Author response: NG2 glia are required for vessel network formation during embryonic development

Abstract

The NG2 + glia, also known as polydendrocytes or oligodendrocyte precursor cells, represent a new entity among glial cell populations in the central nervous system. However, the complete repertoire of their roles is not yet identified. The embryonic NG2 + glia originate from the Nkx2.1 + progenitors of the ventral telencephalon. Our analysis unravels that, beginning from E12.5 until E16.5, the NG2 + glia populate the entire dorsal telencephalon. Interestingly, their appearance temporally coincides with the establishment of blood vessel network in the embryonic brain. NG2 + glia are closely apposed to developing cerebral vessels by being either positioned at the sprouting tip cells or tethered along the vessel walls. Absence of NG2 + glia drastically affects the vascular development leading to severe reduction of ramifications and connections by E18.5. By revealing a novel and fundamental role for NG2 + glia, our study brings new perspectives to mechanisms underlying proper vessels network formation in embryonic brains.

Neuronal and glial regulation of CNS angiogenesis and barriergenesis

“…Astrocytes of the adult brain have been reported to express Src-suppressed C-kinase substrate (SSeCKS), which decreases expression of astrocyte-derived VEGFA and induces expression of Ang-1, a factor involved in vessel stability (Lee et al, 2003). Similarly, loss of NG2 + oligodendrocyte or astrocyte precursor cells leads to reduced vascular density in the cerebral cortex (Minocha et al, 2015), although the precise molecular mechanisms underlying this phenotype remain unclear. Our current understanding of the role of astrocyte-derived signals in regulation of BBB physiology is very limited, despite some early studies claiming that astrocytes are crucial for BBB development.…”