Shortened Protein Length Linked to Higher Emphysema Risk in Mice

Studies in animals have shown that a shortened telomere length is closely associated with a higher risk of developing emphysema, according to a recent study from Johns Hopkins University published in the American Journal of Respiratory and Critical Care Medicine.

A protein structure at the end of a chromosome, a telomere is a specialized structure involved in the stability and replication of the chromosome. More specifically, it protects the chromosome tip from degradation. Although telomere length is genetically determined, researchers note that they gradually become shorter with cell division. Shortened telomeres are also seen as a sign of aging in cells.

Researchers set out to determine the role of telomeres in lung disease by studying mice with shortened telomeres and exposing them to cigarette smoke for six hours daily, five days a week, for a total of six months. Researchers then assessed the mice’s pulmonary function by analyzing lung tissue. Findings reveal that mice with shortened telomeres have an increased risk of developing emphysema after exposure to cigarette smoke.

Dr. Armanios and team previously demonstrated that shortened telomeres cause idiopathic pulmonary fibrosis (IPF), a diagnosis that may be accompanied by emphysema—especially in older patients who smoke. Researchers note that by linking telomere length to both disorders, there is now a clear suggestion that they may share a common mechanism that can be traced to telomeres.

“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,” said Mary Armanios, MD, assistant professor of oncology, in an article on Medical News Today. “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.”

Authors of the study note that additional research is needed to learn if the same findings hold true in humans.

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