Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bleach-producing enzyme found to modulate blood vessel dilation during inflammation

28.06.2002


Findings important in developing new drugs to treat inflammatory vascular diseases



An enzyme that stimulates the production of chlorine bleach in cells to kill bacteria and other invading pathogens also turns off a signal that regulates blood vessel dilation during inflammation, researchers at the UC Davis School of Medicine and Medical Center have found.

The research -- conducted in collaboration with scientists at the University of Alabama at Birmingham, UCLA and the University of Iowa and reported in the June 28 issue of the journal Science -- is important because it identifies a previously unrecognized function for an abundant protein of the immune system and may reveal a new molecular target for the development of drugs to treat a variety of inflammatory vascular diseases.


The bleach-producing enzyme, known as myeloperoxidase, is a green-colored protein found in abundant supply in white blood cells, one of the sentries of the immune system. As white blood cells circulate in the bloodstream and accumulate at sites of infection or injury, they engulf bacteria and other foreign organisms. Just as bleach disinfects kitchens and bathrooms, this enzyme is released from storage sites within the white blood cell to locally produce hypochlorous acid, or chlorine bleach, as a bactericidal agent.

"Myeloperoxidase has been known to be an important component of the immune system," said Jason P. Eiserich, lead author and assistant professor of medicine and human physiology at the UC Davis School of Medicine and Medical Center. "It is present in very high concentrations in white blood cells and provides an important line of defense against invading micro-organisms. Since neutrophils are also known to contribute to impaired vascular function during acute inflammatory responses, we reasoned that myeloperoxidase may be a central player. Our studies show that myeloperoxidase does affect the vasculature, but by a pathway independent of its well-characterized capacity to produce chlorine bleach."

Under normal conditions, a chemical signal, nitric oxide, produced by endothelial cells lining the blood vessel wall, acts as an important vasodilator. The research team found that following the induction of acute inflammation in rodent models, myeloperoxidase is released from activated white blood cells, permeates vascular cells and is deposited within the blood vessel wall where it acts to consume nitric oxide, thereby blocking the signal that dilates blood vessels. Cellular and biochemical studies have corroborated the inhibitory role of myeloperoxidase.

"Identifying a protein that modulates nitric oxide-dependent blood vessel dilation has important implications for the potential treatment of inflammatory vascular diseases," said Eiserich. "Under acute inflammatory conditions, such as intense bacterial infection, this enzyme may provide a physiologic means for removing excessive nitric oxide levels and preventing severe low blood pressure conditions from developing. Drugs aimed at mimicking this enzymatic activity may be useful for treating systemic hypotension during septic shock. Alternatively, drugs aimed at blocking the activity of myeloperoxidase may be useful for treating chronic vascular diseases, such as atherosclerosis, which are commonly characterized by a deficit in the vasodilatory substance nitric oxide and the accumulation of myeloperoxidase in the blood vessel wall."

The research findings also may help guide future studies aimed at identifying whether individuals without the myeloperoxidase enzyme due to hereditary deficiency display abnormal vascular responses during inflammation.


Other scientists contributing to this research include Stephan Baldus, Wenxin Ma, Chunxiang Zhang, Albert Tousson, Laura Castro, C. Roger White and Bruce A. Freeman from the University of Alabama; Marie-Luise Brennan and Aldons J. Lusis from UCLA; and William M. Nauseef from the University of Iowa. The research was supported by grants from the National Institutes of Health, the American Heart Association and the Veterans Affairs Administration.

Carole Gan | EurekAlert!
Further information:
http://news.ucdmc.ucdavis.edu

More articles from Health and Medicine:

nachricht Lung images of twins with asthma add to understanding of the disease
05.12.2019 | University of Western Ontario

nachricht Between Arousal and Inhibition
05.12.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Detailed insight into stressed cells

05.12.2019 | Life Sciences

State of 'hibernation' keeps haematopoietic stem cells young - Niches in the bone marrow protect from ageing

05.12.2019 | Life Sciences

First field measurements of laughing gas isotopes

05.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>