Background: In the last decade, much attention has been drawn to probiotic bacteria in the context of inflammatory bowel disease (IBD), since the potential of certain strains to attenuate inflammation was demonstrated in several animal experiments and clinical studies. Data in humans elucidating the molecular mechanism of probiotic action are still scarce. To this end, we used an organ culture system of human colon mucosa and investigated the gene expression profiles after treatment with different probiotic bacteria in phorbol 12-myristate 13-acetate (PMA)/ionomycin (IO)) stimulated samples using whole genome microarrays. Moreover, we analyzed changes occurring in the intestinal explants cultured for 8 hours when compared to fresh, directly frozen mucosa, in order to infer the suitability of the system to study an inflammatory stimulus and likely antiinflammatory responses. Results: Culturing intestinal colon fragments during 8 hours elicited differential gene expression in 283 genes, 229 upregulated and 54 downregulated. Upregulated genes were predominantly related to apoptosis, whereas downregulated genes encoded mitochondrial proteins. No specific enrichment of genes related to inflammation or immune response could be detected, confirming the suitability of the system to further study the inmunomodulatory/anti-inflammatory properties of Lactobacillus casei BL23 (BL23), L.plantarum 299v (LP299v) and L.plantarum 299v (A-) (LP299v (A-)), a mutant strain with reduced adhesive properties to enterocytes. Intestinal explants were stimulated with PMA/IO for 3 hours and subsequently incubated with probiotic bacteria for 4 h. ANOVA analysis (p 0,01) revealed 205 differentially expressed genes between Control, PMA/IO (Inflamed), and the 3 bacterial treatments. Most importantly, a number of PMA/IO induced genes related to immune response and immune system process such as IL-2, IFN-, IL17A and pro-inflammatory cytokines CXCL9 and CXCL11 were downregulated by BL23, LP299v and LP299v (A-). The behaviour of the three Lactobacillus strains was quite similar, although their presence induced differential expression of a small number of genes in a strain dependent manner. Conclusion: The human colon organ culture was found to be a suitable model for the study of inflammatory/anti-inflammatory stimuli, and therefore it constitutes a valuable tool to determine the inmunomodulatory effect of probiotic bacteria. The global transcriptional profile evoked by strains BL23, LP299v and LP299v (A-) in artificially inflamed tissue indicated a clear homeostasis restoring effect, including a decrease of the signals produced by activated T cells.
Lactobacillus paracasei and Lactobacillus plantarum strains downregulate proinflammatory genes in an ex vivo system of cultured human colonic mucosa.
Specimen part
View SamplesWine produced at low temperature is often considered to improve sensory qualities. However, there are certain drawbacks to low temperature fermentations: e.g. low growth rate, long lag phase, and sluggish or stuck fermentations. Selection and development of new Saccharomyces cerevisiae strains well adapted at low temperature is interesting for future biotechnological applications. This study aimed to select and develop wine yeast strains that well adapt to ferment at low temperature through evolutionary engineering, and to decipher the process underlying the obtained phenotypes. To this end, we used a pool of 27 commercial yeast strains and set up batch serial dilution experiments to mimic wine fermentation conditions at 12 C. Evolutionary engineering was accomplished by using the natural yeast mutation rate and mutagenesis procedures. One strain (P5) outcompeted the others under both experimental conditions and was able to impose after 200 generations. The evolved strains showed improved growth and low-temperature fermentation performance compared to the ancestral strain. This improvement was acquired only under inositol limitation. The transcriptomic comparison between the evolved and parental strains showed the greatest up-regulation in four mannoprotein coding genes, which belong to the DAN/TIR family (DAN1, TIR1, TIR4 and TIR3). Genome sequencing of the evolved strain revealed the presence of a SNP in the GAA1 gene and the construction of a site-directed mutant (GAA1Thr108) in a derivative haploid of the ancestral strain resulted in improved fermentation performance. GAA1 encodes a GPI transamidase complex subunit that adds GPI, which is required for inositol synthesis, to newly synthesized proteins, including mannoproteins. Thus we demonstrate the importance of inositol and mannoproteins in yeast adaptation at low temperature and the central role of the GAA1 gene by linking both metabolisms.
Evolutionary engineering of a wine yeast strain revealed a key role of inositol and mannoprotein metabolism during low-temperature fermentation.
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View SamplesWe examined the effect of quercetin on the gene expression and function of epididymal adipose tissue (EAT) in Western diet-induced obese mice. Quercetin suppressed the increase in the number of macrophages and the decrease in the ratio of CD4+ to CD8+ T cells in EAT, and the elevation of plasma leptin and TNF levels in mice fed the Western diet. Comprehensive gene expression analysis revealed that quercetin suppressed gene expression associated with the accumulation and activation of immune cells, including macrophages and lymphocytes in EAT. It also improved the expression of the oxidative stress-sensitive transcription factor NFB, NADPH oxidases, and antioxidant enzymes. Quercetin markedly increased gene expression associated with mitochondrial oxidative phosphorylation and mitochondrial DNA Quercetin most likely universally suppresses the accumulation and activation of immune cells, including anti-inflammatory cells, whereas it specifically increased gene expression associated with mitochondrial oxidative phosphorylation. Suppression of oxidative stress and NFB activity likely contributed to the prevention of the accumulation and activation of immune cells and resulting chronic inflammation.
Quercetin suppresses immune cell accumulation and improves mitochondrial gene expression in adipose tissue of diet-induced obese mice.
Sex, Specimen part
View SamplesWe previously showed that a diet containing phloridzin suppressed the blood glucose levels in streptozotocin-induced diabetic mice most likely by inhibiting glucose absorption from the small intestine. In this study, we showed that 0.5% and 1% phloridzin diets significantly reduce the blood glucose levels in healthy normal BALB/c mice after 7 days of feeding.
Phloridzin reduces blood glucose levels and alters hepatic gene expression in normal BALB/c mice.
Sex, Specimen part
View SamplesQuercetin is a food component that may ameliorate the diabetic symptoms. We examined hepatic gene expression of BALB/c mice with streptozotocin (STZ)-induced diabetes to elucidate the mechanism of the protective effect of dietary quercetin on diabetes-associated liver injury.
Dietary quercetin alleviates diabetic symptoms and reduces streptozotocin-induced disturbance of hepatic gene expression in mice.
Sex, Specimen part
View SamplesWe showed that diets containing 0.1% or 0.5% quercetin lowered the STZ-induced increase in blood glucose levels and improved plasma insulin levels. A cluster analysis of the hepatic gene expressions showed that 0.5% quercetin diet suppressed STZ-induced alteration of gene expression. Gene set enrichment analysis (GSEA) and quantitative RT-PCR analysis showed that the quercetin diets had their greatest suppressive effect on the STZ-induced elevation of expression of cyclin dependent kinase inhibitor p21(WAF1/Cip1) (Cdkn1a).
Dietary quercetin alleviates diabetic symptoms and reduces streptozotocin-induced disturbance of hepatic gene expression in mice.
Sex, Specimen part
View SamplesPhloridzin is a dihydrochalcone typically contained in apples. A diet containing 0.5 % phloridzin significantly improves hyperglycemia but not hypoinsulinemia and tissue lipid peroxidation in streptozotocin (STZ)-induced diabetic mice after 14 days. The phloridzin diet has no effect on the alteration of hepatic gene expression in STZ-induced diabetic mice.
Dietary phloridzin reduces blood glucose levels and reverses Sglt1 expression in the small intestine in streptozotocin-induced diabetic mice.
Sex, Specimen part
View SamplesAstaxanthin alleviates hepatic lipid accumulation and peroxidation, inflammation, and fibrosis in mice with high-cholesterol, high-cholate, and high-fat (CL) diet-induced nonalcoholic steatohepatitis (NASH). It has been proposed as a potential new treatment to inhibit the progression of NASH in humans. Therefore, we compared hepatic gene expression profiles after treatment with astaxanthin or the antioxidant vitamin E in mice with CL diet-induced NASH. Comprehensive gene expression analyses of the livers of mice fed a standard, CL, or CL diet containing astaxanthin or vitamin E for 12 weeks were performed using a DNA microarray. Both astaxanthin and vitamin E effectively improved gene expression associated with eukaryotic initiation factor-2 (EIF2) signaling, which is suppressed in NASH by endoplasmic reticulum (ER) stress in the liver.
Hepatic Transcriptome Profiles of Mice with Diet-Induced Nonalcoholic Steatohepatitis Treated with Astaxanthin and Vitamin E.
Sex, Specimen part
View SamplesTo determine the effect of consumption of a quercetin-rich diet on obesity and dysregulated hepatic gene expression, C56BL/6J mice were fed for 20 weeks on control or a Western diet high in fat, cholesterol and sucrose, both with or without 0.05% quercetin. Chronic dietary intake of quercetin reduced body weight gain and visceral and liver fat accumulation, and improved hyperglyceamia, hyperinsulinaemia, dyslipidaemia in mice fed a Western-style diet.
Chronic dietary intake of quercetin alleviates hepatic fat accumulation associated with consumption of a Western-style diet in C57/BL6J mice.
Sex, Specimen part
View SamplesBoth the 0.05% and 1% querceitn diets did not significantly affect the body weight, fat accumulation, and blood components. However, 0.05% quercetin significantly increased the glutathione/oxidized glutathione ratio in the liver. Moreover, the 1% quercetin diet reduced the lipid peroxidation markers 8-isoprostane in plasma and malondialdehyde in the liver, epididymal adipose tissues, and small intestine.
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Sex, Specimen part, Treatment
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