Project description:The intestinal ecosystem is balanced by dynamic interactions between resident and incoming microbes, the gastrointestinal barrier, and the mucosal immune system. However, in the context of inflammatory bowel diseases (IBD) where the integrity of the gastrointestinal barrier is compromised, resident microbes contribute to the development and perpetuation of inflammation and disease. In this context, probiotic bacteria exert beneficial effects enhancing epithelial barrier integrity. However, the mechanisms underlying these beneficial effects are only poorly understood. Here, we comparatively investigated the effects of four probiotic lactobacilli, namely L. acidophilus, L. fermentum, L. gasseri, and L. rhamnosus in a T84 cell epithelial barrier model. Results of DNA-microarray experiments indicating that lactobacilli modulate the regulation of genes encoding in particular adherence junction proteins such as E-cadherin and b-catenin were confirmed by qRT-PCR. Furthermore, we show that epithelial barrier function is modulated by Gram-positive probiotic lactobacilli via their effect on adherence junction protein expression and complex formation. In addition, incubation with lactobacilli differentially influences the phosphorylation of adherence junction proteins and of PKC isoforms such as PKCd which thereby positively modulates epithelial barrier function. Further insight into the underlying molecular mechanisms triggered by these probiotics might also foster the development of novel strategies for the treatment of gastrointestinal diseases (e.g. IBD).
Project description:Investigation of the genetic diversity of Emiliania huxleyi, genomic DNA from 15 different strains were compared with the genomic DNA of the sequenced E. huxleyi strain CCMP1516. Gephyrocapsa oceanica and Isochrysis galbana as phylogenetic closely related taxa were used as out-groups.
Project description:Here we describe TROL (thylakoid rhodanese-like protein), a nuclear-encoded component of thylakoid membranes that is required for sustaining efficient linear electron flow in vascular plants. Thus, TROL might represent a missing thylakoid membrane linker for the assembly of a ternary complex between FNR, ferredoxin and NADP+. Such a complex is necessary for maintaining photosynthetic redox poise and balancing between several alternative electron-transport pathways of oxygenic photosynthesis. TROL inactivation modulates the expression of 638 nuclear genes, revealing a novel retrograde signaling pathway. Chloroplasts are the major source of NADPH which is exported to the cytosol where it participates in various redox-dependent processes. TROL is most likely the first element in a metabolic signaling pathway which influences the expression of a large set of stress related genes. Among them are O-methyltransferases and anthocyanin 5-aromatic acyltransferase which are highly upregulated. Microarray analysis was performed in order to identify metabolic networks and pathways regulated by the deficient protein TROL. Comparing ATH1 Affymetrix data results, 317 genes were down-regulated and 321 genes were classified as up-regulated, amongst which mostly affected enzymes were catalyses, oxigenases, monooxygenases and reductases involved in the process of photosynthesis.
Project description:Reference experiment of wild type Saccharomyces cerevisiae cells of the BJ5457 background. Cells were grown in synthetic complete medium (SC) with the addition of the necessary aminoacids and factors (leucine, uracil, histidine, tryptophane) and harvested in exponential phase (OD=0.7-1). Cells were grown in the presence of BCS and BPS chelators. <br>