RESUMO
Intestinal mucus forms the first line of defense against bacterial invasion while providing nutrition to support microbial symbiosis. How the host controls mucus barrier integrity and commensalism is unclear. We show that terminal sialylation of glycans on intestinal mucus by ST6GALNAC1 (ST6), the dominant sialyltransferase specifically expressed in goblet cells and induced by microbial pathogen-associated molecular patterns, is essential for mucus integrity and protecting against excessive bacterial proteolytic degradation. Glycoproteomic profiling and biochemical analysis of ST6 mutations identified in patients show that decreased sialylation causes defective mucus proteins and congenital inflammatory bowel disease (IBD). Mice harboring a patient ST6 mutation have compromised mucus barriers, dysbiosis, and susceptibility to intestinal inflammation. Based on our understanding of the ST6 regulatory network, we show that treatment with sialylated mucin or a Foxo3 inhibitor can ameliorate IBD.
Assuntos
Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Sialiltransferases/genética , Animais , Homeostase , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Camundongos , Muco/metabolismo , Sialiltransferases/metabolismo , SimbioseRESUMO
Transcription factors specialized to limit the destructive potential of inflammatory immune cells remain ill-defined. We discovered loss-of-function variants in the X-linked ETS transcription factor gene ELF4 in multiple unrelated male patients with early onset mucosal autoinflammation and inflammatory bowel disease (IBD) characteristics, including fevers and ulcers that responded to interleukin-1 (IL-1), tumor necrosis factor or IL-12p40 blockade. Using cells from patients and newly generated mouse models, we uncovered ELF4-mutant macrophages having hyperinflammatory responses to a range of innate stimuli. In mouse macrophages, Elf4 both sustained the expression of anti-inflammatory genes, such as Il1rn, and limited the upregulation of inflammation amplifiers, including S100A8, Lcn2, Trem1 and neutrophil chemoattractants. Blockade of Trem1 reversed inflammation and intestine pathology after in vivo lipopolysaccharide challenge in mice carrying patient-derived variants in Elf4. Thus, ELF4 restrains inflammation and protects against mucosal disease, a discovery with broad translational relevance for human inflammatory disorders such as IBD.
Assuntos
Proteínas de Ligação a DNA/genética , Doenças Hereditárias Autoinflamatórias/genética , Doenças Inflamatórias Intestinais/genética , Macrófagos/imunologia , Fatores de Transcrição/genética , Animais , Calgranulina A/metabolismo , Feminino , Regulação da Expressão Gênica/genética , Doenças Hereditárias Autoinflamatórias/imunologia , Doenças Hereditárias Autoinflamatórias/patologia , Humanos , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Proteína Antagonista do Receptor de Interleucina 1/imunologia , Lipocalina-2/metabolismo , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Th17/imunologia , Transcrição Gênica/genética , Receptor Gatilho 1 Expresso em Células Mieloides/antagonistas & inibidores , Receptor Gatilho 1 Expresso em Células Mieloides/metabolismoRESUMO
Immune cells survey their microenvironment by forming dynamic cellular protrusions that enable chemotaxis, contacts with other cells, and phagocytosis. Podosomes are a unique type of protrusion structured by an adhesive ring of active integrins that surround an F-actin-rich core harboring degradative proteases. Although the features of podosomes, once-established, have been well defined, the steps that lead to podosome formation remain poorly understood by comparison. In this study, we report that spleen tyrosine kinase (Syk) is a critical regulator of podosome formation. Deletion of Syk or targeting its kinase activity eliminated the ability for murine macrophages to form podosomes. We found that the kinase activity of Syk was important for the phosphorylation of its substrates, HS1 and Pyk2, both of which regulate podosome formation. Additionally, before podosomes form, we report that the tandem Src homology 2 domains of Syk afforded multivalent clustering of ITAM-containing adaptors that associated with integrins to structure platforms that initiate podosomes. We therefore propose that Syk has a dual role in regulating podosomes: first, by facilitating the assembly of multivalent signaling hubs that nucleate their formation and second, by sustaining tyrosine kinase activity of the podosomes once they form against their substrates. In cells expressing recently identified gain-of-function variants of SYK, podosomes were dysregulated. These results implicate SYK in the (patho)physiological functions of podosomes in macrophages.
RESUMO
Defining monogenic drivers of autoinflammatory syndromes elucidates mechanisms of disease in patients with these inborn errors of immunity and can facilitate targeted therapeutic interventions. Here, we describe a cohort of patients with a Behçet's- and inflammatory bowel disease (IBD)-like disorder termed "deficiency in ELF4, X-linked" (DEX) affecting males with loss-of-function variants in the ELF4 transcription factor gene located on the X chromosome. An international cohort of fourteen DEX patients was assessed to identify unifying clinical manifestations and diagnostic criteria as well as collate findings informing therapeutic responses. DEX patients exhibit a heterogeneous clinical phenotype including weight loss, oral and gastrointestinal aphthous ulcers, fevers, skin inflammation, gastrointestinal symptoms, arthritis, arthralgia, and myalgia, with findings of increased inflammatory markers, anemia, neutrophilic leukocytosis, thrombocytosis, intermittently low natural killer and class-switched memory B cells, and increased inflammatory cytokines in the serum. Patients have been predominantly treated with anti-inflammatory agents, with the majority of DEX patients treated with biologics targeting TNFα.
Assuntos
Artrite , Síndrome de Behçet , Produtos Biológicos , Doenças Inflamatórias Intestinais , Masculino , Humanos , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/genética , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/genética , Artralgia , Proteínas de Ligação a DNA , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Long-term outcomes of congenital diarrheas and enteropathies (CODE) are poorly described. We evaluated the morbidity and mortality of children with CODE followed by an intestinal rehabilitation program (IRP) compared to children with short bowel syndrome (SBS). METHODS: Matched case-control study of children with intestinal failure (IF) due to CODE (diagnosed between 2006 and 2020; N = 15) and SBS (N = 42), matched 1:3, based on age at diagnosis and duration of parenteral nutrition (PN). Nutritional status, growth, and IF-related complications were compared. Survival and enteral autonomy were compared to a nonmatched SBS cohort (N = 177). RESULTS: Fifteen CODE patients (five males, median age 3.2 years) were followed for a median of 2.9 years. Eleven children were alive at the end of the follow-up, and two achieved enteral autonomy. The CODE group had higher median PN fluid and calorie requirements than their matched SBS controls at the end of the follow-up (83 vs. 45 mL/kg/day, p = 0.01; 54 vs. 30.5 kcal/kg/day, p < 0.01), but had similar rates of growth parameters, intestinal failure associated liver disease, central venous catheter complications and nephrocalcinosis. Kaplan-Meier analyses of 10-year survival and enteral autonomy were significantly lower in CODE patients compared to the nonmatched SBS population (60% vs. 89% and 30% vs. 87%, respectively; log-rank p < 0.008). CONCLUSIONS: Despite higher PN needs in CODE, rates of IF complications were similar to matched children with SBS. Enteral autonomy and survival rates were lower in CODE patients. Treatment by IRP can mitigate IF-related complications and improve CODE patient's outcome.
Assuntos
Diarreia , Nutrição Parenteral , Síndrome do Intestino Curto , Humanos , Masculino , Feminino , Estudos de Casos e Controles , Pré-Escolar , Síndrome do Intestino Curto/reabilitação , Síndrome do Intestino Curto/terapia , Diarreia/etiologia , Criança , Lactente , Resultado do Tratamento , Insuficiência Intestinal , Estudos Retrospectivos , Seguimentos , Estado NutricionalRESUMO
BACKGROUND: Toll-like receptors (TLRs) are important pattern recognition receptors that sense microbes and control host defense. Myeloid differentiation protein 2 (MD2) is the indispensable coreceptor for TLR4, facilitating the binding to the gram-negative bacterial cell wall component LPS and activation of downstream signaling. OBJECTIVE: We sought to provide phenotypic and mechanistic insights into human MD2 deficiency. METHODS: To elucidate the genetic cause in a patient with very early onset inflammatory bowel disease, we performed whole-exome sequencing and studied the functional consequences of the identified mutation in LY96 (encoding for MD2) in genetically engineered induced pluripotent stem cell-derived macrophages with knockout of MD2 or knockin of the patient-specific mutation, including TLR4-mediated signaling, cytokine production, and bacterial handling. RESULTS: Whole-exome sequencing identified a homozygous in-frame deletion in the LY96 gene (c.347_349delCAA; p.Thr116del) in a patient with very early onset inflammatory bowel disease and a sibling presenting with pneumonia and otitis media. Induced pluripotent stem cell-derived macrophages with knockout of MD2 or expression of the Thr116del mutation showed impaired activation of nuclear factor kappa B and mitogen-activated protein kinase signaling as well as TLR4 endocytosis on challenge with LPS or bacteria. In addition, MD2-deficient macrophages showed decreased cytokine expression (eg, IL-6, TNF, and IL-10) in response to LPS or gram-negative but not gram-positive bacteria. CONCLUSIONS: Human MD2 deficiency causes defective TLR4 signaling in response to LPS or gram-negative bacteria. The clinical manifestations and expressivity might be variable due to unknown secondary risk factors. Because TLR4 represents a therapeutic target for multiple inflammatory conditions, our study may provide insights into potential side effects of pharmacological TLR4 targeting.
Assuntos
Lipopolissacarídeos , Receptor 4 Toll-Like , Humanos , Citocinas/metabolismo , Lipopolissacarídeos/farmacologia , Antígeno 96 de Linfócito/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/genética , Receptores Toll-Like/metabolismoRESUMO
Diarrhoeal disorders in childhood extend beyond the inflammatory bowel diseases. Persistent and severe forms of diarrhoea can occur from birth and are associated with significant morbidity and mortality. These disorders can affect not only the gastrointestinal tract but frequently have extraintestinal manifestations, immunodeficiencies and endocrinopathies. Genomic analysis has advanced our understanding of these conditions and has revealed precision-based treatment options such as potentially curative haematopoietic stem cell transplant. Although many new mutations have been discovered, there is frequently no clear genotype-phenotype correlation. The functional effects of gene mutations can be studied in model systems such as patient-derived organoids. This allows us to further characterise these disorders and advance our understanding of the pathophysiology of the intestinal mucosa. In this review, we will provide an up to date overview of genes involved in diarrhoeal disorders of early onset, particularly focussing on the more recently described gene defects associated with protein loosing enteropathy.
Assuntos
Doenças Inflamatórias Intestinais , Humanos , Doenças Inflamatórias Intestinais/genética , Diarreia/genética , Mucosa IntestinalRESUMO
Balancing natural selection is a process by which genetic variants arise in populations that are beneficial to heterozygous carriers, but pathogenic when homozygous. We systematically investigated the prevalence, structural, and functional consequences of pathogenic IL10RA variants that are associated with monogenic inflammatory bowel disease. We identify 36 non-synonymous and non-sense variants in the IL10RA gene. Since the majority of these IL10RA variants have not been functionally characterized, we performed a systematic screening of their impact on STAT3 phosphorylation upon IL-10 stimulation. Based on the geographic accumulation of confirmed pathogenic IL10RA variants in East Asia and in Northeast China, the distribution of infectious disorders worldwide, and the functional evidence of IL-10 signaling in the pathogenesis, we identify Schistosoma japonicum infection as plausible selection pressure driving variation in IL10RA. Consistent with this is a partially augmented IL-10 response in peripheral blood mononuclear cells from heterozygous variant carriers. A parasite-driven heterozygote advantage through reduced IL-10 signaling has implications for health care utilization in regions with high allele frequencies and potentially indicates pathogen eradication strategies that target IL-10 signaling.
Assuntos
Interleucina-10 , Leucócitos Mononucleares , Humanos , Receptores de Interleucina-10/genética , Interleucina-10/genética , Subunidade alfa de Receptor de Interleucina-10/genética , Seleção GenéticaRESUMO
BACKGROUND & AIMS: In this nationwide study from the Israeli Inflammatory Bowel Disease Research Nucleus, we aimed to describe the incidence of very early onset inflammatory bowel diseases (VEOIBDs) with a focus on infantile-onset disease and to compare management and disease course with older children. METHODS: Data were retrieved from the 4 Israeli Health Maintenance Organizations covering 98% of the population. Pediatric-onset IBD was categorized as follows: adolescent onset (10 to <18 y), early onset (6 to <10 y), VEOIBD (0 to <6 y), toddler onset (2 to <6 y), and infantile onset (<2 y). RESULTS: A total of 5243 children with 35,469 person-years of follow-up evaluation, were diagnosed with IBD during 2005 to 2020: 4444 (85%) with adolescent onset, 548 (10%) with early onset, and 251 (4.8%) with VEOIBD, of whom 81 (1.5%) had infantile onset. The incidence of pediatric-onset IBD increased from 10.8 per 100,000 in 2005 to 15.3 per 100,000 in 2019 (average annual percentage change, 2.8%; 95% CI, 2.2%-3.4%), but that of VEOIBD remained stable (average annual percentage change, 0%; 95% CI, -2.5% to 2.6%). The infantile-onset and toddler-onset groups were treated less often with biologics (36% and 35%, respectively) vs the early onset (57%) and adolescent-onset groups (53%; P < .001). The time to steroid dependency was shorter in infantile-onset (hazard ratio [HR], 2.1; 95% CI, 1.5-2.9) and toddler-onset disease (HR, 1.6; 95% CI, 1.2-2.0) vs early onset and adolescent-onset disease, but time to hospitalizations, time to surgery, and growth delay were worse only in infantile-onset disease. In a multivariable model, infantile-onset patients had a higher risk for surgery (HR, 1.4; 95% CI, 1.1-1.9) and hospitalization (HR, 1.7; 95% CI, 1.2-2.4) than the toddler-onset group. CONCLUSIONS: The incidence of VEOIBD remained stable. Infantile-onset IBD had worse outcomes than older children, while toddler onset had mostly similar outcomes, despite less frequent use of biologics.
Assuntos
Produtos Biológicos , Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Adolescente , Humanos , Criança , Doença de Crohn/epidemiologia , Incidência , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/terapia , Intestinos , Colite Ulcerativa/epidemiologiaRESUMO
BACKGROUND & AIMS: Monogenic forms of inflammatory bowel disease (IBD) illustrate the essential roles of individual genes in pathways and networks safeguarding immune tolerance and gut homeostasis. METHODS: To build a taxonomy model, we assessed 165 disorders. Genes were prioritized based on penetrance of IBD and disease phenotypes were integrated with multi-omics datasets. Monogenic IBD genes were classified by (1) overlapping syndromic features, (2) response to hematopoietic stem cell transplantation, (3) bulk RNA-sequencing of 32 tissues, (4) single-cell RNA-sequencing of >50 cell subsets from the intestine of healthy individuals and patients with IBD (pediatric and adult), and (5) proteomes of 43 immune subsets. The model was validated by addition of newly identified monogenic IBD defects. As a proof-of-concept, we explore the intersection between immunometabolism and antimicrobial activity for a group of disorders (G6PC3/SLC37A4). RESULTS: Our quantitative integrated taxonomy defines the cellular landscape of monogenic IBD gene expression across 102 genes with high and moderate penetrance (81 in the model set and 21 genes in the validation set). We illustrate distinct cellular networks, highlight expression profiles across understudied cell types (e.g., CD8+ T cells, neutrophils, epithelial subsets, and endothelial cells) and define genotype-phenotype associations (perianal disease and defective antimicrobial activity). We illustrate processes and pathways shared across cellular compartments and phenotypic groups and highlight cellular immunometabolism with mammalian target of rapamycin activation as one of the converging pathways. There is an overlap of genes and enriched cell-specific expression between monogenic and polygenic IBD. CONCLUSION: Our taxonomy integrates genetic, clinical and multi-omic data; providing a basis for genomic diagnostics and testable hypotheses for disease functions and treatment responses.
Assuntos
Doenças Inflamatórias Intestinais/classificação , Doenças Inflamatórias Intestinais/genética , Idade de Início , Antiporters/genética , Células Cultivadas , Classificação , Perfilação da Expressão Gênica , Estudos de Associação Genética , Genótipo , Glucose-6-Fosfatase/genética , Glucose-6-Fosfato/metabolismo , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Macrófagos , Metabolômica , Proteínas de Transporte de Monossacarídeos/genética , Penetrância , Fenótipo , Transdução de Sinais/genéticaRESUMO
Intact interleukin-10 receptor (IL-10R) signaling on effector and T regulatory (Treg) cells are each independently required to maintain immune tolerance. Here we show that IL-10 sensing by innate immune cells, independent of its effects on T cells, was critical for regulating mucosal homeostasis. Following wild-type (WT) CD4(+) T cell transfer, Rag2(-/-)Il10rb(-/-) mice developed severe colitis in association with profound defects in generation and function of Treg cells. Moreover, loss of IL-10R signaling impaired the generation and function of anti-inflammatory intestinal and bone-marrow-derived macrophages and their ability to secrete IL-10. Importantly, transfer of WT but not Il10rb(-/-) anti-inflammatory macrophages ameliorated colitis induction by WT CD4(+) T cells in Rag2(-/-)Il10rb(-/-) mice. Similar alterations in the generation and function of anti-inflammatory macrophages were observed in IL-10R-deficient patients with very early onset inflammatory bowel disease. Collectively, our studies define innate immune IL-10R signaling as a key factor regulating mucosal immune homeostasis in mice and humans.
Assuntos
Colite Ulcerativa/genética , Colite Ulcerativa/imunologia , Interleucina-10/imunologia , Receptores de Interleucina-10/imunologia , Transferência Adotiva , Animais , Diferenciação Celular/imunologia , Proliferação de Células , Células Cultivadas , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Humanos , Tolerância Imunológica/genética , Tolerância Imunológica/imunologia , Imunidade Inata/genética , Imunidade Inata/imunologia , Inflamação/imunologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Interleucina-10/deficiência , Receptores de Interleucina-10/genética , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
The NOX2 NADPH oxidase (NOX2) produces reactive oxygen species to kill phagosome-confined bacteria. However, we previously showed that Listeria monocytogenes is able to avoid the NOX2 activity in phagosomes and escape to the cytosol. Thus, despite the established role of NOX2 limiting L. monocytogenes infection in mice, the underlying mechanisms of this antibacterial activity remain unclear. In this article, we report that NOX2 controls systemic L. monocytogenes spread through modulation of the type I IFN response, which is known to be exploited by L. monocytogenes during infection. NOX2 deficiency results in increased expression of IFN-stimulated genes in response to type I IFN and leads to 1) promotion of cell-to-cell spread by L. monocytogenes, 2) defective leukocyte recruitment to infection foci, and 3) production of anti-inflammatory effectors IL-10 and thioredoxin 1. Our findings report a novel antimicrobial role for NOX2 through modulation of type I IFN responses to control bacterial dissemination.
Assuntos
Inflamação/imunologia , Interferon Tipo I/metabolismo , Leucócitos/imunologia , Listeria monocytogenes/fisiologia , Listeriose/imunologia , Macrófagos/metabolismo , NADPH Oxidase 2/metabolismo , Animais , Movimento Celular , Células Cultivadas , Interleucina-10/metabolismo , Listeriose/transmissão , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NADPH Oxidase 2/genética , TiorredoxinasRESUMO
BACKGROUND & AIMS: Advances in genomic technologies have led to increasing reports of monogenic inflammatory bowel disease (IBD). Here, we systematically review the literature to determine the clinical features, genetic profile, and previously used treatment strategies in monogenic IBD. METHODS: A systematic review of MEDLINE articles published between January 2000 and December 2020 was conducted. A total of 750 individual monogenic IBD cases were identified from 303 eligible articles. RESULTS: The most frequently reported monogenic IBD genes were IL10RA/B, XIAP, CYBB, LRBA, and TTC7A. In total, 63.4% of patients developed IBD before 6 years of age, 17.4% developed IBD between ages 10 and 17.9 years, and 10.9% developed IBD after age 18. There was a substantial difference between these age groups and the underlying monogenic disorders. Only 31.7% had any history of extraintestinal comorbidity (EIC) before IBD onset, but 76.0% developed at least 1 EIC during their clinical course. The most common EICs were atypical infection (44.7%), dermatologic abnormality (38.4%), and autoimmunity (21.9%). Bowel surgery, biologic therapy, and hematopoietic stem cell transplantation were performed in 27.1%, 32.9%, and 23.1% of patients, respectively. CONCLUSIONS: Monogenic IBD cases, although rare, have varied extraintestinal comorbidities and limited treatment options including surgery and transplant. Early identification and improved understanding of the characteristics of the genes and underlying disease processes in monogenic IBD is important for effective management.
Assuntos
Colite , Doenças Inflamatórias Intestinais , Proteínas Adaptadoras de Transdução de Sinal , Adolescente , Idade de Início , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/terapia , ProteínasRESUMO
BACKGROUND/AIMS: Pediatric Crohn disease (CD) treatment goals have evolved. Among children receiving adalimumab (ADA) we examined long-term durability of clinical remission, linear growth, and associations of trough concentration (TC) with biomarker, endoscopic and imaging outcomes. METHODS: Single-center retrospective study. Pediatric CD activity index, C-reactive protein, fecal calprotectin, and height measured longitudinally. Discontinuation due to secondary loss of response (LOR) was assessed using Cox proportional hazards model. Associations between TC and clinical and biomarker remission, endoscopic and magnetic resonance imaging (MRI) improvements were assessed using Cox regression with time-dependent covariates. RESULTS: Between January 2007 and June 2018, 213 children (median age 14.1âyears (interquartile range [IQR] 12.5-15.7) 65% males) initiated ADA. One hundred and seventy-four (82%) achieved clinical remission (PCDAI < 10). During 24.8 (IQR 15.6-38.4) months follow-up, 26 (15%) discontinued ADA due to LOR, and 10 (6%) due to adverse events. Being anti-tumor necrosis factor (TNF) naïve and inflammatory behavior associated with increased likelihood of clinical remission (odds ratio [OR] 2.39, Pâ=â0.033, and 3.13, Pâ=â0.013, respectively) and with decreased LOR (hazard ratio [HR] 0.3, Pâ=â0.002, and HR 0.35, Pâ=â0.01, respectively). Cumulative LOR among 135 anti-TNF naïve patients: 0%, 8%, 15% within 1, 2, 3âyears, similarly durable with mono- and immunomodulator combination therapy. Among pre-/early pubertal children mean height (-0.82) normalized to -0.07. TC consistently >7.5âug/mL was associated with durable clinical remission (HRâ=â17.24, Pâ<â0.001); TC >10âug/mL with durable biomarker remission (HRâ=â6.56, Pâ<â0.001) and endoscopic (OR 10.4, Pâ=â0.002) and MRI (OR 7.6, Pâ=â0.001) improvements. CONCLUSION: ADA monotherapy maintains durable clinical remission. Biomarker remission, mucosal and transmural improvements were associated with greater ADA exposure.
Assuntos
Doença de Crohn , Adalimumab/efeitos adversos , Adolescente , Biomarcadores , Criança , Doença de Crohn/tratamento farmacológico , Feminino , Humanos , Infliximab/uso terapêutico , Masculino , Indução de Remissão , Estudos Retrospectivos , Resultado do Tratamento , Inibidores do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa/uso terapêuticoRESUMO
BACKGROUND AND AIMS: The initial description of a heterozygous dominant ACTG2 variant in familial visceral myopathy was followed by the identification of additional variants in other forms of intestinal dysmotility disorders. we aimed to describe the diverse phenotype of this newly reported and rare disease. METHODS: Report of 4 new patients, and a systematic review of ACTG2-related disorders. we analyzed the population frequency and used in silico gene damaging predictions. Genotype-phenotype correlations were explored. RESULTS: One hundred three patients (52% girls), from 14 publications, were included. Twenty-eight unique variants were analyzed, all exceedingly rare, and 27 predicted to be highly damaging. The median Combined Annotation Dependent Depletion (CADD) score was 29.2 (Interquartile range 26.3-29.4). Most patients underwent abdominal surgery (66%), about half required intermittent bladder catheterization (48.5%), and more than half were parenteral nutrition (PN)-dependent (53%). One-quarter of the patients died (25.7%), and 6 required transplant (5.8%). Girls had a higher rate of microcolon (Pâ =â0.009), PN dependency (Pâ=â0.003), and death/transplant (Pâ=â0.029) compared with boys, and early disease onset (<2âyears of age) was associated with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) features. There was no statistical association between disease characteristics and CADD scores. CONCLUSIONS: Damaging ACTG2 variants are rare, often associated with MMIHS phenotype, and overall have a wide phenotypic variation. Symptoms usually present in the perinatal period but can also appear at a later age. The course of the disease is marked by frequent need for surgical interventions, PN support, and mortality. Poor outcomes are more common among girls with ACTG2 variants.
Assuntos
Anormalidades Múltiplas , Pseudo-Obstrução Intestinal , Anormalidades Múltiplas/diagnóstico , Actinas/genética , Colo/anormalidades , Feminino , Humanos , Pseudo-Obstrução Intestinal/diagnóstico , Pseudo-Obstrução Intestinal/genética , Masculino , Fenótipo , Gravidez , Bexiga Urinária/anormalidadesRESUMO
BACKGROUND: Research on the utilization and effectiveness of antitumor necrosis factor (TNF) biologics in children with very early onset inflammatory bowel disease (VEOIBD) is urgently needed. Here we describe anti-TNF use and durability in a multicenter cohort. METHODS: We performed a retrospective cohort study of patients diagnosed with VEOIBD (<6 years) between 2008 and 2013 at 25 North American centers. We performed chart abstraction at diagnosis and 1, 3, and 5 years after diagnosis. We examined the rate of initiation and durability of infliximab and adalimumab and evaluated associations between treatment durability and the following covariates with multivariate Cox proportional hazard regression: age at diagnosis, sex, disease duration, disease classification, and presence of combined immunomodulatory treatment versus monotherapy. RESULTS: Of 294 children with VEOIBD, 120 initiated treatment with anti-TNF therapy and 101 had follow-up data recorded [50% Crohn disease (CD), 31% ulcerative colitis (UC), and 19% IBD unclassified (IBD-U)]. The cumulative probability of anti-TNF treatment was 15% at 1 year, 30% at 3 years, and 45% at 5 years from diagnosis; 56 (55%) were treated between 0 and 6 years old. Anti-TNF durability was 90% at 1 year, 75% at 3 years, and 55% at 5 years. The most common reason for discontinuation of anti-TNF were loss of response in 24 (57%) children. Children with UC/IBD-U had lower durability than those with CD (hazard ratio [HR] 0.17; 95% confidence interval [CI], 0.06-0.51; P = 0.001). CONCLUSIONS: Utilization and durability of anti-TNF in VEOIBD is relatively high and comparable with older children. Having Crohn disease (compared with UC/IBD-U) is associated with greater durability.
Assuntos
Produtos Biológicos , Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Adalimumab/uso terapêutico , Adolescente , Produtos Biológicos/uso terapêutico , Criança , Pré-Escolar , Estudos de Coortes , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Humanos , Lactente , Recém-Nascido , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab/uso terapêutico , Necrose , Estudos Retrospectivos , Inibidores do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfaRESUMO
Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a critical regulator of cell death and inflammation, but its relevance for human disease pathogenesis remains elusive. Studies of monogenic disorders might provide critical insights into disease mechanisms and therapeutic targeting of RIPK1 for common diseases. Here, we report on eight patients from six unrelated pedigrees with biallelic loss-of-function mutations in RIPK1 presenting with primary immunodeficiency and/or intestinal inflammation. Mutations in RIPK1 were associated with reduced NF-κB activity, defective differentiation of T and B cells, increased inflammasome activity, and impaired response to TNFR1-mediated cell death in intestinal epithelial cells. The characterization of RIPK1-deficient patients highlights the essential role of RIPK1 in controlling human immune and intestinal homeostasis, and might have critical implications for therapies targeting RIPK1.
Assuntos
Diferenciação Celular , Imunidade nas Mucosas/genética , Doenças Inflamatórias Intestinais , Mucosa Intestinal , Proteína Serina-Treonina Quinases de Interação com Receptores , Imunodeficiência Combinada Severa , Linfócitos B/imunologia , Linfócitos B/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Células HCT116 , Células HEK293 , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Masculino , Mutação , NF-kappa B/genética , NF-kappa B/imunologia , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/imunologia , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
BACKGROUND & AIMS: Mutations in the tetratricopeptide repeat domain 7A gene (TTC7A) cause intestinal epithelial and immune defects. Patients can become immune deficient and develop apoptotic enterocolitis, multiple intestinal atresia, and recurrent intestinal stenosis. The intestinal disease in patients with TTC7A deficiency is severe and untreatable, and it recurs despite resection or allogeneic hematopoietic stem cell transplant. We screened drugs for those that prevent apoptosis of in cells with TTC7A deficiency and tested their effects in an animal model of the disease. METHODS: We developed a high-throughput screen to identify compounds approved by the US Food and Drug Administration that reduce activity of caspases 3 and 7 in TTC7A-knockout (TTC7A-KO) HAP1 (human haploid) cells and reduce the susceptibility to apoptosis. We validated the effects of identified agents in HeLa cells that stably express TTC7A with point mutations found in patients. Signaling pathways in cells were analyzed by immunoblots. We tested the effects of identified agents in zebrafish with disruption of ttc7a, which develop intestinal defects, and colonoids derived from biopsy samples of patients with and without mutations in TTC7A. We performed real-time imaging of intestinal peristalsis in zebrafish and histologic analyses of intestinal tissues from patients and zebrafish. Colonoids were analyzed by immunofluorescence and for ion transport. RESULTS: TTC7A-KO HAP1 cells have abnormal morphology and undergo apoptosis, due to increased levels of active caspases 3 and 7. We identified drugs that increased cell viability; leflunomide (used to treat patients with inflammatory conditions) reduced caspase 3 and 7 activity in cells by 96%. TTC7A-KO cells contained cleaved caspase 3 and had reduced levels of phosphorylated AKT and X-linked inhibitor of apoptosis (XIAP); incubation of these cells with leflunomide increased levels of phosphorylated AKT and XIAP and reduced levels of cleaved caspase 3. Administration of leflunomide to ttc7a-/- zebrafish increased gut motility, reduced intestinal tract narrowing, increased intestinal cell survival, increased sizes of intestinal luminal spaces, and restored villi and goblet cell morphology. Exposure of patient-derived colonoids to leflunomide increased cell survival, polarity, and transport function. CONCLUSIONS: In a drug screen, we identified leflunomide as an agent that reduces apoptosis and activates AKT signaling in TTC7A-KO cells. In zebrafish with disruption of ttc7a, leflunomide restores gut motility, reduces intestinal tract narrowing, and increases intestinal cell survival. This drug might be repurposed for treatment of TTC7A deficiency.
Assuntos
Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Leflunomida/farmacologia , Proteínas/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Colo/citologia , Técnicas de Inativação de Genes , Haploidia , Humanos , Doenças Inflamatórias Intestinais/genética , Fosforilação/efeitos dos fármacos , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismoRESUMO
BACKGROUND & AIMS: A proportion of infants and young children with inflammatory bowel diseases (IBDs) have subtypes associated with a single gene variant (monogenic IBD). We aimed to determine the prevalence of monogenic disease in a cohort of pediatric patients with IBD. METHODS: We performed whole-exome sequencing analyses of blood samples from an unselected cohort of 1005 children with IBD, aged 0-18 years (median age at diagnosis, 11.96 years) at a single center in Canada and their family members (2305 samples total). Variants believed to cause IBD were validated using Sanger sequencing. Biopsies from patients were analyzed by immunofluorescence and histochemical analyses. RESULTS: We identified 40 rare variants associated with 21 monogenic genes among 31 of the 1005 children with IBD (including 5 variants in XIAP, 3 in DOCK8, and 2 each in FOXP3, GUCY2C, and LRBA). These variants occurred in 7.8% of children younger than 6 years and 2.3% of children aged 6-18 years. Of the 17 patients with monogenic Crohn's disease, 35% had abdominal pain, 24% had nonbloody loose stool, 18% had vomiting, 18% had weight loss, and 5% had intermittent bloody loose stool. The 14 patients with monogenic ulcerative colitis or IBD-unclassified received their diagnosis at a younger age, and their most predominant feature was bloody loose stool (78%). Features associated with monogenic IBD, compared to cases of IBD not associated with a single variant, were age of onset younger than 2 years (odds ratio [OR], 6.30; P = .020), family history of autoimmune disease (OR, 5.12; P = .002), extra-intestinal manifestations (OR, 15.36; P < .0001), and surgery (OR, 3.42; P = .042). Seventeen patients had variants in genes that could be corrected with allogeneic hematopoietic stem cell transplantation. CONCLUSIONS: In whole-exome sequencing analyses of more than 1000 children with IBD at a single center, we found that 3% had rare variants in genes previously associated with pediatric IBD. These were associated with different IBD phenotypes, and 1% of the patients had variants that could be potentially corrected with allogeneic hematopoietic stem cell transplantation. Monogenic IBD is rare, but should be considered in analysis of all patients with pediatric onset of IBD.
Assuntos
Colite Ulcerativa/genética , Doença de Crohn/genética , Sequenciamento do Exoma , Variação Genética , Adolescente , Fatores Etários , Produtos Biológicos/uso terapêutico , Criança , Pré-Escolar , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/terapia , Doença de Crohn/diagnóstico , Doença de Crohn/epidemiologia , Doença de Crohn/terapia , Feminino , Predisposição Genética para Doença , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Recém-Nascido , Masculino , Ontário/epidemiologia , Fenótipo , Prevalência , Medição de Risco , Fatores de Risco , Transplante Homólogo , Resultado do TratamentoRESUMO
BACKGROUND: It is important to identify patients with monogenic IBD as management may differ from classical IBD. In this position statement we formulate recommendations for the use of genomics in evaluating potential monogenic causes of IBD across age groups. METHODS: The consensus included paediatric IBD specialists from the Paediatric IBD Porto group of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and specialists from several monogenic IBD research consortia. We defined key topics and performed a systematic literature review to cover indications, technologies (targeted panel, exome and genome sequencing), gene panel setup, cost-effectiveness of genetic screening, and requirements for the clinical care setting. We developed recommendations that were voted upon by all authors and Porto group members (32 voting specialists). RESULTS: We recommend next-generation DNA-sequencing technologies to diagnose monogenic causes of IBD in routine clinical practice embedded in a setting of multidisciplinary patient care. Routine genetic screening is not recommended for all IBD patients. Genetic testing should be considered depending on age of IBD-onset (infantile IBD, very early-onset IBD, paediatric or young adult IBD), and further criteria, such as family history, relevant comorbidities, and extraintestinal manifestations. Genetic testing is also recommended in advance of hematopoietic stem cell transplantation. We developed a diagnostic algorithm that includes a gene panel of 75 monogenic IBD genes. Considerations are provided also for low resource countries. CONCLUSIONS: Genomic technologies should be considered an integral part of patient care to investigate patients at risk for monogenic forms of IBD.