Differentiation-specific mRNA expression of a mouse bipotential glial cellline

We have previously reported that a bipotential glial cell line from mouse c erebrum, designated OS3, phenotypically differentiates into oligodendrocyte s and astrocytes both in vitro and in vivo. To study the potential mechanis ms of differentiation, in this study we investigated mRNA expression of cyt okines and developmentally regulated proteins in OS3 during differentiation into oligodendrocytes by semi-quantitative reverse transcription and polym erase chain reaction. In the presence of 10% calf serum OS3 cells expressed IL-1 alpha and IL-1 beta mRNA. However, when the cells were cultured in ch emically defined medium or low serum-containing medium the expression of IL -1 alpha and IL-1 beta mRNA was down-regulated. Under stimulation of phorbo l ester, expression of IL-6 and nerve growth factor mRNA was up-regulated. The capacity for differentiation of OS3 cells into oligodendrocytes in vitr o was limited and most OS3 cells ceased their differentiation at the prolig odendroblast stage. However, expression of proteolipid protein (PLP) and DM 20 mRNA was detectable and was up-regulated in accordance with the differen tiation into oligodendrocytes. As a control, primary astrocytes expressed D M20 mRNA but not PLP mRNA and the expression of DM20 mRNA was independent o f culture condition. Therefore, OS3 cells will be of use for the study of d ifferentiation of progenitor cells into type-e astrocytes or oligodendrocyt es at the molecular level. (C) 1998 Elsevier Science Ireland Ltd. All right s reserved.