Transcriptomic and Functional Responses of Human Airway Cells to Vaped ?8-THC and its Oxidation Product ?8-THCQ
?8-tetrahydrocannabinol (?8-THC) vaping products rapidly expanded following the 2018 Farm Bill, yet remain largely unregulated despite high cannabinoid concentrations, additives and contaminants, and growing links to adverse respiratory outcomes. Here we show that the reactive electrophile ?8-THC quinone (?8-THCQ, HU-336) is present in significant quantities in commercial ?8-THC distillate and disposable products and increases after vaping. Across high concentration products, ?8-THCQ rose an average of 3.67-fold, reaching millimolar levels. While ?8-THC itself produced no measurable transcriptomic response in a bronchial epithelial cell line, ?8-THCQ markedly altered gene expression, prominently upregulating cilia and stress related programs alongside xenobiotic metabolism and inflammatory pathways. Using primary differentiated human bronchial epithelial cells exposed with the UNC Vaping Product Exposure System (VaPES), we demonstrate that vaped commercial ?8-THC mixtures induce immediate early stress genes, suppress ribosome and mitochondrial pathways, and trigger fibrosis associated signaling, while juices caused comparatively modest effects, primarily limited to upregulation of cell-cycle and proliferation-associated genes. Computational analysis further mechanistically linked coordinated chemical features of ?8-THC aerosols to the airway transcriptional programs they induced, identifying clusters of chemicals that drive specific biological responses. Functionally, distillate and disposable aerosols rapidly impaired motile cilia activity. Together, these data identify ?8-THCQ as a major vaping-generated reactive product in ?8-THC aerosols and suggest that repeated inhalation may disrupt mucociliary defense and promote chronic airway injury. Overall design: To characterize the effects of ?8-THC vaping product mixtures, we performed transcriptomic analysis (RNA-seq) on primary human bronchial epithelial cells or HBECs (n = 4 donors, 2 replicate wells/donor) exposed to the 6 commercially available ?8-THC products previously used for chemical analysis (10 puffs) using the UNC Vaping Product Exposure System (VaPES). Commercial products were compared to a 40/60 propylene glycol/vegetable glycerin (PG/VG) vaping control. Distillate products were aerosolized with a Silo Battery (Ccell; Phoenix, Arizona; 500 mAh; ~3.7 V; Ceramic Coil) and the juices and control were aerosolized with a CBDFx Tank (part of CBDFx Vape Kit) (CBDFx; Chatsworth, CA; 1000mAh; ceramic coil).