Project description:Mouse cuprizone (CPZ ) model of experimental de- and remyelination was applied to mimic demyelination pathology of multiple sclerosis. The aim of the study was to profile whole genome expression to identify differentially expressed genes during the demyelinisation and after discontinuation of cuprizon treatment, during rapid remyelinisation in affected areas of mouse corpus callosum. Control mice were kept on a normal diet. The following groups representing de- and remyelinisation pathology in corpus callosum of CPZ-treated mice were compared: Partial demyelination: 2weeks CPZ (dem_2w); Complete demyelination: 4weeks CPZ (dem_4w); Remyelination: 4weeks CPZ + UNTREATED (rem); and UNTREATED control (C). The experiments were performed using 3-4 animals per groups.
Project description:Mouse cuprizone (CPZ ) model of experimental de- and remyelination was applied to mimic demyelination pathology of multiple sclerosis. In order to identify differentially expressed microRNAs involved in de- and remyelination, the affected areas of corpus callosum were isolated from mice exposed to CPZ and conducted an Agilent microarray analysis. To induce demyelination, CPZ was administrated for four weeks. Spontaneous remyelination occurs as mice returned to the regular diet after four weeks feeding with CPZ (DEM_4w). Remyelination was examined at two time points: acute remyelination induced by four weeks CPZ feeding followed by two days of regular diet (two days remyelination: REM_2d), and full remyelination induced by four weeks CPZ feeding followed by two weeks of regular diet (two weeks remyelination: REM_2w). Control mice (C) were kept on a normal diet. The following groups representing de- and remyelinisation pathology in corpus callosum of CPZ-treated mice were compared: Demyelination: 4weeks CPZ: DEM_4w; Acute remyelination: 4 weeks CPZ +2 days UNTREATED: REM_2d; Full remyelination: 4 weeks CPZ +2 weeks UNTREATED: REM_2w; and UNTREATED control (C). The experiments were performed using 2-4 animals per groups.
Project description:Purpose: The central nervous system (CNS) possesses intrinsic remyelination capabilities in response to demyelinating injury. However, this remyelination potential is diminished as demyelinating disease such as multiple sclerosis progresses overtime. To better understand myelin repair processes, the goal of this study was to determine temporal transcriptomic changes in cerebral white matter (corpus callosum) and gray matter (cortex and hippocampus) after acute and chronic demyelinating injury. The cuprizone mouse model of de- and remyelination was used for this investigation. Methods: Adult C57BL/6 mice were exposed to cuprizone diet (0.2%) for 3, 5 or 12 weeks followed by returning to normal diet for up to 12 weeks for recovery. Brain regions were dissected for bulk RNA-seq. Conclusion: RNA-seq analyses suggest common and distinct spatiotemporal transcriptional alterations during CNS demyelination and remyelination. Dataset for this study represents the first that covers gene expression landscapes of three brain regions over extended regenerative periods after chronic CNS demyelination.
Project description:Demyelination and dysregulated myelination in the CNS are hallmarks of many neurodegenerative diseases such as multiple sclerosis (MS) and leukodystrophies. Here, we studied GFAP+ astrocytes during de- and remyelination in the cuprizone mouse by exploiting the ribosomal tagging (RiboTag) technology. Analyses were performed 5 weeks after cuprizone feeding, at the peak of demyelination in the corpus callosum, and 0.5 and 2 weeks after cuprizone withdrawal, when remyelination and tissue repair is initiated. After 5 weeks of cuprizone feeding, reactive astrocytes showed inflammatory signatures with enhanced expression of genes that modulate leukocyte migration (Tlr2, Cd86, Parp14,Cxcl10). Furthermore, demyelination-induced reactive astrocytes expressed numerous ligands including Cx3cl1, Csf1, Il34, and Gas6 that act on homeostatic as well as activated microglia and thus potentially mediate activation and recruitment of microglia as well as enhancement of their phagocytosis. During early remyelination, region-specific astrocytes displayed reduced inflammatory response signatures as indicated by shut down of CXCL10 production. During late remyelination, the signatures of GFAP+ astrocytes shifted towards resolving inflammation by active suppression of lymphocyte activation and differentiation and support of glia cell differentiation. Astrocytes showed enhanced expression of osteopontin (SPP1) as well as of factors that are relevant for tissue remodelling (Timp1), regeneration and axonal repair. In conclusion, we detected highly dynamic astroglial transcriptomic signatures in the cuprizone model, which reflects excessive communication amongst glia cells and highlights different astrocyte functions during neurodegeneration and regeneration.
Project description:Demyelination and dysregulated myelination in the CNS are hallmarks of many neurodegenerative diseases such as multiple sclerosis (MS) and leukodystrophies. Here, we studied GFAP+ astrocytes during de- and remyelination in the cuprizone mouse by exploiting the ribosomal tagging (RiboTag) technology. Analyses were performed 5 weeks after cuprizone feeding, at the peak of demyelination in the corpus callosum, and 0.5 and 2 weeks after cuprizone withdrawal, when remyelination and tissue repair is initiated. After 5 weeks of cuprizone feeding, reactive astrocytes showed inflammatory signatures with enhanced expression of genes that modulate leukocyte migration (Tlr2, Cd86, Parp14,Cxcl10). Furthermore, demyelination-induced reactive astrocytes expressed numerous ligands including Cx3cl1, Csf1, Il34, and Gas6 that act on homeostatic as well as activated microglia and thus potentially mediate activation and recruitment of microglia as well as enhancement of their phagocytosis. During early remyelination, region-specific astrocytes displayed reduced inflammatory response signatures as indicated by shut down of CXCL10 production. During late remyelination, the signatures of GFAP+ astrocytes shifted towards resolving inflammation by active suppression of lymphocyte activation and differentiation and support of glia cell differentiation. Astrocytes showed enhanced expression of osteopontin (SPP1) as well as of factors that are relevant for tissue remodelling (Timp1), regeneration and axonal repair. In conclusion, we detected highly dynamic astroglial transcriptomic signatures in the cuprizone model, which reflects excessive communication amongst glia cells and highlights different astrocyte functions during neurodegeneration and regeneration.
Project description:Regional differences in neurons, astrocytes, oligodendrocytes, and microglia exist in the brain during health, and regional differences in the transcriptome may occur for each cell type during neurodegeneration. Multiple sclerosis (MS) is multifocal, and regional differences in the astrocyte transcriptome occur in experimental autoimmune encephalomyelitis (EAE), an MS model. MS and EAE are characterized by inflammation, demyelination, and axonal damage, with minimal remyelination. Here, RNA-sequencing analysis of MS tissues from six brain regions suggested a focus on oligodendrocyte lineage cells (OLCs) in corpus callosum. Olig1-RiboTag mice were used to determine the translatome of OLCs in vivo in corpus callosum during the remyelination phase of a chronic cuprizone model with axonal damage. Cholesterol-synthesis gene pathways dominated as the top up-regulated pathways in OLCs during remyelination. In EAE, remyelination was induced with estrogen receptor-β (ERβ) ligand treatment, and up-regulation of cholesterol-synthesis gene expression was again observed in OLCs. ERβ-ligand treatment in the cuprizone model further increased cholesterol synthesis gene expression and enhanced remyelination. Conditional KOs of ERβ in OLCs demonstrated that increased cholesterol-synthesis gene expression in OLCs was mediated by direct effects in both models. To address this direct effect, ChIP assays showed binding of ERβ to the putative estrogen-response element of a key cholesterol-synthesis gene (Fdps). As fetal OLCs are exposed in utero to high levels of estrogens in maternal blood, we discuss how remyelinating properties of estrogen treatment in adults during injury may recapitulate normal developmental myelination through targeting cholesterol homeostasis in OLCs.
Project description:NestinCreERT2:RosaYFP mice were fed with cuprizone for 4 weeks to induce brain demyelination. Corpus callosum was then dissected, dissociated and YFP+ subventricular zone-derived cells were isolated by FACS. 1931 cells were then processed for single-cell RNA-seq analysis. Single Cell RNA sequencing library were generated using the 10x Genomics Chromium Platform and sequenced on the Illumina Nextseq 500.
Project description:CX3CR1-GFP mice were fed with cuprizone for 4 weeks to induce brain demyelination. The central and lateral parts of the corpus callosum (CC) were then separately dissected, dissociated and GFP+ microglial cells were isolated by FACS. 2133 migroglial cells from medial CC and 2304 cells from lateral CC were then processed for single-cell RNA-seq analysis. Single Cell RNA sequencing library were generated using the 10x Genomics Chromium Platform and sequenced on the Illumina Nextseq 500.
Project description:Myelin abnormalities, oligodendrocyte damage, and concomitant glia activation are common in demyelinating diseases of the central nervous system (CNS). The neurotoxicant cuprizone (CPZ) has been extensively used to create a mouse model of demyelination. However, the changes of miRNA expression and effects on behavior of cuprizone treatment have not been clearly reported. We have analyzed the behavioral changes of mice given a diet containing 0.2% cuprizone for 6 weeks. To evaluate the changes of miRNA expression in CPZ-induced demyelination compared with control, we performed the Affymetrix GeneChip® miRNA 4.0 Array. We identified 1348 and 1253 differentially expressed miRNAs for control and CPZ-treated mice, respectively. Furthermore, the expression of 240 miRNAs was significantly changed in CPZ-induced mice comparing with control mice. These results suggest that the changes of miRNA expression in vivo may provide a new potential remyelination therapeutic target.
Project description:Purpose: Following 4 weeks of 0.2% cuprizone treatment, Mertk-KO mice accumulate dying cells in the corpus callosum (based on cleaved-cas3 staining). These cells are not seen in Mertk-WT animals at the same cuprizone timepoint. The goal of this study is to identify these dying cells in the Mertk-KO corpus callosum Methods: 2 biological replicates (mice) were used. Corpus callosa were dissected from Mertk-KO mice after 4 weeks of 0.2% cuprizone treatment. Tissues were dissected into single cells using Miltenyi Neural Tissue Dissociation Kit (P) and stained with Annexin V. The stained cell suspensions were then FAC sorted into Annexin V+ and Annexin V- populations. RNA from these cells were extracted using QIAGEN RNeasy kit. Results: Bulk RNA-Seq data were analyzed using an in-house pipeline consisting of GSNAP HTSeqGenie. Reads aligning uniquely to exons were counted to each gene, and size-factor normalization was used to calculating nRPKM statistic. Conclusions: Based on the differences of transcriptomic profiles of AnnexinV+ and AnnexinV- cells, we conclude that the dying AnnexinV+ cells are microglia.