RESUMO
Immunoglobulin A (IgA)-mediated mucosal immunity is important for the host because it contributes to reducing infection risk and to establishing host-microbe symbiosis. BTB and CNC homology 1 (Bach1) is a transcriptional repressor with physiological and pathophysiological functions that are of particular interest for their relation to gastrointestinal diseases. However, Bach1 effects on IgA-mediated mucosal immunity remain unknown. For this study using Bach1-deficient (Bach1-/-) mice, we investigated the function of Bach1 in IgA-mediated mucosal immunity. Intestinal mucosa, feces, and plasma IgA were examined using immunosorbent assay. After cell suspensions were prepared from Peyer's patches and colonic lamina propria, they were examined using flow cytometry. The expression level of polymeric immunoglobulin receptor (pIgR), which plays an important role in the transepithelial transport of IgA, was evaluated using Western blotting, quantitative real-time PCR, and immunohistochemistry. Although no changes in the proportions of IgA-producing cells were observed, the amounts of IgA in the intestinal mucosa were increased in Bach1-/- mice. Furthermore, plasma IgA was increased in Bach1-/- mice, but fecal IgA was decreased, indicating that Bach1-/- mice have abnormal secretion of IgA into the intestinal lumen. In fact, Bach1 deficiency reduced pIgR expression in colonic mucosa at both the protein and mRNA levels. In the human intestinal epithelial cell line LS174T, suppression of Bach1 reduced pIgR mRNA stability. In contrast, overexpression of Bach1 increased pIgR mRNA stability. These results demonstrate that Bach1 deficiency causes abnormal secretion of IgA into the intestinal lumen via suppression of pIgR expression.
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Maintaining the mucus layer is crucial for the innate immune system. Urolithin A (Uro A) is a gut microbiota-derived metabolite; however, its effect on mucin production as a physical barrier remains unclear. This study aimed to elucidate the protective effects of Uro A on mucin production in the colon. In vivo experiments employing wild-type mice, NF-E2-related factor 2 (Nrf2)-deficient mice, and wild-type mice treated with an aryl hydrocarbon receptor (AhR) antagonist were conducted to investigate the physiological role of Uro A. Additionally, in vitro assays using mucin-producing cells (LS174T) were conducted to assess mucus production following Uro A treatment. We found that Uro A thickened murine colonic mucus via enhanced mucin 2 expression facilitated by Nrf2 and AhR signaling without altering tight junctions. Uro A reduced mucosal permeability in fluorescein isothiocyanate-dextran experiments and alleviated dextran sulfate sodium-induced colitis. Uro A treatment increased short-chain fatty acid-producing bacteria and propionic acid concentration. LS174T cell studies confirmed that Uro A promotes mucus production through the AhR and Nrf2 pathways. In conclusion, the enhanced intestinal mucus secretion induced by Uro A is mediated through the actions of Nrf-2 and AhR, which help maintain intestinal barrier function.
Assuntos
Colite , Cumarínicos , Mucosa Intestinal , Fator 2 Relacionado a NF-E2 , Receptores de Hidrocarboneto Arílico , Animais , Fator 2 Relacionado a NF-E2/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Camundongos , Mucosa Intestinal/metabolismo , Cumarínicos/farmacologia , Colite/metabolismo , Colite/induzido quimicamente , Mucina-2/metabolismo , Mucina-2/genética , Humanos , Colo/metabolismo , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Masculino , Microbioma Gastrointestinal , Camundongos Knockout , Sulfato de Dextrana , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Função da Barreira IntestinalRESUMO
Purpose: To investigate the molecular mechanism of pathological keratinization in the chronic phase of ocular surface (OS) diseases. Methods: In this study, a comprehensive gene expression analysis was performed using oligonucleotide microarrays on OS epithelial cells obtained from three patients with pathological keratinization (Stevens-Johnson syndrome [n = 1 patient], ocular cicatricial pemphigoid [n = 1 patient], and anterior staphyloma [n = 1 patient]). The controls were three patients with conjunctivochalasis. The expression in some transcripts was confirmed using quantitative real-time PCR. Results: Compared to the controls, 3118 genes were significantly upregulated by a factor of 2 or more than one-half in the pathological keratinized epithelial cells (analysis of variance P < 0.05). Genes involved in keratinization, lipid metabolism, and oxidoreductase were upregulated, while genes involved in cellular response, as well as known transcription factors (TFs), were downregulated. Those genes were further analyzed with respect to TFs and retinoic acid (RA) through gene ontology analysis and known reports. The expression of TFs MYBL2, FOXM1, and SREBF2, was upregulated, and the TF ELF3 was significantly downregulated. The expression of AKR1B15, RDH12, and CRABP2 (i.e., genes related to RA, which is known to suppress keratinization) was increased more than twentyfold, whereas the expression of genes RARB and RARRES3 was decreased by 1/50. CRABP2, RARB, and RARRES3 expression changes were also confirmed by qRT-PCR. Conclusions: In pathological keratinized ocular surfaces, common transcript changes, including abnormalities in vitamin A metabolism, are involved in the mechanism of pathological keratinization.
Assuntos
Regulação da Expressão Gênica , Reação em Cadeia da Polimerase em Tempo Real , Humanos , Feminino , Masculino , Idoso , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Perfilação da Expressão Gênica , Penfigoide Mucomembranoso Benigno/genética , Penfigoide Mucomembranoso Benigno/metabolismo , Queratinas/metabolismo , Queratinas/genética , Doenças da Córnea/genética , Doenças da Córnea/metabolismo , Doenças da Córnea/patologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Doenças da Túnica Conjuntiva/genética , Doenças da Túnica Conjuntiva/metabolismo , Doenças da Túnica Conjuntiva/patologiaRESUMO
The consumption of functional foods in a daily diet is a promising approach for the maintenance of cognitive health. The present study examines the effects of water-soluble prebiotic dietary-fiber, partially hydrolyzed guar gum (PHGG), on cognitive function and mental health in healthy elderly individuals. Participants consumed either 5 g/day of PHGG or a placebo daily for 12 weeks in this randomized, double-blind, placebo-controlled, and parallel-group study. An assessment of cognitive functions, sleep quality, and subjective mood evaluations was performed at baseline and after 8 and 12 weeks of either PHGG or placebo intake. The visual memory scores in cognitive function tests and sleepiness on rising scores related to sleep quality were significantly improved in the PHGG group compared to the placebo group. No significant differences were observed in mood parameters between the groups. Vigor-activity scores were significantly improved, while the scores for Confusion-Bewilderment decreased significantly in the PHGG group when compared to the baseline. In summary, supplementation with PHGG was effective in improving cognitive functions, particularly visual memory, as well as enhancing sleep quality and vitality in healthy elderly individuals (UMIN000049070).
Assuntos
Cognição , Galactanos , Mananas , Gomas Vegetais , Humanos , Galactanos/farmacologia , Mananas/farmacologia , Mananas/administração & dosagem , Gomas Vegetais/farmacologia , Método Duplo-Cego , Cognição/efeitos dos fármacos , Idoso , Masculino , Feminino , Sono/efeitos dos fármacos , Prebióticos/administração & dosagem , Qualidade do Sono , Fibras na Dieta/farmacologia , Fibras na Dieta/administração & dosagem , Hidrólise , Memória/efeitos dos fármacos , Suplementos Nutricionais , Pessoa de Meia-Idade , Voluntários Saudáveis , Afeto/efeitos dos fármacosRESUMO
BACKGROUND: Linked color imaging (LCI) is a new image enhancement technology that facilitates the recognition of subtle differences in mucosal color. In the large-scale, multicenter randomized controlled trial LCI-FIND, LCI demonstrated good diagnostic performance for the detection of tumor lesions in the upper gastrointestinal tract. The aim of the present study was to exploratively evaluate the diagnostic performance of LCI according to H. pylori infection status as a subanalysis of LCI-FIND trial. METHODS: The patients were randomly allocated to receive white light imaging (WLI) first, followed by LCI (WLI group), or vice versa (LCI group), and the two groups were compared for the detection of tumors. Data from this trial were analyzed by the presence/absence of H. pylori infection and further analyzed by successful or unsuccessful eradication in the H. pylori infection group. RESULTS: The 752 patients in the WLI group and 750 patients in the LCI group who had participated in the LCI-FIND trial were included. In the successful eradication group, more gastric lesions were detected by primary mode in the LCI group than in the WLI group, indicating that more lesions were missed by WLI. Fisher's exact probability test for the comparison of the WLI and LCI groups yielded a p-value of 0.0068, with missed gastric lesions being detected 0.136 times (95% confidence interval: 0.020-0.923), significantly less with LCI than with WLI. CONCLUSION: The current study suggests that LCI should be used for gastric cancer screening, particularly in patients with successful H. pylori eradication.
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Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Infecções por Helicobacter/diagnóstico , Neoplasias Gástricas/diagnóstico por imagem , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Adulto , CorRESUMO
Patients with diarrhea-predominant irritable bowel syndrome (IBS-D) show excessive peristalsis, and antispasmodic agents may be useful therapeutic agents. There are few reports on the use of Kampo medicines for the treatment of IBS-D. Shakuyakukanzoto (SKT) is a Kampo medicine that is effective against abdominal pain. We examined the relationship between SKT and intestinal peristalsis in an animal model and a prospective study. In the animal model, SKT and its components were administered from the serosal side of the colon and colonic peristalsis was evaluated using intraluminal pressure and spatiotemporal mapping before and after the administration of SKT and its components. In this clinical trial, we used abdominal ultrasonography (US) to obtain long-axis images of the sigmoid colon of 11 patients. The frequency of intestinal peristalsis was measured using US in five patients with SKT and six patients without medication after the ingestion of a test meal. The primary outcome was the frequency of peristalsis. The Clinical Trial Registry Website (Trial No. UMIN-CTR; UMIN000051547). In the animal model, peony did not suppress peristalsis frequency, but SKT (p = 0.005) and glycyrrhiza (p = 0.001) significantly suppressed peristalsis frequency compared with saline and peony. Among the glycyrrhiza components, glycycoumarin and isoliquiritigenin suppressed the peristalsis frequency compared to dimethyl sulfoxide (control) (p = 0.001, 0.01, respectively). In a clinical trial, peristalsis was significantly suppressed after oral administration in patients taking SKT (p = 0.03). Administration of SKT was found to inhibit colonic peristalsis, with glycicumarin and isoliquiritigenin being particularly relevant among its components.
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Chalconas , Síndrome do Intestino Irritável , Humanos , Animais , Peristaltismo , Estudos Prospectivos , Modelos Animais , DiarreiaRESUMO
BACKGROUND AND AIMS: Free D-amino acids, which have different functions from L-amino acids, have recently been discovered in various tissues. However, studies on the potential interactions between intestinal inflammation and D-amino acids are limited. We examined the inhibitory effects of D-alanine on the pathogenesis of intestinal inflammation. METHODS: We investigated serum D-amino acid levels in 40 patients with ulcerative colitis and 34 healthy volunteers. For 7 days [d], acute colitis was induced using dextran sulphate sodium in C57BL/6J mice. Plasma D-amino acid levels were quantified in mice with dextran sulphate sodium-induced colitis, and these animals were administered D-alanine via intraperitoneal injection. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression in the colonic mucosa was measured using real-time polymerase chain reaction [PCR]. In vitro proliferation assays were performed to assess naïve CD4+ T cell activation under Th-skewing conditions. Bone marrow cells were stimulated with mouse macrophage-colony stimulating factor to generate mouse bone marrow-derived macrophages. RESULTS: Serum D-alanine levels were significantly lower in patients with ulcerative colitis than in healthy volunteers. Dextran sulphate sodium-treated mice had significantly lower plasma D-alanine levels than control mice. D-alanine-treated mice had significantly lower disease activity index than control mice. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression levels were significantly lower in D-alanine-administered mice than in control mice. D-alanine suppressed naïve T cell differentiation into Th1 cells in vitro, and inhibited the production of IL-12p35 and IL-23p19 in bone marrow-derived macrophages. CONCLUSIONS: Our results suggest that D-alanine prevents dextran sulphate sodium-induced colitis in mice and suppresses IL-12p35 and IL-23p19 production in macrophages.
Assuntos
Alanina , Colite Ulcerativa , Sulfato de Dextrana , Interleucina-23 , Macrófagos , Camundongos Endogâmicos C57BL , Animais , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/metabolismo , Colite Ulcerativa/imunologia , Colite Ulcerativa/patologia , Colite Ulcerativa/tratamento farmacológico , Humanos , Camundongos , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Masculino , Adulto , Feminino , Alanina/farmacologia , Interleucina-23/metabolismo , Interleucina-12/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Interferon gama/metabolismo , Interleucina-17/metabolismo , Pessoa de Meia-Idade , Modelos Animais de Doenças , Estudos de Casos e Controles , RNA Mensageiro/metabolismo , Subunidade p35 da Interleucina-12/metabolismo , Subunidade p19 da Interleucina-23/metabolismo , Adulto JovemRESUMO
Oxidative stress is a persistent threat to the genome and is associated with major causes of human mortality, including cancer, atherosclerosis, and aging. Here we established a method to generate libraries of genomic DNA fragments containing oxidatively modified bases by using specific monoclonal antibodies to immunoprecipitate enzyme-digested genome DNA. We applied this technique to two different base modifications, 8-hydroxyguanine and 1,N6-propanoadenine (acrotein-Ade), in a ferric nitrilotriacetate-induced murine renal carcinogenesis model. Renal cortical genomic DNA derived from 10- to 12-week-old male C57BL/6 mice, of untreated control or 6 hours after intraperitoneal injection of 3 mg iron/kg ferric nitrilotriacetate, was enzyme digested, immunoprecipitated, cloned, and mapped to each chromosome. The results revealed that distribution of the two modified bases was not random but differed in terms of chromosomes, gene size, and expression, which could be partially explained by chromosomal territory. In the wild-type mice, low GC content areas were more likely to harbor the two modified bases. Knockout of OGG1, a repair enzyme for genomic 8-hydroxyguanine, increased the amounts of acrolein-Ade as determined by quantitative polymerase chain reaction analyses. This versatile technique would introduce a novel research area as a high-throughput screening method for critical genomic loci under oxidative stress.
Assuntos
Masculino , Feminino , Humanos , Animais , DNA , Genética/classificação , Genoma HumanoRESUMO
Red wine polyphenolic compounds have been demonstrated to possess antioxidant properties, and several studies have suggested that they might constitute a relevant dietary factor in the protection from coronary heart disease. The aim of the present study is to examine whether red wine extracts (RWE) can ameliorate oxysterol-induced endothelial response, and whether inhibition of adhesion molecule expression is involved in monocyte adhesion to endothelial cells. Surface expression and mRNA levels of adhesion molecules (intercellular adhesion molecule 1 and vascular cell adhesion molecule 1) were determined by ELISA and RT-PCR performed on human aortic endothelial cells (HAEC) monolayers stimulated with 7b-hydroxycholesterol or 25-hydroxycholesterol. Incubation of HAEC with oxysterols (10 µM) increased expression of adhesion molecules in a time-dependent manner. Pretreatment of HAEC with RWE at final concentrations of 1, 10, and 100 ng/ml significantly inhibited the increase of surface protein expression and mRNA levels. Adherence of monocytes to oxysterol-stimulated HAEC was increased compared to that of unstimulated cells. Treatment of HAEC with RWE significantly inhibited adherence of monocytes. These results suggest that RWE works as an anti-atherogenic agent through the inhibition of endothelial-dependent adhesive interactions with monocytes induced by oxysterols.