Nilotinib attenuates NLRP3 inflammasome activation and GSDMD/NINJ1-mediated pyroptosis via modulation of NF-κB signaling and enhancement of BAG3-dependent aggrephagy and ESCRT-III-mediated plasma membrane repair in microglia.

Abstract

Microglia are the resident immune cells of the brain and serve as key regulators of innate immune responses within the central nervous system (CNS). The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a multiprotein complex that plays a central role in innate immunity, and its excessive activation contributes to the pathogenesis of neurodegenerative diseases. Nilotinib, a second-generation tyrosine kinase inhibitor, has recently attracted attention due to its neuroprotective and immunomodulatory properties in the CNS. In the present study, we investigated the effects of nilotinib on NLRP3 inflammasome activation, GSDMD/NINJ1-mediated pyroptosis, NF-κB signaling, BAG3-dependent aggrephagy, and ESCRT-III-mediated plasma membrane repair in LPS plus ATP-induced murine N9 microglial cells. Our findings demonstrated that nilotinib significantly attenuated NLRP3 inflammasome activation, as evidenced by reduced NLRP3 expression, decreased caspase-1 activation, and suppressed secretion of proinflammatory cytokines IL-1β and IL-18 through modulation of the IκBα/NF-κB signaling axis. Furthermore, nilotinib markedly inhibited pyroptotic cell death by reducing GSDMD-N and NINJ1 expression, thereby preserving membrane integrity. In parallel, nilotinib enhanced BAG3-dependent selective autophagy and increased LC3B expression, suggesting activation of aggrephagy pathways involved in the clearance of inflammasome-associated components. Notably, nilotinib also restored VPS4A expression, indicating activation of ESCRT-III-mediated plasma membrane repair mechanisms. Collectively, our results reveal that nilotinib exerts a multi-layered regulatory effect on microglial inflammatory responses by suppressing inflammasome activation and pyroptosis while promoting autophagy-dependent clearance and membrane repair pathways. These findings highlight a novel integrative mechanism linking autophagy, pyroptosis, and membrane repair in the neuroprotective actions of nilotinib.