Extracellular ADP augments microglial inflammasome and NF-κB activation via the P2Y12 receptor

Eur J Immunol. 2020 Feb;50(2):205-219. doi: 10.1002/eji.201848013. Epub 2019 Oct 2.


The NLRP3 inflammasome is a molecular complex that translates signals from pathogens and tissue damage into inflammatory responses, and plays crucial roles in numerous neurological diseases. Activation of the NLRP3 inflammasome leads to caspase-1 dependent cleavage of pro-IL-1β to form mature IL-1β. By acting on the P2X7 purinergic receptor, extracellular ATP is one of the major stimuli that activates the NLRP3 inflammasome. Although microglia express multiple purinergic receptors, their roles in inflammasome-mediated inflammation are largely unknown. We studied the role of the P2Y12 receptor, a metabotropic P2Y receptor enriched in microglia, on inflammation in vitro. Inhibition of the microglial P2Y12 receptor by PSB0739 or siRNA knockdown suppressed IL-1β release. P2Y12 receptor-deficient microglia displayed markedly attenuated IL-1β mRNA expression and release. P2Y12 receptor blockade also suppressed IL-6 production. Both IL-1β and IL-6 responses were augmented by extracellular ADP or ADP-βS and were abrogated by PSB0739. Mechanistically, ADP-βS potentiated NF-κB activation. In addition, ADP altered mitochondrial membrane potential in combination with ATP and increased the number of caspase-1 positive cells through the P2Y12 receptor. These results elucidate a novel inflammatory mechanism by which extracellular ADP acts on the P2Y12 receptor to activate NF-κB and the NLRP3 inflammasome to enhance microglial inflammation.

Keywords: IL-1β; NF-κB; NLRP3 inflammasome; P2Y12 receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / metabolism*
  • Animals
  • Caspase 1 / metabolism
  • Cell Line
  • Cytokines / metabolism
  • Gene Expression Regulation / physiology
  • Inflammasomes / metabolism*
  • Inflammation / metabolism
  • Inflammation Mediators / metabolism
  • Interleukin-1beta / metabolism
  • Macrophages / metabolism
  • Mice
  • NF-kappa B / metabolism*
  • Reactive Oxygen Species / metabolism
  • Receptors, Purinergic P2Y12 / metabolism*
  • Signal Transduction / physiology


  • Cytokines
  • Inflammasomes
  • Inflammation Mediators
  • Interleukin-1beta
  • NF-kappa B
  • P2ry12 protein, mouse
  • Reactive Oxygen Species
  • Receptors, Purinergic P2Y12
  • Adenosine Diphosphate
  • Caspase 1