Featured Research

from universities, journals, and other organizations

Newly Recognized Cell-Surface Receptor Protects Heart Tissue Against Damage

Date:
June 9, 1998
Source:
University Of Pennsylvania Medical Center
Summary:
Scientists at the University of Pennsylvania Medical Center and the National Institutes of Health (NIH) have identified a new molecular target that could lead to novel and improved therapies for ischemic cardiovascular disease. This disease, which occurs when heart cells don't get enough oxygen, accounts for nearly 90 percent of the 1.5 million heart attacks Americans suffer annually.

Scientists at the University of Pennsylvania Medical Center and the National Institutes of Health (NIH) have identified a new molecular target that could lead to novel and improved therapies for ischemic cardiovascular disease. This disease, which occurs when heart cells don't get enough oxygen, accounts for nearly 90 percent of the 1.5 million heart attacks Americans suffer annually.

The research team found that receptors for adenosine -- a nucleic-acid derivative -- found on the surface of ventricle cells exert a powerful, sustained protection against injury during exposure to ischemia. "Consequently, adenosine mimics could be given as drugs to alter the effect of a heart attack," suggests cardiac biologist Bruce T. Liang, MD, an associate professor of medicine at Penn. "Potential drugs would attach in a lock-and-key fashion to the adenosine receptor, triggering molecular events that could reduce the severity of a heart attack."

"We have known for decades that adenosine protects the heart when it is overstressed," says co-author Kenneth A. Jacobson, PhD, chief of the Molecular Recognition Section at the National Institute of Diabetes and Digestive and Kidney Diseases. "Now we have shown that a specific target molecule on the cell -- the A3 adenosine receptor -- protects the heart muscle lacking oxygen and nutrients more effectively than any other. This marriage of chemistry and biology brings us one step closer to designing a drug to minimize damage to heart muscle." Liang and Jacobson report their findings in the June 9 issue of the Proceedings of the National Academy of Sciences.

Heart cells release adenosine under such stressful conditions as blockage of the coronary artery. Adenosine binds to receptors on cell surfaces, rendering the cells more resistant to the deleterious effects of ischemia by essentially shutting them down.

Previous studies from Penn, NIH, and other labs have suggested that many types of adenosine receptors in an array of species, including humans, exert a protective effect on the heart, but never to this degree of fine-tuning. This study, which used cultured cells from chicks, teases apart the differing effects of two receptor subtypes -- A1 and A3 -- showing that activation of A3 receptors elicits sustained protection whereas activation of A1 receptors triggers a short-lived effect. "We showed that the A3 receptor is the dominant cardioprotective receptor, and therefore should be the one for drug targets," says Liang.

The study also showed a second difference between the two receptors. A pre-conditioning therapy that could help reduce post-operative heart attacks can be induced using A3 receptors, but not using A1. Ironically, prior exposure of heart cells to ischemia protects them against subsequent damage. This pre-conditioning is again triggered by adenosine, which ultimately causes changes to heart cell ion channels. "If we can pre-condition the heart before surgery with a drug that acts on ion channels, then perhaps we may lessen the chances of an attack," notes Liang. "During heart surgery you want to have as much of a window of protection as possible."

The researchers also found that the protective properties of the A3 receptor can be conferred -- via gene transfer -- onto tissues without this type of receptor. "We've shown that chick atrial tissue, which doesn't contain A3 receptors, can be protected by transferring human A3 receptors into them," states Liang. "One could potentially broaden this to tissue types outside the heart, as long as the machinery exists in that tissue to link up with the receptor."

The next steps, say the researchers, will be to develop a drug that activates the A3 receptor and to design pre-clinical drug safety trials.


Story Source:

The above story is based on materials provided by University Of Pennsylvania Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

University Of Pennsylvania Medical Center. "Newly Recognized Cell-Surface Receptor Protects Heart Tissue Against Damage." ScienceDaily. ScienceDaily, 9 June 1998. <www.sciencedaily.com/releases/1998/06/980609081709.htm>.
University Of Pennsylvania Medical Center. (1998, June 9). Newly Recognized Cell-Surface Receptor Protects Heart Tissue Against Damage. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/1998/06/980609081709.htm
University Of Pennsylvania Medical Center. "Newly Recognized Cell-Surface Receptor Protects Heart Tissue Against Damage." ScienceDaily. www.sciencedaily.com/releases/1998/06/980609081709.htm (accessed September 3, 2014).

Share This



More Health & Medicine News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 Video provided by AFP
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