CB1 receptor activation induces intracellular Ca2+ mobilization and 2-arachidonoylglycerol release in rodent spinal cord astrocytes

Sci Rep. 2018 Jul 12;8(1):10562. doi: 10.1038/s41598-018-28763-6.

Abstract

Accumulating evidence supports the role of astrocytes in endocannabinoid mediated modulation of neural activity. It has been reported that some astrocytes express the cannabinoid type 1 receptor (CB1-R), the activation of which is leading to Ca2+ mobilization from internal stores and a consecutive release of glutamate. It has also been documented that astrocytes have the potential to produce the endocannabinoid 2-arachidonoylglycerol, one of the best known CB1-R agonist. However, no relationship between CB1-R activation and 2-arachidonoylglycerol production has ever been demonstrated. Here we show that rat spinal astrocytes co-express CB1-Rs and the 2-arachidonoylglycerol synthesizing enzyme, diacylglycerol lipase-alpha in close vicinity to each other. We also demonstrate that activation of CB1-Rs induces a substantial elevation of intracellular Ca2+ concentration in astrocytes. Finally, we provide evidence that the evoked Ca2+ transients lead to the production of 2-arachidonoylglycerol in cultured astrocytes. The results provide evidence for a novel cannabinoid induced endocannabinoid release mechanism in astrocytes which broadens the bidirectional signaling repertoire between astrocytes and neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arachidonic Acids / metabolism*
  • Astrocytes / metabolism*
  • Calcium / metabolism*
  • Cell Communication
  • Cells, Cultured
  • Endocannabinoids / metabolism*
  • Glycerides / metabolism*
  • Lipoprotein Lipase / metabolism
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neurons / metabolism
  • Primary Cell Culture
  • Rats
  • Rats, Inbred WKY
  • Receptor, Cannabinoid, CB1 / genetics
  • Receptor, Cannabinoid, CB1 / metabolism*
  • Spinal Cord Dorsal Horn / cytology
  • Spinal Cord Dorsal Horn / metabolism

Substances

  • Arachidonic Acids
  • CNR1 protein, mouse
  • Cnr1 protein, rat
  • Endocannabinoids
  • Glycerides
  • Receptor, Cannabinoid, CB1
  • glyceryl 2-arachidonate
  • Lipoprotein Lipase
  • Calcium