17
Discovery of CB2 (Munro et al. 1993) In situ hybridization
Discovery of CB2
(Munro et al. 1993)
In situ hybridization
Discovery of CB2
(Munro et al. 1993)
Binding studies
Discovery of CB2
(Munro et al. 1993)
In situ hybridization
GPR55 a putative third cannabinoid receptor?
First described as a cannabinoid receptor in a patent by Astra-Zeneca in 2004
(Brown 2007)(Brown 2007)
GPR55 a putative third cannabinoid receptor?
(Brown 2007)
Discovery of endogenous cannabinoids(Devane et al. 1992)
• Screening for endogenous cannabinoid ligands using porcine brain
• Identification of an arachidonic acid derivative (arachidonylethanolamide) that binds to CB receptor
• This arachidonic acid derivative inhibited in a concentration dependent manner the binding of radiolabelled cannabinoid to synaptosomal membrane.
• The compound is named Anandamide from the Sanskrit ananda (bliss, delight)
Endogenous cannabinoids
Mechanisms of anandamide formation
(Cadas et al 1996)
Mechanisms of 2-AG formation
(Piomelli 2003)
Endocannabinoids’ inactivation system
Accumulation of [3H] ethanolamide following incubation with [3H]AEA
Fatty acid amido-hydrolase(FAAH)
Degradation
(Di Marzo et al 1994)
Accumulation of [3H] ethanolamideor [3H] arachidonate in phopholipidsfollowing incubation with [3H]AEA
(Beltramo et al 1997)
Time course of [3H]AEA accumulation in neurons (circle) or astrocytes (square)
Linewaver-Burk analysis of [3H]AEA accumulation in neurons (B) and astrocytes (C)
Internalization
Endocannabinoids’ inactivation system
(Beltramo et al 1997)
Inhibition of [3H]AEA accumulation by AM404
Internalization
Endocannabinoids’ inactivation system
AEA inactivation
(Piomelli 2003)
AEA inactivation
(Giuffrida and McMahon 2009)
Fatty acid amide hydrolase (FAAH) Cycloxygenase-2 (COX-2), 12- and 15-lipoxygenases (LOXs)Cytochrome P450 (P450)
2-AG inactivation
Monoacylglycerol lipase (MAGL) is consideredthe major enzyme responsible for 2-AG metabolism
AEA and 2-AG internalization occur througha substantially common mechanism
The endocannabinoid systemNAT
NAPE
PLD
PLC
DAG
DGL
Endocannabinoids
PE-PC
PIPX
Endocannabinoids(AEA, 2-AG, noladin ehter, virodhamine, NADA)
uptake
FAAH MAGL
uptake
NFkappaB
AC-
ATP cAMP
SMase
ceramide
Raf-1
JNK
Ca2+K
+
- +
+/--
-
CB3
Gα12-13?
+MAPK
?
?CB2
Gi/o Gi/oCB1
Cannabinoid system physiological effects
• Motor impairement
• Memory impairement
• Catalepsy
• Temperature decrease
• Analgesia
• Pressure modification
• Immune suppression/stimulation
