| 1. |
- 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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| 2. |
- Zhang, Tianji, et al.
(författare)
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Interacting polymer-modification enzymes in heparan sulfate biosynthesis
- 2023
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 299
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Tidskriftsartikel (refereegranskat)abstract
- Glucuronyl 5-epimerase (Hsepi) converts D-glucuronic acid (GlcA) into L-iduronic acid (IdoA) units, through a mechanism involving reversible abstraction of a proton at C5 of hexuronic acid residues. Incubations of a [4GlcA beta 1-4GlcNSO3 alpha 1-]n precursor substrate with recombinant enzymes in a D2O/H2O medium enabled an isotope exchange approach to the assessment of functional interactions of Hsepi with hexuronyl 2-O-sulfotrans-ferase (Hs2st) and glucosaminyl 6-O-sulfotransferase (Hs6st), both involved in the final polymer-modification steps. Enzyme complexes were supported by computational modeling and homogeneous time resolved fluores-cence. GlcA and IdoA D/H ratios related to product composition revealed kinetic isotope effects that were interpreted in terms of efficiency of the coupled epimerase and sulfotransferase reactions. Evidence for a func-tional Hsepi/Hs6st complex was provided by selective incorporation of D atoms into GlcA units adjacent to 6-O -sulfated glucosamine residues. The inability to achieve simultaneous 2-O-and 6-O-sulfation in vitro supported topologically separated reactions in the cell. These findings provide novel insight into the roles of enzyme in-teractions in heparan sulfate biosynthesis.
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| 3. |
- Gockel, Lukas M., et al.
(författare)
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Inhibition of Tumor-Host Cell Interactions Using Synthetic Heparin Mimetics
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:6, s. 7080-7093
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Tidskriftsartikel (refereegranskat)abstract
- Low-molecular-weight heparin (LMWH) is the guideline-based drug for antithrombotic treatment of cancer patients, while its direct antitumor effects are a matter of ongoing debate. Although therapeutically established for decades, LMWH has several drawbacks mainly associated with its origin from animal sources. Aiming to overcome these limitations, a library of synthetic heparin mimetic polymers consisting of homo- and copolymers of sulfonated and carboxylated noncarbohydrate monomers has recently been synthesized via reversible addition-fragmentation chain transfer polymerization. These heparin mimetics were investigated for their capacities to interfere with simulated steps of tumor cell metastasis. Among them, homo- and copolymers from sodium 4-styrenesulfonate (poly(SSS)) with acrylic acid (poly(SSS-co-AA)) with an MW between 5 and 50 kDa efficiently attenuated cancer cell-induced coagulation and thus platelet activation and degranulation similar to or even better than LMWH. Furthermore, independent of anticoagulant activities, these polymers affected other metastasis-relevant targets with impressive affinities. Hence, they blocked heparanase enzymatic activity outmatching commercial heparins or a glycosidic drug candidate. Furthermore, these polymers bind P-selectin and the integrin VLA-4 similar to or even better than heparin, indicated by a biosensor approach and thus efficiently blocked melanoma cell binding to endothelium under blood flow conditions. This is the first report on the prospects of synthetic heparin mimetics as promising nontoxic compounds in oncology to potentially substitute heparin as an anticoagulant and to better understand its role as an antimetastatic drug.
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| 4. |
- Li, Honglian, et al.
(författare)
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Heparanase Modulates Chromatin Accessibility
- 2023
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Ingår i: Cells. - : MDPI. - 2073-4409. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Heparanase is the sole endoglucuronidase that degrades heparan sulfate in the cell surface and extracellular matrix (ECM). Several studies have reported the localization of heparanase in the cell nucleus, but the functional role of the nuclear enzyme is still obscure. Subjecting mouse embryonic fibroblasts (MEFs) derived from heparanase knockout (Hpse-KO) mice and applying transposase-accessible chromatin with sequencing (ATAC-seq), we revealed that heparanase is involved in the regulation of chromatin accessibility. Integrating with genome-wide analysis of chromatin states revealed an overall low activity in the enhancer and promoter regions of Hpse-KO MEFs compared with wild-type (WT) MEFs. Western blot analysis of MEFs and tissues derived from Hpse-KO vs. WT mice confirmed reduced expression of H3K27ac (acetylated lysine at N-terminal position 27 of the histone H3 protein). Our results offer a mechanistic explanation for the well-documented attenuation of inflammatory responses and tumor growth in Hpse-KO mice.
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| 5. |
- Maccarana, Marco, et al.
(författare)
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Implications of Heparanase on Heparin Synthesis and Metabolism in Mast Cells
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 23:9
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Tidskriftsartikel (refereegranskat)abstract
- Heparin is a polysaccharide expressed in animal connective tissue-type mast cells. Owing to the special pentasaccharide sequence, heparin specifically binds to antithrombin (AT) and increases the inhibitory activity of AT towards coagulation enzymes. Heparin isolated from porcine intestinal mucosa has an average molecular weight of 15 kDa, while heparins recovered from rat skin and the peritoneal cavity were 60-100 kDa and can be fragmented by the endo-glucuronidase heparanase in vitro. In this study, we have examined heparin isolated from in vitro matured fetal skin mast cells (FSMC) and peritoneal cavity mast cells (PCMC) collected from wildtype (WT), heparanase knockout (Hpa-KO), and heparanase overexpressing (Hpa-tg) mice. The metabolically S-35-labeled heparin products from the mast cells of WT, Hpa-KO, and Hpa-tg mice were compared and analyzed for molecular size and AT-binding activity. The results show that PCMC produced heparins with a size similar to heparin from porcine intestinal mast cells, whilst FSMC produced much longer chains. As expected, heparanase overexpression resulted in the generation of smaller fragments in both cell types, while heparins recovered from heparanase knockout cells were slightly longer than heparin from WT cells. Unexpectedly, we found that heparanase expression affected the production of total glycosaminoglycans (GAGs) and the proportion between heparin and other GAGs but essentially had no effect on heparin catabolism.
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| 6. |
- Veraldi, Noemi, et al.
(författare)
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Low-molecular weight sulfated marine polysaccharides : Promising molecules to prevent neurodegeneration in mucopolysaccharidosis IIIA?
- 2023
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 320
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Tidskriftsartikel (refereegranskat)abstract
- Mucopolysaccharidosis IIIA is a hereditary disease caused by mutations in the sulfamidase enzyme that participates in catabolism of heparan sulfate (HS), leading to HS fragment accumulation and multisystemic failure. No cure exists and death occurs around the second decade of life. Two low molecular weight highly sulfated compounds derived from marine diabolican and infernan exopolysaccharides (A5_3 and A5_4, respectively) with heparanase inhibiting properties were tested in a MPSIIIA cell line model, resulting in limited degradation of intracellular HS. Next, we observed the effects of intraperitoneal injections of the diabolican derivative A5_3 from 4 to 12 weeks of age on MPSIIIA mice. Brain metabolism and microstructure, levels of proteins and genes involved in MPSIIIA brain pathophysiology were also investigated. 1H-Magnetic Resonance Spectroscopy (MRS) indicated deficits in energetic metabolism, tissue integrity and neurotransmission at both 4 and 12 weeks in MPSIIIA mice, with partial protective effects of A5_3. Ex-vivo Diffusion Tensor Imaging (DTI) showed white matter microstructural damage in MPSIIIA, with noticeable protective effects of A5_3. Protein and gene expression assessments displayed both pro-inflammatory and pro-apoptotic profiles in MPSIIIA mice, with benefits of A5_3 counteracting neuroinflammation. Overall, derivative A5_3 was well tolerated and was shown to be efficient in preventing brain metabolism failure and inflammation, resulting in preserved brain microstructure in the context of MPSIIIA.
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| 7. |
- Zhang, Xiao, et al.
(författare)
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Heparanase overexpression impedes perivascular clearance of amyloid-beta from murine brain : relevance to Alzheimer's disease
- 2021
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Ingår i: Acta neuropathologica communications. - : BioMed Central (BMC). - 2051-5960. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Defective amyloid-beta (A beta) clearance from the brain is a major contributing factor to the pathophysiology of Alzheimer's disease (AD). A beta clearance is mediated by macrophages, enzymatic degradation, perivascular drainage along the vascular basement membrane (VBM) and transcytosis across the blood-brain barrier (BBB). AD pathology is typically associated with cerebral amyloid angiopathy due to perivascular accumulation of A beta. Heparan sulfate (HS) is an important component of the VBM, thought to fulfill multiple roles in AD pathology. We previously showed that macrophage-mediated clearance of intracortically injected A beta was impaired in the brains of transgenic mice overexpressing heparanase (Hpa-tg). This study revealed that perivascular drainage was impeded in the Hpa-tg brain, evidenced by perivascular accumulation of the injected A beta in the thalamus of Hpa-tg mice. Furthermore, endogenous A beta accumulated at the perivasculature of Hpa-tg thalamus, but not in control thalamus. This perivascular clearance defect was confirmed following intracortical injection of dextran that was largely retained in the perivasculature of Hpa-tg brains, compared to control brains. Hpa-tg brains presented with thicker VBMs and swollen perivascular astrocyte endfeet, as well as elevated expression of the BBB-associated water-pump protein aquaporin 4 (AQP4). Elevated levels of both heparanase and AQP4 were also detected in human AD brain. These findings indicate that elevated heparanase levels alter the organization and composition of the BBB, likely through increased fragmentation of BBB-associated HS, resulting in defective perivascular drainage. This defect contributes to perivascular accumulation of A beta in the Hpa-tg brain, highlighting a potential role for heparanase in the pathogenesis of AD.
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| 8. |
- Xu, Zijie, et al.
(författare)
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The mode I fracture toughness alternation and crack propagation behavior evolution due to long-term Sc-CO2 saturation
- 2022
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Ingår i: Engineering Fracture Mechanics. - : Elsevier. - 0013-7944 .- 1873-7315. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- The mode I fracture toughness is a critical parameter which defines the rock's resistance to crack propagation, especially in hydraulic fracturing. Recently, Supercritical carbon dioxide (Sc-CO2) has been proposed as a fracturing fluid candidate in hydraulic fracturing stimulations of shale reservoirs. However, its effects on fracture toughness transition and crack propagation behaviors have not been understood well. In this study, we performed a series of semicircular bend speci-mens (SCB) before the Longmaxi shale specimens' saturation. Three-point bending tests along divider orientation showed that after Sc-CO2 saturation, mode I fracture toughness (KIC), elastic modulus (E) and absorbed energy (U-e) of shale were decreased by 22.1%, 24.5% and 44.3%, respectively. High speed camera images indicated that after Sc-CO2 saturation, mode I crack directly propagated straight along artificial pre-crack direction, decreasing the degree of crack deviation as in KIC. The results of Cronos high-precision 3D scanning system and scanning elec-tron microscopy (SEM) revealed complicated fracture mechanisms (transgranular, intergranular and mutual coupling crack mechanisms) of shale after Sc-CO2 saturation, which reduced the roughness and area of fracture crack surface. The generation of pore and cracks was the main reason for the decrease of shale resistance to fracture. Furthermore, Sc-CO2 saturated shale specimens only needed to absorb less energy to more rapidly cause the initiation and propagation of mode I cracks with the main fracture mode being transgranular cracks.
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| 9. |
- Zhou, Wei, et al.
(författare)
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Mass Spectrometry and Computer Simulation Predict the Interactions of AGPS and HNRNPK in Glioma
- 2021
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Ingår i: BioMed Research International. - : Hindawi Publishing Corporation. - 2314-6133 .- 2314-6141. ; 2021
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Tidskriftsartikel (refereegranskat)abstract
- Ether lipids are overexpressed in malignant tumor and play an important role in tumor process. Glioma is the most common malignant central nervous system tumor, and the content of ether lipids is higher than that of normal tissues. Alkylglycerone phosphate synthase (AGPS) is a key enzyme in the synthesis of ether esters and plays a vital role in maintaining the morphology and pathogenic properties of tumor cells. The cell proliferation and the content of tumor-related lipid such as monoalkylglycerol ether (MAGe), lysophosphatidic acid ether (LPAe), lysophosphatidylcholine ether (LPCe), lysophosphatidylethanolamine ether (LPEe), phosphatidyl inositol (PI), phosphatidylcholine (PC), and phosphatidylserine (PS) were suppressed after AGPS silencing in U251, H4, and TJ905 cells; however, heterogeneous nuclear ribonucleoprotein K (HNRNPK) could reverse the above phenomenon such as cellar proliferation and ether lipid secretion. We found that HNRNPK was the target protein of AGPS by coimmunoprecipitation and mass spectrometry assay and verified by western blot assay in U251 cells. It confirmed that AGPS and HNRNPK are coexpressed in the cellular nucleus by a confocal laser microscope. The main protein-protein interaction mechanism between AGPS and HNRNPK is hydrogen bond, conjugation bond, hydrophobic bond, and electrostatic force by computer simulation prediction.
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