| 1. |
- Akatsu, Chizuru, et al.
(författare)
-
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
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 21:5, s. 565-574
-
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.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Andersson, Rolf, et al.
(författare)
-
Structures of two novel, serologically nonrelated core oligosaccharides of Yokenella regensburgei lipopolysaccharides differing only by a single hexose substitution
- 2010
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 20, s. 207-214
-
Tidskriftsartikel (refereegranskat)abstract
- Immunochemical analysis of the Yokenella regensburgei lipopolysaccharides (LPS) indicated the presence of the core oligosaccharide-related immunotypes among the investigated strains. The structure of the core oligosaccharide segment of the Y. regensburgei LPS has been investigated using chemical methods, mass spectrometry, and (1)H, (13)C NMR spectroscopy. It was concluded that the core oligosaccharides of the strains PCM 2476 and PCM 2477 are composed of an undecasaccharide. The combined data revealed two immunotypes of the core oligosaccharide recognized by antibodies against the whole bacterial cells. The structural differences between the core oligosaccharides are limited to the outermost terminal hexopyranose residue. In the core oligosaccharide of the strain PCM 2476, it was identified as alpha-D-Glcp and in that of the strain PCM 2477 as alpha-D-Galp. This subtle difference between the glycoforms of the LPS core appeared to be essential for formation of the epitopes recognized by the specific antibodies directed against the Y. regensburgei whole bacterial cells. The oligosaccharides are not substituted by phosphate groups. Instead, the carboxyl groups of Kdo and galacturonic acid residues present in the core provide the negative charges. The undecasaccharides represent a novel core type of bacterial LPS, which is characteristic for Y. regensburgei.
|
|
| 5. |
- Andersson Sjöland, Annika, et al.
(författare)
-
Versican in inflammation and tissue remodelling: the impact on lung disorders.
- 2015
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 25:3, s. 243-251
-
Forskningsöversikt (refereegranskat)abstract
- Versican is a proteoglycan that has many different roles in tissue homeostasis and inflammation. The biochemical structure is comprised of four different types of the core protein with attached glycosaminoglycans that can be sulphated to various extents and has the capacity to regulate differentiation of different cell types, migration, cell adhesion, proliferation, tissue stabilization and inflammation. Versican's regulatory properties are of importance during both homeostasis and changes that lead to disease progression. The glycosaminoglycans that are attached to the core protein are of the chondroitin sulfate/dermatan sulfate type and are known to be important in inflammation through interactions with cytokines and growth factors. For a more complex understanding of versican it is of importance to study the tissue niche, where the wound healing process in both healthy and diseased conditions take place. In previous studies our group has identified changes in the amount of the multifaceted versican in chronic lung disorders such as asthma, chronic obstructive pulmonary disease and bronchiolitis obliterans syndrome, which could be a result of pathologic, transforming growth factor β driven, on-going remodelling processes. Reversely, the context of versican in its niche is of great importance since versican has been reported to have a beneficial role in other contexts e.g. emphysema. Here we explore the vast mechanisms of versican in healthy lung and in lung disorders.
|
|
| 6. |
- Arike, Liisa, et al.
(författare)
-
Intestinal Muc2 mucin O-glycosylation is affected by microbiota and regulated by differential expression of glycosyltranferases
- 2017
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 27:4, s. 318-328
-
Tidskriftsartikel (refereegranskat)abstract
- Intestinal cells are covered by mucus. In the small intestine, a single unattached mucus is present whereas the colon has both an inner attached mucus layer and an outer loose mucus. The attached mucus of the colon is impenetrable to bacteria while the loose mucus acts as a habitat for commensal bacteria. In germ-free (GF) mice, small intestinal mucus is attached to the epithelium and the inner colon mucus is penetrable. O-glycosylation plays an important role in the host-microbiota interactions as the commensal bacteria use glycans as nutrient sources and attachment sites. While mucus protein composition is relatively homogenous along the intestine, its main component the Muc2 mucin shows regiospecific O-glycan patterns. We have now analyzed the glycosyltransferase relative concentrations in the epithelial cells along the intestine in GF and conventionally raised mice and compared this with the O-glycans formed. As Muc2 is the main O-glycosylated product in mucus, we made the simplified assumption that most of the glycosyltransferases found in the epithelial cells are involved in Muc2 O-glycan biosynthesis. The O-glycosyltransferase abundances along the intestine correlated well with the Muc2 O-glycan patterns. Some of the glycosyltransferases involved in the O-glycan elongation were decreased in GF mice, something that is in concordance with the observed shorter Muc2 O-glycans.
|
|
| 7. |
- Asplund, Annika, 1979, et al.
(författare)
-
Hypoxic regulation of secreted proteoglycans in macrophages.
- 2010
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 20:1, s. 33-40
-
Tidskriftsartikel (refereegranskat)abstract
- Macrophages are prominent in hypoxic areas of atherosclerotic lesions, and their secreted proteoglycans (PG), such as versican, can modulate the retention of lipoproteins and the activity of enzymes, cytokines, and growth factors involved in atherogenesis. In this study, we report the effects of hypoxia on PG secreted by human monocyte-derived macrophages (HMDM) and the potential regulation by the transcription factor hypoxia-inducible factor (HIF-1alpha and HIF-2alpha). We found that versican co-localized with HIF-1alpha in macrophage-rich areas in human advanced atherosclerotic lesions. Versican and perlecan mRNA expression increased after exposure to 0.5% O(2) (hypoxia) compared with 21% O(2) (control cells). Using precursors to GAG biosynthesis combined with immunoabsorption with a versican antibody an increased versican synthesis was detected at hypoxia. Furthermore, siRNA knockdown of HIF-1alpha and HIF-2alpha in THP-1 cells showed that the hypoxic induction of versican and perlecan mRNA expression involved HIF signaling. Versican expression was co-regulated by HIF-1alpha and HIF-2alpha but expression of perlecan was influenced only by HIF-1alpha and not by HIF-2alpha knockdown. The results show that oxygen concentration is an important modulator of PG expression in macrophages. This may be a novel component of the complex role of macrophages in atherosclerosis.
|
|
| 8. |
- Axelsson, Magnus A. B., et al.
(författare)
-
Neutralization of pH in the Golgi apparatus causes redistribution of glycosyltransferases and changes in the O-glycosylation of mucins.
- 2001
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 11:8, s. 633-44
-
Tidskriftsartikel (refereegranskat)abstract
- Addition of the weak base ammonium chloride (NH4Cl) or the proton pump inhibitor bafilomycin A1 to cultured HeLa and LS 174T cells effectively neutralized the pH gradient of the secretory pathway. This resulted in relocalization of the three studied glycosyltransferases, N-acetylgalactosaminyltransferase 2, beta1,2 N-acetylglucosaminyltransferase I, and beta1,4 galactosyltransferase 1, normally localized to the Golgi stack, the medial/trans-Golgi and the trans-Golgi/TGN, respectively. Indirect immunofluorescence microscopy, immunoelectron microscopy, and subcellular fractionation of the tagged or native glycosyltransferases showed that NH4Cl caused a relocalization of the enzymes mainly to vesicles of endosomal type, whereas bafilomycin A1 gave mainly cell surface staining. The general morphology of the endoplasmic reticulum and Golgi apparatus was retained as judged from immunofluorescence and electron microscopy studies. When the O-glycans on the guanidinium chloride insoluble gel-forming mucins from the LS 174T cells were analyzed by gas chromatography-mass spectrometry after neutralization of the secretory pathway pH by NH4Cl over 10 days shorter O-glycans were observed. However, no decrease in the number of oligosaccharide chains was indicated. Together, the results suggest that pH is a contributing factor for proper steady-state distribution of glycosyltransferases over the Golgi apparatus and that altered pH may cause alterations in glycosylation possibly due to a relocalization of glycosyltransferases.
|
|
| 9. |
|
|
| 10. |
- Bartolini, Barbara, et al.
(författare)
-
Mouse development is not obviously affected by the absence of dermatan sulfate epimerase 2 in spite of a modified brain dermatan sulfate composition.
- 2012
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 22:7, s. 1007-1016
-
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.
|
|
