Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mucopolysaccharidosis type IIIA (MPS IIIA) is a specific lysosomal storage disorder caused by an enzyme deficiency in sulphamidase, which is required for the degradation of heparan sulphate glycosaminoglycan (gag). This deficiency results in widespread gag storage and leads to severe CNS degeneration and mild somatic pathology. We have developed substrate deprivation as a therapy (SDT) for MPS disorders to reduce the initial production of gag substrate for the deficient enzyme, using the compound rhodamine B as an inhibitor of gag biosynthesis. This should restore the balance between gag level and residual enzyme activity towards normal and improve patient outcome. To determine if SDT improved CNS function, MPS IIIA mice were treated for 6months with weekly, intravenous 1mg/kg rhodamine B and then tested in a 4-arm water cross maze, which measures spatial learning and memory. MPS IIIA untreated mice were unable to perform to the same level as normal littermates, having increased escape latency, increased incorrect entries and decreased correct entries. Rhodamine B treatment improved MPS IIIA performance towards normal with treated mice having decreased escape latency, decreased incorrect entries and increased correct entries when compared to MPS IIIA untreated littermates. This provides the first report of SDT resulting in a beneficial effect on CNS function in an MPS disorder and SDT targeting gag synthesis may be a viable treatment option for children with MPS.
Mol Genet Metab
PMID:Improvement in behaviour after substrate deprivation therapy with rhodamine B in a mouse model of MPS IIIA. 1768 80

Mucopolysaccharidosis type IIIA (MPS-IIIA or Sanfilippo syndrome) is a lysosomal storage disorder caused by the congenital deficiency of sulfamidase (SGSH) enzyme and consequent accumulation of partially degraded heparan sulfate (HS) in lysosomes. The central nervous system (CNS) is the predominant site of tissue damage in MPS-IIIA. Here we describe a gene therapy approach for MPS-IIIA in a mouse model using recombinant adeno-associated virus serotype 5 (AAV2/5) as a vehicle to deliver therapeutic genes to the CNS. SUMF1 (SUlfatase Modifying Factor 1) exhibits an enhancing effect on sulfatase activity when co-expressed with sulfatases. Consistent with these findings, we demonstrated that co-delivery of SUMF1 and SGSH (via an AAV2/5-CMV-SGSH-IRES-SUMF1 vector) resulted in a synergistic increase in SGSH activity, both in primary neural cells and in murine brain. A study aimed at testing the therapeutic efficacy of simultaneous brain administration of SUMF1 and SGSH was then performed by injecting the lateral ventricles of newborn MPS-IIIA/normal mice with either AAV2/5-CMV-SGSH-IRES-SUMF1 or AAV2/5-CMV-GFP vectors. Widespread GFP expression was observed within the GFP-injected brain, and a stable and significant increase of SGSH activity was detected in several brain regions following SGSH-IRES-SUMF1 administration. Treatment with AAV2/5-CMV-SGSH-IRES-SUMF1 vectors resulted in a visible reduction in lysosomal storage and inflammatory markers in transduced brain regions. Finally, the MPS-IIIA mice treated with therapeutic genes displayed an improvement in both motor and cognitive functions. Our results suggest that early treatment of CNS lesions by AAV-mediated intraventricular injection of both SGSH and SUMF1 genes may represent a feasible therapy for MPS-IIIA.
Hum Mol Genet 2007 Nov 15
PMID:Functional correction of CNS lesions in an MPS-IIIA mouse model by intracerebral AAV-mediated delivery of sulfamidase and SUMF1 genes. 1772 87

Mucopolysaccharidosis type IIIA (MPS IIIA) is a heritable glycosaminoglycan (GAG) storage disorder which is characterised by lysosomal accumulation of heparan sulphate, secondary to a deficiency of sulphamidase (heparan-N-sulphatase, N-sulphoglucosamine sulphohydrolase, EC No. 3.10.1.1.). There is currently no treatment for affected individuals who experience progressive CNS deterioration prior to an early death. As a first step towards developing gene therapy as a treatment for MPS IIIA, an MPS IIIA mouse model was used to examine the efficacy of intravenous lentiviral-mediated gene therapy. Five-week-old mice were injected with virus expressing murine sulphamidase and analysed 6 months after treatment. Transduction by the lentiviral vector was highest in the liver and spleen of treated animals, and sulphamidase activity in these tissues averaged 68% and 186% of normal, respectively. Storage was assessed using histochemical, chemical and mass spectrometric analyses. Storage in most somatic tissues was largely normalised, although chondrocytes were an obvious exception. Histologically, improvement of lysosomal storage within the brain was variable. However, beta-hexosaminidase activity, which is abnormally elevated in MPS IIIA, was significantly reduced in every treated tissue, including the brain. Total uronic acid was also significantly reduced in the brains of treated mice. The level of a disaccharide marker (hexosamine-N-sulphate[alpha-1,4]hexuronic acid; HNS-UA) of heparan sulphate storage was also decreased in the brains of treated mice, albeit non-significantly. These results suggest that lentiviral-mediated somatic gene transfer may affect not only the somatic, but possibly also the CNS pathology, found in MPS IIIA.
Mol Genet Metab 2008 Apr
PMID:Lentiviral-mediated gene therapy for murine mucopolysaccharidosis type IIIA. 1824 29

In order to evaluate the mechanisms leading to neuropathology in Mucopolysaccharidosis type IIIA (MPS-IIIA, Sanfilippo syndrome), we have harvested and cultured primary neural cells isolated from the cerebellum of newborn and adult MPS-IIIA and unaffected mice. Cell viability and plating efficiency were comparable for brain tissue obtained from either newborn or adult MPS-IIIA and unaffected mice. Cultures (newborn and adult) comprised a mixed brain cell population including astrocytes, oligodendrocytes, and neurons. Newborn MPS-IIIA cells contained inclusions and vacuoles consistent with the pathology present in affected brain tissue. Newborn and adult MPS-IIIA brain cells had approximately 5-7% of the sulfamidase activity present in primary neural cells cultured from unaffected newborn and adult mice. In addition, high levels of glucosamine-N-sulfate[alpha-1,4]hexuronic acid, a heparan sulfate-derived disaccharide, were detected in both newborn and adult MPS-IIIA brain cells. These results suggest that the primary MPS-IIIA brain cells exhibit characteristics of MPS-IIIA phenotype at the histopathological and biochemical level in culture.
Cell Mol Neurobiol 2008 Nov
PMID:Primary culture of neural cells isolated from the cerebellum of newborn and adult mucopolysaccharidosis type IIIA mice. 1829 92

Mucopolysaccharidosis type IIIA (MPS IIIA), which is a lysosomal storage disorder (LSD) caused by inherited deficiency of sulfamidase, is characterized by severe, progressive central nervous system (CNS) dysfunction. Enzyme replacement therapy (ERT) to treat CNS storage is challenging, because the access of enzymes to the brain is restricted by the blood-brain barrier (BBB). In a prior study, we found that phosphorylated beta-glucuronidase (P-GUS) could be transcytosed across the BBB in newborn mice by the mannose 6-phosphate (M6P) receptor. In order to determine whether sulfamidase can utilize this pathway, we examined brain influx and the specificity of uptake of sulfamidase after intravenous (i.v.) injection in 2-day-old and 8-week-old mice. [(131)I]Sulfamidase was transported across the BBB in neonates at rates higher than that of simultaneously injected [(125)I]albumin. In contrast, the transport of [(131)I]sulfamidase was negligible in 8-week-old mice, thereby showing that the BBB transport mechanism is developmentally downregulated. Capillary depletion revealed that 83.7% of the [(131)I]sulfamidase taken up by the brain was in the parenchyma, demonstrating transfer across the capillary wall. The uptake of [(131)I]sulfamidase into the brain was significantly reduced by co-injections of M6P and P-GUS. That is, the transport of sulfamidase into the brain parenchyma in early postnatal life is mediated by the M6P receptor, which is shared with P-GUS and is likely accessible to other M6P-containing lysosomal enzymes.
Mol Ther 2008 Jul
PMID:Mannose 6-phosphate receptor-mediated transport of sulfamidase across the blood-brain barrier in the newborn mouse. 1844 1

Mucopolysaccharidosis type IIIA (MPS IIIA) results from lack of functional sulfamidase (SGSH), a lysosomal enzyme. Its substrate, heparan sulfate, and other secondarily-stored compounds subsequently accumulate primarily within the central nervous system (CNS), resulting in progressive mental deterioration and early death. Presently there is no treatment. As a potential therapeutic strategy, recombinant human sulfamidase (rhSGSH) was administered into the CSF (via the cerebellomedullary cistern) of three adult MPS IIIA dogs either twice with a 4 day interval, or weekly for up to 4 weeks. The dogs were euthanased 24 h post-injection along with one untreated unaffected and two MPS IIIA controls. We have examined the three dimensional pattern of distribution of enzyme in the CNS and its ability to reduce primary substrate storage. High concentrations of rhSGSH protein, with up to 39-fold normal enzyme activity levels were detected within widespread areas of the CNS. RhSGSH protein was also detectable by immunohistochemistry in neurons and glia in all three enzyme-treated dogs. In both weekly-treated dogs, relative levels of a heparan sulfate-derived disaccharide, measured using tandem mass spectrometry, were lower in many brain regions when compared to untreated MPS IIIA controls. A moderately severe meningitis was also present as well as antibodies to rhSGSH in CSF/plasma. These findings demonstrate proof of principle that MPS IIIA can be treated by intracisternal enzyme replacement warranting further experiments in animals tolerant to rhSGSH. This enzyme delivery method may represent a means of treating neuropathology in MPS IIIA and other lysosomal storage disorders affecting the CNS.
Mol Genet Metab 2009 Dec
PMID:Effect of cisternal sulfamidase delivery in MPS IIIA Huntaway dogs--a proof of principle study. 1969 66

Mucopolysaccharide (MPS) diseases are lysosomal storage disorders caused by deficiencies of enzymes catabolising glycosaminoglycans (GAGs). Abnormal GAG accumulation leads to symptoms including severe progressive neurological decline, skeletal deformities, organomegally, respiratory compromise and premature death. Treatment is available for some MPS diseases; enzyme replacement therapy for MPS I, II and VI, and haematopoietic stem cell transplantation for MPS I, VI and VII. These treatments are reliant on early diagnosis of the disease and accurate monitoring of treatment outcomes. Blood enzyme levels and total urinary GAGs are commonly used biomarkers in diagnosis of MPS but are not good measures of treatment outcome. Serum heparin cofactor II-thrombin complex (HCII-T), which is a GAG regulated serpin-protease complex, has recently been identified as a promising biomarker for MPS diseases. Here we present an assessment of the HCII-T biomarker in mouse models of MPS I, IIIA and IIIB, which suggests that HCII-T is a reliable marker for MPS I when measured in serum or dried blood spots stored for over a year at 4 degrees C, but that murine MPS IIIA and IIIB cannot be reliably detected using this biomarker. We also show that HCII-T formation in vivo is dependent on the presence of excess intravenous dermatan sulphate (DS), whilst intravenous heparan sulphate (HS), does not promote complex formation effectively. This suggests that HCII-T will prove effective as a biomarker for MPS I, II, VI and VII diseases, storing dermatan sulphate but may not be as appropriate for MPS III, storing heparan sulphate. With careful sample preparation, HCII-T ELISA could prove to be a useful biomarker for both newborn screening and measurement of treatment outcomes in selected MPS diseases.
Mol Genet Metab 2010 Mar
PMID:Evaluation of heparin cofactor II-thrombin complex as a biomarker on blood spots from mucopolysaccharidosis I, IIIA and IIIB mice. 1992 22

Many viral backbones have been used as gene transfer vectors. However, the efficacy of therapy based on human-derived vectors may be limited by the high incidence of pre-existing humoral and cellular memory immunity. To circumvent some of the clinical disadvantages of vectors derived from common human pathogens, we have used an E1-deleted vector derived from a xenogenic adenovirus, canine adenovirus serotype 2 (CAV-2) to ameliorate neuropathological changes associated with the lysosomal storage disorder, mucopolysaccharidosis type IIIA (MPS IIIA). This presently untreatable condition is caused by N-sulfoglucosamine sulfohydrolase (SGSH) deficiency and is characterized by heparan sulfate accumulation and progressive neurodegeneration. Injection of CAV-SGSH-GFP into the thalamus of adult MPS IIIA mouse brain resulted in short-term gene expression. In contrast, intra-ventricular injection of newborn mice yielded dose-dependent transgene expression which persisted for at least 20-weeks and improved neuropathology. Together, these studies suggest that this E1-deleted CAV-2 vector is capable of mediating regional medium-term gene expression and facilitating improvements in neuropathology in MPS IIIA mice.
Mol Genet Metab 2010 Jun
PMID:SGSH gene transfer in mucopolysaccharidosis type IIIA mice using canine adenovirus vectors. 2023 Nov 9

MPS IIIA is a lysosomal storage disorder caused by mutations in the sulphamidase gene, resulting in the accumulation of heparan sulphate glycosaminoglycans (HS GAGs). Symptoms predominantly manifest in the CNS and there is no current therapy that effectively addresses neuropathology in MPS IIIA patients. Recent studies in MPS IIIA mice have shown that rhodamine B substrate deprivation therapy (SDT) (also termed substrate reduction therapy/SRT) inhibits GAG biosynthesis and, improves both somatic and CNS disease pathology. Acute overexposure to high doses of rhodamine B results in liver toxicity and is detrimental to reproductive ability. However, the long-term effects of decreasing GAG synthesis, at the low dose sufficient to alter neurological function are unknown. A trans-generational study was therefore initiated to evaluate the continuous exposure of rhodamine B treatment in MPS IIIA mice over 4 generations, including treatment during pregnancy. No alterations in litter size, liver histology or liver function were observed. Overall, there are no long-term issues with the administration of rhodamine B at the low dose tested and no adverse effects were noted during pregnancy in mice.
Mol Genet Metab
PMID:Trans-generational exposure to low levels of rhodamine B does not adversely affect litter size or liver function in murine mucopolysaccharidosis type IIIA. 2065 Jun 70

Sanfilippo disease (MPS IIIA) is an autosomal recessive lysosomal storage disorder resulting from sulfamidase deficiency, which is characterized by severe neurological impairment. Various tissues of MPS IIIA mice accumulate undegraded glycosaminoglycans and mimic the human neurodegenerative disorder, and are an excellent tool to both delineate disease pathogenesis and test potential therapies. The relationship between abnormal glycosaminoglycan storage and neurodysfunction remains ill defined. Pathways such as inflammation or oxidative stress have been highlighted in many neurodegenerative disorders, including lysosomal storage diseases, as major components of the neuropathology. By using quantitative polymerase chain reaction, we have compared the expression of selected genes in normal and MPS IIIA mouse cerebral tissues, focusing on inflammation, apoptosis and oxidative stress-related genes. We have identified several genes strongly over-expressed in the central nervous system of a MPS IIIA mouse, reflecting a neurological deterioration state. We have used these genes as markers to follow-up a long-term aspirin treatment. Aspirin treatment led to the normalization of inflammation- and oxidative stress-related mRNA levels in treated MPS IIIA mouse brains. A biochemical correction of an oxidative stress phenomenon both in the brain and peripheral organs of treated MPS IIIA mice was also obtained. These results suggest that anti-inflammatory intervention may be of potential benefit in MPS IIIA disease.
Mol Genet Metab 2011 May
PMID:Neuroinflammatory and oxidative stress phenomena in MPS IIIA mouse model: the positive effect of long-term aspirin treatment. 2135 10


<< Previous 1 2 3 4 5 Next >>