Tripotential Differentiation of Adherently Expandable Neural Stem (NS) Cells

Tamara Glaser,Oliver Brüstle,Austin Smith,Steven M Pollard,Maarten Van Lohuizen

doi:10.1371/journal.pone.0000298

Abstract

BackgroundA recent study has shown that pure neural stem cells can be derived from embryonic stem (ES) cells and primary brain tissue. In the presence of fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF), this population can be continuously expanded in adherent conditions. In analogy to continuously self-renewing ES cells, these cells were termed ‘NS’ cells (Conti et al., PLoS Biol 3: e283, 2005). While NS cells have been shown to readily generate neurons and astrocytes, their differentiation into oligodendrocytes has remained enigmatic, raising concerns as to whether they truly represent tripotential neural stem cells.Methodology/Principal FindingsHere we provide evidence that NS cells are indeed tripotent. Upon proliferation with FGF2, platelet-derived growth factor (PDGF) and forskolin, followed by differentiation in the presence of thyroid hormone (T3) and ascorbic acid NS cells efficiently generate oligodendrocytes (∼20%) alongside astrocytes (∼40%) and neurons (∼10%). Mature oligodendroglial differentiation was confirmed by transplantation data showing that NS cell-derived oligodendrocytes ensheath host axons in the brain of myelin-deficient rats.Conclusions/SignificanceIn addition to delineating NS cells as a potential donor source for myelin repair, our data strongly support the view that these adherently expandable cells represent bona fide tripotential neural stem cells.

Highlights

Neural stem cells are defined as clonogenic cells capable of selfrenewal and multipotent differentiation into the three principle cell types of the central nervous system (CNS) – neurons, astrocytes and oligodendrocytes
Neural stem cells have been frequently propagated as neurospheres, multicellular aggregates which proliferate in the presence of epidermal growth factor (EGF) and/or fibroblast growth factor 2 (FGF2) [7,25]
To promote oligodendroglial differentiation cells were cultured on polyornithine/laminin coated dishes in medium containing N2 supplement plus FGF2, platelet-derived growth factor (PDGF) and forskolin, a growth factor combination known to enhance oligodendrocyte progenitor proliferation

Summary

Background

A recent study has shown that pure neural stem cells can be derived from embryonic stem (ES) cells and primary brain tissue. In the presence of fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF), this population can be continuously expanded in adherent conditions. While NS cells have been shown to readily generate neurons and astrocytes, their differentiation into oligodendrocytes has remained enigmatic, raising concerns as to whether they truly represent tripotential neural stem cells. Upon proliferation with FGF2, platelet-derived growth factor (PDGF) and forskolin, followed by differentiation in the presence of thyroid hormone (T3) and ascorbic acid NS cells efficiently generate oligodendrocytes (,20%) alongside astrocytes (,40%) and neurons (,10%). In addition to delineating NS cells as a potential donor source for myelin repair, our data strongly support the view that these adherently expandable cells represent bona fide tripotential neural stem cells

INTRODUCTION

RESULTS AND DISCUSSION

MATERIALS AND METHODS