Mannosylerythritol lipid increases levels of galactoceramide in and neurite outgrowth from PC12 pheochromocytoma cells

We report here that a microbial extracellular glycolipid, mannosylerythrito l lipid (MEL), induces the outgrowth of neurites from and enhances the acti vity of acetylcholinesterase (AChE) in PC12 pheochromocytoma cells. Further more, treatment of PC12 cells with MEL increased levels of galactosylcerami de (Gal beta 1-1'Cer; GalCer). Exposure of PC12 cells to exogenous GalCer c aused the dose-dependent outgrowth of neurites. By contrast, treatment of P C12 cells with nerve growth factor (NGF) did not increase the level of GalC er in the cells. The neurite-related morphological changes induced by GalCe r differend from those induced by NGF, indicating differences between the s ignal transduction pathways triggered by NGF and by GalCer.