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Updated: May 22, 2026
Activation and Measurement of NLRP3 Inflammasome Activity Using IL-1β in Human Monocyte-derived Dendritic Cells
Published on: May 22, 2014
The NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation
Fushan Shi1, Lifeng Yang, Mohammed Kouadir
1State Key Laboratories for Agrobiotechnology, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
Background:
Prion diseases are neurodegenerative disorders characterized by the accumulation of an abnormal disease-associated prion protein, PrPSc. In prion-infected brains, activated microglia are often present in the vicinity of PrPSc aggregates, and microglial activation is thought to play a key role in the pathogenesis of prion diseases. Although interleukin (IL)-1β release by prion-induced microglia has been widely reported, the mechanism by which primed microglia become activated and secrete IL-1β in prion diseases has not yet been elucidated. In this study, we investigated the role of the NACHT, LRR and PYD domains-containing protein (NALP)3 inflammasome in IL-1β release from lipopolysaccharide (LPS)-primed microglia after exposure to a synthetic neurotoxic prion fragment (PrP106-126).
Methods:
The inflammasome components NALP3 and apoptosis-associated speck-like protein (ASC) were knocked down by gene silencing. IL-1β production was assessed using ELISA. The mRNA expression of NALP3, ASC, and pro-inflammatory factors was measured by quantitative PCR. Western blot analysis was used to detect the protein level of NALP3, ASC, caspase-1 and nuclear factor-κB.
Results:
We found that that PrP106-126-induced IL-1β release depends on NALP3 inflammasome activation, that inflammasome activation is required for the synthesis of pro-inflammatory and chemotactic factors by PrP106-126-activated microglia, that inhibition of NF-κB activation abrogated PrP106-126-induced NALP3 upregulation, and that potassium efflux and production of reactive oxygen species were implicated in PrP106-126-induced NALP3 inflammasome activation in microglia.
Conclusions:
We conclude that the NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation. To our knowledge, this is the first time that strong evidence for the involvement of NALP3 inflammasome in prion-associated inflammation has been found.
Insights
The NALP3 inflammasome plays a key role in activating microglia and releasing IL-1β in response to neurotoxic prion peptides. This study reveals the NALP3 inflammasome
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Prion diseases involve abnormal prion protein accumulation and microglial activation.
- Microglial activation and IL-1β release are implicated in prion disease pathogenesis.
- The precise mechanism of microglial activation and IL-1β secretion in prion diseases remains unclear.
Purpose of the Study:
- Investigate the role of the NACHT, LRR and PYD domains-containing protein (NALP)3 inflammasome.
- Elucidate the mechanism of IL-1β release from microglia exposed to a synthetic neurotoxic prion fragment (PrP106-126).
Main Methods:
- Gene silencing of NALP3 and apoptosis-associated speck-like protein (ASC).
- ELISA for IL-1β production assessment.
- Quantitative PCR for mRNA expression analysis.
- Western blot for protein level detection of key inflammasome and signaling molecules.
Main Results:
- PrP106-126-induced IL-1β release is dependent on NALP3 inflammasome activation.
- NALP3 inflammasome activation is essential for pro-inflammatory and chemotactic factor synthesis.
- NF-κB inhibition blocked PrP106-126-induced NALP3 upregulation.
- Potassium efflux and reactive oxygen species production are involved in PrP106-126-induced NALP3 inflammasome activation.
Conclusions:
- The NALP3 inflammasome is implicated in neurotoxic prion peptide-induced microglial activation.
- This study provides significant evidence for NALP3 inflammasome involvement in prion-associated neuroinflammation.
