O-GlcNAcylation Mediated by OGA Activates NEK7/NLRP3 Pathway to Promote Pyroptosis in Parkinson's Disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterised by pyroptosis. O-GlcNAcylation, regulated solely by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), has been shown to mitigate PD. This study aimed to investigate whether pyroptosis and PD pathogenesis are modulated by O-GlcNAcylation. In PD model cells, O-GlcNAc protein levels were downregulated, while OGA expression was upregulated. Knockdown of OGA significantly protected BV2 cells from LPS-induced injury by inhibiting pyroptosis. Inhibition of OGA notably increased the O-GlcNAc levels of NEK7. Furthermore, O-GlcNAcylated NEK7 protein levels were significantly reduced by mutations at T170 or T172, whereas phosphorylated NEK7 protein levels were downregulated only by mutations at T172. Co-immunoprecipitation (co-IP) confirmed the endogenous interaction between NEK7 and NLRP3, which was weakened by OGA knockdown. In animal experiments, OGA deficiency significantly reduced motor dysfunctions and dopaminergic neurodegeneration in MPTP-treated mice. OGT deficiency abolished the protective effects of OGA knockdown against MPTP-induced injury. Additionally, OGT inhibition in OGA knockdown mice promoted pyroptosis. Collectively, these findings indicate that high OGA levels decrease O-GlcNAcylation in PD, thereby promoting pyroptosis via the activation of the NEK7/NLRP3 pathway.