| 1. |
- Leonard, Dag, et al.
(författare)
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Coronary Heart Disease in Systemic Lupus Erythematosus Is Associated With Interferon Regulatory Factor-8 Gene Variants
- 2013
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Ingår i: Circulation: Cardiovascular Genetics. - : BMJ. - 1942-325X .- 1942-3268. ; 72:Suppl. 3, s. 270-270
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Tidskriftsartikel (refereegranskat)abstract
- Background- Patients with systemic lupus erythematosus have increased morbidity and mortality in coronary heart disease (CHD). We asked whether there was a genetic influence on CHD in systemic lupus erythematosus. Methods and Results- The association between single-nucleotide polymorphisms (SNPs) and CHD in 2 populations of patients with systemic lupus erythematosus was assessed. Patients were genotyped on a custom 12k Illumina Array. The allele frequencies were compared between patients with (n=66) and without (n=509) CHD. We found 61 SNPs with an association (P<0.01) to CHD, with the strongest association for 3 SNPs located in the interferon regulatory factor-8 (IRF8) gene. Comparison of the allele frequencies of these 61 SNPs in patients with (n=27) and without (n=212) CHD in the second study population revealed that 2 SNPs, rs925994 and rs10514610 in IRF8 (linkage disequilibrium, r(2)=0.84), were associated with CHD in both study populations. Meta-analysis of the SNP rs925994 gave an odds ratio of 3.6 (2.1-6.3), P value 1.9x10(-6). The identified IRF8 allele remained as a risk factor for CHD after adjustment for traditional CHD risk factors. The IRF8 risk allele was associated with the presence of carotid plaques (P<0.001) and increased intima-media thickness (P=0.01). By electrophoretic mobility shift assays, we show weaker binding of protein to the risk allele of the highly linked SNP rs11117415, and by flow cytometry, a reduced frequency of circulating B cells was detected in patients with the IRF8 risk allele. Conclusions- There is a considerable genetic component for CHD in systemic lupus erythematosus, with IRF8 as a strong susceptibility locus.
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| 2. |
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| 3. |
- 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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| 4. |
- Sandling, Johanna K., et al.
(författare)
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A candidate gene study of the type I interferon pathway implicates IKBKE and IL8 as risk loci for SLE
- 2011
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 19:4, s. 479-484
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Tidskriftsartikel (refereegranskat)abstract
- Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease in which the type I interferon pathway has a crucial role. We have previously shown that three genes in this pathway, IRF5, TYK2 and STAT4, are strongly associated with risk for SLE. Here, we investigated 78 genes involved in the type I interferon pathway to identify additional SLE susceptibility loci. First, we genotyped 896 single-nucleotide polymorphisms in these 78 genes and 14 other candidate genes in 482 Swedish SLE patients and 536 controls. Genes with P<0.01 in the initial screen were then followed up in 344 additional Swedish patients and 1299 controls. SNPs in the IKBKE, TANK, STAT1, IL8 and TRAF6 genes gave nominal signals of association with SLE in this extended Swedish cohort. To replicate these findings we extracted data from a genomewide association study on SLE performed in a US cohort. Combined analysis of the Swedish and US data, comprising a total of 2136 cases and 9694 controls, implicates IKBKE and IL8 as SLE susceptibility loci (P(meta)=0.00010 and P(meta)=0.00040, respectively). STAT1 was also associated with SLE in this cohort (P(meta)=3.3 × 10(-5)), but this association signal appears to be dependent of that previously reported for the neighbouring STAT4 gene. Our study suggests additional genes from the type I interferon system in SLE, and highlights genes in this pathway for further functional analysis.
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| 5. |
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| 6. |
- Wang, Chuan, et al.
(författare)
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Contribution of IKBKE and IFIH1 gene variants to SLE susceptibility
- 2013
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 14:4, s. 217-222
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Tidskriftsartikel (refereegranskat)abstract
- The type I interferon system genes IKBKE and IFIH1 are associated with the risk of systemic lupus erythematosus (SLE). To identify the sequence variants that are able to account for the disease association, we resequenced the genes IKBKE and IFIH1. Eighty-six single-nucleotide variants (SNVs) with potentially functional effect or differences in allele frequencies between patients and controls determined by sequencing were further genotyped in 1140 SLE patients and 2060 controls. In addition, 108 imputed sequence variants in IKBKE and IFIH1 were included in the association analysis. Ten IKBKE SNVs and three IFIH1 SNVs were associated with SLE. The SNVs rs1539241 and rs12142086 tagged two independent association signals in IKBKE, and the haplotype carrying their risk alleles showed an odds ratio of 1.68 (P-value=1.0 × 10−5). The risk allele of rs12142086 affects the binding of splicing factor 1 in vitro and could thus influence its transcriptional regulatory function. Two independent association signals were also detected in IFIH1, which were tagged by a low-frequency SNV rs78456138 and a missense SNV rs3747517. Their joint effect is protective against SLE (odds ratio=0.56; P-value=6.6 × 10−3). In conclusion, we have identified new SLE-associated sequence variants in IKBKE and IFIH1, and proposed functional hypotheses for the association signals.
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| 7. |
- Wang, Chuan, et al.
(författare)
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Evidence of association between interferon regulatory factor 5 gene polymorphisms and asthma
- 2012
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Ingår i: Gene. - : Elsevier BV. - 0378-1119 .- 1879-0038. ; 504:2, s. 220-225
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Tidskriftsartikel (refereegranskat)abstract
- Asthma is a heterogeneous disorder hallmarked by chronic inflammation in the respiratory system. Exacerbations of asthma are correlated with respiratory infections. Considering the implication of interferon regulatory factor 5 (IRF5) in innate and adaptive immunity, we investigated the preferential transmission patterns of ten IRF5 gene polymorphisms in two asthmatic family cohorts. A common IRF5 haplotype was found to be associated with asthma and the severity of asthmatic symptoms. Stratified analysis of subgroups of asthmatic individuals revealed that the associations were more pronounced in nonatopic asthmatic individuals. In addition, the risk alleles of IRF5 polymorphisms for asthma were almost completely opposite to those for autoimmune disorders. Our study provides the first evidence of association between IRF5 and asthma, and sheds light on the related but potentially distinct roles of IRF5 alleles in the pathogenesis of asthma and autoimmune disorders.
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| 8. |
- Wang, Chuan, et al.
(författare)
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Genes identified in Asian SLE GWASs are also associated with SLE in Caucasian populations
- 2013
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group: Open Access Hybrid Model Option B. - 1018-4813 .- 1476-5438. ; 21:9, s. 994-999
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Tidskriftsartikel (refereegranskat)abstract
- Recent genome-wide association studies (GWASs) conducted in Asian populations have identified novel risk loci for systemic lupus erythematosus (SLE). Here, we genotyped 10 single-nucleotide polymorphisms (SNPs) in eight such loci and investigated their disease associations in three independent Caucasian SLE case–control cohorts recruited from Sweden, Finland and the United States. The disease associations of the SNPs in ETS1, IKZF1, LRRC18-WDFY4, RASGRP3, SLC15A4, TNIP1 and 16p11.2 were replicated, whereas no solid evidence of association was observed for the 7q11.23 locus in the Caucasian cohorts. SLC15A4 was significantly associated with renal involvement in SLE. The association of TNIP1 was more pronounced in SLE patients with renal and immunological disorder, which is corroborated by two previous studies in Asian cohorts. The effects of all the associated SNPs, either conferring risk for or being protective against SLE, were in the same direction in Caucasians and Asians. The magnitudes of the allelic effects for most of the SNPs were also comparable across different ethnic groups. On the contrary, remarkable differences in allele frequencies between Caucasian and Asian populations were observed for all associated SNPs. In conclusion, most of the novel SLE risk loci identified by GWASs in Asian populations were also associated with SLE in Caucasian populations. We observed both similarities and differences with respect to the effect sizes and risk allele frequencies across ethnicities.
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| 9. |
- Wang, Chuan, et al.
(författare)
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Genome-wide profiling of target genes for the systemic lupus erythematosus-associated transcription factors IRF5 and STAT4
- 2013
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 72:1, s. 96-103
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:The transcription factors interferon regulatory factor 5 (IRF5) and signal transducer and activator of transcription 4 (STAT4) are encoded by two of the strongest susceptibility genes for systemic lupus erythematosus (SLE).OBJECTIVE:To investigate the target genes and functional roles of IRF5 and STAT4 in human peripheral blood mononuclear cells (PBMCs).METHODS: Chromatin immunoprecipitation-sequencing (ChIP-seq) was performed in PBMCs stimulated to activate IRF5 and STAT4. The expression of the target genes of IRF5 and STAT4 was investigated in a publicly available dataset generated from PBMCs from patients with SLE and healthy controls. The genomic regions bound by the transcription complexes mediated by IRF5 and STAT4 were examined for transcription factor binding motifs and SLE-associated sequence variants.RESULTS: More than 7000 target genes for IRF5 and STAT4 were identified in stimulated PBMCs. These genes were enriched to functional pathways in the type I interferon system, and have key roles in the inflammatory response. The expression patterns of the target genes were characteristic for patients with SLE. The transcription factors high mobility group-I/Y, specificity protein 1, and paired box 4 may function cooperatively with IRF5 and STAT4 in transcriptional regulation. Eight of the target regions for IRF5 and STAT4 contain SLE-associated sequence variants.CONCLUSIONS:By participating in transcription complex with other co-factors, IRF5 and STAT4 harbour the potential of regulating a large number of target genes, which may contribute to their strong association with SLE.
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| 10. |
- Wang, Chuan, et al.
(författare)
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Preferential Association of Interferon Regulatory Factor 5 Gene Variants with Seronegative Rheumatoid Arthritis in 2 Swedish Case-Control Studies
- 2011
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Ingår i: Journal of Rheumatology. - Toronto : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 38:10, s. 2130-2132
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Tidskriftsartikel (refereegranskat)abstract
- Objective.Two interferon regulatory factor 5 (IRF5) gene variants were examined for association with rheumatoid arthritis (RA).Methods.A total of 2300 patients with RA and 1836 controls were recruited from 2 independent RA studies in Sweden. One insertion-deletion polymorphism (CGGGG indel) and one single-nucleotide polymorphism (rs10488631) in the IRF5 gene were genotyped and analyzed within RA subgroups stratified by rheumatoid factor (RF) and anticitrullinated peptide antibodies (ACPA).Results.The CGGGG indel was preferentially associated with the RF-negative (OR 1.29, p = 7.9 × 10−5) and ACPA-negative (OR 1.27, p = 7.3 × 10−5) RA subgroups compared to the seropositive counterparts. rs10488631 was exclusively associated within the seronegative RA subgroups (RF-negative: OR 1.24, p = 0.016; ACPA-negative: OR 1.27, p = 4.1 × 10−3).Conclusion.Both the CGGGG indel and rs10488631 are relevant for RA susceptibility, especially for seronegative RA.
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