"We found that in mice that have short telomeres, there was a significant increased risk of developing emphysema after exposure to cigarette smoke," said Mary Armanios, MD, assistant professor of oncology at the Johns Hopkins School of Medicine.
The study appears online ahead of the print edition of the American Journal of Respiratory and Critical Care Medicine.
Telomeres are DNA protein structures that protect chromosome ends from degradation. Their length is genetically determined, but they also shorten progressively with cell division. Short telomeres are considered one marker of ageing in cells.
"With age, short telomeres accumulate and cause cells to stop dividing. Telomeres can be thought of as 'biological clocks,'" Dr. Armanios explained. "We wanted to determine whether telomere length itself was why susceptibility to emphysema increases with age."
Dr. Armanios and her colleagues examined the role of telomeres in lung disease by studying mice that have shortened telomeres. The mice were exposed to cigarette smoke for six hours a day, five days a week for six months.
The researchers then analyzed the lung tissue and pulmonary function of the mice. "Although the mice had no lung disease at baseline, after exposure to cigarette smoke, they surprisingly developed emphysema. In contrast, mice with long telomeres did not develop lung disease during our experiments," said Dr. Armanios.
In emphysema, alveoli, the small air sacs where oxygen exchange occurs, are permanently lost. Emphysema changes are normally found in older individuals, and occasionally even in those who have never smoked. But they are most commonly found in smokers.
Emphysema is a common cause of disability, and among the top 10 causes of mortality in the United States, it remains on the increase. While smoking cigarettes is the most common risk factor, it is not known why some people are more prone to developing emphysema than others. There are currently no available medical treatments, and affected individuals often require lung transplantation.
"We found that cells with damaged DNA stopped dividing, and lung cells with too much damage could no longer be repaired, thus contributing to the emphysema," she continued. "These results are one of the clearest examples of telomere length, which is an inherited factor, interacting with an environmental insult to cause disease. In fact, our results in mice suggest that short telomeres might contribute to how cigarette smoke accelerates aging in the lung in some individuals."
Dr. Armanios hopes that this new research will lead into new insights into identifying new ways to preserve lung function with age.
"It's important to remember that there is no good reason to smoke and the best way to prevent emphysema is to stop smoking," she said.
Previously, Dr. Armanios and her group had shown that shortened telomeres cause a disease known as idiopathic pulmonary fibrosis (IPF), a disorder of unrelenting scarring in the lung. IPF occurs with emphysema in some individuals, and the incidence of both disorders increases with age and with smoking. "By linking telomere length to both disorders, there is now clear suggestion that they may share a common mechanism that can be traced to telomeres."
Further research must be done to confirm that the observed findings are applicable to humans, and, if so, what mechanisms might underlie them. "Now that we have examined the question of susceptibility in a rigorous genetic model, we can begin to study how telomere length affects emphysema risk in susceptible populations."
Keely Savoie | EurekAlert!
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences