NBN defined medium supports the development of O4+/O1- immunopanned pro-oligodendroglia

Maintenance of immunopanned cells in culture medium in the absence of serum or pre-conditioning by other neural cell types such as astrocytes can be problematic. Here we report the novel use of a chemically defined medium, which we refer to as NBN since it contains N-2 supplement, B-27 supplement, and N-acetyl-L-cysteine, for maintaining O4+/O1- immunopanned pro-oligodendroglia. Since we had previously characterized O4+/O1- immunopanned pro-oligodendroglia in astrocyte-conditioned basal defined medium (BDM; [24]), we compared their proliferation and differentiation in NBN medium or in NBN medium containing 40% NBN medium pre-conditioned by astrocytes. At 4 DIC in NBN, 23% of O4+ cells were BrdU+ while in conditioned NBN medium, 91% of O4+ cells were BrdU+. At 7 DIC in either medium, less than 25% of O4+ cells were BrdU+. O4+/O1- immunopanned pro-oligodendroglia cultured in NBN medium developed extensive processes and membranous expansions characteristic of mature oligodendroglia. At 4 DIC in NBN medium, approximately 100% of cells were O4+, 80% were O1+, and 54% were MBP+. By contrast, at 4 DIC in conditioned NBN, 87% of cells were O4+, 12% were O1+, and 2% were MBP+. At 7 DIC, there were no differences in the percentages of cells that expressed O4, O1, or MBP in either NBN or conditioned NBN. These results indicate that NBN defined medium supports the development of O4+/O1- immunopanned pro-oligodendroglia, and promotes more rapid maturation than conditioned NBN. The ability to maintain cells of the oligodendroglial lineage immunopanned at specific developmental stages in NBN defined medium should facilitate studies designed to identify effects of growth factors or toxins on oligodendroglia.