Analytical and preparative separation of glucosylceramide and galactosylceramide by borate-impregnated silica gel chromatography

Glycolipid analysis of different tissues and cerebrospinal fluid in type II Gaucher disease

The lipid composition or the liver, spleen, brain, cerebellum and cerebrospinal fluid of a Gaucher disease type II patient who died at the age of 5 months was examined. The glycolipid analysis demonstrated a marked increase of total amounts not only in the peripheral tissues but also in the brain cerebellum and cerebrospinal fluid, with a prevalence of glucosylceramide. A reduction in gangliosides was observed in all the analysed tissues with a relative increase of GD3 in the nervous tissue. The fatty acid composition of glucosylceramide showed a prevalence of stearic acid in the central nervous system, while in the peripheral tissues palmitic acid was prevalent. This result suggests a different origin of the glucosylceramide stored in different tissues. The generalized reduction of gangliosides and their modified distribution together with the central nervous system GD3 increment represent a new observation. These data could be useful in the effort to clarify the pathophysiological mechanism of brain damage in neuronopathic Gaucher disease.

Glycosphingolipid patterns in human promyelocytic HL-60 leukemia cells susceptible or resistant to differentiation induction by phorbol 12-myristate 13-acetate

The patterns of glycosphingolipids (GSLs) were analyzed in an HL-60 cell variant, HL-205, which is susceptible to phorbol 12-myristate 13-acetate (PMA)-induced monocyte/macrophage differentiation, and in an HL-60 cell variant, HL-525, which is resistant to such differentiation. The amounts and types of the GSLs were similar in both the HL-205 and HL-525 cells and they resemble those of granulocytes. Treatment with 3 nM PMA caused the susceptible HL-205 cells (but not the resistant cells) to acquire a new GSL pattern which resembles that of monocytes. This new pattern was characterized by increases in the level of a neutral GSL, Gb3Cer, from trace levels to 0.05 mg/10(9) cells and of an acidic GSL, GM3 ganglioside, from 0.03 to 0.33 mg/10(9) cells. The increases in the level of this ganglioside were found to be due to an increase in CMP-N-acetylneuraminic acid:lactosylceramide sialyltransferase activity. These results indicate an association between PMA-induced terminal differentiation along the monocyte/macrophage cell lineage and PMA-evoked increases in specific GSLs, GM3 in particular, which is due to a rise in the activity of its synthetic enzyme.

Glycolipids of a human glioma cell line bearing receptors for platelet-derived growth factor (PDGF)

Glycolipids of U-1242 MG were characterized because results of previous studies showed that exogenous gangliosides, especially GM3, inhibit PDGF-stimulated growth of this human glioma cell line. GM3 and GM2 are the major gangliosides; both separate as doublets with thin-layer chromatography. The major neutral glycolipid is glucocerebroside with nonhydroxy fatty acids, but paragloboside, ceramide dihexoside, globoside, and asialoGM2 (GA2) are also present. The coexistence in U-1242 MG of these gangliosides and the PDGF receptor, whose mitogenic signal is modulated by GM3 in these cells, suggests a possible functional relationship among them with respect to growth regulation.