trichostatin-a and Bipolar-Disorder

The emerging field of psychiatric epigenetics is constrained by the dearth of research methods feasible in living patients. With this focus, we report on two separate approaches, one in vitro and one in vivo, developed in our laboratory.. In the first approach, we isolated lymphocytes from 12 subjects and cultured their cells with either 0.7 mM valproic acid (VPA), 100 nM Trichostatin A (TSA), or DMSO (control) for 24h based upon previous dose response experiments. We then measured GAD67 mRNA expression using realtime RT-PCR, total acetylated histone 3 (H3K9,K14ac) levels using Western blot analysis, and attachment of H3K9,K14ac to the GAD67 promoter using ChIP. In the second approach, we measured GAD67 mRNA and total H3K9,K14ac levels in lymphocytes from 11 schizophrenia and 7 bipolar patients before and after 4 weeks of clinical treatment with Depakote ER (VPA).. In the first approach, VPA induced a 383% increase in GAD67 mRNA, an 89% increase in total H3K9,K14ac levels, and a 482% increase in H3K9,K14ac attachment to the GAD67 promoter. TSA induced comparable changes on all measures. In the second approach, bipolar subjects had significantly higher baseline levels of H3K9,K14ac compared to subjects with schizophrenia. Subjects with clinically relevant serum levels of VPA (> or = 65 microg/mL) showed a significant increase in GAD67 mRNA expression.. Our results utilizing two separate approaches for examining chromatin remodeling in real clinical time provide possible means to investigate epigenetic events in living patients.

Topics: Acetylation; Adult; Bipolar Disorder; Blotting, Western; Cell Culture Techniques; Enzyme Inhibitors; Female; Gene Expression Regulation; Glutamate Decarboxylase; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Lymphocytes; Male; Middle Aged; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Schizophrenia; Up-Regulation; Valproic Acid; Young Adult

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.

Topics: Animals; Animals, Newborn; Antimanic Agents; Bipolar Disorder; Calcium-Calmodulin-Dependent Protein Kinases; Carbamazepine; Cell Aggregation; Chemotaxis; Dictyostelium; Ganglia, Spinal; Genes, Protozoan; Glycogen Synthase Kinases; Growth Cones; Histone Deacetylase Inhibitors; Histone Deacetylases; Hydroxamic Acids; Inositol 1,4,5-Trisphosphate; Lithium; Mice; Mutation; Neurons, Afferent; Rats; Signal Transduction; Valproic Acid