| 1. |
- Lauc, Gordan, et al.
(författare)
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Loci Associated with N-Glycosylation of Human Immunoglobulin G Show Pleiotropy with Autoimmune Diseases and Haematological Cancers
- 2013
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Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 9:1, s. e1003225-
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Tidskriftsartikel (refereegranskat)abstract
- Glycosylation of immunoglobulin G (IgG) influences IgG effector function by modulating binding to Fc receptors. To identify genetic loci associated with IgG glycosylation, we quantitated N-linked IgG glycans using two approaches. After isolating IgG from human plasma, we performed 77 quantitative measurements of N-glycosylation using ultra-performance liquid chromatography (UPLC) in 2,247 individuals from four European discovery populations. In parallel, we measured IgG N-glycans using MALDI-TOF mass spectrometry (MS) in a replication cohort of 1,848 Europeans. Meta-analysis of genome-wide association study (GWAS) results identified 9 genome-wide significant loci (P<2.27x10(-9)) in the discovery analysis and two of the same loci (B4GALT1 and MGAT3) in the replication cohort. Four loci contained genes encoding glycosyltransferases (ST6GAL1, B4GALT1, FUT8, and MGAT3), while the remaining 5 contained genes that have not been previously implicated in protein glycosylation (IKZF1, IL6ST-ANKRD55, ABCF2-SMARCD3, SUV420H1, and SMARCB1-DERL3). However, most of them have been strongly associated with autoimmune and inflammatory conditions (e. g., systemic lupus erythematosus, rheumatoid arthritis, ulcerative colitis, Crohn's disease, diabetes type 1, multiple sclerosis, Graves' disease, celiac disease, nodular sclerosis) and/or haematological cancers (acute lymphoblastic leukaemia, Hodgkin lymphoma, and multiple myeloma). Follow-up functional experiments in haplodeficient Ikzf1 knock-out mice showed the same general pattern of changes in IgG glycosylation as identified in the meta-analysis. As IKZF1 was associated with multiple IgG N-glycan traits, we explored biomarker potential of affected N-glycans in 101 cases with SLE and 183 matched controls and demonstrated substantial discriminative power in a ROC-curve analysis (area under the curve=0.842). Our study shows that it is possible to identify new loci that control glycosylation of a single plasma protein using GWAS. The results may also provide an explanation for the reported pleiotropy and antagonistic effects of loci involved in autoimmune diseases and haematological cancer.
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| 2. |
- Saksida, Tamara, et al.
(författare)
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Galectin-3 deficiency protects pancreatic islet cells from cytokine-triggered apoptosis in vitro
- 2013
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 1097-4652 .- 0021-9541. ; 228:7, s. 1568-1576
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Tidskriftsartikel (refereegranskat)abstract
- Beta cell apoptosis is a hallmark of diabetes. Since we have previously shown that galectin-3 deficient (LGALS3/) mice are relatively resistant to diabetes induction, the aim of this study was to examine whether beta cell apoptosis depends on the presence of galectin-3 and to delineate the underlying mechanism. Deficiency of galectin-3, either hereditary or induced through application of chemical inhibitors, -lactose or TD139, supported survival and function of islet beta cells compromised by TNF-+IFN-+IL-1 stimulus. Similarly, inhibition of galectin-3 by -lactose or TD139 reduced cytokine-triggered apoptosis of beta cells, leading to conclusion that endogenous galectin-3 propagates beta apoptosis in the presence of an inflammatory milieu. Exploring apoptosis-related molecules expression in primary islet cells before and after treatment with cytokines we found that galectin-3 ablation affected the expression of major components of mitochondrial apoptotic pathway, such as BAX, caspase-9, Apaf, SMAC, caspase-3, and AIF. In contrast, anti-apoptotic molecules Bcl-2 and Bcl-XL were up-regulated in LGALS3/ islet cells when compared to wild-type (WT) counterparts (C57BL/6), resulting in increased ratio of anti-apoptotic versus pro-apoptotic molecules. However, Fas-triggered apoptotic pathway as well as extracellular signal-regulated kinase 1/2 (ERK1/2) was not influenced by LGALS-3 deletion. All together, these results point to an important role of endogenous galectin-3 in beta cell apoptosis in the inflammatory milieu that occurs during diabetes pathogenesis and implicates impairment of mitochondrial apoptotic pathway as a key event in protection from beta cell apoptosis in the absence of galectin-3. J. Cell. Physiol. 228: 15681576, 2013. (c) 2012 Wiley Periodicals, Inc.
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| 3. |
- Volarevic, Vladislav, et al.
(författare)
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Galectin-3 deficiency prevents concanavalin A-induced hepatitis in mice
- 2012
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Ingår i: Hepatology. - : Ovid Technologies (Wolters Kluwer Health). - 1527-3350 .- 0270-9139. ; 55:6, s. 1954-1964
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Tidskriftsartikel (refereegranskat)abstract
- We used concanavalin A (Con A)-induced liver injury to study the role of galectin-3 (Gal-3) in the induction of inflammatory pathology and hepatocellular damage. We tested susceptibility to Con Ainduced hepatitis in galectin-3-deficient (Gal-3-/-) mice and analyzed the effects of pretreatment with a selective inhibitor of Gal-3 (TD139) in wild-type (WT) C57BL/6 mice, as evaluated by a liver enzyme test, quantitative histology, mononuclear cell (MNC) infiltration, cytokine production, intracellular staining of immune cells, and percentage of apoptotic MNCs in the liver. Gal-3-/- mice were less sensitive to Con Ainduced hepatitis and had a significantly lower number of activated lymphoid and dendritic cells (DCs) in the liver. The level of tumor necrosis factor alpha (TNFa), interferon gamma (IFN?), and interleukin (IL)-17 and -4 in the sera and the number of TNFa-, IFN?-, and IL-17- and -4-producing cluster of differentiation (CD)4+ cells as well as IL-12-producing CD11c+ DCs were lower, whereas the number of IL-10-producing CD4+ T cells and F4/80+ macrophages were significantly higher in livers of Gal-3-/- mice. Significantly higher percentages of late apoptotic Annexin V+ propidium-idodide+ liver-infiltrating MNCs and splenocytes were observed in Gal-3-/- mice, compared to WT mice. Pretreatment of WT C57BL/6 mice with TD139 led to the attenuation of liver injury and milder infiltration of IFN?- and IL-17- and -4-producing CD4+ T cells, as well as an increase in the total number of IL-10-producing CD4+ T cells and F4/80+ CD206+ alternatively activated macrophages and prevented the apoptosis of liver-infiltrating MNCs. Conclusions: Gal-3 plays an important proinflammatory role in Con Ainduced hepatitis by promoting the activation of T lymphocytes and natural killer T cells, maturation of DCs, secretion of proinflammatory cytokines, down-regulation of M2 macrophage polarization, and apoptosis of MNCs in the liver. (HEPATOLOGY 2012;55:19541964)
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