title: Compartmentalization of endocannabinoids into lipid rafts in a microglial cell line devoid of caveolin-1.
abstract: OBJECTIVE
  N-acyl ethanolamines (NAEs) and 2-arachidonoyl glycerol (2-AG) are endogenous cannabinoids and along with related lipids are synthesized on demand from membrane phospholipids. Here, we have studied the compartmentalization of NAEs and 2-AG into lipid raft fractions isolated from the caveolin-1-lacking microglial cell line BV-2, following vehicle or cannabidiol (CBD) treatment. Results were compared with those from the caveolin-1-positive F-11 cell line.
  
  
  METHODS
  BV-2 cells were incubated with CBD or vehicle. Cells were fractionated using a detergent-free continuous OptiPrep density gradient. Lipids in fractions were quantified using HPLC/MS/MS. Proteins were measured using Western blot.
  
  
  RESULTS
  BV-2 cells were devoid of caveolin-1. Lipid rafts were isolated from BV-2 cells as confirmed by co-localization with flotillin-1 and sphingomyelin. Small amounts of cannabinoid CB(1) receptors were found in lipid raft fractions. After incubation with CBD, levels and distribution in lipid rafts of 2-AG, N-arachidonoyl ethanolamine (AEA), and N-oleoyl ethanolamine (OEA) were not changed. Conversely, the levels of the saturated N-stearoyl ethanolamine (SEA) and N-palmitoyl ethanolamine (PEA) were elevated in lipid raft fractions. In whole cells with growth medium, CBD treatment increased AEA and OEA time-dependently, while levels of 2-AG, PEA and SEA did not change.
  
  
  CONCLUSIONS
  Whereas levels of 2-AG were not affected by CBD treatment, the distribution and levels of NAEs showed significant changes. Among the NAEs, the degree of acyl chain saturation predicted the compartmentalization after CBD treatment suggesting a shift in cell signalling activity.
  
  
  BACKGROUND
  This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel. Neta.rimmerman@weizmann.ac.il
authors: Neta
authors: N
authors: Rimmerman
authors: Heather B
authors: HB
authors: Bradshaw
authors: Ewa
authors: E
authors: Kozela
authors: Rivka
authors: R
authors: Levy
authors: Ana
authors: A
authors: Juknat
authors: Zvi
authors: Z
authors: Vogel
mesh_terms: D000818:Animals; D002185:Cannabidiol / Q000494:pharmacology*; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D051242:Caveolin 1 / Q000172:deficiency; D002460:Cell Line; D063388:Endocannabinoids; D021962:Membrane Microdomains / Q000378:metabolism*; D051379:Mice; D017628:Microglia / Q000378:metabolism; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism
chemical_list: D063385:Cannabinoid Receptor Modulators; D051242:Caveolin 1; C571431:Cnr2 protein, mouse; D063388:Endocannabinoids; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D002185:Cannabidiol