Fatty Acid-binding Protein 5 (FABP5) Regulates Cognitive Function Both by Decreasing Anandamide Levels and by Activating the Nuclear Receptor Peroxisome Proliferator-activated Receptor β/δ (PPARβ/δ) in the Brain |
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| Authors: | Shuiliang Yu Liraz Levi Gemma Casadesus George Kunos Noa Noy |
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| Institution: | From the Departments of ‡Pharmacology.;§Neuroscience, and ;‖Nutrition, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106 and ;the ¶Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892 |
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| Abstract: | Endocannabinoids modulate multiple behaviors, including learning and memory. We show that the endocannabinoid anandamide (AEA) can alter neuronal cell function both through its established role in activation of the G-protein-coupled receptor CB1, and by serving as a precursor for a potent agonist of the nuclear receptor PPARβ/δ, in turn up-regulating multiple cognition-associated genes. We show further that the fatty acid-binding protein FABP5 controls both of these functions in vivo. FABP5 both promotes the hydrolysis of AEA into arachidonic acid and thus reduces brain endocannabinoid levels, and directly shuttles arachidonic acid to the nucleus where it delivers it to PPARβ/δ, enabling its activation. In accordance, ablation of FABP5 in mice results in excess accumulation of AEA, abolishes PPARβ/δ activation in the brain, and markedly impairs hippocampus-based learning and memory. The data indicate that, by controlling anandamide disposition and activities, FABP5 plays a key role in regulating hippocampal cognitive function. |
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| Keywords: | Arachidonic Acid Endocannabinoids Lipids Lipid-binding Protein Peroxisome Proliferator-activated Receptor (PPAR) |
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