title: Modulation of adipocyte biology by δ(9)-tetrahydrocannabinol.
abstract: It is recognized that the endocannabinoid system (ECS) plays a crucial role in the modulation of food intake and other aspects of energy metabolism. In this study, we aimed to investigate the effects of Δ(9)-tetrahydrocannabinol (THC) on adipocyte biology. 3T3-L1 cells were used to evaluate proliferation by sulforhodamine B (SRB) staining and methyl-(3)H-thymidine incorporation after 48 or 72 h of treatment with THC (1-500 nmol/l). Cells were differentiated in the presence or absence of the cannabinoid, and adipogenesis was determined by measuring lipid accumulation and peroxisome proliferator-activated receptor γ (PPARγ) transcription through reverse transcriptase-PCR (RT-PCR). Lipolysis was quantified under basal conditions or after isoproterenol (IP, 100 nmol/l) or insulin (INS, 100 nmol/l) treatment. Transforming growth factor β (TGFβ), diacylglycerol lipase α, and N-acylphosphatidylethanolamine-specific phospholipase D (NAPE-PLD) transcriptions were determined by RT-PCR in preadipocytes and adipocytes and adiponectin only in adipocytes. THC treatment increased culture protein content and reduced methyl-(3)H-thymidine incorporation. Cells treated with THC underwent adipogenesis shown by the expression of PPARγ and had increased lipid accumulation. Basal and IP-stimulated lipolyses were inhibited by THC and there was no effect on lipolysis of INS-treated adipocytes. The effects on methyl-(3)H-thymidine incorporation and lipolysis seem to be mediated through CB1- and CB2-dependent pathways. THC decreased NAPE-PLD in preadipocytes and increased adiponectin and TGFβ transcription in adipocytes. These results show that the ECS interferes with adipocyte biology and may contribute to adipose tissue (AT) remodeling. Although these observations point toward increased AT deposition, the stimulation of adiponectin production and inhibition of lipolysis may be in favor of improved INS sensitivity under cannabinoid influence.
authors.affiliation: Department of Biochemistry U38-FCT, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Diana
authors.initials: D
authors.lastname: Teixeira
authors.forename: Diogo
authors.initials: D
authors.lastname: Pestana
authors.forename: Ana
authors.initials: A
authors.lastname: Faria
authors.forename: Conceição
authors.initials: C
authors.lastname: Calhau
authors.forename: Isabel
authors.initials: I
authors.lastname: Azevedo
authors.forename: Rosário
authors.initials: R
authors.lastname: Monteiro
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects* / Q000502:physiology; D052242:Adiponectin / Q000378:metabolism; D000818:Animals; D002188:Cannabis / Q000737:chemistry; D013759:Dronabinol / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance; D007545:Isoproterenol / Q000494:pharmacology; D050356:Lipid Metabolism / Q000187:drug effects*; D008066:Lipolysis / Q000187:drug effects; D008071:Lipoprotein Lipase / Q000378:metabolism; D051379:Mice; D047495:PPAR gamma / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011619:Psychotropic Drugs / Q000494:pharmacology*; D043882:Receptors, Cannabinoid / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D052242:Adiponectin; D007328:Insulin; D047495:PPAR gamma; D011506:Proteins; D011619:Psychotropic Drugs; D043882:Receptors, Cannabinoid; D016212:Transforming Growth Factor beta; D013759:Dronabinol; D008071:Lipoprotein Lipase; D010739:Phospholipase D; D007545:Isoproterenol