scholarly journals A9 BACTERIAL BILE SALT HYDROLASE GENE ABUNDANCE IS ASSOCIATED WITH RORC GENE EXPRESSION IN INTESTINAL MUCOSA OF INFLAMMATORY DISEASE PATIENTS

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 11-12
Author(s):  
C Hernandez-Rocha ◽  
K Borowski ◽  
W Turpin ◽  
M Smith ◽  
J Stempak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bile Acid ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Host Gene Expression ◽  
Biopsy Site ◽  
Endoscopic Score

Abstract Background The role of gut microbes involved in bile acid metabolism and their impact on mucosal immune regulation is beginning to be appreciated. For instance, changes in microbial bile salt hydrolase (BSH) activity which deconjugates bile acids in the gastrointestinal tract of gnotobiotic mice, significantly alters gene expression patterns of immune-related genes in ileum. Moreover, bile acid dysmetabolism may participate in the chronic inflammation loop of Inflammatory bowel disease (IBD). Aims We carried out an integrated mucosal microbiome-transcriptome analysis to elucidate associations between microbial bile-acid metabolizing function and host gene expression. Methods Crohn’s disease (CD), ulcerative colitis (UC) and IBD unclassified (IBDU) patients were recruited prior to scheduled colonoscopy performed as part of clinical care. Only patients with non-inflamed mucosa defined as a segmental simple endoscopic score 0–2 in CD and a segmental Mayo endoscopic score of 0 in UC/IBDU were included in this analysis to minimize the effect of inflammation on gene expression. Biopsy samples were obtained from terminal ileum, ascending colon and sigmoid colon, and microbial DNA and human RNA was extracted. V4 region of 16S rRNA gene was sequenced and the relative abundance of bile acid-metabolizing genes was inferred using PICRUSt. RNA-seq was used to sequence total human RNA and a supervised transcript reduction analysis focus upon 65 genes previously associated with bile acid metabolism and IBD was utilized. Associations between microbiome clusters of orthologous groups (COGs), transcriptome, diagnosis (CD vs UC/IBDU), and biopsy site were analyzed using linear mixed-effects model with lmer4 function in R. An adjusted-p value after false discovery rate correction < 0.05 was considered significant. Results A total of 126 samples from 86 subjects were analyzed corresponding to 35 CD and 51 UC/IBDU. Mean age for the total cohort was 34.7 ± 11 years and 35 (40.6%) were females. There was a significant negative correlation between relative abundance of bacterial bsh genes (COG3049) and human RORC gene (p < 0.03). This association was independent of type of diagnosis and biopsy site. There was no association among other analyzed bacterial COGs and host genes. Conclusions Using an integrative microbiome-host transcriptome approach, our data provide new evidence linking microbial bile acid deconjugation (bsh genes) and host gene expression in the mucosal-luminal interface in quiescent IBD-affected tissue. Nuclear receptor RORC is pivotal in the differentiation and function of innate lymphoid cells and T-helper 17 cells. Modulation of this pathway by bile acids or gut bacteria involved in their metabolism could shed light on the immune role of bile acids in IBD patients. Funding Agencies CAG, CIHRNational Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

scholarly journals The influence of probiotics on individual fecal secondary bile acid levels: a two-case study of schizophrenic patients receiving an atypical antipsychotic drug

2017 ◽  
Vol 7 (11) ◽  
pp. 849
Author(s):  
Yosuke Saito ◽  
Hiroyuki Nishimiya ◽  
Yasue Kondo ◽  
Toyoaki Sagae
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Atypical Antipsychotic Drug ◽  
Secondary Bile Acid ◽  
Secondary Bile Acids ◽  
Bsh Activity

Background: Probiotics is used as a promising approach in the prevention and treatment of hypercholesterolemia. Modification of bile acid metabolism through the deconjugation of bile salts by microbial bile salt hydrolase (BSH) is considered to be the core mechanism of the hypocholesterolemic effects of probiotics. Nevertheless, BSH activity is reported to be detrimental to the human host due to the generation of toxic secondary bile acids. Thus, the influence of probiotic intake on bile acid metabolism needs to be elucidated. We analyzed the bile acid levels and microbiota in human fecal samples after probiotic supplementation to assess the influence of probiotic intake on fecal bile acid levels. Two patients hospitalized for schizophrenia and dyslipidemia, receiving an atypical antipsychotic drug, were enrolled in this study (Subjects A and B). Both subjects received Lactobacillus rhamnosus GG (LGG) for 4 weeks, and no probiotics for the following 4 weeks. Fecal samples were collected at baseline and after 4 and 8 weeks.Results: Conjugated bile acids may be modified by indigenous intestinal bacteria into unconjugated bile acids and secondary bile acids through deconjugation reactions by BSH activity and the subsequent 7a-dehydroxylation pathway, respectively. In the fecal microbiota from Subject A, the relative abundance of Bifidobacterium increased after LGG supplementation (30%–49%). Most Bifidobacterium and Lactobacillus strains that colonize mammalian intestines may report BSH activity, and in general bifidobacteria reveals a higher BSH activity than lactobacilli. The fecal unconjugated bile acid and secondary bile acid levels in Subject A increased after the LGG supplementation (0.36–1.79 and 1.82–16.19 mmol/g respectively). Although the LGG supplementation appears to promote bile acid deconjugation, most of the unconjugated bile acids in Subject A appear to have been modified into secondary bile acids. Alternatively, in Subject B there were no significant changes throughout the study.Conclusion: We observed a significant increase in the fecal secondary bile acid levels after probiotic administration in one of our cases. Further studies are needed to elucidate the factors affecting 7a-dehydroxylation of bile acids to confirm the safety of using probiotics.Keywords: bile salt hydrolase; BSH; dihydroxylation; Bifidobacterium

scholarly journals Obesity diabetes and the role of bile acids in metabolism

2016 ◽  
Vol 4 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Gerald H. Tomkin ◽  
Daphne Owens
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Cholesterol Homeostasis ◽  
Bile Acid Metabolism ◽  
Forkhead Transcription Factor ◽  
Obesity And Diabetes ◽  
Glucagon Like Peptide 1 ◽  
Fat Soluble Vitamins

AbstractBile acids have many activities over and above their primary function in aiding absorption of fat and fat soluble vitamins. Bile acids are synthesized from cholesterol, and thus are involved in cholesterol homeostasis. Bile acids stimulate glucagon-like peptide 1 (GLP1) production in the distal small bowel and colon, stimulating insulin secretion, and therefore, are involved in carbohydrate and fat metabolism. Bile acids through their insulin sensitising effect play a part in insulin resistance and type 2 diabetes. Bile acid metabolism is altered in obesity and diabetes. Both dietary restriction and weight loss due to bariatric surgery, alter the lipid carbohydrate and bile acid metabolism. Recent research suggests that the forkhead transcription factor FOXO is a central regulator of bile, lipid, and carbohydrate metabolism, but conflicting studies mean that our understanding of the complexity is not yet complete.

scholarly journals Role of Nrf2 in the alteration of cholesterol and bile acid metabolism-related gene expression by dietary cholesterol in high fat-fed mice

2014 ◽  
Vol 54 (2) ◽  
pp. 90-94 ◽  
Author(s):  
Toshinori Kamisako ◽  
Yuji Tanaka ◽  
Yoshizumi Kishino ◽  
Takanori Ikeda ◽  
Kazuo Yamamoto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bile Acid ◽  
Acid Metabolism ◽  
Dietary Cholesterol ◽  
Bile Acid Metabolism ◽  
Related Gene ◽  
High Fat

scholarly journals Aryl hydrocarbon receptor (AhR) activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) dose-dependently shifts the gut microbiome consistent with the progression of steatosis to steatohepatitis with fibrosis

2021 ◽  
Author(s):  
Russell R Fling ◽  
Tim Zacharewski
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Lactobacillus Species ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Metagenomic Sequencing ◽  
Secondary Bile Acid ◽  
Alcoholic Fatty Liver ◽  
Dose Dependent

Gut dysbiosis with disrupted enterohepatic bile acid metabolism is commonly associated with non-alcoholic fatty liver disease (NAFLD) and recapitulated in a NAFLD-phenotype elicited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in mice. TCDD induces hepatic fat accumulation and increases levels of secondary bile acids including taurolithocholic acid and deoxycholic acid, microbial modified bile acids involved in host bile acid regulation signaling pathways. To investigate the effects of TCDD on the gut microbiota, cecum contents of male C57BL/6 mice orally gavaged with sesame oil vehicle or 0.3, 3, or 30 µg/kg TCDD were examined using shotgun metagenomic sequencing. Taxonomic analysis identified dose-dependent increases in Lactobacillus species (i.e., Lactobacillus reuteri). Increased species were also associated with dose-dependent increases in bile salt hydrolase sequences, responsible for deconjugation reactions in secondary bile acid metabolism. Increased L. reuteri levels were further associated with mevalonate-dependent isopentenyl diphosphate (IPP) biosynthesis and menaquinone biosynthesis genes. Analysis of gut microbiomes from cirrhosis patients identified increased abundance of these pathways as identified in the mouse cecum metagenomic analysis. These results extend the association of lactobacilli with the AhR/intestinal axis in NAFLD progression and highlight the similarities between TCDD-elicited phenotypes in mice to human NAFLD.

Abstract 49: The Transcriptional Repressor MafG Regulates Cholesterol Catabolism

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Thomas Q de Aguiar Vallim ◽  
Elizabeth J Tarling ◽  
Hannah Ahn ◽  
Lee R Hagey ◽  
Casey E Romanoski ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Metabolic Diseases ◽  
Cholesterol Metabolism ◽  
Transcriptional Repressor ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Bile Acid Metabolism ◽  
Biliary Bile Acid

Elevated circulating cholesterol levels is a major risk factor for cardiovascular diseases (CVD), and therefore understanding pathways that affect cholesterol metabolism are important for potential treatment of CVD. The major route for cholesterol excretion is through its catabolism to bile acids. Specific bile acids are also potent signaling molecules that modulate metabolic pathways affecting lipid, glucose and bile acid homeostasis. Bile acids are synthesized from cholesterol in the liver, and the key enzymes involved in bile acid synthesis ( Cyp7a1 , Cyp8b1 ) are regulated transcriptionally by the nuclear receptor FXR. We have identified an FXR-regulated pathway upstream of a transcriptional repressor that controls multiple bile acid metabolism genes. We identify MafG as an FXR target gene and show that hepatic MAFG overexpression represses genes of the bile acid synthetic pathway, and modifies the biliary bile acid composition. In contrast, MafG loss-of-function studies cause de-repression of the bile acid genes with concordant changes in biliary bile acid levels. Finally, we identify functional MafG response elements in bile acid metabolism genes using ChIP-Seq analysis. Our studies identify a molecular mechanism for the complex feedback regulation of bile acid synthesis controlled by FXR. The identification of this pathway will likely have important implications in metabolic diseases.

scholarly journals Identification of bile acids in the serum and urine in cholestasis. Evidence for 6α-hydroxylation of bile acids in man

1976 ◽  
Vol 154 (2) ◽  
pp. 507-516 ◽  
Author(s):  
J A. Summerfield ◽  
B H. Billing ◽  
C H. L. Shackleton
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Gas Chromatography Mass Spectrometry ◽  
Acid Mixture ◽  
Bile Acid Metabolism ◽  
Hyodeoxycholic Acid ◽  
Normal Man ◽  
Hyocholic Acid ◽  
Sulphate Conjugate

In this qualitative study of the pattern of bile acid excretion in cholestasis, methods are described for the isolation of bile acids from large volumes of urine and plasma. The bile acids were subjected to a group separation and identified by combined gas chromatography-mass spectrometry. The techniques were developed to allow identification of the minor components of the bile acid mixture. Four bile acids that have not previously been described in human urine and plasma were detected, namely 3β, 7α-dihydroxy-5β-cholan-24-oic acid, 3α, 6α-dihydroxy-5β-cholan-24-oic acid (hyodeoxycholic acid), 3α, 6α, 7α-trihydroxy-5β-cholan-24-oic acid (hyocholic acid) and 3α, 7β, 12α-trihydroxy-5β-cholan-24-oic acid. In addition three C27 steroids were found; 26-hydroxycholesterol and a trihydroxy cholestane, probably 5 β-cholestane-3α, 7α, 26-triol were found in the sulphate fraction of plasma and urine. In the plasma sample, a sulphate conjugate of 24-hydroxycholesterol was found. The presence of these compounds probably reflects the existence of further pathways for bile acid metabolism. It is not yet known whether this is a consequence of the cholestasis or whether they are also present in normal man, at much lower concentrations.

scholarly journals Multiple Roles of 25-Hydroxycholesterol in Lipid Metabolism, Antivirus Process, Inflammatory Response, and Cell Survival

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qin Cao ◽  
Zhongzhong Liu ◽  
Yan Xiong ◽  
Zibiao Zhong ◽  
Qifa Ye
Keyword(s):  
Lipid Metabolism ◽  
Bile Acid ◽  
Inflammatory Response ◽  
Acid Metabolism ◽  
Membrane Lipid ◽  
Multiple Roles ◽  
Bile Acid Metabolism ◽  
Radical Process ◽  
Underlying Mechanisms

As an essential lipid, cholesterol is of great value in keeping cell homeostasis, being the precursor of bile acid and steroid hormones, and stabilizing membrane lipid rafts. As a kind of cholesterol metabolite produced by enzymatic or radical process, oxysterols have drawn much attention in the last decades. Among which, the role of 25-hydroxycholesterol (25-HC) in cholesterol and bile acid metabolism, antivirus process, and inflammatory response has been largely disclosed. This review is aimed at revealing these functions and underlying mechanisms of 25-HC.

The influence of rosuvastatin on the gastrointestinal microbiota and host gene expression profiles

2017 ◽  
Vol 312 (5) ◽  
pp. G488-G497 ◽  
Author(s):  
J. A. Nolan ◽  
P. Skuse ◽  
K. Govindarajan ◽  
E. Patterson ◽  
N. Konstantinidou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Community Structure ◽  
Bile Acid ◽  
Microbial Community ◽  
Gut Microbiota ◽  
Acid Metabolism ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Bile Acid Metabolism ◽  
Gastrointestinal Microbiota

Statins are the most widely prescribed medications worldwide for the treatment of hypercholesterolemia. They inhibit the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-R), an enzyme involved in cholesterol synthesis in higher organisms and in isoprenoid biosynthesis in some bacteria. We hypothesized that statins may influence the microbial community in the gut through either direct inhibition or indirect mechanisms involving alterations to host responses. We therefore examined the impact of rosuvastatin (RSV) on the community structure of the murine gastrointestinal microbiota. RSV was orally administered to mice and the effects on the gut microbiota, host bile acid profiles, and markers of inflammation were analyzed. RSV significantly influenced the microbial community in both the cecum and feces, causing a significant decrease in α-diversity in the cecum and resulting in a reduction of several physiologically relevant bacterial groups. RSV treatment of mice significantly affected bile acid metabolism and impacted expression of inflammatory markers known to influence microbial community structure (including RegIIIγ and Camp) in the gut. This study suggests that a commonly used statin (RSV) leads to an altered gut microbial composition in normal mice with attendant impacts on local gene expression profiles, a finding that should prompt further studies to investigate the implications of statins for gut microbiota stability and health in humans. NEW & NOTEWORTHY This work demonstrates that rosuvastatin administration in mice affects the gastrointestinal microbiota, influences bile acid metabolism, and alters transcription of genes encoding factors involved in gut homeostasis and immunity in the gastrointestinal tract.

Sign in / Sign up

Export Citation Format

Share Document