Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

beta-Glucuronidase injected i.v. into newborn mucopolysaccharidosis VII mice was cleared from the circulation in less than 1 h and taken up by tissues in a distribution corresponding to the location of the mannose 6-phosphate receptor. One h after a 3.5-mg/kg beta-glucuronidase injection, beta-glucuronidase levels were equal to or greater than normal in every organ examined with the exception of the brain, where 31% normal activity was present. Enzyme was detectable histochemically in the major sites of pathology for mucopolysaccharidosis VII including bone, brain, heart, and fixed tissue macrophages. The half-life of recombinant beta-glucuronidase activity in various organs of injected mucopolysaccharidosis VII mice was 1.5 to 4.5 d. These studies show that recombinant beta-glucuronidase administered to newborn mice reaches the sites of clinically important storage in murine mucopolysaccharidosis VII.
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PMID:Enzyme replacement with recombinant beta-glucuronidase in the newborn mucopolysaccharidosis type VII mouse. 810 4

A patient with hydrops fetalis caused by beta-glucuronidase deficiency was found to be homozygous for a C to T transition at nucleotide position 672 in his cDNA. Genomic analysis showed the presence of pseudogenes for the beta-glucuronidase gene. After separation of PCR products of the gene and the pseudogenes it was shown that the patient and his father were heterozygous for the C-T 672 transition and the mother did not carry the mutation.
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PMID:Molecular analysis of a patient with hydrops fetalis caused by beta-glucuronidase deficiency, and evidence for additional pseudogenes. 811 12

Four prior mutations have been reported in three patients with beta-glucuronidase deficiency mucopolysaccharidosis (MPS VII), none of whom had the severe, infantile, hydropic form of the disease. We identified two mutations in the first reported case of nonimmune hydropic MPS VII whose cultured fibroblasts had < 1% of residual activity. The first mutation was a C-->T transition at position 1061 of the cDNA in exon 6 that gave rise to an Ala-->Val substitution in codon 354 (A354V). The second was a C-->T transition at position 1831 in exon 12 that produced an Arg-->Trp substitution in codon 611 (R611W). Transient expression in COS-7 cells revealed that both mutant enzymes were synthesized as normal-size precursors in normal quantities, but both exhibited accelerated turnover. The expressed A354V enzyme had a t0.5 (half-life) of 33 hr (wild-type t0.5 > 60 hr) and a specific activity 35% of wild-type enzyme. The R611W enzyme had a t0.5 of 20 hr and no detectable catalytic activity. The t0.5 of enzyme produced on cotransfection with A354V and R611W was nearly identical to that of A354V alone. Mutant enzyme expressed in transfected murine MPS VII cells gave similar residual activities relative to the wild-type enzyme. In COS cells, the A354V monomers formed mixed tetramers with coexpressed rat monomers, but the product of R611W did not. The higher than expected activity, both in COS cells and in murine MPS VII cells expressing A354V, provides further evidence that overexpression can partially correct some beta-glucuronidase mutations, apparently by driving the folding reaction of monomers or the assembly into tetramers by mass action.
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PMID:Mutational studies in a patient with the hydrops fetalis form of mucopolysaccharidosis type VII. 811 13

The postmortem biochemical and pathological findings in the first patient reported with mucopolysaccharidosis VII are described. Clinical, radiographic, and biochemical features of this 19-yr-old black man were initially reported in 1973 when, at age 2 1/2 yr his enzymatic defect, deficiency of beta-glucuronidase, was identified. The autopsy findings are now described with biochemical data further characterizing the enzyme deficiency and resultant glycosaminoglycan accumulation. He had dysostosis multiplex and extensive cardiovascular lesions including arterial stenosis, and marked fibrous thickening of the atrioventricular and aortic valves. Microscopic evidence of lysosomal storage was found in bone, cartilage, arteries and cardiac valves, liver, spleen, lymph nodes, eyes, adrenal, pituitary, and the central nervous system. In the brain, storage was localized to specific regions, primarily intraneuronal, and appeared ultrastructurally as delicate whorled filamentous accumulations in lysosomes. Similar filamentous storage also occurred in medial cells of the aorta. Multiple postmortem tissues contained only trace amounts of beta-glucuronidase and elevated glycosaminoglycans, predominantly chondroitin 4- and 6-sulfate.
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PMID:Mucopolysaccharidosis VII: postmortem biochemical and pathological findings in a young adult with beta-glucuronidase deficiency. 815 43

Genetic defects of lysosomal hydrolases result in severe storage diseases and treatments based on enzyme replacement have been proposed. In mice lacking beta-glucuronidase, which develop a disease homologous to human mucopolysaccharidosis type VII (MPS VII, sly syndrome), we have used autologous implants of genetically-modified cells for the continuous in vivo production of the enzyme. A retroviral vector containing the human beta-glucuronidase cDNA under the control of the mouse phosphoglycerate kinase promoter was used to infect primary skin fibroblasts, bone marrow cells, or myoblasts from mutant MPS VII animals. The fibroblasts were embedded into collagen lattices and reimplanted into the peritoneal cavity of recipient MPS VII mice. All animals, when analysed 10 to 155 days later, expressed beta-glucuronidase from the vascularised neo-organs that developed after implantation, and accumulated the enzyme in their tissues. A complete disappearance of the lysosomal storage lesions was observed in their liver and spleen. This procedure has been scaled up for long term lysosomal enzyme delivery in dogs. The bone marrow cells were used for partial hematopoietic reconstruction of sublethally irradiated MPS VII mice. Five months after gene transfer, animals in which under 5% of genetically-modified hematopoietic cells were detected in the spleen showed a drastic reduction of lysosomal storage lesions in the liver and spleen. Genetically-modified myoblasts were transplanted into injured muscles, where they participated in the regeneration of a significant proportion of muscle fibers. Enzyme secretion and liver uptake were observed for at least one month.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Gene therapy for lysosomal disorders. 817 9

We have explored the use of myoblasts obtained from adult animals as a target for somatic gene therapy. Myoblasts from an adult beta-glucuronidase deficient (MPS VII) mouse were isolated and infected with a retroviral vector carrying the human beta-glucuronidase cDNA. Beta-glucuronidase was used as a reporter gene to follow the fate of genetically-modified myoblasts after transplantation into the tibialis anterior of MPS VII recipients. When experimental necrosis had been induced in the recipient muscle prior to cell injection, histological analysis demonstrated efficient engraftment of adult derived myoblasts following gene transfer. The reconstituted myofibres expressed the transgene for at least 10 weeks following transplantation.
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PMID:Transplantation of adult-derived myoblasts in mice following gene transfer. 818 84

Recombinant mouse beta-glucuronidase administered intravenously to newborn mice with mucopolysaccharidosis type VII (MPS VII) is rapidly cleared from the circulation and localized in many tissues. Here we determine the tissue distribution of injected enzyme and describe its effects on the histopathology in 6-wk-old MPS VII mice that received either one injection of 28,000 U recombinant beta-glucuronidase at 5 wk of age or received six injections of 28,000 U given at weekly intervals beginning at birth. These mice were compared with untreated 6-wk-old MPS VII mice. The single injection decreased lysosomal distention in the fixed tissue macrophage system. MPS VII mice that received multiple injections had 27.8, 3.5, and 3.3% of normal levels of beta-glucuronidase in liver, spleen, and kidney, respectively. Brain had detectable beta-glucuronidase, ranging from 2.0-12.1% of normal. Secondary elevations of alpha-galactosidase and beta-hexosaminidase in brain, spleen, liver, and kidney were decreased compared with untreated MPS VII mice. Although no improvement was observed in chondrocytes, glia, and some neurons, the skeleton had less clinical and pathological evidence of disease and the brain had reduced lysosomal storage in meninges and selected neuronal groups. These data show that recombinant beta-glucuronidase treatment begun in newborn MPS VII mice provides enzyme to most tissues and significantly reduces or prevents the accumulation of lysosomal storage during the first 6 wk of life. Whether therapy begun later in life can achieve this level of correction remains to be established.
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PMID:Enzyme replacement therapy for murine mucopolysaccharidosis type VII. 820 Sep 66

Genetic defects of lysosomal hydrolases result in severe storage diseases and treatments based on enzyme replacement have been proposed. In mice lacking beta-glucuronidase, which develop a disease homologous to human mucopolysaccharidosis type VII (Sly syndrome), we have used autologous implants of genetically-modified skin fibroblasts for the continuous in vivo production of the enzyme. The human beta-glucuronidase cDNA was introduced with a retroviral vector into mutant mice skin fibroblasts grown in primary culture. Fourteen mutant mice were implanted intraperitoneally with these modified cells embedded into collagen lattices. All animals expressed beta-glucuronidase from the vascularized neo-organs that developed after implantation and accumulated the enzyme in their tissues. A complete disappearance of the lysosomal storage lesions was observed in their liver and spleen.
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PMID:Correction of lysosomal storage in the liver and spleen of MPS VII mice by implantation of genetically modified skin fibroblasts. 834 42

Mice homozygous for the gusmps allele lack beta-glucuronidase activity and provide a useful model for human Mucopolysaccharidosis type VII (MPS VII), also known as Sly syndrome. Bone marrow (BM) transplantation was shown to correct the metabolic defect and to increase the life span of diseased animals. We have used this murine model in a preclinical study aimed at evaluating whether the techniques currently available for gene transfer into large mammalian and human BM cells will provide efficient enzyme replacement therapy in MPS patients. Autologous BM was transplanted into deficient mice after retrovirus-mediated transfer of the human beta-glucuronidase cDNA. Conditioning of recipients was performed by a single sublethal irradiation of 4.5 Gy, giving rise to low donor engraftment. In recipient mice analyzed until 145 days after gene transfer, the percentage of genetically modified hematopoietic cells was less than 5%. Nevertheless, beta-glucuronidase enzyme activity was detectable in various organs, including the brain, and disappearance of lysosomal storage was obvious in the liver and spleen. These results show that the autologous transplantation of genetically engineered BM cells could be beneficial in MPS patients.
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PMID:Disappearance of lysosomal storage in spleen and liver of mucopolysaccharidosis VII mice after transplantation of genetically modified bone marrow cells. 835 94

Four pregnancies at risk for mucopolysaccharidosis VII were monitored by chorionic villus sampling obtained in the first or second trimester of gestation. One fetus showed reduced beta-glucuronidase activity following simultaneous sampling of chorionic villus and amniotic fluid at 17 weeks of gestation. The pregnancy was terminated. Subsequent assay of beta-glucuronidase activity in the fetal tissues was consistent with a diagnosis of mucopolysaccharidosis VII, thus confirming that chorionic villus samples provide useful information for diagnosis of this condition.
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PMID:beta-Glucuronidase deficiency: identification of an affected fetus with simultaneous sampling of chorionic villus and amniotic fluid. 837 67


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