title: Towards understanding the schizophrenia code: an expanded convergent functional genomics approach.
abstract: Identifying genes for schizophrenia through classical genetic approaches has proven arduous. Here, we present a comprehensive convergent analysis that translationally integrates brain gene expression data from a relevant pharmacogenomic mouse model (involving treatments with a psychomimetic agent - phencyclidine (PCP), and an anti-psychotic - clozapine), with human genetic linkage data and human postmortem brain data, as a Bayesian strategy of cross validating findings. Topping the list of candidate genes, we have three genes involved in GABA neurotransmission (GABRA1, GABBR1, and GAD2), one gene involved in glutamate neurotransmission (GRIA2), one gene involved in neuropeptide signaling (TAC1), two genes involved in synaptic function (SYN2 and KCNJ4), six genes involved in myelin/glial function (CNP, MAL, MBP, PLP1, MOBP and GFAP), and one gene involved in lipid metabolism (LPL). These data suggest that schizophrenia is primarily a disorder of brain functional and structural connectivity, with GABA neurotransmission playing a prominent role. These findings may explain the EEG gamma band abnormalities detected in schizophrenia. The analysis also revealed other high probability candidates genes (neurotransmitter signaling, other structural proteins, ion channels, signal transduction, regulatory enzymes, neuronal migration/neurite outgrowth, clock genes, transcription factors, RNA regulatory genes), pathways and mechanisms of likely importance in pathophysiology. Some of the pathways identified suggest possible avenues for augmentation pharmacotherapy of schizophrenia with other existing agents, such as benzodiazepines, anticonvulsants and lipid modulating agents. Other pathways are new potential targets for drug development. Lastly, a comparison with our earlier work on bipolar disorder illuminates the significant molecular overlap between schizophrenia and bipolar disorder.
authors.affiliation: Laboratory of Neurophenomics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: H
authors.initials: H
authors.lastname: Le-Niculescu
authors.forename: Y
authors.initials: Y
authors.lastname: Balaraman
authors.forename: S
authors.initials: S
authors.lastname: Patel
authors.forename: J
authors.initials: J
authors.lastname: Tan
authors.forename: K
authors.initials: K
authors.lastname: Sidhu
authors.forename: R E
authors.initials: RE
authors.lastname: Jerome
authors.forename: H J
authors.initials: HJ
authors.lastname: Edenberg
authors.forename: R
authors.initials: R
authors.lastname: Kuczenski
authors.forename: M A
authors.initials: MA
authors.lastname: Geyer
authors.forename: J I
authors.initials: JI
authors.lastname: Nurnberger
authors.forename: S V
authors.initials: SV
authors.lastname: Faraone
authors.forename: M T
authors.initials: MT
authors.lastname: Tsuang
authors.forename: A B
authors.initials: AB
authors.lastname: Niculescu
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015415:Biomarkers; D003024:Clozapine / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D008040:Genetic Linkage; D023281:Genomics / Q000379:methods*; D018698:Glutamic Acid / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009186:Myelin Sheath / Q000187:drug effects / Q000235:genetics; D018377:Neurotransmitter Agents / Q000235:genetics; D010622:Phencyclidine / Q000494:pharmacology; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000235:genetics*; D005680:gamma-Aminobutyric Acid / Q000235:genetics
chemical_list: D015415:Biomarkers; D018377:Neurotransmitter Agents; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D010622:Phencyclidine; D003024:Clozapine