Evaluation of the potential of 4 micro algae extracts to modulate the immune response and metabolic state in intestinal epithelium cells
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ABSTRACT: 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.
Project description:Non-starch soluble polysaccharides (NSPs) produced by yeasts are used in animal nutrition to improve health and performance. However, the magnitude of the effect may be dependent upon the quantity and the composition of the polysaccharides. As seaweeds are attractive sources of NSPs, this study was set up to evaluate their potential to improve intestinal health. The effect of NSP extracts prepared from Saccharomyces cerevisiae containing β-glucan and mannan (PSY1, positive control) or a mixture of mannanoligosaccharides (PSY2, positive control), micro algae containing β-glucan (PSA1), brown macro algae containing fucoidan and laminarin (PSA2), and green macro algae containing ulvan (PSA3) on intestinal porcine epithelial cells J2 (IPEC-J2) was studied in the presence and absence of the enterotoxigenic bacterium Escherichia coli k99 strain (ETEC) as an in vitro challenge. The E.coli-k99 strain with adhesion factor F41 (41/32) was isolated from a mastitis-infected udder. In addition, a mixed extract prepared from vegatal orgin supplemented with phenolic compounds from vegetal origin, zinc and selenium (9631), and ZnO were tested to compare responses to NSP extracts. Gene expression was measured in IPEC-J2 cells after 2 and 6 hours of incubation using “whole genome” porcine microarrays (submission as a conference paper at the SEAGRICULTURE 2017 6th International Seaweed Conference).
Project description:Nitrogen starvation is an efficient environmental pressure used to increase lipid accumulation and oil droplet formation in microalgal cells. Various studies focused on metabolic changes occurring in microalgae in nitrogen starvation conditions, but the mechanisms at the basis of these changes are not completely understood. Between microalgae, green algae, with more than 7000 species growing in a variety of habitats, have been frequently studied for energy purposes, but also as source of bioactive extracts/compounds. In this study, de novo transcriptome of the green algae Tetraselmis suecica has been performed in order to (1) deeply study its response to nitrogen starvation, (2) to look for enzymes with antioxidant capacity and for polyketide synthases (PKSs), (3) if present, to evaluate if nutrient starvation can influence their expression levels.
Project description:Green hydra (Hydra viridissima) harbors endosymbiotic Chlorella and have established a mutual relation. To identify the host hydra genes involved in the specific symbiotic relationship, transcriptomes of intact H. viridissima colonized with symbiotic Chlorella strain A99, aposymbiotic H.viridissima and H. viridissima artificially infected with other symbiotic Chlorella were compared by microarray analysis. The results indicated that genes involved in nutrition supply to Chlorella were upregulated in the symbiotic hydra. In addition, it was induced by supply of photosynthates from the symbiont to the host, suggesting cooperative metabolic interaction between the host and the symbiotic algae.
Project description:Cypermethrin (CYP) is one of the most widely used pesticides in large scale for agricultural and domestic purpose and the residue often seriously affects aquatic system. Environmental pollutants induced protein changes in organisms could be detected by proteomics, leading to discovery of potential biomarkers and understanding of mode of action. While proteomics investigations of CYP stress in some animal models have been well studied, few reports about the effects of exposure to CYP on algae proteome were published. To determine CYP effect in algae, the impact of various dosages (0.001 µg/L, 0.01 µg/L and 1 µg/L) of CYP on green algae Chlorella Vulgaris for 24h and 96h were investigated by using iTRAQ quantitative proteomics technique. A total of 162 and 198 proteins were significantly altered after CYP exposure for 24h and 96h, respectively. Overview of iTRAQ results indicated that the influence of CYP on algae protein might be dosage-dependent. Functional analysis of differentially expressed proteins showed that CYP could induce protein alterations related to photosynthesis, stress responses and carbohydrates metabolism. This study provides a comprehensive view of complex mode of action of algae under CYP stress and highlights several potential biomarkers for further investigation of pesticides exposed plant and algae.
Project description:Micractinium conductrix SAG 241.80 secretes sugars (especially maltose) at pH 5.7 while very little sugar is found at pH 7.6. Another algae, Chlorella sorokiniana does not secrete sugars at either pH. We evaluated the transcriptional profiles of both species of algae at pH 5.7 and 7.6 to make comparisons in the regulation of potential genes involved in these pathways.
Project description:The accumulation of triacylglycerol (TAG) as a storage compound in eukaryotic algae has been the subject of extensive studies over the last 25 years. The model industrial alga Chlorella sorokiniana accumulates TAG and other storage compounds under nitrogen (N)-limited growth. Previously we used transcriptomics to explore the regulation of TAG synthesis in C. sorokiniana. Surprisingly, our analysis showed that the expression of several key genes encoding enzymes involved in plastidic fatty acid synthesis are significantly repressed. Metabolic labeling with radiolabeled acetate showed that de novo fatty acid synthesis is indeed downregulated under N-limitation. Likewise, inhibition of the Target of Rapamycin kinase (TOR), a key regulator of metabolism and growth, decreased fatty acid synthesis. We compared the changes induced in the quantitative proteome and phosphoproteome of cells under N-limitation or TOR inhibition and found extensive overlap between the N-limited and TOR-inhibited conditions. We also detected variations in the phosphorylation of TOR complex proteins under N-limitation, indicating that TOR signaling is altered. Our results indicate that under N-limitation there is significant metabolic remodeling, including fatty acid synthesis, mediated by TOR signaling. We find that TOR-mediated metabolic remodeling of fatty acid synthesis under N-limitation is conserved in the chlorophyte algae Chlorella sorokiniana and Chlamydomonas reinhardtii.
Project description:Evaluation of the potential of 4 micro algae extracts to modulate the immune response and metabolic state in intestinal epithelium cells