Recent advances in gene expression analysis using microarray technology should assist in our understanding of complex psychiatric diseases such as schizophrenia. The aim of this thesis was to identify differentially expressed genes in schizophrenic patients using post-mortem prefrontal cortex (DLPFC) (BA 10) with a genome approach and compare the expression pattern obtained with a microarray study using prefrontal cortex tissue from a chronic phencyclidine (PCP) model of schizophrenia (Cochran et aI., 2003). It is hypothesised that the identification of common altered genes in these two independent strategies will reveal genes that relate to the cognitive deficits observed in schizophrenia. A microarray study using total RNAs extracted from control and schizophrenic prefrontal cortices and Affymetrix Human Genome U-133A GeneChips was performed. Significance Analysis of Microarray (SAM) and two-tailed t test for data mining identified 236 probe sets (SAM; false positive rate (FDR) , 39%) and 918 probe sets (p<0.05, t test) as being differentially expressed. Further analyses revealed that Pyk/Nck pathway and Ca2+ sensitive gene signalling pathways may be dysfunctional in subjects with schizophrenia. Moreover, 123/671 genes showing more than 10% change were located on chromosomal loci linked to schizophrenia. These were relatively concentrated on 9q34.3, 11q22-23, 22q12-13 or proximal regions to these. Importantly 11 q22- 23 and 22q 12-13 have been described as strongly linked genetic loci (Prasad et al. 2002). In RT-qPCR confirmation stuclies, almost 2/3 of selected genes were validated. This suggested that the microarray study was successfully detecting gene expression changes despite the fold changes being small (≤l.5-fold), In vitro functional studies were performed on selected candidate genes using molecular based experiments. These demonstrated that the activity of CaMKIV was regulated by Serine/Threonine phosphatase, POPX 1, in CRE-dependent gene expression via direct interaction with POPXl, and that SLCIAl (neuronal excitatory amino acid transporter EAAT3)"could be involved in GABAergic machinery by participation in the supply of the substrate of GABA, glutamate, into cells via its transport activity. In conclusion, this project enabled construction of novel hypotheses about candidate genes relate to schizophrenia. The results suggest that there is prefrontal cortex dysregulation in glutamatergic and GABAergic neurotransmission associated with the candidate genes participating in Pyk/Nck pathway and Ca2+ sensitive gene signalling pathways. Moreover these could be potential targets for drug development in schizophrenia.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:570450 |
| Date | January 2006 |
| Creators | Ozeki, Hiromitsu |
| Publisher | University of Strathclyde |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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