Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cigarette smoking increases production of mucus in patients with bronchitis

18.02.2011
Cigarette smoking has been linked with overproduction of mucus associated with chronic bronchitis, according to a study conducted by researchers in New Mexico. The study indicates cigarette smoke suppresses a protein that causes the natural death of mucus-producing cells in the airways of bronchitis patients.

The findings were published online ahead of the print edition of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

"Although it is known that chronic mucus secretion is a hallmark of chronic bronchitis, the mechanisms underlying this condition are largely unknown," said Yohannes Tesfaigzi, PhD, director of the COPD Program at Lovelace Respiratory Research Institute in Albuquerque. "This study shows that the airway cells that secrete mucus are sustained by cigarette smoke, which suppresses a cell death-inducing protein called Bik."

Chronic bronchitis is commonly associated with chronic obstructive pulmonary disease (COPD). Cigarette smoking is the leading cause of disease for 15 million individuals with COPD in the United States alone and for over 200 million people worldwide.

"Previous studies have shown overproduction of mucus cells is common in the large and small airways of cigarette smokers," Dr. Tesfaigzi said. "This overproduction in the small airways is responsible for airway obstruction and reduced lung function and in the pathogenesis of acute exacerbations of COPD.

"Our previous studies show that following inflammatory responses, up to 30 percent of cells lining the airways undergo death and return to the original cell numbers," he continued. "This cell death is aided in part by proteins, including Bik. Disruption of this recovery process may lead to persistent elevation of mucus cell numbers and contribute to airway obstruction found in chronic lung diseases such as chronic bronchitis.

"Based on these earlier findings we wanted to determine if Bik may be responsible for sustained mucus cell growth in the airways of cigarette smokers," he said.

To test their hypothesis, the researchers examined both human airway tissue samples and mouse models. Human samples were derived from autopsy tissues and from bronchial brushings taken from individuals with chronic bronchitis as well as healthy controls. Chronic bronchitis was defined as a daily cough with phlegm production for 3 consecutive months, 2 years in a row.

Mice were exposed to cigarette smoke for six hours per day, five days per week for three weeks. Following exposure, lung tissue samples were collected and examined for the presence of Bik.

The researchers determined Bik was significantly reduced in bronchial brushings of patients with chronic bronchitis compared to non-diseased controls. Examination of autopsy tissues confirmed the finding. Mice exposed to cigarette smoking also had significantly reduced Bik levels and increased numbers of mucus-producing cells.

In another arm of the study, mice exposed to cigarette smoke were subsequently exposed to filtered air for 60 days and evaluated for Bik levels to determine whether Bik remains suppressed even after cessation of cigarette smoking. They found mice exposed to cigarette smoke still exhibited significantly lower levels of Bik, even after being exposed to filtered air.

"We found that cigarette smoke suppresses Bik levels in humans and in mice models, and mucus cells increased threefold in mice exposed to cigarette smoke," he said. "Moreover, the mouse study suggests that Bik remains suppressed in former cigarette smokers that have persistent chronic bronchitis. In humans, Bik was reduced even more in former smokers who had chronic bronchitis compared to former smokers without.

"The possible therapeutic value of these findings was tested by restoring Bik levels in the airways of cigarette smoke-exposed mice or human airway epithelial cells using genetic approaches," Dr. Tesfaigzi said. "This approach reduced the epithelial cells in cigarette smoke-exposed mice.

"These studies lay the foundation to investigate therapies that may restore expression of Bik and reduce the numbers of mucus-producing cells," he added. "This method may reduce excess secretion of mucus and the airway blockages in patients with chronic bronchitis."

Brian Kell | EurekAlert!
Further information:
http://www.thoracic.org

More articles from Health and Medicine:

nachricht New study points the way to therapy for rare cancer that targets the young
22.11.2017 | Rockefeller University

nachricht Penn study identifies new malaria parasites in wild bonobos
21.11.2017 | University of Pennsylvania School of Medicine

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: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>