Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.190
Filtrar
1.
Anticancer Res ; 40(10): 5457-5462, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988867

RESUMO

BACKGROUND/AIM: Several studies have found elevated soluble CD40 Ligand (sCD40L) in the serum of patients with malignancies as well as those with inflammatory bowel disease (IBD). Our goal was to determine the possible causal role of sCD40L in colitis-associated colorectal cancer (CAC) by using the well-established azoxymethane/dextran sulfate sodium (AOM/DSS) protocol. MATERIALS AND METHODS: Twelve wild type (WT) and twelve TLR4 knock out (KO) female C57BL6 mice were divided into 4 experimental groups. Six WT and six TLR4 KO mice were treated with a single intraperitoneal dose (10 mg/kg of body weight) of AOM followed by three 7-day cycles of oral 2.5% DSS. The other two groups included 6 WT and 6 TLR4 KO mice that received only water and served as the control groups. The mice were sacrificed after 84 days. RESULTS: All mice in the AOM/DSS WT group developed CAC while all mice from the AOM/DSS TLR4 KO group were protected from CAC. We measured the serum and pathologic tissue levels of sCD40L with quantitative sandwich enzyme-linked immunoassay (ELISA) and found that serum sCD40L was significantly higher in wild-type mice that developed CAC compared to their healthy counterparts (wild-type and TLR-4 KO controls). In comparison, serum sCD40L levels were comparable between TLR-4 KO mice, which are protected from developing CAC, and their healthy counterparts (wild-type and TLR-4 KO controls). Of note, tissue levels of sCD40L were not affected by the development of CAC. CONCLUSION: Our findings point to the presence of an axis between TLR-4 and sCD40L, which may lead to decreased immunosurveillance and the subsequent development of colitis-associated cancer.


Assuntos
Ligante de CD40/genética , Colite/imunologia , Neoplasias Colorretais/induzido quimicamente , Receptor 4 Toll-Like/genética , Animais , Azoximetano/toxicidade , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Imunidade Inata/genética , Camundongos , Camundongos Knockout
2.
PLoS Pathog ; 16(8): e1008763, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32834002

RESUMO

The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric (typhoid) fever. In contrast, most non-typhoidal serovars of Salmonella are primarily restricted to gut tissues. Across Africa, invasive non-typhoidal Salmonella (iNTS) have emerged with an ability to spread beyond the gastrointestinal tract and cause systemic bloodstream infections with increased morbidity and mortality. To investigate this evolution in pathogenesis, we compared the genomes of African iNTS isolates with other Salmonella enterica serovar Typhimurium and identified several macA and macB gene variants unique to African iNTS. MacAB forms a tripartite efflux pump with TolC and is implicated in Salmonella pathogenesis. We show that macAB transcription is upregulated during macrophage infection and after antimicrobial peptide exposure, with macAB transcription being supported by the PhoP/Q two-component system. Constitutive expression of macAB improves survival of Salmonella in the presence of the antimicrobial peptide C18G. Furthermore, these macAB variants affect replication in macrophages and influence fitness during colonization of the murine gastrointestinal tract. Importantly, the infection outcome resulting from these macAB variants depends upon both the Salmonella Typhimurium genetic background and the host gene Nramp1, an important determinant of innate resistance to intracellular bacterial infection. The variations we have identified in the MacAB-TolC efflux pump in African iNTS may reflect evolution within human host populations that are compromised in their ability to clear intracellular Salmonella infections.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Colite/patologia , Variação Genética , Macrófagos/imunologia , Salmonelose Animal/patologia , Salmonella typhimurium/imunologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Linhagem da Célula , Colite/induzido quimicamente , Colite/imunologia , Colite/microbiologia , Análise Mutacional de DNA , Modelos Animais de Doenças , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Replicação Viral
3.
J Comput Assist Tomogr ; 44(4): 619-626, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32558769

RESUMO

OBJECTIVE: The aim of the study was to study clinical, imaging findings, response patterns, and immune-related adverse events in classical Hodgkin lymphoma (cHL) and non-Hodgkin lymphoma (NHL) patients treated with immune checkpoint inhibitors (ICIs). METHODS: A retrospective search was performed to identify patients with relapsed/refractory cHL and NHL treated with ICIs from 2015 to 2019. Clinical and laboratory data were collected. Imaging studies were reviewed for treatment response and immune-related adverse events. RESULTS: Ten patients with relapsed/refractory cHL (median age, 41 years) and 14 patients with relapsed/refractory NHL (median age, 61 years) were identified. Overall response rate was 70% for cHL patients. None of the NHL patients demonstrated complete or partial response. One case of hyperprogression and one case with atypical response were radiologically detected in cHL patients. Hypothyroidism requiring treatment occurred in 2 (20%) of 10 cHL patients, one of which had imaging correlate. Of 14 NHL patients, 1 (7%) had radiologic evidence of pneumonitis and 1 (7%) had colitis. CONCLUSIONS: This single-institution observational study demonstrated that overall response rate was higher in patients with cHL undergoing ICI. Immune checkpoint inhibitor therapy has unique response patterns and toxicities in both cHL and NHL patients that radiologists should keep in mind.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Colite/epidemiologia , Doença de Hodgkin/tratamento farmacológico , Hipotireoidismo/epidemiologia , Linfoma não Hodgkin/tratamento farmacológico , Pneumonia/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos Imunológicos/efeitos adversos , Colite/induzido quimicamente , Feminino , Doença de Hodgkin/diagnóstico por imagem , Humanos , Hipotireoidismo/induzido quimicamente , Linfoma não Hodgkin/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Nivolumabe/efeitos adversos , Nivolumabe/uso terapêutico , Pneumonia/induzido quimicamente , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos , Análise de Sobrevida , Centros de Atenção Terciária , Resultado do Tratamento , Adulto Jovem
4.
Am J Med Sci ; 360(2): 176-191, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32553747

RESUMO

BACKGROUND: This study aimed to investigate the role of Clostridium butyricum (C. butyricum) in conjunction with the Toll-like receptor2 (TLR2) signaling pathway and T helper 17 (Th17) cells in dextran sodium sulfate (DSS)-induced colitis in mice. METHODS: Forty 8-week-old BALB/c mice were randomly divided into 5 groups of 8 mice for 7 days: control, DSS (5% DSS), DSS+C. butyricum (1 × 109 CFU), DSS+C. butyricum (1 × 108 CFU) and DSS+C. butyricum (1 × 107 CFU) groups. We assessed the disease activity index (DAI) and histological damage scores. The expression levels of TLR2, myeloid differentiation factor 88 (MyD88), nuclear factor kappa-B p65 (NF-κBp65), interleukin (IL) 17 (IL17), IL23 and retineic acid receptor related orphan nuclear receptor gamma t (RORγt) were determined through immunohistochemical staining, western blot and quantitative real-time PCR (qRT-PCR). The expression levels of CD3+CD4+IL17+ cells in peripheral blood were measured by flow cytometry. RESULTS: C. butyricum dose-dependently decreased DAI and histological damage scores in DSS mice and down-regulated the mRNA and protein levels of TLR2, MyD88 and NF-κBp65 in mouse colon tissue (all P < 0.05). In addition, C. butyricum dose-dependently decreased the levels of CD3+CD4+IL17+ cells in peripheral blood and down-regulated the mRNA and protein levels of IL17, IL23 and RORγt in mouse colon tissue (all P < 0.05). Moreover, the effect of C. butyricum on TLR2 was positively correlated with IL17, IL23 and RORγt. CONCLUSIONS: C. butyricum exerts a dose-dependently protective effect on acute intestinal inflammation induced by DSS in mice, by inhibiting the TLR2 signaling pathway, down-regulating the expression of IL23 and RORγt, and inhibiting the secretion of IL17.


Assuntos
Clostridium butyricum , Colite/imunologia , Fator 88 de Diferenciação Mieloide/imunologia , Probióticos , Células Th17/imunologia , Receptor 2 Toll-Like/imunologia , Fator de Transcrição RelA/imunologia , Animais , Peso Corporal , Colite/induzido quimicamente , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Comportamento de Ingestão de Líquido , Comportamento Alimentar , Feminino , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-17/metabolismo , Interleucina-23/genética , Interleucina-23/imunologia , Interleucina-23/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , RNA Mensageiro/metabolismo , Distribuição Aleatória , Transdução de Sinais , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo
5.
Toxicol Appl Pharmacol ; 400: 115075, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32470352

RESUMO

NLRP3, one of the HSP-90 clients, has been defined as a critical component of IBD. In a rat model of DSS-induced colitis, we investigated the anti-inflammatory potential of the combined therapy with CP-456773 (CP), an NLRP3 inhibitor, and celastrol (CSR), an NF-κB inhibitor. Our results revealed that the CSR/CP combined therapy (CCCT) attenuated colon shortening, DAI and MDI in addition to improvement of the colonic histological picture. Moreover, the CCCT increased the antioxidant defense machinery of the colonic tissue and decreased MPO activity. Furthermore, the inflammation markers such as TNF-α and IL-6 were downregulated. These effects might be attributed to the inhibitory effect of CSR on the priming step of the NLRP3 inflammasome activation by interrupting NF-κB signalling and inhibition of HSP-90 (at the protein and mRNA levels) along with inhibitory effect of CP on the expression of the NLRP3. These latter effects resulted in decreased tissue expression and activity of the caspase-1 and repressing the subsequent release of the active forms of IL-1ß and IL-18, hence, the pyroptosis process is restrained. Additionally, the CCCT resulted in inducing autophagy by AMPK/mTOR-dependent mechanisms leading to the accumulation of BECN1 protein and a significant decrease in the levels of p62 SQSTM1. The inhibitory effect on HSP-90 in conjunction with induction of autophagy suggest increased autophagic degradation of NLRP3. This novel approach provides a basis for the clinical application of this combination in IBD treatment and might also be promising for the pharmacological intervention of other NLRP3 inflammasome-dependent inflammatory conditions.


Assuntos
Anti-Inflamatórios/farmacologia , Autofagia/efeitos dos fármacos , Colite/tratamento farmacológico , Proteínas de Choque Térmico HSP90/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Sulfonas/farmacologia , Triterpenos/farmacologia , Animais , Anti-Inflamatórios/administração & dosagem , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Citocinas/metabolismo , Sulfato de Dextrana/farmacologia , Modelos Animais de Doenças , Quimioterapia Combinada , Proteínas de Choque Térmico HSP90/sangue , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Inflamassomos/efeitos dos fármacos , Inflamassomos/imunologia , Masculino , Ratos Sprague-Dawley , Sulfonas/administração & dosagem , Sulfonas/uso terapêutico , Triterpenos/administração & dosagem , Triterpenos/uso terapêutico
6.
Am J Pathol ; 190(8): 1657-1666, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32380082

RESUMO

Increasingly, the ß-galactoside binding lectins, termed galectins, are being recognized as critical regulators of cell function and organismal homeostasis. Within the context of the mucosal surface, galectins are established regulators of innate and adaptive immune responses, microbial populations, and several critical epithelial functions, including cell migration, proliferation, and response to injury. However, given their complex tissue distribution and expression patterns, their role within specific processes remains poorly understood. We took a genetic approach to understand the role of endogenous galectin-9 (Gal-9), a mucosal galectin that has been linked to inflammatory bowel disease, within the context of the murine intestine. Gal-9-deficient (Gal9-/-, also known as Lgals9-/-) animals show increased sensitivity to chemically induced colitis and impaired proliferation in the setting of acute injury. Moreover, Gal9-/--derived enteroids showed impaired growth ex vivo. Consistent with a model in which endogenous Gal-9 controls epithelial growth and repair, Gal9-/- animals showed increased sensitivity to intestinal challenge in multiple models of epithelial injury, including acute irradiation injury and ectopic wound biopsies. Finally, regenerating crypts from patient biopsies showed increased expression of Gal-9, indicating these processes may be conserved in humans. Taken together, these studies implicate Gal-9 in the regulation of cellular proliferation and epithelial restitution after intestinal epithelial injury.


Assuntos
Colite/metabolismo , Colo/metabolismo , Galectinas/metabolismo , Mucosa Intestinal/metabolismo , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Colo/patologia , Galectinas/genética , Humanos , Mucosa Intestinal/patologia , Camundongos , Camundongos Knockout
7.
Nat Commun ; 11(1): 2591, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444641

RESUMO

The intestine is a highly dynamic environment that requires tight control of the various inputs to maintain homeostasis and allow for proper responses to injury. It was recently found that the stem cell niche and epithelium is regenerated after injury by de-differentiated adult cells, through a process that gives rise to Sca1+ fetal-like cells and is driven by a transient population of Clu+ revival stem cells (revSCs). However, the molecular mechanisms that regulate this dynamic process have not been fully defined. Here we show that TNFAIP8 (also known as TIPE0) is a regulator of intestinal homeostasis that is vital for proper regeneration. TIPE0 functions through inhibiting basal Akt activation by the commensal microbiota via modulating membrane phospholipid abundance. Loss of TIPE0 in mice results in injury-resistant enterocytes, that are hyperproliferative, yet have regenerative deficits and are shifted towards a de-differentiated state. Tipe0-/- enterocytes show basal induction of the Clu+ regenerative program and a fetal gene expression signature marked by Sca1, but upon injury are unable to generate Sca-1+/Clu+ revSCs and could not regenerate the epithelium. This work demonstrates the role of TIPE0 in regulating the dynamic signaling that determines the injury response and enables intestinal epithelial cell regenerative plasticity.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Microbioma Gastrointestinal/fisiologia , Intestinos/citologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Ataxina-1/metabolismo , Diferenciação Celular , Colite/induzido quimicamente , Colite/patologia , Enterócitos/patologia , Feminino , Técnicas de Silenciamento de Genes , Homeostase , Intestinos/irrigação sanguínea , Intestinos/patologia , Intestinos/efeitos da radiação , Isquemia/genética , Isquemia/patologia , Antígenos Comuns de Leucócito/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/patologia , Regeneração/fisiologia , Transdução de Sinais , Nicho de Células-Tronco , Células-Tronco/metabolismo
8.
Nat Commun ; 11(1): 2577, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444671

RESUMO

The gut microbiome consists of a multi-kingdom microbial community. Whilst the role of bacteria as causal contributors governing host physiological development is well established, the role of fungi remains to be determined. Here, we use germ-free mice colonized with defined species of bacteria, fungi, or both to differentiate the causal role of fungi on microbiome assembly, immune development, susceptibility to colitis, and airway inflammation. Fungal colonization promotes major shifts in bacterial microbiome ecology, and has an independent effect on innate and adaptive immune development in young mice. While exclusive fungal colonization is insufficient to elicit overt dextran sulfate sodium-induced colitis, bacterial and fungal co-colonization increase colonic inflammation. Ovalbumin-induced airway inflammation reveals that bacterial, but not fungal colonization is necessary to decrease airway inflammation, yet fungi selectively promotes macrophage infiltration in the airway. Together, our findings demonstrate a causal role for fungi in microbial ecology and host immune functionality, and therefore prompt the inclusion of fungi in therapeutic approaches aimed at modulating early life microbiomes.


Assuntos
Fungos/fisiologia , Microbioma Gastrointestinal/fisiologia , Sistema Imunitário/crescimento & desenvolvimento , Intestinos/microbiologia , Animais , Fenômenos Fisiológicos Bacterianos , Colite/induzido quimicamente , Colite/microbiologia , Sulfato de Dextrana/toxicidade , Fezes/microbiologia , Feminino , Fungos/isolamento & purificação , Microbioma Gastrointestinal/imunologia , Vida Livre de Germes , Humanos , Inflamação/induzido quimicamente , Inflamação/microbiologia , Metaboloma , Camundongos Endogâmicos C57BL , Ovalbumina/toxicidade
9.
Nat Commun ; 11(1): 1802, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286276

RESUMO

Inflammatory bowel disease patients have a greatly increased risk of developing colitis-associated colon cancer (CAC); however, the basis for inflammation-induced genetic damage requisite for neoplasia is unclear. Using three models of CAC, we find that sustained inflammation triggers 8-oxoguanine DNA lesions. Strikingly, antioxidants or iNOS inhibitors reduce 8-oxoguanine and polyps in CAC models. Because the mismatch repair (MMR) system repairs 8-oxoguanine and is frequently defective in colorectal cancer (CRC), we test whether 8-oxoguanine mediates oncogenesis in a Lynch syndrome (MMR-deficient) model. We show that microbiota generates an accumulation of 8-oxoguanine lesions in MMR-deficient colons. Accordingly, we find that 8-oxoguanine is elevated in neoplastic tissue of Lynch syndrome patients compared to matched untransformed tissue or non-Lynch syndrome neoplastic tissue. While antioxidants reduce 8-oxoguanine, they do not reduce CRC in Lynch syndrome models. Hence, microbe-induced oxidative/nitrosative DNA damage play causative roles in inflammatory CRC models, but not in Lynch syndrome models.


Assuntos
Colite/complicações , Colite/patologia , Neoplasias Colorretais/complicações , Neoplasias Colorretais/patologia , Dano ao DNA , Helicobacter pylori/fisiologia , Estresse Oxidativo , Polipose Adenomatosa do Colo/complicações , Polipose Adenomatosa do Colo/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antioxidantes/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Colite/induzido quimicamente , Colite/microbiologia , Colo/efeitos dos fármacos , Colo/patologia , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo do DNA/efeitos dos fármacos , Sulfato de Dextrana , Modelos Animais de Doenças , Disbiose/complicações , Disbiose/patologia , Escherichia coli/metabolismo , Feminino , Guanosina/análogos & derivados , Guanosina/metabolismo , Infecções por Helicobacter/complicações , Helicobacter pylori/efeitos dos fármacos , Humanos , Inflamação/complicações , Inflamação/patologia , Interleucina-10/deficiência , Interleucina-10/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mutação/genética , Estresse Oxidativo/efeitos dos fármacos
10.
Adv Exp Med Biol ; 1244: 247-253, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32301019

RESUMO

Immune checkpoint inhibitors (ICIs) have shown significant benefit in cancer patients. Their success, however, is associated with immune-related adverse events (irAEs), which commonly affect the gastrointestinal tract, resulting in diarrhea and colitis. IrAEs range from mild self-limiting to severe life-threatening diseases and potentially limit the use of these medications. Diagnosis of ICI-induced enterocolitis is based on clinical symptoms, physical examination, stool tests, endoscopic and histologic evaluation, and/or imaging. Current management strategy is mainly anti-diarrheal agents for mild symptoms and immunosuppressants (e.g., corticosteroids, and infliximab or vedolizumab) for more severe diseases.


Assuntos
Colite/induzido quimicamente , Diarreia/induzido quimicamente , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/patologia , Imunoterapia/efeitos adversos , Neoplasias/tratamento farmacológico , Colite/tratamento farmacológico , Colite/imunologia , Colite/patologia , Diarreia/tratamento farmacológico , Diarreia/imunologia , Diarreia/patologia , Humanos , Neoplasias/imunologia
11.
BMC Biol ; 18(1): 29, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32183814

RESUMO

BACKGROUND: Immune checkpoint inhibitor (ICPI) can augment the anti-tumour response by blocking negative immunoregulators with monoclonal antibodies. The anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) antibody is the first ICPI which has shown remarkable benefits in the clinical treatment of cancers. However, the increased activity of the immune system also causes some side effects called immune-related adverse events (irAEs). Colitis is one of the most common irAEs related to anti-CTLA-4 immunotherapy. RESULTS: We identified that CD4+ T cells were the primary responders in CTLA-4 blockade and that the expansion of gut-homing CD4+ T cells by anti-CTLA-4 therapy was independent of CD103. We used dextran sulfate sodium (DSS)-induced colitis mice as our model and tested the possibility of using a trafficking-blocking antibody to treat anti-CTLA-4 antibody-induced irAEs. We found that blocking T cell homing increased colitis severity in the context of CTLA-4 blockade and that gut-trafficking blockade had different effects on different Th subsets and could facilitate the proliferation of Th17 cells in the lamina propria (LP). CONCLUSIONS: Our data reveals the fundamental mechanism underlying trafficking-blocking antibody therapy for CTLA-4 blockade-induced colitis and provide a caution in regard to apply trafficking-blocking antibody treatment under CTLA-4 blockade condition.


Assuntos
Anticorpos Bloqueadores/farmacologia , Antígeno CTLA-4/antagonistas & inibidores , Colite/imunologia , Linfócitos T/imunologia , Animais , Colite/induzido quimicamente , Colite/patologia , Sulfato de Dextrana/efeitos adversos , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
12.
Biol Pharm Bull ; 43(3): 450-457, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32115503

RESUMO

Resveratrol (Res) is a natural active antioxidant that is effective in relieving inflammatory bowel disease (IBD). However, the specific mechanism for its function is unknown. In our study, dextran sodium sulfate (DSS)-induced mouse IBD disease model was constructed. All mice were randomly divided into three groups. The treatment effects of resveratrol on IBD were evaluated by observing the body weight, fecal traits, colon/spleen gross appearance, tissue hematoxylin-eosin (H&E)/immunohistochemistry (IHC) and inflammatory factors. The expression of small ubiquitin-like modifier protein 1 (SUMO1) and its Wnt/ß-catenin pathway-related genes was analyzed by IHC, Western blot, Real-time PCR (RT-PCR) and Immunofluorescence. The outcome indicated that resveratrol treatment significantly relieved the symptoms of IBD. The expression level of anti-inflammatory cytokines was increased while that of pro-inflammatory cytokines was decreased in both colon and spleen tissues of resveratrol-treated mice. SUMO1 expression and Wnt/ß-catenin pathway were suppressed in colon and spleen tissues of IBD mice treated with resveratrol. In addition, we provided evidence that resveratrol inhibited SUMO1 and ß-catenin expression and their nuclear localization in human colonic epithelial cell line (FHC). Moreover, we found that SUMO1 and ß-catenin had higher expression levels in colorectal cancer patients than in health and colitis patients. In conclusions, resveratrol alleviates DSS-induced IBD by modulating SUMO1 through Wnt/ß-catenin pathway.


Assuntos
Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Resveratrol/farmacologia , Proteína SUMO-1/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Técnicas de Cultura de Células , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colo/efeitos dos fármacos , Colo/metabolismo , Neoplasias Colorretais/metabolismo , Citocinas/metabolismo , Sulfato de Dextrana/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Baço/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina
13.
Phytomedicine ; 68: 153179, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32062328

RESUMO

BACKGROUND: Intestinal epithelial barrier dysfunction, which involves myosin light chain kinase (MLCK) activation, contributes to the occurrence and progression of inflammation in inflammatory bowel disease (IBD). Wogonoside helps maintain intestinal homeostasis in mice with dextran sulfate sodium (DSS)-induced colitis, but it is unclear whether it modulates intestinal barrier function. PURPOSE: Here, we demonstrate that wogonoside protects against intestinal barrier dysfunction in colitis via the MLCK/pMLC2 pathway both in vivo and in vitro. METHODS: Caco-2 cell monolayers treated with the proinflammatory cytokine TNF-α showed barrier dysfunction and were assessed in the absence and presence of wogonoside for various physiological, morphological, and biochemical parameters. Colitis was induced by 3% DSS in mice, which were used as an animal model to explore the pharmacodynamics of wogonoside. We detected MLCK/pMLC2 pathway proteins via western blot analysis, assessed the cytokines IL-13 and IFN-γ via ELISA, tested bacterial translocation via fluorescence in situ hybridization (FISH) and a proper sampling of secondary lymphoid organs for bacterial culture. In addition, the docking affinity of wogonoside and MLCK was observed with DS2.5 software. RESULTS: Wogonoside alleviated the disruption of transepithelial electrical resistance (TER) in TNF-α exposured Caco-2 cell; FITC-dextran hyperpermeability; loss of the tight junction (TJ) proteins occludin, ZO-1 and claudin-1 in Caco-2 cell monolayers; and bacterial translocation in colitic mice. Moreover, wogonoside reduced the levels of the proinflammatory cytokines IL-13 and IFN-γ to maintain intestinal immune homeostasis. Transmission electron microscopy (TEM) confirmed that wogonoside ameliorated the destruction of intestinal epithelial TJs. Wogonoside not only inhibited the cytoskeletal F-actin rearrangement induced by TNF-α, stabilized the cytoskeletal structure, suppressed MLCK protein expression, and reduced MLC2 phosphorylation. In addition, the results of molecular docking analysis showed that wogonoside had a high affinity for MLCK and formed hydrogen bonds with the amino acid residue LYS261 and π bonds with LYS229. CONCLUSION: Collectively, our study indicates that wogonoside alleviates colitis by protecting against intestinal barrier dysfunction, and the potential mechanism may involve regulation of TJs via the MLCK/pMLC2 signaling pathway. Meanwhile, our study also explains the success of S. baicalensis in the treatment of ulcerative colitis (UC).


Assuntos
Miosinas Cardíacas/metabolismo , Colite/tratamento farmacológico , Flavanonas/farmacologia , Glucosídeos/farmacologia , Cadeias Leves de Miosina/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , Animais , Células CACO-2 , Colite/induzido quimicamente , Colite/metabolismo , Sulfato de Dextrana/toxicidade , Flavanonas/química , Glucosídeos/química , Humanos , Mucosa Intestinal/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Fosforilação , Proteínas de Junções Íntimas/metabolismo
14.
Nat Microbiol ; 5(4): 610-619, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32015497

RESUMO

Although much research has been done on the diversity of the gut microbiome, little is known about how it influences intestinal homeostasis under normal and pathogenic conditions. Epigenetic mechanisms have recently been suggested to operate at the interface between the microbiota and the intestinal epithelium. We performed whole-genome bisulfite sequencing on conventionally raised and germ-free mice, and discovered that exposure to commensal microbiota induced localized DNA methylation changes at regulatory elements, which are TET2/3-dependent. This culminated in the activation of a set of 'early sentinel' response genes to maintain intestinal homeostasis. Furthermore, we demonstrated that exposure to the microbiota in dextran sodium sulfate-induced acute inflammation results in profound DNA methylation and chromatin accessibility changes at regulatory elements, leading to alterations in gene expression programs enriched in colitis- and colon-cancer-associated functions. Finally, by employing genetic interventions, we show that microbiota-induced epigenetic programming is necessary for proper intestinal homeostasis in vivo.


Assuntos
Colite/genética , DNA/genética , Epigênese Genética , Microbioma Gastrointestinal/fisiologia , Genoma , Simbiose/genética , Animais , Colite/induzido quimicamente , Colite/microbiologia , Colite/patologia , Colo/metabolismo , Colo/microbiologia , DNA/metabolismo , Metilação de DNA , Sulfato de Dextrana/administração & dosagem , Vida Livre de Germes , Homeostase/genética , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sequenciamento Completo do Genoma
15.
J Pharmacol Exp Ther ; 373(2): 167-174, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32029576

RESUMO

We hypothesized that, in mice, histamine via the histamine receptor subtype 4 (H4R) on colon epithelial cells affects epithelial barrier integrity, perturbing physiologic function of the colonic mucosa and thus aggravating the severity of colitis. To test this hypothesis, bone marrow-chimeric mice were generated from H4R knockout (H4R-/-) and wild-type (WT) BALB/cJ mice and subjected to the dextrane sodium sulfate (DSS)-induced acute colitis model. Clinical symptoms and pathohistological derangements were scored. Additionally, total RNA was extracted from either mouse whole-colon homogenates or primary cell preparations enriched for epithelial cells, and gene expression was analyzed by real-time quantitative polymerase chain reaction. The impact of the H4R on epithelial barrier function was assessed by measurement of transepithelial electrical resistence of organoid-derived two-dimensional monolayers from H4R-/- and WT mice using chopstick electrodes. Bone marrow-chimeric mice with genetic depletion of the H4R in nonhematopoietic cells exhibited less severe DSS-induced acute colitis symptoms compared with WT mice, indicating a functional proinflammatory expression of H4R in nonimmune cells of the colon. Analysis of H4R expression revealed the presence of H4R mRNA in colon epithelial cells. This expression could be confirmed and complemented by functional analyses in organoid-derived epithelial cell monolayers. Thus, we conclude that the H4R is functionally expressed in mouse colon epithelial cells, potentially modulating mucosal barrier integrity and intestinal inflammatory reactions, as was demonstrated in the DSS-induced colitis model, in which presence of the H4R on nonhematopoietic cells aggravated the inflammatory phenotype. SIGNIFICANCE STATEMENT: The histamine H4 receptor (H4R) is functionally expressed on mouse colon epithelial cells, thereby aggravating dextrane sodium sulfate-induced colitis in BALB/cJ mice. Histamine via the H4R reduces transepithelial electrical resistance of colon epithelial monolayers, indicating a function of H4R in regulation of epithelial barrier integrity.


Assuntos
Colo/fisiologia , Mucosa Intestinal/fisiologia , Receptores Histamínicos H4/fisiologia , Animais , Colite/induzido quimicamente , Sulfato de Dextrana , Impedância Elétrica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/análise , Receptores Histamínicos H4/genética
16.
Benef Microbes ; 11(1): 47-57, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32066260

RESUMO

This study evaluated the effects of Bifidobacterium longum 51A on the intestinal mucosa and inflammatory response in experimental colitis. Colitis was induced by administration of 3.5% dextran sodium sulphate (DSS) solution for 7 days. Two periods of administration were performed: treatment (T) group, mice received Bifidobacterium only during disease induction (7 days); total treatment (TT) group, mice received Bifidobacterium for 10 days before and during disease induction. The probiotic effects on intestinal permeability, inflammatory infiltrate, histological analysis, cytokines, chemokines and sIgA were evaluated. Bifidobacterium administration in the T group showed reduction in intestinal permeability and lower IL-1ß, myeloperoxidase, and eosinophil peroxidase levels compared to those in the colitis group (P<0.05). Bifidobacterium administration in the TT group attenuated severe lesions in the colon and reduced eosinophil peroxidase level (P<0.05). B. longum 51A treatment modality was more effective than total treatment and reduced the inflammatory response and its consequences on intestinal epithelium.


Assuntos
Bifidobacterium longum , Doenças Inflamatórias Intestinais/tratamento farmacológico , Probióticos/uso terapêutico , Animais , Colite/induzido quimicamente , Colo/efeitos dos fármacos , Colo/microbiologia , Colo/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Peroxidase de Eosinófilo/metabolismo , Feminino , Imunoglobulina A Secretora/metabolismo , Inflamação/tratamento farmacológico , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/microbiologia , Interleucina-1beta/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Intestinos/efeitos dos fármacos , Intestinos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Peroxidase/metabolismo
17.
Int J Med Microbiol ; 310(2): 151391, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32007342

RESUMO

Lactobacillus plantarum has been identified as a probiotic bacterium owing to its role in immune regulation and maintenance of intestinal permeability. Here, we investigated the anti-colitic effects and mechanism of L. plantarum CBT LP3 (LP3). This in vivo study was performed using dextran sodium sulfate (DSS) to induce colitis in mice. Mice were randomly divided into three groups: a control supplied with normal drinking water, a DSS-treated group followed by oral administration of vehicle, and a DSS-treated group gavaged with LP3 daily for 7 days following DSS administration. An analysis of macrophages and T cell subsets harvesting from peritonium cavity cells and splenocytes was performed using a flow cytometric assay. Gene expression and cytokine profiles were measured using quantitative reverse transcriptase polymerase chain reaction. The administration of LP3 significantly attenuated disease activity and histolopathology compared to control. LP3 had anti-inflammatory effects, with increased induction of regulatory T cells and type 2 helper T cells in splenocytes and restoration of goblet cells accompanied by suppression of proinflammatory cytokine expressions. These findings suggest that L. plantarum CBT LP3 can be used as a potent immunomodulator, which has significant implications for IBD treatment.


Assuntos
Colite/imunologia , Colite/terapia , Lactobacillus plantarum , Probióticos/uso terapêutico , Subpopulações de Linfócitos T/imunologia , Animais , Colite/induzido quimicamente , Citocinas/imunologia , Sulfato de Dextrana , Modelos Animais de Doenças , Fatores Imunológicos/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/imunologia , Células Th2/imunologia
18.
Int J Med Sci ; 17(2): 145-152, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32038097

RESUMO

The azoxymethane (AOM)/dextran sulfate sodium (DSS) murine model is commonly used to study colitis-associated cancer. The human commensal bacterium, enterotoxigenic Bacteroides fragilis (ETBF) secretes the Bacteroides fragilis toxin (BFT) which is necessary and sufficient to cause colitis. We report that BALB/c mice infected with WT-ETBF and administered three cycles of AOM/DSS developed numerous, large-sized polyps predominantly in the colorectal region. In addition, AOM/DSS-treated BALB/c mice orally inoculated with wild-type nontoxigenic Bacteroides fragilis (WT-NTBF) overexpressing bft (rETBF) developed numerous polyps whereas mice infected with WT-NTBF overexpressing a biologically inactive bft (rNTBF) did not promote polyp formation. Unexpectedly, the combination of AOM+ETBF did not induce polyp formation whereas ETBF+DSS did induce polyp development in a subset of BALB/c mice. In conclusion, WT-ETBF promoted polyp development in AOM/DSS murine model with increased colitis in BALB/c mice. The model described herein provides an experimental platform for understanding ETBF-induced colonic tumorigenesis and studying colorectal cancer in wild-type mice.


Assuntos
Infecções por Bacteroides/patologia , Carcinogênese/genética , Colite/patologia , Neoplasias Colorretais/patologia , Animais , Azoximetano/toxicidade , Toxinas Bacterianas/toxicidade , Infecções por Bacteroides/induzido quimicamente , Infecções por Bacteroides/complicações , Infecções por Bacteroides/microbiologia , Bacteroides fragilis/patogenicidade , Carcinogênese/induzido quimicamente , Colite/induzido quimicamente , Colite/complicações , Colite/microbiologia , Colo/efeitos dos fármacos , Colo/patologia , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/complicações , Neoplasias Colorretais/microbiologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Metaloendopeptidases/toxicidade , Camundongos , Pólipos/induzido quimicamente
20.
PLoS One ; 15(2): e0220756, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32040478

RESUMO

Adipose tissue derived mesenchymal stem/stromal cell (ASC)-derived extracellular vesicles (EV) have been reported to be beneficial against dextran sulfate sodium (DSS)-induced colitis in mice. However, the underlying mechanisms have not been fully elucidated. We hypothesize that the tumor necrosis factor-α-stimulated gene/protein 6 (TSG-6) in EVs is a key factor influencing the alleviation of colitis symptoms. DSS-induced colitis mice (C57BL/6, male, Naïve = 6, Sham = 8, PBS = 8 EV = 8, CTL-EV = 8, TSG-6 depleted EV = 8) were intraperitoneally administered EVs (100 ug/mice) on day 1, 3, and 5; colon tissues were collected on day 10 for histopathological, RT-qPCR, western blot and immunofluorescence analyses. In mice injected with EV, inflammation was alleviated. Indeed, EVs regulated the levels of pro- and anti-inflammatory cytokines, such as TNF-α, IL-1ß, IFN-γ, IL-6, and IL-10 in inflamed colons. However, when injected with TSG-6 depleted EV, the degree of inflammatory relief was reduced. Furthermore, TSG-6 in EVs plays a key role in increasing regulatory T cells (Tregs) and polarizing macrophage from M1 to M2 in the colon. In conclusion, this study shows that TSG-6 in EVs is a major factor in the relief of DSS-induced colitis, by increasing the number of Tregs and macrophage polarization from M1 to M2 in the colon.


Assuntos
Moléculas de Adesão Celular/farmacologia , Colite/prevenção & controle , Vesículas Extracelulares/química , Células-Tronco Mesenquimais/química , Animais , Contagem de Células , Colite/induzido quimicamente , Colite/terapia , Citocinas/metabolismo , Sulfato de Dextrana/efeitos adversos , Cães , Vesículas Extracelulares/transplante , Inflamação/terapia , Macrófagos/citologia , Células-Tronco Mesenquimais/ultraestrutura , Camundongos , Linfócitos T Reguladores/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA