Prudence Talbot, Ph.D.
University of California, Riverside
An NIEHS-funded study found that exposure to electronic cigarettes (e-cigarettes) can produce a stress response in brain cells called neural stem cells (NSCs). The grantees reported that nicotine, rather than other components of e-cigarettes, was responsible for the cellular damage.
The researchers exposed mouse NSCs to either refill fluids from a leading brand of e-cigarettes, e-cigarette aerosols, or nicotine alone. They found that exposure to e-liquids, aerosols, and nicotine produced a stress response and increased oxidative stress in the mitochondria, which are the energy-producing component of cells.
The team observed that nicotine bound to special receptors in the neural cell membrane, causing it to open up. This led to an overload of calcium entering the cell. Too much calcium in the mitochondria can alter its shape and function. The exposed cells showed activation of stress-induced mitochondrial hyperfusion (SIMH), which is a rescue mechanism that makes mitochondria less vulnerable to degradation. However, chronic exposure to nicotine overwhelmed SIMH protection and increased mitochondrial damage.
The study provides evidence that nicotine and nicotine-containing products like e-cigarettes trigger a series of cellular events that damage NSC mitochondria, which can accelerate aging and lead to neurodegenerative diseases. According to the authors, this may have long-term repercussions for both e-cigarette users and individuals passively exposed to nicotine-containing aerosols.
Citation: Zahedi A, Phandthong R, Chaili A, Leung S, Omaiye E, Talbot P. 2019. Mitochondrial stress response in neural stem cells exposed to electronic cigarettes. iScience 16:250-269.