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

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.