Transcriptomic and barrier responses of human airway epithelial cells exposed to cannabis smoke

Abstract

Globally, many jurisdictions are legalizing or decriminalizing cannabis, creating a potential public health issue that would benefit from experimental evidence to inform policy, government regulations, and user practices. Tobacco smoke exposure science has created a body of knowledge that demonstrates the conclusive negative impacts on respiratory health; similar knowledge remains to be established for cannabis. To address this unmet need, we performed in vitro functional and transcriptomic experiments with a human airway epithelial cell line (Calu‐3) exposed to cannabis smoke, with tobacco smoke as a positive control. Demonstrating the validity of our in vitro model, tobacco smoke induced gene expression profiles that were significantly correlated with gene expression profiles from published tobacco exposure datasets from bronchial brushings and primary human airway epithelial cell cultures. Applying our model to cannabis smoke, we demonstrate that cannabis smoke induced functional and transcriptional responses that overlapped with tobacco smoke. Ontology and pathway analysis revealed that cannabis smoke induced DNA replication and oxidative stress responses. Functionally, cannabis smoke impaired epithelial cell barrier function, antiviral responses, and increased inflammatory mediator production. Our study reveals striking similarities between cannabis and tobacco smoke exposure on impairing barrier function, suppressing antiviral pathways, potentiating of pro‐inflammatory mediators, and inducing oncogenic and oxidative stress gene expression signatures. Collectively our data suggest that cannabis smoke exposure is not innocuous and may possess many of the deleterious properties of tobacco smoke, warranting additional studies to support public policy, government regulations, and user practices.

Isolation, sequence, infectivity and replication kinetics of SARS-CoV-2

“…Vero E6 cells (African green monkey cells; ATCC, https://www.atcc.org) were maintained in Dulbecco’s modified Eagle’s media (DMEM) supplemented with 10% fetal bovine serum (FBS; Sigma-Aldrich, https://www.sigmaaldrich.com), 1x L-Glutamine and Penicillin/Streptomycin (Pen/Strep; Corning, https://ca.vwr.com). Calu-3 cells (human lung adenocarcinoma derived; ATCC, https://www.atcc.org) were cultured as previously mentioned (4). THF cells (human telomerase life-extended cells) were cultured as previously mentioned (5).…”

Expression of the endocannabinoid system in the human airway epithelial cells – Impact of sex and chronic respiratory disease status

“…Inhaled cannabis smoke travels through the upper and lower airways, with airway epithelial cells being a major site of first contact. We have demonstrated with an in vitro model of airway epithelial cell culture that cannabis smoke induces a concentration-dependent reduction in airway epithelial cell viability, barrier function, while promoting pro-inflammatory cytokine secretion (31, 32). Complementary profiling of human epithelial cells isolated via bronchial brushings has demonstrated cannabis consumption-dependent elevations in TLR5, TLR6, and TLR9 gene expression(101).…”

“…It has been demonstrated that the inhalation of air pollution, tobacco smoke, and cannabis smoke can compromise airway epithelial function(30-32). Notably, recent findings show that cannabis smoke exposure can lead to impaired airway epithelium barrier integrity, attenuated antiviral capacity, and exacerbated inflammatory response to immune challenges(31, 32). However, the contribution of the endocannabinoid system to these observations has not been defined.…”

Effect of long-acting β-agonists/glucocorticoids on human airway epithelial cell cytokine, transcriptomic and oxidative stress responses to cannabis smoke

“…The log 2 fold change (FC) of would require repeated exposures over time in vitro. Despite this limitation, we emphasise that our previous publication using this model demonstrated strong significant correlations of gene expression with in situ bronchial brushes from human smokers and primary air-liquid interface cultures exposed to tobacco smoke [8]. Additional experiments using primary human airway epithelial cells grown under air-liquid interface culture conditions and exposed to whole-smoke extract should be explored to complement the present data.…”

“…We next interrogated RNA sequencing data to address the efficacy of LABA/GC intervention on attenuating CSE-and TSE-induced transcriptomic responses observed in our previous study [8]. First, we observed that the most upregulated gene exclusive to Form/Bud treatment was HSD11B2 (corticosteroid 11-β-dehydrogenase) (vehicle+Form/Bud FC 34.80, CSE+Form/Bud FC 33.99 and TSE+Form/Bud FC 27.32), indicating that our intervention was efficacious on modulating glucocorticoid signalling (data not shown).…”