Isolation of a glial‐restricted tripotential cell line from embryonic spinal cord cultures

Abstract

Neuroepithelial stem cells (NEPs), glial-restricted precursors (GRPs), and neuron-restricted precursors (NRPs) are present during early differentiation of the spinal cord and can be identified by cell surface markers. In this article, we describe the properties of GRP cells that have been immortalized using a regulatable v-myc retrovirus construct. Immortalized GRP cells can be maintained in an undifferentiated dividing state for long periods and can be induced to differentiate into two types of astrocytes and into oligodendrocytes in culture. A clonal cell line prepared from immortalized GRP cells, termed GRIP-1, was also shown to retain the properties of a glial-restricted tripotential precursor. Transplantation of green fluorescent protein (GFP)-labeled subclones of the immortalized cells into the adult CNS demonstrates that this cell line can also participate in the in vivo development of astrocytes and oligodendrocytes. Late passages of the immortalized cells undergo limited transdifferentiation into neurons as assessed by expression of multiple neuronal markers. The availability of a conditionally immortalized cell line obviates the difficulties of obtaining a large and homogeneous population of GRPs that can be used for studying the mechanism and signals for glial cell differentiation as well as their application in transplantation protocols.

Human Astrocytes Derived from Glial Restricted Progenitors Support Regeneration of the Injured Spinal Cord

“…Culture heterogeneity is dependent on the technical limitations associated with the process of isolating a pure population of GRP, 1,3,4,9,11,19,47 allowing for other cells present in the culture to secrete soluble factors that affect the properties of glial phenotypes. [48][49][50] Aside from technical limitations, culture heterogeneity also reflects the diversity and complexity of the A2B5 + progenitor populations, which include tripotential GRP and bipotential O-2A cells present in the CNS at different stages of development.…”

“…[1][2][3][4] Initial studies using GRP isolated from E13.5 rat spinal cord demonstrated that these cells can give rise to astrocytes and oligodendrocytes in vitro 3,5 and in vivo. 6,7 Further, acute transplantation of rodent GRP into SCI models demonstrated their ability not only to survive and differentiate into astrocytes and oligodendrocytes but also their capability to provide significant neuroprotection, modify the local microenvironment, alter the glial scar and deposition of inhibitory molecules, and promote axonal growth, 8 underscoring the therapeutic potential of these cells.…”

Dividing Olig2‐expressing progenitor cells derived from ES cells

“…O2A cells are characterized by the ability to differentiate into oligodendrocytes and type 2 astrocytes. Another model proposes that glial cells arise from a progenitor cell termed a glial restricted progenitor (GRP) that has a broader developmental potential than O2A cells, in that it can differentiate into oligodendrocytes and type 1 and type 2 astrocytes (Mujtaba et al, 1999;Wu et al, 2002). A unifying scheme for gliogenesis has been proposed in which GRPs are the foundation of the glial lineage and differentiate into O2A cells and oligodendrocyte precursor cells which in turn give rise to astrocytes and oligodendrocytes (Gregori et al, 2002).…”

Astrocytes in Pathogenesis of ALS Disease and Potential Translation into Clinic

“…Glial restricted progenitors (GRP) are early cell population of the CNS that can self-renew and give rise to astrocytes and oligodendrocytes [76,77]. Isolation of GRPs from human fetal tissues (i.e., 20-week-old fetal cadaveric brain tissue) [78] was described.…”