Heart muscle can regenerate itself in very limited amounts, scientists find

June 25, 2014, University of California, Los Angeles
Heart diagram. Credit: Wikipedia

(Medical Xpress)—Researchers from UCLA's Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research are the first to directly measure the division of heart muscle cells, proving that while such division is very rare, it does occur.

The study, conducted by assistant professor of cardiology Dr. Reza Ardehali and colleagues, resolves a recent controversy over whether the has the power to regenerate itself. The findings are also important for future research that could lead to the regeneration of heart tissue to repair damage caused by disease or .

The findings were published May 29 in Proceedings of the National Academy of Sciences.

It was initially believed that , or cardiomyocytes, were unable to replicate themselves and that their total number was firmly set at birth. However, research over the past two decades has indicated that these cardiac cells have limited proliferative activity, though there has been no clear agreement within the scientific community as to why and how much.

In part, the indirect methods used to measure this potential have been difficult, and at times inaccurate, preventing a scientific consensus. Some groups of researchers used carbon dating to detect the age of cardiomyocytes in humans to determine whether they divided after initial fetal development, but the accuracy of this technique was debated. Others published theories that the heart muscle had a very high proliferative ability; recently, many of those papers were retracted because colleagues were unable to replicate the data.

Creating a model for direct measurement

To address the problems of measurement, Ardehali and his colleagues pioneered a novel genetic approach called mosaic analysis with double markers, or MADAM, to directly measure for the first time heart cell division in a mouse model. They found that limited, lifelong symmetric division of cardiomyocytes, while rare, is evident in mice, but it diminishes significantly after the first month of life. No stem cells are involved in this process, the researchers said, and division of cardiomyocytes is limited to less than 1 percent per year.

The daughter cardiomyocytes that are the products of this rare cell division also divide, the researchers said, though very seldomly, which had not been shown before. The scientists found that the rate of cell division did not increase as a reparative response when myocardial infarction was induced in the mice.

"This is one of the most convincing and direct ways of showing that the heart has a very limited regenerative power," Ardehali said. "This is a very exciting discovery because we hope to use this knowledge to eventually be able to regenerate . The goal is to identify the molecular pathways involved in symmetric division of and use them to induce regeneration to replenish after disease or injury."

Explore further: Study urges caution in stem cell clinical trials for heart attack patients

More information: Shah R. Ali, Simon Hippenmeyer, Lily V. Saadat, Liqun Luo, Irving L. Weissman, and Reza Ardehali. "Existing cardiomyocytes generate cardiomyocytes at a low rate after birth in mice." PNAS 2014 111 (24) 8850-8855; published ahead of print May 29, 2014, DOI: 10.1073/pnas.1408233111

Related Stories

Study urges caution in stem cell clinical trials for heart attack patients

May 7, 2014
A new study in Nature challenges research data that form the scientific basis of clinical trials in which heart attack patients are injected with stem cells to try and regenerate damaged heart tissue.

The birth of new cardiac cells

December 5, 2012
Recent research has shown that there are new cells that develop in the heart, but how these cardiac cells are born and how frequently they are generated remains unclear. In new research from Brigham and Women's Hospital (BWH), ...

Fate of the heart: Researchers track cellular events leading to cardiac regeneration

June 19, 2013
In a study published in the June 19 online edition of the journal Nature, a scientific team led by researchers from the University of California, San Diego School of Medicine visually monitored the dynamic cellular events ...

Stem cell therapy regenerates heart muscle damaged from heart attacks in primates

April 30, 2014
Heart cells created from human embryonic stem cells successfully restored damaged heart muscles in monkeys. The results of the experiment appear in the April 30 advanced online edition of the journal Nature in a paper titled, ...

Breakthrough in adult heart repair

November 19, 2013
Researchers from the Baylor College of Medicine and the Texas Heart Institute have discovered a new way to dramatically improve heart repair. The future goal is to use this knowledge to combat human cardiovascular disease ...

Spurt of heart muscle cell division seen in mice well after birth

May 8, 2014
The entire heart muscle in young children may hold untapped potential for regeneration, new research suggests.

Recommended for you

A nanoparticle inhalant for treating heart disease

January 18, 2018
A team of researchers from Italy and Germany has developed a nanoparticle inhalant for treating people suffering from heart disease. In their paper published in the journal Science Translational Medicine, the group describes ...

Starting periods before age of 12 linked to heightened risk of heart disease and stroke

January 15, 2018
Starting periods early—before the age of 12—is linked to a heightened risk of heart disease and stroke in later life, suggests an analysis of data from the UK Biobank study, published online in the journal Heart.

'Decorated' stem cells could offer targeted heart repair

January 10, 2018
Although cardiac stem cell therapy is a promising treatment for heart attack patients, directing the cells to the site of an injury - and getting them to stay there - remains challenging. In a new pilot study using an animal ...

Two simple tests could help to pinpoint cause of stroke

January 10, 2018
Detecting the cause of the deadliest form of stroke could be improved by a simple blood test added alongside a routine brain scan, research suggests.

Exercise is good for the heart, high blood pressure is bad—researchers find out why

January 10, 2018
When the heart is put under stress during exercise, it is considered healthy. Yet stress due to high blood pressure is bad for the heart. Why? And is this always the case? Researchers of the German Centre for Cardiovascular ...

Heart-muscle patches made with human cells improve heart attack recovery

January 10, 2018
Large, human cardiac-muscle patches created in the lab have been tested, for the first time, on large animals in a heart attack model. This clinically relevant approach showed that the patches significantly improved recovery ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.