| 44251. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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Identification of transient glycosylation alterations of sialylated mucin oligosaccharides during infection by the rat intestinal parasite Nippostrongylus brasiliensis.
- 2000
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Ingår i: The Biochemical journal. - 0264-6021. ; 350 Pt 3, s. 805-14
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Tidskriftsartikel (refereegranskat)abstract
- The sialylation of the oligosaccharides from small-intestinal mucins during a 13-day infectious cycle was studied in Sprague-Dawley rats with the parasite Nippostrongylus brasiliensis. Sialic acid analysis and release, permethylation and analysis by GC-MS of the sialylated oligosaccharides isolated from the 'insoluble' mucin complex revealed a relative decrease (4-7-fold) of N-glycolylneuraminic acid compared with N-acetylneuraminic acid just before parasite expulsion. Northern blots showed that this effect was due to the decreased expression of a hydroxylase converting CMP-N-acetylneuraminic acid into CMP-N-glycolylneuraminic acid. Analysis of other rat strains showed that this parasite infection also caused the same effect in these animals. Detailed analysis of infected Sprague-Dawley rats revealed four sialylated oligosaccharides not found in the uninfected animals. These new oligosaccharides were characterized in detail and all shown to contain the trisaccharide epitope NeuAc/NeuGcalpha2-3(GalNAcbeta1-4)Galbeta1 (where NeuGc is N-glycolyl neuraminic acid). This epitope is similar to the Sd(a)- and Cad-type blood-group antigens and suggests that the infection causes the induction of a GalNAcbeta1-4 glycosyltransferase. This model for an intestinal infection suggests that the glycosylation of intestinal mucins is a dynamic process being modulated by the expression of specific enzymes during an infection process.
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| 44252. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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Molecular characterization of the large heavily glycosylated domain glycopeptide from the rat small intestinal Muc2 mucin.
- 1996
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Ingår i: Glycoconjugate journal. - 0282-0080. ; 13:5, s. 823-31
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Tidskriftsartikel (refereegranskat)abstract
- The largest high-glycosylated domain, glycopeptide A, of the "insoluble' mucin complex of the rat small intestine has earlier been purified and characterized (Carlstedt et al., 1993, J Biol Chem 268: 18771-81). A rabbit antiserum raised against deglycosylated glycopeptide A was used to clone part of a mucin showing homology to the human MUC2 mucin (Hansson et al., 1994, Biochem Biophys Res Commun 198. 181-90). This serum specifically stained goblet cells (paranuclear) in the mouse small intestine. The size of the coding sequence of glycopeptide A was estimated by using reversed transcriptase PCR of mRNA from an inbred rat strain (GOT-W) using primers in the unique central and C-terminal parts of the proposed rat Muc2 sequences. The PCR and Southern blot of the PCR products showed a fragment of about 5.5 kb corresponding to about 1700 amino acids when the known Cys-rich sequences used for the primers were subtracted. This is slightly larger than the size estimated earlier by biochemical studies. The mRNA encoding the rat Muc2 was slightly smaller than the mRNA encoding the human MUC2 in a colorectal cell line. Although the size of glycopeptide A estimated from biochemical results and by PCR is not identical, the results obtained here further support that the "insoluble' mucin of the rat small intestine is encoded by the Muc2 gene. Most of the oligosaccharides in glycopeptide A were either neutral (40%) or sialylated (40%). The remaining ones were sulfated with the sulfate group attached to C-6 of N-acetylglucosamine linked to C-6 of the N-acetylgalactosaminitol as revealed by tandem mass spectrometry of the perdeuteroacetylated oligosaccharides. Eighteen oligosaccharides were found of which fourteen were characterized and found to be mostly novel. Our findings thus expand the current knowledge of the core peptide of the rat intestinal goblet cell mucin and provide a relatively complete picture of the glycosylation of a defined mucin domain.
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| 44253. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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O-Linked glycome and proteome of high-molecular-mass proteins in human ovarian cancer ascites: Identification of sulfation, disialic acid and O-linked fucose
- 2012
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 22:7, s. 918-929
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Tidskriftsartikel (refereegranskat)abstract
- The O-linked glycosylation of the main acidic high-molecular-weight glycoprotein from ascites fluid from patients with ovarian cancer were analyzed. The O-linked oligosaccharides were shown to consist of mainly highly sialylated core 1 and 2 structures with a smaller amount of sulfated core 2 structures. These structures were shown to be able to be further extended into small keratan sulfate (KS)-type oligosaccharides with up to four N-acetyllactosamine units. Proteomic studies of the acidic fraction of ascites fluid from patients with ovarian cancer showed that this fraction was enriched in proteoglycans. Among them, lumican, agrin, versican and dystroglycans were potential candidates, with threonine- and serine-rich domains that could carry a significant amount of O-linked glycosylation, including also the O-linked KS. Glycomic analysis using liquid chromatography (LC)-tandem mass spectrometry (MS/MS) also showed that the disialic acid NeuAc-NeuAc- was frequently found as the terminating structure on the O-linked core 1 and 2 oligosaccharides from one ascites sample. Also, a small amount of the epidermal growth factor (EGF)-associated O-linked fucose structure Gal-GlcNAc-Fucitol was detected with and without sialic acid in the LC-MS/MS analysis. Candidate proteins containing O-linked fucose were suggested to be proteoglycan-type molecules containing the O-linked fucose EGF consensus domain.
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| 44254. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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Salivary MUC7 is a major carrier of blood group I type O-linked oligosaccharides serving as the scaffold for sialyl Lewis x.
- 2009
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19:3, s. 288-300
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Tidskriftsartikel (refereegranskat)abstract
- Isolation of salivary MUC7 with gel electrophoresis allowed analysis by LC-MS and LC-MS(2) of released O-linked oligosaccharides and a thorough description of the glycosylation of this molecule, where high-molecular-weight oligosaccharides up to the size of 2790 Da and with up to three sialic acid residues were identified. A common theme of these novel high abundant oligosaccharides on MUC7 showed that the C-3 branch of the oligosaccharides consisted of branched I-antigen type structural epitopes (GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-), where the branch point was initiated on core 1 and core 2 galactose residues, and the branches were terminated by sialyl type 2 and sialyl Lewis x epitopes. Six sulfated sialylated oligosaccharides of low intensity were also identified, with the sulfate mainly on N-acetyl glucosamine residues located close to the reducing termini. One of these oligosaccharides was identified as a candidate for the high-affinity L-selectin ligand 6'-sulfo sialyl Lewis x. Neutral oligosaccharides and blood group antigens were found to be less abundant on MUC7 and the glycosylation appeared to be more preserved between individuals as compared to salivary MUC5B. This was illustrated by comparing the LC-MS spectra of MUC7 and MUC5B glycans from secretors (23 individuals) and nonsecretors (6 individuals). The data show that MUC7 provides a multivalent scaffold for sialylation, meeting the requirement for high-avidity binding via its glycosylation and mediator of the interaction between immune cells such as salivary neutrophils and oral bacteria.
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| 44255. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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Strategy for the investigation of O-linked oligosaccharides from mucins based on the separation into neutral, sialic acid- and sulfate-containing species.
- 1995
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Ingår i: Glycoconjugate journal. - 0282-0080. ; 12:1, s. 69-76
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Tidskriftsartikel (refereegranskat)abstract
- A method for the separation of O-linked oligosaccharides into neutral, sialic acid-containing and sulfated species was applied to oligosaccharides released by alkaline borohydride from mucin glycopeptides from porcine small intestine. The released mixture of reduced oligosaccharides was applied to an anion exchange column, and the neutral oligosaccharides were collected as the unretarded fraction. A mixture of dimethyl sulfoxide and iodomethane was passed through the column to convert the sialic acid-containing oligosaccharides into methyl esters that were eluted and converted to methyl amides by methyl amine. Finally the sulfated oligosaccharide fraction was eluted with salt. The neutral and the derivatized sialic acid-containing oligosaccharides were analysed by gas chromatography-mass spectrometry after permethylation and the sulfated oligosaccharide fraction was analysed by high performance anion exchange chromatography.
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| 44256. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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Sulphated mucin oligosaccharides from porcine small intestine analysed by four-sector tandem mass spectrometry.
- 1996
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Ingår i: Journal of mass spectrometry : JMS. - 1076-5174. ; 31:5, s. 560-72
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Tidskriftsartikel (refereegranskat)abstract
- The fraction of sulphated oligosaccharide alditols isolated from mucin glycopeptides of porcine small intestine 'insoluble' mucin complex was analysed by negative-ion fast atom bombardment (FAB) tandem mass spectrometry. Collision-induced dissociation (CID) tandem mass spectra of native and peracetylated species were compared with standards of sulphated monosaccharides. The tandem mass spectra revealed structural information of the carbohydrate sequence and sulphate position. Negative-ion FAB ionization of the peracetylated sulphated oligo-saccharide alditols was at least three times more sensitive than that of the native sulphated oligosaccharide alditols, as revealed by comparing the signal-to-noise ratios, and allowed the detection of eleven compared with six pseudo-molecular ions. Fourteen structures were determined from the CID tandem mass spectra obtained. The main sulphation site was C-6 of an N-acetylglucosamine 6-linked to the N-acetylgalactosaminitol. C-3 of the N-acetylgalactosaminitol could be unsubstituted or extended with a series of up to three monosaccharide residues including blood group H determinants and blood group A determinants. Also, the sulphated N-acetylglucosamine could be further extended. The most abundant structure was a monosulphated trisaccharide with the sequence Gal-->3(SO3-->6GlcNAc-->6)GalNAcol. The sulphation at C-6 of N-acetylglucosamine seems to be a common feature for O-linked oligosaccharides, and has been described both for skeletal keratan sulphates and respiratory mucin oligosaccharides. Low-abundance ions were also detected from oligosaccharides with sulphation at C-3 of an amino sugar residue. This seems to be a novel sulphation site for mucin oligosaccharides.
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| 44257. |
- Karlsson, Niclas G., 1966, et al.
(författare)
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The glycosylation of rat intestinal Muc2 mucin varies between rat strains and the small and large intestine. A study of O-linked oligosaccharides by a mass spectrometric approach.
- 1997
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 272:43, s. 27025-34
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Tidskriftsartikel (refereegranskat)abstract
- The large glycosylated domains obtained from the rat intestinal mucin Muc2 were isolated from the large and small intestine of the inbred rat strains GOT-W and GOT-BW. The expression of the rat Muc2 in the large intestine was confirmed immunochemically and by Northern blotting. Released oligosaccharides were structurally characterized by gas chromatography-mass spectrometry (neutral and sialylated species) or by tandem mass spectrometry (sulfated species), and a total of 63 structures was assigned. The large intestinal oligosaccharides were found to be identical between the strains, while the small intestinal glycosylation differed. Until now, detailed structural analysis of oligosaccharides isolated from a single mucin core or mucin domain with different origin have not been performed, and the information of different mucin glycoforms has been limited to immunochemistry. Blood group A-determinants (GalNAcalpha1-3(Fucalpha1-2)Galbeta1-, and structures related to the blood group Sda/Cad-related epitope NeuAc/NeuGcalpha1-3(GalNAcbeta1-4)Galbeta1-, were found in GOT-BW small intestine, and also in both large intestines. Blood group H-determinants and NeuAc/NeuGcalpha1-3Galbeta1- were found in all samples. Core 1 (Galbeta1-3GalNAcalpha1-), core 2 (Galbeta1-3(GlcNAcbeta1-6)GalNAcalpha1-), core 3 (GlcNAcbeta1-3GalNAcalpha1-), and core 4 (GlcNAcbeta1-3(GlcNAcbeta1-6)GalNAcalpha1- were also found in all the samples. The large intestine were enriched in sulfated oligosaccharides and the small intestine contained higher amounts of sialylated species. Sulfation were found exclusively on C-6 of GlcNAc.
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| 44258. |
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| 44259. |
- Karlsson, Niklas, et al.
(författare)
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Learning and activity after irradiation of the young mouse brain analyzed in adulthood using unbiased monitoring in a home cage environment.
- 2011
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Ingår i: Radiation research. - 1938-5404. ; 175:3, s. 336-46
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Tidskriftsartikel (refereegranskat)abstract
- Cranial radiotherapy during the treatment of pediatric malignancies may cause adverse late effects. It is important to find methods to assess the functional effects of ionizing radiation in animal models and to evaluate the possible ameliorating effects of preventive or reparative treatment strategies. We investigated the long-term effects of a single 8-Gy radiation dose to the brains of 14-day-old mice. Activity and learning were evaluated in adulthood using open field and trace fear conditioning (TFC). These established methods were compared with the novel IntelliCage platform, which enables unbiased analysis of both activity and learning over time in a home cage environment. Neither activity nor learning was changed after irradiation, as judged by the open field and TFC analyses. The IntelliCage, however, revealed both altered activity and learning impairment after irradiation. Place learning and reversal learning were both impaired in the IntelliCage 3 months after irradiation. These results indicate that activity and learning should be assessed using multiple methods and that unbiased analysis over time in a home cage environment may offer advantages in the detection of subtle radiation-induced effects on the young brain.
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| 44260. |
- Karlsson, Nadine, et al.
(författare)
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Risk of disability pension in relation to gender and age in a Swedish county; a 12-year population based, prospective cohort study.
- 2006
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Ingår i: Work (Reading, Mass.). - : IOS Press. - 1051-9815 .- 1875-9270. ; 27:2, s. 173-9
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Tidskriftsartikel (refereegranskat)abstract
- Residents of the county of Ostergötland, Sweden, who were 16-64 years of age in December 1984 and not pensioned (n=229,864), were followed in a prospective, cohort, study of data collected between 1985 and 1996. Using survival methods as the method of analysis, the likelihood of being granted a disability pension was 14% for women, 11% for men, and increased with age. Women less than 54 years of age were at higher risk than men (P<0.001), 69% of disability pensions granted were full-time and 31% were part-time, more women received part-time pensions (P<0.001). Whether the differences observed are due to gender bias in social insurance practices, to disease patterns, to occupational and work-related factors, or to a cohort effect has yet to be determined.
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