Project description:During the course of multiple sclerosis (MS), inflammatory insults drive neuro-axonal loss and disability progression. However, pathways that guide neurons toward survival or death during central nervous system (CNS) inflammation are largely unexplored. Here we show that somatic deposition of the presynaptic protein bassoon (Bsn) in inflamed neurons directly contributes to neurodegeneration in MS. By comparing neuron-specific RNA-seq of healthy mice to mice undergoing experimental autoimmune encephalomyelitis (EAE), the animal model of MS, we identified key components of neurodegenerative pathways, including reduced mitochondrial ATP synthesis and increased protein catabolism. These changes were accompanied by neuronal induction and deposition of the intrinsically disordered protein Bsn in both EAE and in patients with MS. Somatic Bsn also accumulated in Bsn-overexpressing Neuro-2a (N2a) cells and single cell RNA-seq revealed dose-dependent repression of energy metabolism and induction of the unfolded protein response, reminiscent of our in vivo findings. Furthermore, Bsn overexpression in N2a cells or in Drosophila melanogaster neurons led to decreased survival and shortened lifespan, respectively. Conversely, genetic disruption of Bsn in mice was neuroprotective, with reduced neuro-axonal injury and clinical disability during EAE, establishing a toxic gain-of-function of Bsn during CNS inflammation. Our study provides systemic insights into neuronal responses to inflammation and identifies protein accumulation as a generic pathomechanism uniting primary and inflammatory neurodegeneration. Moreover, it offers a new explanation and possible treatment strategy to halt disability progression in MS, irrespective of immunotherapies.
Project description:We compared the gene expression in untransfected N2A cells and in pCDNA3.1myc/his vector transfected N2A cells 1 sample each of untransfected and transfected N2A cells were analyzed
Project description:To determine whether target genes were specifically knocked down by RfxCas13d in N2a cells, we performed RNA-seq to compare the differentially expressed genes between cells transfected with targeting crRNAs and non-targeting crRNA.
Project description:To analyze the role of Fus, Ewsr1, and Taf15 in alternative RNA processing, we performed exon array analysis in N2A cells using exon arrays. N2A cells were transfected with siRNA using Lipofectamine RNAiMAX (Life Technologies) according to the manufacturer’s instructions.
Project description:To determine what effect the collateral activity of RfxCas13d has on N2acells. The plasmids encoding RfxCas13d/dRfxCas13d and crRNA were transfected into N2a cells. After 48 hours of transfection, GFP-positive cells were collected using FCAS and extracted for total RNA. Then, we analyzed the transcriptome of each group with RNA-seq and analyzed the differential genes among the groups.
Project description:Genetic investigations of X-linked intellectual disabilities have implicated the ARX (Aristaless-related homeobox) gene in a wide spectrum of disorders extending from phenotypes characterised by severe neuronal migration defects such as lissencephaly, to mild or moderate forms of mental retardation without apparent brain abnormalities but with associated features of dystonia and epilepsy. Analysis of Arx spatio-temporal localisation profile in mouse revealed expression in telencephalic structures, mainly restricted to populations of GABAergic neurons at all stages of development. Furthermore, studies of the effects of ARX loss of function in humans and animal models revealed varying defects, suggesting multiple roles of this gene during brain development. However, to date, little is known about how ARX functions as a transcription factor and the nature of its targets. To better understand its role, we combined chromatin immunoprecipitation and mRNA expression with microarray analysis and identified a total of 1006 gene promoters bound by Arx in transfected neuroblastoma (N2a) cells and in mouse embryonic brain. Some of these promoters were enriched for a sequence very similar to a motif previously identified as Arx-binding motif and approximately 24% of Arx-bound genes were found to show expression changes following Arx overexpression or knock-down. Several of the Arx target genes we identified are known to be important for a variety of functions in brain development, including axonal guidance and synaptic plasticity and some of them suggest new functions for Arx. Overall, these results identified multiple new candidate targets for Arx and should help to better understand the pathophysiological mechanisms of intellectual disability and epilepsy associated with ARX mutations. N2a cells were transfected with either Arx or the corresponding empty vector. Eight different independent experiments were performed. The 16 samples were randomly distributes on the 2 expression microarrays.
Project description:APP misexpression plays a crucial role in triggering a complex pathological cascade, leading to Alzheimer’s disease (AD). The aim of this study is for determine the influence of APP ectopic expression on the miRNA profiles of neuronal exosomes. In study, miRNA sequencing was done using the exosomes derived from N2A (control) and APP-N2A (N2A with APP overexpression).
Project description:To identify high-confidence NMD targets in mouse N2A neuroblastoma cells, we used our established transcriptome-wide RNA sequencing (RNA-seq) methodologies. Through parallel analyses of RNA-seq upon UPF1-knockdown (KD) and RNA immunoprecipitation (RIP-seq) footprinting of p-UPF1-bound RNAs, we identified 1027 high-confidence neuronal NMD targets.