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1.
Ann Rheum Dis ; 78(12): 1653-1662, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31563893

RESUMO

OBJECTIVES: The human leucocyte antigen (HLA)-B27 confers an increased risk of spondyloarthritis (SpA) by unknown mechanism. The objective of this work was to uncover HLA-B27 non-canonical properties that could explain its pathogenicity, using a new Drosophila model. METHODS: We produced transgenic Drosophila expressing the SpA-associated HLA-B*27:04 or HLA-B*27:05 subtypes, or the non-associated HLA-B*07:02 allele, alone or in combination with human ß2-microglobulin (hß2m), under tissue-specific drivers. Consequences of transgenes expression in Drosophila were examined and affected pathways were investigated by the genetic interaction experiments. Predictions of the model were further tested in immune cells from patients with SpA. RESULTS: Loss of crossveins in the wings and a reduced eye phenotype were observed after expression of HLA-B*27:04 or HLA-B*27:05 in Drosophila but not in fruit flies expressing the non-associated HLA-B*07:02 allele. These HLA-B27-induced phenotypes required the presence of hß2m that allowed expression of well-folded HLA-B conformers at the cell surface. Loss of crossveins resulted from a dominant negative effect of HLA-B27 on the type I bone morphogenetic protein (BMP) receptor saxophone (Sax) with which it interacted, resulting in elevated mothers against decapentaplegic (Mad, a Drosophila receptor-mediated Smad) phosphorylation. Likewise, in immune cells from patients with SpA, HLA-B27 specifically interacted with activin receptor-like kinase-2 (ALK2), the mammalian Sax ortholog, at the cell surface and elevated Smad phosphorylation was observed in response to activin A and transforming growth factor ß (TGFß). CONCLUSIONS: Antagonistic interaction of HLA-B27 with ALK2, which exerts inhibitory functions on the TGFß/BMP signalling pathway at the cross-road between inflammation and ossification, could adequately explain SpA development.

2.
Arthritis Res Ther ; 21(1): 46, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30717755

RESUMO

BACKGROUND: Spondyloarthritis (SpA) is a chronic inflammatory disease affecting primarily axial and peripheral joints and sometimes also extra-articular organs, such as the gut. Rats transgenic for HLA-B27 and human ß2-microglobulin (B27-Tg rat) develop clinical manifestations resembling human disease. In this model, it has been shown that CD103+ conventional dendritic cells (cDCs) exhibited altered functions, likely promoting SpA development. CD4- cDC subpopulation expressing XCR1, a chemokine receptor involved in their migration, have been described to be tolerogenic in steady state. Thus, in this study, we wished to examine the fate of XCR1+ cDCs in this animal model of SpA. METHODS: cDC populations were isolated from the spleen, mesenteric lymph nodes (MLN), and colonic lamina propria from B27-TG and control nontransgenic (NTG) and/or HLA-B7 transgenic rats after collagenase digestion and density gradient and characterized with flow cytometry or real-time PCR. Migration of cDCs from intestinal mucosa to MLN was assessed, using TLR-7 stimulation with Resiquimod. RESULTS: We observed a reduced frequency of cCD4- DCs in B27-Tg rats, as compared to control rats. Furthermore, such decrease was not due to excessive death of CD4- cDCs in B27-Tg rats. Interestingly, we observed a decrease frequency of the XCR1+ subpopulation among CD4- cDCs in the spleen, MLN, and lamina propria from B27-Tg rats. Finally, after TLR-7 stimulation, the migration of XCR1+ cDCs to MLN was proportionally reduced in B27-Tg rats. CONCLUSION: Our results demonstrate for the first time a decreased proportion of the tolerogenic XCR1+ cDC subpopulation in SpA target organs in B27-Tg rat, which may affect the maintenance of self-tolerance and control of inflammation.

3.
Cell Death Dis ; 10(3): 190, 2019 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-30804327

RESUMO

Fas-associated death domain (FADD) is a key adaptor molecule involved in numerous physiological processes including cell death, proliferation, innate immunity and inflammation. Therefore, changes in FADD expression have dramatic cellular consequences. In mice and humans, FADD regulation can occur through protein secretion. However, the molecular mechanisms accounting for human FADD secretion were still unknown. Here we report that canonical, non-canonical, but not alternative, NLRP3 inflammasome activation in human monocytes/macrophages induced FADD secretion. NLRP3 inflammasome activation by the bacterial toxin nigericin led to the proinflammatory interleukin-1ß (IL-1ß) release and to the induction of cell death by pyroptosis. However, we showed that FADD secretion could occur in absence of increased IL-1ß release and pyroptosis and, reciprocally, that IL-1ß release and pyroptosis could occur in absence of FADD secretion. Especially, FADD, but not IL-1ß, secretion following NLRP3 inflammasome activation required extracellular glucose. Thus, FADD secretion was an active process distinct from unspecific release of proteins during pyroptosis. This FADD secretion process required K+ efflux, NLRP3 sensor, ASC adaptor and CASPASE-1 molecule. Moreover, we identified FADD as a leaderless protein unconventionally secreted through microvesicle shedding, but not exosome release. Finally, we established human soluble FADD as a new marker of joint inflammation in gout and rheumatoid arthritis, two rheumatic diseases involving the NLRP3 inflammasome. Whether soluble FADD could be an actor in these diseases remains to be determined. Nevertheless, our results advance our understanding of the mechanisms contributing to the regulation of the FADD protein expression in human cells.

4.
Artigo em Inglês | MEDLINE | ID: mdl-29951575

RESUMO

In this work we present a systematic effort to summarize current biological pathway knowledge concerning Rheumatoid Arthritis (RA). We are constructing a detailed molecular map based on exhaustive literature scanning, strict curation criteria, re-evaluation of previously published attempts and most importantly experts' advice. The RA map will be web-published in the coming months in the form of an interactive map, using the MINERVA platform, allowing for easy access, navigation and search of all molecular pathways implicated in RA, serving thus, as an on line knowledgebase for the disease. Moreover the map could be used as a template for Omics data visualization offering a first insight about the pathways affected in different experimental datasets. The second goal of the project is a dynamical study focused on synovial fibroblasts' behavior under different initial conditions specific to RA, as recent studies have shown that synovial fibroblasts play a crucial role in driving the persistent, destructive characteristics of the disease. Leaning on the RA knowledgebase and using the web platform Cell Collective, we are currently building a Boolean large scale dynamical model for the study of RA fibroblasts' activation.

5.
J Vasc Surg ; 68(6S): 60S-71S.e3, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29519688

RESUMO

BACKGROUND: Recent evidence suggests that adaptive immunity develops during abdominal aortic aneurysm evolution. Uncertainties remain about the antigens implicated and their role in inducing rupture. Because antigens from the extracellular matrix (ECM) have been suspected, the aim of this experimental study was to characterize the role of adaptive immunity directed against antigens from the aortic ECM. METHODS: In a first step, an experimental model of abdominal aortic aneurysm rupture based on adaptive immunity against the ECM was developed and characterized. Forty 4-week-old male Lewis rats were divided into two groups. In the ECM group (n = 20), rats were presensitized against the guinea pig aortic ECM before implantation of a decellularized aortic xenograft (DAX). In the control group (n = 20), rats were not presensitized before DAX implantation. In each group, half the rats were sacrificed at day 3 to analyze early mechanisms involved after DAX implantation. In a second step, we aimed to assess which ECM component was most efficient in inducing rupture. For this purpose, the nonfibrillar and fibrillar ECM components were sequentially extracted from the guinea pig aortic wall. Forty Lewis rats were then divided into four groups. Each group was presensitized against one ECM component (structural glycoproteins and proteoglycans, collagen, elastin alone, and elastin-associated glycoproteins) before DAX implantation. Apart from those that experienced rupture, rats were sacrificed at day 21. Xenografts were harvested for histologic, immunofluorescence, and conditioned medium analyses. RESULTS: In total, early aortic rupture occurred in 80% of the ECM group vs 0% of the control group (P < .001). In the ECM group, major circumferential immunoglobulin deposits were observed in combination with the C3 complement fraction, without cell infiltration. Conditioned medium analysis revealed that matrix metalloproteinase 9 and myeloperoxidase levels and elastase activities were significantly increased in this group. Immunofluorescence analysis demonstrated that myeloperoxidase co-localized with tissue-free DNA and histone H4, highlighting local neutrophil activation and formation of neutrophil extracellular traps. Following differential presensitization, it appeared that rats presensitized against structural glycoproteins and proteoglycans were significantly more susceptible to rupture after DAX implantation. CONCLUSIONS: Stimulating adaptive immunity against the aortic ECM, especially structural glycoproteins and proteoglycans, triggers rupture after DAX implantation. Further studies are needed to assess the precise proteins involved.

6.
Cell Mol Immunol ; 15(2): 158-170, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27499044

RESUMO

CD5 is constitutively expressed on T cells and a subset of mature normal and leukemic B cells in patients with chronic lymphocytic leukemia (CLL). Important functional properties are associated with CD5 expression in B cells, including signal transducer and activator of transcription 3 activation, IL-10 production and the promotion of B-lymphocyte survival and transformation. However, the pathway(s) by which CD5 influences the biology of B cells and its dependence on B-cell receptor (BCR) co-signaling remain unknown. In this study, we show that CD5 expression activates a number of important signaling pathways, including Erk1/2, leading to IL-10 production through a novel pathway independent of BCR engagement. This pathway is dependent on extracellular calcium (Ca2+) entry facilitated by upregulation of the transient receptor potential channel 1 (TRPC1) protein. We also show that Erk1/2 activation in a subgroup of CLL patients is associated with TRPC1 overexpression. In this subgroup of CLL patients, small inhibitory RNA (siRNA) for CD5 reduces TRPC1 expression. Furthermore, siRNAs for CD5 or for TRPC1 inhibit IL-10 production. These findings provide new insights into the role of CD5 in B-cell biology in health and disease and could pave the way for new treatment strategies for patients with B-CLL.

7.
Ann Rheum Dis ; 76(9): 1614-1622, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28606969

RESUMO

OBJECTIVE: Altered microbiota composition or dysbiosis is suspected to be implicated in the pathogenesis of chronic inflammatory diseases, such as spondyloarthritis (SpA) and rheumatoid arthritis (RA). METHODS: 16S ribosomal RNA gene sequencing was performed on faecal DNA isolated from stool samples in two consecutive cross-sectional cohorts, each comprising three groups of adult volunteers: SpA, RA and healthy controls (HCs). In the second study, HCs comprised a majority of aged-matched siblings of patients with known HLA-B27 status. Alpha and beta diversities were assessed using QIIME, and comparisons were performed using linear discriminant analysis effect size to examine differences between groups. RESULTS: In both cohorts, dysbiosis was evidenced in SpA and RA, as compared with HCs, and was disease specific. A restriction of microbiota biodiversity was detected in both disease groups. The most striking change was a twofold to threefold increased abundance of Ruminococcus gnavus in SpA, as compared with both RA and HCs that was significant in both studies and positively correlated with disease activity in patients having a history of inflammatory bowel disease (IBD). Among HCs, significant difference in microbiota composition were also detected between HLA-B27+ and HLA-B27 negative siblings, suggesting that genetic background may influence gut microbiota composition. CONCLUSION: Our results suggest that distinctive dysbiosis characterise both SpA and RA and evidence a reproducible increase in R. gnavus that appears specific for SpA and a marker of disease activity. This observation is consistent with the known proinflammatory role of this bacteria and its association with IBD. It may provide an explanation for the link that exists between SpA and IBD.


Assuntos
Artrite Reumatoide/microbiologia , Disbiose/microbiologia , Microbioma Gastrointestinal/genética , RNA Ribossômico 16S/genética , Espondiloartropatias/microbiologia , Adulto , Idoso , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Estudos de Casos e Controles , Estudos de Coortes , Estudos Transversais , Disbiose/imunologia , Fezes/microbiologia , Feminino , Antígeno HLA-B27/genética , Humanos , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/microbiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Ruminococcus/genética , Irmãos , Espondiloartropatias/genética , Espondiloartropatias/imunologia
8.
Ann Rheum Dis ; 76(1): 310-314, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27461236

RESUMO

OBJECTIVE: More than 40 loci have been associated with ankylosing spondylitis (AS), but less is known about genetic associations in spondyloarthritis (SpA) as a whole. We conducted a family-based genome-wide association study (GWAS) to identify new non-major histocompatibility complex (MHC) genetic factors associated with SpA. METHODS: 906 subjects from 156 French multiplex families, including 438 with SpA, were genotyped using Affymetrix 250K microarrays. Association was tested with Unphased. The best-associated non-MHC single nucleotide polymorphisms (SNPs) were then genotyped in two independent familial cohorts (including 215 French and 294 North American patients with SpA, respectively) to replicate associations. RESULTS: 43 non-MHC SNPs yielded an association signal with SpA in the discovery cohort (p<1×10-4). In the extension studies, association was replicated at a nominal p value of p<0.05 for 16 SNPs in the second cohort and for three SNPs in the third cohort. Combined analysis identified an association close to genome-wide significance between rs7761118, an intronic SNP of MAPK14, and SpA (p=3.5×10-7). Such association appeared to be independent of HLA-B27. CONCLUSIONS: We report here for the first time a family-based GWAS study on SpA and identified an associated polymorphism near MAPK14. Further analyses are needed to better understand the functional basis of this genetic association.


Assuntos
Proteína Quinase 14 Ativada por Mitógeno/genética , Espondilartrite/genética , Adulto , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
9.
Proc Natl Acad Sci U S A ; 113(27): E3901-10, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27298374

RESUMO

Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40-OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease, we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation.


Assuntos
Ligante OX40/antagonistas & inibidores , Ligante OX40/sangue , Fibrose Pulmonar/prevenção & controle , Escleroderma Sistêmico/sangue , Pele/patologia , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Biomarcadores/sangue , Bleomicina , Estudos de Casos e Controles , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Fibrose , Antígeno 2 Relacionado a Fos/genética , Humanos , Hipertensão Pulmonar/prevenção & controle , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Fibrose Pulmonar/genética , Escleroderma Sistêmico/tratamento farmacológico , Pele/metabolismo , Fator de Transcrição AP-1/metabolismo
10.
Ann Rheum Dis ; 75(7): 1380-5, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26275432

RESUMO

OBJECTIVE: Spondyloarthritis (SpA) is a chronic inflammatory disorder with high heritability but with complex genetics. Apart from HLA-B27, most of the underlying genetic components remain to be identified. We conducted a whole-genome high-density non-parametric linkage analysis to identify new genetic factors of susceptibility to SpA. METHODS: 914 subjects including 462 with SpA from 143 multiplex families were genotyped using Affymetrix 250K microarrays. After quality control, 189 368 single nucleotide polymorphisms (SNPs) were kept for further analyses. Both non-parametric and parametric linkage analyses were performed using Merlin software. Association was tested with Unphased. RESULTS: Non-parametric linkage analysis identified two regions significantly linked to SpA: the major histocompatibility complex (LODmax=24.77) and a new 13q13 locus (LODmax=5.03). Additionally, eight loci achieved suggestive LOD scores, including the previously identified SPA2 locus at 9q33 (LODmax=3.51). Parametric analysis supported a codominant model in 13q13 with a maximum heterogeneity LOD, 'HLOD' score of 3.084 (α=0.28). Identification of meiotic recombination events around the 13q13 linkage peak in affected subjects from the 43 best-linked families allowed us to map the disease interval between 38.753 and 40.040 Mb. Family-based association analysis of the SNPs inside this interval in the best-linked families identified a SNP near FREM2 (rs1945502) which reached a p value close to statistical significance (corrected p=0.08). CONCLUSION: We report here for the first time a significant linkage between 13q13 and SpA. Identification of susceptibility factor inside this chromosomal region through targeted sequencing in linked families is underway.


Assuntos
Cromossomos Humanos Par 13/genética , Ligação Genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Espondilartrite/genética , Adulto , Feminino , Loci Gênicos , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem
12.
RMD Open ; 1(1): e000180, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26635969

RESUMO

OBJECTIVES: We compared the ability of antibodies against cyclic citrullinated peptides (anti-CCP2), against mutated citrullinated vimentin (anti-MCV) and against citrullinated fibrinogen (AhFibA) to predict 1 year rapid radiographic progression (RRP; total Sharp score variation ≥5 points), in early rheumatoid arthritis (RA). METHODS: We analysed 566 patients from the ESPOIR cohort with early RA fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria at year 1. We assayed the 3 anticitrullinated peptide antibodies (ACPA) tests on baseline sera. We compared the performance of these 3 ACPA tests to predict first-year RRP, by comparing areas under the receiver operating characteristic curves (ROCs). We assessed the 1 year RRP risk by ACPA titres. We used a logistic multivariate regression to analyse RRP risk in terms either of ACPA positivity or titre: high (>3 times the N cut-off) and low (1 to 3N). RESULTS: 145 patients displayed RRP. Areas under the ROCs were similar (0.60) for the 3 tests. High ACPA titres were associated with 1 year RRP, whatever the test was, and with similar ORs. Low+ anti-MCV titres were not associated with 1-year RRP, whereas low+ anti-CCP2 titres (p=0.0226) and low+ AhFibA titres (p=0.0332) were significantly associated. In multivariate analysis, 1 year RRP was associated with anti-CCP2 positivity (p<0.0001), AhFibA positivity (p<0.0001) and high anti-MCV titres (p<0.0001). CONCLUSIONS: Anti-CCP2 antibodies and AhFibA were predictive of 1 year RRP in early RA whatever their titre was, whereas only high anti-MCV antibody titres were predictive, potentially making them more discriminant to predict 1 year RRP risk.

13.
RMD Open ; 1(1): e000070, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26509068

RESUMO

OBJECTIVES: To determine the prevalence of eosinophilia in patients with recent-onset arthritis suggestive of rheumatoid arthritis (RA) and to describe their features and outcomes. METHODS: We performed an ancillary study of data from a French prospective multicentre cohort study monitoring clinical, laboratory and radiographic data in patients with inflammatory arthritis of 6 weeks to 6 months duration. We determined the proportion of patients with eosinophilia, defined as a count >500/mm(3), at baseline and after 3 years. Features of patients with and without baseline eosinophilia were compared. RESULTS: Baseline eosinophilia was evidenced in 26 of 804 (3.2%) patients; their mean eosinophil count was 637.7±107/mm(3). Baseline eosinophilia was ascribed to atopic syndrome in 6 of 26 (23.1%) patients. After 3 years, patients with eosinophilia had higher Health Assessment Questionnaire scores (0.9 vs 0.5, p=0.004), higher patient visual analogue scale activity score and morning stiffness intensity (p=0.05), and were more often taking disease-modifying antirheumatic drugs (p=0.02). Baseline eosinophilia was not associated with presence of extra-articular manifestations. CONCLUSIONS: Eosinophilia is rare in recent-onset arthritis suggestive of RA, and is usually directly related to the rheumatic disease. Our data suggest that patients with mild eosinophilia at diagnosis could respond worse to the treatment than those without.

14.
Biochim Biophys Acta ; 1853(11 Pt A): 2885-96, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26253696

RESUMO

The Fas associated death domain protein (FADD) is the key adaptor molecule of the apoptotic signal triggered by death receptors of the TNF-R1 superfamily. Besides its crucial role in the apoptotic machinery, FADD has proved to be important in many biological processes like tumorigenesis, embryonic development or cell cycle progression. In a process to decipher the regulatory mechanisms underlying FADD regulation, we identified the anti-apoptotic kinase, CK2, as a new partner and regulator of FADD sub-cellular localization. The blockade of CK2 activity induced FADD re-localization within the cell. Moreover, cytoplasmic FADD was increased when CK2ß was knocked down. In vitro kinase and pull down assays confirmed that FADD could be phosphorylated by the CK2 holoenzyme. We found that phosphorylation is weak with CK2α alone and optimal in the presence of stoichiometric amounts of CK2α catalytic and CK2ß regulatory subunit, showing that FADD phosphorylation is undertaken by the CK2 holoenzyme in a CK2ß-driven fashion. We found that CK2 can phosphorylate FADD on the serine 200 and that this phosphorylation is important for nuclear localization of FADD. Altogether, our results show for the first time that multifaceted kinase, CK2, phosphorylates FADD and is involved in its sub-cellular localization. This work uncovered an important role of CK2 in stable FADD nuclear localization.


Assuntos
Caseína Quinase II/metabolismo , Núcleo Celular/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Caseína Quinase II/genética , Linhagem Celular Tumoral , Núcleo Celular/genética , Proteína de Domínio de Morte Associada a Fas/genética , Humanos , Fosforilação/fisiologia
16.
Nat Commun ; 6: 7146, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25994336

RESUMO

Ankylosing spondylitis (AS) is a common, highly heritable, inflammatory arthritis for which HLA-B*27 is the major genetic risk factor, although its role in the aetiology of AS remains elusive. To better understand the genetic basis of the MHC susceptibility loci, we genotyped 7,264 MHC SNPs in 22,647 AS cases and controls of European descent. We impute SNPs, classical HLA alleles and amino-acid residues within HLA proteins, and tested these for association to AS status. Here we show that in addition to effects due to HLA-B*27 alleles, several other HLA-B alleles also affect susceptibility. After controlling for the associated haplotypes in HLA-B, we observe independent associations with variants in the HLA-A, HLA-DPB1 and HLA-DRB1 loci. We also demonstrate that the ERAP1 SNP rs30187 association is not restricted only to carriers of HLA-B*27 but also found in HLA-B*40:01 carriers independently of HLA-B*27 genotype.


Assuntos
Aminopeptidases/genética , Antígeno HLA-B27/genética , Antígeno HLA-B40/genética , Espondilite Anquilosante/etiologia , Estudos de Casos e Controles , Epistasia Genética , Predisposição Genética para Doença , Humanos , Complexo Principal de Histocompatibilidade , Antígenos de Histocompatibilidade Menor , Polimorfismo de Nucleotídeo Único
18.
Curr Rheumatol Rep ; 17(6): 516, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25903667

RESUMO

Spondyloarthritis (SpA) refers to a variety of inflammatory rheumatic disorders with strong heritability. Shared genetic predisposition, as shown by familial aggregation, is largely attributable to the major histocompatibility complex (MHC) locus, which was estimated to account for approximately half of the whole disease heritability. The first predisposing allele identified more than 40 years ago is HLA-B27, which is a major gene predisposing to all forms of SpA. However, despite intensive research, its pathogenesis remains uncertain. Other MHC alleles belonging to the class I and class II regions have been identified to exert additional effect. Candidate-gene approaches and genome-wide studies have recently allowed identification of several new loci residing outside of the MHC region that are involved in the predisposition to SpA. Interestingly, some of those new genes, such as ERAP1, ERAP2, and NPEPPS, code for aminopeptidases that are involved in MHC class I presentation and were shown to interact with HLA-B27.


Assuntos
Complexo Principal de Histocompatibilidade/genética , Espondilartrite/genética , Aminopeptidases/genética , Genes MHC Classe I , Predisposição Genética para Doença , Antígeno HLA-B27/genética , Humanos , Polimorfismo Genético , Receptores KIR/genética
19.
Arthritis Rheumatol ; 67(6): 1525-34, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25740711

RESUMO

OBJECTIVE: Several polymorphisms in ERAP1 are strongly associated with susceptibility to spondyloarthritis (SpA). The combination of rs17482078, rs10050860, and rs30187 results in the construction of 3 major haplotypes that are associated with SpA (the "protective" haplotype T/T/C, the "neutral" haplotype C/C/C, and the "susceptibility" haplotype C/C/T). The aim of the present study was to determine whether such haplotypes might affect endoplasmic reticulum aminopeptidase 1 (ERAP-1) messenger RNA (mRNA) expression, protein level, and/or enzymatic activity in antigen-presenting cells, a type of cell that is potentially relevant to disease pathogenesis. METHODS: Monocyte-derived dendritic cells (DCs) were generated in 2 cohorts (a discovery cohort and a replication cohort) comprising a total of 23 SpA patients and 44 healthy controls. Lymphoblastoid B cell lines were established from individuals who were homozygous for the risk, the neutral, or the protective ERAP1 haplotype, respectively. In those samples, we investigated the relationship between ERAP1 haplotypes and mRNA expression level. We also used Western blot analysis to measure the relative protein expression of ERAP-1 and a fluorogenic assay to measure its enzymatic activity. RESULTS: In monocyte-derived DCs, there was a strong association between ERAP1 haplotypes and the ERAP-1 mRNA expression level, with higher levels in subjects harboring the susceptibility haplotype (P = 0.001 and P = 5.6 × 10(-7) in the discovery and replication cohorts, respectively). In lymphoblastoid B cell lines, we observed a significant correlation between haplotype risk score and ERAP1 transcript or protein level (P = 0.003, ρ = 0.92 for both). Enzymatic activity followed a similar trend both in monocyte-derived DCs and in lymphoblastoid B cell lines. CONCLUSION: These data provide strong evidence that SpA-associated ERAP1 polymorphisms affect the level of gene expression in antigen-presenting cells. How increased production/activity of ERAP-1 may influence susceptibility to SpA remains to be determined.


Assuntos
Aminopeptidases/genética , Células Dendríticas/metabolismo , RNA Mensageiro/metabolismo , Espondilite Anquilosante/genética , Adulto , Aminopeptidases/metabolismo , Western Blotting , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Predisposição Genética para Doença , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor , Fatores de Proteção , Espondiloartropatias/enzimologia , Espondiloartropatias/genética , Espondiloartropatias/metabolismo , Espondilite Anquilosante/enzimologia , Espondilite Anquilosante/metabolismo
20.
J Inflamm (Lond) ; 12: 9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25685070

RESUMO

BACKGROUND: Genetic studies have pointed out that CD226 variants, encoding DNAM-1, could be associated with susceptibility to rheumatoid arthritis. Therefore, we aimed to determine the influence of DNAM-1 on the development of arthritis using the collagen-induced arthritis (CIA) mouse model. METHODS: CIA was induced in mice on a DBA/1 background, treated in parallel with a DNAM-1 neutralizing monoclonal antibody, a control IgG and PBS, respectively. CIA was also induced in mice deficient for DNAM-1(dnam1-/-) and control dnam-1+/+ mice on a C57/BL6 background. Mice were monitored for clinical and ultrasound signs of arthritis. Histological analysis was performed to search for inflammatory infiltrates and erosions. The Mann-Whitney U test for non-related samples was used for statistical analysis. RESULTS: There was a non-significant trend for a less arthritic phenotype in mice receiving anti-DNAM-1 mAb at both clinical, ultrasound and histological assessments. But, we did not observe any difference between dnam1+/+ and dnam1-/- mice for incidence nor severity of clinical arthritis. Histological analysis revealed inflammatory scores similar in both groups, without evidence of erosion. Collagen antibodies levels were similar in all mice, confirming immunization with collagen. CONCLUSION: Despite some clues suggesting a role of DNAM-1 in arthritis, these complementary approaches demonstrate no contribution of CD226/DNAM-1 in the arthritic phenotype. These results contrast with previous studies showing a role in vivo of DNAM-1 in some autoimmune disorders.

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