Project description:We performed gene-expression analysis of mouse cerebellar granule cell layer as compared to that of Purkinje cells. DNA microarray analysis detected genes in cerebellar granule cell layer, 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.
Project description:We performed gene-expression analysis of mouse cerebellar granule cell layer as compared to that of Purkinje cells. DNA microarray analysis detected genes in cerebellar granule cell layer, 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: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.
2022-02-24 | PXD020124 | Pride
Project description:Gene expression of cerebellar Purkinje cells and granule cell layer
Project description:SCA1, a fatal neurodegenerative disorder, is caused by a CAG expansion encoding a polyglutamine stretch in the protein ATXN1. We used RNA-seq to profile cerebellar RNA expression in ATXN1 mice, including lines with ataxia and progressive pathology and lines having ataxia in absence of Purkinje cell progressive pathology. Weighted Gene Coexpression Network Analysis of the cerebellar RNA-seq data revealed two gene networks that significantly correlated with disease, the Magenta (342 genes) and Light Yellow (35 genes) Modules. Features of the Magenta and Light Yellow Modules indicate they reflect distinctive pathways. The Magenta Module provides a description of suppressed transcriptional programs reflecting disease progression in Purkinje cells, while the Lt Yellow Module reflects other transcriptional programs activated in response to disease in Purkinje cells as well as other cerebellar cell types. We also found that up-regulation of cholecystokinin (Cck) blocked progression of Purkinje cell pathology and that loss of Cck function in mice lacking progressive disease enabled Purkinje cell pathology to progress to cell death.