RESUMO
Sjögren's syndrome (SjS) is a chronic autoimmune disease primarily involving the exocrine glands in which the involvement of the innate immune system is largely uncharacterized. Mer signaling has been found to be protective in several autoimmune diseases but remains unstudied in SjS. Here, we investigated the role of Mer signaling in SjS. Mer knockout (MerKO) mice were examined for SjS disease criteria. SjS-susceptible (SjSS) C57BL/6.NOD-Aec1Aec2 mice were assessed for defective Mer signaling outcomes, soluble Mer (sMer) levels, A disintegrin and metalloprotease 17 (ADAM17) activity, and Rac1 activation. In addition, SjS patient plasma samples were evaluated for sMer levels via ELISA, and sMer levels were correlated to disease manifestations. MerKO mice developed submandibular gland (SMG) lymphocytic infiltrates, SMG apoptotic cells, anti-nuclear autoantibodies (ANA), and reduced saliva flow. Mer signaling outcomes were observed to be diminished in SjSS mice, as evidenced by reduced Rac1 activation in SjSS mice macrophages in response to apoptotic cells and impaired efferocytosis. Increased sMer was also detected in SjSS mouse sera, coinciding with higher ADAM17 activity, the enzyme responsible for cleavage and inactivation of Mer. sMer levels were elevated in patient plasma and positively correlated with focus scores, ocular staining scores, rheumatoid factors, and anti-Ro60 levels. Our data indicate that Mer plays a protective role in SjS, similar to other autoimmune diseases. Furthermore, we suggest a series of events where enhanced ADAM17 activity increases Mer inactivation and depresses Mer signaling, thus removing protection against the loss of self-tolerance and the onset of autoimmune disease in SjSS mice.
Assuntos
Regulação Enzimológica da Expressão Gênica , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/metabolismo , c-Mer Tirosina Quinase/genética , Proteína ADAM17/metabolismo , Animais , Anticorpos Antinucleares/química , Apoptose , Autoanticorpos/metabolismo , Autoimunidade , Modelos Animais de Doenças , Feminino , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Fenótipo , Saliva/metabolismo , Transdução de Sinais , Timócitos/metabolismoRESUMO
Sjögren's syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10-14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10-9; odds ratio = 0.75; 95% confidence interval = 0.66-0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease.
Assuntos
2',5'-Oligoadenilato Sintetase/genética , Interferon Tipo I/genética , Locos de Características Quantitativas/genética , Síndrome de Sjogren/genética , 2',5'-Oligoadenilato Sintetase/biossíntese , Alelos , Processamento Alternativo/genética , Feminino , Regulação da Expressão Gênica , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Interferon Tipo I/metabolismo , Masculino , Síndrome de Sjogren/metabolismo , Síndrome de Sjogren/patologia , Viroses/genética , Viroses/virologiaRESUMO
OBJECTIVES: Evaluate the presence of minor salivary gland (SG) fibrosis in primary Sjögren's syndrome (pSS) as a function of disease pathology or a consequence of ageing. METHODS: Subjects with sicca symptoms attending a Sjögren's research clinic were classified by American European Consensus Group (AECG) criteria as either pSS or non-SS (nSS). Discovery (n=34 pSS, n=28 nSS) and replication (n=35 pSS, n=31 nSS) datasets were evaluated. Minor SG cross-sections from haematoxylin and eosin stained slides were imaged, digitally reconstructed and analysed for percent area fibrosis. Relationships between SG fibrosis, age, and clinical measures were evaluated using Spearman correlations. Association with SS was assessed by: ROC curve, Variable Selection Using Random Forests (VSURF) and uni- and bi-variate regression analyses. RESULTS: SS subjects had significantly more fibrotic tissue in their minor labial salivary glands (median 24.39%, range 5.12-51.67%) than nSS participants (median 16.7%, range 5.97-38.65%, p<0.0001); age did not differ between groups (average ± SD pSS 50.2 ±13.9 years, nSS 53.8±12.4 years). In both the discovery and replication data sets, multiple regression models showed that the area of minor salivary gland fibrosis predicted pSS significantly better than age alone. Age-corrected linear regression revealed that the area of minor salivary gland fibrosis positively associated with vanBijsterveld score (p=0.042) and biopsy focus score (p=0.002). ROC curve and VSURF analyses ranked fibrosis as a significantly more important variable for subject discrimination than age. CONCLUSIONS: SG fibrosis is an element of pSS pathology that is related to focus score and is not solely attributable to age.
Assuntos
Glândulas Salivares Menores/patologia , Síndrome de Sjogren/patologia , Adulto , Fatores Etários , Idoso , Área Sob a Curva , Biópsia , Estudos de Casos e Controles , Feminino , Fibrose , Humanos , Modelos Lineares , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Glândulas Salivares Menores/imunologia , Índice de Gravidade de Doença , Síndrome de Sjogren/imunologiaRESUMO
OBJECTIVES: Autoantibodies reactive with Ro52 are often found in sera of patients with Sjögren's syndrome (SS). This study was undertaken to investigate the role of Ro52-induced immune responses in pathogenesis of SS. METHODS: New Zealand Mixed (NZM) 2758 mice were immunised with Ro52 in alum adjuvant. Control mice were immunised either with maltose-binding protein or injected with alum alone. Mice were monitored for anti-Ro52 antibody, sialoadenitis and pilocarpine-induced salivation. Antibody binding to salivary gland (SG) cells was analysed in vivo and in vitro by immunofluorescence. Sera from immunised mice were passively transferred into untreated or alum injected NZM2758 mice. RESULTS: By day 30 post-immunisation, Ro52 immunised mice generated immunoprecipitating anti-Ro52 antibodies and they had the maximum drop in saliva production. Both Ro52 immunised and control mice showed evidence of mild sialoadenitis. However, only Ro52 immunised mice had antibody deposition in their SG. Passive transfer of Ro52-immune sera induced SG dysfunction in recipient mice, only if the recipients were primed with alum. In vitro, antibodies from Ro52-immune sera were internalised by a SG cell line and this uptake was inhibited by cytochalasin D treatment. CONCLUSIONS: Our data show for the first time that antibodies induced by Ro52 are capable of inducing SG dysfunction, and that this phenomenon is dependent on the activation of innate immunity. The mouse model described in this study implies that autoantibody deposition in the SG might be an important step in the induction of xerostomia and pathogenesis of SS.
Assuntos
Autoanticorpos/imunologia , Modelos Animais de Doenças , Imunidade Inata/imunologia , Imunização Passiva , Camundongos , Ribonucleoproteínas/imunologia , Sialadenite/imunologia , Síndrome de Sjogren/imunologia , Glândula Submandibular/imunologia , Animais , Humanos , Imunoglobulina G/imunologia , Sialadenite/patologia , Síndrome de Sjogren/patologia , Glândula Submandibular/patologiaRESUMO
OBJECTIVE: The diagnosis of SS is often difficult and many patients are symptomatic for years with other diagnoses before confirmation of SS. Our aim was to determine whether overlapping clinical and serologic features with RA and SLE may in part drive the misdiagnoses. METHODS: A total of 1175 sicca patients were evaluated in a multidisciplinary clinic and classified as having SS based on the American-European Consensus Group Criteria. They were interrogated for a past history of suspicion or diagnosis of RA, SLE or SSc. These diseases were confirmed or ruled out by applying the corresponding classification criteria if the patients responded affirmatively. RESULTS: Of these, 524 (44.6%) subjects reported previous diagnosis or suspicion of RA, SLE or SSc, which was confirmed in 130 (24.8%) but excluded in 394 (75.2%) subjects. Of those previously diagnosed with another illness, 183 (34.9%) met the criteria for primary SS. RF was present in 70/191 patients with previous diagnosis of RA compared with 445/845 without a prior RA diagnosis (P = 3.38E-05), while 128/146 with a diagnosis of SLE had positive ANA compared with 622/881 without the diagnosis (P = 8.77E-06). Age also influenced former diagnoses: people with suspected RA were older than those without the diagnosis (P = 5.89E-06), while patients with SLE suspicion were younger (P = 0.0003). Interestingly, the previous diagnoses did not significantly delay a final classification of SS. CONCLUSION: Among subjects classified as SS, the presence of a positive ANA or RF was associated with a previous, apparently erroneous diagnosis of SLE or RA, respectively.
Assuntos
Artrite Reumatoide/diagnóstico , Erros de Diagnóstico , Lúpus Eritematoso Sistêmico/diagnóstico , Síndrome de Sjogren/diagnóstico , Idoso , Anticorpos Antinucleares/sangue , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fator Reumatoide/sangue , Síndrome de Sjogren/sangueRESUMO
Systemic lupus erythematosus (SLE) is a chronic heterogeneous autoimmune disorder characterized by the loss of tolerance to self-antigens and dysregulated interferon responses. The etiology of SLE is complex, involving both heritable and environmental factors. Candidate-gene studies and genome-wide association (GWA) scans have been successful in identifying new loci that contribute to disease susceptibility; however, much of the heritable risk has yet to be identified. In this study, we sought to replicate 1,580 variants showing suggestive association with SLE in a previously published GWA scan of European Americans; we tested a multiethnic population consisting of 7,998 SLE cases and 7,492 controls of European, African American, Asian, Hispanic, Gullah, and Amerindian ancestry to find association with the disease. Several genes relevant to immunological pathways showed association with SLE. Three loci exceeded the genome-wide significance threshold: interferon regulatory factor 8 (IRF8; rs11644034; p(meta-Euro) = 2.08 × 10(-10)), transmembrane protein 39A (TMEM39A; rs1132200; p(meta-all) = 8.62 × 10(-9)), and 17q21 (rs1453560; p(meta-all) = 3.48 × 10(-10)) between IKAROS family of zinc finger 3 (AIOLOS; IKZF3) and zona pellucida binding protein 2 (ZPBP2). Fine mapping, resequencing, imputation, and haplotype analysis of IRF8 indicated that three independent effects tagged by rs8046526, rs450443, and rs4843869, respectively, were required for risk in individuals of European ancestry. Eleven additional replicated effects (5 × 10(-8) < p(meta-Euro) < 9.99 × 10(-5)) were observed with CFHR1, CADM2, LOC730109/IL12A, LPP, LOC63920, SLU7, ADAMTSL1, C10orf64, OR8D4, FAM19A2, and STXBP6. The results of this study increase the number of confirmed SLE risk loci and identify others warranting further investigation.
Assuntos
Proteínas do Ovo/genética , Predisposição Genética para Doença , Fator de Transcrição Ikaros/genética , Fatores Reguladores de Interferon/genética , Lúpus Eritematoso Sistêmico/genética , Proteínas de Membrana/genética , Povo Asiático/genética , População Negra/genética , Mapeamento Cromossômico , Feminino , Haplótipos/genética , Hispânico ou Latino/genética , Humanos , Indígenas Norte-Americanos/genética , Lúpus Eritematoso Sistêmico/etnologia , Masculino , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA , População Branca/genéticaRESUMO
Systemic lupus erythematosus (SLE) is considered to be the prototypic autoimmune disease, with a complex genetic architecture influenced by environmental factors. We sought to replicate a putative association at 11p13 not yet exceeding genome-wide significance (p < 5 × 10(-8)) identified in a genome-wide association study (GWAS). Our GWA scan identified two intergenic SNPs located between PDHX and CD44 showing suggestive evidence of association with SLE in cases of European descent (rs2732552, p = 0.004, odds ratio [OR] = 0.78; rs387619, p = 0.003, OR = 0.78). The replication cohort consisted of >15,000 subjects, including 3562 SLE cases and 3491 controls of European ancestry, 1527 cases and 1811 controls of African American (AA) descent, and 1265 cases and 1260 controls of Asian origin. We observed robust association at both rs2732552 (p = 9.03 × 10(-8), OR = 0.83) and rs387619 (p = 7.7 × 10(-7), OR = 0.83) in the European samples with p(meta) = 1.82 × 10(-9) for rs2732552. The AA and Asian SLE cases also demonstrated association at rs2732552 (p = 5 × 10(-3), OR = 0.81 and p = 4.3 × 10(-4), OR = 0.80, respectively). A meta-analysis of rs2732552 for all racial and ethnic groups studied produced p(meta) = 2.36 × 10(-13). This locus contains multiple regulatory sites that could potentially affect expression and functions of CD44, a cell-surface glycoprotein influencing immunologic, inflammatory, and oncologic phenotypes, or PDHX, a subunit of the pyruvate dehydrogenase complex.
Assuntos
Cromossomos Humanos Par 11/genética , Loci Gênicos , Predisposição Genética para Doença , Receptores de Hialuronatos/genética , Lúpus Eritematoso Sistêmico/genética , Complexo Piruvato Desidrogenase/genética , Negro ou Afro-Americano/genética , Indígena Americano ou Nativo do Alasca/genética , Povo Asiático/genética , Estudos de Coortes , Feminino , Haplótipos , Hispânico ou Latino/genética , Humanos , Desequilíbrio de Ligação , Lúpus Eritematoso Sistêmico/etnologia , Masculino , Polimorfismo de Nucleotídeo Único , População Branca/genéticaRESUMO
OBJECTIVE: To compare the performance of the American-European Consensus Group (AECG) and the newly proposed American College of Rheumatology (ACR) classification criteria for Sjögren's Syndrome (SS) in a well-characterised sicca cohort, given ongoing efforts to resolve discrepancies and weaknesses in the systems. METHODS: In a multidisciplinary clinic for the evaluation of sicca, we assessed features of salivary and lacrimal gland dysfunction and autoimmunity as defined by tests of both AECG and ACR criteria in 646 participants. Global gene expression profiles were compared in a subset of 180 participants. RESULTS: Application of the AECG and ACR criteria resulted in classification of 279 and 268 participants with SS, respectively. Both criteria were met by 244 participants (81%). In 26 of the 35 AECG+/ACR participants, the minor salivary gland biopsy focal score was ≥1 (74%), while nine had positive anti-Ro/La (26%). There were 24 AECG-/ACR+ who met ACR criteria mainly due to differences in the scoring of corneal staining. All patients with SS, regardless of classification, had similar gene expression profiles, which were distinct from the healthy controls. CONCLUSIONS: The two sets of classification criteria yield concordant results in the majority of cases and gene expression profiling suggests that patients meeting either set of criteria are more similar to other SS participants than to healthy controls. Thus, there is no clear evidence for increased value of the new ACR criteria over the old AECG criteria from the clinical or biological perspective. It is our contention, supported by this report, that improvements in diagnostic acumen will require a more fundamental understanding of the pathogenic mechanisms than is at present available.
Assuntos
Síndrome de Sjogren/classificação , Transcriptoma , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Consenso , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome de Sjogren/diagnóstico , Síndrome de Sjogren/genética , Estados Unidos , Adulto JovemRESUMO
We designed a massively parallel reporter assay (MPRA) in an Epstein-Barr virus transformed B cell line to directly characterize the potential for histone post-translational modifications, i.e., histone quantitative trait loci (hQTLs), expression QTLs (eQTLs), and variants on systemic lupus erythematosus (SLE) and autoimmune (AI) disease risk haplotypes to modulate regulatory activity in an allele-dependent manner. Our study demonstrates that hQTLs, as a group, are more likely to modulate regulatory activity in an MPRA compared with other variant classes tested, including a set of eQTLs previously shown to interact with hQTLs and tested AI risk variants. In addition, we nominate 17 variants (including 11 previously unreported) as putative causal variants for SLE and another 14 for various other AI diseases, prioritizing these variants for future functional studies in primary and immortalized B cells. Thus, we uncover important insights into the mechanistic relationships among genotype, epigenetics, and gene expression in SLE and AI disease phenotypes.
Assuntos
Infecções por Vírus Epstein-Barr , Lúpus Eritematoso Sistêmico , Humanos , Locos de Características Quantitativas/genética , Histonas/genética , Infecções por Vírus Epstein-Barr/genética , Herpesvirus Humano 4/genética , Lúpus Eritematoso Sistêmico/genéticaRESUMO
Objective: To systematically characterize the potential for histone post-translational modifications, i.e., histone quantitative trait loci (hQTLs), expression QTLs (eQTLs), and variants on systemic lupus erythematosus (SLE) and autoimmune (AI) disease risk haplotypes to modulate gene expression in an allele dependent manner. Methods: We designed a massively parallel reporter assay (MPRA) containing ~32K variants and transfected it into an Epstein-Barr virus transformed B cell line generated from an SLE case. Results: Our study expands our understanding of hQTLs, illustrating that epigenetic QTLs are more likely to contribute to functional mechanisms than eQTLs and other variant types, and a large proportion of hQTLs overlap transcription start sites (TSS) of noncoding RNAs. In addition, we nominate 17 variants (including 11 novel) as putative causal variants for SLE and another 14 for various other AI diseases, prioritizing these variants for future functional studies primary and immortalized B cells. Conclusion: We uncover important insights into the mechanistic relationships between genotype, epigenetics, gene expression, and SLE and AI disease phenotypes.
RESUMO
Fine mapping and bioinformatic analysis of the DDX6-CXCR5 genetic risk association in Sjögren's Disease (SjD) and Systemic Lupus Erythematosus (SLE) identified five common SNPs with functional evidence in immune cell types: rs4938573, rs57494551, rs4938572, rs4936443, rs7117261. Functional interrogation of nuclear protein binding affinity, enhancer/promoter regulatory activity, and chromatin-chromatin interactions in immune, salivary gland epithelial, and kidney epithelial cells revealed cell type-specific allelic effects for all five SNPs that expanded regulation beyond effects on DDX6 and CXCR5 expression. Mapping the local chromatin regulatory network revealed several additional genes of interest, including lnc-PHLDB1-1. Collectively, functional characterization implicated the risk alleles of these SNPs as modulators of promoter and/or enhancer activities that regulate cell type-specific expression of DDX6, CXCR5, and lnc-PHLDB1-1, among others. Further, these findings emphasize the importance of exploring the functional significance of SNPs in the context of complex chromatin architecture in disease-relevant cell types and tissues.
RESUMO
OBJECTIVE: Sjögren's disease (SjD) is an autoimmune disease characterised by inflammatory destruction of exocrine glands. Patients with autoantibodies to Ro/SSA (SjDRo+) exhibit more severe disease. Long non-coding RNAs (lncRNAs) are a functionally diverse class of non-protein-coding RNAs whose role in autoimmune disease pathology has not been well characterised. METHODS: Whole blood RNA-sequencing (RNA-seq) was performed on SjD cases (n=23 Ro/SSA negative (SjDRo-); n=27 Ro/SSA positive (SjDRo+) and healthy controls (HCs; n=27). Bioinformatics and pathway analyses of differentially expressed (DE) transcripts (log2 fold change ≥2 or ≤0.5; padj<0.05) were used to predict lncRNA function. LINC01871 was characterised by RNA-seq analyses of HSB-2 cells with CRISPR-targeted LINC01871 deletion (LINC01871-/ -) and in vitro stimulation assays. RESULTS: Whole blood RNA-seq revealed autoantibody-specific transcription profiles and disproportionate downregulation of DE transcripts in SjD cases relative to HCs. Sixteen DE lncRNAs exhibited correlated expression with the interferon (IFN)-regulated gene, RSAD2, in SjDRo+ (r≥0.65 or ≤-0.6); four antisense lncRNAs exhibited IFN-regulated expression in immune cell lines. LINC01871 was upregulated in all SjD cases. RNA-seq and pathway analyses of LINC01871-/ - cells implicated roles in cytotoxic function, differentiation and IFNγ induction. LINC01871 was induced by IFNγ in a myeloid cell line and regulated by calcineurin/NFAT pathway and T cell receptor (TCR) signalling in primary human T cells. CONCLUSION: LINC01871 influences expression of many immune cell genes and growth factors, is IFNγ inducible, and regulated by calcineurin signalling and TCR ligand engagement. Altered LINC01871 expression may influence the dysregulated T cell inflammatory pathways implicated in SjD.
Assuntos
Doenças Autoimunes , RNA Longo não Codificante , Síndrome de Sjogren , Humanos , Interferons , RNA Longo não Codificante/genética , Calcineurina , Antivirais , Síndrome de Sjogren/genética , Autoanticorpos , Imunidade , Receptores de Antígenos de Linfócitos TRESUMO
Sjögren's disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjögren's cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands.
Assuntos
Estudo de Associação Genômica Ampla , Síndrome de Sjogren , Predisposição Genética para Doença , Humanos , Polimorfismo de Nucleotídeo Único , Síndrome de Sjogren/genéticaRESUMO
OBJECTIVE: Primary Sjögren syndrome (SS) is characterized by a focal lymphocytic infiltrate in exocrine glands. We describe patients who lacked this key feature. METHODS: We evaluated patients with sicca in a comprehensive clinic at which medical, dental, and ophthalmological examinations were performed. All subjects underwent a minor salivary gland biopsy with focus score calculation. Extraglandular manifestations were also determined. We categorized subjects as high, intermediate, or low in terms of expression of interferon (IFN)-regulated genes. RESULTS: About 20% (51 of 229, 22%) of those classified as having primary SS had a focus score of zero. Compared to those with anti-Ro positivity and a focus score > 1.0, the patients with focus score of zero (who by classification criteria must be anti-Ro-positive) were statistically less likely to have anti-La (or SSB) and elevated immunoglobulin, as well as less severe corneal staining. The focus score zero patients were less likely to have elevated expression of IFN-regulated genes in peripheral blood mononuclear cells than anti-Ro-positive SS patients with a focal salivary infiltrate. CONCLUSION: There are only a few clinical differences between patients with primary SS with focus score zero and those with both anti-Ro and a focus score > 1.0. The small subset of focus score zero patients tested did not have elevated expression of IFN-regulated genes, but did have systemic disease. Thus, extraglandular manifestations are perhaps more related to the presence of anti-Ro than increased IFN. This may have relevance to pathogenesis of SS.
Assuntos
Movimento Celular/imunologia , Ceratoconjuntivite Seca/imunologia , Linfócitos/imunologia , Glândulas Salivares/imunologia , Síndrome de Sjogren/imunologia , Anticorpos Antinucleares/sangue , Autoanticorpos/sangue , Autoantígenos/imunologia , Biópsia , Regulação da Expressão Gênica , Técnicas Histológicas , Humanos , Interferons/genética , Interferons/metabolismo , Ceratoconjuntivite Seca/sangue , Ceratoconjuntivite Seca/patologia , Linfócitos/patologia , RNA Citoplasmático Pequeno/imunologia , Fator Reumatoide/sangue , Ribonucleoproteínas/imunologia , Glândulas Salivares/patologia , Síndrome de Sjogren/sangue , Síndrome de Sjogren/patologia , Antígeno SS-BRESUMO
Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized primarily by immune-mediated destruction of exocrine tissues, such as those of the salivary and lacrimal glands, resulting in the loss of saliva and tear production, respectively. This disease predominantly affects middle-aged women, often in an insidious manner with the accumulation of subtle changes in glandular function occurring over many years. Patients commonly suffer from pSS symptoms for years before receiving a diagnosis. Currently, there is no effective cure for pSS and treatment options and targeted therapy approaches are limited due to a lack of our overall understanding of the disease etiology and its underlying pathology. To better elucidate the underlying molecular nature of this disease, we have performed RNA-sequencing to generate a comprehensive global gene expression profile of minor salivary glands from an ethnically diverse cohort of patients with pSS. Gene expression analysis has identified a number of pathways and networks that are relevant in pSS pathogenesis. Moreover, our detailed integrative analysis has revealed a primary Sjögren's syndrome molecular signature that may represent important players acting as potential drivers of this disease. Finally, we have established that the global transcriptomic changes in pSS are likely to be attributed not only to various immune cell types within the salivary gland but also epithelial cells which are likely playing a contributing role. Overall, our comprehensive studies provide a database-enriched framework and resource for the identification and examination of key pathways, mediators, and new biomarkers important in the pathogenesis of this disease with the long-term goals of facilitating earlier diagnosis of pSS and to mitigate or abrogate the progression of this debilitating disease.
Assuntos
Células Epiteliais/metabolismo , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Glândulas Salivares Menores/metabolismo , Síndrome de Sjogren/genética , Transcriptoma , Estudos de Casos e Controles , Biologia Computacional , Células Epiteliais/imunologia , Feminino , Humanos , Pessoa de Meia-Idade , Glândulas Salivares Menores/imunologia , Síndrome de Sjogren/diagnóstico , Síndrome de Sjogren/imunologiaRESUMO
To assess the types of salivary gland (SG) T cells contributing to Sjögren's syndrome (SS), we evaluated SG T cell subtypes for association with disease features and compared the SG CD4+ memory T cell transcriptomes of subjects with either primary SS (pSS) or non-SS sicca (nSS). SG biopsies were evaluated for proportions and absolute numbers of CD4+ and CD8+ T cells. SG memory CD4+ T cells were evaluated for gene expression by microarray. Differentially-expressed genes were identified, and gene set enrichment and pathways analyses were performed. CD4+CD45RA- T cells were increased in pSS compared to nSS subjects (33.2% vs. 22.2%, p < 0.0001), while CD8+CD45RA- T cells were decreased (38.5% vs. 46.0%, p = 0.0014). SG fibrosis positively correlated with numbers of memory T cells. Proportions of SG CD4+CD45RA- T cells correlated with focus score (r = 0.43, p < 0.0001), corneal damage (r = 0.43, p < 0.0001), and serum Ro antibodies (r = 0.40, p < 0.0001). Differentially-expressed genes in CD4+CD45RA- cells indicated a T follicular helper (Tfh) profile, increased homing and increased cellular interactions. Predicted upstream drivers of the Tfh signature included TCR, TNF, TGF-ß1, IL-4, and IL-21. In conclusion, the proportions and numbers of SG memory CD4+ T cells associate with key SS features, consistent with a central role in disease pathogenesis.
RESUMO
OBJECTIVE: To describe the clinical and serologic manifestations of Sjögren's syndrome (SS) in ethnic groups of the US. METHODS: This was a cross-sectional study of 648 patients with primary SS: 20 African American (AA), 164 American Indian (AI), 426 European American (EA), and 38 patients of other races evaluated in a multidisciplinary Sjögren's International Collaborative Clinical Alliance research clinic. RESULTS: AA subjects comprised 3.1% of the SS cohort, much lower than the percentage of AA in the state of Oklahoma (P = 3.01 × E - 05), the US (P = 2.24E - 13), or a systemic lupus erythematosus (SLE) cohort at the same institution (P = 4.26 × 10E - 27). In contrast, the percentage of AI in the SS cohort (25.3%) was much higher than expected (P = 3.17E - 09 versus SLE cohort, P = 6.36 - 26 versus Oklahoma, and P = 8.14E - 96 versus US population). The SS classification criteria were similar between AA and EA, but subjects of AI ancestry had lower rates of abnormal tear and salivary flow, as well as anti-Ro/SSA and anti-La/SSB antibodies. Paradoxically, AI had higher levels of disease activity (mean ± SD European League Against Rheumatism Sjögren's Syndrome Disease Activity Index score 3.77 ± 4.78) in comparison to EA (2.90 ± 4.12; P = 0.011) and more extraglandular manifestations affecting mainly the articular and glandular domains. Meanwhile, AA patients were characterized by higher rates of hypergammaglobulinemia (odds ratio [OR] 1.39 [95% confidence interval (95% CI) 1.39-8.65]; P = 0.01), elevated erythrocyte sedimentation rate (ESR) (OR 3.95 [95% CI 1.46-9.95]; P = 0.009), and parotid enlargement (OR 4.40 [95% CI 1.49-13.07]; P = 0.02). CONCLUSION: AI are affected at high rates with SS but present with few classical features, potentially preventing timely diagnosis. In contrast to SLE, SS is infrequent and not more severe among AA, but the triad of hypergammaglobulinemia, increased ESR, and parotid enlargement warrants extra vigilance for lymphomagenesis.
Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Indígenas Norte-Americanos/estatística & dados numéricos , Síndrome de Sjogren/etnologia , Síndrome de Sjogren/epidemiologia , População Branca/estatística & dados numéricos , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oklahoma/epidemiologia , Fatores de RiscoRESUMO
OBJECTIVE: The objective of this study was to assess the performance and reproducibility of the two currently used ocular surface staining scores in the assessment of keratoconjunctivitis sicca in Sjögren syndrome (SS) research classification. METHODS: In a multidisciplinary clinic for the evaluation of sicca, we performed all tests for the American European Consensus Group (AECG) and the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria, including the van Bijsterveld score (vBS) and the Ocular Staining Score (OSS), in 994 participants with SS or with non-SS sicca. We analyzed the concordance between the scores, the diagnostic accuracy and correlation with clinical variables, and interrater and intrasubject reproducibility. RESULTS: A total of 308 (31.1%) participants had a discordant vBS and OSS that was due to extra corneal staining points in the OSS. The presence of one or more of the additional points was highly predictive of SS classification (odds ratio = 3.66; P = 1.65 × 10e-20) and was associated with abnormal results of all measures of autoimmunity and glandular dysfunction. Receiver operating characteristic curves showed optimal cutoff values of four for the vBS (sensitivity = 0.62; specificity = 0.71; Youden's J = 0.33) and five for the OSS (sensitivity = 0.56; specificity = 0.75; Youden's J = 0.31). Notably, there was very poor consistency in interobserver mean scores and distributions (P < 0.0001) and in intrasubject scores after a median of 5.5 years (35% changed status of the ocular criterion). CONCLUSION: Ocular surface staining scores are useful for SS research classification; however, they are subject to significant interrater and intrasubject variability, which could result in changes in classification in 5%-10% of all subjects. These results highlight the need for objective and reproducible markers of disease that have thus far remained elusive for SS.
RESUMO
The cho-1 gene in Caenorhabditis elegans encodes a high-affinity plasma-membrane choline transporter believed to be rate limiting for acetylcholine (ACh) synthesis in cholinergic nerve terminals. We found that CHO-1 is expressed in most, but not all cholinergic neurons in C. elegans. cho-1 null mutants are viable and exhibit mild deficits in cholinergic behavior; they are slightly resistant to the acetylcholinesterase inhibitor aldicarb, and they exhibit reduced swimming rates in liquid. cho-1 mutants also fail to sustain swimming behavior; over a 33-min time course, cho-1 mutants slow down or stop swimming, whereas wild-type animals sustain the initial rate of swimming over the duration of the experiment. A functional CHO-1GFP fusion protein rescues these cho-1 mutant phenotypes and is enriched at cholinergic synapses. Although cho-1 mutants clearly exhibit defects in cholinergic behaviors, the loss of cho-1 function has surprisingly mild effects on cholinergic neurotransmission. However, reducing endogenous choline synthesis strongly enhances the phenotype of cho-1 mutants, giving rise to a synthetic uncoordinated phenotype. Our results indicate that both choline transport and de novo synthesis provide choline for ACh synthesis in C. elegans cholinergic neurons.