Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Receptor-mediated endocytosis of ?-galactosidase A in human podocytes in Fabry disease.

ABSTRACT: Injury to the glomerular podocyte is a key mechanism in human glomerular disease and podocyte repair is an important therapeutic target. In Fabry disease, podocyte injury is caused by the intracellular accumulation of globotriaosylceramide. This study identifies in the human podocyte three endocytic receptors, mannose 6-phosphate/insulin-like growth II receptor, megalin, and sortilin and demonstrates their drug delivery capabilities for enzyme replacement therapy. Sortilin, a novel ?-galactosidase A binding protein, reveals a predominant intracellular expression but also surface expression in the podocyte. The present study provides the rationale for the renal effect of treatment with ?-galactosidase A and identifies potential pathways for future non-carbohydrate based drug delivery to the kidney podocyte and other potential affected organs.

SUBMITTER: Prabakaran T

PROVIDER: S-EPMC3176300 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Receptor-mediated endocytosis of α-galactosidase A in human podocytes in Fabry disease.

Prabakaran Thaneas T Nielsen Rikke R Larsen Jakob V JV Sørensen Søren S SS Feldt-Rasmussen Ulla U Saleem Moin A MA Petersen Claus M CM Verroust Pierre J PJ Christensen Erik I EI

PloS one 20110919 9

Injury to the glomerular podocyte is a key mechanism in human glomerular disease and podocyte repair is an important therapeutic target. In Fabry disease, podocyte injury is caused by the intracellular accumulation of globotriaosylceramide. This study identifies in the human podocyte three endocytic receptors, mannose 6-phosphate/insulin-like growth II receptor, megalin, and sortilin and demonstrates their drug delivery capabilities for enzyme replacement therapy. Sortilin, a novel α-galactosida ...[more]

PMID: 21949853

Similar Datasets

α-Galactosidase a Deficiency in Fabry Disease Leads to Extensive Dysregulated Cellular Signaling Pathways in Human Podocytes.

Project description:Fabry disease (FD) is caused by mutations in the α-galactosidase A (GLA) gene encoding the lysosomal AGAL enzyme. Loss of enzymatic AGAL activity and cellular accumulation of sphingolipids (mainly globotriaosylcermide) may lead to podocyturia and renal loss of function with increased cardiovascular morbidity and mortality in affected patients. To identify dysregulated cellular pathways in FD, we established a stable AGAL-deficient podocyte cell line to perform a comprehensive proteome analysis. Imbalanced protein expression and function were analyzed in additional FD cell lines including endothelial, epithelial kidney, patient-derived urinary cells and kidney biopsies. AGAL-deficient podocytes showed dysregulated proteins involved in thermogenesis, lysosomal trafficking and function, metabolic activity, cell-cell interactions and cell cycle. Proteins associated with neurological diseases were upregulated in AGAL-deficient podocytes. Rescues with inducible AGAL expression only partially normalized protein expression. A disturbed protein expression was confirmed in endothelial, epithelial and patient-specific cells, pointing toward fundamental pathway disturbances rather than to cell type-specific alterations in FD. We conclude that a loss of AGAL function results in profound changes of cellular pathways, which are ubiquitously in different cell types. Due to these profound alterations, current approved FD-specific therapies may not be sufficient to completely reverse all dysregulated pathways.

| S-EPMC8583658 | biostudies-literature

<i>Nicotiana benthamiana</i> α-galactosidase A1.1 can functionally complement human α-galactosidase A deficiency associated with Fabry disease.

Project description:α-Galactosidases (EC 3.2.1.22) are retaining glycosidases that cleave terminal α-linked galactose residues from glycoconjugate substrates. α-Galactosidases take part in the turnover of cell wall-associated galactomannans in plants and in the lysosomal degradation of glycosphingolipids in animals. Deficiency of human α-galactosidase A (α-Gal A) causes Fabry disease (FD), a heritable, X-linked lysosomal storage disorder, characterized by accumulation of globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3). Current management of FD involves enzyme-replacement therapy (ERT). An activity-based probe (ABP) covalently labeling the catalytic nucleophile of α-Gal A has been previously designed to study α-galactosidases for use in FD therapy. Here, we report that this ABP labels proteins in Nicotiana benthamiana leaf extracts, enabling the identification and biochemical characterization of an N. benthamiana α-galactosidase we name here A1.1 (gene accession ID GJZM-1660). The transiently overexpressed and purified enzyme was a monomer lacking N-glycans and was active toward 4-methylumbelliferyl-α-d-galactopyranoside substrate (Km = 0.17 mm) over a broad pH range. A1.1 structural analysis by X-ray crystallography revealed marked similarities with human α-Gal A, even including A1.1's ability to hydrolyze Gb3 and lyso-Gb3, which are not endogenous in plants. Of note, A1.1 uptake into FD fibroblasts reduced the elevated lyso-Gb3 levels in these cells, consistent with A1.1 delivery to lysosomes as revealed by confocal microscopy. The ease of production and the features of A1.1, such as stability over a broad pH range, combined with its capacity to degrade glycosphingolipid substrates, warrant further examination of its value as a potential therapeutic agent for ERT-based FD management.

| S-EPMC6028973 | biostudies-literature

Human α-Galactosidase A Mutants: Priceless Tools to Develop Novel Therapies for Fabry Disease.

Project description:Fabry disease (FD) is a lysosomal storage disease caused by mutations in the gene for the α-galactosidase A (GLA) enzyme. The absence of the enzyme or its activity results in the accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3), in different tissues, leading to a wide range of clinical manifestations. More than 1000 natural variants have been described in the GLA gene, most of them affecting proper protein folding and enzymatic activity. Currently, FD is treated by enzyme replacement therapy (ERT) or pharmacological chaperone therapy (PCT). However, as both approaches show specific drawbacks, new strategies (such as new forms of ERT, organ/cell transplant, substrate reduction therapy, or gene therapy) are under extensive study. In this review, we summarize GLA mutants described so far and discuss their putative application for the development of novel drugs for the treatment of FD. Unfavorable mutants with lower activities and stabilities than wild-type enzymes could serve as tools for the development of new pharmacological chaperones. On the other hand, GLA mutants showing improved enzymatic activity have been identified and produced in vitro. Such mutants could overcome several complications associated with current ERT, as lower-dose infusions of these mutants could achieve a therapeutic effect equivalent to that of the wild-type enzyme.

| S-EPMC8234732 | biostudies-literature

Alpha-Galactosidase A p.A143T, a non-Fabry disease-causing variant.

Project description:Fabry disease (FD) is an X-linked multisystemic disorder with a heterogeneous phenotype. Especially atypical or late-onset type 2 phenotypes present a therapeutical dilemma.To determine the clinical impact of the alpha-Galactosidase A (GLA) p.A143T/ c.427G?>?A variation, we retrospectively analyzed 25 p.A143T patients in comparison to 58 FD patients with other missense mutations.p.A143T patients suffering from stroke/ transient ischemic attacks had slightly decreased residual GLA activities, and/or increased lyso-Gb3 levels, suspecting FD. However, most male p.A143T patients presented with significant residual GLA activity (~50 % of reference), which was associated with normal lyso-Gb3 levels. Additionally, p.A143T patients showed less severe FD-typical symptoms and absent FD-typical renal and cardiac involvement in comparison to FD patients with other missense mutations. Two tested female p.A143T patients with stroke/TIA did not show skewed X chromosome inactivation. No accumulation of neurologic events in family members of p.A143T patients with stroke/transient ischemic attacks was observed.We conclude that GLA p.A143T seems to be most likely a neutral variant or a possible modifier instead of a disease-causing mutation. Therefore, we suggest that p.A143T patients with stroke/transient ischemic attacks of unknown etiology should be further evaluated, since the diagnosis of FD is not probable and subsequent ERT or chaperone treatment should not be an unreflected option.

| S-EPMC4855861 | biostudies-literature

Recombinant enzyme therapy for Fabry disease: absence of editing of human alpha-galactosidase A mRNA.

Project description:For more than a decade, protein-replacement therapy has been employed successfully for the treatment of Gaucher disease. Recently, a comparable therapy has become available for the related lipid-storage disorder Fabry disease. Two differently produced recombinant alpha-galactosidase A (alpha-gal A) preparations are used independently for this purpose. Agalsidase alpha is obtained from human fibroblasts that have been modified by gene activation; agalsidase beta is obtained from Chinese hamster ovary cells that are transduced with human alpha-gal A cDNA. It has previously been claimed that alpha-gal A mRNA undergoes editing, which may result in coproduction of an edited protein (Phe 396 Tyr) that might have a relevant physiological function. We therefore analyzed the occurrence of alpha-gal A editing, as well as the precise nature, in this respect, of the therapeutic enzymes. No indications were obtained for the existence of editing at the protein or RNA level. Both recombinant enzymes used in therapy are unedited and are capable of functionally correcting cultured fibroblasts from Fabry patients in their excessive globotriaosylceramide accumulation. Although RNA editing is apparently not relevant in the case of alpha-gal A, a thorough analysis of the potential occurrence of editing of transcripts is nevertheless advisable in connection with newly developed protein-replacement therapies.

| S-EPMC420010 | biostudies-literature

A Novel α-Galactosidase A Splicing Mutation Predisposes to Fabry Disease.

Project description:Fabry disease (FD) is a rare X-linked α-galactosidase A (GLA) deficiency, resulting in progressive lysosomal accumulation of globotriaosylceramide (Gb3) in a variety of cell types. Here, we report a novel splicing mutation (c.801 + 1G > A) that results in alternative splicing in GLA of a FD patient with variable phenotypic presentations of renal involvement. Sequencing of the RT-PCR products from the patient's blood sample reveals a 36-nucleotide (nt) insertion exists at the junction between exons 5 and 6 of the GLA cDNA. Splicing assay indicates that the mutated minigene produces an alternatively spliced transcript which causes a frameshift resulting in an early termination of protein expression. Immunofluorescence shows puncta in cytoplasm for mutated GLA whereas uniform staining small dots evenly distributed inside cytoplasm for wild type GLA in transfected HeLa cells. The increased senescence and decreased GLA enzyme activity suggest that the abnormalities might be due to the altered localization which further might result from the lack of the C-terminal end of GLA. Our study reveals the pathogenesis of splicing mutation c.801 + 1G > A to FD and provides scientific foundation for accurate diagnosis and precise medical intervention for FD.

| S-EPMC6396734 | biostudies-literature

Mannose 6-phosphate receptor and sortilin mediated endocytosis of α-galactosidase A in kidney endothelial cells.

Project description:Prominent vasculopathy in Fabry disease patients is caused by excessive intracellular accumulation of globotriaosylceramide (GL-3) throughout the vascular endothelial cells causing progressive cerebrovascular, cardiac and renal impairments. The vascular lesions lead to myocardial ischemia, atherogenesis, stroke, aneurysm, thrombosis, and nephropathy. Hence, injury to the endothelial cells in the kidney is a key mechanism in human glomerular disease and endothelial cell repair is an important therapeutic target. We investigated the mechanism of uptake of α-galactosidase A (α-Gal A) in renal endothelial cells, in order to clarify if the recombinant enzyme is targeted to the lysosomes via the universal mannose 6-phosphate receptor (M6PR) and possibly other receptors. Immunohistochemical localization of infused recombinant α-Gal A in a renal biopsy from a classic Fabry disease patient showed that recombinant protein localize in the endothelial cells of the kidney. Affinity purification studies using α-Gal A resins identified M6PR and sortilin as α-Gal A receptors in cultured glomerular endothelial cells. Immunohistochemical analyses of normal human kidney with anti-sortilin and anti-M6PR showed that sortilin and M6PR were expressed in the endothelium of smaller and larger vessels. Uptake studies in cultured glomerular endothelial cells of α-Gal A labeled with fluorescence and (125)I showed by inhibition with RAP and M6P that sortilin and M6PR mediated uptake of α-Gal A. Biacore studies revealed that α-Gal A binds to human M6PR with very high affinity, but M6PR also binds to sortilin in a way that prevents α-Gal A binding to sortilin. Taken together, our data provide evidence that sortilin is a new α-Gal A receptor expressed in renal endothelial cells and that this receptor together with the M6PR is able to internalize circulating α-Gal A during enzyme replacement therapy in patients with Fabry disease.

| S-EPMC3386966 | biostudies-literature

Rats deficient in α-galactosidase A develop ocular manifestations of Fabry disease.

Project description:Fabry disease is an X-linked lysosomal storage disease caused by deficiency of α-galactosidase A. Ocular findings, such as cornea verticillata, cataracts, and retinal vascular tortuosity, serve as important diagnostic markers. We aimed to evaluate ocular phenotypes in α-galactosidase A-deficient (Fabry) rats and hypothesized that these rats would manifest ocular signs similar to those observed in patients. Slit lamp biomicroscopy was used to evaluate the cornea and lens, and retinal vasculature was examined by fluorescein angiography in WT and Fabry rats. Mass spectrometry was used to characterize and quantify ocular glycosphingolipids, and histology and electron microscopy revealed the location of the glycosphingolipid storage. We found that Fabry rats developed corneal and lenticular opacities to a statistically greater degree than WT rats. Retinal vascular morphology did not appear grossly different, but there was vascular leakage in at least one Fabry rat. Fabry rat eyes accumulated substrates of α-galactosidase A, and these α-galactosyl glycoconjugates were found in corneal keratocytes, lens fibers, and retinal vascular endothelial cells. Electron-dense lamellar inclusions were observed in keratocytes. Because Fabry rats recapitulate many ocular phenotypes observed in patients, they can be used to study disease pathogenesis and determine whether ocular findings serve as noninvasive indicators of therapeutic efficacy.

| S-EPMC6599056 | biostudies-literature

Globotriaosylsphingosine accumulation and not alpha-galactosidase-A deficiency causes endothelial dysfunction in Fabry disease.

Project description:BackgroundFabry disease (FD) is caused by a deficiency of the lysosomal enzyme alpha-galactosidase A (GLA) resulting in the accumulation of globotriaosylsphingosine (Gb3) in a variety of tissues. While GLA deficiency was always considered as the fulcrum of the disease, recent attention shifted towards studying the mechanisms through which Gb3 accumulation in vascular cells leads to endothelial dysfunction and eventually multiorgan failure. In addition to the well-described macrovascular disease, FD is also characterized by abnormalities of microvascular function, which have been demonstrated by measurements of myocardial blood flow and coronary flow reserve. To date, the relative importance of Gb3 accumulation versus GLA deficiency in causing endothelial dysfunction is not fully understood; furthermore, its differential effects on cardiac micro- and macrovascular endothelial cells are not known.Methods and resultsIn order to assess the effects of Gb3 accumulation versus GLA deficiency, human macro- and microvascular cardiac endothelial cells (ECs) were incubated with Gb3 or silenced by siRNA to GLA. Gb3 loading caused deregulation of several key endothelial pathways such as eNOS, iNOS, COX-1 and COX-2, while GLA silencing showed no effects. Cardiac microvascular ECs showed a greater susceptibility to Gb3 loading as compared to macrovascular ECs.ConclusionsDeregulation of key endothelial pathways as observed in FD vasculopathy is likely caused by intracellular Gb3 accumulation rather than deficiency of GLA. Human microvascular ECs, as opposed to macrovascular ECs, seem to be affected earlier and more severely by Gb3 accumulation and this notion may prove fundamental for future progresses in early diagnosis and management of FD patients.

| S-EPMC3340376 | biostudies-literature

α-Galactosidase A-deficient rats accumulate glycosphingolipids and develop cardiorenal phenotypes of Fabry disease.

Project description:Fabry disease is an X-linked lysosomal storage disease caused by α-galactosidase A (α-Gal A) deficiency. Kidney and heart failure are frequent complications in adulthood and greatly contribute to patient morbidity and mortality. Because α-Gal A-deficient mouse models do not recapitulate cardiorenal findings observed in patients, a nonmouse model may be beneficial to our understanding of disease pathogenesis. In this study, we evaluated disease processes in a recently generated Fabry rat model. We found that male Fabry rats weighed significantly less than wild-type (WT) males, whereas female Fabry rats weighed significantly more than WT females. Whereas no difference in female survival was detected, we observed that male Fabry rats had a decreased lifespan. Skin histology revealed that inflammation and lipoatrophy may be chief disease mediators in patients. With respect to the kidney and heart, we found that both organs accumulate α-Gal A substrates, including the established biomarkers, globotriaosylceramide and globotriaosylsphingosine. Longitudinal serum and urine chemistry panels demonstrated pronounced renal tubule dysfunction, which was confirmed histologically. Mitral valve thickening was observed in Fabry rats using echocardiography. We conclude that Fabry rats recapitulate important kidney and heart phenotypes experienced by patients and can be further used to study disease mechanisms and test therapies.-Miller, J. J., Aoki, K., Mascari, C. A., Beltrame, A. K., Sokumbi, O., North, P. E., Tiemeyer, M., Kriegel, A. J., Dahms, N. M., α-Galactosidase A-deficient rats accumulate glycosphingolipids and develop cardiorenal phenotypes of Fabry disease.

| S-EPMC6629127 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data