Featured Research

from universities, journals, and other organizations

New Light On The Role Of Microbial Pathogens In Atherosclerosis

Date:
October 19, 1999
Source:
French National Institute For Health And Medical Research (INSERM)
Summary:
Cardiovascular disease is the leading cause of death in industrialized countries (32% of all deaths in France, for example), and atherosclerosis is often the underlying process. Genetic and environmental factors (such as smoking, obesity, hypertension and high cholesterol levels) are known to play a role in atherosclerosis, but various lines of evidence also suggest that microbial pathogens are involved in the formation of atheroma plaque (i.e. atherosclerosis) or in its rupture (potentially leading to cardiovascular events).

Cardiovascular disease is the leading cause of death in industrialized countries (32% of all deaths in France, for example), and atherosclerosis is often the underlying process. Genetic and environmental factors (such as smoking, obesity, hypertension and high cholesterol levels) are known to play a role in atherosclerosis, but various lines of evidence also suggest that microbial pathogens are involved in the formation of atheroma plaque (i.e. atherosclerosis) or in its rupture (potentially leading to cardiovascular events). Bacteria (especially Chlamydia pneumoniae) and viruses have been detected at an abnormally high frequency in atheroma plaque, and have been forwarded either as co-factors in people already at risk, or as the chief cause of atherosclerosis in people with none of the classical risk factors.

Related Articles


Alain Tedgui, Ziad Mallat (Inserm unit 141, headed by Bernard Lévy) and their coworkers found that microbial pathogens induced atherosclerosis in experimental mice when an antiinflammatory cytokine, interleukin 10 (IL-10), was lacking. IL-10 production is under genetic control. Between 50 and 60% of the human population can produce high levels of this cytokine, while 40 to 50% produce intermediate levels and 5 to 10% can only synthesize small amounts.

The Inserm team worked on a mouse strain deficient in IL-10. The animals were raised in cages with filtered air (protecting them from air-borne microbes), and received a diet designed to induce atheroma plaque. The researchers found that the plaques were three times bigger than in similarly treated mice with normal IL-10 production, thereby demonstrating that IL-10 limits atheroma plaque formation.

The team then examined what happened when IL-10-deficient mice and their normal counterparts mice were exposed to unfiltered air containing microbial pathogens. This time the atheroma plaques in the deficient mice were 30 times larger than in their IL-10-producing counterparts. In other words, exposure to air-borne pathogens multiplied atheroma plaque formation by a factor of 10 in IL-10-deficient mice.

Finally, the researchers examined the composition of the atheroma plaque (proportions of lipids, macrophages, fibers and muscle cells), because this is an important factor in its stability, i.e. its tendency to break free from the vessel wall. The proportion of collagen fibers - a factor protecting against rupture - was four times lower in IL-10-deficient mice than in normal mice. Thus, the absence of IL-10 not only multiplied by a factor of 10 the size of the atheroma plaque when mice were exposed to air-borne pathogens, but it also made the plaque far more likely to rupture.

These results, published by Inserm unit 141, pave the way for studies designed to examine whether the risk of human cardiovascular disease is linked to IL-10 production capacity. They also lay the foundations for studies that may finally show whether certain microbial pathogens are involved in atherosclerosis.

If confirmed in humans, these findings may shortly lead to new treatment possibilities for atherosclerosis, as recombinant interleukin 10 is already being used to treat certain diseases.


Story Source:

The above story is based on materials provided by French National Institute For Health And Medical Research (INSERM). Note: Materials may be edited for content and length.


Cite This Page:

French National Institute For Health And Medical Research (INSERM). "New Light On The Role Of Microbial Pathogens In Atherosclerosis." ScienceDaily. ScienceDaily, 19 October 1999. <www.sciencedaily.com/releases/1999/10/991019080305.htm>.
French National Institute For Health And Medical Research (INSERM). (1999, October 19). New Light On The Role Of Microbial Pathogens In Atherosclerosis. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/1999/10/991019080305.htm
French National Institute For Health And Medical Research (INSERM). "New Light On The Role Of Microbial Pathogens In Atherosclerosis." ScienceDaily. www.sciencedaily.com/releases/1999/10/991019080305.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) — A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) — Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) — A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Hugging It Out Could Help You Ward Off A Cold

Hugging It Out Could Help You Ward Off A Cold

Newsy (Dec. 21, 2014) — Carnegie Mellon researchers found frequent hugs can help people avoid stress-related illnesses. 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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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