Background: The selective absorption of nutrients and other food constituents in the small intestine is mediated by a group of transport proteins and metabolic enzymes, often collectively called intestinal barrier proteins. An important receptor that mediates the effects of dietary lipids on gene expression is the peroxisome proliferator-activated receptor alpha (PPAR), which is abundantly expressed in enterocytes. In this study we examined the effects of acute nutritional activation of PPAR on expression of genes encoding intestinal barrier proteins. To this end we used triacylglycerols composed of identical fatty acids in combination with gene expression profiling in wild-type and PPAR-null mice. Treatment with the synthetic PPAR agonist WY14643 served as reference.
PPARalpha-mediated effects of dietary lipids on intestinal barrier gene expression.
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View SamplesWe studied the effect of dietary fat type, varying in polyunsaturated/saturated fatty acid ratio's (P/S) on development of metabolic syndrome. C57Bl/6J mice were fed purified high-fat diets (45E% fat) containing palm oil (HF-PO; P/S 0.4), olive oil (HF-OO; P/S 1.1) or safflower oil (HF-SO; P/S 7.8) for 8 weeks. A low-fat palm oil diet (LF-PO; 10E% fat) was used as a reference. Additionally, we analyzed diet-induced changes in gut microbiota composition and mucosal gene expression. The HF-PO diet induced a higher body weight gain and liver triglyceride content compared to the HF-OO, HF-SO or LF-PO diet. In the intestine, the HF-PO diet reduced microbial diversity and increased the Firmicutes/Bacteroidetes ratio. Although this fits a typical obesity profile, our data clearly indicate that an overflow of the HF-PO diet to the distal intestine, rather than obesity itself, is the main trigger for these gut microbiota changes. A HF-PO diet-induced elevation of lipid metabolism-related genes in the distal small intestine confirmed the overflow of palm oil to the distal intestine. Some of these lipid metabolism-related genes were previously already associated with the metabolic syndrome. In conclusion, our data indicate that saturated fat (HF-PO) has a more stimulatory effect on weight gain and hepatic lipid accumulation than unsaturated fat (HF-OO and HF-SO). The overflow of fat to the distal intestine on the HF-PO diet induced changes in gut microbiota composition and mucosal gene expression. We speculate that both are directly or indirectly contributive to the saturated fat-induced development of obesity and hepatic steatosis.
Saturated fat stimulates obesity and hepatic steatosis and affects gut microbiota composition by an enhanced overflow of dietary fat to the distal intestine.
Sex, Specimen part
View SamplesBackground: Gq-coupled G protein-coupled receptors (GPCR) mediate the actions of a variety of messengers that are key regulators of cardiovascular function. Enhanced Gaq-mediated signaling plays an important role in cardiac hypertrophy and in the transition to heart failure. We have recently described that Gaq acts as an adaptor protein that facilitates PKCz-mediated activation of ERK5 in epithelial cells. Since the ERK5 cascade is known to be involved in cardiac hypertrophy, we have investigated the potential relevance of this pathway in Gq-dependent signaling in cardiac cells.
Protein kinase C (PKC)ζ-mediated Gαq stimulation of ERK5 protein pathway in cardiomyocytes and cardiac fibroblasts.
Sex, Age, Specimen part
View SamplesFNDC4 is a novel secreted factor sharing high homology with the exercise-associated myokine irisin (FNDC5). Here we report that Fndc4 is robustly upregulated in various mouse models of inflammation as well as in human inflammatory conditions. Specifically, subjects with inflammatory bowel disease show increased FNDC4 levels locally at inflamed sites of the intestine. Interestingly, administration of recombinant FNDC4 during colitis development in mice resulted in markedly reduced disease severity compared to mice injected with a control protein. Conversely, mice that lacked Fndc4 showed increased colitis severity. Analysis of binding of FNDC4 to different immune cell types revealed strong and specific binding to macrophages and monocytes. FNDC4 treatment of bone marrow-derived macrophages in vitro resulted in reduced phagocytosis, improved survival and reduced pro-inflammatory chemokine expression. Hence, treatment with FNDC4 resulted in a state of dampened macrophage activity, while enhancing their survival. Thus, we have characterized a novel factor with direct therapeutic potential in inflammatory bowel disease and possibly other inflammatory diseases.
FNDC4 acts as an anti-inflammatory factor on macrophages and improves colitis in mice.
Sex, Specimen part, Treatment
View SamplesPBMC from house dust mite (HDM) sensitized atopics with or without asthma (or nonallergic controls) were cultured in the presence or absence of HDM extract for 24 hours.
Differential gene network analysis for the identification of asthma-associated therapeutic targets in allergen-specific T-helper memory responses.
Specimen part, Disease stage, Subject
View SamplesAsthma exacerbations are associated with subsequent deficits in lung function.
Decreased activation of inflammatory networks during acute asthma exacerbations is associated with chronic airflow obstruction.
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View SamplesThe aim of this study was to employ a systems-level analysis to elucidate gene expression networks operating in the CD4 T-cell responses which underpin human atopic disease.
A network modeling approach to analysis of the Th2 memory responses underlying human atopic disease.
Time
View SamplesPost-traumatic stress disorder is a concerning psycho behavioral disorder thought to emerge from the complex interaction between genetic and environmental factors. For soldiers exposed to combat, the risk of developing this disorder is two-fold and diagnosis is often late, when much sequela has set in. To be able to identify and diagnose in advance those at “risk” of developing PTSD, would greatly taper the gap between late sequelae and treatment. Therefore, this study sought to test the hypothesis that the transcriptome can be used to track the development of PTSD in this unique and susceptible cohort of individuals. Gene expression levels in peripheral blood samples from 85 Canadian infantry soldiers (n = 58 subjects negative for PTSD symptoms and n = 27 subjects with PTSD symptoms) were determined by RNA sequencing technology following their return from deployment to Afghanistan. Count-based gene expression quantification, normalization and differential analysis (with thorough correction for confounders) revealed significant differences in two genes, LRP8 and GOLM1 . These preliminary results provide a proof-of-principle for the diagnostic utility of blood-based gene expression profiles for tracking symptoms of post-traumatic stress disorder in soldiers returning from tour. It is also the first to report transcriptome-wide expression profiles alongside a post-traumatic symptom checklist. Overall design: Peripheral blood samples from 85 Canadian infantry soldiers (n = 58 subjects negative for PTSD symptoms and n = 27 subjects with PTSD symptoms)
Using Next-Generation Sequencing Transcriptomics To Determine Markers of Post-traumatic Symptoms: Preliminary Findings from a Post-deployment Cohort of Soldiers.
Sex, Subject
View SamplesDendritic cells differentiate from their precursors in the airway mucosa under local environmental instruction. Airway epithelial cells (AEC) are a potent source of both pro- and anti-inflammatory mediators and are in intimate contact with intraepithelial DC and their precursors. Thus, AEC are likely candidates for influencing this differentiation process in order to tailor the DC for optimal function in the airway mucosa.
Airway epithelial cells regulate the functional phenotype of locally differentiating dendritic cells: implications for the pathogenesis of infectious and allergic airway disease.
No sample metadata fields
View SamplesDengue fever is an important tropical illness for which there is currently no virus-specific treatment. To shed light on mechanisms involved in the cellular response to dengue virus (DV), we assessed gene expression changes, using Affymetrix GeneChips (HG-U133A), of infected primary human cells and identified changes common to all cells. The common response genes included a set of 23 genes significantly induced upon DV infection of human umbilical vein endothelial cells (HUVECs), dendritic cells (DCs), monocytes, and B cells (analysis of variance, P < 0.05). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), one of the common response genes, was identified as a key link between type I and type II interferon response genes. We found that DV induces TRAIL expression in immune cells and HUVECs at the mRNA and protein levels. The induction of TRAIL expression by DV was found to be dependent on an intact type I interferon signaling pathway. A significant increase in DV RNA accumulation was observed in anti-TRAIL antibody-treated monocytes, B cells, and HUVECs, and, conversely, a decrease in DV RNA was seen in recombinant TRAIL-treated monocytes. Furthermore, recombinant TRAIL inhibited DV titers in DV-infected DCs by an apoptosis-independent mechanism. These data suggest that TRAIL plays an important role in the antiviral response to DV infection and is a candidate for antiviral interventions against DV.
TRAIL is a novel antiviral protein against dengue virus.
No sample metadata fields
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