globotriaosylceramide and Disease-Models--Animal

Fabry's disease is a genetic disorder of X-linked inheritance caused by mutations in the alpha galactosidase A gene resulting in deficiency of this lysosomal enzyme. The progressive accumulation of glycosphingolipids, caused by the inadequate enzymatic activity, is responsible of organ dysfunction and thus of clinical manifestations. In the presence of a high clinical suspicion, a careful physical examination and specific laboratory tests are required, finally diagnosis of Fabry's disease is confirmed by the demonstration of absence or reduced alpha-galactosidase A enzyme activity in hemizygous men and gene typing in heterozygous females; in fact the performance of enzymatic activity assay alone in women is inconclusive. Measurement of the biomarkers Gb3 and Lyso Gb3 in biological specimens may facilitate diagnosis. Because of its multisystemic involvement Fabry's disease may present a large spectrum of clinical manifestations as acroparesthesias, hypohidrosis, angiokeratomas, signs and symptoms of cardiac, renal, cerebrovascular involvement (renal insufficiency, proteinuria, left ventricular hypertrophy, strokes). Enzyme replacement therapy with recombinant α- galactosidase A is actually the specific therapy for Fabry disease. Early beginning of this treatment has shown beneficial effects in particular in cardiac and renal disease, a less efficacy it has been reported in central nervous system involvement. ERT has shown to be associated to a significant reduction of Gb3 accumulation in several tissues, in particular heart and kidney; moreover it improves pain related quality of life. Next generation lysosomal storage disorder treatment is based on new strategic approaches as stem cell based therapy, pharmacological chaperones, viral gene therapy; concerning Fabry's disease, it has been recently addressed to great interest this last innovative method, that is to say viral gene therapy, for delivering recombination enzyme into main involved tissues; promising results have been reported in animal models. Great efforts have been made and are still required in this field in order to make available a more effective, safer, advantageous therapeutic strategy for patients with Fabry's disease.

Topics: alpha-Galactosidase; Animals; Biomarkers; Dependovirus; Disease Models, Animal; Enzyme Replacement Therapy; Fabry Disease; Genetic Therapy; Genetic Vectors; Humans; Isoenzymes; Mice; Mutation; Rare Diseases; Recombinant Proteins; Trihexosylceramides

Topics: Bacterial Toxins; Base Sequence; Carbohydrate Sequence; Disease Models, Animal; Dysentery, Bacillary; Endocytosis; Enterotoxins; Escherichia coli; Gastrointestinal Hemorrhage; Gene Expression Regulation, Bacterial; Genes, Bacterial; Hemolytic-Uremic Syndrome; Humans; Molecular Sequence Data; Protein Biosynthesis; Receptors, Cell Surface; Shiga Toxin 1; Shiga Toxin 2; Shiga Toxins; Shigella; Structure-Activity Relationship; Trihexosylceramides; Virulence

Fabry disease (FD) is a lysosome storage disease (LSD) characterized by significantly reduced intracellular autophagy function. This contributes to the progression of intracellular pathologic signaling and can lead to organ injury. Phospholipid-polyethyleneglycol-capped Ceria-Zirconia antioxidant nanoparticles (PEG-CZNPs) have been reported to enhance autophagy flux. We analyzed whether they suppress globotriaosylceramide (Gb3) accumulation by enhancing autophagy flux and thereby attenuate kidney injury in both cellular and animal models of FD.. PEG-CZNPs alleviate FD associated kidney injury by enhancing autophagy function and thus provide a foundation for the development of new drugs to treat of storage disease.

Topics: Animals; Autophagy; Disease Models, Animal; Fabry Disease; Kidney; Male; Mice; Nanoparticles; Trihexosylceramides; Zirconium

Fabry disease (FD) is an X-linked metabolic storage disorder arising from the deficiency of lysosomal α-galactosidase A, which leads to the gradual accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3), throughout the body. Pain in the extremities is an early symptom of FD; however, the underlying pathophysiological mechanisms remain unknown. α-Galactosidase A knockout animals exhibit nociceptive behaviors, with enhanced expression levels of several ion channels. These characteristics are observed in animals treated with nerve growth factor (NGF). Here, we aimed to elucidate the potential of NGF signaling as a cause of FD-associated pain, using intraplantar Gb3-treated mice displaying mechanical allodynia. Treatment with a neutralizing antibody against a precursor of NGF (proNGF) or its receptor, p75 neurotrophin receptor (p75

Topics: Analgesics; Animals; Antibodies, Neutralizing; Cyclic AMP-Dependent Protein Kinases; Disease Models, Animal; Ganglia, Spinal; Hyperalgesia; Male; Membrane Microdomains; Mice, Inbred C57BL; Nerve Growth Factor; Pain Threshold; Protein Precursors; Receptor, trkA; Receptors, Nerve Growth Factor; Signal Transduction; Skin; Trihexosylceramides

Topics: Acylation; Animals; Chromatography, High Pressure Liquid; Disease Models, Animal; Fabry Disease; Humans; Kidney; Liver; Male; Mice; Myocardium; Spleen; Tandem Mass Spectrometry; Trihexosylceramides

Shiga toxin (Stx) produced by enterohemorrhagic

Topics: Animals; Brain Diseases; Cytokines; Disease Models, Animal; Enterohemorrhagic Escherichia coli; Escherichia coli Infections; Heat-Shock Response; Hemolytic-Uremic Syndrome; Inflammation; Lipopolysaccharides; Macrophages; Microglia; Rats; Rats, Wistar; Shiga Toxin 2; Trihexosylceramides

Alteration of glycosphingolipid (GSL) expression plays key roles in the pathogenesis and pathophysiology of many important human diseases, including cancer, diabetes and glycosphingolipidosis. Inflammatory processes are involved in development and progression of diabetic nephropathy, a major complication of type 2 diabetes mellitus. GSLs are known to play roles in inflammatory responses in various diseases, and levels of renal GSLs are elevated in mouse models of diabetic nephropathy; however, little is known regarding the pathophysiological role of these GSLs in this disease process. We studied proinflammatory activity of GSLs in diabetic nephropathy using spontaneously diabetic mouse strain KK. Mice were fed a high-fat diet (HFD) (60% kcal from fat) or normal diet (ND) (4.6% kcal from fat) for a period of 8 wk. HFD-feeding resulted in quantitative and qualitative changes of renal globo-series GSLs (particularly Gb3Cer), upregulation of TNF-α, and induction of renal inflammation. Gb3Cer/Gb4Cer treatment enhanced inflammatory responses via TLR4 in TLR4/MD-2 complex expressing cells, including HEK293T, mouse bone marrow-derived macrophages (BMDMs) and human monocytes. Our findings suggest that HFD-induced increase of Gb3Cer/Gb4Cer positively modulate TLR4-mediated inflammatory response, and that such GSLs play an important pathophysiological role in diabetic nephropathy.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diet, High-Fat; Disease Models, Animal; Disease Progression; Glycosphingolipids; HEK293 Cells; Humans; Inflammation; Kidney; Macrophages; Male; Mice; Signal Transduction; Toll-Like Receptor 4; Trihexosylceramides; Tumor Necrosis Factor-alpha

Fabry disease is an X-linked lysosomal storage disease caused by loss of alpha galactosidase A (α-Gal A) activity and is characterized by progressive accumulation of globotriaosylceramide and its analogs in all cells and tissues. Although enzyme replacement therapy (ERT) is considered standard of care, the long-term effects of ERT on renal and cardiac manifestations remain uncertain and thus novel therapies are desirable. We herein report preclinical studies evaluating systemic messenger RNA (mRNA) encoding human α-Gal A in wild-type (WT) mice, α-Gal A-deficient mice, and WT non-human primates (NHPs). The pharmacokinetics and distribution of h-α-Gal A mRNA encoded protein in WT mice demonstrated prolonged half-lives of α-Gal A in tissues and plasma. Single intravenous administration of h-α-Gal A mRNA to Gla-deficient mice showed dose-dependent protein activity and substrate reduction. Moreover, long duration (up to 6 weeks) of substrate reductions in tissues and plasma were observed after a single injection. Furthermore, repeat i.v. administration of h-α-Gal A mRNA showed a sustained pharmacodynamic response and efficacy in Fabry mice model. Lastly, multiple administrations to non-human primates confirmed safety and translatability. Taken together, these studies across species demonstrate preclinical proof-of-concept of systemic mRNA therapy for the treatment of Fabry disease and this approach may be useful for other lysosomal storage disorders.

Topics: alpha-Galactosidase; Animals; Disease Models, Animal; Endocytosis; Enzyme Replacement Therapy; Fabry Disease; Genetic Therapy; Humans; Lipids; Lysosomes; Macaca fascicularis; Male; Mice; Mice, Knockout; RNA, Messenger; Tissue Distribution; Trihexosylceramides

Fabry disease (FD) is an X-linked inherited disease and occurs due to mutations in GLA gene that encodes the α-galactosidase enzyme. Consequently, there is an accumulation of enzyme substrates, namely globotriaosylceramide (GB3). FD is a multisystemic disease, caused by storage of GB3 in vascular endothelia, with significant renal, cardiac and vascular involvement. The aim of this work was to evaluate the in vitro effect of GB3 on electron transport chain complexes (ETC) and redox parameters. Biochemical biomarkers were determined in homogenates of cerebral cortex, kidneys and liver of Wistar rats in the presence or absence of GB3 at concentrations of 3, 6, 9 and 12 mg/L. We found that GB3 caused an increase of ETC complexes II and IV activities, increased production of reactive species and decreased superoxide dismutase enzyme activity in homogenates of cerebral cortex. As well also increased production of reactive species and superoxide dismutase activity in kidney homogenates. The results obtained in our work suggest that GB3 interferes in ETC complexes II and IV activities, however, the magnitude of this increase seems to be too low to present a physiologically importance. However, the imbalance in cellular redox state indicating that these alterations may be involved in the pathophysiology of FD, mainly in renal and cerebral manifestations.

Topics: Animals; Cerebral Cortex; Disease Models, Animal; Electron Transport; Fabry Disease; Kidney; Liver; Male; Oxidation-Reduction; Rats; Rats, Wistar; Trihexosylceramides

A main feature of Fabry disease is nephropathy, with polyuria an early manifestation; however, the mechanism that underlies polyuria and affected tubules is unknown. To increase globotriaosylceramide (Gb3) levels, we previously crossbred asymptomatic Gla

Topics: Animals; Disease Models, Animal; Fabry Disease; Kidney Concentrating Ability; Kidney Diseases; Kidney Medulla; Male; Mice; Mice, Inbred C57BL; Polyuria; Sodium; Sodium-Potassium-Chloride Symporters; Sodium-Potassium-Exchanging ATPase; Trihexosylceramides

Fabry disease (FD) is a life-threatening X-linked lysosomal storage disorder caused by α-galactosidase A (α-GAL) deficiency. Small fiber pathology and pain are major FD symptoms of unknown pathophysiology. α-GAL deficient mice (GLA KO) age-dependently accumulate globotriaosylceramide (Gb3) in dorsal root ganglion (DRG) neurons paralleled by endoplasmic stress and apoptosis as contributors to skin denervation. Old GLA KO mice show increased TRPV1 protein in DRG neurons and heat hypersensitivity upon i.pl. capsaicin. In turn, GLA KO mice are protected from heat and mechanical hypersensitivity in neuropathic and inflammatory pain models based on reduced neuronal I

Topics: alpha-Galactosidase; Animals; Disease Models, Animal; Fabry Disease; Ganglia, Spinal; Gene Knockdown Techniques; Mice; Mice, Knockout; NAV1.7 Voltage-Gated Sodium Channel; Neurons; Trihexosylceramides

Formation of antibodies against a therapeutic enzyme is an important complication during enzyme replacement therapy (ERT) for lysosomal storage diseases. Fabry disease (FD) is caused by a deficiency of alpha-galactosidase (GLA), which results in the accumulation of globotriaosylceramide (GL-3). We have shown immune tolerance induction (ITI) during ERT in FD model mice by using an anti-B lymphocyte stimulator (anti-BlyS) antibody (belimumab). A single dose of the anti-BlyS antibody temporarily lowered the percentage of B cells and IgG antibody titer against recombinant human GLA. Administration of a low maintenance dose of the anti-BlyS antibody suppressed the B cell population and immunotolerance was induced in 20% of mice, but antibody formation could not be prevented. We then increased the maintenance dose of the anti-BlyS antibody and immunotolerance was induced in 50% of mice. Therapeutic enzyme distribution and clearance of GL-3 were also enhanced by a high maintenance dose of the anti-BlyS antibody.

Topics: alpha-Galactosidase; Animals; Antibodies, Monoclonal, Humanized; B-Lymphocytes; Disease Models, Animal; Enzyme Replacement Therapy; Fabry Disease; Immune Tolerance; Immunoglobulin G; Immunosuppressive Agents; Mice; Recombinant Proteins; Trihexosylceramides

Globotriaosylceramide (Gb3) is a glycosphingolipid present in cellular membranes that progressively accumulates in Fabry disease. Invariant Natural Killer T (iNKT) cells are a population of lipid-specific T cells that are phenotypically and functionally altered in Fabry disease. The mechanisms responsible for the iNKT-cell alterations in Fabry disease are not well understood. Here, we analyzed the effect of Gb3 on CD1d-mediated iNKT-cell activation in vitro using human cells and in vivo in the mouse model. We found that Gb3 competes with endogenous and exogenous antigens for CD1d binding, thereby reducing the activation of iNKT cells. This effect was exerted by a reduction in the amount of stimulatory CD1d:α-GalCer complexes in the presence of Gb3 as demonstrated by using an mAb specific for the complex. We also found that administration of Gb3 delivered to the same APC as α-GalCer, induces reduced iNKT-cell activation in vivo. This work highlights the complexity of iNKT-cell activation and the importance of nonantigenic glycosphingolipids in the modulation of this process.

Topics: Animals; Antigens, CD1d; Disease Models, Animal; Fabry Disease; Flow Cytometry; Humans; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Trihexosylceramides

Fabry disease is caused by deficient activity of α-galactosidase A and subsequent intracellular accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3). Vascular endothelial cells may play important roles in disease pathogenesis, and are one of the main target cell types in therapeutic interventions. In this study, we generated immortalized aortic endothelial cell lines from a mouse model of Fabry disease. These cells retained endothelial cell-specific markers and functions. Gb3 expression level in one of these clones (referred to as FMEC2) was highly susceptible to culture media, and appeared to be regulated by glucosylceramide synthase. Results also showed that Gb3 could be upregulated by hydrocortisone. FMEC2 express the mannose 6-phosphate receptor and sortilin but not the mannose receptor. Uptake studies suggested that sortilin plays a role in the binding and internalization of mammalian cell-produced α-galactosidase A. Moss-aGal (a plant-made enzyme) was endocytosed by FMEC2 via a receptor other than the aforementioned receptors. In conclusion, this study suggests that glucosylceramide synthase and hydrocortisone may play important roles in modulating Gb3 levels in Fabry mouse aortic endothelial cells, and that endocytosis of recombinant α-galactosidase A involves a combination of multiple receptors depending on the properties of the enzyme.

Topics: Adaptor Proteins, Vesicular Transport; alpha-Galactosidase; Animals; Aorta; Biomarkers; Cell Line; Disease Models, Animal; Endocytosis; Endothelial Cells; Endothelium, Vascular; Fabry Disease; Glucosyltransferases; Glycosphingolipids; Lectins, C-Type; Male; Mannose Receptor; Mannose-Binding Lectins; Mice; Mice, Inbred C57BL; Receptor, IGF Type 2; Receptors, Cell Surface; Trihexosylceramides

Fabry disease, an X-linked glycosphingolipid storage disorder, is caused by the deficient activity of α-galactosidase A (α-Gal A). This results in the lysosomal accumulation in various cell types of its glycolipid substrates, including globotriaosylceramide (GL-3) and lysoglobotriaosylceramide (globotriaosyl lysosphingolipid, lyso-GL-3), leading to kidney, heart, and cerebrovascular disease. To complement and potentially augment the current standard of care, biweekly infusions of recombinant α-Gal A, the merits of substrate reduction therapy (SRT) by selectively inhibiting glucosylceramide synthase (GCS) were examined. Here, we report the development of a novel, orally available GCS inhibitor (Genz-682452) with pharmacological and safety profiles that have potential for treating Fabry disease. Treating Fabry mice with Genz-682452 resulted in reduced tissue levels of GL-3 and lyso-GL-3 and a delayed loss of the thermal nociceptive response. Greatest improvements were realized when the therapeutic intervention was administered to younger mice before they developed overt pathology. Importantly, as the pharmacologic profiles of α-Gal A and Genz-682452 are different, treating animals with both drugs conferred the greatest efficacy. For example, because Genz-682452, but not α-Gal A, can traverse the blood-brain barrier, levels of accumulated glycosphingolipids were reduced in the brain of Genz-682452-treated but not α-Gal A-treated mice. These results suggest that combining substrate reduction and enzyme replacement may confer both complementary and additive therapeutic benefits in Fabry disease.

Topics: alpha-Galactosidase; Animals; Blood-Brain Barrier; Carbamates; Disease Models, Animal; Fabry Disease; Glucosyltransferases; Glycolipids; Humans; Mice; Quinuclidines; Sphingolipids; Trihexosylceramides

Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the gene encoding the α-galactosidase A (α-Gal A) lysosomal enzyme, which results in globotriaosylceramide (Gb3) storage in vascular endothelial cells and different cell types throughout the body. Involvement of the kidney and heart is life threatening, and fibrosis of these organs is considered to be involved in the pathogenesis of Fabry disease. An increased concentration of deacylated Gb3 (lyso‑Gb3) in the plasma of symptomatic patients has also been suggested as a causative molecular event. To elucidate the molecular mechanisms involved in renal fibrosis in Fabry disease, the present analyzed the changes in global gene expression prior to and following Gb3 or lyso‑Gb3 treatment in two types of kidney cell lines, human proximal renal tubular epithelial (HK‑2) and mouse renal glomerular mesangial (SV40 MES 13) cells. Gb3 and lyso‑Gb3 treatment regulated the expression of 199 and 328 genes in each cell type, demonstrating a >2.0‑fold change. The majority of the biological functions of the regulated genes were associated with fibrogenesis or epithelial‑mesenchymal transition (EMT). The gene expression patterns of sphingolipid‑treated HK‑2 cells were distinguishable from the patterns in the SV40 MES 13 cells. Several genes associated with the EMT were selected and evaluated further in kidney cells and in Fabry mouse kidney tissues. In the SV40 MES 13 cells, the DLL1, F8, and HOXA11 genes were downregulated, and FOXP2 was upregulated by treatment with Gb3 or lyso‑Gb3. In the HK‑2 cells, the ADAMTS6, BEST1, IL4, and MYH11 genes were upregulated. Upregulation of the FOXP2, COL15A1, IL4, and MYH11 genes was also observed in the Fabry mouse kidney tissues. The gene expression profiles in kidney cells following the addition of Gb3 or lyso‑Gb3 revealed substrate‑specific and cell‑specific patterns. These findings suggested that Gb3 and lyso‑Gb3 lead to renal fibrosis in Fabry disease through different biochemical modulations.

Topics: ADAM Proteins; ADAMTS Proteins; Animals; Bestrophins; Calcium-Binding Proteins; Cell Line, Transformed; Chloride Channels; Disease Models, Animal; Epithelial Cells; Epithelial-Mesenchymal Transition; Eye Proteins; Fabry Disease; Gene Expression Profiling; Gene Expression Regulation; Glycolipids; Homeodomain Proteins; Humans; Intercellular Signaling Peptides and Proteins; Kidney Tubules; Male; Mesangial Cells; Mice; Mice, Transgenic; Molecular Sequence Annotation; Organ Specificity; Signal Transduction; Sphingolipids; Transcriptome; Trihexosylceramides

Fabry disease is caused by deficient activity of α-galactosidase A (GLA) and characterized by systemic accumulation of glycosphingolipids, substrates of the enzyme. To gain insight into the pathogenesis of Fabry disease based on accumulated substrates, we examined the tissue and plasma distributions of globotriaosylceramide (Gb3) isoforms, and globotriaosylsphingosine (lyso-Gb3) and its analogues in a GLA knockout mouse, a model of Fabry disease, by means of liquid chromatography-mass spectrometry and nano-liquid chromatography-tandem mass spectrometry, respectively. The results revealed that the contents of these substrates in the liver, kidneys, heart, and plasma of GLA knockout mice were apparently higher than in those of wild-type ones, and organ specificity in the accumulation of Gb3 isoforms was found. Especially in the kidneys, accumulation of a large amount of Gb3 isoforms including hydroxylated residues was found. In the GLA knockout mice, the proportion of hydrophobic Gb3 isoforms was apparently higher than that in the wild-type mice. On the other hand, hydrophilic residues were abundant in plasma. Unlike that of Gb3, the concentration of lyso-Gb3 was high in the liver, and the lyso-Gb3/Gb3 ratio in plasma was significantly higher than those in the organs. The concentration of lyso-Gb3 was apparently higher than those of its analogues in the organs and plasma from both the GLA knockout and wild-type mice. This information will be useful for elucidating the basis of Fabry disease.

Topics: alpha-Galactosidase; Animals; Chromatography, High Pressure Liquid; Disease Models, Animal; Fabry Disease; Female; Glycolipids; Isomerism; Kidney; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardium; Sphingolipids; Tandem Mass Spectrometry; Trihexosylceramides

Globotriaosylceramide (Gb3) induces KCa3.1 downregulation in Fabry disease (FD). We investigated whether Gb3 induces KCa3.1 endocytosis and degradation.. KCa3.1, especially plasma membrane-localized KCa3.1, was downregulated in both Gb3-treated mouse aortic endothelial cells (MAECs) and human umbilical vein endothelial cells. Gb3-induced KCa3.1 downregulation was prevented by lysosomal inhibitors but not by a proteosomal inhibitor. Endoplasmic reticulum stress-inducing agents did not induce KCa3.1 downregulation. Gb3 upregulated the protein levels of early endosome antigen 1 and lysosomal-associated membrane protein 2 in MAECs. Compared with MAECs from age-matched wild-type mice, those from aged α-galactosidase A (Gla)-knockout mice, an animal model of FD, showed downregulated KCa3.1 expression and upregulated early endosome antigen 1 and lysosomal-associated membrane protein 2 expression. In contrast, no significant difference was found in early endosome antigen 1 and lysosomal-associated membrane protein 2 expression between young Gla-knockout and wild-type MAECs. In aged Gla-knockout MAECs, clathrin was translocated close to the cell border and clathrin knockdown recovered KCa3.1 expression. Rab5, an effector of early endosome antigen 1, was upregulated, and Rab5 knockdown restored KCa3.1 expression, the current, and endothelium-dependent relaxation.. -Gb3 accelerates the endocytosis and lysosomal degradation of endothelial KCa3.1 via a clathrin-dependent process, leading to endothelial dysfunction in FD.

Topics: alpha-Galactosidase; Animals; Cells, Cultured; Clathrin; Disease Models, Animal; Endocytosis; Endothelial Cells; Endothelium, Vascular; Fabry Disease; Human Umbilical Vein Endothelial Cells; Humans; Intermediate-Conductance Calcium-Activated Potassium Channels; Lysosomal-Associated Membrane Protein 2; Lysosomes; Mice; Mice, Knockout; Protein Transport; Proteolysis; rab5 GTP-Binding Proteins; RNA Interference; Transfection; Trihexosylceramides; Vasodilation; Vesicular Transport Proteins

Fabry disease is a lysosomal storage disorder in which neutral glycosphingolipids, predominantly Gb3 (globotriaosylceramide), accumulate due to deficient α-Gal A (α-galactosidase A) activity. The GLAko (α-Gal A-knockout) mouse has been used as a model for Fabry disease, but it does not have any symptomatic abnormalities. In the present study, we generated a symptomatic mouse model (G3Stg/GLAko) by cross-breeding GLAko mice with transgenic mice expressing human Gb3 synthase. G3Stg/GLAko mice had high Gb3 levels in major organs, and their serum Gb3 level at 5-25 weeks of age was 6-10-fold higher than that in GLAko mice of the same age. G3Stg/GLAko mice showed progressive renal impairment, with albuminuria at 3 weeks of age, decreased urine osmolality at 5 weeks, polyuria at 10 weeks and increased blood urea nitrogen at 15 weeks. The urine volume and urinary albumin concentration were significantly reduced in the G3Stg/GLAko mice when human recombinant α-Gal A was administered intravenously. These data suggest that Gb3 accumulation is a primary pathogenic factor in the symptomatic phenotype of G3Stg/GLAko mice, and that this mouse line is suitable for studying the pathogenesis of Fabry disease and for preclinical studies of candidate therapies.

Topics: Albuminuria; alpha-Galactosidase; Animals; Disease Models, Animal; Fabry Disease; Galactosyltransferases; Humans; Mice; Mice, Transgenic; Trihexosylceramides

Fabry disease is a lysosomal storage disease caused by deficient activity of the α-Galactosidase A (α-Gal A) enzyme, which leads to abnormal accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3), in the lysosome. Glycosphingolipids are known to be invariant Natural Killer T (iNKT) cell antigens. Several animal models of lysosomal storage diseases, including Fabry disease, present a defect in iNKT cell selection by the thymus. We have studied the effect of age and the impact of enzyme replacement therapy on Gb3 accumulation and iNKT cells of Fabry knockout mice. At 4 weeks of age, Fabry knockout mice already showed Gb3 accumulation and a reduction in the percentage of iNKT cells. In older mice (12-week old), we observed an accentuated peripheral iNKT deficiency. 12-week old animals also showed a reduced splenic CD4+/CD4- iNKT cell ratio due to greater loss in the iNKT CD4+ subset. Treatment of Fabry knockout mice with α-Gal A replacement therapy efficiently reduced Gb3 deposition in the liver and spleen. Moreover, enzyme replacement therapy had a positive effect on the number of iNKT cells in an organ-dependent fashion. Indeed, treatment of Fabry knockout mice with α-Gal A did not alter iNKT cell percentage in the thymus and liver but increased splenic iNKT cell percentage when compared to untreated mice. Study of animals prior to treatment indicates that enzyme replacement therapy stabilized iNKT cell percentage in the spleen. This stabilization is due to a specific effect on the iNKT CD4+ subset, preventing the decrease on the number of these cells that occurs with age in Fabry knockout mice. This study reveals that enzyme replacement therapy has a positive organ and subset-dependent effect in iNKT cells of Fabry knockout mice.

Topics: alpha-Galactosidase; Animals; CD4 Lymphocyte Count; Disease Models, Animal; Enzyme Replacement Therapy; Fabry Disease; Humans; Liver; Lysosomes; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Spleen; Trihexosylceramides

Fabry disease is an inherited lysosomal disorder caused by a deficiency of alpha-galactosidase A (α-gal A). The systemic accumulation of substrate, mainly globotriaosylceramide (Gb3), results in organ failure. Although Gb3 accumulation has been observed in an α-gal A-deficient mouse model, important clinical manifestations were not seen. The pursuit of effective treatment for Fabry disease through gene therapy, for example, has been hampered by the lack of a relevant large animal model to assess the efficacy and safety of novel therapies. Towards assembling the tools to generate an alternative animal model, we have sequenced and characterized the porcine ortholog of the α-gal A gene. When compared to the human α-gal A, the porcine α-gal A showed a high level of homology in the coding regions and located at chromosome Xq22. Cell lysate and supernatants from Fabry patient-derived fibroblasts transduced with a lentiviral vector (LV) carrying the porcine α-gal A cDNA (LV/porcine α-gal A), showed high levels of α-gal A activity and its enzymological stability was similar to that of human α-gal A. Uptake of secreted porcine α-gal A was observed into non-transduced cells and was partially inhibited by soluble mannose-6-phosphate. Furthermore, Gb3 accumulation was reduced in Fabry patient-derived fibroblasts transduced with the LV/porcine α-gal A. In conclusion, we elucidated and characterized the porcine α-gal A gene and enzyme. Similarity in enzymatic profile and chromosomal location between α-gal A of porcine and human origins may be of great advantage for the development of a large animal model for Fabry disease.

Topics: alpha-Galactosidase; Animals; Cloning, Molecular; Disease Models, Animal; Fabry Disease; Fibroblasts; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; HeLa Cells; Humans; Lentivirus; Sus scrofa; Trihexosylceramides

Fabry disease is a lysosomal storage disorder caused by an α-galactosidase A (α-Gal A) deficiency and resulting in the accumulation of glycosphingolipids, predominantly globotriaosylceramide (Gb3). A transgenic mouse expressing the human α-Gal A R301Q mutant in an α-Gal A-knockout background (TgM/KO) should be useful for studying active-site-specific chaperone (ASSC) therapy for Fabry disease. However, the Gb3 content in the heart tissue of this mouse was too low to detect an ASSC-induced effect. To increase the Gb3 levels in mouse organs, we created transgenic mice (TgG3S) expressing human α1,4-galactosyltransferase (Gb3 synthase). High levels of Gb3 were observed in all major organs of the TgG3S mouse. A TgG3S (+/-)M(+/-)/KO mouse was prepared by cross-breeding the TgG3S and TgM/KO mice and the Gb3 content in the heart of the TgG3S(+/-)M(+/-)/KO mouse was 1.4 µg/mg protein, higher than in the TgM(+/-)/KO (<0.1 µg/mg protein). Treatment with an ASSC, 1-deoxygalactonojirimycin, caused a marked induction of α-Gal A activity and a concomitant reduction of the Gb3 content in the TgG3S(+/-) M(+/-)/KO mouse organs. These data indicated that the TgG3S(+/-) M(+/-)/KO mouse was suitable for studying ASSC therapy for Fabry disease, and that the TgG3S mouse would be useful for studying the effect of high Gb3 levels in mouse organs.

Topics: 1-Deoxynojirimycin; alpha-Galactosidase; Animals; Crosses, Genetic; Disease Models, Animal; Enzyme Activation; Fabry Disease; Female; Galactosyltransferases; Humans; Kidney; Liver; Mice; Mice, Knockout; Mice, Transgenic; Molecular Chaperones; Spleen; Trihexosylceramides; Up-Regulation

Excessive endothelial globotriaosylceramide (Gb3) accumulation is associated with endothelial dysfunction and impaired endothelium-dependent relaxation in Fabry disease. In endothelial cells, K(Ca)3.1 channels contribute to endothelium-dependent relaxation. However, the effect of Gb3 on K(Ca)3.1 channels and the underlying mechanisms of Gb3-induced dysfunction are unknown. Herein, we hypothesized that Gb3 accumulation induces K(Ca)3.1 channel dysfunction and aimed to clarify the underlying mechanisms.. The animal model of Fabry disease, α-galactosidase A (Gla) knockout mice, displayed age-dependent K(Ca)3.1 channel dysfunction. K(Ca)3.1 current and the channel expression were significantly reduced in mouse aortic endothelial cells (MAECs) of aged Gla knockout mice, whereas they were not changed in MAECs of wild-type and young Gla knockout mice. In addition, K(Ca)3.1 current and the channel expression were concentration-dependently reduced in Gb3-treated MAECs. In both Gb3-treated and aged Gla knockout MAECs, extracellular signal-regulated kinase (ERK) and activator protein-1 (AP-1) were down-regulated and repressor element-1 silencing transcription factor (REST) was up-regulated. Gb3 inhibited class III phosphoinositide 3-kinase and decreased intracellular levels of phosphatidylinositol 3-phosphate [PI(3)P]. In addition, endothelium-dependent relaxation was significantly attenuated in Gb3-treated mouse aortic rings.. Gb3 accumulation reduces K(Ca)3.1 channel expression by down-regulating ERK and AP-1 and up-regulating REST and the channel activity by decreasing intracellular levels of PI(3)P. Gb3 thereby evokes K(Ca)3.1 channel dysfunction, and the channel dysfunction in vascular endothelial cells may contribute to vasculopathy in Fabry disease.

Topics: alpha-Galactosidase; Animals; Cells, Cultured; Class III Phosphatidylinositol 3-Kinases; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelial Cells; Endothelium, Vascular; Extracellular Signal-Regulated MAP Kinases; Fabry Disease; Intermediate-Conductance Calcium-Activated Potassium Channels; Membrane Potentials; Mice; Mice, Knockout; Phosphatidylinositol Phosphates; Repressor Proteins; Signal Transduction; Transcription Factor AP-1; Trihexosylceramides; Vasodilation; Vasodilator Agents

Topics: Aged; Animals; Biopsy; Disease Models, Animal; Endocardium; Fabry Disease; Humans; Male; Mass Spectrometry; Mice; Molecular Weight; Trihexosylceramides

Postdiarrhea hemolytic uremic syndrome is the most common cause of acute renal failure in children in Argentina. Renal damage has been strongly associated with Shiga toxin (Stx), which binds to the globotriaosylceramide (Gb3) receptor on the plasma membrane of target cells. The purpose of the study was to evaluate the in vivo effects of C-9, a potent inhibitor of glucosylceramide synthase and Gb3 synthesis, on kidney and colon in an experimental model of hemolytic uremic syndrome in rats. Rats were i.p. injected with supernatant from recombinant Escherichia coli expressing Stx2 (sStx2). A group of these rats were orally treated with C-9 during 6 d, from 2 d prior until 4 d after sStx2 injection. The injection of sStx2 caused renal damage as well as a loss of goblet cells in colonic mucosa. Oral treatment with C-9 significantly decreased rat mortality to 50% and reduced the extension of renal and intestinal injuries in the surviving rats. The C-9 also decreased Gb3 and glucosylceramide expression levels in rat kidneys. It is particularly interesting that an improvement was seen when C-9 was administered 2 d before challenge, which makes it potentially useful for prophylaxis.

Topics: Administration, Oral; Animals; Biomarkers; Colon; Creatinine; Dioxanes; Disease Models, Animal; Enzyme Inhibitors; Glucosyltransferases; Hemolytic-Uremic Syndrome; Intestinal Mucosa; Kidney; Male; Pyrrolidines; Rats; Rats, Sprague-Dawley; Shiga Toxin 2; Time Factors; Trihexosylceramides; Urea

Fabry disease (FD) is a lysosomal storage disorders characterized by a deficiency of the lysosomal enzyme, α-galactosidase A. This results in the accumulation of glycolipids, mainly globotriaosylceramide (GL-3), in the lysosomes of various organs. Although bone marrow transplantation and hematopoietic stem cell-based gene therapy can offer the potential of a curative therapeutic outcome for FD, the minimum requirement of donor cells or gene-corrected cells to reduce GL-3 levels is not known.. Lethally-irradiated FD mice were transplanted intravenously with normal bone marrow cells (Ly5.1 positive) mixed with those of FD mice (Ly5.2 positive) at various ratios to investigate the level of engraftment and enzyme activity necessary to effect a reduction in GL-3 storage.. Chimerism of whole white blood cells of recipients' peripheral blood remained stable at 8 weeks after transplantation, and chimerism of granulocytes, monocytes, B cells and T cells was equal to that of white blood cells. GL-3 levels were significantly reduced in the lung and heart of animals with a 30% and 50% chimera, respectively. The extent of reduction in these mice was almost identical to that with 100% chimera.. In FD mice, reconstitution with 100% donor cells is not required to obtain a therapeutic effect following bone marrow transplantation. These results suggest that a 30% gene correction might be sufficient to reverse disease manifestations in FD.

Topics: alpha-Galactosidase; Animals; Bone Marrow Transplantation; Disease Models, Animal; Fabry Disease; Glycolipids; Mice; Mice, Inbred C57BL; Transplantation Chimera; Trihexosylceramides

The aim of our study was to measure globotriaosylceramide (Gb(3)) and lyso-Gb(3) levels by tandem mass spectrometry in the urine and kidney in Fabry (gla knockout) mice and wild-type controls. We found that urine Gb(3) of male and female Fabry mice was higher than wild-type mice of the same sex but also significantly higher in male mice compared with females of the same genotype. In kidney tissue, sex and genotype-dependent differences in Gb(3) levels paralleled those in the urine. Isoforms C16, C22:1, and C24OHA were particularly higher in males compared with females in both wild-type and Fabry mice. Similarly, kidney lyso-Gb(3) concentrations were significantly higher in 12-month-old male Fabry mice than in their homozygous female counterparts. However, lyso-Gb(3) was undetectable in wild-type mice of both sexes. α-Galactosidase A activity and mRNA levels in kidney were significantly lower in male wild-type mice compared with female mice. This study shows the sex differences in kidney and urine Gb(3) and kidney lyso-Gb(3) levels in both wild-type and Fabry mice, and it suggests that these male-female differences should be taken into consideration when using murine models for Fabry disease.

Topics: alpha-Galactosidase; Animals; Biomarkers; Disease Models, Animal; Fabry Disease; Female; Humans; Kidney; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Sex Characteristics; Tandem Mass Spectrometry; Trihexosylceramides

Fabry disease is an X-linked lysosomal storage disorder caused by a deficiency in alpha-galactosidase A (alpha-Gal A) activity and subsequent accumulation of the substrate globotriaosylceramide (GL-3), which contributes to disease pathology. The pharmacological chaperone (PC) DGJ (1-deoxygalactonojirimycin) binds and stabilizes alpha-Gal A, increasing enzyme levels in cultured cells and in vivo. The ability of DGJ to reduce GL-3 in vivo was investigated using transgenic (Tg) mice that express a mutant form of human alpha-Gal A (R301Q) on a knockout background (Tg/KO), which leads to GL-3 accumulation in disease-relevant tissues. Four-week daily oral administration of DGJ to Tg/KO mice resulted in significant and dose-dependent increases in alpha-Gal A activity, with concomitant GL-3 reduction in skin, heart, kidney, brain, and plasma; 24-week administration resulted in even greater reductions. Compared to daily administration, less frequent DGJ administration, including repeated cycles of 4 days with DGJ followed by 3 days without or every other day with DGJ, resulted in even greater GL-3 reductions that were comparable to those obtained with Fabrazyme. Collectively, these data indicate that oral administration of DGJ increases mutant alpha-Gal A activity and reduces GL-3 in disease-relevant tissues in Tg/KO mice, and thus merits further evaluation as a treatment for Fabry disease.

Topics: 1-Deoxynojirimycin; alpha-Galactosidase; Animals; Blotting, Western; Disease Models, Animal; Fabry Disease; Humans; Immunohistochemistry; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Trihexosylceramides

Fabry disease is an X-linked glycosphingolipid storage disorder caused by a deficiency in the activity of the lysosomal hydrolase α-galactosidase A (α-gal). This deficiency results in accumulation of the glycosphingolipid globotriaosylceramide (GL-3) in lysosomes. Endothelial cell storage of GL-3 frequently leads to kidney dysfunction, cardiac and cerebrovascular disease. The current treatment for Fabry disease is through infusions of recombinant α-gal (enzyme-replacement therapy; ERT). Although ERT can markedly reduce the lysosomal burden of GL-3 in endothelial cells, variability is seen in the clearance from several other cell types. This suggests that alternative and adjuvant therapies may be desirable. Use of glucosylceramide synthase inhibitors to abate the biosynthesis of glycosphingolipids (substrate reduction therapy, SRT) has been shown to be effective at reducing substrate levels in the related glycosphingolipidosis, Gaucher disease. Here, we show that such an inhibitor (eliglustat tartrate, Genz-112638) was effective at lowering GL-3 accumulation in a mouse model of Fabry disease. Relative efficacy of SRT and ERT at reducing GL-3 levels in Fabry mouse tissues differed with SRT being more effective in the kidney, and ERT more efficacious in the heart and liver. Combination therapy with ERT and SRT provided the most complete clearance of GL-3 from all the tissues. Furthermore, treatment normalized urine volume and uromodulin levels and significantly delayed the loss of a nociceptive response. The differential efficacies of SRT and ERT in the different tissues indicate that the combination approach is both additive and complementary suggesting the possibility of an improved therapeutic paradigm in the management of Fabry disease.

Topics: alpha-Galactosidase; Animals; Chromatography, High Pressure Liquid; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Enzyme Replacement Therapy; Fabry Disease; Female; Glucosyltransferases; Humans; Male; Mass Spectrometry; Mice; Mice, 129 Strain; Mice, Knockout; Pyrrolidines; Treatment Outcome; Trihexosylceramides; Uromodulin

Fabry disease (OMIM 301500) is a rare X-linked recessive disorder caused by mutations in the alpha-galactosidase gene (GLA). Loss of alpha-galactosidase (alpha-Gal) activity leads to the abnormal accumulation of glycosphingolipids in lysosomes predominantly of vascular endothelial cells. Clinically the disorder presents with angiokeratomas, clouding of the cornea, and renal, cardiac, and cerebrovascular complications. In addition, there is an increased incidence of neuropathic pain in Fabry patients. In this study, we investigated the implications of loss of alpha-galactosidase A activity on sensorimotor function and peripheral nervous system. Similar to the described in Fabry disease patients, the sensorimotor assessment of Fabry mice revealed diminished locomotor activity and warm hypoalgesia as assessed in the hot-plate. Moreover Fabry mice displayed alterations both in balance and co-ordination. By histological analysis, the cyto-architecture of Fabry mice sciatic nerves showed an increase in mean cross-sectional area accompanied by a decrease in the density of non-myelinated fibers as well as a trend for a decreased number of small myelinated fibers, a well established feature of Fabry disease. A relative preservation of large myelinated fibers and nerve conduction velocity measurements was observed. Our findings demonstrate for the first time that Fabry knockout mice have Gb3 accumulation in the peripheral nervous system, alterations in sensorimotor function, hypoalgesia and no impairment of motor nerve conduction.

Topics: alpha-Galactosidase; Animals; Ataxia; Disease Models, Animal; Fabry Disease; Female; Glycosphingolipids; Hot Temperature; Hypesthesia; Male; Mice; Mice, Knockout; Motor Activity; Nerve Fibers; Neural Conduction; Pain; Peripheral Nervous System; Phenotype; Postural Balance; Sciatic Nerve; Thermosensing; Trihexosylceramides

Shiga toxin 1 and 2 production is a cardinal virulence trait of enterohemorrhagic Escherichia coli infection that causes a spectrum of intestinal and systemic pathology. However, intestinal sites of enterohemorrhagic E. coli colonization during the human infection and how the Shiga toxins are taken up and cross the globotriaosylceramide (Gb3) receptor-negative intestinal epithelial cells remain largely uncharacterized. We used samples of human intestinal tissue from patients with E. coli O157:H7 infection to detect the intestinal sites of bacterial colonization and characterize the distribution of Shiga toxins. We further used a model of largely Gb3-negative T84 intestinal epithelial monolayers treated with B-subunit of Shiga toxin 1 to determine the mechanisms of non-receptor-mediated toxin uptake. We now report that E. coli O157:H7 were found at the apical surface of epithelial cells only in the ileocecal valve area and that both toxins were present in large amounts inside surface and crypt epithelial cells in all tested intestinal samples. Our in vitro data suggest that macropinocytosis mediated through Src activation significantly increases toxin endocytosis by intestinal epithelial cells and also stimulates toxin transcellular transcytosis. We conclude that Shiga toxin is taken up by human intestinal epithelial cells during E. coli O157:H7 infection regardless of the presence of bacterial colonies. Macropinocytosis might be responsible for toxin uptake by Gb3-free intestinal epithelial cells and transcytosis. These observations provide new insights into the understanding of Shiga toxin contribution to enterohemorrhagic E. coli-related intestinal and systemic diseases.

Topics: Actins; Animals; cdc42 GTP-Binding Protein; Cell Line; Cell Membrane; Chlorpromazine; Clathrin; Disease Models, Animal; Endocytosis; Enzyme Activation; Epithelial Cells; Escherichia coli Infections; Escherichia coli O157; Ethylmaleimide; Humans; Intestinal Mucosa; Intestines; Male; N-Ethylmaleimide-Sensitive Proteins; Pinocytosis; Rabbits; Recombinant Proteins; Shiga Toxin 1; Shiga Toxin 2; src-Family Kinases; Tetradecanoylphorbol Acetate; Time Factors; Trihexosylceramides

Fabry disease is a lysosomal storage disorder that results in an accumulation of globotriaosylceramide in vascular tissue secondary to a deficiency in alpha-galactosidase A. The glycolipid-associated vasculopathy results in strokes and cardiac disease, but the basis for these complications is poorly understood. Recent studies in the alpha-galactosidase A-knockout mouse suggested that a decrease in nitric oxide (NO) bioavailability may play a role in the abnormal thrombosis, atherogenesis, and vasorelaxation that are characteristic of these mice. To understand better the association between impaired NO bioavailability and glycolipid accumulation, we studied alpha-galactosidase A-knockout mice or primary cultures of their aortic endothelial cells. Treatment of knockout mice with a potent inhibitor of glucosylceramide synthase reversed accumulation of globotriaosylceramide but failed to normalize the defect in vasorelaxation. Basal and insulin-stimulated endothelial NO synthase (eNOS) activities in endothelial cells derived from knockout mice were lower than those observed from wild-type mice; normalization of glycolipid only partially reversed this reduction in eNOS activity. The loss of eNOS activity associated with a decrease in high molecular weight caveolin oligomers in endothelial cells and isolated caveolae, suggesting a role for glycolipids in caveolin assembly. Finally, concentrations of ortho-tyrosine and nitrotyrosine in knockout endothelial cells were markedly elevated compared with wild-type endothelial cells. These findings are consistent with a loss of NO bioavailability, associated with eNOS uncoupling, in the alpha-galactosidase A-knockout mouse.

Topics: Acetylcholine; Aging; alpha-Galactosidase; Animals; Aorta; Caveolae; Caveolin 1; Cells, Cultured; Disease Models, Animal; Endothelial Cells; Fabry Disease; Glucosyltransferases; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide; Nitric Oxide Synthase Type III; Trihexosylceramides; Vasodilation

Fabry disease is a lysosomal storage disease caused by a deficiency of alpha-galactosidase A, which results in aberrant glycosphingolipid metabolism and accumulation of globotriaosylceramide (Gb3). Since a correlation between the level of Gb3 and clinical manifestations of Fabry disease has not been observed, we investigated potential diagnostic biomarkers. Hepatic and renal gene expression of male alpha-galactosidase A-deficient mice (Fabry mice) was compared with that of wild-type mice. Microarray analyses were performed using samples taken before and after intravenous infusion of alpha-galactosidase A. The identified genes were validated using quantitative real-time PCR and Western blot assay. Expression of hepatic Serum Amyloid A1 (Saa1), S100 Calcium-binding protein A8 and A9 (S100a8 and a9), and Lipocalin 2 (Lcn2) and renal Neuropeptide Y (Npy), Thrombospondin 2 and 4 (Tsp-2 and -4) was significantly upregulated in Fabry mice compared with wild-type mice and normalized by enzyme replacement therapy. Plasma concentrations of Lcn2 and Npy were also greater in Fabry mice and reduced to wild-type levels after enzyme replacement therapy, although the plasma concentrations of these proteins show heterogeneity. Upregulation of Saa1, S100a8, S100a9 and Lcn2 may modulate inflammation and Lcn2, Npy and Tsp may be associated with vascular and renal involvement in Fabry disease. Furthermore, these genes are promising targets for developing biomarkers for monitoring disease progression and therapeutic efficacy in patients with Fabry disease.

Topics: Acute-Phase Proteins; alpha-Galactosidase; Animals; Blotting, Western; Disease Models, Animal; Fabry Disease; Gene Expression Profiling; Gene Expression Regulation; Genetic Therapy; Kidney; Lipocalin-2; Lipocalins; Liver; Mice; Neuropeptide Y; Oncogene Proteins; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction; Thrombospondin 1; Trihexosylceramides

A modified alpha-N-acetylgalactosaminidase (NAGA) with alpha-galactosidase A (GLA)-like substrate specificity was designed on the basis of structural studies and was produced in Chinese hamster ovary cells. The enzyme acquired the ability to catalyze the degradation of 4-methylumbelliferyl-alpha-D-galactopyranoside. It retained the original NAGA's stability in plasma and N-glycans containing many mannose 6-phosphate (M6P) residues, which are advantageous for uptake by cells via M6P receptors. There was no immunological cross-reactivity between the modified NAGA and GLA, and the modified NAGA did not react to serum from a patient with Fabry disease recurrently treated with a recombinant GLA. The enzyme cleaved globotriaosylceramide (Gb3) accumulated in cultured fibroblasts from a patient with Fabry disease. Furthermore, like recombinant GLA proteins presently used for enzyme replacement therapy (ERT) for Fabry disease, the enzyme intravenously injected into Fabry model mice prevented Gb3 storage in the liver, kidneys, and heart and improved the pathological changes in these organs. Because this modified NAGA is hardly expected to cause an allergic reaction in Fabry disease patients, it is highly promising as a new and safe enzyme for ERT for Fabry disease.

Topics: alpha-N-Acetylgalactosaminidase; Amino Acid Substitution; Animals; Binding Sites; Catalysis; Cells, Cultured; CHO Cells; Cricetinae; Cricetulus; Culture Media, Conditioned; Disease Models, Animal; DNA, Complementary; Drug Stability; Enzyme Replacement Therapy; Fabry Disease; Fibroblasts; Fluorescent Dyes; Galactosides; Genetic Vectors; Humans; Hydrogen-Ion Concentration; Hymecromone; Immunohistochemistry; Kidney; Liver; Mice; Mice, Knockout; Models, Molecular; Molecular Weight; Myocardium; Recombinant Proteins; Retroviridae; Transfection; Trihexosylceramides

Shiga toxins (Stxs) are the major agents responsible for hemorrhagic colitis and hemolytic-uremic syndrome (HUS) during infections caused by Stx-producing Escherichia coli (STEC) such as serotype O157:H7. Central nervous system (CNS) involvement is an important determinant of mortality in diarrhea associated-HUS. It has been suggested that vascular endothelial injuries caused by Stxs play a crucial role in the development of the disease. The current study investigates the relationship between the cytotoxic effects of Stxs and inflammatory responses in a rabbit brain treated with Stx2.. In a rabbit model treated with purified Stx2 or PBS(-), we examined the expression of the Stx receptor globotriaosylceramide (Gb3)/CD77 in the CNS and microglial activation using immunohistochemistry. The relationship between inflammatory responses and neuronal cell death was analyzed by the following methods: real time quantitative reverse transcriptase (RT)-polymerase chain reaction (PCR) to determine the expression levels of pro-inflammatory cytokines, and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method to detect apoptotic changes.. Gb3/CD77 expression was detected in endothelial cells but not in neurons or glial cells. In the spinal cord gray matter, significant levels of Gb3/CD77 expression were observed. Severe endothelial injury and microvascular thrombosis resulted in extensive necrotic infarction, which led to acute neuronal damage. Conversely, in the brain, Stx receptor expression was much lower. The observed neuropathology was less severe. However, neuronal apoptosis was observed at the onset of neurological symptoms, and the number of apoptotic cells significantly increased in the brain at a later stage, several days after onset. Microglial activation was observed, and tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA in the CNS parenchyma was significantly up-regulated. There was significant overexpression of TNF-alpha transcripts in the brain.. This study indicates that Stx2 may not directly damage neural cells, but rather inflammatory responses occur in the brain parenchyma in response to primary injury by Stx2 in vascular endothelial cells expressing Gb3/CD77. These findings suggest that neuroinflammation may play a critical role in neurodegenerative processes during STEC infection and that anti-inflammatory intervention may have therapeutic potential.

Topics: Animals; Apoptosis; Central Nervous System Diseases; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelium, Vascular; Inflammation; Interleukin-1beta; Male; Neuroglia; Neurons; Rabbits; RNA, Messenger; Shiga Toxin 2; Trihexosylceramides; Tumor Necrosis Factor-alpha; Up-Regulation

Enterohemorrhagic Escherichia coli (EHEC) produces Shiga toxin (Stx) and causes renal disease in humans. Dutch Belted (DB) rabbits naturally infected with EHEC O153 develop hemolytic-uremic syndrome-like disease. The aims of this study were to experimentally reproduce O153-induced renal disease in DB rabbits and investigate bacterial and host factors involved in pathogenesis. The pathogenicity of E. coli O157:H7 was also investigated in rabbits. The stx1AB region of O153 was sequenced. By use of liquid chromatography-tandem mass spectrometry, we identified homologs of the Stx receptor, globotriaosylceramide (Gb3), in rabbit kidney extracts. Infected rabbits developed clinical signs and intestinal and kidney lesions. Renal pathological changes consisted of intimal swelling, perivascular edema, erythrocyte fragmentation, capillary thickening, luminal constriction, leukocytic infiltration, mesangial deposits, and changes in Bowman's capsule and space. Sequence analysis of a approximately 7-kb region of the O153 chromosome indicated homology to the Stx1-producing bacteriophage H19B. Our findings indicate that DB rabbits are suitable for the study of the renal manifestations of EHEC infection in humans.

Topics: Animals; Bacteriophages; Caco-2 Cells; Cecum; Disease Models, Animal; DNA, Bacterial; Escherichia coli Infections; Escherichia coli O157; Feces; Female; Hemolytic-Uremic Syndrome; Humans; Kidney; Male; Molecular Sequence Data; Rabbits; Sequence Analysis; Shiga Toxin; Time Factors; Trihexosylceramides

We have shown that the ABC transporter, multiple drug resistance protein 1 (MDR1, P-glycoprotein) translocates glucosyl ceramide from the cytosolic to the luminal Golgi surface for neutral, but not acidic, glycosphingolipid (GSL) synthesis. Here we show that the MDR1 inhibitor, cyclosporin A (CsA) can deplete Gaucher lymphoid cell lines of accumulated glucosyl ceramide and Fabry cell lines of globotriaosyl ceramide (Gb3), by preventing de novo synthesis. In the Fabry mouse model, Gb3 is increased in the heart, liver, spleen, brain and kidney. The lack of renal glomerular Gb3 is retained, but the number of verotoxin 1 (VT1)-staining renal tubules, and VT1 tubular targeting in vivo, is markedly increased in Fabry mice. Adult Fabry mice were treated with alpha-galactosidase (enzyme-replacement therapy, ERT) to eliminate serum Gb3 and lower Gb3 levels in some tissues. Serum Gb3 was monitored using a VT1 ELISA during a post-ERT recovery phase +/- biweekly intra peritoneal CsA. After 9 weeks, tissue Gb3 content and localization were determined using VT1/TLC overlay and histochemistry. Serum Gb3 recovered to lower levels after CsA treatment. Gb3 was undetected in wild-type liver, and the levels of Gb3 (but not gangliosides) in Fabry mouse liver were significantly depleted by CsA treatment. VT1 liver histochemistry showed Gb3 accumulated in Kupffer cells, endothelial cell subsets within the central and portal vein and within the portal triad. Hepatic venule endothelial and Kupffer cell VT1 staining was considerably reduced by in vivo CsA treatment. We conclude that MDR1 inhibition warrants consideration as a novel adjunct treatment for neutral GSL storage diseases.

Topics: alpha-Galactosidase; Animals; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line; Cyclosporine; Disease Models, Animal; Fabry Disease; Gaucher Disease; Kidney; Liver; Mice; Trihexosylceramides

Fabry disease is an X-linked inherited loss of alpha-galactosidase A (alpha-Gal A). Affected patients experience complications that include neuropathy, renal failure, and cardiovascular disease. Although the genetic and biochemical basis of this sphingolipidosis is well studied, the basis for the vascular disease remains poorly understood. In an attempt to create a suitable in vitro model of this disease, conditions for the growth of primary cultures of aortic endothelial cells from wild-type and alpha-Gal A -/0 mice were established. The cultured cells demonstrated CD-31 expression by flow cytometry and LDL binding by immunofluorescence. The glycolipid expression patterns were compared between wild-type and alpha-Gal A null cells. Importantly, cells from alpha-Gal A -/0 mice but not alpha-Gal A +/0 mice expressed high levels of the globo-series glycosphingolipid globotriaosylceramide (Gb3). The age-dependent elevation in Gb3 was measured. By 4 mo of age, alpha-Gal A -/0 mouse aortic endothelial cells achieved their peak Gb3 levels. The ability to lower Gb3 levels pharmacologically was assessed next. The glucosylceramide synthase inhibitor ethylenedioxyphenyl-P4 significantly lowered but did not eliminate Gb3 levels by 96 h of treatment. Gb3 synthesis was completely blocked as measured by [14C]galactose labeling. Recombinant alpha-Gal A more significantly lowered Gb3 levels by 48 h but had a more limited effect on de novo synthesis. Together, both agents eliminated detectable Gb3. In summary, primary cultures of aortic endothelial cells from Fabry mice retain the phenotype of elevated globo-series glycosphingolipids. These cells provide a useful model for comparing pharmacologic agents used for glycolipid reduction.

Topics: alpha-Galactosidase; Animals; Cells, Cultured; Disease Models, Animal; Endothelium, Vascular; Enzyme Inhibitors; Fabry Disease; Glucosyltransferases; Humans; In Vitro Techniques; Mice; Mice, Inbred C57BL; Mice, Knockout; Propanolamines; Pyrrolidines; Recombinant Proteins; Trihexosylceramides

Fabry disease is a recessive, X-linked disorder caused by a deficiency of the lysosomal enzyme alpha-galactosidase A, leading to an accumulation of the glycosphingolipid globotriaosylceramide (GL-3) in most tissues of the body. The goal of this study was to determine if systemic delivery of a nonviral vector could correct the enzyme deficiency and reduce the levels of GL-3 in different tissues of a transgenic knockout mouse model of the disease.. Cationic lipid was complexed with a CpG-depleted plasmid DNA vector and then injected intravenously into Fabry mice. The levels of alpha-galactosidase A and GL-3 in different tissues were assayed at various time points after injection.. Expression of alpha-galactosidase A was detected in the different tissues of Fabry mice for up to 3 months after complex administration, but resulted in minimal reductions in GL-3 levels. However, the use of the anti-inflammatory drug dexamethasone and multiple dosing increased alpha-galactosidase A expression and resulted in significant reductions of GL-3 in all the organs with the exception of the kidney. In addition, injecting complex into young Fabry mice partially prevented the normal accumulation of GL-3 in the heart, lung, and liver.. Systemic delivery of a cationic lipid-pDNA complex partially corrected the enzyme deficiency and reduced glycolipid storage in a mouse model of Fabry disease. The results are one of the few demonstrations of long-term efficacy in a genetic disease model using nonviral vectors. However, substantial improvements in expression, especially in critical organs such as the kidney, are required before these vectors can become a viable approach to treat Fabry disease and other lysosomal storage disorders.

Topics: alpha-Galactosidase; Animals; Disease Models, Animal; Fabry Disease; Female; Gene Expression; Genetic Therapy; Genetic Vectors; Lipids; Mice; Mice, Inbred BALB C; Plasmids; Trihexosylceramides

Shiga toxin (Stx) is a major virulence factor in infection with Stx-producing Escherichia coli (STEC). We developed a series of linear polymers of acrylamide, each with a different density of trisaccharide of globotriaosylceramide (Gb3), which is a receptor for Stx, and identified Gb3 polymers with highly clustered trisaccharides as Stx adsorbents functioning in the gut. The Gb3 polymers specifically bound to both Stx1 and Stx2 with high affinity and markedly inhibited the cytotoxic activities of these toxins. Oral administration of the Gb3 polymers protected mice after administration of a fatal dose of E. coli O157:H7, even when the polymers were administered after the infection had been established. In these mice, the serum level of Stx was markedly reduced and fatal brain damage was substantially suppressed, which suggests that the Gb3 polymers entrap Stx in the gut and prevent its entrance into the circulation. These results indicate that the Gb3 polymers can be used as oral therapeutic agents that function in the gut against STEC infections.

Topics: Acrylamide; Animals; Brain Chemistry; Carbohydrate Sequence; Disease Models, Animal; Dose-Response Relationship, Drug; Escherichia coli Infections; Escherichia coli O157; Female; Hemolytic-Uremic Syndrome; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Polymers; Protein Binding; Receptors, Cell Surface; Shiga Toxin 1; Shiga Toxin 2; Shiga Toxins; Trihexosylceramides; Trisaccharides

Fabry disease is an inborn error of glycosphingolipid metabolism caused by the deficiency of lysosomal alpha-galactosidase A (alpha-Gal A). We have established transgenic mice that exclusively express human mutant alpha-Gal A (R301Q) in an alpha-Gal A knock-out background (TgM/KO mice). This serves as a biochemical model to study and evaluate active-site specific chaperone (ASSC) therapy for Fabry disease, which is specific for those missense mutations that cause misfolding of alpha-Gal A. The alpha-Gal A activities in the heart, kidney, spleen, and liver of homozygous TgM/KO mice were 52.6, 9.9, 29.6 and 44.4 unit/mg protein, respectively, corresponding to 16.4-, 0.8-, 0.6- and 1.4-fold of the endogenous enzyme activities in the same tissues of non-transgenic mice with a similar genetic background. Oral administration of 1-deoxygalactonojirimycin (DGJ), a competitive inhibitor of alpha-Gal A and an effective ASSC for Fabry disease, at 0.05 mM in the drinking water of the mice for 2 weeks resulted in 13.8-, 3.3-, 3.9-, and 2.6-fold increases in enzyme activities in the heart, kidney, spleen and liver, respectively. No accumulation of globotriaosylceramide, a natural substrate of alpha-Gal A, could be detected in the heart of TgM/KO mice after DGJ treatment, indicating that degradation of the glycolipid in the heart was not inhibited by DGJ at that dosage. The alpha-Gal A activity in homozygous or heterozygous fibroblasts established from TgM/KO mice (TMK cells) was approximately 39 and 20 unit/mg protein, respectively. These TgM/KO mice and TMK cells are useful tools for studying the mechanism of ASSC therapy, and for screening ASSCs for Fabry disease.

Topics: 1-Deoxynojirimycin; alpha-Galactosidase; Animals; Binding Sites; Cells, Cultured; Disease Models, Animal; Fabry Disease; Fibroblasts; Genetic Therapy; Heart; Humans; Mice; Mice, Knockout; Mice, Transgenic; Molecular Chaperones; Mutation; Myocardium; Protein Folding; RNA, Messenger; Sensitivity and Specificity; Trihexosylceramides

Both verotoxin (VT)1 and VT2 share the same receptor, globotriaosyl ceramide (Gb(3)). Although VT1 is slightly more cytotoxic in vitro and binds Gb(3) with higher affinity, VT2 is more toxic in mice and may be associated with greater pathology in human infections. In this study we have compared the biodistribution of iodine 125 ((125)I)-VT1 and (125)I-VT2 versus pathology in the mouse.. (125)I-VT1 whole-body autoradiography defined the tissues targeted. VT1 and VT2 tissue distribution, clearance, and tissue binding sites were compared. The effect of a soluble receptor analogue, adamantylGb(3), on VT2/Gb3 binding and in vivo pathology was assessed.. (125)I-VT1 autoradiography identified the lungs and nasal turbinates as major, previously unrecognized, targets, while kidney cortex and the bone marrow of the spine, long bones, and ribs were also significant targets. VT2 did not target the lung, but accumulated in the kidney to a greater extent than VT1. The serum half-life of VT1 was 2.7 minutes with 90% clearance at 5 minutes, while that of VT2 was 3.9 minutes with only 40% clearance at 5 minutes. The extensive binding of VT1, but not VT2, within the lung correlated with induced lung disease. Extensive hemorrhage into alveoli, edema, alveolitis and neutrophil margination was seen only after VT1 treatment. VT1 targeted lung capillary endothelial cells. Identical tissue binding sites (subsets of proximal/distal tubules and collecting ducts) for VT1 and VT2 were detected by toxin overlay of serial frozen kidney sections. Glucosuria was found to be a new marker of VT1- and VT2-induced renal pathology and positive predictor of outcome in the mouse, consistent with VT-staining of proximal tubules. Lung Gb3 migrated on thin-layer chromatography (TLC) faster than kidney Gb(3), suggesting a different lipid composition. AdamantylGb(3), a soluble Gb(3) analogue, competed effectively for Gb3 binding by VT1 and VT2 in vitro. However, the effect in the mouse model (only measured against VT2, due to the lower LD(50), a concentration required for 50% lethality) was to increase, rather than reduce, pathology and further reduce the VT2 serum clearance rate. Additional renal pathology was seen in VT2 + adamantylGb(3)-treated mice.. The lung is a preferential (Gb(3)) "sink" for VT1, which explains the relatively slower clearance of VT2 and subsequent increased VT2 renal targeting and VT2 mortality in this animal model.

Topics: Animals; Autoradiography; Disease Models, Animal; Female; Hemolytic-Uremic Syndrome; Iodine Radioisotopes; Kidney; Lung; Mice; Mice, Inbred BALB C; Radionuclide Imaging; Shiga Toxin 1; Shiga Toxin 2; Tissue Distribution; Trihexosylceramides

Oral infection with enterohemorrhagic Escherichia coli (EHEC) may cause severe enteritis, followed in up to 10% of cases by an extraintestinal complication, the hemolytic uremic syndrome (HUS). HUS is characterized by a triad of symptoms: anemia, thrombocytopenia, and acute renalfailure due to thrombotic microangiopathy. EHEC produces several virulence factors, among which a family of phage-encoded cytotoxins, called Shiga toxin 1 and Shiga toxin 2, seems to be most important. However, since an appropriate animal model is not available, pathogenicity of these emerging enteric pathogens is still poorly understood. Germ-free gnotobiotic piglets infected orally with an O1577:H7 or an O26:H11 EHEC wild-type isolate, both producing Shiga toxin 2, developed intestinal and extraintestinal manifestations of EHEC disease, including thrombotic microangiopathy in the kidneys, the morphologic hallmark of HUS in humans. Thus, gnotobiotic piglets are suitable to further study the pathophysiology of EHEC-induced HUS. It can be expected that data obtainedfrom this animal model will improve our current standard of knowledge about this emerging infectious disease.

Topics: Animals; Child, Preschool; Digestive System; Disease Models, Animal; Endothelium, Vascular; Escherichia coli Infections; Escherichia coli O157; Female; Germ-Free Life; Hemolytic-Uremic Syndrome; Humans; Immunohistochemistry; Kidney; Microcirculation; Purpura, Thrombotic Thrombocytopenic; Shiga Toxin 2; Swine; Swine Diseases; Trihexosylceramides

Fabry disease is a systemic disease caused by genetic deficiency of a lysosomal enzyme, alpha-galactosidase A (alpha-gal A), and is thought to be an important target for enzyme replacement therapy. We studied the feasibility of gene-mediated enzyme replacement for Fabry disease. The adeno-associated virus (AAV) vector containing the alpha-gal A gene was injected into the right quadriceps muscles of Fabry knockout mice. A time course study showed that alpha-gal A activity in plasma was increased to approximately 25% of normal mice and that this elevated activity persisted for up to at least 30 weeks without development of anti-alpha-gal A antibodies. The alpha-gal A activity in various organs of treated Fabry mice remained 5-20% of those observed in normal mice. Accumulated globotriaosylceramide in these organs was completely cleared by 25 weeks after vector injection. Reduction of globotriaosylceramide levels was also confirmed by immunohistochemical and electronmicroscopic analyses. Echocardiographic examination of treated mice demonstrated structural improvement of cardiac hypertrophy 25 weeks after the treatment. AAV vector-mediated muscle-directed gene transfer provides an efficient and practical therapeutic approach for Fabry disease.

Topics: alpha-Galactosidase; Animals; Cell Line; Dependovirus; Disease Models, Animal; Fabry Disease; Female; Genetic Therapy; Genetic Vectors; HeLa Cells; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Skeletal; Myocardium; Trihexosylceramides