globotriaosylceramide and Gaucher-Disease

Human plasma contains low concentrations of four neutral glycosphingolipids (glucosylceramide, lactosylceramide, globotriaosylceramide, and globotetraosylceramide) and GM3 ganglioside which occur as part of the plasma lipoproteins, particularly low density lipoprotein (LDL, d 1.006-1.063 g. mL-1) and to a lesser extent with high density lipoprotein (HDL, d 1.063-1.21 g.mL-1). Plasma glucosylceramide appears to exchange freely between plasma lipoproteins and erythrocytes, and probably also between different lipoprotein fractions, in the circulation. Free exchange of other major neutral glycosphingolipids (GSLs) between lipoproteins and erythrocytes, or between lipoprotein fractions, does not normally occur. The GSL profile of each lipoprotein fraction is the same as the overall GSL composition of unfractionated plasma. In Fabry disease and Gaucher disease, GSL storage diseases, the excess glycolipid in plasma is distributed among the various lipoprotein fractions in the same relative proportions as in healthy individuals. In familial hypercholesterolemia, in which the levels of all plasma GSLs are elevated, the excess GSL is largely associated with the increased concentrations of LDL. In patients with hereditary hypolipoproteinemias, the levels of GSL in plasma are decreased less than those of other lipids. The relative excess of GSL in these patients is distributed among the remaining lipoprotein fractions. Excess GSL such as occurs in Fabry disease, does not appear to have a biologically significant effect on the physical stability of human LDL.

Topics: Adult; Animals; Cholesterol, Dietary; Erythrocytes; Fabry Disease; Female; Gaucher Disease; Globosides; Glucosylceramides; Glycosphingolipids; Humans; Lactosylceramides; Lipoproteins; Lipoproteins, LDL; Male; Trihexosylceramides

We have shown that the ABC transporter, multiple drug resistance protein 1 (MDR1, P-glycoprotein) translocates glucosyl ceramide from the cytosolic to the luminal Golgi surface for neutral, but not acidic, glycosphingolipid (GSL) synthesis. Here we show that the MDR1 inhibitor, cyclosporin A (CsA) can deplete Gaucher lymphoid cell lines of accumulated glucosyl ceramide and Fabry cell lines of globotriaosyl ceramide (Gb3), by preventing de novo synthesis. In the Fabry mouse model, Gb3 is increased in the heart, liver, spleen, brain and kidney. The lack of renal glomerular Gb3 is retained, but the number of verotoxin 1 (VT1)-staining renal tubules, and VT1 tubular targeting in vivo, is markedly increased in Fabry mice. Adult Fabry mice were treated with alpha-galactosidase (enzyme-replacement therapy, ERT) to eliminate serum Gb3 and lower Gb3 levels in some tissues. Serum Gb3 was monitored using a VT1 ELISA during a post-ERT recovery phase +/- biweekly intra peritoneal CsA. After 9 weeks, tissue Gb3 content and localization were determined using VT1/TLC overlay and histochemistry. Serum Gb3 recovered to lower levels after CsA treatment. Gb3 was undetected in wild-type liver, and the levels of Gb3 (but not gangliosides) in Fabry mouse liver were significantly depleted by CsA treatment. VT1 liver histochemistry showed Gb3 accumulated in Kupffer cells, endothelial cell subsets within the central and portal vein and within the portal triad. Hepatic venule endothelial and Kupffer cell VT1 staining was considerably reduced by in vivo CsA treatment. We conclude that MDR1 inhibition warrants consideration as a novel adjunct treatment for neutral GSL storage diseases.

Topics: alpha-Galactosidase; Animals; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line; Cyclosporine; Disease Models, Animal; Fabry Disease; Gaucher Disease; Kidney; Liver; Mice; Trihexosylceramides

The aim of this study was to diagnose lipid storage diseases in embryos at the preimplantation stage. Two parallel approaches were employed. Firstly, activities of several sphingolipid hydrolases were determined in extracts of murine embryos and also human oocytes and polyspermic embryos. Sensitive fluorescent or fluorogenic procedures provided indications that Tay-Sachs, Gaucher and Krabbe diseases might be diagnosed in one human blastomere, while for Niemann-Pick disease two might be required. Secondly, pyrene lipids were administered into murine embryos and their fluorescence was quantified by computerized imaging microscopy. As a model of Gaucher disease, the fluorescent substrate pyrene glucosylceramide was administered into murine embryos in the presence or absence of an inhibitor of the enzyme beta-glucosidase. Because of decreased degradation of the substrate in enzyme-inhibited cells, the fluorescence per blastomere was considerably greater relative to those which received no inhibitor. The results indicated that lipid storage diseases might be diagnosed in single human blastomeres at the preimplantation stage, obviating the need for pre-natal diagnosis and abortion of affected foetuses.

Topics: Animals; Blastocyst; Fluorescence; Gaucher Disease; Humans; Mice; Photosensitizing Agents; Pyrenes; Sphingolipidoses; Sphingomyelins; Trihexosylceramides; Ultraviolet Rays

The lipids accumulated in organs of patients with Gaucher's, Tay-Sachs, and Fabry's disease were identified by means of the combination of thin-layer chromatography and matrix-assisted secondary ion mass spectrometry. The total lipid extract of each lipidosis tissue was chromatographed on a TLC plate and then analyzed directly by mass spectrometry without elution of the sample from the TLC plate. The amount of material needed to obtain an adequate spectrum is in the order of a few micrograms of lipids per band for both positive and negative ion detection. By scanning the plates, mass spectral and chromatographic information can be obtained simultaneously, which was shown to be useful for the qualitative identification of the components on the plates.

Topics: Chromatography, Thin Layer; Fabry Disease; G(M2) Ganglioside; Gaucher Disease; Globosides; Glucosylceramides; Glycolipids; Humans; Mass Spectrometry; Sphingolipidoses; Tay-Sachs Disease; Trihexosylceramides