Limits...
Comparison of gene expression profiles in the blood, hippocampus and prefrontal cortex of rats.

Witt SH, Sommer WH, Hansson AC, Sticht C, Rietschel M, Witt CC - In Silico Pharmacol (2013)

Bottom Line: Limitations of our study comprise possible contamination of brain tissue with blood and the non-detection of genes with very low expression levels.Genes that are more highly expressed in the brain than in the blood are of particular interest since changes in their expression, e.g. due to disease status, or treatment, are likely to be detected in an experiment.In contrast, genes with higher expression in the blood than in the brain are less informative since their higher baseline levels could superimpose variation in brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, J5, 68159 Mannheim, Germany.

ABSTRACT

Background: The comparability of gene expression between blood and brain tissues is a central issue in neuropsychiatric research where the analysis of molecular mechanisms in the brain is of high importance for the understanding of the diseases and the discovery of biomarkers. However, the accessibility of brain tissue is limited. Therefore, knowledge about how easily accessible peripheral tissue, e. g. blood, is comparable to and reflects gene expression of brain regions will help to advance neuropsychiatric research.

Description: Gene expression in the blood, hippocampus (HC) and prefrontal cortex (PFC) of genetically identical rats was compared using a genome-wide Affymetrix gene expression microarray covering 29,215 expressed genes. A total of 56.8% of 15,717 expressed genes were co-expressed in blood and at least one brain tissue, while 55.3% of all genes were co-expressed in all three tissues simultaneously. The overlapping genes included a set of genes of relevance to neuropsychiatric diseases, in particular bipolar disorder, schizophrenia and alcohol addiction. These genes included CLOCK, COMT, FAAH, NPY, NR3C1, NRGN, PBRM1, TCF4, and SYNE.

Conclusions: This study provides baseline data on absolute gene expression and differences between gene expression in the blood, HC and PFC brain tissue of genetically identical rats. The present data represents a valuable resource for future studies as it might be used for first information on gene expression levels of genes of interest in blood and brain under baseline conditions. Limitations of our study comprise possible contamination of brain tissue with blood and the non-detection of genes with very low expression levels. Genes that are more highly expressed in the brain than in the blood are of particular interest since changes in their expression, e.g. due to disease status, or treatment, are likely to be detected in an experiment. In contrast, genes with higher expression in the blood than in the brain are less informative since their higher baseline levels could superimpose variation in brain.

No MeSH data available.


Related in: MedlinePlus

Venn diagramm: absolute number of expressed genes found in blood, PFC and HC.
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Fig1: Venn diagramm: absolute number of expressed genes found in blood, PFC and HC.

Mentions: Figure 1 (Venn diagram) shows the absolute number of expressed genes found in blood, PFC and HC. Table 1 depicts number and percentages of total expressed genes and of the overlap in the different tissues (cut-off level of 6.2 for all data and present in all samples p < 0.05). All raw and normalized data have been deposited in the Gene-expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo/; accession number GSE49352).Figure 1


Comparison of gene expression profiles in the blood, hippocampus and prefrontal cortex of rats.

Witt SH, Sommer WH, Hansson AC, Sticht C, Rietschel M, Witt CC - In Silico Pharmacol (2013)

Venn diagramm: absolute number of expressed genes found in blood, PFC and HC.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230692&req=5

Fig1: Venn diagramm: absolute number of expressed genes found in blood, PFC and HC.
Mentions: Figure 1 (Venn diagram) shows the absolute number of expressed genes found in blood, PFC and HC. Table 1 depicts number and percentages of total expressed genes and of the overlap in the different tissues (cut-off level of 6.2 for all data and present in all samples p < 0.05). All raw and normalized data have been deposited in the Gene-expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo/; accession number GSE49352).Figure 1

Bottom Line: Limitations of our study comprise possible contamination of brain tissue with blood and the non-detection of genes with very low expression levels.Genes that are more highly expressed in the brain than in the blood are of particular interest since changes in their expression, e.g. due to disease status, or treatment, are likely to be detected in an experiment.In contrast, genes with higher expression in the blood than in the brain are less informative since their higher baseline levels could superimpose variation in brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, J5, 68159 Mannheim, Germany.

ABSTRACT

Background: The comparability of gene expression between blood and brain tissues is a central issue in neuropsychiatric research where the analysis of molecular mechanisms in the brain is of high importance for the understanding of the diseases and the discovery of biomarkers. However, the accessibility of brain tissue is limited. Therefore, knowledge about how easily accessible peripheral tissue, e. g. blood, is comparable to and reflects gene expression of brain regions will help to advance neuropsychiatric research.

Description: Gene expression in the blood, hippocampus (HC) and prefrontal cortex (PFC) of genetically identical rats was compared using a genome-wide Affymetrix gene expression microarray covering 29,215 expressed genes. A total of 56.8% of 15,717 expressed genes were co-expressed in blood and at least one brain tissue, while 55.3% of all genes were co-expressed in all three tissues simultaneously. The overlapping genes included a set of genes of relevance to neuropsychiatric diseases, in particular bipolar disorder, schizophrenia and alcohol addiction. These genes included CLOCK, COMT, FAAH, NPY, NR3C1, NRGN, PBRM1, TCF4, and SYNE.

Conclusions: This study provides baseline data on absolute gene expression and differences between gene expression in the blood, HC and PFC brain tissue of genetically identical rats. The present data represents a valuable resource for future studies as it might be used for first information on gene expression levels of genes of interest in blood and brain under baseline conditions. Limitations of our study comprise possible contamination of brain tissue with blood and the non-detection of genes with very low expression levels. Genes that are more highly expressed in the brain than in the blood are of particular interest since changes in their expression, e.g. due to disease status, or treatment, are likely to be detected in an experiment. In contrast, genes with higher expression in the blood than in the brain are less informative since their higher baseline levels could superimpose variation in brain.

No MeSH data available.


Related in: MedlinePlus