scholarly journals Golgi requires a new casting in the screenplay of mucopolysaccharidosis II cytopathology

2021 ◽  
Author(s):  
Kinga Molnár ◽  
Julianna Kobolák ◽  
András Dinnyés

AbstractLysosome (L), a hydrolytic compartment of the endo-lysosomal system (ELS), plays a central role in the metabolic regulation of eukaryotic cells. Furthermore, it has a central role in the cytopathology of several diseases, primarily in lysosomal storage diseases (LSDs). Mucopolysaccharidosis II (MPS II, Hunter disease) is a rare LSD caused by idunorate-2-sulphatase (IDS) enzyme deficiency. To provide a new platform for drug development and clarifying the background of the clinically observed cytopathology, we established a human in vitro model, which recapitulates all cellular hallmarks of the disease. Some of our results query the traditional concept by which the storage vacuoles originate from the endosomal system and suggest a new concept, in which endoplasmic reticulum-Golgi intermediate compartment (ERGIC) and RAB2/LAMP positive Golgi (G) vesicles play an initiative role in the vesicle formation. In this hypothesis, Golgi is not only an indirectly affected organelle but enforced to be the main support of vacuole formation. The purposes of this minireview are to give a simple guide for understanding the main relationships in ELS, to present the storage vacuoles and their relation to ELS compartments, to recommend an alternative model for vacuole formation, and to place the Golgi in spotlight of MPS II cytopathology.

Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 2142-2150 ◽  
Author(s):  
Brian J. Freeman ◽  
Marie S. Roberts ◽  
Carole A. Vogler ◽  
Andrew Nicholes ◽  
A. Alex Hofling ◽  
...  

Abstract Bone marrow transplantation (BMT) is relatively effective for the treatment of lysosomal storage diseases. To better understand the contribution of specific hematopoietic lineages to the efficacy of BMT, we transplanted β-glucuronidase–positive mononuclear phagocytes derived from either the peritoneum or from bone marrow in vitro into syngeneic recipients with mucopolysaccharidosis type VII (MPS VII). Cell surface marking studies indicate that the bone marrow-derived cells are less mature than the peritoneal macrophages. However, both cell types retain the ability to home to tissues rich in cells of the reticuloendothelial system after intravenous injection into MPS VII mice. The half-life of both types of donor macrophages is approximately 7 days, and some cells persist for at least 30 days. In several tissues, therapeutic levels of β-glucuronidase are present, and histopathologic analysis demonstrates that lysosomal storage is dramatically reduced in the liver and spleen. Macrophages intravenously injected into newborn MPS VII mice localize to the same tissues as adult mice but are also observed in the meninges and parenchyma of the brain. These data suggest that macrophages play a significant role in the therapeutic efficacy of BMT for lysosomal storage diseases and may have implications for treatments such as gene therapy.


Author(s):  
Kevin B. Hoover

Chapter 84 discusses mucopolysaccharidoses, which are genetic, lysosomal storage diseases resulting in the accumulation of glycosaminoglycans (GAG) in the soft tissues. Musculoskeletal complications of mucopolysaccharidosis (MPS) are common beginning in childhood. These result from abnormal ossification and periarticular GAG accumulation. Radiographs of the axial and appendicular skeleton (skeletal survey) are used for the baseline assessment of MPS disease. Progression of skeletal abnormalities is monitored with annual cervical spine MRI. Stem cell transplantation is the treatment of choice in MPS I, and enzyme replacement therapy (ERT) is the treatment of choice in MPS I Hurler-Scheie and Scheie, MPS II, and MPS VI.


2015 ◽  
Vol 61 (11) ◽  
pp. 1363-1371 ◽  
Author(s):  
Arun Babu Kumar ◽  
Sophia Masi ◽  
Farideh Ghomashchi ◽  
Naveen Kumar Chennamaneni ◽  
Makoto Ito ◽  
...  

Abstract BACKGROUND There is interest in newborn screening and diagnosis of lysosomal storage diseases because of the development of treatment options that improve clinical outcome. Assays of lysosomal enzymes with high analytical range (ratio of assay response from the enzymatic reaction divided by the assay response due to nonenzymatic processes) are desirable because they are predicted to lead to a lower rate of false positives in population screening and to more accurate diagnoses. METHODS We designed new tandem mass spectrometry (MS/MS) assays that give the largest analytical ranges reported to date for the use of dried blood spots (DBS) for detection of mucopolysaccharidoses type II (MPS-II), MPS-IVA, and MPS-VI. For comparison, we carried out fluorometric assays of 6 lysosomal enzymes using 4-methylumbelliferyl (4MU)-substrate conjugates. RESULTS The MS/MS assays for MPS-II, -IVA, and -VI displayed analytical ranges that are 1–2 orders of magnitude higher than those for the corresponding fluorometric assays. The relatively small analytical ranges of the 4MU assays are due to the intrinsic fluorescence of the 4MU substrates, which cause high background in the assay response. CONCLUSIONS These highly reproducible MS/MS assays for MPS-II, -IVA, and -VI can support multiplex newborn screening of these lysosomal storage diseases. MS/MS assays of lysosomal enzymes outperform 4MU fluorometric assays in terms of analytical range. Ongoing pilot studies will allow us to gauge the impact of the increased analytical range on newborn screening performance.


2021 ◽  
Vol 7 (20) ◽  
pp. eabf4155
Author(s):  
Alexei Gorelik ◽  
Katalin Illes ◽  
S. M. Naimul Hasan ◽  
Bhushan Nagar ◽  
Mohammad T. Mazhab-Jafari

The enzymes β-galactosidase (GLB1) and neuraminidase 1 (NEU1; sialidase 1) participate in the degradation of glycoproteins and glycolipids in the lysosome. To remain active and stable, they associate with PPCA [protective protein cathepsin A (CTSA)] into a high–molecular weight lysosomal multienzyme complex (LMC), of which several forms exist. Genetic defects in these three proteins cause the lysosomal storage diseases GM1-gangliosidosis/mucopolysaccharidosis IV type B, sialidosis, and galactosialidosis, respectively. To better understand the interactions between these enzymes, we determined the three-dimensional structure of the murine LMC core. This 0.8-MDa complex is composed of three GLB1 dimers and three CTSA dimers, adopting a triangular architecture maintained through six copies of a unique GLB1-CTSA polar interface. Mutations in this contact surface that occur in GM1-gangliosidosis prevent formation of the LMC in vitro. These findings may facilitate development of therapies for lysosomal storage disorders.


Author(s):  
Juan Camilo Losada Diaz ◽  
Jacobo Cepeda Del Castillo ◽  
Edwin Alexander Rodríguez López ◽  
Carlos Javier Alméciga-Díaz

The mucopolysaccharidoses (MPS) are a group of 11 lysosomal storage diseases (LSDs) produced by mutations in the enzymes involved in the lysosomal catabolism of glycosaminoglycans. Most of the mutations affecting these enzymes may lead to changes in processing, folding, glycosylation, pH stability, protein aggregation, and defective transport to the lysosomes. The use of small molecules, called pharmacological chaperones (PCs), that can restore the folding, trafficking and biological activity of mutated enzymes has been extensively explored in LSDs as a therapeutic alternative. PCs have the advantage of wide tissue distribution, potential oral administration, lower production cost, and fewer issues of immunogenicity. In this paper, we will review the advances in the identification and characterization of PCs for the MPS. These molecules, mainly based in molecules mimicking the enzyme substrates, have been described for MPS II, IVA, and IVB, showing a mutation-dependent enhancement of the mutated enzymes. Although the results show the potential of this strategy, further studies should focus in the development of disease-specific cellular models that allow a proper screening and evaluation of the identified PCs. In addition, in vivo evaluation, both pre-clinical and clinical, should be performed, before they can become a real therapeutic strategy for the treatment of MPS patients.


2021 ◽  
Vol 5 (2) ◽  
pp. 26-30
Author(s):  
Affandi Omar ◽  
Dyg Pertiwi Abg Kamaludin ◽  
Salina Abdul Rahman ◽  
Rosnani Mohamed ◽  
Fatimah Diana Amin Nordin ◽  
...  

Background: Mucopolysaccharidoses type II (MPS II) is an X-linked lysosomal storage disease (LSD). It is due to mutation in IDS gene encoding iduronate-2-sulphatase (IDS) involved in the catabolism of dermatan sulphate and heparan sulphate. Currently, the treatments for MPS II patients are enzyme replacement therapy (ERT) and bone marrow transplantation (BMT). However, ERT is not effectively reducing the central nervous system manifestation and finding the suitable donor maybe quite challenging in BMT. Over the past decades, pharmacological chaperone has been an alternative approach for management of MPS II patient. Here, we described the in vitro profiling of small molecules in group of chondroitin/dermatan (CD) sulphate disaccharide, heparin oligosaccharides, unsaturated heparin disaccharides and 6-O-desulphated heparin oligosaccharide, using recombinant human iduronate-2-sulphatase (rhIDS). Twenty-one small molecule compounds with several concentrations were each screened by inhibition and thermal stability assays. Results: Our study revealed that condroitin dermatan trisulphate (CD3S), heparin tetrasaccharide (H4Sac), heparin octasaccharide (H8Sac) and heparin octadecasaccharide (H18Sac) showed high inhibition constant, Ki and low inhibition concentration, IC50 in comparison to others. In the thermal stability study, only rhIDS incubated with CD3S was found to preserve enzyme activity (20%) after incubated at 67oC. Conclusion: Overall, our experiments discovered that CD3S was able to bind, inhibit and chaperone rhIDS. These features suggest a potential pharmacological chaperone for MPS II.


Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 2142-2150 ◽  
Author(s):  
Brian J. Freeman ◽  
Marie S. Roberts ◽  
Carole A. Vogler ◽  
Andrew Nicholes ◽  
A. Alex Hofling ◽  
...  

Bone marrow transplantation (BMT) is relatively effective for the treatment of lysosomal storage diseases. To better understand the contribution of specific hematopoietic lineages to the efficacy of BMT, we transplanted β-glucuronidase–positive mononuclear phagocytes derived from either the peritoneum or from bone marrow in vitro into syngeneic recipients with mucopolysaccharidosis type VII (MPS VII). Cell surface marking studies indicate that the bone marrow-derived cells are less mature than the peritoneal macrophages. However, both cell types retain the ability to home to tissues rich in cells of the reticuloendothelial system after intravenous injection into MPS VII mice. The half-life of both types of donor macrophages is approximately 7 days, and some cells persist for at least 30 days. In several tissues, therapeutic levels of β-glucuronidase are present, and histopathologic analysis demonstrates that lysosomal storage is dramatically reduced in the liver and spleen. Macrophages intravenously injected into newborn MPS VII mice localize to the same tissues as adult mice but are also observed in the meninges and parenchyma of the brain. These data suggest that macrophages play a significant role in the therapeutic efficacy of BMT for lysosomal storage diseases and may have implications for treatments such as gene therapy.


Diagnostics ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 155 ◽  
Author(s):  
Galina Baydakova ◽  
Alex Ilyushkina ◽  
Lidia Gaffke ◽  
Karolina Pierzynowska ◽  
Igor Bychkov ◽  
...  

Mucopolysaccharidoses (MPSs) are a group of lysosomal storage disorders associated with impaired glycosaminoglycans (GAGs) catabolism. In MPS I, II, III, and VII, heparan sulfate (HS) cannot be degraded because of the lack of sufficient activity of the respective enzymes, and its accumulation in the brain causes neurological symptoms. Globotriaosylsphingosine (LysoGb3), the deacylated form of globotriaosylceramide (Gb3), is described as a highly sensitive biomarker for another lysosomal storage disease—Fabry disease. The connection between MPSs and LysoGb3 has not yet been established. This study included 36—MPS I, 15—MPS II, 25—MPS III, 26—MPS IV, and 14—MPS VI patients who were diagnosed by biochemical and molecular methods and a control group of 250 males and 250 females. The concentration of lysosphingolipids (LysoSLs) was measured in dried blood spots by high pressure liquid chromatography—tandem mass spectrometry. We have demonstrated that LysoGb3 concentration was significantly elevated (p < 0.0001) in untreated MPS I (3.07 + 1.55 ng/mL), MPS II (5.24 + 2.13 ng/mL), and MPS III (6.82 + 3.69 ng/mL) patients, compared to the control group (0.87 + 0.55 ng/mL). LysoGb3 level was normal in MPS VI and MPS IVA (1.26 + 0.39 and 0.99 + 0.38 ng/mL, respectively). Activity of α-galactosidase A (α-Gal A), an enzyme deficient in Fabry disease, was not, however, inhibited by heparan sulfate in vitro, indicating that an increase of LysoGb3 level in MPS I, MPS II, and MPS III is an indirect effect of stored MPSs rather than a direct result of impairment of degradation of this compound by HS. Our findings indicate some association of elevated LysoGb3 concentration with the neuronopathic forms of MPSs. The pathological mechanism of which is still to be studied.


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