MicroRNA alterations in a mouse model of prion disease
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE146013 | GEO | 2020/06/17
REPOSITORIES: GEO
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Project description:Scrapie is a Transmissible Spongiform Encephalopathy (TSE) that affects sheep and goats and it is considered a good natural animal model to study prion diseases. Although changes in DNA methylation occur in many neurodegenerative diseases including human prion diseases, potential DNA methylation alterations have not yet been investigated in the central nervous system (CNS) of any prion disease models or naturally infected cases. We present here a whole genome bisulfite sequencing analysis (WGBS) from thalamus of four naturally scrapie infected sheep and four controls. All animals were female, carried the ARQ/ARQ genotype for the PRNP allele and were sacrificed at similar age (4 to 6 years old). Even if genomes displayed similar average methylation levels, we identified 39 differentially methylated promoters (DMP) and a total of 8,907 differentially methylated regions (DMR). Gene Ontology enrichment revealed that hypomethylated DMRs were enriched in genes involved in transmembrane transport and cell adhesion whereas hypermethylated DMRs were related with intracellular signal transduction genes. Moreover, we compared the set of identified DMRs with genes previously described to be differentially expressed in scrapie and with a set of genes encoding proteins defined to be tenfold more abundant in specific types of CNS cells finding that some of these genes also harboured DMRs. Finally, a validation study using qPCR was conducted showing differences in the expression of five genes (PCDH19, SNCG, WDR45B, PEX1 and CABIN1) that matched the methylation changes observed in the genomic study. Altogether, these findings suggest a potential regulatory role of CNS DNA methylation in prion diseases.
2022-03-10 | GSE184767 | GEO
Project description:While prion infections have been extensively characterized in the laboratory mouse, little is known regarding the molecular responses to prions in other rodents. To explore these responses and make comparisons, we generated a prion disease in the laboratory rat by successive passage of mouse RML prions. Here we describe the accumulation of prions and associated pathology in the rat and describe the transcriptional impact throughout prion disease. Comparative transcriptional profiling between laboratory mice and rats suggests that similar molecular processes are unfolding in response to prion infection. At the level of individual transcripts, however, variability exists between mice and rats and many genes deregulated in mouse scrapie are not affected in rats. Notwithstanding these differences, many transcriptome responses are conserved between mice and rats infected with scrapie. Our findings highlight the usefulness of comparative approaches to understanding neurodegeneration and prion diseases in particular. We Adapted RML Mouse Scrapie into Rats and measured the resulting gene expression changes in brain as a result of disease progression. Rats were infected by intracranial inoculation with prion isolates obtained by adaptation of mouse RML scrapie prions into rats. Brain samples were collected from third and fourth passage infected rats and age-matched controls at specified timepoints and gene expression profiles obtained. For each time point, 3 diseased and control brain samples were profiled.
2015-09-01 | E-GEOD-63930 | biostudies-arrayexpress
Project description:While prion infections have been extensively characterized in the laboratory mouse, little is known regarding the molecular responses to prions in other rodents. To explore these responses and make comparisons, we generated a prion disease in the laboratory rat by successive passage of mouse RML prions. Here we describe the accumulation of prions and associated pathology in the rat and describe the transcriptional impact throughout prion disease. Comparative transcriptional profiling between laboratory mice and rats suggests that similar molecular processes are unfolding in response to prion infection. At the level of individual transcripts, however, variability exists between mice and rats and many genes deregulated in mouse scrapie are not affected in rats. Notwithstanding these differences, many transcriptome responses are conserved between mice and rats infected with scrapie. Our findings highlight the usefulness of comparative approaches to understanding neurodegeneration and prion diseases in particular.
2015-09-01 | GSE63930 | GEO
Project description:Sheep scrapie (Sc) is the classical transmissible spongiform encephalopathy (prion disease). The conversion of normal cellular prion protein (PrPC) to disease-associated prion protein (PrPSc) is a fundamental component of prion disease pathogenesis. The molecular mechanisms contributing to prion diseases and the impact of PrPSc accumulation on cellular biology are not fully understood. To define the molecular changes associated with PrPSc accumulation, primary sheep microglia were inoculated with PrPSc and then the transcriptional profile of these PrPSc-accumulating microglial cells was compared to the profile of PrPSc-lacking microglial cells using the Affymetrix Bovine Genome Array. The experimental design included three biological replicates, each with three technical replicates, and samples that were collected at the point of maximal PrPSc accumulation levels as measured by ELISA. The array analysis revealed 19 upregulated genes and 30 downregulated genes in PrPSc-accumulating microglia. Three transcripts (CCL2, SGK1, and AASDHPPT) were differentially regulated in a direction similar to previous reports from mouse or human models, whereas the response of three other transcripts (MT1E, NR4A1, PKP2) conflicted with previous reports. Overall, the results demonstrated a limited transcriptional response to PrPSc accumulation, when compared to microglia and macrophage cultures infected with other agents such as viruses and bacteria. This is the first microarray-based analysis of prion accumulation in primary cells derived from a natural TSE-host. Keywords: disease state analysis
2008-09-06 | GSE12688 | GEO
Project description:Prion infection results in progressive neurodegeneration of the central nervous system invariably resulting in death. The pathological effects of prion diseases in the brain are morphologically well defined, such as gliosis, vacuolation, and the accumulation of disease-specific protease-resistant prion protein (PrPSc). However, the underlying molecular events that lead to the death of neurons are poorly characterised. In this study cDNA microarrays were used to profile gene expression changes in the brains of two different strains of mice infected with three strains of mouse-adapted scrapie. Extensive data was collected and analyzed, from which we identified a core group of 349 prion-related genes (PRGs) that consistently showed altered expression in mouse models. Gene ontology analysis assigned many of the up-regulated genes to functional groups associated with one of the primary neuropathological features of prion diseases, astrocytosis and gliosis; protein synthesis, inflammation, cell proliferation and lipid metabolism. Using a computational tool, Ingenuity Pathway Analysis (IPA), we were able to build networks of interacting genes from the PRG list. The regulatory cytokine TGFB1, involved in modulating the inflammatory response, was identified as the outstanding interaction partner for many of the PRGs. The majority of genes expressed in neurons were down-regulated; a number of these were involved in regulatory pathways including synapse function, calcium signalling, long-term potentiation and ERK/MAPK signalling. Two down-regulated genes coding for the transcription regulators, EGR1 and CREB1, were also identified as central to interacting networks of genes; these factors are often used as markers of neuronal activity and their deregulation could be key to loss of neuronal function. These data provides a comprehensive list of genes that are consistently differentially expressed in multiple scrapie infected mouse models. Building networks of interactions between these genes provides a means to understand the complex interplay in the brain during neurodegeneration. Resolving the key regulatory and signaling events that underlie prion pathogenesis will provide targets for the design of novel therapies and the elucidation of biomarkers. Keywords: disease state analysis C57BL/6 mice were inoculated by intracerebral infection of brain homogenate from mice clinically infected with the ME7, 79a and 22A strains of scrapie. In addition VM mice were also inoculated with the 22A scrapie strain. Mice were sacrificed at the onset of clinical diseases as manifested by uncoordinated gait, flaccid paralysis of the hind limbs, rigidity and abolishment of the righting reflex. Brain tissue was collected from these mice and the RNA isolated. Mouse CNS gene expression was analysed by two-colour microarray experiments using an in house manufactured 11K mouse cDNA microarray. RNA from individual infected mice was hybridized to each array versus pooled reference RNA from an equivalent number of age-matched, mock-infected control mice. In total we hybridized 34 different samples to microarrays in this experiment; 8-10 individual mice from each of the four sample groups were individually processed for separate microarrays. Hierachical clustering shows that the patterns of gene expression are for the most part common to the different mouse models . We used the program EDGE to identify genes that were differentially expressed in mouse brain during clinical disease. We used a P value cut-off of 0.05 as the criteria for selection of significantly differentially expressed genes. A similar design was used to determine gene expression profiles from C57BL/6 mice infected with a fourth strain of scrapie, RML. Total RNA from three mice, plus dye swaps, was hybridized to Agilent whole genome mouse arrays to validate genes identified using our manufactured BMAP arrays.
2010-05-26 | E-GEOD-10310 | biostudies-arrayexpress
Project description:In vertebrates, the prion protein (PrP, gene name Prnp) is expressed in diverse cell types and tissues, especially in the brain. In the adult brain, PrP contributes to homeostasis. Here, proteins expressed in the adult mouse brain which coimmunoprecipitated with PrP via the Fab antibody D18 were identified by comparison to PrP-specific immunoprecipitates from Prnp knockout brain.
2021-11-02 | PXD024870 | Pride
Project description:Sheep scrapie (Sc) is the classical transmissible spongiform encephalopathy (prion disease). The conversion of normal cellular prion protein (PrPC) to disease-associated prion protein (PrPSc) is a fundamental component of prion disease pathogenesis. The molecular mechanisms contributing to prion diseases and the impact of PrPSc accumulation on cellular biology are not fully understood. To define the molecular changes associated with PrPSc accumulation, primary sheep microglia were inoculated with PrPSc and then the transcriptional profile of these PrPSc-accumulating microglial cells was compared to the profile of PrPSc-lacking microglial cells using the Affymetrix Bovine Genome Array. The experimental design included three biological replicates, each with three technical replicates, and samples that were collected at the point of maximal PrPSc accumulation levels as measured by ELISA. The array analysis revealed 19 upregulated genes and 30 downregulated genes in PrPSc-accumulating microglia. Three transcripts (CCL2, SGK1, and AASDHPPT) were differentially regulated in a direction similar to previous reports from mouse or human models, whereas the response of three other transcripts (MT1E, NR4A1, PKP2) conflicted with previous reports. Overall, the results demonstrated a limited transcriptional response to PrPSc accumulation, when compared to microglia and macrophage cultures infected with other agents such as viruses and bacteria. This is the first microarray-based analysis of prion accumulation in primary cells derived from a natural TSE-host. Experiment Overall Design: Primary sheep microglial cells were either inoculated with PrPSc (Inoc) or sham-inoculated (Mock) Experiment Overall Design: Three biological replicates per treatment. Experiment Overall Design: Three technical replicates per biological replicate. Experiment Overall Design: biological replicate: Inoc12A, Inoc12B.2, Inoc12C Experiment Overall Design: biological replicate: Mock12A, Mock12B.2, Mock12C Experiment Overall Design: technical replicate - extract: Inoc12A.1, Inoc12A.2, Inoc12A.3 Experiment Overall Design: technical replicate - extract: Inoc12B.2.1, Inoc12B.2.2, Inoc12B.2.3 Experiment Overall Design: technical replicate - extract: Inoc12C.1, Inoc12C.2, Inoc12C.3 Experiment Overall Design: technical replicate - extract: Mock12A.1, Mock12A.2, Mock12A.3 Experiment Overall Design: technical replicate - extract: Mock12B.2.1, Mock12B.2.2, Mock12B.2.3 Experiment Overall Design: technical replicate - extract: Mock12C.1, Mock12C.2, Mock12C.3
2008-11-04 | E-GEOD-12688 | biostudies-arrayexpress
Project description:Aggregation of the prion protein (PrP) and formation of PrP amyloid (APrP) is severe in some Prion diseases. In the dominantly inherited prion protein amyloidosis known as Gerstmann-Sträussler-Scheinker (GSS) disease, plaques made of PrP amyloid are a distinct feature. The TTC to TCC mutation in Prion protein gene (PRNP), resulting in a phenylalanine to serine amino acid substitution at PrP residue 198, causes a severe amyloidosis in a well-studied GSS variant. The neuropathologic phenotype of this neurodegenerative disease is characterized by the presence of numerous extracellular APrP plaques and intracytoplasmic tau neuronal inclusions which are identical to neurofibrillary tangles of Alzheimer disease. Using cryogenic electron microscopy (cryo-EM), we determined for the first time the structures of filaments of human APrP, isolated post-mortem from the brain of a symptomatic PRNP F198S mutation carrier. We report that in GSS (F198S) APrP filaments are composed of dimeric, trimeric and tetrameric left-handed protofilaments with their protomers sharing a common protein fold. The protomers in the cross-β spines consist of sixty-two amino acids and span from glycine 80 to phenylalanine 141, adopting a previously unseen spiral fold with a thicker outer layer and a thinner inner layer. Each protomer comprises nine short β-strands. The β1 and β8 strands as well as the β4 and β9 strands are engaged in a steric zipper. The new data, obtained by Cryo-EM, provide insights into the complexity of the structure of pathogenic PrP, and reveal the difference of PrP’s structure in brain disease versus that of recombinant PrP, highlighting the urgency of extending our knowledge of the structure of the amyloid filaments involved in human neurodegenerative diseases.
2022-07-18 | PXD032402 | Pride
Project description:Prion disease is caused by misfolding of the prion protein (PrP) into pathogenic self-propagating conformations, leading to rapid onset dementia and death. However, elimination of endogenous PrP can halt prion disease progression. Here, we describe CHARM, a compact, enzyme-free epigenetic editor capable of silencing transcription through programmable targeted DNA methylation. Using a histone H3 tail-Dnmt3l fusion, CHARM recruits and activates the endogenous DNA methyltransferases, thereby reducing transgene size and bystander effects. When delivered to the mouse brain by an adeno-associated viral (AAV) vector, PRNP-targeted CHARM ablates PrP expression across the brain. We temporally limit editor expression by implementing a kinetically-tuned self-silencing approach. CHARM represents a broadly applicable strategy to programmably prevent expression of pathogenic proteins, including those implicated in other neurodegenerative diseases.
2024-05-03 | GSE255987 | GEO
Project description:We constructed a searchable genome-wide atlas of mRNA abundance, splicing and editing alterations during the course of disease in prion-inoculated mice.
2020-06-12 | GSE144738 | GEO