Project description:Astrocytes, a major cell type found throughout the central nervous system, have general roles in the modulation of synapse formation and synaptic transmission, blood-brain-barrier formation and regulation of blood flow, as well as metabolic support of other brain resident cells. To investigate the true extent of astrocyte molecular diversity across forebrain regions, we used single cell RNA sequencing and generated a database containing ~2000 astrocytes. Our analysis identifies five transcriptomically distinct astrocyte subtypes in adult mouse cortex and hippocampus. Validation of our data in situ reveals distinct spatial positioning of defined subtypes, reflecting the distribution of morphologically and physiologically distinct astrocyte populations. Our findings are evidence for specialized astrocyte subtypes between and within brain regions.
Project description:We isolated and gene expression profiled distinct astrocyte subtypes from three central nervous system regions: forebrain, hindbrain, and spinal cord, using a FACS-based protocol. Cell surface expression of Glast/Slc1a3 (G) and Acsa-2/Atp1b2 (A) was used to distinguish subpopulations of astrocytes. Furthermore, we assessed the transcriptome of cultured primary neonatal astrocytes. The local brain environment proved key in establishing different transcriptional programs in astrocyte subtypes. Functional differences between subtypes were also apparent in experimental autoimmune encephalomyelitics (EAE) mice, where these astrocyte subtypes showed distinct responses. While gene expression signatures associated with blood-brain-barrier maintenance were lost during EAE, signatures contributing to neuroinflammation were increased specifically in astrocytes in the spinal cord.
Project description:Macroglia (astrocytes and oligodendrocytes) are required for normal development and function of the central nervous system, yet many questions remain about their emergence in the brain and spinal cord. Here we used single-cell RNA sequencing (scRNAseq) to analyze over 298,000 cells and nuclei during macroglia differentiation from mouse embryonic and human induced pluripotent stem cells. We computationally identify candidate genes involved in fate specification of glia in both species, and report heterogeneous expression of astrocyte surface markers across dif- ferentiating cells. We then used our scRNAseq data to optimize a previous mouse astrocyte differentiation protocol, decreasing the overall protocol length and complexity. Finally, we used multiomic, dual single nuclei (sn)RNAseq/snA- TACseq analysis to uncover potential genomic regulatory sites mediating glial differentiation. These datasets enable future optimization of glial differentiation protocols and provide insight into human glial differentiation.