Prenatal cannabis use is associated with altered miRNA and protein expression in the developing human brain

BACKGROUND: Cannabis is widely used during pregnancy, increasing with cannabis legalization, and has been associated with altered neurodevelopment, yet the precise molecular mechanisms remain poorly understood. AIMS: To assess whether utilizing fetal central nervous system-derived extracellular vesicles (fCNSEVs) isolated from maternal blood reflects cannabis-associated changes in the fetal brain. METHODS: microarray). Selected miRNAs were validated by qPCR. Bayesian Generalized Linear Models were used to assess exposure-group by sex effects. RESULTS: Maternal cannabis use was associated with altered CB1R and D2R levels in the brain with opposite directional changes in fCNSEVs. 21 miRNAs were differentially expressed: 14 downregulated and 6 upregulated, following a sex-dependent pattern (males>>females), while miR-216a-5p follows the opposite pattern (females>>males). We confirmed concordant miRNA changes in fetal brain and fCNSEVs. Many of the identified molecules are associated with pathways linked to adverse neurodevelopmental outcomes. CONCLUSIONS: Our data suggest that fCNSEV-based assays may provide the ability to monitor fetal brain effects of maternal cannabis in ongoing pregnancies in clinical cohorts. A critical next step is to determine if alterations in fCNSEV protein and miRNA markers predict changes in fetal brain connectivity and neurodevelopment measures of executive function.