Project description:Metabolite profiling was performed on metabolites extracted from the entorhinal cortex and primary visual cortex of 14-15 month old APOE3/3, APOE3/4 and APOE4/4 mice. Metabolites were run on a TOF Mass Spectrometer using an ANP column. Initial analysis was done in an untargeted manner, and processing was done to determine the differentially expressed metabolites based on their mass and retention times. Further analysis was then performed to assign identities to the differentially expressed metabolites using a database of biologically-relevant metabolites whose standards had been run under identical conditions as the samples in the study.
Project description:Patterns of gene expression in the aged entorhinal cortex and hippocampus were examined one month after entorhinal administration of BDNF lentivirus. Whole-genome patterns of expression were examined using Affymetrix arrays four weeks after entorhinal injection of lentiviral-BDNF or GFP injection compared to control subjects. Keywords: Treatment effect
Project description:Patterns of gene expression in the aged entorhinal cortex and hippocampus were examined one month after entorhinal administration of BDNF lentivirus. Whole-genome patterns of expression were examined using Affymetrix arrays four weeks after entorhinal injection of lentiviral-BDNF or GFP injection compared to control subjects. Experiment Overall Design: 27 Samples total: 4 biological replicates of Age rats BDNF treated, 3 biological replicates of Age rats eGFP treated, and 4 biological replicates each of Aged and Young rats controls for the Entorhinal cortex tissue. 2 biological replicates of Age rats BDNF treated, 2 biological replicates of Age rats eGFP treated, and 4 biological replicates each of Age and Young rats controls for the hippocampus tissue.
Project description:To determine if there is an APOE isoform-specific response to TBI we performed controlled cortical impact on 3-month-old mice expressing human APOE3 or APOE4 isoforms. Following injury, we used several behavior paradigms to test for anxiety and learning and found that APOE3 and APOE4 targeted replacement mice demonstrate cognitive impairments following moderate TBI. Transcriptional profiling 14 days following injury revealed a significant effect of TBI, which was similar in both genotypes.
Project description:Transplantation is a clinically relevant approach for brain repair, but much remains to be understood about influences of the disease environment in the host on transplant connectivity. To explore the influence of ageing and amyloid pathology in Alzheimer's disease (AD) we examined graft connectivity using monosynaptic Rabies virus tracing in APP/PS1 mice and in 16-18 month-old wild type mice. Neurons differentiated within 4 weeks and integrated well into the host visual cortex receiving input from the regions appropriate for visual cortex. Surprisingly, however, we found a prominent several-fold increase in local visual cortex input connectivity in both amyloid-loaded and aged environment. State-of-the-art deep proteome analysis using mass spectrometry provides first insights into the composition of environments promoting or not local exuberant input connectivity. These data therefore highlight the key role of the host pathology in shaping the input connectome calling for caution in extrapolating from one to another pathological condition.
Project description:The entorhinal cortex of the mouse seems to be sensitive to molecular mechanisms that have been linked to the pathology of Alzheimer's disease. In this microarray study we are interested in comparing the expression profile of the left versus the right EC of the mouse, in order to understand if there is a significant difference in gene expression that might reveal any insights into the differential activation of these areas. We used microarrays to detail the global programme of gene expression underlying a possible lateralization of the EC in the mouse brain (left versus right EC). The left and the right entorhinal cortices of 6 month-old C57BL/6 wild-type mice was dissected out by following anatomical landmarks and guided by the Mouse Brain Paxinos and Franklin’s atlas. Samples were immediately processed for RNA extraction by using the RNeasy Kit from QIAGEN according to manufacturer’s instructions. Before running the microarrays, RNA quality and integrity was monitored on an Agilent BioAnalyzer. Samples were then run on Affymetrix Genechip Mouse gene 2.0 ST arrays following Affymetrix’s standard procedures (n=3 per cortical hemisphere). Microarrays data were analyzed through the use of Ingenuity® iReport (Ingenuity® Systems, www.ingenuity.com).
Project description:Layer II stellate neurons (entorhinal cortex) and layer III cortical neurons (hippocampus CA1, middle temporal gyrus, posterior cingulate, superior frontal gyrus, primary visual cortex) were gene expression profiled. Brain regions are from non-demented individuals with intermediate Alzheimer's disease neuropathologies Keywords: neuronal gene expression profiling
Project description:The apolipoprotein E (APOE) gene is the strongest genetic risk modifier for Alzheimer's disease (AD), with the APOE4 allele increasing risk and APOE2 decreasing it compared to the common APOE3 allele. Using single-nuclei RNA sequencing of the temporal cortex from APOE2 carriers, APOE3 homozygotes, and APOE4 carriers, we found that AD-associated transcriptomic changes were highly APOE genotype-dependent. Comparing AD with controls, APOE2 carriers showed upregulated synaptic and myelination-related pathways, preserving synapses and myelination at the protein level. Conversely, these pathways were downregulated in APOE3 homozygotes, resulting in reduced synaptic and myelination proteins. In APOE4 carriers, excitatory neurons displayed reduced synaptic pathways similar to APOE3, but oligodendrocytes showed upregulated myelination pathways like APOE2. However, their synaptic and myelination protein levels remained unchanged or increased. APOE4 carriers also showed increased pro-inflammatory signatures in microglia but reduced responses to amyloid-β pathology. These findings reveal APOE genotype-specific molecular alterations in AD across cell types.
Project description:Layer II stellate neurons (entorhinal cortex) and layer III cortical neurons (hippocampus CA1, middle temporal gyrus, posterior cingulate, superior frontal gyrus, primary visual cortex) were gene expression profiled. Brain regions are from individuals who had been diagnosed with mild cognitive impairment. Experiment Overall Design: ~500 neurons were selected from each of 6 brain regions. Total RNA was isolated from each batch of neurons, double round amplified, and hybridized to Affymetrix Human Genome U133 Plus 2.0 arrays.