Developmental sevoflurane exposure leads to neuronal cell death, and subsequent learning and memory cognitive defects. The underlyi\ng mechanism remains to be elucidated. Gasdermin D (GSDMD)-mediated pyroptosis is a form of inflammatory cell death and participates in a variety of neurodegenerative diseases. Several studies illustrated that dysregulation of mTOR activity is involved in pyroptotic cell death. The current study was designed to interrogate the role of GSDMD-mediated pyroptosis and mTOR activity in developmental sevoflurane exposure. We found that inhibition of GSDMD pore formation with Disulfiram (DSF) or Necrosulfonamide (NSA) significantly attenuated sevoflurane neurotoxicity in vitro. In addition, treatment with DSF or NSA also mitigated damage-associated molecular patterns (DAMPs) release and subsequent plasma membrane rupture (PMR) induced by sevoflurane challenge. Further investigation showed that the overactivation of mTOR signaling is involved in sevoflurane induced pyroptosis both in vivo and in vitro. Intriguingly, we found that the DAMPs release and subsequent PMR triggered by developmental sevoflurane priming were compromised by knocking down the expression of mTORC1 component Raptor, but not mTORC2 component Rictor. Moreover, sevoflurane induced pyroptosis could also be restored by suppressing mTOR activity or knocking down the expressions of Ras-related small GTPases RagA or RagC. Finally, administration of DSF or NSA dramatically improved the spatial and emotional cognitive disorders without alternation of locomotor activity. Taken together, these results indicate that mTORC1-dependent and GSDMD-mediated pyroptosis contributes to the developmental sevoflurane neurotoxicity. Characterizing these processes may provide experimental evidence for the possible prevention of developmental sevoflurane neurotoxicity.

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Wang Wen-Yuan et al.
Molecular neurobiology January 2023