Adenosine A2A receptor mediates microglial process retraction Academic Article uri icon


MeSH Major

  • Microglia
  • Receptors, Adenosine A2
  • Receptors, Purinergic P2


  • Cell motility drives many biological processes, including immune responses and embryonic development. In the brain, microglia are immune cells that survey and scavenge brain tissue using elaborate and motile cell processes. The motility of these processes is guided by the local release of chemoattractants. However, most microglial processes retract during prolonged brain injury or disease. This hallmark of brain inflammation remains unexplained. We identified a molecular pathway in mouse and human microglia that converted ATP-driven process extension into process retraction during inflammation. This chemotactic reversal was driven by upregulation of the A(2A) adenosine receptor coincident with P2Y(12) downregulation. Thus, A(2A) receptor stimulation by adenosine, a breakdown product of extracellular ATP, caused activated microglia to assume their characteristic amoeboid morphology during brain inflammation. Our results indicate that purine nucleotides provide an opportunity for context-dependent shifts in receptor signaling. Thus, we reveal an unexpected chemotactic switch that generates a hallmark feature of CNS inflammation.

publication date

  • July 2009



  • Academic Article



  • eng

PubMed Central ID

  • PMC2712729

Digital Object Identifier (DOI)

  • 10.1038/nn.2341

PubMed ID

  • 19525944

Additional Document Info

start page

  • 872

end page

  • 8


  • 12


  • 7