| 1. |
- Noborn, Fredrik, et al.
(författare)
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Expanding the chondroitin glycoproteome of Caenorhabditis elegans
- 2018
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 293:1, s. 379-389
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Tidskriftsartikel (refereegranskat)abstract
- Chondroitin sulfate proteoglycans (CSPGs) are important structural components of connective tissues in essentially all metazoan organisms. In vertebrates, CSPGs are involved also in more specialized processes such as neurogenesis and growth factor signaling. In invertebrates, however, knowledge of CSPGs core proteins and proteoglycan-related functions is relatively limited, even for Caenorhabditis elegans. This nematode produces large amounts of non-sulfated chondroitin in addition to low-sulfated chondroitin sulfate chains. So far, only nine core proteins (CPGs) have been identified, some of which have been shown to be involved in extracellular matrix formation. We recently introduced a protocol to characterize proteoglycan core proteins by identifying CS-glycopeptides with a combination of biochemical enrichment, enzymatic digestion, and nano-scale liquid chromatography MS/MS analysis. Here, we have used this protocol to map the chondroitin glycoproteome in C. elegans, resulting in the identification of 15 novel CPG proteins in addition to the nine previously established. Three of the newly identified CPGs displayed homology to vertebrate proteins. Bioinformatics analysis of the primary protein sequences revealed that the CPG proteins altogether contained 19 unique functional domains, including Kunitz and endostatin domains, suggesting direct involvement in protease inhibition and axonal migration, respectively. The analysis of the core protein domain organization revealed that all chondroitin attachment sites are located in unstructured regions. Our results suggest that CPGs display a much greater functional and structural heterogeneity than previously appreciated and indicate that specialized proteoglycan-mediated functions evolved early in metazoan evolution.
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| 2. |
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| 3. |
- Rydell, Gustaf E, et al.
(författare)
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Human noroviruses recognize sialyl Lewis x neoglycoprotein
- 2009
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 19:3, s. 309-320
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Tidskriftsartikel (refereegranskat)abstract
- The carbohydrate binding characteristics of a norovirus GII.3 (Chron1) and a GII.4 (Dijon) strain were investigated using virus-like particles (VLPs) and saliva samples from 81 individuals genotyped for FUT2 (secretor) and FUT3 (Lewis) and phenotyped for ABO and Lewis blood groups. The two VLPs showed a typical secretor-gene-dependent binding and bound significantly stronger to saliva from A, B, and AB than from O individuals (P < 0.0001 and P < 0.001) but did not bind to any samples from secretor-negative individuals. The GII.3 strain showed larger interindividual variation and bound stronger to saliva from B than from A(2) secretors (P < 0.01). When assaying for binding to neoglycoproteins, the GII.3 and GII.4 strains were compared with the Norwalk GI.1 prototype strain. Although all three strains bound to Lewis b (and H type 1 chain) glycoconjugates, only the two GII strains showed an additional binding to sialyl Lewis x. This novel binding was specific since the VLPs did not bind to structural analogs, e.g., Lewis x or sialyl Lewis a, but only to sialyl Lewis x, sialyl diLewis x and sialylated type 2 chain conjugates. In inhibition experiments, the sialyl Lewis x conjugate was the most potent inhibitor. The minimal requirement for this potential receptor structure is Neu5Ac alpha 3Gal beta 4(Fuc alpha 3)GlcNAc beta 3Gal beta- where Fuc is not absolutely necessary for binding. Our study shows that some human norovirus GII strains have at least two binding specificities: one secretor-gene-dependent related to alpha 1,2-fucosylated carbohydrates and another related to alpha 2,3-sialylated carbohydrates of the type 2 chain, e.g., sialyl Lewis x.
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| 4. |
- Sharma, Sumit, et al.
(författare)
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Human Sera Collected between 1979 and 2010 Possess Blocking-Antibody Titers to Pandemic GII.4 Noroviruses Isolated over Three Decades
- 2017
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Ingår i: Journal of Virology. - : AMER SOC MICROBIOLOGY. - 0022-538X .- 1098-5514. ; 91:14
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of pandemic GII.4 norovirus (NoV) strains has been proposed to occur due to changes in receptor usage and thereby to lead to immune evasion. To address this hypothesis, we measured the ability of human sera collected between 1979 and 2010 to block glycan binding of four pandemic GII. 4 noroviruses isolated in the last 4 decades. In total, 268 sera were investigated for 50% blocking titer (BT50) values of virus-like particles (VLPs) against pig gastric mucin (PGM) using 4 VLPs that represent different GII. 4 norovirus variants identified between 1987 and 2012. Pre- and postpandemic sera (sera collected before and after isolation of the reference NoV strain) efficiently prevented binding of VLP strains MD145 (1987), Grimsby (1995), and Houston (2002), but not the Sydney (2012) strain, to PGM. No statistically significant difference in virus-blocking titers was observed between pre- and postpandemic sera. Moreover, paired sera showed that blocking titers of amp;gt;= 160 were maintained over a 6-year period against MD145, Grimsby, and Houston VLPs. Significantly higher serum blocking titers (geometric mean titer [GMT], 1,704) were found among IgA-deficient individuals than among healthy blood donors (GMT, 90.9) (P amp;lt; 0.0001). The observation that prepandemic sera possess robust blocking capacity for viruses identified decades later suggests a common attachment factor, at least until 2002. Our results indicate that serum IgG possesses antibody-blocking capacity and that blocking titers can be maintained for at least 6 years against 3 decades of pandemic GII. 4 NoV. IMPORTANCE Human noroviruses (NoVs) are the major cause of acute gastroenteritis worldwide. Histo-blood group antigens (HBGAs) in saliva and gut recognize NoV and are the proposed ligands that facilitate infection. Polymorphisms in HBGA genes, and in particular a nonsense mutation in FUT2 (G428A), result in resistance to global dominating GII. 4 NoV. The emergence of new pandemic GII. 4 strains occurs at intervals of several years and is proposed to be attributable to epochal evolution, including amino acid changes and immune evasion. However, it remains unclear whether exposure to a previous pandemic strain stimulates immunity to a pandemic strain identified decades later. We found that prepandemic sera possess robust virus-blocking capacity against viruses identified several decades later. We also show that serum lacking IgA antibodies is sufficient to block NoV VLP binding to HBGAs. This is essential, considering that 1 in every 600 Caucasian children is IgA deficient.
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| 5. |
- Stanaway, Jeffrey D., et al.
(författare)
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Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1923-1994
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Tidskriftsartikel (refereegranskat)abstract
- Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk- outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
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| 7. |
- Zaborowski, AM, et al.
(författare)
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Microsatellite instability in young patients with rectal cancer: molecular findings and treatment response
- 2022
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Ingår i: The British journal of surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 109:3, s. 251-255
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Tidskriftsartikel (refereegranskat)abstract
- In this study of 400 patients with early-onset rectal cancer, 12.5 per cent demonstrated microsatellite instability (MSI). MSI was associated with a reduced likelihood of nodal positivity, an increased rate of pathological complete response, and improved disease-specific survival.
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