g(m1)-ganglioside and Tay-Sachs-Disease

Topics: Adolescent; beta-Galactosidase; Brain Diseases, Metabolic; Child; Child, Preschool; Clinical Enzyme Tests; Female; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosidoses; Humans; Infant; Infant, Newborn; Isoenzymes; Mass Screening; Metabolism, Inborn Errors; Models, Genetic; Phenotype; Pregnancy; Prenatal Diagnosis; Sandhoff Disease; Tay-Sachs Disease

Tay-Sachs disease (TSD), a deficiency of b-hexosaminidase A (Hex A), is a rare but debilitating hereditary metabolic disorder. Symptoms include extensive neurodegeneration and often result in death in infancy. We report an

Topics: beta-N-Acetylhexosaminidases; Computer Simulation; G(M1) Ganglioside; Hexosaminidase A; Mutation; Tay-Sachs Disease

Gangliosides (GGs) are considered as diagnostic biomarkers and therapeutic targets and agents. The goal of this study was to develop a tandem mass spectrometry (MS/MS) method for the simultaneous measurement of both GM1 and GM2 gangliosides in human cerebrospinal fluid (CSF) samples in order to be able to determine their concentrations in patients with Tay-Sachs and Sandhoff disease and assess whether drugs or transplantation affect their concentrations.. An API-4000 tandem mass spectrometer equipped with TurboIonSpray source and Shimadzu HPLC system was employed to perform the analysis using isotope dilution with deuterium labeled internal standards. To a 1.5 mL conical plastic Eppendorf centrifuge tube, 40 microL of human CSF sample was added and mixed with 400 microL of internal standard solution for deproteinization. After centrifugation, 100 microL of supernatant was injected onto a C-18 column. After a 2.5 min wash, the switching valve was activated and the analytes were eluted from the column with a water/methanol gradient into the MS/MS system. Quantification by multiple reaction-monitoring (MRM) analysis was performed in the negative mode.. The within-day coefficients of variation were <3% for GM1 and <2% for GM2 and the between-day coefficients of variation were <5% for both GM1 and GM2 at all concentrations tested. Accuracy ranged between 98% and 102% for both analytes. Good linearity was also obtained within the concentration range of 10-200 ng/mL (6.5-129.3 nmol/L) for GM1 and 5-100 ng/mL (3.6-72.3 nmol/L) for GM2 (r> or =0.995).. A new simple, accurate, and fast isotope dilution tandem mass spectrometry method was developed for the simultaneous quantification of GM1 and GM2 gangliosides in a small amount of human CSF. Concentrations were measured in "normal" CSF and in CSF from patients with Tay-Sachs disease.

Topics: G(M1) Ganglioside; G(M2) Ganglioside; Humans; Indicator Dilution Techniques; Molecular Structure; Reproducibility of Results; Sandhoff Disease; Sensitivity and Specificity; Tandem Mass Spectrometry; Tay-Sachs Disease

The ganglioside-activator protein is an essential cofactor for the lysosomal degradation of ganglioside GM2 (GM2) by beta-hexosaminidase A. It mediates the interaction between the water-soluble exohydrolase and its membrane-embedded glycolipid substrate at the lipid-water interphase. Mutations in the gene encoding this glycoprotein result in a fatal neurological storage disorder, the AB variant of GM2-gangliosidosis. In order to efficiently and sensitively probe the glycolipid binding and membrane activity of this cofactor, we synthesized two new fluorescent glycosphingolipid (GSL) probes, 2-NBD-GM1 and 2-NBD-GM2. Both compounds were synthesized in a convergent and multistep synthesis starting from the respective gangliosides isolated from natural sources. The added functionality of 2-aminogangliosides allowed us to introduce the chromophore into the region between the polar head group and the hydrophobic anchor of the lipid. Both fluorescent glycolipids exhibited an extremely low off-rate in model membranes and displayed very efficient resonance energy transfer to rhodamine-dioleoyl phosphoglycerol ethanolamine (rhodamine-PE) as acceptor. The binding to GM2-activator protein (GM2AP) and the degrading enzyme was shown to be unaltered compared to their natural analogues. A novel fluorescence-resonance energy transfer (FRET) assay was developed to monitor in real time the protein-mediated intervesicular transfer of these lipids from donor to acceptor liposomes. The data obtained indicate that this rapid and robust system presented here should serve as a valuable tool to probe quantitatively and comprehensively the membrane activity of GM2AP and other sphingolipid activator proteins and facilitate further structure-function studies aimed at delineating independently the lipid- and the enzyme-binding mode of these essential cofactors.

Topics: Animals; beta-N-Acetylhexosaminidases; Brain; Carbohydrate Sequence; Catalysis; Cattle; Chromatography, Thin Layer; Fluorescence Resonance Energy Transfer; Fluorescent Dyes; G(M1) Ganglioside; G(M2) Activator Protein; G(M2) Ganglioside; Gangliosides; Gangliosidoses; Glycolipids; Glycoproteins; Humans; Lipids; Models, Chemical; Molecular Sequence Data; Mutation; Spectrometry, Fluorescence; Sphingolipid Activator Proteins; Sphingolipids; Structure-Activity Relationship; Tay-Sachs Disease; Time Factors

A novel fluorescent ganglioside, sulforhodamine-GM1 was administered into cells derived from carriers and patients with different subtypes of GM2 gangliosidosis, resulting from various mutations in the gene encoding the lysosomal enzyme hexosaminidase (Hex) A. The cells used were skin fibroblasts and white blood cells, i.e. lymphocytes, monocytes and macrophages. In the severe infantile form of the GM2 gangliosidosis, Tay-Sachs disease, the sulforhodamine-GM1 was hydrolyzed within the lysosomes to the corresponding sulforhodamine-GM2 which, because of lack of Hex A activity, was not further degraded. In comparison, in the cells derived from GM2 gangliosidoses carriers, as well as pseudodeficient and adult forms of GM2 gangliosidosis, the sulforhodamine-GM2 was further processed and sequentially degraded by the lysosomal glycosidases to sulforhodamine-ceramide. The latter was converted to sulforhodamine-sphingomyelin, which was secreted into the culture medium. The fluorescence of the sulforhodamine ceramide in cell extracts and/or sulforhodamine-sphingomyelin in the culture medium was quantified and related to parallel data obtained using cells of normal individuals. This permitted distinguishing between the various GM2 gangliosidoses subtypes and relating the intracellular hydrolysis of sulforhodamine-GM1 to the genotypes of the respective GM2 gangliosidoses variants.

Topics: Cell Line; Fibroblasts; Fluorescence; G(M1) Ganglioside; Gangliosidoses; Humans; Leukocytes; Mutation; Rhodamines; Tay-Sachs Disease

GM1- and GM2-gangliosides were isolated from brain and radiolabelled. The labelled moieties were localized by hydrolysis with lysosomal enzymes, followed by thin-layer chromatography of the products. High-resolution loading tests with labelled gangliosides were developed and found to differentiate infantile and juvenile forms of GM1- and GM2-gangliosidoses as well as the identification of B, O and AB types of GM2-gangliosidosis.

Topics: Animals; Brain Chemistry; Chromatography, Thin Layer; Diagnosis, Differential; Fibroblasts; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosidoses; Gangliosidosis, GM1; Genetic Variation; Humans; Kinetics; Mice; Sandhoff Disease; Tay-Sachs Disease

GM1 gangliosidosis in the infantile form is a rapidly fatal storage disease produced by deficiency of acid beta-galactosidase. Ultrastructural studies of the eyes from two fetuses affected with GM1 gangliosidosis were performed in an effort to assess tissue-specific distribution of storage inclusions in the different ocular components derived from neuroectoderm, surface ectoderm, and mesoderm. Two major configurations of inclusions were observed: electronlucent vacuoles and pleiomorphic osmiophilic membranes. Although the latter changes mainly affected the retinal neurons, they were occasionally found in cells of epithelial and mesenchymal origin. The findings indicate that the lysosomal storage process in GM1 gangliosidosis, type 1, has a wide morphologic spectrum that is already present in the early period of fetal life.

Topics: Diagnosis, Differential; Eye; Female; Fetal Diseases; G(M1) Ganglioside; Gangliosidoses; Humans; Microscopy, Electron; Pregnancy; Pregnancy Trimester, Second; Tay-Sachs Disease

Among lipids, gangliosides can be selectively stained with Schiff's reagent if the oxidizing agent (sodium metaperiodate) is sufficiently dilute to exclude all but the readily oxidized sialic acid sugars. A borohydride-periodate-Schiff (BhPS) sequence is recommended as a reliable method, convenient to perform, for the detection of the intraneuronal lipid accumulations in the ganglioside storage disorders.

Topics: Borohydrides; Brain Chemistry; G(M1) Ganglioside; Gangliosides; Gangliosidoses; Histocytochemistry; Humans; Oxidation-Reduction; Periodic Acid-Schiff Reaction; Spinal Cord; Tay-Sachs Disease

Neurophysiological studies (EEG, ERG, VEP and BAEP) have been carried out on a total of fifty-four patients (fourty-five GM2 and nine GM1 gangliosidosis) at various stages of the disease process. In infantile GM2 gangliosidosis, the EEG was midly abnormal from an early age but by the age of one year there was a rapid and progressive deterioration. EEG changes in late onset GM2 gangliosidosis were very variable and unrelated to age or enzyme defect. In both Type 1 and Type 2 GM1 gangliosidosis there was a progressive deterioration of the EEG. Paroxysmal features were not prominent in any of the gangliosidoses, despite the occurrence of seizures. The ERG remained normal in both GM2 and GM1 patients. In the infantile GM2 patients there was progressive loss of the VEP between nine and fifteen months of age but the timing of VEP changes were more variable in all the other groups. Evidence of brainstem dysfunction was found in one of the two TSD patients tested. The combined neurophysiological features appear to be characteristic for each group of gangliosidosis and differ from other neurometabolic disorders of childhood.

Topics: Arousal; Brain; Child; Child, Preschool; Electroencephalography; Electroretinography; Evoked Potentials; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Gangliosidoses; Humans; Infant; Sandhoff Disease; Synaptic Transmission; Tay-Sachs Disease

GM1 and GM2 gangliosidoses are progressive neurodegenerative diseases which accumulate intralysosomal gangliosides--and to a lesser extent oligosaccharides--chiefly in the central and peripheral nervous system owing to deficiencies of beta-galactosidase and hexosaminidases A or/and B, respectively. This intralysosomal "storage" in neuronal pericarya and their processes, and subsequent loss of such nerve cells provide the background for clinical symptoms of the central nervous system and the retina, while involvement of the peripheral nervous system and the visceral organs largely remains free of clinical findings. The morphological involvement of the latter organs is widespread though varying, thus allowing morphological investigations of lymphocytes, skin, or rectum for morphological diagnosis and as a screening procedure.

Topics: Astrocytes; Brain; Child; Dendrites; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Gangliosidoses; Humans; Inclusion Bodies; Lysosomes; Microscopy, Electron; Nerve Degeneration; Neurons; Peripheral Nerves; Sandhoff Disease; Spinal Cord; Synaptic Membranes; Tay-Sachs Disease; Vacuoles

In order to understand the mechanism of action of the activator proteins for the enzymic hydrolysis of GM1 (GM1-activator; Li, S.-C. and Li, Y.-T. (1976) J. Biol. Chem. 251, 1159-1163; for ganglioside designations, see Svennerholm, L. (1963) J. Neurochem. 10, 613) and GM2 (GM2-activator; Li, S.-C., Hirabayashi, Y., and Li, Y.-T. (1981) J. Biol. Chem. 256, 6234-6240), we have studied the effect of chemical modifications of GM1 and GM2 on their susceptibility to the activator-assisted enzymic hydrolysis. Chemically modified GM1 and GM2 were prepared by methyl esterification (Me-GM1 or Me-GM2) and reduction (HO-GM1 or HO-GM2) of the -COO- group of the sialic acid. Me-GM1 and HO-GM1 could be hydrolyzed by human hepatic beta-galactosidase in the presence of GM1-activator at rates comparable to that of the native GM1. However, in contrast to native GM2, Me-GM2 and HO-GM2 were resistant to the hydrolysis by human hepatic beta-hexosaminidase A in the presence of GM2-activator. When GM2-activator was replaced by sodium taurodeoxycholate, the native GM2 and both modified GM2 could be hydrolyzed by beta-hexosaminidase A. These results suggest that the carboxyl function of sialic acid in GM1 is not vital for beta-galactosidase or GM1-activator to carry out the cleavage of the terminal Gal. In the case of GM2 hydrolysis, the carboxyl function of sialic acid is involved in the interaction with GM2-activator. Our results also indicate that the mode of action of GM1-activator is different from that of GM2-activator and that the action of GM2-activator is different from that of sodium taurodeoxycholate.

Topics: beta-Galactosidase; beta-N-Acetylhexosaminidases; Brain; G(M1) Ganglioside; G(M2) Ganglioside; Galactosidases; Gangliosides; Hexosaminidases; Humans; Hydrolysis; Kinetics; Liver; Sialic Acids; Tay-Sachs Disease

Topics: beta-Galactosidase; beta-N-Acetylhexosaminidases; Brain; Child; Fibroblasts; G(M1) Ganglioside; G(M2) Activator Protein; G(M2) Ganglioside; Gangliosides; Gangliosidoses; Glycoproteins; Hexosaminidases; Humans; Lysosomes; Mutation; Protein Deficiency; Proteins; Sandhoff Disease; Saposins; Sphingolipid Activator Proteins; Tay-Sachs Disease

Abnormal membranous cytoplasmic inclusions were found in the retinal ganglion cells of two fetuses with gangliosidosis. One was a documented case of incipient Tay-Sachs disease (Gm2) and the other a case of generalized gangliosidosis (Gm1). Both specimens were obtained iatrogenically in the 20th to 21st week of gestation after amniocentesis had indicated the enzyme deficiency.

Topics: Amniocentesis; Female; G(M1) Ganglioside; Gangliosides; Gangliosidoses; Gestational Age; Humans; Inclusion Bodies; Microscopy, Electron; Pregnancy; Retina; Retinal Ganglion Cells; Tay-Sachs Disease

Rectal mucosa biopsy specimens from patients with neuronal storage diseases were examined by electron microscopy. The diseases were Tay-Sachs disease, Sandhoff's disease, Niemann-Pick disease types B and C, late infantile metachromatic leukodystrophy, GM1 gangliosidosis type 1, beta-galactosidase-neuraminidase deficiency, I-cell disease, and mucopolysaccharidoses (Hunter's syndrome and Sanfilippo's syndrome type A). Unmyelinated nerve fibers, endothelial cells, fibroblasts, plasma cells, and histiocytes were seen in the specimens. Except for plasma cells, the results thus obtained for various cells were similar to those obtained from skin and conjunctival biopsy specimens, which have been already reported. There has been no report so far on ultrastructure of the plasma cell in these diseases. Storage materials, eg, dense bodies and membrane-bound vacuoles, were observed in the plasma cells in various storage diseases, with the exception of late infantile metachromatic leukodystrophy. Thus, electron microscopy of rectal mucosa is useful in making diagnoses and examining plasma cells in some neuronal storage diseases.

Topics: Adolescent; Axons; Biopsy; Brain Diseases, Metabolic; Child, Preschool; G(M1) Ganglioside; Humans; Infant; Intestinal Mucosa; Leukodystrophy, Metachromatic; Lymphocytes; Microscopy, Electron; Niemann-Pick Diseases; Plasma Cells; Rectum; Sandhoff Disease; Tay-Sachs Disease

Topics: G(M1) Ganglioside; Gangliosidoses; Humans; Mucopolysaccharidoses; Tay-Sachs Disease

Total ganglioside extracts prepared from brain tissue were concentrated either by dialysis against Carbowax or by employing Millipore filter cones. Thin-layer chromatography was then carried out using silica gel plates. After location of the various fractions quantitation was effected by direct densitometry. The methods that have been adopted are rapid and suitable for the study of brain gangliosides in post mortem and biopsy material in a clinical chemistry laboratory.

Topics: Animals; Brain; Cats; Chromatography, Thin Layer; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Gangliosidoses; Humans; Mucopolysaccharidosis III; Tay-Sachs Disease

Thermotropic behaviour of human Tay-Sachs ganglioside and of mixed bovine brain gangliosides, before and after interaction with peanut lectin, serotonin and daunomycin, was investigated. Interaction of mixed brain gangliosides with peanut lectin or serotonin causes a decrease in the enthalpy of melting, whereas interaction of this lectin with Tay-Sachs ganglioside does not influence the enthalpy of melting. Serotonin causes a small increase in the enthalpy of melting of the Tay-Sachs ganglioside.

Topics: Arachis; Brain Chemistry; Calorimetry, Differential Scanning; Daunorubicin; G(M1) Ganglioside; Gangliosides; Humans; Lectins; Plant Lectins; Serotonin; Tay-Sachs Disease

Four different glycolipid:glycosyltransferase activities involved in the biosynthesis in vitro of gangliosides and blood group-related glycosphingolipids have been tested in a simian virus 40-transformed glial cell culture derived from the cerebrum of a fetus with Tay-Sachs disease (TSD). The TSD cultured brain cells contained little activity of either UDP-Gal:GM2(beta 1-3)galactosyltransferase (GalT-3; EC 2.4.1.62), which catalyzes the formation of GM1a from GM2 (tay-Sachs) ganglioside, or GDP-Fuc:nLcOse4Cer (alpha 1-2)fucosyltransferase (FucT-2; EC 2.4.1.89), which catalyzes the formation of H1 glycolipid from nLcOse4Cer. These cells contained a potent inhibitor of the second reaction (catalyzed by a Golgi-rich membrane fraction from bovine spleen), whereas no inhibition of the first reaction (catalyzed by a membrane fraction from 14-day-old embryonic chicken brain) was observed. The activity of UDP-Gal:LcOse3Cer(beta 1-4)galactosyltransferase (GalT-4; EC 2.4.1.86) was 30- to 80-fold higher than the activity of GalT-3. The presence of CMP-AcNeu:nLcOse4Cer sialyltransferase activity and the absence of either GalT-3 or FucT-2 suggested a probable pathway for the synthesis of sialylneolactotetraosylceramide [GM1b(GlcNAc)] in addition to a specific blockage of GM1a ganglioside synthesis from GM2 in these TSD transformed cells.

Topics: ABO Blood-Group System; Brain; Fucosyltransferases; G(M1) Ganglioside; Galactosyltransferases; Gangliosides; Glycosphingolipids; Humans; Neuroglia; Sialyltransferases; Tay-Sachs Disease