New study casts doubt on heart regeneration in mammals

April 3, 2014, Cell Press
The resected area is still missing and scarformation (red) is seen in the border of the resection line. Red: Non-muscle myosin, green: Desmin, blue: Dapi. Credit: Stem Cell Reports, Andersen et al.

The mammalian heart has generally been considered to lack the ability to repair itself after injury, but a 2011 study in newborn mice challenged this view, providing evidence for complete regeneration after resection of 10% of the apex, the lowest part of the heart. In a study published in Stem Cell Reports on April 3, 2014, researchers attempted to replicate these recent findings but failed to uncover any evidence of complete heart regeneration in newborn mice that underwent apex resection.

"Our results question the usefulness of the apex resection model for identifying molecular mechanisms underlying heart regeneration after damage and underscore the need for the scientific community to firmly establish whether or not the mammalian heart is capable of regeneration," says lead study author Ditte Andersen of Odense University Hospital and the University of Southern Denmark.

Cardiovascular disease is currently one of the leading causes of death worldwide, and scientists have mainly attributed this high mortality rate to the inability of the mammalian heart to regenerate after . Novel therapies capable of enhancing the heart's ability to recover after a or other type of injury are urgently needed. That's why a 2011 Science report from Porrello et al. that provided evidence of complete heart regeneration in newborn mice attracted a great deal of attention and raised hopes for identifying factors that could improve heart regeneration.

This study prompted Andersen, Søren Sheikh, and their colleagues to look for factors that enable heart regeneration, but they were surprised to find no signs of true heart regeneration in newborn mice that underwent apex resection. Three weeks after this procedure, the damaged hearts were about 10% shorter and weighed 14% less than the hearts of control mice that underwent the same surgical procedure without apex resection. Moreover, the damaged hearts had large scars and lacked proliferating muscle cells crucial for restoring heart function.

The AR heart is more rounded and the apex is line by a scar coposed of Collagen (red). Credit: Stem Cell Reports, Andersen et al.

The apex is still missing in AR hearts and scarformation with connective tissue and fat is seen. Credit: Stem Cell Reports, Andersen et al.
"The notion of mammalian heart regeneration has given a lot of hope in the scientific community for finding important factors that may be used for improving adult heart regeneration," Andersen says. "We hope that our study will add another view on this important matter and spur a lot of studies from other independent labs that may shed further light on this controversial area of research."

Explore further: Breakthrough in adult heart repair

More information: Stem Cell Reports, Andersen et al.: "Do neonatal mouse hearts regenerate following heart apex resection?." dx.doi.org/10.1016/j.stemcr.2014.02.008

Related Stories

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 ...

Team finds gene therapy a promising tool for cardiac regeneration

February 20, 2014
After a heart attack, there is often permanent damage to a portion of the heart. This happens, in part, because cardiac muscle cells are terminally differentiated and cannot proliferate after blood flow is blocked off to ...

The heart's own stem cells play their part in regeneration

November 29, 2013
(Medical Xpress)—Up until a few years ago, the common school of thought held that the mammalian heart had very little regenerative capacity. However, scientists now know that heart muscle cells constantly regenerate, albeit ...

Researchers use microRNAs to induce regeneration of heart tissue

December 6, 2012
(Medical Xpress)—A research team working at Italy's International Centre for Genetic Engineering and Biotechnology has succeeded in causing heart tissue to regenerate by introducing two microRNAs into damaged mice hearts. ...

Gene regenerates heart tissue, critical finding for heart failure prevention

April 17, 2013
Researchers at UT Southwestern Medical Center have identified a specific gene that regulates the heart's ability to regenerate after injuries.

Recommended for you

Forces from fluid in the developing lung play an essential role in organ development

January 23, 2018
It is a marvel of nature: during gestation, multiple tissue types cooperate in building the elegantly functional structures of organs, from the brain's folds to the heart's multiple chambers. A recent study by Princeton researchers ...

More surprises about blood development—and a possible lead for making lymphocytes

January 22, 2018
Hematopoietic stem cells (HSCs) have long been regarded as the granddaddy of all blood cells. After we are born, these multipotent cells give rise to all our cell lineages: lymphoid, myeloid and erythroid cells. Hematologists ...

How metal scaffolds enhance the bone healing process

January 22, 2018
A new study shows how mechanically optimized constructs known as titanium-mesh scaffolds can optimize bone regeneration. The induction of bone regeneration is of importance when treating large bone defects. As demonstrated ...

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Bioengineered soft microfibers improve T-cell production

January 18, 2018
T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

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.