No abstract

SCFAs (short-chain fatty acids), fermentation products of bacteria, influence epithelial-specific gene expression. We hypothesize that SCFAs affect goblet-cell-specific mucin MUC2 expression and thereby alter epithelial protection. In the present study, our aim was to investigate the mechanisms that regulate butyrate-mediated effects on MUC2 synthesis. Human goblet cell-like LS174T cells were treated with SCFAs, after which MUC2 mRNA levels and stability, and MUC2 protein expression were analysed. SCFA-responsive regions and cis-elements within the MUC2 promoter were identified by transfection and gel-shift assays. The effects of butyrate on histone H3/H4 status at the MUC2 promoter were established by chromatin immunoprecipitation. Butyrate (at 1 mM), as well as propionate, induced an increase in MUC2 mRNA levels. MUC2 mRNA levels returned to basal levels after incubation with 5-15 mM butyrate. Interestingly, this decrease was not due to loss of RNA stability. In contrast, at concentrations of 5-15 mM propionate, MUC2 mRNA levels remained increased. Promoter-regulation studies revealed an active butyrate-responsive region at -947/-371 within the MUC2 promoter. In this region we identified an active AP1 (c-Fos/c-Jun) cis-element at -818/-808 that mediates butyrate-induced activation of the promoter. Finally, MUC2 regulation by butyrate at 10-15 mM was associated with increased acetylation of histone H3 and H4 and methylation of H3 at the MUC2 promoter. In conclusion, 1 mM butyrate and 1-15 mM propionate increase MUC2 expression. The effects of butyrate on MUC2 mRNA are mediated via AP-1 and acetylation/methylation of histones at the MUC2 promoter.

BackgroundObesity treatment is by large ineffective long term, and more emphasis on the prevention of excessive weight gain in childhood and adolescence is warranted. To inform energy balance related behaviour (EBRB) change interventions, insight in the potential personal, family and school environmental correlates of these behaviours is needed. Studies on such multilevel correlates of EBRB among schoolchildren in Europe are lacking. The ENERGY survey aims to (1) provide up-to-date prevalence rates of measured overweight, obesity, self-reported engagement in EBRBs, and objective accelerometer-based assessment of physical activity and sedentary behaviour and blood-sample biomarkers of metabolic function in countries in different regions of Europe, (2) to identify personal, family and school environmental correlates of these EBRBs. This paper describes the design, methodology and protocol of the survey.Method/DesignA school-based cross-sectional survey was carried out in 2010 in seven different European countries; Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, and Spain. The survey included measurements of anthropometrics, child, parent and school-staff questionnaires, and school observations to measure and assess outcomes (i.e. height, weight, and waist circumference), EBRBs and potential personal, family and school environmental correlates of these behaviours including the social-cultural, physical, political, and economic environmental factors. In addition, a selection of countries conducted accelerometer measurements to objectively assess physical activity and sedentary behaviour, and collected blood samples to assess several biomarkers of metabolic function.DiscussionThe ENERGY survey is a comprehensive cross-sectional study measuring anthropometrics and biomarkers as well as assessing a range of EBRBs and their potential correlates at the personal, family and school level, among 10-12 year old children in seven European countries. This study will result in a unique dataset, enabling cross country comparisons in overweight, obesity, risk behaviours for these conditions as well as the correlates of engagement in these risk behaviours.

Inflammatory bowel disease (IBD) is characterized by a chronically inflamed mucosa of the gastrointestinal tract, caused by an underlying immune imbalance and triggered by luminal substances, including bacteria. Mucus forms a gel layer covering the gastrointestinal tract, acting as a semi-permeable barrier between the lumen and the epithelium. Mucins, the building blocks of the mucus gel, determine the thickness and properties of mucus. In IBD in humans, alterations in both membrane-bound and secretory mucins have been described involving genetic mutations in mucin genes, changes in mucin mRNA and protein levels, degree of glycosylation, sulphation, and degradation of mucins. As mucins are strategically positioned between the vulnerable mucosa and the bacterial contents of the bowel, changes in mucin structure and/or quantity probably influence their protective functions and therefore constitute possible aetiological factors in the pathogenesis of IBD. This hypothesis, however, is difficult to prove in humans. Animal models for IBD permit detailed analysis of those aspects of mucins necessary for protection against disease. These models revealed pertinent data as for how changes in mucins, in particular in MUC2, imposed by immunological or microbial factors, may contribute to the development and/or perpetuation of chronic IBD, and shed some light on possible strategies to counteract disease.