Pulk Kerda, Somelar-Duracz Kelli, Rooden Mikk, Anier Kaili, Kalda Anti
Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.
Transl Psychiatry. 2025 Jun 12;15(1):198. doi: 10.1038/s41398-025-03419-y.
Cannabis is among the most used illicit substances in the world, and approximately 10% of regular cannabis users are estimated to be susceptible to developing cannabis use disorder (CUD). We examined the effect of different concentrations of delta-9-tetrahydrocannabinol (THC) on the epigenetic DNA modifiers DNA methyltransferases (DNMTs) and ten-eleven translocation enzymes (TETs); cannabinoid CB1 and CB2 receptors; and the cytokines IL-1β, IL-6, IL-10, and TNF-α. We used two in vitro study designs on human peripheral blood mononuclear cells (PBMCs) collected from healthy donors: (a) repeated THC incubations and (b) repeated THC incubations followed by an "abstinence" period and a THC challenge incubation. We observed no significant effects on DNMTs and TETs mRNA levels, enzymatic activity, or CB1 and CB2 mRNA levels at an average THC concentration (50 ng/ml, n = 8 donors). However, repeated incubations at a high THC concentration (200 ng/ml, n = 16 donors) significantly downregulated DNMTs and upregulated TETs, CB1, and CB2 mRNA levels. Both THC concentrations upregulated the gene expression of IL-1β, IL-6, and IL-10, but had no effect on TNF-α gene expression. At the genome-wide level, repeated THC incubations resulted in a significant number of differentially hydroxymethylated genes being hyperhydroxymethylated. An additional THC challenge shifted the hyperhydroxymethylated state to hypohydroxymethylation. The genes with the strongest associations with THC exposure were found to be functionally significant for various signaling pathways. These findings suggest that repeated incubations with high concentrations of THC may affect the expression of genes critical for the development of CUD through aberrant demethylation.
大麻是世界上使用最广泛的非法物质之一，据估计，约10%的经常使用大麻的人易患大麻使用障碍（CUD）。我们研究了不同浓度的δ-9-四氢大麻酚（THC）对表观遗传DNA修饰因子DNA甲基转移酶（DNMTs）和十一-易位酶（TETs）、大麻素CB1和CB2受体以及细胞因子白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）和肿瘤坏死因子-α（TNF-α）的影响。我们对从健康供体采集的人外周血单核细胞（PBMCs）采用了两种体外研究设计：（a）重复进行THC孵育；（b）重复进行THC孵育，随后进入“戒断”期并进行THC激发孵育。在平均THC浓度（50 ng/ml，n = 8名供体）下，我们未观察到对DNMTs和TETs mRNA水平、酶活性或CB1和CB2 mRNA水平有显著影响。然而，在高THC浓度（200 ng/ml，n = 16名供体）下重复孵育显著下调了DNMTs并上调了TETs、CB1和CB2 mRNA水平。两种THC浓度均上调了IL-1β、IL-6和IL-10的基因表达，但对TNF-α基因表达无影响。在全基因组水平上，重复进行THC孵育导致大量差异羟甲基化基因发生超羟甲基化。额外的THC激发将超羟甲基化状态转变为低羟甲基化。发现与THC暴露关联最强的基因在各种信号通路中具有功能重要性。这些发现表明，高浓度THC的重复孵育可能通过异常去甲基化影响对CUD发展至关重要的基因的表达。
