| 1. |
- Noborn, Fredrik, et al.
(författare)
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Heparan sulfate/heparin promotes transthyretin fibrillization through selective binding to a basic motif in the protein
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:14, s. 5584-5589
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Tidskriftsartikel (refereegranskat)abstract
- Transthyretin (TTR) is a homotetrameric protein that transports thyroxine and retinol. Tetramer destabilization and misfolding of the released monomers result in TTR aggregation, leading to its deposition as amyloid primarily in the heart and peripheral nervous system. Over 100 mutations of TTR have been linked to familial forms of TTR amyloidosis. Considerable effort has been devoted to the study of TTR aggregation of these mutants, although the majority of TTR-related amyloidosis is represented by sporadic cases due to the aggregation and deposition of the otherwise stable wild-type (WT) protein. Heparan sulfate (HS) has been found as a pertinent component in a number of amyloid deposits, suggesting its participation in amyloidogenesis. This study aimed to investigate possible roles of HS in TTR aggregation. Examination of heart tissue from an elderly cardiomyopathic patient revealed substantial accumulation of HS associated with the TTR amyloid deposits. Studies demonstrated that heparin/HS promoted TTR fibrillization through selective interaction with a basic motif of TTR. The importance of HS for TTR fibrillization was illustrated in a cell model; TTR incubated with WT Chinese hamster ovary cells resulted in fibrillization of the protein, but not with HS-deficient cells (pgsD-677). The effect of heparin on TTR fibril formation was further demonstrated in a Drosophila model that overexpresses TTR. Heparin was colocalized with TTR deposits in the head of the flies reared on heparin-supplemented medium, whereas no heparin was detected in the nontreated flies. Heparin of low molecular weight (Klexane) did not demonstrate this effect.
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| 2. |
- Abramsson, Alexandra, 1973, et al.
(författare)
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Defective N-sulfation of heparan sulfate proteoglycans limits PDGF-BB binding and pericyte recruitment in vascular development
- 2007
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Ingår i: GENES & DEVELOPMENT. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 21:3, s. 316-331
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Tidskriftsartikel (refereegranskat)abstract
- During vascular development, endothelial platelet-derived growth factor B (PDGF-B) is critical for pericyte recruitment. Deletion of the conserved C-terminal heparin-binding motif impairs PDGF-BB retention and pericyte recruitment in vivo, suggesting a potential role for heparan sulfate (HS) in PDGF-BB function during vascular development. We studied the participation of HS chains in pericyte recruitment using two mouse models with altered HS biosynthesis. Reduction of N-sulfation due to deficiency in N-deacetylase/N-sulfotransferase-1 attenuated PDGF-BB binding in vitro, and led to pericyte detachment and delayed pericyte migration in vivo. Reduced N-sulfation also impaired PDGF-BB signaling and directed cell migration, but not proliferation. In contrast, HS from glucuronyl C5-epimerase mutants, which is extensively N- and 6-O-sulfated, but lacks 2-O-sulfated L-iduronic acid residues, retained PDGF-BB in vitro, and pericyte recruitment in vivo was only transiently delayed. These observations were supported by in vitro characterization of the structural features in HS important for PDGF-BB binding. We conclude that pericyte recruitment requires HS with sufficiently extended and appropriately spaced N-sulfated domains to retain PDGF-BB and activate PDGF receptor β (PDGFRβ) signaling, whereas the detailed sequence of monosaccharide and sulfate residues does not appear to be important for this interaction.
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| 3. |
- Batool, Tahira
(författare)
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Heparan sulfate dependent cell signaling and associated pathophysiology : Implications in tumorigenesis and embryogenesis
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Heparan sulfate proteoglycans (HSPGs) consist of a protein core to which several linear, negatively charged heparan sulfate (HS) chains are covalently attached. HSPGs are expressed on the cell surface and in the extra-cellular matrix (ECM) where they have diverse biological functions, for example co-receptor functions. The diverse functions of HS are linked to structural variability of the polysaccharide. In this thesis, I investigated HS structure-function relationship by using different cell and animal models of one HS-biosynthetic enzyme, glucuronyl C5-epimerase (Hsepi) and one enzyme responsible for post synthetic modification, heparanase.Deletion of Hsepi in mice resulted in neonatal lethality, with multiple organ defects, indicating the importance of HS in embryogenesis. Up-regulated expression of heparanase is found in most human tumor tissues, correlating with increased metastatic potential and decreased survival of cancer patients.In the first project, I focused on the effects of HS on cancer associated cell signaling and found that heparanase overexpression attenuated TGF-β1 stimulated Smad phosphorylation in tumor cells because of increased sulfation degree and turnover rate of HS.Heparanase role in cancer progression has led to clinical trials where inhibition of heparanase activity is currently being evaluated as a potential cancer treatment. Heparin, a HS-related polysaccharide, is being used to inhibit heparanase activity. In my second project, we studied the effect of low molecular weight heparin (LMWH) on cisplatin resistance of ovarian cancer cells (A2780cis). LMWH treatment of A2780cis cells reduced Wnt-activity in these cells and consequently reduce the drug resistance.In paper III, we continued exploring the HS/heparanase role in cancer by using heparanase overexpressing mice (Hpa-tg). We found Lewis Lung Carcinoma (LLC2) cells showed faster growth, bigger tumors and more metastasis in the Hpa-tg mice as compared to wild-type (WT) mice, because of suppressed antitumor immunity in the Hpa-tg mice.In paper IV and V, we studied the structure-function relationship of HS by using Hsepi-/- mice model. Hsepi-/- results in HS-chains lacking IdoA, which makes the chain rigid and consequently affects its co-receptor function. Skeletal malformation in Hsepi-/- mice, led us in paper IV to investigate bone morphogenic protein (BMP), an important signal molecule during embryogenesis and known to interact with HS. We found upregulation of a number of BMPs and expression of P-smad1/5/8, but reduced expression of inhibitory Smads and Gremlin1 in the Hsepi-/- MEF cells. The study indicated that the developmental defects in Hsepi mice could be contributed by a higher BMP signaling. In paper V we investigated the lung of the Hsepi-/- mice. The distal lung of 17.5 days old embryos remained populated by epithelial tubules, because of impaired differentiation of type I cells of the lungs. Potential mechanisms behind the failure of type I cell formation was identified to be reduced vascularization and a sustained signaling of Smad pathways.
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| 4. |
- Li, Binjie, et al.
(författare)
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Identification of a Pentasaccharide Lead Compound with High Affinity to the SARS-CoV-2 Spike Protein via In Silico Screening
- 2023
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 24:22
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Tidskriftsartikel (refereegranskat)abstract
- The spike (S) protein on the surface of the SARS-CoV-2 virus is critical to mediate fusion with the host cell membrane through interaction with angiotensin-converting enzyme 2 (ACE2). Additionally, heparan sulfate (HS) on the host cell surface acts as an attachment factor to facilitate the binding of the S receptor binding domain (RBD) to the ACE2 receptor. Aiming at interfering with the HS-RBD interaction to protect against SARS-CoV-2 infection, we have established a pentasaccharide library composed of 14,112 compounds covering the possible sulfate substitutions on the three sugar units (GlcA, IdoA, and GlcN) of HS. The library was used for virtual screening against RBD domains of SARS-CoV-2. Molecular modeling was carried out to evaluate the potential antiviral properties of the top-hit pentasaccharide focusing on the interactive regions around the interface of RBD-HS-ACE2. The lead pentasaccharide with the highest affinity for RBD was analyzed via drug-likeness calculations, showing better predicted druggable profiles than those currently reported for RBD-binding HS mimetics. The results provide significant information for the development of HS-mimetics as anti-SARS-CoV-2 agents.
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| 5. |
- Maccarana, Marco, et al.
(författare)
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Inhibitors of dermatan sulfate epimerase 1 decreased accumulation of glycosaminoglycans in mucopolysaccharidosis type I fibroblasts
- 2024
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Ingår i: Glycobiology. - : Oxford University Press. - 0959-6658 .- 1460-2423. ; 34:6
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Tidskriftsartikel (refereegranskat)abstract
- Genetic deficiency of alpha-L-iduronidase causes mucopolysaccharidosis type I (MPS-I) disease, due to accumulation of glycosaminoglycans (GAGs) including chondroitin/dermatan sulfate (CS/DS) and heparan sulfate (HS) in cells. Currently, patients are treated by infusion of recombinant iduronidase or by hematopoietic stem cell transplantation. An alternative approach is to reduce the L-iduronidase substrate, through limiting the biosynthesis of iduronic acid. Our earlier study demonstrated that ebselen attenuated GAGs accumulation in MPS-I cells, through inhibiting iduronic acid producing enzymes. However, ebselen has multiple pharmacological effects, which prevents its application for MPS-I. Thus, we continued the study by looking for novel inhibitors of dermatan sulfate epimerase 1 (DS-epi1), the main responsible enzyme for production of iduronic acid in CS/DS chains. Based on virtual screening of chemicals towards chondroitinase AC, we constructed a library with 1,064 compounds that were tested for DS-epi1 inhibition. Seventeen compounds were identified to be able to inhibit 27%–86% of DS-epi1 activity at 10 μM. Two compounds were selected for further investigation based on the structure properties. The results show that both inhibitors had a comparable level in inhibition of DS-epi1while they had negligible effect on HS epimerase. The two inhibitors were able to reduce iduronic acid biosynthesis in CS/DS and GAG accumulation in WT and MPS-I fibroblasts. Docking of the inhibitors into DS-epi1 structure shows high affinity binding of both compounds to the active site. The collected data indicate that these hit compounds may be further elaborated to a potential lead drug used for attenuation of GAGs accumulation in MPS-I patients.
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| 6. |
- Morris, Abigail, et al.
(författare)
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The Role of Heparanase in Pulmonary Cell Recruitment in Response to an Allergic but Not Non-Allergic Stimulus
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Heparanase is an endo-a-glucuronidase that specifically cleaves heparan sulfate proteoglycans in the extracellular matrix. Expression of this enzyme is increased in several pathological conditions including inflammation. We have investigated the role of heparanase in pulmonary inflammation in the context of allergic and non-allergic pulmonary cell recruitment using heparanase knockout (Hpa(-/-)) mice as a model. Following local delivery of LPS or zymosan, no significant difference was found in the recruitment of neutrophils to the lung between Hpa(-/-) and wild type (WT) control. Similarly neutrophil recruitment was not inhibited in WT mice treated with a heparanase inhibitor. However, in allergic inflammatory models, Hpa(-/-) mice displayed a significantly reduced eosinophil (but not neutrophil) recruitment to the airways and this was also associated with a reduction in allergen-induced bronchial hyperresponsiveness, indicating that heparanase expression is associated with allergic reactions. This was further demonstrated by pharmacological treatment with a heparanase inhibitor in the WT allergic mice. Examination of lung specimens from patients with different severity of chronic obstructive pulmonary disease (COPD) found increased heparanase expression. Thus, it is established that heparanase contributes to allergen-induced eosinophil recruitment to the lung and could provide a novel therapeutic target for the development of anti-inflammatory drugs for the treatment of asthma and other allergic diseases.
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| 7. |
- Van Bergen, Tine, et al.
(författare)
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Heparanase Deficiency Is Associated with Disruption, Detachment, and Folding of the Retinal Pigment Epithelium
- 2021
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Ingår i: Current Eye Research. - : Taylor & Francis. - 0271-3683 .- 1460-2202. ; 46:8, s. 1166-1170
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Pentosan polysulfate sodium (PPS; Elmiron) is a FDA-approved heparanase inhibitor for the treatment of bladder pain and interstitial cystitis. The chronic use of PPS has been associated with a novel pigmentary maculopathy, associated with discrete vitelliform deposits that exhibit hyperfluorescence, macular hyper-pigmentary spots, and foci of nodular RPE enlargement. Therefore, this study aimed to investigate the retinal morphology of heparanase knockout mice. Material and methods: The retinal morphology of heparanase knock-out and age-matched control wild type mice of 3-, 9- and 15-weeks old was characterized by means of histological evaluation. Immuno-histological stains for RPE65, F4/80 and Ki67 were performed for investigating the RPE, inflammatory and proliferating cells, respectively. Results: Histological analysis showed no changes in age-matched wild-type controls, whereas the eyes of heparanase null mice were characterized by alterations in RPE and neural retina, as manifest by RPE folds and choroidal thickening, detached RPE cells, thickening of the photoreceptor layer and retinal disorganization. The presence of discrete hyperfluorescent foci, however, was absent. The prevalence of the RPE/choroidal changes or protrusions seemed to progress over time and were correlated with more RPE65 signal rather than influx of F4/80- or Ki67-positive cells. These results indicate that the subretinal alterations were mostly RPE driven, without influx of inflammatory or proliferating cells. Conclusions: Our results indicate that heparanase deficiency in the mice leads to RPE folds, choroidal thickening, and retinal disorganization. The presence of discrete hyperfluorescent foci, a key characteristic of the human disease, was not observed. However, it can be concluded that some of the observations in mice are similar to those seen after chronic use of PPS in humans. These findings indicate that the toxicity observed in the presence of heparanase inhibitors is target-related and will preclude the clinical use of heparanase inhibition as a therapeutic intervention.
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| 8. |
- Jia, Juan, et al.
(författare)
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Lack of L-iduronic acid in heparan sulfate affects interaction with growth factors and cell signaling
- 2009
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 284:23, s. 15942-15950
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Tidskriftsartikel (refereegranskat)abstract
- Glucuronyl C5-epimerase (Hsepi) catalyzes the conversion of D-glucuronic acid to L-iduronic acid in heparan sulfate (HS) biosynthesis. Disruption of the Hsepi gene in mouse yielded a lethal phenotype with selective organ defects, but had remarkably little effect on other organ systems. We have approached the underlying mechanisms by examining the course and effects of FGF2 signaling in a mouse embryonic fibroblast (MEF) cell line derived from the Hsepi-/- mouse. The HS produced by these cells is devoid of IdoA residues, but shows upregulated N- and 6-O-sulfation compared to wildtype (WT) MEF HS. In medium fortified with 10% FCS the Hsepi-/- MEFs proliferated and migrated similar to WT cells. Under starvation conditions both cell types showed attenuated proliferation and migration, that could be restored by addition of FGF2 to WT cells whereas Hsepi-/- cells were resistant. Moreover, ERK phosphorylation following FGF2 stimulation was delayed in Hsepi-/- compared to WT cells. Assessment of HS-growth factor interaction by nitrocellulose filter trapping revealed strikingly aberrant binding property of FGF2 and glia-derived neurotropic factor (GDNF) to Hsepi-/- but not to WT HS. GDNF has a key role in kidney development, defective in Hsepi-/- mice. By contrast, Hsepi-/- and WT HS interacted similarly and in conventional mode with FGF10. These findings correlate defective function of growth factors with their mode of HS interaction, and may help explain the partly modest organ phenotypes observed after genetic ablation of selected enzymes in HS biosynthesis.
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| 9. |
- Maccarana, Marco, et al.
(författare)
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Inhibition of iduronic acid biosynthesis by ebselen reduces glycosaminoglycan accumulation in mucopolysaccharidosis type I fibroblasts
- 2021
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Ingår i: Glycobiology. - : Oxford University Press. - 0959-6658 .- 1460-2423. ; 31:10, s. 1319-1329
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Tidskriftsartikel (refereegranskat)abstract
- Mucopolysaccharidosis type I (MPS-I) is a rare lysosomal storage disorder caused by deficiency of the enzyme alpha-L-iduronidase, which removes iduronic acid in both chondroitin/dermatan sulfate (CS/DS) and heparan sulfate (HS) and thereby contributes to the catabolism of glycosaminoglycans (GAGs). To ameliorate this genetic defect, the patients are currently treated by enzyme replacement and bone marrow transplantation, which have a number of drawbacks. This study was designed to develop an alternative treatment by inhibition of iduronic acid formation. By screening the Prestwick drug library, we identified ebselen as a potent inhibitor of enzymes that produce iduronic acid in CS/DS and HS. Ebselen efficiently inhibited iduronic acid formation during CS/DS synthesis in cultured fibroblasts. Treatment of MPS-I fibroblasts with ebselen not only reduced accumulation of CS/DS but also promoted GAG degradation. In early Xenopus embryos, this drug phenocopied the effect of downregulation of DS-epimerase 1, the main enzyme responsible for iduronic production in CS/DS, suggesting that ebselen inhibits iduronic acid production in vivo. However, ebselen failed to ameliorate the CS/DS and GAG burden in MPS-I mice. Nevertheless, the results propose a potential of iduronic acid substrate reduction therapy for MPS-I patients.
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| 10. |
- O'Callaghan, Paul, et al.
(författare)
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Microglial heparan sulfate proteoglycans mediate pro-inflammatory signaling
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Microglia are the central nervous system’s (CNS) first line of defense against pathogenic insults and acute inflammatory responses are necessary for the resolution of infection. However, unregulated and/or chronic activation of microglia is associated with neurodegeneration. Heparan sulfate proteoglycans (HSPGs) have been attributed various roles in inflammation, but the possibility that HSPGs are integral to pro-inflammatory signaling mechanisms has not been fully explored. To analyze the relevance of microglial HSPGs in the pro-inflammatory response we isolated primary microglia from mice overexpressing human heparanase (Hpa-tg), the HS-degrading endoglucuronidase, and challenged them with the pro-inflammatory endotoxin lipopolysaccharide (LPS). The LPS-induced upregulation of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) was inhibited in Hpa-tg microglia, as was upregulation of the LPS-receptor CD14. Analysis of HSPG structures revealed that Hpa-tg microglia produced truncated HS chains. Importantly, co-treatment of microglia with heparin attenuated LPS-induced cytokine upregulation. Together these findings implicate microglial HSPGs as key facilitators of the pro-inflammatory response. Astrocytes constitute a critical support network in the CNS, but are also implicated in inflammation. LPS induced comparable levels of TNF-α in Hpa-tg and Ctrl astrocytes, indicating that the mechanism of HSPG-dependent inflammation is specific to microglia. We conclude that microglial HSPGs are required for pro-inflammatory signaling events and that heparanase, through its HS-degrading activity, can regulate this mechanism.
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