used next-generation sequencing to compare the genetic information in these vesicles compared to vesicles secreted by undifferentiated stem cells.

They found that extracellular vesicles from cardiomyocytes, not from undifferentiated stem cells, contained powerful regulatory molecules called “cardiogenic and vasculogenic microRNAs.”

Next researchers developed a collagen-based patch that takes the vesicles and releases them slowly over four weeks. They implanted the patch into the hearts of rats used as a model of heart attack. Researchers found that the rate of arrhythmia was much lower in this scenario than with cell therapy.

“By four weeks after treatment, the hearts treated with extracellular vesicles had similar cardiac function as those that were never injured,” Vunjak-Novakovic said.

"Once we better understand how exactly the extracellular vesicles do what they do," Vunjak-Novakovic concluded, "we should be able to extend their use to a range of cardiovascular diseases, and significantly advance the field of cell-free heart therapy."

The present study was published in the journal Nature Biomedical Engineering.

Source: Columbia University School of Engineering and Applied Science

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
APR 28, 2018
Cardiology
APR 28, 2018
Eating Dark Chocolate Reduces Stress, Improves Mood
We’ve heard that dark chocolate is good for us in reasonable amounts, but two unique studies from the Loma Linda University Adventist Health Sciences...
JUN 11, 2018
Cardiology
JUN 11, 2018
Mangoes for A Healthy Heart
The newest fruit under study for promoting heart health is the mango. Now demonstrated to be effective at lowering blood pressure for post-menopausal women...
JUN 29, 2018
Cardiology
JUN 29, 2018
The Drug That's Best for Both Kidney Failure and Arrhythmia Patients
A specific drug is the best to prescribe to people with both an irregular heartbeat and kidney failure. This population of people is at a particularly high...
JUL 02, 2018
Cardiology
JUL 02, 2018
AF Treatment Zaps Faulty Heart Tissue
Treating atrial fibrillation (AF), the most common type of arrhythmia, with what was previously a last-resort therapeutic approach will help reduce the ris...
AUG 07, 2018
Cardiology
AUG 07, 2018
Hookah Smoking, Not as Safe as it Claims
Despite advertisements to the contrary, hookah smoking has been linked to adverse health effects including increase arterial stiffness....
AUG 23, 2018
Cardiology
AUG 23, 2018
A Faster and Safe Heart Attack Diagnosis
A new clinical score can diagnose heart attack quickly and safely compared to traditional diagnostic methods....
Loading Comments...