scholarly journals Optimization of Enzyme Essays to Enhance Reliability of Activity Measurements in Leukocyte Lysates for the Diagnosis of Metachromatic Leukodystrophy and Gangliosidoses

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2553
Author(s):  
Sebastian Strobel ◽  
Naomi Hesse ◽  
Vidiyaah Santhanakumaran ◽  
Samuel Groeschel ◽  
Gernot Bruchelt ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Enzyme Activities ◽  
Metachromatic Leukodystrophy ◽  
Gradient Centrifugation ◽  
Lysosomal Storage Diseases ◽  
Total Leukocyte Count ◽  
Lysosomal Storage ◽  
Inherited Disorders ◽  
Activity Measurements ◽  
Magnetic Cell Separation

(1) Lysosomal storage diseases are rare inherited disorders with no standardized or commercially available tests for biochemical diagnosis. We present factors influencing the quality of enzyme assays for metachromatic leukodystrophy (MLD) and gangliosidoses (GM1; GM2 variants B and 0) and validate the reliability and stability of testing in a retrospective analysis of 725 samples. (2) Patient leukocytes were isolated from ethylene-diamine-tetra-acetic acid (EDTA) blood and separated for subpopulation experiments using density gradient centrifugation or magnetic cell separation. Enzyme activities in whole leukocyte lysate and leukocyte subpopulations were determined. (3) The enzyme activities in leukocyte subpopulations differed significantly. Compared to lymphocytes, the respective enzyme activities were 2.31–4.57-fold higher in monocytes and 1.64–2.81-fold higher in granulocytes. During sample preparation, a considerable amount of the lysosomal enzymes was released from granulocytes. Nevertheless, with the sample preparation method used here, total leukocyte count proved to be more accurate than total protein amount as a reference unit for enzyme activities. Subsequent analysis of 725 individuals showed clear discrimination of enzyme activities in patient samples (48 MLD; 21 gangliosidoses), with a sensitivity of 100% and specificity of 98–99%.

scholarly journals Lyso-glycosphingolipids: presence and consequences

2020 ◽  
Vol 64 (3) ◽  
pp. 565-578 ◽  
Author(s):  
Marco van Eijk ◽  
Maria J. Ferraz ◽  
Rolf G. Boot ◽  
Johannes M.F.G. Aerts
Keyword(s):  
Metachromatic Leukodystrophy ◽  
Lysosomal Storage Diseases ◽  
Krabbe Disease ◽  
Lysosomal Storage ◽  
Gm2 Gangliosidosis ◽  
Acid Ceramidase ◽  
Lysosomal Diseases ◽  
Type C ◽  
Niemann Pick ◽  
Storage Disorders

Abstract Lyso-glycosphingolipids are generated in excess in glycosphingolipid storage disorders. In the course of these pathologies glycosylated sphingolipid species accumulate within lysosomes due to flaws in the respective lipid degrading machinery. Deacylation of accumulating glycosphingolipids drives the formation of lyso-glycosphingolipids. In lysosomal storage diseases such as Gaucher Disease, Fabry Disease, Krabbe disease, GM1 -and GM2 gangliosidosis, Niemann Pick type C and Metachromatic leukodystrophy massive intra-lysosomal glycosphingolipid accumulation occurs. The lysosomal enzyme acid ceramidase generates the deacylated lyso-glycosphingolipid species. This review discusses how the various lyso-glycosphingolipids are synthesized, how they may contribute to abnormal immunity in glycosphingolipid storing lysosomal diseases and what therapeutic opportunities exist.

scholarly journals Hurler-like Phenotype

2001 ◽  
Vol 47 (12) ◽  
pp. 2098-2102 ◽  
Author(s):  
Néstor A Chamoles ◽  
Mariana B Blanco ◽  
Daniela Gaggioli ◽  
Carina Casentini
Keyword(s):  
Enzyme Activities ◽  
Lysosomal Storage Diseases ◽  
Dried Blood Spots ◽  
Lysosomal Storage ◽  
Testing Laboratory ◽  
Storage Diseases ◽  
Blood Spots ◽  
Sample Stability ◽  
Mucolipidosis Ii ◽  
Radioactive Substrate

Abstract Background: Clinical differentiation among mucopolysaccharidosis, oligosaccharidosis, and mucolipidosis II and III is difficult. We describe methods for the assay of 8 lysosomal enzymes in dried blood spots on filter paper that allow screening for 12 lysosomal storage diseases that present with a Hurler-like phenotype. Methods: To test tubes containing 3-mm blood spots, we added elution liquid and fluorescent or radioactive substrate solution. After incubation at 37 °C, the reaction was terminated by the addition of a stop buffer. The amount of hydrolyzed product was compared with a calibrator to allow the quantification of enzyme activity. Sample stability was studied during storage for 21 days and during shipment of samples. We measured enzyme activities in 85 healthy controls (35 newborn, 50 adult), 57 patients suffering from 11 lysosomal storage diseases, and 46 obligate carriers. Results: Intra- and interassay CVs were <9% and <15%, respectively. Mean activity losses during transportation or storage for up to 21 days at 4 °C were ≤27%. Enzyme activities in all patients were outside the ranges of values seen for carriers and controls. Conclusions: The described methodology distinguishes between patients and controls with samples that are sufficiently stable to be mailed to the testing laboratory.

scholarly journals Dysregulation of autophagy as a common mechanism in lysosomal storage diseases

2017 ◽  
Vol 61 (6) ◽  
pp. 733-749 ◽  
Author(s):  
Elena Seranova ◽  
Kyle J. Connolly ◽  
Malgorzata Zatyka ◽  
Tatiana R. Rosenstock ◽  
Timothy Barrett ◽  
...  
Keyword(s):  
Negative Impact ◽  
Late Onset ◽  
Lysosomal Storage Diseases ◽  
Common Mechanism ◽  
Lysosomal Storage ◽  
Inherited Disorders ◽  
Current Therapies ◽  
Autophagy Pathway ◽  
Cellular Components ◽  
Cellular Stressors

The lysosome plays a pivotal role between catabolic and anabolic processes as the nexus for signalling pathways responsive to a variety of factors, such as growth, nutrient availability, energetic status and cellular stressors. Lysosomes are also the terminal degradative organelles for autophagy through which macromolecules and damaged cellular components and organelles are degraded. Autophagy acts as a cellular homeostatic pathway that is essential for organismal physiology. Decline in autophagy during ageing or in many diseases, including late-onset forms of neurodegeneration is considered a major contributing factor to the pathology. Multiple lines of evidence indicate that impairment in autophagy is also a central mechanism underlying several lysosomal storage disorders (LSDs). LSDs are a class of rare, inherited disorders whose histopathological hallmark is the accumulation of undegraded materials in the lysosomes due to abnormal lysosomal function. Inefficient degradative capability of the lysosomes has negative impact on the flux through the autophagic pathway, and therefore dysregulated autophagy in LSDs is emerging as a relevant disease mechanism. Pathology in the LSDs is generally early-onset, severe and life-limiting but current therapies are limited or absent; recognizing common autophagy defects in the LSDs raises new possibilities for therapy. In this review, we describe the mechanisms by which LSDs occur, focusing on perturbations in the autophagy pathway and present the latest data supporting the development of novel therapeutic approaches related to the modulation of autophagy.

scholarly journals Gene therapy: prospects for glycolipid storage diseases

2003 ◽  
Vol 358 (1433) ◽  
pp. 921-925 ◽  
Author(s):  
Volkmar Gieselmann ◽  
Ulrich Matzner ◽  
Diana Klein ◽  
Jan Eric Mansson ◽  
Rudi D'Hooge ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Mouse Models ◽  
Metachromatic Leukodystrophy ◽  
Lysosomal Storage Diseases ◽  
Degradation Pathway ◽  
Lysosomal Storage ◽  
Storage Diseases ◽  
Lysosomal Disorders ◽  
Lysosomal Diseases

Lysosomal storage diseases comprise a group of about 40 disorders, which in most cases are due to the deficiency of a lysosomal enzyme. Since lysosomal enzymes are involved in the degradation of various compounds, the diseases can be further subdivided according to which pathway is affected. Thus, enzyme deficiencies in the degradation pathway of glycosaminoglycans cause mucopolysaccharidosis, and deficiencies affecting glycopeptides cause glycoproteinosis. In glycolipid storage diseases enzymes are deficient that are involved in the degradation of sphingolipids. Mouse models are available for most of these diseases, and some of these mouse models have been used to study the applicability of in vivo gene therapy. We review the rationale for gene therapy in lysosomal disorders and present data, in particular, about trials in an animal model of metachromatic leukodystrophy. The data of these trials are compared with those obtained with animal models of other lysosomal diseases.

scholarly journals Simplified Newborn Screening Protocol for Lysosomal Storage Disorders

2011 ◽  
Vol 57 (9) ◽  
pp. 1286-1294 ◽  
Author(s):  
Thomas F Metz ◽  
Thomas P Mechtler ◽  
Joseph J Orsini ◽  
Monica Martin ◽  
Bori Shushan ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Solid Phase ◽  
New York State ◽  
Lysosomal Storage Disorders ◽  
Krabbe Disease ◽  
Lysosomal Storage ◽  
Enzyme Replacement ◽  
Storage Disorders

BACKGROUND Interest in lysosomal storage disorders, a collection of more than 40 inherited metabolic disorders, has increased because of new therapy options such as enzyme replacement, stem cell transplantation, and substrate reduction therapy. We developed a high-throughput protocol that simplifies analytical challenges such as complex sample preparation and potential interference from excess residual substrate associated with previously reported assays. METHODS After overnight incubation (16–20 h) of dried blood spots with a cassette of substrates and deuterated internal standards, we used a TLX-2 system to quantify 6 lysosomal enzyme activities for Fabry, Gaucher, Niemann-Pick A/B, Pompe, Krabbe, and mucopolysaccharidosis I disease. This multiplexed, multidimensional ultra-HPLC–tandem mass spectrometry assay included Cyclone P Turbo Flow and Hypersil Gold C8 columns. The method did not require offline sample preparation such as liquid–liquid and solid-phase extraction, or hazardous reagents such as ethyl acetate. RESULTS Obviating the offline sample preparation steps led to substantial savings in analytical time (approximately 70%) and reagent costs (approximately 50%). In a pilot study, lysosomal enzyme activities of 8586 newborns were measured, including 51 positive controls, and the results demonstrated 100% diagnostic sensitivity and high specificity. The results for Krabbe disease were validated with parallel measurements by the New York State Screening Laboratory. CONCLUSIONS Turboflow online sample cleanup and the use of an additional analytical column enabled the implementation of lysosomal storage disorder testing in a nationwide screening program while keeping the total analysis time to <2 min per sample.

Electron Microscopy in the diagnosis of lysosomal storage diseases

1989 ◽  
Vol 47 ◽  
pp. 866-867
Author(s):  
Carole Vogler ◽  
Harvey S. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Lysosomal Enzyme ◽  
Rectal Mucosa ◽  
Lysosomal Storage Diseases ◽  
Cell Types ◽  
Lysosomal Storage ◽  
Storage Material ◽  
Ultrastructural Examination ◽  
Blood Leukocytes ◽  
Storage Diseases

Diagnostic procedures for evaluation of patients with lysosomal storage diseases (LSD) seek to identify a deficiency of a responsible lysosomal enzyme or accumulation of a substance that requires the missing enzyme for degradation. Most patients with LSD have progressive neurological degeneration and may have a variety of musculoskeletal and visceral abnormalities. In the LSD, the abnormally diminished lysosomal enzyme results in accumulation of unmetabolized catabolites in distended lysosomes. Because of the subcellular morphology and size of lysosomes, electron microscopy is an ideal tool to study tissue from patients with suspected LSD. In patients with LSD all cells lack the specific lysosomal enzyme but the distribution of storage material is dependent on the extent of catabolism of the substrate in each cell type under normal circumstances. Lysosmal storages diseases affect many cell types and tissues. Storage material though does not accumulate in all tissues and cell types and may be different biochemically and morphologically in different tissues.Conjunctiva, skin, rectal mucosa and peripheral blood leukocytes may show ultrastructural evidence of lysosomal storage even in the absence of clinical findings and thus any of these tissues can be used for ultrastructural examination in the diagnostic evaluation of patients with suspected LSD. Biopsy of skin and conjunctiva are easily obtained and provide multiple cell types including endothelium, epithelium, fibroblasts and nerves for ultrastructural study. Fibroblasts from skin and conjunctiva can also be utilized for the initiation of tissue cultures for chemical assays. Brain biopsy has been largely replaced by biopsy of more readily obtained tissue and by biochemical assays. Such assays though may give equivical or nondiagnostic results and in some lysosomal storage diseases an enzyme defect has not yet been identified and diagnoses can be made only by ultrastructural examination.

Sign in / Sign up

Export Citation Format

Share Document