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Actions of dexmedetomidine in regulating NLRP3 in postoperative cognitive dysfunction in aged mice via the autophagy-lysosome pathway

  • 0Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, China.
British Journal of Pharmacology +

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January 16, 2025

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January 16, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

Dexmedetomidine (Dex) alleviates postoperative cognitive dysfunction (POCD) by activating the autophagy-lysosome pathway. This action inhibits NLRP3 inflammasome-mediated microglial activation and astrocyte differentiation, improving cognitive function in POCD models.

Area Of Science

  • Neuroscience
  • Cell Biology
  • Pharmacology

Background

  • Autophagy-lysosomal pathway dysfunction is linked to postoperative cognitive dysfunction (POCD).
  • Dexmedetomidine (Dex) has shown potential in improving POCD.
  • The precise mechanisms of Dex's action on the autophagy-lysosome pathway in POCD remain under investigation.

Purpose Of The Study

  • To investigate the effects of Dexmedetomidine (Dex) on autophagy-lysosomal pathway dysfunction in a mouse model of postoperative cognitive dysfunction (POCD).
  • To elucidate the role of the NLRP3 inflammasome and microglial activation in Dex's protective effects against POCD.

Main Methods

  • Establishment of a POCD mouse model with Dexmedetomidine (Dex) administration.
  • Assessment of cognitive function using behavioral tests (Morris water maze, open field, novel object recognition).
  • Quantification of hippocampal neurotransmitters, inflammatory cytokines, and key proteins (NLRP3, ASC, Cleaved Caspase-1) via ELISA and Western blot.
  • Immunofluorescence analysis of microglial activation and astrocyte differentiation in the hippocampus.
  • In vitro studies using BV-2 cells and primary astrocytes to validate Dex's effects on microglial activation and astrocyte differentiation, including TFEB manipulation.

Main Results

  • Dexmedetomidine (Dex) significantly alleviated cognitive deficits in POCD mice.
  • Dex treatment suppressed NLRP3 inflammasome activation, microglial activation, and astrocyte A1 differentiation in the hippocampus.
  • Dex promoted TFEB nuclear translocation, enhancing microglial autophagy and lysosomal biogenesis.
  • In vitro experiments confirmed Dex's inhibitory effects on microglial activation and astrocyte differentiation.

Conclusions

  • Dexmedetomidine (Dex) ameliorates postoperative cognitive dysfunction (POCD) by modulating the NLRP3 inflammasome pathway.
  • Dex activates the autophagy-lysosome pathway through TFEB nuclear translocation, reducing neuroinflammation and astrocyte reactivity.
  • These findings highlight Dex as a potential therapeutic agent for preventing or treating POCD.

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