Cannabis use is associated with potentially heritable widespread changes in autism candidate gene DLGAP2 DNA methylation in sperm

ABSTRACT

Parental cannabis use has been associated with adverse neurodevelopmental outcomes in offspring, but how such phenotypes are transmitted is largely unknown. Using reduced representation bisulphite sequencing (RRBS), we recently demonstrated that cannabis use is associated with widespread DNA methylation changes in human and rat sperm. Discs-Large Associated Protein 2 (DLGAP2), involved in synapse organization, neuronal signaling, and strongly implicated in autism, exhibited significant hypomethylation (p < 0.05) at 17 CpG sites in human sperm. We successfully validated the differential methylation present in DLGAP2 for nine CpG sites located in intron seven (p < 0.05) using quantitative bisulphite pyrosequencing. Intron 7 DNA methylation and DLGAP2 expression in human conceptal brain tissue were inversely correlated (p < 0.01). Adult male rats exposed to delta-9-tetrahydrocannabinol (THC) showed differential DNA methylation at Dlgap2 in sperm (p < 0.03), as did the nucleus accumbens of rats whose fathers were exposed to THC prior to conception (p < 0.05). Altogether, these results warrant further investigation into the effects of preconception cannabis use in males and the potential effects on subsequent generations.

KEYWORDS:

• Cannabis
• sperm
• DNA methylation
• autism
• heritability

Author contributions

RS contributed to study conception and design, acquisition and interpretation of data, and drafting and revising the manuscript. KA contributed to acquisition of data and revising the manuscript. NIR was involved with study design, acquisition of data, and revising the manuscript. ABH was involved in acquisition of data and revising the manuscript. EP was involved in acquisition of data and revising the manuscript. JTM contributed to study design, acquisition of data, and revising the manuscript. SHK contributed to study conception, study design, acquisition, analysis and interpretation of data, and revising the manuscript. EDL contributed to study conception and design, acquisition, analysis and interpretation of data, and revising the manuscript. SKM contributed to study conception, study design, acquisition, analysis and interpretation of data, and drafting and revising the manuscript.

Acknowledgments

We thank the CIPHERS study participants for their generosity and willingness to be involved in this study. We also thank Zhiqing Huang and Carole Grenier for their expert assistance with this project.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This research was supported in part by the John Templeton Foundation under Grant 60564.