Navigation Links
Scarring a necessary evil to prevent further damage after heart attack
Date:11/15/2011

CHAPEL HILL, N.C. After a heart attack, the portions of the heart damaged by a lack of oxygen become scar tissue. Researchers have long sought ways to avoid this scarring, which can harden the walls of the heart, lessen its ability to pump blood throughout the body and eventually lead to heart failure. But new research from the University of North Carolina at Chapel Hill School of Medicine shows that interrupting this process can weaken heart function even further.

In a study appearing online November 15, 2011, in the EMBO Journal, the investigators observed that cells in the outer layer of the heart generated scar tissue. But when they blocked these cells from doing so, they essentially demonstrated that when fixing a broken heart, timing may be everything.

"We now know that scarring is a good thing, because it prevents a precipitous decline in heart function immediately after heart injury," said Arjun Deb, MD, senior study author and assistant professor of medicine and cell and molecular physiology at the UNC School of Medicine. "The question is not whether, but when it makes the most sense to manipulate the cells of the heart to decrease scarring and enhance regeneration." Deb is also a member of UNC's McAllister Heart Institute and the Lineberger Comprehensive Cancer Center.

Regeneration happens naturally in lower organisms like zebrafish the striped, thumb-sized inhabitants of household aquariums but for some reason not in higher organisms like humans. Years ago researchers noticed that a thin outer layer of cells on the surface of the heart muscle known as the epicardium was playing an important role in regenerating the zebrafish heart after injury. But what role the epicardium might have in an injured mammalian heart was an open question.

By studying a mouse model of cardiac injury, Deb and his colleagues found that the epicardium of the mammalian heart was also activated after a heart attack. But unlike in zebrafish where the epicardium contributed to generation of heart muscle cells, in the mouse the epicardium generated fibroblasts, the fibrous cells that underlie scar tissue.

The researchers then found that a protein called Wnt1, which they had formerly shown to enhance function of human vascular stem cells, was driving stem cells within the epicardium to become fibroblasts. They wondered if interrupting this molecular pathway could ameliorate scarring and improve heart function. Surprisingly, when they interrupted Wnt1 signaling in genetically engineered mice, the mutants developed heart failure within 2 weeks after cardiac injury.

"There are clearly evolutionary parallels between the zebrafish and the mouse, but there must be some sort of a selection pressure in mammals to respond to heart injury by scarring, because if we interrupt this process then the heart quickly fails following injury," said Deb. "In organisms where there is a high pressure of blood flow, these cells may need to turn into scar tissue to maintain the tensile strength of the heart wall and prevent catastrophic rupture," speculates Deb.

Now Deb and his colleagues are genetically manipulating the stem cells residing in the epicardium at later time points to see if they can coax them to stop turning into fibroblasts and start forming heart-regenerating myocytes. If so, the approach could prove to be an invaluable way to help patients recover from a heart attack.


'/>"/>

Contact: Les Lang
llang@med.unc.edu
919-966-9366
University of North Carolina School of Medicine
Source:Eurekalert  

Related biology news :

1. Preventing a broken heart: Research aims to reduce scarring from heart attacks
2. Sustainable fishing is possible and necessary
3. Avoiding dairy due to lactose intolerance is unnecessary in most cases
4. Enzyme necessary for development of healthy immune system
5. Cholesterol necessary for brain development
6. Enzyme boosts metabolism, prevents weight gain in mice
7. New approaches may prevent certain side effects in BRAF mutation-positive melanoma
8. Rutgers neuroscientist says protein could prevent secondary damage after stroke
9. Animal study suggests that newborn period may be crucial time to prevent later diabetes
10. Preventing cancer development inside the cell cycle
11. A coating that prevents barnacles forming colonies
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Scarring a necessary evil to prevent further damage after heart attack
(Date:4/19/2016)... , UAE, April 20, 2016 ... be implemented as a compact web-based "all-in-one" system solution ... the biometric fingerprint reader or the door interface with ... of modern access control systems. The minimal dimensions of ... ID readers into the building installations offer considerable freedom ...
(Date:4/15/2016)... 15, 2016 Research and ... Biometrics Market 2016-2020,"  report to their offering.  , ... , ,The global gait biometrics market is expected ... the period 2016-2020. Gait analysis generates ... be used to compute factors that are not ...
(Date:4/13/2016)... 2016  IMPOWER physicians supporting Medicaid patients in ... clinical standard in telehealth thanks to a new partnership ... platform, IMPOWER patients can routinely track key health measurements, ... index, and, when they opt in, share them with ... a local retail location at no cost. By leveraging ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... June 24, 2016  Regular discussions on a range of ... between the two entities said Poloz. Speaking at ... Ottawa , he pointed to the country,s inflation target, ... government. "In certain ... institutions have common economic goals, why not sit down and ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... pleased to announce the launch of their brand, UP4™ Probiotics, into Target stores ... 35 years, is proud to add Target to its list of well-respected retailers. ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... Plate® YM (Yeast and Mold) microbial test has received AOAC Research Institute approval ... of microbial tests introduced last year,” stated Bob Salter, Vice President of Regulatory ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the ... at the Arkansas State Crime Laboratory, has joined STACS DNA as a Field Application ... team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further expanding our ...
Breaking Biology Technology: