scholarly journals Astragalus Polysaccharides Ameliorate Diet-Induced Gallstone Formation by Modulating Synthesis of Bile Acids and the Gut Microbiota

2021 ◽  
Vol 12 ◽  
Author(s):  
Qian Zhuang ◽  
Xin Ye ◽  
Shuang Shen ◽  
Jinnian Cheng ◽  
Yan Shi ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bile Acids ◽  
Enterohepatic Circulation ◽  
Cholesterol Gallstone ◽  
Saturation Index ◽  
Quantitative Polymerase Chain Reaction ◽  
Gallbladder Bile ◽  
Farnesoid X Receptor ◽  
Chow Diet ◽  
Hydrophobicity Index

Cholesterol gallstone (CG) disease has relationships with several metabolic abnormalities. Astragalus polysaccharides (APS) have been shown to have multiple benefits against metabolic disorders. We attempted to uncover the effect and mechanism of action of APS on diet-induced CG formation in mice. Animals were fed a chow diet or lithogenic diet (LD) with or without APS supplementation. The effect of APS on CG formation was evaluated. The level of individual bile acids (BAs) in gallbladder bile and ileum were measured by liquid chromatography-tandem mass spectrometry. Real-time reverse transcription-quantitative polymerase chain reaction and western blotting were used to assess expression of the genes involved in BA metabolism and the enterohepatic circulation. Cecal contents were collected to characterize microbiota profiles. APS ameliorated LD-induced CG formation in mice. APS reduced the level of total cholesterol, bile acid hydrophobicity index and cholesterol saturation index in gallbladder bile. The protective effect of APS might result from reduced absorption of cholic acid in the intestine and increased hepatic BA synthesis. APS relieved the LD-induced activation of the intestinal farnesoid X receptor and decreased ileal expression of fibroblast growth factor 15. In the liver, expression of cytochrome P450 (Cyp) enzyme Cyp7a1 and Cyp7b1 was increased, whereas expression of adenosine triphosphate-binding cassette (Abc) transporters Abcg5 and Abcg8 was decreased by APS. APS improved the diversity of the gut microbiota and increased the relative abundance of the Bacteroidetes phylum. APS had demonstratable benefits against CG disease, which might be associated with enhanced BA synthesis and improved gut microbiota. Our results suggest that APS may be a potential strategy for the prevention of CG disease.

scholarly journals Arbutin Alleviates the Liver Injury of α-Naphthylisothiocyanate-induced Cholestasis Through Farnesoid X Receptor Activation

2021 ◽  
Vol 9 ◽  
Author(s):  
Peijie Wu ◽  
Ling Qiao ◽  
Han Yu ◽  
Hui Ming ◽  
Chao Liu ◽  
...  
Keyword(s):  
Bile Acid ◽  
Liver Injury ◽  
Protective Effect ◽  
Bile Acids ◽  
Liver Toxicity ◽  
Enterohepatic Circulation ◽  
Receptor Activation ◽  
Farnesoid X Receptor ◽  
Bile Acid Metabolism ◽  
Cholestatic Diseases

Cholestasis is a kind of stressful syndrome along with liver toxicity, which has been demonstrated to be related to fibrosis, cirrhosis, even cholangiocellular or hepatocellular carcinomas. Cholestasis usually caused by the dysregulated metabolism of bile acids that possess high cellular toxicity and synthesized by cholesterol in the liver to undergo enterohepatic circulation. In cholestasis, the accumulation of bile acids in the liver causes biliary and hepatocyte injury, oxidative stress, and inflammation. The farnesoid X receptor (FXR) is regarded as a bile acid–activated receptor that regulates a network of genes involved in bile acid metabolism, providing a new therapeutic target to treat cholestatic diseases. Arbutin is a glycosylated hydroquinone isolated from medicinal plants in the genus Arctostaphylos, which has a variety of potentially pharmacological properties, such as anti-inflammatory, antihyperlipidemic, antiviral, antihyperglycemic, and antioxidant activity. However, the mechanistic contributions of arbutin to alleviate liver injury of cholestasis, especially its role on bile acid homeostasis via nuclear receptors, have not been fully elucidated. In this study, we demonstrate that arbutin has a protective effect on α-naphthylisothiocyanate–induced cholestasis via upregulation of the levels of FXR and downstream enzymes associated with bile acid homeostasis such as Bsep, Ntcp, and Sult2a1, as well as Ugt1a1. Furthermore, the regulation of these functional proteins related to bile acid homeostasis by arbutin could be alleviated by FXR silencing in L-02 cells. In conclusion, a protective effect could be supported by arbutin to alleviate ANIT-induced cholestatic liver toxicity, which was partly through the FXR pathway, suggesting arbutin may be a potential chemical molecule for the cholestatic disease.

Disease-Associated Changes in Bile Acid Profiles and Links to Altered Gut Microbiota

2017 ◽  
Vol 35 (3) ◽  
pp. 169-177 ◽  
Author(s):  
Susan A. Joyce ◽  
Cormac G.M. Gahan
Keyword(s):  
Bile Acid ◽  
Gut Microbiota ◽  
Bile Acids ◽  
Farnesoid X Receptor ◽  
Gastrointestinal Microbiota ◽  
Signalling Molecules ◽  
Disease States ◽  
Irritable Bowel ◽  
Bile Acid Profiles ◽  
Bile Acid Receptors

The gastrointestinal microbiota plays a central role in the host metabolism of bile acids through deconjugation and dehydroxylation reactions, which generate unconjugated free bile acids and secondary bile acids respectively. These microbially generated bile acids are particularly potent signalling molecules that interact with host bile acid receptors (including the farnesoid X receptor, vitamin D receptor and TGR5 receptor) to trigger cellular responses that play essential roles in host lipid metabolism, electrolyte transport and immune regulation. Perturbations of microbial populations in the gut can therefore profoundly alter bile acid profiles in the host to impact upon the digestive and signalling properties of bile acids in the human superorganism. A number of recent studies have clearly demonstrated the occurrence of microbial disturbances allied to alterations in host bile acid profiles that occur across a range of disease states. Intestinal diseases including irritable bowel syndrome, inflammatory bowel disease (IBD), short bowel syndrome and Clostridium difficile infection all exhibit concurrent alterations in the composition of the gut microbiota and changes to host bile acid profiles. Similarly, extraintestinal diseases and syndromes such as asthma and obesity may be linked to aberrant bile acid profiles in the host. Here, we focus upon recent studies that highlight the links between alterations to gut microbial communities and altered bile acid profiles across a range of diseases from asthma to IBD.

Reabsorption of bile acids regulated by FXR-OATP1A2 is the main factor for the formation of cholesterol gallstone

2020 ◽  
Vol 319 (3) ◽  
pp. G303-G308
Author(s):  
Jingli Cai ◽  
Zhaowen Wang ◽  
Guiming Chen ◽  
Dapeng Li ◽  
Jun Liu ◽  
...  
Keyword(s):  
Bile Acids ◽  
Cholesterol Gallstone ◽  
Organic Anion ◽  
Farnesoid X Receptor ◽  
Organic Anion Transporter ◽  
Anion Transporter ◽  
First Time ◽  
Main Factor

For the first time, our results indicate that the axis of farnesoid X receptor-organic anion transporter polypeptide 1A2 that physiologically regulates the reabsorption of bile acids might play an important role in the regulation of the composition of bile acids and make contribution to the development of cholelithiasis.

scholarly journals Peroxisome Proliferator-Activated Receptor-γ Prevents Cholesterol Gallstone Formation in C57bl Mice by Regulating Bile Acid Synthesis and Enterohepatic Circulation

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Gang Wang ◽  
Tao Han ◽  
ShiJia Wang ◽  
Min Chen ◽  
Yueming Sun ◽  
...  
Keyword(s):  
Bile Acid ◽  
Enterohepatic Circulation ◽  
Cholesterol Gallstone ◽  
Gallstone Formation ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Chow Diet ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Expression Of Genes

To investigate the role of the peroxisome proliferator-activated receptor-γ (PPARγ) in the progression of cholesterol gallstone disease (CGD), C57bl/6J mice were randomized to the following groups (n=7/group): L (lithogenic diet, LGD), LM (LGD+pioglitazone), CM (chow diet+pioglitazone), and NC (normal control, chow diet). Gallbladder stones were observed by microscopy. Histological gallbladder changes were assessed. Bile acids (BA) and cholesterol were measured in the serum, bile, and feces. Proteins and mRNA expression of genes involved in BA metabolism and enterohepatic circulation were assessed by western blotting and real-time RT-PCR. PPARγ activation was performed in LO2 cell by lentivirus transfection and in Caco2 cell by PPARγ agonist treatment. Downregulation of farnesoid X receptor (FXR) by small interference RNA (siRNA) was performed in L02 cells and Caco2 cells, respectively. Results showed that pharmacological activation of PPARγ by pioglitazone prevents cholesterol gallstone formation by increasing biliary BA synthesis and enterohepatic circulation. Activated PPARγ induced the expression of genes involved in enterohepatic circulation and bile acid synthesis (like PCG1α, BSEP, MRP2, MRP3, MRP4, NTCP, CYP7A1, CYP27A1, ASBT, OSTα, and OSTβ). Downregulation of FXR repressed expression of partial genes involved in BA enterohepatic circulation. These findings suggest a new function of PPARγ in preventing CGD by handling BA synthesis and transport through a FXR dependent or independent pathway.

scholarly journals Recent advances in understanding and managing cholestasis

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 705 ◽  
Author(s):  
Martin Wagner ◽  
Michael Trauner
Keyword(s):  
Bile Acids ◽  
Drug Targets ◽  
Molecular Mechanisms ◽  
Enterohepatic Circulation ◽  
Farnesoid X Receptor ◽  
Regulatory Mechanisms ◽  
Cholestatic Liver Disease ◽  
Sodium Dependent ◽  
Bile Acid Transporter ◽  
Fibroblast Growth Factor 19

Cholestatic liver diseases are hereditary or acquired disorders with impaired hepatic excretion and enterohepatic circulation of bile acids and other cholephiles. The distinct pathological mechanisms, particularly for the acquired forms of cholestasis, are not fully revealed, but advances in the understanding of the molecular mechanisms and identification of key regulatory mechanisms of the enterohepatic circulation of bile acids have unraveled common and central mechanisms, which can be pharmacologically targeted. This overview focuses on the central roles of farnesoid X receptor, fibroblast growth factor 19, and apical sodium-dependent bile acid transporter for the enterohepatic circulation of bile acids and their potential as new drug targets for the treatment of cholestatic liver disease.

Farnesoid X receptor protects human and murine gastric epithelial cells against inflammation-induced damage

2011 ◽  
Vol 438 (2) ◽  
pp. 315-323 ◽  
Author(s):  
Fan Lian ◽  
Xiangbin Xing ◽  
Gang Yuan ◽  
Claus Schäfer ◽  
Sandra Rauser ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bile Acids ◽  
Cell Damage ◽  
Regulatory Element ◽  
Duodenogastric Reflux ◽  
Farnesoid X Receptor ◽  
Chow Diet ◽  
Dependent Manner ◽  
Gastric Epithelial Cells ◽  
Ags Cells

Bile acids from duodenogastric reflux promote inflammation and increase the risk for gastro-oesophageal cancers. FXR (farnesoid X receptor/NR1H4) is a transcription factor regulated by bile acids such as CDCA (chenodeoxycholic acid). FXR protects the liver and the intestinal tract against bile acid overload; however, a functional role for FXR in the stomach has not been described. We detected FXR expression in the normal human stomach and in GC (gastric cancer). FXR mRNA and protein were also present in the human GC cell lines MKN45 and SNU5, but not in the AGS cell line. Transfection of FXR into AGS cells protected against TNFα (tumour necrosis factor α)-induced cell damage. We identified K13 (keratin 13), an anti-apoptotic protein of desmosomes, as a novel CDCA-regulated FXR-target gene. FXR bound to a conserved regulatory element in the proximal human K13 promoter. Gastric expression of K13 mRNA was increased in an FXR-dependent manner by a chow diet enriched with 1% (w/w) CDCA and by indomethacin (35 mg/kg of body weight intraperitoneal) in C57BL/6 mice. FXR-deficient mice were more susceptible to indomethacin-induced gastric ulceration than their WT (wild-type) littermates. These results suggest that FXR increases the resistance of human and murine gastric epithelial cells to inflammation-mediated damage and may thus participate in the development of GC.

scholarly journals Alleviation of Cholesterol Gallstones by Lactobacillus Targeting the Gut Microbiota Depends on Global Farnesoid X Receptor-Mediated Bile Acid Metabolism

2020 ◽  
Author(s):  
Xinjian Wan ◽  
Xin Ye ◽  
Qian Zhuang ◽  
Zhixia Dong ◽  
Xiaoxin Wang ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Bile Acid ◽  
Gut Microbiota ◽  
Lactobacillus Reuteri ◽  
Cholesterol Gallstone ◽  
Farnesoid X Receptor ◽  
Bile Acid Metabolism ◽  
Protective Effects ◽  
Lithogenic Diet ◽  
Cytochrome P450 Family

Abstract Background Cholesterol gallstone (CGS) disease is characterized by an imbalance in bile acid (BA) metabolism and is closely associated with gut microbiota disorders. However, the role and mechanism by which probiotics targeting the gut microbiota attenuate CGS are still unknown. In this study, Lactobacillus reuteri CGMCC 17942 (LR) and L. plantarum CGMCC 14407 (LP) were individually administered to lithogenic diet (LD)-fed mice at a dosage of 109 CFU/day for 8 weeks. Results Both Lactobacillus strains significantly reduced LD-induced gallstones, hepatic steatosis, and hyperlipidemia. These strains modulated serum BA profiles, with significantly decreased conjugated primary BA taurine-β-muricholic acid (T-β-MCA), an FXR antagonist. At the molecular level, LR and LP increased Farnesoid X Receptor (FXR) expression in the liver but not in the ileum, increased the levels of ileum and liver fibroblast growth factor 15 (FGF15) and liver FGFR4, small heterodimer partner (SHP), and subsequently reduced cholesterol 7α-hydroxylase (CYP7A1) and cytochrome P450 family 7 subfamily B polypeptide 1 (CYP7B1) to inhibit BA synthesis in the liver. At the same time, the two strains enhanced BA transport by increasing the levels of multidrug-resistance-associated protein homologs (MRP) 3/4, multidrug-resistance-associated protein homologs (MRP) 3/4, hepatic multidrug resistance protein (MDR2) and bile salt export pump (BSEP) mRNA in the liver. In addition, both LR and LP reduced LD-associated gut microbiota dysbiosis. LR increased the relative abundance of Muribaculaceae, while LP increased that of Akkermansia. The changed gut microbiota was significantly negatively correlated with the grade and incidence of gallstones, hyperlipidemia, the level of T-β-MCA in serum, or the gene expression levels of Fxr in liver. Furthermore, the protective effects of the two strains were abolished by a global but not intestinal-specific FXR antagonist. Conclusions Taken together, our results suggested that Lactobacillus might relieve gallstones through FXR-dependent regulation of BA synthesis and transport.

scholarly journals Gut Dysbiosis and Abnormal Bile Acid Metabolism in Colitis-Associated Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Li Liu ◽  
Min Yang ◽  
Wenxiao Dong ◽  
Tianyu Liu ◽  
Xueli Song ◽  
...  
Keyword(s):  
Bile Acid ◽  
Gut Microbiota ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Farnesoid X Receptor ◽  
Mucosal Barrier ◽  
Bile Acid Metabolism ◽  
Preventive Strategy ◽  
Gut Dysbiosis ◽  
Bile Acid Receptors

Background. Patients with prolonged inflammatory bowel disease (IBD) can develop into colorectal cancer (CRC), also called colitis-associated cancer (CAC). Studies have shown the association between gut dysbiosis, abnormal bile acid metabolism, and inflammation process. Here, we aimed to investigate these two factors in the CAC model. Methods. C57BL/6 mice were randomly allocated to two groups: azoxymethane/dextran sodium sulfate (AOM/DSS) and control. The AOM/DSS group received AOM injection followed by DSS drinking water. Intestinal inflammation, mucosal barrier, and bile acid receptors were determined by real-time PCR and immunohistochemistry. Fecal microbiome and bile acids were detected via 16S rRNA sequencing and liquid chromatography-mass spectrometry. Results. The AOM/DSS group exhibited severe mucosal barrier impairment, inflammatory response, and tumor formation. In the CAC model, the richness and biodiversity of gut microbiota were decreased, along with significant alteration of composition. The abundance of pathogens was increased, while the short-chain fatty acids producing bacteria were reduced. Interestingly, Clostridium XlV and Lactobacillus, which might be involved in the bile acid deconjugation, transformation, and desulfation, were significantly decreased. Accordingly, fecal bile acids were decreased, accompanied by reduced transformation of primary to secondary bile acids. Given bile acid receptors, the ileum farnesoid X receptor-fibroblast growth factor 15 (FXR-FGF15) axis was downregulated, while Takeda G-protein receptor 5 (TGR5) was overexpressed in colonic tumor tissues. Conclusion. Gut dysbiosis might alter the metabolism of bile acids and promote CAC, which would provide a potential preventive strategy of CAC by regulating gut microbiota and bile acid metabolism.

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