Piperine inhibits NLRP3 inflammasome activation and alleviates inflammatory disease.

BACKGROUND

Excessive or aberrant activation of the NLRP3 inflammasome is implicated in the initiation and progression of various inflammatory diseases.

PURPOSE: This study aimed to investigate whether piperine (PIP) inhibited NLRP3 inflammasome activation and disrupting the NEK7-NLRP3 interaction, and to evaluate its anti-inflammatory effects in vivo.

METHODS

We identified NLRP3 as a potential target of PIP through COMET database and RNA sequencing. A classic NLRP3 inflammasome activation model was established in immortalized bone marrow-derived macrophages (iBMDMs) primed with lipopolysaccharide (LPS) and then activated with nigericin. Protein interactions and binding modes were analyzed using co-immunoprecipitation and molecular modeling. The protective effects of PIP were evaluated in mouse models of acute lung injury and colitis.

RESULTS

PIP effectively inhibited NLRP3 inflammasome activation without affecting NLRC4 or AIM2 inflammasome. Furthermore, PIP blocked NLRP3 protein oligomerization and ASC recruitment, and inhibited inflammasome assembly by interfering with NEK7-NLRP3 interaction. Molecular simulation confirmed that PIP binds noncovalently to NLRP3 at lysine 232 via a hydrogen bond, and mutating this residue to alanine eliminated its inhibitory effect on the NEK7-NLRP3 interaction. In vivo, PIP markedly alleviated LPS-induced acute lung injury and dextran sulfate sodium-induced colitis by reducing inflammatory responses.

CONCLUSION

These findings demonstrate that PIP inhibited NLRP3 inflammasome activation by targeting Lys232 and exerted potent anti-inflammatory effects in vivo, supporting its potential as a therapeutic candidate for NLRP3-driven inflammatory diseases.