| 1. |
- Bergman, Marie-Louise, et al.
(författare)
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Diabetes protection and restoration of thymocyte apoptosis in NOD Idd6 congenic strains
- 2003
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 52:7, s. 1677-1682
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes in the nonobese diabetic (NOD) mouse is a multifactorial and polygenic disease. The NOD-derived genetic factors that contribute to type 1 diabetes are named Idd (insulin-dependent diabetes) loci. To date, the biological functions of the majority of the Idd loci remain unknown. We have previously reported that resistance of NOD immature thymocytes to depletion by dexamethazone (Dxm) maps to the Idd6 locus. Herein, we refine this phenotype using a time-course experiment of apoptosis induction upon Dxm treatment. We confirm that the Idd6 region controls apoptosis resistance in immature thymocytes. Moreover, we establish reciprocal Idd6 congenic NOD and B6 strains to formally demonstrate that the Idd6 congenic region mediates restoration of the apoptosis resistance phenotype. Analysis of the Idd6 congenic strains indicates that a 3-cM chromosomal region located within the distal part of the Idd6 region controls apoptosis resistance in NOD immature thymocytes. Together, these data support the hypothesis that resistance to Dxm-induced apoptosis in NOD immature thymocytes is controlled by a genetic factor within the region that also contributes to type 1 diabetes pathogenesis. We propose that the diabetogenic effect of the Idd6 locus is exerted at the level of the thymic selection process.
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| 2. |
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| 3. |
- Duarte, Nádia, 1977-
(författare)
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Molecular and cellular mechanisms contributing to the pathogenesis of autoimmune diabetes
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes is an autoimmune disorder determined both by genetic and environmental factors. The Non-obese diabetic (NOD) mouse is one of the best animal models of this disease. It spontaneously develops diabetes through a process resembling the human pathogenesis. The strong association of NOD Type 1 diabetes to the MHC region and the existence of other diabetes susceptibility loci are also in parallel with the human disease. The identity of the genetic factors and biological function mediated by these loci remain, however, largely unknown. Like in other autoimmune diseases, defects in tolerance mechanisms are thought to be at the origin of type 1 diabetes. Accordingly, defects in both central and peripheral tolerance mechanisms have been reported in the NOD mouse model. Using a subphenotype approach that aimed to dissect the disease into more simple phenotypes, we have addressed this issue. In paper I, we analyzed resistance to dexamethasone-induced apoptosis in NOD immature thymocytes previously mapped to the Idd6 locus. Using a set of congenic mice carrying B6-derived Idd6 regions on a NOD background and vice-versa we could restrict the Idd6 locus to an 8cM region on the telomeric end of chromosome 6 and the control of apoptosis resistance to a 3cM region within this area. In paper II, further analysis of diabetes incidence in these congenic mice separated the genes controlling these two traits, excluding the region controlling the resistance to apoptosis as directly mediating susceptibility to diabetes. These results also allowed us to further restrict the Idd6 locus to a 3Mb region. Expression analysis of genes in this chromosomal region highlighted the Lrmp/Jaw1 gene as a prime candidate for Idd6. Lrmp encodes an endoplasmatic reticulum resident protein. Papers III and IV relate to peripheral tolerance mechanisms. Several T cell populations with regulatory functions have been implicated in type 1 diabetes. In paper III, we analyzed NOD transgenic mice carrying a diverse CD1d-restricted TCR αVa3.2b9), named 24abNOD mice. The number of nonclassical NKT cells was found to be increased in these mice and almost complete protection from diabetes was observed. These results indicate a role for nonclassical NKT cells in the regulation of autoimmune diabetes. In paper IV, we studied the effects of introducing the diverse CD1d-restricted TCR (Va3.2b9) in immunodeficient NOD Rag-/- mice (24abNODRag-/- mice). This resulted in a surprising phenotype with inflammation of the ears and augmented presence of mast cells as well as spleenomegaly and hepatomegaly associated with extended fibrosis and increased numbers of mast cells and eosinophils in the tissues. These observations supported the notion that NKT cells constitute an “intermediary” cell type, not only able to elicit the innate immune system to mount an inflammatory response, but also able to interact with the adaptive immune system affecting the action of effector T cells in an autoimmune situation. In this context the 24abNODRag-/- mice provide an appropriate animal model for studying the interaction of NKT cells with both innate and adaptive components of the immune systemα.
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| 4. |
- Duarte, Nadia, et al.
(författare)
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Prevention of diabetes in nonobese diabetic mice mediated by CD1d-restricted nonclassical NKT cells.
- 2004
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Ingår i: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 173:5, s. 3112-3118
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Tidskriftsartikel (refereegranskat)abstract
- A role for regulatory lymphocytes has been demonstrated in the pathogenesis of type 1 diabetes in the NOD mouse but the nature of these cells is debated. CD1d-restricted NKT lymphocytes have been implicated in this process. Previous reports of reduced diabetes incidence in NOD mice in which the numbers of NKT cells are artificially increased have been attributed to the enhanced production of IL-4 by these cells and a role for classical NKT cells, using the Valpha14-Jalpha18 rearrangement. We now show that overexpression in NOD mice of CD1d-restricted TCR Valpha3.2(+)Vbeta9(+) NKT cells producing high levels of IFN-gamma but low amounts of IL-4 leads to prevention of type 1 diabetes, demonstrating a role for nonclassical CD1d-restricted NKT cells in the regulation of autoimmune diabetes.
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| 5. |
- Duarte, Nádia, et al.
(författare)
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The Idd6.2 diabetes susceptibility region controls defective expression of the Lrmp gene in nonobese diabetic (NOD) mice
- 2007
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Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 59:5, s. 407-416
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Tidskriftsartikel (refereegranskat)abstract
- The identification of genes mediating susceptibility to type 1 diabetes (T1D) remains a challenging task. Using a positional cloning approach based on the analysis of nonobese diabetic (NOD) mice congenic over the Idd6 diabetes susceptibility region, we found that the NOD allele at this locus mediates lower mRNA expression levels of the lymphoid restricted membrane protein gene (Lrmp/Jaw1). Analysis of thymic populations indicates that Lrmp is expressed mainly in immature thymocytes. The Lrmp gene encodes a type 1 transmembrane protein that localizes to the ER membrane and has homology to the inositol 1,4,5-triphosphate receptor-associated cGMP kinase substrate gene, which negatively regulates intracellular calcium levels. We hypothesize that the observed decrease in expression of the Lrmp gene in NOD mice may constitute a T1D susceptibility factor in the Idd6 region.
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| 6. |
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| 7. |
- Espinosa-Parrilla, Yolanda, et al.
(författare)
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Genetic association of gastric cancer with miRNA clusters including the cancer-related genes MIR29, MIR25, MIR93 and MIR106: Results from the EPIC-EURGAST study
- 2014
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 135:9, s. 2065-2076
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are post-transcriptional gene regulators involved in a wide range of biological processes including tumorigenesis. Deregulation of miRNA pathways has been associated with cancer but the contribution of their genetic variability to this disorder is poorly known. We analyzed the genetic association of gastric cancer (GC) and its anatomical and histological subtypes, with 133 single-nucleotide polymorphisms (SNPs) tagging 15 isolated miRNAs and 24 miRNA clusters potentially involved in cancer, in 365 GC cases and 1,284 matched controls within the European Prospective Investigation into Cancer and Nutrition cohort. Various SNPs were associated with GC under the log-additive model. Furthermore, several of these miRNAs passed the gene-based permutation test when analyzed according to GC subtypes: three tagSNPs of the miR-29a/miR-29b-1 cluster were associated with diffuse subtype (minimum p-value=1.7 x 10(-4); odds ratio, OR=1.72; 95% confidence interval, CI=1.30-2.28), two tagSNPs of the miR-25/miR-93/miR-106b cluster were associated with cardia GC (minimum p-value=5.38 x 10(-3); OR=0.56, 95% CI=0.37-0.86) and one tagSNP of the miR-363/miR-92a-2/miR-19b-2/miR-20b/miR-18b/miR-106a cluster was associated with noncardia GC (minimum p-value=5.40 x 10(-3); OR=1.41, 95% CI=1.12-1.78). Some functionally validated target genes of these miRNAs are implicated in cancer-related processes such as methylation (DNMT3A, DNMT3B), cell cycle (E2F1, CDKN1A, CDKN1C), apoptosis (BCL2L11, MCL1), angiogenesis (VEGFA) and progression (PIK3R1, MYCN). Furthermore, we identified genetic interactions between variants tagging these miRNAs and variants in their validated target genes. Deregulation of the expression of these miRNAs in GC also supports our findings, altogether suggesting for the fist time that genetic variation in MIR29, MIR25, MIR93 and MIR106b may have a critical role in genetic susceptibility to GC and could contribute to the molecular mechanisms of gastric carcinogenesis.
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| 8. |
- Fedirko, Veronika, et al.
(författare)
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Pre-diagnostic anthropometry and survival after colorectal cancer diagnosis in Western European populations
- 2014
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 135:8, s. 1949-1960
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Tidskriftsartikel (refereegranskat)abstract
- General and abdominal adiposity are associated with a high risk of developing colorectal cancer (CRC), but the role of these exposures on cancer survival has been less studied. The association between pre-diagnostic anthropometric characteristics and CRC-specific and all-cause death was examined among 3,924 men and women diagnosed with CRC between 1992 and 2009 in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Multivariable Cox proportional hazards models were used to calculate hazard ratios (FIRS) and corresponding 95% confidence intervals (as). Over a mean follow-up period of 49 months, 1,309 deaths occurred of which 1,043 (79.7%) were due to CRC. In multivariable analysis, prediagnostic BMI kg/m2 was associated with a high risk for CRC-specific (HR = 1.26, 95% CI = 1.04-1.52) and all-cause (HR = 1.32, 95% CI = 1.12-1.56) death relative to BMI <25 kg/m(2). Every 5 kg/m(2) increase in BMI was associated with a high risk for CRC-specific (HR = 1.10, 95% CI = 1.02-1.19) and all-cause death (HR = 1.12, 95% Cl = 1.05-1.20); and every 10 cm increase in waist circumference was associated with a high risk for CRC-specific (HR = 1.09, 95% Cl = 1.02-1.16) and allcause death (HR= 1.11, 95% CI= 1.05-1.18). Similar associations were observed for waist-to-hip and waist-to-height ratios. Height was not associated with CRC-specific or all-cause death. Associations tended to be stronger among men than in women. Possible interactions by age at diagnosis, cancer stage, tumour location, and hormone replacement therapy use among postmenopausal women were noted. Pre-diagnostic general and abdominal adiposity are associated with lower survival after CRC diagnosis.
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| 9. |
- Fernandez-Anez, Nieves, et al.
(författare)
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Current Wildland Fire Patterns and Challenges in Europe : A Synthesis of National Perspectives
- 2021
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Ingår i: Air, Soil and Water Research. - : SAGE Publications. - 1178-6221. ; 14, s. 1-19
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Forskningsöversikt (refereegranskat)abstract
- Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by national representatives, supplemented by national fire statistics (2009–2018) across Europe. For each of the 31 countries included, we present a perspective authored by scientists or practitioners from each respective country, representing a wide range of disciplines and cultural backgrounds. The authors were selected from members of the COST Action “Fire and the Earth System: Science & Society” funded by the European Commission with the aim to share knowledge and improve communication about wildland fire. Where relevant, a brief overview of key studies, particular wildland fire challenges a country is facing, and an overview of notable recent fire events are also presented. Key perceived challenges included (1) the lack of consistent and detailed records for wildland fire events, within and across countries, (2) an increase in wildland fires that pose a risk to properties and human life due to high population densities and sprawl into forested regions, and (3) the view that, irrespective of changes in management, climate change is likely to increase the frequency and impact of wildland fires in the coming decades. Addressing challenge (1) will not only be valuable in advancing national and pan-European wildland fire management strategies, but also in evaluating perceptions (2) and (3) against more robust quantitative evidence.
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| 10. |
- Hughes, David J, et al.
(författare)
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Selenium status is associated with colorectal cancer risk in the European prospective investigation of cancer and nutrition cohort.
- 2015
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 136:5, s. 1149-1161
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Tidskriftsartikel (refereegranskat)abstract
- Suboptimal intakes of the micronutrient selenium (Se) are found in many parts of Europe. Low Se status may contribute to colorectal cancer (CRC) development. We assessed Se status by measuring serum levels of Se and Selenoprotein P (SePP) and examined the association with CRC risk in a nested case-control design (966 CRC cases; 966 matched controls) within the European Prospective Investigation into Cancer and Nutrition. Se was measured by total reflection X-ray fluorescence and SePP by immunoluminometric sandwich assay. Multivariable incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Respective mean Se and SePP levels were 84.0 μg/L and 4.3 mg/L in cases and 85.6 μg/L and 4.4 mg/L in controls. Higher Se concentrations were associated with a non-significant lower CRC risk (IRR = 0.92, 95% CI: 0.82-1.03 per 25 μg/L increase). However, sub-group analyses by sex showed a statistically significant association for women (ptrend = 0.032; per 25 μg/L Se increase, IRR = 0.83, 95% CI: 0.70-0.97) but not for men. Higher SePP concentrations were inversely associated with CRC risk (ptrend = 0.009; per 0.806 mg/L increase, IRR = 0.89, 95% CI: 0.82-0.98) with the association more apparent in women (ptrend = 0.004; IRR = 0.82, 95% CI: 0.72-0.94 per 0.806 mg/L increase) than men (ptrend = 0.485; IRR = 0.98, 95% CI: 0.86-1.12 per 0.806 mg/L increase). The findings indicate that Se status is suboptimal in many Europeans and suggest an inverse association between CRC risk and higher serum Se status, which is more evident in women.
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