| 1. |
- Akatsu, Chizuru, et al.
(författare)
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Dermatan sulfate epimerase 2 is the predominant isozyme in the formation of the chondroitin sulfate/dermatan sulfate hybrid structure in postnatal developing mouse brain
- 2011
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 21:5, s. 565-574
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Tidskriftsartikel (refereegranskat)abstract
- Chondroitin sulfate (CS) and dermatan sulfate (DS) are expressed in significant amounts in the brain and play important roles in the development of the central nervous system in mammals. CS and DS structures are often found in a single CS/DS hybrid chain. The L-iduronic acid (IdoA)-containing domain, which defines a DS-type domain, appears key to the biological functions of the CS/DS hybrid chain. In this study, to clarify the distribution of the DS-type structure in the brain during development, the expression patterns of DS epimerase 1 (DS-epi1) and DS-epi2, both of which convert D-glucuronic acid into IdoA, were investigated by in situ hybridization. DS-epi2 was ubiquitously expressed in the developing brain after birth, whereas the expression of DS-epi1 was faint and obscure at all developmental stages. Quantitative real-time polymerase chain reaction revealed the expression of DS-epi2 to be higher than that of DS-epi1 throughout development, suggesting that DS-epi2 but not DS-epi1 is mostly expressed in the brain and plays key roles in the epimerization of CS/DS during its biosynthesis. Moreover, an analysis of the disaccharides of CS/DS demonstrated significant amounts of IdoA-containing iD units [IdoA(2S)-GalNAc(6S)] and iB units [IdoA(2S)-GalNAc(4S)], where 2S, 4S and 6S stand for 2-O-, 4-O- and 6-O-sulfate, respectively, in every region of the brain examined. The proportion of these units in cerebellar CS/DS was greatly altered during postnatal development. These results suggest that the IdoA-containing structures in the developing brain are mainly produced by the actions of DS-epi2 and play crucial roles in postnatal development.
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| 2. |
- Bartolini, Barbara, et al.
(författare)
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Mouse development is not obviously affected by the absence of dermatan sulfate epimerase 2 in spite of a modified brain dermatan sulfate composition.
- 2012
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 22:7, s. 1007-1016
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Tidskriftsartikel (refereegranskat)abstract
- Dermatan sulfate epimerase 2 (DS-epi2), together with its homologue DS-epi1, transform glucuronic acid into iduronic acid in dermatan sulfate polysaccharide chains. Iduronic acid gives dermatan sulfate increased chain flexibility and promotes protein binding. DS-epi2 is ubiquitously expressed and is the predominant epimerase in brain. Here we report the generation and initial characterization of DS-epi2 null mice. DS-epi2 deficient mice showed no anatomical, histological or morphological abnormalities. The body weights and lengths of mutated and wild-type littermates were indistinguishable. They were fertile and had a normal lifespan. Chondroitin/dermatan sulfate (CS/DS) isolated from newborn mutated mouse brains had a 38% reduction in iduronic acid compared to wild type littermates and compositional analysis revealed a decrease of 4-O-sulfate and an increase of 6-O-sulfate containing structures. Despite the reduction in iduronic acid, adult DS-epi2-/- brain showed normal extracellular matrix features by immunohistological stainings. We conclude that DS-epi1 compensates in vivo for the loss of DS-epi2.. These results extend previous findings of functional redundancy of brain extracellular matrix components.
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| 3. |
- Dick, Gunnar, et al.
(författare)
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PAPST1 regulates sulfation of heparan sulfate proteoglycans in epithelial MDCK II cells.
- 2015
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 25:1, s. 30-41
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Tidskriftsartikel (refereegranskat)abstract
- Proteoglycan (PG) sulfation depends on activated nucleotide sulfate, 3'-phosphoadenosine-5'-phosphosulfate (PAPS). Transporters in the Golgi membrane translocate PAPS from the cytoplasm into the organelle lumen where PG sulfation occurs. Silencing of PAPS transporter (PAPST) 1 in epithelial MDCK cells reduced PAPS uptake into Golgi vesicles. Surprisingly, at the same time sulfation of heparan sulfate (HS) was stimulated. The effect was pathway specific in polarized epithelial cells. Basolaterally secreted PGs displayed an altered HS sulfation pattern and increased growth factor binding capacity. In contrast, the sulfation pattern of apically secreted PGs was unchanged while the secretion was reduced. Regulation of PAPST1 allows epithelial cells to prioritize between PG sulfation in the apical and basolateral secretory routes at the level of the Golgi apparatus. This provides sulfation patterns that ensure PG functions at the extracellular level, such as growth factor binding.
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| 4. |
- 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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| 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. |
- Pacheco, Benny, et al.
(författare)
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Dermatan 4-O-sulfotransferase 1 is pivotal in the formation of iduronic acid blocks in dermatan sulfate.
- 2009
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19, s. 1197-1203
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Tidskriftsartikel (refereegranskat)abstract
- Chondroitin/dermatan sulfate is a highly complex linear polysaccharide ubiquitously found in the extracellular matrix and at the cell surface. Several of its functions, such as binding to growth factors, are mediated by domains composed of alternating iduronic acid and 4-O-sulfated N-acetylgalactosamine residues, named 4-O-sulfated iduronic acid blocks. These domains are generated by the action of two DS-epimerases, which convert D-glucuronic acid into its epimer L-iduronic acid, in close connection with 4-O-sulfation. In this study, dermatan sulfate structure was evaluated after downregulating or increasing dermatan 4-O-sulfotransferase 1 (D4ST-1) expression. SiRNA-mediated downregulation of D4ST-1 in primary human lung fibroblasts led to a drastic specific reduction of iduronic acid blocks. No change of epimerase activity was found, indicating that the influence of D4ST-1 on epimerization is not due to an altered expression level of the DS-epimerases. Analysis of the dermatan sulfate chains showed that D4ST-1 is essential for the biosynthesis of the disulfated structure iduronic acid-2-O-sulfate-N-acetylgalactosamine-4-O-sulfate, thus confirmed to be strictly connected with the iduronic acid blocks. Also the biologically important residue hexuronic acid-N-acetylgalactosamine-4,6-O-disulfate considerably decreased after D4ST-1 downregulation. In conclusion, D4ST-1 is a key enzyme and is indispensable in the formation of important functional domains in dermatan sulfate and cannot be compensated by other 4-O-sulfotransferases.
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| 7. |
- Tiedemann, K, et al.
(författare)
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Regulation of the chondroitin/dermatan fine structure by transforming growth factor-beta 1 through effects on polymer-modifying enzymes
- 2005
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 15:12, s. 1277-1285
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Tidskriftsartikel (refereegranskat)abstract
- The chondroitin/dermatan sulfate proteoglycans (CS/DSPGs), biglycan, decorin, and versican play several important roles in extracellular matrix influencing matrix organization, cell proliferation, and recruitment. Moreover, they bind and regulate growth factors in the extracellular matrix. We have previously shown that cultured human lung fibroblasts treated with transforming growth factor-beta (TGF-beta) alone or in combination with epidermal growth factor and platelet-derived growth factor, increase the production of these PGs. In this report, we describe that the structure of their galactosaminoglycan side chains is altered, albeit there is no alteration of polysaccharide length. The findings showed that iduronic acid content is reduced by 50% in decorin and biglycan, whereas 4-O-sulfation is increased 2-fold in versican. To unravel the mechanism behind these changes, the activities of chondroitin C-5 epimerase and of O-sulfotransferases in cellular fractions prepared from fibroblasts were quantitated, and transcript levels of the relevant sulfotransferases were measured by real time polymerase chain reaction (RT-PCR). The C-5 epimerase activity was reduced by 25% in TGF-beta 1 treated cells and 50% in fibroblasts treated with the growth factor combination. No change in activity in dermatan 4-O sulfotransferase was observed, and only a minor decrease in dermatan 4-O-sulfotransferase-1 (D4ST-1) mRNA was observed. On the other hand, chondroitin 4-O sulfotransferase activity increased 2-fold upon TGF-beta 1 treatment and 3-fold upon treatment with the growth factor combination. This is in agreement with a 2-fold up-regulation of chondroitin-4-O-sulfotransferase 1 (C4ST-1) mRNA, and no changes in chondroitin-4-O-sulfotransferase 2 (C4ST-2) mRNA. Thus, cellular activity and transcript level correlated well with the changes in the structure of the dermatan/chondroitin sulfate chains.
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| 8. |
- Tykesson, Emil, et al.
(författare)
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Recombinant dermatan sulfate is a potent activator of heparin cofactor II-dependent inhibition of thrombin
- 2019
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423. ; 29:6, s. 446-451
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Tidskriftsartikel (refereegranskat)abstract
- The glycosaminoglycan dermatan sulfate (DS) is a well-known activator of heparin cofactor II-dependent inactivation of thrombin. In contrast to heparin, dermatan sulfate has never been prepared recombinantly from material of non-animal origin. Here we report on the enzymatic synthesis of structurally well-defined DS with high anticoagulant activity. Using a microbial K4 polysaccharide and the recombinant enzymes DS-epimerase 1, dermatan 4-O-sulfotransferase 1, uronyl 2-O-sulfotransferase and N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase, several new glycostructures have been prepared, such as a homogenously sulfated IdoA-GalNAc-4S polymer and its 2-O-, 6-O- and 2,6-O-sulfated derivatives. Importantly, the recombinant highly 2,4-O-sulfated DS inhibits thrombin via heparin cofactor II, approximately 20 times better than heparin, enabling manipulation of vascular and extravascular coagulation. The potential of this method can be extended to preparation of specific structures that are of importance for binding and activation of cytokines, and control of inflammation and metastasis, involving extravasation and migration.
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