A synthetic coolant (WS-23) in disposable electronic cigarettes impairs cytoskeletal function in EpiAirway microtissues exposed at the air liquid interface.

The design of popular disposable electronic cigarettes (ECs) was analyzed, and the concentrations of WS-23, a synthetic coolant, in EC fluids were determined for 22 devices from 4 different brands. All products contained WS-23 in concentrations that ranged from 1.0 to 40.1 mg/mL (mean = 21.4 ± 9.2 mg/mL). To determine the effects of WS-23 on human bronchial epithelium in isolation of other chemicals, we exposed EpiAirway 3-D microtissues to WS-23 at the air liquid interface (ALI) using a cloud chamber that generated aerosols without heating. Proteomics analysis of exposed tissues revealed that the cytoskeleton was a major target of WS-23. BEAS-2B cells were exposed to WS-23 in submerged culture to validate the main results from proteomics. F-actin, which was visualized with phalloidin, decreased concentration dependently in WS-23 treated BEAS-2B cells, and cells became immotile in concentrations above 1.5 mg/mL. Gap closure, which depends on both cell proliferation and migration, was inhibited by 0.45 mg/mL of WS-23. These data show that WS-23 is being added to popular EC fluids at concentrations that can impair processes dependent on the actin cytoskeleton and disturb homeostasis of the bronchial epithelium. The unregulated use of WS-23 in EC products may harm human health.

The aphid Myzus persicae (Hemiptera: Aphididae) acquires chloroplast DNA during feeding on host plants.

Aphids (Hemiptera: Aphididae) extract nutrients from host plant phloem via stylets that facilitate salivation and sap uptake. When navigating to the phloem, aphids periodically puncture nonvascular cells and sample cell contents, but rarely cause significant cell damage. As a result, aphids are considered "stealthy" feeders. In contrast, insects that do cause damage, such as chewing herbivores, will take up host cell contents-including DNA-into their guts. Researchers can use molecular barcoding methods to identify recent host use patterns of chewing herbivores. This information is valuable for both pest management and basic ecological studies. Because of their stealthy feeding style, it was assumed that host plant DNA could not be recovered from aphids and other Sternorrhyncha. However, several recent studies document host plant DNA uptake by psyllids, which feed in a similar manner to aphids. Therefore, we hypothesized that aphids may also acquire DNA from host plants. Since aphids puncture and sample cytosol contents from cells, we predicted that aphids would be most likely to acquire DNA from chloroplasts. To test this, we performed host feeding and host transfer experiments with Myzus persicae (Sulzer), then used PCR to recover and sequence a region between the trnT and trnF genes from acquired chloroplast DNA. We found that M. persicae readily acquires chloroplast DNA, even prior to phloem contact, and that fragment sizes sufficient for host plant identification can be recovered. Our work suggests that molecular gut content analysis is a viable tool for studying aphid-host interactions.