RNA Profiling of the Human and Mouse Spinal Cord Stem Cell Niches Reveals an Embryonic-like Regionalization with MSX1+ Roof-Plate-Derived Cells

Abstract

Summary: Anamniotes, rodents, and young humans maintain neural stem cells in the ependymal zone (EZ) around the central canal of the spinal cord, representing a possible endogenous source for repair in mammalian lesions. Cell diversity and genes specific for this region are ill defined. A cellular and molecular resource is provided here for the mouse and human EZ based on RNA profiling, immunostaining, and fluorescent transgenic mice. This uncovered the conserved expression of 1,200 genes including 120 transcription factors. Unexpectedly the EZ maintains an embryonic-like dorsal-ventral pattern of expression of spinal cord developmental transcription factors (ARX, FOXA2, MSX1, and PAX6). In mice, dorsal and ventral EZ cells express Vegfr3 and are derived from the embryonic roof and floor plates. The dorsal EZ expresses a high level of Bmp6 and Gdf10 genes and harbors a subpopulation of radial quiescent cells expressing MSX1 and ID4 transcription factors. : A niche of stem cells is present around the central canal of the adult spinal cord. A better description of cell diversity and genes expressed in this niche may help to use it to promote spinal cord regeneration after lesions. In this article, based on several techniques, Ghazale and colleagues provide a cellular and molecular resource for the adult human and mouse stem cell niches. Keywords: spinal cord, niche, neural stem cells, regionalization, ependyma, ependymal cells, radial glial cells, transcription factors, Msx1, roof plate, floor plate