Japanese encephalitis virus activates the NLRP3/caspase-1/GSDMD signaling pathway in dopaminergic neurons.

Japanese encephalitis virus (JEV) preferentially targets brain regions rich in dopaminergic neurons, including the thalamus, midbrain, and striatum, leading to severe neuroinflammation. However, the underlying pathological mechanisms remain unclear. This study hypothesizes that JEV-induced pyroptosis exacerbates neuroinflammation by activating the NLRP3/caspase-1/GSDMD signaling pathway. In vivo experiments using JEV-infected mice revealed virus-specific targeting of dopaminergic neurons, concurrent activation of the NLRP3 inflammasome, and induction of inflammatory responses. In vitro studies with mouse midbrain dopaminergic cells showed significant viral replication, progressive cell membrane damage, and colocalization of JEV with pyroptotic markers. The pharmacological inhibition of NLRP3, while suppressing viral load and NLRP3 inflammasome activation, fails to delay the onset of neuroinflammation, potentially due to the activation of glial cells. This suggests that glial cell-mediated inflammatory pathways independent of NLRP3 may drive neuroinflammation despite NLRP3 inhibition. The unimpeded activation of glia could sustain pro-inflammatory responses, highlighting the need to target glial activation alongside NLRP3 to effectively mitigate neuroinflammation.