JUN 01, 2016 6:19 PM PDT

Boosting the Heart's Capacity For Self-Repair Post-Heart Attack

WRITTEN BY: Kara Marker
After the heart muscle cells of a newborn develop to a certain point where the body has seemed to consider is sturdy enough to support life, the chromosomes of these cells wear away, a process that occurs very quickly after birth. A team of scientists at the Spanish National Center for Cardiovascular Research (CNIC) are picking apart the disappearing act pulled by newborn cardiomyocytes, hypothesizing that the resurrection of these chromosomes later in life could help adult hearts struggling with repair following damaging cardiac events.
 
Telomerase-deficient heart tissue (right) with large fibrotic regions (blue) versus wildtype myocardium (left)
 
After cardiomyocyte chromosomes wear away, these cells are limited in their ability to multiply and replace damaged tissue. For adults at risk for heart failure, stroke, and even death following a heart attack, gaining back cardiomyocytes’ capability early in human life to self-proliferate could be the difference between life and death.
 
CNIC researchers hypothesized that the initial disappearance of cardiomyocyte chromosomes is connected to a disconnect between telomeres, repetitive and protective sequences of DNA found on each end of chromosomes like the cap on a water bottle, and the enzyme that helps to produce them.
 
Without this enzyme, called telomerase, other cells in the body recognize stunted telomeres as damaged DNA, stopping the cell cycle from continuing to produce more cells. CNIC researchers initially though the lack or mutation of the telomerase enzyme causes the cardiomyocyte chromosomes to disappear early in life, and providing adult cells with intact telomerase could then be the solution to restoring self-replicative abilities in cardiomyocytes.
 
To test their hypothesis, CNIC researchers first examined the length of telomeres in newborn mouse cardiomyocytes, and they found that the mice telomeres quickly disintegrated by the time the mice reached a week of life. They simultaneously saw both a decrease in telomerase expression and activation of the DNA damage response that halts the cell cycle as well as activation of a cell cycle inhibitor molecule called p21.
 
Next, they experimented with telomerase-deficient mice. The cardiomyocytes of these mice stop proliferating just one day after birth. When the mice experienced cardiovascular damage the second day after birth, muscle tissue failed to regenerate, while mice with normal levels of telomerase responded as expected, by self-proliferating new muscle tissue.
 
Lastly, the researchers tested the regenerative capacity of cardiomyocytes when the cell cycle inhibitor p21 was knocked out. These mutants showed an enhanced ability to regenerate cardiomyocytes, as p21-deficient mice repaired damaged cardiac tissue on their own more effectively than normal wildtype mice of the same age.
 
The take-away is this: manipulating and/or maintaining cardiomyocyte telomere length could boost the regenerative capacity of adult cells, helping people to heal themselves after a heart attack to prevent the dangerous aftermath that can come from this type of dangerous cardiac event. The CNIC researchers next plan to develop telomerase overexpression mouse models to see if they can extend the “regenerative window.” Will they be successful? Only time will tell.
 
Their current study was recently published in The Journal of Cell Biology.
 
 
Sources: Rockefeller University Press, YourGenome.org
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
JUN 19, 2019
Cardiology
JUN 19, 2019
TAVR Procedure Shares Spotlight With Rock Legend
While legendary rockstar Mick Jagger recently underwent a Transcatheter Aortic Valve Replacement (TAVR) at a hospital in New York, many are not candidates...
JUL 20, 2019
Cardiology
JUL 20, 2019
Hacking Fat Cells
The high-fat energy-dense diet we consume today is nothing like what humans ate for all of history before us. Luckily, we no longer have to hunt and kill o...
OCT 09, 2019
Cardiology
OCT 09, 2019
Diagnosed With Atopic Dermatitis?
Eczema, dermatitis, atopic dermatitis: all names for the same disease of the skin. Although common in children during the first year of life, the condition...
OCT 25, 2019
Cardiology
OCT 25, 2019
Cardiac Mapping for Arrhythmia Diagnosis
Cardiac mapping is an essential diagnostic tool. These imagining tools are used for diagnosing arrhythmias in the heart. Cardiac mapping can be done in sev...
JAN 08, 2020
Cardiology
JAN 08, 2020
Insecticides Linked to Increased Risk of Cardiovascular Disease and Death
New research from the University of Iowa has shown that prolonged exposure to common household insecticides may increase one’s risk for developing ca...
JAN 15, 2020
Cardiology
JAN 15, 2020
Women's Blood Vessels Age Faster than Men's, Study shows
Around 75 million Americans have high blood pressure, or roughly 1 in every 3 adults. Now, new research has shown that women’s blood vessels age fast...
Loading Comments...