The role of neurogenetics in Gaucher disease.

Gaucher disease is the most prevalent hereditary metabolic storage disorder, and the most common genetic disease in individuals of Ashkenazic Jewish ancestry. Patients with Gaucher disease have been classified into three clinical phenotypes. Patients with type 1 disease exhibit markedly variable hepatosplenomegaly, anemia, thrombocytopenia, skeletal, and, to a lesser extent, pulmonary and kidney involvement.

Synthesis and use of novel fluorescent glycosphingolipids for estimating beta-glucosidase activity in vitro in the absence of detergents and subtyping Gaucher disease variants following administration into intact cells.

Two novel fluorescent glycolipids, LRO-glucosylceramide (LRO-GC) and LRO-trihexosylceramide (LRO-THC) were synthesized and utilized for estimating activities of the lysosomal, acid beta-glucosidase in cell extracts and intact skin fibroblasts, derived from normal individuals and patients with Gaucher disease subtypes. The uniqueness of the glycolipids is the fact that a fluorescent probe (lissamine rhodamine) is linked in a sulfonylamide linkage to the sphingosyl residue of the sphingolipid. Thus, the product of enzymatic hydrolysis, lissamine rhodamine sulfonylamido sphingosine (LRO-ceramide) cannot be further hydrolyzed and remains a metabolic end product.

An in situ study of beta-glucosidase activity in normal and Gaucher fibroblasts with fluorogenic probes.

Beta-glucosidase activity was evaluated in situ by means of fluorogenic probes in normal human fibroblasts and fibroblasts from homozygous carriers of the Gaucher trait. Probe internalization, targeting to lysosomes and post-cleavage probe retention were the primary concerns. Internalization and targeting were attempted by in situ photosensitized labilization of lysosomal membranes, lysosomotropic detergents and the use of low density lipid (LDL) or the receptor ligand apolipoprotein E (ApoE).

Enzyme therapy in Gaucher disease type 1: dosage efficacy and adverse effects in 33 patients treated for 6 to 24 months.

Gaucher disease is the most frequent lysosomal storage disease and the most prevalent genetic disease among the Ashkenazi Jews (q approximately 0.047). The disease results from inherited defects of acid beta-glucosidase and the accumulation of the substrate, glucosylceramide, in cells of monocyte/macrophage origin.

Human acid beta-glucosidase. N-glycosylation site occupancy and the effect of glycosylation on enzymatic activity.

The five potential N-glycosylation sites (sequons) of human acid beta-glucosidase were individually mutated to determine site occupancy and the effect of site occupancy on selected catalytic and stability properties of this enzyme. Each N-glycosylation consensus sequence [Asn-Xaa-(Ser/Thr)] was obliterated by individually substituting glutamine (Q) for asparagine (N). By expression of the normal and mutated cDNAs in insect (Sf9) and COS-1 cells and subsequent immunoblotting with anti-human acid beta-glucosidase antibodies, the four sequons at Asn-19, Asn-59, Asn-146, and Asn-270 were shown to be glycosylated in either source.

Phenotype/genotype correlations in Gaucher disease type I: clinical and therapeutic implications.

Gaucher disease is the most frequent lysosomal storage disease and the most prevalent genetic disease among Ashkenazi Jews. Gaucher disease type 1 is characterized by marked variability of the phenotype and by the absence of neuronopathic involvement. To test the hypothesis that this phenotypic variability was due to genetic compounds of several different mutant alleles, 161 symptomatic patients with Gaucher disease type 1 (> 90% Ashkenazi Jewish) were analyzed for clinical involvement, and their genotypes were determined.

MR imaging in adults with Gaucher disease type I: evaluation of marrow involvement and disease activity.

An investigation was conducted to determine the usefulness of magnetic resonance imaging (MRI) in the evaluation of bone marrow involvement in patients with Gaucher disease type I. T1- and T2-weighted images were obtained of the lower extremities of 29 adult patients. Patients were classified into one of three groups based on marrow signal patterns on T1- and T2-weighted images as well as change in signal intensity from T1- to T2-weighted images.

Gaucher disease: A G+1----A+1 IVS2 splice donor site mutation causing exon 2 skipping in the acid beta-glucosidase mRNA.

Gaucher disease is the most frequent lysosomal storage disease and the most prevalent Jewish genetic disease. About 30 identified missense mutations are causal to the defective activity of acid beta-glucosidase in this disease. cDNAs were characterized from a moderately affected 9-year-old Ashkenazi Jewish Gaucher disease type 1 patient whose 80-year-old, enzyme-deficient, 1226G (Asn370----Ser [N370S]) homozygous grandfather was nearly asymptomatic.

Structure and evolution of the human prosaposin chromosomal gene.

The gene for prosaposin was characterized by sequence analysis of chromosomal DNA to gain insight into the evolution of this locus that encodes four highly conserved sphingolipid activator proteins or saposins. The 13 exons ranged in size from 57 to 1200 bp, while the introns were from 91 to 3812 bp in length. The regions encoding saposins A, B, and D each had three exons, while that for saposin C had only two.

Allogenic bone marrow transplantation in severe Gaucher disease.

Gaucher disease is the most prevalent lysosomal storage disease. This autosomal recessive disease is caused by the defective activity of the enzyme acid beta-glucosidase and the resultant accumulation of glucosylceramide primarily within cells of the reticuloendothelial system. Because the primary manifestations of Gaucher disease are due to involvement of monocyte/macrophage-derived cells, this disease is thought to be an excellent candidate for curative intervention via bone marrow transplantation (BMT).

Enzyme augmentation in moderate to life-threatening Gaucher disease.

Gaucher disease type 1 (GD type 1) is the most prevalent lysosomal storage disease and has its highest frequency in the Ashkenazi Jewish population. Deficiency of the enzyme, acid beta-glucosidase, results in the deposition of glucocerebroside primarily in macrophages. The accumulation of such "Gaucher cells" leads to visceromegaly, hepatic and bone marrow dysfunction, hypersplenism, and bony disease.

High frequency of the Gaucher disease mutation at nucleotide 1226 among Ashkenazi Jews.

Reliable estimates of the frequency of Gaucher disease-producing mutations are not available. The high frequency of Gaucher disease in the Ashkenazi Jewish population is due to the occurrence of a mutation at nucleotide (nt) 1226. We have screened 593 DNA samples from normal Ashkenazi Jews, as well as 62 DNA samples from all our Ashkenazi Jewish patients with Gaucher disease, for the presence of the 1226 mutation.

Gaucher disease: heterologous expression of two alleles associated with neuronopathic phenotypes.

To investigate the molecular basis for the distinct neuronopathic phenotypes of Gaucher disease, acid beta-glucosidases expressed from mutant DNAs in Gaucher disease type 2 (acute) and type 3 (subacute) patients were characterized in fibroblasts and with the baculovirus expression system in insect cells. Expression of the mutant DNA encoding a proline-for-leucine substitution at amino acid 444 (L444P) resulted in a catalytically defective, unstable acid beta-glucosidase in either fibroblasts from L444P/L444P homozygotes or in insect cells. This mutation was found to be homoallelic in subacute neuronopathic (type 3) Gaucher disease.

Human acid beta-glucosidase. Use of inhibitory and activating monoclonal antibodies to investigate the enzyme's catalytic mechanism and saposin A and C binding sites.

Of 14 identified epitopes on human GCase (acid beta-glucosidase), monoclonal antibodies (MCABs) recognizing 3 produced inhibition and 1 resulted in activation of GCase. MCABs F1 and F2 completely, and MCAB 61 partially (approximately 70%), inhibited GCase activity. Substrates and active site-directed inhibitors (specific sphingolipid and 5-amino-5-deoxyglucose derivatives) protected the enzyme from inhibition by MCAB F1 and F2, but not that by MCAB 61.

A 27-year experience with splenectomy for Gaucher's disease.

Gaucher's disease is an inherited metabolic disorder caused by the defective activity of acid beta-glucosidase and the resultant accumulation of glucosyl ceramide-laden macrophages in the liver, bone, and spleen. Splenectomy is the preferred treatment for patients with Gaucher's disease who develop massive splenomegaly with accompanying hypersplenism and/or mechanical pressure symptoms. The charts of 48 patients with Gaucher's disease undergoing splenectomy at our institution between January 1963 and December 1989 were analyzed to determine the short- and long-term results of this procedure.

Heterogeneity of mutations in the acid beta-glucosidase gene of Gaucher disease patients.

Gaucher disease is inherited in an autosomal recessive manner and is the most prevalent lysosomal storage disease. Gaucher disease has marked phenotypic variation and molecular heterogeneity, and several simple and complex alleles of the acid beta-glucosidase gene have been identified as causal to this disease. Certain combinations of alleles have been shown to correlate well with the severity of the disease, but many Gaucher disease patients exist whose disease is not explained by any of the published mutations.

Complex alleles of the acid beta-glucosidase gene in Gaucher disease.

Gaucher disease is inherited in an autosomal recessive manner and is the most prevalent lysosomal storage disease. Gaucher disease has marked phenotypic variation and molecular heterogeneity, and seven point mutations in the acid beta-glucosidase (beta-Glc) gene have been identified. By means of sequence-specific oligonucleotides (SSO), mutation 6433C has been detected homozygously in neuronopathic type 2 (acute) and type 3 (subacute) patients, as well as in children with severe visceral involvement who are apparently free of neuronopathic disease.

Human acid beta-glucosidase: use of sphingosyl and N-alkyl-glucosylamine inhibitors to investigate the properties of the active site.

Human acid beta-glucosidase (D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.

Human acid beta-glucosidase: glycosylation is required for catalytic activity.

The role of oligosaccharide modification in human acid beta-glucosidase function was investigated. This lysosomal enzyme has five putative N-glycosylation sites, four of which are occupied. The unglycosylated human protein was stable when expressed in bacteria or in Spodoptera frugiperda cells in the presence of tunicamycin but lacked catalytic activity.

Analyses of catalytic activity and inhibitor binding of human acid beta-glucosidase by site-directed mutagenesis. Identification of residues critical to catalysis and evidence for causality of two Ashkenazi Jewish Gaucher disease type 1 mutations.

Analyses of catalytic properties and inhibitor binding were conducted to investigate the molecular basis of active site function of human acid beta-glucosidases (EC 3.2.1.

Mutagenic activity of BKV and JCV in human and other mammalian cells.

We present data suggesting that human polyomaviruses BKV and JCV, widely distributed throughout human populations, are able to induce gene mutations in cultured cells. In this study, using different infecting agents, cell lines to be infected, mutation expression periods, and selection systems, we observed mutagenic effects of varying extent with values of spontaneous mutant frequencies being increased after BKV infection up to 100-fold in BHK cells (6-thioguanine resistance) and nearly 35-fold in virus-transformed human Lesch-Nyhan cells (ouabain resistance). In experiments with BKV the viral mutagenic potential was found to be raised both in moderately uv-irradiated cells, or when wild-type virus was replaced by the variant BKV-IR isolated from a human tumor.