title: Gene expression changes in the prefrontal cortex, anterior cingulate cortex and nucleus accumbens of mood disorders subjects that committed suicide.
abstract: Suicidal behaviors are frequent in mood disorders patients but only a subset of them ever complete suicide. Understanding predisposing factors for suicidal behaviors in high risk populations is of major importance for the prevention and treatment of suicidal behaviors. The objective of this project was to investigate gene expression changes associated with suicide in brains of mood disorder patients by microarrays (Affymetrix HG-U133 Plus2.0) in the dorsolateral prefrontal cortex (DLPFC: 6 Non-suicides, 15 suicides), the anterior cingulate cortex (ACC: 6NS, 9S) and the nucleus accumbens (NAcc: 8NS, 13S). ANCOVA was used to control for age, gender, pH and RNA degradation, with P ≤ 0.01 and fold change ± 1.25 as criteria for significance. Pathway analysis revealed serotonergic signaling alterations in the DLPFC and glucocorticoid signaling alterations in the ACC and NAcc. The gene with the lowest p-value in the DLPFC was the 5-HT2A gene, previously associated both with suicide and mood disorders. In the ACC 6 metallothionein genes were down-regulated in suicide (MT1E, MT1F, MT1G, MT1H, MT1X, MT2A) and three were down-regulated in the NAcc (MT1F, MT1G, MT1H). Differential expression of selected genes was confirmed by qPCR, we confirmed the 5-HT2A alterations and the global down-regulation of members of the metallothionein subfamilies MT 1 and 2 in suicide completers. MTs 1 and 2 are neuro-protective following stress and glucocorticoid stimulations, suggesting that in suicide victims neuroprotective response to stress and cortisol may be diminished. Our results thus suggest that suicide-specific expression changes in mood disorders involve both glucocorticoids regulated metallothioneins and serotonergic signaling in different regions of the brain.
authors.affiliation: Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, California, United States of America. psequeir@uci.edu
authors.forename: Adolfo
authors.initials: A
authors.lastname: Sequeira
authors.forename: Ling
authors.initials: L
authors.lastname: Morgan
authors.forename: David M
authors.initials: DM
authors.lastname: Walsh
authors.forename: Preston M
authors.initials: PM
authors.lastname: Cartagena
authors.forename: Prabhakara
authors.initials: P
authors.lastname: Choudary
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Alan F
authors.initials: AF
authors.lastname: Schatzberg
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Watson
authors.forename: Huda
authors.initials: H
authors.lastname: Akil
authors.forename: Richard M
authors.initials: RM
authors.lastname: Myers
authors.forename: Edward G
authors.initials: EG
authors.lastname: Jones
authors.forename: William E
authors.initials: WE
authors.lastname: Bunney
authors.forename: Marquis P
authors.initials: MP
authors.lastname: Vawter
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D002140:California; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics*; D006179:Gyrus Cinguli / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism; D046228:Microarray Analysis; D008875:Middle Aged; D019964:Mood Disorders / Q000235:genetics / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000378:metabolism*; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics / Q000378:metabolism; D012737:Sex Factors; D013405:Suicide
chemical_list: D044402:Receptor, Serotonin, 5-HT2A; D008668:Metallothionein