Project description:Scope: Alcoholic liver disease (ALD) is a major cause of chronic liver disease and is induced by alcohol consumption. Acetaldehyde produced by alcohol metabolism enhances the fibrosis of the liver through hepatic stellate cells. Additionally, alcohol administration causes the accumulation of reactive oxygen species (ROS), which induce hepatocyte-injury-mediated lipid peroxidation. The purpose of this study was to investigate the protective effects of iso-α-acids against alcoholic liver injury in hepatocytes in mice. Methods and results: C57BL/6N mice were fed diets containing isomerized hop extract, which mainly consists of iso-α-acids. After 7 days of feeding, acetaldehyde was administered by a single intraperitoneal injection. The acetaldehyde-induced increases in serum AST and ALT levels were suppressed by iso-α-acids intake. Hepatic gene expression analyses showed the upregulation of the glutathione-S-transferase, alcohol dehydrogenase and aldehyde dehydrogenase genes. In vitro, iso-α-acids induced the nuclear translocation of nuclear factor erythroid 2-like 2 (Nfe2l2; Nrf2), a master regulator of antioxidant and detoxifying systems, and upregulated the enzymatic activities of glutathione-S-transferase and aldehyde dehydrogenase. Conclusions: These results suggest that iso-α-acids intake prevents alcoholic liver disease injury by reducing oxidative stress via the Nrf2-mediated pathway.
Project description:The hop plant, Humulus lupulus L., contains an exceptionally high content of secondary metabolites, the hop iso-α-acids, which possess a range of beneficial properties including antiseptic action. Studies performed on the mode of action of hop iso-α-acids have hitherto been restricted to lactic acid bacteria. The present study investigates molecular mechanisms of hop iso-α-acid resistance in the model eukaryote Saccharomyces cerevisiae. Growth inhibition occurred at concentrations of hop iso-α-acids that were an order of magnitude higher than those found with hop-tolerant prokaryotes. Chemostat-based transcriptome analysis and phenotype screening of the S. cerevisiae haploid gene deletion collection were used as complementary methods to screen for genes involved in hop iso-α-acids detoxification and tolerance. Further analysis of deletion mutants confirmed that yeast tolerance to hop iso-α-acids involves two major processes: active export of iso-α-acids across the plasma membrane and active proton pumping into the vacuole by the V-ATPase to enable vacuolar sequestration of iso-α-acids. Furthermore, iso-α-acids were shown to affect cellular metal homeostasis by acting as strong zinc and iron chelator.
Project description:The hop plant, Humulus lupulus L., contains an exceptionally high content of secondary metabolites, the hop iso-α-acids, which possess a range of beneficial properties including antiseptic action. Studies performed on the mode of action of hop iso-α-acids have hitherto been restricted to lactic acid bacteria. The present study investigates molecular mechanisms of hop iso-α-acid resistance in the model eukaryote Saccharomyces cerevisiae. Growth inhibition occurred at concentrations of hop iso-α-acids that were an order of magnitude higher than those found with hop-tolerant prokaryotes. Chemostat-based transcriptome analysis and phenotype screening of the S. cerevisiae haploid gene deletion collection were used as complementary methods to screen for genes involved in hop iso-α-acids detoxification and tolerance. Further analysis of deletion mutants confirmed that yeast tolerance to hop iso-α-acids involves two major processes: active export of iso-α-acids across the plasma membrane and active proton pumping into the vacuole by the V-ATPase to enable vacuolar sequestration of iso-α-acids. Furthermore, iso-α-acids were shown to affect cellular metal homeostasis by acting as strong zinc and iron chelator. Experiment Overall Design: Two complementary genome-wide approaches were employed to investigate cellular responses of S. cerevisiae to hop extracts enriched in iso-α-acids. Microarray transcriptome analysis was performed on chemostat cultures of an S. cerevisiae reference strain grown in the presence and absence of iso-α-acids. In addition, screening of the nearly complete set of yeast open reading frame (ORF) haploid knock-outs generated by the Saccharomyces Genome Deletion Project (SGDP) (Open Biosystems) identified the mutants with increased hop sensitivity. Subsequently, involvement of selected genes and cellular processes in hop acid sensitivity and tolerance was analyzed by construction and detailed analysis of selected mutant strains.
Project description:Transcriptional profiling of Lactobacillus brevis UCCLBBS124 and UCCLBBS449 comparing control strain grown in MRS broth with strains growing in different stress conditons (5 % EtOH, pH4 or 30 ppm iso-a-acids).This study aimed to evaluate how certain Lb. brevis isolates are adapted so as to allow them to survive and grow in beer.
Project description:free fatty acids(palmitate, oleate, linoleate) 0.7mM and tnf-alpha (0 20,100 ng/ml) were subjected to HepG2 cell line to study the cytotoxicity induced by these two factors Keywords: stress response
Project description:Analysis of variation in subcutaneous adipose tissue gene expression in response to dietary intake of n-3 polyunsaturated fatty acids, as assessed in a cohot of individuals with metabolic syndrome. Outcomes from this study provide insight on molecular details of dietary effects on gene expression and metabolic health. Subcutaneous adipose tissue samples were taken from a cohort of seventeen individuals with metabolic syndrome. Habitual intake of n-3 polyunsaturated fatty acids was assessed with 3-day weighed food journals.
Project description:To investigate effects of intake of Eucommia ulmoides leaves on hyperlipidemia, we performed gene expression profiling on rat liver by microarray analysis. Microarray analysis revealed that Eucommia ulmoides leaves up-regulated the gene expression involved in alpha-, beta-, and omega-oxidation of fatty acids, mainly relating to peroxisome proliferator-activated receptor signaling pathway. Rats were fed a high-fat diet and high-fructose water without/with orally administration of Eucommia ulmoides leaves for 5 weeks. Livers were taken for RNA extraction and hybridization on Agilent microarrays.