Modulation of Schwann cell Po glycoprotein and galactocerebroside by the surface organization of axolemma

The nature of the axon signal for the induction of proliferation and differentiation of peripheral glial cells is still unknown. Besides the existence of interactions among surface molecules the cellular responses can also be regulated by physicochemical parameters of the membrane. We have previously reported that planar axolemma monolayers coated on glass cover-slips at different defined surface molecular packing affected the Schwann cell (SC) morphology and their proliferative response (Calderon et al.: J Neurosci Res 34:206-218, 1993). In this paper we report that relative to SC cultured on uncoated coverslips, the level of expression of both glycoprotein Po and galactocerebroside (GC) (as revealed by immunofluorescence) was increased 2-4 times in SC cultured on axolemma monolayers with either high or low molecular packing. However, the cellular distribution of these antigens was profoundly influenced by the molecular packing density of the axolemma monolayer. SC cultured on an axolemma monolayer at high molecular packing showed preferential expression of Po at the SC surface whereas GC was concentrated intracellularly. On the other hand, SC grown on an axolemma monolayer at low molecular density GC showed preferential expression at the cell surface whereas Po was concentrated intracellularly.