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BACKGROUND & AIMS: Biomarkers that integrate genetic and environmental factors and predict outcome in complex immune diseases such as inflammatory bowel disease (IBD; including Crohn's disease [CD] and ulcerative colitis [UC]) are needed. We showed that morphologic patterns of ileal Paneth cells (Paneth cell phenotype [PCP]; a surrogate for PC function) is one such cellular biomarker for CD. Given the shared features between CD and UC, we hypothesized that PCP is also associated with molecular/genetic features and outcome in UC. Because PC density is highest in the ileum, we further hypothesized that PCP predicts outcome in UC subjects who underwent total colectomy and ileal pouch-anal anastomosis (IPAA). METHODS: Uninflamed ileal resection margins from UC subjects with colectomy and IPAA were used for PCP and transcriptomic analyses. PCP was defined using defensin 5 immunofluorescence. Genotyping was performed using Immunochip. UC transcriptomic and genotype associations of PCP were incorporated with data from CD subjects to identify common IBD-related pathways and genes that regulate PCP. RESULTS: The prevalence of abnormal ileal PCP was 27%, comparable to that seen in CD. Combined analysis of UC and CD subjects showed that abnormal PCP was associated with transcriptomic pathways of secretory granule maturation and polymorphisms in innate immunity genes. Abnormal ileal PCP at the time of colectomy was also associated with pouch complications including de novo CD in the pouch and time to first episode of pouchitis. CONCLUSIONS: Ileal PCP is biologically and clinically relevant in UC and can be used as a biomarker in IBD.
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Environmental enteric dysfunction (EED) is a diffuse small bowel disorder associated with poor growth, inadequate responses to oral vaccines, and nutrient malabsorption in millions of children worldwide. We identify loss of the small intestinal Paneth and goblet cells that are critical for innate immunity, reduced villous height, increased bile acids, and dysregulated nicotinamide adenine dinucleotide (NAD+) synthesis signaling as potential mechanisms underlying EED and which also correlated with diminished length-for-age z score. Isocaloric low-protein diet (LPD) consumption in mice recapitulated EED histopathology and transcriptomic changes in a microbiota-independent manner, as well as increases in serum and fecal bile acids. Children with refractory EED harbor single-nucleotide polymorphisms in key enzymes involved in NAD+ synthesis. In mice, deletion of Nampt, the gene encoding the rate-limiting enzyme in the NAD+ salvage pathway, from intestinal epithelium also reduced Paneth cell function, a deficiency that was further aggravated by LPD. Separate supplementation with NAD+ precursors or bile acid sequestrant partially restored LPD-associated Paneth cell defects and, when combined, fully restored all histopathology defects in LPD-fed mice. Therapeutic regimens that increase protein and NAD+ contents while reducing excessive bile acids may benefit children with refractory EED.
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Ácidos e Sais Biliares , NAD , Humanos , Criança , Camundongos , Animais , NAD/genética , NAD/metabolismo , Citocinas/metabolismoRESUMO
Tuberculosis remains an international health threat partly because of limited protection from pulmonary tuberculosis provided by standard intradermal vaccination with Bacillus of Calmette and Guérin (BCG); this may reflect the inability of intradermal vaccination to optimally induce pulmonary immunity. In contrast, respiratory Mycobacterium tuberculosis infection usually results in the immune-mediated bacillary containment of latent tuberculosis infection (LTBI). Here we present RNA-Seq-based assessments of systemic and pulmonary immune cells from LTBI participants and recipients of intradermal and oral BCG. LTBI individuals uniquely display ongoing immune activation and robust CD4 T cell recall responses in blood and lung. Intradermal BCG is associated with robust systemic immunity but only limited pulmonary immunity. Conversely, oral BCG induces limited systemic immunity but distinct pulmonary responses including enhanced inflammasome activation potentially associated with mucosal-associated invariant T cells. Further, IL-9 is identified as a component of systemic immunity in LTBI and intradermal BCG, and pulmonary immunity following oral BCG.
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Tuberculose Latente , Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculose , Humanos , Vacina BCG , Mycobacterium tuberculosis/genética , Transcriptoma , Tuberculose/prevenção & controle , VacinaçãoRESUMO
NEW FINDINGS: What is the central question of this study? Non-responsive stunting is characterised by a progressive decline of circulating glucagon-like peptide 2: what are the possible causes of this decline? What is the main finding and its importance? In contrast with the established loss of Paneth and goblet cells in environmental enteropathy, there was no evidence of a parallel loss of enteroendocrine cells as seen by positive tissue staining for chromogranin A. Transcriptomic and genomic analyses showed evidence of genetic transcripts that could account for some of the variability seen in circulating glucagon-like peptide 2 values. ABSTRACT: Nutrient sensing determines digestive and hormonal responses following nutrient ingestion. We have previously reported decreased levels of glucagon-like peptide 2 (GLP-2) in children with stunting. Here we demonstrate the presence of enteroendocrine cells in stunted children and explore potential pathways that may be involved in reduced circulating levels of GLP-2. At the time of performing diagnostic endoscopies for non-responsive stunted children, intestinal biopsies were collected for immunofluorescence staining of enteroendocrine cells and transcriptomic analysis. Circulating levels of GLP-2 were also measured and correlated with transcriptomic data. An exploratory genome-wide association study (GWAS) was conducted on DNA samples (n = 158) to assess genetic contribution to GLP-2 variability. Intestinal tissue sections collected from non-responsive stunted children stained positive for chromogranin A (88/89), alongside G-protein-coupled receptors G-protein receptor 119 (75/87), free fatty acid receptor 3 (76/89) and taste 1 receptor 1 (39/45). Transcriptomic analysis found three pathways correlated with circulating GLP-2: sugar metabolism, epithelial transport, and barrier function, which likely reflect downstream events following receptor-ligand interaction. GWAS analysis revealed potential genetic contributions to GLP-2 half-life and receptor binding. Enteroendocrine cell loss was not identified in stunted Zambian children as has been observed for goblet and Paneth cells. Transcriptomic analysis suggests that GLP-2 has pleiotrophic actions on the intestinal mucosa in malnutrition, but further work is needed to dissect pathways leading to perturbations in nutrient sensing.
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Estudo de Associação Genômica Ampla , Peptídeo 2 Semelhante ao Glucagon , Transtornos do Crescimento , Criança , Humanos , Cromogranina A , Transtornos do Crescimento/metabolismo , ZâmbiaRESUMO
Enterotoxigenic E. coli (ETEC) produce heat-labile (LT) and/or heat-stable (ST) enterotoxins, and commonly cause diarrhea in resource-poor regions. ETEC have been linked repeatedly to sequelae in children including enteropathy, malnutrition, and growth impairment. Although cellular actions of ETEC enterotoxins leading to diarrhea are well-established, their contributions to sequelae remain unclear. LT increases cellular cAMP to activate protein kinase A (PKA) that phosphorylates ion channels driving intestinal export of salt and water resulting in diarrhea. As PKA also modulates transcription of many genes, we interrogated transcriptional profiles of LT-treated intestinal epithelia. Here we show that LT significantly alters intestinal epithelial gene expression directing biogenesis of the brush border, the major site for nutrient absorption, suppresses transcription factors HNF4 and SMAD4 critical to enterocyte differentiation, and profoundly disrupts microvillus architecture and essential nutrient transport. In addition, ETEC-challenged neonatal mice exhibit substantial brush border derangement that is prevented by maternal vaccination with LT. Finally, mice repeatedly challenged with toxigenic ETEC exhibit impaired growth recapitulating the multiplicative impact of recurring ETEC infections in children. These findings highlight impacts of ETEC enterotoxins beyond acute diarrheal illness and may inform approaches to prevent major sequelae of these common infections including malnutrition that impact millions of children.
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Escherichia coli Enterotoxigênica , Infecções por Escherichia coli , Proteínas de Escherichia coli , Desnutrição , Camundongos , Animais , Enterotoxinas/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli Enterotoxigênica/genética , Escherichia coli Enterotoxigênica/metabolismo , Infecções por Escherichia coli/prevenção & controle , DiarreiaRESUMO
Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Prior studies examining the mutational landscape of GBM revealed recurrent alterations in genes that regulate the same growth control pathways. To this regard, ~ 40% of GBM harbor EGFR alterations, whereas BRAF variants are rare. Existing data suggests that gain-of-function mutations in these genes are mutually exclusive. This study was designed to explore the clinical, pathological, and molecular differences between EGFR- and BRAF-mutated GBM. We reviewed retrospective clinical data from 89 GBM patients referred for molecular testing between November 2012 and December 2015. Differences in tumor mutational profile, location, histology, and survival outcomes were compared in patients with EGFR- versus BRAF-mutated tumors, and microarray data from The Cancer Genome Atlas was used to assess differential gene expression between the groups. Individuals with BRAF-mutant tumors were typically younger and survived longer relative to those with EGFR-mutant tumors, even in the absence of targeted treatments. BRAF-mutant tumors lacked distinct histomorphology but exhibited unique localization in the brain, typically arising adjacent to the lateral ventricles. Compared to EGFR- and IDH1-mutant tumors, BRAF-mutant tumors showed increased expression of genes related to a trophoblast-like phenotype, specifically HLA-G and pregnancy specific glycoproteins, that have been implicated in invasion and immune evasion. Taken together, these observations suggest a distinct clinical presentation, brain location, and gene expression profile for BRAF-mutant tumors. Pending further study, this may prove useful in the stratification and management of GBM.
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Neoplasias Encefálicas/genética , Receptores ErbB/genética , Glioblastoma/genética , Proteínas Proto-Oncogênicas B-raf/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/patologia , Criança , Feminino , Perfilação da Expressão Gênica , Genes MHC Classe I/genética , Glioblastoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estudos RetrospectivosRESUMO
BACKGROUND: Environmental enteropathy (EE) contributes to growth failure in millions of children worldwide, but its relationship to clinical malnutrition has not been elucidated. We used RNA sequencing to compare duodenal biopsies from adults and children with EE, and from children with severe acute malnutrition (SAM), to define key features of these malnutrition-related enteropathies. METHODS: RNA was extracted and sequenced from biopsies of children with SAM in hospital (n=27), children with non-responsive stunting in the community (n=30), and adults living in the same community (n=37) using an identical sequencing and analysis pipeline. Two biopsies each were profiled and differentially expressed genes (DEGs) were computed from the comparisons of the three groups. DEG lists from these comparisons were then subjected to analysis with CompBio software to assemble a holistic view of the biological landscape and IPA software to interrogate canonical pathways. FINDINGS: Dysregulation was identified in goblet cell/mucin production and xenobiotic metabolism/detoxification for both cohorts of children, versus adults. Within the SAM cohort, substantially greater induction of immune response and barrier function, including NADPH oxidases was noted, concordant with broadly reduced expression of genes associated with the brush border and intestinal structure/transport/absorption. Interestingly, down regulation of genes associated with the hypothalamic-pituitary-adrenal axis was selectively observed within the cohort of children with stunting. INTERPRETATION: Gene expression profiles in environmental enteropathy and severe acute malnutrition have similarities, but SAM has several distinct transcriptional features. The intestinal capacity to metabolise drugs and toxins in malnourished children requires further study. FUNDING: Bill & Melinda Gates Foundation (OPP1066118).
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Enteropatias/genética , Desnutrição/complicações , Transcriptoma , Adulto , Pré-Escolar , Feminino , Células Caliciformes/metabolismo , Humanos , Lactente , Enteropatias/etiologia , Enteropatias/metabolismo , Masculino , Mucinas/genética , Mucinas/metabolismo , ZâmbiaRESUMO
Intestinal Paneth cells modulate innate immunity and infection. In Crohn's disease, genetic mutations together with environmental triggers can disable Paneth cell function. Here, we find that a western diet (WD) similarly leads to Paneth cell dysfunction through mechanisms dependent on the microbiome and farnesoid X receptor (FXR) and type I interferon (IFN) signaling. Analysis of multiple human cohorts suggests that obesity is associated with Paneth cell dysfunction. In mouse models, consumption of a WD for as little as 4 weeks led to Paneth cell dysfunction. WD consumption in conjunction with Clostridium spp. increased the secondary bile acid deoxycholic acid levels in the ileum, which in turn inhibited Paneth cell function. The process required excess signaling of both FXR and IFN within intestinal epithelial cells. Our findings provide a mechanistic link between poor diet and inhibition of gut innate immunity and uncover an effect of FXR activation in gut inflammation.
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Dieta Ocidental/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Interferon Tipo I/metabolismo , Obesidade/metabolismo , Celulas de Paneth/efeitos dos fármacos , Celulas de Paneth/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Ácidos e Sais Biliares/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Imunidade Inata/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Transdução de SinaisRESUMO
BACKGROUND: A non-synonymous single nucleotide polymorphism of the ATG16L1 gene, T300A, is a major Crohn's disease (CD) susceptibility allele, and is known to be associated with increased apoptosis induction in the small intestinal crypt base in CD subjects and mouse models. We hypothesized that ATG16L1 T300A genotype also correlates with increased tumor apoptosis and therefore could lead to superior clinical outcome in cancer subjects. METHODS: T300A genotyping by Taqman assay was performed for gastric carcinoma subjects who underwent resection from two academic medical centers. Transcriptomic analysis was performed by RNA-seq on formalin-fixed paraffin-embedded cancerous tissue. Tumor apoptosis and autophagy were determined by cleaved caspase-3 and p62 immunohistochemistry, respectively. The subjects' genotypes were correlated with demographics, various histopathologic features, transcriptome, and clinical outcome. FINDINGS: Of the 220 genotyped subjects, 163 (74%) subjects carried the T300A allele(s), including 55 (25%) homozygous and 108 (49%) heterozygous subjects. The T300A/T300A subjects had superior overall survival than the other groups. Their tumors were associated with increased CD-like lymphoid aggregates and increased tumor apoptosis without concurrent increase in tumor mitosis or defective autophagy. Transcriptomic analysis showed upregulation of WNT/ß-catenin signaling and downregulation of PPAR, EGFR, and inflammatory chemokine pathways in tumors of T300A/T300A subjects. INTERPRETATION: Gastric carcinoma of subjects with the T300A/T300A genotype is associated with repressed EGFR and PPAR pathways, increased tumor apoptosis, and improved overall survival. Genotyping gastric cancer subjects may provide additional insight for clinical stratification.
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Proteínas Relacionadas à Autofagia/genética , Carcinoma/genética , Doença de Crohn/genética , Genótipo , Neoplasias Gástricas/genética , Idoso , Idoso de 80 Anos ou mais , Apoptose , Autofagia , Carcinoma/metabolismo , Carcinoma/patologia , Quimiocinas/genética , Quimiocinas/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , PPAR gama/genética , PPAR gama/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Análise de Sobrevida , Transcriptoma , Via de Sinalização WntRESUMO
BACKGROUND: Children with severe acute malnutrition (SAM), with or without diarrhoea, often have enteropathy, but there are few molecular data to guide development of new therapies. We set out to determine whether SAM enteropathy is characterised by specific transcriptional changes which might improve understanding or help identify new treatments. METHODS: We collected intestinal biopsies from children with SAM and persistent diarrhoea. mRNA was extracted from biopsies, sequenced, and subjected to a progressive set of complementary analytical approaches: NOIseq, Gene Set Enrichment Analysis (GSEA), and correlation analysis of phenotypic data with gene expression. FINDINGS: Transcriptomic profiles were generated for biopsy sets from 27 children of both sexes, under 2â¯years of age, of whom one-third were HIV-infected. NOIseq analysis, constructed from phenotypic group extremes, revealed 66 differentially expressed genes (DEGs) out of 21,386 mapped to the reference genome. These DEGs include genes for mucins and mucus integrity, antimicrobial defence, nutrient absorption, C-X-C chemokines, proteases and anti-proteases. Phenotype - expression correlation analysis identified 1221 genes related to villus height, including increased cell cycling gene expression in more severe enteropathy. Amino acid transporters and ZIP zinc transporters were specifically increased in severe enteropathy, but transcripts for xenobiotic metabolising enzymes were reduced. INTERPRETATION: Transcriptomic analysis of this rare collection of intestinal biopsies identified multiple novel elements of pathology, including specific alterations in nutrient transporters. Changes in xenobiotic metabolism in the gut may alter drug disposition. Both NOIseq and GSEA identified gene clusters similar to those differentially expressed in pediatric Crohn's disease but to a much lesser degree than those identified in coeliac disease. FUND: Bill & Melinda Gates Foundation OPP1066118. The funding agency had no role in study design, data collection, data analysis, interpretation, or writing of the report.
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Diarreia/genética , Enteropatias/genética , Desnutrição Aguda Grave/genética , Transcriptoma/genética , Biópsia , Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , Lactente , Enteropatias/epidemiologia , Enteropatias/patologia , Mucosa Intestinal/metabolismo , Masculino , Análise de Sequência de RNA , Desnutrição Aguda Grave/epidemiologia , Desnutrição Aguda Grave/patologia , Zâmbia/epidemiologiaRESUMO
OBJECTIVE: The mechanistic link between Janus kinase (JAK) signaling and structural damage to arthritic joints in rheumatoid arthritis (RA) is poorly understood. This study was undertaken to investigate how selective inhibition of JAK with tofacitinib (CP-690,550) affects osteoclast-mediated bone resorption in a rat adjuvant-induced arthritis (AIA) model, as well as human T lymphocyte RANKL production and human osteoclast differentiation and function. METHODS: Hind paw edema, inflammatory cell infiltration, and osteoclast-mediated bone resorption in rat AIA were assessed using plethysmography, histopathologic analysis, and immunohistochemistry; plasma and hind paw tissue levels of cytokines and chemokines (including RANKL) were also assessed. In vitro RANKL production by activated human T lymphocytes was evaluated by immunoassay, while human osteoclast differentiation and function were assessed via quantitative tartrate-resistant acid phosphatase staining and degradation of human bone collagen, respectively. RESULTS: Edema, inflammation, and osteoclast-mediated bone resorption in rats with AIA were dramatically reduced after 7 days of treatment with the JAK inhibitor, which correlated with reduced numbers of CD68/ED-1+, CD3+, and RANKL+ cells in the paws; interleukin-6 (transcript and protein) levels were rapidly reduced in paw tissue within 4 hours of the first dose, whereas it took 4-7 days of therapy for RANKL levels to decrease. Tofacitinib did not impact human osteoclast differentiation or function, but did decrease human T lymphocyte RANKL production in a concentration-dependent manner. CONCLUSION: These results suggest that the JAK inhibitor tofacitinib suppresses osteoclast-mediated structural damage to arthritic joints, and this effect is secondary to decreased RANKL production.
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Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Janus Quinases/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Ligante RANK/metabolismo , Animais , Artrite Experimental/imunologia , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/imunologia , Reabsorção Óssea/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Feminino , Humanos , Janus Quinases/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/enzimologia , Piperidinas , Ratos , Ratos Endogâmicos Lew , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/enzimologiaRESUMO
Inhibitors of the JAK family of nonreceptor tyrosine kinases have demonstrated clinical efficacy in rheumatoid arthritis and other inflammatory disorders; however, the precise mechanisms by which JAK inhibition improves inflammatory immune responses remain unclear. In this study, we examined the mode of action of tofacitinib (CP-690,550) on JAK/STAT signaling pathways involved in adaptive and innate immune responses. To determine the extent of inhibition of specific JAK/STAT-dependent pathways, we analyzed cytokine stimulation of mouse and human T cells in vitro. We also investigated the consequences of CP-690,550 treatment on Th cell differentiation of naive murine CD4(+) T cells. CP-690,550 inhibited IL-4-dependent Th2 cell differentiation and interestingly also interfered with Th17 cell differentiation. Expression of IL-23 receptor and the Th17 cytokines IL-17A, IL-17F, and IL-22 were blocked when naive Th cells were stimulated with IL-6 and IL-23. In contrast, IL-17A production was enhanced when Th17 cells were differentiated in the presence of TGF-ß. Moreover, CP-690,550 also prevented the activation of STAT1, induction of T-bet, and subsequent generation of Th1 cells. In a model of established arthritis, CP-690,550 rapidly improved disease by inhibiting the production of inflammatory mediators and suppressing STAT1-dependent genes in joint tissue. Furthermore, efficacy in this disease model correlated with the inhibition of both JAK1 and JAK3 signaling pathways. CP-690,550 also modulated innate responses to LPS in vivo through a mechanism likely involving the inhibition of STAT1 signaling. Thus, CP-690,550 may improve autoimmune diseases and prevent transplant rejection by suppressing the differentiation of pathogenic Th1 and Th17 cells as well as innate immune cell signaling.
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Imunidade Adaptativa , Artrite Experimental/imunologia , Proteínas Aviárias/toxicidade , Colágeno Tipo II/toxicidade , Imunidade Inata , Pirimidinas/administração & dosagem , Pirróis/administração & dosagem , Imunidade Adaptativa/genética , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/enzimologia , Células Cultivadas , Galinhas , Humanos , Imunidade Inata/genética , Janus Quinase 3/antagonistas & inibidores , Janus Quinase 3/deficiência , Janus Quinase 3/genética , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/imunologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Piperidinas , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Pirróis/uso terapêuticoRESUMO
In this study, a chronic yet synchronized version of the K/BxN mouse, the KRN-cell transfer model (KRN-CTM), was developed and extensively characterized. The transfer of purified splenic KRN T cells into T cell-deficient B6.TCR.Calpha(-/-)H-2(b/g7) mice induced anti-glucose 6-phosphate isomerase antibody-dependent chronic arthritis in 100% of the mice with uniform onset of disease 7 days after T cell transfer. Cellular infiltrations were assessed by whole-ankle transcript microarray, cytokine and chemokine levels, and microscopic and immunohistochemical analyses 7 through 42 days after T cell transfer. Transcripts identified an influx of monocytes/macrophages and neutrophils into the ankles and identified temporal progression of cartilage damage and bone resorption. In both serum and ankle tissue there was a significant elevation in interleukin-6, whereas macrophage inflammatory protein-1 alpha and monocyte chemotactic protein-1 were only elevated in tissue. Microscopic and immunohistochemical analyses revealed a time course for edema, synovial hypertrophy and hyperplasia, infiltration of F4/80-positive monocytes/macrophages and myeloperoxidase-positive neutrophils, destruction of articular cartilage, pannus invasion, bone resorption, extra-articular fibroplasia, and joint ankylosis. The KRN cell transfer model replicates many features of chronic rheumatoid arthritis in humans in a synchronized manner and lends itself to manipulation of adoptively transferred T cells and characterizing specific genes and T cell subsets responsible for rheumatoid arthritis pathogenesis and progression.
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Artrite Reumatoide/patologia , Modelos Animais de Doenças , Articulações/patologia , Linfócitos T/patologia , Linfócitos T/transplante , Animais , Artrite Reumatoide/etiologia , Artrite Reumatoide/metabolismo , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imuno-Histoquímica , Inflamação , Articulações/metabolismo , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Camundongos Transgênicos , Monócitos/metabolismo , Monócitos/patologia , Linfócitos T/metabolismoRESUMO
In this report, we show that apoptosis signal-regulating kinase 1(-/-) (ASK1 KO) mice were resistant to inflammatory arthritis induced in the K/BxN serum transfer model of rheumatoid arthritis (RA). The p38 inhibitor, SD-0006 was administered to wild type (WT) mice as a comparator. Both ASK1 KO and p38 inhibition resulted in marked attenuation of edema, cartilage damage, bone resorption, and general inflammatory responses. Transcriptional profiling of mRNA prepared from paw tissue demonstrated that the production of many proinflammatory genes including cytokines, chemokines, and extracellular matrix degradative enzymes were maintained at basal levels by either ASK1 KO or prophylactic p38 MAPK inhibition. In the mouse whole blood (MWB) assay, tumor necrosis factor-α (TNF-α)-induced KC and CCL2 levels and also LPS-induced interleukin-6 (IL-6), CCL2, and KC levels in MWB from ASK1 KO were significantly lower than those from WT. Furthermore, both p38 and JNK were activated by TNF-α in human synovial fibroblasts isolated from RA patients (RASF). SD-0006 or SP600125, a JNK inhibitor, partially blocked the elevation of IL-6 production in RASF following stimulation with TNF-α. In contrast, dual inhibition with both p38/JNK inhibitors almost completely abolished TNF-α-induced IL-6 production from these cells. Ablation of ASK1 expression in RASF using siRNA for ASK1 resulted in inhibition of TNF-α-induced IL-6 and PGE(2) production. This study is the first to suggest that ASK1 is critical for the development of RA and that ASK1 may be involved in the production of proinflammatory mediators in response to TNF-α stimulation in the RA joint.
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Apoptose/fisiologia , Artrite/induzido quimicamente , MAP Quinase Quinase Quinase 5/metabolismo , Animais , Artrite/patologia , Artrite Reumatoide/metabolismo , Células Cultivadas , Dinoprostona/genética , Dinoprostona/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Humanos , Interleucina-6 , MAP Quinase Quinase Quinase 5/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pirazóis/toxicidade , Pirimidinas/toxicidade , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
It is unclear why disease occurs in only a small proportion of persons carrying common risk alleles of disease susceptibility genes. Here we demonstrate that an interaction between a specific virus infection and a mutation in the Crohn's disease susceptibility gene Atg16L1 induces intestinal pathologies in mice. This virus-plus-susceptibility gene interaction generated abnormalities in granule packaging and unique patterns of gene expression in Paneth cells. Further, the response to injury induced by the toxic substance dextran sodium sulfate was fundamentally altered to include pathologies resembling aspects of Crohn's disease. These pathologies triggered by virus-plus-susceptibility gene interaction were dependent on TNFalpha and IFNgamma and were prevented by treatment with broad spectrum antibiotics. Thus, we provide a specific example of how a virus-plus-susceptibility gene interaction can, in combination with additional environmental factors and commensal bacteria, determine the phenotype of hosts carrying common risk alleles for inflammatory disease.