Discovery of a NAPE-PLD inhibitor that modulates emotional behavior in mice

N-acylethanolamines (NAEs), which include the endocannabinoid anandamide, represent an important family of signaling lipids in the brain. The lack of chemical probes that modulate NAE biosynthesis in living systems hamper the understanding of the biological role of these lipids. Using a high-throughput screen, chemical proteomics and targeted lipidomics, we report here the discovery and characterization of LEI-401 as a CNS-active N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) inhibitor. LEI-401 reduced NAE levels in neuroblastoma cells and in the brain of freely moving mice, but not in NAPE-PLD KO cells and mice, respectively. LEI-401 activated the hypothalamus–pituitary–adrenal axis and impaired fear extinction, thereby emulating the effect of a cannabinoid CB1 receptor antagonist, which could be reversed by a fatty acid amide hydrolase inhibitor. Our findings highlight the distinctive role of NAPE-PLD in NAE biosynthesis in the brain and suggest the presence of an endogenous NAE tone controlling emotional behavior.NWOMicrobial Biotechnolog

Rapid Synapse Elimination After Postsynaptic Protein Synthesis Inhibition In Vivo

To examine the role of retrograde signals on synaptic maintenance, we inhibited protein synthesis in individual postsynaptic cells in vivo while monitoring presynaptic terminals. Within 12 h, axon terminals begin to atrophy and withdraw from normal postsynaptic sites. Structural similarities between this process and naturally occurring synapse elimination suggest that short-lived target derived factors not only participate in synaptic maintenance in adults, but also regulate elimination of connections during development. Copyright © 2007 Society for Neuroscience.272260646067Bishop, D.L., Misgeld, T., Walsh, M.K., Gan, W.B., Lichtman, J.W., Axon branch removal at developing synapses by axosome shedding (2004) Neuron, 44, pp. 651-661Culican, S.M., Nelson, C.C., Lichtman, J.W., Axon withdrawal during synapse elimination at the neuromuscular junction is accompanied by disassembly of the postsynaptic specialization and withdrawal of Schwann cell processes (1998) J Neurosci, 18, pp. 4953-4965Feng, G., Mellor, R.H., Bernstein, M., Keller-Peck, C., Nguyen, Q.T., Wallace, M., Nerbonne, J.M., Sanes, J.R., Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP (2000) Neuron, 28, pp. 41-51Gan, W.B., Lichtman, J.W., Synaptic segregation at the developing neuromuscular junction (1998) Science, 282, pp. 1508-1511Keller-Peck, C.R., Walsh, M.K., Gan, W.B., Feng, G., Sanes, J.R., Lichtman, J.W., Asynchronous synapse elimination in neonatal motor units: Studies using GFP transgenic mice (2001) Neuron, 31, pp. 381-394Kerschensteiner, M., Schwab, M.E., Lichtman, J.W., Misgeld, T., In vivo imaging of axonal degeneration and regeneration in the injured spinal cord (2005) Nat Med, 11, pp. 572-577Kishida, K., Masuho, Y., Hara, T., Protein-synthesis inhibitory protein from seeds of Luffa cylindria roem (1983) FEBS Letters, 153, pp. 209-212Lichtman, J.W., Magrassi, L., Purves, D., Visualization of neuromuscular junctions over periods of several months in living mice (1987) J Neurosci, 7, pp. 1215-1222Nguyen, Q.T., Parsadanian, A.S., Snider, W.D., Lichtman, J.W., Hyperinnervation of neuromuscular junctions caused by GDNF overexpression in muscle (1998) Science, 279, pp. 1725-1729Portera-Cailliau, C., Weimer, R.M., De Paola, V., Caroni, P., Svoboda, K., Diverse modes of axon elaboration in the developing neocortex (2005) PLoS Biol, 3, pp. e272Reynolds, M.L., Woolf, C.J., Terminal Schwann cells elaborate extensive processes following denervation of the motor endplate (1992) J Neurocytol, 21, pp. 50-66Sanes, J.R., Lichtman, J.W., Induction, assembly, maturation and maintenance of a postsynaptic apparatus (2001) Nat Rev Neurosci, 2, pp. 791-805Sigrist, S.J., Thiel, P.R., Reiff, D.F., Lachance, P.E., Lasko, P., Schuster, C.M., Postsynaptic translation affects the efficacy and morphology of neuromuscular junctions (2000) Nature, 405, pp. 1062-1065Stirpe F, Gasperi-Campani A, Barbieri L, Falasca A, Abbondanza A, Stevens WA (1983) Ribosome-inactivating proteins from the seeds of Saponaria officinalis L. (soapwort), of Agrostemma githago L. (corn cockle) and of Asparagus officinalis L. (asparagus), and from the latex of Hura crepitans L. (sandbox tree). Biochem J 216:617-625Stirpe, F., Barbieri, L., Battelli, M.G., Soria, M., Lappi, D.A., Ribosome-inactivating proteins from plants: Present status and future prospects (1992) Biotechnology (NY), 10, pp. 405-412Tao, H.W., Poo, M., Retrograde signaling at central synapses (2001) Proc Natl Acad Sci USA, 98, pp. 11009-11015Walsh, M.K., Lichtman, J.W., In vivo time-lapse imaging of synaptic takeover associated with naturally occurring synapse elimination (2003) Neuron, 37, pp. 67-73Watts, R.J., Schuldiner, O., Perrino, J., Larsen, C., Luo, L., Glia engulf degenerating axons during developmental axon pruning (2004) Curr Biol, 14, pp. 678-684Zuo, Y., Lubischer, J.L., Kang, H., Tian, L., Mikesh, M., Marks, A., Scofield, V.L., Thompson, W.J., Fluorescent proteins expressed in mouse transgenic lines mark subsets of glia, neurons, macrophages, and dendritic cells for vital examination (2004) J Neurosci, 24, pp. 10999-1100