1Am. J. Med. Genet. B Neuropsychiatr. Genet. 2010 Oct 153B: 1347-9
PMID20583128
TitleVariation at the GABAA receptor gene, Rho 1 (GABRR1) associated with susceptibility to bipolar schizoaffective disorder.
AbstractWe have previously reported evidence that variation at GABA(A) receptor genes is associated with susceptibility to bipolar disorder with schizophrenia-like psychotic features (Research Diagnostic Criteria (RDC) schizoaffective disorder, bipolar type) with gene-wide significance at GABRB1, GABRA4, GABRB3, GABRA5, and GABRR3. Here we provide suggestive evidence implicating a sixth member of the gene family, GABRR1 (gene-wide P?=?0.0058; experiment-wide corrected significance P?=?0.052).
SCZ Keywordsschizophrenia
2Neuropharmacology 2014 Aug 83: 1-8
PMID24704148
TitleChronic LSD alters gene expression profiles in the mPFC relevant to schizophrenia.
AbstractChronic administration of lysergic acid diethylamide (LSD) every other day to rats results in a variety of abnormal behaviors. These build over the 90 day course of treatment and can persist at full strength for at least several months after cessation of treatment. The behaviors are consistent with those observed in animal models of schizophrenia and include hyperactivity, reduced sucrose-preference, and decreased social interaction. In order to elucidate molecular changes that underlie these aberrant behaviors, we chronically treated rats with LSD and performed RNA-sequencing on the medial prefrontal cortex (mPFC), an area highly associated with both the actions of LSD and the pathophysiology of schizophrenia and other psychiatric illnesses. We observed widespread changes in the neurogenetic state of treated animals four weeks after cessation of LSD treatment. QPCR was used to validate a subset of gene expression changes observed with RNA-Seq, and confirmed a significant correlation between the two methods. Functional clustering analysis indicates differentially expressed genes are enriched in pathways involving neurotransmission (Drd2, GABRB1), synaptic plasticity (Nr2a, Krox20), energy metabolism (Atp5d, Ndufa1) and neuropeptide signaling (Npy, Bdnf), among others. Many processes identified as altered by chronic LSD are also implicated in the pathogenesis of schizophrenia, and genes affected by LSD are enriched with putative schizophrenia genes. Our results provide a relatively comprehensive analysis of mPFC transcriptional regulation in response to chronic LSD, and indicate that the long-term effects of LSD may bear relevance to psychiatric illnesses, including schizophrenia.
SCZ Keywordsschizophrenia
3J Psychiatr Res 2014 Mar 50: 73-8
PMID24365204
TitleProtein-interaction-network-based analysis for genome-wide association analysis of schizophrenia in Han Chinese population.
Abstractschizophrenia is a severe neuropsychiatric disorder with a strong and complex genetic background. Recent genome-wide association studies (GWAS) have successfully identified several susceptibility loci of schizophrenia. In order to interpret the functional role of the genetic variants and detect the combined effects of some of these genes on schizophrenia, protein-interaction-network-based analysis (PINBA) has emerged as an effective approach. In the current study, we conducted a PINBA of our previous GWAS data taken from the Han Chinese population. In order to do so, we used dense module search (DMS), a method that locates densely connected modules for complex diseases by integrating the association signal from GWAS datasets into the human protein-protein interaction (PPI) network. As a result, we identified one gene set with a joint effect significantly associated with schizophrenia and gene expression profiling analysis suggested that they were mainly neuro- and immune-related genes, such as glutamatergic gene (GRM5), GABAergic genes (GABRB1, GABARAP) and genes located in the MHC region (HLA-C, TAP2, HIST1H1B). Further pathway enrichment analysis suggested that these genes are involved in processes related to neuronal and immune systems, such as the Adherens junction pathway, the Neurotrophin signaling pathway and the Toll-like receptor signaling pathway. In our study, we identified a set of susceptibility genes that had been missed in single-marker GWAS, and our findings could promote the study of the genetic mechanisms in schizophrenia.
SCZ Keywordsschizophrenia
4J. Mol. Neurosci. 2016 May 59: 36-47
PMID26894264
TitleAripiprazole Increases the PKA Signalling and Expression of the GABAA Receptor and CREB1 in the Nucleus Accumbens of Rats.
AbstractThe GABAA receptor is implicated in the pathophysiology of schizophrenia and regulated by PKA signalling. Current antipsychotics bind with D2-like receptors, but not the GABAA receptor. The cAMP-responsive element-binding protein 1 (CREB1) is also associated with PKA signalling and may be related to the positive symptoms of schizophrenia. This study investigated the effects of antipsychotics in modulating D2-mediated PKA signalling and its downstream GABAA receptors and CREB1. Rats were treated orally with aripiprazole (0.75 mg/kg, ter in die (t.i.d.)), bifeprunox (0.8 mg/kg, t.i.d.), haloperidol (0.1 mg/kg, t.i.d.) or vehicle for 1 week. The levels of PKA-C? and p-PKA in the prefrontal cortex (PFC), nucleus accumbens (NAc) and caudate putamen (CPu) were detected by Western blots. The mRNA levels of GABRB1, Gabrb2, Gabrb3 and Creb1, and their protein expression were measured by qRT-PCR and Western blots, respectively. Aripiprazole elevated the levels of p-PKA and the ratio of p-PKA/PKA in the NAc, but not the PFC and CPu. Correlated with this elevated PKA signalling, aripiprazole elevated the mRNA and protein expression of the GABAA (?-1) receptor and CREB1 in the NAc. While haloperidol elevated the levels of p-PKA and the ratio of p-PKA/PKA in both NAc and CPu, it only tended to increase the expression of the GABAA (?-1) receptor and CREB1 in the NAc, but not the CPu. Bifeprunox had no effects on PKA signalling in these brain regions. These results suggest that aripiprazole has selective effects on upregulating the GABAA (?-1) receptor and CREB1 in the NAc, probably via activating PKA signalling.
SCZ Keywordsschizophrenia
5Pharmacogenomics 2016 Feb 17: 199-208
PMID26780210
TitleCandidate gene analysis of pharmacodynamic targets for antipsychotic dosage.
AbstractIn order to administer antipsychotic medication with the most beneficial outcome, the appropriate drug and dose needs to be identified. Though often not considered in pharmacogenetic studies, dosage plays an important role in treatment outcome. This study set out to analyze the association between 109 SNPs and antipsychotic dosage among schizophrenia patients. In a previous study, we tested 134 SNPs in regards to antipsychotic dosage. In the current study, we tested additional markers in the same candidate genes that we investigated in the previous study to confirm our previous findings.
We included 263 participants with schizophrenia spectrum disorders between the ages of 18-75. Each participant was assessed cross-sectionally to collect clinical and antipsychotic treatment information through a semi-structured interview. The antipsychotic dosage for each individual was standardized according to chlorpromazine equivalents (CPZe), defined daily dose, and the percentage of maximum dosage (PM%). For each participant, 109 SNPs from 29 candidate genes were imputed or genotyped using a Customized Illumina Chip.
Polymorphisms in the GABRB1 gene were significantly associated with higher antipsychotic dosage according to CPZe and PM% standardization.
Our analysis suggests that variation in the GABRB1 gene may be significantly associated with antipsychotic dosage according to CPZe and PM% standardization. Antipsychotic dosage remains an integral measure for treatment response that warrants future pharmacogenetic testing and studies with larger sample sizes.
SCZ Keywordsschizophrenia