TGFbeta1 expression in colonic mucosa: modulation by dietary lipids.
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ABSTRACT:
SUBMITTER: Biasi F
PROVIDER: S-EPMC2474948 | biostudies-other | 2007 Nov
REPOSITORIES: biostudies-other
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Project description:BackgroundDespite tremendous interest in modulating the microbiome to improve health, the association between diet and the colonic mucosa-associated gut microbiome in healthy individuals has not been examined.ObjectiveTo investigate the associations between Healthy Eating Index (HEI)-2005 and the colonic mucosa-associated microbiota.MethodsIn this cross-sectional observational study, we analyzed bacterial community composition and structure using 16S rRNA gene (V4 region) sequencing of 97 colonic mucosal biopsies obtained endoscopically from different colon segments of 34 polyp-free participants. Dietary consumption was ascertained using an FFQ. Differences in α- and β-diversity and taxonomic relative abundances between the higher and lower score of total HEI and its components were compared, followed by multivariable analyses.ResultsThe structure of the microbiota significantly differed by the scores for total HEI, total and whole fruits (HEI 1 and HEI 2), whole grains (HEI 6), milk products and soy beverages (HEI 7), and solid fat, alcohol, and added sugar (HEI 12). A lower score for total HEI and HEIs 2, 7, and 12 was associated with significantly lower richness. A lower score for total HEI was associated with significantly reduced relative abundance of Parabacteroides, Roseburia, and Subdoligranulum but higher Fusobacterium. A lower score for HEI 2 was associated with lower Roseburia but higher Bacteroides. A lower score for HEI 7 was associated with lower Faecalibacterium and Fusobacterium but higher Bacteroides. A lower score for HEI 12 was associated with lower Subdoligranulum but higher Escherichia and Fusobacterium (false discovery rate-adjusted P values <0.05). The findings were confirmed by multivariate analysis. Less abundant bacteria such as Alistipes, Odoribacter, Bilophila, and Tyzzerella were also associated with dietary quality.ConclusionsA lower score for total HEI-2005 was significantly associated with reduced relative abundance of potentially beneficial bacteria but increased potentially harmful bacteria in the colonic mucosa of endoscopically normal individuals.
| S-EPMC6736447 | biostudies-literature
Project description:Myofibroblasts are contractile cells that are characterized by the expression of alpha-smooth muscle actin and mediate the closure of wounds and the formation of collagen-rich scars. Their presence in organs such as lungs, liver, and kidney has long been established as a marker of progressive fibrosis. The transforming growth factor beta(1)-driven differentiation of fibroblasts is a major source of myofibroblasts, and recent data have shown that hyaluronan is a major modulator of this process. This study examines this differentiation mechanism in more detail. Transforming growth factor beta(1)-dependent differentiation to the myofibroblastic phenotype was antagonized by the inhibition of hyaluronan synthesis, confirming that hyaluronan was necessary for differentiation. This response, however, was not reproduced by simply adding hyaluronan to fibroblasts, as the results implicated hyaladherins, as well as the macromolecular assembly of de novo hyaluronan, as essential in this process. We previously suggested that there is a relocalization of lipid-raft components during myofibroblastic differentiation. The present study demonstrates that the hyaluronan receptor CD44, the hyaluronidase HYAL 2, and the transforming growth factor beta(1)-receptor ALK5 all relocalized from raft to non-raft locations, which was reversed by the addition of exogenous hyaluronan. These data highlight a role for endogenous hyaluronan in the mediation of myofibroblastic differentiation. While hyaluronan synthesis was both essential and necessary for differentiation, exogenously provided hyaluronan antagonized differentiation, underscoring a pathological role for hyaluronan in such cell fate processes.
| S-EPMC2708802 | biostudies-literature
Project description:OBJECTIVE:Chronic HIV-1 infection leads to widespread inflammation and immune dysregulation. The gastrointestinal mucosa, a primary site for HIV-1 replication, is thought to play a significant role in this response. MicroRNAs (miRs) are small noncoding RNAs that regulate gene expression, including immune activation and inflammation. Here we investigate miR expression and function in the colonic mucosa during HIV-1 infection. DESIGN AND METHODS:Using miR profiling, we examined miR expression in the colonic mucosa of HIV-infected patients. These miRs were further parsed to identify those that most likely function in HIV-related inflammation. Using bioinformatics tools, we identified potential target genes which were confirmed using in-vitro functional testing. RESULTS:We identified 12 miRs that were differentially expressed in the colonic mucosa of HIV-infected patients with high versus undetectable plasma viral concentrations. Of these, both miR-26a and miR-29a were downregulated in untreated HIV-1 infection, yet not in the colonic mucosa from inflammatory bowel disease. This downregulation occurs within the first hours after infection. These miRs were further shown to directly target IL-6 and STAT3, respectively, with similar changes confirmed in an ex-vivo explant infection model. CONCLUSION:miR-26a and miR-29a levels are decreased in the colonic mucosa during chronic HIV-1 infection, and this change may be initiated during acute infection. Both miRs de-repress the IL-6/STAT3 signaling pathway, which could contribute to increased inflammation during infection. These miRs may represent novel therapeutic targets for HIV-1-associated inflammation in the colonic mucosa.
| S-EPMC5578872 | biostudies-literature
Project description:In 2020, the worldwide incidence and mortality of colorectal cancer (CRC) were third and second, respectively. As the 5-y survival rate is low when CRC is diagnosed at an advanced stage, a reliable method to predict CRC susceptibility is important for preventing the onset and development and improving the prognosis of CRC. Therefore, we focused on the normal colonic mucosa to investigate changes in gene expression that may induce subsequent genetic alterations that induce malignant transformation. Comprehensive gene expression profiling in the normal mucosa adjacent to colon cancer (CC) compared with tissue from non-colon cancer patients was performed. PCR arrays and qRT-PCR revealed that the expression of 5 genes involved in the immune response, including MYD88, was increased in the normal mucosa of CC patients. The expression levels of MYD88 were strikingly increased in precancerous normal mucosa specimens, which harbored no somatic mutations, as shown by immunohistochemistry. Microarray analysis identified 2 novel RNA-controlling molecules, EXOSC3 and CNOT4, that were significantly upregulated in the normal mucosa of CC patients and were clearly visualized in the nuclei. Forced expression of EXOSC3 and CNOT4 in human colonic epithelial cells increased the expression of IFNGR1, MYD88, NFκBIA, and STAT3 and activated ERK1/2 and JNK in 293T cells. Taken together, these results suggested that, in the inflamed mucosa, EXOSC3- and CNOT4-mediated RNA stabilization, including that of MYD88, may trigger the development of cancer and can serve as a potential predictive marker and innovative treatment to control cancer development.
| S-EPMC8645755 | biostudies-literature
Project description:The colonic microbiota is a major modulator of the mucosal immune system; therefore, its manipulation through supplementation with probiotics may significantly affect the host's immune responses. Since different probiotics seem to exert various effects in vivo, we tested the relevance of the autoaggregation phenotype on the intestinal persistence of lactobacilli and their ability to modulate the host's innate immune responses. After 14 days of diet supplementation, the aggregating strain Lactobacillus crispatus M247 but not aggregation-deficient isogenic mutant MU5 was recovered from the feces and colonic mucosa of mice. This observation was confirmed by strain-specific PCR amplification and by Lactobacillus-specific denaturing gradient gel electrophoresis analysis. Indeed, L. crispatus M247 increased Toll-like receptor 2 (TLR2) mRNA levels, while it reduced TLR4 mRNA and protein levels in the colonic mucosa, whereas MU5 was ineffective. In colonic epithelial cells (CMT-93 cells) L. crispatus M247 but not MU5 induced time-dependent extracellular signal-regulated kinase-1 (ERK1) tyrosine phosphorylation and TLR modulation, which were abolished in the presence of PD98059 (an ERK1 inhibitor). To assess the functional relevance of probiotic-induced TLR modulation, we determined the consequences of L. crispatus preexposure on TLR4 (lipopolysaccharide [LPS]) and TLR2 [Pam3Cys-Ser-(Lys)4] ligand-mediated effects in intestinal epithelial cells. Preexposure to L. crispatus M247 blunted LPS-induced interleukin-6 (IL-6) release and inhibition of CMT-93 migration over a wound edge, whereas it enhanced TLR2-mediated IL-10 up-regulation. In summary, the aggregation phenotype is required for L. crispatus persistence in the colon and for modulation of TLR2/TLR4 expression through an ERK-dependent pathway. We speculate that the aggregation phenotype in L. crispatus M247 is required to temper epithelial cell responsiveness to bacterial endotoxins, which thus affects the evolution of intestinal inflammatory processes.
| S-EPMC2043298 | biostudies-literature
Project description:BACKGROUND: We have previously reported the effects of age and diet on nutrient digestibility, intestinal morphology, and large intestinal fermentation patterns in healthy young adult and senior dogs. However, a genome-wide molecular analysis of colonic mucosa as a function of age and diet has not yet been performed in dogs. METHODOLOGY/PRINCIPAL FINDINGS: Colonic mucosa samples were collected from six senior (12-year old) and six young adult (1-year old) female beagles fed one of two diets (animal protein-based vs. plant protein-based) for 12 months. Total RNA in colonic mucosa was extracted and hybridized to Affymetrix GeneChip® Canine Genome Arrays. Results indicated that the majority of gene expression changes were due to age (212 genes) rather than diet (66 genes). In particular, the colonic mucosa of senior dogs had increased expression of genes associated with cell proliferation, inflammation, stress response, and cellular metabolism, whereas the expression of genes associated with apoptosis and defensive mechanisms were decreased in senior vs. young adult dogs. No consistent diet-induced alterations in gene expression existed in both age groups, with the effects of diet being more pronounced in senior dogs than in young adult dogs. CONCLUSION: Our results provide molecular insight pertaining to the aged canine colon and its predisposition to dysfunction and disease. Therefore, our data may aid in future research pertaining to age-associated gastrointestinal physiological changes and highlight potential targets for dietary intervention to limit their progression.
| S-EPMC2943922 | biostudies-literature
Project description:ObjectivesMicroRNAs (miRNAs) are small, non-protein-coding RNA molecules that are commonly dysregulated in colorectal tumors. The objective of this study was to identify smaller subsets of highly predictive miRNAs.MethodsData come from population-based studies of colorectal cancer conducted in Utah and the Kaiser Permanente Medical Care Program. Tissue samples were available for 1,953 individuals, of which 1,894 had carcinoma tissue and 1,599 had normal mucosa available for statistical analysis. Agilent Human miRNA Microarray V.19.0 was used to generate miRNA expression profiles; validation of expression levels was carried out using quantitative PCR. We used random forest analysis and verified findings with logistic modeling in separate data sets. Important microRNAs are identified and bioinformatics tools are used to identify target genes and related biological pathways.ResultsWe identified 16 miRNAs for colon and 17 miRNAs for rectal carcinoma that appear to differentiate between carcinoma and normal mucosa; of these, 12 were important for both colon and rectal cancer, hsa-miR-663b, hsa-miR-4539, hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-21-5p, hsa-miR-4506, hsa-miR-92a-3p, hsa-miR-93-5p, hsa-miR-145-5p, hsa-miR-3651, hsa-miR-378a-3p, and hsa-miR-378i. Estimated misclassification rates were low at 4.83% and 2.5% among colon and rectal observations, respectively. Among independent observations, logistic modeling reinforced the importance of these miRNAs, finding the primary principal components of their variation statistically significant (P<0.001 among both colon and rectal observations) and again producing low misclassification rates. Repeating our analysis without those miRNAs initially identified as important identified other important miRNAs; however, misclassification rates increased and distinctions between remaining miRNAs in terms of classification importance were reduced.ConclusionsOur data support the hypothesis that while many miRNAs are dysregulated between carcinoma and normal mucosa, smaller subsets of these miRNAs are useful and informative in discriminating between these tissues.
| S-EPMC4822091 | biostudies-literature
Project description:Colorectal cancer is currently the third leading cause of cancer related deaths. There is considerable interest in using dietary intervention strategies to prevent chronic diseases including cancer. Cardamonin is a spice derived nutraceutical and herein, for the first time we evaluated the therapeutic benefits of cardamonin in Azoxymethane (AOM) induced mouse model of colorectal cancer. Mice were divided into 4 groups of which three groups were given six weekly injections of AOM. One group served as untreated control and remaining groups were treated with either vehicle or Cardamonin starting from the same day or 16 weeks after the first AOM injection. Cardamonin treatment inhibited the tumor incidence, tumor multiplicity, Ki-67 and ?-catenin positive cells. The activation of NF-kB signaling was also abrogated after cardamonin treatment. To elucidate the mechanism of action a global microRNA profiling of colon samples was performed. Computational analysis revealed that there is a differential expression of miRNAs between these groups. Subsequently, we extend our findings to human colorectal cancer and found that cardamonin inhibited the growth, induces cell cycle arrest and apoptosis in human colorectal cancer cell lines. Taken together, our study provides a better understanding of chemopreventive potential of cardamonin in colorectal cancer.
| S-EPMC5655681 | biostudies-literature
Project description:AimA few studies have applied genomic-wide gene expression analysis in inflamed colon tissue sample in ulcerative colitis (UC). We reported the first study of non-inflamed mucosal gene expression in UC and explored its clinical implication.MethodsNon-inflamed mucosa was obtained from 6 UC patients who received total colectomy. The gene expression of UC in noninflamed mucosa was monitored with a microarray. For a selected gene, RT-PCR was performed to verify array results and to further examine expression pattern in inflamed mucosa of UC, colorectal cancer tissue and normal mucosa using additional matched pairs.ResultsTwo genes showing 2.5-fold decreased expression with significance set at in UC samples were homeo box a4 (HOXa4) and mads box transcription enhancer factor 2, polypeptide B (MEF2b). RT-PCR showed that MEF2b expression in non-inflamed mucosa was significantly downregulated, whereas the expression of MEF2b increased in accordance with the severity of mucosal inflammation. HOXa4 expression both in inflamed and non-inflamed mucosa in UC was consistently downregulated, and the downregulation of HOXa4 was also found in colorectal carcinoma.ConclusionIt is suggested that the MEF2b expression in UC which increase in accordance with inflammation may be induced by the inflammatory mediator. In contrast the downregulation of HOXa4 may be partly involved in the pathogenesis of disease including UC and UC-related carcinogenesis.
| S-EPMC4320387 | biostudies-literature
Project description:BACKGROUND: Dietary fibre influences the turnover and differentiation of the colonic epithelium, but its effects on barrier function are unknown. AIMS: To determine whether altering the type and amount of fibre in the diet affects paracellular permeability of intestinal epithelium, and to identify the mechanisms of action. METHODS: Rats were fed isoenergetic low fibre diets with or without supplements of wheat bran (10%) or methylcellulose (10%), for four weeks. Paracellular permeability was determined by measurement of conductance and 51Cr-EDTA flux across tissue mounted in Ussing chambers. Faecal short chain fatty acid (SCFA) concentrations were assessed by gas chromatography, epithelial kinetics stathmokinetically, and mucosal brush border hydrolase activities spectrophotometrically. RESULTS: Body weight was similar across the dietary groups. Conductance and 51Cr-EDTA flux were approximately 25% higher in animals fed no fibre, compared with those fed wheat bran or methylcellulose in the distal colon, but not in the caecum or jejunum. Histologically, there was no evidence of epithelial injury or erosion associated with any diet. The fibres exerted different spectra of effects on luminal SCFA concentrations and pH, and on mucosal indexes, but both bulked the faeces, were trophic to the epithelium, and stimulated expression of a marker of epithelial differentiation. CONCLUSIONS: Both a fermentable and a non-fermentable fibre reduce paracellular permeability specifically in the distal colon, possibly by promoting epithelial cell differentiation. The mechanisms by which the two fibres exert their effects are likely to be different.
| S-EPMC1727405 | biostudies-other