Presence of the cannabinoid receptors, CB1 and CB2, in human omental and subcutaneous adipocytes.
To investigate the expression of the endocannabinoid 1 and 2 receptors by human adipocyte cells of omental and subcutaneous fat tissue, as well as to determine whether these receptors are functional. The expression of CB1 and CB2 receptors on human adipocytes was analyzed by western blotting, immunohistology and immunocytology. We also investigated intracytoplasmic cyclic AMP level modulation following CB1 and CB2 receptor stimulation by an enzymatic immuno assay. All mature adipocytes, from visceral (epiploon) and subcutaneous fat tissue, express CB1 and CB2 on their plasma membranes. We also demonstrate in this study that adipocyte precursors (pre-adipocytes) express CB1 and CB2 on their plasma membranes and that both receptors are functional. Activation of CB1 increases intracytoplasmic cyclic AMP whilst CB2 activation leads to a cyclic AMP decrease. Here we demonstrate, for the first time, that adipocytes of human adipose tissue (mature adipocytes and pre-adipocytes) express functional plasma membrane CB1 and CB2 receptors. Their physiological role on the adipose tissue is not known. However, their major involvement in the physiology of other tissues leads us to suppose that they could play a significant role in the homeostasis of the energy balance and/or in the regulation of adipose tissue inflammation.
Roche
Régis
R
LBGM, Laboratoire de Biochimie et de Génétique Moléculaire, Université de l'île de la Réunion, 15 avenue René Cassin, 97715 Saint Denis Messag Cedex, France.
Hoareau
Laurence
L
Bes-Houtmann
Sandrine
S
Gonthier
Marie-Paule
MP
Laborde
Christine
C
Baron
Jean-François
JF
Haffaf
Yacine
Y
Cesari
Maya
M
Festy
Franck
F
D017667:Adipocytes / Q000378:metabolism*; D000328:Adult; D002462:Cell Membrane / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009852:Omentum / Q000166:cytology / Q000378:metabolism*; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism*; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism*; D050151:Subcutaneous Fat / Q000166:cytology / Q000378:metabolism*
D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D000242:Cyclic AMP