Lipopolysaccharide Induces Anandamide Synthesis in Macrophages via CD14/MAPK/Phosphoinositide 3-Kinase/NF-κB Independently of Platelet-activating Factor

• Published in: The Journal of biological chemistry 2003-11, Vol.278 (45), p.45034-45039
• Main Authors: Liu, Jie, Bátkai, Sándor, Pacher, Pál, Harvey-White, Judith, Wagner, Jens A., Cravatt, Benjamin F., Gao, Bin, Kunos, George
• Format: Article
• Language: English
• Subjects: anandamide; CD14 antigen; fatty acid amidohydrolase; platelet-activating factor
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M306062200

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-κB-, 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.