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
MAR 01, 2020
Cardiology
Vegetarian Diet May Reduce Stroke Risk
MAR 01, 2020
Vegetarian Diet May Reduce Stroke Risk
Stroke is the world’s second leading cause of death. Now, researchers from Tzu Chi University in Hualien, Taiwan h ...
APR 25, 2020
Cardiology
Young People with COVID-19 Die from Stroke
APR 25, 2020
Young People with COVID-19 Die from Stroke
Hospitals around the US have reported that people aged between 20 and 50 with no risk factors are dying from strokes aft ...
APR 27, 2020
Cardiology
Almost Half of College Female Athletes Have High Blood Pressure
APR 27, 2020
Almost Half of College Female Athletes Have High Blood Pressure
According to the World Health Organization (WHO) an estimated 1.13 billion people worldwide have hypertension, or high b ...
MAY 15, 2020
Cardiology
Cardiovascular Disease Mortality is Greater in Rural Areas
MAY 15, 2020
Cardiovascular Disease Mortality is Greater in Rural Areas
A wide variation in cardiovascular disease mortality rates has been noted among counties in the United States. Residents ...
JUN 29, 2020
Neuroscience
Stroke Most Common Brain Side Effect from COVID-19
JUN 29, 2020
Stroke Most Common Brain Side Effect from COVID-19
Researchers from the UK have identified having a stroke as the most common neurological side-effect of COVID-19. They al ...
JUL 09, 2020
Cardiology
Broken Heart Syndrome Found to Increase During Pandemic
JUL 09, 2020
Broken Heart Syndrome Found to Increase During Pandemic
Reporting in JAMA Network Open, scientists have found that broken heart syndrome, called stress cardiomyopathy, has been ...
Loading Comments...