Lipopolysaccharide induces anandamide synthesis in macrophages via CD14/MAPK/phosphoinositide 3-kinase/NF-kappaB independently of platelet-activating factor.
Macrophage-derived endocannabinoids have been implicated in endotoxin (lipopolysaccharide (LPS))-induced hypotension, but the endocannabinoid involved and the mechanism of its regulation by LPS are unknown. In RAW264.7 mouse macrophages, LPS (10 ng/ml) increases anandamide (AEA) levels >10-fold via CD14-, NF-kappaB-, and p44/42-dependent, platelet-activating factor-independent activation of the AEA biosynthetic enzymes, N-acyltransferase and phospholipase D. LPS also induces the AEA-degrading enzyme fatty acid amidohydrolase (FAAH), and inhibition of FAAH activity potentiates, whereas actinomycin D or cycloheximide blocks the LPS-induced increase in AEA levels and N-acyltransferase and phospholipase D activities. In contrast, cellular levels of the endocannabinoid 2-arachidonoylglycerol (2-AG) are unaffected by LPS but increased by platelet-activating factor. LPS similarly induces AEA, but not 2-AG, in mouse peritoneal macrophages where basal AEA levels are higher, and the LPS-stimulated increase in AEA is potentiated in cells from FAAH-/- as compared with FAAH+/+ mice. Intravenous administration of 107 LPS-treated mouse macrophages to anesthetized rats elicits hypotension, which is much greater in response to FAAH-/- than FAAH+/+ cells and is susceptible to inhibition by SR141716, a cannabinoid CB1 receptor antagonist. We conclude that AEA and 2-AG synthesis are differentially regulated in macrophages, and AEA rather than 2-AG is a major contributor to LPS-induced hypotension.
Liu
Jie
J
Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA.
Batkai
Sándor
S
Pacher
Pál
P
Harvey-White
Judith
J
Wagner
Jens A
JA
Cravatt
Benjamin F
BF
Gao
Bin
B
Kunos
George
G
D000217:Acyltransferases / Q000378:metabolism; D000581:Amidohydrolases / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D000818:Animals; D001095:Arachidonic Acids / Q000096:biosynthesis*; D002460:Cell Line; D063388:Endocannabinoids; D005989:Glycerides / Q000096:biosynthesis; D007022:Hypotension / Q000209:etiology; D007700:Kinetics; D018950:Lipopolysaccharide Receptors / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism* / Q000637:transplantation; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000502:physiology*; D010714:Phosphatidylethanolamines; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism; D010972:Platelet Activating Factor / Q000502:physiology; D053284:Polyunsaturated Alkamides; D051381:Rats; D017207:Rats, Sprague-Dawley; D000099252:Fatty Acid Amide Hydrolases
D000217:Acyltransferases; D000581:Amidohydrolases; D001095:Arachidonic Acids; D063388:Endocannabinoids; D005989:Glycerides; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D016328:NF-kappa B; D010714:Phosphatidylethanolamines; D019869:Phosphatidylinositol 3-Kinases; D010739:Phospholipase D; D010972:Platelet Activating Factor; D053284:Polyunsaturated Alkamides; D000099252:Fatty Acid Amide Hydrolases; C109143:N-arachidonylphosphatidylethanolamine; C094503:glyceryl 2-arachidonate; C078814:anandamide