| 1 | Schizophr. Res. 2008 Jan 98: 118-28 |
|---|---|
| PMID | 18029146 |
| Title | Schizophrenia and sex associated differences in the expression of neuronal and oligodendrocyte-specific genes in individual thalamic nuclei. |
| Abstract | Considerable evidence based on the study of postmortem brain tissue suggests deficits in both neuronal and myelin systems in schizophrenia (SZ). To date, the majority of the biochemical and molecular biological studies have focused on the cerebral cortex. Most information traveling to or from the cortex is relayed or synaptically gated through the thalamus, and numerous studies suggest structural and functional abnormalities in interconnected regions of the thalamus and cortex in SZ. The present study extends our gene expression studies of neuronal and myelin systems to the thalamus. Quantitative PCR was employed to assess the expression of 10 genes in 5 divisions of the thalamus which were precisely harvested using Laser Capture Microdissection. The divisions studied were present on coronal sections at the level of the centromedian nucleus (CMN) taken from 14 schizophrenic and 16 normal control postmortem brains. The genes examined were specific for oligodendrocytes (MAG, CNP, MBP), neurons (ENO2), glutamatergic neurons (VGlut1, VGlut2, PV, CB) or GABAergic neurons (GAD65, GAD67). Expression levels for each of these markers were quantitated and compared between diagnoses, between sexes, and across nuclei. CB was much more highly expressed in the CMN in SZs compared to NCs. No other diagnosis related differences in gene expression were observed. The expression levels of CNP and MAG, but not MBP, were highly correlated with one another and both, but not MBP, were much more highly expressed in females than in males in all thalamic divisions examined. All markers were differentially expressed across nuclei. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 2 | Schizophr. Res. 2008 Jan 98: 118-28 |
| PMID | 18029146 |
| Title | Schizophrenia and sex associated differences in the expression of neuronal and oligodendrocyte-specific genes in individual thalamic nuclei. |
| Abstract | Considerable evidence based on the study of postmortem brain tissue suggests deficits in both neuronal and myelin systems in schizophrenia (SZ). To date, the majority of the biochemical and molecular biological studies have focused on the cerebral cortex. Most information traveling to or from the cortex is relayed or synaptically gated through the thalamus, and numerous studies suggest structural and functional abnormalities in interconnected regions of the thalamus and cortex in SZ. The present study extends our gene expression studies of neuronal and myelin systems to the thalamus. Quantitative PCR was employed to assess the expression of 10 genes in 5 divisions of the thalamus which were precisely harvested using Laser Capture Microdissection. The divisions studied were present on coronal sections at the level of the centromedian nucleus (CMN) taken from 14 schizophrenic and 16 normal control postmortem brains. The genes examined were specific for oligodendrocytes (MAG, CNP, MBP), neurons (ENO2), glutamatergic neurons (VGlut1, VGlut2, PV, CB) or GABAergic neurons (GAD65, GAD67). Expression levels for each of these markers were quantitated and compared between diagnoses, between sexes, and across nuclei. CB was much more highly expressed in the CMN in SZs compared to NCs. No other diagnosis related differences in gene expression were observed. The expression levels of CNP and MAG, but not MBP, were highly correlated with one another and both, but not MBP, were much more highly expressed in females than in males in all thalamic divisions examined. All markers were differentially expressed across nuclei. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 3 | BMC Med. Genet. 2008 -1 9: 39 |
| PMID | 18460190 |
| Title | The estrogen hypothesis of schizophrenia implicates glucose metabolism: association study in three independent samples. |
| Abstract | schizophrenia is a highly heritable complex psychiatric disorder with an underlying pathophysiology that is still not well understood. Metaanalyses of schizophrenia linkage studies indicate numerous but rather large disease-associated genomic regions, whereas accumulating gene- and protein expression studies have indicated an equally large set of candidate genes that only partially overlap linkage genes. A thorough assessment, beyond the resolution of current GWA studies, of the disease risk conferred by the numerous schizophrenia candidate genes is a daunting and presently not feasible task. We undertook these challenges by using an established clinical paradigm, the estrogen hypothesis of schizophrenia, as the criterion to select candidates among the numerous genes experimentally implicated in schizophrenia. Bioinformatic tools were used to build and priorities the signaling networks implicated by the candidate genes resulting from the estrogen selection. We identified ten candidate genes using this approach that are all active in glucose metabolism and particularly in the glycolysis. Thus, we tested the hypothesis that variants of the glycolytic genes are associated with schizophrenia or at least with gender-associated aspects of the illness. We genotyped 185 SNPs in three independent case-control samples of Scandinavian origin (a total of 765 patients and 1274 control subjects). Variants of the mitogen-activated protein kinase 14 gene (MAPK14) and the phosphoenolpyruvate carboxykinase 1 (PCK1) and fructose-1,6-biphosphatase (FBP1) were nominal significantly associated with schizophrenia, and several haplotypes within enolase 2 gene (ENO2) consist of the same SNP allele having elevated risk of schizophrenia. Importantly, we find no evidence of stratification due to nationality or gender. Several gene variants in the Glycolysis were associated with schizophrenia in three independent samples. However, the findings are weak and not resistant to correction for multiple testing, which may indicate that they are either spurious or may relate to a particular subtype or aspect of the illness. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 4 | BMC Res Notes 2012 -1 5: 146 |
| PMID | 22420779 |
| Title | The application of selective reaction monitoring confirms dysregulation of glycolysis in a preclinical model of schizophrenia. |
| Abstract | Establishing preclinical models is essential for novel drug discovery in schizophrenia. Most existing models are characterized by abnormalities in behavioral readouts, which are informative, but do not necessarily translate to the symptoms of the human disease. Therefore, there is a necessity of characterizing the preclinical models from a molecular point of view. Selective reaction monitoring (SRM) has already shown promise in preclinical and clinical studies for multiplex measurement of diagnostic, prognostic and treatment-related biomarkers. We have established an SRM assay for multiplex analysis of 7 enzymes of the glycolysis pathway which is already known to be affected in human schizophrenia and in the widely-used acute PCP rat model of schizophrenia. The selected enzymes were hexokinase 1 (Hk1), aldolase C (Aldoc), triosephosphate isomerase (Tpi1), glyceraldehyde-3-phosphate dehydrogenase (Gapdh), phosphoglycerate mutase 1 (Pgam1), phosphoglycerate kinase 1 (Pgk1) and enolase 2 (ENO2). The levels of these enzymes were analyzed using SRM in frontal cortex from brain tissue of PCP treated rats. Univariate analyses showed statistically significant altered levels of Tpi1 and alteration of Hk1, Aldoc, Pgam1 and Gapdh with borderline significance in PCP rats compared to controls. Most interestingly, multivariate analysis which considered the levels of all 7 enzymes simultaneously resulted in generation of a bi-dimensional chart that can distinguish the PCP rats from the controls. This study not only supports PCP treated rats as a useful preclinical model of schizophrenia, but it also establishes that SRM mass spectrometry could be used in the development of multiplex classification tools for complex psychiatric disorders such as schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 5 | Front Cell Neurosci 2015 -1 9: 180 |
| PMID | 26029051 |
| Title | MK-801 treatment affects glycolysis in oligodendrocytes more than in astrocytes and neuronal cells: insights for schizophrenia. |
| Abstract | schizophrenia is a debilitating mental disorder, affecting more than 30 million people worldwide. As a multifactorial disease, the underlying causes of schizophrenia require analysis by multiplex methods such as proteomics to allow identification of whole protein networks. Previous post-mortem proteomic studies on brain tissues from schizophrenia patients have demonstrated changes in activation of glycolytic and energy metabolism pathways. However, it is not known whether these changes occur in neurons or in glial cells. To address this question, we treated neuronal, astrocyte, and oligodendrocyte cell lines with the NMDA receptor antagonist MK-801 and measured the levels of six glycolytic enzymes by Western blot analysis. MK-801 acts on the glutamatergic system and has been proposed as a pharmacological means of modeling schizophrenia. Treatment with MK-801 resulted in significant changes in the levels of glycolytic enzymes in all cell types. Most of the differences were found in oligodendrocytes, which had altered levels of hexokinase 1 (HK1), enolase 2 (ENO2), phosphoglycerate kinase (PGK), and phosphoglycerate mutase 1 after acute MK-801 treatment (8 h), and HK1, ENO2, PGK, and triosephosphate isomerase (TPI) following long term treatment (72 h). Addition of the antipsychotic clozapine to the cultures resulted in counter-regulatory effects to the MK-801 treatment by normalizing the levels of ENO2 and PGK in both the acute and long term cultures. In astrocytes, MK-801 affected only aldolase C (ALDOC) under both acute conditions and HK1 and ALDOC following long term treatment, and TPI was the only enzyme affected under long term conditions in the neuronal cells. In conclusion, MK-801 affects glycolysis in oligodendrocytes to a larger extent than neuronal cells and this may be modulated by antipsychotic treatment. Although cell culture studies do not necessarily reflect the in vivo pathophysiology and drug effects within the brain, these results suggest that neurons, astrocytes, and oligodendrocytes are affected differently in schizophrenia. Employing in vitro models using neurotransmitter agonists and antagonists may provide new insights about the pathophysiology of schizophrenia which could lead to a novel system for drug discovery. |
| SCZ Keywords | schizophrenia, schizophrenic |