Gene expression imprinting of N2a sublines upon infection with the prion strain 22L
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ABSTRACT: Cell culture models allow prion propagation studies ex vivo after contact with infectious brain homogenates. To date, among the neural cell lines, the mouse neuroblastoma-derived cell line N2a has been one of the most widely used model and has yet provided interesting insights into cell biology of prion propagation. Remarkably, persistently-infected N2a sublines have been set up and replicate prions without exhibiting any pathological changes. One further interesting feature of N2a is the possibility to establish by subcloning, sublines with a range of susceptibility to prions. Indeed, susceptible sublines propagate prions and accumulate the pathogenic isoform of the prion protein, PrPSc, at the opposite of resistant sublines. The aim of our study was to apply large-scale expression analysis using microarrays combined with quantitative real-time PCR to examine the gene expression profile in a persistently-infected N2a cell line, N2a58, infected with the mouse-adapted prion strain 22L, to seek for prion-specific gene transcription. We also questioned if we could observe identical variations of expression of these genes in three other 22L-infected N2a sublines. Finally, we examined the transcriptional state of a N2a subline considered as resistant when exposed to prions. Common pathways of gene transcription would disclose information on the molecular basis of the cell infection and help to identify potential therapeutic targets. Keywords: other
Project description:The underlying pathogenic mechanisms of prion infection are not well characterized. To study the effect of prion infection on gene expression in neuronal cell cultures, a neuroblastoma (N2a) cell clone was infected with either the mouse adapted prion strain 22L or exposed to uninfected brain homogenate as a negative control. Large scale expression analysis was performed using a cDNA microarray chip comprising about 21,000 spotted ESTs. Over hundred genes were identified that are differentially expressed in 22L-infected cells when compared to uninfected cells. Several of the identified changes in gene expression have also been reported for other neurodegenerative diseases such as Alzheimer`s disease. Keywords: cDNA arrays, prion, N2a, neuroblastoma cell line, murine A neuroblastoma (N2a) cell clone was infected with either the mouse adapted prion strain 22L or exposed to uninfected brain homogenate as a negative control. Eight replicates including four dye swap experiments have been performed for the comparison of prion infected cells versus control cells.
Project description:The neuroblastoma-derived cell line N2a is permissive to certain prion strains but resistant sublines unable to accumulate the pathological proteinase-K resistant form of the prion protein can be isolated. We compared for gene expression and phenotypes different N2a sublines that were susceptible or resistant to the 22L prion strain. Karyotypes and comparative genomic hybridization arrays revealed chromosomal imbalances but did not demonstrate a characteristic profile of genomic alterations linked to prion susceptibility. Likewise, we showed that this phenotype was not dependent on the binding of PrPres, the expression of the prion protein gene, or on its primary sequence. We completed this analysis by looking using real-time quantitative PCR at the expression of a set of genes encoding proteins linked to prion biology. None of the candidates could account by itself for the infection phenotype, nevertheless sublines had distinct transcriptional profiles. Taken together, our results do not support a role for specific genomic abnormalities and possible candidate proteins in N2a prion susceptibility. They also reveal genetic heterogeneity among the sublines and serve as a guidance for further investigation into the molecular mechanisms of prion infection.
Project description:The underlying pathogenic mechanisms of prion infection are not well characterized. To study the effect of prion infection on gene expression in neuronal cell cultures, a neuroblastoma (N2a) cell clone was infected with either the mouse adapted prion strain 22L or exposed to uninfected brain homogenate as a negative control. Large scale expression analysis was performed using a cDNA microarray chip comprising about 21,000 spotted ESTs. Over hundred genes were identified that are differentially expressed in 22L-infected cells when compared to uninfected cells. Several of the identified changes in gene expression have also been reported for other neurodegenerative diseases such as Alzheimer`s disease. Keywords: cDNA arrays, prion, N2a, neuroblastoma cell line, murine
Project description:The neuroblastoma-derived cell line N2a is permissive to certain prion strains but resistant sublines unable to accumulate the pathological proteinase-K resistant form of the prion protein can be isolated. We compared for gene expression and phenotypes different N2a sublines that were susceptible or resistant to the 22L prion strain. Karyotypes and comparative genomic hybridization arrays revealed chromosomal imbalances but did not demonstrate a characteristic profile of genomic alterations linked to prion susceptibility. Likewise, we showed that this phenotype was not dependent on the binding of PrPres, the expression of the prion protein gene, or on its primary sequence. We completed this analysis by looking using real-time quantitative PCR at the expression of a set of genes encoding proteins linked to prion biology. None of the candidates could account by itself for the infection phenotype, nevertheless sublines had distinct transcriptional profiles. Taken together, our results do not support a role for specific genomic abnormalities and possible candidate proteins in N2a prion susceptibility. They also reveal genetic heterogeneity among the sublines and serve as a guidance for further investigation into the molecular mechanisms of prion infection. In a first approach, CGHa profiles were established for the parental cell line N2apcl, a sensitive (G9) and a resistant (F1) sublines, as compared to A/HeJ mouse strain normal DNA. To allow a more precise description of the differences between N2apcl and six of its derived sub-lines (58, D11, F1, G9, R4, R10), N2apcl DNA was used as reference DNA in a series of CGHa experiments, avoiding the potential copy number polymorphisms between the cell lines and A/HeJ murine DNAs.
Project description:Affymetrix genechip profiling analsysis (MOE430A and MOE430B) of murine neuroblastoma cells infected with either RML prion strain or mock brain homogenate Experiment Overall Design: Parental N2a cells were split into 6 aliquots, 3 of which were infected with RML prions and 3 of which were mock-infected with normal brain homogenate. There are three biological replicates in total for each experimental group.
Project description:Mammalian prion diseases are fatal and transmissible neurological conditions caused by the propagation of prions, self-replicating multimeric assemblies of misfolded forms of host cellular prion protein. Despite extensive studies investigating the changes in transcriptional profiles in prion diseases the mechanisms by which prion diseases induce cellular toxicity, including changes in gene expression profiles are yet to be fully characterized. Here, we took advantage of the recent developments in single-cell technologies and performed an unbiased whole-transcriptome single-nucleus transcriptomic analysis in prion disease.
Project description:Mammalian prion diseases are fatal and transmissible neurological conditions caused by the propagation of prions, self-replicating multimeric assemblies of misfolded forms of host cellular prion protein. Despite extensive studies investigating the changes in transcriptional profiles in prion diseases the mechanisms by which prion diseases induce cellular toxicity, including changes in gene expression profiles are yet to be fully characterized. Here, we took advantage of the recent developments in single-cell technologies and performed an unbiased whole-transcriptome single-nucleus transcriptomic analysis in prion disease.
Project description:Mammalian prion diseases are fatal and transmissible neurological conditions caused by the propagation of prions, self-replicating multimeric assemblies of misfolded forms of host cellular prion protein. Despite extensive studies investigating the changes in transcriptional profiles in prion diseases the mechanisms by which prion diseases induce cellular toxicity, including changes in gene expression profiles are yet to be fully characterized. Here, we took advantage of the recent developments in single-cell technologies and performed an unbiased whole-transcriptome single-nucleus transcriptomic analysis in prion disease.
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.