PP2A-associated tau hyperphosphorylation was involved in sevoflurane induced neonatal neurotoxicity

The effects of sevoflurane anesthesia on childhood neurodevelopment and adult brain function have attracted increasing scientific attentions. However, the exact mechanisms underlying hyperphosphorylation of tau protein in sevoflurane induced abnormalities in central nervous system (CNS) development, particularly in the hippocampus, have not been fully determined.We utilized molecular biological and behavioral approaches to compare the changes in cognitive function in mice exposed to repeated sevoflurane during the neonatal stage, and to assess whether PP2A-associated tau hyperphosphorylation is involved in sevoflurane induced neonatal neurotoxicity.We reported that mice anesthetized with repeated sevoflurane during the neonatal period caused cognitive dysfunction during the adulthood. More importantly, we found that hyperphosphorylation of tau protein and decreased level of protein phosphatase 2A (PP2A) were detected in the hippocampus of mice after neonatal exposure of sevoflurane. Meanwhile, GSK-3β activity was found to be increased with repeated sevoflurane exposure, but not for more than 2 weeks.Our results suggest that PP2A-associated hyperphosphorylation of tau protein might contribute to sevoflurane induced developmental neurotoxicity. These findings could provide a theoretical basis for the safely usage of sevoflurane in pediatric surgeries, and offer a valuable reference and potential therapeutic targets for the development of neuroprotective drugs.