title: A common mechanism of action for three mood-stabilizing drugs.
abstract: Lithium, carbamazepine and valproic acid are effective mood-stabilizing treatments for bipolar affective disorder. The molecular mechanisms underlying the actions of these drugs and the illness itself are unknown. Berridge and colleagues suggested that inositol depletion may be the way that lithium works in bipolar affective disorder, but others have suggested that glycogen synthase kinase (GSK3) may be the relevant target. The action of valproic acid has been linked to both inositol depletion and to inhibition of histone deacetylase (HDAC). We show here that all three drugs inhibit the collapse of sensory neuron growth cones and increase growth cone area. These effects do not depend on GSK3 or HDAC inhibition. Inositol, however, reverses the effects of the drugs on growth cones, thus implicating inositol depletion in their action. Moreover, the development of Dictyostelium is sensitive to lithium and to valproic acid, but resistance to both is conferred by deletion of the gene that codes for prolyl oligopeptidase, which also regulates inositol metabolism. Inhibitors of prolyl oligopeptidase reverse the effects of all three drugs on sensory neuron growth cone area and collapse. These results suggest a molecular basis for both bipolar affective disorder and its treatment.
authors.affiliation: Intracellular Signalling Group, MRC Laboratory for Molecular Cell Biology, University College London, Gower St, London WC1E 6BT, UK.
authors.forename: Robin S B
authors.initials: RS
authors.lastname: Williams
authors.forename: Lili
authors.initials: L
authors.lastname: Cheng
authors.forename: Anne W
authors.initials: AW
authors.lastname: Mudge
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Harwood
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D018692:Antimanic Agents / Q000494:pharmacology*; D001714:Bipolar Disorder / Q000188:drug therapy; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002220:Carbamazepine / Q000494:pharmacology*; D002449:Cell Aggregation / Q000187:drug effects; D002633:Chemotaxis / Q000187:drug effects; D004023:Dictyostelium / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D005727:Ganglia, Spinal / Q000166:cytology; D017125:Genes, Protozoan / Q000235:genetics; D038341:Glycogen Synthase Kinases; D020439:Growth Cones / Q000187:drug effects* / Q000201:enzymology; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000378:metabolism; D006877:Hydroxamic Acids / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008094:Lithium / Q000494:pharmacology*; D051379:Mice; D009154:Mutation / Q000235:genetics; D009475:Neurons, Afferent / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D014635:Valproic Acid / Q000494:pharmacology*
chemical_list: D018692:Antimanic Agents; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D002220:Carbamazepine; C012589:trichostatin A; D014635:Valproic Acid; D015544:Inositol 1,4,5-Trisphosphate; D008094:Lithium; D038341:Glycogen Synthase Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D006655:Histone Deacetylases