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 Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

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: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Metamolds: Molding a mold

20.08.2018 | Information Technology

It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

20.08.2018 | Power and Electrical Engineering

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>