With the advent of electronic cigarettes (e- cigs), people have begun inhaling purified nicotine in a liquid vehicle – typically vegetable glycerin/propylene glycol. Nicotine is the pharmacologically active compound in tobacco products, including e-cigarettes, and though the effects of nicotine on the brain and cardiovascular system are well known, the compound’s effects on the lungs have been less studied. Even less is known about the effects of inhaling vaporized nicotine, also known as vaping.
Rob Tarran, PhD, associate professor of cell biology and physiology, and Mehmet Kesimer, PhD, associate professor of pathology and laboratory medicine, will lead a $2.3-million, five-year project to investigate fundamental biological effects of nicotine on the lung. Both are members of the UNC Marsico Lung Institute. Tarran directs the UNC Center of Tobacco Regulatory Science and Lung Health (TCORS). Raymond Pickles, PhD, associate professor of microbiology and immunology, and Alessandra Livraghi-Butrico, PhD, assistant professor of medicine, are co-investigators on the grant.
“Our initial data indicate that e-cig users have drastically altered mucus proteins in the lung.”
“Our initial data indicate that e-cig users have drastically altered mucus proteins in the lung,” said Kesimer. “This suggests that the immune response is being suppressed and that there’s a significant inflammatory response in the airways.”
Also, Tarran and colleagues have found that nicotine use may lead to the inactivation of CFTR – the gene at the heart of cystic fibrosis – and lead to altered mucus/mucin properties and flow. Mucins are the large proteins that give mucus its gel-like features necessary for normal respiratory health.
“Our data also suggest that nicotine exposure adversely affects the normal ability of the airways to activate CFTR and hydrate mucus to generate an “airway flush,” which is important for removing inhaled viruses,” Tarran said. “We think this can lead to a failure to resolve common viral infections, such as respiratory syncytial virus.”
“During the next five years, we plan to determine whether nicotine affects the lungs’ very basic innate defense mechanisms by altering the lungs’ protein composition and hydration, and therefore hindering the lungs’ ability to respond to and keep out pathogens and other intruders.”
The grant is another indication that the UNC School of Medicine and the Marsico Lung Institute are leaders in nicotine and e-cigarette research in addition to the TCORS grant.