Project description:Using mice deficient in hepatic cytochrome-P450 oxidoreductase (POR), which disables the liver cytochrome P450 system, the metabolism and biological response of the anti-carcinogenic flavonoid, quercetin, was examined. Profiling circulating metabolites revealed similar profiles over 72 h in wild type (WT) and POR-null (KO) mice, showing that hepatic P450 and reduced biliary secretion do not affect quercetin metabolism. Transcriptional profiling at 24 h revealed that 2-3 fold more genes responded significantly to quercetin in WT compared to KO in the jejunum, ileum, colon, and liver, suggesting that hepatic P450s mediate many of the biological effects of quercetin, such as immune function, estrogen receptor signaling and lipid, glutathione, purine, and amino acid metabolism, even though quercetin metabolism is not modified. The functional interpretation of expression data in response to quercetin (single dose of 7 mg/animal) revealed a molecular relationship between the liver and jejunum. In WT animals, amino acid and sterol metabolism were predominantly modulated in the liver, fatty acid metabolism response was shared between the liver and jejunum, and glutathione metabolism was modulated in the small intestine. In contrast, KO animals do not regulate amino acid metabolism in the liver or small intestine, they share the control of fatty acid metabolism between the liver and jejunum, and regulation of sterol metabolism is shifted from the liver to the jejunum and that of glutathione metabolism from the jejunum to the liver. This demonstrates that the quercetin-mediated regulation of these biological functions in extrahepatic tissues is dependent on the functionality of the liver POR. In conclusion, using a systems biology approach to explore the contribution of hepatic phase I detoxification on quercetin metabolism demonstrated the resiliency and adaptive capacity of a biological organism in dealing with a bioactive nutrient when faced with a tissue-specific molecular dysfunction. Experiment Overall Design: All animals were adapted to the RM3 (E) 801710 Soya-free powdered diet (B. S & S. [Scotland] Ltd, UK) over a period of 14 days. Quercetin was added separately to the semi-purified diets at a concentration of 6200 ppm (0.62 %; 6.2 g per kg). 65 male cytochrome P450 reductase null (KO) mice and 65 wild type (WT) C57BL/6 mice were reared, all aged between 6-8 weeks. Animals were housed 3 per cage, where both temperature and relative humidity were maintained within a range of 19-23oC and 40-70%, respectively. Twelve-hour periods of light were cycled with twelve-hour periods of darkness. Experiment Overall Design: For each strain of mouse, the following experimental design was used: a control group (25 mice) receiving powdered RM3 diet ad libitum and a group (25 mice) receiving a âhigh doseâ of quercetin (7 mg / mouse). The experimental diet was administered on day 15, following a 14-day adaptation period to the RM3 diet. Animals were sacrificed after 24 h. Experiment Overall Design: RNA samples destined for microarray analysis were only accepted and pooled into three groups if no aberrant signs of degradation (e.g. multiple peaks) were observed. The comprehensive gene expression profiles of the liver, jejunum, ileum, and colon were analyzed. In all cases, except those listed, RNA from 3 mice was pooled to form sample 1, another 3 mice to form sample 2, etc. Thus, 9 mice were used for the four experimental groups: wild-type, wild-type+quercetin, POR-null, POR-null+quercetin.

Project description:Using mice deficient in hepatic cytochrome-P450 oxidoreductase (POR), which disables the liver cytochrome P450 system, the metabolism and biological response of the anti-carcinogenic flavonoid, quercetin, was examined. Profiling circulating metabolites revealed similar profiles over 72 h in wild type (WT) and POR-null (KO) mice, showing that hepatic P450 and reduced biliary secretion do not affect quercetin metabolism. Transcriptional profiling at 24 h revealed that 2-3 fold more genes responded significantly to quercetin in WT compared to KO in the jejunum, ileum, colon, and liver, suggesting that hepatic P450s mediate many of the biological effects of quercetin, such as immune function, estrogen receptor signaling and lipid, glutathione, purine, and amino acid metabolism, even though quercetin metabolism is not modified. The functional interpretation of expression data in response to quercetin (single dose of 7 mg/animal) revealed a molecular relationship between the liver and jejunum. In WT animals, amino acid and sterol metabolism were predominantly modulated in the liver, fatty acid metabolism response was shared between the liver and jejunum, and glutathione metabolism was modulated in the small intestine. In contrast, KO animals do not regulate amino acid metabolism in the liver or small intestine, they share the control of fatty acid metabolism between the liver and jejunum, and regulation of sterol metabolism is shifted from the liver to the jejunum and that of glutathione metabolism from the jejunum to the liver. This demonstrates that the quercetin-mediated regulation of these biological functions in extrahepatic tissues is dependent on the functionality of the liver POR. In conclusion, using a systems biology approach to explore the contribution of hepatic phase I detoxification on quercetin metabolism demonstrated the resiliency and adaptive capacity of a biological organism in dealing with a bioactive nutrient when faced with a tissue-specific molecular dysfunction. Experiment Overall Design: All animals were adapted to the RM3 (E) 801710 Soya-free powdered diet (B. S & S. [Scotland] Ltd, UK) over a period of 14 days. Quercetin was added separately to the semi-purified diets at a concentration of 6200 ppm (0.62 %; 6.2 g per kg). 65 male cytochrome P450 reductase null (KO) mice and 65 wild type (WT) C57BL/6 mice were reared, all aged between 6-8 weeks. Animals were housed 3 per cage, where both temperature and relative humidity were maintained within a range of 19-23oC and 40-70%, respectively. Twelve-hour periods of light were cycled with twelve-hour periods of darkness. Experiment Overall Design: For each strain of mouse, the following experimental design was used: a control group (25 mice) receiving powdered RM3 diet ad libitum and a group (25 mice) receiving a â??high doseâ?? of quercetin (7 mg / mouse). The experimental diet was administered on day 15, following a 14-day adaptation period to the RM3 diet. Animals were sacrificed after 24 h. Experiment Overall Design: RNA samples destined for microarray analysis were only accepted and pooled into three groups if no aberrant signs of degradation (e.g. multiple peaks) were observed. The comprehensive gene expression profiles of the liver, jejunum, ileum, and colon were analyzed. In all cases, except those listed, RNA from 3 mice was pooled to form sample 1, another 3 mice to form sample 2, etc. Thus, 9 mice were used for the four experimental groups: wild-type, wild-type+quercetin, POR-null, POR-null+quercetin.

Project description:Using mice deficient in hepatic cytochrome-P450 oxidoreductase (POR), which disables the liver cytochrome P450 system, the metabolism and biological response of the anti-carcinogenic flavonoid, quercetin, was examined. Profiling circulating metabolites revealed similar profiles over 72 h in wild type (WT) and POR-null (KO) mice, showing that hepatic P450 and reduced biliary secretion do not affect quercetin metabolism. Transcriptional profiling at 24 h revealed that 2-3 fold more genes responded significantly to quercetin in WT compared to KO in the jejunum, ileum, colon, and liver, suggesting that hepatic P450s mediate many of the biological effects of quercetin, such as immune function, estrogen receptor signaling and lipid, glutathione, purine, and amino acid metabolism, even though quercetin metabolism is not modified. The functional interpretation of expression data in response to quercetin (single dose of 7 mg/animal) revealed a molecular relationship between the liver and jejunum. In WT animals, amino acid and sterol metabolism were predominantly modulated in the liver, fatty acid metabolism response was shared between the liver and jejunum, and glutathione metabolism was modulated in the small intestine. In contrast, KO animals do not regulate amino acid metabolism in the liver or small intestine, they share the control of fatty acid metabolism between the liver and jejunum, and regulation of sterol metabolism is shifted from the liver to the jejunum and that of glutathione metabolism from the jejunum to the liver. This demonstrates that the quercetin-mediated regulation of these biological functions in extrahepatic tissues is dependent on the functionality of the liver POR. In conclusion, using a systems biology approach to explore the contribution of hepatic phase I detoxification on quercetin metabolism demonstrated the resiliency and adaptive capacity of a biological organism in dealing with a bioactive nutrient when faced with a tissue-specific molecular dysfunction. Experiment Overall Design: All animals were adapted to the RM3 (E) 801710 Soya-free powdered diet (B. S & S. [Scotland] Ltd, UK) over a period of 14 days. Quercetin was added separately to the semi-purified diets at a concentration of 6200 ppm (0.62 %; 6.2 g per kg). 65 male cytochrome P450 reductase null (KO) mice and 65 wild type (WT) C57BL/6 mice were reared, all aged between 6-8 weeks. Animals were housed 3 per cage, where both temperature and relative humidity were maintained within a range of 19-23oC and 40-70%, respectively. Twelve-hour periods of light were cycled with twelve-hour periods of darkness. Experiment Overall Design: For each strain of mouse, the following experimental design was used: a control group (25 mice) receiving powdered RM3 diet ad libitum and a group (25 mice) receiving a âhigh doseâ of quercetin (7 mg / mouse). The experimental diet was administered on day 15, following a 14-day adaptation period to the RM3 diet. Animals were sacrificed after 24 h. Experiment Overall Design: RNA samples destined for microarray analysis were only accepted and pooled into three groups if no aberrant signs of degradation (e.g. multiple peaks) were observed. The comprehensive gene expression profiles of the liver, jejunum, ileum, and colon were analyzed. In all cases, except those listed, RNA from 3 mice was pooled to form sample 1, another 3 mice to form sample 2, etc. Thus, 9 mice were used for the four experimental groups: wild-type, wild-type+quercetin, POR-null, POR-null+quercetin.

Project description:In order to obtain a global view of energy metabolism pathways of the sulfate-reducer Desulfovibrio vulgaris Hildenborough and the proteins involved therein whole-genome microarrays were used to compare the transcriptional response of cells grown with hydrogen/sulfate, pyruvate/sulfate, lactate/thiosulfate, and pyruvate with limiting sulfate, relative to growth in standard lactate/sulfate condition. Growth with hydrogen/sulfate showed the largest number of differently expressed genes and the largest changes in expression levels. The most up-regulated energy metabolism genes were those coding for the periplasmic [NiFeSe] hydrogenase, followed by the Ech hydrogenase, and the most down-regulated were genes coding for the Coo hydrogenase. The results point to the involvement of formate cycling and the ethanol pathway during growth on hydrogen, whereas there is evidence for CO cycling during growth on lactate and pyruvate, but not on H2. Growth with thiosulfate showed the hallmarks of a reduced energy status of the cells with down regulation of the ATP synthase and the Qmo and Dsr complexes., whereas growth with pyruvate showed the smallest differences but an increased role for the Ech hydrogenase.that in this case functions in reverse from the case of growth with H2. The multiple periplasmic hydrogenases and formate dehydrogenases, do not display the same regulation pattern showing that their metabolic roles are not totally interchangeable. This result together with the observation that several genes coding for proteins that have not been biochemically characterised were considerably affected in this study, reveals a more complex energy metabolism than previously considered and provides guidance for further studies. Keywords: Growth protocol Desulfovibrio vulgaris from our laboratory culture collection was cultured at 37°C with pyruvate as the only substrate (without sulfate as the electron acceptor) to mid-log phase. Cultures were also cultivated similarly in Lactate-Sulfate medium to mid-log phase. Gene expression profiles of cultures grown under pyruvate fermentation were compared with those of the cultures grown via sulfate reduction. Total RNA was harvested from four replicate cultures for microarray analysis. RNA extraction, purification, and labeling were performed independently on each cell sample.Two samples of each total RNA preparation were labeled, one with Cy3-dUTP and another with Cy5-dUTP for microarray hybridization.

Project description:Desulfovibrio vulgaris has been studied extensively for its potential in the bioremediation of heavy metals and radionuclides. Hydrocarbons and solvents, as frequent environmental co-contaminants, have been reported to inhibit microbial activities and thereby pose a limitation on bioremediation efficiency. As a part of the Genomes: GTL project to deduce the stress response pathways in metal/radionuclide reducing bacteria, we studied the responses of D. vulgaris to acetone, which is a ketone solvent frequently observed at contaminated DOE sites. Growth experiments in closed vessels at 37 Â°C indicated that D. vulgaris could maintain normal growth with 3%(v/v) acetone following a 1-h lag phase. When the acetone concentration was raised to 5%(v/v), we observed a 2-h lag phase followed by a growth rate which was only 15% that of normal. At an acetone concentration of 8%(v/v), no active growth was observed following 10 hours of incubation. To assess the mechanism of acetone inhibition, genome-wide transcriptional profiles were analyzed from D. vulgaris cultures following acetone (5% v/v) treatment using whole-genome microarrays. This acetone shock altered the expression of a large number of genes in the D. vulgaris genome, of which 309 were up-regulated greater than 2 fold and 199 were down-regulated by over 2 fold. Transcripts highly up-regulated included genes encoding the flagella structural subunits, flgB (15 fold), fliE (11 fold), and flgH (10 fold). Another group of genes highly induced were chaperones, such as dnaJ (11 fold), groES (8 fold), and hsp20 (8 fold). Down-regulated genes included two groups of genes, ribosomal proteins and amino acid transporters, suggesting a state of growth arrest upon acetone addition. These results were interpreted to mean that D. vulgaris responds to elevated solvent levels by increased motility and maintenance of proper protein functions. Current work is focused on the analysis of regulatory pathways based on temporal transcriptional dynamics. Keywords: Stress response Desulfovibrio vulgaris from our laboratory culture collection was cultured at 37Â°C in Lactate-Sulfate medium to mid-log phase. Subsequently, acetone (5% v/v) was added into triplicate cultures. Gene expression profiles 30 and 100 minutes following acetone exposure were compared with those of the control cultures without acetone treatment. Total RNA was harvested from three replicate control and treated cultures at two time points following acetone addition. RNA extraction, purification, and labeling were performed independently on each cell sample.Two samples of each total RNA preparation were labeled, one with Cy3-dUTP and another with Cy5-dUTP for microarray hybridization (Dye swap).

Project description:Desulfovibrio vulgaris has been studied extensively for its potential in the bioremediation of heavy metals and radionuclides. Hydrocarbons and solvents, as frequent environmental co-contaminants, have been reported to inhibit microbial activities and thereby pose a limitation on bioremediation efficiency. As a part of the Genomes: GTL project to deduce the stress response pathways in metal/radionuclide reducing bacteria, we studied the responses of D. vulgaris to ethanol, which is a solvent and co-contaminant frequently encountered at contaminated DOE sites. Growth experiments in closed vessels at 37 Â°C indicated that D. vulgaris could maintain normal growth with 1%(v/v) ethanol. The growth rates were reduced with increasing ethanol concentrations at 2% and 5%. Growth ceased when ethanol concentration was raised to 5%(v/v). Cell lysis was apparent with decreasing optical density following 10% ethanol addition. To assess the mechanism of ethanol inhibition, genome-wide transcriptional profiles were analyzed from D. vulgaris cultures following ethanol (5% v/v) treatment using whole-genome microarrays. The ethanol treatment altered the expression of a large number of genes in the D. vulgaris genome, of which 354 were up-regulated greater than 2 fold and 217 were down-regulated by over 2 fold. As expected, changes in the transcriptional profile were similar to those of the stress response to acetone, which is also a solvent. Transcripts highly up-regulated included genes encoding the flagella structural subunits, suggesting motility as a mechanism of solvent stress response. Another group of genes highly induced were chaperones, such as dnaJ, groES, and hsp20, indicating the importance of maintaining proper protein folding under ethanol stress. Down-regulated genes included two groups of genes, ribosomal proteins and amino acid transporters, consistent with the growth inhibition by ethanol observed in growth studies. These results were interpreted that D. vulgaris responds to elevated solvent levels by increased motility and maintenance of proper protein functions. Current work is focused on the analysis of regulatory pathways based on temporal transcriptional dynamics. Keywords: Stress response Desulfovibrio vulgaris from our laboratory culture collection was cultured at 37Â°C in Lactate-Sulfate medium to mid-log phase. Subsequently, ethanol (5% v/v) was added into triplicate cultures. Gene expression profiles 30 and 100 minutes following ethanol exposure were compared with those of the control cultures without ethanol treatment. Total RNA was harvested from three replicate control and treated cultures at two time points following ethanol addition. RNA extraction, purification, and labeling were performed independently on each cell sample.Two samples of each total RNA preparation were labeled, one with Cy3-dUTP and another with Cy5-dUTP for microarray hybridization (Dye swap).

Dataset Information

Transcription profiling of colon, ileum, jejunum and liver from wild type and hepatic cytochrome P-450 reductase null mice treated with quercetin to identify differential transcriptional responses to quercetin.

Publications

Hepatic cytochrome P-450 reductase-null mice show reduced transcriptional response to quercetin and reveal physiological homeostasis between jejunum and liver.

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