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 August 21, 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 August 21, 2014).

Share This




More Health & Medicine News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Reasons Why Teen Birth Rates Are At An All-Time Low

Reasons Why Teen Birth Rates Are At An All-Time Low

Newsy (Aug. 20, 2014) A CDC report says birth rates among teenagers have been declining for decades, reaching a new low in 2013. We look at several popular explanations. 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