| 1. |
- Dideberg, Vinciane, et al.
(författare)
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An insertion-deletion polymorphism in the Interferon Regulatory Factor 5 (IRF5) gene confers risk of inflammatory bowel diseases
- 2007
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 16:24, s. 3008-3016
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Tidskriftsartikel (refereegranskat)abstract
- The interferon regulatory factor 5 (IRF5) gene encodes a transcriptionfactor that plays an important role in the innate as well asin the cell-mediated immune responses. The IRF5 gene has beenshown to be associated with systemic lupus erythematosus andrheumatoid arthritis. We studied whether the IRF5 gene is alsoassociated with inflammatory bowel diseases (IBD), Crohn disease(CD) and ulcerative colitis (UC). Twelve polymorphisms in theIRF5 gene were genotyped in a cohort of 1007 IBD patients (748CD and 241 UC) and 241 controls from Wallonia, Belgium. Thesame polymorphisms were genotyped in a confirmatory cohort of311 controls and 687 IBD patients (488 CD and 192 UC) from Leuven,Belgium. A strong signal of association (p = 1.9 x 10–5,OR: 1.81 (1.37-2.39)) with IBD was observed for a 5bp indel(CGGGG) polymorphism in the promoter region of the IRF5 gene.The association was detectable (p = 6.8 x 10–4) also inCD patients, and was particularly strong among the UC patients(p = 5.3 x 10–8, OR 2.42 (1.76 -3.34)). The associationof the CGGGG indel was confirmed in the second cohort (p = 3.2x 10–5, OR 1.59 (1.28 - 1.98)). The insertion of one CGGGGunit is predicted to create an additional binding site for thetranscription factor SP1. Using an electrophoretic mobilityshift assay we show allele-specific differences in protein bindingto this repetitive DNA-stretch, which suggest a potential functionrole for the CGGGG indel.
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| 2. |
- Flannick, Jason, et al.
(författare)
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Data Descriptor : Sequence data and association statistics from 12,940 type 2 diabetes cases and controls
- 2017
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the genetic basis of type 2 diabetes (T2D) to high resolution, the GoT2D and T2D-GENES consortia catalogued variation from whole-genome sequencing of 2,657 European individuals and exome sequencing of 12,940 individuals of multiple ancestries. Over 27M SNPs, indels, and structural variants were identified, including 99% of low-frequency (minor allele frequency [MAF] 0.1-5%) non-coding variants in the whole-genome sequenced individuals and 99.7% of low-frequency coding variants in the whole-exome sequenced individuals. Each variant was tested for association with T2D in the sequenced individuals, and, to increase power, most were tested in larger numbers of individuals (> 80% of low-frequency coding variants in similar to ~82 K Europeans via the exome chip, and similar to ~90% of low-frequency non-coding variants in similar to ~44 K Europeans via genotype imputation). The variants, genotypes, and association statistics from these analyses provide the largest reference to date of human genetic information relevant to T2D, for use in activities such as T2D-focused genotype imputation, functional characterization of variants or genes, and other novel analyses to detect associations between sequence variation and T2D.
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| 3. |
- Manning, Alisa, et al.
(författare)
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A Low-Frequency Inactivating AKT2 Variant Enriched in the Finnish Population Is Associated With Fasting Insulin Levels and Type 2 Diabetes Risk
- 2017
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Ingår i: Diabetes. - : AMER DIABETES ASSOC. - 0012-1797 .- 1939-327X. ; 66:7, s. 2019-2032
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Tidskriftsartikel (refereegranskat)abstract
- To identify novel coding association signals and facilitate characterization of mechanisms influencing glycemic traits and type 2 diabetes risk, we analyzed 109,215 variants derived from exome array genotyping together with an additional 390,225 variants from exome sequence in up to 39,339 normoglycemic individuals from five ancestry groups. We identified a novel association between the coding variant (p.Pro50Thr) in AKT2 and fasting plasma insulin (FI), a gene in which rare fully penetrant mutations are causal for monogenic glycemic disorders. The low-frequency allele is associated with a 12% increase in FI levels. This variant is present at 1.1% frequency in Finns but virtually absent in individuals from other ancestries. Carriers of the FI-increasing allele had increased 2-h insulin values, decreased insulin sensitivity, and increased risk of type 2 diabetes (odds ratio 1.05). In cellular studies, the AKT2-Thr50 protein exhibited a partial loss of function. We extend the allelic spectrum for coding variants in AKT2 associated with disorders of glucose homeostasis and demonstrate bidirectional effects of variants within the pleckstrin homology domain of AKT2.
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| 4. |
- Ghotbi, Roza, et al.
(författare)
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Allele-specific expression and gene methylation in the control of CYP1A2 mRNA level in human livers
- 2009
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Ingår i: The Pharmacogenomics Journal. - : Springer Science and Business Media LLC. - 1470-269X .- 1473-1150. ; 9:3, s. 208-217
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Tidskriftsartikel (refereegranskat)abstract
- The basis for interindividual variation in the CYP1A2 gene expression is not fully understood and the known genetic polymorphisms in the gene provide no explanation. We investigated whether the CYP1A2 gene expression is regulated by DNA methylation and displays allele-specific expression (ASE) using 65 human livers. Forty-eight percent of the livers displayed ASE not associated to the CYP1A2 mRNA levels. The extent of DNA methylation of a CpG island including 17 CpG sites, close to the translation start site, inversely correlated with hepatic CYP1A2 mRNA levels (P=0.018). The methylation of two separate core CpG sites was strongly associated with the CYP1A2 mRNA levels (P=0.005) and ASE phenotype (P=0.01), respectively. The CYP1A2 expression in hepatoma B16A2 cells was strongly induced by treatment with 5-aza-2'-deoxycytidine. In conclusion, the CYP1A2 gene expression is influenced by the extent of DNA methylation and displays ASE, mechanisms contributing to the large interindividual differences in CYP1A2 gene expression.
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| 5. |
- Gupta, Manu, et al.
(författare)
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Expression of BCR-ABL1 oncogene relative to ABL1 gene changes overtime in chronic myeloid leukemia
- 2008
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 366:3, s. 848-851
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Using a quantitative single nucleotide polymorphism (SNP) assay we have investigated the changes in the expression of the BCR-ABL1 oncogene relative to the wild-type ABL1 and BCR alleles in cells from chronic myeloid leukemia (CML) patients not responding to therapy. The results show a progressive increase in the BCR-ABL1 oncogene expression at the expense of decreased expression of the ABL1 allele, not involved in the fusion. No relative changes in the expression of the two BCR alleles were found. These results demonstrate that allele-specific charities in gene expression, with selective, progressive silencing of the wild-type A BL1 allele in favor of the oncogenic BCR-ABL1 allele occur in CML patients with therapy-resistant disease.
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| 6. |
- Kaleviste, Epp, et al.
(författare)
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Interferon signature in patients with STAT1 gain-of-function mutation is epigenetically determined
- 2019
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Ingår i: European Journal of Immunology. - : WILEY. - 0014-2980 .- 1521-4141. ; 49:5, s. 790-800
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Tidskriftsartikel (refereegranskat)abstract
- STAT1 gain-of-function (GOF) variants lead to defective Th17 cell development and chronic mucocutaneous candidiasis (CMC), but frequently also to autoimmunity. Stimulation of cells with STAT1 inducing cytokines like interferons (IFN) result in hyperphosphorylation and delayed dephosphorylation of GOF STAT1. However, the mechanism how the delayed dephosphorylation exactly causes the increased expression of STAT1-dependent genes, and how the intracellular signal transduction from cytokine receptors is affected, remains unknown. In this study we show that the circulating levels of IFN-alpha were not persistently elevated in STAT1 GOF patients. Nevertheless, the expression of interferon signature genes was evident even in the patient with low or undetectable serum IFN-alpha levels. Chromatin immunoprecipitation (ChIP) experiments revealed that the active chromatin mark trimethylation of lysine 4 of histone 3 (H3K4me3), was significantly enriched in areas associated with interferon-stimulated genes in STAT1 GOF cells in comparison to cells from healthy donors. This suggests that the chromatin binding of GOF STAT1 variant promotes epigenetic changes compatible with higher gene expression and elevated reactivity to type I interferons, and possibly predisposes for interferon-related autoimmunity. The results also suggest that epigenetic rewiring may be responsible for treatment failure of Janus kinase 1/2 (JAK1/2) inhibitors in certain patients.
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| 7. |
- Kristjansdottir, Gudlaug, et al.
(författare)
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Interferon Regulatory Factor 5 (IRF5) Gene Variants are Associated with Multiple Sclerosis in Three Distinct Populations
- 2008
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Ingår i: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 45:6, s. 362-369
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: IRF5 is a transcription factor involved both in the type I interferon and the toll-like receptor signalling pathways. Previously, IRF5 has been found to be associated with systemic lupus erythematosus, rheumatoid arthritis and inflammatory bowel diseases. Here we investigated whether polymorphisms in the IRF5 gene would be associated with yet another disease with features of autoimmunity, multiple sclerosis (MS). METHODS: We genotyped nine single nucleotide polymorphisms and one insertion-deletion polymorphism in the IRF5 gene in a collection of 2337 patients with MS and 2813 controls from three populations: two case-control cohorts from Spain and Sweden, and a set of MS trio families from Finland. RESULTS: Two single nucleotide polymorphism (SNPs) (rs4728142, rs3807306), and a 5 bp insertion-deletion polymorphism located in the promoter and first intron of the IRF5 gene, showed association signals with values of p<0.001 when the data from all cohorts were combined. The predisposing alleles were present on the same common haplotype in all populations. Using electrophoretic mobility shift assays we observed allele specific differences in protein binding for the SNP rs4728142 and the 5 bp indel, and by a proximity ligation assay we demonstrated increased binding of the transcription factor SP1 to the risk allele of the 5 bp indel. CONCLUSION: These findings add IRF5 to the short list of genes shown to be associated with MS in more than one population. Our study adds to the evidence that there might be genes or pathways that are common in multiple autoimmune diseases, and that the type I interferon system is likely to be involved in the development of these diseases.
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| 8. |
- Limbach, Maia, et al.
(författare)
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Epigenetic profiling in CD4+and CD8+T cells from Graves' disease patients reveals changes in genes associated with T cell receptor signaling
- 2016
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Ingår i: Journal of Autoimmunity. - : Elsevier BV. - 0896-8411 .- 1095-9157. ; 67, s. 46-56
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Tidskriftsartikel (refereegranskat)abstract
- In Graves' disease (GD), a combination of genetic, epigenetic and environmental factors causes an autoimmune response to the thyroid gland, characterized by lymphocytic infiltrations and autoantibodies targeting the thyroid stimulating hormone receptor (TSHR) and other thyroid antigens. To identify the epigenetic changes involved in GD, we performed a genome-wide analysis of DNA methylation and enrichment of H3K4me3 and H3K27ac histone marks in sorted CD4+ and CD8+ T cells. We found 365 and 3322 differentially methylated CpG sites in CD4+ and CD8+ T cells, respectively. Among the hypermethylated CpG sites, we specifically found enrichment of genes involved in T cell signaling (CD247, LCK, ZAP70, CD3D, CD3E, CD3G, CTLA4 and CD8A) and decreased expression of CD3 gene family members. The hypermethylation was accompanied with decreased levels of H3K4me3 and H3K27ac marks at several T cell signaling genes in ChIP-seq analysis. In addition, we found hypermethylation of the TSHR gene first intron, where several GD-associated polymorphisms are located. Our results demonstrate an involvement of dysregulated DNA methylation and histone modifications at T cell signaling genes in GD patients.
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| 9. |
- Locke, Adam E, et al.
(författare)
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Genetic studies of body mass index yield new insights for obesity biology.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 197-401
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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| 10. |
- Milani, Lili, et al.
(författare)
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Allele-specific gene expression patterns in primary leukemic cells reveal regulation of gene expression by CpG site methylation
- 2009
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 19:1, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- To identify genes that are regulated by cis-acting functional elements in acute lymphoblastic leukemia (ALL) we determined the allele-specific expression (ASE) levels of 2, 529 genes by genotyping a genome-wide panel of single nucleotide polymorphisms in RNA and DNA from bone marrow and blood samples of 197 children with ALL. Using a reproducible, quantitative genotyping method and stringent criteria for scoring ASE, we found that 16% of the analyzed genes display ASE in multiple ALL cell samples. For most of the genes, the level of ASE varied largely between the samples, from 1.4-fold overexpression of one allele to apparent monoallelic expression. For genes exhibiting ASE, 55% displayed bidirectional ASE in which overexpression of either of the two SNP alleles occurred. For bidirectional ASE we also observed overall higher levels of ASE and correlation with the methylation level of these sites. Our results demonstrate that CpG site methylation is one of the factors that regulates gene expression in ALL cells.
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