Paracrine transactivation of the CB1 cannabinoid receptor by AT1 angiotensin and other Gq/11 protein-coupled receptors

J Biol Chem. 2009 Jun 19;284(25):16914-16921. doi: 10.1074/jbc.M109.003681. Epub 2009 Apr 7.

Abstract

Intracellular signaling systems of G protein-coupled receptors are well established, but their role in paracrine regulation of adjacent cells is generally considered as a tissue-specific mechanism. We have shown previously that AT(1) receptor (AT(1)R) stimulation leads to diacylglycerol lipase-mediated transactivation of co-expressed CB(1)Rs in Chinese hamster ovary cells. In the present study we detected a paracrine effect of the endocannabinoid release from Chinese hamster ovary, COS7, and HEK293 cells during the stimulation of AT(1) angiotensin receptors by determining CB(1) cannabinoid receptor activity with bioluminescence resonance energy transfer-based sensors of G protein activation expressed in separate cells. The angiotensin II-induced, paracrine activation of CB(1) receptors was visualized by detecting translocation of green fluorescent protein-tagged beta-arrestin2. Mass spectrometry analyses have demonstrated angiotensin II-induced stimulation of 2-arachidonoylglycerol production, whereas no increase of anandamide levels was observed. Stimulation of G(q/11)-coupled M(1), M(3), M(5) muscarinic, V(1) vasopressin, alpha(1a) adrenergic, B(2) bradykinin receptors, but not G(i/o)-coupled M(2) and M(4) muscarinic receptors, also led to paracrine transactivation of CB(1) receptors. These data suggest that, in addition to their retrograde neurotransmitter role, endocannabinoids have much broader paracrine mediator functions during activation of G(q/11)-coupled receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrestins / genetics
  • Arrestins / metabolism
  • CHO Cells
  • COS Cells
  • Cannabinoid Receptor Modulators / metabolism
  • Cell Line
  • Chlorocebus aethiops
  • Cricetinae
  • Cricetulus
  • Fluorescence Resonance Energy Transfer
  • GTP-Binding Protein alpha Subunits, Gq-G11 / genetics*
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism*
  • Humans
  • Paracrine Communication
  • Rats
  • Receptor, Angiotensin, Type 1 / genetics*
  • Receptor, Angiotensin, Type 1 / metabolism*
  • Receptor, Cannabinoid, CB1 / genetics*
  • Receptor, Cannabinoid, CB1 / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transcriptional Activation
  • beta-Arrestins

Substances

  • Arrestins
  • Cannabinoid Receptor Modulators
  • Receptor, Angiotensin, Type 1
  • Receptor, Cannabinoid, CB1
  • Recombinant Fusion Proteins
  • beta-Arrestins
  • GTP-Binding Protein alpha Subunits, Gq-G11