Featured Research

from universities, journals, and other organizations

Enzyme triggers cell death in heart attack

Date:
October 11, 2012
Source:
University of Iowa Health Care
Summary:
A new study shows that CaM kinase II enzyme activity triggers heart cell death by making the cells' energy-producing mitochondria leaky. Inhibiting the enzyme in mitochondria protected mice from heart cell death during heart attack and other forms of heart stress. The findings could lead to better therapies for common forms of heart disease.

University of Iowa researchers have previously shown that an enzyme called CaM kinase II plays a pivotal role in the death of heart cells following a heart attack or other conditions that damage or stress heart muscle. Loss of beating heart cells is generally permanent and leads to heart failure, a serious, debilitating condition that affects 5.8 million people in the United States.

Now the UI team, led by Mark Anderson, M.D., Ph.D., professor and head of internal medicine at the UI Carver College of Medicine, has honed in on how CaM kinase II triggers heart cell death following heart damage, showing that the action takes place in the cells' energy-producing mitochondria. In animal tests, the team reports that blocking the enzyme can prevent heart cells from dying, and protects the animals from heart failure.

Mitochondrial are the cells' batteries, generating the energy cells need to work. In heart cells, energy produced by these small cellular components fuels each heartbeat. However, when the heart is stressed, for example during a heart attack, the mitochondria become leaky and non-functional, which triggers cell death and heart failure.

"We found that activity of the CaM kinase II enzyme in mitochondria promotes cell death when the heart is stressed," says Mei-ling Joiner, Ph.D., UI assistant professor of internal medicine and lead author of the study, which was published online Oct. 10 in the journal Nature. "The findings might help us advance treatment of heart diseases and reduce mortality after a heart attack."

The new study shows that activated CaM kinase II promotes leakiness of mitochondria and increases heart muscle damage by allowing too much calcium to enter mitochondria. Specifically, the UI team found that CaM kinase II regulates calcium entry into mitochondria by modifying a special mitochondrial calcium channel. Too much enzyme activity increased the amount of calcium flowing into mitochondria, and this calcium overload triggers cell death.

Using genetically modified mice, the team also showed that inhibiting CaM kinase II activity in mitochondria prevented the calcium overloading, reduced mitochondrial disruption, and protected the mice from heart cell death during heart attack.

These findings provide insight into molecular mechanisms for mitochondrial function and suggest that inhibiting the CaM kinase II enzyme in mitochondria could lead to new and more effective therapies for common forms of heart disease.

"Because mitochondria also play important roles in other diseases in brain and skeletal muscle, for example, our findings could also have broad implications for understanding and treating non-cardiac diseases," says Anderson, who also is director of the UI Cardiovascular Research Center.


Story Source:

The above story is based on materials provided by University of Iowa Health Care. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mei-ling A. Joiner, Olha M. Koval, Jingdong Li, B. Julie He, Chantal Allamargot, Zhan Gao, Elizabeth D. Luczak, Duane D. Hall, Brian D. Fink, Biyi Chen, Jinying Yang, Steven A. Moore, Thomas D. Scholz, Stefan Strack, Peter J. Mohler, William I. Sivitz, Long-Sheng Song, Mark E. Anderson. CaMKII determines mitochondrial stress responses in heart. Nature, 2012; DOI: 10.1038/nature11444

Cite This Page:

University of Iowa Health Care. "Enzyme triggers cell death in heart attack." ScienceDaily. ScienceDaily, 11 October 2012. <www.sciencedaily.com/releases/2012/10/121011162154.htm>.
University of Iowa Health Care. (2012, October 11). Enzyme triggers cell death in heart attack. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2012/10/121011162154.htm
University of Iowa Health Care. "Enzyme triggers cell death in heart attack." ScienceDaily. www.sciencedaily.com/releases/2012/10/121011162154.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins