title: The activation of cannabinoid CB2 receptors stimulates in situ and in vitro beta-amyloid removal by human macrophages.
abstract: The endocannabinoid system is a promising therapeutic target in a wide variety of diseases. However, the non-desirable psychotropic effects of natural and synthetic cannabinoids have largely counteracted their clinical usefulness. These effects are mostly mediated by cannabinoid receptors of the CB(1) type, that exhibit a wide distribution in neuronal elements of the CNS. Thus, the presence of other elements of this system in the CNS, such as CB(2) receptors, may open new possibilities for the development of cannabinoid-based therapies. These receptors are almost absent from the CNS in normal conditions but are up-regulated in glial cells under chronic neuroinflammatory stimuli, as has been described in Alzheimer's disease. To understand the functional role of these receptors, we tested their role in the process of beta-amyloid removal, that is currently considered as one of the most promising experimental approaches for the treatment of this disease. Our results show that a CB(2) agonist (JWH-015) is capable of inducing the removal of native beta-amyloid removal from human frozen tissue sections as well as of synthetic pathogenic peptide by a human macrophage cell line (THP-1). Remarkably, this effect was achieved at low doses (maximum effect at 10 nM) and was specific for this type of cells, as U373MG astrocytoma cells did not respond to the treatment. The effect was CB(2)-mediated, at least partially, as the selective CB(2) antagonist SR144528 prevented the JWH-015-induced plaque removal in situ. These data corroborate the possible therapeutic interest of CB(2) cannabinoid specific chemicals in the treatment of Alzheimer's disease.
authors.affiliation: Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, 28922 Alcorcón, Madrid, Spain.
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Tolón
authors.forename: Estefanía
authors.initials: E
authors.lastname: Núñez
authors.forename: María Ruth
authors.initials: MR
authors.lastname: Pazos
authors.forename: Cristina
authors.initials: C
authors.lastname: Benito
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Castillo
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Martínez-Orgado
authors.forename: Julián
authors.initials: J
authors.lastname: Romero
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000187:drug effects* / Q000378:metabolism; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D001892:Camphanes / Q000494:pharmacology; D002186:Cannabinoids / Q000494:pharmacology* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004660:Encephalitis / Q000188:drug therapy / Q000503:physiopathology / Q000517:prevention & control; D005911:Gliosis / Q000188:drug therapy / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D007211:Indoles / Q000494:pharmacology* / Q000627:therapeutic use; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology; D058225:Plaque, Amyloid / Q000187:drug effects / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology; D043885:Receptor, Cannabinoid, CB2 / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D001892:Camphanes; D002186:Cannabinoids; D007211:Indoles; D011720:Pyrazoles; D043885:Receptor, Cannabinoid, CB2; C110630:SR 144528; C402944:JHW 015