Flavored e-liquids increase cytoplasmic Ca2+ levels in airway epithelia

E-cigarettes are noncombustible, electronic nicotine-delivery devices that aerosolize an e-liquid, i.e., nicotine, in a propylene glycol-vegetable glycerin vehicle that also contains flavors. While the effects of nicotine are relatively well understood, more information regarding the potential biological effects of the other e-liquid constituents is needed. This is a serious concern, because e-liquids are available in >7,000 distinct flavors. We previously demonstrated that many e-liquids affect cell growth/viability through an unknown mechanism. Since Ca2+ is a ubiquitous second messenger that regulates cell growth, we characterized the effects of e-liquids on cellular Ca2+ homeostasis. To better understand the extent of this effect, we screened e-liquids for their ability to alter cytosolic Ca2+ levels and found that 42 of 100 flavored e-liquids elicited a cellular Ca2+ response. Banana Pudding (BP) e-liquid, a representative e-liquid from this group, caused phospholipase C activation, endoplasmic reticulum (ER) Ca2+ release, store-operated Ca2+ entry (SOCE), and protein kinase C (PKCα) phosphorylation. However, longer exposures to BP e-liquid depleted ER Ca2+ stores and inhibited SOCE, suggesting that this e-liquid may alter Ca2+ homeostasis by short- and long-term mechanisms. Since dysregulation of Ca2+ signaling can cause chronic inflammation, ER stress, and abnormal cell growth, flavored e-cigarette products that can elicit cell Ca2+ responses should be further screened for potential toxicity.

Photo-patterned oxygen sensing films based on Pt porphyrin for controlling cell growth and studying metabolism

Developing biocompatible and photo-polymerizable hydrogels with oxygen sensors for microengineering to affect cell growth and monitor cell respiration simultaneously.

Fitness effects ofcis-regulatory variants in theSaccharomyces cerevisiae TDH3promoter

Variation in gene expression is widespread within and between species, but fitness consequences of this variation are generally unknown. Here we use mutations in theSaccharomyces cerevisiae TDH3promoter to assess how changes inTDH3expression affect cell growth. From these data, we predict the fitness consequences ofde novomutations and natural polymorphisms in theTDH3promoter. Nearly all mutations and polymorphisms in theTDH3promoter were found to have no significant effect on fitness in the environment assayed, suggesting that the wild type allele of this promoter is robust to the effects of most newcis-regulatory mutations.