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Dorans E, Jagadeesh K, Dey K, Price AL. Linking regulatory variants to target genes by integrating single-cell multiome methods and genomic distance. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.24.24307813. [PMID: 38826240 PMCID: PMC11142273 DOI: 10.1101/2024.05.24.24307813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Methods that analyze single-cell paired RNA-seq and ATAC-seq multiome data have shown great promise in linking regulatory elements to genes. However, existing methods differ in their modeling assumptions and approaches to account for biological and technical noise-leading to low concordance in their linking scores-and do not capture the effects of genomic distance. We propose pgBoost, an integrative modeling framework that trains a non-linear combination of existing linking strategies (including genomic distance) on fine-mapped eQTL data to assign a probabilistic score to each candidate SNP-gene link. We applied pgBoost to single-cell multiome data from 85k cells representing 6 major immune/blood cell types. pgBoost attained higher enrichment for fine-mapped eSNP-eGene pairs (e.g. 21x at distance >10kb) than existing methods (1.2-10x; p-value for difference = 5e-13 vs. distance-based method and < 4e-35 for each other method), with larger improvements at larger distances (e.g. 35x vs. 0.89-6.6x at distance >100kb; p-value for difference < 0.002 vs. each other method). pgBoost also outperformed existing methods in enrichment for CRISPR-validated links (e.g. 4.8x vs. 1.6-4.1x at distance >10kb; p-value for difference = 0.25 vs. distance-based method and < 2e-5 for each other method), with larger improvements at larger distances (e.g. 15x vs. 1.6-2.5x at distance >100kb; p-value for difference < 0.009 for each other method). Similar improvements in enrichment were observed for links derived from Activity-By-Contact (ABC) scores and GWAS data. We further determined that restricting pgBoost to features from a focal cell type improved the identification of SNP-gene links relevant to that cell type. We highlight several examples where pgBoost linked fine-mapped GWAS variants to experimentally validated or biologically plausible target genes that were not implicated by other methods. In conclusion, a non-linear combination of linking strategies, including genomic distance, improves power to identify target genes underlying GWAS associations.
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Rafaqat S, Rafaqat S. Role of IL-2/IL-2 receptor in pathogenesis of autoimmune disorders: Genetic and therapeutic aspects. World J Med Genet 2023; 11:28-38. [DOI: 10.5496/wjmg.v11.i3.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/10/2023] [Accepted: 06/30/2023] [Indexed: 07/20/2023] Open
Abstract
Interleukin-2 (IL-2) is an important cytokine that plays a key role in the immune response. The IL-2 receptor (IL-2R) is composed of three subunits, alpha, beta, and gamma, with the alpha subunit having the highest affinity for IL-2. Several studies reported that immune dysregulation of IL-2 may cause tissue injury as well as damage leading to the pathogenesis of various autoimmune diseases such as acute necrotizing vasculitis in systemic lupus erythematosus (SLE), inflammatory synovitis in rheumatoid arthritis (RA), salivary and lacrimal gland dys-function in Sjogren syndrome (SS), obliterative vasculopathy fibrosis in systemic sclerosis (SSc), and inflammatory demyelination in multiple sclerosis (MS). The aim of this review paper was to examine the role of IL-2/IL-2R in various autoimmune disorders, taking into account recent advancements and discoveries, gaps in the current literature, ongoing debates, and potential avenues for future research. The focus of this review is on systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, sjogren syndrome, and multiple sclerosis, which are all linked to the malfunctioning of IL-2/IL-2R. In genetic studies, gene polymorphisms of IL-2 such as IL-2 330/T, IL-2 330/G, and rs2069763 are involved in increasing the risk of SLE. Furthermore, genetic associations of IL-2/IL-2R such as rs791588, rs2281089, rs2104286, rs11594656, and rs35285258 are significantly associated with RA susceptibility. The IL-2 polymorphism including rs2069762A, rs6822844T, rs6835457G, and rs907715T are significant connections with systemic sclerosis. In addition, rs2104286 (IL-2), rs11594656 (IL-2RA), rs35285258 (IL-2RB) gene polymorphism significant increases the risk of multiple sclerosis. In therapeutic approaches, low-dose IL-2 therapy could regulate Tfr and Tfh cells, resulting in a reduction in disease activity in the SLE patients. In addition, elevated sIL-2R levels in the peripheral blood of SLE patients could be linked to an immunoregulatory imbalance, which may contribute to the onset and progression of SLE. Consequently, sIL-2R could potentially be a target for future SLE therapy. Moreover, Low dose-IL2 was well-tolerated, and low levels of Treg and high levels of IL-21 were associated with positive responses to Ld-IL2 suggested to be a safe and effective treatment for RA. Additionally, low-dose IL-2 treatment improves the exocrine glands' ability to secrete saliva in SS-affected mice. Whereas, Basiliximab targets the alpha chain of the IL-2 receptor suggested as a potential treatment for SSc. Also, pre-and post-treatment with Tregs, MDSCs, and IL-2 may have the potential to prevent EAE induction in patients with MS. It is suggested that further studies should be conducted on IL-2 polymorphism in Sjogren syndrome.
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Affiliation(s)
- Sana Rafaqat
- Department of Biotechnology (Specialized in Human Genetics), Lahore College for Women University, Lahore 54000, Pakistan
| | - Saira Rafaqat
- Department of Zoology, Lahore College for Women University, Lahore 54000, Pakistan
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The Role of CD1 Gene Polymorphism in the Genetic Susceptibility to Spondyloarthropathies in the Moroccan Population and the Possible Cross-Link with Celiac Disease. Vaccines (Basel) 2023; 11:vaccines11020237. [PMID: 36851115 PMCID: PMC9963915 DOI: 10.3390/vaccines11020237] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/26/2023] Open
Abstract
Spondyloarthropathies (SpA) are a group of chronic inflammatory disorders usually affecting the axial spine and asymmetrical peripheral joints. Strong evidence links genetic and environmental factors to SpA pathogenesis. The HLA-B27 is the most important genetic factor associated with SpA. Nevertheless, the involvement of other HLA and non-HLA loci has been also reported. Some patients with SpA may also manifest features of celiac disease (CeD), thus suggesting a genetic overlap across these autoimmune diseases. Recently, CD1 glycoproteins, a class of molecules able to bind and present non peptidic antigens to T cells, aroused interest for their contribution to the pathogenesis of CeD. Therefore, to evaluate whether functional polymorphisms of CD1A and E genes also influence susceptibility to SpA, we analyzed 86 patients from Morocco affected by SpA and 51 healthy controls, using direct sequencing analysis. An increase of CD1E*01/01 homozygous genotype (p = 0.046) was found in SpA, compared with controls. CD1E*01/01 genotype was associated particularly to patients with sacroiliac joints/spine/peripheral joints pain (p = 0.0068), while a decrease of CD1E*01/02 genotype was evidenced compared to controls (p = 0.0065). Results from haplotypes analysis demonstrated that CD1A*02-E*02 decreased the risk of SpA, while CD1A*02-E*01 increased risk to develop disease. Our data indicate a relationship between CD1 genes and susceptibility to SpA in the Moroccan population and suggest the existence of shared genetic risk loci across SpA and CeD that might be useful to explain common pathogenetic features and define novel therapeutic strategies.
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The Immunogenetics of Systemic Sclerosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1367:259-298. [DOI: 10.1007/978-3-030-92616-8_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Pu W, Zhang R, Ma Y, Liu Q, Jiang S, Liu J, Zhao Y, Tu W, Guo G, Zuo X, Wang Q, Chen Y, Wu W, Zhou X, Distler JHW, Reveille JD, Zou H, Jin L, Mayes MD, Wang J. Genetic associations of non-MHC susceptibility loci with systemic sclerosis in a Han Chinese population. J Invest Dermatol 2021; 142:2039-2042.e7. [PMID: 34919939 DOI: 10.1016/j.jid.2021.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 11/16/2021] [Accepted: 11/30/2021] [Indexed: 10/19/2022]
Affiliation(s)
- Weilin Pu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China; Research Unit of dissecting the population genetics and developing new technologies for treatment and prevention of skin phenotypes and dermatological diseases (2019RU058), Chinese Academy of Medical Sciences
| | - Rui Zhang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China; Institute for Six-sector Economy, Fudan University, Shanghai, 200433, China
| | - Yanyun Ma
- Institute for Six-sector Economy, Fudan University, Shanghai, 200433, China; Research Unit of dissecting the population genetics and developing new technologies for treatment and prevention of skin phenotypes and dermatological diseases (2019RU058), Chinese Academy of Medical Sciences
| | - Qingmei Liu
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China; MOE Key Laboratory of Contemporary Anthropology, Fudan University, Shanghai, China
| | - Shuai Jiang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China; Department of Rheumatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China; Department of Rheumatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yinhuan Zhao
- Division of Rheumatology, Shanghai TCM-integrated Hospital, Shanghai, China
| | - Wenzhen Tu
- Division of Rheumatology, Shanghai TCM-integrated Hospital, Shanghai, China
| | - Gang Guo
- Department of Rheumatology, Yiling Hospital, Shijiazhuang, China
| | - Xiaoxia Zuo
- Department of Rheumatology, Xiangya Hospital, Central South University
| | - Qingwen Wang
- Rheumatology and Immunology Department, Peking University Shenzhen Hospital, Shenzhen, China
| | - Yuanyuan Chen
- Division of Rheumatology, Shanghai TCM-integrated Hospital, Shanghai, China
| | - Wenyu Wu
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China; Institute of Rheumatology, Immunology and Allergy, Fudan University, Shanghai, China
| | - Xiaodong Zhou
- Division of Rheumatology and Clinical Immunogenetics, the University of Texas-McGovern Medical School, Houston, TX, USA
| | - Jörg H W Distler
- Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen, Nuremberg, Germany
| | - John D Reveille
- Division of Rheumatology and Clinical Immunogenetics, the University of Texas-McGovern Medical School, Houston, TX, USA
| | - Hejian Zou
- Department of Rheumatology, Huashan Hospital, Fudan University, Shanghai, China; Institute of Rheumatology, Immunology and Allergy, Fudan University, Shanghai, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China; Research Unit of dissecting the population genetics and developing new technologies for treatment and prevention of skin phenotypes and dermatological diseases (2019RU058), Chinese Academy of Medical Sciences; Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China
| | - Maureen D Mayes
- Division of Rheumatology and Clinical Immunogenetics, the University of Texas-McGovern Medical School, Houston, TX, USA
| | - Jiucun Wang
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China; Research Unit of dissecting the population genetics and developing new technologies for treatment and prevention of skin phenotypes and dermatological diseases (2019RU058), Chinese Academy of Medical Sciences; Institute of Rheumatology, Immunology and Allergy, Fudan University, Shanghai, China; Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China.
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Prince C, Mitchell RE, Richardson TG. Integrative multiomics analysis highlights immune-cell regulatory mechanisms and shared genetic architecture for 14 immune-associated diseases and cancer outcomes. Am J Hum Genet 2021; 108:2259-2270. [PMID: 34741802 PMCID: PMC8715275 DOI: 10.1016/j.ajhg.2021.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 10/13/2021] [Indexed: 12/17/2022] Open
Abstract
Developing functional insight into the causal molecular drivers of immunological disease is a critical challenge in genomic medicine. Here, we systematically apply Mendelian randomization (MR), genetic colocalization, immune-cell-type enrichment, and phenome-wide association methods to investigate the effects of genetically predicted gene expression on ten immune-associated diseases and four cancer outcomes. Using whole blood-derived estimates for regulatory variants from the eQTLGen consortium (n = 31,684), we constructed genetic risk scores for 10,104 genes. Applying the inverse-variance-weighted MR method transcriptome wide while accounting for linkage disequilibrium structure identified 664 unique genes with evidence of a genetically predicted effect on at least one disease outcome (p < 4.81 × 10-5). We next undertook genetic colocalization to investigate cell-type-specific effects at these loci by using gene expression data derived from 18 types of immune cells. This highlighted many cell-type-dependent effects, such as PRKCQ expression and asthma risk (posterior probability = 0.998), which was T cell specific. Phenome-wide analyses on 311 complex traits and endpoints allowed us to explore shared genetic architecture and prioritize key drivers of disease risk, such as CASP10, which provided evidence of an effect on seven cancer-related outcomes. Our atlas of results can be used to characterize known and novel loci in immune-associated disease and cancer susceptibility, both in terms of elucidating cell-type-dependent effects as well as dissecting shared disease pathways and pervasive pleiotropy. As an exemplar, we have highlighted several key findings in this study, although similar evaluations can be conducted via our interactive web platform.
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Affiliation(s)
- Claire Prince
- Medical Research Council Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, UK
| | - Ruth E Mitchell
- Medical Research Council Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, UK
| | - Tom G Richardson
- Medical Research Council Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, UK; Novo Nordisk Research Centre, Headington, Oxford OX3 7FZ, UK.
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Some Common SNPs of the T-Cell Homeostasis-Related Genes Are Associated with Multiple Sclerosis, but Not with the Clinical Manifestations of the Disease, in the Polish Population. J Immunol Res 2020; 2020:8838014. [PMID: 33224992 PMCID: PMC7673932 DOI: 10.1155/2020/8838014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 12/30/2022] Open
Abstract
Purpose Multiple sclerosis (MS) is an autoimmune disease, and genetic factors play an important role in its pathogenesis and progression. The aim of our study was to evaluate the frequencies of alleles and genetic variants of the T-cell homeostasis-related genes, in subjects with MS, as well as to investigate the association with MS clinical manifestations and disability. Methods 94 subjects with MS and 160 healthy individuals have been genotyped for seven common single-nucleotide variants in IL-2RA, CTLA4, CD40, and PADI4 genes. The ages of onset, duration of the disease, and clinical condition of the MS subjects were analysed. We used the Chi2 test confirmed with Fisher's exact test for statistical analysis. Results The frequency of allele T and CT/TT genotypes (rs7093069) in the IL2RA gene, as well as the T allele and CT/TT genotypes in rs12722598, were significantly higher in the control group. The significant differences between studied groups we also found for the G allele and GG/GA genotypes of rs3087243 in CTLA4 gene, which were more common among the control group. The heterozygous genotype TC (rs1883832) of CD40 gene was more common in the control subjects, and the frequency of the alleles and genotypes in the rs1748033 of the PADI4 gene did not differ between the studied groups. Between the studied genotypes, we did not observe any significant differences in the age of onset and duration of disease, including sex stratification. Conclusion Our results highlight the protective role of some of the T-cell homeostasis-related genetic variants in MS development, but not in its clinical manifestation.
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Unravelling the Roles of Susceptibility Loci for Autoimmune Diseases in the Post-GWAS Era. Genes (Basel) 2018; 9:genes9080377. [PMID: 30060490 PMCID: PMC6115971 DOI: 10.3390/genes9080377] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/06/2018] [Accepted: 07/23/2018] [Indexed: 12/18/2022] Open
Abstract
Although genome-wide association studies (GWAS) have identified several hundred loci associated with autoimmune diseases, their mechanistic insights are still poorly understood. The human genome is more complex than single nucleotide polymorphisms (SNPs) that are interrogated by GWAS arrays. Apart from SNPs, it also comprises genetic variations such as insertions-deletions, copy number variations, and somatic mosaicism. Although previous studies suggest that common copy number variations do not play a major role in autoimmune disease risk, it is possible that certain rare genetic variations with large effect sizes are relevant to autoimmunity. In addition, other layers of regulations such as gene-gene interactions, epigenetic-determinants, gene and environmental interactions also contribute to the heritability of autoimmune diseases. This review focuses on discussing why studying these elements may allow us to gain a more comprehensive understanding of the aetiology of complex autoimmune traits.
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Multiple genes, especially immune-regulating genes, contribute to disease susceptibility in systemic sclerosis. Curr Opin Rheumatol 2016; 28:595-605. [DOI: 10.1097/bor.0000000000000334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Chairta P, Nicolaou P, Christodoulou K. Genomic and genetic studies of systemic sclerosis: A systematic review. Hum Immunol 2016; 78:153-165. [PMID: 27984087 DOI: 10.1016/j.humimm.2016.10.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/27/2016] [Accepted: 10/27/2016] [Indexed: 12/12/2022]
Abstract
Systemic sclerosis is an autoimmune rheumatic disease characterised by fibrosis, vasculopathy and inflammation. The exact aetiology of SSc remains unknown but evidences show that various genetic factors may be involved. This review aimed to assess HLA alleles/non-HLA polymorphisms, microsatellites and chromosomal abnormalities that have thus far been associated with SSc. PubMed, Embase and Scopus databases were searched up to July 29, 2015 using a combination of search-terms. Articles retrieved were evaluated based on set exclusion and inclusion criteria. A total of 150 publications passed the filters. HLA and non-HLA studies showed that particular alleles in the HLA-DRB1, HLA-DQB1, HLA-DQA1, HLA-DPB1 genes and variants in STAT4, IRF5 and CD247 are frequently associated with SSc. Non-HLA genes analysis was performed using the PANTHER and STRING10 databases. PANTHER classification revealed that inflammation mediated by chemokine and cytokine, interleukin and integrin signalling pathways are among the common extracted pathways associated with SSc. STRING10 analysis showed that NFKB1, CSF3R, STAT4, IFNG, PRL and ILs are the main "hubs" of interaction network of the non-HLA genes associated with SSc. This study gathers data of valid genetic factors associated with SSc and discusses the possible interactions of implicated molecules.
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Affiliation(s)
- Paraskevi Chairta
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2370, Cyprus; Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia 2370, Cyprus
| | - Paschalis Nicolaou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2370, Cyprus; Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia 2370, Cyprus
| | - Kyproula Christodoulou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2370, Cyprus; Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia 2370, Cyprus.
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Abstract
Purpose of review Large-scale and follow-up genetic association studies in systemic sclerosis (SSc) have implicated over 40 regions in disease risk, 15 of which with robust associations. Nevertheless, the causal variants and the functional mechanisms underlying the genetic associations remain elusive, and the reasons for the higher disease burden in African Americans unknown. Incorporating tools from diverse fields is beginning to unveil the role of genetic diversity and regulatory variation in SSc susceptibility. This review will summarize recent advances in SSc genetics, including autoimmune disease overlap, evidence of natural selection, and current progress towards the dissection of the functional role of associated risk variants. Recent findings In the past year, multiple large-scale studies reported novel strong and suggestive SSc associations. These results, coupled with the regions shared with other autoimmune diseases, emphasize the role of dysregulation of immune pathways as a key causative factor in SSc pathogenesis. Strong evidence implicates natural selection as a mechanism contributing to the maintenance of some of these SSc alleles in the population. Studies integrating genomic, transcriptomic, and epigenomic datasets in specific cell types to identify causal autoimmune disease variants are emerging. Summary The identification and comprehensive understanding of the factors and mechanisms contributing to SSc will contribute to improved diagnosis and disease management.
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Wei P, Yang Y, Guo X, Hei N, Lai S, Assassi S, Liu M, Tan F, Zhou X. Identification of an Association of TNFAIP3 Polymorphisms With Matrix Metalloproteinase Expression in Fibroblasts in an Integrative Study of Systemic Sclerosis-Associated Genetic and Environmental Factors. Arthritis Rheumatol 2016; 68:749-60. [PMID: 26474180 PMCID: PMC4767670 DOI: 10.1002/art.39476] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Systemic sclerosis (SSc) is a fibrotic disease attributed to both genetic susceptibility and environmental factors. This study was undertaken to investigate the associations between SSc-associated genetic variants and the expression of extracellular matrix (ECM) genes in human fibroblasts stimulated with silica particles in time-course and dose-response experiments. METHODS A total of 200 fibroblast strains were examined for ECM gene expression after stimulation with silica particles. The fibroblasts were genetically profiled using Immunochip assays and then subjected to whole-genome genotype imputation. Associations of genotypes and gene expression were first analyzed in a Caucasian cohort and then validated in a meta-analysis combining the results from Caucasian, African American, and Hispanic subjects. A linear mixed model for longitudinal data analysis was used to identify genetic variants associated with the expression of ECM genes, and the associations were validated by using a haplotype-based longitudinal association test on regions that included the loci identified. RESULTS The single-nucleotide polymorphism rs58905141 in TNFAIP3 was consistently associated with time-course and/or dose-response expression of MMP3 and MMP1 in the fibroblasts stimulated with silica particles in both the analysis of Caucasian subjects only and the meta-analysis. Results of the haplotype-based analysis validated the association signals. CONCLUSION Our findings indicate that a genetic variant of TNFAIP3 is strongly associated with the silica-induced profibrotic response of fibroblasts. In silico functional analysis based on the ENCODE database revealed that rs58905141 might affect the binding activities of the transcription factors for TNFAIP3. This is the first genome-wide study of interactions between genetic and environmental factors in a complex SSc fibroblast model.
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Affiliation(s)
- Peng Wei
- Human Genetics Center and Department of Biostatistics, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Yang Yang
- Human Genetics Center and Department of Biostatistics, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX 77030
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Xinjian Guo
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Nainan Hei
- Human Genetics Center and Department of Biostatistics, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Syeling Lai
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030
| | - Shervin Assassi
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Mengyuan Liu
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Filemon Tan
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Xiaodong Zhou
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030
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Makino T, Jinnin M. Genetic and epigenetic abnormalities in systemic sclerosis. J Dermatol 2016; 43:10-8. [DOI: 10.1111/1346-8138.13221] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 12/12/2022]
Affiliation(s)
- Takamitsu Makino
- Department of Dermatology and Plastic Surgery; Faculty of Life Sciences; Kumamoto University; Kumamoto Japan
| | - Masatoshi Jinnin
- Department of Dermatology and Plastic Surgery; Faculty of Life Sciences; Kumamoto University; Kumamoto Japan
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Abstract
Significant advances have been made in understanding the genetic basis of systemic sclerosis (SSc) in recent years. Genomewide association and other large-scale genetic studies have identified 30 largely immunity-related genes which are significantly associated with SSc. We review these studies, along with genomewide expression studies, proteomic studies, genetic mouse models, and insights from rare sclerodermatous diseases. Collectively, these studies have begun to identify pathways that are relevant to SSc pathogenesis. The findings presented in this review illustrate how both genetic and genomic aberrations play important roles in the development of SSc. However, despite these recent discoveries, there remain major gaps between current knowledge of SSc, a unified understanding of pathogenesis, and effective treatment. To this aim, we address the important issue of SSc heterogeneity and discuss how future research needs to address this in order to develop a clearer understanding of this devastating and complex disease.
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Pattanaik D, Brown M, Postlethwaite BC, Postlethwaite AE. Pathogenesis of Systemic Sclerosis. Front Immunol 2015; 6:272. [PMID: 26106387 PMCID: PMC4459100 DOI: 10.3389/fimmu.2015.00272] [Citation(s) in RCA: 256] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 05/16/2015] [Indexed: 01/04/2023] Open
Abstract
Systemic scleroderma (SSc) is one of the most complex systemic autoimmune diseases. It targets the vasculature, connective tissue-producing cells (namely fibroblasts/myofibroblasts), and components of the innate and adaptive immune systems. Clinical and pathologic manifestations of SSc are the result of: (1) innate/adaptive immune system abnormalities leading to production of autoantibodies and cell-mediated autoimmunity, (2) microvascular endothelial cell/small vessel fibroproliferative vasculopathy, and (3) fibroblast dysfunction generating excessive accumulation of collagen and other matrix components in skin and internal organs. All three of these processes interact and affect each other. The disease is heterogeneous in its clinical presentation that likely reflects different genetic or triggering factor (i.e., infection or environmental toxin) influences on the immune system, vasculature, and connective tissue cells. The roles played by other ubiquitous molecular entities (such as lysophospholipids, endocannabinoids, and their diverse receptors and vitamin D) in influencing the immune system, vasculature, and connective tissue cells are just beginning to be realized and studied and may provide insights into new therapeutic approaches to treat SSc.
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Affiliation(s)
- Debendra Pattanaik
- Department of Medicine, Division of Connective Tissue Diseases, The University of Tennessee Health Science Center , Memphis, TN , USA ; Department of Veterans Affairs Medical Center , Memphis, TN , USA
| | - Monica Brown
- Section of Pediatric Rheumatology, Department of Pediatrics, The University of Tennessee Health Science Center , Memphis, TN , USA
| | - Bradley C Postlethwaite
- Department of Medicine, Division of Connective Tissue Diseases, The University of Tennessee Health Science Center , Memphis, TN , USA
| | - Arnold E Postlethwaite
- Department of Medicine, Division of Connective Tissue Diseases, The University of Tennessee Health Science Center , Memphis, TN , USA ; Department of Veterans Affairs Medical Center , Memphis, TN , USA
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Abstract
Systemic sclerosis (SSc) is a complex autoimmune disease that occurs in a genetically susceptible host. Genetic studies performed so far reveal that multiple genetic loci contribute to disease susceptibility in SSc. The purpose of this review is to discuss the current knowledge of genetics in SSc by exploring the observational evidence, the different genetic studies, and their modalities as well as the most relevant genes discovered by these. The importance of gene expression variation and the different mechanisms that govern it, including the recently discovered field of epigenetics, are also explored, with an emphasis on microRNA.
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Affiliation(s)
- Gloria Salazar
- Division of Rheumatology and Clinical Immunogenetics, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 5.270, Houston, TX 77030, USA
| | - Maureen D Mayes
- Division of Rheumatology and Clinical Immunogenetics, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 5.270, Houston, TX 77030, USA.
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Jin J, Chou C, Lima M, Zhou D, Zhou X. Systemic Sclerosis is a Complex Disease Associated Mainly with Immune Regulatory and Inflammatory Genes. Open Rheumatol J 2014; 8:29-42. [PMID: 25328554 PMCID: PMC4200700 DOI: 10.2174/1874312901408010029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/04/2014] [Accepted: 08/07/2014] [Indexed: 12/21/2022] Open
Abstract
Systemic sclerosis (SSc) is a fibrotic and autoimmune disease characterized clinically by skin and internal organ fibrosis and vascular damage, and serologically by the presence of circulating autoantibodies. Although etiopathogenesis is not yet well understood, the results of numerous genetic association studies support genetic contributions as an important factor to SSc. In this paper, the major genes of SSc are reviewed. The most recent genome-wide association studies (GWAS) are taken into account along with robust candidate gene studies. The literature search was performed on genetic association studies of SSc in PubMed between January 2000 and March 2014 while eligible studies generally had over 600 total participants with replication. A few genetic association studies with related functional changes in SSc patients were also included. A total of forty seven genes or specific genetic regions were reported to be associated with SSc, although some are controversial. These genes include HLA genes, STAT4, CD247, TBX21, PTPN22, TNFSF4, IL23R, IL2RA, IL-21, SCHIP1/IL12A, CD226, BANK1, C8orf13-BLK, PLD4, TLR-2, NLRP1, ATG5, IRF5, IRF8, TNFAIP3, IRAK1, NFKB1, TNIP1, FAS, MIF, HGF, OPN, IL-6, CXCL8, CCR6, CTGF, ITGAM, CAV1, MECP2, SOX5, JAZF1, DNASEIL3, XRCC1, XRCC4, PXK, CSK, GRB10, NOTCH4, RHOB, KIAA0319, PSD3 and PSOR1C1. These genes encode proteins mainly involved in immune regulation and inflammation, and some of them function in transcription, kinase activity, DNA cleavage and repair. The discovery of various SSc-associated genes is important in understanding the genetics of SSc and potential pathogenesis that contribute to the development of this disease.
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Affiliation(s)
- Jingxiao Jin
- University of Texas Medical School at Houston, USA ; Duke University, USA
| | - Chou Chou
- University of Texas Medical School at Houston, USA
| | - Maria Lima
- University of Texas Medical School at Houston, USA ; Rice University, USA
| | - Danielle Zhou
- University of Texas Medical School at Houston, USA ; Washington University, USA
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Wallace C. Statistical testing of shared genetic control for potentially related traits. Genet Epidemiol 2013; 37:802-13. [PMID: 24227294 PMCID: PMC4158901 DOI: 10.1002/gepi.21765] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/30/2013] [Accepted: 08/14/2013] [Indexed: 12/19/2022]
Abstract
Integration of data from genome‐wide single nucleotide polymorphism (SNP) association studies of different traits should allow researchers to disentangle the genetics of potentially related traits within individually associated regions. Formal statistical colocalisation testing of individual regions requires selection of a set of SNPs summarising the association in a region. We show that the SNP selection method greatly affects type 1 error rates, with published studies having used methods expected to result in substantially inflated type 1 error rates. We show that either avoiding variable selection and instead testing the most informative principal components or integrating over variable selection using Bayesian model averaging can help control type 1 error rates. Application to data from Graves' disease and Hashimoto's thyroiditis reveals a common genetic signature across seven regions shared between the diseases, and indicates that in five of six regions associated with Graves' disease and not Hashimoto's thyroiditis, this more likely reflects genuine absence of association with the latter rather than lack of power. Our examination, by simulation, of the performance of colocalisation tests and associated software will foster more widespread adoption of formal colocalisation testing. Given the increasing availability of large expression and genetic association datasets from disease‐relevant tissue and purified cell populations, coupled with identification of regulatory sequences by projects such as ENCODE, colocalisation analysis has the potential to reveal both shared genetic signatures of related traits and causal disease genes and tissues.
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Affiliation(s)
- Chris Wallace
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, NIHR Cambridge Biomedical Research Centre, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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D'Amico F, Skarmoutsou E, Marchini M, Malaponte G, Caronni M, Scorza R, Mazzarino MC. Genetic polymorphisms of FOXP3 in Italian patients with systemic sclerosis. Immunol Lett 2013; 152:109-13. [PMID: 23707908 DOI: 10.1016/j.imlet.2013.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 04/15/2013] [Accepted: 05/13/2013] [Indexed: 11/29/2022]
Abstract
A case control study to evaluate the possible influence of FOXP3 polymorphisms (rs3761548 and rs2280883) in the susceptibility of systemic sclerosis in an Italian Caucasian population. Subgroup analysis was also performed to test association between these SNPs and specific disease phenotypes. The study groups consisted of 467 individuals: 228 patients (194 with limited cutaneous form and 34 with diffuse cutaneous form of the disease) and 239 healthy control subjects. Genotyping was performed by high resolution melting analysis. Genotype distribution and allele frequency of the FOXP3 polymorphisms were analyzed statistically, using χ(2) or Fisher exact test. Single-marker analysis of allelic and genotype frequencies revealed that SNP rs3761548 was not associated with systemic sclerosis susceptibility. Analysis of genotype and allele distributions of the rs2280883 genetic variant was associated, only in female subjects with systemic sclerosis, its limited subtype, and anti-centromere autoantibodies. Although these findings require replication in a larger set and other populations, FOXP3 rs2280883 may represent a novel susceptibility locus for systemic sclerosis in female subjects.
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Affiliation(s)
- Fabio D'Amico
- Department of Bio-medical Sciences, University of Catania, via Androne 83, I-95124 Catania, Italy.
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20
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Systemic sclerosis: genetics and epigenetics. J Autoimmun 2013; 41:161-7. [PMID: 23415078 DOI: 10.1016/j.jaut.2013.01.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 01/10/2013] [Accepted: 01/13/2013] [Indexed: 12/26/2022]
Abstract
Systemic sclerosis (SSc) is an autoimmune disease characterized by immune abnormalities, vascular obliteration, excessive extracellular matrix deposition, and fibrosis of the skin and/or internal organs. To date, the exact etiology of this complicated disease remains unknown. Over the past few years, however, the role of genetic susceptibility and epigenetic modifications caused by environmental factors have been intensively studied in relation to the pathogenesis of this disease, and important advances have been made. This review focuses on the recent progress in the field of SSc research, including HLA and non-HLA susceptibility genes identified in genome-wide association studies (GWAS), and aberrant epigenetic modifications of gene loci associated with SSc. HLA genes most closely linked with SSc susceptibility include HLA-A, -B, -C, -DR, -DP and -DQ. A large number of non-HLA genes were also reported. It has also been noted that different genetic variants can be linked to specific clinical patterns. Finally, DNA demethylation of regulatory genes (eNOS, CD40L and CD70), therapeutic effects associated with Trichostatin A (TSA) treatment, and abnormal expression of a large spectrum of microRNAs (miR-21, -31, -146, -503, -145, -29b, etc.) are all observed in SSc. Overall, the findings presented in this review illustrate how both genetic and epigenetic aberrations play important roles in the development of SSc; however, several unanswered questions continue to impede our understanding of this complex disease. Future research should focus on the identification of new biomarkers for early diagnosis and prognosis, which will help improve the clinical outcome of patients with SSc.
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Abstract
PURPOSE OF REVIEW The last decade has seen enormous progress in understanding genetic associations of systemic sclerosis to explain the observed heritability. This review highlights the most recent findings and places them in the context of proposed functional roles. RECENT FINDINGS Over 30 genes and gene regions have now been identified as scleroderma susceptibility loci. These include both human leukocyte antigen (HLA) and non-HLA genes, most of which involve immune-related pathways and modifiers of immune function. Many of these associations have also been reported in other systemic autoimmune diseases and suggest that there are multiple autoimmunity genes resulting in disease occurrence. SUMMARY In spite of these advances, only a small proportion of the heritability of systemic sclerosis has been explained. Ongoing studies include fine mapping and sequencing studies to identify causal variants, whereas other studies focus on functional consequences of these variants in order to identify the link between these genetic variants and disease susceptibility. Such knowledge should lead to more targeted and effective treatment in this disease.
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Affiliation(s)
- Maureen D Mayes
- Division of Rheumatology and Clinical Immunogenetics, University of Texas Health Science Center, Houston, Texas 77030, USA.
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Jabbari A, Petukhova L, Cabral RM, Clynes R, Christiano AM. Genetic basis of alopecia areata: a roadmap for translational research. Dermatol Clin 2012; 31:109-17. [PMID: 23159180 DOI: 10.1016/j.det.2012.08.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alopecia areata (AA) is a recurrent autoimmune type of hair loss that affects about 5.3 million people in the United States alone. Despite being the most prevalent autoimmune disease, the molecular and cellular mechanisms underlying this complex disease are still poorly understood, and rational treatments are lacking. Further efforts are necessary to clearly pinpoint the causes and molecular pathways leading to this disease and to find evidence-based treatments for AA. The authors focus on the central role of genetics for gaining insight into disease pathogenesis and setting the stage for the rational development of novel effective therapeutic approaches.
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Affiliation(s)
- Ali Jabbari
- Department of Dermatology, Russ Berrie Medical Science Pavilion, Columbia University, 1150 Saint Nicholas Avenue, New York, NY 10032, USA
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23
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Martín JE, Bossini-Castillo L, Martín J. Unraveling the genetic component of systemic sclerosis. Hum Genet 2012; 131:1023-37. [PMID: 22218928 DOI: 10.1007/s00439-011-1137-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/21/2011] [Indexed: 02/07/2023]
Abstract
Systemic sclerosis (SSc) is a severe connective tissue disorder characterized by extensive fibrosis, vascular damage, and autoimmune events. During the last years, the number of genetic markers convincingly associated with SSc has exponentially increased. In this report, we aim to offer an updated review of the classical and novel genetic associations with SSc, analyzing the firmest and replicated signals within HLA and non-HLA genes, identified by both candidate gene and genome-wide association (GWA) studies. We will also provide an insight into the future perspectives and approaches that might shed more light into the complex genetic background underlying SSc. In spite of the remarkable advance in the field of SSc genetics during the last decade, the use of the new genetic technologies such as next generation sequencing (NGS), as well as the deep phenotyping of the study cohorts, to fully characterize the genetic component of this disease is imperative.
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Affiliation(s)
- José Ezequiel Martín
- Instituto de Parasitología y Biomedicina López-Neyra, IPBLN-CSIC, Consejo Superior de Investigaciones Científicas, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento, 18100-Armilla, Granada, Spain
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