| 1. |
- Abelson, Anna-Karin, et al.
(författare)
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STAT4 Associates with SLE through two independent effects that correlate with gene expression and act additively with IRF5 to increase risk
- 2009
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 68:11, s. 1746-1753
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To confirm and define the genetic association of STAT4 and systemic lupus erythematosus, investigate the possibility of correlations with differential splicing and/or expression levels, and genetic interaction with IRF5. METHODS: 30 tag SNPs were genotyped in an independent set of Spanish cases and controls. SNPs surviving correction for multiple tests were genotyped in 5 new sets of cases and controls for replication. STAT4 cDNA was analyzed by 5'-RACE PCR and sequencing. Expression levels were measured by quantitative PCR. RESULTS: In the fine-mapping, four SNPs were significant after correction for multiple testing, with rs3821236 and rs3024866 as the strongest signals, followed by the previously associated rs7574865, and by rs1467199. Association was replicated in all cohorts. After conditional regression analyses, two major independent signals represented by SNPs rs3821236 and rs7574865, remained significant across the sets. These SNPs belong to separate haplotype blocks. High levels of STAT4 expression correlated with SNPs rs3821236, rs3024866 (both in the same haplotype block) and rs7574865 but not with other SNPs. We also detected transcription of alternative tissue-specific exons 1, indicating presence of tissue-specific promoters of potential importance in the expression of STAT4. No interaction with associated SNPs of IRF5 was observed using regression analysis. CONCLUSIONS: These data confirm STAT4 as a susceptibility gene for SLE and suggest the presence of at least two functional variants affecting levels of STAT4. Our results also indicate that both genes STAT4 and IRF5 act additively to increase risk for SLE.
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| 2. |
- Alarcón-Riquelme, Marta E., et al.
(författare)
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La Etiopatogenia en el Lupus Eritematoso Sistémico
- 2013. - 1
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Ingår i: Lupus eritematoso sistémico. - Rosario, Argentina : Carlos Antonio Battagliotti. - 9789872960407 ; , s. 65-85
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Bokkapitel (refereegranskat)
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| 3. |
- Castillejo-Lopez, Casimiro, et al.
(författare)
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Genetic and physical interaction of the B-cell systemic lupus erythematosus-associated genes BANK1 and BLK
- 2012
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 71:1, s. 136-142
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesAltered signalling in B cells is a predominant feature of systemic lupus erythematosus (SLE). The genes BANK1 and BLK were recently described as associated with SLE. BANK1 codes for a B-cell-specific cytoplasmic protein involved in B-cell receptor signalling and BLK codes for an Src tyrosine kinase with important roles in B-cell development. To characterise the role of BANK1 and BLK in SLE, a genetic interaction analysis was performed hypothesising that genetic interactions could reveal functional pathways relevant to disease pathogenesis.MethodsThe GPAT16 method was used to analyse the gene-gene interactions of BANK1 and BLK. Confocal microscopy was used to investigate co-localisation, and immunoprecipitation was used to verify the physical interaction of BANK1 and BLK.ResultsEpistatic interactions between BANK1 and BLK polymorphisms associated with SLE were observed in a discovery set of 279 patients and 515 controls from northern Europe. A meta-analysis with 4399 European individuals confirmed the genetic interactions between BANK1 and BLK. As BANK1 was identified as a binding partner of the Src tyrosine kinase LYN, the possibility that BANK1 and BLK could also show a protein-protein interaction was tested. The co-immunoprecipitation and co-localisation of BLK and BANK1 were demonstrated. In a Daudi cell line and primary naive B cells endogenous binding was enhanced upon B-cell receptor stimulation using anti-IgM antibodies.ConclusionsThis study shows a genetic interaction between BANK1 and BLK, and demonstrates that these molecules interact physically. The results have important consequences for the understanding of SLE and other autoimmune diseases and identify a potential new signalling pathway.
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| 4. |
- Delgado Vega, Angélica María, 1982-
(författare)
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Dissecting the Genetic Basis of Systemic Lupus Erythematosus : The Pursuit of Functional Variants
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Systemic lupus erythematosus (SLE) is a chronic and systemic autoimmune disease that primarily affects women during the childbearing years. SLE is characterized by the production of autoantibodies against nucleic acids and their interacting proteins. The exact molecular mechanisms leading to the breakdown of self-tolerance remain to a large extent unknown, but it is well established that they are influenced by both non-genetic (i.e. environmental and hormonal) and genetic factors. SLE is a complex, polygenic disease. Several susceptibility variants have been identified in SLE. However, the functional role in disease pathogenesis for the majority of them remains largely unknown.This thesis includes case-control association studies where the role of the genes TNFSF4 (Paper I), STAT4 (Paper II), CD226 (Paper III), and BLK (Papers IV and V) in the susceptibility of developing SLE was investigated. The primary focus was on the identification of the functional variants underlying the association. For each of these genes, fine mapping was performed using single nucleotide polymorphisms (SNPs), the linkage disequilibrium (LD) was characterized, and the association was narrowed down to specific haplotypes by means of several different statistical genetic strategies. Candidate variants were prioritized for further functional analysis on the basis of their potential effect on the gene function, their association, and/or biological plausibility. In Paper I, the association of TNFSF4 with SLE was validated and attributed to a risk haplotype tagged by SNPs rs1234317-T and rs12039904-T. Paper II provides evidence supporting the presence of at least two independent genetic effects within the STAT4 gene represented by rs3821236-A and rs7574865-A, which correlated with increased levels of gene expression. In Paper III, a functional allele in CD226 (rs727088-C) was identified, which was responsible for decreased levels in both mRNA and protein expression. In Paper IV, two independent genetic effects in the BLK gene were demonstrated. The first one comprised multiple regulatory variants in high LD that were enriched for NFκB and IRF4 binding sites and correlated with low BLK mRNA levels. The second was a low-frequency missense substitution (Ala71Thr) that decreased the BLK protein half-life. In Paper V, a genetic epistatic interaction between BANK1 rs10516487 (GG) and BLK rs2736340 (TT+TC) was demonstrated. Additional molecular analyses established that these molecules interact physically. These studies have contributed to the dissection of the genetic architecture of SLE. They highlight the allelic heterogeneity of the disease and provide functional links to the associated variants, which has significantly aided in the understanding of SLE disease pathogenesis.
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| 5. |
- Delgado-Vega, Angelica Maria, et al.
(författare)
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Family History and Warning Symptoms Precede Sudden Cardiac Death in Arrhythmogenic Right Ventricular Cardiomyopathy (From A Nationwide Study in Sweden)
- 2022
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Ingår i: American Journal of Cardiology. - : Elsevier. - 0002-9149 .- 1879-1913. ; 178, s. 124-130
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Tidskriftsartikel (refereegranskat)abstract
- Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiacdisease explaining about 4% of sudden cardiac death (SCD) cases among the youngin Sweden. The aim of this study was to describe the circumstances preceding SCDdue to ARVC in all victims <35 years of age who received an autopsy-confirmeddiagnosis of ARVC from January 1st, 2000 to December 31st, 2010 in Sweden (n=22).Data on demographics, medical and family history, circumstances of death, andanatomopathological findings were collected from several compulsory national healthregistries, clinical records, family interviews, and autopsy reports. Registry-based datawas compared with age-, sex- and geographically-matched population controls. Duringthe 6 months preceding SCD, 15 cases (68%) had experienced symptoms of cardiacorigin, mainly syncope or presyncope (54%), and chest discomfort (27%). Eight cases(36%) had sought medical care due to cardiac symptoms. The occurrence of hospitalvisits was significantly increased in cases compared with controls (OR 4.62 [1.35-15.8]). Ten cases (45%) had a family history of SCD. The most common activity at thetime of death was exercise (41%). Complete cardiac investigation was seldomperformed, only one case was diagnosed with ARVC before death. In conclusion, inthis nationwide study we observed a high prevalence of symptoms of cardiac origin,health-care utilization, and family history of SCD preceding SCD due to ARVC amongthe young. Increased awareness of these warning signals in the young is critical toimprove risk stratification and early disease detection.
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| 6. |
- Delgado-Vega, Angélica M., et al.
(författare)
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Fine mapping and conditional analysis identify a new mutation in the autoimmunity susceptibility gene BLK that leads to reduced half-life of the BLK protein
- 2012
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 71:7, s. 1219-1226
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo perform fine mapping of the autoimmunity susceptibility gene BLK and identify functional variants involved in systemic lupus erythematosus (SLE).MethodsGenotyping of 1163 European SLE patients and 1482 controls and imputation were performed covering the BLK gene with 158 single-nucleotide polymorphisms. Logistic regression analysis was done using PLINK and conditional analyses using GENABEL's test score. Transfections of BLK constructs on HEK293 cells containing the novel mutation or the wild type form were analysed for their effect on protein half-life using a protein stability assay, cycloheximide and western blot. CHiP-qPCR for detection of nuclear factor. B (NFkB) binding.ResultsFine mapping of BLK identified two independent genetic effects with functional consequences: one represented by two tightly linked associated haplotype blocks significantly enriched for NF kappa B-binding sites and numerous putative regulatory variants whose risk alleles correlated with low BLK mRNA levels. Binding of NFkBp50 and p65 to an associated 1.2 Kb haplotype segment was confirmed. A second independent genetic effect was represented by an Ala71Thr, low-frequency missense substitution with an OR = 2.31 (95% CI 1.38 to 3.86). The 71Thr decreased BLK protein half-life.ConclusionsThese results show that rare and common regulatory variants in BLK are involved in disease susceptibility and both, albeit independently, lead to reduced levels of BLK protein.
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| 7. |
- Delgado-Vega, Angelica M., et al.
(författare)
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Genetic associations in type I interferon related pathways with autoimmunity
- 2010
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Ingår i: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 12, s. S2-
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Forskningsöversikt (refereegranskat)abstract
- Type I interferons play an outstanding role in innate and adaptive immunity by enhancing functions of dendritic cells, inducing differentiation of monocytes, promoting immunoglobulin class switching in B cells and stimulating effector functions of T cells. The increased production of IFN alpha/beta by plasmacytoid dendritic cells could be responsible for not only efficient antiviral defence, but it also may be a pathological factor in the development of various autoimmune disorders. The first evidence of a genetic link between type I interferons and autoimmune diseases was the observation that elevated IFN alpha activity is frequently detected in the sera of patients with systemic lupus erythematosus, and that this trait shows high heritability and familial aggregation in their first-degree healthy relatives. To date, a number of genes involved in interferon signalling have been associated with various autoimmune diseases. Patients with systemic lupus erythematosus, Sjogren's syndrome, dermatomyositis, psoriasis, and a fraction of patients with rheumatoid arthritis display a specific expression pattern of interferon-dependent genes in their leukocytes, termed the interferon signature. Here, in an attempt to understand the role of type I interferons in the pathogenesis of autoimmunity, we review the recent advances in the genetics of autoimmune diseases focusing on the association of genes involved in type I interferon pathways.
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| 8. |
- Delgado-Vega, Angelica M., et al.
(författare)
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Replication of the TNFSF4 (OX40L) promoter region association with systemic lupus erythematosus
- 2009
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 10:3, s. 248-253
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Tidskriftsartikel (refereegranskat)abstract
- The tumor necrosis factor ligand superfamily member 4 gene (TNFSF4) encodes the OX40 ligand (OX40L), a costimulatory molecule involved in T-cell activation. A recent study demonstrated the association of TNFSF4 haplotypes located in the upstream region with risk for or protection from systemic lupus erythematosus (SLE). To replicate this association, five single nucleotide polymorphisms (SNPs) tagging the previously associated haplotypes and passing the proper quality-control filters were tested in 1312 cases and 1801 controls from Germany, Italy, Spain and Argentina. The association of TNFSF4 with SLE was replicated in all the sets except Spain. There was a unique risk haplotype tagged by the minor alleles of the SNPs rs1234317 (pooled odds ratio (OR)=1.39, P=0.0009) and rs12039904 (pooled OR=1.38, P=0.0012). We did not observe association to a single protective marker (rs844644) or haplotype as the first study reported; instead, we observed different protective haplotypes, all carrying the major alleles of both SNPs rs1234317 and rs12039904. Association analysis conditioning on the haplotypic background confirmed that these two SNPs explain the entire haplotype effect. This first replication study confirms the association of genetic variation in the upstream region of TNFSF4 with susceptibility to SLE.
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| 9. |
- Delgado-Vega, Angélica M., et al.
(författare)
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Whole Exome Sequencing of Patients from Multicase Families with Systemic Lupus Erythematosus Identifies Multiple Rare Variants
- 2018
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1, s. 8775-
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Tidskriftsartikel (refereegranskat)abstract
- In an effort to identify rare alleles associated with SLE, we have performed whole exome sequencing of the most distantly related affected individuals from two large Icelandic multicase SLE families followed by Ta targeted genotyping of additional relatives. We identified multiple rare likely pathogenic variants in nineteen genes co-segregating with the disease through multiple generations. Gene co-expression and protein-protein interaction analysis identified a network of highly connected genes comprising several loci previously implicated in autoimmune diseases. These genes were significantly enriched for immune system development, lymphocyte activation, DNA repair, and V(D)J gene recombination GO-categories. Furthermore, we found evidence of aggregate association and enrichment of rare variants at the FAM71E1/EMC10 locus in an independent set of 4,254 European SLE-cases and 4,349 controls. Our study presents evidence supporting that multiple rare likely pathogenic variants, in newly identified genes involved in known disease pathogenic pathways, segregate with SLE at the familial and population level.
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| 10. |
- Delgado-Vega, Angelica, et al.
(författare)
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Recent findings on genetics of systemic autoimmune diseases
- 2010
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Ingår i: Current Opinion in Immunology. - : Elsevier BV. - 0952-7915 .- 1879-0372. ; 22:6, s. 698-705
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Forskningsöversikt (refereegranskat)abstract
- Association studies of over 1 million SNPs capturing most of the human genome common variation became possible thanks to the information provided by the HapMap International project and the development of high-throughput genotyping technologies at accessible prices. Genome-wide scans analyzing thousands of individuals have now identified most if not all of the major genes involved in susceptibility for several systemic autoimmune diseases. In particular, results for rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and systemic sclerosis (SSc) are reviewed here. While most genes are shared between diseases, few seem to be unique reflecting that we still are long before knowing all genes, their interactions with other genes and the environment and their impact on biological functions.
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