RNA-seq of frontal cortex in a novel mouse model of Alzheimer's disease.
ABSTRACT: There is accumulating evidence that amyloid beta and tau proteins may act synergistically to cause synapse and neural circuit degeneration in Alzheimer’s disease. In order to study this, we designed a new mouse model which lacks endogenous mouse tau, but expresses both the APP/PS1 transgene, which causes well-characterised plaque-associated synapse loss, and also reversibly expresses wild-type human tau (which can be suppressed with doxycycline). We examined the transcriptional changes in the frontal cortex of this mouse model, along with behaviour, pathology, synaptic plasticity, synapse degeneration and accumulation of amyloid beta and tau at synapses, and compared with littermate control genotypes: those lacking endogenous mouse tau, those lacking endogenous mouse tau but expressing the APP/PS1 transgene only, and those lacking endogenous mouse tau but reversibly expressing wild-type human tau only.
Project description:There is accumulating evidence that amyloid beta and tau proteins may act synergistically to cause synapse and neural circuit degeneration in Alzheimer’s disease. In order to study this, we designed a new mouse model which lacks endogenous mouse tau, but expresses both the APP/PS1 transgene, which causes well-characterised plaque-associated synapse loss, and also reversibly expresses wild-type human tau (which can be suppressed with doxycycline). We examined the transcriptional changes in the frontal cortex of this mouse model, along with behaviour, pathology, synaptic plasticity, synapse degeneration and accumulation of amyloid beta and tau at synapses, and compared with littermate control genotypes: those lacking endogenous mouse tau, those lacking endogenous mouse tau but expressing the APP/PS1 transgene only, and those lacking endogenous mouse tau but reversibly expressing wild-type human tau only.
Project description:In this study, we particularly focused on short ncRNA expression profiling of three, ten and twenty month old triple transgenic mouse model for Alzheimers disease (Oddo et al.; 2003;Neuron). These mice harbor presenilin PS1(M146V), APP(Swedish) and tau(P301L) mutations and develop beta-amyloid plaques and at later stages also a tau pathology. Controls are age matched B6129SF2/J mice.
Project description:Early-onset Alzheimer’s disease-like pathology in Down syndrome (DS, trisomy 21) is commonly attributed to an increased dosage of the amyloid precursor protein (APP) gene. To test this central tenet of the amyloid-cascade hypothesis we deleted the supernumerary copy of the APP gene in trisomic DS iPSC, or upregulated APP expression in euploid human pluripotent stem cell lines with dCas9-VP64, and subjected these lines to prolonged cortical neural differentiation. Our data reveal that increased APP gene dosage and expression is necessary and sufficient for increased beta-amyloid production and pyroglutamate(E3)-containing plaque deposition, but is neither sufficient nor required for tau hyperphosphorylation, neurofibrillary tangle formation, or increased oxidative stress-induced apoptosis in neurons. Transcriptome comparisons of the isogenic neurons demonstrates that the supernumerary APP gene copy has profound temporally-modulated genome-wide effects on gene expression during differentiation and maturation of DS neuronal cultures that link APP function to regulation of genes involved in neuronal synaptic function and outgrowth of neuronal processes. Collectively, our data reveal that APP plays an important role in the amyloidogenic aspects of Alzheimer’s disease, but challenge the hypothesis that increased APP levels are solely responsible for hyperphosphorylation of tau or enhanced oxidative stress-induced neuronal cell death in Down syndrome associated AD-pathogenesis. Overall design: 34 samples
Project description:Gene expression changes in mice overexpressing amyloid precursor protein with the Swedish mutation (Tg2576; APPSw). The gene expression levels in male 12 month-old APPSw mice (GSM26708, GSM26709) were compared to those in male nontransgenic littermate control mice (GSM26706, GSM26707). Data were analyzed with MAS 5.0 and scaled to 2500. See Stein, TD, Anders, NJ, DeCarli, C, Chan, SL, Mattson, MP, and Johnson JA. Neutralization of transthyretin reverses the neuroprotective effects of secreted APP in APPSw mice resulting in tau phosphorylation and loss of hippocampal neurons: support for the amyloid hypothesis. J Neurosci. in press.
Project description:The goal of this study was to assess the number and types of differentially expressed genes in a transgenic (genomic) mouse model of tau pathology. Notably, we crossed previously described genomic mouse line called ‘8c’ that expresses all isoforms of human tau protein (Duff et al., Neurobiology of Disease, 2000;7(2):87) with a mouse tau knockout line (Dawson et al., J Cell Sci 2001;114:1179) and generated humanized mice line called ‘hTau Dk/Dk’. These mice are complete knockout of endogenous mouse tau and express all six isoforms of human tau driven by the endogenous human tau promoter. We performed microarray analysis in the hippocampal tissue from six-month old hTau Dk/Dk mice (n=3) and compared it with age-matched non-transgenic control group. Both the lines are in C57BL/6J genetic background.
Project description:The purpose of this project was to compare whole genome expression in 5 transgenic mice with human genes for dementia that result in either plaques or tangle pathology to the expression in wild-type control mice and to each other at different stages of disease progression. Total RNA was obtained from hippocampus, cortex and cerebellum in four lines of ‘amyloid’ transgenic mice (mutant human APP and APP/PSEN1 genes) and ‘TAU’ transgenic mice (mutant human MAPT gene) as well as wild-type control mice at 8,16, 32 and 72 weeks
Project description:The abnormal regulation of amyloid-b (Ab) metabolism (e.g., production, cleavage, clearance) plays a central role in Alzheimer’s disease (AD). Among endogenous factors believed to participate in AD progression are the small regulatory non-coding microRNAs (miRs). In particular, the miR-132/212 cluster is severely reduced in the AD brain. In previous studies we have shown that miR-132/212 deficiency in mice leads to impaired memory and enhanced Tau pathology as seen in AD patients. Here we demonstrate that the genetic deletion of miR-132/212 promotes Ab deposition and amyloid (senile) plaque formation in triple transgenic AD (3xTg-AD) mice. Using RNA-Seq and bioinformatics, we identified genes of the miR-132/212 network with documented roles in the regulation of Ab metabolism, including Tau, Mapk, and Sirt1. We used RNA-Seq to analyse the hippocampus of 3xTg-AD mice lacking the miR-132/212 cluster as well as Neuro2a cells overexpressing miR-132 mimics.
Project description:Gene expression changes induced by alpha-secretase cleaved amyloid precursor protein (sAPPalpha) in organotypic hippocampal slice cultures of male, postnatal day 15 mice (C57B6/SJL). Hippocampal slice cultures were treated with phosphate buffered saline (GSM26700, GSM26701, GSM26702) or 1 nM sAPPalpha (GSM26703, GSM26704, GSM26705) for 24 h. Each sample consists of total RNA isolated from 8-12 slices from 4 mice. Data were analyzed with MAS 5.0 and scaled to 2500. sAPPalpha induces the amyloid sequestration protein transthyretin, insulin-like growth factor 2, insulin-like growth factor binding protein 2, and other genes involved in protective pathways such as apoptosis inhibition, detoxification, and retinol transport. See Stein, TD, Anders, NJ, DeCarli, C, Chan, SL, Mattson, MP, and Johnson JA. Neutralization of transthyretin reverses the neuroprotective effects of secreted APP in APPSw mice resulting in tau phosphorylation and loss of hippocampal neurons: support for the amyloid hypothesis. J Neurosci. in press.
Project description:In a transgenic mouse model of Alzheimer disease (AD), cleavage of the amyloid precursor protein (APP) by the α-secretase ADAM10 prevented amyloid plaque formation and alleviated cognitive deficits. Furthermore, there was a positive influence of ADAM10 over-expression on neurotransmitter-specific formation of synapses and on synaptic plasticity. To assess the influence of ADAM10 on the gene expression profile in the brain we performed microarray analysis using RNA isolated from brains of five month old mice over-expressing either the α-secretase ADAM10 or a dominant-negative mutant (dn) of this enzyme. As compared to non-transgenic wild-type mice, 355 genes were found to be differentially expressed in ADAM10 transgenic mice and 143 genes in dnADAM10 mice. A higher number of genes was found to be differentially regulated in double-transgenic mouse strains additionally expressing the human APP V717I mutant (APP[V717I]). Thus, α-secretase cleavage of over-expressed APP[V717I] alters CNS gene expression additionally. Keywords: genetic modification Overall design: We performed microarray analysis with cDNA transcribed from total RNA of brains from five month old mice. Mono-transgenic ADAM10 as well as dnADAM10 mice were investigated in comparison to non-transgenic FVB/N wild-type mice (n = 3 females), to analyze the influence of the a -secretase ADAM10 or its catalytically inactive form (dnADAM10) on the gene expression profile of the CNS. To elucidate the effect of ADAM10 and dnADAM10 on gene expression we compared samples derived from double-transgenic ADAM10/APP[V717I] and dnADAM10/APP[V717I] mice to those from mono-transgenic APP[V717I] mice (n = 3 females and n = 3 males). At the age of 5 months, APP[V717I] show cognitive deficits, whereas amyloid plaque formation occurs several months later (Moechars et al., 1999). Both were investigated in order to examine an influence of sex. ChipInspector carries out significance analysis on the single probe level. Normalized probe set level data not provided for individual Sample records. Processed data is available on Series record.
Project description:We examined transgenic (TG) mice expressing human APP695 bearing the double Swedish (671KM>NL) and Indiana (717V>F) amyloid precursor protein (APP) mutations. Lentiviral vectors constitutively expressing BDNF-GFP under control of the CMV/ß-actin hybrid promoter or GFP alone were injected into the entorhinal cortices of TG mice bilaterally at age 6 months, a time point by which neuropathological degeneration and cell loss are established. Age-matched wild-type littermates underwent sham surgery or injection of lentivirus expressing GFP into the entorhinal cortices bilaterally. Keywords: Treatment effect Overall design: 26 Samples total: 4 biological replicates of APP transgenic mice BDNF treated, 4 biological replicates of APP transgenic mice GFP treated, 3 biological replicates of non-trangenic mice sham lesion and 2 biological replicates of non-transgenic mice GFP treated for both tissues: Entorhinal cortex and hippocampus.