Project description:Gene expression profiling was performed on frontal and temporal cortex from vascular dementia (VaD), Alzheimer's disease (AD), and non-demented controls (Control) obtained from the University of Michigan Brain Bank. Controls and AD cases had no infarcts in the autopsied hemisphere. Vascular dementia cases had low Braak staging.
Project description:Alzheimer's Disease (AD) and Non-Demented Control (NDC) human sera were probed onto human protein microarrays in order to identify differentially expressed autoantibody biomarkers that could be used as diagnostic indicators. In the study presented here, 50 AD and 40 NDC human serum samples were probed onto human protein microarrays in order to identify differentially expressed autoantibodies. Microarray data was analyzed using several statistical significance algorithms, and autoantibodies that demonstrated significant group prevelance were selected as biomarkers of disease. Prediction classification analysis tested the diagnostic efficacy of the identified biomarkers; and differentiation of AD samples from other neurodegeneratively-diseased and non-neurodegeneratively-diseased controls (Parkinson's disease and breast cancer, respectively) confirmed their specificity.
Project description:Dissecting the shared etiology of different diseases could benefit from a systematic search for associated molecules and their interactions. We investigated genome-wide disruptions in the co-regulation of genes in two neurodegenerative diseases, Alzheimer's or Huntington's disease (AD or HD), using expression profiles from postmortem prefrontal cortex samples of 624 demented patients and non-demented control individuals with matched genotype and clinical data. A meta-analysis based screen for changes in coordinate expression patterns revealed differentially co-expressed (DC) gene pairs that either gained or lost correlation in disease cases relative to the control group, with the former being dominant for both AD and HD. Integration of disruptions common to AD and HD with large-scale data on protein-protein and protein-DNA interactions yielded a 242-gene sub-network that was enriched for proteins involved in neuronal differentiation and genetic associations to brain structural changes and dementia in subjects aged over 70 years. Replication of the AD DC network in independent human and mouse cohorts lends confidence to the comprehensive view we offer on dysregulated brain molecular pathways in AD and HD. DLPFC (BA9) brain tissues of AD patients, HD patients and non-demented controls samples were obtained from Harvard Brain tissue resource center (HBTRC). The HBTRC samples were primarily of Caucasian ancestry, as only eight non-Caucasian outliers were identified, and therefore excluded for further analysis. Post-mortem interval (PMI) was 17.8+8.3 hours (mean ± standard deviation), sample pH was 6.4±0.3 and RNA integrity number (RIN) was 6.8±0.8 for the average sample in the overall cohort. Tissues were profiled on a custom-made Agilent 44K array (GPL4372). 624 individual DLPFC samples were profiled against a common DLPFC pool constructed from the same set of samples.
Project description:Alzheimer's Disease (AD) and Non-Demented Control (NDC) human sera were probed onto human protein microarrays in order to identify differentially expressed autoantibody biomarkers that could be used as diagnostic indicators.
Project description:Along with the two hallmark pathologies—intracellular neurofibrillary tangles (NFTs) and extracellular amyloid plaques—transcriptional studies suggest that Alzheimer's disease (AD) results from dysfunction of many cellular pathways including synaptic transmission, cytoskeletal dynamics, and apoptosis. While these studies consistently point to the same pathways involved in AD, there is no consensus on which genes in each pathway are disease-relevant, much less on whether these genes play causative roles or are downstream effects of disease progression. To address these issues, we have performed a large-scale transcriptional analysis in brain of individuals with advanced AD and non-demented controls, focusing specifically on CA1 and the relatively less affected CA3. For comparisons between regions and across disease status, we find consistency in both pathway enrichment as well as specific differentially expressed genes across several studies. Furthermore, genes that show decreased expression with AD progression also tend to show enrichment in CA3 (and vice versa), suggesting that transcription levels in a region may reflect that region's vulnerability to disease. In particular, we find several strong candidate vulnerability (ABCA1, MT1H, PDK4, RHOBTB3) and protection (FAM13A1, LINGO2, UNC13C) genes based on expression patterns. We have also applied weighted gene coexpression network analysis (WGCNA) to explore the pathophysiology of AD from a systems perspective, finding modules for major cell types, which each show distinct disease-relevant expression patterns. In particular, a microglial module shows increased expression in the brain of non-demented controls harboring early NFT pathology, suggesting that microglial activation is an early event in AD progression. Total RNA obtained from 60um sections of frozen human hippocampus was collected using scalpel dissection. Control and AD brains were matched for all non-disease characteristics as closely as possible. CA1 and CA3 dissections for a given individual were taken from the same section. Several region- and disease-related comparisons were performed.
Project description:To further development of our gene expression profile of Alzheimer's disease, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential biomarker for early disease detection Total RNA from peripheral blood cells was extracted, reverse-transcribed and labelled, then analysed for gene expression using GeneSpring GX12 (Agilent Technologies, USA). About 180 samples (AD=90, Non-demented control=90) was used for microarray analysis.
Project description:Dissecting the shared etiology of different diseases could benefit from a systematic search for associated molecules and their interactions. We investigated genome-wide disruptions in the co-regulation of genes in two neurodegenerative diseases, Alzheimer's or Huntington's disease (AD or HD), using expression profiles from postmortem prefrontal cortex samples of 624 demented patients and non-demented control individuals with matched genotype and clinical data. A meta-analysis based screen for changes in coordinate expression patterns revealed differentially co-expressed (DC) gene pairs that either gained or lost correlation in disease cases relative to the control group, with the former being dominant for both AD and HD. Integration of disruptions common to AD and HD with large-scale data on protein-protein and protein-DNA interactions yielded a 242-gene sub-network that was enriched for proteins involved in neuronal differentiation and genetic associations to brain structural changes and dementia in subjects aged over 70 years. Replication of the AD DC network in independent human and mouse cohorts lends confidence to the comprehensive view we offer on dysregulated brain molecular pathways in AD and HD.
Project description:Alternative polyadenylation (APA) contributes to post-transcriptional regulation, but its role in Alzheimer’s disease (AD) is largely unknown. Using high-resolution SQUARE multiple 3’ primer-based sequencing, we discovered massive APA differences in temporal gyrus tissues from demented AD patients compared to either healthy controls or non-demented donors with AD neuropathology (NDWP). Advanced statistics, microfluidics RT-PCR and protein measurements validated known and novel APA-modified 3’-intact transcripts. Moreover, APA modifications, more than total transcript counts, distinguished AD patients from both controls and NDWP donors and identified cell type-characteristic, cognition-associated and neuropathology-related changes. AD-enhanced APA variants included known therapeutic targets of brain, vascular and autoimmune disorders, predicting co-involvement of these target genes in AD progression; AD/NDWP increases in 3’-intact proteinopathy-related hnRNP mRNAs were inversely associated with protein decreases, whereas NDWP-potentiated cognition was accompanied by distinct ATP and mitochondrial variants. APA variations thus provide a novel resource of unique value for both basic and translational neuroscience researchers.
Project description:Alternative polyadenylation (APA) contributes to post-transcriptional regulation, but its role in Alzheimer’s disease (AD) is largely unknown. Using high-resolution SQUARE multiple 3’ primer-based sequencing, we discovered massive APA differences in temporal gyrus tissues from demented AD patients compared to either healthy controls or non-demented donors with AD neuropathology (NDWP). Advanced statistics, microfluidics RT-PCR and protein measurements validated known and novel APA-modified 3’-intact transcripts. Moreover, APA modifications, more than total transcript counts, distinguished AD patients from both controls and NDWP donors and identified cell type-characteristic, cognition-associated and neuropathology-related changes. AD-enhanced APA variants included known therapeutic targets of brain, vascular and autoimmune disorders, predicting co-involvement of these target genes in AD progression; AD/NDWP increases in 3’-intact proteinopathy-related hnRNP mRNAs were inversely associated with protein decreases, whereas NDWP-potentiated cognition was accompanied by distinct ATP and mitochondrial variants. APA variations thus provide a novel resource of unique value for both basic and translational neuroscience researchers.