Pregnancy exposure to carbon black nanoparticles induced neurobehavioral deficits that are associated with altered m6A modification in offspring

Increasing occupational and accidental exposure to carbon black nanoparticles (CBNPs) raise concerns over their possible effects on the nervous system. However, the influences of CBNPs on the neurodevelopment remain unclear. Thus, in this study, pregnant mice were exposed to different doses of CBNPs by intranasal instillation on gestation days 9–18. Our results demonstrated that maternal exposure to CBNPs caused significant changes on maternal behaviors. Pregnancy exposure to CBNPs also delayed the onset of incisor eruption, testes descent and vaginal opening in offspring, and caused the reduced body weight until adulthood. In the neurobehavioral tests, CBNPs-exposed offspring exhibited the elevated latency of negative geotaxis and surface right reflex, reduced grasping time and increased cliff avoidance. Histopathological changes were present in F1 generation but not in F2 generation. Intriguingly, our data revealed that the levels of total m6A modification were significantly decreased by CBNPs. Similar trends were observed on the mRNA expressions of m6A methyltransferases and demethylases. In summary, these findings provide the novel evidence that pregnancy exposure to CBNPs affects the maternal behaviors and partially induces the neurobehavioral, muscular and histopathological changes in offspring. Of note, these adverse effects may be associated with reduced levels of total m6A modification in brain.