Inactivation of NLRP3 inflammasome by dephosphorylation at Serine 658 alleviates glial inflammation in the mouse model of Parkinson’s disease

BACKGROUND: Parkinson's disease (PD) is a leading neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons, contributing to considerable disability worldwide. Current treatments offer only symptomatic relief, highlighting the need for novel therapeutic strategies targeting disease progression. Neuroinflammation plays a pivotal role in PD pathogenesis, with the NLRP3 inflammasome emerging as a key contributor. METHODS: The virtual screening of a natural product library comprising 5,088 compounds was applied to identify five potential NLRP3 inhibitors through molecular docking scores. Then surface plasmon resonance assays were used to detect their binding affinities to the NLRP3 protein. Functional studies in macrophages and glial cells were used to demonstrate the effect of Psoralen on NLRP3 phosphorylation and inflammasome activation. RESULTS: Psoralen treatment improved PD-like symptoms and reduced dopaminergic neuronal death by targeting glial NLRP3 inflammasome activation in the MPTP/p mouse model. By performing 4D label-free quantitative phosphorylation proteomics and site mutation assays, we identified that Psoralen prevents NLRP3 phosphorylation at Serine 658 by binding to its NACHT and LRR domains. CONCLUSIONS: These findings position Psoralen as a promising NLRP3 inflammasome inhibitor, offering a potential therapeutic avenue for PD and other NLRP3 inflammasome-related diseases. Additionally, this research highlights the innovative approach of targeting specific phosphorylation sites on the NLRP3 protein to reduce neuroinflammation.