Zinc Oxide Nanoparticles Exacerbate Epileptic Seizures by Modulating the TLR4-Autophagy Axis

Int J Nanomedicine. 2024 Feb 29:19:2025-2038. doi: 10.2147/IJN.S442623. eCollection 2024.

Abstract

Background: Zinc oxide nanoparticles (ZnO NPs) has been widely used in various fields and has had an important impact on human public health. In addition, it inevitably damages human health, including neurological diseases. Therefore, this study explored the effect of ZnO NPs on epilepsy.

Methods: The effect of ZnO NPs on epilepsy was observed by behavioral analysis. TLR4 expression and autophagy related pathways were detected by RNA-seq and Western blot. In addition, the cell types of autophagy were detected by immunofluorescence. Further, the electrophysiological changes of ZnO NPs induced autophagy were detected by whole-cell patch-clamp. Finally, the recovery experiment was carried out by TLR4 inhibitor (TAK-242).

Results: We found that ZnO NPs enhanced epilepsy susceptibility and severity. Through RNA-seq analysis and Western blot, it was found that ZnO NPs affected the changes of TLR4 and autophagy related pathways. In addition, we found that ZnO NPs mainly affects autophagy of inhibitory neurons, resulting in excitation/inhibition imbalance. The autophagy and epileptic phenotypes were reversed with TAK-242. In general, ZnO NPs exacerbate epileptic seizures by modulating the TLR4-autophagy axis.

Conclusion: ZnO NPs enhanced the susceptibility and severity of epilepsy. Mechanistically, ZnO NPs affected autophagy by changing the expression of TLR4. In particular, the ZnO NPs mainly affected the synaptic function of inhibitory neuron, leading to excitation/inhibition imbalances.

Keywords: autophage; epilepsy; excitation/inhibition balance; zinc oxide nanoparticles.

MeSH terms

  • Autophagy
  • Epilepsy*
  • Humans
  • Nanoparticles*
  • Oxidative Stress
  • Reactive Oxygen Species / metabolism
  • Seizures
  • Sulfonamides*
  • Toll-Like Receptor 4 / metabolism
  • Zinc Oxide* / pharmacology

Substances

  • ethyl 6-(N-(2-chloro-4-fluorophenyl)sulfamoyl)cyclohex-1-ene-1-carboxylate
  • Reactive Oxygen Species
  • Zinc Oxide
  • Toll-Like Receptor 4
  • TLR4 protein, human
  • Sulfonamides

Grants and funding

This study is supported by National Natural Science Foundation of China (82001378), Young and Middle-aged Medical Excellence Team Program of Chongqing, Chongqing Chief Expert Studio program, Science and Technology Research Program of Chongqing Education Commission (KJQN202200435), Chongqing Talents: Exceptional Young Talents Project (CQYC202005014), China Postdoctoral Science Foundation(2023M730443), Natural Science Foundation of Chongqing (CSTB2023NSCQ-JQX0035, CSTB2022NSCQ-LZX0038, cstc2021ycjh-bgzxm0035), the Joint Project of Chongqing Health Commission and Science and Technology Bureau (2023QNXM009), the Natural Science Foundation of Chongqing (CSTB2023NSCQ-MSX0720).