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1.
Autoimmun Rev ; 19(9): 102602, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32659476

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) is a lethal complication affecting 8-15% of patients. Screening tests such as echocardiography and pulmonary function tests allow for triaging patients for diagnosis by right heart catheterization. Understanding risk factors of SSc-PAH could help differentiate high-risk patients. METHODS: A systematic review was conducted to determine associations with SSc-PAH, including clinical/disease characteristics, antibodies, labs and biomarkers. The frequencies of publications featuring each risk/association were reported. RESULTS: Among 2654 articles, 984 duplicates and 1578 irrelevant articles were removed, leaving 92 articles for manual screening. After excluding 55 papers with small sample sizes, publications from identical cohorts, not English language, or PAH not ascertained by RHC, 37 articles were eligible. A total of 43 factors for SSc-PAH were identified within seven categories. Several associations were due to PAH and risk factors such as dynpnea, right heart failure, and short 6-minute walk distance. Patient characteristics (14), pulmonary physiology (6), antibody profiles (6) and genetics/epigenetics (6) had the most numerous and diverse factors, while biomarkers (4) and other labs (2) features were infrequent. Low carbon monoxide (DLCO) (6), older age (4), longer disease duration (4), positive anticentromere antibodies (ACA) (4), telangiectasias (4), high brain natriuretic peptide (4) were frequent associations. CONCLUSIONS: Risk factors for SSc-PAH such as ACA, older age, longer disease duration limited cutaneous SSc subset and presence of ILD may enrich screening programs. Genes and other antibody profiles are inconsistent and requires further validation.


Assuntos
Hipertensão Arterial Pulmonar , Escleroderma Sistêmico , Envelhecimento , Humanos , Peptídeo Natriurético Encefálico , Hipertensão Arterial Pulmonar/genética , Hipertensão Arterial Pulmonar/imunologia , Fatores de Risco , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/imunologia
2.
Ann Rheum Dis ; 79(9): 1218-1226, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32561607

RESUMO

OBJECTIVES: The analysis of annotated transcripts from genome-wide expression studies may help to understand the pathogenesis of complex diseases, such as systemic sclerosis (SSc). We performed a whole blood (WB) transcriptome analysis on RNA collected in the context of the European PRECISESADS project, aiming at characterising the pathways that differentiate SSc from controls and that are reproducible in geographically diverse populations. METHODS: Samples from 162 patients and 252 controls were collected in RNA stabilisers. Cases and controls were divided into a discovery (n=79+163; Southern Europe) and validation cohort (n=83+89; Central-Western Europe). RNA sequencing was performed by an Illumina assay. Functional annotations of Reactome pathways were performed with the Functional Analysis of Individual Microarray Expression (FAIME) algorithm. In parallel, immunophenotyping of 28 circulating cell populations was performed. We tested the presence of differentially expressed genes/pathways and the correlation between absolute cell counts and RNA transcripts/FAIME scores in regression models. Results significant in both populations were considered as replicated. RESULTS: Overall, 15 224 genes and 1277 functional pathways were available; of these, 99 and 225 were significant in both sets. Among replicated pathways, we found a deregulation in type-I interferon, Toll-like receptor cascade, tumour suppressor p53 protein function, platelet degranulation and activation. RNA transcripts or FAIME scores were jointly correlated with cell subtypes with strong geographical differences; neutrophils were the major determinant of gene expression in SSc-WB samples. CONCLUSIONS: We discovered a set of differentially expressed genes/pathways validated in two independent sets of patients with SSc, highlighting a number of deregulated processes that have relevance for the pathogenesis of autoimmunity and SSc.


Assuntos
Autoimunidade/genética , Escleroderma Sistêmico/genética , Transdução de Sinais/genética , Transcriptoma/genética , Adulto , Idoso , Estudos de Coortes , Europa (Continente) , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Humanos , Imunofenotipagem , Interferon Tipo I/sangue , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Análise de Sequência de RNA , Receptores Toll-Like/sangue
3.
Ann Rheum Dis ; 79(9): 1227-1233, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32482644

RESUMO

OBJECTIVES: Coactivators are a heterogeneous family of transcriptional regulators that are essential for modulation of transcriptional outcomes and fine-tune numerous cellular processes. The aim of the present study was to evaluate the role of the coactivator peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in the pathogenesis of systemic sclerosis (SSc). METHODS: Expression of PGC-1α was analysed by real-time PCR, western blot and immunofluorescence. Modulation of autophagy was analysed by reporter studies by expression of autophagy-related genes. The effects of PGC-1α knockdown on collagen production and myofibroblast differentiation were analysed in cultured human fibroblasts and in two mouse models with fibroblast-specific knockout of PGC-1α. RESULTS: The expression of PGC-1α was induced in dermal fibroblasts of patients with SSc and experimental murine fibrosis. Transforming growth factor beta (TGFß), hypoxia and epigenetic mechanisms regulate the expression of PGC-1α in fibroblasts. Knockdown of PGC-1α prevented the activation of autophagy by TGFß and this translated into reduced fibroblast-to-myofibroblast differentiation and collagen release. Knockout of PGC-1α in fibroblasts prevented skin fibrosis induced by bleomycin and by overexpression of a constitutively active TGFß receptor type I. Moreover, pharmacological inhibition of PGC-1α by SR18292 induced regression of pre-established, bleomycin-induced skin fibrosis. CONCLUSION: PGC-1α is upregulated in SSc and promotes autophagy to foster TGFß-induced fibroblast activation. Targeting of PGC-1α prevents aberrant autophagy, inhibits fibroblast activation and tissue fibrosis and may over therapeutic potential.


Assuntos
Autofagia/genética , Fibroblastos/fisiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/fisiologia , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/patologia , Animais , Bleomicina/farmacologia , Western Blotting , Colágeno/biossíntese , Modelos Animais de Doenças , Fibrose , Imunofluorescência , Humanos , Camundongos , Reação em Cadeia da Polimerase , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo , Regulação para Cima
4.
Adv Exp Med Biol ; 1253: 375-403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32445102

RESUMO

Scleroderma (systemic sclerosis; SSc) is a complex and highly heterogeneous multisystem rheumatic disease characterized by vascular abnormality, immunologic derangement, and excessive deposition of extracellular matrix (ECM) proteins. To date, the etiology of this life-threatening disorder remains not fully clear. More and more studies show epigenetic modifications play a vital role. The aberrant epigenetic status of certain molecules such as Fli-1, BMPRII, NRP1, CD70, CD40L, CD11A, FOXP3, KLF5, DKK1, SFRP1, and so on contributes to the pathogenesis of progressive vasculopathy, autoimmune dysfunction, and tissue fibrosis in SSc. Meanwhile, numerous miRNAs including miR-21, miR-29a, miR-196a, miR-202-3p, miR-150, miR-let-7a, and others are involved in the process. In addition, the abnormal epigenetic biomarker levels of CD11a, Foxp3, HDAC2, miR-30b, miR-142-3p, miR-150, miR-5196 in SSc are closely correlated with disease severity. In this chapter, we not only review new advancements on the epigenetic mechanisms involved in the pathogenesis of SSc and potential epigenetic biomarkers, but also discuss the therapeutic potential of epigenetic targeting therapeutics such as DNA methylation inhibitors, histone acetylase inhibitors, and miRNA replacement.


Assuntos
Epigênese Genética , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/terapia , Biomarcadores , Humanos , MicroRNAs , Escleroderma Sistêmico/patologia , Escleroderma Sistêmico/fisiopatologia
5.
An Bras Dermatol ; 95(3): 314-319, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32307203

RESUMO

BACKGROUND: Although not fully understood, oxidative stress has been implicated in the pathogenesis of different autoimmune diseases such as systemic sclerosis. Accumulating evidence indicates that oxidative stress can induce mitochondrial DNA (mtDNA) damage and variations in mtDNA copy number (mtDNAcn). OBJECTIVE: The aim of this study was to explore mtDNAcn and oxidative DNA damage byproducts in peripheral blood of patients with systemic sclerosis and healthy controls. METHODS: Forty six patients with systemic sclerosis and forty nine healthy subjects were studied. Quantitative real-time PCR used to measure the relative mtDNAcn and the oxidative damage (oxidized purines) of each sample. RESULTS: The mean mtDNAcn was lower in patients with systemic sclerosis than in healthy controls whereas the degree of mtDNA damage was significantly higher in cases as compared to controls. Moreover, there was a negative correlation between mtDNAcn and oxidative DNA damage. STUDY LIMITATIONS: The lack of simultaneous analysis and quantification of DNA oxidative damage markers in serum or urine of patients with systemic sclerosis and healthy controls. CONCLUSION: These data suggest that alteration in mtDNAcn and increased oxidative DNA damage may be involved in the pathogenesis of systemic sclerosis.


Assuntos
Variações do Número de Cópias de DNA , Dano ao DNA , DNA Mitocondrial/sangue , DNA Mitocondrial/genética , Estresse Oxidativo/genética , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/genética , Adulto , Estudos de Casos e Controles , Eletroforese em Gel de Ágar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/sangue , Reação em Cadeia da Polimerase em Tempo Real , Valores de Referência , Estatísticas não Paramétricas
6.
Arthritis Rheumatol ; 72(7): 1160-1169, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32134204

RESUMO

OBJECTIVE: Genome-wide gene expression studies implicate macrophages as mediators of fibrosis in systemic sclerosis (SSc), but little is known about how these cells contribute to fibrotic activation in SSc. We undertook this study to characterize the activation profile of SSc monocyte-derived macrophages and assessed their interaction with SSc fibroblasts. METHODS: Plasma and peripheral blood mononuclear cells (PBMCs) were obtained from whole blood from SSc patients (n = 24) and age- and sex-matched healthy controls (n = 12). Monocytes were cultured with autologous or allogeneic plasma to differentiate cells into macrophages. For reciprocal activation studies, macrophages were cocultured with fibroblasts using Transwell plates. RESULTS: The gene expression signature associated with blood-derived human SSc macrophages was enriched in SSc skin in an independent cohort and correlated with skin fibrosis. SSc macrophages expressed surface markers associated with activation and released CCL2, interleukin-6, and transforming growth factor ß under basal conditions (n = 8) (P < 0.05). Differentiation of healthy donor monocytes in plasma from SSc patients conferred the immunophenotype of SSc macrophages (n = 13) (P < 0.05). Transwell experiments demonstrated that coculture of SSc macrophages with SSc fibroblasts induced fibroblast activation (n = 3) (P < 0.05). CONCLUSION: These data demonstrate that the activation profile of SSc macrophages is profibrotic. SSc macrophages are activated under basal conditions and release mediators and express surface markers associated with both alternative and inflammatory macrophage activation. These findings also suggest that activation of SSc macrophages arises from soluble factors in local microenvironments. These studies implicate macrophages as likely drivers of fibrosis in SSc and suggest that therapeutic targeting of these cells may be beneficial in ameliorating disease in SSc patients.


Assuntos
Fibroblastos/metabolismo , Macrófagos/imunologia , Escleroderma Sistêmico/genética , Pele/metabolismo , Adulto , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Diferenciação Celular , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Técnicas de Cocultura , Feminino , Fibrose/genética , Fibrose/imunologia , Fibrose/metabolismo , Antígenos HLA-DR/imunologia , Humanos , Imunofenotipagem , Interleucina-6/genética , Interleucina-6/imunologia , Lectinas Tipo C/imunologia , Leucócitos Mononucleares , Ativação de Macrófagos , Macrófagos/metabolismo , Masculino , Lectinas de Ligação a Manose/imunologia , Pessoa de Meia-Idade , Monócitos/metabolismo , Fosforilação , RNA Mensageiro/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/genética , Receptor do Fator de Crescimento Transformador beta Tipo I/imunologia , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptor do Fator de Crescimento Transformador beta Tipo II/imunologia , Receptores de Superfície Celular/imunologia , Fator de Transcrição STAT3/metabolismo , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/metabolismo , Pele/patologia , Transcriptoma , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/imunologia
7.
Sci Rep ; 10(1): 1862, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024964

RESUMO

Genome-wide association studies (GWASs) have identified a number of genetic risk loci associated with systemic sclerosis (SSc) and Crohn's disease (CD), some of which confer susceptibility to both diseases. In order to identify new risk loci shared between these two immune-mediated disorders, we performed a cross-disease meta-analysis including GWAS data from 5,734 SSc patients, 4,588 CD patients and 14,568 controls of European origin. We identified 4 new loci shared between SSc and CD, IL12RB2, IRF1/SLC22A5, STAT3 and an intergenic locus at 6p21.31. Pleiotropic variants within these loci showed opposite allelic effects in the two analysed diseases and all of them showed a significant effect on gene expression. In addition, an enrichment in the IL-12 family and type I interferon signaling pathways was observed among the set of SSc-CD common genetic risk loci. In conclusion, through the first cross-disease meta-analysis of SSc and CD, we identified genetic variants with pleiotropic effects on two clinically distinct immune-mediated disorders. The fact that all these pleiotropic SNPs have opposite allelic effects in SSc and CD reveals the complexity of the molecular mechanisms by which polymorphisms affect diseases.


Assuntos
Doença de Crohn/genética , Loci Gênicos/genética , Predisposição Genética para Doença/genética , Escleroderma Sistêmico/genética , Estudos de Casos e Controles , Feminino , Expressão Gênica/genética , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética
8.
Ann Rheum Dis ; 79(4): 507-517, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32041748

RESUMO

BACKGROUND: Systemic sclerosis (SSc) is characterised by autoimmune activation, tissue and vascular fibrosis in the skin and internal organs. Tissue fibrosis is driven by myofibroblasts, that are known to maintain their phenotype in vitro, which is associated with epigenetically driven trimethylation of lysine 27 of histone 3 (H3K27me3). METHODS: Full-thickness skin biopsies were surgically obtained from the forearms of 12 adult patients with SSc of recent onset. Fibroblasts were isolated and cultured in monolayers and protein and RNA extracted. HOX transcript antisense RNA (HOTAIR) was expressed in healthy dermal fibroblasts by lentiviral induction employing a vector containing the specific sequence. Gamma secretase inhibitors were employed to block Notch signalling. Enhancer of zeste 2 (EZH2) was blocked with GSK126 inhibitor. RESULTS: SSc myofibroblasts in vitro and SSc skin biopsies in vivo display high levels of HOTAIR, a scaffold long non-coding RNA known to direct the histone methyltransferase EZH2 to induce H3K27me3 in specific target genes. Overexpression of HOTAIR in dermal fibroblasts induced EZH2-dependent increase in collagen and α-SMA expression in vitro, as well as repression of miRNA-34A expression and consequent NOTCH pathway activation. Consistent with these findings, we show that SSc dermal fibroblast display decreased levels of miRNA-34a in vitro. Further, EZH2 inhibition rescued miRNA-34a levels and mitigated the profibrotic phenotype of both SSc and HOTAIR overexpressing fibroblasts in vitro. CONCLUSIONS: Our data indicate that the EZH2-dependent epigenetic phenotype of myofibroblasts is driven by HOTAIR and is linked to miRNA-34a repression-dependent activation of NOTCH signalling.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Fibroblastos/metabolismo , MicroRNAs/metabolismo , Miofibroblastos/metabolismo , RNA Longo não Codificante/metabolismo , Receptores Notch/metabolismo , Escleroderma Sistêmico/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Epigênese Genética , Fibrose , Código das Histonas , Humanos , Indóis/farmacologia , Fenótipo , Piridonas/farmacologia , Receptores Notch/antagonistas & inibidores , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/patologia , Transdução de Sinais , Pele/citologia , Pele/metabolismo , Pele/patologia
9.
PLoS Comput Biol ; 16(2): e1007684, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32058996

RESUMO

Identification of differentially expressed genes (DEGs) is well recognized to be variable across independent replications of genome-wide transcriptional studies. These are often employed to characterize disease state early in the process of discovery and prioritize novel targets aimed at addressing unmet medical need. Increasing reproducibility of biological findings from these studies could potentially positively impact the success rate of new clinical interventions. This work demonstrates that statistically sound combination of gene expression data with prior knowledge about biology in the form of large protein interaction networks can yield quantitatively more reproducible observations from studies characterizing human disease. The novel concept of Well-Associated Proteins (WAPs) introduced herein-gene products significantly associated on protein interaction networks with the differences in transcript levels between control and disease-does not require choosing a differential expression threshold and can be computed efficiently enough to enable false discovery rate estimation via permutation. Reproducibility of WAPs is shown to be on average superior to that of DEGs under easily-quantifiable conditions suggesting that they can yield a significantly more robust description of disease. Enhanced reproducibility of WAPs versus DEGs is first demonstrated with four independent data sets focused on systemic sclerosis. This finding is then validated over thousands of pairs of data sets obtained by random partitions of large studies in several other diseases. Conditions that individual data sets must satisfy to yield robust WAP scores are examined. Reproducible identification of WAPs can potentially benefit drug target selection and precision medicine studies.


Assuntos
Biologia Computacional/métodos , Perfilação da Expressão Gênica , Mapas de Interação de Proteínas , Proteínas/química , Área Sob a Curva , Reações Falso-Positivas , Regulação da Expressão Gênica , Humanos , Modelos Lineares , Análise Multivariada , Medicina de Precisão , Probabilidade , Reprodutibilidade dos Testes , Escleroderma Sistêmico/genética
10.
Clin Exp Immunol ; 201(1): 25-33, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31970748

RESUMO

Systemic sclerosis (SSc) is a severe autoimmune fibrotic disease characterized by fibrosis, vasculopathy, and immune dysregulation. Dendritic cells (DCs) are the most potent antigen-presenting cells, specialized in pathogen sensing, with high capacity to shape the immune responses. The most recent technological advances have allowed the discovery of new DC subsets with potential implications in inflammatory conditions. Alterations of DC distribution in circulation and affected tissue as well as impaired DC function have been described in SSc patients, pointing towards a crucial role of these cells in SSc pathogenesis. In particular, recent studies have shown the importance of plasmacytoid DCs either by their high capacity to produce type I interferon or other inflammatory mediators implicated in SSc pathology, such as chemokine C-X-C motif ligand 4 (CXCL4). In-vivo models of SSc have been vital to clarify the implications of DCs in this disease, especially DCs depletion and specific gene knock-down studies. This review provides these new insights into the contribution of the different DCs subsets in the pathogenesis of SSc, as well as to the novel developments on DCs in in-vivo models of SSc and the potential use of DCs and their mediators as therapeutic targets.


Assuntos
Células Dendríticas/imunologia , Escleroderma Sistêmico/imunologia , Animais , Células Dendríticas/patologia , Modelos Animais de Doenças , Humanos , Fator Plaquetário 4/genética , Fator Plaquetário 4/imunologia , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/patologia
11.
Best Pract Res Clin Rheumatol ; 34(1): 101469, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31973938

RESUMO

Epidemiological studies reporting demographic, clinical and serological factors predictive of various outcomes in systemic sclerosis (SSc) range from the prediction of mortality to the development and progression of disease manifestations. However, predicting the disease trajectory in the individual patient is a challenging but important step towards a stratified approach to disease management. Recent technological advances provide the opportunity for new subgroupings of disease based on risk stratification, through the systematic analysis of high-dimensional clinical data combined with genes, their transcription products and their corresponding translated proteins. In addition, these variables offer a rich vein of research to identify non-invasive biomarkers for predicting organ involvement and to assess disease activity and response to therapy. Selection of patients with a clinical phenotype or molecular signature relevant to the therapy under study combined with recent efforts to standardise outcome measures, show promise for improving clinical trial design and the identification of effective targeted therapies.


Assuntos
Escleroderma Sistêmico , Biomarcadores , Progressão da Doença , Humanos , Prognóstico , Escleroderma Sistêmico/diagnóstico , Escleroderma Sistêmico/tratamento farmacológico , Escleroderma Sistêmico/genética
12.
Biochem Biophys Res Commun ; 523(4): 1001-1006, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-31973816

RESUMO

Remodelling of the extracellular matrix by myofibroblasts is crucial for wound repair, but if deregulated, it might contribute to the development of fibrosis. Fibroblast-to-myofibroblast differentiation is promoted by aberrant microRNA-145-5p (miR-145) expression in response to transforming growth factor ß1 (TGFß1). One of several myofibroblast markers is human xylosyltransferase-I (XT-I), which is the initial and rate-limiting enzyme of proteoglycan biosynthesis. Increased serum XT activity was quantified in patients with systemic sclerosis (SSc), but the underlying cellular mechanism of this disease remains unknown. This study aims to determine the underlying molecular basis of XT-I induction by considering the miR-mediated regulation of XT-I. We found that miR-145 is upregulated in TGFß1-treated dermal fibroblasts and correlates with an increased cellular XYLT1 expression and XT activity. Overexpression of miR-145 in dermal fibroblasts induced XYLT1 expression and XT activity and enhanced TGFß1-promoted XT activity increase. Since direct XYLT1 3'-UTR targeting by miR-145 could be experimentally excluded, an indirect effect of miR-145 on XT-I regulation was indicated. We identified six transcription factor-binding sites for Krueppel-like factor 4 (KLF4), a zinc-finger transcription regulator and putative miR-145 target, in the XYLT1 promoter in silico. A suppressive role of KLF4 on XYLT1 expression was confirmed by targeted gene silencing in dermal fibroblasts and the quantification of KLF4 expression in SSc fibroblasts. Taken together, this study improves the mechanistic understanding of fibrotic remodelling in SSc by identifying a hitherto unknown miR-145/KLF4 pathway mediating the fibrogenic XT-I induction. This knowledge on XYLT1 may lead to the development of novel approaches in the therapy of fibrosis.


Assuntos
Fatores de Transcrição Kruppel-Like/metabolismo , MicroRNAs/metabolismo , Pentosiltransferases/biossíntese , Sequência de Bases , Sítios de Ligação , Indução Enzimática , Humanos , MicroRNAs/genética , Miofibroblastos , Pentosiltransferases/genética , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Escleroderma Sistêmico/genética , Regulação para Cima/efeitos dos fármacos
13.
G3 (Bethesda) ; 10(1): 151-163, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31694854

RESUMO

Scleroderma, or systemic sclerosis (SSc), is an autoimmune disease characterized by progressive fibrosis of the skin and internal organs. The most common cause of death in people with SSc is lung disease, but the pathogenesis of lung disease in SSc is insufficiently understood to devise specific treatment strategies. Developing targeted treatments requires not only the identification of molecular processes involved in SSc-associated lung disease, but also understanding of how these processes interact to drive pathology. One potentially powerful approach is to identify alleles that interact genetically to influence lung outcomes in patients with SSc. Analysis of interactions, rather than individual allele effects, has the potential to delineate molecular interactions that are important in SSc-related lung pathology. However, detecting genetic interactions, or epistasis, in human cohorts is challenging. Large numbers of variants with low minor allele frequencies, paired with heterogeneous disease presentation, reduce power to detect epistasis. Here we present an analysis that increases power to detect epistasis in human genome-wide association studies (GWAS). We tested for genetic interactions influencing lung function and autoantibody status in a cohort of 416 SSc patients. Using Matrix Epistasis to filter SNPs followed by the Combined Analysis of Pleiotropy and Epistasis (CAPE), we identified a network of interacting alleles influencing lung function in patients with SSc. In particular, we identified a three-gene network comprising WNT5A, RBMS3, and MSI2, which in combination influenced multiple pulmonary pathology measures. The associations of these genes with lung outcomes in SSc are novel and high-confidence. Furthermore, gene coexpression analysis suggested that the interactions we identified are tissue-specific, thus differentiating SSc-related pathogenic processes in lung from those in skin.


Assuntos
Epistasia Genética , Estudo de Associação Genômica Ampla/métodos , Fibrose Pulmonar/genética , Escleroderma Sistêmico/genética , Feminino , Redes Reguladoras de Genes , Pleiotropia Genética , Humanos , Masculino , Fibrose Pulmonar/etiologia , Proteínas de Ligação a RNA/genética , Escleroderma Sistêmico/complicações , Transativadores/genética , Proteína Wnt-5a/genética
14.
J Invest Dermatol ; 140(2): 348-360.e11, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31421124

RESUMO

Both systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) are autoimmune diseases sharing similar genetic backgrounds. Genome-wide association studies have constantly disclosed numerous genetic variants conferring to both disease risks at 7q32.1, but the functional mechanisms underlying them are still largely unknown. Through a series of bioinformatics and functional analyses, we prioritized a potential independent functional single-nucleotide polymorphism (rs13239597) within TNPO3 promoter region, residing in a putative enhancer element and validated that IRF5 is the distal target gene (∼118 kb) of rs13239597, which is a key regulator involved in pathogenic autoantibody dysregulation, increasing risk of both SLE and SSc. We experimentally validated the long-range chromatin interactions between rs13239597 and IRF5 using chromosome conformation capture assay. We further demonstrated that rs13239597-A acted as an allele-specific enhancer regulating IRF5 expression, independently of TNPO3 by using dual-luciferase reporter assays and CRISPR-Cas9. Particularly, the transcription factor EVI1 could preferentially bind to rs13239597-A allele and increase the enhancer activity to regulate IRF5 expression. Taken together, our results uncovered a mechanistic insight of a noncoding functional variant acting as an allele-specific distal enhancer to directly modulate IRF5 expression, which might obligate in understanding of complex genetic architectures of SLE and SSc pathogenesis.


Assuntos
Cromatina/metabolismo , Fatores Reguladores de Interferon/genética , Lúpus Eritematoso Sistêmico/genética , Proteína do Locus do Complexo MDS1 e EVI1/metabolismo , Escleroderma Sistêmico/genética , Alelos , Imunoprecipitação da Cromatina , Cromossomos Humanos Par 7/genética , Biologia Computacional , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica , Predisposição Genética para Doença , Humanos , Desequilíbrio de Ligação , Lúpus Eritematoso Sistêmico/imunologia , Polimorfismo de Nucleotídeo Único/imunologia , Regiões Promotoras Genéticas/genética , Locos de Características Quantitativas/imunologia , Escleroderma Sistêmico/imunologia , beta Carioferinas/genética
15.
Arthritis Rheumatol ; 72(3): 477-487, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31509349

RESUMO

OBJECTIVE: Pulmonary arterial hypertension (PAH), one of the major complications of systemic sclerosis (SSc), is a rare disease with unknown etiopathogenesis and noncurative treatments. As mice deficient in P-selectin glycoprotein ligand 1 (PSGL-1) develop a spontaneous SSc-like syndrome, we undertook this study to analyze whether they develop PAH and to examine the molecular mechanisms involved. METHODS: Doppler echocardiography was used to estimate pulmonary pressure, immunohistochemistry was used to assess vascular remodeling, and myography of dissected pulmonary artery rings was used to analyze vascular reactivity. Angiotensin II (Ang II) levels were quantified by enzyme-linked immunosorbent assay, and Western blotting was used to measure Ang II type 1 receptor (AT1 R), AT2 R, endothelial cell nitric oxide synthase (eNOS), and phosphorylated eNOS expression in lung lysates. Flow cytometry allowed us to determine cytokine production by immune cells and NO production by endothelial cells. In all cases, there were 4-8 mice per experimental group. RESULTS: PSGL-1-/- mice showed lung vessel wall remodeling and a reduced mean ± SD expression of pulmonary AT2 R (expression ratio [relative to ß-actin] in female mice age >18 months: wild-type mice 0.799 ± 0.508 versus knockout mice 0.346 ± 0.229). With aging, female PSGL-1-/- mice had impaired up-regulation of estrogen receptor α (ERα) and developed lung vascular endothelial dysfunction coinciding with an increase in mean ± SEM pulmonary Ang II levels (wild-type 48.70 ± 5.13 pg/gm lung tissue versus knockout 78.02 ± 28.09 pg/gm lung tissue) and a decrease in eNOS phosphorylation, leading to reduced endothelial NO production. These events led to a reduction in the pulmonary artery acceleration time:ejection time ratio in 33% of aged female PSGL-1-/- mice, indicating pulmonary hypertension. Importantly, we found expanded populations of interferon-γ-producing PSGL-1-/- T cells and B cells and a reduced presence of regulatory T cells. CONCLUSION: The absence of PSGL-1 induces a reduction in Treg cells, NO production, and ERα expression and causes an increase in Ang II in the lungs of female mice, favoring the development of PAH.


Assuntos
Hipertensão Pulmonar/genética , Glicoproteínas de Membrana/deficiência , Escleroderma Sistêmico/genética , Angiotensina II/metabolismo , Animais , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Feminino , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase Tipo III/biossíntese , Remodelação Vascular/genética
16.
Arthritis Rheumatol ; 72(1): 137-149, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31350829

RESUMO

OBJECTIVE: Expression of dipeptidylpeptidase 4 (DPP-4) identifies a dermal fibroblast lineage involved in scarring during wound healing. The role of DDP-4 in tissue fibrosis is, however, unknown. The aim of the present study was to evaluate DPP-4 as a potential target for the treatment of fibrosis in patients with systemic sclerosis (SSc). METHODS: Expression of DPP-4 in skin biopsy samples and dermal fibroblasts was analyzed by real-time polymerase chain reaction, immunofluorescence, and Western blot analyses. The activity of DPP-4 was modulated by overexpression, knockdown, and pharmacologic inhibition of DPP4 using sitagliptin and vildagliptin. The effects of DPP4 inhibition were analyzed in human dermal fibroblasts and in different mouse models of SSc (each n = 6). RESULTS: The expression of DPP-4 and the number of DPP-4-positive fibroblasts were increased in the fibrotic skin of SSc patients, in a transforming growth factor ß (TGFß)-dependent manner. DPP-4-positive fibroblasts expressed higher levels of myofibroblast markers and collagen (each P < 0.001 versus healthy controls). Overexpression of DPP4 promoted fibroblast activation, whereas pharmacologic inhibition or genetic inactivation of DPP4 reduced the proliferation, migration, and expression of contractile proteins and release of collagen (each P < 0.001 versus control mice) by interfering with TGFß-induced ERK signaling. DPP4-knockout mice were less sensitive to bleomycin-induced dermal and pulmonary fibrosis (P < 0.0001 versus wild-type controls). Treatment with DPP4 inhibitors promoted regression of fibrosis in mice that had received bleomycin challenge and mice with chronic graft-versus-host disease, and ameliorated fibrosis in TSK1 mice (each P < 0.001 versus untreated controls). These antifibrotic effects were associated with a reduction in inflammation. CONCLUSION: DPP-4 characterizes a population of activated fibroblasts and shows that DPP-4 regulates TGFß-induced fibroblast activation in the fibrotic skin of SSc patients. Inhibition of DPP4 exerts potent antifibrotic effects when administered in well-tolerated doses. As DPP4 inhibitors are already in clinical use for diabetes, these results may have direct translational implications for the treatment of fibrosis in patients with SSc.


Assuntos
Dipeptidil Peptidase 4/metabolismo , Fibroblastos/metabolismo , Escleroderma Sistêmico/genética , Pele/metabolismo , Adulto , Idoso , Animais , Bleomicina/toxicidade , Movimento Celular , Proliferação de Células , Colágeno , Dipeptidil Peptidase 4/genética , Inibidores da Dipeptidil Peptidase IV/farmacologia , Modelos Animais de Doenças , Feminino , Fibrose , Imunofluorescência , Técnicas de Silenciamento de Genes , Doença Enxerto-Hospedeiro , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Miofibroblastos , Reação em Cadeia da Polimerase em Tempo Real , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia , Fosfato de Sitagliptina/farmacologia , Pele/efeitos dos fármacos , Pele/patologia , Fator de Crescimento Transformador beta , Vildagliptina/farmacologia
18.
Ann Rheum Dis ; 79(3): 370-378, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31818805

RESUMO

BACKGROUND: In this study, we investigated the impact of the new haemodynamic definition of pulmonary arterial hypertension (PAH) as proposed by the 6th PH World Symposium on phenotypes and survival in patients with systemic sclerosis (SSc). METHODS: In SSc patients who were prospectively and consecutively screened for PAH including right heart catheterisation in Heidelberg or Zurich, haemodynamic and clinical variables have been reassessed according to the new PAH definition. Patients have been followed for 3.7±3.7 (median 3.4) years; Kaplan-Meier survival analysis was performed. Patients with significant lung or left heart disease were excluded from comparative analyses. RESULTS: The final dataset included 284 SSc patients, 146 patients (49.2%) had mean pulmonary arterial pressure (mPAP) ≤20 mm Hg, 19.3% had mPAP 21-24 mm Hg and 29.4% had mPAP ≥25 mm Hg. In the group of mildly elevated mPAP, only four patients (1.4% of the whole SSc cohort) had pulmonary vascular resistance (PVR) values ≥3 Wood Units (WU) and could be reclassified as manifest SSc-APAH. Twenty-eight (9.8%) patients with mPAP of 21-24 mm Hg and PVR ≥2 WU already presented with early pulmonary vascular disease with decreased 6 min walking distance (6MWD) (p<0.001), TAPSE (p=0.004) and pulmonary arterial compliance (p<0.001). A PVR ≥2 WU was associated with reduced long-term survival (p=0.002). PVR and 6MWD were independent prognostic predictors in multivariate analysis. CONCLUSION: The data of this study show that a PVR threshold ≥3 WU is too high to enable an early diagnosis of PAH. A PVR threshold ≥2 WU was already associated with pulmonary vascular disease, significantly reduced survival and would be more appropriate in SSc patients with mild PAH.


Assuntos
Hemodinâmica/genética , Hipertensão Arterial Pulmonar/mortalidade , Escleroderma Sistêmico/mortalidade , Idoso , Pressão Arterial/genética , Feminino , Humanos , Estimativa de Kaplan-Meier , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fenótipo , Prognóstico , Estudos Prospectivos , Hipertensão Arterial Pulmonar/genética , Artéria Pulmonar/fisiopatologia , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/genética , Resistência Vascular/genética
19.
Am J Respir Crit Care Med ; 201(6): 650-660, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31841044

RESUMO

Systemic sclerosis (SSc) is a complex, multiorgan, autoimmune disease. Lung fibrosis occurs in ∼80% of patients with SSc; 25% to 30% develop progressive interstitial lung disease (ILD). The pathogenesis of fibrosis in SSc-associated ILD (SSc-ILD) involves cellular injury, activation/differentiation of mesenchymal cells, and morphological/biological changes in epithelial/endothelial cells. Risk factors for progressive SSc-ILD include older age, male sex, degree of lung involvement on baseline high-resolution computed tomography imaging, reduced DlCO, and reduced FVC. SSc-ILD does not share the genetic risk architecture observed in idiopathic pulmonary fibrosis (IPF), with key risk factors yet to be identified. Presence of anti-Scl-70 antibodies and absence of anti-centromere antibodies indicate increased likelihood of progressive ILD. Elevated levels of serum Krebs von den Lungen-6 and C-reactive protein are both associated with SSc-ILD severity and predict SSc-ILD progression. A promising prognostic indicator is serum chemokine (C-C motif) ligand 18. SSc-ILD shares similarities with IPF, although clear differences exist. Histologically, a nonspecific interstitial pneumonia pattern is commonly observed in SSc-ILD, whereas IPF is defined by usual interstitial pneumonia. The course of SSc-ILD is variable, ranging from minor, stable disease to a progressive course, whereas all patients with IPF experience progression of disease. Although appropriately treated patients with SSc-ILD have better chances of stabilization and survival, a relentlessly progressive course, akin to IPF, is seen in a minority. Better understanding of cellular and molecular pathogenesis, genetic risk, and distinctive features of SSc-ILD and identification of robust prognostic biomarkers are needed for optimal disease management.


Assuntos
Biomarcadores/sangue , Currículo , Educação Médica Continuada/organização & administração , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/genética , Escleroderma Sistêmico/etiologia , Escleroderma Sistêmico/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Predisposição Genética para Doença , Humanos , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Escleroderma Sistêmico/fisiopatologia
20.
Proc Natl Acad Sci U S A ; 117(1): 552-562, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31871193

RESUMO

Systemic sclerosis (SSc) is a clinically heterogeneous autoimmune disease characterized by mutually exclusive autoantibodies directed against distinct nuclear antigens. We examined HLA associations in SSc and its autoantibody subsets in a large, newly recruited African American (AA) cohort and among European Americans (EA). In the AA population, the African ancestry-predominant HLA-DRB1*08:04 and HLA-DRB1*11:02 alleles were associated with overall SSc risk, and the HLA-DRB1*08:04 allele was strongly associated with the severe antifibrillarin (AFA) antibody subset of SSc (odds ratio = 7.4). These African ancestry-predominant alleles may help explain the increased frequency and severity of SSc among the AA population. In the EA population, the HLA-DPB1*13:01 and HLA-DRB1*07:01 alleles were more strongly associated with antitopoisomerase (ATA) and anticentromere antibody-positive subsets of SSc, respectively, than with overall SSc risk, emphasizing the importance of HLA in defining autoantibody subtypes. The association of the HLA-DPB1*13:01 allele with the ATA+ subset of SSc in both AA and EA patients demonstrated a transancestry effect. A direct correlation between SSc prevalence and HLA-DPB1*13:01 allele frequency in multiple populations was observed (r = 0.98, P = 3 × 10-6). Conditional analysis in the autoantibody subsets of SSc revealed several associated amino acid residues, mostly in the peptide-binding groove of the class II HLA molecules. Using HLA α/ß allelic heterodimers, we bioinformatically predicted immunodominant peptides of topoisomerase 1, fibrillarin, and centromere protein A and discovered that they are homologous to viral protein sequences from the Mimiviridae and Phycodnaviridae families. Taken together, these data suggest a possible link between HLA alleles, autoantibodies, and environmental triggers in the pathogenesis of SSc.


Assuntos
Autoanticorpos/imunologia , Autoantígenos/genética , Antígenos HLA/genética , Mimetismo Molecular/imunologia , Escleroderma Sistêmico/genética , Afro-Americanos/genética , Alelos , Sequência de Aminoácidos/genética , Antígenos Virais/genética , Antígenos Virais/imunologia , Autoantígenos/imunologia , Biologia Computacional , Conjuntos de Dados como Assunto , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Predisposição Genética para Doença , Antígenos HLA/imunologia , Humanos , Masculino , Mimiviridae/imunologia , Phycodnaviridae/imunologia , Estrutura Secundária de Proteína/genética , Medição de Risco , Escleroderma Sistêmico/epidemiologia , Escleroderma Sistêmico/imunologia , Homologia de Sequência de Aminoácidos
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