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1.
Eur J Immunol ; 54(2): e2250248, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37957831

RESUMO

Human intestinal organoids are an ideal model system for studying gastrointestinal physiology and immunopathology. Altered physiology and mucosal immune response are hallmarks of numerous intestinal functional and inflammatory diseases, including inflammatory bowel disease (IBD), coeliac disease, irritable bowel syndrome (IBS), and obesity. These conditions impact the normal epithelial functions of the intestine, such as absorption, barrier function, secretion, and host-microbiome communication. They are accompanied by characteristic intestinal symptoms and have significant societal, economic, and healthcare burdens. To develop new treatment options, cutting-edge research is required to investigate their etiology and pathology. Human intestinal organoids derived from patient tissue recapitulate the key physiological and immunopathological aspects of these conditions, providing a promising platform for elucidating disease mechanisms. This review will summarize recent reports on patient-derived human small intestinal and colonic organoids and highlight how these models have been used to study intestinal epithelial functions in the context of inflammation, altered physiology, and immune response. Furthermore, it will elaborate on the various organoid systems in use and the techniques/assays currently available to study epithelial functions. Finally, it will conclude by discussing the limitations and future perspectives of organoid technology.


Assuntos
Doenças Inflamatórias Intestinais , Mucosa Intestinal , Humanos , Intestinos/patologia , Organoides/patologia , Organoides/fisiologia , Intestino Delgado/patologia
2.
Nat Immunol ; 14(9): 927-36, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23892723

RESUMO

Mutations that result in loss of function of Nod2, an intracellular receptor for bacterial peptidoglycan, are associated with Crohn's disease. Here we found that the E3 ubiquitin ligase Pellino3 was an important mediator in the Nod2 signaling pathway. Pellino3-deficient mice had less induction of cytokines after engagement of Nod2 and had exacerbated disease in various experimental models of colitis. Furthermore, expression of Pellino3 was lower in the colons of patients with Crohn's disease. Pellino3 directly bound to the kinase RIP2 and catalyzed its ubiquitination. Loss of Pellino3 led to attenuation of Nod2-induced ubiquitination of RIP2 and less activation of the transcription factor NF-κB and mitogen-activated protein kinases (MAPKs). Our findings identify RIP2 as a substrate for Pellino3 and Pellino3 as an important mediator in the Nod2 pathway and regulator of intestinal inflammation.


Assuntos
Colite/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Citrobacter rodentium/imunologia , Colite/genética , Colite/imunologia , Colite/microbiologia , Doença de Crohn/genética , Doença de Crohn/imunologia , Doença de Crohn/metabolismo , Modelos Animais de Doenças , Feminino , Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteína Serina-Treonina Quinase 2 de Interação com Receptor , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Adulto Jovem
3.
Int J Mol Sci ; 24(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36768196

RESUMO

Environmental factors, including westernised diets and alterations to the gut microbiota, are considered risk factors for inflammatory bowel diseases (IBD). The mechanisms underpinning diet-microbiota-host interactions are poorly understood in IBD. We present evidence that feeding a lard-based high-fat (HF) diet can protect mice from developing DSS-induced acute and chronic colitis and colitis-associated cancer (CAC) by significantly reducing tumour burden/incidence, immune cell infiltration, cytokine profile, and cell proliferation. We show that HF protection was associated with increased gut microbial diversity and a significant reduction in Proteobacteria and an increase in Firmicutes and Clostridium cluster XIVa abundance. Microbial functionality was modulated in terms of signalling fatty acids and bile acids (BA). Faecal secondary BAs were significantly induced to include moieties that can activate the vitamin D receptor (VDR), a nuclear receptor richly represented in the intestine and colon. Indeed, colonic VDR downstream target genes were upregulated in HF-fed mice and in combinatorial lipid-BAs-treated intestinal HT29 epithelial cells. Collectively, our data indicate that HF diet protects against colitis and CAC risk through gut microbiota and BA metabolites modulating vitamin D targeting pathways. Our data highlights the complex relationship between dietary fat-induced alterations of microbiota-host interactions in IBD/CAC pathophysiology.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Neoplasias , Camundongos , Animais , Vitamina D/metabolismo , Inflamação/metabolismo , Colite/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Colo/patologia , Dieta Hiperlipídica/efeitos adversos , Bactérias , Ácidos e Sais Biliares/metabolismo , Camundongos Endogâmicos C57BL , Sulfato de Dextrana/efeitos adversos , Neoplasias/metabolismo
4.
Am J Physiol Gastrointest Liver Physiol ; 323(5): G439-G460, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36165492

RESUMO

DNA sensor pathways can initiate inflammasome, cell death, and type I interferon (IFN) signaling in immune-mediated inflammatory diseases (IMIDs), including type I interferonopathies. We investigated the involvement of these pathways in the pathogenesis of ulcerative colitis (UC) by analyzing the expression of DNA sensor, inflammasome, and type I IFN biomarker genes in colonic mucosal biopsy tissue from control (n = 31), inactive UC (n = 31), active UC (n = 33), and a UC single-cell RNA-Seq dataset. The effects of type I IFN (IFN-ß), IFN-γ, and TNF-α on gene expression, cytokine production, and cell death were investigated in human colonic organoids. In organoids treated with cytokines alone, or in combination with NLR family pyrin domain-containing 3 (NLRP3), caspase, or JAK inhibitors, cell death was measured, and supernatants were assayed for IL-1ß/IL-18/CXCL10. The expression of DNA sensor pathway genes-PYHIN family members [absent in melanoma 2 (AIM2), IFI16, myeloid cell nuclear differentiation antigen (MNDA), and pyrin and HIN domain family member 1 (PYHIN1)- as well as Z-DNA-binding protein 1 (ZBP1), cyclic GMP-AMP synthase (cGAS), and DDX41 was increased in active UC and expressed in a cell type-restricted pattern. Inflammasome genes (CASP1, IL1B, and IL18), type I IFN inducers [stimulator of interferon response cGAMP interactor 1 (STING), TBK1, and IRF3), IFNB1, and type I IFN biomarker genes (OAS2, IFIT2, and MX2) were also increased in active UC. Cotreatment of organoids with IFN-ß or IFN-γ in combination with TNFα increased expression of IFI16, ZBP1, CASP1, cGAS, and STING induced cell death and IL-1ß/IL-18 secretion. This inflammatory cell death was blocked by the JAK inhibitor tofacitinib but not by inflammasome or caspase inhibitors. Increased type I IFN activity may drive elevated expression of DNA sensor genes and JAK-dependent but inflammasome-independent inflammatory cell death of colonic epithelial cells in UC.NEW & NOTEWORTHY This study found that patients with active UC have significantly increased colonic gene expression of cytosolic DNA sensor, inflammasome, STING, and type I IFN signaling pathways. The type I IFN, IFN-ß, in combination with TNF-α induced JAK-dependent but NLRP3 and inflammasome-independent inflammatory cell death of colonic organoids. This novel inflammatory cell death phenotype is relevant to UC immunopathology and may partially explain the efficacy of the JAKinibs tofacitinib and upadacitinib in patients with UC.


Assuntos
Colite Ulcerativa , Interferon Tipo I , Inibidores de Janus Quinases , Humanos , Inflamassomos/metabolismo , Interleucina-18 , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fator de Necrose Tumoral alfa , Inibidores de Caspase , Organoides/metabolismo , Pirina , Caspase 1/metabolismo , Nucleotidiltransferases/metabolismo , DNA , Morte Celular , Proteínas de Ligação a DNA/metabolismo , Antígenos de Diferenciação
5.
Int J Mol Sci ; 23(15)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35955491

RESUMO

Crohn's disease (CD) is a complex, disabling, idiopathic, progressive, and destructive disorder with an unknown etiology. The pathogenesis of CD is multifactorial and involves the interplay between host genetics, and environmental factors, resulting in an aberrant immune response leading to intestinal inflammation. Due to the high morbidity and long-term management of CD, the development of non-pharmacological approaches to mitigate the severity of CD has recently attracted great attention. The gut microbiota has been recognized as an important player in the development of CD, and general alterations in the gut microbiome have been established in these patients. Thus, the gut microbiome has emerged as a pre-eminent target for potential new treatments in CD. Epidemiological and interventional studies have demonstrated that diet could impact the gut microbiome in terms of composition and functionality. However, how specific dietary strategies could modulate the gut microbiota composition and how this would impact host-microbe interactions in CD are still unclear. In this review, we discuss the most recent knowledge on host-microbe interactions and their involvement in CD pathogenesis and severity, and we highlight the most up-to-date information on gut microbiota modulation through nutritional strategies, focusing on the role of the microbiota in gut inflammation and immunity.


Assuntos
Doença de Crohn , Microbioma Gastrointestinal , Microbiota , Doença de Crohn/terapia , Dieta , Microbioma Gastrointestinal/fisiologia , Interações entre Hospedeiro e Microrganismos , Humanos , Inflamação/terapia
6.
Int J Mol Sci ; 22(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361102

RESUMO

Interactions between the intestinal microbiota, immune system and nervous system are essential for homeostasis in the gut. Inflammasomes contribute to innate immunity and brain-gut interactions, but their role in microbiota-neuro-immune interactions is not clear. Therefore, we investigated the effect of the inflammasome on visceral pain and local and systemic neuroimmune responses after antibiotic-induced changes to the microbiota. Wild-type (WT) and caspase-1/11 deficient (Casp1 KO) mice were orally treated for 2 weeks with an antibiotic cocktail (Abx, Bacitracin A and Neomycin), followed by quantification of representative fecal commensals (by qPCR), cecal short chain fatty acids (by HPLC), pathways implicated in the gut-neuro-immune axis (by RT-qPCR, immunofluorescence staining, and flow cytometry) in addition to capsaicin-induced visceral pain responses. Abx-treatment in WT-mice resulted in an increase in colonic macrophages, central neuro-immune interactions, colonic inflammasome and nociceptive receptor gene expression and a reduction in capsaicin-induced visceral pain. In contrast, these responses were attenuated in Abx-treated Casp1 KO mice. Collectively, the data indicate an important role for the inflammasome pathway in functional and inflammatory gastrointestinal conditions where pain and alterations in microbiota composition are prominent.


Assuntos
Caspase 1/fisiologia , Microbioma Gastrointestinal , Inflamassomos/imunologia , Inflamação/complicações , Neuroimunomodulação , Dor Visceral/patologia , Animais , Antibacterianos/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/microbiologia , Encéfalo/patologia , Capsaicina/toxicidade , Colo/efeitos dos fármacos , Colo/imunologia , Colo/microbiologia , Colo/patologia , Feminino , Inflamassomos/efeitos dos fármacos , Inflamação/imunologia , Inflamação/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Dor Visceral/etiologia , Dor Visceral/metabolismo
7.
Appl Microbiol Biotechnol ; 102(24): 10645-10663, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30306201

RESUMO

Members of the Bifidobacterium genus are widely used as probiotics in fermented milk products. Bifidobacterium animalis subsp. animalis CNCM I-4602 grows and survives poorly in reconstituted skimmed milk (RSM). Availing of genome and transcriptome information, this poor growth and survival phenotype in milk was substantially improved by the addition of certain compounds, such as yeast extract, uric acid, glutathione, cysteine, ferrous sulfate, and a combination of magnesium sulfate and manganese sulfate. Carbohydrate utilization of CNCM I-4602 was also investigated, allowing the identification of several carbohydrate utilization gene clusters, and highlighting this strain's inability to utilize lactose, unlike the type strain of this subspecies, B. animalis subsp. animalis ATCC25527 and the B. animalis subsp. lactis subspecies. In addition, the ability of B. animalis subsp. animalis CNCM I-4602 to colonize a murine model was investigated, which showed that this strain persists in the murine gut for a period of at least 4 weeks. Associated in vivo transcriptome analysis revealed that, among other genes, a gene cluster encoding a predicted type IVb tight adherence (Tad) pilus was upregulated, indicating that this extracellular structure plays a role in the colonization/adaptation of the murine gastrointestinal tract by this strain.


Assuntos
Bifidobacterium animalis/crescimento & desenvolvimento , Bifidobacterium animalis/genética , Microbiologia de Alimentos/métodos , Leite/microbiologia , Animais , Bifidobacterium animalis/efeitos dos fármacos , Metabolismo dos Carboidratos , Resistência Microbiana a Medicamentos , Feminino , Microbioma Gastrointestinal , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Camundongos Endogâmicos BALB C , Probióticos
8.
Cell Mol Life Sci ; 74(1): 141-151, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27510419

RESUMO

Colonic inflammation is associated with decreased tissue oxygenation, significantly affecting gut homeostasis. However, the crosstalk between O2 consumption and supply in the inflamed tissue are not fully understood. Using a murine model of colitis, we analysed O2 in freshly prepared samples of healthy and inflamed colon tissue. We developed protocols for efficient ex vivo staining of mouse distal colon mucosa with a cell-penetrating O2 sensitive probe Pt-Glc and high-resolution imaging of O2 concentration in live tissue by confocal phosphorescence lifetime-imaging microscopy (PLIM). Microscopy analysis revealed that Pt-Glc stained mostly the top 50-60 µm layer of the mucosa, with high phosphorescence intensity in epithelial cells. Measured O2 values in normal mouse tissue ranged between 5 and 35 µM (4-28 Torr), tending to decrease in the deeper tissue areas. Four-day treatment with dextran sulphate sodium (DSS) triggered colon inflammation, as evidenced by an increase in local IL6 and mKC mRNA levels, but did not affect the gross architecture of colonic epithelium. We further observed an increase in oxygenation, partial activation of hypoxia inducible factor (HIF) 1 signalling, and negative trends in pyruvate dehydrogenase activity and O2 consumption rate in the colitis mucosa, suggesting a decrease in mitochondrial respiration, which is known to be regulated via HIF-1 signalling and pyruvate oxidation rate. These results along with efficient staining with Pt-Glc of rat and human colonic mucosa reveal high potential of PLIM platform as a powerful tool for the high-resolution analysis of the intestinal tissue oxygenation in patients with inflammatory bowel disease and other pathologies, affecting tissue respiration.


Assuntos
Colite/patologia , Colo/patologia , Mucosa Intestinal/patologia , Oxigênio/análise , Animais , Células CACO-2 , Colite/imunologia , Colo/imunologia , Humanos , Mucosa Intestinal/imunologia , Medições Luminescentes , Masculino , Camundongos Endogâmicos C57BL , Microscopia Confocal , Imagem Óptica , Oxigênio/imunologia , Ratos Sprague-Dawley , Coloração e Rotulagem
9.
Am J Physiol Endocrinol Metab ; 313(1): E1-E11, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28325732

RESUMO

We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance-related parameters was investigated. As part of a high-sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake. The energy expenditure was unaffected, but epididymal weight was reduced, indicating an energy loss. Notably, there was a reduction in the ileum gene expression for amino acid transporter SLC6a19, glucose transporter 2, and fatty acid transporter 4. The composition of the gut microbiota also changed, where Firmicutes were reduced. The above changes indicated reduced energy absorption through the intestine. We propose that this mobilized energy in the adipose tissue and caused hypothalamic changes that increased energy intake, acting to counteract the energy deficit arising in the intestine. Lowering the sucrose content in the WPI diet increased energy expenditure. This further reduced epididymal weight and plasma leptin, whereupon hypothalamic ghrelin gene expression and the intestinal weight were both increased. These data suggest that when the intestine-adipose-hypothalamic pathway is subjected to an additional energy loss (now in the adipose tissue), compensatory changes attempt to assimilate more energy. Notably, WPI and sucrose content interact to enable the component mechanisms of this pathway.


Assuntos
Adiposidade/fisiologia , Proteínas Alimentares/farmacologia , Metabolismo Energético/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Absorção Intestinal/efeitos dos fármacos , Neuropeptídeos/genética , Proteínas do Soro do Leite/farmacologia , Administração Oral , Animais , Proteínas Alimentares/metabolismo , Ingestão de Energia/efeitos dos fármacos , Metabolismo Energético/fisiologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Absorção Intestinal/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuropeptídeos/metabolismo
10.
Biochim Biophys Acta ; 1847(10): 1254-66, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26143176

RESUMO

Abnormal accumulation of oncometabolite fumarate and succinate is associated with inhibition of mitochondrial function and carcinogenesis. By competing with α-ketoglutarate, oncometabolites also activate hypoxia inducible factors (HIFs), which makes oncometabolite mimetics broadly utilised in hypoxia research. We found that dimethyloxalylglycine (DMOG), a synthetic analogue of α-ketoglutarate, commonly used to induce HIF signalling, inhibits O2 consumption in cancer cell lines HCT116 and PC12, well before activation of HIF pathways. A rapid suppression of cellular respiration was accompanied by a decrease in histone H4 lysine 16 acetylation and not abolished by double knockdown of HIF-1α and HIF-2α. In agreement with this, production of NADH and state 3 respiration in isolated mitochondria were down-regulated by the de-esterified DMOG derivative, N-oxalylglycine. Exploring the roles of DMOG as a putative inhibitor of glutamine/α-ketoglutarate metabolic axis, we found that the observed suppression of OxPhos and compensatory activation of glycolytic ATP flux make cancer cells vulnerable to combined treatment with DMOG and inhibitors of glycolysis. On the other hand, DMOG treatment impairs deep cell deoxygenation in 3D tissue culture models, demonstrating a potential to relieve functional stress imposed by deep hypoxia on tumour, ischemic or inflamed tissues. Indeed, using a murine model of colitis, we found that O2 availability in the inflamed colon tissue rapidly increased after application of DMOG, which could contribute to the known therapeutic effect of this compound. Overall, our results provide new insights into the relationship between mitochondrial function, O2 availability, metabolic reprogramming and associated diseases.

11.
Scand J Gastroenterol ; 50(8): 991-1001, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25861827

RESUMO

BACKGROUND: The aim of this study was to examine the effect of colitis and anti-inflammatory therapies on the healing of colonic anastomoses in mice. METHODS: Female C57BL/6 mice were randomized into eight groups; four groups receiving plain tap-water and four groups receiving dextran sulfate sodium. Intra-peritoneal treatment was given therapeutically for 14 days with placebo, prednisolone, azathioprine, or infliximab (IFX). Colonic anastomoses were performed and bursting pressure (BP) measurements were recorded and the inflammation evaluated with histology and zymography. RESULTS: The mice with colitis had a more active inflammation based on histology and bowel weight compared with the tap water group, 8.3 (7.6-9.5) mg/mm and 5.5 (4.8-6.2) mg/mm respectively (p < 0.0001). Similarly mice with colitis receiving placebo had a more active inflammation, 12.8 (10.6-15.0) mg/mm, which differed significantly from all the other therapy arms among the colitic mice; prednisolone 8.1 (7.5-9.1) mg/mm (p = 0.014), azathioprine 8.2 (7.0-8.5) mg/mm (p = 0.0046), IFX 6.7 (6.4-7.9) mg/mm (p = 0.0055). BP for the placebo group was 90.0 (71.5-102.8) mmHg and did not differ from azathioprine or IFX groups, 84.4 (70.5-112.5) and 92.3 (75.8-122.3) mmHg respectively. In contrast BP for the prednisolone group was significantly decreased compared to placebo, 55.5 (42.8-73.0) mmHg (p = 0.0004). CONCLUSIONS: All therapies had a beneficial effect on the colitis. An impaired BP of colonic anastomoses was noted after preoperative steroids but not after azathioprine or IFX in this model.


Assuntos
Anti-Inflamatórios/uso terapêutico , Azatioprina/uso terapêutico , Colite/tratamento farmacológico , Colite/patologia , Infliximab/uso terapêutico , Prednisolona/uso terapêutico , Anastomose Cirúrgica/efeitos adversos , Animais , Colite/induzido quimicamente , Sulfato de Dextrana , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Pressão , Cicatrização/efeitos dos fármacos
12.
Infect Immun ; 81(2): 460-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23208605

RESUMO

Natural killer (NK) cells are traditionally considered in the context of tumor surveillance and viral defense, but their role in bacterial infections, particularly those caused by enteric pathogens, is less clear. C57BL/6 mice were orally gavaged with Citrobacter rodentium, a murine pathogen related to human diarrheagenic Escherichia coli. We used polyclonal anti-asialo GM1 antibody to actively deplete NK cells in vivo. Bioluminescent imaging and direct counts were used to follow infection. Flow cytometry and immunofluorescence microscopy were used to analyze immune responses. During C. rodentium infection, NK cells were recruited to mucosal tissues, where they expressed a diversity of immune-modulatory factors. Depletion of NK cells led to higher bacterial loads but less severe colonic inflammation, associated with reduced immune cell recruitment and lower cytokine levels. NK cell-depleted mice also developed disseminated systemic infection, unlike control infected mice. NK cells were also cytotoxic to C. rodentium in vitro.


Assuntos
Citrobacter rodentium/imunologia , Infecções por Enterobacteriaceae/imunologia , Células Matadoras Naturais/imunologia , Mucosa/imunologia , Animais , Ceco/imunologia , Citrobacter rodentium/patogenicidade , Colo/imunologia , Citocinas/imunologia , Infecções por Enterobacteriaceae/microbiologia , Feminino , Fatores Imunológicos/imunologia , Inflamação/imunologia , Camundongos , Camundongos Endogâmicos C57BL
13.
Gut Microbes ; 15(1): 2229948, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37424323

RESUMO

A high-fat (HF) diet reduces resistance to the foodborne pathogen Listeria monocytogenes. We demonstrate that short-term gavage with A. muciniphila increases resistance to oral and systemic L. monocytogenes infection in mice fed a HF diet. A. muciniphila reduced inflammation in the gut and liver of mice fed a high-fat diet prior to infection and reduced inflammatory cell infiltration in the ileum to levels similar to mice fed a low-fat (LF) diet. Akkermansia administration had minimal impacts upon the microbiota and microbial metabolites and did not affect individual taxa or impact the Bacteroidetes to Firmicutes ratio. In summary, A. muciniphila increased resistance to L. monocytogenes infection in mice fed a HF diet by moderating immune/physiological effects through specific interaction between A. muciniphila and the host gut.


Assuntos
Microbioma Gastrointestinal , Listeria monocytogenes , Listeriose , Animais , Camundongos , Dieta Hiperlipídica/efeitos adversos , Verrucomicrobia/fisiologia , Camundongos Endogâmicos C57BL
14.
Gut Microbes ; 15(1): 2163838, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36656595

RESUMO

Conflicting evidence exists on the association between consumption of non-steroidal anti-inflammatory drugs (NSAIDs) and symptomatic worsening of inflammatory bowel disease (IBD). We hypothesized that the heterogeneous prevalence of pathobionts [e.g., adherent-invasive Escherichia coli (AIEC)], might explain this inconsistent NSAIDs/IBD correlation. Using IL10-/- mice, we found that NSAID aggravated colitis in AIEC-colonized animals. This was accompanied by activation of the NLRP3 inflammasome, Caspase-8, apoptosis, and pyroptosis, features not seen in mice exposed to AIEC or NSAID alone, revealing an AIEC/NSAID synergistic effect. Inhibition of NLRP3 or Caspase-8 activity ameliorated colitis, with reduction in NLRP3 inflammasome activation, cell death markers, activated T-cells and macrophages, improved histology, and increased abundance of Clostridium cluster XIVa species. Our findings provide new insights into how NSAIDs and an opportunistic gut-pathobiont can synergize to worsen IBD symptoms. Targeting the NLRP3 inflammasome or Caspase-8 could be a potential therapeutic strategy in IBD patients with gut inflammation, which is worsened by NSAIDs.


Assuntos
Anti-Inflamatórios não Esteroides , Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Animais , Camundongos , Anti-Inflamatórios não Esteroides/efeitos adversos , Caspase 8/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/microbiologia , Inflamassomos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/microbiologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inibidores de Caspase/farmacologia , Escherichia coli/patogenicidade
15.
Infect Immun ; 80(8): 2712-23, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22615252

RESUMO

The sphingosine-1-phosphate (S1P) analogue FTY720 is therapeutically efficacious in multiple sclerosis and in the prevention of transplant rejection. It prevents the migration of lymphocytes to sites of pathology by trapping them within the peripheral lymph nodes, mesenteric lymph nodes (MLNs), and Peyer's patches. However, evidence suggests that its clinical use may increase the risk of mucosal infections. We investigated the impact of FTY720 treatment on susceptibility to gastrointestinal infection with the mouse enteric pathogen Citrobacter rodentium. This attaching and effacing bacterium induces a transient bacterial colitis in immunocompetent mice that resembles human infection with pathogenic Escherichia coli. FTY720 treatment induced peripheral blood lymphopenia, trapped lymphocytes in the MLNs, and prevented the clearance of bacteria when mice were infected with luciferase-tagged C. rodentium. FTY720-treated C. rodentium-infected mice had enhanced colonic inflammation, with significantly higher colon mass, colon histopathology, and neutrophil infiltration than vehicle-infected animals. In addition, FTY720-treated infected mice had significantly lower numbers of colonic dendritic cells, macrophages, and T cells. Gene expression analysis demonstrated that FTY720-treated infected mice had an impaired innate immune response and a blunted mucosal adaptive immune response, including Th1 cytokines. The data demonstrate that the S1P analogue FTY720 adversely affects the immune response to and clearance of C. rodentium.


Assuntos
Citrobacter rodentium/efeitos dos fármacos , Infecções por Enterobacteriaceae/microbiologia , Imunossupressores/farmacologia , Propilenoglicóis/farmacologia , Esfingosina/análogos & derivados , Animais , Citrobacter rodentium/imunologia , Infecções por Enterobacteriaceae/imunologia , Feminino , Cloridrato de Fingolimode , Regulação da Expressão Gênica/imunologia , Imunidade nas Mucosas/efeitos dos fármacos , Linfopenia/induzido quimicamente , Camundongos , Camundongos Endogâmicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Organismos Livres de Patógenos Específicos , Esfingosina/farmacologia
16.
Am J Physiol Gastrointest Liver Physiol ; 303(9): G1029-41, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-22961803

RESUMO

Enhanced barrier function is one mechanism whereby commensals and probiotic bacteria limit translocation of foreign antigens or pathogens in the gut. However, barrier protection is not exhibited by all probiotic or commensals and the strain-specific molecules involved remain to be clarified. We evaluated the effects of 33 individual Lactobacillus salivarius strains on the hydrogen peroxide (H(2)O(2))-induced barrier impairment in human epithelial Caco-2 cells. These strains showed markedly different effects on H(2)O(2)-induced reduction in transepithelial resistance (TER). The effective strains such as UCC118 and CCUG38008 attenuated H(2)O(2)-induced disassembly and relocalization of tight junction proteins, but the ineffective strain AH43324 did not. Strains UCC118 and CCUG38008 induced phosphorylation of extracellular signal-regulated kinase (ERK) in Caco-2 cells, and the ERK inhibitor U0126 attenuated the barrier-protecting effect of these strains. In contrast, the AH43324 strain induced phosphorylation of Akt and p38, which was associated with an absence of a protective effect. Global transcriptome analysis of UCC118 and AH43324 revealed that some genes in a bacteriocin gene cluster were upregulated in AH43324 under TER assay conditions. A bacteriocin-negative UCC118 mutant displayed significantly greater suppressive effect on H(2)O(2)-induced reduction in TER compared with wild-type UCC118. The wild-type strain augmented H(2)O(2)-induced phosphorylation of Akt and p38, whereas a bacteriocin-negative UCC118 mutant did not. These observations indicate that L. salivarius strains are widely divergent in their capacity for barrier protection, and this is underpinned by differences in the activation of intracellular signaling pathways. Furthermore, bacteriocin production appears to have an attenuating influence on lactobacillus-mediated barrier protection.


Assuntos
Bacteriocinas , Mucosa Intestinal , Lactobacillus , Junções Íntimas , Bacteriocinas/biossíntese , Células CACO-2 , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Peróxido de Hidrogênio/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Lactobacillus/genética , Lactobacillus/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oxidantes/farmacologia , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Proteínas de Junções Íntimas/metabolismo , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo
17.
Clin Dev Immunol ; 2012: 808157, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22162719

RESUMO

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, is associated with enhanced leukocyte infiltration to the gut, which is directly linked to the clinical aspects of these disorders. Thus, leukocyte trafficking is a major target for IBD therapy. Past and emerging techniques to study leukocyte trafficking both in vitro and in vivo have expanded our knowledge of the leukocyte migration process and the role of inhibitors. Various strategies have been employed to target chemokine- and integrin-ligand interactions within the multistep adhesion cascade and the S1P/S1PR1 axis in leukocyte migration. Though there is an abundance of preclinical data demonstrating efficacy of leukocyte trafficking inhibitors, many have yet to be confirmed in clinical studies. Vigilance for toxicity and further research is required into this complex and emerging area of IBD therapy.


Assuntos
Intestinos/patologia , Animais , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/metabolismo , Leucócitos/fisiologia
18.
Annu Rev Food Sci Technol ; 13: 489-512, 2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-34990225

RESUMO

Diet exerts a major influence upon host immune function and the gastrointestinal microbiota. Although components of the human diet (including carbohydrates, fats, and proteins) are essential sources of nutrition for the host, they also influence immune function directly through interaction with innate and cell-mediated immune regulatory mechanisms. Regulation of the microbiota community structure also provides a mechanism by which food components influence host immune regulatory processes. Here, we consider the complex interplay between components of the modern (Western) diet, the microbiota, and host immunity in the context of obesity and metabolic disease, inflammatory bowel disease, and infection.


Assuntos
Microbioma Gastrointestinal , Microbiota , Dieta , Dieta Ocidental/efeitos adversos , Humanos , Estado Nutricional , Obesidade
19.
Gut Microbes ; 14(1): 2007743, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35023810

RESUMO

In healthy hosts the gut microbiota is restricted to gut tissues by several barriers some of which require MyD88-dependent innate immune sensor pathways. Nevertheless, some gut taxa have been reported to disseminate to systemic tissues. However, the extent to which this normally occurs during homeostasis in healthy organisms is still unknown. In this study, we recovered viable gut bacteria from systemic tissues of healthy wild type (WT) and MyD88-/- mice. Shotgun metagenomic-sequencing revealed a marked increase in the relative abundance of L. johnsonii in intestinal tissues of MyD88-/- mice compared to WT mice. Lactobacillus johnsonii was detected most frequently from multiple systemic tissues and at higher levels in MyD88-/- mice compared to WT mice. Viable L. johnsonii strains were recovered from different cell types sorted from intestinal and systemic tissues of WT and MyD88-/- mice. L. johnsonii could persist in dendritic cells and may represent murine immunomodulatory endosymbionts.


Assuntos
Microbioma Gastrointestinal , Lactobacillus johnsonii/fisiologia , Fator 88 de Diferenciação Mieloide/deficiência , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Células Dendríticas/microbiologia , Trato Gastrointestinal/microbiologia , Lactobacillus johnsonii/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética
20.
Gut Microbes ; 14(1): 2149023, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36420990

RESUMO

The mechanisms by which early microbial colonizers of the neonate influence gut development are poorly understood. Bacterial bile salt hydrolase (BSH) acts as a putative colonization factor that influences bile acid signatures and microbe-host signaling pathways and we considered whether this activity can influence infant gut development. In silico analysis of the human neonatal gut metagenome confirmed that BSH enzyme sequences are present as early as one day postpartum. Gastrointestinal delivery of cloned BSH to immature gnotobiotic mice accelerated shortening of the colon and regularized gene expression profiles, with monocolonised mice more closely resembling conventionally raised animals. In situ expression of BSH decreased markers of cell proliferation (Ki67, Hes2 and Ascl2) and strongly increased expression of ALPI, a marker of cell differentiation and barrier function. These data suggest an evolutionary paradigm whereby microbial BSH activity potentially influences bacterial colonization and in-turn benefits host gastrointestinal maturation.


Assuntos
Microbioma Gastrointestinal , Transcriptoma , Feminino , Humanos , Camundongos , Animais , Amidoidrolases/genética , Amidoidrolases/metabolismo , Trato Gastrointestinal/microbiologia , Bactérias/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo
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