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1.
J Inherit Metab Dis ; 30(1): 68-78, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17206462

ABSTRACT

BACKGROUND: Fabry disease (OMIM 301500) is an X-linked lysosomal storage disorder with characteristic vascular, renal, cardiac and cerebral complications. Globotriaosylceramide (Gb(3)) accumulates in Fabry patients as a result of alpha-galactosidase A deficiency. The phenotypic variability is high, but the relationship between clinical symptoms in individual Fabry patients has not been uniformly documented. Also, the relation between the most prominent biochemical abnormalities, elevated Gb(3) levels in plasma and urine, and clinical symptoms is not firmly established. METHODS: Clinical and biochemical characteristics of 96 (25 deceased) Dutch Fabry patients were collected retrospectively and before the initiation of enzyme therapy. RESULTS: Clinical assessment revealed that median life expectancy was 57 years for male and 72 years for female patients. Cerebral complications, acroparaesthesias and gastrointestinal complications, but not cardiac and auditory complications, were all seen more frequently in male than female patients. Glomerular filtration rate (GFR) was highly variable in male patients, including 2 patients with GFR < 30 ml/min, but median GFR did not differ between males and females (103 and 101 ml/min, respectively). Hyperfiltration was more frequently observed in the female patient group. Microalbuminuria was present in 60% of males and 45% of females. No specific pattern of combined symptoms existed except for a relationship between left ventricular hypertrophy (LVH) and cerebral complications (males 36%, females 32%), or proteinuria (males 35%, females 31%). Gb(3) was found to be more elevated in plasma samples from male (n = 26; median 6.27 micromol/L (1.39-9.74)) than female Fabry patients (n = 37; median 2.16 (0.77-4.18)). This was also observed for urinary Gb(3): males (n = 22) median 1851 nmol/24 h (40-3724); females (n = 29) median 672 (86-2052). Plasma and urinary Gb(3) levels correlated with each other in both males (r = 0.4, p = 0.05) and females (r = 0.4, p = 0.03), but no correlation between elevated Gb(3) levels and clinical symptoms could be detected. CONCLUSION: Analysis of the characteristics of the Dutch Fabry cohort has revealed that a limited relationship between various disease manifestations exists and that individual symptoms do not correlate with elevated urinary or plasma Gb(3) levels, limiting their value as surrogate disease markers.


Subject(s)
Fabry Disease/diagnosis , Fabry Disease/genetics , Trihexosylceramides/blood , Trihexosylceramides/urine , Adolescent , Aged , Cohort Studies , Female , Glomerular Filtration Rate , Humans , Hypertrophy, Left Ventricular/diagnosis , Male , Middle Aged , Netherlands , Phenotype , Quality of Life , Retrospective Studies , Sex Factors , Surveys and Questionnaires
2.
J Inherit Metab Dis ; 29(1): 106-11, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16601876

ABSTRACT

Fabry disease is an X-linked lysosomal storage disorder caused by deficiency of the lysosomal enzyme alpha-galactosidase A. Manifestations of the disease in placental tissue have been reported only twice. We report for the first time on the biochemical, histological and genetic features of two cases: placenta A derived from a mother heterozygous for Fabry disease who gave birth to a hemizygous son, and placenta B obtained from a healthy mother who carried a heterozygous daughter. Biopsies of placentae A, B and of four healthy controls were taken directly after birth. Assessment of alpha-galactosidase A (alpha-Gal) activity was performed both in fetal leukocytes (derived from umbilical cord blood) and in the biopsy specimens. The tissue was further examined by electron microscopy, immunohistochemistry and biochemical analysis for the presence of storage material (ceramide trihexoside (CTH)). In placenta A, characteristic zebra bodies reflecting accumulated storage material were seen in all biopsies evaluated. CTH values were markedly elevated as compared to the controls and alpha-Gal activity in both fetal leukocytes and placental tissue was very low. Placenta B showed no storage material at all. CTH values were within the control range. alpha-Gal activity ranged from intermediate to near normal; enzyme activity in fetal leukocytes was significantly decreased. As placental tissue is mainly derived from fetal cells, we may conclude that, in a boy suffering from Fabry disease, extensive storage of CTH is already present at birth. As complications develop only around the age of 10 years, it may be not the CTH itself but secondary processes that cause cellular and organ damage.


Subject(s)
Fabry Disease/diagnosis , Fabry Disease/metabolism , Placenta/metabolism , Adult , Female , Heterozygote , Humans , Immunohistochemistry , Infant, Newborn , Lipids/chemistry , Male , Microscopy, Electron , Placenta/ultrastructure , alpha-Galactosidase/metabolism
3.
J Biol Chem ; 273(41): 26522-7, 1998 Oct 09.
Article in English | MEDLINE | ID: mdl-9756888

ABSTRACT

The existence of a non-lysosomal glucosylceramidase in human cells has been documented (van Weely, S., Brandsma, M., Strijland, A., Tager, J. M., and Aerts, J. M. F. G. (1993) Biochim. Biophys. Acta 1181, 55-62). Hypothetically, the activity of this enzyme, which is localized near the cell surface, may influence ceramide-mediated signaling processes. To obtain insight in the physiological importance of the non-lysosomal glucosylceramidase, the availability of specific inhibitors would be helpful. Here we report on the generation of hydrophobic deoxynojirimycin (DNM) derivatives that potently inhibit the enzyme. The inhibitors were designed on the basis of the known features of the non-lysosomal glucosylceramidase and consist of a DNM moiety, an N-alkyl spacer, and a large hydrophobic group that promotes insertion in membranes. In particular, N-(5-adamantane-1-yl-methoxy)pentyl)-DNM is a very powerful inhibitor of the non-lysosomal glucosylceramidase at nanomolar concentrations. At such concentrations, the lysosomal glucocerebrosidase and alpha-glucosidase, the glucosylceramide synthase, and the N-linked glycan-trimming alpha-glucosidases of the endoplasmic reticulum are not affected.


Subject(s)
1-Deoxynojirimycin/pharmacology , Enzyme Inhibitors/pharmacology , Glucosylceramidase/antagonists & inhibitors , 1-Deoxynojirimycin/analogs & derivatives , Cells, Cultured , Enzyme Inhibitors/chemical synthesis , Humans , Lysosomes/enzymology , Subcellular Fractions/enzymology , Substrate Specificity , Tumor Cells, Cultured
4.
J Biol Chem ; 273(40): 25680-5, 1998 Oct 02.
Article in English | MEDLINE | ID: mdl-9748235

ABSTRACT

The human chitinase, named chitotriosidase, is a member of family 18 of glycosylhydrolases. Following the cloning of the chitotriosidase cDNA (Boot, R. G., Renkema, G. H., Strijland, A., van Zonneveld, A. J., and Aerts, J. M. F. G. (1995) J. Biol. Chem. 270, 26252-26256), the gene and mRNA have been investigated. The chitotriosidase gene is assigned to chromosome 1q31-q32. The gene consists of 12 exons and spans about 20 kilobases. The nature of the common deficiency in chitotriosidase activity is reported. A 24-base pair duplication in exon 10 results in activation of a cryptic 3' splice site, generating a mRNA with an in-frame deletion of 87 nucleotides. All chitotriosidase-deficient individuals tested were homozygous for the duplication. The observed carrier frequency of about 35% indicates that the duplication is the predominant cause of chitotriosidase deficiency. The presence of the duplication in individuals from various ethnic groups suggests that this mutation is relatively old.


Subject(s)
Hexosaminidases/genetics , Amino Acid Sequence , Base Sequence , Chromosome Mapping , Chromosomes, Human, Pair 1/genetics , Cloning, Molecular , DNA Mutational Analysis , Genotype , Hexosaminidases/deficiency , Homozygote , Humans , In Situ Hybridization , Macrophages/enzymology , Molecular Sequence Data , Netherlands/ethnology , RNA, Messenger/genetics , Repetitive Sequences, Nucleic Acid/genetics , Sequence Analysis, DNA , Sequence Deletion/genetics
5.
Eur J Biochem ; 251(1-2): 504-9, 1998 Jan 15.
Article in English | MEDLINE | ID: mdl-9492324

ABSTRACT

In various mammals, enzymatically active and inactive members of family 18 glycosyl hydrolases, containing chitinases, have been identified. In man, chitotriosidase is the functional chitinolytic enzyme, whilst the homologous human cartilage 39-kDa glycoprotein (HC gp-39) does not exhibit chitinase activity and its function is unknown. This study establishes that HC gp-39 is a chitin-specific lectin. It is experimentally demonstrated that a single amino acid substitution in the catalytic centre of the 39-kDa isoform of chitotriosidase, which generates a similar sequence to that in HC gp-39, results in a loss of hydrolytic activity and creates the capacity to bind to chitin. The possible implication of the finding for chitinolytic and chitin-binding proteins that are produced in high quantities by activated macrophages are discussed.


Subject(s)
Chitin/metabolism , Glycoproteins/metabolism , Hexosaminidases/metabolism , Macrophages/metabolism , Adipokines , Amino Acid Sequence , Animals , Binding Sites , COS Cells , Cells, Cultured , Chitinase-3-Like Protein 1 , Hexosaminidases/genetics , Humans , Lectins , Macrophages/enzymology , Molecular Sequence Data , Mutagenesis, Site-Directed , Sequence Homology, Amino Acid
6.
Eur J Biochem ; 244(2): 279-85, 1997 Mar 01.
Article in English | MEDLINE | ID: mdl-9118991

ABSTRACT

Chitotriosidase, the human analogue of chitinases from non-vertebrate species, has recently been identified. The macrophage-derived enzyme is remarkably heterogeneous in molecular mass and isoelectric point. The synthesis and modification of the enzyme in cultured macrophages is reported. Chitotriosidase is synthesized as a 50-kDa protein with a pI of about 6.5 and 7.2. It is predominantly secreted, but in part processed into a 39-kDa form with a pI of 8.0 that accumulates in lysosomes. In the C-terminal extension of the 50-kDa chitotriosidase, sialic-acid containing O-linked glycans are present, causing its heterogeneous acidic isoelectric point. Chitotriosidase lacks N-linked glycans and the mechanism of routing to lysosomes proves to be distinct from that of soluble, N-glycosylated, lysosomal enzymes. It was observed that, in macrophages, alternative splicing generates a distinct chitotriosidase mRNA species, encoding a 40-kDa chitotriosidase that is C-terminally truncated. This enzyme is almost identical to the 39-kDa chitotriosidase formed from the 50-kDa precursor by proteolytic processing. It is concluded that the C-terminus present in the 50-kDa chitotriosidase, but absent in the 39-kDa isoform, was found to mediate tight binding to chitin. In the blood stream the secretory 50-kDa chitotriosidase occurs predominantly, whilst in tissues the 39-kDa form is also abundant. These findings are consistent with the data on the synthesis and processing of chitotriosidase in the cultured macrophage model.


Subject(s)
Hexosaminidases/biosynthesis , Isoenzymes/biosynthesis , Macrophages/enzymology , Animals , Cells, Cultured , Enzyme Precursors/biosynthesis , Enzyme Precursors/chemistry , Enzyme Precursors/metabolism , Gaucher Disease/enzymology , Glycosylation , Hexosaminidases/chemistry , Hexosaminidases/metabolism , Humans , Isoelectric Point , Isoenzymes/chemistry , Isoenzymes/metabolism , Lysosomes/enzymology , Macrophages/ultrastructure , Mass Spectrometry , Microscopy, Immunoelectron , Molecular Weight , Protein Processing, Post-Translational
7.
J Biol Chem ; 270(44): 26252-6, 1995 Nov 03.
Article in English | MEDLINE | ID: mdl-7592832

ABSTRACT

We have recently observed that chitotriosidase, a chitinolytic enzyme, is secreted by activated human macrophages and is markedly elevated in plasma of Gaucher disease patients (Hollak, C. E. M., van Weely, S., van Oers, M. H. J., and Aerts, J. M. F. G. (1994) J. Clin. Invest. 93, 1288-1292). Here, we report on the cloning of the corresponding cDNA. The nucleotide sequence of the cloned cDNA predicts a protein with amino acid sequences identical to those established for purified chitotriosidase. Secretion of active chitotriosidase was obtained after transient transfection of COS-1 cells with the cloned cDNA, confirming its identity as chitotriosidase cDNA. Chitotriosidase contains several regions with high homology to those present in chitinases from different species belonging to family 18 of glycosyl hydrolases. Northern blot analysis shows that expression of chitotriosidase mRNA occurs only at a late stage of differentiation of monocytes to activated macrophages in culture. Our results show that, in contrast to previous beliefs, human macrophages can synthesize a functional chitinase, a highly conserved enzyme with a strongly regulated expression. This enzyme may play a role in the degradation of chitin-containing pathogens and can be used as a marker for specific disease states.


Subject(s)
Hexosaminidases/biosynthesis , Macrophages/enzymology , Amino Acid Sequence , Animals , Base Sequence , Cell Differentiation , Cell Line , Cells, Cultured , Chlorocebus aethiops , Cloning, Molecular/methods , DNA Primers , DNA, Complementary , Female , Hexosaminidases/metabolism , Humans , Kidney , Macrophages/cytology , Molecular Sequence Data , Monocytes/cytology , Polymerase Chain Reaction , Recombinant Proteins/biosynthesis , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Transfection
8.
Biochim Biophys Acta ; 1220(1): 15-20, 1993 Dec 16.
Article in English | MEDLINE | ID: mdl-8268239

ABSTRACT

The biogenesis, assembly and import of the peroxisomal enzyme catalase was studied in human skin fibroblasts from control persons and from patients with the Zellweger syndrome. For this purpose, two monoclonal antibodies were generated which are able to discriminate between the monomeric or dimeric form and the tetrameric, enzymically active conformation of the enzyme. Metabolic labelling studies showed that catalase is assembled to the tetrameric conformation within one hour after its synthesis, while it is still in the cytosol of the cell. Subsequently, the enzyme becomes particle-bound in the control cells, a process that is retarded by addition of the catalase inhibitor 3-amino-1,2,4-triazole. However, the tetramer remains in the cytosol in cells from Zellweger patients. It is concluded that newly synthesized catalase can be assembled to a tetramer in the cytosol in human skin fibroblasts. Unfolding of this tetramer prior to import into peroxisomes is indicated.


Subject(s)
Catalase/metabolism , Fibroblasts/enzymology , Antibodies, Monoclonal , Blotting, Western , Catalase/chemistry , Cell Fractionation , Cell Line , Enzyme Activation , Fibroblasts/cytology , Humans , Precipitin Tests , Protein Conformation , Zellweger Syndrome/enzymology
9.
Biochim Biophys Acta ; 1181(1): 55-62, 1993 Mar 24.
Article in English | MEDLINE | ID: mdl-8457606

ABSTRACT

In addition to the lysosomal glucocerebrosidase, a distinct beta-glucosidase that is also active towards glucosylceramide could be demonstrated in various human tissues and cell types. Subcellular fractionation analysis revealed that the hitherto undescribed glucocerebrosidase is not located in lysosomes but in compartments with a considerably lower density. The non-lysosomal glucocerebrosidase differed in several respects from lysosomal glucocerebrosidase. The non-lysosomal isoenzyme proved to be tightly membrane-bound, whereas lysosomal glucocerebrosidase is weakly membrane-associated. The pH optimum of the non-lysosomal isoenzyme is less acidic than that of lysosomal glucocerebrosidase. Non-lysosomal glucocerebrosidase, in contrast to the lysosomal isoenzyme, was not inhibited by low concentrations of conduritol B-epoxide, was markedly inhibited by taurocholate, was not stimulated in activity by the lysosomal activator protein saposin C, and was not deficient in patients with Gaucher disease. Non-lysosomal glucocerebrosidase proved to be less sensitive to inhibition by castanospermine or deoxynojirimycin but more sensitive to inhibition by D-gluconolactone than the lysosomal glucocerebrosidase. The physiological function of this second, non-lysosomal, glucocerebrosidase is as yet unknown.


Subject(s)
Gaucher Disease/enzymology , Glucosylceramidase/metabolism , Isoenzymes/metabolism , Cells, Cultured , Glucosylceramidase/antagonists & inhibitors , Glucosylceramidase/deficiency , Humans , Hydrogen-Ion Concentration , Inositol/analogs & derivatives , Inositol/pharmacology , Isoenzymes/antagonists & inhibitors , Lysosomes/enzymology , beta-Glucosidase/metabolism
10.
Hum Genet ; 89(4): 439-44, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1618493

ABSTRACT

The genetic relationship between 10 patients with clinical manifestations of rhizomelic chondrodysplasia punctata (RCDP) was studied by complementation analysis after somatic cell fusion. Biochemically, 9 out of the 10 patients were characterized by a partial deficiency of acyl-CoA: dihydroxyacetone phosphate acyltransferase (DHAP-AT) and an impairment of plasmalogen biosynthesis, phytanate catabolism and the maturation of peroxisomal 3-oxoacyl-CoA thiolase; 3-oxoacyl-CoA thiolase was strongly reduced in the peroxisomes of these patients. Fusion of fibroblasts from these 9 patients with Zellweger fibroblasts resulted in complementation as indicated by the restoration of DHAP-AT activity, plasmalogen biosynthesis, and punctate fluorescence after staining with a monoclonal antibody to peroxisomal thiolase. No complementation was observed after fusion of different combinations of the 9 RCDP cell lines, suggesting that they belong to a single complementation group. The tenth patient was characterized biochemically by a deficiency of DHAP-AT and an impairment of plasmalogen biosynthesis. However, maturation and localization of peroxisomal thiolase were normal. Fusion of fibroblasts from this patient with fibroblasts from the other 9 patients resulted in complementation as indicated by the restoration of plasmalogen biosynthesis. We conclude that mutations in at least two different genes can lead to the clinical phenotype of RCDP.


Subject(s)
Alkyl and Aryl Transferases , Chondrodysplasia Punctata/genetics , Genetic Complementation Test , Acetyl-CoA C-Acyltransferase/metabolism , Acyltransferases/deficiency , Acyltransferases/genetics , Acyltransferases/metabolism , Cell Fusion , Cell Line , Chondrodysplasia Punctata/metabolism , Humans , Immunoblotting , Microscopy, Fluorescence , Phytanic Acid/metabolism , Plasmalogens/biosynthesis , Transferases/deficiency , Transferases/genetics , Transferases/metabolism
11.
Eur J Cell Biol ; 57(2): 165-71, 1992 Apr.
Article in English | MEDLINE | ID: mdl-1511694

ABSTRACT

Previous studies have shown that in fibroblasts from patients with the Zellweger syndrome (ZS) aberrant membrane structures are present which contain peroxisomal membrane proteins (Santos, M. J. et al., Science 239, 1536-1538 (1988)). In order to characterize these structures we have performed double labeling immunoelectron microscopy experiments using antisera directed against the 69 kDa peroxisomal integral membrane protein (PMP) and lysosomal hydrolases. The results indicate that at least 80% of the structures earlier referred to as 'peroxisomal ghosts' contain lysosomal hydrolases. In addition, we have studied the effect of culture of ZS fibroblasts in the presence of 3-methyladenine, an inhibitor of autophagy, on the intracellular distribution of the 69 kDa PMP. Immunofluorescence experiments showed that in the presence of 3-methyladenine there is an increase in fluorescent spots and a change in the distribution of the spots from mainly perinuclear to randomly distributed throughout the cytoplasm. Double labeling immunoelectron microscopy revealed that after culture in the presence of 3-methyladenine the 69 kDa PMP also accumulates mainly in compartments containing lysosomal hydrolases. In one ZS cell line we found that after culture in the presence of 3-methyladenine there was also an accumulation of structures which were as small as normal microperoxisomes. We conclude that in ZS fibroblasts the 69 kDa PMP is mainly present in lysosomal compartments, presumably degradative autophagic vacuoles. Furthermore, in ZS fibroblasts peroxisomes of apparently normal morphology may be synthesized, but they are degraded by autophagic proteolysis.


Subject(s)
Autophagy/physiology , Fibroblasts/physiology , Microbodies/physiology , Zellweger Syndrome/physiopathology , Adenine/analogs & derivatives , Adenine/pharmacology , Autophagy/drug effects , Cell Line , Fibroblasts/ultrastructure , Fluorescent Antibody Technique , Humans , Hydrolases/analysis , Leupeptins/pharmacology , Lysosomes/enzymology , Membrane Proteins/analysis , Microbodies/chemistry
12.
Biochim Biophys Acta ; 1097(1): 62-70, 1991 Jul 26.
Article in English | MEDLINE | ID: mdl-1677591

ABSTRACT

Rhizomelic Chondrodysplasia Punctata (RCDP) is an autosomal recessive disorder in which plasmalogen biosynthesis and phytanate catabolism are impaired. Peroxisomal structure and the intracellular localization of catalase, the 69 kDa peroxisomal integral membrane protein (PMP), and 3-oxoacyl-CoA thiolase were studied in cultured skin fibroblasts from control subjects and patients with RCDP. A punctate fluorescence pattern characteristic for peroxisomes was seen in control cells incubated with either anti-(catalase), anti-(69 kDa PMP) or anti-(3-oxoacyl-CoA thiolase). Incubation of mutant cells with anti-(catalase) or anti-(69 kDa PMP) resulted in the same pattern. However, when RCDP fibroblasts were incubated with a monoclonal anti-(3-oxoacyl-CoA thiolase) antibody no punctate fluorescence could be observed. Cryosections from control and RCDP cells were examined by electron microscopy using double immunogold labelling. RCDP fibroblasts contained structures indistinguishable from control peroxisomes, the membranes reacting with anti-(69 kDa PMP) and the matrix with anti-(catalase). However, the matrix of RCDP peroxisomes, unlike control peroxisomes, did not react with anti-(3-oxoacyl-CoA thiolase). We conclude that RCDP fibroblasts contain regularly shaped peroxisomes, comparable to control peroxisomes in number as well as in content of catalase and 69 kDa PMP. However, in RCDP peroxisomes the amount of 3-oxoacyl-CoA thiolase protein proved to be below the limit of detection.


Subject(s)
Acetyl-CoA C-Acetyltransferase/deficiency , Chondrodysplasia Punctata/enzymology , Fibroblasts/enzymology , Microbodies/enzymology , Animals , Cell Line , Cells, Cultured , Humans , Immunoblotting , Microbodies/ultrastructure , Microscopy, Fluorescence , Microscopy, Immunoelectron , Rats , Zellweger Syndrome
13.
FEBS Lett ; 279(1): 79-82, 1991 Feb 11.
Article in English | MEDLINE | ID: mdl-1995347

ABSTRACT

Fusion of complementary cell lines from patients with diseases of peroxisome biogenesis leads to peroxisome assembly in the heterokaryons and to uptake of cytosolic catalase by the newly assembled peroxisomes. Here we show that catalase import is inhibited by prior binding to catalase of the inhibitor 3-amino-1,2,4-triazole, which appears to retard unfolding of the protein.


Subject(s)
Amitrole/pharmacology , Catalase/antagonists & inhibitors , Microbodies/drug effects , Biological Transport , Cells, Cultured , Electrophoresis, Polyacrylamide Gel , Fluorescent Antibody Technique , Humans , Microbodies/metabolism , Protein Conformation , Zellweger Syndrome/metabolism
14.
Prog Clin Biol Res ; 321: 545-58, 1990.
Article in English | MEDLINE | ID: mdl-2183242

ABSTRACT

The peroxisomal diseases can be divided into three categories: 1) diseases in which morphologically distinguishable peroxisomes are virtually absent (Zellweger syndrome; infantile Refsum disease; Hyperpipecolic Acidaemia; neonatal Adrenoleukodystrophy); 2) diseases in which peroxisomes are present but several peroxisomal functions are impaired (rhizomelic Chondrodysplasia punctata; Zellweger-like syndrome?); and 3) diseases in which a single peroxisomal function is impaired. We have used complementation analysis after somatic cell fusion in order to investigate the genetic relationship between diseases in category 1. The activity of acyl-CoA: dihydroxyacetonephosphate acyltransferase, which is deficient in these diseases and in rhizomelic Chondrodysplasia punctata, was used as an index of complementation. The cell lines studied, all of which complemented with rhizomelic Chondrodysplasia punctata, could be divided into at least 4 and possibly 5 complementation groups. This indicates that at least 5 and possibly 6 genes are involved in the assembly of peroxisomes. One of the complementation groups is comprised of cell lines from patients with the Zellweger syndrome, infantile Refsum disease and Hyperpipecolic Acidaemia. Thus mutations in the same gene can lead to clinically distinguishable diseases. On the other hand, the Zellweger cell lines studied fall into 3 complementation groups and the infantile Refsum disease cell lines into 2 groups. Thus mutations in different genes can lead to the same clinical phenotype. Fusion of complementary cell lines lacking morphologically distinguishable peroxisomes leads to assembly of peroxisomes, which can be monitored by measuring particle-bound catalase biochemically or by immunofluorescence. In two combinations of cell lines assembly of peroxisomes was rapid and cycloheximide insensitive. Thus the components required for peroxisome assembly must be present in a stable form in the parental cell lines, at least one of which must contain peroxisomal ghost-like structures.


Subject(s)
Metabolism, Inborn Errors/genetics , Microbodies/pathology , Zellweger Syndrome/genetics , Alleles , Cell Line , Fibroblasts , Fluorescent Antibody Technique , Genetic Complementation Test , Humans , Microbodies/metabolism , Phenotype , Zellweger Syndrome/complications , Zellweger Syndrome/pathology
15.
J Clin Invest ; 81(6): 1710-5, 1988 Jun.
Article in English | MEDLINE | ID: mdl-2454948

ABSTRACT

We have used complementation analysis after somatic cell fusion to investigate the genetic relationships among various genetic diseases in humans in which there is a simultaneous impairment of several peroxisomal functions. The activity of acyl-coenzyme A:dihydroxyacetonephosphate acyltransferase, which is deficient in these diseases, was used as an index of complementation. In some of these diseases peroxisomes are deficient and catalase is present in the cytosol, so that the appearance of particle-bound catalase could be used as an index of complementation. The cell lines studied can be divided into at least five complementation groups. Group 1 is represented by a cell line from a patient with the rhizomelic form of chondrodysplasia punctata. Group 2 consists of cell lines from four patients with the Zellweger syndrome, a patient with the infantile form of Refsum disease and a patient with hyperpipecolic acidemia. Group 3 comprises one cel line from a patient with the Zellweger syndrome, group 4 one cell line from a patient with the neonatal form of adrenoleukodystrophy, and group 5 one cell line from a patient with the Zellweger syndrome. We conclude that at least five genes are required for the assembly of a functional peroxisome.


Subject(s)
Acyltransferases/deficiency , Metabolism, Inborn Errors/genetics , Microbodies/enzymology , Acyltransferases/analysis , Adrenoleukodystrophy/genetics , Catalase/analysis , Cell Fusion , Cell Line , Centrifugation, Density Gradient , Chondrodysplasia Punctata/genetics , Digitonin , Fibroblasts , Genetic Complementation Test , Humans , Refsum Disease/genetics , Syndrome
16.
Biochem Biophys Res Commun ; 152(3): 1083-9, 1988 May 16.
Article in English | MEDLINE | ID: mdl-3377768

ABSTRACT

We have recently identified four complementation groups in fibroblasts from patients deficient in peroxisomes. Here we describe a kinetic analysis of the complementation process. The kinetics of peroxisome assembly was assessed in heterokaryons of complementary cell lines by measuring the rate of incorporation of catalase, initially present in the cytosol, into particles. In two combinations of cell lines assembly was rapid and insensitive to cycloheximide. Thus the components required for peroxisome assembly must have been present in the parental cell lines, at least one of which presumably contained peroxisomal ghosts. In three other combinations of cell lines assembly of peroxisomes was slow and sensitive to cycloheximide.


Subject(s)
Microbodies/ultrastructure , Brain Diseases , Catalase/metabolism , Cell Fusion , Cell Line , Cycloheximide/pharmacology , Fibroblasts , Humans , Kidney Diseases , Liver Diseases , Microbodies/drug effects , Microbodies/enzymology , Syndrome
17.
Biochim Biophys Acta ; 964(3): 303-8, 1988 Mar 17.
Article in English | MEDLINE | ID: mdl-3349099

ABSTRACT

Labelling of cultured human skin fibroblasts from either control subjects or patients with mucolipidosis II (I-cell disease) with [32P]phosphate resulted in tight association of phosphate with immunoprecipitated glucocerebrosidase, a membrane-associated lysosomal enzyme. Endoglycosidase F digestion of the immunoprecipitated glucocerebrosidase did not release labelled phosphate, suggesting that the phosphate was not associated with the oligosaccharide moiety of this glycoprotein. Purification of the enzyme from cells labelled with [32P]phosphate and [35S]methionine by an immunoaffinity chromatography procedure, which included a washing step with detergent, resulted in complete separation of the phosphate label from the peak of glucocerebrosidase activity and methionine labelling. We conclude that oligosaccharide phosphorylation, which is essential for transport of soluble lysosomal enzymes to the lysosomes in fibroblasts, does not occur in glucocerebrosidase.


Subject(s)
Glucosidases/metabolism , Glucosylceramidase/metabolism , Lysosomes/enzymology , Phosphoproteins/metabolism , Cells, Cultured , Glycoproteins/metabolism , Humans , In Vitro Techniques , Mucolipidoses/enzymology , Oligosaccharides/metabolism , Phosphorylation , Protein Processing, Post-Translational
18.
Eur J Biochem ; 164(1): 171-9, 1987 Apr 01.
Article in English | MEDLINE | ID: mdl-3549301

ABSTRACT

The biosynthesis and maturation of glucocerebrosidase were studied in fibroblasts from patients with the neurological and non-neurological forms of Gaucher disease and in control cells. In control fibroblasts the precursor of glucocerebrosidase (62-63 kDa), observed after a short pulse with [35S]methionine, was converted during the chase period to a 66-kDa intermediate form and, finally, to the 59-kDa mature protein. In fibroblasts from patients with the non-neurological phenotype of Gaucher disease (type 1) the same biosynthetic forms were seen as in control fibroblasts. These biosynthetic forms correspond to the three-banded pattern seen in control and Gaucher type 1 fibroblast extracts analysed by the immunoblotting procedure, or after electrophoresis and fluorography of extracts of such fibroblasts cultured for 5 days with [14C]leucine. The 59-kDa protein seen in type 1 fibroblasts was unstable and disappeared after a prolonged chase; this disappearance was not observed when the cells were grown in the presence of leupeptin. In fibroblasts from patients with the neurological forms of Gaucher disease (types 2 and 3) the 62.5-kDa precursor of glucocerebrosidase was present in near-normal amounts after a short pulse, but the 59-kDa form was not detected even when cells were cultured with leupeptin. These results are in accordance with the absence of the 59-kDa band in immunoblots of types 2 and 3 fibroblast extracts. Culturing of type 1, type 2 and type 3 Gaucher fibroblasts in the presence of leupeptin led to an increase in the activity of glucocerebrosidase.


Subject(s)
Gaucher Disease/enzymology , Glucosidases/biosynthesis , Glucosylceramidase/biosynthesis , Cell Line , Cross Reactions , Fibroblasts/enzymology , Humans , Immunosorbent Techniques , Leupeptins/pharmacology , Methionine/metabolism , Molecular Weight , Mutation
19.
Biochim Biophys Acta ; 923(3): 478-82, 1987 Mar 19.
Article in English | MEDLINE | ID: mdl-3828388

ABSTRACT

We have compared the properties of catalase in cultured skin fibroblasts from patients with the cerebro-hepato-renal (Zellweger) syndrome, in which peroxisomes are deficient, with those of catalase in fibroblasts from control subjects. The enzymes from the two types of fibroblasts are indistinguishable with respect to kinetic properties, subunit size and molecular mass of the native enzyme. The turnover of the enzyme, measured by following the rate of reappearance of catalase activity in fibroblasts after irreversible inactivation of existing molecules by 3-aminotriazole treatment of the cells, was the same in Zellweger fibroblasts as in control cells. These findings indicate that normal maturation of catalase can occur in the soluble cytoplasm and provide an explanation for the occurrence of extra-peroxisomal catalase in tissues and cells.


Subject(s)
Brain Diseases/enzymology , Catalase/metabolism , Kidney Diseases/enzymology , Liver Diseases/enzymology , Microbodies/ultrastructure , Skin/enzymology , Brain Diseases/pathology , Cells, Cultured , Fibroblasts/enzymology , Fibroblasts/ultrastructure , Humans , Kidney Diseases/pathology , Liver Diseases/pathology , Skin/cytology , Skin/ultrastructure , Syndrome
20.
Proc Natl Acad Sci U S A ; 83(16): 6156-8, 1986 Aug.
Article in English | MEDLINE | ID: mdl-2426710

ABSTRACT

The biosynthesis of the peroxisomal enzymes acyl-CoA oxidase, 3-oxoacyl-CoA thiolase (acetyl-CoA acyl-transferase, EC 2.3.1.16), and catalase (EC 1.11.1.6) was studied in cultured skin fibroblasts from a control subject and from patients with Zellweger syndrome and the infantile form of Refsum disease, inherited disorders in which peroxisomes are deficient and certain peroxisomal functions are impaired. The results of continuous labeling and pulse-chase experiments indicate that in control fibroblasts, as in rat liver, acyl-CoA oxidase is synthesized as a 72-kDa percursor that is converted to two polypeptides of 52 and 20 kDa and 3-oxoacyl-CoA thiolase is synthesized as a 44-kDa precursor that is converted to the 41-kDa mature protein. In fibroblasts from the patients the precursors of the two enzymes are formed but their maturation is impaired, and they are rapidly degraded. In contrast, the biosynthesis of catalase is not impaired. We conclude that functional peroxisomes are required for the maturation and stability of acyl-CoA oxidase and 3-oxoacyl-CoA thiolase but not for catalase.


Subject(s)
Acetyl-CoA C-Acetyltransferase/biosynthesis , Acetyltransferases/biosynthesis , Catalase/biosynthesis , Diffuse Cerebral Sclerosis of Schilder/enzymology , Microbodies/enzymology , Oxidoreductases/biosynthesis , Refsum Disease/enzymology , Abnormalities, Multiple/enzymology , Acyl-CoA Oxidase , Cell Line , Fibroblasts/enzymology , Humans , Infant , Leucine/metabolism , Methionine/metabolism , Oxidation-Reduction , Reference Values , Syndrome
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