Project description:In this study, we performed single-cell RNA sequencing of E16.5 and E18.5 mouse cerebella to analyze diversity in in Purkinje cells during development.
Project description:The signalling protein PKCγ is a major regulator of Purkinje cell development and synaptic function. We have shown previously that increased PKCγ activity impairs dendritic development of cerebellar Purkinje cells. Mutations in the protein kinase Cγ gene (PRKCG) cause spinocerebellar ataxia type 14 (SCA14). In a transgenic mouse model of SCA14 expressing the human S361G mutation, Purkinje cell dendritic development is impaired in cerebellar slice cultures similar to pharmacological activation of PKC. The mechanisms of PKCγ-driven inhibition of dendritic growth are still unclear. Using immunoprecipitation-coupled mass spectrometry analysis we have identified Collapsin Response Mediator Protein 2 (CRMP2) as a protein interacting with constitutive active PKCγ(S361G) and confirmed the interaction with the Duolink™ proximity ligation assay. We show that in cerebellar slice cultures from PKCγ(S361G)- mice, phosphorylation of CRMP2 at the known PKC target site Thr555 is increased in Purkinje cells confirming phosphorylation of CRMP2 by PKCγ. miRNA-mediated CRMP2 knockdown decreased Purkinje cell dendritic outgrowth in dissociated cerebellar cultures as did the transfection of CRMP2 mutants with a modified Thr555 site. In contrast, dendritic development was normal after wildtype CRMP2 overexpression. In a novel knock-in mouse expressing only the phospho-defective T555A-mutant CRMP2, Purkinje cell dendritic development was reduced in dissociated cultures. This reduction could be rescued by transfecting wildtype CRMP2 but only partially by the phospho-mimetic T555D-mutant. Our findings establish CRMP2 as an important target of PKCγ phosphorylation in Purkinje cells mediating its control of dendritic development. Dynamic regulation of CRMP2 phosphorylation via PKCγ is required for its correct function.
Project description:We analyzed Purkinje cell transcriptome dynamics in the developing mouse cerebellum during the first three postnatal weeks, a key developmental period equivalent to the third trimester in human cerebellar development. Our study represents the first detailed analysis of developmental Purkinje cell transcriptomes and provides a valuable dataset for gene network analyses and biological questions on genes implicated in cerebellar and Purkinje cell development.
Project description:Human cerebellar development is precisely orchestrated by molecular regulatory networks. Here, we combined single-cell transcriptomics, spatial transcriptomics and chromatin accessibility states to systematically depict an integrative temporal-spatial landscape of human fetal cerebellar development. The multiomic data reveal molecular networks, providing an informative regulatory map to show how and when cell fates are determined. Spatial transcriptomics illustrated the distinct molecular signatures of the progenitors, Purkinje cells and granule cells located in different regions of the developing cerebellar cortex. We identified RORB as a new marker of developing human Purkinje cells, which was not expressed in mice. In addition, the RL progenitors highly expressed the human-specific gene ARHGAP11B , and ARHGAP11B expression led to cerebellar cortex expansion and folding in mice. We finally mapped the genes and single-nucleotide polymorphisms (SNPs) of diseases related to cerebellar dysfunction onto cell types, indicating the cellular basis and possible pathogenesis mechanisms of neuropsychiatric disorders.
Project description:Research on human cerebellar development and disease has been hampered by the need for a human cell-based system that recapitulates the human cerebellum's cellular diversity and functional features. Here, we report a human organoid model (hCerOs) capable of developing the complex cellular diversity of the fetal cerebellum, including human-specific rhombic lip progenitor populations that have never been generated in vitro prior to this study. Two months old hCerOs form distinct cytoarchitectural features, including laminar organized layering and create functional connections between inhibitory and excitatory neurons that display coordinated network activity. Long-term culture of hCerOs allows for healthy survival and maturation of Purkinje cells that display molecular and electrophysiological hallmarks of their in vivo counterparts, addressing a long-standing challenge in the field. This study therefore provides a physiologically relevant, all-human model system to elucidate the cell type specific mechanisms governing cerebellar development and disease.
Project description:Previous studies in bulk tissue suggest that there are abundant expression quantitative trait loci (eQTLs) in human brain. This sample series is of cerebellar Purkinje cells isolated using laser capture microdissection from human cases without neurological disease but of known genotypes. These data may be helpful in confirming eQTLs in bulk tissue or in mapping other gene expression traits in an enriched neuronal population. Authorized Access data: Mapping of GEO sample accessions to dbGaP subject/sample IDs is available through dbGaP Authorized Access, see http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs000249 The aim of this study was to examine gene expression in isolated purkinje cells from the human cerebellum. We obtained frozen brain tissue from the cerebellum. We stained sections with cresyl violet and separated Purkinje cells based on morphology and location within the cerebellum using laser capture microdissection. Expression analyses were then performed.
Project description:Cerebellar organoids differentiated from human induced pluripotent stem cells (iPSCs) contain key cerebellar cell types and are increasingly used to study cerebellar diseases. In this study, we demonstrate the potential of cerebellar organoids for studying features of early human cerebellar development. Forkhead box protein P2 (FOXP2) is a transcription factor associated with speech and language development that is highly expressed in the developing brain. However, little attention has been directed to the study of FOXP2 in the early developing cerebellum. Here we used CRISPR gene editing in human iPSCs to generate a fluorescent FOXP2-reporter line. By combining transcriptomic analysis of iPSC-derived cerebellar organoids with published cerebellar datasets, we describe the expression and identify potential downstream targets of FOXP2 in the early developing human cerebellum. Our results highlight expression of FOXP2 in early human Purkinje cells and cerebellar nuclei neurons, and the vulnerability of these cell populations to neurodevelopmental disorders. Our study demonstrates the power of cerebellar organoids to model early human developmental processes and disorders.
Project description:We performed gene-expression analysis of mouse Purkinje cells as a model M-bM-^@M-^\single-type neuronM-bM-^@M-^]. DNA microarray analysis detected at least 7,055 genes in Purkinje cells, most of which are classified into functional molecule categories. Our comparative analysis between Purkinje cells and the granule cell layer showed that the characteristic expression pattern in Purkinje cells was particularly represented by M-bM-^@M-^\the neural communication systemM-bM-^@M-^] components. Pukinje cells and granule cell layer of the mouse cerebellum were collected by laser microdissection for RNA extraction and hybridization on Affymetrix microarrays.
Project description:We performed gene-expression analysis of mouse Purkinje cells as a model “single-type neuron”. DNA microarray analysis detected at least 7,055 genes in Purkinje cells, most of which are classified into functional molecule categories. Our comparative analysis between Purkinje cells and the granule cell layer showed that the characteristic expression pattern in Purkinje cells was particularly represented by “the neural communication system” components.