Expression of sulfated gangliosides in the central nervous system

Several sulfated lipids were detected in the ganglioside fraction isolated from a cell line of oligodendrocyte progenitors that had been metabolically labeled with [35S] sulfate. Separation of the ganglioside fraction by two-dimensional TLC showed that, except for galactosylceramide-sulfate, none of the sulfate-labeled lipids comigrated with those glycosphingolipids visualized by orcinol staining, indicating that these sulfolipids were quantitatively minor components. At least eight sulfate-labeled lipid bands were susceptible to desialylation by Arthrobacter ureafaciens neuraminidase, which resulted in the formation of three new bands that retained the labeled sulfate. Six of the sulfate-labeled lipid bands containing sialic acid were also susceptible to Vibrio cholerae neuraminidase, which generated two labeled bands that appeared identical to the two major products formed after treatment with A. ureafaciens neuraminidase. In vivo labeling of lipids from 14-day-old rat brain with [35S]-sulfate demonstrated that the synthesis of sulfated lipids containing sialic acid also occurred in intact brain tissue. These results show that sulfated gangliosides are synthesized in the CNS and that oligodendrocytes are one cell type that contributes to this synthesis.