Duke University Program in Environmental Health, Nicholas School of the Environment, Duke University, Duke, PO Box 90534, Durham, NC, 27701, USA.
Department of Obstetrics and Gynecology, Division of Reproductive Sciences, Duke University Medical Center, Durham, NC, USA.
Epigenetics Chromatin. 2022 Sep 10;15(1):33. doi: 10.1186/s13072-022-00466-3.
Cannabis legalization is expanding and men are the predominant users. We have limited knowledge about how cannabis impacts sperm and whether the effects are heritable.
Whole genome bisulfite sequencing (WGBS) data were generated for sperm of rats exposed to: (1) cannabis extract (CE) for 28 days, then 56 days of vehicle only (~ one spermatogenic cycle); (2) vehicle for 56 days, then 28 days of CE; or (3) vehicle only. Males were then mated with drug-naïve females to produce F1 offspring from which heart, brain, and sperm tissues underwent analyses. There were 3321 nominally significant differentially methylated CpGs in F0 sperm identified via WGBS with select methylation changes validated via bisulfite pyrosequencing. Significant methylation changes validated in F0 sperm of the exposed males at the gene 2-Phosphoxylose Phosphatase 1 (Pxylp1) were also detectable in their F1 sperm but not in controls. Changes validated in exposed F0 sperm at Metastasis Suppressor 1-Like Protein (Mtss1l) were also present in F1 hippocampal and nucleus accumbens (NAc) of the exposed group compared to controls. For Mtss1l, a significant sex-specific relationship between DNA methylation and gene expression was demonstrated in the F1 NAc. Phenotypically, rats born to CSE-exposed fathers exhibited significant cardiomegaly relative to those born to control fathers.
This is the first characterization of the effect of cannabis exposure on the entirety of the rat sperm methylome. We identified CE-associated methylation changes across the sperm methylome, some of which persisted despite a "washout" period. Select methylation changes validated via bisulfite pyrosequencing, and genes associated with methylation changes were involved in early developmental processes. Preconception CE exposure is associated with detectable changes in offspring DNA methylation that are functionally related to changes in gene expression and cardiomegaly. These results support that paternal preconception exposure to cannabis can influence offspring outcomes.
大麻合法化正在扩大，而男性是主要使用者。我们对大麻如何影响精子以及这些影响是否具有遗传性知之甚少。
为接触过以下物质的大鼠精子生成了全基因组亚硫酸氢盐测序（WGBS）数据：（1）大麻提取物（CE）28 天，然后仅用载体 56 天（大约一个精子发生周期）；（2）仅用载体 56 天，然后用 CE 28 天；或（3）仅用载体。然后，雄性与未使用药物的雌性交配，从其产生 F1 后代，从 F1 后代中提取心脏、大脑和精子组织进行分析。通过 WGBS 鉴定了 F0 精子中 3321 个名义上显著的差异甲基化 CpG，通过亚硫酸氢盐焦磷酸测序验证了一些甲基化变化。在暴露雄性的 F0 精子中验证的基因 2-磷酸木酮糖磷酸酶 1（Pxylp1）的显著甲基化变化在其 F1 精子中也可检测到，但在对照组中不可检测。在暴露 F0 精子中验证的转移抑制物 1 样蛋白（Mtss1l）的变化在暴露组的 F1 海马体和伏隔核（NAc）中也存在于对照组。对于 Mtss1l，在 F1 NAc 中证明了 DNA 甲基化与基因表达之间存在显著的性别特异性关系。表型上，与对照组相比，来自 CSE 暴露父亲的大鼠表现出明显的心脏增大。
这是首次描述大麻暴露对大鼠精子全甲基组的影响。我们在精子甲基组中发现了与 CE 相关的甲基化变化，其中一些变化尽管有“冲洗”期仍持续存在。通过亚硫酸氢盐焦磷酸测序验证的一些甲基化变化，以及与甲基化变化相关的基因，都参与了早期的发育过程。受孕前 CE 暴露与后代 DNA 甲基化的可检测变化相关，这些变化与基因表达和心脏增大的变化有关。这些结果表明，父亲在受孕前接触大麻会影响后代的结果。
