Project description:We used microarray expression profiling to assess protein-coding and non-coding gene expression across 8 brain samples and 7 other human tissues. We measured commercial human cDNA samples from 15 tissues: cerebellum, brain stem, frontal cortex, occipital cortex, parietal cortex, fetal brain, whole adult brain, colon, heart, kidney, liver, lung, breast and adrenal gland
Project description:Schizophrenia (SCZ) and bipolar disorder (BD) are highly heritable psychiatric disorders. Associated genetic and gene expression changes have been identified, but many have not been replicated and have unknown functions. We identified groups of genes whose expressions varied together, that is co-expression modules, then tested them for association with SCZ. Using weighted gene co-expression network analysis, we show that two modules were differentially expressed in patients versus controls. One, upregulated in cerebral cortex, was enriched with neuron differentiation and neuron development genes, as well as disease genome-wide association study genetic signals; the second, altered in cerebral cortex and cerebellum, was enriched with genes involved in neuron protection functions. The findings were preserved in five expression data sets, including sets from three brain regions, from a different microarray platform, and from BD patients. From those observations, we propose neuron differentiation and development pathways may be involved in etiologies of both SCZ and BD, and neuron protection function participates in pathological process of the diseases.
Project description:Background: Autism spectrum disorder (ASD) is a severe early onset neurodevelopmental disorder with high heritability but significant heterogeneity. Traditional genome-wide approaches to test for association of common variants with autism susceptibility risk has met with limited success. However, novel methods to identify moderate risk alleles in attainable sample sizes are now gaining momentum. Methods:M-BM- In this study, we utilized publically available GWAS data from the Autism Genome Project (AGP) and annotated the results (p < 0.001) for eQTLs present in the parietal lobe, cerebellum, and lymphoblastoid cell lines. We then performed a test of enrichment by comparing these results to simulated data conditioned on minor allele frequency in order to generate an empirical p-value indicating statistically significant enrichment of eQTLs in top results from the autism GWAS. Results:M-BM- Our findings show a global enrichment of brain eQTLs, but not LCL eQTLs, among top SNPs from an autism GWAS. Additionally, the data implicates individual genesM-BM- SLC25A12,M-BM- PANX1M-BM- andM-BM- PANX2, as well as pathways previously implicated in autism. Conclusions:M-BM- These findings provide supportive rationale for the use of annotation-based approaches to GWAS. We use microarray technology to understand the etiology and pathology of psychiatric diseases at the transcriptomic level. Postmortem human brain samples came from the Stanley Medical Research InstituteM-bM-^@M-^Ys Neuropathology Consortium and Array collections, including schizophrenia, bipolar disorder and control samples.
Project description:Post mortem human brain tissue comparison between HD patients and controls from 3 brain regions - cerebellum, frontal cortex [BA4, BA9] and caudate nucleus. Gene expression analysed using linear models from LIMMA package in Bioconductor suite. Keywords: disease state analysis
Project description:Human brain tissue was obtained from the New Zealand Brain Bank from donors with Alzheimer's disease (AD) or age-matched controls (n=9/group). Mean post mortem delays were ~12h. Six distinct brain regions were dissected, Hippocampus, Cingulate Gyrus, Entorhinal Cortex (severely affected), Motor and Sensory Cortex (less affected) and Cerebellum (spared). Protein was extracted from each sample and, each region was analysed independently. For each region, samples were divided into 3 sets of 3 cases and 3 controls and assigned to an iTRAQ 8 plex, alongside two aliquots of a pooled QC sample. Samples were digested, iTRAQ labelled and analysed. For each region, between 3000 and 4200 proteins were compared between AD and control, identifying a series of known and novel protein expression changes associated with the progression of AD.
Project description:Ion channel splice array data from cerebellum brain tissue samples collected from Alzheimer's disease patients. Temporal cortex (Alzheimer's disease affected brain tissue structure) and cerebellum (Alzheimer's disease unaffected brain tissue structure) samples from control subjects were compared to temporal cortex and cerebellum of patients with Alzheimer's disease.
Project description:The most widely utilized approaches for quantifying DNA methylation involve the treatment of genomic DNA with sodium bisulfite, although this method cannot distinguish between DNA methylation (5mC) and DNA hydroxymethylation (5hmC). Previous studies have shown that 5hmC is enriched in the brain, although little is known about its genomic distribution and how it differs between anatomical regions and individuals. In this study, we combined oxidative bisulfite (oxBS) treatment with the Illumina Infinium 450K BeadArray to quantify genome-wide patterns of 5hmC in two distinct anatomical regions of the brain (prefrontal cortex and cerebellum) dissected from multiple individuals. We identified 37,145 and 65,563 sites passing our threshold for detectable 5hmC in the prefrontal cortex and cerebellumm, respectively, with 23,445 loci common across both brain regions. Distinct patterns of 5hmC were identified in each brain region, with notable differences in the genomic location of the most hydroxymethylated loci between these brain regions. Tissue-specific patterns of 5hmC were subsequently confirmed in an independent set of prefrontal cortex and cerebellum samples. Our data are available as downloadable UCSC genome browser tracks (http://epigenetics.iop.kcl.ac.uk/HMC/) as a resource to the community. Our study represents the first systematic analysis of 5hmC in the human brain, identifying tissue-specific hydroxymethylated positions and genomic regions characterized by inter-individual variation in DNA hydroxymethylation. This study demonstrates the utility of combining oxBS-treatment with the Illumina 450k methylation array to systematically quantify 5hmC across the genome and the potential utility of this approach for epigenomic studies of brain disorders.
Project description:Background: Autism spectrum disorder (ASD) is a severe early onset neurodevelopmental disorder with high heritability but significant heterogeneity. Traditional genome-wide approaches to test for association of common variants with autism susceptibility risk has met with limited success. However, novel methods to identify moderate risk alleles in attainable sample sizes are now gaining momentum. Methods:M-BM- In this study, we utilized publically available GWAS data from the Autism Genome Project (AGP) and annotated the results (p < 0.001) for eQTLs present in the parietal lobe, cerebellum, and lymphoblastoid cell lines. We then performed a test of enrichment by comparing these results to simulated data conditioned on minor allele frequency in order to generate an empirical p-value indicating statistically significant enrichment of eQTLs in top results from the autism GWAS. Results:M-BM- Our findings show a global enrichment of brain eQTLs, but not LCL eQTLs, among top SNPs from an autism GWAS. Additionally, the data implicates individual genesM-BM- SLC25A12,M-BM- PANX1M-BM- andM-BM- PANX2, as well as pathways previously implicated in autism. Conclusions:M-BM- These findings provide supportive rationale for the use of annotation-based approaches to GWAS. We use microarray technology to understand the etiology and pathology of psychiatric diseases at the transcriptomic level. Postmortem human brain samples came from the Stanley Medical Research InstituteM-bM-^@M-^Ys Neuropathology Consortium and Array collections, including schizophrenia, bipolar disorder and control samples.
Project description:Schizophrenia (SCZ) and bipolar disorder (BD) are highly heritable psychiatric disorders. Associated genetic and gene expression changes have been identified, but many have not been replicated and have unknown functions. We identified groups of genes whose expressions varied together, that is co-expression modules, then tested them for association with SCZ. Using weighted gene co-expression network analysis, we show that two modules were differentially expressed in patients versus controls. One, upregulated in cerebral cortex, was enriched with neuron differentiation and neuron development genes, as well as disease genome-wide association study genetic signals; the second, altered in cerebral cortex and cerebellum, was enriched with genes involved in neuron protection functions. The findings were preserved in five expression data sets, including sets from three brain regions, from a different microarray platform, and from BD patients. From those observations, we propose neuron differentiation and development pathways may be involved in etiologies of both SCZ and BD, and neuron protection function participates in pathological process of the diseases.
Project description:The main goal of the study was to measure the epigenetic age (also known as DNA methylation age) of human tissues and to relate it to chronological age. Toward this end, we used the epigenetic clock software described in Horvath S (n=2013) DNA methylation age of human tissues and cell types. Genome Biology.2013, 14:R115. DOI: 10.1186/10.1186/gb-2013-14-10-r115 PMID: 24138928 Human DNA methylation Beadchip v1.2 was used to obtain n=260 Illumina DNA methylation array from the following human Brain regions: caudate nucleus (n=n=12), cingulate gyrus (n=n12), cerebellum (n=32), frontal cortex (n=41), hippocampus (n=25), midBrain (n=18), motor cortex (n=33), occipital cortex (n=33), parietal lobe (n=23), sensory cortex (n=12), temporal cortex (n=29), visual cortex (n=11).