Methylation and acetylation of 15-hydroxyanandamide modulate its interaction with the endocannabinoid system.
The biological activity of endocannabinoids like anandamide (AEA) and 2-arachidonoylglycerol (2-AG) is subjected in vivo to a "metabolic control", exerted mainly by catabolic enzymes. AEA is inactivated by fatty acid amide hydrolase (FAAH), that is inhibited competitively by hydroxyanandamides (HAEAs) generated from AEA by lipoxygenase activity. Among these derivatives, 15-HAEA has been shown to be an effective (K(i) approximately 0.6 muM) FAAH inhibitor, that blocks also type-1 cannabinoid receptor (CB1R) but not other components of the "endocannabinoid system (ECS)", like the AEA transporter (AMT) or CB2R. Here, we extended the study of the effect of 15-HAEA on the AEA synthetase (NAPE-PLD) and the AEA-binding vanilloid receptor (TRPV1), showing that 15-HAEA activates the former (up to approximately 140% of controls) and inhibits the latter protein (down to approximately 70%). We also show that 15-HAEA halves the synthesis of 2-AG and almost doubles the transport of this compound across the membrane. In addition, we synthesized methyl and acetyl derivatives of 15-HAEA (15-MeOAEA and 15-AcOAEA, respectively), in order to check their ability to modulate FAAH and the other ECS elements. In fact, methylation and acetylation are common biochemical reactions in the cellular environment. We show that 15-MeOAEA, unlike 15-AcOAEA, is still a powerful competitive inhibitor of FAAH (K(i) approximately 0.7 muM), and that both derivatives have negligible interactions with the other proteins of ECS. Therefore, 15-MeOAEA is a FAAH inhibitor more selective than 15-HAEA. Further molecular dynamics analysis gave clues to the molecular requirements for the interaction of 15-HAEA and 15-MeOAEA with FAAH.
Amadio
Daniele
D
Department of Experimental Medicine and Biochemical Sciences, University of Rome, Tor Vergata, Rome, Italy.
Fezza
Filomena
F
Catanzaro
Giuseppina
G
Incani
Ottaviano
O
van Zadelhoff
Guus
G
Finazzi Agrò
Alessandro
A
Maccarrone
Mauro
M
D000107:Acetylation; D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism* / Q000494:pharmacology; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D063388:Endocannabinoids; D007700:Kinetics; D008745:Methylation; D051379:Mice; D010739:Phospholipase D / Q000187:drug effects / Q000378:metabolism; D053284:Polyunsaturated Alkamides / Q000378:metabolism* / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000187:drug effects; D050916:TRPV Cation Channels / Q000378:metabolism; D000099252:Fatty Acid Amide Hydrolases
D000581:Amidohydrolases; D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D010739:Phospholipase D; D053284:Polyunsaturated Alkamides; D043884:Receptor, Cannabinoid, CB1; D050916:TRPV Cation Channels; D000099252:Fatty Acid Amide Hydrolases; C549837:15-hydroxyanandamide; C493921:TRPV1 protein, mouse; C506062:Napepld protein, mouse