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 July 22, 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 July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) — The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) — Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) — New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) — Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. 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