Large-Scale Profiling of Coding and Long Noncoding Transcriptomes in the Hippocampus of Mice Acutely Exposed to...

Cannabis vaping, particularly involving cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), rapidly delivers highly concentrated cannabinoids to the brain, potentially affecting the hippocampus. This study examined differential expression of long noncoding RNAs (lncRNAs) and mRNAs in the hippocampus after acute exposure to vaporized CBD or THC. Male ICR mice were exposed to vaporized CBD or THC (50 mg, n = 5/group), and hippocampal tissues were collected at 1, 3, and 14 days post-exposure. Total RNA sequencing was conducted on day 1 samples, and selected transcripts were validated using qRT-PCR across multiple time points. CBD led to significant up- or downregulation of L3mbtl1, Wnt7a, and Camk2b at day 1. However, Wnt7a showed gradual recovery at days 3 and 14. In the THC group, Grin2a, Gria3, and Golga2 were significantly upregulated, while Drd1, Drd2, Gnal, and Adcy5 were significantly downregulated at day 1. Time-course analysis showed that Drd2 expression returned to baseline by day 14, whereas Adcy5 remained persistently downregulated through days 3 and 14. In the CBD group, NONMMUT069014.2 was upregulated, while NONMMUT033147.2 and NONMMUT072606.2 were downregulated at day 1; notably, NONMMUT072606.2 showed a transient increase at day 3 before returning to baseline. In the THC group, NONMMUT085523.1 and NONMMUT123548.1 were upregulated, whereas NONMMUT019734.2, NONMMUT057101.2, and NONMMUT004928.2 were downregulated, with most showing gradual recovery by day 14. Correlation analysis revealed that THC-responsive lncRNAs-including NONMMUT004928.2, NONMMUT057101.2, and NONMMUT019734.2-were strongly associated with downregulated mRNAs such as Drd2 and Adcy5. These findings highlight cannabinoid-specific hippocampal transcriptomic responses and suggest potential regulatory roles for lncRNA-mRNA interactions in cannabinoid-induced neural changes.