title: Protection by sigma-1 receptor agonists is synergic with donepezil, but not with memantine, in a mouse model of amyloid-induced memory impairments.
abstract: Drugs activating the sigma-1 (σ1) chaperone protein are anti-amnesic and neuroprotective in neurodegenerative pathologies like Alzheimer's disease (AD). Since these so-called σ1 receptor (σ1R) agonists modulate cholinergic and glutamatergic systems in a variety of physiological responses, we addressed their putative additive/synergistic action in combination with cholinergic or glutamatergic drugs. The selective σ1 agonist PRE-084, or the non-selective σ1 drug ANAVEX2-73 was combined with the acetylcholinesterase inhibitor donepezil or the NMDA receptor antagonist memantine in the nontransgenic mouse model of AD-like memory impairments induced by intracerebroventricular injection of oligomeric Aβ25-35 peptide. Two behavioral tests, spontaneous alternation and passive avoidance response, were used in parallel and both protective and symptomatic effects were examined. After determination of the minimally active doses for each compound, the combinations were tested and the combination index (CI) calculated. Combinations between the σ1 agonists and donepezil showed a synergic protective effect, with CI<1, whereas the combinations with memantine showed an antagonist effect, with CI>1. Symptomatic effects appeared only additive for all combinations, with CI=1. A pharmacological analysis of the PRE-084+donepezil combination revealed that the synergy could be due to an inter-related mechanism involving α7 nicotinic ACh receptors and σ1R. These results demonstrated that σ1 drugs do not only offer a protective potential alone but also in combination with other therapeutic agents. The nature of neuromodulatory molecular chaperone of the σ1R could eventually lead to synergistic combinations.
authors.affiliation: Molecular Mechanisms in Neurodegenerative Diseases, MMDN Laboratory, Institut National de la Recherche et de la Santé Médicale, unit 1198, 34095 Montpellier, France; University of Montpellier, 34095 Montpellier, France; Ecole Pratique des Hautes Etudes, 75014 Paris, France. Electronic address: maurice@univ-montp2.fr.
authors.forename: Tangui
authors.initials: T
authors.lastname: Maurice
mesh_terms: D016229:Amyloid beta-Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D004195:Disease Models, Animal; D000077265:Donepezil; D004357:Drug Synergism; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D005663:Furans / Q000008:administration & dosage / Q000494:pharmacology; D007189:Indans; D008297:Male; D008559:Memantine; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy*; D051379:Mice; D009025:Morpholines / Q000008:administration & dosage / Q000494:pharmacology; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D017480:Receptors, sigma / Q000819:agonists*; D000097605:Sigma-1 Receptor
chemical_list: D016229:Amyloid beta-Peptides; D002800:Cholinesterase Inhibitors; D000077265:Donepezil; D018691:Excitatory Amino Acid Antagonists; D005663:Furans; D007189:Indans; D008559:Memantine; D009025:Morpholines; D018696:Neuroprotective Agents; D010446:Peptide Fragments; D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate; D017480:Receptors, sigma; D000097605:Sigma-1 Receptor; C074636:amyloid beta-protein (25-35); C568535:tetrahydro-N, N-dimethyl-2,2-diphenyl-3-furanmethanamine hydrochloride; C071738:2-(4-morpholino)ethyl-1-phenylcyclohexane-1-carboxylate
keywords: Alzheimer's disease; Donepezil; Memantine; Memory; Neuroprotection; σ(1) Protein