Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Genes involved in synthesis of lipoteichoic acids are induced when Bifidobacterium animalis subsp. lactis BB12 is incubated with Human Enterocyte-Like Caco-2 Cells

ABSTRACT: Bifidobacterium animalis subsp. lactis BB12 is a widely used probiotic bacterium. However the molecular mechanism by which this bacterium confers positive health effects to the host is largely unknown. The importance of lipoteichoic acids (LTA) in the cross-talk between the bacteria and human enterocyte-like Caco-2 cells was investigated in the present study. A microarray-based analysis of gene expression revealed induction of genes encoding enzymes involved in the synthesis of lipoteichoic acids of BB12. This observation was confirmed in phenotypic experiments, where a specific galactofuranosyl carbohydrate epitope present in the structure of lipoteichoic acids of BB12 was used as a detection marker. An exopolysaccharide EPS/LTA extract isolated from BB12 and commercially available pure LTAs from the human pathogen S. pyogenes were tested in competitive adhesion experiments. The adhesion of B. animalis subsp. lactis BB12 to Caco-2 cells was inhibited in presence of LTA. The strongest inhibition was observed in the concentration range 0.5-10 ug/ml for LTAs from S. pyogenes and 5-10 ug/ml for EPS/LTA extract from BB12. The inhibitory concentrations in both cases likely reflect the physico-chemical properties of LTAs with the highest efficacy below the critical micelle concentration, and therefore we ascribe the main inhibitory effect to LTAs for the BB12 isolated EPS/LTA extract as well. In conclusion we present increased biosynthesis of lipoteichoic acids of BB12 co-incubated with human Caco-2 cells and evidence that LTA serve as important cell wall factors involved in adhesion to these human enterocyte-like cells. The experimental design is described under the single sample. Data desribed in the manuscript (as briefly described under Summary/Abstract) were validated by qPCR.

ORGANISM(S): Bifidobacterium animalis subsp. lactis BB-12

SUBMITTER: Martin Pedersen

PROVIDER: E-GEOD-21588 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:N-nitroso compounds (NOC) may be implicated in human colon carcinogenesis, but the toxicological mechanisms involved have not been elucidated. Since it was previously demonstrated that nitrosamines and nitrosamides, representing two classes of NOC, induce distinct gene expression effects in colon cells that are particularly related to oxidative stress, we hypothesized that different radical mechanisms are involved. Using ESR spectroscopy, we investigated radical generating properties of genotoxic NOC concentrations in human colon adenocarcinoma cells (Caco-2). Cells were exposed to nitrosamides (N-methyl-N'-nitro-N-nitrosoguanidine, N-methyl-N-nitrosurea) or nitrosamines (N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitrosopiperidine, N-nitrosopyrrolidine). Nitrosamines caused formation of reactive oxygen species (ROS) and carbon centered radicals which was further stimulated in presence of Caco-2 cells. N-methyl-N-nitrosurea exposure resulted in a small ROS signal, and formation of nitrogen centered radicals (NCR), also stimulated by Caco-2 cells. N-methyl-N'-nitro-N-nitrosoguanidine did not cause radical formation at genotoxic concentrations, but at increased exposure levels, both ROS and NCR formation was observed. By associating gene expression patterns with ROS formation, several cellular processes responding to nitrosamine exposure were identified, including apoptosis, cell cycle blockage, DNA repair and oxidative stress. These findings suggest that following NOC exposure in Caco-2 cells, ROS formation plays an important role in deregulation of gene expression patterns which may be relevant for the process of chemical carcinogenesis in the human colon, in addition to the role of DNA alkylation. Keywords: Nitrosamines, nitrosamides, N-nitroso compounds, free radicals, toxicogenomics, colon carcinogenesis The study investigated differential gene expression in Caco-2 cell line mRNA following 1, 6 or 24 hours of exposure to six different N-nitroso compounds. Two biological replicates per sample compound. One compound per array, hybridized against vehicle control. Dye-swap between biological replicates.

Dataset Information

Genes involved in synthesis of lipoteichoic acids are induced when Bifidobacterium animalis subsp. lactis BB12 is incubated with Human Enterocyte-Like Caco-2 Cells

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets