Culture protocol and transcriptomic analysis of murine SVZ NPCs and OPCs

The mammalian adult brain contains two neural stem and precursor (NPC) niches: subventricular zone [SVZ] lining the lateral ventricles and subgranular zone [SGZ] in the hippocampus. From these SVZ NPCs represent the largest NPC pool. Notably, while SGZ NPCs typically only produce neurons and astrocytes, SVZ NPCs produce neurons, astrocytes and oligodendrocytes throughout life. Of particular importance is the generation and replacement of oligodendrocytes, the only myelinating cells of the central nervous system (CNS). SVZ NPCs contribute to myelination by regenerating oligodendrocyte precursor cell (OPC) pool and by differentiating into oligodendrocytes in the developing and demyelinated brain. The neurosphere assay has been widely adopted by the scientific community to facilitate the study of NPCs in vitro. Here, we present a streamlined protocol for culturing postnatal and adult SVZ NPCs and OPCs from primary neurosphere cells. We characterize the purity and differentiation potential as well as provide RNA-sequencing profiles of postnatal SVZ NPCs, postnatal SVZ OPCs and adult SVZ NPCs. We show that primary neurospheres cells generated from postnatal and adult SVZ differentiate into neurons, astrocytes and oligodendrocytes concurrently and at comparable levels. SVZ OPCs are generated by subjecting primary neurosphere cells to OPC growth factors fibroblast growth factor (FGF) and platelet-derived growth factor-AA (PDGF-AA). We further show SVZ OPCs can differentiate into oligodendrocytes in the absence and presence of thyroid hormone T3. Transcriptomic analysis confirmed the identities of each cell population and revealed novel immune and signalling pathways expressed in an age and cell type specific manner. Overall design: Comparative gene expression profiling analysis of RNA-seq data for primary postnatal or adult SVZ neural stem cells (neurospheres) and postnatal oligodendrocyte precursor cells generated from neurospheres. Cultures were generated from 4 independent litters of CD1 mice to achieve n=4 biological replicates, each sequenced separately for a total of 12 individual datasets (adult neural stem cells [2 months], postnatal neural stem cells [P0-2], postnatal oligodendrocyte precursor cells [P0-2])