eliglustat-tartrate 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

Fabry disease is an X-linked disorder of glycosphingolipid metabolism that results in progressive accumulation of neutral glycosphingolipids, (predominately globotriaosylceramide; GL-3) in lysosomes, as well as other cellular compartments and the extracellular space. Our aim was to characterize the cardiac phenotype of male knock-out mice that are deficient in alpha-galactosidase A activity, as a model for Fabry disease and test the efficacy of Enzyme Replacement Therapy with agalsidase-beta. Male mice (3-4 months of age) were characterized with awake blood pressure and heart rate measurements, cardiac echocardiography and electrocardiography measurements under light anesthesia, histological studies and molecular studies with real-time polymerase chain reaction. The Fabry knock-out mouse has bradycardia and lower blood pressure than control wild type (CB7BL/6J) mice. In Fabry knock-out mice, the cardiomyopathy associated mild hypertrophy at echography with normal systolic LV function and mild diastolic dysfunction. Premature atrial contractions were more frequent in without conduction defect. Heart weight normalized to tibial length was increased in Fabry knock-out mice. Ascending aorta dilatation was observed. Molecular studies were consistent with early stages of cardiac remodeling. A single dose of agalsidase-beta (3 mg/kg) did not affect the LV hypertrophy, function or heart rate, but did improve the mRNA signals of early cardiac remodeling. In conclusion, the alpha-galactosidase A deficient mice at 3 to 4 months of age have cardiac and vascular alterations similar to that described in early clinical stage of Fabry disease in children and adolescents. Enzyme replacement therapy affects cardiac molecular remodeling after a single dose.

Topics: alpha-Galactosidase; Animals; Aorta; Blood Pressure; Cardiomyopathies; Disease Models, Animal; Electrocardiography; Enzyme Replacement Therapy; Fabry Disease; Gene Knockout Techniques; Heart Rate; Heart Ventricles; Isoenzymes; Male; Mice; Mice, Inbred C57BL; Organ Size; Time Factors; Treatment Outcome

We compared two recombinant alpha-galactosidases developed for enzyme replacement therapy for Fabry disease, agalsidase alfa and agalsidase beta, as to specific alpha-galactosidase activity, stability in plasma, mannose 6-phosphate (M6P) residue content, and effects on cultured human Fabry fibroblasts and Fabry mice. The specific enzyme activities of agalsidase alfa and agalsidase beta were 1.70 and 3.24 mmol h(-1) mg protein(-1), respectively, and there was no difference in stability in plasma between them. The M6P content of agalsidase beta (3.6 mol/mol protein) was higher than that of agalsidase alfa (1.3 mol/mol protein). The administration of both enzymes resulted in marked increases in alpha-galactosidase activity in cultured human Fabry fibroblasts, and Fabry mouse kidneys, heart, spleen and liver. However, the increase in enzyme activity in cultured fibroblasts, kidneys, heart and spleen was higher when agalsidase beta was used. An immunocytochemical analysis revealed that the incorporated recombinant enzyme degraded the globotriaosyl ceramide accumulated in cultured Fabry fibroblasts in a dose-dependent manner, with the effect being maintained for at least 7 days. Repeated administration of agalsidase beta apparently decreased the number of accumulated lamellar inclusion bodies in renal tubular cells of Fabry mice.

Topics: alpha-Galactosidase; Animals; Cells, Cultured; Disease Models, Animal; Fabry Disease; Fibroblasts; Humans; Isoenzymes; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron; Recombinant Proteins