Cannabinoid receptor subtype 2 (CB2R) agonist, GW405833 reduces agonist-induced Ca(2+) oscillations in mouse pancreatic acinar cells

Sci Rep. 2016 Jul 19:6:29757. doi: 10.1038/srep29757.

Abstract

Emerging evidence demonstrates that the blockade of intracellular Ca(2+) signals may protect pancreatic acinar cells against Ca(2+) overload, intracellular protease activation, and necrosis. The activation of cannabinoid receptor subtype 2 (CB2R) prevents acinar cell pathogenesis in animal models of acute pancreatitis. However, whether CB2Rs modulate intracellular Ca(2+) signals in pancreatic acinar cells is largely unknown. We evaluated the roles of CB2R agonist, GW405833 (GW) in agonist-induced Ca(2+) oscillations in pancreatic acinar cells using multiple experimental approaches with acute dissociated pancreatic acinar cells prepared from wild type, CB1R-knockout (KO), and CB2R-KO mice. Immunohistochemical labeling revealed that CB2R protein was expressed in mouse pancreatic acinar cells. Electrophysiological experiments showed that activation of CB2Rs by GW reduced acetylcholine (ACh)-, but not cholecystokinin (CCK)-induced Ca(2+) oscillations in a concentration-dependent manner; this inhibition was prevented by a selective CB2R antagonist, AM630, or was absent in CB2R-KO but not CB1R-KO mice. In addition, GW eliminated L-arginine-induced enhancement of Ca(2+) oscillations, pancreatic amylase, and pulmonary myeloperoxidase. Collectively, we provide novel evidence that activation of CB2Rs eliminates ACh-induced Ca(2+) oscillations and L-arginine-induced enhancement of Ca(2+) signaling in mouse pancreatic acinar cells, which suggests a potential cellular mechanism of CB2R-mediated protection in acute pancreatitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / pharmacology
  • Acinar Cells / drug effects*
  • Acinar Cells / metabolism
  • Acinar Cells / physiology
  • Animals
  • Arginine / pharmacology
  • Calcium / metabolism*
  • Calcium Signaling / drug effects*
  • Cholinergic Agonists / pharmacology
  • Indoles / pharmacology*
  • Male
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Morpholines / pharmacology*
  • Pancreas / cytology
  • Receptor, Cannabinoid, CB1 / genetics
  • Receptor, Cannabinoid, CB1 / metabolism
  • Receptor, Cannabinoid, CB2 / agonists*
  • Receptor, Cannabinoid, CB2 / genetics
  • Receptor, Cannabinoid, CB2 / metabolism

Substances

  • 1-(2,3-dichlorobenzoyl)-5-methoxy-2-methyl-(2-(mopholin-4-yl)ethyl)-1H-indole
  • Cholinergic Agonists
  • Indoles
  • Morpholines
  • Receptor, Cannabinoid, CB1
  • Receptor, Cannabinoid, CB2
  • Arginine
  • Acetylcholine
  • Calcium