Identification of a Sulf2-dependant astrocyte subtype that stands out through the expression of Olig2 in the ventral spinal cord

Abstract

During spinal cord development, both spatial and temporal mechanisms operate to generate glial cell diversity. Here, we addressed the role of the Heparan Sulfate-editing enzyme Sulf2 in the control of gliogenesis in the mouse developing spinal cord and found an unanticipated function for this enzyme. Sulf2 is expressed in ventral spinal progenitors at initiation of gliogenesis, including in Olig2-expressing cells of the pMN domain known to generate most spinal cord oligodendrocyte precursor cells (OPCs). We found that Sulf2 is dispensable for OPC development but required for proper generation of an as-yet-unidentified astrocyte precursor cell (AP) subtype. These cells, like OPCs, express Olig2 while populating the spinal parenchyma at embryonic stages but also retain Olig2 expression as they differentiate into mature astrocytes. We therefore identify a spinal Olig2-expressing AP subtype that segregates early under the influence of the extracellular enzyme Sulf2.

PSmad3+/Olig2− expression defines a subpopulation of gfap-GFP+/Sox9+ neural progenitors and radial glia-like cells in mouse dentate gyrus through embryonic and postnatal development

“…Recent studies have shown that Olig2+ astrocytes are present in both embryonic and adult CNS (Ohayon et al, 2018;Tatsumi et al, 2018;Wang et al, 2021). While it has previously been shown that the majority of Olig2+ astrocytes are GFAP− in the adult CNS (Tatsumi et al, 2018;Wang et al, 2021), we were able to Olig2+/GFP+ astrocytes by using gfap-GFP mice (Figure 9).…”

“…However, the TFs expression that could discern the two distinct cell types remains unclear. Given that Olig2 is expressed not only in oligodendrocyte progenitors but also in astrocyte progenitors (Marshall et al, 2005;Zhu et al, 2012;Ohayon et al, 2018;Tatsumi et al, 2018;Wang et al, 2021), we next examined whether Olig2 is expressed in astrocytes of the developing DG. Very few Olig2+ cells were found in DG at E16 (Figures 9A1-A6).…”

Astrocyte development in the cerebral cortex: Complexity of their origin, genesis, and maturation

“…Indeed, Olig2 is a marker for more than 80% of the mature astrocytes located in the globus pallidus, olfactory bulb, midbrain, thalamus, medulla, and spinal cord (Tatsumi et al, 2018;Wang et al, 2021). In the spinal cord, Olig2 progenitors of the pMN domain give rise to motor neurons, OPCs as well as a subpopulation of Olig2+ astrocyte progenitors that retained Olig2 expression as they differentiate and mature until adulthood (Ohayon et al, 2019). Interestingly, Olig2+ and GFAP+ astrocytes occupy mutually exclusive areas in the adult brain (Tatsumi et al, 2018).…”