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 Plasmonic biosensors enable development of new easy-to-use health tests
14.12.2017 | Aalto University

nachricht ASU scientists develop new, rapid pipeline for antimicrobials
14.12.2017 | Arizona State University

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>