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1.
Front Immunol ; 10: 2449, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824476

RESUMO

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) characterized by mucosa damage associated with an uncontrolled inflammatory response. This immunological impairment leads to altered inflammatory mediators such as IL-33, which is shown to increase in the mucosa of active UC (aUC) patients. MicroRNAs present a distorted feature in inflamed colonic mucosa and are potential IL-33 regulating candidates in UC. Therefore, we studied the microRNA and mRNA profiles in inflamed colonic samples of UC patients, evaluating the effect of a microRNA (selected by in silico analysis and its expression in UC patients), on IL-33 under inflammatory conditions. We found that inflamed mucosa (n = 8) showed increased expression of 40 microRNAs and 2,120 mRNAs, while 49 microRNAs and 1,734 mRNAs were decreased, as determined by microarrays. In particular, IL-33 mRNA showed a 3.8-fold increase and eight members of a microRNA family (miR-378), which targets IL-33 mRNA in the 3'UTR, were decreased (-3.9 to -3.0 times). We selected three members of the miR-378 family (miR-378a-3p, miR-422a, and miR-378c) according to background information and interaction energy analysis, for further correlation analyses with IL-33 expression through qPCR and ELISA, respectively. We determined that aUC (n = 24) showed high IL-33 levels, and decreased expression of miR-378a-3p and miR-422a compared to inactive UC (n = 10) and controls (n = 6). Moreover, both microRNAs were inversely correlated with IL-33 expression, while miR-378c does not show a significant difference. To evaluate the effect of TNFα on the studied microRNAs, aUC patients with anti-TNF therapy were compared to aUC receiving other treatments. The levels of miR-378a-3p and miR-378c were higher in aUC patients with anti-TNF. Based on these findings, we selected miR-378a-3p to exploring the molecular mechanism involved by in vitro assays, showing that over-expression of miR-378a-3p decreased the levels of an IL-33 target sequence ß-gal-reporter gene in HEK293 cells. Stable miR-378a-3p over-expression/inhibition inversely modulated IL-33 content and altered viability of HT-29 cells. Additionally, in an inflammatory context, TNFα decreased miR-378a-3p levels in HT-29 cells enhancing IL-33 expression. Together, our results propose a regulatory mechanism of IL-33 expression exerted by miR-378a-3p in an inflammatory environment, contributing to the understanding of UC pathogenesis.

3.
Front Immunol ; 10: 277, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30915065

RESUMO

Ulcerative colitis (UC) and Crohn's disease (CD), collectively known as Inflammatory Bowel Diseases (IBD), are caused by a complex interplay between genetic, immunologic, microbial and environmental factors. Dysbiosis of the gut microbiome is increasingly considered to be causatively related to IBD and is strongly affected by components of a Western life style. Bacteria that ferment fibers and produce short chain fatty acids (SCFAs) are typically reduced in mucosa and feces of patients with IBD, as compared to healthy individuals. SCFAs, such as acetate, propionate and butyrate, are important metabolites in maintaining intestinal homeostasis. Several studies have indeed shown that fecal SCFAs levels are reduced in active IBD. SCFAs are an important fuel for intestinal epithelial cells and are known to strengthen the gut barrier function. Recent findings, however, show that SCFAs, and in particular butyrate, also have important immunomodulatory functions. Absorption of SCFAs is facilitated by substrate transporters like MCT1 and SMCT1 to promote cellular metabolism. Moreover, SCFAs may signal through cell surface G-protein coupled receptors (GPCRs), like GPR41, GPR43, and GPR109A, to activate signaling cascades that control immune functions. Transgenic mouse models support the key role of these GPCRs in controlling intestinal inflammation. Here, we present an overview of microbial SCFAs production and their effects on the intestinal mucosa with specific emphasis on their relevance for IBD. Moreover, we discuss the therapeutic potential of SCFAs for IBD, either applied directly or by stimulating SCFAs-producing bacteria through pre- or probiotic approaches.

5.
Front Immunol ; 9: 1026, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29867993

RESUMO

Crohn's disease (CD) is a chronic inflammatory bowel disorder characterized by deregulated inflammation triggered by environmental factors. Notably, adherent-invasive Escherichia coli (AIEC), a bacterium with the ability to survive within macrophages is believed to be one of such factors. Glucocorticoids are the first line treatment for CD and to date, it is unknown how they affect bactericidal and inflammatory properties of macrophages against AIEC. The aim of this study was to evaluate the impact of glucocorticoid treatment on AIEC infected macrophages. First, THP-1 cell-derived macrophages were infected with a CD2-a AIEC strain, in the presence or absence of the glucocorticoid dexamethasone (Dex) and mRNA microarray analysis was performed. Differentially expressed mRNAs were confirmed by TaqMan-qPCR. In addition, an amikacin protection assay was used to evaluate the phagocytic and bactericidal activity of Dex-treated macrophages infected with E. coli strains (CD2-a, HM605, NRG857c, and HB101). Finally, cytokine secretion and the inflammatory phenotype of macrophages were evaluated by ELISA and flow cytometry, respectively. The microarray analysis showed that CD2-a, Dex, and CD2-a + Dex-treated macrophages have differential inflammatory gene profiles. Also, canonical pathway analysis revealed decreased phagocytosis signaling by Dex and anti-inflammatory polarization on CD2-a + Dex macrophages. Moreover, amikacin protection assay showed reduced phagocytosis upon Dex treatment and TaqMan-qPCR confirmed Dex inhibition of three phagocytosis-associated genes. All bacteria strains induced TNF-α, IL-6, IL-23, CD40, and CD80, which was inhibited by Dex. Thus, our data demonstrate that glucocorticoids impair phagocytosis and induce anti-inflammatory polarization after AIEC infection, possibly contributing to the survival of AIEC in infected CD patients.


Assuntos
Doença de Crohn/microbiologia , Dexametasona/farmacologia , Infecções por Escherichia coli/imunologia , Glucocorticoides/farmacologia , Macrófagos/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Animais , Aderência Bacteriana , Doença de Crohn/imunologia , Citocinas/imunologia , Escherichia coli/patogenicidade , Humanos , Inflamação , Macrófagos/microbiologia , Camundongos , Camundongos Knockout , Análise em Microsséries , Proteína Adaptadora de Sinalização NOD2/genética , Reação em Cadeia da Polimerase em Tempo Real , Células THP-1 , Fator de Necrose Tumoral alfa/imunologia
6.
World J Gastroenterol ; 23(36): 6628-6638, 2017 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-29085208

RESUMO

Inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn's disease, are chronic pathologies associated with a deregulated immune response in the intestinal mucosa, and they are triggered by environmental factors in genetically susceptible individuals. Exogenous glucocorticoids (GCs) are widely used as anti-inflammatory therapy in IBDs. In the past, patients with moderate or severe states of inflammation received GCs as a first line therapy with an important effectiveness in terms of reduction of the disease activity and the induction of remission. However, this treatment often results in detrimental side effects. This downside drove the development of second generation GCs and more precise (non-systemic) drug-delivery methods. Recent clinical trials show that most of these new treatments have similar effectiveness to first generation GCs with fewer adverse effects. The remaining challenge in successful treatment of IBDs concerns the refractoriness and dependency that some patients encounter during GCs treatment. A deeper understanding of the molecular mechanisms underlying GC response is key to personalizing drug choice for IBDs patients to optimize their response to treatment. In this review, we examine the clinical characteristics of treatment with GCs, followed by an in depth analysis of the proposed molecular mechanisms involved in its resistance and dependence associated with IBDs. This thorough analysis of current clinical and biomedical literature may help guide physicians in determining a course of treatment for IBDs patients and identifies important areas needing further study.


Assuntos
Anti-Inflamatórios/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Glucocorticoides/uso terapêutico , Imunossupressores/uso terapêutico , Anti-Inflamatórios/farmacologia , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/genética , Colite Ulcerativa/imunologia , Doença de Crohn/epidemiologia , Doença de Crohn/genética , Doença de Crohn/imunologia , Sistemas de Liberação de Medicamentos/métodos , Resistência a Medicamentos/genética , Epigênese Genética , Glucocorticoides/farmacologia , Humanos , Sistema Imunitário/efeitos dos fármacos , Imunossupressores/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/fisiopatologia , Prevalência , Resultado do Tratamento
7.
Tumour Biol ; 39(9): 1010428317724517, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28936923

RESUMO

Colorectal cancer is a multistep process affecting several signaling pathways including EGFR (epidermal growth factor receptor), a therapeutic target for metastatic disease. Our aim was to characterize the mutational and expression profiles of the EGFR pathway in colorectal tumors and to integrate these results according to five previously defined groups. We screened seven genes for mutations ( KRAS-BRAF-PIK3CA-PIK3R1-AKT1-MAP2K1-PTEN) and six proteins (EGFR-p110α-p85α-PTEN-phosphoAKT-phosphoMEK1) by immunohistochemistry, PTEN deletion, and MSI. At least one mutated gene was observed in 68% of tumors ( KRAS 45%, PIK3CA 21%, BRAF 14%, and PTEN 7%). PTEN deletion was observed in 10.7% of tumors and 19.6% were MSI-High. In all, 54% of tumors showed a high EGFR expression, 48% p110α, 4.4% phosphoAKT, and 22% phosphoMEK1; and 43% showed low PTEN expression and 22% p85α. In total, five groups of tumors were defined based on MSI, BRAF, and KRAS mutations. Three groups gather mainly early-stage tumors, whereas a fourth group is mostly conformed by advanced tumors. We described here that 71.4% of tumors from one group have a mutated PI3K/PTEN pathway, in comparison to other groups having 32%, 27%, and 25%. In addition, the five groups are differentiated by molecular features such as EGFR, p85α, p110α, and PTEN, showing variable expression among tumor groups. In conclusion, alterations on the EGFR pathway were found in a high percentage of colorectal cancer patients. Using the integration of diverse molecular markers, we ratified previous classification in an ethnic group having relevant genetic differences and living in a different environmental background, adding complementary molecular targets related to therapy.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Receptores ErbB/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Chile , Análise Mutacional de DNA , Feminino , Genes erbB-1 , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Transdução de Sinais/genética , Análise Serial de Tecidos , Transcriptoma
8.
Sci Rep ; 7(1): 10180, 2017 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-28860510

RESUMO

The ST2/IL33 signalling pathway has been associated with ulcerative colitis (UC). ST2, encoded by the IL1RL1 gene, is expressed as both a membrane-anchored receptor (ST2L) activated by IL33 and as a soluble receptor (sST2) with anti-inflammatory properties. In UC patients, sST2 is further increased by corticosteroid treatment; however, the glucocorticoid-mediated molecular regulation remains unknown. We therefore tested whether genetic variants in the IL1RL1 distal promoter are involved in UC and affect glucocorticoid-mediated ST2 expression. Serum ST2 levels and genetic variants in the IL1RL1 distal promoter were examined by ELISA and PCR sequencing in UC patients receiving corticosteroids. Glucocorticoid-mediated ST2 production was evaluated in intestinal mucosa cultures. Molecular regulation of glucocorticoid-mediated ST2 was assessed by RT-qPCR, ChIP assay and luciferase reporter assay. Dexamethasone effect on ST2 transcript expression was analyzed in leukocytes and related to IL1RL1 variants. Sequencing of a distal IL1RL1 promoter region demonstrated that SNPs rs6543115(C) and rs6543116(A) are associated with increased sST2 in UC patients on corticosteroids. Dexamethasone up-regulated sST2 transcription through interaction with the glucocorticoid-response element (GRE) carrying rs6543115(C) variant. Our data indicate that IL1RL1 SNPs rs6543115(C) confer susceptibility to UC and is contained in the GRE, which may modulate glucocorticoid-induced sST2 expression.


Assuntos
Corticosteroides/farmacologia , Colite Ulcerativa/tratamento farmacológico , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Polimorfismo de Nucleotídeo Único , Regulação para Cima , Corticosteroides/uso terapêutico , Adulto , Células Cultivadas , Colite Ulcerativa/genética , Colite Ulcerativa/metabolismo , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/efeitos dos fármacos , Análise de Sequência de DNA
9.
Rev. méd. Chile ; 145(9): 1129-1136, set. 2017. tab, graf
Artigo em Espanhol | LILACS-Express | ID: biblio-902597

RESUMO

Background: Different strains of invasive Escherichia coli (E. coli), isolated from intestinal mucosa of patients, are related to the pathogenesis of inflammatory bowel diseases (IBD). Aim: To evaluate an association between intracellular E. coli and IBD; its clinical characteristics and use of steroids. Material and Methods: Sixty one patients with Crohn's disease and 83 with ulcerative colitis were studied. To determine the intracellular E. coli content, colonoscopy biopsies of these patients and 29 control subjects were processed using the gentamicin protection assay. Differences in the bacterial content between patient groups were evaluated using Mann-Whitney test, while the association between presence of E. coli with endoscopic activity, location/extension and use of corticosteroid as anti-inflammatory treatment were evaluated with Fisher's exact test or Chi-square test. Results: E. coli strains were detected in 36.1, 39.3 and 10.3% of patients with ulcerative colitis, Crohn's disease and controls, respectively. The number of bacteria per biopsy in Crohn's disease and ulcerative colitis was significantly higher than in controls (p < 0.01 between patients and controls). In ulcerative colitis, significant associations were found between the presence of bacteria and disease location and use of corticosteroids. In Crohn's disease, no association was found. Conclusions: IBD are associated with the presence of intracellular E. coli strains in the intestinal mucosa, suggesting an alteration in the microbiota or loss of integrity of the epithelial barrier. The association of intracellular E. coli with clinical features and the use of corticosteroids in ulcerative colitis suggests that different factors could promote colonization or proliferation of these bacteria.

10.
Front Microbiol ; 8: 639, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28596755

RESUMO

Adherent-invasive Escherichia coli (AIEC) strains are genetically variable and virulence factors for AIEC are non-specific. FimH is the most studied pathogenicity-related protein, and there have been few studies on other proteins, such as Serine Protease Autotransporters of Enterobacteriacea (SPATEs). The goal of this study is to characterize E. coli strains isolated from patients with Crohn's disease (CD) in Chile and Spain, and identify genetic differences between strains associated with virulence markers and clonality. We characterized virulence factors and genetic variability by pulse field electrophoresis (PFGE) in 50 E. coli strains isolated from Chilean and Spanish patients with CD, and also determined which of these strains presented an AIEC phenotype. Twenty-six E. coli strains from control patients were also included. PFGE patterns were heterogeneous and we also observed a highly diverse profile of virulence genes among all E. coli strains obtained from patients with CD, including those strains defined as AIEC. Two iron transporter genes chuA, and irp2, were detected in various combinations in 68-84% of CD strains. We found that the most significant individual E. coli genetic marker associated with CD E. coli strains was chuA. In addition, patho-adaptative fimH mutations were absent in some of the highly adherent and invasive strains. The fimH adhesin, the iron transporter irp2, and Class-2 SPATEs did not show a significant association with CD strains. The V27A fimH mutation was detected in the most CD strains. This study highlights the genetic variability of E. coli CD strains from two distinct geographic origins, most of them affiliated with the B2 or D E. coli phylogroups and also reveals that nearly 40% of Chilean and Spanish CD patients are colonized with E.coli with a characteristic AIEC phenotype.

11.
Rev Med Chil ; 145(9): 1129-1136, 2017 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-29424399

RESUMO

BACKGROUND: Different strains of invasive Escherichia coli (E. coli), isolated from intestinal mucosa of patients, are related to the pathogenesis of inflammatory bowel diseases (IBD). AIM: To evaluate an association between intracellular E. coli and IBD; its clinical characteristics and use of steroids. MATERIAL AND METHODS: Sixty one patients with Crohn's disease and 83 with ulcerative colitis were studied. To determine the intracellular E. coli content, colonoscopy biopsies of these patients and 29 control subjects were processed using the gentamicin protection assay. Differences in the bacterial content between patient groups were evaluated using Mann-Whitney test, while the association between presence of E. coli with endoscopic activity, location/extension and use of corticosteroid as anti-inflammatory treatment were evaluated with Fisher's exact test or Chi-square test. RESULTS: E. coli strains were detected in 36.1, 39.3 and 10.3% of patients with ulcerative colitis, Crohn's disease and controls, respectively. The number of bacteria per biopsy in Crohn's disease and ulcerative colitis was significantly higher than in controls (p < 0.01 between patients and controls). In ulcerative colitis, significant associations were found between the presence of bacteria and disease location and use of corticosteroids. In Crohn's disease, no association was found. CONCLUSIONS: IBD are associated with the presence of intracellular E. coli strains in the intestinal mucosa, suggesting an alteration in the microbiota or loss of integrity of the epithelial barrier. The association of intracellular E. coli with clinical features and the use of corticosteroids in ulcerative colitis suggests that different factors could promote colonization or proliferation of these bacteria.


Assuntos
Colite Ulcerativa/microbiologia , Doença de Crohn/microbiologia , Escherichia coli/isolamento & purificação , Mucosa Intestinal/microbiologia , Adolescente , Corticosteroides/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios/uso terapêutico , Estudos de Casos e Controles , Colite Ulcerativa/tratamento farmacológico , Contagem de Colônia Microbiana , Doença de Crohn/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Estatísticas não Paramétricas , Adulto Jovem
12.
BMC Gastroenterol ; 16: 103, 2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27565556

RESUMO

BACKGROUND: The ST2/IL-33 pathway has been related to ulcerative colitis (UC), and soluble ST2 (sST2), to disease severity. We tested the potential usefulness of sST2 as a predictive marker of treatment response and patients' outcome. METHODS: Twenty-six patients with active UC were prospectively recruited and grouped according to an endoscopic score and therapy response. Colonoscopic biopsies were collected at baseline and 6 months or when patients showed clinical activity. The protocol was reinitiated in patients requiring rescue therapy. Blood and stool were collected at baseline, 1, 3, 6 and 12 months. Serum and mucosal ST2, and fecal calprotectin (FC) content were determined by ELISA and correlated to Mayo clinical and endoscopic subscore. Intestinal ST2 was evaluated by immunofluorescence. Wilcoxon signed rank test and Spearman correlations (Rs) were applied (p <0.05). RESULTS: Follow-up was completed in 24 patients. sST2 levels (median and range) varied from 173.5 [136.6-274.0] to 86.5 [54.6-133.2] in responders (p < 0.05), and 336.3 [211.0-403.2] to 385.3 pg/mL [283.4-517.3] in non-responders at baseline and 6 months, respectively. sST2 levels correlated with Mayo clinical and endoscopic subscore, mucosal ST2 and FC (Rs = 0.57, 0.66, 0.74 and 0.42, respectively; p < 0.0001) and showed a trend similar to that of FC in responders. Non-responders revealed an increased ST2 content, restricted to the lamina propria's cellular infiltrate. CONCLUSIONS: Consecutive sST2 measurement to follow changes in inflammatory activity of UC patients who respond or not to treatment identifies sST2, like FC, as a useful biomarker in predicting clinical outcome of UC patients.


Assuntos
Colite Ulcerativa/sangue , Colite Ulcerativa/patologia , Proteína 1 Semelhante a Receptor de Interleucina-1/análise , Adulto , Biomarcadores/análise , Biópsia/métodos , Colite Ulcerativa/terapia , Colonoscopia , Ensaio de Imunoadsorção Enzimática , Fezes/química , Feminino , Imunofluorescência , Humanos , Mucosa Intestinal/patologia , Complexo Antígeno L1 Leucocitário/análise , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Índice de Gravidade de Doença , Estatísticas não Paramétricas
13.
Cytokine Growth Factor Rev ; 26(6): 615-23, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26271893

RESUMO

IL-33, an IL-1 family member, is expressed by many cell types and can regulate gene transcription. IL-33 is released upon cell necrosis and the precursor form is enzymatically processed, and then drives inflammation as a damage-associated molecular pattern. The IL-33 receptor ST2, encoded by IL1RL1, is expressed as both a membrane-anchored receptor (ST2L) activated by IL-33, and as a soluble variant (sST2) that exhibits anti-inflammatory properties. The IL-33/ST2 axis is involved in the pathogenesis of atopic and autoimmune diseases, cancer, and central nervous system disorders. Here, we review recent findings on the role of the IL-33/ST2 axis in health and disease.


Assuntos
Inflamação/imunologia , Interleucina-33/imunologia , Neoplasias/imunologia , Receptores de Superfície Celular/imunologia , Dermatopatias/imunologia , Animais , Autoimunidade , Humanos , Inflamação/fisiopatologia , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/fisiopatologia , Proteína 1 Semelhante a Receptor de Interleucina-1 , Interleucina-33/genética , Interleucina-33/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Dermatopatias/fisiopatologia
14.
PLoS One ; 9(12): e104624, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25531754

RESUMO

Toll-like receptor (TLR) 2, a type I membrane receptor that plays a key role in innate immunity, recognizes conserved molecules in pathogens, and triggering an inflammatory response. It has been associated with inflammatory and autoimmune diseases. Soluble TLR2 (sTLR2) variants have been identified in human body fluids, and the TLR2 ectodomain can negatively regulate TLR2 activation by behaving as a decoy receptor. sTLR2 generation does not involve alternative splicing mechanisms, indicating that this process might involve a post-translational modification of the full-length receptor; however, the specific mechanism has not been studied. Using CD14+ peripheral human monocytes and the THP-1 monocytic leukemia-derived cell line, we confirm that sTLR2 generation increases upon treatment with pro-inflammatory agents and requires a post-translational mechanism. We also find that the constitutive and ligand-induced release of sTLR2 is sensitive to pharmacological metalloproteinase activator and inhibitors leading us to conclude that metalloproteinase TLR2 shedding contributes to soluble receptor production. By expressing human TLR2 in ADAM10- or ADAM17-deficient MEF cells, we find both enzymes to be implicated in TLR2 ectodomain shedding. Moreover, using a deletion mutant of the TLR2 juxtamembrane region, we demonstrate that this domain is required for sTLR2 generation. Functional analysis suggests that sTLR2 generated by metalloproteinase activation inhibitsTLR2-induced cytokine production by this monocytic leukemia-derived cell line. The identification of the mechanisms involved in regulating the availability of soluble TLR2 ectodomain and cell surface receptors may contribute further research on TLR2-mediated processes in innate immunity and inflammatory disorders.


Assuntos
Metaloproteases/metabolismo , Receptor 2 Toll-Like/biossíntese , Receptor 2 Toll-Like/química , Proteínas ADAM/metabolismo , Proteína ADAM10 , Proteína ADAM17 , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide/metabolismo , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Interleucina-8/biossíntese , Ligantes , Lipopeptídeos/farmacologia , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Estrutura Terciária de Proteína , Solubilidade , Receptor 2 Toll-Like/metabolismo
15.
J Immunol Res ; 2014: 149185, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24901008

RESUMO

Acute inflammation is a response to an alteration induced by a pathogen or a physical or chemical insult, which functions to eliminate the source of the damage and restore homeostasis to the affected tissue. However, chronic inflammation triggers cellular events that can promote malignant transformation of cells and carcinogenesis. Several inflammatory mediators, such as TNF-α, IL-6, TGF-ß, and IL-10, have been shown to participate in both the initiation and progression of cancer. In this review, we explore the role of these cytokines in important events of carcinogenesis, such as their capacity to generate reactive oxygen and nitrogen species, their potential mutagenic effect, and their involvement in mechanisms for epithelial mesenchymal transition, angiogenesis, and metastasis. Finally, we will provide an in-depth analysis of the participation of these cytokines in two types of cancer attributable to chronic inflammatory disease: colitis-associated colorectal cancer and cholangiocarcinoma.


Assuntos
Neoplasias dos Ductos Biliares/metabolismo , Colangiocarcinoma/metabolismo , Colite/metabolismo , Neoplasias Colorretais/metabolismo , Microambiente Tumoral/genética , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Carcinogênese/genética , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Doença Crônica , Colite/complicações , Colite/genética , Colite/patologia , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Expressão Gênica , Humanos , Inflamação/complicações , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Estresse Oxidativo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
16.
Int J Med Microbiol ; 304(3-4): 384-92, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24581881

RESUMO

Crohn's disease (CD) is a multifactorial pathology associated with the presence of adherent-invasive Escherichia coli (AIEC) and NLRP3 polymorphic variants. The presence of intracellular E. coli in other intestinal pathologies (OIP) and the role of NLRP3-inflammasome in the immune response activated by these bacteria have not been investigated. In this study, we sought to characterize intracellular strains isolated from patients with CD, ulcerative colitis (UC) and OIP, and analyze NLRP3-inflammasome role in the immune response and bactericidal activity induced in macrophages exposed to invasive bacteria. For this, intracellular E. coli isolation from ileal biopsies, using gentamicin-protection assay, revealed a prevalence and CFU/biopsy of E. coli higher in biopsies from CD, UC and OIP patients than in controls. To characterize bacterial isolates, pulsed-field gel electrophoresis (PFGE) patterns, virulence genes, serogroup and phylogenetic group were analyzed. We found out that bacteria isolated from a given patient were closely related and shared virulence factors; however, strains from different patients were genetically heterogeneous. AIEC characteristics in isolated strains, such as invasive and replicative properties, were assessed in epithelial cells and macrophages, respectively. Some strains from CD and UC demonstrated AIEC properties, but not strains from OIP. Furthermore, the role of NLRP3 in pro-inflammatory cytokines production and bacterial elimination was determined in macrophages. E. coli strains induced IL-1ß through NLRP3-dependent mechanism; however, their elimination by macrophages was independent of NLRP3. Invasiveness of intracellular E. coli strains into the intestinal mucosa and IL-1ß production may contribute to CD and UC pathogenesis.


Assuntos
Proteínas de Transporte/metabolismo , Escherichia coli/fisiologia , Interações Hospedeiro-Patógeno , Inflamassomos/metabolismo , Doenças Inflamatórias Intestinais/microbiologia , Macrófagos/microbiologia , Viabilidade Microbiana , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Carga Bacteriana , Biópsia , Linhagem Celular , Citosol/microbiologia , Células Epiteliais/microbiologia , Escherichia coli/genética , Escherichia coli/imunologia , Escherichia coli/isolamento & purificação , Feminino , Genótipo , Humanos , Íleo/microbiologia , Íleo/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Proteína 3 que Contém Domínio de Pirina da Família NLR , Fatores de Virulência/genética , Adulto Jovem
17.
Rev. méd. Chile ; 140(11): 1457-1463, nov. 2012. ilus
Artigo em Espanhol | LILACS | ID: lil-674014

RESUMO

Recently, MUTYH mutations have been reported to predispose to the development of polyposis. However, polyposis caused by mutations in MUTYH has been characterized as an autosomal recessive hereditary disease, different from the autosomal dominant pattern observed in polyposis caused by APC mutations. We report a 41-year-old female consulting for anemia. Colonoscopy detected multiple sessile polyps and a cecal carcinoma. The patient was operated and in the surgical piece, the tumor invaded serosa and there was lymph node involvement. Approximately 100 polyps were found. The patient received 5-fluorouracil, as adjuvant therapy. The patient had a sister (of a total of 12 brothers) with a colorectal carcinoma. The genetic study identified a homozygous mutation of the MUTYH gene, called c.340T > C, that produces an amino acid change of tyrosine for histidine called p.Y114H. The sister with colorectal cancer was a heterozygous carrier of this mutation.


Assuntos
Adulto , Feminino , Humanos , Polipose Adenomatosa do Colo/genética , DNA Glicosilases/genética , Mutação em Linhagem Germinativa/genética , Predisposição Genética para Doença/etiologia , Homozigoto , Linhagem , Reação em Cadeia da Polimerase
18.
Immunobiology ; 217(6): 634-42, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22101184

RESUMO

Toll-like receptor 2 (TLR2) is a type I pattern recognition receptor that has been shown to participate in intestinal homeostasis. Its increased expression in the lamina propria has been associated with the pathogenesis in inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn's disease (CD). Recently, soluble TLR2 (sTLR2) variants have been shown to counteract inflammatory responses driven by the cognate receptor. Despite the evident roles of TLR2 in intestinal immunity, no study has elucidated the production and cellular source of sTLR2 in IBD. Furthermore, an increase in the population of activated macrophages expressing TLR2 that infiltrates the intestine in IBD has been reported. We aimed first to assess the production of the sTLR2 by UC and CD organ culture biopsies and lamina propria mononuclear cells (LPMCs) as well as the levels of sTLR2 in serum, and then characterize the cell population from lamina propria producing the soluble protein. Mucosa explants, LPMCs and serum were obtained from UC, CD patients and control subjects. The level of sTLR2 was higher in conditioned media from organ culture biopsies and LPMCs from UC patients in comparison to CD and controls. Moreover, an inverse correlation between the content of intestinal and serum sTLR2 levels was observed in UC patients. Additionally, when characterizing the cellular source of the increased sTLR2 by LPMCs from UC patients, an increase in TLR2(+)/CD33(+) cell population was found. Also, these cells expressed CX3CR1, which was related to the increased levels of intestinal FKN in UC patients, suggesting that a higher proportion of TLR2(+) mononuclear cells infiltrate the lamina propria. The increased production of sTLR2 suggests that a differential regulating factor of the innate immune system is present in the intestinal mucosa of UC patients.


Assuntos
Colite Ulcerativa/metabolismo , Doença de Crohn/metabolismo , Leucócitos Mononucleares/metabolismo , Membrana Mucosa/metabolismo , Receptor 2 Toll-Like/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Receptor 1 de Quimiocina CX3C , Movimento Celular/imunologia , Quimiocina CX3CL1/genética , Quimiocina CX3CL1/imunologia , Colite Ulcerativa/imunologia , Colite Ulcerativa/patologia , Doença de Crohn/imunologia , Doença de Crohn/patologia , Feminino , Expressão Gênica , Humanos , Imunidade Inata , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/patologia , Masculino , Pessoa de Meia-Idade , Membrana Mucosa/imunologia , Membrana Mucosa/patologia , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/imunologia , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Solubilidade , Técnicas de Cultura de Tecidos
19.
Dis Colon Rectum ; 53(4): 450-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20305446

RESUMO

PURPOSE: Lynch syndrome is the most common inherited syndrome of colorectal cancer, caused principally by germline mutations in MLH1 and MSH2. We report our experience with genetic screening in the diagnosis of Lynch syndrome in Chile, a country previously underserved in the capacity to diagnose hereditary colorectal cancer. METHODS: Families from our Familial Colorectal Cancer Registry were selected for this study if they fulfilled either Amsterdam I/II or Bethesda criteria for classification of Lynch syndrome. Analysis of colorectal tumors from probands included a microsatellite instability study and immunohistochemical evaluation for MLH1 and MSH2. Screening of germline mutations was performed by single-strand conformation polymorphism analysis and DNA sequencing. RESULTS: A total of 21 families were evaluated, 14 meeting Amsterdam criteria and 7 meeting Bethesda criteria. Tumors in 20 families (95%) showed microsatellite instability (19 high and 1 low) and 9 of these 20 families (45%) harbored a germline mutation (7 of 13 Amsterdam and 2 of 7 Bethesda families). Of the 9 mutations identified, 6 were in MLH1 and 3 in MSH2. Two of the mutations were novel, 3 were previously found in 1 to 2 European populations, and 4 were previously found in various ethnic populations worldwide. Only 2 mutations were previously found in another Latin American population (Colombia). In our probands, colorectal cancer was located mainly (57%) in the right or transverse colon. Pedigree information from 104 family affected members of 21 studied families showed endometrial cancer to be the most frequent primary extracolonic tumor, accounting for 15.1% of total cases, followed by stomach (13.2%) and breast cancer (11.3%). Analysis of mitochondrial DNA haplotypes showed a strong Amerindian genetic component in 15 (71.4%) of the 21 families analyzed. CONCLUSION: The study of Lynch syndrome in families of different ethnic origins contributes to the definition of genetic and clinical differences among populations. Wide distribution in other ethnic populations strongly suggests varying origins of 4 the mutations found. Although cancer phenotype was consistent with those from other Latin American populations, only 2 of 9 mutations were shared with other South American populations and 2 novel mutations were found. The Chilean population is considered to be an admixture of Amerindian and European-mainly Spanish-populations, producing an ethnic group with significant genetic differences from populations previously studied.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Adolescente , Adulto , Idoso , Sequência de Bases , Chile , Feminino , Predisposição Genética para Doença , Testes Genéticos , Mutação em Linhagem Germinativa , Humanos , Técnicas Imunoenzimáticas , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Fenótipo , Polimorfismo Conformacional de Fita Simples/genética , Sistema de Registros , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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