Oligodendrocyte-substratum adhesion activates the synthesis of specific lipid species involved in cell signaling

J Neurosci Res. 1992 May;32(1):69-78. doi: 10.1002/jnr.490320109.

Abstract

Ovine oligodendrocytes (OLGs) undergo biochemical and morphological changes following attachment to polylysine. Autoradiographs of two-dimensional thin-layer chromatograms of [14C]Gal-labeled OLG cultures revealed that attachment of OLGs to a polylysine substratum and their subsequent morphological differentiation is accompanied by an increased synthesis of multiple forms of galactosylceramide, sulfogalactosylceramide, and both sulfogalactosyl- and galactosyl-diglycerides, together with an array of complex sialoglycosphingolipids, predominantly GM2 ganglioside. As previously reported, overall lipid synthesis measured by [14C]acetate incorporation into glycerophosphatides, sphingomyelin, and neutral lipids also increased dramatically for up to 60 days (last time point examined) following OLG-substratum adhesion, reflecting membrane growth. Attachment was associated with a rapid augmentation in the synthesis of ethanolamine plasmalogen from 12 to 27% within 24 hr to reach a 35% plateau at 30 days and remain constant thereafter. In contrast, the plasmalogen content of phosphatidylcholine remained constant at 3-5%. This rapid increase in lipid synthesis (especially in the ethanolamine plasmalogen content following attachment) closely paralleled increased diacylglycerol (DAG) production and protein kinase C-dependent phosphorylation of both myelin basic protein and 2',3'-cyclic nucleotide phosphohydrolase. Labeling studies indicated that the major source of [3H]arachidonate-labeled DAG following attachment was from phosphatidylinositol turnover (and to a lesser extent phosphatidylcholine) rather than polyphosphoinositides or plasmalogens. Enhanced lipid synthesis is not only required for the production of membranes in these myelin-producing cells but is also a source of second messengers required in the posttranslational modification of key myelin and cellular proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Arachidonic Acid / metabolism
  • Cell Adhesion / physiology
  • Diglycerides / biosynthesis
  • Glycosphingolipids / biosynthesis
  • Lipid Metabolism*
  • Oligodendroglia / metabolism
  • Oligodendroglia / physiology*
  • Phospholipids / metabolism
  • Phosphotransferases / metabolism
  • Signal Transduction*

Substances

  • Diglycerides
  • Glycosphingolipids
  • Phospholipids
  • Arachidonic Acid
  • Phosphotransferases