In vitro RNA-seq-based toxicogenomics assessment shows reduced biological effect of tobacco heating products when compared to cigarette smoke

Abstract The battery of regulatory tests used to evaluate the risk of novel tobacco products such as heated tobacco products (THPs) presents some limitations including a bias towards the apical endpoint tested, and limited information on the mode of action. This is driving a paradigm shift to more holistic systems biology approaches. In this study, we used RNA-sequencing to compare the transcriptomic perturbations following acute exposure of a 3D airway tissue to the aerosols from two commercial THPs and a reference 3R4F cigarette. 2809 RNAs were differentially expressed for the 3R4F treatment and 115 and 2 RNAs for the two THPs (pFDR  1.5), respectively. The relationship between the identified RNA features and gene ontologies were mapped showing a strong association with stress response, xenobiotics metabolism, and COPD-related terms for 3R4F. In contrast, fewer ontologies were found enriched for the THPs aerosols. “Response to wounding” was a common COPD-related term over-represented for the two THPs but at a reduced significance. Quantification of a cytokine panel post-exposure confirmed a pro-inflammatory effect of cigarette smoke but not for THPs. In conclusion, THPs have a reduced impact on gene expression compared to 3R4F

Assessment of biomarkers of exposure and potential harm, and physiological and subjective health measures in exclusive users of nicotine pouches and current, former and never smokers

Oral nicotine pouches (NPs) are smokeless, tobacco-free products that have a potential role in tobacco harm reduction strategies. In a cross-sectional study in Sweden/Denmark, several recognised biomarkers of potential harm (BoPHs) linked to smoking-related diseases/their initiating biological processes, and biomarkers of exposure (BoEs) to tobacco/tobacco smoke toxicants were compared among exclusive adult users of Velo NPs and current/former/never smokers. Over 24 hours, participants used their usual product (Velo NP or cigarette) as normal, and BoEs/BoPHs were assessed via blood/24-h urine/exhaled breath/physiological assessments. Among the primary endpoints, total NNAL (16.9 ± 29.47 vs 187.4 ± 228.93 pg/24h), white blood cell count (5.59 ± 1.223 vs 6.90 ± 1.758 x109/L), and COHb (4.36 ± 0.525 vs 8.03 ± 2.173% saturation) were significantly lower among Velo users than among smokers (91%, 19% and 46% lower respectively, all P P a]P (82.4 ± 217.58 vs 258.3 ± 190.20), HMPMA (135.1 ± 77.85 vs 368.8 ± 183.15 μg/24h), MHBMA (0.22 ± 0.166 vs 3.39 ± 2.943 μg/24h), S-PMA (0.10 ± 0.059 vs 3.53 ± 2.736 µg/24h) and total NNN (7.5 ± 24.84 vs 9.7 ± 5.93 ng/24 h)), were significantly lower among Velo users (78.8%, 68.1%, 63.4%, 93.5%, 97.2% and 22.7% lower respectively, P P  International Standard Registered Clinical Trial number: ISRCTN16988167</p

Suppression of the optokinetic reflex in human infants: implications for stable fixation and shifts of attention.

The ability of 1-, 2-, and 4-month-old infants to attend to a small, stationary visual target while a large background texture moved horizontally was assessed using electrooculography. The background texture, consisting of a randomly arranged field of dots or a set of vertically oriented stripes, was effective at all ages in eliciting the optokinetic reflex (OKR), which stabilizes gaze on a moving display. When the target, consisting of a red bar, was added to the center of the moving background display, it was effective in suppressing the OKR, except in 1-month-olds. Under monocular viewing conditions, background motion in the nasal-temporal direction was ineffective in eliciting robust OKR in 1- and 2-month-olds. These same infants presented with temporal-nasal background motion showed robust OKR equal to their OKR under binocular viewing conditions. However, the 2-month-olds showed OKR suppression only half as often as they did under binocular viewing conditions, and the 1-month-olds did not show OKR suppression. The 4-month-olds showed no nasal-temporal OKR asymmetry under monocular viewing conditions, and, like the 2-month-olds, OKR suppression was present about half as often as under binocular viewing conditions

Letter to Nature. Viral infection switches non-plasmacytoid dendritic cells into high interferon producers

Type I interferons (IFN-I) are important cytokines linking innate and adaptive immunity. Plasmacytoid dendritic cells make high levels of IFN-I in response to viral infection and are thought to be the major source of the cytokines in vivo. Here, we show that conventional non-plasmacytoid dendritic cells taken from mice infected with a dendritic-cell-tropic strain of lymphocytic choriomeningitis virus make similarly high levels of IFN-I on subsequent culture. Similarly, non-plasmacytoid dendritic cells secrete high levels of IFN-I in response to double-stranded RNA (dsRNA), a major viral signature, when the latter is introduced into the cytoplasm to mimic direct viral infection. This response is partially dependent on the cytosolic dsRNA-binding enzyme protein kinase R4 and does not require signalling through toll-like receptor (TLR), a surface receptor for dsRNA5. Furthermore, we show that sequestration of dsRNA by viral NS1 explains the inability of conventional dendritic cells to produce IFN-I on infection with influenza. Our results suggest that multiple dendritic cell types, not just plasmacytoid cells, can act as specialized interferon-producing cells in certain viral infections, and reveal the existence of a TLR-independent pathway for dendritic cell activation that can be the target of viral interference