Department of Obstetrics and Gynecology, Duke University Medical Center, 701 West Main Street, Suite 510, Durham, NC, 27701, USA.
Duke Nicholas School of the Environment, University Program in Environmental Health, Durham, NC, USA.
Sci Rep. 2020 Jul 23;10(1):12251. doi: 10.1038/s41598-020-69204-7.
As marijuana legalization is increasing, research regarding possible long-term risks for users and their offspring is needed. Little data exists on effects of paternal tetrahydrocannabinol (THC) exposure prior to reproduction. This study determined if chronic THC exposure alters sperm DNA methylation (DNAm) and if such effects are intergenerationally transmitted. Adult male rats underwent oral gavage with THC or vehicle control. Differentially methylated (DM) loci in motile sperm were identified using reduced representation bisulfite sequencing (RRBS). Another cohort was injected with vehicle or THC, and sperm DNAm was analyzed. Finally, THC-exposed and control adult male rats were mated with THC-naïve females. DNAm levels of target genes in brain tissues of the offspring were determined by pyrosequencing. RRBS identified 2,940 DM CpGs mapping to 627 genes. Significant hypermethylation was confirmed (p < 0.05) following oral THC administration for cytochrome P450 oxidoreductase (Por), involved in toxin processing and disorders of sexual development. Por hypermethylation was not observed after THC injection or in the subsequent generation. These results support that THC alters DNAm in sperm and that route of exposure can have differential effects. Although we did not observe evidence of intergenerational transmission of the DNAm change, larger studies are required to definitively exclude this possibility.
随着大麻合法化的增加，需要研究其对使用者及其后代可能存在的长期风险。关于父代四氢大麻酚（THC）暴露对生殖前的影响的数据很少。本研究旨在确定慢性 THC 暴露是否会改变精子 DNA 甲基化（DNAm），以及这种影响是否会在代际间传递。成年雄性大鼠经口灌胃给予 THC 或载体对照。使用重亚硫酸盐限制性测序（RRBS）鉴定运动精子中的差异甲基化（DM）位点。另一队列接受载体或 THC 注射，并分析精子 DNAm。最后，用经 THC 暴露和对照的成年雄性大鼠与未经 THC 处理的雌性大鼠交配。通过焦磷酸测序确定后代脑组织中靶基因的 DNAm 水平。RRBS 鉴定出 2940 个 DM CpG 映射到 627 个基因。经口给予 THC 后，细胞色素 P450 氧化还原酶（Por）的 DM 被确认（p<0.05），Por 参与毒素处理和性发育障碍。在 THC 注射后或随后的代中未观察到 Por 高甲基化。这些结果支持 THC 改变精子中的 DNAm，并且暴露途径可能具有不同的影响。尽管我们没有观察到 DNAm 变化的代际传递的证据，但需要更大的研究来明确排除这种可能性。
