Sample records for bile salt hydrolase

  1. Bile salt hydrolase of Bifidobacterium longum - Biochemical and genetic characterization

    Tanaka, H; Hashiba, Honoo; Kok, Jan; Mierau, Igor


    A bile salt hydrolase (BSH) was isolated from Bifidobacterium longum SBT2928, purified, and characterized, Furthermore, we describe for the first time cloning and analysis of the gene encoding BSII (bsh) in a member of the genus Bifidobacterium. The enzyme has a native molecular weight of 125,000 to

  2. Effect of Bile Salt Hydrolase Inhibitors on a Bile Salt Hydrolase from Lactobacillus acidophilus

    Jun Lin


    Full Text Available Bile salt hydrolase (BSH, a widely distributed function of the gut microbiota, has a profound impact on host lipid metabolism and energy harvest. Recent studies suggest that BSH inhibitors are promising alternatives to antibiotic growth promoters (AGP for enhanced animal growth performance and food safety. Using a high-purity BSH from Lactobacillus salivarius strain, we have identified a panel of BSH inhibitors. However, it is still unknown if these inhibitors also effectively inhibit the function of the BSH enzymes from other bacterial species with different sequence and substrate spectrum. In this study, we performed bioinformatics analysis and determined the inhibitory effect of identified BSH inhibitors on a BSH from L. acidophilus. Although the L. acidophilus BSH is phylogenetically distant from the L. salivarius BSH, sequence analysis and structure modeling indicated the two BSH enzymes contain conserved, catalytically important amino residues and domain. His-tagged recombinant BSH from L. acidophilus was further purified and used to determine inhibitory effect of specific compounds. Previously identified BSH inhibitors also exhibited potent inhibitory effects on the L. acidophilus BSH. In conclusion, this study demonstrated that the BSH from L. salivarius is an ideal candidate for screening BSH inhibitors, the promising alternatives to AGP for enhanced feed efficiency, growth performance and profitability of food animals.

  3. Allelic variation of bile salt hydrolase genes in Lactobacillus salivarius does not determine bile resistance levels.

    Fang, Fang


    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host.

  4. Crystal structure of bile salt hydrolase from Lactobacillus salivarius.

    Xu, Fuzhou; Guo, Fangfang; Hu, Xiao Jian; Lin, Jun


    Bile salt hydrolase (BSH) is a gut-bacterial enzyme that negatively influences host fat digestion and energy harvesting. The BSH enzyme activity functions as a gateway reaction in the small intestine by the deconjugation of glycine-conjugated or taurine-conjugated bile acids. Extensive gut-microbiota studies have suggested that BSH is a key mechanistic microbiome target for the development of novel non-antibiotic food additives to improve animal feed production and for the design of new measures to control obesity in humans. However, research on BSH is still in its infancy, particularly in terms of the structural basis of BSH function, which has hampered the development of BSH-based strategies for improving human and animal health. As an initial step towards the structure-function analysis of BSH, C-terminally His-tagged BSH from Lactobacillus salivarius NRRL B-30514 was crystallized in this study. The 1.90 Å resolution crystal structure of L. salivarius BSH was determined by molecular replacement using the structure of Clostridium perfringens BSH as a starting model. It revealed this BSH to be a member of the N-terminal nucleophile hydrolase superfamily. Crystals of apo BSH belonged to space group P21212, with unit-cell parameters a = 90.79, b = 87.35, c = 86.76 Å (PDB entry 5hke). Two BSH molecules packed perfectly as a dimer in one asymmetric unit. Comparative structural analysis of L. salivarius BSH also identified potential residues that contribute to catalysis and substrate specificity. PMID:27139829

  5. Functional Analysis of Four Bile Salt Hydrolase and Penicillin Acylase Family Members in Lactobacillus plantarum WCFS1▿ †

    Lambert, J M; Bongers, R.S.; Vos, de, R.; Kleerebezem, M.


    Bile salts play an important role in the digestion of lipids in vertebrates and are synthesized and conjugated to either glycine or taurine in the liver. Following secretion of bile salts into the small intestine, intestinal microbes are capable of deconjugating the glycine or taurine from the bile salts, using an enzyme called bile salt hydrolase (Bsh). Intestinal lactobacilli are regarded as major contributors to bile salt hydrolysis in vivo. Since the bile salt-hydrolyzing strain Lactobaci...

  6. Functional analysis of four bile salt hydrolase and penicillin acylase family members in Lactobacillus plantarum WCFS1

    Lambert, J. M.; Bongers, R.S.; Vos; Kleerebezem, M.


    Bile salts play an important role in the digestion of lipids in vertebrates and are synthesized and conjugated to either glycine or taurine in the liver. Following secretion of bile salts into the small intestine, intestinal microbes are capable of deconjugating the glycine or taurine from the bile salts, using an enzyme called bile salt hydrolase (Bsh). Intestinal lactobacilli are regarded as major contributors to bile salt hydrolysis in vivo. Since the bile salt-hydrolyzing strain Lactobaci...

  7. Bile salt hydrolase in Lactobacillus plantarum: functional analysis and delivery to the intestinal tract of the host

    Lambert, J.M.


    In the liver of mammals, bile salts are synthesised from cholesterol and conjugated to either taurine or glycine. Following release into the intestine, conjugated bile salts can be deconjugated by members of the endogenous microbiota that produce an enzyme called bile salt hydrolase (Bsh). Bsh appea

  8. Characterization and purification of bile salt hydrolase from Lactobacillus sp. strain 100-100

    The authors have characterized and purified the bile salt hydrolase from Lactobacillus sp. strain 100-100. Bile salt hydrolase from cells of the strain was purified with column and high-performance liquid chromatography. The activity was assayed in whole cells and cell-free extracts with either a radiochemical assay involving [14C]taurocholic acid or a nonradioactive assay involving trinitrobenzene sulfonate. The activity was detectable only in stationary-phase cells. Within 20 min after conjugated bile acids were added to stationary-phase cultures of strain 100-100, the activity in whole cells increased to levels three- to fivefold higher than in cells from cultures grown in medium free of bile salts. In cell-free extracts, however, the activity was about equal whether or not the cells have been grown with bile salts present. When supernatant solutions from cultures grown in medium containing taurocholic acid were used to suspend cells grown in medium free of the bile salt, the bile salt hydrolase activity detected in whole cells increased two- to threefold. Two forms of the hydrolase were purified from the cells and designated hydrolases A and B. They eluted from anion-exchange high-performance liquid chromatography in two sets of fractions, A at 0.15 M NaCl and B at 0.18 M NaCl. Their apparent molecular weights in nondenaturing polyacrylamide gel electrophoresis were 115,000 and 105,000, respectively. However, discrepancies existed in the apparent molecular weights and number of peptides detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the two forms. Whether the enzyme exists in two forms in the cells remains to be determined


    Previous work in this laboratory has revealed the presence of both acidic and neutral bile-salt independent retinyl ester hydrolase activities in rat liver homogenates. Here we present the purification, identification and characterization of an acid retinyl ester hydrolase activity from solubilized ...

  10. Isolation and characterization of a Lactobacillus amylovorus mutant depleted in conjugated bile salt hydrolase activity: relation between activity and bile salt resistance.

    Grill, J P; Cayuela, C; Antoine, J M; Schneider, F


    Growth experiments were conducted on Lactobacillus amylovorus DN-112 053 in batch culture, with or without pH regulation. Conjugated bile salt hydrolase (CBSH) activity was examined as a function of culture growth. The CBSH activity increased during growth but its course depended on bile salts type and culture conditions. A Lact. amylovorus mutant was isolated from the wild-type strain of Lact. amylovorus DN-112 053 after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. An agar plate assay was used to detect mutants without CBSH activity. In resting cell experiments, the strain showed reduced activity. Differences between growth parameters determined for wild-type and mutant strains were not detected. Comparative native gel electrophoresis followed by CBSH activity staining demonstrated the loss of proteins harbouring this activity in the mutant. Four protein bands corresponding to CBSH were observed in the wild-type strain but only one was detected in the mutant. The specific growth rate of the mutant strain was affected more by bile salts than the wild-type strain. Nevertheless, bile was more toxic for the wild-type strain. In viability studies in the presence of nutrients, it was demonstrated that glycodeoxycholic acid exerted a higher toxicity than taurodeoxycholic acid in a pH-dependent manner. No difference was apparent between the two strains. In the absence of nutrients, the wild-type strain died after 2 h whereas no effect was observed for the mutant. The de-energization experiments performed using the ionophores nigericin and valinomycin suggested that the chemical potential of protons (ZDeltapH) was involved in Lactobacillus bile salt resistance. PMID:11054157

  11. Isolation, Identification and Partial Characterization of a Lactobacillus casei Strain with Bile Salt Hydrolase Activity from Pulque.

    González-Vázquez, R; Azaola-Espinosa, A; Mayorga-Reyes, L; Reyes-Nava, L A; Shah, N P; Rivera-Espinoza, Y


    The aim of this study was to isolate, from pulque, Lactobacillus spp. capable of survival in simulated gastrointestinal stress conditions. Nine Gram-positive rods were isolated; however, only one strain (J57) shared identity with Lactobacillus and was registered as Lactobacillus casei J57 (GenBank accession: JN182264). The other strains were identified as Bacillus spp. The most significant observation during the test of tolerance to simulated gastrointestinal conditions (acidity, gastric juice and bile salts) was that L. casei J57 showed a rapid decrease (p ≤ 0.05) in the viable population at 0 h. Bile salts were the stress condition that most affected its survival, from which deoxycholic acid and the mix of bile salts (oxgall) were the most toxic. L. casei J57 showed bile salt hydrolase activity over primary and secondary bile salts as follows: 44.91, 671.72, 45.27 and 61.57 U/mg to glycocholate, taurocholate, glycodeoxycholate and taurodeoxycholate. In contrast, the control strain (L. casei Shirota) only showed activity over tauroconjugates. These results suggest that L. casei J57 shows potential for probiotic applications. PMID:26566892

  12. Cloning and Expression of Bile Salt Hydrolase Gene from Lactobacillus plantarum M1-UVS29

    Yu Chang-qing; Li Rong


    We cloned and expressed bile salt hydrolase gene ofLactobacillus plantarum M1-UVS29 inLactococcus lactis NZ9000 successfully. Gene-specific primers for amplification ofL. plantarum bsh were designed by using sequence which availabled from GenBank. The production of PCR amplicon was confirmed by sequencing and cloned into pMD18-T vector, and then recombined into expression vector pNZ8148 and yielding vector pNZ8148-BSH. pNZ8148-BSH was transferred intoLactococcus lactis NZ9000. Sequencing indicated that the clonedbsh fragment contained 995 nucleotides, and shared 99.3% sequence homology withbsh gene fromL. plantarum MBUL10. Clonedbsh fragment was successfully transduced into NICE expression system and confirmed by PCR and restriction digest. Recombinant BSH protein was analyzed by SDS-PAGE. The molecular weight of BSH protein was approximately 37 ku. Activity of the expressed protein was 0.77 µmol• min-1. The successfully expressed proteins by genetic engineering technology made the function of lactic acid bacteria be abundant and laid the foundation for further researches into cholesterol-lowering lactic acid bacterium food and probiotics.

  13. Functional analysis of four bile salt hydrolase and penicillin acylase family members in Lactobacillus plantarum WCFS1

    Lambert, J.M.; Bongers, R.S.; Vos, de W.M.; Kleerebezem, M.


    Bile salts play an important role in the digestion of lipids in vertebrates and are synthesized and conjugated to either glycine or taurine in the liver. Following secretion of bile salts into the small intestine, intestinal microbes are capable of deconjugating the glycine or taurine from the bile

  14. Improved annotation of conjugated bile acid hydrolase superfamily members in Gram-positive bacteria

    Lambert, J.M.; Siezen, R.J.; Vos, de W.M.; Kleerebezem, M.


    Most Gram-positive bacteria inhabiting the gastrointestinal tract are capable of hydrolysing bile salts. Bile salt hydrolysis is thought to play an important role in various biological processes in the host. Therefore, correct annotation of bacterial bile salt hydrolases (Bsh) in public databases (E

  15. Cholesterol-Lowering Potentials of Lactic Acid Bacteria Based on Bile-Salt Hydrolase Activity and Effect of Potent Strains on Cholesterol Metabolism In Vitro and In Vivo

    Cheng-Chih Tsai


    Full Text Available This study collected different probiotic isolates from animal and plant sources to evaluate the bile-salt hydrolase activity of probiotics in vitro. The deconjugation potential of bile acid was determined using high-performance liquid chromatography. HepG2 cells were cultured with probiotic strains with high BSH activity. The triglyceride (TG and apolipoprotein B (apo B secretion by HepG2 cells were evaluated. Our results show that the BSH activity and bile-acid deconjugation abilities of Pediococcus acidilactici NBHK002, Bifidobacterium adolescentis NBHK006, Lactobacillus rhamnosus NBHK007, and Lactobacillus acidophilus NBHK008 were higher than those of the other probiotic strains. The cholesterol concentration in cholesterol micelles was reduced within 24 h. NBHK007 reduced the TG secretion by 100% after 48 h of incubation. NBHK002, NBHK006, and NBHK007 could reduce apo B secretion by 33%, 38%, and 39%, respectively, after 24 h of incubation. The product PROBIO S-23 produced a greater decrease in the total concentration of cholesterol, low-density lipoprotein, TG, and thiobarbituric acid reactive substance in the serum or livers of hamsters with hypercholesterolemia compared with that of hamsters fed with a high-fat and high-cholesterol diet. These results show that the three probiotic strains of lactic acid bacteria are better candidates for reducing the risk of cardiovascular disease.

  16. Bacterial degradation of bile salts

    Philipp, Bodo


    Bile salts are surface-active steroid compounds. Their main physiological function is aiding the digestion of lipophilic nutrients in intestinal tracts of vertebrates. Many bacteria are capable of transforming and degrading bile salts in the digestive tract and in the environment. Bacterial bile salt transformation and degradation is of high ecological relevance and also essential for the biotechnological production of steroid drugs. While biotechnological aspects have been reviewed many time...

  17. Low Retinol Levels Differentially Modulate Bile Salt-Induced Expression of Human and Mouse Hepatic Bile Salt Transporters

    Hoeke, Martijn O.; Plass, Jacqueline R. M.; Heegsma, Janette; Geuken, Mariska; van Rijsbergen, Duncan; Baller, Julius F. W.; Kuipers, Folkert; Moshage, Han; Jansen, Peter L. M.; Faber, Klaas Nico


    The farnesoid X receptor/retinoid X receptor-alpha (FXR/RXR alpha) complex regulates bile salt homeostasis, in part by modulating transcription of the bile salt export pump (BSEP/ABCB11 I) and small heterodimer partner (SHP/NR0B2). FXR is activated by bile salts, RXR alpha by the vitamin A derivativ

  18. Low retinol levels differentially modulate bile salt-induced expression of human and mouse hepatic bile salt transporters

    M.O. Hoeke; J.R.M. Plass; J. Heegsma; M. Geuken; D. van Rijsbergen; J.F.W. Baller; F. Kuipers; H. Moshage; P.L.M. Jansen; K.N. Faber


    The farnesoid X receptor/retinoid X receptor-alpha (FXR/RXRalpha) complex regulates bile salt homeostasis, in part by modulating transcription of the bile salt export pump (BSEP/ABCB11) and small heterodimer partner (SHP/NR0B2). FXR is activated by bile salts, RXRalpha by the vitamin A derivative 9-

  19. Bile salts and their importance for drug absorption

    Holm, René; Müllertz, Anette; Mu, Huiling


    Bile salts are present in the intestines of humans as well as the animals used during the development of pharmaceutical products. This review provides a short introduction into the physical chemical properties of bile salts, a description of the bile concentration and composition of bile in...... different animal species and an overview of the literature investigating the influence of bile salts on the in vivo performance of different compounds and drug formulations. Generally, there is a positive effect on bioavailability when bile is present in the gastro-intestinal tract, independent of the...

  20. [Structure and Activity of Fungal Lipases in Bile Salt Solutions].

    Bogdanova, L R; Bakirova, D R; Valiullina, Yu A; Idiyatullin, B Z; Faizullin, D A; Zueva, O S; Zuev, Yu F


    The changes in structure and catalytic properties of fungal lipases (Candida rugosa, Rhizomucor miehei, Mucor javanicus) were investigated in micellar solutions of bile salts that differ in hydrophilic-lypophilic balance and reaction medium properties. The methods of circular dichroism and tryptophan fluorescence were applied to estimate the changes in peptide structure within complexes with bile salt micelles. Bile salts do not exert a significant influence on the structure of the enzymes under study: in Rh. miehei and M. javanicus lipases the alpha helix content slightly decreased, the influence of bile salts on the C. rugosa structure was not revealed. Despite negligible structural modifications in the enzymes, in bile salt solutions a considerable change in their catalytic properties was observed: an abrupt decrease in catalytic effectiveness. Substrate-bile salts micelles complex formation was demonstrated by the NMR self-diffusion method. The model of a regulation of fungal lipase activity was proposed. PMID:27192825

  1. Role of the bile salt export pump, BSEP, in acquired forms of cholestasis

    B. Stieger


    Generation of bile is a key function of the liver. Its impairment leads to accumulation of cytotoxic bile salts in hepatocytes and, consequently, to liver disease. The bile salt export pump, BSEP, is critically involved in the secretion of bile salts into bile. Its function can be disturbed or aboli

  2. The Role of the Sodium-Taurocholate Cotransporting Polypeptide (NTCP) and of the Bile Salt Export Pump (BSEP) in Physiology and Pathophysiology of Bile Formation

    Stieger, B


    Bile formation is an important function of the liver. Bile salts are a major constituent of bile and are secreted by hepatocytes into bile and delivered into the small intestine, where they assist in fat digestion. In the small intestine, bile salts are almost quantitatively reclaimed and transported back via the portal circulation to the liver. In the liver, hepatocytes take up bile salts and secrete them again into bile for ongoing enterohepatic circulation. Uptake of bile salts into hepato...

  3. Mechanism by which bile salt disrupts the gastric mucosal barrier in the dog.

    Duane, W C; Wiegand, D M


    Bile salts disrupt a functional "gastric mucosal barrier" increasing net forward-diffusion (+) of Na+ and back-diffusion (-) of H+. Studying canine Heidenhain pouches, we attempted to distinguish between two possible mechanisms for this effect: (a) mucosal uptake of bile salt with subsequent cellular injury or (b) dissolution of mucosal lipids by intralumenal bile salt. A 10 mM mixture of six conjugated bile salts simulating the proportions found in human bile induced net Na+ flux of 15.5 +/-...

  4. Bile salts of the West Indian manatee, Trichechus manatus latirostris: novel bile alcohol sulfates and absence of bile acids.

    Kuroki, S; Schteingart, C D; Hagey, L R; Cohen, B I; Mosbach, E H; Rossi, S S; Hofmann, A F; Matoba, N; Une, M; Hoshita, T


    The bile salts present in gallbladder bile of the West Indian manatee, Trichechus manatus latirostris, an herbivorous marine mammal of the tropical and subtropical margins of the Atlantic Ocean, were found to consist of a mixture of bile alcohol sulfates. Bile acids, previously believed to be present in all mammals, were not detected. Using chromatography, mass spectrometry, and 1H- and 13C-nuclear magnetic resonance spectroscopy, the major bile alcohol was identified as 5 beta-cholestane-3 alpha,6 beta,7 alpha-25,26-pentol; that is, it had the nuclear structure of alpha-muricholic acid and the side chain structure of bufol. This compound has not been described previously and the trivial name "alpha-trichechol" is proposed. The second most abundant compound was 5 beta-cholestane-3 alpha,7 alpha,25,26-tetrol. Other bile alcohols were tentatively identified as 5 beta-cholestane-3 alpha,6 beta,7 beta,25,26-pentol (named beta-trichechol), 3 alpha,6 alpha,7 beta, 25-26-pentol (named omega-trichechol) and 5 beta-cholestane-3 alpha,6 beta,7 alpha,26-tetrol. The 1H and 13C NMR spectra of the four 6,7 epimers of 3,6,7 trihydroxy bile acids are described and discussed. All bile alcohols were present as ester sulfates, the sulfate group being tentatively assigned to the 26-hydroxy group. 12-Hydroxy compounds were not detected. The manatee is the first mammal found to lack bile acids, presumably because it lacks the enzymes required for oxidation of the 26-hydroxy group to a carboxylic acid. Trichechols, like other bile salts, are water-soluble end products of cholesterol metabolism; whether they also function as biological surfactants in promoting biliary cholesterol secretion or lipid digestion is unknown. PMID:3392467

  5. Function and regulation of the human bile salt export pump

    Plass, Jacqueline Regina Maria


    During the past decade, important progress has been made in our understanding of the pathophysiology of cholestasis. Inherited disorders have been explained at the molecular level and were shown to be the result of mutations in enzymes involved in bile salt biosynthesis or transmembrane transporters involved in bile formation. Acquired cholestasis, for instance due to inflammation, is linked to disregulation of these proteins. The challenge of future research is to use this knowledge to devel...

  6. Biosynthesis and Trafficking of the Bile Salt Export Pump, BSEP: Therapeutic Implications of BSEP Mutations

    Soroka, Carol J.; Boyer, James L.


    The bile salt export pump (BSEP, ABCB11) is the primary transporter of bile acids from the hepatocyte to the biliary system. This rate-limiting step in bile formation is essential to the formation of bile salt dependent bile flow, the enterohepatic circulation of bile acids, and the digestion of dietary fats. Mutations in BSEP are associated with cholestatic diseases such as progressive familial intrahepatic cholestasis type 2 (PFIC2), benign recurrent intrahepatic cholestasis type 2 (BRIC2),...

  7. Role of the bile salt export pump, BSEP, in acquired forms of cholestasis

    Stieger, B


    Generation of bile is a key function of the liver. Its impairment leads to accumulation of cytotoxic bile salts in hepatocytes and, consequently, to liver disease. The bile salt export pump, BSEP, is critically involved in the secretion of bile salts into bile. Its function can be disturbed or abolished by inherited mutations. This will lead to progressive intrahepatic cholestais and severe liver disease. In addition to mutations, BSEP can be inhibited by acquired factors, such as xenobiotics...

  8. Prevention of Endotoxaemia in Obstructive Jaundice — a Comparative Study of Bile Salts

    Pain, J A; Bailey, M. E.


    Systemic endotoxaemia is associated with postoperative renal dysfunction in obstructive jaundice, and can be prevented by the pre-operative administration of certain bile salts. In order to find the most effective bile salt for use in this condition, a comparison of the anti-endotoxic activities of different bile salts was performed. Bile salts were incubated in vitro with endotoxin and the resultant endotoxin level was measured with a quantitative limulus assay. The in vivo effec...

  9. Flagging Drugs That Inhibit the Bile Salt Export Pump.

    Montanari, Floriane; Pinto, Marta; Khunweeraphong, Narakorn; Wlcek, Katrin; Sohail, M Imran; Noeske, Tobias; Boyer, Scott; Chiba, Peter; Stieger, Bruno; Kuchler, Karl; Ecker, Gerhard F


    The bile salt export pump (BSEP) is an ABC-transporter expressed at the canalicular membrane of hepatocytes. Its physiological role is to expel bile salts into the canaliculi from where they drain into the bile duct. Inhibition of this transporter may lead to intrahepatic cholestasis. Predictive computational models of BSEP inhibition may allow for fast identification of potentially harmful compounds in large databases. This article presents a predictive in silico model based on physicochemical descriptors that is able to flag compounds as potential BSEP inhibitors. This model was built using a training set of 670 compounds with available BSEP inhibition potencies. It successfully predicted BSEP inhibition for two independent test sets and was in a further step used for a virtual screening experiment. After in vitro testing of selected candidates, a marketed drug, bromocriptin, was identified for the first time as BSEP inhibitor. This demonstrates the usefulness of the model to identify new BSEP inhibitors and therefore potential cholestasis perpetrators. PMID:26642869

  10. Clinical application of transcriptional activators of bile salt transporters ☆

    Baghdasaryan, Anna; Chiba, Peter; Trauner, Michael


    Hepatobiliary bile salt (BS) transporters are critical determinants of BS homeostasis controlling intracellular concentrations of BSs and their enterohepatic circulation. Genetic or acquired dysfunction of specific transport systems causes intrahepatic and systemic retention of potentially cytotoxic BSs, which, in high concentrations, may disturb integrity of cell membranes and subcellular organelles resulting in cell death, inflammation and fibrosis. Transcriptional regulation of canalicular...

  11. Evolution of the pregnane X receptor: adaptation to cross-species differences in biliary bile salts

    Krasowski, Matthew D; Yasuda, Kazuto; Hagey, Lee R.; Schuetz, Erin G.


    The pregnane X receptor (PXR) regulates the metabolism and elimination of bile salts, steroids, and xenobiotics. The sequence of the PXR ligand-binding domain diverges extensively between different animals suggesting inter-species differences in ligands. Of the endogenous ligands known to activate PXR, biliary bile salts vary the most across vertebrate species, ranging from 27-carbon (C27) bile alcohol sulfates (early fish, amphibians) to C24 bile acids (birds, mammals). Using a luciferase-ba...

  12. Recent insights into the function and regulation of the bile salt export pump (ABCB11)

    Stieger, B


    PURPOSE OF REVIEW: Generation of bile is an important function of the liver. Its impairment can be caused by inherited mutations or by acquired factors and leads to cholestasis. Bile salts are an important constituent of bile and are secreted by the bile salt export pump (BSEP) from hepatocytes. RECENT FINDINGS: Significant progress was made in the understanding of mechanisms and consequences of malfunctioning BSEP. This information was gained from extensive characterization of patients with ...

  13. Ursodeoxycholate modulates bile flow and bile salt pool independently from the cystic fibrosis transmembrane regulator (Cftr) in mice

    Bodewes, Frank A. J. A.; Wouthuyzen-Bakker, Marjan; Bijvelds, Marcel J.; Havinga, Rick; de Jonge, Hugo R.; Verkade, Henkjan J.


    Bodewes FAJA, Wouthuyzen-Bakker M, Bijvelds MJ, Havinga R, de Jonge HR, Verkade HJ. Ursodeoxycholate modulates bile flow and bile salt pool independently from the cystic fibrosis transmembrane regulator (Cftr) in mice. Am J Physiol Gastrointest Liver Physiol 302: G1035-G1042, 2012. First published F

  14. Solubilization and Interaction Studies of Bile Salts with Surfactants and Drugs: a Review.

    Malik, Nisar Ahmad


    In this review, bile salt, bile salt-surfactant, and bile salt-drug interactions and their solubilization studies are mainly focused. Usefulness of bile salts in digestion, absorption, and excretion of various compounds and their rare properties in ordering the shape and size of the micelles owing to the presence of hydrophobic and hydrophilic faces are taken into consideration while compiling this review. Bile salts as potential bio-surfactants to solubilize drugs of interest are also highlighted. This review will give an insight into the selection of drugs in different applications as their properties get modified by interaction with bile salts, thus influencing their solution behavior which, in turn, modifies the phase-forming behavior, microemulsion, and clouding phenomenon, besides solubilization. Finally, their future perspectives are taken into consideration to assess their possible uses as bio-surfactants without side effects to human beings. PMID:26781714

  15. Differential proteomic analysis of outer membrane enriched extracts of Bacteroides fragilis grown under bile salts stress.

    Boente, Renata F; Pauer, Heidi; Silva, Deborah N S; Filho, Joaquim Santos; Sandim, Vanessa; Antunes, Luis Caetano M; Ferreira, Rosana Barreto Rocha; Zingali, Russolina B; Domingues, Regina M C P; Lobo, Leandro A


    Bacteroides fragilis is the most commonly isolated anaerobic bacteria from infectious processes. Several virulence traits contribute to the pathogenic nature of this bacterium, including the ability to tolerate the high concentrations of bile found in the gastrointestinal tract (GIT). The activity of bile salts is similar to detergents and may lead to membrane permeabilization and cell death. Modulation of outer membrane proteins (OMPs) is considered a crucial event to bile salts resistance. The primary objective of the current work was to identify B. fragilis proteins associated with the stress induced by high concentration of bile salts. The outer membrane of B. fragilis strain 638R was isolated after growth either in the presence of 2% conjugated bile salts or without bile salts. The membrane fractions were separated on SDS-PAGE and analyzed by ESI-Q/TOF tandem mass spectrometry. A total of 37 proteins were identified; among them nine were found to be expressed exclusively in the absence of bile salts whereas eight proteins were expressed only in the presence of bile salts. These proteins are related to cellular functions such as transport through membrane, nutrient uptake, and protein-protein interactions. This study demonstrates the alteration of OMPs composition in B. fragilis during bile salts stress resistance and adaptation to environmental changes. Proteomics of OMPs was also shown to be a useful approach in the identification of new targets for functional analyses. PMID:26948242

  16. Altered intestinal bile salt biotransformation in a cystic fibrosis (Cftr(-/-)) mouse model with hepato-biliary pathology

    Bodewes, Frank A. J. A.; van der Wulp, Mariette Y. M.; Beharry, Satti; Doktorova, Marcela; Havinga, Rick; Boverhof, Renze; Phillips, M. James; Durie, Peter R.; Verkade, Henkjan J.


    Background: Cftr(-/-tm1UC) mice develop progressive hepato-biliary pathology. We hypothesize that this liver pathology is related to alterations' in biliary bile hydrophobicity and bile salt metabolism in Cftr(-/-tm1Unc) mice. Methods: We determined bile production, biliary and fecal bile salt- and

  17. The Role of Bile Salt Export Pump Gene Repression in Drug-Induced Cholestatic Liver Toxicity

    Garzel, Brandy; Yang, Hui; Zhang, Lei; Huang, Shiew-Mei; Polli, James E.; Wang, Hongbing


    The bile salt export pump (BSEP, ABCB11) is predominantly responsible for the efflux of bile salts, and disruption of BSEP function is often associated with altered hepatic homeostasis of bile acids and cholestatic liver injury. Accumulating evidence suggests that many drugs can cause cholestasis through interaction with hepatic transporters. To date, a relatively strong association between drug-induced cholestasis and attenuated BSEP activity has been proposed. However, whether repression of...

  18. The Bile Salt Export Pump: Clinical and Experimental Aspects of Genetic and Acquired Cholestatic Liver Disease

    Lam, Ping; Soroka, Carol J.; Boyer, James L.


    The primary transporter responsible for bile salt secretion is the bile salt export pump (BSEP, ABCB11), a member of the ATP-binding cassette (ABC) superfamily, which is located at the bile canalicular apical domain of hepatocytes. In humans, BSEP deficiency results in several different genetic forms of cholestasis, which include progressive familial intrahepatic cholestasis type 2 (PFIC2), benign recurrent intrahepatic cholestasis type 2 (BRIC2), as well as other acquired forms of cholestasi...

  19. Review article: the function and regulation of proteins involved in bile salt biosynthesis and transport

    Pellicoro, Antonella; Faber, Klaas Nico


    Background Bile salts are produced and secreted by the liver and are required for intestinal absorption of fatty food components and excretion of endobiotics and xenobiotics. They are reabsorbed in the terminal ileum and transported back to the liver via the portal tract. Dedicated bile salt transpo

  20. Hepatocyte transplantation in bile salt export pump-deficient mice: selective growth advantage of donor hepatocytes under bile acid stress

    Chen, Huey-Ling; Chen, Hui-Ling; Yuan, Ray-Hwang; Wu, Shang-Hsin; Chen, Ya-Hui; Chien, Chin-Sung; Chou, Shi-Ping; Wang, Renxue; Ling, Victor; Chang, Mei-Hwei


    The bile salt export pump (Bsep) mediates the hepatic excretion of bile acids, and its deficiency causes progressive familial intrahepatic cholestasis. The current study aimed to induce bile acid stress in Bsep −/− mice and to test the efficacy of hepatocyte transplantation in this disease model. We fed Bsep −/− and wild-type mice cholic acid (CA) or ursodeoxycholic acid (UDCA). Both CA and UDCA caused cholestasis and apoptosis in the Bsep −/− mouse liver. Wild-type mice had minimal liver inj...

  1. Bile acid salt binding with colesevelam HCl is not affected by suspension in common beverages.

    Hanus, Martin; Zhorov, Eugene


    It has been previously reported that anions in common beverages may bind to bile acid sequestrants (BAS), reducing their capacity for binding bile acid salts. This study examined the ability of the novel BAS colesevelam hydrochloride (HCl), in vitro, to bind bile acid sodium salts following suspension in common beverages. Equilibrium binding was evaluated under conditions of constant time and varying concentrations of bile acid salts in simulated intestinal fluid (SIF). A stock solution of sodium salts of glycochenodeoxycholic acid (GCDC), taurodeoxycholic acid (TDC), and glycocholic acid (GC), was added to each prepared sample of colesevelam HCl. Bile acid salt binding was calculated by high-performance liquid chromatography (HPLC) analysis. Kinetics experiments were conducted using constant initial bile acid salt concentrations and varying binding times. The affinity, capacity, and kinetics of colesevelam HCl binding for GCDC, TDC, and GC were not significantly altered after suspension in water, carbonated water, Coca-Cola, Sprite, grape juice, orange juice, tomato juice, or Gatorade. The amount of bile acid sodium salt bound as a function of time was unchanged by pretreatment with any beverage tested. The in vitro binding characteristics of colesevelam HCl are unchanged by suspension in common beverages. PMID:16937334

  2. The adsorption-desorption behaviour and structure function relationships of bile salts.

    Parker, Roger; Rigby, Neil M; Ridout, Michael J; Gunning, A Patrick; Wilde, Peter J


    The digestion of dietary components in the human gastrointestinal (GI) tract is a complex, dynamic, inherently heterogeneous process. A key aspect of the digestion of lipid in the GI tract is the combined action of bile salts, lipase and colipase in hydrolysing and solubilising dispersed lipid. The bile salts are a mixture of steroid acid conjugates with surfactant properties. In order to examine whether the different bile salts have different interfacial properties their dynamic interfacial behaviour was characterised. Differences in the adsorption behaviour to solid hydrophobic surfaces of bile salt species were studied using dual polarisation interferometry and atomic force microscopy (AFM) under physiological conditions. Specifically, the cholates adsorbed more slowly and a significant proportion were irreversibly adsorbed following buffer rinsing; whereas the deoxycholates and chenodeoxycholates adsorbed more rapidly and desorbed to a greater extent following buffer rinsing. The conjugating groups (taurine, glycine) did not influence the behaviour. AFM showed that the interfacial structures that remained following buffer rinsing were also different between these two groups. In addition, the adsorption-desorption behaviour affected the adsorption of colipase to a solid surface. This supports the idea that cooperative adsorption occurs between certain bile salts and colipase to facilitate the adsorption and activity of pancreatic lipase in order to restore lipolytic activity in the presence of bile salts. This study provides insights into how differences in bile salt structure could affect lipase activity and solubilisation of lipolysis products and other lipid-soluble bioactive molecules. PMID:25008989

  3. Bile Salts: Natural Detergents for the Prevention of Sexually Transmitted Diseases

    Herold, Betsy C.; Kirkpatrick, Risa; Marcellino, Daniel; Travelstead, Anna; Pilipenko, Valentina; Krasa, Holly; Bremer, James; Dong, Li Jin; Cooper, Morris D.


    The development of new, safe, topical microbicides for intravaginal use for the prevention of sexually transmitted diseases is imperative. Previous studies have suggested that bile salts may inhibit human immunodeficiency virus infection; however, their activities against other sexually transmitted pathogens have not been reported. To further explore the potential role of bile salts in preventing sexually transmitted diseases, we examined the in vitro activities and cytotoxicities of select b...

  4. Bile Salt Export Pump is Dysregulated with Altered Farnesoid X Receptor Isoform Expression in Patients with Hepatocellular Carcinoma

    Chen, Yuan; Song, Xiulong; Valanejad, Leila; Vasilenko, Alexander; More, Vijay; Qiu, Xi; Chen, Weikang; Lai, Yurong; Slitt, Angela; Stoner, Matthew; Yan, Bingfang; Deng, Ruitang


    As a canalicular bile acid effluxer, bile salt export pump (BSEP) plays a vital role in maintaining bile acid homeostasis. BSEP deficiency leads to severe cholestasis and hepatocellular carcinoma (HCC) in young children. Regardless of the etiology, chronic inflammation is the common pathological process for HCC development. Clinical studies showed that bile acid homeostasis is disrupted in HCC patients with elevated serum bile acid level as a proposed marker for HCC. However, the underlying m...

  5. Estrogen and Estrogen Receptor-α-Mediated Transrepression of Bile Salt Export Pump

    Chen, Yuan; Vasilenko, Alex; Song, Xiulong; Valanejad, Leila; Verma, Ruchi; You, Sangmin; Yan, Bingfang; Shiffka, Stephanie; Hargreaves, Leeza; Nadolny, Christina; Deng, Ruitang


    Among diseases unique to pregnancy, intrahepatic cholestasis of pregnancy is the most prevalent disorder with elevated serum bile acid levels. We have previously shown that estrogen 17β-estradiol (E2) transrepresses bile salt export pump (BSEP) through an interaction between estrogen receptor (ER)-α and farnesoid X receptor (FXR) and transrepression of BSEP by E2/ERα is an etiological contributing factor to intrahepatic cholestasis of pregnancy. Currently the mechanistic insights into such tr...

  6. Liver receptor homolog 1 transcriptionally regulates human bile salt export pump expression*

    Song, Xiulong; Kaimal, Rajani; Yan, Bingfang; Deng, Ruitang


    The metabolic conversion of cholesterol into bile acids in liver is initiated by the rate-limiting cholesterol 7α-hydroxylase (CYP7A1), whereas the bile salt export pump (BSEP) is responsible for the canalicular secretion of bile acids. Liver receptor homolog 1 (LRH-1) is a key transcriptional factor required for the hepatic expression of CYP7A1. We hypothesized that LRH-1 was also involved in the transcriptional regulation of BSEP. In support of our hypothesis, we found that overexpression o...

  7. Quercetin solubilisation in bile salts: A comparison with sodium dodecyl sulphate.

    Buchweitz, Maria; Kroon, Paul A; Rich, Gillian T; Wilde, Peter J


    To understand the bioaccessibility of the flavonoid quercetin we studied its interaction with bile salt micelles. The environmental sensitivity of quercetin's UV-visible absorption spectrum gave information about quercetin partitioning. Two quercetin absorption peaks gave complementary information: Peak A (240-280nm) on the intermicellar phase and Peak B (340-440nm) on the micellar phase. Thus, by altering pH, we showed that only non-ionised quercetin partitions into micelles. We validated our interpretation by studying quercetin's interaction with SDS micelles. Pyrene fluorescence and the quercetin UV-visible spectra show that the adsorption site for pyrene and quercetin in bile salt micelles is more hydrophobic than that for SDS micelles. Also, both quercetin and pyrene reported a higher critical micelle concentration for bile salts than for SDS. Our method of using a flavonoid as an intrinsic probe, is generally applicable to other lipophilic bioactives, whenever they have observable environmental dependent properties. PMID:27283643

  8. Dietary fat assimilation and bile salt absorption in the killifish intestine

    Radiolabeled taurocholate (TC) and triolein were used to study fat assimilation and bile salt absorption in the stomachless saltwater killifish, Fundulus heteroclitus. Fat absorption occurred primarily in the proximal intestine with approximately 87% of a single dose (9 mg fat/8 g fish) absorbed in 2 h. Luminal triolein hydrolysis and enterocyte triolein resynthesis were tightly coupled. Killifish gallbladder bile contains taurocholate and cholate in an equal molar ratio at a combined concentration of 237 +/- 25 mM (n = 10) in 24-h-fasted fish. During fat assimilation luminal bile salt and fatty acid concentrations ranged between 10 and 30 mM. Between and during meals the total concentration of bile salts in the intestinal tissue remained roughly constant (4-6 mM) with the proximal one-third of the intestine containing 40% of the total and the remainder equally distributed between the mid and distal regions. All three regions of the intestine rapidly incorporated ingested TC in vivo, with the amount incorporated proportional to the pool size. In contrast, in vitro at low TC concentrations (60 nM), the distal one-third of the intestine incorporated 10 times as much TC in 2-min uptake experiments as the proximal and mid regions. Although there are many similarities between fat and bile salt assimilation in killifish and mammals, overall the processes are much simpler in killifish

  9. FXR-dependent reduction of hepatic steatosis in a bile salt deficient mouse model.

    Kunne, Cindy; Acco, Alexandra; Duijst, Suzanne; de Waart, Dirk R; Paulusma, Coen C; Gaemers, Ingrid; Oude Elferink, Ronald P J


    It has been established that bile salts play a role in the regulation of hepatic lipid metabolism. Accordingly, overt signs of steatosis have been observed in mice with reduced bile salt synthesis. The aim of this study was to identify the mechanism of hepatic steatosis in mice with bile salt deficiency due to a liver specific disruption of cytochrome P450 reductase. In this study mice lacking hepatic cytochrome P450 reductase (Hrn) or wild type (WT) mice were fed a diet supplemented with or without either 0.1% cholic acid (CA) or 0.025% obeticholic acid, a specific FXR-agonist. Feeding a CA-supplemented diet resulted in a significant decrease of plasma ALT in Hrn mice. Histologically, hepatic steatosis ameliorated after CA feeding and this was confirmed by reduced hepatic triglyceride content (115.5±7.3mg/g liver and 47.9±4.6mg/g liver in control- and CA-fed Hrn mice, respectively). The target genes of FXR-signaling were restored to normal levels in Hrn mice when fed cholic acid. VLDL secretion in both control and CA-fed Hrn mice was reduced by 25% compared to that in WT mice. In order to gain insight in the mechanism behind these bile salt effects, the FXR agonist also was administered for 3weeks. This resulted in a similar decrease in liver triglycerides, indicating that the effect seen in bile salt fed Hrn animals is FXR dependent. In conclusion, steatosis in Hrn mice is ameliorated when mice are fed bile salts. This effect is FXR dependent. Triglyceride accumulation in Hrn liver may partly involve impaired VLDL secretion. PMID:24548803

  10. Transcriptional Dynamics of Bile Salt Export Pump during Pregnancy: Mechanisms and Implications in Intrahepatic Cholestasis of Pregnancy

    Song, Xiulong; Vasilenko, Alexander; Chen, Yuan; Valanejad, Leila; Verma, Ruchi; Yan, Bingfang; Deng, Ruitang


    Bile salt export pump (BSEP) is responsible for biliary secretion of bile acids, a rate limiting step in the enterohepatic circulation of bile acids and transactivated by nuclear receptor farnesoid x receptor (FXR). Intrahepatic cholestasis of pregnancy (ICP) is the most prevalent disorder among diseases unique to pregnancy and primarily occurs in the third trimester of pregnancy with a hallmark of elevated serum bile acids. Currently, the transcriptional regulation of BSEP during pregnancy a...

  11. Genetic variations of bile salt transporters as predisposing factors for drug-induced cholestasis, intrahepatic cholestasis of pregnancy and therapeutic response of viral hepatitis

    Stieger, B; Geier, A.


    INTRODUCTION: Drug-induced cholestasis, intrahepatic cholestasis of pregnancy and viral hepatitis are acquired forms of liver disease. Cholestasis is a pathophysiologic state with impaired bile formation and subsequent accumulation of bile salts in hepatocytes. The bile salt export pump (BSEP) (ABCB11) is the key export system for bile salts from hepatocytes. AREAS COVERED: This article provides an introduction into the physiology of bile formation followed by a summary of the current knowled...

  12. Biliary excretion of pravastatin and taurocholate in rats with bile salt export pump (Bsep) impairment.

    Cheng, Yaofeng; Freeden, Chris; Zhang, Yueping; Abraham, Pamela; Shen, Hong; Wescott, Debra; Humphreys, W Griffith; Gan, Jinping; Lai, Yurong


    The bile salt export pump (BSEP) is expressed on the canalicular membrane of hepatocytes regulating liver bile salt excretion, and impairment of BSEP function may lead to cholestasis in humans. This study explored drug biliary excretion, as well as serum chemistry, individual bile acid concentrations and liver transporter expressions, in the SAGE Bsep knockout (KO) rat model. It was observed that the Bsep protein in KO rats was decreased to 15% of that in the wild type (WT), as quantified using LC-MS/MS. While the levels of Ntcp and Mrp2 were not significantly altered, Mrp3 expression increased and Oatp1a1 decreased in KO animals. Compared with the WT rats, the KO rats had similar serum chemistry and showed normal liver transaminases. Although the total plasma bile salts and bile flow were not significantly changed in Bsep KO rats, individual bile acids in plasma and liver demonstrated variable changes, indicating the impact of Bsep KO. Following an intravenous dose of deuterium labeled taurocholic acid (D4-TCA, 2 mg/kg), the D4-TCA plasma exposure was higher and bile excretion was delayed by approximately 0.5 h in the KO rats. No differences were observed for the pravastatin plasma concentration-time profile or the biliary excretion after intravenous administration (1 mg/kg). Collectively, the results revealed that these rats have significantly lower Bsep expression, therefore affecting the biliary excretion of endogenous bile acids and Bsep substrates. However, these rats are able to maintain a relatively normal liver function through the remaining Bsep protein and via the regulation of other transporters. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27059119

  13. The mechanism of increased biliary lipid secretion in mice with genetic inactivation of bile salt export pump

    Gooijert, K. E. R.; Havinga, R.; Wolters, Henk; Wang, R.; Ling, V.; Tazuma, S.; Verkade, H. J.


    Human bile salt export pump (BSEP) mutations underlie progressive familial intrahepatic cholestasis type 2 (PFIC2). In the PFIC2 animal model, Bsep(-/-) mice, biliary secretion of bile salts (BS) is decreased, but that of phospholipids (PL) and cholesterol (CH) is increased. Under physiological cond

  14. A progressive familial intrahepatic cholestasis type 2 mutation causes an unstable, temperature-sensitive bile salt export pump

    Plass, JRM; Mol, O; Heegsma, J; Geuken, M; Elling, G; Muller, M; Faber, KN; Jansen, PLM


    Background Aims: Progressive familial intrahepatic cholestasis type 2 (PFIC-2) patients have a defect in the hepatocanalicular bile salt secretion. The disease is caused by mutations in the bile salt export pump (BSEP). Ten different missense mutations have been described. In this study, we analysed

  15. A study of salt effects on the complexation between beta-cyclodextrins and bile salts based on the Hofmeister series

    Holm, Rene; Schonbeck, Christian; Somprasirt, Pitchayanun;


    bound drug molecules. The influence of Hofmeister ions on the binding constants of complexes between CDs (β-CD and hydroxypropylated β-CD) and bile salts (glycocholate and glycochenodeoxycholate) were examined by isothermal titration calorimetry. The chaotropic anions tended to weaken these inclusion...

  16. Thermodynamics of the interaction of γ-cyclodextrin and tauro- and glyco-conjugated bile salts

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, René;


    The structural differences in the interaction between natural γ-cyclodextrin and bile salts common in rat, dog and man was were investigated by 1H-ROESY and 13C NMR and molecular modeling and the thermodynamic parameters of the reaction by isothermal titration calorimetry. The γ-cyclodextrin was...

  17. Severe bile salt export pump deficiency : 82 different ABCB11 mutations in 109 families

    Strautnieks, Sandra S.; Byrne, Jane A.; Pawlikowska, Ludmila; Cebecauerova, Dita; Rayner, Anne; Dutton, Laura; Meier, Yvonne; Antoniou, Anthony; Stieger, Bruno; Arnell, Henrik; Ozcay, Figen; Al-Hussaini, Hussa F.; Bassas, Atif F.; Verkade, Henkjan J.; Fischler, Bjorn; Nemeth, Antal; Kotalova, Radana; Shneider, Benjamin L.; Cielecka-Kuszyk, Joanna; McClean, Patricia; Whitington, Peter F.; Sokal, Etienne; Jirsa, Milan; Wali, Sami H.; Jankowska, Irena; Pawlowska, Joanna; Mieli-Vergani, Giorgina; Knisely, A. S.; Bull, Laura N.; Thompson, Richard J.


    Background & Aims: Patients with severe bile salt export pump (BSEP) deficiency present as infants with progressive cholestatic liver disease. We characterized mutations of ABCB11 (encoding BSEP) in such patients and correlated genotypes with residual protein detection and risk of malignancy. Method

  18. Interaction between dietary bioactive peptides of short length and bile salts in submicellar or micellar state.

    Guerin, Justine; Kriznik, Alexandre; Ramalanjaona, Nick; Le Roux, Yves; Girardet, Jean-Michel


    Bile salts act as steroidal detergents in the gut, and could also interact with peptides and improve their bioavailability, although the mechanism is unclear. The occurrence of direct interaction between milk bioactive peptides, Ile-Asn-Tyr-Trp, Leu-Asp-Gln-Trp, and Leu-Gln-Lys-Trp, and different bile salts in the submicellar or micellar state was investigated by intrinsic fluorescence measurement and dynamic light scattering, above the critical micellar concentration, the latter being determined by isothermal titration calorimetry. The peptides form aggregates, spontaneously. In the presence of bile salts, some released peptide monomers were bound to the micellar surface. The lack of hydrogen bonding involving the C12OH group of the steroid skeleton, and the acidic function of some bile salts, might promote the interaction with the peptides, as could the lack of the C12OH group, rather than that of the C7OH group. At submicellar concentrations, sodium taurochenodeoxycholate and taurodeoxycholate readily interacted with the most hydrophobic peptide Ile-Asn-Tyr-Trp. PMID:27173542

  19. Analysis of the Bile Salt Export Pump (ABCB11) Interactome Employing Complementary Approaches.

    Przybylla, Susanne; Stindt, Jan; Kleinschrodt, Diana; Schulte Am Esch, Jan; Häussinger, Dieter; Keitel, Verena; Smits, Sander H; Schmitt, Lutz


    The bile salt export pump (BSEP, ABCB11) plays an essential role in the formation of bile. In hepatocytes, BSEP is localized within the apical (canalicular) membrane and a deficiency of canalicular BSEP function is associated with severe forms of cholestasis. Regulation of correct trafficking to the canalicular membrane and of activity is essential to ensure BSEP functionality and thus normal bile flow. However, little is known about the identity of interaction partners regulating function and localization of BSEP. In our study, interaction partners of BSEP were identified in a complementary approach: Firstly, BSEP interaction partners were co-immunoprecipitated from human liver samples and identified by mass spectrometry (MS). Secondly, a membrane yeast two-hybrid (MYTH) assay was used to determine protein interaction partners using a human liver cDNA library. A selection of interaction partners identified both by MYTH and MS were verified by in vitro interaction studies using purified proteins. By these complementary approaches, a set of ten novel BSEP interaction partners was identified. With the exception of radixin, all other interaction partners were integral or membrane-associated proteins including proteins of the early secretory pathway and the bile acyl-CoA synthetase, the second to last, ER-associated enzyme of bile salt synthesis. PMID:27472061

  20. Brucella abortus choloylglycine hydrolase affects cell envelope composition and host cell internalization.

    María Inés Marchesini

    Full Text Available Choloylglycine hydrolase (CGH, E.C. is a conjugated bile salt hydrolase that catalyses the hydrolysis of the amide bond in conjugated bile acids. Bile salt hydrolases are expressed by gastrointestinal bacteria, and they presumably decrease the toxicity of host's conjugated bile salts. Brucella species are the causative agents of brucellosis, a disease affecting livestock and humans. CGH confers Brucella the ability to deconjugate and resist the antimicrobial action of bile salts, contributing to the establishment of a successful infection through the oral route in mice. Additionally, cgh-deletion mutant was also attenuated in intraperitoneally inoculated mice, which suggests that CGH may play a role during systemic infection other than hydrolyzing conjugated bile acids. To understand the role CGH plays in B. abortus virulence, we infected phagocytic and epithelial cells with a cgh-deletion mutant (Δcgh and found that it is defective in the internalization process. This defect along with the increased resistance of Δcgh to the antimicrobial action of polymyxin B, prompted an analysis of the cell envelope of this mutant. Two-dimensional electrophoretic profiles of Δcgh cell envelope-associated proteins showed an altered expression of Omp2b and different members of the Omp25/31 family. These results were confirmed by Western blot analysis with monoclonal antibodies. Altogether, the results indicate that Brucella CGH not only participates in deconjugation of bile salts but also affects overall membrane composition and host cell internalization.

  1. A C-terminal tyrosine-based motif in the bile salt export pump directs clathrin-dependent endocytosis

    Lam, Ping; Xu, Shuhua; Soroka, Carol J.; Boyer, James L.


    The liver specific bile salt export pump (BSEP) is crucial for bile-acid dependent bile flow at the apical membrane. BSEP, a member of the family of structurally related ATP-Binding Cassette (ABC) proteins, is composed of 12 transmembrane segments (TMS) and 2 large cytoplasmic nucleotide binding domains (NBD). The regulation of trafficking of BSEP to and from the cell surface is not well understood, but is believed to play an important role in cholestatic liver diseases such as primary famili...

  2. Supra-molecular Association and Polymorphic Behaviour In Systems Containing Bile Acid Salts

    Camillo La Mesa


    Full Text Available A wide number of supra-molecular association modes are observed in mixtures containing water and bile salts, BS, (with, eventually, other components. Molecular or micellar solutions transform into hydrated solids, fibres, lyotropic liquid crystals and/or gels by raising the concentration, the temperature, adding electrolytes, surfactants, lipids and proteins. Amorphous or ordered phases may be formed accordingly. The forces responsible for this very rich polymorphism presumably arise from the unusual combination of electrostatic, hydrophobic and hydrogen-bond contributions to the system stability, with subsequent control of the supra-molecular organisation modes. The stabilising effect due to hydrogen bonds does not occur in almost all surfactants or lipids and is peculiar to bile acids and salts. Some supra-molecular organisation modes, supposed to be related to malfunctions and dis-metabolic diseases in vivo, are briefly reported and discussed.

  3. Supra-molecular Association and Polymorphic Behaviour In Systems Containing Bile Acid Salts

    Camillo La Mesa; Patrizia Andreozzi; Marco Calabresi


    A wide number of supra-molecular association modes are observed in mixtures containing water and bile salts, BS, (with, eventually, other components). Molecular or micellar solutions transform into hydrated solids, fibres, lyotropic liquid crystals and/or gels by raising the concentration, the temperature, adding electrolytes, surfactants, lipids and proteins. Amorphous or ordered phases may be formed accordingly. The forces responsible for this very rich polymorphism presumably arise from th...

  4. Severe bile salt export pump deficiency: 82 different ABCB11 mutations in 109 families

    Strautnieks, S S; Byrne, J A; Pawlikowska, L.; Cebecauerova, D; Rayner, A; Dutton, L; Meier, Y; Antoniou, A; Stieger, B; Arnell, H; Ozcay, F; Al-Hussaini, H F; Bassas, A F; Verkade , H.J.; Fischler, B


    BACKGROUND & AIMS: Patients with severe bile salt export pump (BSEP) deficiency present as infants with progressive cholestatic liver disease. We characterized mutations of ABCB11 (encoding BSEP) in such patients and correlated genotypes with residual protein detection and risk of malignancy. METHODS: Patients with intrahepatic cholestasis suggestive of BSEP deficiency were investigated by single-strand conformation polymorphism analysis and sequencing of ABCB11. Genotypes sorted by likely ph...

  5. Hydrolysis of human milk fat globules by pancreatic lipase: role of colipase, phospholipase A2, and bile salts.

    Bläckberg, L; Hernell, O; Olivecrona, T


    Human milk fat globules were used to explore how dietary triglycerides are hydrolyzed by pancreatic lipase. These triglycerides were hydrolyzed very slowly by lipase alone as if the surface layer of proteins and phospholipids impeded the action of the enzyme. The inhibition of lipase activity could be overcome by addition either of colipase or of pancreatic phospholipase A2. Colipase enhanced triglyceride hydrolysis in a dose-dependent manner whether bile salts were present or not. Bile salts...

  6. The Association between Bile Salt Export Pump Single-Nucleotide Polymorphisms and Primary Biliary Cirrhosis Susceptibility and Ursodeoxycholic Acid Response

    Rui-rui Chen; Yuan-jun Li; Xin-min Zhou; Lu Wang; Juan Xing; Shuang Han; Li-na Cui; Lin-hua Zheng; Kai-chun Wu; Yong-quan Shi; Zhe-yi Han; Ying Han; Dai-ming Fan


    Background. Primary biliary cirrhosis (PBC) is a chronic and progressive cholestasis liver disease. Bile salt export pump (BSEP) is the predominant bile salt efflux system of hepatocytes. BSEP gene has been attached great importance in the susceptibility of PBC and the response rate of ursodeoxycholic acid (UDCA) treatment of PBC patients. Methods. In this study, TaqMan assay was used to genotype four variants of BSEP, and the Barcelona criteria were used for evaluating the response rate of U...

  7. Degradation of the Bile Salt Export Pump at Endoplasmic Reticulum in Progressive Familial Intrahepatic Cholestasis Type II (PFIC II)

    Wang, Lin; Dong, Huiping; Soroka, Carol J.; WEI, NING; Boyer, James L.; Hochstrasser, Mark


    The bile salt export pump (Bsep) represents the major bile salt transport system at the canalicular membrane of hepatocytes. When examined in model cell lines, genetic mutations in the BSEP gene impair its targeting and transport function, contributing to the pathogenesis of PFIC II. PFIC II mutations are known to lead to a deficiency of BSEP in human hepatocytes, suggesting that PFIC II mutants are unstable and degraded in the cell. To investigate this further, we have characterized the impa...

  8. Hydrolysis of milk fat globules by pancreatic lipase. Role of colipase, phospholipase A2, and bile salts.

    Borgström, B.; Erlanson-Albertsson, C


    Human milk fat globules require colipase to be hydrolyzed by pancreatic lipase in the presence of bile salts. This is contrary to a recent report in this Journal (J. Clin. Invest. 67: 1748-1752.) according to which inhibition of lipase by bile salt could be overcome by the addition of colipase or phospholipase A2. This latter finding is shown to be due to contamination of commercially available pancreatic phospholipase A2 by colipase.

  9. Bile salt recognition by human liver fatty acid binding protein.

    Favretto, Filippo; Santambrogio, Carlo; D'Onofrio, Mariapina; Molinari, Henriette; Grandori, Rita; Assfalg, Michael


    Fatty acid binding proteins (FABPs) act as intracellular carriers of lipid molecules, and play a role in global metabolism regulation. Liver FABP (L-FABP) is prominent among FABPs for its wide ligand repertoire, which includes long-chain fatty acids as well as bile acids (BAs). In this work, we performed a detailed molecular- and atomic-level analysis of the interactions established by human L-FABP with nine BAs to understand the binding specificity for this important class of cholesterol-derived metabolites. Protein-ligand complex formation was monitored using heteronuclear NMR, steady-state fluorescence spectroscopy, and mass spectrometry. BAs were found to interact with L-FABP with dissociation constants in the narrow range of 0.6-7 μm; however, the diverse substitution patterns of the sterol nucleus and the presence of side-chain conjugation resulted in complexes endowed with various degrees of conformational heterogeneity. Trihydroxylated BAs formed monomeric complexes in which single ligand molecules occupied similar internal binding sites, based on chemical-shift perturbation data. Analysis of NMR line shapes upon progressive addition of taurocholate indicated that the binding mechanism departed from a simple binary association equilibrium, and instead involved intermediates along the binding path. The co-linear chemical shift behavior observed for L-FABP complexes with cholate derivatives added insight into conformational dynamics in the presence of ligands. The observed spectroscopic features of L-FABP/BA complexes, discussed in relation to ligand chemistry, suggest possible molecular determinants of recognition, with implications regarding intracellular BA transport. Our findings suggest that human L-FABP is a poorly selective, universal BA binder. PMID:25639618

  10. Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate

    Ćirin Dejan M


    Full Text Available Abstract Background In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100 or anionic (sodium lauryl ether sulfate surfactant having oxyethylene groups in the polar head and following bile salts: cholate, deoxycholate and 7-oxodeoxycholate. Results The micellization behaviour of binary anionic-nonionic and anionic-anionic surfactant mixtures was investigated by conductivity and surface tension measurements. The results of the study have been analyzed using Clint's, Rubingh's, and Motomura's theories for mixed binary systems. The negative values of the interaction parameter indicate synergism between micelle building units. It was noticed that Triton X-100 and sodium lauryl ether sulfate generate the weakest synergistic interactions with sodium deoxycholate, while 7-oxodeoxycholate creates the strongest attractive interaction with investigated co-surfactants. Conclusion It was concluded that increased synergistic interactions can be attributed to the larger number of hydrophilic groups at α side of the bile salts. Additionally, 7-oxo group of 7-oxodeoxycholate enhance attractive interactions with selected co-surfactants more than 7-hydroxyl group of sodium cholate.

  11. Evaluation of resistance to low pH and bile salts of human Lactobacillus spp. isolates.

    Fuochi, Virginia; Petronio, Giulio Petronio; Lissandrello, Edmondo; Furneri, Pio Maria


    There are nearly 100 trillion bacteria in the intestine that together form the intestinal microbiota. They are 'good' bacteria because they help to maintain a physiological balance and are called probiotics. Probiotics must have some important characteristics: be safe for humans, be resistant to the low pH in the stomach, as well as bile salts and pancreatic juice. Indeed, their survival is the most important factor, so that they can arrive alive in the intestine and are able to form colonies, at least temporarily. The aim of our study was the evaluation of resistance of Lactobacillus isolates from fecal and oral swabs compared to that found in a commercial product. Seven strains were randomly chosen: L. jensenii, L. gasseri, L. salivarius, L. fermentum, L. rhamnosus, L. crispatus, and L. delbrueckii. We observed a large variability in the results: L. gasseri and L. fermentum were the most resistance to low pH, while only L. gasseri showed the best survival rate to bile salts. Interestingly, the commercial product did not show tolerance to both low pH and bile salts. PMID:26216909

  12. Aggregation behaviour of amphiphilic drug and bile salt mixtures at different compositions and temperatures

    Highlights: • Aggregation behavior of promethazine hydrochloride-bile salt mixtures has been investigated. • The negative β values indicate attractive interactions between the components. • For PMT/PMT-bile salt systems, ΔHm∘ values change from negative to positive with temperature. • The ΔSm∘ values are positive, their magnitude being more at T = 298.15 K and above. • The results have applicability in drug delivery. -- Abstract: The micellization and adsorption behaviour of the amphiphilic drug promethazine hydrochloride (PMT – a phenothiazine) and bile salts mixtures were analyzed at different compositions in pure and mixed states in aqueous solutions. By using regular solution theory (RST) and Rosen’s model different physicochemical properties such as critical micellar concentration (cmc), micellar composition, surface excess concentration (Γmax), minimum area per molecule (Amin), interaction parameters (βm, βσ), energetic parameters of micellization as well as other micellar and surface properties have been determined. The values of interaction parameters (β) and activity coefficients f1 and f2 (for both, in mixed monolayer as well as in mixed micelles) indicate the synergistic behaviour. The thermodynamic parameters propose release of water from the hydrophobic portion of the drug at higher temperatures

  13. The mitigating effects of phosphatidylcholines on bile salt- and lysophosphatidylcholine-induced membrane damage.

    el-Hariri, L M; Marriott, C; Martin, G P


    The effects, at pH 7.0, of a series of 0.2 mM phosphatidylcholines (PC), namely dicaproyl-PC (DCPC), didecanoyl-PC (DDPC), dilauroyl-PC (DLaPC), dimyristoyl-PC (DMPC), dipalmitoyl-PC (DPPC), dioleoyl-PC (DOPC) and dilinoleoyl-PC (DLPC) and a series of 0.2 mM fatty acid salts (namely sodium myristate, palmitate, stearate, oleate and linoleate) upon the erythrocyte haemolysis induced by 2 mM sodium taurodeoxycholate (STDC) were determined. The influence of egg PC and dihexadecyl phosphate (DHDP) concentration upon the haemolysis induced by 1.4 mM sodium deoxycholate (SDC), 2 mM STDC and 0.1 mM lysophosphatidylcholine (LPC) were also established. A bile salt:egg PC mole ratio of 0.5 virtually abolished the haemolysis induced by SDC and STDC, whereas the same ratio of LPC:egg PC only reduced haemolysis from 65 to 40% (maximum haemolysis). DHDP had no effect on the haemolytic action of SDC or STDC. The salts of the fatty acids were non-haemolytic, and when mixed with STDC did not affect the level of haemolysis induced by the bile salt. In contrast, DDPC and DLaPC enhanced the haemolysis of STDC and DCPC had no effect, whereas DMPC, DPPC, DSPC, DOPC, DLPC and egg PC all reduced haemolysis. Maximum reduction was determined for DMPC and egg PC. The mixed micelle preparation temperature (either room or 60 degrees C) and temperature of incubation (either 20 degrees C for 30 min or 37 degrees C for 5 min) had only minor effects on the net haemolysis induced by STDC. These findings may be of significance in understanding the aetiology of certain gastrointestinal diseases and in determining whether mixed bile salt micelles have a role as drug penetration enhancers. PMID:1359088

  14. Bile Salt and Acid Tolerant of Lactic Acid Bacteria Isolated from Proventriculus of Broiler Chicken

    E. Damayanti


    Full Text Available The aim of this research was to obtain the lactic acid bacteria (LAB as probiotic candidates which have resistance to bile salt and acid condition. LAB was obtained using isolation method from proventriculus of broiler chicken. Selective MRS media with 0.2% CaCO3 addition were used for LAB isolation using pour plate sampling method under anaerobic condition. The result showed that four selected isolates had morphological and biochemical characteristics as LAB. The selected LAB was characterized as follow: antibacterial activities, antibiotic sensitivity, resistance on bile salt, gastric juice and acid condition, and biochemical identification. Antibacterial activities assay of cell free supernatant was confirmed using disc paper diffusion method which was arranged on factorial design and each treatment consisted of three replications. The cell free supernatant of LAB isolates had antibacterial activities against Escherichia coli, Pseudomonas aerugenosa, and Salmonella pullorum. Molecular identification procedure using 16S rRNA sequence analysis showed that R01 and R02 as Pediococcus acidilactici. The viability of the two isolates were tested by acid pH (pH 1, 2, and 3, gastric juice pH 2, and bile salt condition for digestives tract simulation. The result showed that R01 and R02 had a high viability percentages at pH 1, 2, and 3 (95.45%, 99.49%, 104.01%, and 67.17%, 120.74%, 103.4%, respectively and at bile salt simulation for 1-2 hours (100.35%-102.71% and 100.02%-102.65%, respectively, but at gastric juice simulation for 1-2 hours, the P. acidilactici R01 had higher viability than P. acidilactici R02 (59.69%-76.53% versus 43.57%-40.69%, respectively. In the antibiotic sensitivity test for three antibiotics (i.e. erythromicin 15 µg, penicillin G 10 µg, and streptomycin 10 µg, the P. acidilactici R02 showed resistance to Streptomycin and Penicillin. It is concluded that P. acidilactici R01 and P. acidilactici R02 isolated from proventriculus

  15. In vitro lipid peroxidation of intestinal bile salt-based nanoemulsions

    Courraud, J; Charnay, C; Cristol, J P;


    . Several nanoemulsions were compared in terms of physical characteristics and reactivity to 2,2'-azobis-(2-amidinopropane) hydrochloride (AAPH)-induced oxidation. Formulations included different types of lipids, a detergent (a conjugated bile salt or sodium dodecyl sulfate) and, finally, lipophilic......Over the last decades, oxidative stress has been described as a deleterious phenomenon contributing to numerous noncommunicable diseases such as cardiovascular disease, diabetes, and cancers. As many authors ascribed the healthy effect of fruit and vegetable consumption mainly to their antioxidant...

  16. The role of bile salt export pump mutations in progressive familial intrahepatic cholestasis type II

    Wang, Lin; Soroka, Carol J.; Boyer, James L.


    PFIC II is a subtype of progressive familial intrahepatic cholestasis (PFIC) that is associated with mutations in the ABCB11 gene encoding the bile salt export pump (BSEP). However it is not known how these mutations cause this disease. To evaluate these mechanisms, we introduced seven PFIC II–associated missense mutations into rat Bsep and assessed their effects on Bsep membrane localization and transport function in MDCK and Sf9 cells, respectively. Five mutations, G238V, E297G, G982R, R115...

  17. The feline bile salt export pump: a structural and functional comparison with canine and human Bsep/BSEP

    Beusekom, C.D. van; Heuvel, J.J.M.W. van den; Koenderink, J.B.; Schrickx, J.A.; Russel, F G M


    Background The bile salt export pump (BSEP/ABCB11) is the primary transporter for the excretion of bile acids from hepatocytes into bile. In human, inhibition of BSEP by drugs has been related to drug-induced cholestasis and subsequent cytotoxic effects. The role of BSEP in canine and feline liver diseases has not been studied in detail, but the same mechanism of inhibition by drugs as in humans could play a role in veterinary medicine. The aim of this study was to investigate the functional ...

  18. Computational Investigation of Enthalpy-Entropy Compensation in Complexation of Glycoconjugated Bile Salts with β-Cyclodextrin and Analogs

    Tidemand, Kasper Damgaard; Schonbeck, Christian; Holm, Rene; Westh, Peter; Peters, Günther H.J.


    of the HP substituents. Good agreement with experimental data was found with respect to penetration depths of CDs. An increased degree of HP substitution (DS) resulted in an increased probability of blocking the cavity opening, thereby hindering the bile salt from entering CD. Further, the residence......The inclusion complexes of glycoconjugated bile salts with beta-cyclodextrin (beta-CD) and 2-hydroxypropyl-beta-cyclodextrins (HP-beta-CD) in aqueous solution were investigated by molecular dynamics simulations to provide a molecular explanation of the experimentally observed destabilizing effect...... change in complexation entropy with DS was not able to compensate for this unfavorable change in enthalpy induced by the HP substituents, resulting in a destabilizing effect. This was found to originate from fixation of the HP substituents and decreased free rotation of the bile salts within the CD...

  19. Structural investigation into the influence of lipolysis products on the structure of bile salt micelles

    Free fatty acids play a vital role as fuel for cells and in lipid metabolism. During lipid digestion in the gastrointestinal tract, triglycerides are hydrolyzed resulting in the amphiphilic products free fatty acids and monoglycerides. These components, together with bile salts, are responsible for the transport of lipids and poorly water soluble nutrients and xenobiotics from the intestine into the circulatory system of the body. In this study we show that the self-assembly of digestion products from medium chain triglycerides (tricaprylin) in combination with bile salt and phospholipid is highly pH responsive. Individual building blocks of caprylic acid within the mixed colloidal structures are mapped using a combination of neutron scattering combined with both solvent contrast variation and selective deuteration as well as synchrotron-based small angle Xray scattering. Modelling of the scattering data shows transitions in size and shape of the micelles in combination with a transfer of the caprylic acid from the core of the micelles to the shell or into the bulk water upon increasing pH. The results help to understand the process of lipid digestion with a focus on colloidal structure formation and transformation for the delivery of triglyceride lipids and other hydrophobic functional molecules.

  20. Membranolytic Activity of Bile Salts: Influence of Biological Membrane Properties and Composition

    Alfred Blume


    Full Text Available The two main steps of the membranolytic activity of detergents: 1 the partitioning of detergent molecules in the membrane and 2 the solubilisation of the membrane are systematically investigated. The interactions of two bile salt molecules, sodium cholate (NaC and sodium deoxycholate (NaDC with biological phospholipid model membranes are considered. The membranolytic activity is analysed as a function of the hydrophobicity of the bile salt, ionic strength, temperature, membrane phase properties, membrane surface charge and composition of the acyl chains of the lipids. The results are derived from calorimetric measurements (ITC, isothermal titration calorimetry. A thermodynamic model is described, taking into consideration electrostatic interactions, which is used for the calculation of the partition coefficient as well as to derive the complete thermodynamic parameters describing the interaction of detergents with biological membranes (change in enthalpy, change in free energy, change in entropy etc. The solubilisation properties are described in a so-called vesicle-to-micelle phase transition diagram. The obtained results are supplemented and confirmed by data obtained from other biophysical techniques (DSC differential scanning calorimetry, DLS dynamic light scattering, SANS small angle neutron scattering.

  1. Multifaceted applications of bile salts in pharmacy: an emphasis on nanomedicine

    Elnaggar YS


    Full Text Available Yosra SR Elnaggar Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt Abstract: The human body has long provided pharmaceutical science with biomaterials of interesting applications. Bile salts (BSs are biomaterials reminiscent of traditional surfactants with peculiar structure and self-assembled topologies. In the pharmaceutical field, BSs were employed on the basis of two different concepts. The first concept exploited BSs’ metabolic and homeostatic functions in disease modulation, whereas the second one utilized BSs’ potential to modify drug-delivery characteristics, which recently involved nanotechnology. This review is the first to gather major pharmaceutical applications of BSs from endogenous organotropism up to integration into nanomedicine, with a greater focus on the latter domain. Endogenous applications highlighted the role of BS in modulating hypercholesterolemia and cancer therapy in view of enterohepatic circulation. In addition, recent BS-integrated nanomedicines have been surveyed, chiefly size-tunable cholate nanoparticles, BS-lecithin mixed micelles, bilosomes, probilosomes, and surface-engineered bilosomes. A greater emphasis has been laid on nanosystems for vaccine and cancer therapy. The comparative advantages of BS-integrated nanomedicines over conventional nanocarriers have been noted. Paradoxical effects, current pitfalls, future perspectives, and opinions have also been outlined. Keywords: bile salt, nanomedicine, bilosomes, liposomes, size-tunable nanoparticles 

  2. Oxysterol 22(R)-Hydroxycholesterol Induces the Expression of the Bile Salt Export Pump through Nuclear Receptor Farsenoid X Receptor but Not Liver X Receptor

    Deng, Ruitang; Yang, Dongfang; Yang, Jian; Yan, Bingfang


    Oxysterols are intermediates in the synthesis of bile acids and steroid hormones from cholesterol and function as ligands for liver X receptor (LXR). Bile salt export pump (BSEP) is responsible for canalicular secretion of bile acids and is tightly regulated by its substrates bile acids through nuclear receptor farnesoid X receptor (FXR). In a microarray study using human hepatocytes, BSEP was markedly induced not only by chenodeoxycholic acid (CDCA) but also by oxysterol 22(R)-hydroxycholest...


    Kruglov, Emma A.; Gautam, Samir; Guerra, Mateus T.; Nathanson, Michael H.


    Bile salt secretion is mediated primarily by the bile salt export pump (Bsep), a transporter on the canalicular membrane of the hepatocyte. However, little is known about the short-term regulation of Bsep activity. Ca2+ regulates targeting and insertion of transporters in many cell systems, and Ca2+ release near the canalicular membrane is mediated by the type II inositol 1,4,5-trisphosphate receptor (InsP3R2), so we investigated the possible role of InsP3R2 in modulating Bsep activity. The k...

  4. The unique ligand binding features of subfamily-II iLBPs with respect to bile salts and related drugs.

    Favretto, Filippo; Ceccon, Alberto; Zanzoni, Serena; D'Onofrio, Mariapina; Ragona, Laura; Molinari, Henriette; Assfalg, Michael


    Intracellular lipid binding proteins (iLBPs) are a family of evolutionarily related small cytoplasmic proteins implicated in the transcellular transport of lipophilic ligands. Subfamily-II iLBPs include the liver fatty acid binding protein (L-FABP), and the ileal and the liver and ileal bile acid binding proteins (L-BABP and I-BABP). Atomic-level investigations during the past 15-20 years have delivered relevant information on bile acid binding by this protein group, revealing unique features including binding cooperativity, promiscuity, and site selectivity. Using NMR spectroscopy and other biophysical techniques, our laboratories have contributed to an understanding of the molecular determinants of some of these properties and their generality among proteins from different animal species. We focused especially on formation of heterotypic complexes, considering the mixed compositions of physiological bile acid pools. Experiments performed with synthetic bile acid derivatives showed that iLBPs could act as targets for cell-specific contrast agents and, more generally, as effective carriers of amphiphilic drugs. This review collects the major findings related to bile salt interactions with iLBPs aiming to provide keys for a deeper understanding of protein-mediated intracellular bile salt trafficking. PMID:25468388

  5. The Role of the Enterohepatic Circulation of Bile Salts and Nuclear Hormone Receptors in the Regulation of Cholesterol Homeostasis: Bile Salts as Ligands for Nuclear Hormone Receptors

    Redinger, Richard N.


    The coordinated effect of lipid activated nuclear hormone receptors; liver X receptor (LXR), bound by oxysterol ligands and farnesoid X receptor (FXR), bound by bile acid ligands, act as genetic transcription factors to cause feed-forward cholesterol catabolism to bile acids and feedback repression of bile acid synthesis, respectively. It is the coordinated action of LXR and FXR, each dimerized to retinoid X receptor, that signal nuclear DNA response elements to encode proteins that prevent e...

  6. Determination of the faecal excretion of labelled bile salts after i.v. injection of 14C - cholic acid

    By measuring total faecal radioactivity, correlated to 24-hour enterohepatic circulation, following i.v. administration of 14C -cholic acid, bile salt malabsorption was evaluated before and/or after surgery in 80 patients with Crohn's disease localized to the ileum and/or the colon and the results related to the length of ileum diseased or resected. Before operation bile salt malabsorption was observed only in patients with inflammation of the terminal ileum, but no significant was found between bile salt excretion and the extent of ileal disease. In patients subjected to ileal resection with sacrifice of the ileocaecal valve, bile salt malabsorption correlated strongly to the length of ileum resected. This correlation was about the same in ileostomy patients and in patients subjected to restorative operation. We conclude that determination of 14C in faeces is a more sensitive test than the Schilling test and the faecal fat excretion test in reflecting ileal dysfunction, at least in patients with ileal resections. (Auth)

  7. Mice lacking Mrp3 (Abcc3) have normal bile salt transport, but altered hepatic transport of endogenous glucuronides

    N. Zelcer; K. van de Wetering; R. de Waart; G.L. Scheffer; H.U. Marschall; P.R. Wielinga; A. Kuil; C. Kunne; A. Smith; M. Valk; J. Wijnholds; R. Oude Elferink; P. Borst


    Background/Aim: Multidrug Resistance Protein 3 (MRP3) transports bile salts and glucuronide conjugates in vitro and is postulated to protect the liver in cholestasis. Whether the absence of Mrp3 affects these processes in vivo is tested. Methods: Mrp3-deficient mice were generated and the contributi

  8. Bile duct obstruction

    ... the liver. It contains cholesterol, bile salts, and waste products such as bilirubin . Bile salts help your ... can lead to life-threatening infection and a dangerous buildup of bilirubin. If the blockage lasts a ...

  9. Bile salt liposomes for enhanced lymphatic transport and oral bioavailability of paclitaxel.

    Zhang, Bin; Xue, Aiying; Zhang, Chen; Yu, Jinlong; Chen, Wen; Sun, Deqing


    Paclitaxel (PTX), a BCS class IV drug that is characterized by its poor solubility and is a substrate for P-glycoprotein, is one of the most widely used antineoplastic agents. However, oral administration of PTX for chemotherapy is highly challenging. The aim of this study was to develop bile-salt liposomes (BS-Lips) to enhance the absorption of PTX and thus improve its therapeutic outcome. The BS-Lips were prepared by the thin-film hydration method and characterized in terms of particle size and morphology. Drug release and in vitro stability in simulated gastrointestinal fluids and in media of different pH values were evaluated, as well as in vivo performance, including antitumor activity and pharmacokinetics in rats, with the plasma concentrations determined by a HPLC method. The PTX-loaded BS-Lips were successfully prepared with a diameter of approximately 150 nm and an entrapment efficiency of greater than 90 percent. Moreover, the BS-Lips were not affected by gastrointestinal enzymes or pH alternation, as evident from the unchanged particle size and the drug retained in BS-Lips after 6 h incubation. The insertion of bile salt into the lipid layer of liposomes increased the lymphatic transport of PTX by twofold. Importantly, BS-Lips increased the oral bioavailability of PTX by 2.5 and 4-fold, respectively, compared with conventional liposomes (Lips) and Taxol (free drug), thereby displaying a better inhibition of tumor growth that was similar to the group injected intravenously with Taxol. In conclusion, the BS-Lips represent promising vehicles for the oral delivery of PTX, thereby enabling an intravenous-to-oral switch for cancer chemotherapy. PMID:27455550

  10. Ultrafast fluorescence resonance energy transfer in a bile salt aggregate: Excitation wavelength dependence

    Ujjwal Mandal; Subhadip Ghosh; Dibyendu Kumar Das; Aniruddha Adhikari; Shantanu Dey; Kankan Bhattacharyya


    Fluorescence resonance energy transfer (FRET) from Coumarin 153 (C153) to Rhodamine 6G (R6G) in a secondary aggregate of a bile salt (sodium deoxycholate, NaDC) is studied by femtosecond up-conversion. The emission spectrum of C153 in NaDC is analysed in terms of two spectra-one with emission maximum at 480 nm which corresponds to a non-polar and hydrophobic site and another with maximum at ∼ 530 nm which arises from a polar hydrophilic site. The time constants of FRET were obtained from the rise time of the emission of the acceptor (R6G). In the NaDC aggregate, FRET occurs in multiple time scales -4 ps and 3700 ps. The 4 ps component is assigned to FRET from a donor (D) to an acceptor (A) held at a close distance (DA ∼ 17 Å) inside the bile salt aggregate. The 3700 ps component corresponds to a donor-acceptor distance ∼ 48 Å. The long (3700 ps) component may involve diffusion of the donor. With increase in the excitation wavelength (ex) from 375 to 435 nm, the relative contribution of the ultrafast component of FRET (∼ 4 ps) increases from 3 to 40% with a concomitant decrease in the contribution of the ultraslow component (∼3700 ps) from 97 to 60%. The ex dependence is attributed to the presence of donors at different locations. At a long ex (435 nm) donors in the highly polar peripheral region are excited. A short ex (375 nm) `selects’ donor at a hydrophobic location.

  11. Bacterial Bile Metabolising Gene Abundance in Crohn's, Ulcerative Colitis and Type 2 Diabetes Metagenomes

    Labbé, Alain; Ganopolsky, Jorge G.; Martoni, Christopher J.; Prakash, Satya; Jones, Mitchell L.


    We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh), 7 alpha-dehydroxylase gene (adh) and 7-alpha hydroxysteroid dehydrogenase gene (hsdh) in fecal bacteria in diseased populations of Crohn's disease (CD), Ulc...

  12. Inhibition of bile salt transport by drugs associated with liver injury in primary hepatocytes from human, monkey, dog, rat, and mouse.

    Zhang, Jie; He, Kan; Cai, Lining; Chen, Yu-Chuan; Yang, Yifan; Shi, Qin; Woolf, Thomas F; Ge, Weigong; Guo, Lei; Borlak, Jürgen; Tong, Weida


    Interference of bile salt transport is one of the underlying mechanisms for drug-induced liver injury (DILI). We developed a novel bile salt transport activity assay involving in situ biosynthesis of bile salts from their precursors in primary human, monkey, dog, rat, and mouse hepatocytes in suspension as well as LC-MS/MS determination of extracellular bile salts transported out of hepatocytes. Glycine- and taurine-conjugated bile acids were rapidly formed in hepatocytes and effectively transported into the extracellular medium. The bile salt formation and transport activities were time‒ and bile-acid-concentration‒dependent in primary human hepatocytes. The transport activity was inhibited by the bile salt export pump (BSEP) inhibitors ketoconazole, saquinavir, cyclosporine, and troglitazone. The assay was used to test 86 drugs for their potential to inhibit bile salt transport activity in human hepatocytes, which included 35 drugs associated with severe DILI (sDILI) and 51 with non-severe DILI (non-sDILI). Approximately 60% of the sDILI drugs showed potent inhibition (with IC50 values <50 μM), but only about 20% of the non-sDILI drugs showed this strength of inhibition in primary human hepatocytes and these drugs are associated only with cholestatic and mixed hepatocellular cholestatic (mixed) injuries. The sDILI drugs, which did not show substantial inhibition of bile salt transport activity, are likely to be associated with immune-mediated liver injury. Twenty-four drugs were also tested in monkey, dog, rat and mouse hepatocytes. Species differences in potency were observed with mouse being less sensitive than other species to inhibition of bile salt transport. In summary, a novel assay has been developed using hepatocytes in suspension from human and animal species that can be used to assess the potential for drugs and/or drug-derived metabolites to inhibit bile salt transport and/or formation activity. Drugs causing sDILI, except those by immune

  13. Mechanistic insights into isoform-dependent and species-specific regulation of bile salt export pump by farnesoid X receptor

    Song, Xiulong; Chen, Yuan; Valanejad, Leila; Kaimal, Rajani; Yan, Bingfang; Stoner, Matthew; Deng, Ruitang


    Expression of bile salt export pump (BSEP) is regulated by the bile acid/farnesoid X receptor (FXR) signaling pathway. Two FXR isoforms, FXRα1 and FXRα2, are predominantly expressed in human liver. We previously showed that human BSEP was isoform-dependently regulated by FXR and diminished with altered expression of FXRα1 and FXRα2 in patients with hepatocellular carcinoma. In this study, we demonstrate that FXRα1 and FXRα2 regulate human BSEP through two distinct FXR responsive elements (FXR...

  14. Intracellular Trafficking of Bile Salt Export Pump (ABCB11) in Polarized Hepatic Cells: Constitutive Cycling between the Canalicular Membrane and rab11-positive EndosomesV⃞

    Wakabayashi, Yoshiyuki; Lippincott-Schwartz, Jennifer; Arias, Irwin M.


    The bile salt export pump (BSEP, ABCB11) couples ATP hydrolysis with transport of bile acids into the bile canaliculus of hepatocytes. Its localization in the apical canalicular membrane is physiologically regulated by the demand to secrete biliary components. To gain insight into how such localization is regulated, we studied the intracellular trafficking of BSEP tagged with yellow fluorescent protein (YFP) in polarized WIF-B9 cells. Confocal imaging revealed that BSEP-YFP was localized at t...

  15. Estrogen and Estrogen Receptor-α-Mediated Transrepression of Bile Salt Export Pump.

    Chen, Yuan; Vasilenko, Alex; Song, Xiulong; Valanejad, Leila; Verma, Ruchi; You, Sangmin; Yan, Bingfang; Shiffka, Stephanie; Hargreaves, Leeza; Nadolny, Christina; Deng, Ruitang


    Among diseases unique to pregnancy, intrahepatic cholestasis of pregnancy is the most prevalent disorder with elevated serum bile acid levels. We have previously shown that estrogen 17β-estradiol (E2) transrepresses bile salt export pump (BSEP) through an interaction between estrogen receptor (ER)-α and farnesoid X receptor (FXR) and transrepression of BSEP by E2/ERα is an etiological contributing factor to intrahepatic cholestasis of pregnancy. Currently the mechanistic insights into such transrepression are not fully understood. In this study, the dynamics of coregulator recruitment to BSEP promoter after FXR activation and E2 treatment were established with quantitative chromatin immunoprecipitation assays. Coactivator peroxisome proliferator-activated receptor-γ coactivator-1 was predominantly recruited to the BSEP promoter upon FXR activation, and its recruitment was decreased by E2 treatment. Meanwhile, recruitment of nuclear receptor corepressor was markedly increased upon E2 treatment. Functional evaluation of ERα and ERβ chimeras revealed that domains AC of ERα are the determinants for ERα-specific transrepression on BSEP. Further studies with various truncated ERα proteins identified the domains in ERα responsible for ligand-dependent and ligand-independent transrepression. Truncated ERα-AD exhibited potent ligand-independent transrepressive activity, whereas ERα-CF was fully capable of transrepressing BSEP ligand dependently in vitro in Huh 7 cells and in vivo in mice. Both ERα-AD and ERα-CF proteins were associated with FXR in the coimmunoprecipitation assays. In conclusion, E2 repressed BSEP expression through diminishing peroxisome proliferator-activated receptor-γ coactivator-1 recruitment with a concurrent increase in nuclear receptor corepressor recruitment to the BSEP promoter. Domains AD and CF in ERα mediated ligand-independent and ligand-dependent transrepression on BSEP, respectively, through interacting with FXR. PMID:25675114

  16. Effect of bile salts on the DNA and membrane integrity of enteric bacteria.

    Merritt, Megan E; Donaldson, Janet R


    Enteric bacteria are able to resist the high concentrations of bile encountered throughout the gastrointestinal tract. Here we review the current mechanisms identified in the enteric bacteria Salmonella, Escherichia coli, Bacillus cereus and Listeria monocytogenes to resist the dangerous effects of bile. We describe the role of membrane transport systems, and their connection with DNA repair pathways, in conferring bile resistance to these enterics. We discuss the findings from recent investigations that indicate bile tolerance is dependent upon being able to resist the detergent properties of bile at both the membrane and DNA level. PMID:19762477

  17. Upregulation of miRNA-143, -145, -192, and -194 in esophageal epithelial cells upon acidic bile salt stimulation.

    Bus, P; Siersema, P D; Verbeek, R E; van Baal, J W P M


    Barrett's esophagus (BE) is a metaplastic condition of the distal esophagus that occurs because of chronic gastroesophageal reflux. Previous studies have identified BE-specific microRNAs (miRNAs) in comparison with normal squamous epithelium (SQ). We hypothesized that BE-specific miRNAs could be induced in esophageal SQ cells by exposure to acid and/or bile salts. We aimed to determine whether BE-specific miRNAs are upregulated in an esophageal SQ cell line (Het-1A) in an environment with acid and/or bile salts and whether this is nuclear factor-κB (NF-κB) dependent. Acid and/or bile salt incubations were performed in Het-1A cells. Experiments were performed with or without inhibiting the NF-κB pathway. Quantitative reverse transcriptase polymerase chain reaction was performed to determine expression of miRNA-143, -145, -192, -194, cyclo-oxygenase-2 (COX2), mucin 2 (MUC2), and sex determining region Y-box 9. For validation, we determined levels of these miRNAs in biopsies from patients with reflux esophagitis and normal SQ. Significantly increased expression levels of miRNA-143 (2.7-fold), -145 (2.6-fold), -192 (2.0-fold), -194 (2.2-fold), COX2, MUC2, and sex determining region Y-box 9 were found upon acidic bile salt incubation, but not upon acid or bile salt alone. NF-κB pathway inhibition significantly decreased miRNA-143, -192, -194, COX2, and MUC2 expression. Additionally, miRNA-143, -145 and -194 expression was increased in reflux esophagitis biopsies compared with normal SQ, but no changes were found in miRNA-192 expression. Our findings suggest that upregulation of BE-specific miRNAs by acidic bile may be an early event in the transition of SQ to BE and that their expression is partly regulated by the NF-κB pathway. PMID:24006894

  18. Early Identification of Clinically Relevant Drug Interactions with the Human Bile Salt Export Pump (BSEP; ABCB11)

    Pedersen, Jenny M.; Matsson, Pär; Bergström, Christel A.S.; Hoogstraate, Janet; Norén, Agneta; LeCluyse, Edward L.; Artursson, Per


    A comprehensive analysis was performed to investigate how inhibition of the human bile salt export pump (BSEP/ABCB11) relates to clinically observed drug-induced liver injury (DILI). Inhibition of taurocholate (TA) transport was investigated in BSEP membrane vesicles for a data set of 250 compounds, and 86 BSEP inhibitors were identified. Structure-activity modeling identified BSEP inhibition to correlate strongly with compound lipophilicity, whereas positive molecular charge was associated w...

  19. Heterologous Overexpression and Mutagenesis of the Human Bile Salt Export Pump (ABCB11) Using DREAM (Directed REcombination-Assisted Mutagenesis)

    Jan Stindt; Philipp Ellinger; Claudia Stross; Verena Keitel; Dieter Häussinger; Smits, Sander H. J.; Ralf Kubitz; Lutz Schmitt


    Homologous recombination in Saccharomyces cerevisiae is a well-studied process. Here, we describe a yeast-recombination-based approach to construct and mutate plasmids containing the cDNA of the human bile salt export pump (BSEP) that has been shown to be unstable in E. coli. Using this approach, we constructed the necessary plasmids for a heterologous overexpression of BSEP in the yeast Pichia pastoris. We then applied a new site-directed mutagenesis method, DREAM (Directed REcombination-Ass...

  20. The Hypolipidemic Agent Guggulsterone Regulates the Expression of Human Bile Salt Export Pump: Dominance of Transactivation over Farsenoid X Receptor-Mediated Antagonism

    Deng, Ruitang; Yang, Dongfang; Radke, Amy; Yang, Jian; Yan, Bingfang


    Conversion of cholesterol to bile acids in the liver is initiated by the rate-limiting enzyme cholesterol 7α-hydroxylase (CYP7A1) and excretion of bile acids from the liver is mediated by the bile salt export pump (BSEP). The expression of CYP7A1 and BSEP is coordinately regulated by a negative feedback and positive feed-forward mechanism, respectively, through bile acid-mediated activation of farsenoid X receptor (FXR). It is well established that hypolipidemic agent guggulsterone is an FXR ...

  1. The shark bile salt 5 beta-scymnol abates acetaminophen toxicity, but not covalent binding.

    Slitt, Angela Lucas; Naylor, Lee; Hoivik, J; Manautou, Jose E; Macrides, Theo; Cohen, Steven D


    Acetaminophen (APAP) toxicity involves both arylative and oxidative mechanisms. The shark bile salt, 5 beta-scymnol (5beta-S), has been demonstrated to act as an antioxidant and free radical scavenger in vitro. To determine if 5beta-S protects against either APAP-induced hepatic or renal toxicity, 3-4-month-old male Swiss Laca mice were given APAP (500 mg/kg), and 5beta-S (100 mg/kg) was given at 0 and 2 h after APAP. Plasma SDH at 12 h after APAP alone was 1630 U/l and BUN was 19 mg/dl versus 20 U/l and 10 mg/dl, respectively, in controls. Either simultaneous or 2 h delayed treatment with 5beta-S significantly decreased the APAP-induced SDH increase while only the simultaneous pretreatment prevented the BUN elevation. 5beta-S alone did not increase liver glutathione content. Western analysis of APAP covalent binding using anti-APAP antibodies indicated the 5beta-S did not alter protein arylation either qualitatively or quantitatively. These results suggest that 5beta-S treatment did not impair APAP activation and are consistent with 5beta-S protection that likely results from its antioxidant activity. PMID:15363587

  2. Influence of Phosphatidylcholine and Calcium on Self-Association and Bile Salt Mixed Micellar Binding of the Natural Bile Pigment, Bilirubin Ditaurate.

    Neubrand, Michael W; Carey, Martin C; Laue, Thomas M


    Recently [Neubrand, M. W., et al. (2015) Biochemistry 54, 1542-1557], we determined a concentration-dependent monomer-dimer-tetramer equilibrium in aqueous bilirubin ditaurate (BDT) solutions and explored the nature of high-affinity binding of BDT monomers with monomers and micelles of the common taurine-conjugated bile salts (BS). We now investigate, employing complementary physicochemical methods, including fluorescence emission spectrophotometry and quasi-elastic light scattering spectroscopy, the influence of phosphatidylcholine (PC), the predominant phospholipid of bile and calcium, the major divalent biliary cation, on these self-interactions and heterointeractions. We have used short-chain, lyso and long-chain PC species as models and contrasted our results with those of parallel studies employing unconjugated bilirubin (UCB) as the fully charged dianion. Both bile pigments interacted with the zwitterionic headgroup of short-chain lecithins, forming water-soluble (BDT) and insoluble ion-pair complexes (UCB), respectively. Upon micelle formation, BDT monomers apparently remained at the headgroup mantle of short-chain PCs, but the ion pairs with UCB became internalized within the micelle's hydrophobic core. BDT interacted with the headgroups of unilamellar egg yolk (EY) PC vesicles; however, with the simultaneous addition of CaCl2, a reversible aggregation took place, but not vesicle fusion. With mixed EYPC/BS micelles, BDT became bound to the hydrophilic surface (as with simple BS micelles), and in turn, both BDT and BS bound calcium, but not other divalent cations. The calcium complexation of BDT and BS was enhanced strongly with increases in micellar EYPC, suggesting calcium-mediated cross-bridging of hydrophilic headgroups at the micelle's surface. Therefore, the physicochemical binding of BDT to BS in an artificial bile medium is influenced not only by BS species and concentration but also by long-chain PCs and calcium ions that exert a specific rather

  3. NF-E2- related factor 2 (Nrf2) is a positive regulator of human bile salt export pump (BSEP) expression*

    Weerachayaphorn, Jittima; Cai, Shi-Ying; Soroka, Carol J.; Boyer, James L.


    The bile salt export pump (BSEP, ABCB11) is the major determinant of bile salt dependent bile secretion and its deficiency leads to cholestatic liver injury. BSEP/Bsep gene expression is regulated by the nuclear farnesoid X receptor (FXR). However, BSEP expression is retained in the liver of the Fxr−/− mice although reduced, indicating that there may be additional transcriptional factors that regulate its expression. The NF-E2-related factor-2 (Nrf2) plays a major role in response to oxidativ...

  4. The mechanism of increased biliary lipid secretion in mice with genetic inactivation of bile salt export pump.

    Gooijert, K E R; Havinga, R; Wolters, H; Wang, R; Ling, V; Tazuma, S; Verkade, H J


    Human bile salt export pump (BSEP) mutations underlie progressive familial intrahepatic cholestasis type 2 (PFIC2). In the PFIC2 animal model, Bsep(-/-) mice, biliary secretion of bile salts (BS) is decreased, but that of phospholipids (PL) and cholesterol (CH) is increased. Under physiological conditions, the biliary secretion of PL and CH is positively related ("coupled") to that of BS. We aimed to elucidate the mechanism of increased biliary lipid secretion in Bsep(-/-) mice. The secretion of the BS tauro-β-muricholic acid (TβMCA) is relatively preserved in Bsep(-/-) mice. We infused Bsep(-/-) and Bsep(+/+) (control) mice with TβMCA in stepwise increasing dosages (150-600 nmol/min) and determined biliary bile flow, BS, PL, and CH secretion. mRNA and protein expression of relevant canalicular transporters was analyzed in livers from noninfused Bsep(-/-) and control mice. TβMCA infusion increased BS secretion in both Bsep(-/-) and control mice. The secreted PL or CH amount per BS, i.e., the "coupling," was continuously two- to threefold higher in Bsep(-/-) mice (P Bsep(-/-) mice (Abcg5; P Bsep(-/-) mice could be excluded. We conclude that the mechanism of increased biliary lipid secretion in Bsep(-/-) mice is based on increased expression of the responsible canalicular transporter proteins. PMID:25552583

  5. Bile salt-stimulated lipase plays an unexpected role in arthritis development in rodents.

    Susanne Lindquist

    Full Text Available OBJECTIVE: The present study aimed to explore the hypothesis that bile salt-stimulated lipase (BSSL, in addition to being a key enzyme in dietary fat digestion during early infancy, plays an important role in inflammation, notably arthritis. METHODS: Collagen-induced arthritis (CIA and pristane-induced arthritis (PIA in rodents are commonly used experimental models that reproduce many of the pathogenic mechanisms of human rheumatoid arthritis, i.e. increased cellular infiltration, synovial hyperplasia, pannus formation, and erosion of cartilage and bone in the distal joints. We used the CIA model to compare the response in BSSL wild type (BSSL-WT mice with BSSL-deficient 'knock-out' (BSSL-KO and BSSL-heterozygous (BSSL-HET littermates. We also investigated if intraperitoneal injection of BSSL-neutralizing antibodies affected the development or severity of CIA and PIA in mice and rats, respectively. RESULTS: In two consecutive studies, we found that BSSL-KO male mice, in contrast to BSSL-WT littermates, were significantly protected from developing arthritis. We also found that BSSL-HET mice were less prone to develop disease compared to BSSL-WT mice, but not as resistant as BSSL-KO mice, suggesting a gene-dose effect. Moreover, we found that BSSL-neutralizing antibody injection reduced both the incidence and severity of CIA and PIA in rodents. CONCLUSION: Our data strongly support BSSL as a key player in the inflammatory process, at least in rodents. It also suggests the possibility that BSSL-neutralizing agents could serve as a therapeutic model to reduce the inflammatory response in humans.

  6. Ion pairing with bile salts modulates intestinal permeability and contributes to food-drug interaction of BCS class III compound trospium chloride.

    Heinen, Christian A; Reuss, Stefan; Amidon, Gordon L; Langguth, Peter


    In the current study the involvement of ion pair formation between bile salts and trospium chloride (TC), a positively charged Biopharmaceutical Classification System (BCS) class III substance, showing a decrease in bioavailability upon coadministration with food (negative food effect) was investigated. Isothermal titration calorimetry provided evidence of a reaction between TC and bile acids. An effect of ion pair formation on the apparent partition coefficient (APC) was examined using (3)H-trospium. The addition of bovine bile and bile extract porcine led to a significant increase of the APC. In vitro permeability studies of trospium were performed across Caco-2-monolayers and excised segments of rat jejunum in a modified Ussing chamber. The addition of bile acids led to an increase of trospium permeation across Caco-2-monolayers and rat excised segments by approximately a factor of 1.5. The addition of glycochenodeoxycholate (GCDC) was less effective than taurodeoxycholate (TDOC). In the presence of an olive oil emulsion, a complete extinction of the permeation increasing effects of bile salts was observed. Thus, although there are more bile acids in the intestine in the fed state compared to the fasted state, these are not able to form ion pairs with trospium in fed state, because they are involved in the emulsification of dietary fats. In conclusion, the formation of ion pairs between trospium and bile acids can partially explain its negative food effect. Our results are presumably transferable to other organic cations showing a negative food effect. PMID:23750707

  7. Rapid diagnosis of Zellweger syndrome and infantile Refsum's disease by fast atom bombardment-mass spectrometry of urine bile salts

    A method is described for the rapid determination of urinary bile salt profiles by fast atom bombardment-mass spectrometry (FAB-MS). Negative ion FAB spectra could be obtained from the equivalent of 10 μl of urine loaded onto the target probe with glycerol as matrix. In samples from infants and children with cholestasis the major peaks were produced by the taurine and glycine conjugates of di-, tri- and tetrahydroxycholanoic acids. In samples from patients with Zellweger syndrome and infantile Refsum's disease, a unique ion at m/z 572 indicated the presence of taurine-conjugated tetrahydroxycholestanoic acid(s). Capillary gas chromatography-mass spectrometry (GC-MS) of the bile acids liberated by alkaline hydrolysis indicated the presence of at least two nuclear-tetrahydroxylated cholestanoic acids, probably the 6α- and 1β-hydroxylated derivatives of 3α, 7α, 12α-trihydroxy-5β-cholestan-26-oic acid. (Auth.)

  8. In vitro model systems to investigate bile salt export pump (BSEP) activity and drug interactions: A review.

    Cheng, Yaofeng; Woolf, Thomas F; Gan, Jinping; He, Kan


    The bile salt export pump protein (BSEP), expressed on the canalicular membranes of hepatocytes, is primarily responsible for the biliary excretion of bile salts. The inhibition of BSEP transport activity can lead to an increase in intracellular bile salt levels and liver injury. This review discusses the various in vitro assays currently available for assessing the effect of drugs or other chemical entities to modulate BSEP transport activity. BSEP transporter assays use one of the following platforms: Xenopus laevis oocytes; canalicular membrane vesicles (CMV); BSEP-expressed membrane vesicles; cell lines expressing BSEP; sandwich cultured hepatocytes (SCH); and hepatocytes in suspension. Two of these, BSEP-expressed insect membrane vesicles and sandwich cultured hepatocytes, are the most commonly used assays. BSEP membrane vesicles prepared from transfected insect cells are useful for assessing BSEP inhibition or substrate specificity and exploring mechanisms of BSEP-associated genetic diseases. This model can be applied in a high-throughput format for discovery-drug screening. However, experimental results from use of membrane vesicles may lack physiological relevance and the model does not allow for investigation of in situ metabolism in modulation of BSEP activity. Hepatocyte-based assays that use the SCH format provide results that are generally more physiologically relevant than membrane assays. The SCH model is useful in detailed studies of the biliary excretion of drugs and BSEP inhibition, but due to the complexity of SCH preparation, this model is used primarily for determining biliary clearance and BSEP inhibition in a limited number of compounds. The newly developed hepatocyte in suspension assay avoids many of the complexities of the SCH method. The use of pooled cryopreserved hepatocytes in suspension minimizes genetic variance and individual differences in BSEP activity and also provides the opportunity for higher throughput screening and cross

  9. Photoactive bile salts with critical micellar concentration in the micromolar range.

    Gomez-Mendoza, Miguel; Marin, M Luisa; Miranda, Miguel A


    The aggregation behavior of bile salts is strongly dependent on the number of hydroxyl groups. Thus, cholic acid (CA), with three hydroxyls, starts forming aggregates at 15 mM, while deoxycholic, chenodeoxycholic or ursodeoxycholic acids, with two hydroxyls, start aggregating at 5-10 mM; for lithocholic acid, with only one hydroxyl group, aggregation is observed at lower concentration (2-3 mM). Here, the singular self-assembling properties of dansyl and naproxen derivatives of CA (3β-Dns-CA and 3β-NPX-CA, respectively) have been demonstrated on the basis of their photoactive properties. Thus, the emission spectra of 3β-Dns-CA registered at increasing concentrations (25-140 μM) showed a remarkable non-linear enhancement in the emission intensity accompanied by a hypsochromic shift of the maximum and up to a three-fold increase in the singlet lifetime. The inflection point at around 50-70 μM pointed to the formation of unprecedented assemblies at such low concentrations. In the case of 3β-NPX-CA, when the NPX relative triplet lifetime was plotted against concentration, a marked increase (up to two-fold) was observed at 40-70 μM, indicating the formation of new 3β-NPX-CA assemblies at ca. 50 μM. Additional evidence supporting the formation of new 3β-Dns-CA or 3β-NPX-CA assemblies at 40-70 μM was obtained from singlet excited state quenching experiments using iodide. Moreover, to address the potential formation of hybrid assemblies, 1 : 1 mixtures of 3β-Dns-CA and 3β-NPX-CA (2-60 μM, total concentration) were subjected to steady-state fluorescence experiments, and their behavior was compared to that of the pure photoactive derivatives. A lower increase in the emission was observed for 3β-NPX-CA in the mixture, while a huge increase was experienced by 3β-Dns-CA in the same concentration range (up to 60 μM total). A partial intermolecular energy transfer from NPX to Dns, consistent with their reported singlet energies, was revealed, pointing to the

  10. Complexation of tauro- and glyco-conjugated bile salts with alpha-cyclodextrin and hydroxypropyl-alpha-cyclodextrin studied by affinity capillary electrophoresis and molecular modelling

    Holm, Rene; Schönbeck, Jens Christian Sidney; Askjær, Sune; Jensen, Henrik; Westh, Peter; Østergaard, Jesper


    The interaction of the bile salts taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate present in man, dog, and rat with α-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin was investigated by mobility shift affinity capillary electrop......The interaction of the bile salts taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate present in man, dog, and rat with α-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin was investigated by mobility shift affinity capillary...... electrophoresis. The cyclodextrins are applied as excipients for solubilisation of drug substances with poor aqueous solubility. Accurate determination of stability constants is challenging for weak analyte–ligand interactions such as the conjugated bile salt α-cyclodextrin interactions. A new approach for...

  11. The Association between Bile Salt Export Pump Single-Nucleotide Polymorphisms and Primary Biliary Cirrhosis Susceptibility and Ursodeoxycholic Acid Response

    Rui-rui Chen


    Full Text Available Background. Primary biliary cirrhosis (PBC is a chronic and progressive cholestasis liver disease. Bile salt export pump (BSEP is the predominant bile salt efflux system of hepatocytes. BSEP gene has been attached great importance in the susceptibility of PBC and the response rate of ursodeoxycholic acid (UDCA treatment of PBC patients. Methods. In this study, TaqMan assay was used to genotype four variants of BSEP, and the Barcelona criteria were used for evaluating the response rate of UDCA treatment. Results. Variant A allele of BSEP rs473351 (dominant model, OR = 2.063; 95% CI, 1.254–3.393; P=0.004 was highly associated with PBC susceptibility. On the contrary, variant A allele of BSEP rs2287618 (dominant model, OR = 0.617; 95% CI, 0.411–0.928; P=0.020 provided a protective role and Barcelona evaluation criterion indicated that the frequency of variant allele at BSEP rs2287618 was significantly decreased in UDCA-responsive PBC patients (P=0.021. Conclusion. These results suggested that BSEP rs473351 was closely associated with the susceptibility of PBC and if people with BSEP rs2287618 were diagnosed as PBC, the UDCA treatment was not satisfactory. Larger studies with mixed ethnicity subjects and stratified by clinical and subclinical characteristics are needed to validate our findings.

  12. Transcription of the Human Microsomal Epoxide Hydrolase Gene (EPHX1 Is Regulated by PARP-1 and Histone H1.2. Association with Sodium-Dependent Bile Acid Transport.

    Hui Peng

    Full Text Available Microsomal epoxide hydrolase (mEH is a bifunctional protein that plays a central role in the metabolism of numerous xenobiotics as well as mediating the sodium-dependent transport of bile acids into hepatocytes. These compounds are involved in cholesterol homeostasis, lipid digestion, excretion of xenobiotics and the regulation of several nuclear receptors and signaling transduction pathways. Previous studies have demonstrated the critical role of GATA-4, a C/EBPα-NF/Y complex and an HNF-4α/CAR/RXR/PSF complex in the transcriptional regulation of the mEH gene (EPHX1. Studies also identified heterozygous mutations in human EPHX1 that resulted in a 95% decrease in mEH expression levels which was associated with a decrease in bile acid transport and severe hypercholanemia. In the present investigation we demonstrate that EPHX1 transcription is significantly inhibited by two heterozygous mutations observed in the Old Order Amish population that present numerous hypercholanemic subjects in the absence of liver damage suggesting a defect in bile acid transport into the hepatocyte. The identity of the regulatory proteins binding to these sites, established using biotinylated oligonucleotides in conjunction with mass spectrometry was shown to be poly(ADP-ribosepolymerase-1 (PARP-1 bound to the EPHX1 proximal promoter and a linker histone complex, H1.2/Aly, bound to a regulatory intron 1 site. These sites exhibited 71% homology and may represent potential nucleosome positioning domains. The high frequency of the H1.2 site polymorphism in the Amish population results in a potential genetic predisposition to hypercholanemia and in conjunction with our previous studies, further supports the critical role of mEH in mediating bile acid transport into hepatocytes.

  13. Bile Salts Modulate the Mucin-Activated Type VI Secretion System of Pandemic Vibrio cholerae.

    Verena Bachmann

    Full Text Available The causative agent of cholera, Vibrio cholerae, regulates its diverse virulence factors to thrive in the human small intestine and environmental reservoirs. Among this pathogen's arsenal of virulence factors is the tightly regulated type VI secretion system (T6SS. This system acts as an inverted bacteriophage to inject toxins into competing bacteria and eukaryotic phagocytes. V. cholerae strains responsible for the current 7th pandemic activate their T6SS within the host. We established that T6SS-mediated competition occurs upon T6SS activation in the infant mouse, and that this system is functional under anaerobic conditions. When investigating the intestinal host factors mucins (a glycoprotein component of mucus and bile for potential regulatory roles in controlling the T6SS, we discovered that once mucins activate the T6SS, bile acids can further modulate T6SS activity. Microbiota modify bile acids to inhibit T6SS-mediated killing of commensal bacteria. This interplay is a novel interaction between commensal bacteria, host factors, and the V. cholerae T6SS, showing an active host role in infection.

  14. Comparison of the effects of feeding Indian fish liver oils supplemented with or without cholesterol and bile salts on certain enzymes in liver, heart and serum of rats

    Tanksale K


    Full Text Available The enzymes viz. glucose-6-P-dehydrogenase (EC, cholesterol esterase (EC, aspartate amino transferase (EC and alanine amino transferase ( are intimately related to lipid metabolism. Hence their activities are bound to be affected by the type of dietary fat and substances like bile salts and cholesterol which also influence the lipid metabolism. This relationship between dietary lipid constituent and enzymes was studied in albino rats maintained on diets containing three Indian Shark Liver Oils viz. Waghbeer, Khada mushi and Pisori supple-mented with or without cholesterol and bile salts, Enzyme activities were studied in liver, heart and serum. It was noted that higher unsaturation of dietary fat increased the activity of glucose-6-P-dehydrogenase enzyme while activities of transaminases and chole-sterol esterase were lowered. Addition of cholesterol and bile salts to these diets decreased the activity of glucose-6-P-dehydrogenase and hydrolytic activity of cholesterol esterase. There was increase in the activities of transaminases and esterifying activity of choles-terol esterase due to supplementation with cholesterol and bile salts.

  15. Conjugated primary bile salts reduce permeability of endotoxin through intestinal epithelial cells and synergize with phosphatidylcholine in suppression of inflammatory cytokine production

    Parlesak, Alexandr; Schaeckeler, S.; Moser, L.;


    OBJECTIVE: Endotoxemia was shown to be integral in the pathophysiology of obstructive jaundice. In the current study, the role of conjugated primary bile salts (CPBS) and phosphatidylcholine on the permeability of endotoxin through a layer of intestinal epithelial cells and the consequent...

  16. Conjugated primary bile salts reduce permeability of endotoxin through bacteria-stimulated intestinal epithelial cells and synergize with lecithin in suppression of inflammatory cytokine production

    Parlesak, Alexandr; Schaeckeler, Simone; Moser, Lydia;


    Objective: Endotoxemia was shown to be integral in the pathophysiology of obstructive jaundice. In the current study, the role of conjugated primary bile salts (CPBS) and phosphatidylcholine on the permeability of endotoxin through a layer of intestinal epithelial cells and the consequent activat...

  17. Heterologous overexpression and mutagenesis of the human bile salt export pump (ABCB11 using DREAM (Directed REcombination-Assisted Mutagenesis.

    Jan Stindt

    Full Text Available Homologous recombination in Saccharomyces cerevisiae is a well-studied process. Here, we describe a yeast-recombination-based approach to construct and mutate plasmids containing the cDNA of the human bile salt export pump (BSEP that has been shown to be unstable in E. coli. Using this approach, we constructed the necessary plasmids for a heterologous overexpression of BSEP in the yeast Pichia pastoris. We then applied a new site-directed mutagenesis method, DREAM (Directed REcombination-Assisted Mutagenesis that completely bypasses E. coli by using S. cerevisiae as the plasmid host with high mutagenesis efficiency. Finally, we show how to apply this strategy to unstable non-yeast plasmids by rapidly turning an existing mammalian BSEP expression construct into a S. cerevisiae-compatible plasmid and analyzing the impact of a BSEP mutation in several mammalian cell lines.

  18. Hypolipidemic agent Z-guggulsterone: metabolism interplays with induction of carboxylesterase and bile salt export pump

    Yang, Dongfang; Yang, Jian; Shi, Deshi; Xiao, Da; Chen, Yi-Tzai; Black, Chris; Deng, Ruitang; Yan, Bingfang


    Z-Guggulsterone is a major ingredient in the Indian traditional hypolipidemic remedy guggul. A study in mice has established that its hypolipidemic effect involves the farnesoid X receptor (FXR), presumably by acting as an antagonist of this receptor. It is generally assumed that the antagonism leads to induction of cytochrome P450 7A1 (CYP7A1), the rate-limiting enzyme converting free cholesterol to bile acids. In this study, we tested whether Z-guggulsterone indeed induces human CYP7A1. In ...

  19. Exon-skipping and mRNA decay in human liver tissue: molecular consequences of pathogenic bile salt export pump mutations

    Carola Dröge; Heiner Schaal; Guido Engelmann; Daniel Wenning; Dieter Häussinger; Ralf Kubitz


    The bile salt export pump BSEP mediates bile formation. Over 150 BSEP mutations are associated with progressive familial intrahepatic cholestasis type 2 (PFIC-2), with few characterised specifically. We examined liver tissues from two PFIC-2 patients compound heterozygous for the splice-site mutation c.150 + 3A > C and either c.2783_2787dup5 resulting in a frameshift with a premature termination codon (child 1) or p.R832C (child 2). Splicing was analysed with a minigene system and mRNA sequen...

  20. Technical Pitfalls and Improvements for High-speed Screening and QSAR Analysis to Predict Inhibitors of the Human Bile Salt Export Pump (ABCB11/BSEP)

    Saito, Hikaru; Osumi, Masako; Hirano, Hiroyuki; Shin, Wangsoo; Nakamura, Ryota; Ishikawa, Toshihisa


    Drug-induced hepatotoxicity is one of the major problems encountered in drug discovery and development. Selection of a candidate compound for pre-clinical studies in the drug discovery process is a critical step that can determine the speed and expenditure of clinical development. Because inhibition of human adenosine triphosphate-binding cassette transporter ABCB11 (SPGP/bile salt export pump) has severe consequences, which include intrahepatic cholestasis and hepatotoxicity, resulting from ...

  1. Enhanced oral bioavailability of silymarin using liposomes containing a bile salt: preparation by supercritical fluid technology and evaluation in vitro and in vivo

    Yang G


    Full Text Available Gang Yang,1 Yaping Zhao,2 Yongtai Zhang,1 Beilei Dang,1 Ying Liu,1 Nianping Feng11School of Pharmacy, Shanghai University of Traditional Chinese Medicine, 2School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, People’s Republic of ChinaAbstract: The aim of this investigation was to develop a procedure to improve the dissolution and bioavailability of silymarin (SM by using bile salt-containing liposomes that were prepared by supercritical fluid technology (ie, solution-enhanced dispersion by supercritical fluids [SEDS]. The process for the preparation of SM-loaded liposomes containing a bile salt (SM-Lip-SEDS was optimized using a central composite design of response surface methodology with the ratio of SM to phospholipids (w/w, flow rate of solution (mL/min, and pressure (MPa as independent variables. Particle size, entrapment efficiency (EE, and drug loading (DL were dependent variables for optimization of the process and formulation variables. The particle size, zeta potential, EE, and DL of the optimized SM-Lip-SEDS were 160.5 nm, -62.3 mV, 91.4%, and 4.73%, respectively. Two other methods to produce SM liposomes were compared to the SEDS method. The liposomes obtained by the SEDS method exhibited the highest EE and DL, smallest particle size, and best stability compared to liposomes produced by the thin-film dispersion and reversed-phase evaporation methods. Compared to the SM powder, SM-Lip-SEDS showed increased in vitro drug release. The in vivo AUC0-t of SM-Lip-SEDS was 4.8-fold higher than that of the SM powder. These results illustrate that liposomes containing a bile salt can be used to enhance the oral bioavailability of SM and that supercritical fluid technology is suitable for the preparation of liposomes.Keywords: silymarin, solution-enhanced dispersion by supercritical fluids, liposomes, bile salt, bioavailability

  2. Toward Predicting Drug-Induced Liver Injury: Parallel Computational Approaches to Identify Multidrug Resistance Protein 4 and Bile Salt Export Pump Inhibitors

    Welch, Matthew A.; Köck, Kathleen; Urban, Thomas J.; Brouwer, Kim L.R.; Swaan, Peter W.


    Drug-induced liver injury (DILI) is an important cause of drug toxicity. Inhibition of multidrug resistance protein 4 (MRP4), in addition to bile salt export pump (BSEP), might be a risk factor for the development of cholestatic DILI. Recently, we demonstrated that inhibition of MRP4, in addition to BSEP, may be a risk factor for the development of cholestatic DILI. Here, we aimed to develop computational models to delineate molecular features underlying MRP4 and BSEP inhibition. Models were ...

  3. The complete digestion of human milk triacylglycerol in vitro requires gastric lipase, pancreatic colipase-dependent lipase, and bile salt-stimulated lipase.

    Bernbäck, S; Bläckberg, L; Hernell, O


    Gastric lipase, pancreatic colipase-dependent lipase, and bile salt-stimulated lipase all have potential roles in digestion of human milk triacylglycerol. To reveal the function of each lipase, an in vitro study was carried out with purified lipases and cofactors, and with human milk as substrate. Conditions were chosen to resemble those of the physiologic environment in the gastrointestinal tract of breast-fed infants. Gastric lipase was unique in its ability to initiate hydrolysis of milk t...

  4. Bile salts-containing vesicles: promising pharmaceutical carriers for oral delivery of poorly water-soluble drugs and peptide/protein-based therapeutics or vaccines.

    Aburahma, Mona Hassan


    Most of the new drugs, biological therapeutics (proteins/peptides) and vaccines have poor performance after oral administration due to poor solubility or degradation in the gastrointestinal tract (GIT). Though, vesicular carriers exemplified by liposomes or niosomes can protect the entrapped agent to a certain extent from degradation. Nevertheless, the harsh GIT environment exemplified by low pH, presence of bile salts and enzymes limits their capabilities by destabilizing them. In response to that, more resistant bile salts-containing vesicles (BS-vesicles) were developed by inclusion of bile salts into lipid bilayers constructs. The effectiveness of orally administrated BS-vesicles in improving the performance of vesicles has been demonstrated in researches. Yet, these attempts did not gain considerable attention. This is the first review that provides a comprehensive overview of utilizing BS-vesicles as a promising pharmaceutical carrier with a special focus on their successful applications in oral delivery of therapeutic macromolecules and vaccines. Insights on the possible mechanisms by which BS-vesicles improve the oral bioavailability of the encapsulated drug or immunological response of entrapped vaccine are explained. In addition, methods adopted to prepare and characterize BS-vesicles are described. Finally, the gap in the scientific researches tackling BS-vesicles that needs to be addressed is highlighted. PMID:25390191

  5. Determination of thermodynamic potentials and the aggregation number for micelles with the mass-action model by isothermal titration calorimetry: A case study on bile salts.

    Olesen, Niels Erik; Westh, Peter; Holm, René


    The aggregation number (n), thermodynamic potentials (ΔG, ΔH, ΔS) and critical micelle concentration (CMC) for 6 natural bile salts were determined on the basis of both original and previously published isothermal titration calorimetry (ITC) data. Different procedures to estimate parameters of micelles with ITC were compared to a mass-action model (MAM) of reaction type: n⋅S⇌Mn. This analysis can provide guidelines for future ITC studies of systems behaving in accordance with this model such as micelles and proteins that undergo self-association to oligomers. Micelles with small aggregation numbers, as those of bile salts, are interesting because such small aggregates cannot be characterized as a separate macroscopic phase and the widely applied pseudo-phase model (PPM) is inaccurate. In the present work it was demonstrated that the aggregation number of micelles was constant at low concentrations enabling determination of the thermodynamic potentials by the MAM. A correlation between the aggregation number and the heat capacity was found, which implies that the dehydrated surface area of bile salts increases with the aggregation number. This is in accordance with Tanford's principles of opposing forces where neighbouring molecules in the aggregate are better able to shield from the surrounding hydrophilic environment when the aggregation number increases. PMID:25978555

  6.  Bile salt export pump deficiency disease: two novel, late onset, ABCB11 mutations identified by next generation sequencing.

    Vitale, Giovanni; Pirillo, Martina; Mantovani, Vilma; Marasco, Elena; Aquilano, Adelia; Gamal, Nesrine; Francalanci, Paola; Conti, Fabio; Andreone, Pietro


     Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomal recessive cholestatic diseases of childhood and represents the main indication for liver transplantation at this age; PFIC2 involves ABCB11 gene, that encodes the ATPdependent canalicular bile salt export pump (BSEP). Benign intrahepatic cholestasis (BRIC) identifies a group of diseases involving the same genes and characterized by intermittent attacks of cholestasis with no progression to liver cirrhosis. Diagnosis with standard sequencing techniques is expensive and available only at a few tertiary centers. We report the application of next generation sequencing (NGS) in the diagnosis of the familial intrahepatic cholestasis with a parallel sequencing of three causative genes. We identified the molecular defects in ABCB11 gene in two different probands who developed a severe cholestatic disease of unknown origin. In the first patient a compound heterozygosity for the novel frameshift mutation p.Ser1100GlnfsX38 and the missense variant p.Glu135Lys was detected. In the second patient, triggered by contraceptive therapy, we identified homozygosity for a novel missense variant p.Ala523Gly. In conclusion, these mutations seem to have a late onset and a less aggressive clinical impact, acting as an intermediate form between BRIC and PFIC. PMID:27493120

  7. Hydrophilic bile salt ursodeoxycholic acid protects myocardium against reperfusion injury in a PI3K/Akt dependent pathway.

    Rajesh, Katare Gopalrao; Suzuki, Ryoko; Maeda, Hironori; Yamamoto, Murio; Yutong, Xing; Sasaguri, Shiro


    The opening of mitochondrial permeability transition pore (PTP) during reperfusion injury of heart has been well demonstrated and thus controlling PTP would attenuate the myocardial damage and cell death. Ursodeoxycholic acid (UDCA) is a hydrophilic bile salt and has been shown to prevent apoptosis in hepatocytes by inhibiting the opening of PTP. Here we demonstrate the role of UDCA in preventing the reperfusion injury of heart through its ability to inhibit PTP. Wistar rats underwent 30 min left coronary artery occlusion (LCA) followed by 180 min reperfusion after treatment with 40 mg/kg per iv infusion of UDCA over 30 min before LCA occlusion. Other groups of rats were treated with PTP agonist atractyloside(5 mg/kg) or PI3 kinase inhibitor wortmannin (16 ug/kg) before UDCA treatment. UDCA treatment prior to LCA occlusion, activated phosphorylation of Akt and Bad. Phosphorylating Bad prevented its translocation in to mitochondria, there by preventing the down regulation of Bcl-2 expression and PTP opening. This was confirmed by reduced cytochrome C release from intramitochondrial space in to the cytosol and hence reduced cell death either by apoptosis (4.8 vs 11.8%, Pinjury by inhibiting the PTP in a PI3K/Akt dependent pathway. PMID:16171810

  8. Downregulation of p63 upon exposure to bile salts and acid in normal and cancer esophageal cells in culture.

    Roman, Sabine; Pétré, Aurélia; Thépot, Amélie; Hautefeuille, Agnès; Scoazec, Jean-Yves; Mion, François; Hainaut, Pierre


    p63 is a member of the p53 protein family that regulates differentiation and morphogenesis in epithelial tissues and is required for the formation of squamous epithelia. Barrett's mucosa is a glandular metaplasia of the squamous epithelium that develops in the lower esophagus in the context of chronic, gastroesophageal reflux and is considered as a precursor for adenocarcinoma. Normal or squamous cancer esophageal cells were exposed to deoxycholic acid (DCA, 50, 100, or 200 microM) and chenodeoxycholic and taurochenodeoxycholic acid at pH 5. p63 and cyclooxygenase-2 (COX-2) expressions were studied by Western blot and RT-PCR. DCA exposure at pH 5 led to a spectacular decrease in the levels of all isoforms of the p63 proteins. This decrease was observed within minutes of exposure, with a synergistic effect between DCA and acid. Within the same time frame, levels of p63 mRNA were relatively unaffected, whereas levels of COX-2, a marker of stress responses often induced in Barrett's mucosa, were increased. Similar results were obtained with chenodeoxycholic acid but not its taurine conjugate at pH 5. Proteasome inhibition by lactacystin or MG-132 partially blocked the decrease in p63, suggesting a posttranslational degradation mechanism. These results show that combined exposure to bile salt and acid downregulates a critical regulator of squamous differentiation, providing a mechanism to explain the replacement of squamous epithelium by a glandular metaplasia upon exposure of the lower esophagus to gastric reflux. PMID:17615180

  9. Niosomal carriers enhance oral bioavailability of carvedilol: effects of bile salt-enriched vesicles and carrier surface charge 

    Arzani G


    Full Text Available Gelareh Arzani,1 Azadeh Haeri,1 Marjan Daeihamed,1 Hamid Bakhtiari-Kaboutaraki,1 Simin Dadashzadeh1,2 1Department of Pharmaceutics, Faculty of Pharmacy, 2Pharmaceutical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Abstract: Carvedilol (CRV is an antihypertensive drug with both alpha and beta receptor blocking activity used to preclude angina and cardiac arrhythmias. To overcome the low, variable oral bioavailability of CRV, niosomal formulations were prepared and characterized: plain niosomes (without bile salts, bile salt-enriched niosomes (bilosomes containing various percentages of sodium cholate or sodium taurocholate, and charged niosomes (negative, containing dicetyl phosphate and positive, containing hexadecyl trimethyl ammonium bromide. All formulations were characterized in terms of encapsulation efficiency, size, zeta potential, release profile, stability, and morphology. Various formulations were administered orally to ten groups of Wistar rats (n=6 per group. The plasma levels of CRV were measured by a validated high-performance liquid chromatography (HPLC method and pharmacokinetic properties of different formulations were characterized. Contribution of lymphatic transport to the oral bioavailability of niosomes was also investigated using a chylomicron flow-blocking approach. Of the bile salt-enriched vesicles examined, bilosomes containing 20% sodium cholate (F2 and 30% sodium taurocholate (F5 appeared to give the greatest enhancement of intestinal absorption. The relative bioavailability of F2 and F5 formulations to the suspension was estimated to be 1.84 and 1.64, respectively. With regard to charged niosomes, the peak plasma concentrations (Cmax of CRV for positively (F7 and negatively charged formulations (F10 were approximately 2.3- and 1.7-fold higher than after a suspension. Bioavailability studies also revealed a significant increase in extent of drug absorption from charged

  10. Modification of the bile salts-Irgasan-brilliant green agar for enumeration of Aeromonas species from food.

    Neyts, K; Notebaert, E; Uyttendaele, M; Debevere, J


    The present study evaluated the productivity of BIBG medium for the isolation of Aeromonas spp. from food and describes a modification of the BIBG medium (mBIBG) (increased pH (8.7), replacement of xylose by soluble starch as a carbon source, decreased concentration of bile salts) to increase its selectivity and electivity. Using the mBIBG medium, growth of the majority of the Enterobacteriaceae (9/10) was suppressed except for Citrobacter freundii. The mBIBG medium supported growth of Pseudomonas species but a clear distinction between Aeromonas and Pseudomonas colonies could be made. Interpretation of the mBIBG medium should be performed after 24 h of incubation. It was noted that three of the 27 Aeromonas strains tested did not develop on the mBIBG medium. The ability or inability to grow on a selective medium is strain-dependent. Enumeration of Aeromonas species (A. hydrophila LMG 3771, A. caviae LMG 3775, A. veronii biovar veronii LMG 9075, A. veronii biovar sobria LMG 13071) from artificially contaminated foods (shrimp, minced meat (beef/pork), precut leek, and shredded carrots) confirmed that the mBIBG medium is suitable for quantitative recovery of aeromonads (ca. 10(2)-10(7) cfu/g) in the presence of a high background flora (10(5)-10(6) cfu/g). Screening of naturally contaminated foods (vegetables, seafood, meat) for the presence of Aeromonas resulted in three out of 14 food samples showing presumptive Aeromonas colonies on mBIBG. PMID:10868682

  11. Enhanced oral bioavailability of silymarin using liposomes containing a bile salt: preparation by supercritical fluid technology and evaluation in vitro and in vivo.

    Yang, Gang; Zhao, Yaping; Zhang, Yongtai; Dang, Beilei; Liu, Ying; Feng, Nianping


    The aim of this investigation was to develop a procedure to improve the dissolution and bioavailability of silymarin (SM) by using bile salt-containing liposomes that were prepared by supercritical fluid technology (ie, solution-enhanced dispersion by supercritical fluids [SEDS]). The process for the preparation of SM-loaded liposomes containing a bile salt (SM-Lip-SEDS) was optimized using a central composite design of response surface methodology with the ratio of SM to phospholipids (w/w), flow rate of solution (mL/min), and pressure (MPa) as independent variables. Particle size, entrapment efficiency (EE), and drug loading (DL) were dependent variables for optimization of the process and formulation variables. The particle size, zeta potential, EE, and DL of the optimized SM-Lip-SEDS were 160.5 nm, -62.3 mV, 91.4%, and 4.73%, respectively. Two other methods to produce SM liposomes were compared to the SEDS method. The liposomes obtained by the SEDS method exhibited the highest EE and DL, smallest particle size, and best stability compared to liposomes produced by the thin-film dispersion and reversed-phase evaporation methods. Compared to the SM powder, SM-Lip-SEDS showed increased in vitro drug release. The in vivo AUC(0-t) of SM-Lip-SEDS was 4.8-fold higher than that of the SM powder. These results illustrate that liposomes containing a bile salt can be used to enhance the oral bioavailability of SM and that supercritical fluid technology is suitable for the preparation of liposomes. PMID:26543366

  12. Role of polymorphic bile salt export pump (BSEP, ABCB11) transporters in anti-tuberculosis drug-induced liver injury in a Chinese cohort

    Ru Chen; Jing Wang; Shaowen Tang; Yuan Zhang; Xiaozhen Lv; Shanshan Wu; Zhirong Yang; Yinyin Xia; Dafang Chen; Siyan Zhan


    Evidence indicates that the polymorphisms in bile salt export pump (BSEP, encoded by ABCB11) may play an important role in the development of anti-tuberculosis drug-induced liver injury (ATDILI) and we aim to investigate the association between genetic variants of ABCB11 and the risk of ATDILI in a Chinese cohort. A total of 89 tuberculosis patients with ATDILI and 356 matched ATDILI -free patients constituted cases and controls. Genetic polymorphisms of ABCB11 were determined by TaqMan singl...

  13. Self-assembly of aqueous bilirubin ditaurate, a natural conjugated bile pigment, to contraposing enantiomeric dimers and M(-) and P(+) tetramers and their selective hydrophilic disaggregation by monomers and micelles of bile salts.

    Neubrand, Michael W; Carey, Martin C; Laue, Thomas M


    The solution behavior of bilirubin ditaurate (BDT), the first naturally occurring conjugated bile pigment to be physically and chemically characterized, was assessed in aqueous solution and in monomeric and micellar solutions of common taurine-conjugated bile salts (BS). Analytical ultracentrifugation revealed that BDT self-associates in monomer-dimer equilibria between 1 and 500 μM, forming limiting tetramers at low millimolar concentrations. Self-association was enthalpically driven with ΔG values of ≈5 kcal/mol, suggesting strong hydrophobic interactions. Added NaCl and decreases in temperature shifted the oligomerization to lower BDT concentrations. On the basis of circular dichroism spectra and the limiting size of the self-aggregates, we infer that the tetramers are composed of 2P(+) and 2M(-) enantiomeric BDT pairs in "ridge-tile" conformations interacting in a "double-bookend" structure. With added monomeric BS, blue shifts in the UV-vis spectra and tight isosbestic points revealed that BDT/BS heterodimers form, followed by BDT "decorating" BS micelles mostly via hydrophilic interactions. Conformational enantiomerism, fluorescence intensities, and anisotropy, as well as resistance of the hybrid particles to disaggregation in 6 M urea, suggested that two or three hydrogen-bonding sites bound BDT monomers to the hydroxyl groups of BS, possibly via pyrrole-π-orbital-OH interactions. BDT stabilized these interactions by enveloping the BS in its "ridge-tile" pincers with variable strain that maximized van der Waals interactions. Possibly because the BDT molecule becomes highly strained with BS subtending a 7β-hydroxyl group, BDT became totally resistant to oxidation in air. This work predicts that, because of BS dissolution of the BDT self-aggregates, BS/bilirubin hybrid particles, which are stabilized hydrophilically, are likely to be the dominant mode of transport for all conjugated bilirubins in bile. PMID:25671490

  14. Bile acid transporters in health and disease

    Kosters, Astrid; Karpen, Saul J


    In recent years the discovery of a number of major transporter proteins expressed in the liver and intestine specifically involved in bile acid transport has led to improved understanding of bile acid homeostasis and the enterohepatic circulation. Na+-dependent bile acid uptake from portal blood into the liver is mediated primarily by the Na+ taurocholate co-transporting polypeptide (NTCP), while secretion across the canalicular membrane into bile is carried out by the Bile salt export pump (...

  15. Investigations of the enterohepatic bile salt circulation using the 14C-glycol cholate/14CO2 exhalation test in persons with Billroth-II stomach resection

    A 14C-glycol cholate/14CO2 exhalation test was carried out in 34 normal persons, 32 persons with a Billroth-II resection stomach, and 9 patients with a Billroth-II resection stomach and gastroenterological disorders. Persons with a normal stomach function after B-II resection and an objective lack of symptoms of a gastroenterological disease had normal test results in all cases. In 7 of the 9 B-II resected patients with various disorders or diseases of the intestinal tract of the liver gallbladder on pancreas, 14CO2 exhalation was pathologically increased. In agreement with the hypothesis that deconjugation of bile salts can only be caused by bacterial enzymes, a pathological finding can be explained by a pathological bacteria population in the upper intestinal tract or by a loss of bile salts. However, the clinical importance of pathological test results remains doubtful as 3 out of the 7 patients with pathological results presented with no clinical symptoms. (orig.)




    Full Text Available Processed soybean products especially the fermented ones have beneficial health effects since they are capable of reducing the level of plasmacholesterol (hypocholesterolemic effect. One of the mechanisms is by increasing the binding of bile salt. This research was aimed to assess the ability of soymilk, fermented soymilk products and fermented soymilk products combined with enzymatic hydrolysis to bind bile salts. The stability of the binding against hydrolysis by digestive enzymes (pepsin and pancreatin was also evaluated. Fermented soybean products inoculated with isolates of L. plantarum 1 R.11.1.2 was be able to bind 1.40 μmol/100 mg protein (62.26% of natrium taurocholate. This binding ability is slightly higher than that of soymilk to natrium taurocholate, i.e.1.33 μmol/100 mg protein (59.04%. Addition of a protease enzyme specific to hydrophobic amino acid (thermolysin on fermented soymilk products was able to enhance the ability of bind natrium taurocholate. Enzymatic hydrolysis products having a molecular weight of <7 kDa could bind 1.51 μmol/100 mg protein natrium taurocholate (67.4%. There was a significant increase in the binding, i.e. 7.9% by the fermented products or an increase of 13.5% from soymilk. Meanwhile peptides measuring ≥7 kDa showed no binding ability against natrium taurocholate.


    Lilis Nuraida1,2*


    Full Text Available Hypercholesterolemia is a risk factor for cardiovascular disease, the leading cause of death in many countries. Several studies have shown that reduction of excessive levels of cholesterol in the blood decreases the risk of cardiovascular disease. It is therefore important to develop ways of reducing serum cholesterol. Based on in vitro and in vivo studies, some of lactic acid bacteria (LAB having potential probiotic properties can reduce total cholesterol and low-density lipoprotein cholesterol levels. The aim of this study was to evaluate the ability of LAB isolated from breast milk in reducing cholesterol by assimilation and by bile salt deconjugation activity in vitro.Thirteen strains of LABs were evaluated for their acid and bile salt resistance and selected to test their ability to assimilate cholesterol and to deconjugate bile salt (natrium taurocholate in vitro. Cholesterol assimilation activity was determined by measuring the difference between the remaining cholesterol in broth medium inoculated with LAB with cholesterol in control after incubation. Bile salt deconjugation activity was determined by measuring free cholic acid released in broth medium after incubation with LAB. The results shows that most of the isolates was susceptible to low pH and all isolates used were able to survive in the presence of 0.5% bile salt. The LAB were also able to assimilate cholesterol at varying levels ranging from 0.86-14.97 µg/ml, with the highest activity showed by Pediococcus pentosaceus 1-A38, Pediococcus pentosaceus 2-B2 and Pediococcus pentosaceus 2-A16. Taurocholate deconjugation assay showed that the isolates have weak bile salts deconjugation activity as indicated by free cholic acid released ranging from 0.06-0.25 µmol/ml, with the highest release in Pediococcus pentosaceus 1-A38 and Pediococcus pentosaceus 1-A22. The present study suggest that Pediococcus pentosaceus 1-A38 was potential for the development of probiotic products with

  18. Exon-skipping and mRNA decay in human liver tissue: molecular consequences of pathogenic bile salt export pump mutations.

    Dröge, Carola; Schaal, Heiner; Engelmann, Guido; Wenning, Daniel; Häussinger, Dieter; Kubitz, Ralf


    The bile salt export pump BSEP mediates bile formation. Over 150 BSEP mutations are associated with progressive familial intrahepatic cholestasis type 2 (PFIC-2), with few characterised specifically. We examined liver tissues from two PFIC-2 patients compound heterozygous for the splice-site mutation c.150 + 3A > C and either c.2783_2787dup5 resulting in a frameshift with a premature termination codon (child 1) or p.R832C (child 2). Splicing was analysed with a minigene system and mRNA sequencing from patients' livers. Protein expression was shown by immunofluorescence. Using the minigene, c.150 + 3A > C causes complete skipping of exon 3. In liver tissue of child 1, c.2783_2787dup5 was found on DNA but not on mRNA level, implying nonsense-mediated mRNA decay (NMD) when c.2783_2787dup5 is present. Still, BSEP protein as well as mRNA with and without exon 3 were detectable and can be assigned to the c.150 + 3A > C allele. Correctly spliced transcripts despite c.150 + 3A > C were also confirmed in liver of child 2. In conclusion, we provide evidence (1) for effective NMD due to a BSEP frameshift mutation and (2) partial exon-skipping due to c.150 + 3A > C. The results illustrate that the extent of exon-skipping depends on the genomic and cellular context and that regulation of splicing may have therapeutic potential. PMID:27114171

  19. Selenium- or tellurium- containing bile acids and derivatives thereof

    This invention relates to the preparation of selenium and tellurium derivatives, particularly γ-emitting radioactive derivatives of bile acids and bile salts. Such compounds are valuable in the examination of body function, especially small bowel function. (author)

  20. Role of polymorphic bile salt export pump (BSEP, ABCB11) transporters in anti-tuberculosis drug-induced liver injury in a Chinese cohort.

    Chen, Ru; Wang, Jing; Tang, Shaowen; Zhang, Yuan; Lv, Xiaozhen; Wu, Shanshan; Yang, Zhirong; Xia, Yinyin; Chen, Dafang; Zhan, Siyan


    Evidence indicates that the polymorphisms in bile salt export pump (BSEP, encoded by ABCB11) may play an important role in the development of anti-tuberculosis drug-induced liver injury (ATDILI) and we aim to investigate the association between genetic variants of ABCB11 and the risk of ATDILI in a Chinese cohort. A total of 89 tuberculosis patients with ATDILI and 356 matched ATDILI -free patients constituted cases and controls. Genetic polymorphisms of ABCB11 were determined by TaqMan single-nucleotide polymorphism (SNP) genotyping assay. Odds ratio (OR) with 95% confidence intervals (CIs) was estimated by conditional logistic regression model. There were no significant differences in genotype frequencies of ABCB11 between cases and controls. In the subgroup analysis, polymorphisms of rs2287616 were found to be associated with cholestatic/mixed pattern of liver injury under dominant and addictive model (OR = 3.84, 95% CI:1.16-12.75, P = 0.028 and OR = 2.51, 95% CI:1.12-5.62, P = 0.025, respectively), however the significance disappeared after Bonferroni correction. This study suggested that genetic variants of ABCB11 gene might contribute to anti-tuberculosis drug-induced cholestatic liver injury in Chinese patients. Studies in larger, varied populations are required to confirm these findings. PMID:27293027

  1. Thermal stabilization of bicelles by a bile-salt-derived detergent: a combined ³¹P and ²H nuclear magnetic resonance study.

    Morales, Hannah Hazel; Saleem, Qasim; Macdonald, Peter M


    The properties of bicelles composed of mixtures of long-chain lipids dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylglycerol (DMPG), stabilized by zwitterionic bile salt analogue 3-[(3-cholamidopropyl)dimethyl-d6-ammonio]-2-hydroxy-1-propanesulfonate (CHAPSO-d6), deuterated at both amino methyls, were investigated by a combination of (31)P and (2)H NMR, focusing on the behavior of CHAPSO as a function of temperature. For compositions of molar ratio q = [DMPC + DMPG]/[CHAPSO] = 3, R = [DMPG]/[DMPC + DMPG] = 0, 0.01 and 0.10 and lipid concentration CL = 25 wt % lipid at temperatures of between 30 and 60 °C, magnetic alignment was readily achieved as assessed via both (31)P NMR of the phospholipids and (2)H NMR of CHAPSO-d6. Increasing temperature yielded higher values for the chemical shift anisotropy of the former and the quadrupole splitting of the latter, consistent with the progressive migration of CHAPSO from edge regions into planar regions of the bicellar assemblies. However, relative to dihexadecyl phosphatidylcholine (DHPC), CHAPSO exhibited lower miscibility with DMPC, although the presence of DMPG enhanced this miscibility. At 65 °C, thermal instability became evident in the appearance of a separate isotropic component in both (31)P and (2)H NMR spectra. This isotropic phase was CHAPSO-enriched but less so as a function of increasing DMPG. These findings indicate that the enhanced thermal stability of CHAPSO- versus DHPC-containing bicelles arises from a combination of the larger surface area that edge CHAPSO is able to mask, mole for mole, and its relative preference for edge regions, plus, possibly, specific interactions with DMPG. PMID:25426518

  2. Toward predicting drug-induced liver injury: parallel computational approaches to identify multidrug resistance protein 4 and bile salt export pump inhibitors.

    Welch, Matthew A; Köck, Kathleen; Urban, Thomas J; Brouwer, Kim L R; Swaan, Peter W


    Drug-induced liver injury (DILI) is an important cause of drug toxicity. Inhibition of multidrug resistance protein 4 (MRP4), in addition to bile salt export pump (BSEP), might be a risk factor for the development of cholestatic DILI. Recently, we demonstrated that inhibition of MRP4, in addition to BSEP, may be a risk factor for the development of cholestatic DILI. Here, we aimed to develop computational models to delineate molecular features underlying MRP4 and BSEP inhibition. Models were developed using 257 BSEP and 86 MRP4 inhibitors and noninhibitors in the training set. Models were externally validated and used to predict the affinity of compounds toward BSEP and MRP4 in the DrugBank database. Compounds with a score above the median fingerprint threshold were considered to have significant inhibitory effects on MRP4 and BSEP. Common feature pharmacophore models were developed for MRP4 and BSEP with LigandScout software using a training set of nine well characterized MRP4 inhibitors and nine potent BSEP inhibitors. Bayesian models for BSEP and MRP4 inhibition/noninhibition were developed with cross-validated receiver operator curve values greater than 0.8 for the test sets, indicating robust models with acceptable false positive and false negative prediction rates. Both MRP4 and BSEP inhibitor pharmacophore models were characterized by hydrophobic and hydrogen-bond acceptor features, albeit in distinct spatial arrangements. Similar molecular features between MRP4 and BSEP inhibitors may partially explain why various drugs have affinity for both transporters. The Bayesian (BSEP, MRP4) and pharmacophore (MRP4, BSEP) models demonstrated significant classification accuracy and predictability. PMID:25735837

  3. Identification of the bile salt binding site on ipad from Shigella flexneri and the influence of ligand binding on IpaD structure

    Barta, Michael L.; Guragain, Manita; Adam, Philip; Dickenson, Nicholas E.; Patil, Mrinalini; Geisbrecht, Brian V.; Picking, Wendy L.; Picking, William D. (UMKC); (OKLU)


    Type III secretion (TTS) is an essential virulence factor for Shigella flexneri, the causative agent of shigellosis. The Shigella TTS apparatus (TTSA) is an elegant nano-machine that is composed of a basal body, an external needle to deliver effectors into human cells, and a needle tip complex that controls secretion activation. IpaD is at the tip of the nascent TTSA needle where it controls the first step of TTS activation. The bile salt deoxycholate (DOC) binds to IpaD to induce recruitment of the translocator protein IpaB into the maturing tip complex. We recently used spectroscopic analyses to show that IpaD undergoes a structural rearrangement that accompanies binding to DOC. Here, we report a crystal structure of IpaD with DOC bound and test the importance of the residues that make up the DOC binding pocket on IpaD function. IpaD binds DOC at the interface between helices {alpha}3 and {alpha}7, with concomitant movement in the orientation of helix {alpha}7 relative to its position in unbound IpaD. When the IpaD residues involved in DOC binding are mutated, some are found to lead to altered invasion and secretion phenotypes. These findings suggest that adoption of a DOC-bound structural state for IpaD primes the Shigella TTSA for contact with host cells. The data presented here and in the studies leading up to this work provide the foundation for developing a model of the first step in Shigella TTS activation.

  4. Bile resistance mechanisms in Lactobacillus and Bifidobacterium.

    Ruiz, Lorena; Margolles, Abelardo; Sánchez, Borja


    Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Most of the probiotic bacteria currently available in the market belong to the genera Lactobacillus and Bifidobacterium, and specific health-promoting activities, such as treatment of diarrhea or amelioration of gastrointestinal discomfort, have been attributed to them. In order to be able to survive the gastrointestinal transit and transiently colonize our gut, these bacteria must be able to counteract the deleterious action of bile salts, which are the main components of bile. Bile salts are detergent-like biological substances synthesized in the liver from cholesterol. Host enzymes conjugate the newly synthesized free bile acids in the liver with the amino acids glycine or taurine, generating conjugated bile salts. These compounds are stored in the gall bladder and they are released into the duodenum during digestion to perform their physiological function, which is the solubilization of fat coming from diet. These bile salts possess strong antimicrobial activity, since they are able to disorganize the structure of the cell membrane, as well as trigger DNA damage. This means that bacteria inhabiting our intestinal tract must have intrinsic resistance mechanisms to cope with bile salts. To do that, Lactobacillus and Bifidobacterium display a variety of proteins devoted to the efflux of bile salts or protons, to modify sugar metabolism or to prevent protein misfolding. In this manuscript, we review and discuss specific bile resistance mechanisms, as well as the processes responsible for the adaptation of bifidobacteria and lactobacilli to bile. PMID:24399996

  5. Bile resistance mechanisms in Lactobacillus and Bifidobacterium

    Lorena eRuiz


    Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Most of the probiotic bacteria currently available in the market belong to the genera Lactobacillus and Bifidobacterium, and specific health-promoting activities, such as treatment of diarrhea or amelioration of gastrointestinal discomfort, have been attributed to them. In order to be able to survive the gastrointestinal transit and transiently colonise our gut, these bacteria must be able to counteract the deleterious action of bile salts, which are the main components of bile. Bile salts are detergent-like biological substances synthesised in the liver from cholesterol. Host enzymes conjugate the newly synthesised free bile acids in the liver with the amino acids glycine or taurine, generating conjugated bile salts. These compounds are stored in the gall bladder and they are released into the duodenum during digestion to perform their physiological function, which is the solubilisation of fat coming from diet. These bile salts possess strong antimicrobial activity, since they are able to disorganize the structure of the cell membrane, as well as trigger DNA damage. This means that bacteria inhabiting our intestinal tract must have intrinsic resistance mechanisms to cope with bile salts. To do that, Lactobacillus and Bifidobacterium display a variety of proteins devoted to the efflux of bile salts or protons, to modify sugar metabolism or to prevent protein misfolding. In this manuscript, we review and discuss specific bile resistance mechanisms, as well as the processes responsible for the adaptation of bifidobacteria and lactobacilli to bile.

  6. Study on the ability of bile salt-binding among different tea extracts in vitro%不同茶浸提液对胆酸盐的结合及其降血脂机理的研究

    胡凯; 黄惠华


    The binding capacity of the extracts from green tea,Oolong tea,Puer tea,dark tea and black tea to bile salts were compared as well as the correlation between tea polyphenol and the bile salts binding capability in vitro under the conditions of the simulated human digestive environment.The results showed that the rate of bile salts-binding was fast and there was a significant correlation between the bile salts binding capacity and tea polyphenol content.Relative to cholestyrammine,green tea extract showed the 38.4% binding capacity for sodium taurocholate,46.5% for glycocholate and 42.0% for sodium cholate,exhibiting the maximum binding capability,followed by the semi-fermented(e.g.Oolong tea)and fully fermented teas(e.g.Puer tea,black tea and dark tea).%在体外模拟人体消化环境,研究绿茶浸提液对胆酸盐的等温吸附性质,比较不同茶浸提液对胆酸盐的结合能力,同时探讨了茶多酚含量与茶浸提液结合胆酸盐的相关关系。结果表明,茶浸提液对胆酸盐结合速度较快,Freundilich等温式、Langmiur等温式均能良好地反映绿茶浸提液对胆酸盐的结合;绿茶浸提液结合胆酸盐的能力最强,其结合牛磺胆酸钠、甘氨胆酸钠、胆酸钠的量分别是考来烯胺的38.4%、46.5%和42.0%;其次是半发酵茶(铁观音,35.2%、41.7%和42.6%)、发酵茶(普洱茶、滇红茶和六堡茶)。不同茶浸

  7. Determination of stability constants of tauro- and glyco-conjugated bile salts with the negatively charged sulfobutylether-β-cyclodextrin: comparison of affinity capillary electrophoresis and isothermal titration calorimetry and thermodynamic analysis of the interaction

    Holm, René; Østergaard, Jesper; Schönbeck, Jens Christian Sidney;


    -complexed drugs upon oral administration. This makes a good understanding of this particular interaction important for rational drug formulation. SBEβCD is a modified CD, which has attracted particular interest in formulation science. It is unique in the sense that it carries approximately seven negatively...... charged side chains, which can potentially interact electrostatically with the guest molecule. Bile salts are negatively charged at physiological pH, and the concomitant repulsion from SBEβCD could potentially reduce their affinity for this CD and hence their ability to expel drugs delivered as SBEβ...

  8. Denatured globular protein and bile salt-coated nanoparticles for poorly water-soluble drugs: Penetration across the intestinal epithelial barrier into the circulation system and enhanced oral bioavailability.

    He, Wei; Yang, Ke; Fan, Lifang; Lv, Yaqi; Jin, Zhu; Zhu, Shumin; Qin, Chao; Wang, Yiao; Yin, Lifang


    Oral drug delivery is the most preferred route for patients; however, the low solubility of drugs and the resultant poor absorption compromise the benefits of oral administration. On the other hand, for years, the overwhelmingly accepted mechanism for enhanced oral absorption using lipid nanocarriers was based on the process of lipid digestion and drug solubilization in the small intestine. Few reports indicated that other bypass pathways are involved in drug absorption in the gastrointestinal tract (GIT) for oral delivery of nanocarriers. Herein, we report a new nanoemulsion system with a denatured globular protein with a diameter of 30 nm, soybean protein isolates (SPI), and bile salt as emulsifiers, aiming to enhance the absorption of insoluble drugs and explore other pathways for absorption. A BCS class II drug, fenofibrate (FB), was used as the model drug. The SPI and bile salt-coated Ns with a diameter of approximately 150 nm were prepared via a high-pressure homogenizing procedure. Interestingly, the present Ns could be converted to solid dosage form using fluid-bed coating technology, maintaining a nanoscale size. Most importantly, in a model of in situ rat intestinal perfusion, Ns could penetrate across the intestinal epithelial barrier into the systemic circulation and then obtain biodistribution into other tissues. In addition, Ns significantly improved FB oral absorption, exhibited as a greater than 2- and 2.5-fold increase in Cmax and AUC0-t, respectively, compared to the suspension formulation. Overall, the present Ns are promising nanocarriers for the oral delivery of insoluble drugs, and the penetration of intact Ns across the GIT barrier into systemic circulation may be a new strategy for improved drug absorption with the use of nanocarriers. PMID:26325310

  9. Valpromide inhibits human epoxide hydrolase.

    Pacifici, G. M.; Franchi, M; Bencini, C; Rane, A


    The effect of antipileptic drug valpromide (VPM) on the activity of epoxide hydrolase was studied in human adult and foetal liver, kidneys, lungs, intestine and in placenta. The activity of the epoxide hydrolase was measured with both styrene oxide and benzo(a)pyrene-4,5-oxide as substrates. VPM inhibited the epoxide hydrolase obtained from all organs studied. The degree of inhibition was independent of the substrate used. A lowering of the epoxide hydrolase activity by 50% was observed when ...

  10. Novel, major 2α- and 2β-hydroxy bile alcohols and bile acids in the bile of Arapaima gigas, a large South American river fish.

    Sato née Okihara, Rika; Saito, Tetsuya; Ogata, Hiroaki; Nakane, Naoya; Namegawa, Kazunari; Sekiguchi, Shoutaro; Omura, Kaoru; Kurabuchi, Satoshi; Mitamura, Kuniko; Ikegawa, Shigeo; Raines, Jan; Hagey, Lee R; Hofmann, Alan F; Iida, Takashi


    Bile alcohols and bile acids from gallbladder bile of the Arapaima gigas, a large South American freshwater fish, were isolated by reversed-phase high-performance liquid chromatography. The structures of the major isolated compounds were determined by electrospray-tandem mass spectrometry and nuclear magnetic resonance using (1)H- and (13)C-NMR spectra. The novel bile salts identified were six variants of 2-hydroxy bile acids and bile alcohols in the 5α- and 5β-series, with 29% of all compounds having hydroxylation at C-2. Three C27 bile alcohols were present (as ester sulfates): (24ξ,25ξ)-5α-cholestan-2α,3α,7α,12α,24,26-hexol; (25ξ)-5β-cholestan-2β,3α,7α,12α,26,27-hexol, and (25ξ)-5α-cholestan-2α,3α,7α,12α,26,27-hexol. A single C27 bile acid was identified: (25ξ)-2α,3α,7α,12α-tetrahydroxy-5α-cholestan-26-oic acid, present as its taurine conjugate. Two novel C24 bile acids were identified: the 2α-hydroxy derivative of allochenodeoxycholic acid and the 2β-hydroxy derivative of cholic acid, both occurring as taurine conjugates. These studies extend previous work in establishing the natural occurrence of novel 2α- and 2β-hydroxy-C24 and C27 bile acids as well as C27 bile alcohols in both the normal (5β) as well as the (5α) "allo" A/B-ring juncture. The bile salt profile of A. gigas appears to be unique among vertebrates. PMID:26768415

  11. Bacterial bile metabolising gene abundance in Crohn's, ulcerative colitis and type 2 diabetes metagenomes.

    Alain Labbé

    Full Text Available We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh, 7 alpha-dehydroxylase gene (adh and 7-alpha hydroxysteroid dehydrogenase gene (hsdh in fecal bacteria in diseased populations of Crohn's disease (CD, Ulcerative Colitis (UC and Type 2 diabetes mellitus (T2DM. Phylum level abundance analysis showed a significant reduction in Firmicute-derived bsh in UC and T2DM patients but not in CD patients, relative to healthy controls. Reduction of adh and hsdh genes was also seen in UC and T2DM patients, while an increase was observed in the CD population as compared to healthy controls. A further analysis of the bsh genes showed significant differences in the correlations of certain Firmicutes families with disease or healthy populations. From this observation we proceeded to analyse BSH protein sequences and identified BSH proteins clusters representing the most abundant strains in our analysis of Firmicute bsh genes. The abundance of the bsh genes corresponding to one of these protein clusters was significantly reduced in all disease states relative to healthy controls. This cluster includes bsh genes derived from Lachospiraceae, Clostridiaceae, Erysipelotrichaceae and Ruminococcaceae families. This metagenomic analysis provides evidence of the importance of bile acid modifying enzymes in health and disease. It further highlights the importance of identifying gene and protein clusters, as the same gene may be associated with health or disease, depending on the strains expressing the enzyme, and differences in the enzymes themselves.

  12. Different pathways of canalicular secretion of sulfated and non-sulfated fluorescent bile acids : a study in isolated hepatocyte couplets and TR- rats

    Mills, CO; Milkiewicz, P; Muller, M; Roma, MG; Havinga, R; Coleman, R; Kuipers, F; Jansen, PLM; Elias, E


    Background/Aims: Fluorescent bile acids have proved useful for characterizing bile salt transport mechanisms, The aim of this study was to further validate the use of lysyl-fluorescein conjugated bile acid analogues as surrogate bile acids, Methods: We analyzed biliary excretion kinetics of cholyl l

  13. Early bile duct cancer

    Jae Myung Cha; Myung-Hwan Kim; Se Jin Jang


    Bile duct cancers are frequently diagnosed as advanced diseases. Over half of patients with advanced bile duct cancer present with unresectable malignancies and their prognosis has been very poor even after curative resections. Although there has been a need to diagnose bile duct cancer at its early stage, it has been a difficult goal to achieve due to our lack of knowledge regarding this disease entity. Early bile duct cancer may be defined as a carcinoma whose invasion is confined within the fibromuscular layer of the extrahepatic bile duct or intrahepatic large bile duct without distant metastasis irrespective of lymph node involvement. Approximately 3%-10% of resected bile duct cancers have been reported to be early cancers in the literature. The clinicopathological features of patients with early bile duct cancer differ from those of patients with advanced bile duct cancer, with more frequent asymptomatic presentation, characteristic histopathological findings,and excellent prognosis. This manuscript is organized to emphasize the need for convening an international consensus to develop the concept of early bile duct cancer.

  14. 茶花水溶性蛋白的分离纯化及其体外吸附胆酸盐能力的研究%In vitro Binding of Bile Salts by Water-soluble Protein Extract from Tea Flower

    邓雪; 黄惠华


    通过采用硫酸铵盐析法、DEAE-Sepharose Fast Flow离子交换层析法提取分离制备茶花水溶性蛋白,并通过磷酸盐缓冲液pH值的最佳选择改善分离提纯效果.同时在体外模拟人体消化环境,通过体外吸附胆酸盐能力的测定证实所提取分离得到的茶花水溶性蛋白具有一定的降血脂功能.结果发现:当磷酸盐缓冲溶液pH值为5.0于室温下洗脱的效果最好,得到的3个主要分离组分中峰Ⅲ的体外吸附胆酸盐能力最佳,其对胆酸钠,甘氨胆酸钠,牛磺胆酸钠的吸附量分别为0.78±0.02、0.64±0.00、1.60±0.02 μmol/mL.%Water-soluble protein was extracted from tea flower by salting out with ammonium sulfate and purified by DEAE-Sepharose Fast Flow chromatography. Optimal conditions for the salting out and DEAE-Sepharose Fast Flow chromatographic separation of water-soluble proteins were determined. The results of experiments on bile salt adsorption in vitro demonstrated that the obtained water-soluble protein extract had hypolipidemic effect. Besides, the best elution results of water-soluble proteins on DEAE-Sepharose Fast Flow column were achieved at pH 5.0 and 10 mmol/L phosphate buffer as eluent at room temperature. Peak III exhibited the best bile salt adsorption ability among three separation peaks obtained than peak II and I. The bile salt-binding capability of the three bile salts was 0.78±0.02, 0.6440.00, 1.60±0.02 mmol/mL, respectively.

  15. Bile acid sequestrants

    Hansen, Morten; Sonne, David P; Knop, Filip K


    Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid and...... glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption of the...... enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose...

  16. Painful Bile Extraction Methods


    It was only in the past 20 years that countries in Asia began to search for an alternative to protect moon bears from being killed for their bile and other body parts. In the early 1980s, a new method of extracting bile from living bears was developed in North Korea. In 1983, Chinese scientists imported this technique from North Korea. According to the Animals Asia Foundation, the most original method of bile extraction is to embed a latex catheter, a narrow rubber

  17. Bile acids are nutrient signaling hormones.

    Zhou, Huiping; Hylemon, Phillip B


    Bile salts play crucial roles in allowing the gastrointestinal system to digest, transport and metabolize nutrients. They function as nutrient signaling hormones by activating specific nuclear receptors (FXR, PXR, Vitamin D) and G-protein coupled receptors [TGR5, sphingosine-1 phosphate receptor 2 (S1PR2), muscarinic receptors]. Bile acids and insulin appear to collaborate in regulating the metabolism of nutrients in the liver. They both activate the AKT and ERK1/2 signaling pathways. Bile acid induction of the FXR-α target gene, small heterodimer partner (SHP), is highly dependent on the activation PKCζ, a branch of the insulin signaling pathway. SHP is an important regulator of glucose and lipid metabolism in the liver. One might hypothesize that chronic low grade inflammation which is associated with insulin resistance, may inhibit bile acid signaling and disrupt lipid metabolism. The disruption of these signaling pathways may increase the risk of fatty liver and non-alcoholic fatty liver disease (NAFLD). Finally, conjugated bile acids appear to promote cholangiocarcinoma growth via the activation of S1PR2. PMID:24819989

  18. Regulation of hepatic bile acid transporters Ntcp and Bsep expression

    Cheng, Xingguo; Buckley, David; Klaassen, Curtis D.


    Sodium-taurocholate cotransporting polypeptide (Ntcp) and bile salt export pump (Bsep) are two key transporters for hepatic bile acid uptake and excretion. Alterations in Ntcp and Bsep expression have been reported in pathophysiological conditions. In the present study, the effects of age, gender, and various chemicals on the regulation of these two transporters were characterized in mice. Ntcp and Bsep mRNA levels in mouse liver were low in the fetus, but increased to its highest expression ...

  19. Use of Cassette Dosing in Sandwich-Cultured Rat and Human Hepatocytes to Identify Drugs that Inhibit Bile Acid Transport

    Kristina K Wolf; Vora, Sapana; Webster, Lindsey O.; Generaux, Grant T.; Polli, Joseph W; Brouwer, Kim L.R.


    Hepatocellular accumulation of bile acids due to inhibition of the canalicular bile salt export pump (BSEP/ABCB11) is one proposed mechanism of drug-induced liver injury (DILI). Some hepatotoxic compounds also are potent inhibitors of bile acid uptake by Na+-dependent taurocholate cotransporting polypeptide (NTCP/SLC10A1). This study used a cassette dosing approach in rat and human sandwich-cultured hepatocytes (SCH) to determine whether known or suspected hepatotoxic drugs inhibit bile acid ...

  20. Combination Lopinavir and Ritonavir Alter Exogenous and Endogenous Bile Acid Disposition in Sandwich-Cultured Rat Hepatocytes

    Griffin, LaToya M.; Watkins, Paul B.; Perry, Cassandra H.; Robert L St Claire; Brouwer, Kim L.R.


    Inhibition of the bile salt export pump (BSEP) can cause intracellular accumulation of bile acids and is a risk factor for drug-induced liver injury in humans. Antiretroviral protease inhibitors lopinavir (LPV) and ritonavir (RTV) are reported BSEP inhibitors. However, the consequences of LPV and RTV, alone and combined (LPV/r), on hepatocyte viability, bile acid transport, and endogenous bile acid disposition in rat hepatocytes have not been examined. The effect of LPV, RTV, and LPV/r on cel...

  1. Verification of Thiosulfate-Citrate-Bile Salts-Sucrose (TCBS)Agar Medium Industrial Standard%硫代硫酸盐-柠檬酸盐-胆盐-蔗糖琼脂培养基行业标准验证

    孙楠; 黄杰; 于婷; 孙彬裕; 高尚先; 曲守方


    Objective To verify the application of professional standard for Thiosulfate-Citrate-Bile Salts-Sucrose (TCBS)agar medium.Methods TCBS agar medium produced by different factories are obtained for pH value and microbiological grow test according to the formulated medium standard.pH value and solution of medium are determined and bacterial cultures of the control strains are inoculated in the medium to detected bacterial growth.Results pH value and solution of medium were within the specified range. The control strains grew well. Conclusion As the recommended industrial standard, TCBS agar medium standard may be applied to evaluate and supervise the TCBS agar medium quality in our country.%目的:按照修订的硫代硫酸盐-柠檬酸盐-胆盐-蔗糖(TCBS)琼脂培养基行业标准中的要求进行试验,验证该行业标准的适用性。方法取不同厂家生产的TCBS琼脂培养基,根据TCBS琼脂培养基行业标准的要求,进行pH值、水分的测定和微生物生长试验。测定了TCBS琼脂培养基的pH值和水分,并将质控菌株的培养物接种到受试的培养基平皿中进行微生物生长试验。结果TCBS琼脂培养基的pH值和水分均符合行业标准的规定,且各质控菌株生长良好。结论作为推荐性的国家行业标准,TCBS琼脂培养基行业标准可以用于我国该培养基的质量评价和监管工作的需要。

  2. Radixin定点突变过表达对HepG2细胞膜转运蛋白Bsep的影响%Effect of radixin phosphorylation on bile salt export pump expression on HepG2 cell membrane

    封欣婵; 柴进; 程英; 陈文生


    目的 构建pcDNA3.1-RDX定点突变真核过表达质粒,研究其在胆汁淤积时对HepG2细胞膜转运蛋白胆盐输出泵(bile salt export pump,Bsep)定位表达的影响.方法 从含有RDX野生型质粒中,利用PCR方法钓取RDX野生型基因片段并以野生型为基础进行定点突变,PCR扩增后转入pcDNA3.1载体,其产物转化DH-5α感受态细胞.对长出的单克隆进行菌落PCR鉴定,再对PCR鉴定阳性的克隆进行测序和比对分析,比对正确即为构建成功的目的质粒.将目的质粒转染HepG2细胞,经G418筛选构建稳转细胞株.提取各株细胞的总蛋白,检测磷酸化RDX是否影响HepG2细胞膜上转运蛋白Bsep的表达.结果 PCR和测序结果均证实pcDNA3.1-RDX WT、pcDNA3.1-RDX T564D、pcDNA3.1-RDXT564A过表达载体构建成功.蛋白免疫印迹表明,与转染pcDNA-3.1-RDX-WT的HepG2相比,转染pcDNA-3.1-T564D的HepG2的Bsep膜蛋白表达量显著增加(P<0.05),而转染pcDNA-3.1-T564A的HepG2的Bsep膜蛋白表达量有所下降(P>0.05).结论 成功构建了pcDNA3.1-RDX WT、pcDNA3.1-RDX T564D、pcDNA3.1-RDX T564A过表达载体,并证实RDX的磷酸化能增强HepG2细胞膜上Bsep的表达.

  3. Detection of hepatitis in children with idiopathic cholestatic bile salt export pump gene mutations%特发性胆汁淤积性肝炎患儿胆盐输出泵基因突变的检测

    高国鹏; 王琳琳; 唐清; 单庆文; 云翔; 董淳强


    目的 对特发性胆汁淤积性肝炎患儿的胆盐输出泵(BSEP)基因进行突变筛查.方法 特发性胆汁淤积性肝炎患儿90例,采用聚合酶链反应—单链构象多态性(PCR-SSCP)检查结合DNA测序技术,检测BSEP基因的第7、8、11、12、14、15、18、21、26号外显子的突变情况.针对发现的突变位点,在71例健康婴儿中进行筛查以排除基因多态性.结果 在2例患儿BSEP基因的第7外显子上检测到相同的杂合突变c.499G >T,导致基因编码的BSEP蛋白的第167位丙氨酸(Ala)被丝氨酸(Ser)所替代(p.A167S).该位点的突变未在71例健康婴儿中发现,排除了BSEP基因的多态性.结论 在特发性胆汁淤积性肝炎患儿中,发现一种新的BSEP基因突变,位点为c.499G> T.%Objective To evaluate bile salt export pump gene ( BSEP) mutation in children with cholestasis in idio-pathic infantile hepatitis. Methods 90 cases of cholestasis in idiopathic infantile hepatitis (case group) were studied by polymerase chain reaction-single strand conformation polymorphism ( PCR - SSCP) and DNA sequencing technology to detect BSEP gene mutation in exon7, 8, 11, 12, 14, 15, 18, 21, 26 in idiopathic infantile hepatitis. 71 cases of healthy babies without infantile hepatitis (control group) by DNA sequencing technology to exclude gene polymorphism. Results Exon 7 of BSEP gene in two cases was found the same heterozygous mutation c. 499G > T, and BSEP protein lead to the gene encoding the 167 alanine (Ala) , serine ( Ser) replaced (p. A167S). The sites of mutation is not found in 71 cases of healthy infants, excluding the BSEP gene polymorphism. Conclusion A new BSEP gene mutation is found in children with idiopathic infantile cholestatic hepatitis, sites for the c.499G > T.

  4. Bile culture (image)

    ... tract. A specimen of bile is placed in culture media and observed for growth of microorganisms. If there ... no infection. If there is growth in the culture media, the growth is then isolated and identified to ...

  5. Polyglycine hydrolases secreted by pathogenic fungi

    Pathogens are known to produce proteases that target host defense proteins. Here we describe polyglycine hydrolases, fungal proteases that selectively cleave glycine-glycine peptide bonds within the polyglycine interdomain linker of targeted plant defense chitinases. Polyglycine hydrolases were puri...

  6. Advances in understanding of bile acid diarrhea.

    Camilleri, Michael


    Bile acids (BA) are actively reabsorbed in the terminal ileum by the apical Na(+)-dependent bile salt transporter. This review addresses the epidemiology, pathophysiology, diagnosis and treatment of BA diarrhea (BAD). BAD is typically caused by ileal resection or disease; 25-33% of patients with chronic functional diarrhea or irritable bowel syndrome-diarrhea (IBS-D) have BAD, possibly from deficiency in the ileal hormone, FGF-19, which normally provides feedback inhibition of BA synthesis. Diagnosis of BAD is typically based on reduced BA retention of radiolabeled BA ((75)SeHCAT), increased BA synthesis (serum C4) or increased fecal BA loss. In clinical practice, diagnosis is often based on response to BA sequestrants (e.g., cholestyramine or colesevelam). Diagnostic tests for BA malabsorption (BAM) need to be used more extensively in clinical practice. In the future, farnesoid X receptor agonists that stimulate ileal production of FGF-19 may be alternative treatments of BAD. PMID:24410472

  7. Bile acids for viral hepatitis

    Chen, Weikeng; Liu, J; Gluud, C


    Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness.......Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness....

  8. The effect of theophylline on canine bile flow, biliary excretion and concentration of ioglycamide

    Theophylline (TH), which has been shown in experimental dogs to increase bile-salt-independent bile flow, was studied in its effect on the biliary excretion and concentration of the intravenous contrast medium ioglycamide in cholecystectomized anesthetized dogs equipped with a Thomas cannula through which the common bile duct could be cannulated. One hour after cannulation, i.v. infusion of ioglycamide at the rate of 4 mol/min/kg was started. Two hours later, 10 mg/kg of TH was injected intravenously and the experiment continued for a further 75 minutes. Bile was collected at 15 min, intervals throughout the whole experiment and simultaneous intravenous blood samples were taken. In this study, TH increased bile flow and decreased biliary ioglycamide concentration. Although TH increased bile flow, it had no effect on the biliary excretion of ioglycamide. It may be postulated that the organic anion ioglycamide, and possibly other organic anions, are secreted into the bile by mechanisms, unaffected by drugs which increase bile-salt-independent bile flow in a similar manner to TH. (orig.)

  9. Gallblader and bile duct


    2009215 Construction of the specific MUC5AC-siRNA expression plasmid and effect of siRNA on proliferation and apoptosis in human bile duct cancer line HCCC-9810.HUANG Qing(黄强),et al.Dept General Surg,Affili Prov Hosp,Anhui Med Univ,Hefei 230001.World Chin J Digestol.2009;17(6):566-572.

  10. Bile acid interactions with cholangiocytes

    Xuefeng Xia; Heather Francis; Shannon Glaser; Gianfranco Alpini; Gene LeSage


    Cholangiocytes are exposed to high concentrations of bile acids at their apical membrane. A selective transporter for bile acids, the Apical Sodium Bile Acid Cotransporter (ASBT) (also referred to as Ibat; gene name Slc10a2)is localized on the cholangiocyte apical membrane. On the basolateral membrane, four transport systems have been identified (t-ASBT, multidrug resistance (MDR)3,an unidentified anion exchanger system and organic solute transporter (Ost) heteromeric transporter, OstαOstβ. Together, these transporters unidirectionally move bile acids from ductal bile to the circulation. Bile acids absorbed by cholangiocytes recycle via the peribiliaryplexus back to hepatocytes for re-secretion into bile.This recycling of bile acids between hepatocytes and cholangiocytes is referred to as the cholehepatic shunt pathway. Recent studies suggest that the cholehepatic shunt pathway may contribute in overall hepatobiliary transport of bile acids and to the adaptation to chronic cholestasis due to extrahepatic obstruction. ASBT is acutely regulated by an adenosine 3', 5'-monophosphate (cAMP)-dependent translocation to the apical membrane and by phosphorylation-dependent ubiquitination and proteasome degradation. ASBT is chronically regulated by changes in gene expression in response to biliary bile acid concentration and inflammatory cytokines.Another potential function of cholangiocyte ASBT is to allow cholangiocytes to sample biliary bile acids in order to activate intracellular signaling pathways. Bile acids trigger changes in intracellular calcium, protein kinase C (PKC), phosphoinositide 3-kinase (PI3K), mitogenactivated protein (MAP) kinase and extracellular signalregulated protein kinase (ERK) intracellular signals.Bile acids significantly alter cholangiocyte secretion,proliferation and survival. Different bile acids have differential effects on cholangiocyte intracellular signals,and in some instances trigger opposing effects on cholangiocyte secretion

  11. Low-fat, high-carbohydrate and high-fat, low-carbohydrate diets decrease primary bile acid synthesis in humans

    Bisschop, PH; Bandsma, RHJ; Stellaard, F; Meijer, AJ; Sauerwein, HP; Kuipers, F; Romijn, JA


    Background: Dietary fat content influences bile salt metabolism, but quantitative data from controlled studies in humans are scarce. Objective: The objective of the study was to establish the effect of dietary fat content on the metabolism of primary bile salts. Design: The effects of eucaloric extr

  12. Detoxification Strategy of Epoxide Hydrolase

    Arand, Michael; Cronin, Annette; Hengstler, Jan G.; Herrero Plana, Maria Elena; Lohmann, Matthias; Oesch, Franz


    The human microsomal epoxide hydrolase, a single enzyme, has to detoxify a broad range of structurally diverse, potentially genotoxic epoxides that are formed in the course of xenobiotic metabolism. The enzyme has developed a unique strategy to combine a broad substrate specificity with a high detoxification efficacy, by immediately trapping the reactive compounds as covalent intermediates and by being expressed at high levels for high trapping capacity. Computer simulation and experimental d...

  13. Hierarchical classification of glycoside hydrolases.

    Naumoff, D G


    This review deals with structural and functional features of glycoside hydrolases, a widespread group of enzymes present in almost all living organisms. Their catalytic domains are grouped into 120 amino acid sequence-based families in the international classification of the carbohydrate-active enzymes (CAZy database). At a higher hierarchical level some of these families are combined in 14 clans. Enzymes of the same clan have common evolutionary origin of their genes and share the most important functional characteristics such as composition of the active center, anomeric configuration of cleaved glycosidic bonds, and molecular mechanism of the catalyzed reaction (either inverting, or retaining). There are now extensive data in the literature concerning the relationship between glycoside hydrolase families belonging to different clans and/or included in none of them, as well as information on phylogenetic protein relationship within particular families. Summarizing these data allows us to propose a multilevel hierarchical classification of glycoside hydrolases and their homologs. It is shown that almost the whole variety of the enzyme catalytic domains can be brought into six main folds, large groups of proteins having the same three-dimensional structure and the supposed common evolutionary origin. PMID:21639842

  14. Hormesis in Cholestatic Liver Disease; Preconditioning with Low Bile Acid Concentrations Protects against Bile Acid-Induced Toxicity.

    Esther M Verhaag

    Full Text Available Cholestasis is characterized by accumulation of bile acids and inflammation, causing hepatocellular damage. Still, liver damage markers are highest in acute cholestasis and drop when this condition becomes chronic, indicating that hepatocytes adapt towards the hostile environment. This may be explained by a hormetic response in hepatocytes that limits cell death during cholestasis.To investigate the mechanisms that underlie the hormetic response that protect hepatocytes against experimental cholestatic conditions.HepG2.rNtcp cells were preconditioned (24 h with sub-apoptotic concentrations (0.1-50 μM of various bile acids, the superoxide donor menadione, TNF-α or the Farsenoid X Receptor agonist GW4064, followed by a challenge with the apoptosis-inducing bile acid glycochenodeoxycholic acid (GCDCA; 200 μM for 4 h, menadione (50 μM, 6 h or cytokine mixture (CM; 6 h. Levels of apoptotic and necrotic cell death, mRNA expression of the bile salt export pump (ABCB11 and bile acid sensors, as well as intracellular GCDCA levels were analyzed.Preconditioning with the pro-apoptotic bile acids GCDCA, taurocholic acid, or the protective bile acids (tauroursodeoxycholic acid reduced GCDCA-induced caspase-3/7 activity in HepG2.rNtcp cells. Bile acid preconditioning did not induce significant levels of necrosis in GCDCA-challenged HepG2.rNtcp cells. In contrast, preconditioning with cholic acid, menadione or TNF-α potentiated GCDCA-induced apoptosis. GCDCA preconditioning specifically reduced GCDCA-induced cell death and not CM- or menadione-induced apoptosis. The hormetic effect of GCDCA preconditioning was concentration- and time-dependent. GCDCA-, CDCA- and GW4064- preconditioning enhanced ABCB11 mRNA levels, but in contrast to the bile acids, GW4064 did not significantly reduce GCDCA-induced caspase-3/7 activity. The GCDCA challenge strongly increased intracellular levels of this bile acid, which was not lowered by GCDCA

  15. Hormesis in Cholestatic Liver Disease; Preconditioning with Low Bile Acid Concentrations Protects against Bile Acid-Induced Toxicity

    Verhaag, Esther M.; Buist-Homan, Manon; Koehorst, Martijn; Groen, Albert K.; Moshage, Han; Faber, Klaas Nico


    Introduction Cholestasis is characterized by accumulation of bile acids and inflammation, causing hepatocellular damage. Still, liver damage markers are highest in acute cholestasis and drop when this condition becomes chronic, indicating that hepatocytes adapt towards the hostile environment. This may be explained by a hormetic response in hepatocytes that limits cell death during cholestasis. Aim To investigate the mechanisms that underlie the hormetic response that protect hepatocytes against experimental cholestatic conditions. Methods HepG2.rNtcp cells were preconditioned (24 h) with sub-apoptotic concentrations (0.1–50 μM) of various bile acids, the superoxide donor menadione, TNF-α or the Farsenoid X Receptor agonist GW4064, followed by a challenge with the apoptosis-inducing bile acid glycochenodeoxycholic acid (GCDCA; 200 μM for 4 h), menadione (50 μM, 6 h) or cytokine mixture (CM; 6 h). Levels of apoptotic and necrotic cell death, mRNA expression of the bile salt export pump (ABCB11) and bile acid sensors, as well as intracellular GCDCA levels were analyzed. Results Preconditioning with the pro-apoptotic bile acids GCDCA, taurocholic acid, or the protective bile acids (tauro)ursodeoxycholic acid reduced GCDCA-induced caspase-3/7 activity in HepG2.rNtcp cells. Bile acid preconditioning did not induce significant levels of necrosis in GCDCA-challenged HepG2.rNtcp cells. In contrast, preconditioning with cholic acid, menadione or TNF-α potentiated GCDCA-induced apoptosis. GCDCA preconditioning specifically reduced GCDCA-induced cell death and not CM- or menadione-induced apoptosis. The hormetic effect of GCDCA preconditioning was concentration- and time-dependent. GCDCA-, CDCA- and GW4064- preconditioning enhanced ABCB11 mRNA levels, but in contrast to the bile acids, GW4064 did not significantly reduce GCDCA-induced caspase-3/7 activity. The GCDCA challenge strongly increased intracellular levels of this bile acid, which was not lowered by GCDCA

  16. Bile duct malignancies.

    Tucek, S; Tomasek, J; Halámkova, J; Kiss, I; Andrasina, T; Hemmelová, B; Adámková-Krákorová, D; Vyzula, R


    Bile duct malignancies include intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma (ECC), gall bladder carcinoma (GC) and carcinoma of Vater's ampulla (ampulloma). Bile duct neoplasms are rare tumours with overall poor prognosis. The overall incidence affects up to 12.5 per 100,000 persons in the Czech Republic. The mortality rate has risen recently to 9.5 per 100,000 persons. The incidence and mortality have been remarkably stable over the past 3 decades. The survival rate of patients with these tumours is poor, usually not exceeding 12 months. The diagnostic process is complex, uneasy and usually late. Most cases are diagnosed when unresectable, and palliative treatment is the main approach of medical care for these tumours. The treatment remains very challenging. New approaches have not brought much improvement in this field. Standards of palliative care are lacking and quality of life assessments are surprisingly not common. From the scarce data it seems, however, that multimodal individually tailored treatment can prolong patients'survival and improve the health-related quality of life. The care in specialized centres offers methods of surgery, interventional radiology, clinical oncology and high quality supportive care. These methods are discussed in the article in greater detail. Improvements in this field can be sought in new diagnostic methods and new procedures in surgery and interventional radiology. Understanding the tumour biology on the molecular level could shift the strategy to a more successful one, resulting in more cured patients. Further improvements in palliative care can be sought by defining new targets and new drug development. The lack of patients with bile duct neoplasms has been the limiting factor for any improvements. A new design of larger randomized international multicentric clinical trials with prompt data sharing could help to overcome this major problem. Defining standards of palliative care is a necessity

  17. Labeled bile acids

    A general short procedure for the introduction of 13C to the side chain of bile acids is described. Suitable (Z)-pregn-17(20)-enes are key intermediates, while the isotope is introduced by an ene reaction with [1,2,3-13C3]-methyl propiolate. For the labeling with tritium, the unlabeled product of the ene synthesis, a Δsup(5,16,22)-triene was saturated selectively at 16,17 and 22,23 with tritium gas. (author)

  18. Gallbladder and bile duct


    930559 An experimental study on effective hep-atic blood flow and hepatic energy metabolismfollowing acute obstructive cholangitis and bil-iary obstruction.SUN Wenbing (孙文兵),et al.Hepatobili Surg,Center,Southwest Hosp,Chongqing 630000.Chin J Digest 1992;12(5):261—263.The changes of effective hepatic blood flow(E-HBF)and hepatic energy metabolism were stud-ied following acutc obstructive cholangitis(AOC)and bile duct ligation(BDL)in rats.The resultsshowed that EHBF was significantly decreased at24hs after and further decreased at 48hs afterBDL.And EHBF was significantly decreased at

  19. Bile acid promotes liver regeneration via farnesoid X receptor signaling pathways in rats.

    Ding, Long; Yang, Yu; Qu, Yikun; Yang, Ting; Wang, Kaifeng; Liu, Weixin; Xia, Weibin


    Bile acids, which are synthesized from cholesterol in the hepatocytes of the liver, are amphipathic molecules with a steroid backbone. Studies have shown that bile acid exhibits important effects on liver regeneration. However, the mechanism underlying these effects remains unclear. The aim of the present study was to investigate the effect of bile acid and the farnesoid X receptor (FXR) on hepatic regeneration and lipid metabolism. Rats were fed with 0.2% bile acid or glucose for 7 days and then subjected to a 50 or 70% hepatectomy. Hepatic regeneration rate, serum and liver levels of bile acid, and expression of FXR and Caveolin‑1, were detected at 24, 48 or 72 h following hepatectomy. The expression of proliferating cell nuclear antigen (PCNA) in the liver was measured using immunohistochemistry at the end of the study. Hepatocytes isolated from rats were treated with bile acid, glucose, FXR agonist and FXR antagonist, separately or in combination. Lipid metabolism, the expression of members of the FXR signaling pathway and energy metabolism‑related factors were measured using ELISA kits or western blotting. Bile acid significantly increased the hepatic regeneration rate and the expression of FXR, Caveolin‑1 and PCNA. Levels of total cholesterol and high density lipoprotein were increased in bile acid‑ or FXR agonist‑treated hepatocytes in vitro. Levels of triglyceride, low density lipoprotein and free fatty acid were decreased. In addition, bile acid and FXR agonists increased the expression of bile salt export pump and small heterodimer partner, and downregulated the expression of apical sodium‑dependent bile acid transporter, Na+/taurocholate cotransporting polypeptide and cholesterol 7α‑hydroxylase. These results suggested that physiological concentrations of bile acid may promote liver regeneration via FXR signaling pathways, and may be associated with energy metabolism. PMID:25634785

  20. 5α-Bile alcohols function as farnesoid X receptor antagonists

    The farnesoid X receptor (FXR) is a bile acid/alcohol-activated nuclear receptor that regulates lipid homeostasis. Unlike other steroid receptors, FXR binds bile acids in an orientation that allows the steroid nucleus A to face helix 12 in the receptor, a crucial domain for coactivator-recruitment. Because most naturally occurring bile acids and alcohols contain a cis-oriented A, which is distinct from that of other steroids and cholesterol metabolites, we investigated the role of this 5β-configuration in FXR activation. The results showed that the 5β-(A/B cis) bile alcohols 5β-cyprinol and bufol are potent FXR agonists, whereas their 5α-(A/B trans) counterparts antagonize FXR transactivation and target gene expression. Both isomers bound to FXR, but their ability to induce coactivator-recruitment and thereby induce transactivation differed. These findings suggest a critical role for the A orientation of bile salts in agonist/antagonist function

  1. Bile acids for viral hepatitis

    Chen, Weikeng; Liu, J; Gluud, C


    The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness.......The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness....

  2. Mechanistic Modeling Reveals the Critical Knowledge Gaps in Bile Acid–Mediated DILI

    Woodhead, J L; Yang, K.; Brouwer, K L R; Siler, S. Q.; Stahl, S H; Ambroso, J L; Baker, D; Watkins, P B; Howell, B A


    Bile salt export pump (BSEP) inhibition has been proposed to be an important mechanism for drug-induced liver injury (DILI). Modeling can prioritize knowledge gaps concerning bile acid (BA) homeostasis and thus help guide experimentation. A submodel of BA homeostasis in rats and humans was constructed within DILIsym, a mechanistic model of DILI. In vivo experiments in rats with glibenclamide were conducted, and data from these experiments were used to validate the model. The behavior of DILIs...

  3. Bile Resistance in Lactobacillus rhamnosus GG: Stability and Mechanisms

    Xiao, Kun


    Lactobacillus rhamnosus GG is a lactic acid bacterium that is widely used as probiotic products in the dairy industry. To gain insights into the genome stability of the L. rhamnosus GG in the human gastrointestinal tract and the possible adaption mechanism under different stresses, we first examined the genotype and phenotype of the L. rhamnosus GG grown over 1000 generations under various stresses, including bile salts, osmotic stress or shearing forces. Immunoblotting analysis of L. rhamnos...

  4. The synthesis of taurine-conjugated bile acids and bile acid sulfates labeled with 14C or 3H in the taurine moiety

    Studies of bile acid transport systems require radio-labeled taurine-conjugated bile acids with high specific activity. An established procedure was optimized to provide mild, fast, and effective conjugation of radio-labeled taurine with different types of bile acids, including those with labile 7α-hydroxy-3-oxo-Δ4 or 3β, 7α-dihydroxy-Δ5 structures. Taurine labeled with 14C or 3H was reacted with excess bile acid anhydride formed from the tributylamine salt and ethylchloroformate (2/1 M/M) in aqueous dioxane for 15 min at room temperature. The yields were higher than 95% and less than 2% side products were formed. Bile acid sulfates were conjugated with 14C- or 3H-labeled taurine by using N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline as the coupling reagent. The products were effectively purified by chromatography of the sodium salts on Sephadex LH-20. The yields of taurine-conjugated bile acid sulfates were 65-70%. (author)

  5. Gene evolution of epoxide hydrolases and recommended nomenclature

    Beetham, J K; Grant, D; Arand, M; Garbarino, J; Kiyosue, T; Pinot, F; Oesch, F; Belknap, W R; Shinozaki, K.; Hammock, B. D.


    We have analyzed amino acid sequence relationships among soluble and microsomal epoxide hydrolases, haloacid dehalogenases, and a haloalkane dehalogenase. The amino-terminal residues (1-229) of mammalian soluble epoxide hydrolase are homologous to a haloacid dehalogenase. The carboxy-terminal residues (230-554) of mammalian soluble epoxide hydrolase are homologous to haloalkane dehalogenase, to plant soluble epoxide hydrolase, and to microsomal epoxide hydrolase. The shared identity between t...

  6. Lithocholic acid feeding induces segmental bile duct obstruction and destructive cholangitis in mice.

    Fickert, Peter; Fuchsbichler, Andrea; Marschall, Hanns-Ulrich; Wagner, Martin; Zollner, Gernot; Krause, Robert; Zatloukal, Kurt; Jaeschke, Hartmut; Denk, Helmut; Trauner, Michael


    We determined the mechanisms of hepatobiliary injury in the lithocholic acid (LCA)-fed mouse, an increasingly used model of cholestatic liver injury. Swiss albino mice received control diet or 1% (w/w) LCA diet (for 1, 2, and 4 days), followed by assessment of liver morphology and ultrastructure, tight junctions, markers of fibrosis and key proteins of hepatobiliary function, and bile flow and composition. As expected LCA feeding led to bile infarcts, which were followed by a destructive cholangitis with activation and proliferation of periductal myofibroblasts. At the ultrastructural level, small bile ducts were frequently obstructed by crystals. Biliary-excreted fluorescence-labeled ursodeoxycholic acid accumulated in bile infarcts, whereas most infarcts did not stain with India ink injected into the common bile duct; both findings are indicative of partial biliary obstruction. Expression of the main basolateral bile acid uptake proteins (sodium-taurocholate cotransporter and organic anion-transporting polypeptide 1) was reduced, the canalicular transporters bile salt export pump and multidrug-related protein 2 were preserved, and the basolateral transporter multidrug-related protein 3 and the detoxifying enzyme sulfotransferase 2a1 were induced. Thus, we demonstrate that LCA feeding in mice leads to segmental bile duct obstruction, destructive cholangitis, periductal fibrosis, and an adaptive transporter and metabolic enzyme response. PMID:16436656

  7. Micellar aggregates and hydrogels from phosphonobile salts

    Babu, Ponnusamy; Chopra, D.; Row, Guru TN; Maitra, Uday


    The aggregation properties of novel bile acid analogs-phosphonobile salts (PBS)-have been studied. The critical micellar concentration of 23 and 24-phosphonobile salts were measured using fluorescence and P-31 NMR methods. All the ten synthesized phosphonobile salts formed gels at different pH ranges in water. The pH range at which individual PBSs could gelate water was narrow and influenced by the number and conformation of hydroxyl groups. A reversible thermochromic system has been develope...

  8. Bile acid sequestrants for cholesterol

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  9. Bile loss in the acute intestinal radiation syndrome in rats

    The effects of bile duct ligation (BDL), choledochostomy, bile acid sequestering within the intestinal lumen by cholestyramine, and fluid and electrolyte replacement on survival time and development of diarrhea after whole-body exposure to doses of ionizing radiation that result in death from acute intestinal injury were studied. BDL significantly prolonged survival and delayed the onset of diarrhea after exposure to 137Cs gamma rays, fission neutrons, or cyclotron-produced neutrons in the range of doses that produce intestinal death or death from a combination of intestinal and hematopoietic injuries. Cannulation of the bile duct with exteriorized bile flow (choledochostomy) to protect the irradiated intestine from the mucolytic action of bile salts did not duplicate the effect of BDL in increasing survival time. Choledochostomy without fluid replacement eliminated the occurrence of diarrhea in 15.4 Gy irradiated rats. Diarrhea did occur in irradiated animals with choledochostomy if they received duodenal injections of fluid and electrolytes to replace the fluid lost as a result of bile drainage. Duodenal injection of fluid and electrolytes had no significant effect on survival time in irradiated rats. Injection of fluid and electrolytes into the peritoneal cavity of irradiated rats resulted in an increase in survival time that was comparable to that observed after BDL. Addition of antibiotics to the peritoneally injected fluid and electrolytes further increased survival time (up to 9 days). This survival time approached that seen in animals receiving the same radiation dose but which had the intestine exteriorized and shielded to minimize radiation injury to the intestine. Postmortem histological examinations of the irradiated small intestine showed mucosal regeneration in these long-term survivors receiving fluid and antibiotic therapy

  10. Risk Factors for Development of Cholestatic Drug-Induced Liver Injury: Inhibition of Hepatic Basolateral Bile Acid Transporters Multidrug Resistance-Associated Proteins 3 and 4

    Köck, Kathleen; Ferslew, Brian C.; Netterberg, Ida; Yang, Kyunghee; Urban, Thomas J.; Swaan, Peter W.; Stewart, Paul W.; Brouwer, Kim L.R.


    Impaired hepatic bile acid export may contribute to development of cholestatic drug-induced liver injury (DILI). The multidrug resistance-associated proteins (MRP) 3 and 4 are postulated to be compensatory hepatic basolateral bile acid efflux transporters when biliary excretion by the bile salt export pump (BSEP) is impaired. BSEP inhibition is a risk factor for cholestatic DILI. This study aimed to characterize the relationship between MRP3, MRP4, and BSEP inhibition and cholestatic potentia...

  11. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation

    Berman, Marvin D.; Carey, Martin C.


    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecit...

  12. Intracellular cholesterol transport proteins enhance hydrolysis of HDL-CEs and facilitate elimination of cholesterol into bile.

    Wang, Jing; Bie, Jinghua; Ghosh, Shobha


    While HDL-associated unesterified or free cholesterol (FC) is thought to be rapidly secreted into the bile, the fate of HDL-associated cholesteryl esters (HDL-CEs) that represent >80% of HDL-cholesterol, is only beginning to be understood. In the present study, we examined the hypothesis that intracellular cholesterol transport proteins [sterol carrier protein 2 (SCP2) and fatty acid binding protein-1 (FABP1)] not only facilitate CE hydrolase-mediated hydrolysis of HDL-CEs, but also enhance elimination of cholesterol into bile. Adenovirus-mediated overexpression of FABP1 or SCP2 in primary hepatocytes significantly increased hydrolysis of HDL-[(3)H]CE, reduced resecretion of HDL-CE-derived FC as nascent HDL, and increased its secretion as bile acids. Consistently, the flux of [(3)H]cholesterol from HDL-[(3)H]CE to biliary bile acids was increased by overexpression of SCP2 or FABP1 in vivo and reduced in SCP2(-/-) mice. Increased flux of HDL-[(3)H]CE to biliary FC was noted with FABP1 overexpression and in SCP2(-/-) mice that have increased FABP1 expression. Lack of a significant decrease in the flux of HDL-[(3)H]CE to biliary FC or bile acids in FABP1(-/-) mice indicates the likely compensation of its function by an as yet unidentified mechanism. Taken together, these studies demonstrate that FABP1 and SCP2 facilitate the preferential movement of HDL-CEs to bile for final elimination. PMID:27381048

  13. Chronic intermittent psychological stress promotes macrophage reverse cholesterol transport by impairing bile acid absorption in mice.

    Silvennoinen, Reija; Quesada, Helena; Kareinen, Ilona; Julve, Josep; Kaipiainen, Leena; Gylling, Helena; Blanco-Vaca, Francisco; Escola-Gil, Joan Carles; Kovanen, Petri T; Lee-Rueckert, Miriam


    Psychological stress is a risk factor for atherosclerosis, yet the pathophysiological mechanisms involved remain elusive. The transfer of cholesterol from macrophage foam cells to liver and feces (the macrophage-specific reverse cholesterol transport, m-RCT) is an important antiatherogenic pathway. Because exposure of mice to physical restraint, a model of psychological stress, increases serum levels of corticosterone, and as bile acid homeostasis is disrupted in glucocorticoid-treated animals, we investigated if chronic intermittent restraint stress would modify m-RCT by altering the enterohepatic circulation of bile acids. C57Bl/6J mice exposed to intermittent stress for 5 days exhibited increased transit through the large intestine and enhanced fecal bile acid excretion. Of the transcription factors and transporters that regulate bile acid homeostasis, the mRNA expression levels of the hepatic farnesoid X receptor (FXR), the bile salt export pump (BSEP), and the intestinal fibroblast growth factor 15 (FGF15) were reduced, whereas those of the ileal apical sodium-dependent bile acid transporter (ASBT), responsible for active bile acid absorption, remained unchanged. Neither did the hepatic expression of cholesterol 7α-hydroxylase (CYP7A1), the key enzyme regulating bile acid synthesis, change in the stressed mice. Evaluation of the functionality of the m-RCT pathway revealed increased fecal excretion of bile acids that had been synthesized from macrophage-derived cholesterol. Overall, our study reveals that chronic intermittent stress in mice accelerates m-RCT specifically by increasing fecal excretion of bile acids. This novel mechanism of m-RCT induction could have antiatherogenic potential under conditions of chronic stress. PMID:25969465

  14. Therapeutic uses of animal biles in traditional Chinese medicine: an ethnopharmacological, biophysical chemical and medicinal review.

    Wang, David Q-H; Carey, Martin C


    Forty-four different animal biles obtained from both invertebrates and vertebrates (including human bile) have been used for centuries for a host of maladies in traditional Chinese medicine (TCM) beginning with dog, ox and common carp biles approximately in the Zhou dynasty (c. 1046-256 BCE). Overall, different animal biles were prescribed principally for the treatment of liver, biliary, skin (including burns), gynecological and heart diseases, as well as diseases of the eyes, ears, nose, mouth and throat. We present an informed opinion of the clinical efficacy of the medicinal uses of the different animal biles based on their presently known principal chemical components which are mostly steroidal detergent-like molecules and the membrane lipids such as unesterified cholesterol and mixed phosphatidylcholines and sometimes sphingomyelin, as well as containing lipopigments derived from heme principally bilirubin glucuronides. All of the available information on the ethnopharmacological uses of biles in TCM were collated from the rich collection of ancient Chinese books on materia medica held in libraries in China and United States and the composition of various animal biles was based on rigorous separatory and advanced chemical identification techniques published since the mid-20(th) century collected via library (Harvard's Countway Library) and electronic searches (PubMed and Google Scholar). Our analysis of ethnomedical data and information on biliary chemistry shows that specific bile salts, as well as the common bile pigment bilirubin and its glucuronides plus the minor components of bile such as vitamins A, D, E, K, as well as melatonin (N-acetyl-5-methoxytryptamine) are salutary in improving liver function, dissolving gallstones, inhibiting bacterial and viral multiplication, promoting cardiac chronotropsim, as well as exhibiting anti-inflammatory, anti-pyretic, anti-oxidant, sedative, anti-convulsive, anti-allergic, anti-congestive, anti-diabetic and anti

  15. Endocrine and paracrine role of bile acids

    Verena Keitel, Ralf Kubitz, Dieter Häussinger


    Full Text Available Bile acids are not only important for the absorption of dietary lipids and fat soluble vitamins but are signalling molecules with diverse endocrine and paracrine functions. Bile acids regulate bile acid, lipid and glucose metabolism and modulate temperature and energy homeostasis. Furthermore, bile acids can not only promote cell proliferation and liver regeneration but can also induce programmed cell death. Bile acid functions are mediated through different pathways which comprise the activation of nuclear hormone receptors, of intracellular kinases and of the plasma membrane-bound, G-protein coupled bile acid receptor TGR5/Gpbar-1.

  16. Resolving bile reflux by lanreotide in patients with Roux-en-Y gastrojejunostomy.

    Moubax, K; Mana, F; Urbain, D


    Reflux into the esophagus after partial or total gastrectomy is a well known problem. Even a Roux-en-Y reconstruction is not always a definitive solution. Bile reflux might occur and cause disabling symptoms, unresponsive to the classic anti-acid or anti-reflux therapy. Endoscopy and a Tc-99m-BrIDA hepatobiliary (HIDA) scan can be used to make the diagnosis. Clinical studies have shown that lanreotide (somatuline), which strongly inhibits many gastro-intestinal hormones, reduces the bile salts outputs. We present a case of a patient with bile reflux after Roux-en-Y. After administration of lanreotide he had a good clinical improvement and mucosal healing on endoscopy. Lanreotide can be a good treatment option for bile reflux when classic treatment fails, but clinical trials with more patients will have to confirm this. PMID:25682623

  17. What's New in Bile Duct Cancer Research and Treatment?

    ... bile duct cancer What’s new in bile duct cancer research and treatment? Bile duct cancer is an uncommon ... Doctor After Treatment What`s New in Bile Duct Cancer Research? Other Resources and References Cancer Information Cancer Basics ...

  18. Bile Acid Analysis in Biliary Tract Cancer

    Park, Jeong Youp; Park, Byung Kyu; Ko, Jun Sang; Bang, Seungmin; Song, Si Young; Chung, Jae Bock


    The etiology of biliary tract cancer is obscure, but there are evidences that bile acid plays a role in carcinogenesis. To find the association between biliary tract cancer and bile acid, this study compared the bile acid concentration and composition among patients with biliary cancer, biliary tract stones, and no biliary disease. Bile was compared among patients with biliary tract cancer (n = 26), biliary tract stones (n = 29), and disease free controls (n = 9). Samples were obtained by per...

  19. Effects of bile diversion in rats on intestinal sphingomyelinases and ceramidase

    Duan, R. D.; Verkade, H. J.; Cheng, Y.; Havinga, R.; Nilsson, A.


    Alkaline sphingomyelinase (Alk-SMase) and neutral ceramidase (N-CDase) in the intestinal microvillar membrane are responsible for dietary sphingomyelin digestion. The activities of the enzymes require the presence of bile salt, and the enzymes can be released into the gut lumen in active forms by bi

  20. A proteomic analysis of human bile

    Kristiansen, Troels Zakarias; Bunkenborg, Jakob; Gronborg, Mads; Molina, Henrik; Thuluvath, Paul J; Argani, Pedram; Goggins, Michael G; Maitra, Anirban; Pandey, Akhilesh


    We have carried out a comprehensive characterization of human bile to define the bile proteome. Our approach involved fractionation of bile by one-dimensional gel electrophoresis and lectin affinity chromatography followed by liquid chromatography tandem mass spectrometry. Overall, we identified ...

  1. Roentgendiagnostic of the operated bile duct system

    The roentgendiagnostic after bile duct surgery shall demonstrate postoperative complications, recurrencys of the primary disease and other complications. Planning the diagnostic procedures one has to consider the preceeding operation: surgery of the gall-bladder, the common bile duct, the papilla Vateri, biliodigestive anastomosis, bile duct drainage by plastic tube, and duodenopancreatectomy. (orig.)

  2. Characterization of the role of ABCG2 as a bile acid transporter in liver and placenta.

    Blazquez, Alba G; Briz, Oscar; Romero, Marta R; Rosales, Ruben; Monte, Maria J; Vaquero, Javier; Macias, Rocio I R; Cassio, Doris; Marin, Jose J G


    ABCG2 is involved in epithelial transport/barrier functions. Here, we have investigated its ability to transport bile acids in liver and placenta. Cholylglycylamido fluorescein (CGamF) was exported by WIF-B9/R cells, which do not express the bile salt export pump (BSEP). Sensitivity to typical inhibitors suggested that CGamF export was mainly mediated by ABCG2. In Chinese hamster ovary (CHO cells), coexpression of rat Oatp1a1 and human ABCG2 enhanced the uptake and efflux, respectively, of CGamF, cholic acid (CA), glycoCA (GCA), tauroCA, and taurolithocholic acid-3-sulfate. The ability of ABCG2 to export these bile acids was confirmed by microinjecting them together with inulin in Xenopus laevis oocytes expressing this pump. ABCG2-mediated bile acid transport was inhibited by estradiol 17β-d-glucuronide and fumitremorgin C. Placental barrier for bile acids accounted for 14-fold increased maternal cholanemia induced by obstructive cholestasis in pregnant rats. In rat placenta, the expression of Abcg2, which was much higher than that of Bsep, was not affected by short-term cholestasis. In pregnant rats, fumitremorgin C did not affect uptake/secretion of GCA by the liver but inhibited its fetal-maternal transfer. Compared with wild-type mice, obstructive cholestasis in pregnant Abcg2(-/-) knockout mice induced similar bile acid accumulation in maternal serum but higher accumulation in placenta, fetal serum, and liver. In conclusion, ABCG2 is able to transport bile acids. The importance of this function depends on the relative expression in the same epithelium of other bile acid exporters. Thus, ABCG2 may play a key role in bile acid transport in placenta, as BSEP does in liver. PMID:22096226

  3. Bile acids in regulation of intestinal physiology.

    Keating, Niamh


    In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

  4. Effects of tegaserod on bile composition and hepatic secretion in Richardson ground squirrels on an enriched cholesterol diet

    Pfannkuche Hans-Juergen


    Full Text Available Abstract Background Tegaserod is effective in treating IBS patients with constipation, and does not alter gallbladder motility in healthy individuals or in patients with IBS. However, it is not known if tegaserod affects the biliary tract in gallstone disease, so to this end the effects of tegaserod on bile composition and hepatic secretion of Richardson ground squirrels maintained on an enriched cholesterol diet were examined. Results Animals were fed either a control (0.03% or enriched (1% cholesterol diet for 28 days, and treated s.c. with tegaserod (0.1 mg/kg BID or vehicle. Bile flow, bile acid, phospholipids and cholesterol secretion were measured with standard methods. Tegaserod treatment or enriched cholesterol diet, alone or combination, did not alter body or liver weights. The enriched cholesterol diet increased cholesterol saturation index (CSI, cholesterol concentrations in gallbladder and hepatic duct bile by ~50% and decreased bile acids in gallbladder bile by 17%. Tegaserod treatment reversed these cholesterol-induced changes. None of the treatments, drug or diet, altered fasting gallbladder volume, bile flow and bile salts or phospholipid secretion in normal diet and cholesterol-fed animals. However, tegaserod treatment prevented the decreases in bile acid pool size and cycling frequency caused by the enriched cholesterol diet, consequent to re-establishing normal bile acid to concentrations in the gall bladder. Tegaserod had no effect on these parameters with normal diet animals. Conclusion Tegaserod treatment results in increased enterohepatic cycling and lowers cholesterol saturation in the bile of cholesterol-fed animals. These effects would decrease conditions favorable to cholesterol gallstone formation.

  5. Investigation of antibacterial, acid and bile tolerance properties of lactobacilli isolated from Koozeh cheese

    Hassan Hassanzadazar


    Full Text Available Lactobacillus strains are a major part of the probiotics, microflora of the intestine and of fermented dairy products, and are found in a variety of environments. The aim of this study was to find out the ability of bile and acid tolerance and antibacterial properties of the twenty eight isolates of three group lactobacilli namely Lactobacillus plantarum, Lactobacillus casei and Lactobacillus delbruki. For this purpose Twenty eight different Lactobacillus strains that isolated from Koozeh cheese as a traditional cheese were screened. The acid tolerance test was studied under pH 2.0 and 3.0 with 7.5 as control. The cell count for the acid tolerance test was obtained at an interval of 0, 1, 2 and 3 hours respectively and was pour plated on Man, Rogosa, and Sharpe (MRS agar to be incubated at 37 °C for 24 hours. All cells were selected for bile tolerance test in MRS broth containing bile concentrations of 0% as control and 0.3% as test. Then cell counts were enumerated after 24 hours of incubation on MRS agar. Results showed twenty seven isolates did not have ability to tolerate acid and bile salts and antimicrobial activity against four indicator bacteria included Eshirichia coli, Listeria monocytogenesis, bacillus cereus, Salmonella entritidis. Only one Isolate namely Lactobacillus casei could tolerate acid and bile salt and had antibacterial activity against of L. monocytogenesis. Therefore we can consider this strain as a native probiotic but extra examinations was required.

  6. The influence of ferric (III citrate on ATP-hydrolases of Desulfuromonas acetoxidans ІМV В-7384

    O. Maslovska


    peroxidation products in bacterial cells confirms free radical mechanism of oxidation of polyunsaturated fatty acids. Thus, for fulfiling complete analyses of cell response against oxidative stress it was reasonable to investigate the influence of ferric (III citrate on specific ATP-hydrolase activity, Na+, K+-ATP-hydrolase activity and Mg2+-ATP-hydrolase activity of D. acetoxidans ІМV В-7384. Bacteria were cultivated in the modified Postgaite C medium during four days under the anaerobic conditions and temperature +27°С with addition from 10 to 20 mM of ferric (III citrate into the growth medium. Control samples didn’t contain investigated metal salt. Chosen concentrations of metal salt caused inhibition of bacterial growth by 20–50%. Activities of ATP-hydrolases were investigated as described. It was shown, that specific ATP-hydrolase activity of D. acetoxidans ІМV В-7384 is changing in dependance on duration of ferric (III citrate exposure and concentration of the metal salt. Addition of the ferric (III citrate in relatively low concentrations (10–12 mM causes increasing of specific ATP-hydrolase activity of D. acetoxidans IMV B-7384 in comparison with control. Activity of investigated enzymes was inhibited under the increasing of metal salt concentration in bacterial growth medium. Increase of duration of D. acetoxidans IMV B-7384 cultivation causes decrease of ATP-hydrolase activity. Addition of ferric (III citrate causes simultaneous increasing of Na+, K+-ATP-hydrolase activity and inhibition of Mg2+-ATP-hydrolase activity during four days of bacterial cultivation.

  7. Pancreatoduodenectomy for bile duct and ampullary cancer

    Yamaguchi, Koji


    Pylorus-preserving pancreatoduodenectomy has become a standard operation for distal and middle bile duct cancers. Bile duct cancer typically extends longitudinally and invades vertically. It frequently metastasizes to the lymph nodes and infiltrates the perineural spaces. The presence of residual cancer in the bile duct stump and lymph node metastases are significant prognostic factors. Negative surgical margins and D2 lymph node dissection are necessary for curative resection. The clinical c...

  8. Spontaneous Bile Duct Rupture in Pregnancy

    Piotrowski, Joseph J.; Greg Van Stiegmann; R. Dale Liechty


    Spontaneous bile duct rupture occurred in a 23-year-old who required emergency Cesarean section for fetal distress. This condition has not been reported in association with pregnancy. Only forty cases of spontaneous bile duct perforation in adults have been previously reported. Seventy percent of these perforations were related to biliary calculi. Sites of perforation were evenly distributed between common hepatic duct and common bile duct. Recommended treatment includes cholecystectomy, comm...

  9. Potency of Individual Bile Acids to Regulate Bile Acid Synthesis and Transport Genes in Primary Human Hepatocyte Cultures

    Liu, Jie; Lu, Hong; Lu, Yuan-Fu; Lei, Xiaohong; Cui, Julia Yue; Ellis, Ewa; Strom, Stephen C.; Klaassen, Curtis D.


    Bile acids (BAs) are known to regulate their own homeostasis, but the potency of individual bile acids is not known. This study examined the effects of cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), lithocholic acid (LCA) and ursodeoxycholic acid (UDCA) on expression of BA synthesis and transport genes in human primary hepatocyte cultures. Hepatocytes were treated with the individual BAs at 10, 30, and 100μM for 48 h, and RNA was extracted for real-time PCR analysis. For the classic pathway of BA synthesis, BAs except for UDCA markedly suppressed CYP7A1 (70–95%), the rate-limiting enzyme of bile acid synthesis, but only moderately (35%) down-regulated CYP8B1 at a high concentration of 100μM. BAs had minimal effects on mRNA of two enzymes of the alternative pathway of BA synthesis, namely CYP27A1 and CYP7B1. BAs increased the two major target genes of the farnesoid X receptor (FXR), namely the small heterodimer partner (SHP) by fourfold, and markedly induced fibroblast growth factor 19 (FGF19) over 100-fold. The BA uptake transporter Na+-taurocholate co-transporting polypeptide was unaffected, whereas the efflux transporter bile salt export pump was increased 15-fold and OSTα/β were increased 10–100-fold by BAs. The expression of the organic anion transporting polypeptide 1B3 (OATP1B3; sixfold), ATP-binding cassette (ABC) transporter G5 (ABCG5; sixfold), multidrug associated protein-2 (MRP2; twofold), and MRP3 (threefold) were also increased, albeit to lesser degrees. In general, CDCA was the most potent and effective BA in regulating these genes important for BA homeostasis, whereas DCA and CA were intermediate, LCA the least, and UDCA ineffective. PMID:25055961

  10. Micellar aggregates and hydrogels from phosphonobile salts.

    Babu, Ponnusamy; Chopra, D; Row, T N Guru; Maitra, Uday


    The aggregation properties of novel bile acid analogs-phosphonobile salts (PBS)-have been studied. The critical micellar concentration of 23 and 24-phosphonobile salts were measured using fluorescence and 31P NMR methods. All the ten synthesized phosphonobile salts formed gels at different pH ranges in water. The pH range at which individual PBSs could gelate water was narrow and influenced by the number and conformation of hydroxyl groups. A reversible thermochromic system has been developed (with 23-phosphonodeoxycholate at pH 3.3), which changes color upon gelation. The investigation of the first hydrogels derived from trihydroxy bile acid analogs 1 and 6 was made using fluorescence, 31P NMR, X-ray crystallography, circular dichroism and SEM. The present studies reveal that the gel network consists of a chiral, fibrous structure possessing hydrophobic interiors. PMID:16211104

  11. Disrupting Dimerization Translocates Soluble Epoxide Hydrolase to Peroxisomes.

    Jonathan W Nelson

    Full Text Available The epoxyeicosatrienoic acid (EET neutralizing enzyme soluble epoxide hydrolase (sEH is a neuronal enzyme, which has been localized in both the cytosol and peroxisomes. The molecular basis for its dual localization remains unclear as sEH contains a functional peroxisomal targeting sequence (PTS. Recently, a missense polymorphism was identified in human sEH (R287Q that enhances its peroxisomal localization. This same polymorphism has also been shown to generate weaker sEH homo-dimers. Taken together, these observations suggest that dimerization may mask the sEH PTS and prevent peroxisome translocation. In the current study, we test the hypothesis that dimerization is a key regulator of sEH subcellular localization. Specifically, we altered the dimerization state of sEH by introducing substitutions in amino acids responsible for the dimer-stabilizing salt-bridge. Green Fluorescent Protein (GFP fusions of each of mutants were co-transfected into mouse primary cultured cortical neurons together with a PTS-linked red fluorescent protein to constitutively label peroxisomes. Labeled neurons were analyzed using confocal microscopy and co-localization of sEH with peroxisomes was quantified using Pearson's correlation coefficient. We find that dimer-competent sEH constructs preferentially localize to the cytosol, whereas constructs with weakened or disrupted dimerization were preferentially targeted to peroxisomes. We conclude that the sEH dimerization status is a key regulator of its peroxisomal localization.

  12. Protection of live bacteria from bile acid toxicity using bile acid adsorbing resins.

    Edwards, Alexander D; Slater, Nigel K H


    We previously demonstrated that a dry, room temperature stable formulation of a live bacterial vaccine was highly susceptible to bile, and suggested that this will lead to significant loss of viability of any live bacterial formulation released into the intestine using an enteric coating or capsule. We found that bile and acid tolerance is very rapidly recovered after rehydration with buffer or water, raising the possibility that rehydration in the absence of bile prior to release into the intestine might solve the problem of bile toxicity to dried cells. We describe here a novel formulation that combines extensively studied bile acid adsorbent resins with the dried bacteria, to temporarily adsorb bile acids and allow rehydration and recovery of bile resistance of bacteria in the intestine before release. Tablets containing the bile acid adsorbent cholestyramine release 250-fold more live bacteria when dissolved in a bile solution, compared to control tablets without cholestyramine or with a control resin that does not bind bile acids. We propose that a simple enteric coated oral dosage form containing bile acid adsorbent resins will allow improved live bacterial delivery to the intestine via the oral route, a major step towards room temperature stable, easily administered and distributed vaccine pills and other bacterial therapeutics. PMID:19490986

  13. Relative measurement of heavy elements in the bile gallbladder and gallstone

    Particle Induced X-Ray Emission is a suitable method for the analysis of biological samples in which heavy trace elements are contained in light matrix elements. It is very important to know which factors or probably elements act as initial seed and lead to growing the sands. The goal of this study was to compare the relative values of Fe/K, Cu/K and Zn/K for gallstones, gallbladder, and bile of a specific patient for studying the origination of forming the gallstones. Materials and Methods Human gallbladder, bile, and gallstone samples were obtained by surgical operation from 15 patients and are bombarded by 2.0 MeV energy proton beams produced by van de Graaff accelerator in vacuum. All .. the gallstones were chosen of pigment type of stones and, all the patients were adults. In contrast with conventional methods, the shell and center of the sands has been analyzed separately. The PIXE spectrum analysis was performed using the nonlinear least square fitting code AXIL and GUPIX. Results: The results of detected minor and trace elements shows that the precipitation of calcium salt in the bile lead to reduction of crystals' formation. Elemental comparison of pigment type of gallstone and bile shows that the concentration of calcium in the shell of the stones is four times more than that in the bile. Conclusion: Precipitation of the calcium from the saturated bile on the cholesterols as a seed of gallstones led to reduced sands formation. Analysis of the gallbladder of the same patients revealed no relation between elemental concentrations of bile and gallstones

  14. Iatrogenic bile duct injuries – clinical problems

    Głuszek Stanisław


    Full Text Available Laparoscopic cholecystectomy is one of the most frequently performed surgical procedures in surgical wards. Iatrogenic bile duct injuries (IBDI incurred during the procedures are among postoperative complications that are most difficult to treat. The risk of bile duct injury is 0.2-0.4%, and their consequences are unpleasant both for the surgeon and for the patient.

  15. Bile acid biosynthesis and its regulation

    Areta Hebanowska


    Full Text Available Bile acid biosynthesis is the main pathway of cholesterol catabolism. Bile acids are more soluble than cholesterol so are easier to excrete. As amphipathic molecules they participate in lipid digestion and absorption in the intestine and they help to excrete free cholesterol with bile. They are also ligands for nuclear receptors regulating the expression of genes involved in cholesterol metabolism. Interconversion of cholesterol into bile acids is an important point of its homeostasis. Seventeen enzymes are engaged in this process and many of them are cytochromes P450. Bile acid synthesis initiation may proceed with the “classical” pathway (starting with cholesterol hydroxylation at the C7α position or the “alternative” pathway (starting with cholesterol hydroxylation at the C27 position. Two additional pathways are possible, though their quantitative significance is small (initiated with cholesterol hydroxylations of C24 and C25 positions. Oxysterols produced are not only intermediates of bile acid biosynthesis but also important regulators of metabolism. Bile acid biosynthesis takes place in the liver, but some enzymes are also present in other organs, where they participate in regulation of cholesterol metabolism. Those enzymes are potential targets for new drugs against cholesterol metabolism disturbances. This article is a brief description of the bile acid biosynthesis pathway and participating enzymes.

  16. Bile acids for liver-transplanted patients

    Poropat, Goran; Giljaca, Vanja; Stimac, Davor;


    Liver transplantation has become a widely accepted form of treatment for numerous end-stage liver diseases. Bile acids may decrease allograft rejection after liver transplantation by changing the expression of major histocompatibility complex class molecules in bile duct epithelium and central vein...

  17. Aspergillus niger DLFCC-90 Rhamnoside Hydrolase, a New Type of Flavonoid Glycoside Hydrolase

    Liu, Tingqiang; Yu, Hongshan; Zhang, Chunzhi; Lu, Mingchun; Piao, Yongzhe; Ohba, Masashi; Tang, Minqian; Yuan, Xiaodong; Wei, Shenghua; Wang, Kan; Ma, Anzhou; Feng, Xue; Qin, Siqing; Mukai, Chisato; Tsuji, Akira


    A novel rutin-α-l-rhamnosidase hydrolyzing α-l-rhamnoside of rutin, naringin, and hesperidin was purified and characterized from Aspergillus niger DLFCC-90, and the gene encoding this enzyme, which is highly homologous to the α-amylase gene, was cloned and expressed in Pichia pastoris GS115. The novel enzyme was classified in glycoside-hydrolase (GH) family 13.

  18. Bile acid dissolution therapy of gallbladder stones.

    Fromm, H; Malavolti, M


    Oral cholelitholytic bile acid therapy has become established treatment for selected patients with cholesterol gallstones. The treatment finds its clinical application both alone and in combination with ESWL. UDCA alone or, less commonly, a combination of this bile acid with CDCA is used. Optimal results can be expected only in carefully selected patients. Bile acid dissolution therapy is most successful in patients with radiolucent gallstones which are OCG to be floating. Dissolution is seldom seen when the stones are > 1 cm in size. Cholelitholytic treatment in combination with ESWL yields optimal results in single radiolucent gallstones which are not greater than 2 cm. ESWL thus makes it possible to use medical treatment effectively in single 1-2 cm gallstones when bile acids alone would not be successful. Bile acid treatment is extremely safe, especially if UDCA is given without the addition of CDCA. PMID:1486209

  19. Bile acids in radiation-induced diarrhea

    Radiation-induced bowel disease manifested by debilitating diarrhea is an unfortunate consequence of therapeutic irradiation for pelvic malignancies. Although the mechanism for this diarrhea is not well understood, many believe it is the result of damage to small bowel mucosa and subsequent bile acid malabsorption. Excess amounts of bile acids, especially the dihydroxy components, are known to induce water and electrolyte secretion and increase bowel motility. We have directly measured individual and total bile acids in the stool samples of 11 patients with radiation-induced diarrhea and have found bile acids elevated two to six times normal in eight of them. Our patients with diarrhea and increased bile acids in their stools had prompt improvement when given cholestyramine. They had fewer stools and returned to a more normal life-style

  20. Acute bile nephropathy secondary to anabolic steroids.

    Alkhunaizi, Ahmed M; ElTigani, Mohamed A; Rabah, Rola S; Nasr, Samih H


    Renal dysfunction in cholestatic liver disease is multifactorial. Acute kidney injury may develop secondary to renal vasoconstriction in the setting of peripheral vasodilation and relative hypovolemia, tubular obstruction by bile casts, and direct tubular toxicity from bile. Anabolic steroids are frequently used by athletes to boost endurance and increase muscle mass. These agents are a recently recognized cause of hepatotoxicity and jaundice and may lead to acute kidney injury. To increase awareness about this growing problem and to characterize the pathology of acute kidney injury in this setting, we report on a young male who developed acute kidney injury in the setting of severe cholestatic jaundice related to ingestion of anabolic steroids used for bodybuilding. Kidney biopsy showed bile casts within distal tubular lumina, filamentous bile inclusions within tubular cells, and signs of acute tubular injury. This report supports the recently re-emerged concept of bile nephropathy cholemic nephrosis. PMID:26587777

  1. Pancreatic enzymes in the epithelium of intrahepatic large bile ducts and in hepatic bile in patients with extrahepatic bile duct obstruction.

    Terada, T.; Morita, T; Hoso, M; Nakanuma, Y


    AIM--To determine whether pancreatic enzymes are present in hepatic bile and in intrahepatic bile duct epithelium. METHODS--The activity and proteins of pancreatic enzymes (pancreatic alpha-amylase, lipase, trypsin/trypsinogen) in hepatic bile were investigated using biochemical and western blot analyses in 25 patients with extrahepatic bile duct obstruction. Immunolocalization of enzyme proteins was evaluated by immunohistochemistry in 20 necropsy livers with extrahepatic bile duct obstructi...

  2. Hydrolase activity in Jerusalem artichoke and chicory

    Klaushofer, H.; Abraham, B.; Leichtfried, G.


    Post-harvest storage of chicory and Jerusalem artichoke and overwintering of Jerusalem artichoke in the soil cause a more or less pronounced shortening of the fructan chain, depending on the variety. The proportion of fructose in the total fructan thus shifts towards glucose. This reduction on the fructose/glucose ratio is undesirable if the intention is to obtain a sweetener of high fructose content. In this work an attempt was made, via the quantity of fructose formed after a 4(3)-hour reaction of a tuber (root) extract with inulin, to assign a characteristic value to the depolymerization tendency of the material in question. However, since the plant extract not only contains enzymes (hydrolase A and B) that shorten the fructan chains but the activity of fructosyltransferase (SST, FFT) and enzymes of microbial origin (inulinase II, invertase) must also be considered, the concept of 'hydrolase activity' used by the authors is essentially an expression of 'total activity'. The activity unit (EU) is defined as the ability to split of 1 of fructose from (chicory) inulin per minute under experimental conditions. Values of 0.25 to 0.77 EU/g dry solids were found in Jerusalem artichoke. Considerable differences may occur between varieties from the same cultivated area and the same harvest period. With one and the same variety, the activity appears to be subject to marked yearly fluctuations, so that at present, because of hydrolase activity, nothing certain can be said about the depolymerization tendency of a variety.

  3. Protection of dried probiotic bacteria from bile using bile adsorbent resins.

    Mahbubani, Krishnaa T; Slater, Nigel K H; Edwards, Alexander D


    Enteric coated oral tablets or capsules can deliver dried live cells directly into the intestine. Previously, we found that a live attenuated bacterial vaccine acquired sensitivity to intestinal bile when dried, raising the possibility that although gastric acid can be bypassed, significant loss of viability might occur on release from an enteric coated oral formulations. Here we demonstrate that some food-grade lyophilised preparations of Lactobacillus casei and Lactobacillus salivarius also show temporary bile sensitivity that can be rapidly reversed by rehydration. To protect dried bacterial cells from temporary bile sensitivity, we propose using bile acid adsorbing resins, such as cholestyramine, which are bile acid binding agents, historically used to lower cholesterol levels. Vcaps™ HPMC capsules alone provided up to 830-fold protection from bile. The inclusion of 50% w/w cholestyramine in Vcaps™ HPMC capsules resulted in release of up to 1700-fold more live Lactobacillus casei into simulated intestinal fluid containing 1% bile, when compared to dried cells added directly to bile. We conclude that delivery of dried live probiotic organisms to the intestine may be improved by providing protection from bile by addition of bile adsorbing resins and the use of HPMC capsules. PMID:24080386

  4. Bile Duct Adenoma with Oncocytic Features

    E. J. Johannesen


    Full Text Available Bile duct adenomas are benign bile duct proliferations usually encountered as an incidental finding. Oncocytic bile duct neoplasms are rare and the majority are malignant. A 61-year-old male with a diagnosis of colorectal adenocarcinoma was undergoing surgery when a small white nodule was discovered on the surface of the right lobe of his liver. This lesion was composed of cytologically bland cells arranged in tightly packed glands. These cells were immunopositive for cytokeratin 7, negative for Hep Par 1, contained mucin, and had a Ki67 proliferation index of 8%. The morphology, immunophenotype, presence of mucin, and normal appearing bile ducts, as well as the increased Ki67 proliferation rate, were consistent with a bile duct adenoma with oxyphilic (oncocytic change. Oncocytic tumors in the liver are rare; the first described in 1992. Only two bile duct adenomas with oncocytic change have been reported and neither of them had reported mucin production or the presence of normal appearing bile ducts within the lesion.

  5. The first case of pediatric bile duct adenoma

    Zhi Li; Xiaoyi Sun; Jiexiong Feng


    Intrahepatic bile duct adenoma (BDA) is a rare benign epithelial liver tumor derived from bile duct cells. We report the first case of pediatric bile duct adenoma in the world. Furthermore, we review the diagnosis, pathology, treatment and prognosis of bile duct adenoma.

  6. Determination of bile acids by radioimmunoassays

    The present paper, based on the current literature, considers the practical aspects of bile acid radioimmunoassays. The problems assoziated with the raising of specific antisera and their characterization are discussed. Features of assay design for bile acids are considered. Solid-phase radioimmunoassays are described for separate determination of unconjugated cholic acid and conjugated cholic acid in serum. The clinical application of specific bile acid radioimmunoassays is shown by an 'oral cholate tolerance test' as a sensitive indicator of liver function and by an 'oral cholylglycine tolerance test' for characterization of intenstinal function in diarrheal states. (orig.)

  7. Omeprazole induces altered bile acid metabolism

    Shindo, K; Machida, M.; Fukumura, M; Koide, K.; Yamazaki, R.


    Background—It has been reported that the acidity of gastric contents could be an important factor in regulating jejunal flora. 
Aims—To investigate the effects of omeprazole induced changes in gastric pH on jejunal flora and bile acid metabolism. 
Methods—Twenty one patients with gastric ulcer and 19 healthy volunteers were studied. Deconjugation of bile acids was detected using a bile acid breath test. Jejunal fluid was aspirated using a double lumen tube with a rubber cover o...

  8. Bile acid metabolism in tupaias (lemurs)

    The goal of this work is to study biliary elimination and the metabolism of the most important primary bile acids, cholic acid and chenodesoxycholic acid, and the toxic secondary bile acid, lithocholic acid, which is formed in the intestine as a result of chenodesoxycholate therapy for the dissolving of gall stones. This work herewith offers a contribution to the answering of the question whether tupaias are a relevant animal model for the study of gall stone formation and their medicamentous dissolution by means of bile acids. (orig./MG)

  9. Nuclear receptors, bile acids and cholesterol homeostasis series - bile acids and pregnancy.

    Abu-Hayyeh, Shadi; Papacleovoulou, Georgia; Williamson, Catherine


    Bile acids have been traditionally thought of as having an important role in fat emulsification. It is now emerging that they act as important signalling molecules that not only autoregulate their own synthesis but also influence lipid and glucose metabolism. Although, the mechanisms that underlie the regulation of bile acid homeostasis have been well characterised in normal physiology, the impact of pregnancy on bile acid regulation is still poorly understood. This review summarises the main regulatory mechanisms underlying bile acid homeostasis and discusses how pregnancy, a unique physiological state, can modify them. The fetoplacental adaptations that protect against fetal bile acid toxicity are reviewed. We highlight the importance of bile acid regulation during gestation by discussing the liver disease of pregnancy, intrahepatic cholestasis of pregnancy (ICP) and how genetic, endocrine and environmental factors contribute to the disease aetiology at a cellular and molecular level. PMID:23159988

  10. The Frequency of Bacterial Agents in the Bile Juice of Patients with Bile Stones and

    Tajeddin E


    Background and objectives: Bile in healthy people is a sterile fluid andpresence of any microorganism can be a marker for a disorder likecholelithiasis. The aim of this study was to determine the frequencyof bacterial agents in the bile of patients with bilestone, malignant pancreaticand biliary diseases.Material and Methods: One hundred and two bile samples were obtained,during six months in 2011, from patients subjected to ERCP in Taleghanihospital, Tehran. First, Patient's clinical data, t...

  11. Percutaneous transhepatic biliary drainage in patients with postsurgical bile leakage and nondilated intrahepatic bile ducts

    Jong, Egbert; Moelker, Adriaan; Leertouwer, Trude; Spronk, Sandra; van Dijk, Monique; Eijck, Casper


    textabstractObjective and Background: Bile leakage is a serious postoperative complication and percutaneous transhepatic biliary drainage (PTBD) may be an option when endoscopic treatment is not feasible. In this retrospective study, we established technical and clinical success rates as well as the complication rates of PTBD in a large group of patients with postoperative bile leakage. Methods: Data on all patients with nondilated intrahepatic bile ducts who underwent a PTBD procedure for th...

  12. Re-characterization of mono-2-ethylhexyl phthalate hydrolase belonging to the serine hydrolase family.

    Iwata, Makoto; Imaoka, Takuya; Nishiyama, Takashi; Fujii, Takao


    A novel bacterium assimilating di-2-ethylhexyl phthalate as a sole carbon source was isolated, and identified as a Rhodococcus species and the strain was named EG-5. The strain has a mono-2-ethylhexyl phthalate (MEHP) hydrolase (EG-5 MehpH), which exhibits some different enzymatic features when compared with the previously reported MEHP hydrolase (P8219 MehpH) from Gordonia sp. These differences include different pH optimum activity, maximal reaction temperature and heat stability. The Km and Vmax values of EG-5 MehpH were significantly higher than those of P8219 MehpH. The primary structure of EG-5 MehpH showed the highest sequence identity to that of P8219 MehpH (39%) among hydrolases. The phylogenetic tree suggested that EG-5 MehpH and P8219 MehpH were categorized in different groups of the novel MEHP hydrolase family. Mutation of a conserved R(109) residue of EG-5 MehpH to a hydrophobic residue resulted in a dramatic reduction in the Vmax value towards MEHP without affecting the Km value. These results indicate that this residue may neutralize the negative charge of a carboxylate anion of MEHP, and thus inhibit the catalytic nucleophile from attacking the ester bond. In other words, the R residue blocks inhibition from the carboxylate anion of MEHP. Recently, registered hypothetical proteins exhibiting 98% or 99% identities for EG-5 MehpH or for P8219 MehpH were found from some pathogens belonging to Actinomycetes. The protein may have other activities besides MEHP hydrolysis and function in other physiological reactions in some Actinomycetes. PMID:26868518

  13. Primary hepatocellular carcinoma in extrahepatic bile duct

    Jeong, Seok Tae; Ham, Soo Youn; Park, Cheol Min; Kim, Jung Hyuk; Cha, In Ho; Chung, Kyoo Byung; Suh, Woon Hyuck; Lee, Chang Hong [College of Medicine, Korea University, Seoul (Korea, Republic of)


    Obstructive jaundice due to hepatocellular carcinoma in an extrahepatic bile duct, without a mass lesion in the liver parenchyma, is extremely rare. We experienced two cases of primary hepatocellular carcinoma arising from an extrahepatic bile duct: one in a 53-year-old man whose {alpha} -fetoprotein value was 800 ng/ml, and another in a 39-year-old woman, in whom the mass lesion was found to be attached to an extrahepatic bile duct. These tumors had a well-marginated sausage-like shape on CT and US, and the contrast media passed freely along their margins on both PTC and ERCP. Recurrences of these tumors were observed in the extrahepatic bile duct 6 and 2 months after surgery, respectively.

  14. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation.

    Berman, Marvin D; Carey, Martin C


    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. PMID:25359538

  15. Inhibition of methanogenesis by human bile.

    Florin, T H; Woods, H J


    The factors that regulate methanogenesis in humans have not been established. The presence of bile acid, which is lost into the colon from the small intestine, may be an important regulatory factor of methanogenesis. To examine this possibility, the effect of human bile on methane production by faecal cultures, and the in vivo effect of biliary diversion on breath methane excretion in a methanogenic choledochostomy patient, were investigated. Faecal suspensions (0.1%) from five methanogenic h...

  16. Palliative irradiation of the bile ducts

    Kutzner, J.; Klose, K.; Keller, E.


    Carcinoma of the common hepatic bile duct or common bile duct were treated by interstitial irradiation with gold seeds using the percutaneous transhepatic drainage partly boosted by external irradiation. The interstitial dose of 50 Gy was given in two applications and 40 Gy by linac. Twice histological examination showed wide tumor destruction of local irradiation, but also much more tumor extension than seen before by diagnostic investigation. Mostly the therapy is only palliative because of the infiltration of liver and lymphnodes. (orig.).

  17. Differential expression of cholangiocyte and ileal bile acid transporters following bile acid supplementation and depletion

    N. Sertac Kip; Konstantinos N. Lazaridis; Anatoliy I. Masyuk; Patrick L. Splinter; Robert C. Huebert; Nicholas F. LaRusso


    AIM: We have previously demonstrated that cholangiocytes,the epithelial cells lining intrahepatic bile ducts, encode two functional bile acid transporters via alternative splicing of a single gene to facilitate bile acid vectorial transport.Cholangiocytes possess ASBT, an apical sodium-dependent bile acid transporter to take up bile acids, and t-ASBT, a basolateral alternatively spliced and truncated form of ASBT to efflux bile acids. Though hepatocyte and ileal bile acid transporters are in part regulated by the flux of bile acids,the effect of alterations in bile acid flux on the expression of t-ASBT in terminal ileocytes remains unclear. Thus, we tested the hypothesis that expression of ASBT and t-ASBT in cholangiocytes and ileocytes was regulated by bile acid flux. METHODS: Expression of ASBT and t-ASBT message and protein in cholangiocytes and ileocytes isolated from pairfed rats given control (C) and 1% taurocholate (TCA) or 5% cholestyramine (CY) enriched diets, were assessed by both quantitative RNase protection assays and quantitative immunoblotting. The data obtained from each of the control groups were pooled to reflect the changes observed following TCA and CY treatments with respect to the control diets.Cholangiocyte taurocholate uptake was determined using a novel microperfusion technique on intrahepatic bile duct units (IBDUs) derived from C, TCA and CY fed rats.RESULTS: In cholangiocytes, both ASBT and t-ASBT message RNA and protein were significantly decreased in response to TCA feeding compared to C diet. In contrast,message and protein of both bile acid transporters significantly increased following CY feeding compared to C diet. In the ileum, TCA feeding significantly up-regulated both ASBT and t-ASBT message and protein compared to C diet, while CY feeding significantly down-regulated message and protein of both bile acid transporters compared to C diet. As anticipated from alterations in cholangiocyte ASBT expression, the uptake of

  18. Pharmacology of bile acid receptors: Evolution of bile acids from simple detergents to complex signaling molecules.

    Copple, Bryan L; Li, Tiangang


    For many years, bile acids were thought to only function as detergents which solubilize fats and facilitate the uptake of fat-soluble vitamins in the intestine. Many early observations; however, demonstrated that bile acids regulate more complex processes, such as bile acids synthesis and immune cell function through activation of signal transduction pathways. These studies were the first to suggest that receptors may exist for bile acids. Ultimately, seminal studies by many investigators led to the discovery of several bile acid-activated receptors including the farnesoid X receptor, the vitamin D receptor, the pregnane X receptor, TGR5, α5 β1 integrin, and sphingosine-1-phosphate receptor 2. Several of these receptors are expressed outside of the gastrointestinal system, indicating that bile acids may have diverse functions throughout the body. Characterization of the functions of these receptors over the last two decades has identified many important roles for these receptors in regulation of bile acid synthesis, transport, and detoxification; regulation of glucose utilization; regulation of fatty acid synthesis and oxidation; regulation of immune cell function; regulation of energy expenditure; and regulation of neural processes such as gastric motility. Through these many functions, bile acids regulate many aspects of digestion ranging from uptake of essential vitamins to proper utilization of nutrients. Accordingly, within a short time period, bile acids moved beyond simple detergents and into the realm of complex signaling molecules. Because of the important processes that bile acids regulate through activation of receptors, drugs that target these receptors are under development for the treatment of several diseases, including cholestatic liver disease and metabolic syndrome. In this review, we will describe the various bile acid receptors, the signal transduction pathways activated by these receptors, and briefly discuss the physiological processes that

  19. Radiotherapy of bile duct carcinoma

    Twenty-six patients with cholangiocarcinoma and nineteen patients with carcinoma of the gallbladder treated with external radiotherapy were analyzed. Of the twenty-six patients, eighteen had cancer of the hepatic hilus (Klatskin), four intrahepatic and the remaining four extrahepatic cholangiocarcinoma. All but two of the patients had advanced disease. Thirty-three patients received primary irradiation for unresectable tumors, ten patients adjuvant irradiation after non-curative gross tumor resection, and two patients preoperative radiotherapy. Patients with cholangiocarcinoma who underwent radiotherapy with relatively small radiation field tolerated the treatment well, but there was no significant difference in survival according to field size or radiation doses (TDF). On the other hand, patients with carcinoma of gallbladder were treated with larger field size and lower dose. In the patients without gross tumor resection, those receiving radiation doses≥90 TDF had significantly longer survival than 2) had longer survival (p=0.07). The patients with gross tumor resection had significantly longer survival than that without resection in both cholangiocarcinoma and carcinoma of gallbladder. Postmortem examination revealed tumor recurrence even in the patients with gross tumor resection, but widespread distant metastases were present simultaneously. Cholangitis and liver abscess were special and lethal conditions related to these carcinomas, and intensive therapy must be developed for these conditions. External radiotherapy may be effective in the treatment of bile duct carcinoma in terms of palliation and survival. (author)

  20. Novel microbial epoxide hydrolases for biohydrolysis of glycidyl derivatives

    Kotík, Michael; Břicháč, Jiří; Kyslík, Pavel


    Roč. 120, - (2005), s. 364-375. ISSN 0168-1656 Institutional research plan: CEZ:AV0Z5020903 Keywords : screening * epoxide hydrolase * biotransformation Subject RIV: EE - Microbiology, Virology Impact factor: 2.687, year: 2005

  1. Taurolithocholate impairs bile canalicular motility and canalicular bile secretion in isolated rat hepatocyte couplets

    Norihito Watanabe; Tatehiro Kagawa; Sei-ichiro Kojima; Shinji Takashimizu; Naruhiko Nagata; Yasuhiro Nishizaki; Tetsuya Mine


    AIM: To investigate the effects of taurolithocholate (TLC)on the canalicular motility in isolated rat hepatocyte couplets (IRHC).METHODS: TLC was added to IRHC at concentrations of 10 and 50 μmol/L, respectively. In each group, five time-lapse movies containing 3 representative bile canaliculi were taken under phase-contrast microscopy for 12 h. The number of bile canalicular contractions and the intervals between consecutive canalicular contractions were calculated. Furthermore, the effects of TLC on IRHC were examined by transmission electron microscopy.RESULTS: The bile canalicular contractions were spontaneous and forceful in the controls. Active vesicular movement was observed in the pericanalicular region. Immediately after the addition of TLC, the bile canaliculi were deformed, and canalicular bile was incorporated into the vacuoles. The canaliculi were gradually dilated, and canalicular contractions were markedly inhibited by TLC. The vesicular movements became extremely slow in the pericanalicular region. The number of canalicular contractions significantly decreased in the TLC-treated groups, as compared with that in the controls. The time intervals were prolonged, as the TLC dosage increased,indicating that bile secretion into the canaliculi was impaired with TLC. Transmission electron microscopy revealed the lamellar transformation of the canalicular membranes in IRHC treated with TLC.CONCLUSION: TLC impairs both the bile canalicular contractions and the canalicular bile secretion, possibly by acting directly on the canalicular membranes in TLCinduced cholestasis.

  2. Cationic amphiphilic microfibrillated cellulose (MFC) for potential use for bile acid sorption.

    Zhu, Xuhai; Wen, Yangbing; Cheng, Dong; Li, Changmo; An, Xingye; Ni, Yonghao


    In this work, Micro-fibrillated Cellulose (MFC) was cationically modified by quaternary ammonium groups with different chemical structures aiming to improve the sorption capacity to bile acid. The in-vitro bile acid sorption was performed by investigating various factors, such as quaternary ammonium group content and length of its alkyl substituent of the modified cationic MFC (CMFC), ionic strength, initial concentration and hydrophobicity of bile acid. The results showed that the sorption behavior of the modified CMFC was strongly influenced by the quaternary ammonium group content and the lengths of its alkyl substituent, the sorption capacity for the modified CMFC with a C18 alkyl substituent, was approximately 50% of that of Cholestyramine. The experimental isotherm results were well fitted into the Temkin model. The effect of salts in the solution was smaller for the bile acid sorption onto the hydrophobic CMFC than the CMFC. It was also found that the binding capacity of CMFC was higher for more hydrophobic deoxycholate in comparison with cholate. PMID:26256387

  3. 胆盐输出泵基因多态性与特发性婴儿肝炎肝内胆汁瘀积的关系%Relationship between Bile Salt Export Pump Gene Polymorphisms and lntrahepatic Cholestasis in Idiopathic In-fantile Hepatitis

    邓亚楠; 王琳琳; 陈秀奇; 唐清; 高国鹏; 单庆文; 云翔


    目的 探讨特发性婴儿肝炎肝内胆汁瘀积患儿胆盐输出泵(BSEP)基因的突变情况.方法 收集2008年10月- 2010年2月就诊于广西医科大学第一附属医院儿科的婴儿胆汁瘀积性肝炎患儿81例(病例组),48例无肝内胆汁瘀积、肝功能正常的婴儿为对照组.提取病例组和对照组儿童外周血DNA,采用聚合酶链反应-单链构象多态性(PCR-SSCP)和DNA测序技术检测BSEP基因上2、3、4、5、6、9、10、16、17、23、24外显子基因多态性,分析BSEP基因多态性与特发性婴儿肝炎肝内胆汁瘀积之间的关系.结果在外显子24上检测到BSEP A1028A同义突变,编码的氨基酸未改变,均为丙氨酸;其他10个外显子均未发现异常突变.A1028A基因型在病例组,CC型53例(占65.4%),TC型28例(占34.6%),C等位基因频率为82.7%;对照组中CC型32例(占66.7%),TC型16例(占33.3%),C等位基因频率为83.3%.二组基因型差异经Fisher's精确概率法检验,差异无统计学意义(P>0.05);等位基因频率经Fisher's精确概率法检验,差异亦无统计学意义(P>0.05).结论 尚不能认为BSEP A1028A是特发性婴儿肝炎肝内胆汁瘀积的一个危险因素.BSEP A1028A与特发性婴儿肝炎肝内胆汁瘀积发生的易感性无关.%Objective To evaluate the bile salt export pump(BSEP) gene polymorphisms in the pathogenesis of intrahepatic cholestasis in idiopathic infantile hepatitis. Methods The genomic DNA was obtained from peripheral blood of 81 patients with idiopathic infantile cholestasis as case group, who hospitalized in the Department of Pediatrics of the First Affiliated Hospital of Guangxi Medical University from Oct. 2008 to Feb.2010,and 48 normal liver function infants without intrahepatic cholestasis as control group. The BSEP gene 2,3,4,5,6,9,10, 16,17,23,24 exons polymorphism were genotyped by polymerase chain reaction - single strand conformation polymorphism(PCR - SSCP) and sequenced. The statistical

  4. Further characterization of intestinal lactase/phlorizin hydrolase

    Skovbjerg, H; Norén, O; Sjöström, H;


    enzyme were shown to have a considerable activity against cellotriose and cellotetraose, and a low but significant activity against cellulose. The lactase/phlorizin hydrolase isolated from pigs in which the pancreatic ducts had been disconnected 3 days before death and from Ca2+-precipitated enterocyte...... membranes (basolateral and intracellular membranes) exhibited in SDS-polyacrylamide gel electrophoresis the same size of constituent polypeptides and the same catalytic and immunological properties as a normal brush border lactase/phlorizin hydrolase....

  5. Direct detection, cloning and characterization of a glucoside hydrolase from forest soil.

    Hua, Mei; Zhao, Shubo; Zhang, Lili; Liu, Dongbo; Xia, Hongmei; Li, Fan; Chen, Shan


    A glucoside hydrolase gene, egl01, was cloned from the soil DNA of Changbai Mountain forest by homologous PCR amplification. The deduced sequence of 517 amino acids included a catalytic domain of glycoside hydrolase family 5 and was homologous to a putative cellulase from Bacillus licheniformis. The recombinant enzyme, Egl01, was maximally active at pH 5 and 50 °C and it was stable at pH 3-9, 4-50 °C, and also stable in the presence of metal ions, organic solvents, surfactants and salt. Its activity was above 120 % in 2-3 M NaCl/KCl and over 70 % was retained in 1-4 M NaCl/KCl for 6d. Egl01 hydrolyzed carboxymethyl cellulose, beechwood xylan, crop stalk, laminarin, filter paper, and avicel but not pNPG, indicating its broad substrate specificity. These properties make this recombinant enzyme a promising candidate for industrial applications. PMID:25700816

  6. Hepatic bile acids and bile acid-related gene expression in pregnant and lactating rats

    Qiong N. Zhu


    Full Text Available Background. Significant physiological changes occur during pregnancy and lactation. Intrahepatic cholestasis of pregnancy (ICP is a liver disease closely related to disruption of bile acid homeostasis. The objective of this study was to examine the regulation of bile acid synthesis and transport in normal pregnant and lactating rats. Materials and Methods. Livers from timed pregnant SD rats were collected on gestational days (GD 10, 14 and 19, and postnatal days (PND 1, 7, 14 and 21. Total bile acids were determined by the enzymatic method, total RNA was isolated and subjected to real time RT-PCR analysis. Liver protein was extracted for western-blot analysis. Results. Under physiological conditions hepatic bile acids were not elevated during pregnancy but increased during lactation in rats. Bile acid synthesis rate-limiting enzyme Cyp7a1 was unchanged on gestational days, but increased on PND14 and 21 at mRNA and protein levels. Expression of Cyp8b1, Cyp27a1 and Cyp7b1 was also higher during lactation. The mRNA levels of small heterodimer partner (SHP and protein levels of farnesoid X receptor (FXR were increased during pregnancy and lactation. Bile acid transporters Ntcp, Bsep, Mrp3 and Mrp4 were lower at gestation, but increased during lactation. Hepatic Oatp transporters were decreased during pregnancy and lactation. Conclusion. Hepatic bile acid homeostasis is maintained during normal pregnancy in rats, probably through the FXR-SHP regulation. The expression of bile acid synthesis genes and liver bile acid accumulation were increased during lactation, together with increased expression of bile acid efflux transporter Bsep, Mrp3 and Mrp4.

  7. Bile composition in Alagille Syndrome and PFIC patients having Partial External Biliary Diversion

    Thompson Richard J


    Full Text Available Abstract Background Partial External Biliary Diversion (PEBD is a surgical intervention to treat children with Progressive Familial Intrahepatic Cholestasis (PFIC and Alagille syndrome (AGS. PEBD can reduce disease progression, and examining the alterations in biliary lipid composition may be a prognostic factor for outcome. Methods Biliary lipid composition and the clinical course of AGS and PFIC patients were examined before and after PEBD. Results Pre-PEBD bile from AGS patients had greater chenodeoxycholic/cholic acid (CDCA/CA, bile salt, cholesterol and phospholipid concentrations than PFIC patients. AGS patients, and PFIC patients with familial intrahepatic cholestasis 1 (FIC1 genotype, responded better to PEBD than PFIC patients with bile salt export protein (BSEP genotype. After successful PEBD, AGS patients have higher biliary lipid concentrations than PFIC patients and PEBD also increases biliary phospholipid concentrations in FIC1 patients. Conclusion Both AGS and FIC1 patients can benefit from PEBD, and preserved biliary phospholipid concentrations may be associated with better outcomes post-PEBD.

  8. Salt Tolerance

    Xiong, Liming; Zhu, Jian-Kang


    Studying salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential salt tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are sh...

  9. Bile acid formation in primary human hepatocytes

    Curt Einarsson; Ewa Ellis; Anna Abrahamsson; Bo-G6ran Ericzon; Ingemar Bj rkhem; Magnus Axelson


    AIM To evaluate a culture system for bile acid formation in primary human hepatocytes in comparison with HepG2 cells. METHODS Hepatocytes were isolated from normal human liver tissue and were cultured in serum-free William's E medium. The medium was collected and renewed every 24 h. Bile acids and their precursors in media were finally analysed by gas chromatography-mass spectrometry. RESULTS Cholic acid ( CA ) andchenodeoxycholic acid (CDCA) conjugated with glycine or taurine accounted for 70% and 25% of total steroids. A third of CDCA was also conjugated with sulphuric acid. Dexamathasone and thyroid hormorm alone or in combination did not significantly effect bile acid formation. The addition of cyclosporin A (10 μmol/L) inhibited the synthesis of CA and CDCA by about 13% and 30%, respectively. CONCLUSION Isolated human hepatocytes in primary culture behave as in the intact liver by converting cholesterol to conjugated CA and CDCA. This is in contrast to cultured HepG2 cells, which release large amounts of bile acid precursors and unconjugated bile acids into the medium.

  10. Clinical value of bile acids radioimmunoassay

    In 50 blood donors, 87 patients with various liver and bile disorders, 50 hemodialyse patients and 50 patients prior to and immediately after cardiac swigery, cholyl glycine (CG) and sulfolithocholyl glycine (SLCG) were determined. Long-term observations were carried out on a further 10 patients with non-A/non-B hepatitis and 10 patients without hepatitis. Correlations were found between the values of alkaline phosphatase, GPT, GOT and bilirubin. Consequently the determination of bile acid, here above all SLCG, constitutes a suitable means to detect subclinical functional liver disorders. The examination of the post-operative functional liver disorders following cardiac swigery showed that there is a distinct time shift between the mostly transitory increase in enzyme activity and the SLCG levels. Surprisingly, the long-term observations showed that increased bile acid levels are already measured during the hepatitis incubation period at normal enzyme activities. It was not possible, however to identify hepatitic patients already during incubation by assay of the bile acid level. Whereas the determination of standard laboratory parameters remains predominant in the description of liver cell damage, the importance of serum bile acid determination is seen in the description of functional liver disorders which are not characterized by increased enzyme activities. (orig.)