Featured Research

from universities, journals, and other organizations

Enzyme Weakens The Heart

Date:
February 26, 2009
Source:
University Hospital Heidelberg
Summary:
An enzyme makes the mouse heart prone to chronic cardiac insufficiency -- if it is suppressed, the heart remains strong despite increased stress. Cardiologists have now explained this key mechanism in a mouse model and thus discovered a promising approach for the systematic prevention of chronic cardiac insufficiency.

An enzyme makes the mouse heart prone to chronic cardiac insufficiency – if it is suppressed, the heart remains strong despite increased stress. Cardiologists at the Internal Medicine Clinic at Heidelberg University Hospital in cooperation with scientists at the University of Texas Southwestern Medical Center at Dallas and Gφttingen University Hospital have now explained this key mechanism in a mouse model and thus discovered a promising approach for the systematic prevention of chronic cardiac insufficiency.

Long-term high pressure and stenoses of the valves or aorta make the heart work harder. When it compensates by excessive muscle growth (cardiac hypertrophy), the pump function is affected – rhythm disorders or heart failure can be the result. Other risk factors are overweight and age – more than 40 percent of people over age 70 suffer from cardiac muscle hypertrophy.

Despite progress in medication, around 95,000 people in Germany die annually from the consequences of chronic cardiac insufficiency. “It is essential to find the molecules that are key to the development of cardiac insufficiency in order to develop new, more efficient treatment“ states Dr. Johannes Backs, head of a research group in the Department of Cardiology, Angiology, and Pneumonology (Director Prof. Dr. med. Hugo A. Katus) at Heidelberg University Hospital.

Enzyme activates stress response and hypertrophy of the heart

A key molecule for cardiac hypertrophy brought on by stress is the naturally occurring enzyme CaMKII delta (Calcium/Calmodulin-dependent kinase II delta). Dr. Backs’ international research team proved this in genetically modified mice that could no longer produce this enzyme by surgically obstructing the main aorta to put the heart under greater stress and thus simulate permanent high blood pressure or valve stenosis in humans. The anticipated enlargement of the heart was very slight – the animals were protected.

“With these mice, we succeeded for the first time in specifically suppressing the CaMKII delta enzyme and clarifying its function in detail,” said Dr. Backs. CaMKII delta has a direct effect on the cells’ stress response. If it is missing, certain information in cell DNA is not accessed that is normally activated by stress, leading to hypertrophy of the heart. “There was still some slight enlargement of the heart, but presumably not enough to cause cardiac insufficiency,” said Dr. Backs. Under normal conditions, the genetically modified mice are inconspicuous – their hearts function and react normally.

The function of CaMKII delta as an intermediate of the heart’s stress response is a possible approach for effective therapy – the Heidelberg researchers anticipate that agents that block only this function of the enzyme would prevent the heart muscle from reacting to overload. Other functions of CaMKII delta should not be affected in order to avoid harmful side effects.  


Story Source:

The above story is based on materials provided by University Hospital Heidelberg. Note: Materials may be edited for content and length.


Journal Reference:

  1. Backs J, Backs T, Neef S, Kreusser MM, Lehmann LH, Patrick DM, Grueter CE, Qi X, Richardson JA, Hill JA, Katus HA, Bassel-Duby R, Maier LS, Olson EN. The delta isoform of CaM kinase II is required for pathological cardiac hypertrophy and remodeling after pressure overload. Proc Natl Acad Sci USA, 2009 Jan 28

Cite This Page:

University Hospital Heidelberg. "Enzyme Weakens The Heart." ScienceDaily. ScienceDaily, 26 February 2009. <www.sciencedaily.com/releases/2009/02/090217125540.htm>.
University Hospital Heidelberg. (2009, February 26). Enzyme Weakens The Heart. ScienceDaily. Retrieved August 31, 2014 from www.sciencedaily.com/releases/2009/02/090217125540.htm
University Hospital Heidelberg. "Enzyme Weakens The Heart." ScienceDaily. www.sciencedaily.com/releases/2009/02/090217125540.htm (accessed August 31, 2014).

Share This




More Health & Medicine News

Sunday, August 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) — Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) — California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
3 Things To Know About The Ebola Outbreak's Progression

3 Things To Know About The Ebola Outbreak's Progression

Newsy (Aug. 29, 2014) — Here are three things you need to know about the deadly Ebola outbreak's progression this week. 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