Activation of NLRP3 inflammasome by crystalline structures via cell surface contact

Sci Rep. 2014 Dec 2:4:7281. doi: 10.1038/srep07281.

Abstract

Crystalline structures activate the NLRP3 inflammasome, leading to the production of IL-1β, however, the molecular interactions responsible for NLRP3 activation are not fully understood. Cathepsin B release from the ruptured phagolysosome and potassium ion efflux have been suggested to be critical for this activation. Here, we report that Cathepsin B redistribution was not a crucial event in crystal-induced IL-1β production. Silica and monosodium urate crystal-treated macrophages with undisturbed lysosomes demonstrated strong co-localization of ASC and Caspase-1, indicative of NLRP3 inflammasome activation. Importantly, we provided evidence to suggest that macrophage cell membrane binding to immobilized crystals was sufficient to induce IL-1β release, and this activation of the NLRP3 inflammasome was inhibited by blocking potassium efflux. Therefore, this work reveals additional complexity in crystalline structure-mediated NLRP3 inflammasome regulations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carrier Proteins / metabolism*
  • Caspase 1 / metabolism
  • Cathepsin B / metabolism
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Inflammasomes / metabolism*
  • Interleukin-1beta / metabolism
  • Lysosomes / metabolism
  • Macrophages / metabolism
  • Mice
  • Mice, Inbred C57BL
  • NLR Family, Pyrin Domain-Containing 3 Protein

Substances

  • Carrier Proteins
  • Inflammasomes
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse
  • Cathepsin B
  • Caspase 1