Scientists identify missing link between smoking and inflammation
It's no secret that using tobacco is bad for you, but what has been a mystery until now is how tobacco causes increased inflammation throughout the body. Now, a team of researchers from the United States and Sweden have learned why. In a new report appearing in the November 2016 issue of the Journal of Leukocyte Biology, scientists show that nicotine activates certain white blood cells, called neutrophils, which in turn release molecules that lead to increased inflammation.
"Our study reveals an explanation how nicotine contributes to induction of inflammation and in doing so shows new possibilities for future therapies to treat tobacco-related diseases which each year lead to premature deaths of several million people worldwide," said Constantin Urban, a researcher involved in the work from the Umeå Centre for Microbial Research in Sweden.
To make this discovery, the researchers stimulated isolated neutrophils from humans and mice with nicotine and could measure a dose-dependent release of inflammatory molecules. By using pharmacological small molecule inhibitors as well as neutrophils from genetically modified mouse strains the team could identify essential receptor and signaling pathways involved in the nicotine-mediated activation of neutrophils.
"The cancer-causing effects of smoking have been known for decades, but how smoking is related to immune changes has been less clear," said E. John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. "Because of the direct link between nicotine itself and inflammation, this study has important implications including that alternative forms of nicotine inhalation, such as vaping that lacks other chemicals from cigarette smoke, may nonetheless still have detrimental immunological effects."
The Journal of Leukocyte Biology publishes peer-reviewed manuscripts on original investigations focusing on the cellular and molecular biology of leukocytes and on the origins, the developmental biology, biochemistry and functions of granulocytes, lymphocytes, mononuclear phagocytes and other cells involved in host defense and inflammation. The Journal of Leukocyte Biology is published by the Society for Leukocyte Biology.
Details: Ava Hosseinzadeh, Paul R. Thompson, Brahm H. Segal, and Constantin F. Urban.
Nicotine induces neutrophil extracellular traps. J. Leukoc. Biol. November 2016 100:1105-1112; doi:10.1189/jlb.3AB0815-379RR. Early online: June 16, 2016. http://www.jleukbio.org/content/100/5/1105.abstract