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 New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>