Effects of Digested Onion Extracts on Intestinal Gene Expression: An Interspecies Comparison Using Different Intestine Models.

Human intestinal tissue samples are barely accessible to study potential health benefits of nutritional compounds. Numbers of animals used in animal trials, however, need to be minimalized. Therefore, we explored the applicability of in vitro (human Caco-2 cells) and ex vivo intestine models (rat precision cut intestine slices and the pig in-situ small intestinal segment perfusion (SISP) technique) to study the effect of food compounds. In vitro digested yellow (YOd) and white onion extracts (WOd) were used as model food compounds and transcriptomics was applied to obtain more insight into which extent mode of actions depend on the model. The three intestine models shared 9,140 genes which were used to compare the responses to digested onions between the models. Unsupervised clustering analysis showed that genes up- or down-regulated by WOd in human Caco-2 cells and rat intestine slices were similarly regulated by YOd, indicating comparable modes of action for the two onion species. Highly variable responses to onion were found in the pig SISP model. By focussing only on genes with significant differential expression, in combination with a fold change > 1.5, 15 genes showed similar onion-induced expression in human Caco-2 cells and rat intestine slices and 2 overlapping genes were found between the human Caco-2 and pig SISP model. Pathway analyses revealed that mainly processes related to oxidative stress, and especially the Keap1-Nrf2 pathway, were affected by onions in all three models. Our data fit with previous in vivo studies showing that the beneficial effects of onions are mostly linked to their antioxidant properties. Taken together, our data indicate that each of the in vitro and ex vivo intestine models used in this study, taking into account their limitations, can be used to determine modes of action of nutritional compounds and can thereby reduce the number of animals used in conventional nutritional intervention studies

Gene expression in three different chicken lines after Salmonella infection early in life

Transcriptional profiling of jejunum infected with Salmonella in three different chicken lines early in life. Samples were taken at 8, 24 and 48 hours post infection. Salmonella was orally ingested at day zero (hatch)

Evaluation of the potential of 4 micro algae extracts to modulate the immune response and metabolic state in intestinal epithelium cells

Micro algae's are used as alternative protein source in human and animal diets. Besides micro algae contain substantial amounts of proteins they also contain a high concentration of, often unique, biological and chemical substances with potential to induce beneficial and health promoting effects in humans and animals. This study was set up to evaluate the potential of these substances to improve (intestinal) health. The effect of extracts prepared from 3 monocultures of micro algae's (Chlorella vulgaris [C], Haematococcus pluvialis [H], and Spirulina platensis [S]) and a mixed culture of micro algae's (AM; a mixture of Scenedesmus sp. and Chlorella sp. ) was studied in the presence and absence of the enterotoxigenic bacterium Escherichia coli k99 strain (ETEC, [E]) as an in vitro challenge. The E.coli-k99 strain with adhesion factor F41 (41/32) was isolated from a mastitis-infected udder. Gene expression was measured in cultured intestinal porcine epithelium cells (IPECJ2 cell line) after 2 and 6 hours incubation with C, H, and S extracts, and after 6 hours with the AM extract, using “whole genome” porcine microarrays. Gene expression profiles were analysed using functional bioinformatics programs to provide insight in the biological processes induced by micro algae extracts

Transcriptional response of cultured porcine intestinal epithelial cells to micro algae extracts in the presence and absence of enterotoxigenic Escherichia coli

Abstract Background Micro algae’s are worldwide considered as an alternative source of proteins in diets for animals and humans. Micro algae also produce an array of biological active substances with potential to induce beneficial and health promoting effects. To better understand the mode of action of micro algae’s when applied as additive in diets, porcine intestinal epithelial cells (IPEC-J2), stressed by enterotoxigenic Escherichia coli (ETEC) or under non-stressed conditions, were exposed to micro algae extracts and changes in gene expression were recorded. Methods IPEC-J2 cells were exposed for 2 and 6 h to extracts prepared from the biomass of the microalgae Chlorella vulgaris (C), Haematococcus pluvialis (H), Spirulina platensis (S), or a mixture of Scenedesmus obliques and Chlorella sorokiniana (AM), in the absence and presence of ETEC. Gene expression in cells was measured using porcine “whole genome” microarrays. Results The micro algae extracts alone enhanced the expression of a set of genes coding for proteins with biological activity that are secreted from cells. These secreted proteins (hereafter denoted as effector proteins; EPs) may regulate processes like remodelling of the extracellular matrix, activation of an antiviral/bacterial response and oxygen homeostasis in the intestine and periphery. Elevated gene expression of immunostimulatory proteins CCL17, CXCL2, CXCL8 (alias IL8), IFNA, IFNL1, HMOX1, ITGB3, and THBS1 was observed in response to all four extracts in the absence or presence of ETEC. For several of these immunostimulatory proteins no elevated expression was observed when cells were exposed to ETEC alone. Furthermore, all extracts highly stimulated expression of an antisense RNA of the mitochondrial/peroxisome symporter SLC25A21 gene in ETEC-challenged cells. Inhibition of SLC25A21 translation by this antisense RNA may impose a concentration gradient of 2-oxoadipic and 2-oxoglutarate, both metabolites of fatty acid β-oxidation, between the cytoplasm and the interior of these organelles. Conclusions Exposure of by ETEC stressed intestinal epithelium cells to micro algae extracts affected “fatty acid β-oxidation”, ATP and reactive oxygen species production and (de) hydroxylation of lysine residues in procollagen chains in these cells. Elevated gene expression of specific EPs and immunostimulatory proteins indicated that micro algae extracts, when used as feed/food additive, can steer an array of metabolic and immunological processes in the intestines of humans and monogastric animals stressed by an enteric bacterial pathogen

Transcriptional response of cultured porcine intestinal epithelial cells to micro algae extracts in the presence and absence of enterotoxigenic Escherichia coli

Background: Micro algae’s are worldwide considered as an alternative source of proteins in diets for animals and humans. Micro algae also produce an array of biological active substances with potential to induce beneficial and health promoting effects. To better understand the mode of action of micro algae’s when applied as additive in diets, porcine intestinal epithelial cells (IPEC-J2), stressed by enterotoxigenic Escherichia coli (ETEC) or under non-stressed conditions, were exposed to micro algae extracts and changes in gene expression were recorded. Methods: IPEC-J2 cells were exposed for 2 and 6 h to extracts prepared from the biomass of the microalgae Chlorella vulgaris (C), Haematococcus pluvialis (H), Spirulina platensis (S), or a mixture of Scenedesmus obliques and Chlorella sorokiniana (AM), in the absence and presence of ETEC. Gene expression in cells was measured using porcine “whole genome” microarrays. Results: The micro algae extracts alone enhanced the expression of a set of genes coding for proteins with biological activity that are secreted from cells. These secreted proteins (hereafter denoted as effector proteins; EPs) may regulate processes like remodelling of the extracellular matrix, activation of an antiviral/bacterial response and oxygen homeostasis in the intestine and periphery. Elevated gene expression of immunostimulatory proteins CCL17, CXCL2, CXCL8 (alias IL8), IFNA, IFNL1, HMOX1, ITGB3, and THBS1 was observed in response to all four extracts in the absence or presence of ETEC. For several of these immunostimulatory proteins no elevated expression was observed when cells were exposed to ETEC alone. Furthermore, all extracts highly stimulated expression of an antisense RNA of the mitochondrial/peroxisome symporter SLC25A21 gene in ETEC-challenged cells. Inhibition of SLC25A21 translation by this antisense RNA may impose a concentration gradient of 2-oxoadipic and 2-oxoglutarate, both metabolites of fatty acid β-oxidation, between the cytoplasm and the interior of these organelles. Conclusions: Exposure of by ETEC stressed intestinal epithelium cells to micro algae extracts affected “fatty acid β-oxidation”, ATP and reactive oxygen species production and (de) hydroxylation of lysine residues in procollagen chains in these cells. Elevated gene expression of specific EPs and immunostimulatory proteins indicated that micro algae extracts, when used as feed/food additive, can steer an array of metabolic and immunological processes in the intestines of humans and monogastric animals stressed by an enteric bacterial pathogen.</p

Evaluation of the potential of 4 micro algae extracts to modulate the immune response and metabolic state in intestinal epithelium cells

Micro algae's are used as alternative protein source in human and animal diets. Besides micro algae contain substantial amounts of proteins they also contain a high concentration of, often unique, biological and chemical substances with potential to induce beneficial and health promoting effects in humans and animals. This study was set up to evaluate the potential of these substances to improve (intestinal) health. The effect of extracts prepared from 3 monocultures of micro algae's (Chlorella vulgaris [C], Haematococcus pluvialis [H], and Spirulina platensis [S]) and a mixed culture of micro algae's (AM; a mixture of Scenedesmus sp. and Chlorella sp. ) was studied in the presence and absence of the enterotoxigenic bacterium Escherichia coli k99 strain (ETEC, [E]) as an in vitro challenge. The E.coli-k99 strain with adhesion factor F41 (41/32) was isolated from a mastitis-infected udder. Gene expression was measured in cultured intestinal porcine epithelium cells (IPECJ2 cell line) after 2 and 6 hours incubation with C, H, and S extracts, and after 6 hours with the AM extract, using “whole genome” porcine microarrays. Gene expression profiles were analysed using functional bioinformatics programs to provide insight in the biological processes induced by micro algae extracts

Ability of Lactococcus lactis To Export Viral Capsid Antigens: a Crucial Step for Development of Live Vaccines

Thefood grade bacterium Lactococcus lactis is a potential vehicle for protein delivery in the gastrointestinal tract. As a model, we constructed lactococcal strains producing antigens of infectious bursal disease virus (IBDV). IBDV infects chickens and causes depletion of B-lymphoid cells in the bursa of Fabricius and subsequent immunosuppression, morbidity, or acute mortality. The two major IBDV antigens, i.e., VP2 and VP3, that form the viral capsid were expressed and targeted to the cytoplasm, the cell wall, or the extracellular compartment of L. lactis. Whereas VP3 was successfully targeted to the three compartments by the use of relevant expression and export vectors, VP2 was recalcitrant to export, thus confirming the difficulty of translocating naturally nonsecreted proteins across the bacterial membrane. This defect could be partly overcome by fusing VP2 to a naturally secreted protein (the staphylococcal nuclease Nuc) that carried VP2 through the membrane. Lactococcal strains producing Nuc-VP2 and VP3 in various bacterial compartments were administered orally to chickens. The chickens did not develop any detectable immune response against VP2 and VP3 but did exhibit an immune response against Nuc when Nuc-VP2 was anchored to the cell wall of lactococci