Brain-Derived Neurotrophic Factor Deficiency Exacerbates Innate Immune Responses by Enhancing NLRP3 Inflammasome Activation and GSDMD-Mediated Pyroptosis in Mice

Medicina (Kaunas). 2026 Feb 14;62(2):384. doi: 10.3390/medicina62020384.

Abstract

Background and Objectives: The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a key innate immune complex, and its aberrant activation contributes to metabolic and neurodegenerative diseases. Brain-derived neurotrophic factor (BDNF) is a neurotrophin with anti-inflammatory and metabolic regulatory functions, but its role in NLRP3 inflammasome activation and gasdermin D (GSDMD)-mediated pyroptosis remains unclear. The aim of this study was to investigate the effects of BDNF deficiency on LPS- and nigericin-induced NLRP3 inflammasome activation and GSDMD-mediated pyroptosis in vivo, and to elucidate the involvement of NF-κB signaling, autophagy, and ESCRT-III-dependent plasma membrane repair in this process. Materials and Methods: In this in vivo study, male Bdnf +/+ and Bdnf +/- mice were subjected to lipopolysaccharide (LPS) plus nigericin-induced NLRP3 inflammasome activation. Serum and hippocampus, cortex, liver, epididymal adipose, and muscle tissues were collected 24 h after stimulation for analysis of inflammasome-related, autophagy-related, and membrane repair-related proteins by Western blotting and of serum BDNF, interleukin-1β (IL-1β), and interleukin-18 (IL-18) by ELISA. Results: Bdnf +/- mice displayed significantly reduced circulating BDNF levels and exhibited exaggerated LPS plus nigericin-induced increases in IL-1β and IL-18 compared with Bdnf +/+ mice. Across all tissues, BDNF deficiency enhanced NF-κB p65, NLRP3, active caspase-1 p20, and GSDMD expression, indicating amplified inflammasome activation and pyroptosis. Conversely, LC3B and SQSTM1/p62 levels were decreased, and VPS4A expression, a key component of the ESCRT-III membrane repair machinery, was suppressed in Bdnf +/- mice, suggesting impaired selective autophagy, autophagosome formation, and plasma membrane repair. Conclusions: Together, these findings indicate that BDNF restrains NLRP3 inflammasome activation and GSDMD-mediated pyroptosis through inhibition of NF-κB signaling and coordinated activation of autophagy and ESCRT-III-dependent membrane repair. BDNF thus emerges as an endogenous negative regulator of inflammasome activity and a potential therapeutic target for conditions characterized by aberrant NLRP3-driven inflammation.

Keywords: BDNF; ESCRT-III machinery; NLRP3 inflammasome; pyroptosis; selective autophagy.

MeSH terms

  • Animals
  • Brain-Derived Neurotrophic Factor* / deficiency
  • Gasdermins
  • Immunity, Innate* / immunology
  • Immunity, Innate* / physiology
  • Inflammasomes* / immunology
  • Inflammasomes* / metabolism
  • Intracellular Signaling Peptides and Proteins* / metabolism
  • Lipopolysaccharides / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NF-kappa B / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein* / immunology
  • NLR Family, Pyrin Domain-Containing 3 Protein* / metabolism
  • Nigericin / pharmacology
  • Phosphate-Binding Proteins* / metabolism
  • Pyroptosis* / drug effects
  • Pyroptosis* / immunology
  • Pyroptosis* / physiology
  • Signal Transduction

Substances

  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Brain-Derived Neurotrophic Factor
  • Gsdmd protein, mouse
  • Inflammasomes
  • Phosphate-Binding Proteins
  • Lipopolysaccharides
  • Intracellular Signaling Peptides and Proteins
  • Nlrp3 protein, mouse
  • NF-kappa B
  • Bdnf protein, mouse
  • Nigericin
  • Gasdermins