Association of glucocerebroside homolog biosynthesis with Schwann cell proliferation.

The biosynthesis of myelin-associated glycolipids was studied in quiescent secondary cultures of Schwann cells and in rapidly proliferating population of transfected Schwann cells (TSC) by in vitro incorporation of [3H]galactose. The TSC demonstrated a marked increase (> 10-fold) in [3H]galactose incorporation when compared to quiescent Schwann cells. The level (or amount) of [3H]galactose incorporation into lipids is dependent upon the number of TSC in culture. The majority of 3H-labeled lipids were oligohexosylceramides (GL-2, GL-3, and GL-4). Substrates that inhibit TSC proliferation, collagen type I and Matrigel, and artificial basement membrane, decrease the [3H]galactose incorporation by 25% and 80%, respectively. Our results indicate that the synthesis of glucocerebroside and its homologs is associated with Schwann cell proliferation.