NEDD4 E3 ligase-catalyzed NAMPT ubiquitination and autophagy activation are essential for pyroptosis-independent NAMPT secretion in human monocytes

作者：Marisela Rodriguez, Haifei Xu, Annie Hernandez, Julia Ingraham, Jason Canizales, Fernando Terán Arce, Sara M. Camp, Skyler Briggs, Aikseng Ooi, James M. Burke, Jin H. Song, Joe G. N. Garcia · 发表于：Cell Communication and Signaling · 年份：2025 · DOI：10.1186/s12964-025-02164-5 · 被引用次数：8 · 研究领域：Inflammasome and immune disorders、Heme Oxygenase-1 and Carbon Monoxide、Autophagy in Disease and Therapy

salvage pathway. However, increased cellular stress (infection, inflammation, hypoxia) promotes the secretion of extracellular NAMPT (eNAMPT), a TLR4 ligand and damage-associated molecular pattern protein (DAMP) that directly drives amplification of innate immune-mediated inflammatory, fibrotic, and neoplastic responses to influence disease severity. We sought to examine the mechanisms underlying pyroptotic eNAMPT release from human monocytic THP-1 cells, evoked by Nigericin, and non-pyroptotic eNAMPT secretion elicited by lipopolysaccharide (LPS). Our data indicate eNAMPT secretion/release requires NLRP3 inflammasome activation with substantial attenuation by either NLRP3 inhibition (MCC-950) or targeted genetic deletion of key inflammasome components, including NLRP3, caspase-1, or gasdermin D (GSDMD). Pyroptosis-associated eNAMPT release involved cleavage of the pore-forming GSDMD protein resulting in plasma membrane rupture (PMR) whereas non-pyroptotic LPS-induced eNAMPT secretion involved neither GSDMD cleavage nor PMR, verified utilizing non-cleavable GSDMD mutant constructs. LPS-induced eNAMPT secretion, however, was highly dependent upon NAMPT ubiquitination catalyzed by a complex containing the NEDD4 E3 ligase, Hsp90 (a selective chaperone), and intact GSDMD verified by enzymatic inhibition or silencing of NEDD4, GSDMD, or Hsp90. NAMPT ubiquitination and secretion involves autophagy activation as super-resolution microscopy analyses demonstrate NAMPT co-localization ...