Project description:Given the positive results of quercetin in in vitro genotoxicity studies, it is of interest to test the in vivo genotoxicity of this important dietary flavonoid, especially considering possible high intake by widely available supplements. In the present study quercetin was tested in a transcriptomic analysis for genotoxicity in liver and small intestine of mice. Quercetin (0.33%) supplemented to a high-fat diet was administered to mice during 12 weeks and compared with high-fat diet feeding. Serum ALT and AST levels revealed no indications for hepatotoxicity. General microarray pathway analysis of liver and small intestinal tissue samples showed no regulation of genotoxicity related pathways. In addition, analysis of DNA damage pathways in these samples, also did not point at genotoxicity. Furthermore, comparison with a published classifier set of transcripts for identifying genotoxic compounds did not reveal any similarities with the regulation of these classifier set of transcripts by quercetin, except for two of the transcripts which were regulated in opposite direction. Available microarray datasets of known genotoxic compounds, 2-acetylaminofluorene (2-AAF) and aflatoxin B1 (AFB1) in mice were taken along as positive controls for comparison, and indeed showed genotoxic properties (regulation of genotoxic related genes) in the analyses. This transcriptomic study showed that supplementation with quercetin at ~350 mg/kg bw/day for 12 weeks in mice gave no indications of quercetin-induced genotoxicity in liver and small intestine.
Project description:Both 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. Although comprehensive gene expression analysis dot not detect the genes with significantly different expression levels among the groups of mice, RT-PCR analysis showed that the 1% quercetin diet significantly induced the expression of the antioxidant enzymes Gpx1, Cat, and Sod1 in the liver and Gpx1 and Cat in the epididymal adipose tissues. The transcription factor nuclear factor E2-related factor 2 (Nrf2) was slightly induced in the nuclear fraction of the livers of mice fed the 1% quercetin diet. Quercetin may induce antioxidant enzymes by directly or indirectly activating the Nrf2 pathway in the liver. Five-week-old male mice were fed a AIN-93G diet containing 0% (Control), 0.05% (0.05% quercetin diet), or 1% quercertin (1% quercetin diet) for 20 weeks.
Project description:Both 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. Although comprehensive gene expression analysis dot not detect the genes with significantly different expression levels among the groups of mice, RT-PCR analysis showed that the 1% quercetin diet significantly induced the expression of the antioxidant enzymes Gpx1, Cat, and Sod1 in the liver and Gpx1 and Cat in the epididymal adipose tissues. The transcription factor nuclear factor E2-related factor 2 (Nrf2) was slightly induced in the nuclear fraction of the livers of mice fed the 1% quercetin diet. Quercetin may induce antioxidant enzymes by directly or indirectly activating the Nrf2 pathway in the liver.
Project description:The ketogenic diet has been successful in promoting weight loss among patients that have struggled with weight gain. This is due to the cellular switch in metabolism that utilizes liver-derived ketone bodies for the primary energy source rather than glucose. Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the transport of exogenous long chain fatty acids (LCFA) and in the activation to CoA thioesters of very long chain fatty acids (VLCFA). We have completed a multi-omic study of FATP2-null (Fatp2-/-) mice maintained on a ketogenic diet (KD) or paired control diet (CD), with and without a 24-hour fast (KD-fasted and CD-fasted) to address the impact of deleting FATP2 under high-stress conditions. Control (wt/wt) and Fatp2-/- mice were maintained on their respective diets for 4-weeks. Afterwards, half the population was sacrificed while the remaining were fasted for 24-hours prior to sacrifice. We then performed paired-end RNA-sequencing on the whole liver tissue to investigate differential gene expression. The differentially expressed genes mapped to ontologies such as the metabolism of amino acids and derivatives, fatty acid metabolism, protein localization, and components of the immune system’s complement cascade, and were supported by the proteome and histological staining.
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. Keywords: nutritional intervention, comparative genomic response, genotype variation
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. Keywords: nutritional intervention, comparative genomic response, genotype variation
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. Keywords: nutritional intervention, comparative genomic response, genotype variation
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. Keywords: nutritional intervention, comparative genomic response, genotype variation
Project description:Acetaminophen is a widely used antipyretic and analgesic drug, and its overdose is the leading cause of drug-induced acute liver failure. This study aimed to investigate the effect and mechanism of Lacticaseibacillus casei Shirota (LcS), an extensively used and highly studied probiotic, on acetaminophen-induced acute liver injury. C57BL/6 mice were gavaged with LcS suspension or saline once daily for 7 days before the acute liver injury was induced via intraperitoneal injection of 300 mg/kg acetaminophen. The results showed that LcS significantly decreased acetaminophen-induced liver and ileum injury, as demonstrated by reductions in the increases in aspartate aminotransferase, total bile acids, total bilirubin, indirect bilirubin and hepatic cell necrosis. Moreover, LcS alleviated the acetaminophen-induced intestinal mucosal permeability, elevation in serum IL-1α and lipopolysaccharide, and decreased levels of serum eosinophil chemokine (eotaxin) and hepatic glutathione levels. Furthermore, analysis of the gut microbiota and metabolome showed that LcS reduced the acetaminophen-enriched levels of Cyanobacteria, Oxyphotobacteria, long-chain fatty acids, cholesterol and sugars in the gut. Additionally, the transcriptome and proteomics showed that LcS mitigated the downregulation of metabolism and immune pathways as well as glutathione formation during acetaminophen-induced acute liver injury. This is the first study showing that pretreatment with LcS alleviates acetaminophen-enriched acute liver injury, and it provides a reference for the application of LcS.
Project description:Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the uptake of exogenous long chain fatty acids (LCFAs) and in the activation to CoA thioesters of very long chain fatty acids (VLCFAs). Here we address the phenotypic impacts of deleting FATP2 followed by an unbiased RNA-seq analysis of the liver transcriptome. Wild type (C57BL/6J) and fatp2 null (fatp2-/-) mice (5 weeks old) were maintained on a standard chow diet for 6 weeks (11 weeks old). The male fatp2-/- mice had 258 differentially expressed genes (DEGs) and the female mice had a total of 91. Of significance was the finding that most of the genes with increased expression in the fatp2-/- liver are regulated by the transcription factor peroxisome proliferator-activated receptor alpha (PPARα). Taken together, FATP2 has a broad impact on the expression of key lipid metabolic genes in the liver regulated by PPARα.