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Sample records for human bile salt

  1. Fetal bile salt metabolism

    PubMed Central

    Smallwood, R. A.; Lester, R.; Piasecki, G. J.; Klein, P. D.; Greco, R.; Jackson, B. T.

    1972-01-01

    Bile salt metabolism was studied in fetal dogs 1 wk before term. The size and distribution of the fetal bile salt pool were measured, and individual bile salts were identified. The hepatic excretion of endogenous bile salts was studied in bile fistula fetuses, and the capacity of this excretory mechanism was investigated by the i.v. infusion of a load of sodium taurocholate-14C up to 20 times the endogenous pool size. The total fetal bile salt pool was 30.9±2.7 μmoles, of which two-thirds was in the fetal gallbladder. Expressed on a body weight basis, this was equal to approximately one-half the estimated pool size in the adult dog (119.2±11.3 vs. 247.5±33.1 μmoles/kg body wt). Measurable quantities of bile salt were found in small bowel (6.0±1.8 μmoles), large bowel (1.1±0.3 μmoles), liver (1.2±0.5 μmoles), and plasma (0.1±0.03 μmoles). Plasma bile salt levels were significantly greater in fetal than in maternal plasma (1.01±0.24 μg/ml vs. 0.36±0.06 μg/ml; P < 0.05). Fetal hepatic bile salt excretion showed a fall over the period of study from 2.04±0.34 to 0.30±0.07 μmoles/hr. The maximal endogenous bile salt concentration in fetal hepatic bile was 18.7±1.5 μmoles/ml. The concentration in fetal gallbladder bile was 73.9±8.6 μmoles/ml; and, in those studies in which hepatic and gallbladder bile could be compared directly, the gallbladder appeared to concentrate bile four- to fivefold. Taurocholate, taurochenodeoxycholate, and taurodeoxycholate were present in fetal bile, but no free bile salts were identified. The presence of deoxycholate was confirmed by thin-layer chromatography and gas liquid chromatography, and the absence of microorganisms in fetal gut suggests that it was probably transferred from the maternal circulation. After infusion of a taurocholate load, fetal hepatic bile salt excretion increased 30-fold, so that 85-95% of the dose was excreted by the fetal liver during the period of observation. Placental transfer accounted

  2. Evolutionary diversity of bile salts in reptiles and mammals, including analysis of ancient human and extinct giant ground sloth coprolites.

    PubMed

    Hagey, Lee R; Vidal, Nicolas; Hofmann, Alan F; Krasowski, Matthew D

    2010-05-06

    Bile salts are the major end-metabolites of cholesterol and are also important in lipid and protein digestion and in influencing the intestinal microflora. We greatly extend prior surveys of bile salt diversity in both reptiles and mammals, including analysis of 8,000 year old human coprolites and coprolites from the extinct Shasta ground sloth (Nothrotherium shastense). While there is significant variation of bile salts across species, bile salt profiles are generally stable within families and often within orders of reptiles and mammals, and do not directly correlate with differences in diet. The variation of bile salts generally accords with current molecular phylogenies of reptiles and mammals, including more recent groupings of squamate reptiles. For mammals, the most unusual finding was that the Paenungulates (elephants, manatees, and the rock hyrax) have a very different bile salt profile from the Rufous sengi and South American aardvark, two other mammals classified with Paenungulates in the cohort Afrotheria in molecular phylogenies. Analyses of the approximately 8,000 year old human coprolites yielded a bile salt profile very similar to that found in modern human feces. Analysis of the Shasta ground sloth coprolites (approximately 12,000 years old) showed the predominant presence of glycine-conjugated bile acids, similar to analyses of bile and feces of living sloths, in addition to a complex mixture of plant sterols and stanols expected from an herbivorous diet. The bile salt synthetic pathway has become longer and more complex throughout vertebrate evolution, with some bile salt modifications only found within single groups such as marsupials. Analysis of the evolution of bile salt structures in different species provides a potentially rich model system for the evolution of a complex biochemical pathway in vertebrates. Our results also demonstrate the stability of bile salts in coprolites preserved in arid climates, suggesting that bile salt analysis

  3. Evolutionary diversity of bile salts in reptiles and mammals, including analysis of ancient human and extinct giant ground sloth coprolites

    PubMed Central

    2010-01-01

    Background Bile salts are the major end-metabolites of cholesterol and are also important in lipid and protein digestion and in influencing the intestinal microflora. We greatly extend prior surveys of bile salt diversity in both reptiles and mammals, including analysis of 8,000 year old human coprolites and coprolites from the extinct Shasta ground sloth (Nothrotherium shastense). Results While there is significant variation of bile salts across species, bile salt profiles are generally stable within families and often within orders of reptiles and mammals, and do not directly correlate with differences in diet. The variation of bile salts generally accords with current molecular phylogenies of reptiles and mammals, including more recent groupings of squamate reptiles. For mammals, the most unusual finding was that the Paenungulates (elephants, manatees, and the rock hyrax) have a very different bile salt profile from the Rufous sengi and South American aardvark, two other mammals classified with Paenungulates in the cohort Afrotheria in molecular phylogenies. Analyses of the approximately 8,000 year old human coprolites yielded a bile salt profile very similar to that found in modern human feces. Analysis of the Shasta ground sloth coprolites (approximately 12,000 years old) showed the predominant presence of glycine-conjugated bile acids, similar to analyses of bile and feces of living sloths, in addition to a complex mixture of plant sterols and stanols expected from an herbivorous diet. Conclusions The bile salt synthetic pathway has become longer and more complex throughout vertebrate evolution, with some bile salt modifications only found within single groups such as marsupials. Analysis of the evolution of bile salt structures in different species provides a potentially rich model system for the evolution of a complex biochemical pathway in vertebrates. Our results also demonstrate the stability of bile salts in coprolites preserved in arid climates

  4. Bile salts and calcium absorption.

    PubMed

    Webling, D D; Holdsworth, E S

    1966-09-01

    1. The study of the effect of bile salts on enhancing calcium absorption in the rachitic chick has been extended to bile salts not present in chick bile, e.g. glycine conjugates and bile alcohol sulphates. 2. Bile and bile salts cause an increase in calcium absorption from sparingly soluble calcium hydrogen phosphate when compared with a suspension of calcium hydrogen phosphate in saline. 3. If the bile ducts of normal rats are tied the absorption of calcium from calcium hydrogen phosphate decreases but can be restored by giving bile salts with the calcium salt. 4. Bile salts increase solubility in water of the sparingly soluble calcium salts, phytate and phosphate at pH values between 6 and 8. 5. Bile salts increase the solubility in lipid solvents of calcium in approximately the same proportion as they increase the absorption of calcium from the gut. 6. The physiological role of bile in calcium absorption and its mode of action are discussed.

  5. Crystal structure of the catalytic domain of human bile salt activated lipase.

    PubMed Central

    Terzyan, S.; Wang, C. S.; Downs, D.; Hunter, B.; Zhang, X. C.

    2000-01-01

    Bile-salt activated lipase (BAL) is a pancreatic enzyme that digests a variety of lipids in the small intestine. A distinct property of BAL is its dependency on bile salts in hydrolyzing substrates of long acyl chains or bulky alcoholic motifs. A crystal structure of the catalytic domain of human BAL (residues 1-538) with two surface mutations (N186D and A298D), which were introduced in attempting to facilitate crystallization, has been determined at 2.3 A resolution. The crystal form belongs to space group P2(1)2(1)2(1) with one monomer per asymmetric unit, and the protein shows an alpha/beta hydrolase fold. In the absence of bound bile salt molecules, the protein possesses a preformed catalytic triad and a functional oxyanion hole. Several surface loops around the active site are mobile, including two loops potentially involved in substrate binding (residues 115-125 and 270-285). PMID:11045623

  6. Bile salts and hydrodynamics of bile formation.

    PubMed

    Cotting, J; Reichen, J

    1989-01-01

    We report a novel method to assess bile secretory pressure using a Statham pressure transducer. The studies were performed in vivo in male Sprague-Dawley rats under pentobarbital anesthesia. Maximal secretory pressure averaged 21.8 +/- 1.1 (S.D.) cmH2O. The bile accumulated after 10 min of obstruction was 7.7 +/- 2.8 microliters.g-1; assuming a basal biliary dead space of 2.3 microliters.g-1, the distended capacity of the biliary tree averaged 10 microliters.g-1. The small volume of the strain gauge permitted calculation of compliance of the biliary tree which averaged 0.35 +/- 0.12 microliters.cmH2O-1.g-1. Stimulation of bile flow by bile salts reduced the time required to reach maximal bile secretory pressure. Taurocholate but not taurodehydrocholate decreased maximal secretory pressure within minutes, the pressure-time curves showing a new equilibrium between bile formation and regurgitation forces. Both bile flow and bile salt recoveries were decreased by taurocholate but not by taurodehydrocholate. Taurocholate decreased biliary compliance while taurodehydrocholate had no effect. This provides further evidence that taurocholate increases the biliary permeability and suggests that this bile salt also affects the elastic properties of the biliary tree.

  7. Bile salts and calcium absorption

    PubMed Central

    Webling, D. D'A.; Holdsworth, E. S.

    1966-01-01

    1. The study of the effect of bile salts on enhancing calcium absorption in the rachitic chick has been extended to bile salts not present in chick bile, e.g. glycine conjugates and bile alcohol sulphates. 2. Bile and bile salts cause an increase in calcium absorption from sparingly soluble calcium hydrogen phosphate when compared with a suspension of calcium hydrogen phosphate in saline. 3. If the bile ducts of normal rats are tied the absorption of calcium from calcium hydrogen phosphate decreases but can be restored by giving bile salts with the calcium salt. 4. Bile salts increase solubility in water of the sparingly soluble calcium salts, phytate and phosphate at pH values between 6 and 8. 5. Bile salts increase the solubility in lipid solvents of calcium in approximately the same proportion as they increase the absorption of calcium from the gut. 6. The physiological role of bile in calcium absorption and its mode of action are discussed. PMID:4291037

  8. Bile salt-stimulated lipase: an animal model for human lactation

    SciTech Connect

    Hamosh, M.; Freed, L.M.; York, C.M.; Sturman, J.A.; Hamosh, P.

    1986-03-01

    To date, bile salt-stimulated lipase (BSSL), an important digestive enzyme for the newborn, has only been described in the milk of primates - human and gorilla. The authors report the presence of BSSL in milks of dog and cat. Serial collections from two dogs (day 1-49) and cats (day 5-57) were analyzed for BSSL activity using a /sup 3/H-triolein emulsion as substrate. Comparable analyses of pooled, term human milk were made for comparison. BSSL activity in individual dog milks (x = 32.0; range: 4.8-107.4 U/ml) was similar, while that in cat milk (x = 6.6; range: 2.2-16.9 U/ml) was lower than in human milk (x = 37.0; range: 10-80 U/ml; n = 35). Longitudinal patterns for BSSL differed depending upon the enzyme source. Dog, cat and human milk BSSL all showed a neutral to alkaline pH optimum (pH 7.0-8.4), stability at low pH, and 95-100% inhibition (at concentrations of 0.6 mM) by NaCl and eserine. BSSL activity from all sources had an obligate requirement for primary bile salts. These data are the first to show BSSL activity in milk from mammals other than human and gorilla. Presence of BSSL in nonprimate milk will permit the careful study of BSSL biology in the mammary gland as well as its role in neonatal fat digestion.

  9. COMPLEX EVOLUTION OF BILE SALTS IN BIRDS

    PubMed Central

    Hagey, Lee R.; Vidal, Nicolas; Hofmann, Alan F.; Krasowski, Matthew D.

    2010-01-01

    Bile salts are the major end-metabolites of cholesterol and are important in lipid digestion and shaping of the gut microflora. There have been limited studies of bile-salt variation in birds. The purpose of our study was to determine bile-salt variation among birds and relate this variation to current avian phylogenies and hypotheses on the evolution of bile salt pathways. We determined the biliary bile-salt composition of 405 phylogenetically diverse bird species, including 7 paleognath species. Bile salt profiles were generally stable within bird families. Complex bile-salt profiles were more common in omnivores and herbivores than in carnivores. The structural variation of bile salts in birds is extensive and comparable to that seen in surveys of bile salts in reptiles and mammals. Birds produce many of the bile salts found throughout nonavian vertebrates and some previously uncharacterized bile salts. One difference between birds and other vertebrates is extensive hydroxylation of carbon-16 of bile salts in bird species. Comparison of our data set of bird bile salts with that of other vertebrates, especially reptiles, allowed us to infer evolutionary changes in the bile salt synthetic pathway. PMID:21113274

  10. Predicting human intestinal absorption in the presence of bile salt with micellar liquid chromatography.

    PubMed

    Waters, Laura J; Shokry, Dina S; Parkes, Gareth M B

    2016-10-01

    Understanding intestinal absorption for pharmaceutical compounds is vital to estimate the bioavailability and therefore the in vivo potential of a drug. This study considers the application of micellar liquid chromatography (MLC) to predict passive intestinal absorption with a selection of model compounds. MLC is already known to aid prediction of absorption using simple surfactant systems; however, with this study the focus was on the presence of a more complex, bile salt surfactant, as would be encountered in the in vivo environment. As a result, MLC using a specific bile salt has been confirmed as an ideal in vitro system to predict the intestinal permeability for a wide range of drugs, through the development of a quantitative partition-absorption relationship. MLC offers many benefits including environmental, economic, time-saving and ethical advantages compared with the traditional techniques employed to obtain passive intestinal absorption values. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Bile salts as semiochemicals in fish

    USGS Publications Warehouse

    Buchinger, Tyler J.; Li, Weiming; Johnson, Nicholas S.

    2014-01-01

    Bile salts are potent olfactory stimuli in fishes; however the biological functions driving such sensitivity remain poorly understood. We provide an integrative review of bile salts as semiochemicals in fish. First, we present characteristics of bile salt structure, metabolism, and function that are particularly relevant to chemical communication. Bile salts display a systematic pattern of structural variation across taxa, are efficiently synthesized, and are stable in the environment. Bile salts are released into the water via the intestine, urinary tract, or gills, and are highly water soluble. Second, we consider the potential role of bile salts as semiochemicals in the contexts of detecting nearby fish, foraging, assessing risk, migrating, and spawning. Lastly, we suggest future studies on bile salts as semiochemicals further characterize release into the environment, behavioral responses by receivers, and directly test the biological contexts underlying olfactory sensitivity.

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

    PubMed

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

    2016-08-05

    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. Permeation enhancement of octreotide by specific bile salts in rats and human subjects: in vitro, in vivo correlations.

    PubMed Central

    Fricker, G.; Fahr, A.; Beglinger, C.; Kissel, T.; Reiter, G.; Drewe, J.

    1996-01-01

    study with healthy volunteers. After oral administration of 4 mg octreotide in the presence of 100 mg bile salt, an average bioavailability of the peptide of 1.26% was achieved in the presence of CDCA, whereas in the presence of UDCA a bioavailability of only 0.13% was reached. This difference was statistically significant (P < 0.01). 7. In conclusion, the co-administration of CDCA is able to enhance the enteral absorption of octreotide. The in vitro and in situ experiments were predictive for the observed effect in human subjects. PMID:8825366

  14. Functional genomic analysis of bile salt resistance in Enterococcus faecium

    PubMed Central

    2013-01-01

    Background Enterococcus faecium is a Gram-positive commensal bacterium of the mammalian intestinal tract. In the last two decades it has also emerged as a multi-resistant nosocomial pathogen. In order to survive in and colonize the human intestinal tract E. faecium must resist the deleterious actions of bile. The molecular mechanisms exploited by this bacterium to tolerate bile are as yet unexplored. Results In this study we used a high-throughput quantitative screening approach of transposon mutant library, termed Microarray-based Transposon Mapping (M-TraM), to identify the genetic determinants required for resistance to bile salts in E. faecium E1162. The gene gltK, which is predicted to encode a glutamate/aspartate transport system permease protein, was identified by M-TraM to be involved in bile resistance. The role of GltK in bile salt resistance was confirmed by the subsequent observation that the deletion of gltK significantly sensitized E. faecium E1162 to bile salts. To further characterize the response of E. faecium E1162 to bile salts, we performed a transcriptome analysis to identify genes that are regulated by exposure to 0.02% bile salts. Exposure to bile salts resulted in major transcriptional rearrangements, predominantly in genes involved in carbohydrate, nucleotide and coenzyme transport and metabolism. Conclusion These findings add to a better understanding of the molecular mechanisms by which E. faecium responds and resists the antimicrobial action of bile salts. PMID:23641968

  15. Bile salt-stimulated lipase of human milk: characterization of the enzyme from preterm and term milk

    SciTech Connect

    Freed, L.M.; Hamosh, P.; Hamosh, M.

    1986-03-01

    The bile salt-stimulated lipase (BSSL) of human milk is an important digestive enzyme in the newborn whose pancreatic function is immature. Milk from mothers delivering premature infants (preterm milk) has similar levels of BSSL activity to that of mothers of term infants (term milk). This study has determined whether the BSSL in preterm milk has the same characteristics as that in term milk. Milk samples were collected during the first 12 wk of lactation from seven mothers of infants born at 26-30 wk (very preterm, VPT), 31-37 wk (preterm, PT) and 37-42 wk (term, T) gestation. BSSL activity was measured using /sup 3/H-triolein emulsion as substrate. Time course, bile salt and enzyme concentration, pH and pH stability were studied, as well as inhibition of BSSL by eserine. The characteristics of BSSL from preterm and term milk were identical as were comparisons between colostrum and mature milk BSSL. BSSL from all milk sources had a neutral-to-alkaline pH optimum (pH 7.3-8.9), was stable at low pH for 60 min, and was 95-100% inhibited by eserine (greater than or equal to 0.6 mM). BSSL activity, regardless of enzyme source, was bile-salt dependent and was stimulated only by primary bile salts (taurocholate, glycocholate). The data indicate that the BSSL in milks of mothers delivering as early as 26 wk gestation is identical to that in term milk.

  16. Phosphatidylinositol-3-kinase p110γ Contributes to Bile Salt-Induced Apoptosis in Primary Rat Hepatocytes and Human Hepatoma Cells

    PubMed Central

    Hohenester, Simon; Gates, Anna; Wimmer, Ralf; Beuers, Ulrich; Anwer, M. Sawkat; Rust, Christian; Webster, Cynthia R.L.

    2010-01-01

    Background & Aims Glycochenodeoxycholate (GCDC) and taurolithocholate (TLC) are hepatotoxic and cholestatic bile salts, whereas tauroursodeoxycholate (TUDC) is cytoprotective and anticholestatic. Yet they all act, in part, through phosphatidylinositol-3-kinase(PI3K)-dependent mechanisms (“PI3K-paradox”). Hepatocytes express three catalytic PI3K Class I isoforms (p110α/β/γ), specific functions of which, in liver, are unclear. In other cell types, p110γ is associated with detrimental effects. To shed light on the PI3K enigma, we determined whether hydrophobic and hydrophilic bile salts differentially activate distinct p110 isoforms in hepatocytes, and whether p110γ mediates bile salt-induced hepatocyte cell death. Methods Isoform-specific PI3K activity assays were established to determine isoform activation by bile salts in rat hepatocytes. Activation of Akt and JNK were determined by immunoblotting. Following stimulation with hydrophobic bile salts, hepatocellular apoptosis was determined morphologically after Hoechst staining and by analysis of caspase-3/-7 activity or caspase-3 cleavage. Activity or expression of PI3K p110γ was inhibited pharmacologically (AS604850) or by knockdown using specific siRNA. Results All bile salts tested activated p110β, while p110α was activated by TUDC and GCDC. Intriguingly, only hydrophobic bile salts activated p110γ. Inhibition of p110γ attenuated GCDC-induced Akt- and JNK-activation, but did not alter TUDC- or cAMP-induced Akt signaling in rat hepatocytes. Inhibition or knockdown of p110γ markedly attenuated hydrophobic bile salt-induced apoptosis in rat hepatocytes and human hepatoma cell lines but did not alter Fas-, tumor necrosis factor α- and etoposide-induced apoptosis. Depletion of Ca++ prevented GCDC-induced toxicity in rat hepatocytes but did not affect GCDC-induced Akt- and JNK-activation. Conclusions PI3K p110γ is activated by hydrophobic, but not hydrophilic bile salts. Bile salt-induced hepatocyte

  17. Phosphatidylinositol-3-kinase p110γ contributes to bile salt-induced apoptosis in primary rat hepatocytes and human hepatoma cells.

    PubMed

    Hohenester, Simon; Gates, Anna; Wimmer, Ralf; Beuers, Ulrich; Anwer, M Sawkat; Rust, Christian; Webster, Cynthia R L

    2010-11-01

    Glycochenodeoxycholate (GCDC) and taurolithocholate (TLC) are hepatotoxic and cholestatic bile salts, whereas tauroursodeoxycholate (TUDC) is cytoprotective and anticholestatic. Yet they all act, in part, through phosphatidylinositol-3-kinase(PI3K)-dependent mechanisms ("PI3K-paradox"). Hepatocytes express three catalytic PI3K Class I isoforms (p110α/β/γ), specific functions of which, in liver, are unclear. In other cell types, p110γ is associated with detrimental effects. To shed light on the PI3K enigma, we determined whether hydrophobic and hydrophilic bile salts differentially activate distinct p110 isoforms in hepatocytes, and whether p110γ mediates bile salt-induced hepatocyte cell death. Isoform-specific PI3K activity assays were established to determine isoform activation by bile salts in rat hepatocytes. Activation of Akt and JNK was determined by immunoblotting. Following stimulation with hydrophobic bile salts, hepatocellular apoptosis was determined morphologically after Hoechst staining and by analysis of caspase-3/-7 activity or caspase-3 cleavage. Activity or expression of PI3K p110γ was inhibited pharmacologically (AS604850) or by knock-down using specific siRNA. All bile salts tested activated p110β, while p110α was activated by TUDC and GCDC. Intriguingly, only hydrophobic bile salts activated p110γ. Inhibition of p110γ attenuated GCDC-induced Akt- and JNK-activation, but did not alter TUDC- or cAMP-induced Akt-signaling in rat hepatocytes. Inhibition or knock-down of p110γ markedly attenuated hydrophobic bile salt-induced apoptosis in rat hepatocytes and human hepatoma cell lines but did not alter Fas-, tumor necrosis factor α- and etoposide-induced apoptosis. Depletion of Ca(++) prevented GCDC-induced toxicity in rat hepatocytes but did not affect GCDC-induced Akt- and JNK-activation. PI3K p110γ is activated by hydrophobic, but not hydrophilic bile salts. Bile salt-induced hepatocyte apoptosis is partly mediated via a PI3K p110

  18. Evolution of substrate specificity for the bile salt transporter ASBT (SLC10A2)[S

    PubMed Central

    Lionarons, Daniël A.; Boyer, James L.; Cai, Shi-Ying

    2012-01-01

    The apical Na+-dependent bile salt transporter (ASBT/SLC10A2) is essential for maintaining the enterohepatic circulation of bile salts. It is not known when Slc10a2 evolved as a bile salt transporter or how it adapted to substantial changes in bile salt structure during evolution. We characterized ASBT orthologs from two primitive vertebrates, the lamprey that utilizes early 5α-bile alcohols and the skate that utilizes structurally different 5β-bile alcohols, and compared substrate specificity with ASBT from humans who utilize modern 5β-bile acids. Everted gut sacs of skate but not the more primitive lamprey transported 3H-taurocholic acid (TCA), a modern 5β-bile acid. However, molecular cloning identified ASBT orthologs from both species. Cell-based assays using recombinant ASBT/Asbt's indicate that lamprey Asbt has high affinity for 5α-bile alcohols, low affinity for 5β-bile alcohols, and lacks affinity for TCA, whereas skate Asbt showed high affinity for 5α- and 5β-bile alcohols but low affinity for TCA. In contrast, human ASBT demonstrated high affinity for all three bile salt types. These findings suggest that ASBT evolved from the earliest vertebrates by gaining affinity for modern bile salts while retaining affinity for older bile salts. Also, our results indicate that the bile salt enterohepatic circulation is conserved throughout vertebrate evolution. PMID:22669917

  19. Bile

    MedlinePlus

    ... the digestive tract. Bile contains: Mostly cholesterol Bile acids (also called bile salts) Bilirubin (a breakdown product or red blood cells) It also contains: Water Body salts (such as potassium and sodium) Copper ...

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

    PubMed Central

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

    2008-01-01

    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-based reporter assay, human PXR was activated by a wide variety of bile salts. In contrast, zebrafish PXR was activated efficiently only by cyprinol sulfate, the major zebrafish bile salt, but not by recent bile acids. Chicken, mouse, rat, and rabbit PXRs were all activated by species-specific bile acids and by early fish bile alcohol sulfates. In addition, phylogenetic analysis using maximum likelihood demonstrated evidence for non-neutral evolution of the PXR ligand-binding domain. PXR activation by bile salts has expanded from narrow specificity for C27 bile alcohol sulfates (early fish) to a broader specificity for recent bile acids (birds, mammals). PXR specificity for bile salts has thus paralleled the increasing complexity of the bile salt synthetic pathway during vertebrate evolution, an unusual example of ligand-receptor co-evolution in the nuclear hormone receptor superfamily. PMID:15718292

  1. Bile salts of the coelacanth, Latimeria chalumnae.

    PubMed

    Kihira, K; Akashi, Y; Kuroki, S; Yanagisawa, J; Nakayama, F; Hoshita, T

    1984-12-01

    Bile salts of the coelacanth, Latimeria chalumnae, Smith, have been analyzed and shown to have three bile alcohols, latimerol, 5 alpha-cyprinol, and 5 alpha-cholestane-3 beta, 7 alpha,-12 alpha,25,26-pentol, two C24 bile acids, chenodeoxycholic acid and cholic acid, one C26 bile acid, probably 3 beta, 7 alpha, 12 alpha-trihydroxy-27-nor-5 alpha-cholestan-26-oic acid, and two C27 bile acids, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha-cholestan-26-oic acid and 3 beta,7 alpha,12 alpha-trihydroxy-5 alpha-cholestan-26-oic acid as determined by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry.

  2. DnaK from Bifidobacterium animalis subsp. lactis is a surface-exposed human plasminogen receptor upregulated in response to bile salts.

    PubMed

    Candela, Marco; Centanni, Manuela; Fiori, Jessica; Biagi, Elena; Turroni, Silvia; Orrico, Catia; Bergmann, Simone; Hammerschmidt, Sven; Brigidi, Patrizia

    2010-06-01

    Bifidobacterium animalis subsp. lactis lives in the gastrointestinal tract of most mammals, including humans. Recently, for the probiotic strain B. animalis subsp. lactis BI07, a dose-dependent plasminogen-binding activity was demonstrated and five putative plasminogen-binding proteins were identified. Here we investigated the role of surface DnaK as a B. animalis subsp. lactis BI07 plasminogen receptor. DnaK was visualized on the bacterial cell surface by transmission electron microscopy. The His-tagged recombinant DnaK protein showed a high affinity for human plasminogen, with an equilibrium dissociation constant in the nanomolar range. The capability to tolerate physiological concentrations of bile salts is a crucial feature for an intestinal symbiont micro-organism. By proteome analysis we demonstrated that the long-term exposure of B. animalis subsp. lactis BI07 to bile salts results in the upregulation of important surface plasminogen receptors such as DnaK and enolase. Moreover, adaptation of B. animalis subsp. lactis BI07 to physiological concentrations of bile salts significantly increased its capacity to interact with the host plasminogen system. By enhancing the bacterial capacity to interact with the host plasminogen, the gut bile environment may facilitate the colonization of the human host by B. animalis subsp. lactis BI07.

  3. Impact of Gut Microbiota-Mediated Bile Acid Metabolism on the Solubilization Capacity of Bile Salt Micelles and Drug Solubility.

    PubMed

    Enright, Elaine F; Joyce, Susan A; Gahan, Cormac G M; Griffin, Brendan T

    2017-04-03

    In recent years, the gut microbiome has gained increasing appreciation as a determinant of the health status of the human host. Bile salts that are secreted into the intestine may be biotransformed by enzymes produced by the gut bacteria. To date, bile acid research at the host-microbe interface has primarily been directed toward effects on host metabolism. The aim of this work was to investigate the effect of changes in gut microbial bile acid metabolism on the solubilization capacity of bile salt micelles and consequently intraluminal drug solubility. First, the impact of bile acid metabolism, mediated in vivo by the microbial enzymes bile salt hydrolase (BSH) and 7α-dehydroxylase, on drug solubility was assessed by comparing the solubilization capacity of (a) conjugated vs deconjugated and (b) primary vs secondary bile salts. A series of poorly water-soluble drugs (PWSDs) were selected as model solutes on the basis of an increased tendency to associate with bile micelles. Subsequently, PWSD solubility and dissolution was evaluated in conventional biorelevant simulated intestinal fluid containing host-derived bile acids, as well as in media modified to contain microbial bile acid metabolites. The findings suggest that deconjugation of the bile acid steroidal core, as dictated by BSH activity, influences micellar solubilization capacity for some PWSDs; however, these differences appear to be relatively minor. In contrast, the extent of bile acid hydroxylation, regulated by microbial 7α-dehydroxylase, was found to significantly affect the solubilization capacity of bile salt micelles for all nine drugs studied (p < 0.05). Subsequent investigations in biorelevant media containing either the trihydroxy bile salt sodium taurocholate (TCA) or the dihydroxy bile salt sodium taurodeoxycholate (TDCA) revealed altered drug solubility and dissolution. Observed differences in biorelevant media appeared to be both drug- and amphiphile (bile salt/lecithin) concentration

  4. Supramolecular Complexes Formed in Systems Bile Salt-Bilirubin-Silica

    NASA Astrophysics Data System (ADS)

    Vlasova, N. N.; Severinovskaya, O. V.; Golovkova, L. P.

    The formation of supramolecular complexes between bilirubin and primary micelles of bile salts has been studied. The association constants of bile salts and binding of bilirubin with these associates have been determined. The adsorption of bilirubin and bile salts from individual and mixed aqueous solutions onto hydrophobic silica surfaces has been investigated. The interaction of bilirubin with primary bile salt micelles and the strong retention in mixed micelles, which are supramolecular complexes, result in the adsorption of bilirubin in free state only.

  5. Structure based classification for bile salt export pump (BSEP) inhibitors using comparative structural modeling of human BSEP

    NASA Astrophysics Data System (ADS)

    Jain, Sankalp; Grandits, Melanie; Richter, Lars; Ecker, Gerhard F.

    2017-06-01

    The bile salt export pump (BSEP) actively transports conjugated monovalent bile acids from the hepatocytes into the bile. This facilitates the formation of micelles and promotes digestion and absorption of dietary fat. Inhibition of BSEP leads to decreased bile flow and accumulation of cytotoxic bile salts in the liver. A number of compounds have been identified to interact with BSEP, which results in drug-induced cholestasis or liver injury. Therefore, in silico approaches for flagging compounds as potential BSEP inhibitors would be of high value in the early stage of the drug discovery pipeline. Up to now, due to the lack of a high-resolution X-ray structure of BSEP, in silico based identification of BSEP inhibitors focused on ligand-based approaches. In this study, we provide a homology model for BSEP, developed using the corrected mouse P-glycoprotein structure (PDB ID: 4M1M). Subsequently, the model was used for docking-based classification of a set of 1212 compounds (405 BSEP inhibitors, 807 non-inhibitors). Using the scoring function ChemScore, a prediction accuracy of 81% on the training set and 73% on two external test sets could be obtained. In addition, the applicability domain of the models was assessed based on Euclidean distance. Further, analysis of the protein-ligand interaction fingerprints revealed certain functional group-amino acid residue interactions that could play a key role for ligand binding. Though ligand-based models, due to their high speed and accuracy, remain the method of choice for classification of BSEP inhibitors, structure-assisted docking models demonstrate reasonably good prediction accuracies while additionally providing information about putative protein-ligand interactions.

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

    PubMed

    Malik, Nisar Ahmad

    2016-05-01

    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.

  7. Macitentan does not interfere with hepatic bile salt transport.

    PubMed

    Treiber, Alexander; Äänismaa, Päivi; de Kanter, Ruben; Delahaye, Stephane; Treher, Marianne; Hess, Patrick; Sidharta, Patricia

    2014-07-01

    Treatment of pulmonary arterial hypertension with the endothelin receptor antagonist bosentan has been associated with transient increases in liver transaminases. Mechanistically, bosentan inhibits the bile salt export pump (BSEP) leading to an intrahepatic accumulation of cytotoxic bile salts, which eventually results in hepatocellular damage. BSEP inhibition by bosentan is amplified by its accumulation in the liver as bosentan is a substrate of organic anion-transporting polypeptide (OATP) transport proteins. The novel endothelin receptor antagonist macitentan shows a superior liver safety profile. Introduction of the less acidic sulfamide moiety and increased lipophilicity yield a hepatic disposition profile different from other endothelin receptor antagonists. Passive diffusion rather than OATP-mediated uptake is the driving force for macitentan uptake into the liver. Interaction with the sodium taurocholate cotransporting polypeptide and BSEP transport proteins involved in hepatic bile salt homeostasis is therefore limited due to the low intrahepatic drug concentrations. Evidence for this conclusion is provided by in vitro experiments in drug transporter-expressing cell lines, acute and long-term studies in rats and dogs, absence of plasma bile salt changes in healthy human volunteers after multiple dosing, and finally the liver safety profile of macitentan in the completed phase III morbidity/mortality SERAPHIN (Study with an Endothelin Receptor Antagonist in Pulmonary Arterial Hypertension to Improve Clinical Outcome) trial. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

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

    PubMed

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

    2016-01-01

    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.

  9. Bilirubin chemistry, ionization and solubilization by bile salts.

    PubMed

    Ostrow, J D; Celic, L

    1984-01-01

    Bilirubin is a linear tetrapyrrole whose conformation is affected by internal hydrogen bonds formed between the carboxyl side chains and dipyrromethenone rings. Structural variations include: constitutional isomerism of the vinyl or carboxyethyl side chains, geometric isomerism of the methene bridges, tautomerism of the lactam groups, conformational rotations about the central methylene bridge and ionization of one or both carboxyl groups. Aggregation of the dianion into dimers and multimers may occur. The pKa' values of the two carboxyl groups are affected greatly by the environment and may differ widely in micellar solutions like bile. Solubility of bilirubin in water is less than 1 nM at pH = 7 and about 0.1 microM at pH = 8. Nonetheless, it dissolves poorly in most lipid solvents, except for asymmetrical chloroalkanes. Hydrogen bond-breaking solvents, especially dimethyl sulfoxide, are most effective in solubilizing bilirubin. In bile salt solutions, solubility of bilirubin is well above the concentrations of unconjugated bilirubin found in normal human gallbladder bile, and is impaired by lecithin but unaffected by cholesterol. At physiological pH in bile salt solutions, bilirubin is predominantly in its monoanion form that binds readily to the micelles. In such solutions, addition of physiological concentrations of calcium precipitates calcium bilirubinate, leaving residual bilirubin concentrations of up to 15 microM in 50 mM taurocholate or close to the maximum bilirubin concentrations in normal bile. Studies in which disodium bilirubinate is dissolved in bile salt solutions and pH is adjusted to the physiological range reveal that metastable supersaturation with bilirubin may occur and that a mesophase may also form in the presence of lecithin, akin to that seen with cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Interactions between bile salts, gut microbiota, and hepatic innate immunity.

    PubMed

    Schubert, Kristin; Olde Damink, Steven W M; von Bergen, Martin; Schaap, Frank G

    2017-09-01

    Bile salts are the water-soluble end products of hepatic cholesterol catabolism that are released into the duodenum and solubilize lipids due to their amphipathic structure. Bile salts also act as endogenous ligands for dedicated nuclear receptors that exert a plethora of biological processes, mostly related to metabolism. Bile salts are actively reclaimed in the distal part of the small intestine, released into the portal system, and subsequently extracted by the liver. This enterohepatic cycle is critically dependent on dedicated bile salt transporters. In the intestinal lumen, bile salts exert direct antimicrobial activity based on their detergent property and shape the gut microbiota. Bile salt metabolism by gut microbiota serves as a mechanism to counteract this toxicity and generates bile salt species that are distinct from those of the host. Innate immune cells of the liver play an important role in the early recognition and effector response to invading microbes. Bile salts signal primarily via the membrane receptor TGR5 and the intracellular farnesoid-x receptor, both present in innate immune cells. In this review, the interactions between bile salts, gut microbiota, and hepatic innate immunity are discussed. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. A New Insight into the Physiological Role of Bile Salt Hydrolase among Intestinal Bacteria from the Genus Bifidobacterium

    PubMed Central

    Jarocki, Piotr; Podleśny, Marcin; Glibowski, Paweł; Targoński, Zdzisław

    2014-01-01

    This study analyzes the occurrence of bile salt hydrolase in fourteen strains belonging to the genus Bifidobacterium. Deconjugation activity was detected using a plate test, two-step enzymatic reaction and activity staining on a native polyacrylamide gel. Subsequently, bile salt hydrolases from B. pseudocatenulatum and B. longum subsp. suis were purified using a two-step chromatographic procedure. Biochemical characterization of the bile salt hydrolases showed that the purified enzymes hydrolyzed all of the six major human bile salts under the pH and temperature conditions commonly found in the human gastrointestinal tract. Next, the dynamic rheometry was applied to monitor the gelation process of deoxycholic acid under different conditions. The results showed that bile acids displayed aqueous media gelating properties. Finally, gel-forming abilities of bifidobacteria exhibiting bile salt hydrolase activity were analyzed. Our investigations have demonstrated that the release of deconjugated bile acids led to the gelation phenomenon of the enzymatic reaction solution containing purified BSH. The presented results suggest that bile salt hydrolase activity commonly found among intestinal microbiota increases hydrogel-forming abilities of certain bile salts. To our knowledge, this is the first report showing that bile salt hydrolase activity among Bifidobacterium is directly connected with the gelation process of bile salts. In our opinion, if such a phenomenon occurs in physiological conditions of human gut, it may improve bacterial ability to colonize the gastrointestinal tract and their survival in this specific ecological niche. PMID:25470405

  12. A new insight into the physiological role of bile salt hydrolase among intestinal bacteria from the genus Bifidobacterium.

    PubMed

    Jarocki, Piotr; Podleśny, Marcin; Glibowski, Paweł; Targoński, Zdzisław

    2014-01-01

    This study analyzes the occurrence of bile salt hydrolase in fourteen strains belonging to the genus Bifidobacterium. Deconjugation activity was detected using a plate test, two-step enzymatic reaction and activity staining on a native polyacrylamide gel. Subsequently, bile salt hydrolases from B. pseudocatenulatum and B. longum subsp. suis were purified using a two-step chromatographic procedure. Biochemical characterization of the bile salt hydrolases showed that the purified enzymes hydrolyzed all of the six major human bile salts under the pH and temperature conditions commonly found in the human gastrointestinal tract. Next, the dynamic rheometry was applied to monitor the gelation process of deoxycholic acid under different conditions. The results showed that bile acids displayed aqueous media gelating properties. Finally, gel-forming abilities of bifidobacteria exhibiting bile salt hydrolase activity were analyzed. Our investigations have demonstrated that the release of deconjugated bile acids led to the gelation phenomenon of the enzymatic reaction solution containing purified BSH. The presented results suggest that bile salt hydrolase activity commonly found among intestinal microbiota increases hydrogel-forming abilities of certain bile salts. To our knowledge, this is the first report showing that bile salt hydrolase activity among Bifidobacterium is directly connected with the gelation process of bile salts. In our opinion, if such a phenomenon occurs in physiological conditions of human gut, it may improve bacterial ability to colonize the gastrointestinal tract and their survival in this specific ecological niche.

  13. Quantification of Cholesterol Solubilized in Dietary Micelles: Dependence on Human Bile Salt Variability and the Presence of Dietary Food Ingredients.

    PubMed

    Coreta-Gomes, Filipe M; Vaz, Winchil L C; Wasielewski, Emeric; Geraldes, Carlos F G; Moreno, Maria João

    2016-05-10

    The solubility of cholesterol in bile salt (BS) micelles is important to understand the availability of cholesterol for absorption in the intestinal epithelium and to develop strategies to decrease cholesterol intake from the intestinal lumen. This has been the subject of intense investigation, due to the established relation between the development of diseases such as atherosclerosis and high levels of cholesterol in the blood. In this work we quantify the effect of BS variability on the amount of cholesterol solubilized. The effect of some known hypocholesterolemic agents usually found in the diet is also evaluated, as well as some insight regarding the mechanisms involved. The results show that, depending on the bile salt composition, the average value of sterol per micelle is equal to or lower than 1. The amount of cholesterol solubilized in the BS micelles is essentially equal to its total concentration until the solubility limit is reached. Altogether, this indicates that the maximum cholesterol solubility in the BS micellar solution is the result of saturation of the aqueous phase and depends on the partition coefficient of cholesterol between the aqueous phase and the micellar pseudophase. The effect on cholesterol maximum solubility for several food ingredients usually encountered in the diet was characterized using methodology developed recently by us. This method allows the simultaneous quantification of both cholesterol and food ingredient solubilized in the BS micelles even in the presence of larger aggregates, therefore avoiding their physical separation with possible impacts on the overall equilibrium. The phytosterols stigmasterol and stigmastanol significantly decreased cholesterol solubility with a concomitant reduction in the total amount of sterol solubilized, most pronounced for stigmasterol. Those results point toward coprecipitation being the major cause for the decrease in cholesterol solubilization by the BS micelles. The presence of

  14. Evolution of the bile salt nuclear receptor FXR in vertebrates*s⃞

    PubMed Central

    Reschly, Erica J.; Ai, Ni; Ekins, Sean; Welsh, William J.; Hagey, Lee R.; Hofmann, Alan F.; Krasowski, Matthew D.

    2008-01-01

    Bile salts, the major end metabolites of cholesterol, vary significantly in structure across vertebrate species, suggesting that nuclear receptors binding these molecules may show adaptive evolutionary changes. We compared across species the bile salt specificity of the major transcriptional regulator of bile salt synthesis, the farnesoid X receptor (FXR). We found that FXRs have changed specificity for primary bile salts across species by altering the shape and size of the ligand binding pocket. In particular, the ligand binding pockets of sea lamprey (Petromyzon marinus) and zebrafish (Danio rerio) FXRs, as predicted by homology models, are flat and ideal for binding planar, evolutionarily early bile alcohols. In contrast, human FXR has a curved binding pocket best suited for the bent steroid ring configuration typical of evolutionarily more recent bile acids. We also found that the putative FXR from the sea squirt Ciona intestinalis, a chordate invertebrate, was completely insensitive to activation by bile salts but was activated by sulfated pregnane steroids, suggesting that the endogenous ligands of this receptor may be steroidal in nature. Our observations present an integrated picture of the coevolution of bile salt structure and of the binding pocket of their target nuclear receptor FXR. PMID:18362391

  15. CmeR-dependent gene Cj0561c is induced more effectively by bile salts than the CmeABC efflux pump in both human and poultry Campylobacter jejuni strains.

    PubMed

    Dzieciol, Monika; Wagner, Martin; Hein, Ingeborg

    2011-12-01

    The multidrug efflux pump CmeABC described in the food-borne pathogen Campylobacter jejuni was shown to be an important element of bile resistance and significant for successful colonization of chicken intestines. Recently, another gene (Cj0561c) strongly suppressed by the same repressor (CmeR) that regulates expression of CmeABC was identified in C. jejuni NCTC 11168. Initial data suggested that, similarly to cmeABC, Cj0561c could be induced by bile salts. In the present study, the occurrence of the Cj0561c gene and bile-salt-dependent induction was investigated in ten poultry and eight human C. jejuni strains. The Cj0561c gene was present in all strains. When cultured without addition of bile salts, the transcription level of that gene was about tenfold higher than that of cmeABC. Bile salts cholate and taurocholate induced transcription of cmeABC 1.66-fold and 2.71-fold and that of Cj0561c 3.71-fold and 10.99-fold, respectively. Thus Cj0561c was more effectively induced by bile salts than cmeABC and taurocholate was superior to cholate as an inducer of transcription. More efficient induction of both cmeABC and Cj0561c by taurocholate might be the reason for the higher minimum inhibitory concentrations (MICs) observed with taurocholate than with cholate (100 mg/ml vs. 10 mg/ml). There was no significant difference between poultry and human C. jejuni strains concerning the transcription levels of cmeABC and Cj0561c in cultures without bile salts and concerning bile-salt-induced changes in transcription of cmeABC and Cj0561c. Thus, higher MIC values observed for taurocholate in human strains than in poultry strains (200 mg/ml vs. 75 mg/ml) could not be explained by different responses of cmeABC and Cj0561c to bile salts. Therefore, they must be due to another mechanism.

  16. Bile Salt-Stimulated Lipase from Human Milk Binds DC-SIGN and Inhibits Human Immunodeficiency Virus Type 1 Transfer to CD4+ T Cells

    PubMed Central

    Naarding, Marloes A.; Dirac, Annette M.; Ludwig, Irene S.; Speijer, Dave; Lindquist, Susanne; Vestman, Eva-Lotta; Stax, Martijn J.; Geijtenbeek, Teunis B. H.; Pollakis, Georgios; Hernell, Olle; Paxton, William A.

    2006-01-01

    A wide range of pathogens, including human immunodeficiency virus type 1 (HIV-1), hepatitis C virus, Ebola virus, cytomegalovirus, dengue virus, Mycobacterium, Leishmania, and Helicobacter pylori, can interact with dendritic cell (DC)-specific ICAM3-grabbing nonintegrin (DC-SIGN), expressed on DCs and a subset of B cells. More specifically, the interaction of the gp120 envelope protein of HIV-1 with DC-SIGN can facilitate the transfer of virus to CD4+ T lymphocytes in trans and enhance infection. We have previously demonstrated that a multimeric LeX component in human milk binds to DC-SIGN, preventing HIV-1 from interacting with this receptor. Biochemical analysis reveals that the compound is heat resistant, trypsin sensitive, and larger than 100 kDa, indicating a specific glycoprotein as the inhibitory compound. By testing human milk from three different mothers, we found the levels of DC-SIGN binding and viral inhibition to vary between samples. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and matrix-assisted laser desorption ionization analysis, we identified bile salt-stimulated lipase (BSSL), a Lewis X (LeX)-containing glycoprotein found in human milk, to be the major variant protein between the samples. BSSL isolated from human milk bound to DC-SIGN and inhibited the transfer of HIV-1 to CD4+ T lymphocytes. Two BSSL isoforms isolated from the same human milk sample showed differences in DC-SIGN binding, illustrating that alterations in the BSSL forms explain the differences observed. These results indicate that variations in BSSL lead to alterations in LeX expression by the protein, which subsequently alters the DC-SIGN binding capacity and the inhibitory effect on HIV-1 transfer. Identifying the specific molecular interaction between the different forms may aid in the future design of antimicrobial agents. PMID:17005819

  17. Bile salt-stimulated lipase from human milk binds DC-SIGN and inhibits human immunodeficiency virus type 1 transfer to CD4+ T cells.

    PubMed

    Naarding, Marloes A; Dirac, Annette M; Ludwig, Irene S; Speijer, Dave; Lindquist, Susanne; Vestman, Eva-Lotta; Stax, Martijn J; Geijtenbeek, Teunis B H; Pollakis, Georgios; Hernell, Olle; Paxton, William A

    2006-10-01

    A wide range of pathogens, including human immunodeficiency virus type 1 (HIV-1), hepatitis C virus, Ebola virus, cytomegalovirus, dengue virus, Mycobacterium, Leishmania, and Helicobacter pylori, can interact with dendritic cell (DC)-specific ICAM3-grabbing nonintegrin (DC-SIGN), expressed on DCs and a subset of B cells. More specifically, the interaction of the gp120 envelope protein of HIV-1 with DC-SIGN can facilitate the transfer of virus to CD4+ T lymphocytes in trans and enhance infection. We have previously demonstrated that a multimeric LeX component in human milk binds to DC-SIGN, preventing HIV-1 from interacting with this receptor. Biochemical analysis reveals that the compound is heat resistant, trypsin sensitive, and larger than 100 kDa, indicating a specific glycoprotein as the inhibitory compound. By testing human milk from three different mothers, we found the levels of DC-SIGN binding and viral inhibition to vary between samples. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and matrix-assisted laser desorption ionization analysis, we identified bile salt-stimulated lipase (BSSL), a Lewis X (LeX)-containing glycoprotein found in human milk, to be the major variant protein between the samples. BSSL isolated from human milk bound to DC-SIGN and inhibited the transfer of HIV-1 to CD4+ T lymphocytes. Two BSSL isoforms isolated from the same human milk sample showed differences in DC-SIGN binding, illustrating that alterations in the BSSL forms explain the differences observed. These results indicate that variations in BSSL lead to alterations in LeX expression by the protein, which subsequently alters the DC-SIGN binding capacity and the inhibitory effect on HIV-1 transfer. Identifying the specific molecular interaction between the different forms may aid in the future design of antimicrobial agents.

  18. Deconjugated Bile Salts Produced by Extracellular Bile-Salt Hydrolase-Like Activities from the Probiotic Lactobacillus johnsonii La1 Inhibit Giardia duodenalis In vitro Growth.

    PubMed

    Travers, Marie-Agnès; Sow, Cissé; Zirah, Séverine; Deregnaucourt, Christiane; Chaouch, Soraya; Queiroz, Rayner M L; Charneau, Sébastien; Allain, Thibault; Florent, Isabelle; Grellier, Philippe

    2016-01-01

    Giardiasis, currently considered a neglected disease, is caused by the intestinal protozoan parasite Giardia duodenalis and is widely spread in human as well as domestic and wild animals. The lack of appropriate medications and the spread of resistant parasite strains urgently call for the development of novel therapeutic strategies. Host microbiota or certain probiotic strains have the capacity to provide some protection against giardiasis. By combining biological and biochemical approaches, we have been able to decipher a molecular mechanism used by the probiotic strain Lactobacillus johnsonii La1 to prevent Giardia growth in vitro. We provide evidence that the supernatant of this strain contains active principle(s) not directly toxic to Giardia but able to convert non-toxic components of bile into components highly toxic to Giardia. By using bile acid profiling, these components were identified as deconjugated bile-salts. A bacterial bile-salt-hydrolase of commercial origin was able to mimic the properties of the supernatant. Mass spectrometric analysis of the bacterial supernatant identified two of the three bile-salt-hydrolases encoded in the genome of this probiotic strain. These observations document a possible mechanism by which L. johnsonii La1, by secreting, or releasing BSH-like activity(ies) in the vicinity of replicating Giardia in an environment where bile is present and abundant, can fight this parasite. This discovery has both fundamental and applied outcomes to fight giardiasis, based on local delivery of deconjugated bile salts, enzyme deconjugation of bile components, or natural or recombinant probiotic strains that secrete or release such deconjugating activities in a compartment where both bile salts and Giardia are present.

  19. Deconjugated Bile Salts Produced by Extracellular Bile-Salt Hydrolase-Like Activities from the Probiotic Lactobacillus johnsonii La1 Inhibit Giardia duodenalis In vitro Growth

    PubMed Central

    Travers, Marie-Agnès; Sow, Cissé; Zirah, Séverine; Deregnaucourt, Christiane; Chaouch, Soraya; Queiroz, Rayner M. L.; Charneau, Sébastien; Allain, Thibault; Florent, Isabelle; Grellier, Philippe

    2016-01-01

    Giardiasis, currently considered a neglected disease, is caused by the intestinal protozoan parasite Giardia duodenalis and is widely spread in human as well as domestic and wild animals. The lack of appropriate medications and the spread of resistant parasite strains urgently call for the development of novel therapeutic strategies. Host microbiota or certain probiotic strains have the capacity to provide some protection against giardiasis. By combining biological and biochemical approaches, we have been able to decipher a molecular mechanism used by the probiotic strain Lactobacillus johnsonii La1 to prevent Giardia growth in vitro. We provide evidence that the supernatant of this strain contains active principle(s) not directly toxic to Giardia but able to convert non-toxic components of bile into components highly toxic to Giardia. By using bile acid profiling, these components were identified as deconjugated bile-salts. A bacterial bile-salt-hydrolase of commercial origin was able to mimic the properties of the supernatant. Mass spectrometric analysis of the bacterial supernatant identified two of the three bile-salt-hydrolases encoded in the genome of this probiotic strain. These observations document a possible mechanism by which L. johnsonii La1, by secreting, or releasing BSH-like activity(ies) in the vicinity of replicating Giardia in an environment where bile is present and abundant, can fight this parasite. This discovery has both fundamental and applied outcomes to fight giardiasis, based on local delivery of deconjugated bile salts, enzyme deconjugation of bile components, or natural or recombinant probiotic strains that secrete or release such deconjugating activities in a compartment where both bile salts and Giardia are present. PMID:27729900

  20. Aggregation behavior of bile salts in aqueous solution.

    PubMed

    Coello, A; Meijide, F; Núñez, E R; Tato, J V

    1996-01-01

    Freezing point depression, delta T/k, and pNa are measured and analyzed for aqueous solutions of trihydroxy (NaTC) and dihydroxy (NaDC and NaTDC) bile salts. The results show the existence of break points in the plot of delta T/k vs molality at 0.018, 0.013, and 0.007 m, respectively, in good agreement with previous published critical micelle concentration values. Above the break point bile salts form aggregates with average aggregation numbers of 2.59 +/- 0.12 (NaTC), 5.82 +/- 0.04 (NaDC), and 5.42 +/- 0.47 (NaTDC). Fractions of bound counterions are also deduced, being close to 0.3 for the three bile salts studied. This indicates that only one counterion is bound for every three monomers in the aggregate. The different structural models published for the bile salt aggregates are discussed.

  1. Consequences of bile salt biotransformations by intestinal bacteria

    PubMed Central

    Ridlon, Jason M.; Harris, Spencer C.; Bhowmik, Shiva; Kang, Dae-Joong; Hylemon, Phillip B.

    2016-01-01

    ABSTRACT Emerging evidence strongly suggest that the human “microbiome” plays an important role in both health and disease. Bile acids function both as detergents molecules promoting nutrient absorption in the intestines and as hormones regulating nutrient metabolism. Bile acids regulate metabolism via activation of specific nuclear receptors (NR) and G-protein coupled receptors (GPCRs). The circulating bile acid pool composition consists of primary bile acids produced from cholesterol in the liver, and secondary bile acids formed by specific gut bacteria. The various biotransformation of bile acids carried out by gut bacteria appear to regulate the structure of the gut microbiome and host physiology. Increased levels of secondary bile acids are associated with specific diseases of the GI system. Elucidating methods to control the gut microbiome and bile acid pool composition in humans may lead to a reduction in some of the major diseases of the liver, gall bladder and colon. PMID:26939849

  2. Bile salt-phospholipid aggregation at submicellar concentrations.

    PubMed

    Baskin, Rebekah; Frost, Laura D

    2008-04-01

    The aggregation behavior of the bile salts taurodeoxycholate (NaTDC) and sodium cholate (NaC), are followed at concentrations below critical micelle concentrations (CMCs) using the environment sensitive, fluorescent-labeled phospholipid, 2-(6-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)hexanoyl-1-hexadecanoyl-sn-glycero-3-phosphocholine (NBD-C(6)-HPC). A buffer solution containing NBD-C(6)-HPC is titrated with increasing NaC or NaTDC and the fluorescence changes followed. Both bile salts induced fluorescence changes below their critical micelle concentration indicating the presence of a bile salt-phospholipid aggregate. A critical control experiment using 6-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino) hexanoic acid (NBD-X) shows that the bile salts are interacting with the longer, C16 hydrocarbon tail, not the NBD probe. The fluorescence curves were fitted to the Hill equation as a model for cooperative aggregation. The cooperativity model provides a minimum estimate for the number of bile salts to give maximal fluorescence. This number was calculated for NaC and NaTDC to have a minimum value of approximately 2. A small aggregation number supports the existence of primary micellar aggregates at submicellar concentrations for bile salt-phospholipid aqueous solutions.

  3. Bile salts of the green turtle Chelonia mydas (L.)

    PubMed Central

    Haslewood, G A; Ikawa, S; Tökés, L; Wong, D

    1978-01-01

    1. Bile salts of the green turtle Chelonia mydas (L.) were analysed as completely as possible. 2. They consist of taurine conjugates of 3 alpha, 7 alpha, 12 alpha, 22 xi-tetrahydroxy-5 beta-cholestan-26-oic acid (tetrahydroxysterocholanic acid) and 3 alpha 12 alpha, 22 xi-trihydroxy-5 beta-cholestan-26-oic acid, with minor amounts of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5beta-cholan-24-oic acid (cholic acid), 3alpha, 12 alpha-dihydroxy-5beta-cholan-24-oic acid (deoxycholic acid) and possibly other bile acids. 3. Cholic acid and deoxycholic acid represent the first known examples of bile acids common to chelonians and other animal forms: they may indicate independent evolution in chelonians to C24 bile acids. 4. The discovery of a 7-deoxy C27 bile acid is the first evidence that C27 bile acids or their conjugates have an enterohepatic circulation. PMID:656052

  4. Coexpression of bile salt hydrolase gene and catalase gene remarkably improves oxidative stress and bile salt resistance in Lactobacillus casei.

    PubMed

    Wang, Guohong; Yin, Sheng; An, Haoran; Chen, Shangwu; Hao, Yanling

    2011-08-01

    Lactic acid bacteria (LAB) encounter various types of stress during industrial processes and gastrointestinal transit. Catalase (CAT) and bile salt hydrolase (BSH) can protect bacteria from oxidative stress or damage caused by bile salts by decomposing hydrogen peroxide (H(2)O(2)) or deconjugating the bile salts, respectively. Lactobacillus casei is a valuable probiotic strain and is often deficient in both CAT and BSH. In order to improve the resistance of L. casei to both oxidative and bile salts stress, the catalase gene katA from L. sakei and the bile salt hydrolase gene bsh1 from L. plantarum were coexpressed in L. casei HX01. The enzyme activities of CAT and BSH were 2.41 μmol H(2)O(2)/min/10(8) colony-forming units (CFU) and 2.11 μmol glycine/min/ml in the recombinant L. casei CB, respectively. After incubation with 8 mM H(2)O(2), survival ratio of L. casei CB was 40-fold higher than that of L. casei CK. Treatment of L. casei CB with various concentrations of sodium glycodeoxycholate (GDCA) showed that ~10(5) CFU/ml cells survived after incubation with 0.5% GDCA, whereas almost all the L. casei CK cells were killed when treaded with 0.4% GDCA. These results indicate that the coexpression of CAT and BSH confers high-level resistance to both oxidative and bile salts stress conditions in L. casei HX01.

  5. Effect of acute bile acid pool depletion on total and ionized calcium concentrations in human bile.

    PubMed

    Gleeson, D; Murphy, G M; Dowling, R H

    1995-04-01

    Although calcium salts are important components of gallstones, there are few data on the total and ionized calcium content of human bile. Therefore, in 14 fasting T-tube patients studied 7-11 days after cholecystectomy, we measured bile flow, bile acid [BA], total [CaTOT] and free ionized [Ca++] calcium concentrations, in 20-30 min bile collections during acute BA pool depletion induced by 6-8 h of continuous bile drainage. During washout of the BA pool there were parallel falls in bile flow, BA output and total calcium output (correlation coefficients ranging from 0.59 to 0.99; P < 0.02-0.001). In 12 of the 14 patients, [CaTOT] also fell (from 1.84 +/- 0.29 to 1.32 +/- 0.34 mmol L-1) in parallel with [BA] (from 34.0 +/- 14.0 to 8.2 +/- 8.0 mmol L-1; r = 0.75-0.98; P < 0.005). In contrast, biliary [Ca++] remained virtually unchanged. These data suggest that the BAs are linked to the bound, rather than to the free, ionized, fraction of biliary calcium, which is consistent with in vivo calcium binding by BAs. A model is proposed in which BA-induced biliary calcium secretion results from (i) bile acid-induced water flow via solvent drag; and (ii) calcium binding in the bile canaliculus by bile acids, which induces paracellular diffusion of Ca++, thereby maintaining [Ca++] independent of [BA].

  6. Alterations in nanoparticle protein corona by biological surfactants: impact of bile salts on β-lactoglobulin-coated gold nanoparticles.

    PubMed

    Winuprasith, Thunnalin; Chantarak, Sirinya; Suphantharika, Manop; He, Lili; McClements, David Julian

    2014-07-15

    The impact of biological surfactants (bile salts) on the protein (β-lactoglobulin) corona surrounding gold nanoparticles (200 nm) was studied using a variety of analytical techniques at pH 7: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); UV-visible (UV) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The bile salts adsorbed to the protein-coated nanoparticle surfaces and altered their interfacial composition, charge, and structure. SERS spectra of protein-coated nanoparticles after bile salt addition contained bands from both protein and bile salts, indicating that the protein was not fully displaced by the bile salts. UV, DLS and TEM techniques also indicated that the protein coating was not fully displaced from the nanoparticle surfaces. The impact of bile salts could be described by an orogenic mechanism: mixed interfaces were formed that consisted of islands of aggregated proteins surrounded by a sea of bile salts. This knowledge is useful for understanding the interactions of bile salts with protein-coated colloidal particles, which may be important for controlling the fate of colloidal delivery systems in the human gastrointestinal tract, or the gastrointestinal fate of ingested inorganic nanoparticles.

  7. Recurrence of bile salt export pump deficiency after liver transplantation.

    PubMed

    Jara, Paloma; Hierro, Loreto; Martínez-Fernández, Pilar; Alvarez-Doforno, Rita; Yánez, Francisca; Diaz, María C; Camarena, Carmen; De la Vega, Angela; Frauca, Esteban; Muñoz-Bartolo, Gema; López-Santamaría, Manuel; Larrauri, Javier; Alvarez, Luis

    2009-10-01

    Severe bile salt export pump (BSEP) deficiency is a hereditary cholestatic condition that starts in infancy and leads to end-stage liver disease. Three children who underwent orthotopic liver transplantation for severe BSEP deficiency had post-transplantation episodes of cholestatic dysfunction that mimicked the original disease. Remission of all episodes was achieved by intensifying the immunosuppressive regimen. The phenotypic recurrence of the disease correlated with the presence of circulating high-titer antibodies against BSEP that inhibit transport by BSEP in vitro. When administered to rats, these antibodies targeted the bile canaliculi and impaired bile acid secretion. 2009 Massachusetts Medical Society

  8. Bile salt receptor complex activates a pathogenic type III secretion system

    SciTech Connect

    Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N.; Salomon, Dor; Tomchick, Diana R.; Grishin, Nick V.; Orth, Kim

    2016-07-05

    Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered thatVibrio parahaemolyticusVtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structure of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment.

  9. Bile salt receptor complex activates a pathogenic type III secretion system

    PubMed Central

    Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N; Salomon, Dor; Tomchick, Diana R; Grishin, Nick V; Orth, Kim

    2016-01-01

    Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered that Vibrio parahaemolyticus VtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structure of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment. DOI: http://dx.doi.org/10.7554/eLife.15718.001 PMID:27377244

  10. Bile salt receptor complex activates a pathogenic type III secretion system

    DOE PAGES

    Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N.; ...

    2016-07-05

    Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered that Vibrio parahaemolyticus VtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structuremore » of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment.« less

  11. Proteomic analysis of the effect of bile salts on the intestinal and probiotic bacterium Lactobacillus reuteri.

    PubMed

    Lee, KiBeom; Lee, Hong-Gu; Choi, Yun-Jaie

    2008-10-10

    Lactobacillus reuteri is a resident of the human and animal intestinal tracts. The ability of L. reuteri to survive passage through the intestinal tract is a key point in its function as a probiotic. In order to examine the nature of bile salt tolerance by L. reuteri, its protein synthesis was analyzed in liquid cultures containing two different bile salt conditions. Significant cell growth inhibition was observed in the presence of 1.2g/L (higher concentration) bile salts. Two-dimensional gel electrophoresis allowed us to identify 28 proteins spots that were consistently and significantly altered in the presence of bile in the growth medium. Peptide mass fingerprinting was used to identify these 28 proteins, and functional annotation revealed their involvement in carbohydrate metabolism, transcription-translation, nucleotide metabolism, amino acid biosynthesis, pH homeostasis and stress responses, oxidation-reduction reactions, and unknown functions. These findings, which suggest that bile salts induce complex physiological responses in L. reuteri may provide early new insights into the inducible mechanisms underlying the capacity of intestinal L. reuteri to tolerate bile stress.

  12. Tailoring supramolecular nanotubes by bile salt based surfactant mixtures.

    PubMed

    Gubitosi, Marta; Travaglini, Leana; di Gregorio, Maria Chiara; Pavel, Nicolae V; Vázquez Tato, José; Sennato, Simona; Olsson, Ulf; Schillén, Karin; Galantini, Luciano

    2015-06-08

    An approach for tailoring self-assembled tubular structures is described. By controlling the relative composition of a two-component surfactant mixture comprising the natural bile salt lithocholate and its bolamphiphilic derivative, it was possible to finely tune the nanotube cross-section of the mixed tubular aggregates that self-associated spontaneously in aqueous solution at pH 12. The diameter was found to vary up to 50% when the stoichiometric ratio of the two bile salts was changed. The tuning of supramolecular nanochannels with such remarkable precision is of significant interest for technological applications of these materials.

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

    PubMed

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

    2016-01-04

    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.

  14. Bile salts of vertebrates: structural variation and possible evolutionary significance[S

    PubMed Central

    Hofmann, Alan F.; Hagey, Lee R.; Krasowski, Matthew D.

    2010-01-01

    Biliary bile salt composition of 677 vertebrate species (103 fish, 130 reptiles, 271 birds, 173 mammals) was determined. Bile salts were of three types: C27 bile alcohols, C27 bile acids, or C24 bile acids, with default hydroxylation at C-3 and C-7. C27 bile alcohols dominated in early evolving fish and amphibians; C27 bile acids, in reptiles and early evolving birds. C24 bile acids were present in all vertebrate classes, often with C27 alcohols or with C27 acids, indicating two evolutionary pathways from C27 bile alcohols to C24 bile acids: a) a ‘direct’ pathway and b) an ‘indirect’ pathway with C27 bile acids as intermediates. Hydroxylation at C-12 occurred in all orders and at C-16 in snakes and birds. Minor hydroxylation sites were C-1, C-2, C-5, C-6, and C-15. Side chain hydroxylation in C27 bile salts occurred at C-22, C-24, C-25, and C-26, and in C24 bile acids, at C-23 (snakes, birds, and pinnipeds). Unexpected was the presence of C27 bile alcohols in four early evolving mammals. Bile salt composition showed significant variation between orders but not between families, genera, or species. Bile salt composition is a biochemical trait providing clues to evolutionary relationships, complementing anatomical and genetic analyses. PMID:19638645

  15. [Measurement of the transport activities of bile salt export pump using chemiluminescence detection method].

    PubMed

    Yamaguchi, Kana; Murai, Tsuyoshi; Yabuuchi, Hikaru; Hui, Shu-Ping; Kurosawa, Takao

    2010-05-01

    Monovalent bile acids, such as taurine- and glycine-conjugated bile acids, are excreted into bile by bile salt export pumps (BSEP, ABCB11). Human BSEP (hBSEP) is physiologically important because it was identified as the gene responsible for the genetic disease: progressive familial intrahepatic cholestasis type 2 (PFIC-2). The evaluation of the inhibitory effect of hBSEP transport activity provides significant information for predicting toxic potential in the early phase of drug development. The role and function of hBSEP have been investigated by the examination of the ATP-dependent transport of radioactive isotopically (RI)-labeled bile acid such as a tritium labeled taurocholic acid, in membrane vesicles obtained from hBSEP-expressing cells. The chemiluminescence detection method using 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) had been developed for a simple analysis of bile acids in human biological fluids. This method is extremely sensitive and it may be applicable for the measurements of bile acid transport activities by hBSEP vesicles without using RI-labeled bile acid. The present paper deals with an application of the chemiluminescence detection method using 3alpha-HSD with enzyme cycling method to the measurement of ATP-dependent transport activities of taurocholic acid (T-CA) in membrane vesicles obtained from hBSEP-expressing Sf9 cells. Calibration curves for T-CA was linear over the range from 10 to 400 pmol/ml. The values of the kinetic parameters for hBSEP vesicles obtained by the chemiluminescence detection method were comparable with the values of that obtained by liquid chromatography-mass spectrometry method. This assay method was highly useful for the measurements of bile acid transport activities.

  16. Bile salt/acid induction of DNA damage in bacterial and mammalian cells: implications for colon cancer.

    PubMed

    Kandell, R L; Bernstein, C

    1991-01-01

    Two bile salts, sodium chenodeoxycholate and sodium deoxycholate, induced a DNA repair response in the bacterium Escherichia coli. Similarly, a bile acid and a bile salt, chenodeoxycholic acid and sodium deoxycholate, induced DNA repair (indicated by unscheduled DNA synthesis) in human foreskin fibroblasts. Also, DNA repair-deficient Chinese hamster ovary (CHO) cells were found to be more sensitive than normal cells to killing by bile salts. In particular, mutant UV4 CHO cells, defective in DNA excision repair and DNA cross-link removal, were more sensitive to sodium chenodeoxycholate, and mutant EM9 CHO cells, defective in strand-break rejoining, were more sensitive to sodium deoxycholate than wild-type cells. These results indicate that bile salts/acid damage DNA of both bacterial and mammalian cells in vivo. Previous epidemiological studies have shown that colon cancer incidence correlates with fecal bile acid levels. The findings reported here support the hypothesis that bile salts/acids have an etiologic role in colon cancer by causing DNA damage.

  17. Genetic and Proteomic characterization of Bile Salt Export Pump (BSEP) in Snake Liver

    PubMed Central

    Tan, Xinle; Gao, Fei; Su, Hexiu; Gong, Yajun; Zhang, Jie; Sullivan, Mitchell A.; Chen, Jiachun

    2017-01-01

    Snake gallbladder, a traditional Chinese medicine, has been believed in various Asian countries to improve visual acuity and alleviate rheumatism. Bile acids, a major component of the gallbladder, are toxic to the liver and kidney in humans and animals due to its detergent effects, while also exhibiting therapeutic effects due to an increase in the gallbladder contractions of muscle strips in patients with cholesterol gallstones. Secretion of bile acids in human and mammals depends on the bile salt export pump (BSEP), a liver-specific adenosine triphosphate (ATP)-binding cassette transporter encoded by ABCB11. However, the presence of BSEP in snakes has not been thoroughly explored. Here we confirm the existence of BSEP and its coding DNA sequence in snakes on both the proteomic and genetic level. This work provides information on the snake ABCB11 sequence and helps further potential genetic manipulation to affect bile salt metabolism. Our study provides the foundation for research on bile acid production from snakes by using modern genetic and proteomic methodologies. PMID:28368001

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

    PubMed Central

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

    2016-01-01

    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

  19. Bile salt incorporated polypyrrole thin film for ethanol sensing.

    PubMed

    Sharma, Partha P D; Sarkar, D

    2015-04-01

    Polypyrrole (PPy)-bile salt composite was used for sensing ethanol vapor. PPy was synthesized by interface polymerization for subsequent fabrication of thin film of its composite with bile salt, by in-situ co-dispersion method and then exposed to ethanol vapour. Sensing was visualized through changes in morphological, structural and optical characterizations. The ethanol exposed film showed larger agglomeration as revealed in its surface morphology on scanning electron microscope (SEM) and greater crystallinity as seen through X-Ray diffraction (XRD). Fourier transform infra red (FTIR) and nuclear magnetic resonance spectroscopy (NMR) of the ethanol incorporated film also gave signature of the presence of bile salt and alcohol. Alcohol incorporation pattern resulted in increase in electrical conductance from 7.08539 x 10(-5) mA/V to 8.0356 x 10(-5) mA/V, as determined from current voltage characterizations. Average molecular weight (M(n)) obtained from gel permeation chromatography changed from 6160 to 10300 on ethanol intake. Photoluminescence (PL) intensity was quenched and the PL peak shifted from 430 to 409 on ethanol exposure. Changes in morphological, structural, optical and electrical properties of the composite on ethanol exposure showed its prospective application for sensing ethanol.

  20. Use of D(acid)-, D(bile)-, z(acid)-, and z(bile)-values in evaluating Bifidobacteria with regard to stomach pH and bile salt sensitivity.

    PubMed

    Jia, Li; Shigwedha, Nditange; Mwandemele, Osmund D

    2010-01-01

    The survival of bifidobacteria in simulated conditions of the gastrointestinal (GI) tract was studied based on the D- and z-value concept. Some Bifidobacterium spp. are probiotics that improve microbial balance in the human GI tract. Because they are sensitive to low pH and bile salt concentrations, their viability in the GI tract is limited. The D- and z-value approach was therefore adopted as a result of observing constant log-cell reduction (90%) when Bifidobacterium spp. were exposed to these 2 different stressing factors. Survivals of one strain each or 4 species of Bifidobacterium was studied at pH between 3.0 and 4.5 and in ox-bile between 0.15% and 0.60% for times up to 41 h. From the D(acid)- and D(bile)-values, the order of resistance to acid and bile was B. bifidum > B. infantis > B. longum > B. adolescentis. While the former 3 strains retained high cell viability at pH 3.5 (>5.5 log CFU/mL after 5 h) and at elevated bile salt concentration of 0.6% (>4.5 log CFU/mL after 3 h), B. adolescentis was less resistant (<3.4 log CFU/mL). The z(acid)- and z(bile)-values calculated from the D(acid)- and D(bile)-values ranged from 1.11 to 1.55 pH units and 0.40% to 0.49%, respectively. The results suggest that the D(acid)-, D(bile)-, z(acid)-, and z(bile)-value approach could be more appropriate than the screening and selection method in evaluating survival of probiotic bacteria, and in measuring their tolerance or resistance to gastric acidity and the associated bile salt concentration in the small intestine. The evaluation of the tolerance of bifidobacteria to bile salts and low pH has been made possible by use of D- and z-value concept. The calculated z(acid)- and z(bile)-values were all fairly similar for the strains used and suggest the effect of increasing the bile salt concentration or decreasing the pH on the D(acid)- and D(bile)-values. This approach would be useful for predicting the suitability of bifidobacteria and other lactic acid bacteria (LAB) as

  1. Diversity of Bile Salts in Fish and Amphibians: Evolution of a Complex Biochemical Pathway

    PubMed Central

    Hagey, Lee R.; Møller, Peter R.; Hofmann, Alan F.; Krasowski, Matthew D.

    2010-01-01

    Bile salts are the major end-metabolites of cholesterol and are also important in lipid and protein digestion, as well as shaping of the gut microflora. Previous studies had demonstrated variation of bile salt structures across vertebrate species. We greatly extend prior surveys of bile salt variation in fish and amphibians, particularly in analysis of the biliary bile salts of Agnatha and Chondrichthyes. While there is significant structural variation of bile salts across all fish orders, bile salt profiles are generally stable within orders of fish and do not correlate with differences in diet. This large data set allowed us to infer evolutionary changes in the bile salt synthetic pathway. The hypothesized ancestral bile salt synthetic pathway, likely exemplified in extant hagfish, is simpler and much shorter than the pathway of most teleost fish and terrestrial vertebrates. Thus, the bile salt synthetic pathway has become longer and more complex throughout vertebrate evolution. Analysis of the evolution of bile salt synthetic pathways provides a rich model system for the molecular evolution of a complex biochemical pathway in vertebrates. PMID:20113173

  2. Diversity of bile salts in fish and amphibians: evolution of a complex biochemical pathway.

    PubMed

    Hagey, Lee R; Møller, Peter R; Hofmann, Alan F; Krasowski, Matthew D

    2010-01-01

    Bile salts are the major end metabolites of cholesterol and are also important in lipid and protein digestion, as well as shaping of the gut microflora. Previous studies had demonstrated variation of bile salt structures across vertebrate species. We greatly extend prior surveys of bile salt variation in fish and amphibians, particularly in analysis of the biliary bile salts of Agnatha and Chondrichthyes. While there is significant structural variation of bile salts across all fish orders, bile salt profiles are generally stable within orders of fish and do not correlate with differences in diet. This large data set allowed us to infer evolutionary changes in the bile salt synthetic pathway. The hypothesized ancestral bile salt synthetic pathway, likely exemplified in extant hagfish, is simpler and much shorter than the pathway of most teleost fish and terrestrial vertebrates. Thus, the bile salt synthetic pathway has become longer and more complex throughout vertebrate evolution. Analysis of the evolution of bile salt synthetic pathways provides a rich model system for the molecular evolution of a complex biochemical pathway in vertebrates.

  3. Hepatic cytochrome P450 deficiency in mouse models for intrahepatic cholestasis predispose to bile salt-induced cholestasis.

    PubMed

    Kunne, Cindy; de Graaff, Marijke; Duijst, Suzanne; de Waart, Dirk R; Oude Elferink, Ronald P J; Paulusma, Coen C

    2014-10-01

    Progressive familial intrahepatic cholestasis (PFIC) types 1 and 3 are severe cholestatic liver diseases caused by deficiency of ATB8B1 and ABCB4, respectively. Mouse models for PFIC display mild phenotypes compared with human patients, and this can be explained by the difference in bile salt pool composition. Mice, unlike humans, have the ability to detoxify hydrophobic bile salts by cytochrome P450-mediated (re)hydroxylation and thus have a less toxic bile salt pool. We have crossed mouse models for PFIC1 and PFIC3 with Hrn mice that have a reduced capacity to (re)hydroxylate bile salts. Double transgenes were obtained by backcrossing Atp8b1(G308V/G308V) and Abcb4(-/-) mice with Hrn mice that have a liver-specific disruption of the cytochrome P450 reductase gene and therefore have markedly reduced P450 activity. In these mice, a more hydrophobic bile salt pool was instilled by cholic acid supplementation of the diet, and bile formation and liver pathology was studied. As opposed to single transgenes, Atp8b1(G308V/G308V)/Hrn and Abcb4(-/-)/Hrn mice rapidly developed strong cholestasis that was evidenced by increased plasma bilirubin and bile salt levels. The bile salt pool was more toxic in both models; Atp8b1(G308V/G308V)/Hrn mice had a more hydrophobic plasma pool compared with the single transgene, whereas Abcb4(-/-)/Hrn mice had a more hydrophobic biliary pool compared with the single transgene. In line with these findings, liver damage was not aggravated in Atp8b1(G308V/G308V)/Hrn but was more severe in Abcb4(-/-)/Hrn mice. These data indicate that bile salt pool composition is a critical determinant in the initiation and progression of cholestasis and liver pathology in PFIC1 and PFIC3. Most importantly, our data suggest that the hydrophobicity of the plasma bile salt pool is an important determinant of the severity of cholestasis, whereas the hydrophobicity of the biliary bile salt pool is an important determinant of the severity of liver pathology.

  4. Kinetics of formation of bile salt micelles from coarse-grained Langevin dynamics simulations.

    PubMed

    Vila Verde, Ana; Frenkel, Daan

    2016-06-21

    We examine the mechanism of formation of micelles of dihydroxy bile salts using a coarse-grained, implicit solvent model and Langevin dynamics simulations. We find that bile salt micelles primarily form via addition and removal of monomers, similarly to surfactants with typical head-tail molecular structures, and not via a two-stage mechanism - involving formation of oligomers and their subsequent aggregation to form larger micelles - originally proposed for bile salts. The free energy barrier to removal of single bile monomers from micelles is ≈2kBT, much less than what has been observed for head-tail surfactants. Such a low barrier may be biologically relevant: it allows for rapid release of bile monomers into the intestine, possibly enabling the coverage of fat droplets by bile salt monomers and subsequent release of micelles containing fats and bile salts - a mechanism that is not possible for ionic head-tail surfactants of similar critical micellar concentrations.

  5. Haemolytic activity of formyl- and acetyl-derivatives of bile acids and their gramine salts.

    PubMed

    Kozanecka-Okupnik, Weronika; Jasiewicz, Beata; Pospieszny, Tomasz; Matuszak, Monika; Mrówczyńska, Lucyna

    2017-10-01

    Bile acids (lithocholic: LCA, deoxycholic: DCA and cholic: CA) and their formyl- and acetyl-derivatives can be used as starting material in chemical synthesis of compounds with different biological activity strongly depended on their chemical structures. Our previous studies showed that biological activity of bile acids salts with gramine toward human erythrocytes was significantly different from the activity of bile acids alone. Moreover, gramine effectively modified the membrane perturbing activity of other steroids. As a continuation of our work, the haemolytic activity of formyl- and acetyl-substituet bile acids as well as their gramine salts was studied in vitro. The structures of new compounds were confirmed by spectral (NMR, FT-IR) analysis, mass spectrometry (ESI-MS) as well as PM5 semiempirical methods. The results shown that the haemolytic activity of formyl- and acetyl-LCA and DCA was significantly higher in comparison with their native forms at the whole concentration range. At high concentration, formyl derivative of CA was as effective as LCA and DCA derivatives whereas at lower concentration its haemolytic activity was at the level of original acid. The acetyl-CA was not active as membrane perturbing agents. Furthermore, gramine significantly decreased the membrane-perturbing activity of hydrophobic bile acids derivatives. The results obtained with the cellular system are in line with physicochemical calculation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Adult sea lamprey tolerates biliary atresia by altering bile salt composition and renal excretion

    PubMed Central

    Cai, Shi-Ying; Lionarons, Daniël A.; Hagey, Lee; Soroka, Carol J.; Mennone, Albert; Boyer, James L.

    2012-01-01

    The sea lamprey (Petromyzon marinus) is a genetically programmed animal model for biliary atresia as it loses its bile ducts and gallbladder during metamorphosis. However, in contrast to patients with biliary atresia or other forms of cholestasis who develop progressive disease, the post-metamorphosis lampreys grow normally to adult size. To understand how the adult lamprey thrives without the ability to secrete bile, we examined bile salt homeostasis in larval and adult lampreys. Adult livers were severely cholestatic with levels of bile salts >1 mM, but no evidence of necrosis, fibrosis, or inflammation. Interestingly, both larvae and adults had normal plasma levels (~10 μM) of bile salts. In larvae, petromyzonol sulfate (PZS) was the predominant bile salt, whereas the major bile salts in adult liver were sulfated C27 bile alcohols. Cytotoxicity assays revealed that PZS was highly toxic. Pharmacokinetic studies in free-swimming adults revealed that ~35% of intravenously injected bromosulfophthalein (BSP) was eliminated over a 72 hr period. Collection of urine and feces demonstrated that both endogenous and exogenous organic anions, including biliverdin, bile salts and BSP, were predominantly excreted via the kidney with minor amounts also detected in feces. Gene expression analysis detected marked up-regulation of orthologs of known organic anion and bile salt transporters in the kidney with lesser effects in the intestine and gills in adults compared to larvae. These findings indicate that adult lampreys tolerate cholestasis by altering hepatic bile salt composition, while maintaining normal plasma bile salt levels predominantly through renal excretion of bile products. Therefore, we conclude that strategies to accelerate renal excretion of bile salt and other toxins should be beneficial for patients with cholestasis. PMID:23175353

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

    PubMed Central

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

    2016-01-01

    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

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

    PubMed

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

    2016-04-26

    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.

  9. Cholesterol crystallization from a dilute bile salt-rich model bile

    NASA Astrophysics Data System (ADS)

    Konikoff, Fred M.; Carey, Martin C.

    1994-11-01

    In earlier work we showed that cholesterol monohydrate crystallization from model and native biles can involve filamentous cholesterol crystals, and other metastable intermediates which are covered by a layer of phosphatidylcholine (lecithin) molecules [Konikoff et al., J. Clin. Invest. 90 (1992) 1155]. The aim of the present study was to isolate the initial filamentous cholesterol crystals by density gradient centrifugation and microfiltration and to sequentially monitor their transformations into equilibrium plates within the mother liquor composed of a dilute (1.2 g/dl) bile salt-rich model bile (cholesterol/egg yolk lecithin/sodium taurocholate, 1.7/0.8/97.5 mol%). When assayed by dual radiolabeling at 37°C, total precipitated cholesterol in bile increased from zero at 2-4 h of incubation to 43% at 24 h, reaching a stable value by 48 h when 36% of total cholesterol had crystallized. Isopycnic sucrose density gradient centrifugation at 20°C separated early filamentous crystals from plate-like crystals and revealed densities compatible with anhydrous cholesterol (1.029 g/ml) and cholesterol monohydrate (1.048 g/ml), respectively. Rapid (1 h) density gradient centrifugation carried-out in time-lapse sequence disclosed that cholesterol crystallization involved initially low-density (1.01-1.03 g/ml) filamentous crystals, which reached a maximal concentration at 24 h and disappeared gradually by 156 h of incubation. Concomitantly, the concentrations of high-density (1.04-1.06 g/ml) plate-like cholesterol crystals increased reciprocally throughout the crystallization process suggesting a precursor-product relationship. Rates of crystal filament formation and transitions to thermodynamically stable plates accelerated curvilinearly with increases in temperature from 4 to 60°C, but the crystallization process per se remained unchanged. We conclude that metastable intermediate crystals during cholesterol precipitation from bile may involve either low-density anhydrous

  10. Susceptibility and Adaptive Response to Bile Salts in Propionibacterium freudenreichii: Physiological and Proteomic Analysis

    PubMed Central

    Leverrier, Pauline; Dimova, Diliana; Pichereau, Vianney; Auffray, Yanick; Boyaval, Patrick; Jan, Gwénaël

    2003-01-01

    Tolerance to digestive stresses is one of the main factors limiting the use of microorganisms as live probiotic agents. Susceptibility to bile salts and tolerance acquisition in the probiotic strain Propionibacterium freudenreichii SI41 were characterized. We showed that pretreatment with a moderate concentration of bile salts (0.2 g/liter) greatly increased its survival during a subsequent lethal challenge (1.0 g/liter, 60 s). Bile salts challenge led to drastic morphological changes, consistent with intracellular material leakage, for nonadapted cells but not for preexposed ones. Moreover, the physiological state of the cells during lethal treatment played an important role in the response to bile salts, as stationary-phase bacteria appeared much less sensitive than exponentially growing cells. Either thermal or detergent pretreatment conferred significantly increased protection toward bile salts challenge. In contrast, some other heterologous pretreatments (hypothermic and hyperosmotic) had no effect on tolerance to bile salts, while acid pretreatment even might have sensitized the cells. Two-dimensional electrophoresis experiments revealed that at least 24 proteins were induced during bile salts adaptation. Identification of these polypeptides suggested that the bile salts stress response involves signal sensing and transduction, a general stress response (also triggered by thermal denaturation, oxidative toxicity, and DNA damage), and an alternative sigma factor. Taken together, our results provide new insights into the tolerance of P. freudenreichii to bile salts, which must be taken into consideration for the use of probiotic strains and the improvement of technological processes. PMID:12839748

  11. Self-assembly of micelles in organic solutions of lecithin and bile salt: Mesoscale computer simulation

    NASA Astrophysics Data System (ADS)

    Markina, A.; Ivanov, V.; Komarov, P.; Khokhlov, A.; Tung, S.-H.

    2016-11-01

    We propose a coarse-grained model for studying the effects of adding bile salt to lecithin organosols by means of computer simulation. This model allows us to reveal the mechanisms of experimentally observed increasing of viscosity upon increasing the bile salt concentration. We show that increasing the bile salt to lecithin molar ratio induces the growth of elongated micelles of ellipsoidal and cylindrical shape due to incorporation of disklike bile salt molecules. These wormlike micelles can entangle into transient network displaying perceptible viscoelastic properties.

  12. Effect of substituent pattern and molecular weight of cellulose ethers on interactions with different bile salts.

    PubMed

    Torcello-Gómez, Amelia; Fernández Fraguas, Cristina; Ridout, Mike J; Woodward, Nicola C; Wilde, Peter J; Foster, Timothy J

    2015-03-01

    Some known mechanisms proposed for the reduction of blood cholesterol by dietary fibre are: binding with bile salts in the duodenum and prevention of lipid absorption, which can be partially related with the bile salt binding. In order to gain new insights into the mechanisms of the binding of dietary fibre to bile salts, the goal of this work is to study the main interactions between cellulose derivatives and two types of bile salts. Commercial cellulose ethers: methyl (MC), hydroxypropyl (HPC) and hydroxypropylmethyl cellulose (HPMC), have been chosen as dietary fibre due to their highly functional properties important in manufactured food products. Two types of bile salts: sodium taurocholate (NaTC) and sodium taurodeoxycholate (NaTDC), have been chosen to understand the effect of the bile salt type. Interactions in the bulk have been investigated by means of differential scanning calorimetry (DSC) and linear mechanical spectroscopy. Results show that both bile salts have inhibitory effects on the thermal structuring of cellulose ethers and this depends on the number and type of substitution in the derivatised celluloses, and is not dependent upon molecular weight. Concerning the bile salt type, the more hydrophobic bile salt (NaTDC) has greater effect on these interactions, suggesting more efficient adsorption onto cellulose ethers. These findings may have implications in the digestion of cellulose-stabilised food matrices, providing a springboard to develop new healthy cellulose-based food products with improved functional properties.

  13. Bile salts: natural detergents for the prevention of sexually transmitted diseases.

    PubMed

    Herold, B C; Kirkpatrick, R; Marcellino, D; Travelstead, A; Pilipenko, V; Krasa, H; Bremer, J; Dong, L J; Cooper, M D

    1999-04-01

    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 bile salts against Chlamydia trachomatis, herpes simplex virus (types 1 and 2), Neisseria gonorrhoeae, and human immunodeficiency virus in comparison to those of nonoxynol-9 and benzalkonium chloride using both primary cells and cell lines derived from the human female genital tract. We found that taurolithocholic acid 3-sulfate and a combination of glycocholic acid and taurolithocholic acid 3-sulfate showed excellent activity against all of the pathogens assayed. Moreover, taurolithocholic acid 3-sulfate alone or in combination was less cytotoxic than nonoxynol-9 and benzalkonium chloride. Thus, taurolithocholic acid 3-sulfate alone or in combination warrants further evaluation as a candidate topical microbicidal agent.

  14. Lithocholic acid decreases expression of bile salt export pump through farnesoid X receptor antagonist activity.

    PubMed

    Yu, Jinghua; Lo, Jane-L; Huang, Li; Zhao, Annie; Metzger, Edward; Adams, Alan; Meinke, Peter T; Wright, Samuel D; Cui, Jisong

    2002-08-30

    Bile salt export pump (BSEP) is a major bile acid transporter in the liver. Mutations in BSEP result in progressive intrahepatic cholestasis, a severe liver disease that impairs bile flow and causes irreversible liver damage. BSEP is a target for inhibition and down-regulation by drugs and abnormal bile salt metabolites, and such inhibition and down-regulation may result in bile acid retention and intrahepatic cholestasis. In this study, we quantitatively analyzed the regulation of BSEP expression by FXR ligands in primary human hepatocytes and HepG2 cells. We demonstrate that BSEP expression is dramatically regulated by ligands of the nuclear receptor farnesoid X receptor (FXR). Both the endogenous FXR agonist chenodeoxycholate (CDCA) and synthetic FXR ligand GW4064 effectively increased BSEP mRNA in both cell types. This up-regulation was readily detectable at as early as 3 h, and the ligand potency for BSEP regulation correlates with the intrinsic activity on FXR. These results suggest BSEP as a direct target of FXR and support the recent report that the BSEP promoter is transactivated by FXR. In contrast to CDCA and GW4064, lithocholate (LCA), a hydrophobic bile acid and a potent inducer of cholestasis, strongly decreased BSEP expression. Previous studies did not identify LCA as an FXR antagonist ligand in cells, but we show here that LCA is an FXR antagonist with partial agonist activity in cells. In an in vitro co-activator association assay, LCA decreased CDCA- and GW4064-induced FXR activation with an IC(50) of 1 microm. In HepG2 cells, LCA also effectively antagonized GW4064-enhanced FXR transactivation. These data suggest that the toxic and cholestatic effect of LCA in animals may result from its down-regulation of BSEP through FXR. Taken together, these observations indicate that FXR plays an important role in BSEP gene expression and that FXR ligands may be potential therapeutic drugs for intrahepatic cholestasis.

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

    PubMed Central

    Baghdasaryan, Anna; Chiba, Peter; Trauner, Michael

    2014-01-01

    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 BS efflux through bile salt export pump (BSEP), basolateral elimination through organic solute transporters alpha and beta (OSTα/OSTβ) as well as inhibition of hepatocellular BS uptake through basolateral Na+-taurocholate cotransporting polypeptide (NTCP) represent critical steps in protection from hepatocellular BS overload and can be targeted therapeutically. In this article, we review the potential clinical implications of the major BS transporters BSEP, OSTα/OSTβ and NTCP in the pathogenesis of hereditary and acquired cholestatic syndromes, provide an overview on transcriptional control of these transporters by the key regulatory nuclear receptors and discuss the potential therapeutic role of novel transcriptional activators of BS transporters in cholestasis. PMID:24333169

  16. Liposomes containing bile salts as novel ocular delivery systems for tacrolimus (FK506): in vitro characterization and improved corneal permeation

    PubMed Central

    Dai, Yikang; Zhou, Rui; Liu, Lin; Lu, Yi; Qi, Jianping; Wu, Wei

    2013-01-01

    The objective of this study was to investigate the potential of liposomes containing bile salts as an ophthalmic delivery system for tacrolimus to improve corneal permeability. Liposomes containing bile salts, including sodium taurocholate, sodium deoxycholate, and sodium glycocholate, were produced by the thin-film dispersion method with a particle size of approximately 100 nm and an entrapment efficiency of more than 90%. Less than 5% tacrolimus was released from conventional liposomes and from liposomes containing sodium taurocholate, sodium deoxycholate, or sodium glycocholate over 12 hours. The cellular uptake of conventional liposomes was significantly higher than that of liposomes containing bile salts. However, liposomes containing bile salts exerted a 3–4-fold increase of tacrolimus in ex vivo corneal transport of tacrolimus compared with conventional liposomes. When rabbit eyes were treated with a DiI perchlorate-loaded liposome suspension, liposomes containing bile salts showed fast and sustained penetration across the cornea. Unfortunately, liposomes containing sodium deoxycholate caused toxicity or irritation to both spontaneously derived human corneal epithelial cells and the rabbit cornea. Therefore, liposomes containing sodium taurocholate and sodium glycocholate are potential carriers in ocular drug delivery systems, given their low toxicity and vastly improved permeability. PMID:23690687

  17. Simple steatosis sensitizes cholestatic rats to liver injury and dysregulates bile salt synthesis and transport

    PubMed Central

    Lionarons, Daniël A.; Heger, Michal; van Golen, Rowan F.; Alles, Lindy K.; van der Mark, Vincent A.; Kloek, Jaap J.; de Waart, Dirk R.; Marsman, Hendrik A.; Rusch, Henny; Verheij, Joanne; Beuers, Ulrich; Paulusma, Coen C.; van Gulik, Thomas M.

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder. It is uncertain if simple steatosis, the initial and prevailing form of NAFLD, sensitizes the liver to cholestasis. Here, we compared the effects of obstructive cholestasis in rats with a normal liver versus rats with simple steatosis induced by a methionine/choline-deficient diet. We found that plasma liver enzymes were higher and hepatic neutrophil influx, inflammation, and fibrosis were more pronounced in animals with combined steatosis and cholestasis compared to cholestasis alone. Circulating bile salt levels were markedly increased and hepatic bile salt composition shifted from hydrophilic tauro-β-muricholate to hydrophobic taurocholate. This shift was cytotoxic for HepG2 hepatoma cells. Gene expression analysis revealed induction of the rate-limiting enzyme in bile salt synthesis, cytochrome P450 7a1 (CYP7A1), and modulation of the hepatic bile salt transport system. In conclusion, simple steatosis sensitizes the liver to cholestatic injury, inflammation, and fibrosis in part due to a cytotoxic shift in bile salt composition. Plasma bile salt levels were elevated, linked to dysregulation of bile salt synthesis and enhanced trafficking of bile salts from the liver to the systemic circulation. PMID:27535001

  18. A study of the relationship between bile salts, bile salt-stimulated lipase, and free fatty acids in breast milk: normal infants and those with breast milk jaundice.

    PubMed

    Forsyth, J S; Donnet, L; Ross, P E

    1990-08-01

    Breast milk jaundice has been reported to be associated with increased lipase activity and elevated free fatty acid (FFA) concentrations within breast milk. We have previously shown that bile salts are present in small concentrations in breast milk and the aim of this study was to examine the relationship of bile salt-stimulated lipase (BSSL) activity, FFA concentration, and bile salt concentration in milks of normal infants and the milk of infants with breast milk jaundice. Mothers of healthy newborn infants were recruited in the early newborn period and 42 provided breast milk samples at 2 weeks, 30 at 6 weeks, 16 at 10 weeks, and 13 at 14 weeks postnatally. We initially studied the effect of lactation on bile salts and found there was a significant decline in both cholate and chenodeoxycholate levels with duration of lactation (p less than 0.05). There was also a significant fall in BSSL activity with duration of lactation (p less than 0.05), but no correlation was found between BSSL activity and bile salt concentration. FFA concentrations were similar throughout lactation and were not related to either BSSL activity or bile salt concentration. There was a significant increase in the concentration of cholate and the cholate-to-chenodeoxycholate ratio in the milks of 12 infants with breast milk jaundice compared with normal milks, the BSSL activity was similar and contrary to previous reports, the FFA concentration was not increased in the milks of infants with breast milk jaundice.

  19. Development of a differential medium for bile salt hydrolase-active Lactobacillus spp.

    PubMed Central

    Dashkevicz, M P; Feighner, S D

    1989-01-01

    An agar plate assay was developed to detect bile salt hydrolase activity in lactobacilli. On Lactobacillus-selective MRS or Rogosa SL medium supplemented with taurodeoxycholic, taurocholic, or taurochenodeoxycholic acids, bile salt hydrolysis was manifested at two intensities: (i) the formation of precipitate halos around colonies or (ii) the formation of opaque granular white colonies. Sixty-six lactobacilli were tested for bile salt hydrolase activity by both the plate assay and a sensitive radiochemical assay. No false-positive or false-negative results were detected by the plate assay. Based on results of experiments with Eubacterium lentum and Bacteroides species, the plate assay was dependent on two factors: (i) the presence of bile salt hydrolytic activity and (ii) the ability of the organism to sufficiently acidify the medium to protonate free bile acids. The availability of a differential medium for determination of bile salt hydrolase activity will provide a rapid method for determining shifts in a specific functional activity of intestinal Lactobacillus species and provide a rapid screening capability for identifying bile salt hydrolase-deficient mutants. The latter application should allow bile salt hydrolase activity to be used as a marker enzyme in genetic experiments. Images PMID:2705765

  20. Bile acid formation in primary human hepatocytes

    PubMed Central

    Einarsson, Curt; Ellis, Ewa; Abrahamsson, Anna; Ericzon, Bo-Göran; Björkhem, Ingemar; Axelson, Magnus

    2000-01-01

    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 re newed every 24 h. Bile acids and their precursors in media were finally analysed by gas chromatography-mass spectrometry. RESULTS: Cholic acid (CA) and chenodeoxycholic acid (CDCA) conjugated with glycine or taurine accounted for 70% and 25% of total steroids. A third of CDC A was also conjugated with sulphuric acid. Dexamethasone and thyroid hormone alone or in combination did not significantly effect bile acid formation. The addit ion 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. PMID:11819640

  1. Bile salt-reinforced alginate-chitosan beads.

    PubMed

    Takka, Sevgi; Cali, Aybige Gürel

    2012-01-01

    A polymeric delayed release protein delivery system was investigated with albumin as the model drug. The polysaccharide chitosan was reacted with sodium alginate in the presence of calcium chloride to form beads with a polyelectrolyte. In this study, attempts were made to extend albumin release in the phosphate buffer at pH 6.8 from the alginate-chitosan beads by reinforcing the matrix with bile salts. Sodium taurocholate was able to prevent albumin release at pH 1.2, protecting the protein from the acidic environment and extending the total albumin release at pH 6.8. This effect was explained by an interaction between the permanent negatively charged sulfonic acid of sodium taurocholate with the amino groups of chitosan. Mild formulation conditions, high bovine serum albumin (BSA) entrapment efficiency, and resistance to gastrointestinal release seem to be synergic and promising factors toward the development of an oral protein delivery form.

  2. Viscosity of human bile sampled from the common bile duct.

    PubMed

    Reinhart, Walter H; Näf, Gabriela; Werth, Baseli

    2010-01-01

    Cholestasis is a frequent gastroenterological problem, which is tackled by endoscopic procedures. Little is known about bile viscosity, a major determinant of its flow. We measured the viscosity of bile from the common bile duct during endoscopic retrograde cholangiography. Bile was aspirated immediately after cannulation of the papilla and deep-frozen. Viscosity was measured with a rotational viscometer at 37 degrees C and a broad range of shear rates (0.08-69.5 s(-1)). The majority of the 138 patients (64.5%) had bile viscosities between water (0.7 mPa.s) and the lower limit of plasma (1.1 mPa.s). In 20 patients (14.5%) it was above that of plasma (>1.4 mPa.s), and showed a non-Newtonian behaviour, i.e. the viscosity increased exponentially with decreasing shear rate. Cholecystectomized patients had a lower bile viscosity. Bile viscosities did not differ between patient groups with either choledocholithiasis, sludge, cholangitis, biliary pancreatitis, pancreatic carcinoma, or cholangiocarcinoma. We conclude that bile viscosity in the common bile duct is usually lower than that of plasma, in 15% it is higher and increases exponentially with decreasing flow rate, which may lead to a vicious cycle.

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

    PubMed

    Hanus, Martin; Zhorov, Eugene

    2006-12-01

    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.

  4. Comparison of the bile salts and sodium dodecyl sulfate stress responses in Enterococcus faecalis.

    PubMed Central

    Flahaut, S; Frere, J; Boutibonnes, P; Auffray, Y

    1996-01-01

    The resistance to detergents and detergent-induced tolerance of a gastrointestinal organism, Enterococcus faecalis ATCC 19433, were examined. The most remarkable observation was the rapid response of cells in contact with bile salts and sodium dodecyl sulfate (SDS). The killing by high concentrations of detergents was nearly instantaneous. A 5-s adaptation with moderate sublethal concentrations of bile salts or SDS (0.08 or 0.01%, respectively) was sufficient to induce significant adaptation against homologous lethal conditions (0.3% bile salts or 0.017% SDS). However, resistance to a subsequent lethal challenge progressively increased further to a maximum reached after 30 min of adaptation. Furthermore, extremely strong cross-resistances were observed with bile salts- and SDS-adapted cells. However, no relationship seems to exist between levels of tolerance and de novo-synthesized proteins, since blockage of protein synthesis during adaptation had no effect on induction of resistance to bile salts and SDS. We conclude that this induced tolerance to detergent stress is independent of protein synthesis. Nevertheless, the stress-induced protein patterns of E. faecalis ATCC 19433 showed significant modifications. The rates of synthesis of 45 and 34 proteins were enhanced after treatments with bile salts and SDS, respectively. In spite of the overlap of 12 polypeptides, the protein profiles induced by the two detergents were different, suggesting that these detergents trigger different responses in E. faecalis. Therefore, bile salts cannot be substituted for SDS in biochemical detergent shock experiments with bacteria. PMID:8779581

  5. Repair of DNA Damage Induced by Bile Salts in Salmonella enterica

    PubMed Central

    Prieto, Ana I.; Ramos-Morales, Francisco; Casadesús, Josep

    2006-01-01

    Exposure of Salmonella enterica to sodium cholate, sodium deoxycholate, sodium chenodeoxycholate, sodium glychocholate, sodium taurocholate, or sodium glycochenodeoxycholate induces the SOS response, indicating that the DNA-damaging activity of bile resides in bile salts. Bile increases the frequency of GC → AT transitions and induces the expression of genes belonging to the OxyR and SoxRS regulons, suggesting that bile salts may cause oxidative DNA damage. S. enterica mutants lacking both exonuclease III (XthA) and endonuclease IV (Nfo) are bile sensitive, indicating that S. enterica requires base excision repair (BER) to overcome DNA damage caused by bile salts. Bile resistance also requires DinB polymerase, suggesting the need of SOS-associated translesion DNA synthesis. Certain recombination functions are also required for bile resistance, and a key factor is the RecBCD enzyme. The extreme bile sensitivity of RecB−, RecC−, and RecA− RecD− mutants provides evidence that bile-induced damage may impair DNA replication. PMID:16888329

  6. Bile salt surfactants in micellar electrokinetic capillary chromatography: Application to hydrophobic molecule separations

    SciTech Connect

    Cole, R.O.; Sepaniak, M.J. . Dept. of Chemistry); Hinze, W.L. . Dept. of Chemistry); Gorse, J.; Oldiges, K. . Dept. of Chemistry)

    1990-01-01

    Bile Salt surfactants are used in the micellar electrokinetic capillary chromatography (MECC) separation of various hydrophobic compounds. The use of methanol in the mobile phase allows the separation of previously intractable compounds including polyaromatic hydrocarbons. The effects of methanol on critical micelle concentration is investigated for sodium dodecyl sulfate (SDS) and the bile salt sodium cholate. It is determined that the unique structure of the bile salt micelle is much more tolerant to the addition of organic solvents than SDS, thereby increasing the scope of applications of MECC to include hydrophobic compounds. 30 refs., 9 figs.

  7. Steroid binding to Autotaxin links bile salts and lysophosphatidic acid signalling.

    PubMed

    Keune, Willem-Jan; Hausmann, Jens; Bolier, Ruth; Tolenaars, Dagmar; Kremer, Andreas; Heidebrecht, Tatjana; Joosten, Robbie P; Sunkara, Manjula; Morris, Andrew J; Matas-Rico, Elisa; Moolenaar, Wouter H; Oude Elferink, Ronald P; Perrakis, Anastassis

    2016-04-14

    Autotaxin (ATX) generates the lipid mediator lysophosphatidic acid (LPA). ATX-LPA signalling is involved in multiple biological and pathophysiological processes, including vasculogenesis, fibrosis, cholestatic pruritus and tumour progression. ATX has a tripartite active site, combining a hydrophilic groove, a hydrophobic lipid-binding pocket and a tunnel of unclear function. We present crystal structures of rat ATX bound to 7α-hydroxycholesterol and the bile salt tauroursodeoxycholate (TUDCA), showing how the tunnel selectively binds steroids. A structure of ATX simultaneously harbouring TUDCA in the tunnel and LPA in the pocket, together with kinetic analysis, reveals that bile salts act as partial non-competitive inhibitors of ATX, thereby attenuating LPA receptor activation. This unexpected interplay between ATX-LPA signalling and select steroids, notably natural bile salts, provides a molecular basis for the emerging association of ATX with disorders associated with increased circulating levels of bile salts. Furthermore, our findings suggest potential clinical implications in the use of steroid drugs.

  8. Bile salt adsorption ability of dietary fiber from named varieties of carrot at different developmental ages.

    PubMed

    Robertson, J A; Eastwood, M A; Yeoman, M M

    1980-06-01

    The adsorption of bile salts to fiber has been measured using fiber prepared from different varieties of carrot at different developmental ages. We investigated the carrot varieties Altrinchan and Chantenay and used the bile salts deoxycholate and glycocholate. The method used to measure adsorption distinguished between true adsorption and apparent adsorption due to bile salts trapped within the interstices of the fiber matrix. Adsorption ability was influenced by the developmental age of the carrot but not by variety. Adsorption ability was at a maximum when the carrot fresh weight was at a maximum. The adsorption ability measured was true adsorption and was not dependent on the water holding capacity of the fiber. Deoxycholate was better adsorbed than glycocholate and the results suggest that the developmental age of a fiber source could be important when formulating diets designed to influence bile salt metabolism.

  9. Use of dimethicone to reduce the fall in gastric potential difference induced by bile salts.

    PubMed

    Bergmann, J F; Simoneau, G; Chantelair, G; Caulin, C; Segrestaa, J M

    1989-01-01

    The gastric potential difference (PD) was measured in ten healthy volunteers after sodium taurocholate intake. This bile salt was given after treatment with dimethicone or placebo in a cross-over design study. With dimethicone the fall in PD was lower (16.1 vs. 24.8 mV,) and shorter (32.5 vs. 51.0 min) than with the placebo. Our result suggests that the silicone can prevent the formation of the gastric lesions induced by bile salts.

  10. Submicellar bile salts stimulate phosphatidylcholine transfer activity of sterol carrier protein 2.

    PubMed

    Leonard, A N; Cohen, D E

    1998-10-01

    To explore a potential role for sterol carrier protein 2 (SCP2, also known as non-specific lipid transfer protein) in hepatocellular phospholipid trafficking, we examined the influence of submicellar bile salt concentrations on phosphatidylcholine (PC) transfer activity of SCP2. We measured rate constants for first-order transfer of sn-1 palmitoyl, sn-2 parinaroyl PC, a naturally fluorescent self-quenching phospholipid between model membranes. Purified bovine liver SCP2 promoted transfer of PC from donor to acceptor small unilamellar vesicles. Taurine- and glycine-conjugated bile salts (anionic steroid detergent-like molecules), at concentrations well below their critical micellar concentrations, stimulated PC transfer activity of SCP2 80- to 140-fold. Rate constants increased in proportion to bile salt concentration, temperature, and bile salt-membrane binding affinity. Sodium taurofusidate, a conjugated fungal bile salt analog, also activated PC transfer whereas no effect was observed with the anionic and non-ionic straight chain detergents sodium dodecyl sulfate and octylglucoside, respectively. Thermodynamic and kinetic analyses of PC transfer support a mechanism in which bile salts stimulate SCP2 activity by partitioning into donor vesicles and enhancing membrane association of SCP2. These results imply that under physiological conditions, SCP2 may contribute to hepatocellular selection and transport of biliary PCs.

  11. [Effect of cold preservation and reperfusion injury on early-stage bile salt secretion after liver transplantation in rat model].

    PubMed

    Chen, Geng; Ding, Min; Wang, Meng; Zhang, Yu-Jun; Li, Xiao-Wu; Wang, Shu-Guang; Dong, Jia-Hong

    2007-08-01

    To explore the effect of cold preservation and reperfusion injury (CPRI) on the bile salt spectrum in rat orthotopic liver transplantation (OLT) model. A special analysis method was established to investigate the bile salts in rat by reverse phase high performance liquid chromatography (RP-HPLC). Rats were randomly divided into 3 groups: group A (control group, n = 6), group B (group with 1 h graft preservation pre-OLT, n = 6) and group C (group with 12 h graft preservation pre-OLT, n = 6). The bile samples of 0 - 14 post-transplantation days were analyzed by RP-HPLC. Eleven kinds of bile salts were detected in rat bile. It showed that CPRI could influence the concentration of bile salts significantly in rat model after OLT, the concentration of hydrophobic bile salts (TCA and TCDCA) increased significantly in group B and C. However, the concentration of hydrophilic bile salts (TUDCA and THDCA) just increased in a short-time. The hydrophobicity index (HI) wasn't significantly changed during the first 4 post-transplant days. Thus the HI of bile salts elevated gradually from the 5th day and reached the peak at the 10th day after OLT. The increase of the proportion of hydrophobic bile salts may be one of the major factors leading to the increase of bile toxicity after OLT.

  12. Changes in bile acids, FGF-19 and sterol absorption in response to bile salt hydrolase active L. reuteri NCIMB 30242

    PubMed Central

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

    2015-01-01

    The size and composition of the circulating bile acid (BA) pool are important factors in regulating the human gut microbiota. Disrupted regulation of BA metabolism is implicated in several chronic diseases. Bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, previously shown to decrease LDL-cholesterol and increase circulating BA, was investigated for its dose response effect on BA profile in a pilot clinical study. Ten otherwise healthy hypercholesterolemic adults, recruited from a clinical trial site in London, ON, were randomized to consume delayed release or standard release capsules containing L. reuteri NCIMB 30242 in escalating dose over 4 weeks. In another aspect, 4 healthy normocholesterolemic subjects with LDL-C below 3.4 mmol/l received delayed release L. reuteri NCIMB 30242 at a constant dose over 4 weeks. The primary outcome measure was the change in plasma BA profile over the intervention period. Additional outcomes included circulating fibroblast growth factor (FGF)-19, plant sterols and LDL-cholesterol as well as fecal microbiota and bsh gene presence. After one week of intervention subjects receiving delayed release L. reuteri NCIMB 30242 increased total BA by 1.13 ± 0.67 μmol/l (P = 0.02), conjugated BA by 0.67 ± 0.39 μmol/l (P = 0.02) and unconjugated BA by 0.46 ± 0.43 μmol/l (P = 0.07), which represented a greater than 2-fold change relative to baseline. Increases in BA were largely maintained post-week 1 and were generally correlated with FGF-19 and inversely correlated with plant sterols. This is the first clinical support showing that a BSH-active probiotic can significantly and rapidly influence BA metabolism and may prove useful in chronic diseases beyond hypercholesterolemia. PMID:25612224

  13. The gut microbiome, probiotics, bile acids axis, and human health.

    PubMed

    Jones, Mitchell Lawrence; Tomaro-Duchesneau, Catherine; Prakash, Satya

    2014-06-01

    The human gut microbiome produces potent ligands to bile acid receptors, and probiotics could act as therapeutics of bile acid dysmetabolism. A recent study in Cell Reports demonstrates that probiotic VSL#3 affects bile acid deconjugation and excretion, as well as the gut-liver FXR-FGF15 axis.

  14. Exocrine pancreatic secretion and plasma levels of cholecystokinin, pancreatic polypeptide, and somatostatin after single and combined intraduodenal application of different bile salts in man.

    PubMed

    Riepl, R L; Fiedler, F; Kowalski, C; Teufel, J; Lehnert, P

    1996-01-01

    Bile salts are intraduodenal stimulants of basal pancreatic secretion. This study aims to show whether the three main bile salts of human bile differ in their action on pancreatic secretion, and whether they enhance or inhibit each other after combined use. Furthermore, the effect on gastroenteropancreatic peptide release is evaluated. Twelve subjects were provided with a gastroduodenal double-lumen tube. Equimolar doses (0.6 mmol) of taurocholate (322 mg), taurodeoxycholate (313 mg), and a combination of both stimuli were given intraduodenally. Another 12 subjects received taurochenodeoxycholate (313 mg) instead of taurocholate. Volume, bicarbonate, trypsin, and lipase were determined in duodenal aspirates. Cholecystokinin, pancreatic polypeptide, and somatostatin were measured radioimmunologically in plasma samples. All bile salts and combinations exerted a significant hydrokinetic and ecbolic effect. The hydrokinetic response of the combined stimuli was significantly higher as compared with taurocholate and taurochenodeoxycholate, respectively. As far as concerns the ecbolic response, the difference was significant only for trypsin output as compared with taurochenodeoxycholate. Plasma cholecystokinin rose significantly only after the combined stimuli. Pancreatic polypeptide and somatostatin increased significantly after all stimuli, except pancreatic polypeptide after taurocholate. Combined use enhances the hydrokinetic and ecbolic effects of single bile salts. Cholecystokinin may, hereby, be involved as a mediator of the ecbolic effect. Pancreatic polypeptide release indicates cholinergic mechanisms as further mediators. As demonstrated by somatostatin release, counter-regulatory mechanisms are also triggered by intraduodenal bile salts.

  15. Bile salt hydrolase of Bifidobacterium longum-biochemical and genetic characterization.

    PubMed

    Tanaka, H; Hashiba, H; Kok, J; Mierau, I

    2000-06-01

    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 BSH (bsh) in a member of the genus Bifidobacterium. The enzyme has a native molecular weight of 125,000 to 130,000 and a subunit molecular weight of 35,024, as determined from the deduced amino acid sequence, indicating that the enzyme is a tetramer. The pH optimum of B. longum BSH is between 5 and 7, and the temperature optimum is 40 degrees C. The enzyme is strongly inhibited by thiol enzyme inhibitors, indicating that a Cys residue is likely to be involved in the catalytic reaction. The BSH of B. longum can hydrolyze all six major human bile salts and at least two animal bile salts. A slight preference for glycine-conjugated bile acids was detected based on both the specificity and the K(m) values. The nucleotide sequence of bsh was determined and used for homology studies, transcript analysis, and construction and analysis of various mutants. The levels of homology with BSH of other bacteria and with penicillin V acylase (PVA) of Bacillus sphaericus were high. On the basis of the similarity of BSH and PVA, whose crystal structure has been elucidated, BSH can be classified as an N-terminal nucleophile hydrolase with Cys as the N-terminal amino acid. This classification was confirmed by the fact that a Cys1Ala exchange by site-directed mutagenesis resulted in an inactive protein. Reverse transcription-PCR experiments revealed that bsh is part of an operon containing at least two genes, bsh and glnE (GlnE is glutamine synthetase adenylyltransferase). Two UV-induced BSH-negative mutants and one spontaneous BSH-negative mutant were isolated from B. longum SBT2928 cultures and characterized. These mutants had point mutations that inactivated bsh by premature termination, frameshift, or amino acid exchange.

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

    SciTech Connect

    Lundeen, S.G.; Savage, D.C. )

    1990-08-01

    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 ({sup 14}C)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.

  17. Association of canalicular membrane enzymes with bile acid micelles and lipid aggregates in human and rat bile.

    PubMed

    Accatino, L; Pizarro, M; Solís, N; Koenig, C S

    1995-01-18

    This study was undertaken to gain insights into the characteristics of the polymolecular association between canalicular membrane enzymes, bile acids, cholesterol and phospholipids in bile and into the celular mechanisms whereby the enzymes are secreted into bile. With this purpose, we studied the distribution of bile acids, cholesterol, phospholipids, proteins and representative canalicular membrane enzymes (alkaline phosphatase, 5'-nucleotidase and gamma-glutamyl transpeptidase), which can be considered specific marker constituents, in bile fractions enriched in phospholipid-cholesterol lamellar structures (multilamellar and unilamellar vesicles) and bile acid-mixed micelles. These fractions were isolated by ultracentrifugation from human hepatic bile, normal rat bile and bile of rats treated with diosgenin, a steroid that induces a marked increase in biliary cholesterol secretion, and were characterized by density, lipid composition and transmission electron microscopy. These studies demonstrate that alkaline phosphatase, 5'-nucleotidase and gamma-glutamyl transpeptidase are secreted into both human and rat bile where they are preferentially associated with bile acid-mixed micelles, suggesting a role for bile acids in both release of these enzymes and lipids from the canalicular membrane and solubilization in bile. In addition, heterogeneous association of these enzymes with nonmicellar, lamellar structures in human and rat bile is consistent with the hypothesis that processes independent of the detergent effects of bile acids might also result in the release of specific intrinsic membrane proteins into bile.

  18. Investigations of novel unsaturated bile salts of male sea lamprey as potential chemical cues.

    PubMed

    Johnson, Nicholas S; Yun, Sang-Seon; Li, Weiming

    2014-10-01

    Sulfated bile salts function as chemical cues that coordinate reproduction in sea lamprey, Petromyzon marinus. 7α, 12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) is the most abundant known bile salt released by sexually mature male sea lampreys and attracts ovulated females. However, previous studies showed that the male-produced pheromone consists of unidentified components in addition to 3kPZS. Here, analysis of water conditioned with mature male sea lampreys indicated the presence of 4 oxidized, unsaturated compounds with molecular weights of 466 Da, 468 Da, and 2 of 470 Da. These compounds were not detectable in water conditioned with immature male sea lampreys. By using mass spectrometry, 4 A-ring unsaturated sulfated bile salts were tentatively identified from male washings as 2 4-ene, a 1-ene, and a 1,4-diene analogs. These were synthesized to determine if they attracted ovulated female sea lampreys to spawning nests in natural streams. One of the novel synthetic bile salts, 3 keto-1-ene PZS, attracted ovulated females to the point of application at a concentration of 10(-12) M. This study reveals the structural diversity of bile salts in sea lamprey, some of which have been demonstrated to be pheromonal cues.

  19. Investigations of novel unsaturated bile salts of male sea lamprey as potential chemical cues

    USGS Publications Warehouse

    Johnson, Nicholas S.; Yun, Sang-Seon; Li, Weiming

    2014-01-01

    Sulfated bile salts function as chemical cues that coordinate reproduction in sea lamprey, Petromyzon marinus. 7α, 12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) is the most abundant known bile salt released by sexually mature male sea lampreys and attracts ovulated females. However, previous studies showed that the male-produced pheromone consists of unidentified components in addition to 3kPZS. Here, analysis of water conditioned with mature male sea lampreys indicated the presence of 4 oxidized, unsaturated compounds with molecular weights of 466 Da, 468 Da, and 2 of 470 Da. These compounds were not detectable in water conditioned with immature male sea lampreys. By using mass spectrometry, 4 A-ring unsaturated sulfated bile salts were tentatively identified from male washings as 2 4-ene, a 1-ene, and a 1,4-diene analogs. These were synthesized to determine if they attracted ovulated female sea lampreys to spawning nests in natural streams. One of the novel synthetic bile salts, 3 keto-1-ene PZS, attracted ovulated females to the point of application at a concentration of 10-12 M. This study reveals the structural diversity of bile salts in sea lamprey, some of which have been demonstrated to be pheromonal cues.

  20. Biliary albumin excretion induced by bile salts in rats is a pathological phenomenon

    SciTech Connect

    Ohta, M.; Kitani, K.; Kanai, S. )

    1989-09-01

    The bile to plasma 125I-albumin concentration ratio (B/P ratio) was examined before and during various bile salt infusions in male Wistar rats that had previously received iv injection of 125I-albumin. Endogenous rat albumin and IgG concentrations in the bile were also determined by a single radial immunodiffusion method. Taurocholate (TC) infusion (1.0 mumol/min/100 g body wt) significantly increased the bile flow rate in the first hr but the flow began to decline in the second hr. The B/P ratio as well as rat albumin (and IgG) excretion into the bile significantly increased as early as 15 min after the start of TC infusion, and the increase became more pronounced in the second hr, when the bile flow began to decrease. Infusion of taurochenodeoxycholate (TCDC, 0.4 mumol/min/100 g) caused a reduction in bile flow 15 min after the start of infusion but the B/P ratio increased 40 times at its peak compared with the basal value before the bile salt infusion. Simultaneous infusion of tauroursodeoxycholate (TUDC, 0.6 mumol/min/100 g) and TCDC not only abolished the cholestasis induced by TCDC but maintained stable choleresis as long as for 2 hr. During this choleretic period, the B/P ration never exceeded the basal value. The choleresis induced by either taurodehydrocholate (TDHC) or bucolome was not accompanied by enhanced albumin excretion. In rats given TDHC infusion, albumin excretion started to increase only after the bile flow began to decline following the initial choleretic period. The enhanced excretion of albumin induced by TC and TCDC is therefore suggested to be caused not by the choleresis per se but by a possible concomitant increase in the communication between sinusoids and bile canaliculi, which eventually leads to cholestasis.

  1. Response to Bile Salts in Clinical Strains of Acinetobacter baumannii Lacking the AdeABC Efflux Pump: Virulence Associated with Quorum Sensing

    PubMed Central

    López, Maria; Blasco, Lucia; Gato, Eva; Perez, Astrid; Fernández-Garcia, Laura; Martínez-Martinez, Luis; Fernández-Cuenca, Felipe; Rodríguez-Baño, Jesús; Pascual, Alvaro; Bou, German; Tomás, Maria

    2017-01-01

    Introduction: Acinetobacter baumannii is an opportunistic nosocomial pathogen associated with multiple infections. This pathogen usually colonizes (first stage of microbial infection) host tissues that are in contact with the external environment. As one of the sites of entry in human hosts is the gastrointestinal tract, the pathogen must be capable of tolerating bile salts. However, studies analyzing the molecular characteristics involved in the response to bile salts in clinical strains of A. baumannii are scarce. Material and Methods: Microbiological and transcriptional studies (arrays and RT-PCR) in the response to bile salts were carried out in isogenic (A. baumanni ΔadeB ATCC 17978 and A. baumannii ΔadeL ATCC 17978) and clinical strains from clone ST79/PFGE-HUI-1 which is characterized by lacking the AdeABC efflux pump and by overexpression the AdeFGH efflux pump. Results and Discussion: In presence of bile salts, in addition to the glutamate/aspartate transporter were found overexpressed in A. baumannii ΔadeB ATCC 17978, the virulence factors (surface motility, biofilm, and Type VI Secretion System) which are associated with activation of the Quorum Sensing system. Overexpression of these factors was confirmed in clinical strains of clone ST79/PFGE-HUI-1. Conclusions: This the first study about the adaptive response to bile salts investigating the molecular and microbiological characteristics in response to bile salts of an isogenic model of A. baumannii ATCC 17978 and clinical isolates of A. baumannii (clinical strains of ST79/PFGE-HUI-1) lacking the main RND efflux pump (AdeABC). Clinical isolates of A. baumannii lacking the AdeABC efflux pump (clone ST79/PFGE-HUI-1) displayed a new clinical profile (increased invasiveness) possibly associated with the response to stress conditions (such as the presence of bile salts). PMID:28536672

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

    PubMed

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

    2015-07-01

    Cftr(-/-tm1Unc) 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. We determined bile production, biliary and fecal bile salt- and lipid compositions and fecal bacterial composition of C57BL/6J Cftr(-/-tm1Unc) and control mice. We found no differences between the total biliary bile salt or lipid concentrations of Cftr(-/-) and controls. Compared to controls, Cftr(-/-) mice had a ~30% higher bile production and a low bile hydrophobicity, related to a ~7 fold higher concentration of the choleretic and hydrophilic bile salt ursocholate. These findings coexisted with a significantly smaller quantity of fecal Bacteroides bacteria. Liver pathology in Cftr(-/-tm1Unc) is not related to increased bile hydrophobicity. Cftr(-/-) mice do however display a biliary phenotype characterized by increased bile production and decreased biliary hydrophobicity. Our findings suggest Cftr dependent, alterations in intestinal bacterial biotransformation of bile salts. Copyright © 2014. Published by Elsevier B.V.

  3. An active type IV secretion system encoded by the F plasmid sensitizes Escherichia coli to bile salts.

    PubMed

    Bidlack, James E; Silverman, Philip M

    2004-08-01

    F(+) strains of Escherichia coli infected with donor-specific bacteriophage such as M13 are sensitive to bile salts. We show here that this sensitivity has two components. The first derives from secretion of bacteriophage particles through the cell envelope, but the second can be attributed to expression of the F genes required for the formation of conjugative (F) pili. The latter component was manifested as reduced or no growth of an F(+) strain in liquid medium containing bile salts at concentrations that had little or no effect on the isogenic F(-) strain or as a reduced plating efficiency of the F(+) strain on solid media; at 2% bile salts, plating efficiency was reduced 10(4)-fold. Strains with F or F-like R factors were consistently more sensitive to bile salts than isogenic, plasmid-free strains, but the quantitative effect of bile salts depended on both the plasmid and the strain. Sensitivity also depended on the bile salt, with conjugated bile salts (glycocholate and taurocholate) being less active than unconjugated bile salts (deoxycholate and cholate). F(+) cells were also more sensitive to sodium dodecyl sulfate than otherwise isogenic F(-) cells, suggesting a selectivity for amphipathic anions. A mutation in any but one F tra gene required for the assembly of F pili, including the traA gene encoding F pilin, substantially restored bile salt resistance, suggesting that bile salt sensitivity requires an active system for F pilin secretion. The exception was traW. A traW mutant was 100-fold more sensitive to cholate than the tra(+) strain but only marginally more sensitive to taurocholate or glycocholate. Bile salt sensitivity could not be attributed to a generalized change in the surface permeability of F(+) cells, as judged by the effects of hydrophilic and hydrophobic antibiotics and by leakage of periplasmic beta-lactamase into the medium.

  4. Assessment of conjugal transfer of antibiotic resistance genes in Salmonella Typhimurium exposed to bile salts.

    PubMed

    He, Xinlong; Ahn, Juhee

    2014-08-01

    This study was designed to evaluate the transfer potential of antibiotic resistance genes in antibiotic-resistant Salmonella Typhimurium (S. Typhimurium(R)) in the presence of bile salts. The resistance of S. Typhimurium(R) to ampicillin, kanamycin, and tetracycline was increased by 64-, 64-, and 512-fold, respectively. The highest transfer frequency from S. Typhimurium(R) to Escherichia coli was observed at the bile salt concentration of 160 μg/ml (3.8 × 10(-3) transferrants/cells). The expression of traJ and traY was suppressed in S. Typhimurium(R) by bile salt. This study provides useful information for understanding the conjugative transfer of antibiotic resistance genes in S. Typhimurium under intestinal conditions.

  5. Regulation of mdr2 P-glycoprotein expression by bile salts.

    PubMed Central

    Frijters, C M; Ottenhoff, R; van Wijland, M J; van Nieuwkerk, C M; Groen, A K; Oude Elferink, R P

    1997-01-01

    The phosphatidyl translocating activity of the mdr2 P-glycoprotein (Pgp) in the canalicular membrane of the mouse hepatocyte is a rate-controlling step in the biliary secretion of phospholipid. Since bile salts also regulate the secretion of biliary lipids, we investigated the influence of the type of bile salt in the circulation on mdr2 Pgp expression and activity. Male mice were led a purified diet to which either 0.1% (w/w) cholate or 0.5% (w/w) ursodeoxycholate was added. This led to a near-complete replacement of the endogenous bile salt pool (mainly tauromuricholate) by taurocholate or tauroursodeoxycholate respectively. The phospholipid secretion capacity was then determined by infusion of increasing amounts of tauroursodeoxycholate. Cholate feeding resulted in a 55% increase in maximal phospholipid secretion compared with that in mice on the control diet. Northern blotting revealed that cholate feeding increased mdr2 Pgp mRNA levels by 42%. Feeding with ursodeoxycholate did not influence the maximum rate of phospholipid output or the mdr2 mRNA content. Female mice had a higher basal mdr2 Pgp mRNA level than male mice, and this was also correlated with a higher phospholipid secretion capacity. This could be explained by the 4-fold higher basal cholate content in the bile of female compared with male mice. Our results suggest that the type of bile salts in the circulation influences the expression of the mdr2 gene. PMID:9020871

  6. Direct Measurement of the Thermodynamics of Chiral Recognition in Bile Salt Micelles.

    PubMed

    Anderson, Shauna L; Rovnyak, David; Strein, Timothy G

    2016-04-01

    Isothermal titration calorimetry (ITC) is shown to be a sensitive reporter of bile salt micellization and chiral recognition. Detailed ITC characterization of bile micelle formation as well as the chiral recognition capabilities of sodium cholate (NaC), deoxycholate (NaDC), and taurodeoxycholate (NaTDC) micelle systems are reported. The ΔH(demic) of these bile salt micelle systems is directly observable and is strongly temperature-dependent, allowing also for the determination of ΔCp(demic). Using the pseudo-phase separation model, ΔG(demic) and TΔS(demic) were also calculated. Chirally selective guest-host binding of model racemic compounds 1,1'-bi-2-napthol (BN) and 1,1'-binaphthyl-2,2'-diylhydrogenphosphate (BNDHP) to bile salt micelles was then investigated. The S-isomer was shown to bind more tightly to the bile salt micelles in all cases. A model was developed that allows for the quantitative determination of the enthalpic difference in binding affinity that corresponds to chiral selectivity, which is on the order of 1 kJ mol(-1).

  7. Measurement of transport activities of 3β-hydroxy-Δ(5)-bile acids in bile salt export pump and multidrug resistance-associated proteins using LC-MS/MS.

    PubMed

    Murai, Tsuyoshi; Oda, Kana; Toyo, Terutake; Nittono, Hiroshi; Takei, Hajime; Muto, Akina; Kimura, Akihiko; Kurosawa, Takao

    2013-01-01

    A method has been developed for the measurement of transport activities in membrane vesicles obtained from Sf9 cells for 3β-hydroxy-Δ(5)-bile acids by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Calibration curves for the bile acids were linear over the range of 10 to 2000 pmol/mL, and the detection limit was less than 1 pmol/mL for 3β-hydroxy-Δ(5)-bile acids using selected reaction monitoring analysis. The analytical method was applied to measurements of transport activities in membrane vesicles obtained from human multidrug resistance-associated protein 2-, 3-, and human bile salt export pump-expressing Sf9 cells for conjugated 3β-hydroxy-Δ(5)-bile acids. The present study demonstrated that human multidrug resistance-associated protein 3 vesicles accepted conjugated 3β-hydroxy-Δ(5)-bile acids along with common bile acids such as glycocholic acid and taurolithocholic acid 3-sulfate.

  8. Characterization of the mouse bile salt export pump overexpressed in the baculovirus system.

    PubMed

    Noe, J; Hagenbuch, B; Meier, P J; St-Pierre, M V

    2001-05-01

    The bile salt export pump (Bsep), a member of the ATP-binding cassette superfamily of transporters, mediates the ATP-dependent canalicular secretion of bile salts. We have cloned and expressed the mouse Bsep (mBsep) protein in Sf9 insect cells, and characterized its transport and ATPase properties. Because its deduced amino acid sequence predicts multiple phosphorylation sites for protein kinase A, protein kinase C (PKC) and Ca(2+)-calmodulin dependent kinase II, we have also tested whether mBsep undergoes phosphorylation. MBsep transports both glycine and taurine conjugated bile salts. Sf9 cell membranes that express mBsep exhibit higher basal ATPase activity than control membranes, and this is further stimulated by bile salts and inhibited by vanadate. Taurochenodeoxycholate is transported with the highest affinity and is the most potent inducer of ATPase activity. Cyclosporin A, glibenclamide and rifamycin SV, all competitive inhibitors of Bsep transport, also reduced the bile salt-stimulated ATPase activity. MBsep exists as a phospho-protein when expressed in Sf9 cells and the immunoprecipitated mBsep complex is a substrate for the catalytic subunit of PKC. When mBsep and the alpha-isoform of mouse PKC are co-expressed in Sf9 cells, a ninefold stimulation of phosphorylation occurs. This is further increased to 18-fold after activation by phorbol ester. Given that bile salts activate selected PKC isoforms in hepatocytes, including the alpha isoform, the phosphorylation of mBsep by PKCalpha may represent a point of regulation for this transporter that is mediated by its own substrate.

  9. Intestinal synthesis and secretion of bile salts as an adaptation to developmental biliary atresia in the sea lamprey

    PubMed Central

    Yeh, Chu-Yin; Chung-Davidson, Yu-Wen; Wang, Huiyong; Li, Ke; Li, Weiming

    2012-01-01

    Bile salt synthesis is a specialized liver function in vertebrates. Bile salts play diverse roles in digestion and signaling, and their homeostasis is maintained by controlling input (biosynthesis) and intestinal conservation. Patients with biliary atresia (i.e., obliteration of the biliary tree) suffer liver fibrosis and cirrhosis. In contrast, sea lamprey thrives despite developmental biliary atresia. We discovered that the sea lamprey adapts to biliary atresia through a unique mechanism of de novo synthesis and secretion of bile salts in intestine after developmental biliary atresia, in addition to known mechanisms, such as the reduction of bile salt synthesis in liver. During and after developmental biliary atresia, expression of cyp7a1 in intestine increased by more than 100-fold (P < 0.001), whereas in liver it decreased by the same magnitude (P < 0.001). Concurrently, bile salt pools changed in similar patterns and magnitudes in these two organs and the composition shifted from C24 bile alcohol sulfates to taurine-conjugated C24 bile acids. In addition, both in vivo and ex vivo experiments showed that aductular sea lamprey secreted taurocholic acid into its intestinal lumen. Our results indicate that the sea lamprey, a jawless vertebrate, may be in an evolutionarily transitional state where bile salt synthesis occurs in both liver and intestine. Understanding the molecular basis of these mechanisms may shed light on the evolution of bile salt synthesis and possible therapy for infant biliary atresia. PMID:22733776

  10. Biosynthesis and release of pheromonal bile salts in mature male sea lamprey

    PubMed Central

    2013-01-01

    Background In vertebrates, bile salts are primarily synthesized in the liver and secreted into the intestine where they aid in absorption of dietary fats. Small amounts of bile salts that are not reabsorbed into enterohepatic circulation are excreted with waste. In sexually mature male sea lamprey (Petromyzon marinus L.) a bile salt is released in large amounts across gill epithelia into water where it functions as a pheromone. We postulate that the release of this pheromone is associated with a dramatic increase in its biosynthesis and transport to the gills upon sexual maturation. Results We show an 8000-fold increase in transcription of cyp7a1, a three-fold increase in transcription of cyp27a1, and a six-fold increase in transcription of cyp8b1 in the liver of mature male sea lamprey over immature male adults. LC–MS/MS data on tissue-specific distribution and release rates of bile salts from mature males show a high concentration of petromyzonol sulfate (PZS) in the liver and gills of mature males. 3-keto petromyzonol sulfate (3kPZS, known as a male sex pheromone) is the primary compound released from gills, suggesting a conversion of PZS to 3kPZS in the gill epithelium. The PZS to 3kPZS conversion is supported by greater expression of hsd3b7 in gill epithelium. High expression of sult2b1 and sult2a1 in gill epithelia of mature males, and tissue-specific expression of bile salt transporters such as bsep, slc10a1, and slc10a2, suggest additional sulfation and transport of bile salts that are dependent upon maturation state. Conclusions This report presents a rare example where specific genes associated with biosynthesis and release of a sexual pheromone are dramatically upregulated upon sexual maturation in a vertebrate. We provide a well characterized example of a complex mechanism of bile salt biosynthesis and excretion that has likely evolved for an additional function of bile salts as a mating pheromone. PMID:24188124

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

    PubMed

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

    2012-03-01

    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 addition, the expression of cholesteryl ester hydrolase CES1 and bile salt export pump (BSEP) was monitored. Contrary to the general assumption, Z-guggulsterone did not induce CYP7A1. Instead, this phytosterol significantly induced CES1 and BSEP through transactivation. Z-Guggulsterone underwent metabolism by CYP3A4, and the metabolites greatly increased the induction potency on BSEP but not on CES1. BSEP induction favors cholesterol elimination, whereas CES1 involves both elimination and retention (probably when excessively induced). Interestingly, clinical trials reported the hypolipidemic response rates from 18% to 80% and showed that higher dosages actually increased VLDL cholesterol. Our findings predict that better hypolipidemic outcomes likely occur in individuals who have a relatively higher capacity of metabolizing Z-guggulsterone with moderate CES1 induction, a scenario possibly achieved by lowering the dosing regimens.

  12. The Resistance of Esophageal Adenocarcinoma to Bile Salt Insult is Associated with Manganese Superoxide Dismutase Expression

    PubMed Central

    Schiffman, Suzanne C.; Li, Yan; Xiao, Deyi; Li, Xuanshe; Aiyer, Harini S.; Martin, Robert C.G.

    2010-01-01

    BACKGROUND Bile acids are implicated as etiologic agents in esophageal cancer. We sought to analyze the impact of bile acid exposure on esophageal epithelial cells, Barrett’s metaplastic cells (BE), esophageal adenocarcinoma cells (EAC) and esophageal squamous carcinoma cell (ESC). We sought to determine if cellular resistance is related to manganese superoxide dismutase expression. METHODS Cells were exposed to sodium choleate (CA), sodium deoxycholate (DCA), sodium glycocholate (GCA), sodium taurocholate (TCA) or a 1:1 mixture (MIX) of reagents at concentrations ranging 0.2 – 0.8 mM. Cell viability was evaluated by MTT assay. MnSOD expression was analyzed by Western Blot. Statistical analysis was performed using SPSS 17.0. RESULTS Bile salt exposure inhibited cell viability in esophageal squamous cells in time and growth dependent manner. There was a 50% decrease in cell viability from four to 24 hours. BE, EAC and ESC cell lines were more resistant to bile insult. In untreated cell lines, MnSOD expression was significantly decreased in EAC and ESC cell lines as compared to esophageal squamous epithelial cells and BE cells (p=0.002). Exposure of ESC cells to bile salt increased MnSOD expression. DISCUSSION The confirmation of the role of ROS and bile acids in esophageal carcinogenesis has interesting implications for chemoprevention in patients with reflux esophagitis and Barrett’s esophagus. Further studies are necessary to assess the preventative role of antioxidant supplementation PMID:20638682

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

    PubMed Central

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

    2012-01-01

    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 mechanisms remain largely unknown. In this study, we found that BSEP expression was severely diminished in HCC tissues and markedly reduced in adjacent non-tumor tissues. In contrast to mouse, human BSEP was regulated by farnesoid x receptor (FXR) in an isoform-dependent manner. FXRα2 exhibited a much more potent activity than FXRα1 in transactivating human BSEP in vitro and in vivo. The decreased BSEP expression in HCC was associated with altered relative expression of FXRα1 and FXRα2. The FXRα1/FXRα2 ratios were significantly increased with undetectable FXRα2 expression in one third of the HCC tumor samples. Similar correlation between BSEP and FXR isoform expression was confirmed in hepatoma Huh 7 and HepG2 cells. Further studies showed that intrahepatic proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were significantly elevated in HCC tissues. Treatment of Huh 7 cells with IL-6 and TNF-α resulted in a marked increase in the FXRα1/FXRα2 ratio concurrent with a significant decrease in BSEP expression. In conclusion, BSEP expression was severely diminished in HCC patients associated with alteration of FXR isoform expression induced by inflammation, and the restoration of BSEP expression through suppressing inflammation in the liver may re-establish the bile acid homeostasis. PMID:23213087

  14. Bile salts of germ-free domestic fowl and pigs

    PubMed Central

    Haslewood, G. A. D.

    1971-01-01

    1. The bile of germ-free domestic fowl contains taurine conjugates of 3α,7α-dihydroxy-5β-cholan-24-oic acid (chenodeoxycholic acid), 3α,7α,12α-trihydroxy-5β-cholan-24-oic acid (cholic acid) and its 5α-epimer (allocholic acid): that of germ-free pigs contains glycine and taurine conjugates of chenodeoxycholic acid, 3α,6α-dihydroxy-5β-cholan-24-oic acid (hyodeoxycholic acid), 3α,6α,7α-trihydroxy-5β-cholan-24-oic acid (hyocholic acid) and (probably) cholic acid. Keto acids were not found. 2. Allocholic acid and hyodeoxycholic acid are thus proved to be primary bile acids in intact animals. 3. The evolutionary and biochemical implications of these findings are briefly considered. PMID:5128663

  15. [Preparation and antitussive, expectorant and antiasthmatic activities of verticinone-bile acids salts].

    PubMed

    Xu, Fang-Zhou; Zhang, Yong-Hui; Ruan, Han-Li; Pi, Hui-Fang; Chen, Chang; Wu, Ji-Zhou

    2007-03-01

    To search for potential drugs with potent antitussive, expectorant, antiasthmatic activities and low toxicity, a series of verticinone-bile acids salts were prepared based on the clearly elucidated antitussive, expectorant and antiasthmatic activities of verticinone in bulbs of Fritillaria and different bile acids in Snake Bile. The antitussive, expectorant and antiasthmatic activities of these verticinone-bile acid salts were then screened with different animal models. Ver-CA (verticinone-cholic acid salt) and Ver-CDCA (verticinone-chenodeoxycholic acid salt) showed much more potent activities than other compounds. The bioactivities of Ver-CA and Ver-CDCA are worthy to be intensively studied, and it is also deserved to pay much attention to their much more potent antitussive effects than codeine phosphate. In order to elucidate whether they have synergistic effect and attenuated toxicity, their activities will be continuously compared with single verticinone, cholic acid and chenodeoxycholic acid at the same doses on different animal models. The application of "combination principles" in traditional Chinese medicinal formulations may be a novel way in triditional Chinese medicine research and discovery.

  16. Steroid binding to Autotaxin links bile salts and lysophosphatidic acid signalling

    PubMed Central

    Keune, Willem-Jan; Hausmann, Jens; Bolier, Ruth; Tolenaars, Dagmar; Kremer, Andreas; Heidebrecht, Tatjana; Joosten, Robbie P.; Sunkara, Manjula; Morris, Andrew J.; Matas-Rico, Elisa; Moolenaar, Wouter H.; Oude Elferink, Ronald P.; Perrakis, Anastassis

    2016-01-01

    Autotaxin (ATX) generates the lipid mediator lysophosphatidic acid (LPA). ATX-LPA signalling is involved in multiple biological and pathophysiological processes, including vasculogenesis, fibrosis, cholestatic pruritus and tumour progression. ATX has a tripartite active site, combining a hydrophilic groove, a hydrophobic lipid-binding pocket and a tunnel of unclear function. We present crystal structures of rat ATX bound to 7α-hydroxycholesterol and the bile salt tauroursodeoxycholate (TUDCA), showing how the tunnel selectively binds steroids. A structure of ATX simultaneously harbouring TUDCA in the tunnel and LPA in the pocket, together with kinetic analysis, reveals that bile salts act as partial non-competitive inhibitors of ATX, thereby attenuating LPA receptor activation. This unexpected interplay between ATX-LPA signalling and select steroids, notably natural bile salts, provides a molecular basis for the emerging association of ATX with disorders associated with increased circulating levels of bile salts. Furthermore, our findings suggest potential clinical implications in the use of steroid drugs. PMID:27075612

  17. The influence of bile salt on the chemotherapeutic response of docetaxel-loaded thermosensitive nanomicelles

    PubMed Central

    Kim, Dong Wuk; Ramasamy, Thiruganesh; Choi, Ju Yeon; Kim, Jeong Hwan; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2014-01-01

    The primary aim of this work was to investigate the potential of bile salt, sodium taurocholate (NaTC), in improving the bioavailability and anti-tumor efficacy of docetaxel (DCT) upon rectal administration. Poloxamer-based nanomicelles with thermosensitive and mucoadhesive properties were prepared using the cold method. The optimized nanomicellar formulation was evaluated in terms of physicochemical and viscoelastic parameters. Nanomicelles containing bile salt maintained sufficient gelation strength (234×102 mPa·s) and mucoadhesive force (17.3×102 dyne/cm2) to be retained in the upper part of the rectum. They significantly enhanced the DCT internalization across the rectal mucosa and showed a high plasma level during the first 4 hours of the study period, compared to nanomicelles with no bile salt. As a result, a slightly higher rectal bioavailability of ~33% was observed in nanomicelles containing bile salt, compared to ~28% from the latter system. The higher pharmacokinetic parameters for rectally administered DCT/P407/P188/Tween 80/NaTC (0.25%/11%/15%/10%/0.1% by weight, respectively) resulted in significant anti-tumor efficacy. However, the tumor regression rate for the NaTC group was not statistically different from that for nanomicelles without NaTC. Therefore, overall results suggest that thermosensitive nanomicelles could be a potential dosage form for improvement of the bioavailability and chemotherapeutic profile of DCT. PMID:25143730

  18. The influence of bile salt on the chemotherapeutic response of docetaxel-loaded thermosensitive nanomicelles.

    PubMed

    Kim, Dong Wuk; Ramasamy, Thiruganesh; Choi, Ju Yeon; Kim, Jeong Hwan; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2014-01-01

    The primary aim of this work was to investigate the potential of bile salt, sodium taurocholate (NaTC), in improving the bioavailability and anti-tumor efficacy of docetaxel (DCT) upon rectal administration. Poloxamer-based nanomicelles with thermosensitive and mucoadhesive properties were prepared using the cold method. The optimized nanomicellar formulation was evaluated in terms of physicochemical and viscoelastic parameters. Nanomicelles containing bile salt maintained sufficient gelation strength (234×10(2) mPa·s) and mucoadhesive force (17.3×10(2) dyne/cm(2)) to be retained in the upper part of the rectum. They significantly enhanced the DCT internalization across the rectal mucosa and showed a high plasma level during the first 4 hours of the study period, compared to nanomicelles with no bile salt. As a result, a slightly higher rectal bioavailability of ~33% was observed in nanomicelles containing bile salt, compared to ~28% from the latter system. The higher pharmacokinetic parameters for rectally administered DCT/P407/P188/Tween 80/NaTC (0.25%/11%/15%/10%/0.1% by weight, respectively) resulted in significant anti-tumor efficacy. However, the tumor regression rate for the NaTC group was not statistically different from that for nanomicelles without NaTC. Therefore, overall results suggest that thermosensitive nanomicelles could be a potential dosage form for improvement of the bioavailability and chemotherapeutic profile of DCT.

  19. Noninvasive methods to determine the critical micelle concentration of some bile acid salts.

    PubMed

    Reis, Salette; Moutinho, Carla Guimarães; Matos, Carla; de Castro, Baltazar; Gameiro, Paula; Lima, José L F C

    2004-11-01

    In this work the critical micelle concentrations (cmc) of four bile salts, sodium cholate, sodium glycocholate, sodium deoxycholate, and sodium glycodeoxycholate, are determined and presented. Three independent noninvasive methodologies (potentiometry, derivative spectrophotometry, and light scattering) were used for cmc determination, at 25 degrees C with ionic strength adjusted to 0.10 M with NaCl. Spectrophotometric and potentiometric studies of some bile salts were also executed at various ionic strength values, thus allowing the influence of the ionic strength on the cmc value of the bile salt to be assessed. A critical comparison of the cmc values obtained with data collected from the literature is presented. Furthermore, this work makes an evaluation of the conceptual bases of different methodologies commonly used for cmc determination, since variations in the results obtained can be related mainly to different intrinsic features of the methods used (such as sensitivity or the need to include tracers or probes) or to the operational cmc definition applied. The undoubted definition of the experimental bile salt concentration that corresponds to cmc (operational cmc) is essential since in the case of these amphiphiles the formation of micelles is not as abrupt as in the case of ordinary association colloids. The biphasic nature of their aggregation leads to a "round-shaped" variation of the experimental parameters under analysis, which makes difficult the evaluation of the cmc values and can be responsible for the different results obtained.

  20. Substrate specificity of human ABCC4 (MRP4)-mediated cotransport of bile acids and reduced glutathione.

    PubMed

    Rius, Maria; Hummel-Eisenbeiss, Johanna; Hofmann, Alan F; Keppler, Dietrich

    2006-04-01

    The multidrug resistance protein ABCC4 (MRP4), a member of the ATP-binding cassette superfamily, mediates ATP-dependent unidirectional efflux of organic anions out of cells. Previous studies showed that human ABCC4 is localized to the sinusoidal membrane of hepatocytes and mediates, among other substrates, the cotransport of reduced glutathione (GSH) with bile acids. In the present study, using inside-out membrane vesicles, we demonstrated that human ABCC4 in the presence of physiological concentrations of GSH has a high affinity for the taurine and glycine conjugates of the common natural bile acids as well as the unconjugated bile acid cholate. Chenodeoxycholyltaurine and chenodeoxycholylglycine were the GSH cosubstrates with the highest affinities for ABCC4, with K(m) values of 3.6 and 5.9 microM, respectively. Ursodeoxycholyltaurine and ursodeoxycholylglycine were cotransported together with GSH by ABCC4 with K(m) values of 7.8 and 12.5 microM, respectively, but no transport of ursodeoxycholate and deoxycholate was observed. The simultaneous transport of labeled GSH and cholyltaurine or cholylglycine was demonstrated in double-labeled cotransport experiments with a bile acid-to-GSH ratio of approximately 1:22. K(m) values of the bile acids for ABCC4 were in a range similar to those reported for the canalicular bile salt export pump ABCB11. Under physiological conditions, the sinusoidal ABCC4 may compete with canalicular ABCB11 for bile acids and thereby play a key role in determining the hepatocyte concentration of bile acids. In cholestatic conditions, ABCC4 may become a key pathway for efflux of bile acids from hepatocytes into blood.

  1. Impact of bile salt adaptation of Lactobacillus delbrueckii subsp. lactis 200 on its interaction capacity with the gut.

    PubMed

    Burns, Patricia; Reinheimer, Jorge; Vinderola, Gabriel

    2011-10-01

    In a previous work, bile-salt-resistant derivatives were obtained from non-intestinal lactobacilli. The aim of this work was to investigate the impact of bile adaptation of Lactobacillus delbrueckii subsp. lactis 200 on morphology, surface properties, in vivo interaction capacity with the gut and ability to activate the gut immune response. Electron microscopy studies, growth kinetics in the presence of bovine and porcine bile, the capacity to deconjugate bile acids, hydrophobicity, autoaggregation and co-aggregation capacities were studied for the parental strain and its bile-resistant derivative in vitro. Additionally, survival in intestinal fluid, the interaction with the gut and the immunomodulating capacities were studied in mice. Bile salt adaptation conferred upon the adapted strain a higher capacity to withstand physiological concentrations of bile salts and greater survival capacity in intestinal fluid. However, bile salt exposure reduced cell hydrophobicity, autoaggregation and adhesion capacities, resulting in reduced persistence in the intestinal lumen and delayed capacity to activate the gut immune response. Insight into the effects of bile salts upon the interaction and immunomodulating capacity of lactobacilli with the gut is provided, relating in vitro and in vivo results.

  2. Calcium Enhances Bile Salt-Dependent Virulence Activation in Vibrio cholerae.

    PubMed

    Hay, Amanda J; Yang, Menghua; Xia, Xiaoyun; Liu, Zhi; Hammons, Justin; Fenical, William; Zhu, Jun

    2017-01-01

    Vibrio cholerae is the causative bacteria of the diarrheal disease cholera, but it also persists in aquatic environments, where it displays an expression profile that is distinct from that during infection. Upon entry into the host, a tightly regulated circuit coordinates the induction of two major virulence factors: cholera toxin and a toxin-coregulated pilus (TCP). It has been shown that a set of bile salts, including taurocholate, serve as host signals to activate V. cholerae virulence through inducing the activity of the transmembrane virulence regulator TcpP. In this study, we investigated the role of calcium, an abundant mental ion in the gut, in the regulation of virulence. We show that whereas Ca(2+) alone does not affect virulence, Ca(2+) enhances bile salt-dependent virulence activation for V. cholerae The induction of TCP by murine intestinal contents is counteracted when Ca(2+) is depleted by the high-affinity calcium chelator EGTA, suggesting that the calcium present in the gut is a relevant signal for V. cholerae virulence induction in vivo We further show that Ca(2+) enhances virulence by promoting bile salt-induced TcpP-TcpP interaction. Moreover, fluorescence recovery after photobleaching (FRAP) analysis demonstrated that exposure to bile salts and Ca(2+) together decreases the recovery rate for fluorescently labeled TcpP, but not for another inner membrane protein (TatA). Together, these data support a model in which physiological levels of Ca(2+) may result in altered bile salt-induced TcpP protein movement and activity, ultimately leading to an increased expression of virulence. Copyright © 2016 American Society for Microbiology.

  3. Bile Salts at Low pH Cause Dilation of Intercellular Spaces in In Vitro Stratified Primary Esophageal Cells, Possibly by Modulating Wnt Signaling.

    PubMed

    Ghatak, Sayak; Reveiller, Marie; Toia, Liana; Ivanov, Andrei I; Zhou, Zhongren; Redmond, Eileen M; Godfrey, Tony E; Peters, Jeffrey H

    2016-03-01

    The presence of dilated intercellular spaces in the stratified squamous lining of the esophagus is the pathognomonic feature of reflux esophagitis secondary to gastroesophageal reflux disease (GERD). In addition to stomach acid, bile salts are major constituents of gastroesophageal refluxate. The aim of our study was to determine the effect of bile salts cocktail at different pHs on epithelial junctions in an in vitro transwell model of stratified esophageal squamous epithelium. Human telomerase reverse transcriptase (hTERT) immortalized primary esophageal EPC1 cells were grown on polyester transwell surfaces in calcium-enriched media. The cells exhibited gradual stratification into an 11-layered squamous epithelium over 7 days, together with epithelial barrier function as indicated by increased transepithelial electrical resistance (TEER). This stratified epithelium demonstrated well-formed tight junctions, adherens junctions, and desmosomes as visualized by immunofluorescence and electron microscopy. When exposed to short pulses of bile salts at pH 5, but not either condition alone, there was loss of stratification and decrease in TEER, concomitant with disruption of adherens junctions, tight junctions, and desmosomes, leading to the appearance of dilated intercellular spaces. At the cellular level, bile salts at pH 5 activated the Wnt pathway (indicated by increased β-catenin Ser552 phosphorylation). In conclusion, in our in vitro transwell model bile salts at pH 5, but not bile salts or media at pH 5 alone, modulate Wnt signaling, disrupt different junctional complexes, and cause increased permeability of stratified squamous esophageal epithelium. These changes approximate the appearance of dilated intercellular space similar to that found in GERD patients.

  4. Formation of liquid-crystalline structures in the bile salt-chitosan system and triggered release from lamellar phase bile salt-chitosan capsules.

    PubMed

    Tangso, Kristian J; Lindberg, Seth; Hartley, Patrick G; Knott, Robert; Spicer, Patrick; Boyd, Ben J

    2014-08-13

    Nanostructured capsules comprised of the anionic bile salt, sodium taurodeoxycholate (STDC), and the biocompatible cationic polymer, chitosan, were prepared to assess their potential as novel tailored release nanomaterials. For comparison, a previously studied system, sodium dodecyl sulfate (SDS), and polydiallyldimethylammonium chloride (polyDADMAC) was also investigated. Crossed-polarizing light microscopy (CPLM) and small-angle X-ray scattering (SAXS) identified the presence of lamellar and hexagonal phase at the surfactant-polymer interface of the respective systems. The hydrophobic and electrostatic interactions between the oppositely charged components were studied by varying temperature and salt concentration, respectively, and were found to influence the liquid-crystalline nanostructure formed. The hexagonal phase persisted at high temperatures, however the lamellar phase structure was lost above ca. 45 °C. Both mesophases were found to dissociate upon addition of 4% NaCl solution. The rate of release of the model hydrophilic drug, Rhodamine B (RhB), from the lamellar phase significantly increased in response to changes in the solution conditions studied, suggesting that modulating the drug release from these bile salt-chitosan capsules is readily achieved. In contrast, release from the hexagonal phase capsules had no appreciable response to the stimuli applied. These findings provide a platform for these oppositely charged surfactant and polymer systems to function as stimuli-responsive or sustained-release drug delivery systems.

  5. Acidic bile salts modulate the squamous epithelial barrier function by modulating tight junction proteins.

    PubMed

    Chen, Xin; Oshima, Tadayuki; Tomita, Toshihiko; Fukui, Hirokazu; Watari, Jiro; Matsumoto, Takayuki; Miwa, Hiroto

    2011-08-01

    Experimental models for esophageal epithelium in vitro either suffer from poor differentiation or complicated culture systems. An air-liquid interface system with normal human bronchial epithelial cells can serve as a model of esophageal-like squamous epithelial cell layers. Here, we explore the influence of bile acids on barrier function and tight junction (TJ) proteins. The cells were treated with taurocholic acid (TCA), glycocholic acid (GCA), or deoxycholic acid (DCA) at different pH values, or with pepsin. Barrier function was measured by transepithelial electrical resistance (TEER) and the diffusion of paracellular tracers (permeability). The expression of TJ proteins, including claudin-1 and claudin-4, was examined by Western blotting of 1% Nonidet P-40-soluble and -insoluble fractions. TCA and GCA dose-dependently decreased TEER and increased paracellular permeability at pH 3 after 1 h. TCA (4 mM) or GCA (4 mM) did not change TEER and permeability at pH 7.4 or pH 4. The combination of TCA and GCA at pH 3 significantly decreased TEER and increased permeability at lower concentrations (2 mM). Pepsin (4 mg/ml, pH 3) did not have any effect on barrier function. DCA significantly decreased the TEER and increased permeability at pH 6, a weakly acidic condition. TCA (4 mM) and GCA (4 mM) significantly decreased the insoluble fractions of claudin-1 and claudin-4 at pH 3. In conclusion, acidic bile salts disrupted the squamous epithelial barrier function partly by modulating the amounts of claudin-1 and claudin-4. These results provide new insights for understanding the role of TJ proteins in esophagitis.

  6. Photochromism of a spiropyran and a diarylethene in bile salt aggregates in aqueous solution.

    PubMed

    Santos, Cerize S; Miller, Allyson C; Pace, Tamara C S; Morimitsu, Kentaro; Bohne, Cornelia

    2014-09-30

    Bile salt aggregates incorporate aqueous-insoluble photochromic compounds. The photochromism of a spiropyran (1, 1',3',3'-trimethyl-6-nitrospiro[2H-1]-benzopyran-2,2'-indoline) and a diarylethene derivative (2, 1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)-3,3,4,4,5,5-hexafluoro-1-cyclopentene) was quantified in different bile salt aggregates. These aggregates act as efficient hosts to solubilize aqueous insoluble photochromic compounds where either both isomers are nonpolar, for example, 2, or compounds where one isomer is hydrophobic and the other is more polar, for example, 1. Methodology was developed to determine molar absorptivity coefficients for solutions containing both isomers and to determine the photoconversion quantum yields under continuous irradiation. The methods were validated by determining parameters in homogeneous solution, which were the same as previously reported. In the case of the colored isomer of 1, the molar extinction coefficient in ethanol at 537 nm ((3.68 ± 0.03) × 10(4) cm(-1) M(-1)) was determined with higher precision. The quantum yields for the photoconversion between the isomers of 2 were shown to be the same in cyclohexane and in the aggregates of sodium cholate (NaCh), deoxycholate (NaDC), and taurocholate (NaTC), showing that bile salt aggregates are not sufficiently rigid to affect the equilibrium between the two possible conformers of the colorless form. In contrast, for 1 the quantum yields for the conversion from the colorless to the colored isomer were higher in bile salts than in ethanol, and the quantum yield was highest in the more hydrophobic aggregates of NaDC, followed by NaCh and then NaTC. The structure of the bile salt had no effect on the quantum yield for the conversion of the colored to the colorless isomer of 1, but these values were higher than in ethanol. For all three bile salts, the absorption maximum for the colored form of 1 suggested that this isomer was located in an environment that is more polar than

  7. A single-component multidrug transporter of the major facilitator superfamily is part of a network that protects E scherichia coli from bile salt stress

    PubMed Central

    Paul, Stephanie; Alegre, Kamela O; Holdsworth, Scarlett R; Rice, Matthew; Brown, James A; McVeigh, Paul; Kelly, Sharon M; Law, Christopher J

    2014-01-01

    Resistance to high concentrations of bile salts in the human intestinal tract is vital for the survival of enteric bacteria such as E scherichia coli. Although the tripartite AcrAB–TolC efflux system plays a significant role in this resistance, it is purported that other efflux pumps must also be involved. We provide evidence from a comprehensive suite of experiments performed at two different pH values (7.2 and 6.0) that reflect pH conditions that E . coli may encounter in human gut that MdtM, a single-component multidrug resistance transporter of the major facilitator superfamily, functions in bile salt resistance in E . coli by catalysing secondary active transport of bile salts out of the cell cytoplasm. Furthermore, assays performed on a chromosomal ΔacrB mutant transformed with multicopy plasmid encoding MdtM suggested a functional synergism between the single-component MdtM transporter and the tripartite AcrAB–TolC system that results in a multiplicative effect on resistance. Substrate binding experiments performed on purified MdtM demonstrated that the transporter binds to cholate and deoxycholate with micromolar affinity, and transport assays performed on inverted vesicles confirmed the capacity of MdtM to catalyse electrogenic bile salt/H+ antiport. PMID:24684269

  8. Formation of drug-bearing vesicles in mixed colloids of bile salts and phosphatidylcholine

    SciTech Connect

    Hjelm, R.P.; Mang, J.; Hofmann, A.F.; Schteingart, C.; Alkan-Onyuksel, H.; Ayd, S.

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors used small-angle neutron scattering to study drug interactions with mixed colloids of bile salt and phosphatidylcholine. Because the mixed colloids form liposomes spontaneously, this system is a model for drug-bile interactions that are important in understanding the efficacy of oral drug formulations and in advanced applications for liposome drug delivery systems. The authors studied particle formation in incorporation of enzymatic products formed in the gut and the effects of cholesteric drugs and taxol on vesicle formation. The studies show that particle morphology is not affected by inclusion of most cholesteric drugs and taxol, and is not affected by incorporation of the products of enzymatic action. The findings suggest that particle form is important for the physiological function of bile and they are beginning to show which drugs affect liposome formation.

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

    PubMed

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

    2015-11-17

    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

  10. Optic properties of bile liquid crystals in human body

    PubMed Central

    Yang, Hai Ming; Wu, Jie; Li, Jin Yi; Zhou, Jian Li; He, Li Jun; Xu, Xian Fang

    2000-01-01

    AIM: To further study the properties of bile liquid crystals, and probe into the relationship between bile liquid crystals and gallbladder stone formation, and provide evidence for the prevention and treatment of cholecystolithiasis. METHODS: The optic properties of bile liquid crystals in human body were determined by the method of crystal optics under polarizing microscope with plane polarized light and perpendicular polarized light. RESULTS: Under a polarizing microscope with plane polarized light, bile liquid crystals scattered in bile appeared round, oval or irregularly round. The color of bile liquid crystals was a little lighter than that of the bile around. When the stage was turned round, the color of bile liquid crystals or the darkness and lightness of the color did not change obviously. On the border between bile liquid crystals and the bile around, brighter Becke-Line could be observed. When the microscope tube is lifted, Becke-Line moved inward, and when lowered, Becke-Line moved outward. Under a perpendicular polarized light, bile liquid crystals showd some special interference patterns, called Malta cross. When the stage was turning round at an angle of 360°, the Malta cross showed four times of extinction. In the vibrating direction of 45° angle of relative to upper and lower polarizing plate, gypsum test-board with optical path difference of 530 nm was inserted, the first and the third quadrants of Malt a cross appeared to be blue, and the second and the fourth quadrants appeared orange. When mica test-board with optical path difference of 147 nm was inserted, the first and the third quadrants of Malta cross appeared yellow, and the second and the fourth quadrants appeared dark grey. CONCLUSION: The bile liquid crystals were distributed in bile in the form of global grains. Their polychroism and absorption were slight, but the edge and Becke*Line were very clear. Its refractive index was larger than that of the bile. These liquid crystals were

  11. Effect of Glycine-Conjugated Bile Acids with and without Lecithin on Water and Glucose Absorption in Perfused Human Jejunum

    PubMed Central

    Wingate, David L.; Phillips, Sidney F.; Hofmann, Alan F.

    1973-01-01

    Perfusion studies were performed in healthy volunteers to test whether the secretory effect of conjugated bile acids, previously shown for the colon, was also present in the jejunum. A perfusion system with a proximal occlusive balloon (and continuous aspiration of duodenal secretions) was used; isotonic test solutions contained glycine-conjugated bile acids with or without lecithin. Fluid movement was measured by changes in the concentration of polyethylene glycol (PEG, mol wt 4,000). Conjugated dihydroxy bile acids inhibited electrolyte and fluid absorption and, at higher concentrations, evoked secretion of an isotonic fluid. Glucose absorption continued, despite fluid secretion, but its rate decreased. The secretory effects of bile acids were abolished by the addition of lecithin to the bile acid solutions. A trihydroxy bile acid (cholylglycine) had no effect on jejunal absorption. Small amounts (6-9%) of conjugated bile acids were absorbed in the jejunum; lecithin was well absorbed (72-90%). The results indicate that dihydroxy bile acids influence salt and water transport in the human jejunum but that this effect may be abolished when a polar lipid such as lecithin is present. We speculate that this effect of bile acids may modify fluid movement in the small intestine postprandially after fat absorption has occurred. Images PMID:4700493

  12. Label-free quantitative proteomic analysis of Lactobacillus fermentum NCDC 400 during bile salt exposure.

    PubMed

    Kaur, Gurjeet; Ali, Syed Azmal; Kumar, Sudarshan; Mohanty, Ashok Kumar; Behare, Pradip

    2017-09-07

    Lactobacillus fermentum NCDC 400 is a commonly used and a comprehensively studied probiotic organism. The distinctive capability to endure the harsh environment of the gastrointestinal tract owing to the presence of bile salts in gastric juice facilitates gut microbiota, especially the probiotic organisms to transiently inhabit the host gut. In the present study, Label-Free Quantification (LFQ) approach has been employed to analyze the expression pattern of Lactobacillus fermentum NCDC 400 strain proteins, under bile acid stress, using high-resolution mass spectrometer connected to nano-liquid chromatography (LC) system. We report the identification of a total of 538 differentially expressed (DE) proteins in response to 1.2% bile salt which is required for the growth of this bacterium. Among the DE proteins, 80 were found to be up-regulated, with greater than 1.3 fold change vis-à-vis 107 proteins which were down-regulated with <0.76 fold change (p<0.05). The functions of down-regulated proteins were largely unknown nevertheless; the putative functions of the up-regulated proteins were categorized into categories viz. stress response, DNA repair, peptidoglycan biosynthesis, amino acids metabolism, signal transduction, transcription, translation, and carbohydrate metabolism. These results suggest that the differentially expressed proteins provide the tolerance towards the various gastrointestinal challenges and involved in bile acid stress response mechanism. Copyright © 2017. Published by Elsevier B.V.

  13. Role of reactive oxygen in bile salt stimulation of colonic epithelial proliferation.

    PubMed Central

    Craven, P A; Pfanstiel, J; DeRubertis, F R

    1986-01-01

    Our previous studies had suggested a link between bile salt stimulation of colonic epithelial proliferation and the release and oxygenation of arachidonate via the lipoxygenase pathway. In the present study, we examined the role of reactive oxygen versus end products of arachidonate metabolism via the cyclooxygenase and lipoxygenase pathways in bile salt stimulation of rat colonic epithelial proliferation. Intracolonic instillation of 5 mM deoxycholate increased mucosal ornithine decarboxylase activity and [3H]thymidine incorporation into DNA. Responses to deoxycholate were abolished by the superoxide dismutase mimetic CuII (3,5 diisopropylsalicylic acid)2 (CuDIPS), and by phenidone or esculetin, which inhibit both lipoxygenase and cyclooxygenase activities. By contrast, indomethacin potentiated the response. Phenidone and esculetin suppressed deoxycholate-induced increases in prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and 5, 12, and 15-hydroxyeicosatetraenoic acid (HETE), whereas CuDIPS had no effect. Indomethacin suppressed only PGE2. Deoxycholate (0.5-5 mM) increased superoxide dismutase sensitive chemiluminescence 2-10-fold and stimulated superoxide production as measured by cytochrome c reduction in colonic mucosal scrapings or crypt epithelium. Bile salt-induced increases in chemiluminescence were abolished by CuDIPS, phenidone, and esculetin, but not by indomethacin. Intracolonic generation of reactive oxygen by xanthine-xanthine oxidase increased colonic mucosal ornithine decarboxylase activity and [3H]thymidine incorporation into DNA approximately twofold. These effects were abolished by superoxide dismutase. The findings support a key role for reactive oxygen, rather than more distal products of either the lipoxygenase or cyclooxygenase pathways, in the stimulation of colonic mucosal proliferation by bile salts. PMID:3005368

  14. An investigation into the effect of the structure of bile salt aggregates on the binding interactions and ESIHT dynamics of curcumin: a photophysical approach to probe bile salt aggregates as a potential drug carrier.

    PubMed

    Mandal, Sarthak; Ghosh, Surajit; Banik, Debasis; Banerjee, Chiranjib; Kuchlyan, Jagannath; Sarkar, Nilmoni

    2013-11-07

    This work demonstrates the utilization of bile salt aggregates as a potential biological host system for studying the binding interactions and dynamics of the poorly-water-soluble drug curcumin by means of photophysical techniques. We found that the level of degradation of curcumin is greatly suppressed upon encapsulation into the nanocavities of three different bile salt aggregates. However, NaTC aggregates are more effective to suppress the level of degradation of curcumin than NaCh and NaDC aggregates. We also report the modulation of the photophysical and dynamical properties of curcumin into the nanocavities of bile salt aggregates using steady-state and time-resolved fluorescence spectroscopy. The reduced level of interaction of curcumin with water upon incorporation into the different binding sites of bile salt aggregates results in an enhanced fluorescence intensity along with the blue shift in the emission maxima of curcumin. However, the observation of higher fluorescence quantum yield as well as longer fluorescence lifetime in NaTC aggregates compared to that in NaCh and NaDC aggregates clearly indicates a more effective decrease in the excited-state intramolecular hydrogen atom transfer (ESIHT) mediated nonradiative deactivation of curcumin by the interaction with the anionic headgroup of NaTC. The binding and location of curcumin into the bile salt aggregates has been further confirmed from the steady-state fluorescence anisotropy measurements. In addition, we have shown the effect of addition of salt on the photophysical properties of curcumin in the confined environments of bile salt aggregates. Our results indicate that on addition of salt the time scale of ESIHT process of curcumin in bile salt aggregates is markedly increased.

  15. Chemotactic response of Helicobacter pylori to human plasma and bile.

    PubMed

    Worku, Mulugeta L; Karim, Q Najma; Spencer, John; Sidebotham, Ramon L

    2004-08-01

    To clarify further the role of chemotaxis in Helicobacter pylori colonization, the in vitro bacterium response to human plasma and bile (secretions containing chemoeffector compounds that are present in the gastric mucus layer) was examined. Human plasma, after dilution to 1 % (v/v) with buffer, was found to be a chemoattractant for the motile bacillus. Human gall-bladder bile, after dilution to 2 % (v/v) with buffer, was found to be a chemorepellent, but did not cause the motility of the bacillus to be diminished after prolonged exposure. The basis of the chemoattractant effect of plasma was explored by examining how urea and 12 amino acids found in plasma affected the taxis of H. pylori. Urea and the amino acids histidine, glutamine, glycine and arginine were the strongest chemoattractants. Other amino acids were chemoattractants, with the exceptions of aspartic and glutamic acids, which were chemorepellents. The basis of the chemorepellent effect of bile was explored by examining how the six most abundant conjugated bile acids in human bile affected the taxis of H. pylori. All the bile acids were chemorepellents, with the greatest effects being demonstrated by taurocholic and taurodeoxycholic acids. The implications of these findings for H. pylori colonization of gastric epithelium are discussed.

  16. Effect of perfusion of bile salts solutions into the oesophagus of hiatal hernia patients and controls.

    PubMed Central

    Bachir, G S; Collis, J L

    1976-01-01

    Tests of the response to perfusion of the oesophagus were made in 54 patients divided into three groups. Group I consisted of patients with symptomatic hiatal hernia, group II hiatal hernia patients with peptic stricture, and group III normal individuals. Each individual oesophagus was perfused at a rate of 45-65 drops per minute over 25 minutes with six solutions: normal saline, N/10 HCl, taurine conjugates of bile salts in normal saline, taurine conjugates of bile salts in N/10 HCl, glycine conjugates of bile salts in normal saline, and taurine and glycine conjugates in a ratio of 1 to 2 in normal saline. It was found that acidified taurine solutions were more irritating than acid alone. With a 2mM/l solution of taurine in acid, symptoms are produced even in controls. With a 1 mM/l solution of the same conjugates, the majority of normal people feel slight heartburn or nothing, and therefore perfusion into the oesophagus of such a solution could be used as a test for oesophagitis. PMID:941112

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

    PubMed

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

    2016-11-15

    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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    PubMed

    Elnaggar, Yosra S R

    2015-01-01

    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.

  19. In vitro polyphenol effects on activity, expression and secretion of pancreatic bile salt-dependent lipase.

    PubMed

    Sbarra, Véronique; Ristorcelli, Elodie; Petit-Thévenin, Josette Le; Teissedre, Pierre-Louis; Lombardo, Dominique; Vérine, Alain

    2005-09-05

    The relationship between cholesterol and atherosclerosis has gained wide credence and red wine polyphenols have been shown to have an anti-atherogenic activity. In the present in vitro studies, we have evaluated and compared the effects of resveratrol, an active compound of red wine, and of a whole red wine polyphenolic extract (RWE) on the pancreatic bile salt-dependent lipase (BSDL). BSDL is involved in the duodenal hydrolysis of lipid esters and in part of cholesteryl esters thus favoring the bioavailability of free cholesterol. Resveratrol and RWE decrease the human and rat enzyme activities. Resveratrol and RWE also impaired the secretion of BSDL by the rat pancreatic AR4-2J cells used as secreting model. This effect is reversed by the removal of resveratrol or RWE from the cell culture medium. Further, resveratrol (but not RWE) affects the transcription of the gene encoding BSDL and dramatically diminishes the quantity of the enzyme that is expressed and secreted by AR4-2J cells. Results suggest that the hypolipemic effects of red wine polyphenols could partly originate from the inhibition of BSDL activity and secretion in the duodenum. In vivo, these effects could decrease the hydrolysis of dietary lipid esters and likely the absorption of free cholesterol.

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

    PubMed Central

    Elnaggar, Yosra SR

    2015-01-01

    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. PMID:26109855

  1. Bile Acids Conjugation in Human Bile Is Not Random: New Insights from 1H-NMR Spectroscopy at 800 MHz

    PubMed Central

    Shanaiah, Narasimhamurthy; Cooper, Amanda; Raftery, Daniel

    2017-01-01

    Bile acids constitute a group of structurally closely related molecules and represent the most abundant constituents of human bile. Investigations of bile acids have garnered increased interest owing to their recently discovered additional biological functions including their role as signaling molecules that govern glucose, fat and energy metabolism. Recent NMR methodological developments have enabled single-step analysis of several highly abundant and common glycine- and taurine- conjugated bile acids, such as glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid. Investigation of these conjugated bile acids in human bile employing high field (800 MHz) 1H-NMR spectroscopy reveals that the ratios between two glycine-conjugated bile acids and their taurine counterparts correlate positively (R2 = 0.83–0.97; p = 0.001 × 10−2–0.006 × 10−7) as do the ratios between a glycine-conjugated bile acid and its taurine counterpart (R2 = 0.92–0.95; p = 0.004 × 10−3–0.002 × 10−10). Using such correlations, concentration of individual bile acids in each sample could be predicted in good agreement with the experimentally determined values. These insights into the pattern of bile acid conjugation in human bile between glycine and taurine promise useful clues to the mechanism of bile acids’ biosynthesis, conjugation and enterohepatic circulation, and may improve our understanding of the role of individual conjugated bile acids in health and disease. PMID:19373503

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

    PubMed Central

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

    2014-01-01

    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 and its underlying mechanisms and involvement in ICP are not fully understood. In this study, the dynamics of BSEP transcription in vivo in the same group of pregnant mice before, during and after gestation were established with in vivo imaging system (IVIS). BSEP transcription was markedly repressed in the later stages of pregnancy and immediately recovered after parturition, resembling the clinical course of ICP in human. The transcriptional dynamics of BSEP was inversely correlated with serum 17β-estradiol (E2) levels before, during and after gestation. Further studies showed that E2 repressed BSEP expression in human primary hepatocytes, Huh 7 cells and in vivo in mice. Such transrepression of BSEP by E2 in vitro and in vivo required estrogen receptor α (ERα). Mechanistic studies with chromatin immunoprecipitation (ChIP), protein co-immunoprecipitation (Co-IP) and bimolecular fluorescence complementation (BiFC) assays demonstrated that ERα directly interacted with FXR in living cells and in vivo in mice. In conclusion, BSEP expression was repressed by E2 in the late stages of pregnancy through a non-classical E2/ERα transrepressive pathway, directly interacting with FXR. E2-mediated repression of BSEP expression represents an etiological contributing factor to ICP and therapies targeting the ERα/FXR interaction may be developed for prevention and treatment of ICP. PMID:24729004

  3. "Theranostic" role of bile salt-capped silver nanoparticles - gall stone/pigment stone disruption and anticancer activity.

    PubMed

    Mandal, Ranju Prasad; Mandal, Gunjan; Sarkar, Sudeshna; Bhattacharyya, Arindam; De, Swati

    2017-10-01

    Silver nanoparticles (AgNPs) have been synthesized in situ in micelles formed by the bile salt sodium deoxycholate (NaDC). The AgNPs exhibit "green" fluorescence. It has been shown in the present study that they can disrupt the components of gall stones/pigment stones. This unique ability of the AgNPs has been observed upon detailed study of the interaction between the endobiotic pigment bilirubin (BR) and bile salt (NaDC). In addition, these AgNPs show significant cytotoxicity towards the breast cancer cells (MCF-7). Thus the AgNPs synthesized in this work show important physiological activity and can serve as prospective "Theranostic Materials" in future. Their green fluorescence bears relevance to future diagnostic applications while their anticancer activity and disruptive action upon BR aggregates in bile salt micelles is extremely important for therapeutic purpose. This is the first report of the use of metal nanoparticles in disruption of components of gall stones/pigment stones and thus the present work has very important physiological significance. The detailed spectral studies indicate that bile salts increase the dimerization of BR which could be linked to increased solubilisation of BR in bile salt media and consequent bile stone/pigment stone formation. Importantly, an increase in red fluorescence was observed (upon dimerization of BR), which is important for cancer detection and studying the metabolism of biological tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    PubMed Central

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

    2014-01-01

    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 BSEP transcription would contribute to drug-induced cholestasis is largely unknown. In this study, we selected 30 drugs previously reported as BSEP inhibitors to evaluate their effects on BSEP expression, farnesoid X receptor (FXR) activation, and correlations to clinically reported liver toxicity. Our results indicate that of the 30 BSEP inhibitors, five exhibited potent repression of BSEP expression (≥60% repression), ten were moderate repressors (20–60% repression), whereas others had negligible effects (≤20% repression). Of importance, two drugs (troglitazone and benzbromarone), previously withdrawn from the market because of liver injury, are among the potent repressors. Further investigation of the five potent repressors revealed that transcriptional repression of BSEP by lopinavir and troglitazone may occur through their interaction with FXR, whereas others are via FXR-independent yet unidentified pathways. Our data suggest that in addition to functional inhibition, repression of BSEP expression may play an important role in drug-induced cholestatic liver toxicity. Thus, a combination of the two would reveal a more accurate prediction of drug-induced cholestasis than does either repression or inhibition alone. PMID:24335466

  5. Purification and Characterization of Conjugated Bile Salt Hydrolase from Bifidobacterium longum BB536

    PubMed Central

    Grill, J.; Schneider, F.; Crociani, J.; Ballongue, J.

    1995-01-01

    Bifidobacterium species deconjugate taurocholic, taurodeoxycholic, taurochenodeoxycholic, glycocholic, glycodeoxycholic, and glycochenodeoxycholic acids. The enzyme level increases in the growth phase. No increase in activity is observed for the cytoplasmic enzyme after addition of conjugated bile acids to a stationary-phase culture. Conjugated bile salt hydrolase (BSH) was purified from Bifidobacterium longum BB536. Its apparent molecular mass in denaturing polyacrylamide gel electrophoresis was ca. 40,000 Da. The intact enzyme had a relative molecular weight of ca. 250,000 as determined by gel filtration chromatography, suggesting that the native BSH of B. longum is probably a hexamer. The purified enzyme is active towards both glycine and taurine conjugates of cholate, deoxycholate, and chenodeoxycholate. The pH optimum is in the range of 5.5 to 6.5. A loss of BSH activity is observed after incubation at temperatures higher than 42(deg)C; at 60(deg)C, 50% of the BSH activity is lost. The importance of free sulfhydryl groups at the enzyme active center is suggested. For B. longum BB536, no significant difference in the initial rate of deconjugation and enzymatic efficiency appears between bile salts. The enzymatic efficiency is higher for B. longum BB536 than for other genera. In this paper, a new method which permits a display of BSH activity directly on polyacrylamide gels is described; this method confirms the molecular weight obtained for B. longum BB536 BSH. PMID:16535071

  6. Effect of crilvastatin, a new cholesterol lowering agent, on unesterified LDL-cholesterol metabolism into bile salts by rat isolated hepatocytes.

    PubMed Central

    Clerc, T; Sbarra, V; Diaconescu, N; Lafont, H; Jadot, G; Laruelle, C; Chanussot, F

    1995-01-01

    1. The aim of these experiments was to determine the effect of crilvastatin, a new cholesterol lowering agent, on the metabolism of unesterified low density lipoprotein (LDL)-cholesterol by rat freshly isolated hepatocytes. This preclinical model was developed as an alternative to in vivo experiments, to mimic the metabolic effects of a molecule on its target cells and to define optimal conditions for future experimentation on human hepatocytes. 2. Cells were obtained from normolipidaemic or hypercholesterolaemic rats, hypercholesterolaemia was nutritionally induced. Incubations were performed in a medium containing 600 microM taurocholate and 50 microM or 300 microM crilvastatin. 3. This molecule was shown in vitro to be carried by physiological transporters, i.e., albumin-bile salt micellar associations and LDL. Crilvastatin induced a significance increase in the synthesis and secretion by hepatocytes of bile salts resulting from the metabolism of unesterified LDL-cholesterol in both normolipidaemic and hypercholesterolaemic rats. Stimulation involved non-conjugated as well as tauro- and glyco-conjugated bile salts. These findings corroborate preliminary studies showing in vivo that crilvastatin enhances the secretion of bile acids by stimulating the uptake and incorporation of LDL-cholesterol by the liver. PMID:7735689

  7. Recombinant Bile Salt-Stimulated Lipase in Preterm Infant Feeding: A Randomized Phase 3 Study

    PubMed Central

    Casper, Charlotte; Hascoet, Jean-Michel; Ertl, Tibor; Gadzinowski, Janusz S.; Carnielli, Virgilio; Rigo, Jacques; Lapillonne, Alexandre; Couce, María L.; Vågerö, Mårten; Palmgren, Ingrid; Timdahl, Kristina; Hernell, Olle

    2016-01-01

    Introduction Feeding strategies are critical for healthy growth in preterm infants. Bile salt-stimulated lipase (BSSL), present in human milk, is important for fat digestion and absorption but is inactivated during pasteurization and absent in formula. This study evaluated if recombinant human BSSL (rhBSSL) improves growth in preterm infants when added to formula or pasteurized breast milk. Patients and Methods LAIF (Lipase Added to Infant Feeding) was a randomized, double-blind, placebo-controlled phase 3 study in infants born before 32 weeks of gestation. The primary efficacy variable was growth velocity (g/kg/day) during 4 weeks intervention. Follow-up visits were at 3 and 12 months. The study was performed at 54 centers in 10 European countries. Results In total 415 patients were randomized (rhBSSL n = 207, placebo n = 208), 410 patients were analyzed (rhBSSL n = 206, placebo n = 204) and 365 patients were followed until 12 months. Overall, there was no significantly improved growth velocity during rhBSSL treatment compared to placebo (16.77 vs. 16.56 g/kg/day, estimated difference 0.21 g/kg/day, 95% CI [-0.40; 0.83]), nor were secondary endpoints met. However, in a predefined subgroup, small for gestational age infants, there was a significant effect on growth in favor of rhBSSL during treatment. The incidence of adverse events was higher in the rhBSSL group during treatment. Conclusions Although this study did not meet its primary endpoint, except in a subgroup of infants small for gestational age, and there was an imbalance in short-term safety, these data provide insights in nutrition, growth and development in preterm infants. Trial Registration ClinicalTrials.gov NCT01413581 PMID:27244221

  8. Monohydroxy bile salt sulfates: tauro-3 beta-hydroxy-5-cholenoate-3-sulfate induces intrahepatic cholestasis in rats

    SciTech Connect

    Mathis, U.; Karlaganis, G.; Preisig, R.

    1983-09-01

    The biologic effects of sulfation of tauro-3 beta-hydroxy-5-cholenoate and of taurolithocholate were compared. Equimolar amounts (100 nmol/min X 100 g body wt) of the following were administered intravenously to male Sprague-Dawley rats over a 180-min period: taurolithocholate, (/sup 14/C)taurolithocholate-3-sulfate, tauro-3 beta-hydroxy-5-cholenoate, (/sup 14/C)tauro-3 beta-hydroxy-5-cholenoate-3-sulfate, its combination with taurocholate, and a saline-albumin solution (control). Sulfation of taurolithocholate and of tauro-3 beta-hydroxy-5-cholenoate only prevented the cholestatic effect of the former. Bile flow during infusion of (/sup 14/C)tauro-3 beta-hydroxy-5-cholenoate-3-sulfate was reduced by 80% at the end of the experiment. A dose-dependent bile flow reduction was demonstrated. Recovery of the administered bile acid was 3% in urine, 13% in serum, 23% in the liver tissue, and 52% in bile, respectively. Excretion of biliary cholesterol and phospholipids was significantly reduced during the first hour of infusion. Coadministration of taurocholate abolished the cholestatic effect and enhanced the renal excretion of the sulfated bile salt. These data suggest that (a) the cholestatic effect of tauro-3 beta-hydroxy-5-cholenoate-3-sulfate is comparable with or may even exceed the effect of taurolithocholate and (b) although sulfation renders some bile salts more water soluble, it does not prevent the cholestatic effect of all monohydroxy bile salts.

  9. Comparison of bile salt/phosphatidylcholine mixed micelles in solubilization to sterols and stability.

    PubMed

    Guo, Qin; Cai, Jie; Li, Pengyu; Xu, Dongling; Ni, Xiaomin; Wen, Hui; Liu, Dan; Lin, Suizhen; Hu, Haiyan

    2016-01-01

    Androst-3β,5α,6β-triol (Triol) is a promising neuroprotective agent, but its poor solubility restricts its development into parenteral preparations. In this study, Triol is significantly solubilized by bile salt/phosphatidylcholine mixed micelles (BS/PC-MM). All BS/PC-MM systems are tested to remarkably improve the drug solubility with various stabilities after drug loading. Among them, the sodium glycocholate (SGC)/egg phosphatidylcholine (EPC) system with 2:1 ratio in weight and the total concentration of SGC and EPC of 100 mg/mL is proved to produce stable mixed micelles with high drug loading. It is found that the stability of drug-loaded mixed micelles is quite different, which might be related to the change in critical micelle concentration (CMC) after incorporating drugs. SGC/EPC and SGC/soya phosphatidylcholine (SPC) remain transparent under accelerated conditions and manifest a decreased CMC (dropping from 0.105 to 0.056 mg/mL and from 0.067 to 0.024 mg/mL, respectively). In contrast, swine bile acid-sodium salt (SBA-Na)/PC and sodium deoxycholate (SDC)/PC are accompanied by drug precipitation and reached the maximum CMC on the first and the third days, respectively. Interestingly, the variation of CMC under accelerated testing conditions highly matches the drug-precipitating event in the primary stability experiment. In brief, the bile salt/phosphatidylcholine system exists as a potential strategy of improving sterol drug solubility. CMC variation under accelerated testing conditions might be a simple and easy method to predict the stability of drug-loaded mixed micelles.

  10. Bile salt/phospholipid mixed micelle precursor pellets prepared by fluid-bed coating.

    PubMed

    Dong, Fuxia; Xie, Yunchang; Qi, Jianping; Hu, Fuqiang; Lu, Yi; Li, Sanming; Wu, Wei

    2013-01-01

    Bile salt/phospholipid mixed micelles (MMs) are potent carriers used for oral absorption of drugs that are poorly soluble in water; however, there are many limitations associated with liquid formulations. In the current study, the feasibility of preparing bile salt/phospholipid MM precursor (preMM) pellets with high oral bioavailability, using fluid-bed coating technology, was examined. In this study, fenofibrate (FB) and sodium deoxycholate (SDC) were used as the model drug and the bile salt, respectively. To prepare the MMs and to serve as the micellular carrier, a weight ratio of 4:6 was selected for the sodium deoxycholate/phospholipids based on the ternary phase diagram. Polyethylene glycol (PEG) 6000 was selected as the dispersion matrix for precipitation of the MMs onto pellets, since it can enhance the solubilizing ability of the MMs. Coating of the MMs onto the pellets using the fluid-bed coating technology was efficient and the pellets were spherical and intact. MMs could be easily reconstituted from preMM pellets in water. Although they existed in a crystalline state in the preMM pellets, FB could be encapsulated into the reconstituted MMs, and the MMs were redispersed better than solid dispersion pellets (FB:PEG = 1:3) and Lipanthyl®. The redispersibility of the preMM pellets increased with the increase of the FB/PEG/micellar carrier. PreMM pellets with a FB:PEG:micellar carrier ratio of 1:1.5:1.5 showed 284% and 145% bioavailability relative to Lipanthyl® and solid dispersion pellets (FB:PEG = 1:3), respectively. Fluid-bed coating technology has considerable potential for use in preparing sodium deoxycholate/phospholipid preMM pellets, with enhanced oral bioavailability for poorly water-soluble drugs.

  11. Comparison of bile salt/phosphatidylcholine mixed micelles in solubilization to sterols and stability

    PubMed Central

    Guo, Qin; Cai, Jie; Li, Pengyu; Xu, Dongling; Ni, Xiaomin; Wen, Hui; Liu, Dan; Lin, Suizhen; Hu, Haiyan

    2016-01-01

    Androst-3β,5α,6β-triol (Triol) is a promising neuroprotective agent, but its poor solubility restricts its development into parenteral preparations. In this study, Triol is significantly solubilized by bile salt/phosphatidylcholine mixed micelles (BS/PC-MM). All BS/PC-MM systems are tested to remarkably improve the drug solubility with various stabilities after drug loading. Among them, the sodium glycocholate (SGC)/egg phosphatidylcholine (EPC) system with 2:1 ratio in weight and the total concentration of SGC and EPC of 100 mg/mL is proved to produce stable mixed micelles with high drug loading. It is found that the stability of drug-loaded mixed micelles is quite different, which might be related to the change in critical micelle concentration (CMC) after incorporating drugs. SGC/EPC and SGC/soya phosphatidylcholine (SPC) remain transparent under accelerated conditions and manifest a decreased CMC (dropping from 0.105 to 0.056 mg/mL and from 0.067 to 0.024 mg/mL, respectively). In contrast, swine bile acid-sodium salt (SBA-Na)/PC and sodium deoxycholate (SDC)/PC are accompanied by drug precipitation and reached the maximum CMC on the first and the third days, respectively. Interestingly, the variation of CMC under accelerated testing conditions highly matches the drug-precipitating event in the primary stability experiment. In brief, the bile salt/phosphatidylcholine system exists as a potential strategy of improving sterol drug solubility. CMC variation under accelerated testing conditions might be a simple and easy method to predict the stability of drug-loaded mixed micelles. PMID:27895469

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

    PubMed

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

    2015-12-01

    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.

  13. Structural transition in aqueous lipid/bile salt [DPPC/NaDC] supramolecular aggregates: SANS and DLS study

    NASA Astrophysics Data System (ADS)

    Kiselev, M. A.; Janich, M.; Hildebrand, A.; Strunz, P.; Neubert, R. Н. Н.; Lombardo, D.

    2013-10-01

    Small angle neutron scattering (SANS) and dynamic light scattering (DLS) were used to study different aggregation states in sodium deoxycholate (NaDC)-phosphatidylcholine systems at T = 60 °C. Size and shape of the aggregates investigated as a function of the NaDC bile salt concentration (at the constant DPPC concentration of 6 mM) indicate a strong dependence of the size and morphology of the generated aggregates on the relative amount of NaDC bile salt. More specifically large occupied area of the bile salt induces a steric interaction which promotes the transition toward a variety of supramolecular structures ranging from ellipsoidal vesicles, ribbon-like structures, up to final spherical mixed micelles at the large amount of bile salt of 10 mM NaDC. The findings of the obtained results give important insight for understanding the formation of different topologies in aqueous lipid-bile salt mixtures as well as stimulate new routes for liposome reconstitution-solubilisation processes suitable for technological applications.

  14. Anatomical assessment of bile ducts of Luschka in human fetuses.

    PubMed

    Kocabiyik, Necdet; Yalcin, Bülent; Kilbas, Zafer; Karadeniz, Sinan R; Kurt, Bülent; Comert, Ayhan; Ozan, Hasan

    2009-08-01

    Bile ducts of Luschka (also called subvesical or supravesicular ducts) can cause bile leakage during laparoscopic cholecystectomy, especially if surgery is carried out in ignorance of such variations. The aim of this study was to clarify the clinical anatomy of these ducts in human fetuses and frequency of the ducts locating near gallbladder fossa. Thirty-two fetal cadaver livers were dissected and the gallbladders were separated from the livers and ducts were investigated under a surgical microscope. All observed ducts were examined microscopically and connective tissue cords were excluded. Bile ducts of Luschka locating near cystic fossa were found in 7 of 32 fetuses (21.9%). Three of the seven ducts ran towards to liver segment 5 (S5); three ducts were found in the gallbladder fossa; and one duct ran towards to liver segment 4 (S4). Also it was found that three of the seven ducts drained into the subsegmental duct of S5, two ducts drained into the right hepatic duct, one duct drained into the right anterior branch bile duct, and one duct drained into the subsegmental duct of S4. Subvesical ducts running along the gallbladder fossa between the gallbladder and the liver parenchyma were found in a relatively high incidence in fetuses than adults. Awareness and knowledge about incidence of such ducts alerts the surgeon during laparoscopic cholecystectomy. Therefore morbidity due to bile leaks can be reduced.

  15. Paternal isodisomy of chromosome 2 in a child with bile salt export pump deficiency.

    PubMed

    Giovannoni, Isabella; Terracciano, Alessandra; Gennari, Fabrizio; David, Ezio; Francalanci, Paola; Santorelli, Filippo M

    2012-03-01

    We describe a child with progressive familial intrahepatic cholestasis (PFIC) of type 2 inherited as uniparental isodisomy of chromosome 2. Bile salt export pump (BSEP) deficiency is a severe, genetically determined subtype PFIC caused by mutations in ABCB11, the gene encoding a bile salt transporter protein. Clinical and pathological diagnosis in PFIC2 is corroborated by an ample array of ABCB11 mutations, inherited in an autosomal recessive fashion. We report clinical, pathological, and molecular studies in a child with PFIC2. A 5.5-year-old boy harbored a described pathogenic mutation (p.R832C) in ABCB11. The mutation was found to be homozygous in the patient and heterozygous in DNA from paternal, but not maternal blood. Having ruled out maternal gene deletion and somatic mosaicism, we showed that the child had inherited an isodisomic paternal chromosome 2, including the 2q31.1 region where ABCB11 is located. The present report is the first description of uniparental isodisomy in a hepatic heritable disorder. Recognizing isodisomic transmission may have a significant impact on genetic counseling helping to define the risk of recurrence in subsequent pregnancies.

  16. Redox pathway sensing bile salts activates virulence gene expression in Vibrio cholerae.

    PubMed

    Xue, Yuanyuan; Tu, Fei; Shi, Mengting; Wu, Chun-Qin; Ren, Guoping; Wang, Xiaojie; Fang, Weihuan; Song, Houhui; Yang, Menghua

    2016-12-01

    Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, has evolved signal transduction systems to control co-ordinately the expression of virulence determinants. It was previously shown that the presence of the bile salts glycocholate and taurocholate in the small intestine causes dimerization of the transmembrane transcription factor TcpP by inducing intermolecular disulphide bonds in the TcpP periplasmic domain. In this study, they further investigated the mechanism of how taurocholate affects V. cholerae virulence determinants. In vitro assay of TcpP oxidation by VcDsbA showed that VcDsbA induced TcpP dimerization in the presence of taurocholate. Taurocholate bound to VcDsbA with a KD of 40 ± 2.5 μM, and also bound other Dsb proteins, including EcDsbA, EcDsbC and VcDsbC. Taurocholate inhibited VcDsbA reductase activity without affecting VcDsbA secondary structure or thermostability. VcDsbA and its substrates were more extensively reduced in the presence of taurocholate, as compared with their redox state in the absence of taurocholate. The data presented here not only provide new insights into the mechanism by which bile salts induce V. cholerae virulence but also suggest a means by which to develop inhibitors against DsbA. © 2016 John Wiley & Sons Ltd.

  17. Obeticholic acid, a selective farnesoid X receptor agonist, regulates bile acid homeostasis in sandwich-cultured human hepatocytes.

    PubMed

    Zhang, Yuanyuan; Jackson, Jonathan P; St Claire, Robert L; Freeman, Kimberly; Brouwer, Kenneth R; Edwards, Jeffrey E

    2017-08-01

    Farnesoid X receptor (FXR) is a master regulator of bile acid homeostasis through transcriptional regulation of genes involved in bile acid synthesis and cellular membrane transport. Impairment of bile acid efflux due to cholangiopathies results in chronic cholestasis leading to abnormal elevation of intrahepatic and systemic bile acid levels. Obeticholic acid (OCA) is a potent and selective FXR agonist that is 100-fold more potent than the endogenous ligand chenodeoxycholic acid (CDCA). The effects of OCA on genes involved in bile acid homeostasis were investigated using sandwich-cultured human hepatocytes. Gene expression was determined by measuring mRNA levels. OCA dose-dependently increased fibroblast growth factor-19 (FGF-19) and small heterodimer partner (SHP) which, in turn, suppress mRNA levels of cholesterol 7-alpha-hydroxylase (CYP7A1), the rate-limiting enzyme for de novo synthesis of bile acids. Consistent with CYP7A1 suppression, total bile acid content was decreased by OCA (1 μmol/L) to 42.7 ± 20.5% relative to control. In addition to suppressing de novo bile acids synthesis, OCA significantly increased the mRNA levels of transporters involved in bile acid homeostasis. The bile salt excretory pump (BSEP), a canalicular efflux transporter, increased by 6.4 ± 0.8-fold, and the basolateral efflux heterodimer transporters, organic solute transporter α (OSTα ) and OSTβ increased by 6.4 ± 0.2-fold and 42.9 ± 7.9-fold, respectively. The upregulation of BSEP and OSTα and OSTβ, by OCA reduced the intracellular concentrations of d8 -TCA, a model bile acid, to 39.6 ± 8.9% relative to control. These data demonstrate that OCA does suppress bile acid synthesis and reduce hepatocellular bile acid levels, supporting the use of OCA to treat bile acid-induced toxicity observed in cholestatic diseases. © 2017 Intercept Pharmaceuticals. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and

  18. Parenteral nutrition dysregulates bile salt homeostasis in a rat model of parenteral nutrition-associated liver disease.

    PubMed

    Koelfat, Kiran V K; Schaap, Frank G; Hodin, Caroline M J M; Visschers, Ruben G J; Svavarsson, Björn I; Lenicek, Martin; Shiri-Sverdlov, Ronit; Lenaerts, Kaatje; Olde Damink, Steven W M

    2017-10-01

    Parenteral nutrition (PN), a lifesaving therapy in patients with intestinal failure, has been associated with hepatobiliary complications including steatosis, cholestasis and fibrosis, collectively known as parenteral nutrition-associated liver disease (PNALD). To date, the pathogenesis of PNALD is poorly understood and therapeutic options are limited. Impaired bile salt homeostasis has been proposed to contribute PNALD. The objective of this study was to establish a PNALD model in rats and to evaluate the effects of continuous parenteral nutrition (PN) on bile salt homeostasis. Rats received either PN via the jugular vein or received normal diet for 3, 7 or 14 days. Serum biochemistry, hepatic triglycerides, circulating bile salts and C4, IL-6 and TNF-alpha, and lipogenic and bile salt homeostatic gene expression in liver and ileum were assessed. PN increased hepatic triglycerides already after 3 days of administration, and resulted in conjugated bilirubin elevation after 7 or more days. This indicates PN-induced steatosis and impaired canalicular secretion of bilirubin, the latter which is in line with reduced hepatic expression of Mrp2 mRNA. There was no histological evidence for liver inflammation after PN administration, and circulating levels of pro-inflammatory cytokines IL-6 and TNF-α, were comparable in all groups. Hepatic expression of Fxr mRNA was decreased after 7 days of PN, without apparent effect on expression of Fxr targets Bsep and Shp. Nonetheless, Cyp7a1 expression was reduced after 7 days of PN, indicative for lowered bile salt synthesis. Circulating levels of C4 (marker of bile salt synthesis) were also decreased after 3, 7 and 14 days of PN. Levels of circulating bile salts were not affected by PN. This study showed that PN in rats caused early mild steatosis and cholestasis, while hepatic and systemic inflammation were not present. The onset of these abnormalities was associated with alterations in bile salt synthesis and transport. This

  19. Hydrophobic bile salts inhibit gallbladder smooth muscle function via stimulation of GPBAR1 receptors and activation of KATP channels

    PubMed Central

    Lavoie, Brigitte; Balemba, Onesmo B; Godfrey, Cody; Watson, Conall A; Vassileva, Galya; Corvera, Carlos U; Nelson, Mark T; Mawe, Gary M

    2010-01-01

    Hydrophobic bile salts are thought to contribute to the disruption of gallbladder smooth muscle (GBSM) function that occurs in gallstone disease, but their mechanism of action is unknown. The current study was undertaken to determine how hydrophobic bile salts interact with GBSM, and how they reduce GBSM activity. The effect of hydrophobic bile salts on the activity of GBSM was measured by intracellular recording and calcium imaging using wholemount preparations from guinea pig and mouse gallbladder. RT-PCR and immunohistochemistry were used to evaluate expression of the G protein-coupled bile acid receptor, GPBAR1. Application of tauro-chenodeoxycholate (CDC, 50–100 μm) to in situ GBSM rapidly reduced spontaneous Ca2+ flashes and action potentials, and caused a membrane hyperpolarization. Immunoreactivity and transcript for GPBAR1 were detected in gallbladder muscularis. The GPBAR1 agonist, tauro-lithocholic acid (LCA, 10 μm) mimicked the effect of CDC on GBSM. The actions of LCA were blocked by the protein kinase A (PKA) inhibitor, KT5720 (0.5–1.0 μm) and the KATP channel blocker, glibenclamide (10 μm). Furthermore, LCA failed to disrupt GBSM activity in Gpbar1−/− mice. The findings of this study indicate that hydrophobic bile salts activate GPBAR1 on GBSM, and this leads to activation of the cyclic AMP–PKA pathway, and ultimately the opening of KATP channels, thus hyperpolarizing the membrane and decreasing GBSM activity. This inhibitory effect of hydrophobic bile salt activation of GPBAR1 could be a contributing factor in the manifestation of gallstone disease. PMID:20624794

  20. A comparative study of the sulfation of bile acids and a bile alcohol by the Zebra danio (Danio rerio) and human cytosolic sulfotransferases (SULTs)

    PubMed Central

    Kurogi, Katsuhisa; Krasowski, Matthew D.; Injeti, Elisha; Liu, Ming-Yih; Williams, Frederick E.; Sakakibara, Yoichi; Suiko, Masahito; Liu, Ming-Cheh

    2012-01-01

    The current study was designed to examine the sulfation of bile acids and bile alcohols by the Zebra danio (Danio rerio) SULTs in comparison with human SULTs. A systematic analysis using the fifteen Zebra danio SULTs revealed that SULT3 ST2 and SULT3 ST3 were the major bile acid/alcohol-sulfating SULTs. Among the eleven human SULTs, only SULT2A1 was found to be capable of sulfating bile acids and bile alcohols. To further investigate the sulfation of bile acids and bile alcohols by the two Zebra danio SULT3 STs and the human SULT2A1, pH-dependence and kinetics of the sulfation of bile acids/alcohols were analyzed. pH-dependence experiments showed that the mechanisms underlying substrate recognition for the sulfation of lithocholic acid (a bile acid) and 5α-petromyzonol (a bile alcohol) differed between the human SULT2A1 and the Zebra danio SULT3 ST2 and ST3. Kinetic analysis indicated that both the two Zebra danio SULT3 STs preferred petromyzonol as substrate compared to bile acids. In contrast, the human SULT2A1 was more catalytically efficient toward lithocholic acid than petromyzonol. Collectively, the results imply that the Zebra danio and human SULTs have evolved to serve for the sulfation of, respectively, bile alcohols and bile acids, matching the cholanoid profile in these two vertebrate species. PMID:21839837

  1. A comparative study of the sulfation of bile acids and a bile alcohol by the Zebra danio (Danio rerio) and human cytosolic sulfotransferases (SULTs).

    PubMed

    Kurogi, Katsuhisa; Krasowski, Matthew D; Injeti, Elisha; Liu, Ming-Yih; Williams, Frederick E; Sakakibara, Yoichi; Suiko, Masahito; Liu, Ming-Cheh

    2011-11-01

    The current study was designed to examine the sulfation of bile acids and bile alcohols by the Zebra danio (Danio rerio) SULTs in comparison with human SULTs. A systematic analysis using the fifteen Zebra danio SULTs revealed that SULT3 ST2 and SULT3 ST3 were the major bile acid/alcohol-sulfating SULTs. Among the eleven human SULTs, only SULT2A1 was found to be capable of sulfating bile acids and bile alcohols. To further investigate the sulfation of bile acids and bile alcohols by the two Zebra danio SULT3 STs and the human SULT2A1, pH-dependence and kinetics of the sulfation of bile acids/alcohols were analyzed. pH-dependence experiments showed that the mechanisms underlying substrate recognition for the sulfation of lithocholic acid (a bile acid) and 5α-petromyzonol (a bile alcohol) differed between the human SULT2A1 and the Zebra danio SULT3 ST2 and ST3. Kinetic analysis indicated that both the two Zebra danio SULT3 STs preferred petromyzonol as substrate compared to bile acids. In contrast, the human SULT2A1 was more catalytically efficient toward lithocholic acid than petromyzonol. Collectively, the results imply that the Zebra danio and human SULTs have evolved to serve for the sulfation of, respectively, bile alcohols and bile acids, matching the cholanoid profile in these two vertebrate species. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Mechanism of malabsorption in giardiasis: a study of bacterial flora and bile salt deconjugation in upper jejunum.

    PubMed Central

    Tandon, B N; Tandon, R K; Satpathy, B K; Shriniwas

    1977-01-01

    Sixty-three unselected cases of giardiasis, with no evidence of other systemic disease, were screened for evidence of steatorrhoea. No patient had any evidence of protein-energy malnutrition. Seventeen (27%) of the cases had steatorrhoea; three (17-8%) of the 17 patients having steatorrhoea also had D-xylose malabsorption. Vitamin B12 absorption was normal in all. Bacterial culture and qualitative analysis of bile salt in jejunal fluid was carried out in all the 17 cases having steatorrhoea as well as 13 cases with normal absorptive parameters (eight cases of irritable bowel syndrome and five cases of giardia infection) who served as controls. All the patients showing bacterial overgrowth had free bile acids in their duodenal aspirate. Free bile acids could also be detected in jejunal aspirates of five of the seven patients having no bacterial overgrowth. Two control cases of giardia infection with normal small bowel function and sterile duodenal aspirate showed evidence of bile salt deconjugation. The significance of these findings is discussed in relation to the pathogenesis of steatorrhoea in patients with giardiasis. The possible role of giardia in bile salt deconjugation is suggested. PMID:856675

  3. Increased serum concentrations of secondary bile salts during cholate feeding are due to coprophagy. A study with wild-type and Atp8b1-deficient mice.

    PubMed

    Groen, Annemiek; Kunne, Cindy; Oude Elferink, Ronald P J

    2006-01-01

    Coprophagy (i.e., consumption of feces) is a behavior seen in rodents and other animal species. This behavior can substantially influence the enterohepatic cycling of compounds, including bile salts. Since many studies involve the feeding of rodents with bile salt supplemented diets, it is of importance to know the influence of coprophagy on bile salt composition in such studies. We compared the peripheral and portal bile salt composition of mice in conventional and metabolic cages when fed a control diet or a diet containing 0.5% cholate. We also performed these experiments with Atp8b1-deficient mice as it has been suggested that in the absence of this transporter bile salt absorption in the intestine would be increased. In mice on a control diet there is little difference in bile salt composition between conventional housing and metabolic housing. Metabolic housing led to a near complete disappearance of the low levels of dihydroxy bile salts (i.e., deoxycholate + chenodeoxycholate) in peripheral serum. In mice fed a control diet, the portal blood concentration of unconjugated dihydroxy bile salts was extremely low (<2%), but these rose to about 10% when mice were fed a cholate-supplemented diet. In metabolic cages the portal blood content of these unconjugated dihydroxy bile salts was reduced to undetectable levels. Whether housed in conventional cages or in metabolic cages, wild-type and Atp8b1-deficient mice had similar concentrations in portal blood, suggesting that intestinal bile salt absorption is not altered in Atp8b1-deficient mice.

  4. Effect of Tween Series on Growth and cis-9, trans-11 Conjugated Linoleic Acid Production of Lactobacillus acidophilus F0221 in the Presence of Bile Salts

    PubMed Central

    Li, Jing-Yan; Zhang, Lan-Wei; Du, Ming; Han, Xue; Yi, Hua-Xi; Guo, Chun-Feng; Zhang, Ying-Chun; Luo, Xue; Zhang, Yan-He; Shan, Yu-Juan; Hou, Ai-Ju

    2011-01-01

    Cis-9, trans-11 conjugated linoleic acid (c9, t11 CLA) producing bacteria have attracted much attention as novel probiotics which have shown beneficial effects on host health. However, bile salts are able to inhibit bacterial growth and c9, t11 CLA production. For recovering growth and c9, t11 CLA production of Lactobacillus acidophilus F0221 in the presence of bile salts, Tween series (Tween 20, Tween 40, Tween 60 and Tween 80) were added in growth culture containing 0.3% oxgall. Results showed that the viable counts were significantly (P < 0.05) recovered to 8.58–8.75 log CFU/mL in the presence of all Tween treatments. However, recovery of c9, t11 CLA production was only demonstrated in the presence of Tween 80 (72.89 μg/mL). Stepwise increasing oxgall in a concentrations range from 0.1% to 0.9% according to human intestinal physiological environments, Tween 80 still showed significant (P < 0.05) recovery ability on growth (8.91–8.04 log CFU/mL) and c9, t11 CLA (69.22–34.27 μg/mL) production. The effect of Tween 80 on growth and production was also investigated in the presence of different types of bile salts (sodium salts of cholic acid (CA), deoxycholic acid (DCA), chendeoxycholic acid (CDCA), glycocholic acid (GCA) and taurocholic acid (TCA)). Results showed that Tween 80 could significantly (P < 0.05) recover c9, t11 CLA production in the presence of all types of bile salts, but the Tween 80 could only significantly (P < 0.05) recover viable counts of the strain in the presence of CA, DCA and CDCA. This recovery ability could be attributed to the protection of leakage of intracellular material. Additionally, although bile salts inhibited growth and c9, t11 CLA production by the growing cell, it promoted the c9, t11 CLA production by the resting cell. PMID:22272124

  5. Effect of tween series on growth and Cis-9, trans-11 conjugated linoleic acid production of Lactobacillus acidophilus F0221 in the presence of bile salts.

    PubMed

    Li, Jing-Yan; Zhang, Lan-Wei; Du, Ming; Han, Xue; Yi, Hua-Xi; Guo, Chun-Feng; Zhang, Ying-Chun; Luo, Xue; Zhang, Yan-He; Shan, Yu-Juan; Hou, Ai-Ju

    2011-01-01

    Cis-9, trans-11 conjugated linoleic acid (c9, t11 CLA) producing bacteria have attracted much attention as novel probiotics which have shown beneficial effects on host health. However, bile salts are able to inhibit bacterial growth and c9, t11 CLA production. For recovering growth and c9, t11 CLA production of Lactobacillus acidophilus F0221 in the presence of bile salts, Tween series (Tween 20, Tween 40, Tween 60 and Tween 80) were added in growth culture containing 0.3% oxgall. Results showed that the viable counts were significantly (P < 0.05) recovered to 8.58-8.75 log CFU/mL in the presence of all Tween treatments. However, recovery of c9, t11 CLA production was only demonstrated in the presence of Tween 80 (72.89 μg/mL). Stepwise increasing oxgall in a concentrations range from 0.1% to 0.9% according to human intestinal physiological environments, Tween 80 still showed significant (P < 0.05) recovery ability on growth (8.91-8.04 log CFU/mL) and c9, t11 CLA (69.22-34.27 μg/mL) production. The effect of Tween 80 on growth and production was also investigated in the presence of different types of bile salts (sodium salts of cholic acid (CA), deoxycholic acid (DCA), chendeoxycholic acid (CDCA), glycocholic acid (GCA) and taurocholic acid (TCA)). Results showed that Tween 80 could significantly (P < 0.05) recover c9, t11 CLA production in the presence of all types of bile salts, but the Tween 80 could only significantly (P < 0.05) recover viable counts of the strain in the presence of CA, DCA and CDCA. This recovery ability could be attributed to the protection of leakage of intracellular material. Additionally, although bile salts inhibited growth and c9, t11 CLA production by the growing cell, it promoted the c9, t11 CLA production by the resting cell.

  6. Molecular Dynamics Simulation of the Aggregation Patterns in Aqueous Solutions of Bile Salts at Physiological Conditions.

    PubMed

    Mustan, Fatmegyul; Ivanova, Anela; Madjarova, Galia; Tcholakova, Slavka; Denkov, Nikolai

    2015-12-24

    Classical molecular dynamics simulations are employed to monitor the aggregation behavior of six bile salts (nonconjugated and glycine- and taurine-conjugated sodium cholate and sodium deoxycholate) with concentration of 10 mM in aqueous solution in the presence of 120 mM NaCl. There are 150 ns trajectories generated to characterize the systems. The largest stable aggregates are analyzed to determine their shape, size, and stabilizing forces. It is found that the aggregation is a hierarchical process and that its kinetics depends both on the number of hydroxyl groups in the steroid part of the molecules and on the type of conjugation. The micelles of all salts are similar in shape-deformed spheres or ellipsoids, which are stabilized by hydrophobic forces, acting between the steroid rings. The differences in the aggregation kinetics of the various conjugates are rationalized by the affinity for hydrogen bond formation for the glycine-modified salts or by the longer time needed to achieve optimum packing for the tauro derivatives. Evidence is provided for the hypothesis from the literature that the entirely hydrophobic core of all aggregates and the enhanced dynamics of the molecules therein should be among the prerequisites for their pronounced solubilization capacity for hydrophobic substances in vivo.

  7. Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis

    SciTech Connect

    Woolbright, Benjamin L.; Dorko, Kenneth; Antoine, Daniel J.; Clarke, Joanna I.; Gholami, Parviz; Li, Feng; Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson; Fan, Fang; Jenkins, Rosalind E.; Park, B. Kevin; Hagenbuch, Bruno; Olyaee, Mojtaba; Jaeschke, Hartmut

    2015-03-15

    Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. - Highlights: • Cholestatic liver injury is due to cytoplasmic bile acid accumulation in hepatocytes. • Primary human hepatocytes are resistant to BA-induced injury

  8. Hepatic Farnesoid X-Receptor Isoforms α2 and α4 Differentially Modulate Bile Salt and Lipoprotein Metabolism in Mice

    PubMed Central

    Boesjes, Marije; Bloks, Vincent W.; Hageman, Jurre; Bos, Trijnie; van Dijk, Theo H.; Havinga, Rick; Wolters, Henk; Jonker, Johan W.; Kuipers, Folkert; Groen, Albert K.

    2014-01-01

    The nuclear receptor FXR acts as an intracellular bile salt sensor that regulates synthesis and transport of bile salts within their enterohepatic circulation. In addition, FXR is involved in control of a variety of crucial metabolic pathways. Four FXR splice variants are known, i.e. FXRα1-4. Although these isoforms show differences in spatial and temporal expression patterns as well as in transcriptional activity, the physiological relevance hereof has remained elusive. We have evaluated specific roles of hepatic FXRα2 and FXRα4 by stably expressing these isoforms using liver-specific self-complementary adeno-associated viral vectors in total body FXR knock-out mice. The hepatic gene expression profile of the FXR knock-out mice was largely normalized by both isoforms. Yet, differential effects were also apparent; FXRα2 was more effective in reducing elevated HDL levels and transrepressed hepatic expression of Cyp8b1, the regulator of cholate synthesis. The latter coincided with a switch in hydrophobicity of the bile salt pool. Furthermore, FXRα2-transduction caused an increased neutral sterol excretion compared to FXRα4 without affecting intestinal cholesterol absorption. Our data show, for the first time, that hepatic FXRα2 and FXRα4 differentially modulate bile salt and lipoprotein metabolism in mice. PMID:25506828

  9. Inhibition of buckwheat starch digestion by the formation of starch/bile salt complexes: possibility of its occurrence in the intestine.

    PubMed

    Takahama, Umeo; Hirota, Sachiko

    2011-06-08

    During the digestion of starch in foods, starch is mixed with bile in the duodenum. Because fatty acids and some kinds of polyphenols could bind to starch, it was postulated that bile salts might also bind to starch. The purpose of this paper is to study the effects of bile and bile salts on starch/iodine complex formation and pancreatin-induced starch digestion. Bile suppressed starch/iodine complex formation and inhibited pancreatin-induced starch digestion slightly in control buckwheat starch, but did so significantly in buckwheat starch from which fatty acids and polyphenols had been extracted. Such significant suppression and inhibition by bile were also observed in a reagent soluble starch. The effects of cholate and taurocholate on the starch/iodine complex formation and the pancreatin-induced starch digestion were essentially the same as those of bile. Bile, cholate, and taurocholate suppressed amylose/iodine complex formation more significantly than amylopectin/iodine complex formation and inhibited pancreatin-induced amylose digestion more effectively than the digestion of amylopectin. It is concluded from the results that bile salts could bind to starch, especially amylose, the helical structures of which were not occupied by other molecules such as fatty acids and polyphenols, and that the binding resulted in the inhibition of starch digestion by pancreatin. The conclusion suggests that the function of bile salts can be discussed from the point of not only lipid digestion but also starch digestion.

  10. Hepatocellular carcinoma in ten children under five years of age with bile salt export pump deficiency.

    PubMed

    Knisely, A S; Strautnieks, Sandra S; Meier, Yvonne; Stieger, Bruno; Byrne, Jane A; Portmann, Bernard C; Bull, Laura N; Pawlikowska, Ludmila; Bilezikçi, Banu; Ozçay, Figen; László, Aranka; Tiszlavicz, László; Moore, Lynette; Raftos, Jeremy; Arnell, Henrik; Fischler, Björn; Németh, Antal; Papadogiannakis, Nikos; Cielecka-Kuszyk, Joanna; Jankowska, Irena; Pawłowska, Joanna; Melín-Aldana, Hector; Emerick, Karan M; Whitington, Peter F; Mieli-Vergani, Giorgina; Thompson, Richard J

    2006-08-01

    Hepatocellular carcinoma (HCC) is rare in young children. We attempted to see if immunohistochemical and mutational-analysis studies could demonstrate that deficiency of the canalicular bile acid transporter bile salt export pump (BSEP) and mutation in ABCB11, encoding BSEP, underlay progressive familial intrahepatic cholestasis (PFIC)--or "neonatal hepatitis" suggesting PFIC--that was associated with HCC in young children. We studied 11 cases of pediatric HCC in the setting of PFIC or "neonatal hepatitis" suggesting PFIC. Archival liver were retrieved and immunostained for BSEP. Mutational analysis of ABCB11 was performed in leukocyte DNA from available patients and parents. Among the 11 nonrelated children studied aged 13-52 months at diagnosis of HCC, 9 (and a full sibling, with neonatal hepatitis suggesting PFIC, of a tenth from whom liver was not available) had immunohistochemical evidence of BSEP deficiency; the eleventh child did not. Mutations in ABCB11 were demonstrated in all patients with BSEP deficiency in whom leukocyte DNA could be studied (n = 7). These mutations were confirmed in the parents (n = 14). With respect to the other 3 children with BSEP deficiency, mutations in ABCB11 were demonstrated in all 5 parents in whom leukocyte DNA could be studied. Thirteen different mutations were found. In conclusion, PFIC associated with BSEP deficiency represents a previously unrecognized risk for HCC in young children. Immunohistochemical evidence of BSEP deficiency correlates well with demonstrable mutation in ABCB11.

  11. Bile salt-stimulated phospholipid efflux mediated by ABCB4 localized in nonraft membranes.

    PubMed

    Morita, Shin-ya; Tsuda, Tadanori; Horikami, Manami; Teraoka, Reiko; Kitagawa, Shuji; Terada, Tomohiro

    2013-05-01

    ABCB4 is necessary for the secretion of phospholipids from hepatocytes into bile and for the protection of cell membranes against bile salts. Lipid rafts are plasma membrane microdomains containing high contents of cholesterol and sphingolipids, which are separated by Triton X-100 extraction or OptiPrep gradient centrifugation. In this study, we investigated the relationship between the function of ABCB4 and lipid rafts using mouse canalicular membranes and HEK293 cells stably expressing ABCB4. ABCB4 and ABCB1 were mainly distributed in nonraft membranes. The expression of ABCB4, but not ABCB1, led to significant increases in the phosphatidylcholine (PC), phosphatidylethanolamine (PE), and sphingomyelin (SM) contents in nonraft membranes and further enrichment of SM and cholesterol in raft membranes. The ABCB4-mediated efflux of PC, PE, and SM was significantly stimulated by taurocholate, while the efflux of PE and SM was much less than that of PC. This ABCB4-mediated efflux was completely abolished by BODIPY-verapamil, which hardly partitioned into raft membranes. In addition, ABCB1 and ABCB4 mediated the efflux of rhodamine 123 and rhodamine 6G from nonraft membranes, which was not affected by taurocholate. We conclude that ABCB4 located in nonrafts, but not in rafts, is predominantly involved in the efflux of phospholipids and other substrates.

  12. Bile salt-stimulated phospholipid efflux mediated by ABCB4 localized in nonraft membranes

    PubMed Central

    Morita, Shin-ya; Tsuda, Tadanori; Horikami, Manami; Teraoka, Reiko; Kitagawa, Shuji; Terada, Tomohiro

    2013-01-01

    ABCB4 is necessary for the secretion of phospholipids from hepatocytes into bile and for the protection of cell membranes against bile salts. Lipid rafts are plasma membrane microdomains containing high contents of cholesterol and sphingolipids, which are separated by Triton X-100 extraction or OptiPrep gradient centrifugation. In this study, we investigated the relationship between the function of ABCB4 and lipid rafts using mouse canalicular membranes and HEK293 cells stably expressing ABCB4. ABCB4 and ABCB1 were mainly distributed in nonraft membranes. The expression of ABCB4, but not ABCB1, led to significant increases in the phosphatidylcholine (PC), phosphatidylethanolamine (PE), and sphingomyelin (SM) contents in nonraft membranes and further enrichment of SM and cholesterol in raft membranes. The ABCB4-mediated efflux of PC, PE, and SM was significantly stimulated by taurocholate, while the efflux of PE and SM was much less than that of PC. This ABCB4-mediated efflux was completely abolished by BODIPY-verapamil, which hardly partitioned into raft membranes. In addition, ABCB1 and ABCB4 mediated the efflux of rhodamine 123 and rhodamine 6G from nonraft membranes, which was not affected by taurocholate. We conclude that ABCB4 located in nonrafts, but not in rafts, is predominantly involved in the efflux of phospholipids and other substrates. PMID:23468132

  13. Endogenous bile acid disposition in rat and human sandwich-cultured hepatocytes

    SciTech Connect

    Marion, Tracy L.; Perry, Cassandra H.; St Claire, Robert L.; Brouwer, Kim L.R.

    2012-05-15

    Sandwich-cultured hepatocytes (SCH) are used commonly to investigate hepatic transport protein-mediated uptake and biliary excretion of substrates. However, little is known about the disposition of endogenous bile acids (BAs) in SCH. In this study, four endogenous conjugated BAs common to rats and humans [taurocholic acid (TCA), glycocholic acid (GCA), taurochenodeoxycholic acid (TCDCA), and glycochenodeoxycholic acid (GCDCA)], as well as two BA species specific to rodents (α- and β-tauromuricholic acid; α/β TMCA), were profiled in primary rat and human SCH. Using B-CLEAR{sup ®} technology, BAs were measured in cells + bile canaliculi, cells, and medium of SCH by LC-MS/MS. Results indicated that, just as in vivo, taurine-conjugated BA species were predominant in rat SCH, while glycine-conjugated BAs were predominant in human SCH. Total intracellular BAs remained relatively constant over days in culture in rat SCH. Total BAs in control (CTL) cells + bile, cells, and medium were approximately 3.4, 2.9, and 8.3-fold greater in human than in rat. The estimated intracellular concentrations of the measured total BAs were 64.3 ± 5.9 μM in CTL rat and 183 ± 56 μM in CTL human SCH, while medium concentrations of the total BAs measured were 1.16 ± 0.21 μM in CTL rat SCH and 9.61 ± 6.36 μM in CTL human SCH. Treatment of cells for 24 h with 10 μM troglitazone (TRO), an inhibitor of the bile salt export pump (BSEP) and the Na{sup +}-taurocholate cotransporting polypeptide (NTCP), had no significant effect on endogenous BAs measured at the end of the 24-h culture period, potentially due to compensatory mechanisms that maintain BA homeostasis. These data demonstrate that BAs in SCH are similar to in vivo, and that SCH may be a useful in vitro model to study alterations in BA disposition if species differences are taken into account. -- Highlights: ► Bile acids (BAs) were measured in rat and human sandwich-cultured hepatocytes (SCH). ► Cell and medium BA

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

    PubMed

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

    2016-06-01

    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.

  15. Effects of bile salts and divalent cations on the adsorption of norfloxacin by agricultural soils.

    PubMed

    Kong, Xuesong; Feng, Shixiang; Zhang, Xu; Li, Yan

    2014-04-01

    The effects of bile salts (sodium cholate and sodium deoxycholate, 0-20 mmol/L), divalent cations (Ca(2+), Mg(2+), Cu(2+) and Zn(2+), 0-20 mmol/L) or pH (3.0-10.0) on the adsorption of norfloxacin by three selected soils (Paddy_H, Paddy_G and Red_J) were systematically studied. Soil adsorption of norfloxacin follows a pseudo second-order kinetics model, and the maximum adsorption capacity has been determined from the nonlinear fit of the Langmuir isotherm model to be 88.8, 88.1 and 63.0 μmol/g for the adsorption onto Paddy_H, Paddy_G and Red_J, respectively. The results indicate that norfloxacin has a high adsorption affinity for the agricultural soils tested and that the organic content of these soils have at least a slight influence on this adsorption. The adsorption of norfloxacin to soils was strongly dependent on pH and exhibited a maximum at approximately pH 6. The presence of divalent cations prominently suppressed the adsorption of norfloxacin by paddy soils, which followed an order of Cu(2+) > Mg(2+) > Ca(2+) > Zn(2+), and by red soil, which followed an order of Cu(2+) > Zn(2+) > Ca(2+) > Mg(2+). The adsorption of norfloxacin (by the soils studied) sharply decreased as the amount of bile salts was increased. For uncharged norfloxacin at environmentally relevant pH values, such factors as soil type, exogenous divalent cations and macromolecules significantly altered the environmental fate and transport of norfloxacin between aquatic and soil interfaces. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

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

    PubMed Central

    Unterweger, Daniel; Diaz-Satizabal, Laura; Ogg, Stephen; Pukatzki, Stefan

    2015-01-01

    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. PMID:26317760

  17. Bile salt export pump-reactive antibodies form a polyclonal, multi-inhibitory response in antibody-induced bile salt export pump deficiency.

    PubMed

    Stindt, Jan; Kluge, Stefanie; Dröge, Carola; Keitel, Verena; Stross, Claudia; Baumann, Ulrich; Brinkert, Florian; Dhawan, Anil; Engelmann, Guido; Ganschow, Rainer; Gerner, Patrick; Grabhorn, Enke; Knisely, A S; Noli, Khalid A; Pukite, Ieva; Shepherd, Ross W; Ueno, Takehisa; Schmitt, Lutz; Wiek, Constanze; Hanenberg, Helmut; Häussinger, Dieter; Kubitz, Ralf

    2016-02-01

    Progressive familial intrahepatic cholestasis type 2 (PFIC-2) is caused by mutations in ABCB11, encoding the bile salt export pump (BSEP). In 2009, we described a child with PFIC-2 who developed PFIC-like symptoms after orthotopic liver transplantation (OLT). BSEP-reactive antibodies were demonstrated to account for disease recurrence. Here, we characterize the nature of this antibody response in 7 more patients with antibody-induced BSEP deficiency (AIBD). Gene sequencing and immunostaining of native liver biopsies indicated absent or strongly reduced BSEP expression in all 7 PFIC-2 patients who suffered from phenotypic disease recurrence post-OLT. Immunofluorescence, western blotting analysis, and transepithelial transport assays demonstrated immunoglobulin (Ig) G-class BSEP-reactive antibodies in these patients. In all cases, the N-terminal half of BSEP was recognized, with reaction against its first extracellular loop (ECL1) in six sera. In five, antibodies reactive against the C-terminal half also were found. Only the sera recognizing ECL1 showed inhibition of transepithelial taurocholate transport. In a vesicle-based functional assay, transport inhibition by anti-BSEP antibodies binding from the cytosolic side was functionally proven as well. Within 2 hours of perfusion with antibodies purified from 1 patient, rat liver showed canalicular IgG staining that was absent after perfusion with control IgG. PFIC-2 patients carrying severe BSEP mutations are at risk of developing BSEP antibodies post-OLT. The antibody response is polyclonal, targeting both extra- and intracellular BSEP domains. ECL1, a unique domain of BSEP, likely is a critical target involved in transport inhibition as demonstrated in several patients with AIBD manifest as cholestasis. © 2015 by the American Association for the Study of Liver Diseases.

  18. Molecular interactions of a model bile salt and porcine bile with (1,3:1,4)-β-glucans and arabinoxylans probed by (13)C NMR and SAXS.

    PubMed

    Gunness, Purnima; Flanagan, Bernadine M; Mata, Jitendra P; Gilbert, Elliot P; Gidley, Michael J

    2016-04-15

    Two main classes of interaction between soluble dietary fibres (SDFs), such as (1,3:1,4)-β-D-glucan (βG) and arabinoxylan (AX) and bile salt (BS) or diluted porcine bile, were identified by (13)C NMR and small angle X-ray scattering (SAXS). Small chemical shift differences of BS NMR resonances were consistent with effective local concentration or dilution of BS micelles mostly by βG, suggesting dynamic interactions; whilst the reduced line widths/intensities observed were mostly caused by wheat AX and the highest molecular size and concentrations of βG. SAXS showed evidence of changes in βG but not AX in the presence of BS micelles, at >13 nm length scale consistent with molecular level interactions. Thus intermolecular interactions between SDF and BS depend on both SDF source and its molecular weight and may occur alone or in combination.

  19. The effects of bile salts and lipids on the physicochemical behavior of gemfibrozil.

    PubMed

    Luner, P E; Babu, S R; Radebaugh, G W

    1994-12-01

    Physicochemical effects caused by intestinal fluids on drugs in the gastrointestinal (GI) tract can be a contributing factor in food induced changes in bioavailability. To identify physicochemical properties of gemfibrozil that may be altered by endogenous and dietary lipids, in vitro studies were conducted in model systems approximating the conditions of the upper GI tract. Factors examined include pH, solubility in bile salt micellar and mixed micellar systems with monoolein and lecithin, effect of fatty acids, dissolution, wetting, and partitioning in triglyceride dispersions. Gemfibrozil was solubilized by glycocholate solutions in a manner typical of other lipids and a three-fold increase in solubility was observed over physiologic concentrations. Addition of increasing amounts of swelling amphiphiles (monoolein, lecithin) to glycocholate solutions resulted in a linear increase in solubility. Fatty acid salts had no effect on gemfibrozil solubilization by micellar solutions. The dissolution rate of gemfibrozil increased slightly in the presence of glycocholate relative to buffer, however, addition of monoolein increased the dissolution rate three-fold. In triglyceride dispersions of mixtures of lipids, monoolein increased the fraction of drug in the micellar subphase, whereas fatty acid reduced it. The results indicate that in the conditions of the fed state gemfibrozil solubility and dissolution could be substantially increased relative to the conditions in the fasted state.

  20. Bile Salt Homeostasis in Normal and Bsep Gene Knockout Rats with Single and Repeated Doses of Troglitazone.

    PubMed

    Cheng, Yaofeng; Chen, Shenjue; Freeden, Chris; Chen, Weiqi; Zhang, Yueping; Abraham, Pamela; Nelson, David M; Humphreys, W Griffith; Gan, Jinping; Lai, Yurong

    2017-09-01

    The interference of bile acid secretion through bile salt export pump (BSEP) inhibition is one of the mechanisms for troglitazone (TGZ)-induced hepatotoxicity. Here, we investigated the impact of single or repeated oral doses of TGZ (200 mg/kg/day, 7 days) on bile acid homoeostasis in wild-type (WT) and Bsep knockout (KO) rats. Following oral doses, plasma exposures of TGZ were not different between WT and KO rats, and were similar on day 1 and day 7. However, plasma exposures of the major metabolite, troglitazone sulfate (TS), in KO rats were 7.6- and 9.3-fold lower than in WT on day 1 and day 7, respectively, due to increased TS biliary excretion. With Bsep KO, the mRNA levels of multidrug resistance-associated protein 2 (Mrp2), Mrp3, Mrp4, Mdr1, breast cancer resistance protein (Bcrp), sodium taurocholate cotransporting polypeptide, small heterodimer partner, and Sult2A1 were significantly altered in KO rats. Following seven daily TGZ treatments, Cyp7A1 was significantly increased in both WT and KO rats. In the vehicle groups, plasma exposures of individual bile acids demonstrated variable changes in KO rats as compared with WT. WT rats dosed with TGZ showed an increase of many bile acid species in plasma on day 1, suggesting the inhibition of Bsep. Conversely, these changes returned to base levels on day 7. In KO rats, alterations of most bile acids were observed after seven doses of TGZ. Collectively, bile acid homeostasis in rats was regulated through bile acid synthesis and transport in response to Bsep deficiency and TGZ inhibition. Additionally, our study is the first to demonstrate that repeated TGZ doses can upregulate Cyp7A1 in rats. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  1. Intrarenal mechanisms of salt retention after bile duct ligation in rats.

    PubMed Central

    Yarger, W E; Schrader, N W; Boyd, M A

    1976-01-01

    In order to study renal salt-retaining mechanisms during the early stages of ascites formation, rats were subjected to bile duct ligation. After this procedure, plasma volumes were found to be reduced and hematocrits slightly increased. The whole-kidney glomberular filtration rate and plasma flows were reduced to 59 and 57% of control values, but the filtration fraction was unchanged. Absolute sodium excretion, as well as the fraction of the filtered sodium load excreted, was also significantly reduced. When micropuncture techniques were used to examine the function of single superficial nephrons, the glomerular filtration rate in these nephrons was found to be reduced to 70% of controlled values, and fractional reabsorption was found to be increased at all accessible sites along the nephron. Filtration by intermediate and juxtamedullary nephrons, determined by Hanssen's technique, was reduced to 55 and 48% of control values. By the use of radioactive microspheres, it was demonstrated that blood flow to superficial, intermediate, and juxtamedullary nephrons was reduced to 49, 59, and 73% of control values. Filtration by superficial nephrons decreased much more than plasma flow--a finding which suggests that the measured increase in fractional reabsorption was associated with an increase in the superficial nephron filtration fraction. From this study, it appears that two factors play an important part in the sodium retention observed in the initial stages of ascites formation following bile duct ligation in rats: (a) a decrease in the filtered sodium load and (b) increased fractional reabsorption by the superficial nephrons--the nephrons which show the least decrease in filtration. PMID:1254726

  2. Survival of Bifidobacterium longum immobilized in calcium alginate beads in simulated gastric juices and bile salt solution.

    PubMed

    Lee, K Y; Heo, T R

    2000-02-01

    Bifidobacterium longum KCTC 3128 and HLC 3742 were independently immobilized (entrapped) in calcium alginate beads containing 2, 3, and 4% sodium alginate. When the bifidobacteria entrapped in calcium alginate beads were exposed to simulated gastric juices and a bile salt solution, the death rate of the cells in the beads decreased proportionally with an increase in both the alginate gel concentration and bead size. The initial cell numbers in the beads affected the numbers of survivors after exposure to these solutions; however, the death rates of the viable cells were not affected. Accordingly, a mathematical model was formulated which expressed the influences of several parameters (gel concentration, bead size, and initial cell numbers) on the survival of entrapped bifidobacteria after sequential exposure to simulated gastric juices followed by a bile salt solution. The model proposed in this paper may be useful for estimating the survival of bifidobacteria in beads and establishing optimal entrapment conditions.

  3. Organized media for fluorescence analysis of complex samples: Comparison of bile salt and conventional detergent micelles in coal liquids

    SciTech Connect

    Ritenour Hertz, P.M.; McGown, L.B. )

    1992-12-01

    Accurate quantitative determinations are often difficult to obtain from fluorescence analysis of complex samples due to sample matrix effects and intermolecular interactions between solutes. Organized media can be used to minimize these unwanted processes without physical separation or extraction of the analytes from the sample matrix by isolating the analyte molecules in a uniform microenvironment within the sample. The advantages of bile salt micellar media over conventional detergent micelles are demonstrated for analysis of coal liquids. The bile salt media is shown to increase the sensitivity and dynamic range of fluorescence measurements relative to simple ethanolic solutions, without promoting ground-state and excited-state interactions that occur in the detergent micellar media. 45 refs., 11 figs., 3 tabs.

  4. Increased protein secretion and adherence to HeLa cells by Shigella spp. following growth in the presence of bile salts.

    PubMed Central

    Pope, L M; Reed, K E; Payne, S M

    1995-01-01

    Growth of Shigella spp. in the presence of the bile salt deoxycholate or chenodeoxycholate enhanced the bacterial invasion of HeLa cells. Growth in the presence of other structurally similar bile salts or detergents had little or no effect. Deoxycholate-enhanced invasion was not observed when bacteria were exposed to deoxycholate at low temperatures or when chloramphenicol was added to the growth medium, indicating that bacterial growth and protein synthesis are required. Increased invasion is associated with the presence of an intact Shigella virulence plasmid and is correlated with increased secretion of a set of proteins, including the Ipa proteins, to the outer membrane and into the growth medium. The increased invasion induced by the bile salts appears to be due to increased adherence. The enhanced adherence was specific to Shigella spp., since the enteroinvasive Escherichia coli strains tested did not exhibit the effect in response to growth in bile salts. PMID:7642302

  5. The human gallbladder secretes fibroblast growth factor 19 into bile: towards defining the role of fibroblast growth factor 19 in the enterobiliary tract.

    PubMed

    Zweers, Serge J L B; Booij, Klaske A C; Komuta, Mina; Roskams, Tania; Gouma, Dirk J; Jansen, Peter L M; Schaap, Frank G

    2012-02-01

    Fibroblast growth factor 19 (FGF19) plays a crucial role in the negative feedback regulation of bile salt synthesis. In the postprandial state, activation of ileal farnesoid X receptor (FXR) by bile salts results in transcriptional induction of FGF19 and elevation of circulating FGF19 levels. An intestinal-liver axis of FGF19 signaling results in down-regulation of bile salt synthesis. The aim of this study was to explore a broader signaling activity of FGF19 in organs engaged in the enterohepatic circulation of bile salts. For this aim, FGF19 expression and aspects of FGF19 signaling were studied in surgical specimens and in cell lines of hepatobiliary and intestinal origin. FGF19 messenger RNA was found to be abundantly expressed in the human gallbladder and in the common bile duct, with only minor expression observed in the ileum. Interestingly, human gallbladder bile contains high levels of FGF19 (21.9 ± 13.3 versus 0.22 ± 0.14 ng/mL in the systemic circulation). Gallbladder explants secrete 500 times more FGF19 than FXR agonist-stimulated ileal explants. Factors required for FGF19 signaling (i.e., FGFR4 and βKlotho) are expressed in mucosal epithelial cells of the gallbladder and small intestine. FGF19 was found to activate signaling pathways in cell lines of cholangiocytic, enteroendocrine, and enterocytic origin. The combined findings raise the intriguing possibility that biliary FGF19 has a signaling function in the biliary tract that differs from its established signaling function in the portal circulation. Delineation of the target cells in bile-exposed tissues and the affected cellular pathways, as well as a possible involvement in biliary tract disorders, require further studies. Copyright © 2011 American Association for the Study of Liver Diseases.

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

    PubMed

    Arzani, Gelareh; Haeri, Azadeh; Daeihamed, Marjan; Bakhtiari-Kaboutaraki, Hamid; Dadashzadeh, Simin

    2015-01-01

    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 vesicles. Tissue histology revealed no signs of inflammation or damage. The study proved that the type and concentration of bile salts as well as carrier surface charge had great influences on oral bioavailability of niosomes. Blocking the lymphatic absorption pathway

  7. The flow of bile in the human cystic duct.

    PubMed

    Ooi, R C; Luo, X Y; Chin, S B; Johnson, A G; Bird, N C

    2004-12-01

    Clinical studies suggest that the flow of bile in the biliary system may be a contributing factor in the pathogenesis of cholelithiasis, but little is known about its transport mechanism. This paper reports a numerical study of steady flow in human cystic duct models. In order to obtain parametric data on the effects of various anatomical features in the cystic duct, idealised models were constructed, first with staggered baffles in a channel to represent the valves of Heister and lumen. The qualitative consistency of these findings are validated by modelling two of the real cystic ducts obtained from operative cholangiograms. Three-dimensional (3D) models were also constructed to further verify the two-dimensional (2D) results. It was found that the most significant geometric parameter affecting resistance is the baffle clearance (lumen size), followed by the number of baffles (number of folds in the valves of Heister), whilst the least significant ones are the curvature of the cystic duct and the angle between the neck and the gallbladder. The study presented here forms part of a larger project to understand the functions of the human cystic duct, especially the influence of its various anatomical structures on the resistance to bile flow, so that it may aid the assessment of the risk of stone formation in the gallbladder.

  8. In vitro lipid peroxidation of intestinal bile salt-based nanoemulsions: potential role of antioxidants.

    PubMed

    Courraud, J; Charnay, C; Cristol, J P; Berger, J; Avallone, S

    2013-12-01

    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 contents, it has been hypothesized that their protection could occur from the gut. Therefore, the aim of this study was to develop an original and physiological model of nanoemulsions to study lipid peroxidation within the intestine and to assess the properties of potential antioxidants in this setting. 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 antioxidants. Hemin and myoglobin were also tested as relevant potential oxidants. Fatty acid (FA) peroxidation was monitored by gas chromatography while malondialdehyde and antioxidant contents were measured by HPLC. Investigated nanoemulsions were composed of spherical or cylindrical mixed micelles, the latter being the least resistant to oxidation. In the experimental conditions, AAPH was the only efficient oxidant. Alpha-tocopherol and lutein significantly slowed FA degradation from 4 to 1 μM, respectively. On the contrary, beta-carotene did not show any protective capacity at 4 μM. In conclusion, the tested nanoemulsions were appropriate to assess antioxidant capacity during the intestinal phase of digestion.

  9. A Molecular Dynamics Study of Single-Walled Carbon Nanotubes (SWCNTs) Dispersed in Bile Salt Surfactants

    NASA Astrophysics Data System (ADS)

    Phelan, Frederick, Jr.; Sun, Huai

    2014-03-01

    Single-walled carbon nanotubes (SWNCTs) are materials with structural, electronic and optical properties that make them attractive for a myriad of advanced technology applications. A practical barrier to their use is that SWCNT synthesis techniques produce heterogeneous mixtures of varying lengths and chirality, whereas applications generally require tubes with narrow size distributions and individual type. Most separation techniques currently in use to obtain monodisperse tube fractions rely on dispersion of these materials in aqueous solution using surfactants. The dispersion process results in a mixture of colloidal structures in which individual tubes are dispersed and contained in a surfactant shell. Understanding the structure and properties of the SWCNT-surfactant complex at the molecular level, and how this is affected by chirality, is key to understanding and improving separations processes. In this study, we use molecular dynamics (MD) simulations to study the structure and properties of SWCNT-surfactant colloidal complexes. We tested a number of methods and protocols in order to build an accurate model for simulating SWCNT systems for a variety of bile salt surfactants as well as anionic co-surfactants, components that are widely used and important in experimental separation studies at NIST. The custom force field parameters used here will be stored in WebFF, a Web-hosted smart force-field repository for polymeric and organic materials being developed at NIST for the Materials Genome Initiative.

  10. A Low Energy Route to DNA-Wrapped Carbon Nanotubes via Replacement of Bile Salt Surfactants.

    PubMed

    Streit, Jason K; Fagan, Jeffrey A; Zheng, Ming

    2017-10-03

    DNA-wrapped carbon nanotubes are a class of bionano hybrid molecules that have enabled carbon nanotube sorting, controlled assembly, and biosensing and bioimaging applications. The current method of synthesizing these hybrids via direct sonication of DNA/nanotube mixtures is time-consuming and not suitable for high-throughput synthesis and combinatorial sequence screening. Additionally, the direct sonication method does not make use of nanotubes presorted by extensively developed surfactant-based methods, is not effective for large diameter (>1 nm) tubes, and cannot maintain secondary and tertiary structural and functional domains present in certain DNA sequences. Here, we report a simple, quick, and robust process to produce DNA-wrapped carbon nanotube hybrids with nanotubes of broad diameter range and DNA of arbitrary sequence. This is accomplished by exchanging strong binding bile salt surfactant coating with DNA in methanol/water mixed solvent and subsequent precipitation with isopropyl alcohol. The exchange process can be completed within 10 min and converts over 90% nanotubes into the DNA wrapped form. Applying the exchange process to nanotubes presorted by surfactant-based methods, we show that the resulting DNA-wrapped carbon nanotubes can be further sorted to produce nanotubes with defined handedness, helicity, and endohedral filling. The exchange method greatly expands the structural and functional variety of DNA-wrapped carbon nanotubes and opens possibilities for DNA-directed assembly of structurally sorted nanotubes and high-throughput screening of properties that are controlled by the wrapping DNA sequences.

  11. Multiple forms of bile salt hydrolase from Lactobacillus sp. strain 100-100.

    PubMed Central

    Lundeen, S G; Savage, D C

    1992-01-01

    Four isozymes of bile salt hydrolase (BSH) have been purified from the cytosol of cells of Lactobacillus sp. strain 100-100. The four proteins were designated BSH A, B, C, and D. They eluted from anion-exchange high-pressure liquid chromatography columns at 0.15, 0.18, 0.21, and 0.25 M NaCl, respectively. They are catalytically similar, except that the Vmax of BSH D is about 10-fold lower than those of the other three isozymes. All four proteins consist of one or two polypeptides. The peptides have molecular weights of 42,000 and 38,000 and are designated alpha and beta, respectively. The approximate native molecular weights of BSH A, B, C, and D are 115,000, 105,000, 95,000, and 80,000, respectively. The native proteins are probably trimers; the four isozymes are the array of possible subunit combinations alpha 3, alpha 2 beta 1, alpha 1 beta 2, and beta 3 for A, B, C, and D, respectively. The two subunits are antigenically distinct. Polyclonal antibodies raised against BSH A (all alpha peptide) react in Western blots (immunoblots) only with proteins containing the alpha peptide; such antibodies raised against BSH D (all beta peptide) react only with proteins containing the beta peptide. The amino acid compositions of the two peptides differ. This is the first report of a bacterium that makes four BSH isozymes. Images PMID:1429446

  12. Kinetics of the Micelle-to-Vesicle Transition: Aqueous Lecithin-Bile Salt Mixtures

    PubMed Central

    Leng, J.; Egelhaaf, S. U.; Cates, M. E.

    2003-01-01

    Important routes to lipid vesicles (liposomes) are detergent removal techniques, such as dialysis or dilution. Although they are widely applied, there has been only limited understanding about the structural evolution during the formation of vesicles and the parameters that determine their properties. We use time-resolved static and dynamic light scattering to study vesicle formation in aqueous lecithin-bile salt mixtures. The kinetic rates and vesicle sizes are found to strongly depend on total amphiphile concentration and, even more pronounced, on ionic strength. The observed trends contradict equilibrium calculations, but are in agreement with a kinetic model that we present. This model identifies the key kinetic steps during vesicle formation: rapid formation of disklike intermediate micelles, growth of these metastable micelles, and their closure to form vesicles once line tension dominates bending energy. A comparison of the rates of growth and closure provides a kinetic criterion for the critical size at which disks close and thus for the vesicle size. The model suggests that liposomes are nonequilibrium, kinetically trapped structures of very long lifetime. Their properties are hence controlled by kinetics rather than thermodynamics. PMID:12944278

  13. Immobilization of bile salt hydrolase enzyme on mesoporous SBA-15 for co-precipitation of cholesterol.

    PubMed

    Bhange, Pallavi; Sridevi, N; Bhange, Deu S; Prabhune, Asmita; Ramaswamy, Veda

    2014-02-01

    We describe herein a simple and effective strategy for immobilization of bile salt hydrolase enzyme by grafting glutaraldehyde groups inside channels of APTES functionalized SBA-15. The increase in glutaraldehyde concentration prevents leakage of enzyme but showed a steep decrease in enzyme activity in the immobilized matrix. So the degree of cross-linking should be the minimum possible to ensure sufficient stability without loss of activity. Cross-linking carried out with 0.1% glutaraldehyde concentration showed the highest activity, so this was used in all further experiments. Physico-chemical characterizations of the immobilized enzyme were carried out by XRD, N2 adsorption, TEM, FTIR and (29)Si CP-MAS NMR techniques. Immobilized BSH exhibits enhanced stability over a wide pH (3-11) and temperature range (40-80 °C) and retains an activity even after recycling experiments and six months of storage. From our in vivo research experiment toward co-precipitation of cholesterol, we have shown that immobilized BSH enzyme may be the promising catalyst for the reduction of serum cholesterol levels in our preliminary investigation. Enhancement in pH stability at the extreme side of pH may favor the use of immobilized BSH enzyme for drug delivery purpose to with stand extreme pH conditions in the gastrointestinal conditions.

  14. The Escherichia coli SOS gene dinF protects against oxidative stress and bile salts.

    PubMed

    Rodríguez-Beltrán, Jerónimo; Rodríguez-Rojas, Alexandro; Guelfo, Javier R; Couce, Alejandro; Blázquez, Jesús

    2012-01-01

    DNA is constantly damaged by physical and chemical factors, including reactive oxygen species (ROS), such as superoxide radical (O(2)(-)), hydrogen peroxide (H(2)O(2)) and hydroxyl radical (•OH). Specific mechanisms to protect and repair DNA lesions produced by ROS have been developed in living beings. In Escherichia coli the SOS system, an inducible response activated to rescue cells from severe DNA damage, is a network that regulates the expression of more than 40 genes in response to this damage, many of them playing important roles in DNA damage tolerance mechanisms. Although the function of most of these genes has been elucidated, the activity of some others, such as dinF, remains unknown. The DinF deduced polypeptide sequence shows a high homology with membrane proteins of the multidrug and toxic compound extrusion (MATE) family. We describe here that expression of dinF protects against bile salts, probably by decreasing the effects of ROS, which is consistent with the observed decrease in H(2)O(2)-killing and protein carbonylation. These results, together with its ability to decrease the level of intracellular ROS, suggests that DinF can detoxify, either direct or indirectly, oxidizing molecules that can damage DNA and proteins from both the bacterial metabolism and the environment. Although the exact mechanism of DinF activity remains to be identified, we describe for the first time a role for dinF.

  15. Fecal Bile Salts and the Development of Necrotizing Enterocolitis in Preterm Infants

    PubMed Central

    Hulzebos, Christian V.; van Zoonen, Anne G. J. F.; Hulscher, Jan B. F.; Schat, Trijntje E.; Kooi, Elisabeth M. W.; Koehorst, Martijn; Boverhof, Renze; Krabbe, Paul F. M.; Groen, Albert K.; Verkade, Henkjan J.

    2017-01-01

    Background Intestinal bile salts (BSs) may be implicated in NEC development. We hypothesized that fecal BS levels are higher in preterm infants at risk for NEC. Methods We compared the composition and concentration of fecal BSs in ten preterm infants who developed NEC (Bell’s Stage ≥ II) with twenty matched control infants without NEC. Conjugated and unconjugated fecal BSs were measured after birth (T1) and twice prior to NEC (T2, T3). Data are presented as medians and interquartile ranges. Results GA and BW were similar in all preterms: ~27+4 weeks and ~1010 g. Age of NEC onset was day 10 (8–24). T1 was collected 2 (1–3) days after birth. T2 and T3 were collected 5 (5–6) days and 1 (0–2) day before NEC or at corresponding postnatal ages in controls. The composition of conjugated BSs did not differ between the two groups. Total unconjugated BSs were 3-fold higher before NEC compared to controls at corresponding ages (0.41 μmol/g feces (0.21–0.74) versus 0.14 μmol/g feces (0.06–0.46), p < 0.05). Conclusion Fecal BS concentrations are higher in preterm infants who develop NEC compared to infants without NEC. Further study is needed to determine the predictive value of fecal BSs in the development of NEC. PMID:28045982

  16. Effects of tonicity, digestive enzymes and bile salts, and nutrient media on the survival of excysted metacercariae of Echinostoma caproni.

    PubMed

    Fried, Bernard; Schneck, Jessica L; Ponder, Elizabeth L

    2004-05-01

    The effects of tonicity, digestive enzymes and bile salts, and various nutrients added to Locke's solution were studied on the chemically excysted metacercariae of Echinostoma caproni. Metacercariae were maintained at 37.5 degrees C in multiwell chambers, ten per 0.5 ml of test solution; each experiment was replicated five times. Most metacercariae maintained in deionized water or Locke's 2x solution were dead within 2 h. About 85% and 55% of the metacercariae were alive at 8 h in Locke's 1x and Locke's 0.5x, respectively. Metacercariae of this species are osmoconformers, as is the case for adult digeneans. All metacercariae were dead in an acid saline or acid pepsin medium by 2 h. About 50% of the metacercariae were alive in an alkaline trypsin-bile salts medium at 4 h. These results suggest that the acidic pepsin environment in the stomach of a definitive host would be detrimental to the survival of excysted metacercariae, but prolonged survival in alkaline trypsin-bile salts would facilitate establishment of this larval stage in the mucosa of the host small intestine. Studies on excysted metacercariae in Locke's 1x supplemented with various nutrients showed that optimal survival occurred in Locke's plus 0.1% glucose and in Locke's 1x plus 1% hen's egg yolk. Significant survival of excysted metacercariae in Locke's 1x supplemented with either 0.1% proline, 0.1% threonine, or 0.1% serine did not occur. Copyright 2004 Springer-Verlag

  17. The cell surface protein Ag43 facilitates phage infection of Escherichia coli in the presence of bile salts and carbohydrates.

    PubMed

    Gabig, Magdalena; Herman-Antosiewicz, Anna; Kwiatkowska, Marta; Los, Marcin; Thomas, Mark S; Wegrzyn, Grzegorz

    2002-05-01

    It was found that infection of Escherichia coli by bacteriophage lambda is inhibited in the presence of certain bile salts and carbohydrates when cells are in the "OFF" state for production of the phase-variable cell surface protein antigen 43 (Ag43). The inhibition of phage growth was found to be due to a significant impairment in the process of phage adsorption. Expression of the gene encoding Ag43 (agn43) from a plasmid or inactivation of the oxyR gene (encoding an activator of genes important for defence against oxidative stress) suppressed this inhibition. A mutation, rpoA341, in the gene encoding the alpha subunit of RNA polymerase also facilitated phage adsorption in the presence of bile salts and carbohydrates. The rpoA341 mutation promoted efficient production of Ag43 in a genetic background that would otherwise be in the "OFF" phase for expression of the agn43 gene. Analysis of a reporter gene fusion demonstrated that the promoter for the agn43 gene was more active in the rpoA341 mutant than in the otherwise isogenic rpoA(+) strain. The combined inhibitory action of bile salts and carbohydrates on phage adsorption and the abolition of this inhibition by production of Ag43 was not restricted to lambda, as a similar phenomenon was observed for the coliphages P1 and T4.

  18. Interactions between cellulose ethers and a bile salt in the control of lipid digestion of lipid-based systems.

    PubMed

    Torcello-Gómez, Amelia; Foster, Timothy J

    2014-11-26

    In order to gain new insights into the potential of specific dietary fibres to control lipid digestion, the goal of this work is to study the main interactions between commercial cellulose ethers, as dietary fibre, and a bile salt, as an important duodenal component present during the digestibility of lipids. These interactions have been evaluated in two different scenarios found for an oil-in-water emulsion on its transit through the duodenum. Namely, interactions in the continuous phase and competitive adsorption at the oil-water interface have been looked at by means of micro-differential scanning calorimetry (micro-DSC) and interfacial tension (IT). Micro-DSC revealed that the presence of the bile salt affects the thermogelation process of cellulose derivatives, suggesting binding to cellulose ethers. The effect on thermogelation seems to be cellulose type-dependent. IT measurements proved the ability of cellulose ethers to compete for the oil-water interface in the presence of the bile salt. Interactions in the bulk might have an impact on this interfacial scenario. These findings may have implications in the digestion of emulsified lipids, hence providing a springboard to develop new cellulose-based food products with improved functional properties.

  19. Computational investigation of enthalpy-entropy compensation in complexation of glycoconjugated bile salts with β-cyclodextrin and analogs.

    PubMed

    Tidemand, Kasper D; Schönbeck, Christian; Holm, René; Westh, Peter; Peters, Günther H

    2014-09-18

    The inclusion complexes of glycoconjugated bile salts with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrins (HP-β-CD) in aqueous solution were investigated by molecular dynamics simulations to provide a molecular explanation of the experimentally observed destabilizing effect 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 time of water molecules in the cavity increased with the DS. Release of water from the cavity resulted in a positive enthalpy change, which correlates qualitatively with the experimentally determined increase in complexation enthalpy and contributes to the enthalpy-entropy compensation. The positive 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 cavities.

  20. Endogenous Bile Acid Disposition in Rat and Human Sandwich-Cultured Hepatocytes

    PubMed Central

    Marion, Tracy L.; Perry, Cassandra H.; St. Claire, Robert L.; Brouwer, Kim L. R.

    2013-01-01

    Sandwich-cultured hepatocytes (SCH) are used commonly to investigate hepatic transport protein-mediated uptake and biliary excretion of substrates. However, little is known about the disposition of endogenous bile acids (BAs) in SCH. In this study, four endogenous conjugated BAs common to rats and humans [taurocholic acid (TCA), glycocholic acid (GCA), taurochenodeoxycholic acid (TCDCA), and glycochenodeoxycholic acid (GCDCA)], as well as two BA species specific to rodents (α- and β-tauromuricholic acid; α/β TMCA), were profiled in primary rat and human SCH. Using B-CLEAR® technology, BAs were measured in cells+bile canaliculi, cells, and medium of SCH by LC-MS/MS. Results indicated that, just as in vivo, taurine-conjugated BA species were predominant in rat SCH, while glycine-conjugated BAs were predominant in human SCH. Total intracellular BAs remained relatively constant over days in culture in rat SCH. Total BAs in control (CTL) cells+bile, cells, and medium were approximately 3.4, 2.9, and 8.3-fold greater in human than in rat. The estimated intracellular concentrations of the measured total BAs were 64.3 ± 5.85 μM in CTL rat and 183 ± 55.6 μM in CTL human SCH, while medium concentrations of the total BAs measured were 1.16 ± 0.210 μM in CTL rat SCH and 9.61 ± 6.36 μM in CTL human SCH. Treatment of cells for 24 h with 10 μM troglitazone (TRO), an inhibitor of the bile salt export pump (BSEP) and the Na+-taurocholate cotransporting polypeptide (NTCP), had no significant effect on endogenous BAs measured at the end of the 24-h culture period, potentially due to compensatory mechanisms that maintain BA homeostasis. These data demonstrate that BAs in SCH are similar to in vivo, and that SCH may be a useful in vitro model to study alterations in BA disposition if species differences are taken into account. PMID:22342602

  1. Short communication: Improving the activity of bile salt hydrolases in Lactobacillus casei based on in silico molecular docking and heterologous expression.

    PubMed

    Xiong, Zhi-Qiang; Wang, Qiao-Hui; Kong, Ling-Hui; Song, Xin; Wang, Guang-Qiang; Xia, Yong-Jun; Zhang, Hui; Sun, Yong; Ai, Lian-Zhong

    2017-02-01

    Bile salt hydrolase (BSH) plays an essential role in the cholesterol-removing effect of lactic acid bacteria, which hydrolyze conjugated bile salts to amino acid and deconjugated bile salts. However, Lactobacillus casei lacks the bsh gene, which may make it highly sensitive to bile salt stress. We wanted to improve the BSH activity of L. casei for various food-industry applications (e.g., milk fermentation). Plate assay testing indicated that Lactobacillus plantarum AR113 has the highest BSH activity. We cloned and sequenced 4 bsh genes from the genome of L. plantarum AR113. Structure modeling and molecular docking of BSH indicated that BSH1 and BSH3 could react efficiently with bile salts, so we selected BSH1 and BSH3 for heterologous expression in L. casei. Compared with single expression of BSH1 or BSH3, co-expression of both protein sequences showed the highest hydrolysis activity by HPLC analysis. Our results suggested that heterologous expression of BSH in L. casei can significantly improve host activity against bile salts, and in silico molecular docking could be an efficient method of rapid screening for BSH with high activity.

  2. Fasting levels of monoketonic bile acids in human peripheral and portal circulation.

    PubMed

    Björkhem, I; Angelin, B; Einarsson, K; Ewerth, S

    1982-09-01

    It has been suggested that large amounts of ketonic bile acids may be present in portal venous blood. We have therefore determined the approximate concentration of 3-oxo-, 7-oxo-, and 12-oxo-bile acids (monoketonic bile acids) in human peripheral and portal circulation. These compounds were converted into the corresponding 3alpha-, 7alpha-, and 12alpha-hydroxy bile acids by treatment with sodium borodeuteride, thus increasing the molecular weight of each bile acid formed by one mass unit. The ratio between deuterated and nondeuterated bile acid was determined by combined gas-liquid chromatography-mass spectrometry with use of selected ion monitoring. From the ratio obtained and from the concentration of unlabeled bile acid, determined by isotope dilution-mass spectrometry, the approximate concentration of the different ketonic bile acids could be calculated. This method underestimates 3-oxygenated bile acids by 4-8%, 7-oxygenated bile acids by 2-3%, and 12-oxygenated bile acids by about 25%. The approximate concentration of monoketonic 3,7-oxygenated bile acids was found to be 0.08 +/- 0.02 and 0.37 +/- 0.25 micro mol/l in the peripheral venous serum and the portal venous serum, respectively. The approximate concentration of monoketonic 3,12-oxygenated bile acids was found to be 0.07 +/- 0.02 and 0.32 +/- 0.12 micro mol/l in the peripheral venous serum and the portal venous serum, respectively. The approximate concentration of monoketonic 3,7,12-oxygenated bile acids was found to be 0.03 +/- 0.01 and 0.14 +/- 0.05 micro mol/l in the peripheral venous serum and in the portal venous serum, respectively. The total concentration of the ketonic bile acids constituted only 9 +/- 1% and 8 +/- 3% of the nonoxidized bile acids in the peripheral venous serum and in the portal venous serum, respectively. Thus it seems less likely that the portal inflow of ketonic bile acids is of significant physiological importance under normal conditions.-Björkhem, I., B. Angelin, K

  3. A bile salt-resistant derivative of Bifidobacterium animalis has an altered fermentation pattern when grown on glucose and maltose.

    PubMed

    Ruas-Madiedo, Patricia; Hernández-Barranco, Ana; Margolles, Abelardo; de los Reyes-Gavilán, Clara G

    2005-11-01

    The growth of Bifidobacterium animalis subsp. lactis IPLA 4549 and its derivative with acquired resistance to bile, B. animalis subsp. lactis 4549dOx, was evaluated in batch cultures with glucose or the glucose disaccharide maltose as the main carbon source. The acquisition of bile salt resistance caused a change in growth pattern for both sugars, which mainly resulted in a preferential use of maltose compared to glucose, whereas the mother strain used both carbohydrates in a similar way. High-performance liquid chromatography and gas chromatography-mass spectrometry analyses were performed to determine the amounts of glucose consumption and organic acid and ethanol formation from glucose by buffered resting cells taken at different points during growth. Resting cells of the bile-adapted strain generally consumed less glucose than those of the nonadapted one but showed an enhanced production of ethanol and higher acetic acid-to-lactic acid as well as formic acid-to-lactic acid ratios. These findings suggest a shift in the catabolism of carbohydrates promoted by the acquisition of bile resistance that may cause changes in the redox potential and improvements in the cellular ATP yield.

  4. Bilirubin conjugates of human bile. Isolation of phenylazo derivatives of bile bilirubin

    PubMed Central

    Kuenzle, Clive C.

    1970-01-01

    A method is presented that allows the isolation of eight different phenylazo derivatives of bile bilirubin. In step I of the isolation procedure, three bilirubin fractions (bilirubin fractions 1, 2 and 3) from human hepatic bile are separated by reverse-phase partition chromatography on silicone-treated Celite with the use of a solvent system prepared from butan-1-ol and 5mm-phosphate buffer, pH6.0. Azo coupling is then performed with diazotized aniline. The three azo pigment mixtures are subjected to step II, in which the above chromatography system is used again. With each azo pigment mixture this step brings about the separation of a non-polar and a polar azo pigment fraction (azo 1A and azo 1B, azo 2A and azo 2B, and azo 3A and azo 3B from bilirubin fractions 1, 2 and 3 respectively). Approximately equal amounts of non-polar and polar pigments are obtained from bilirubin fractions 1 and 2, whereas bilirubin fraction 3 yields azo 3B almost exclusively. In step IIIA the non-polar azo pigment fractions are fractionated further by adsorption chromatography on anhydrous sodium sulphate with the use of chloroform followed by a gradient of ethyl acetate in chloroform. Three azo pigments are thus obtained from both azo 2A (azo 2A1, azo 2A2 and azo 2A3) and azo 3A (azo 3A1, azo 3A2 and azo 3A3). The 2A pigments occur in approximately the following proportions: azo 2A1, 90%; azo 2A2, 10%; azo 2A3, traces. The pigments are purified by crystallization, except for the A3 pigments, which are probably degradation products arising from the corresponding A2 pigments. In step IIIB the polar azo pigment fractions are subjected to reverse-phase partition chromatography on silicone-treated Celite with the use of a solvent system prepared from octan-1-ol–di-isopropyl ether–ethyl acetate–methanol–0.2m-acetic acid (1:2:2:3:4, by vol.). Azo pigment fractions 2B and 3B each yield six azo pigments (azo 2B1 to azo 2B6 and azo 3B1 to azo 3B6 respectively) together with small

  5. Expression of truncated bile salt-dependent lipase variant in pancreatic pre-neoplastic lesions

    PubMed Central

    Martinez, Emmanuelle; Crenon, Isabelle; Silvy, Françoise; Del Grande, Jean; Mougel, Alice; Barea, Dolores; Fina, Frederic; Bernard, Jean-Paul; Ouaissi, Mehdi; Lombardo, Dominique; Mas, Eric

    2017-01-01

    Pancreatic adenocarcinoma (PDAC) is a dismal disease. The lack of specific symptoms still leads to a delay in diagnosis followed by death within months for most patients. Exon 11 of the bile salt-dependent lipase (BSDL) gene encoding variable number of tandem repeated (VNTR) sequences has been involved in pancreatic pathologies. We hypothesized that BSDL VNTR sequences may be mutated in PDAC. The amplification of BSDL VNTR from RNA extracted from pancreatic SOJ-6 cells allowed us to identify a BSDL amplicon in which a cytosine residue is inserted in a VNTR sequence. This insertion gives rise to a premature stop codon, resulting in a truncated protein and to a modification of the C-terminal amino-acid sequence; that is PRAAHG instead of PAVIRF. We produced antibodies directed against these sequences and examined pancreatic tissues from patients with PDAC and PanIN. Albeit all tissues were positive to anti-PAVIRF antibodies, 72.2% of patient tissues gave positive reaction with anti-PRAAHG antibodies, particularly in dysplastic areas of the tumor. Neoplastic cells with ductal differentiation were not reactive to anti-PRAAHG antibodies. Some 70% of PanIN tissues were also reactive to anti-PRAAHG antibodies, suggesting that the C insertion occurs early during pancreatic carcinogenesis. Data suggest that anti-PRAAHG antibodies were uniquely reactive with a short isoform of BSDL specifically expressed in pre-neoplastic lesions of the pancreas. The detection of truncated BSDL reactive to antibodies against the PRAAHG C-terminal sequence in pancreatic juice or in pancreatic biopsies may be a new tool in the early diagnosis of PDAC. PMID:27602750

  6. Encapsulation of adenoviral vectors into chitosan-bile salt microparticles for mucosal vaccination.

    PubMed

    Lameiro, Maria Helena; Malpique, Rita; Silva, Ana Carina; Alves, Paula M; Melo, Eurico

    2006-11-01

    The objective of this study is the incorporation of adenoviral vectors into a microparticulate system adequate for mucosal delivery. Microencapsulation of the vectors was accomplished by ionotropic coacervation of chitosan, using bile salts as counter-anion. The process was optimized in order to promote high encapsulation efficiency, with a minimal loss of viral infectivity. The maintenance of sterility during all the encapsulation procedure was also taken into account. The principle relies on the simple addition of a solution containing adenoviral vectors to a solution of neutralized chitosan, under stirring. Some surfactants were added to the chitosan solution, to improve the efficiency of this process, such as Tween 80, and Pluronic F68 at 1% (w/v). Encapsulation efficiency higher than 84% was achieved with formulations containing sodium deoxycholate as counter-anion and Pluronic F68 as dispersant agent. The infectivity of the adenoviral vectors incorporated into microparticles was assessed by release assays in PBS and by direct inoculation in 293 and Caco-2 cells. The release in aqueous media was negligible but, when in contact with monolayers of the cells, an effective release of bioactive adenovirus was obtained. Our work shows that encapsulation in microparticles, not only appear to protect the adenovirus from the external medium, namely from low pH, but can also delay their release that is fully dependent on cell contact, an advantage for mucosal vaccination purposes. The formulations developed are able to maintain AdV infectivity and permit a delayed release of the bioactives that is promoted by digestion in situ of the microparticles by the cell monolayers. The onset of delivery is, that way, host-controlled. In view of these results, these formulations showed good properties for mucosal adenovirus delivery.

  7. Discovery of Bile Salt Hydrolase Inhibitors Using an Efficient High-Throughput Screening System

    PubMed Central

    Smith, Katie; Zeng, Ximin; Lin, Jun

    2014-01-01

    The global trend of restricting the use of antibiotic growth promoters (AGP) in animal production necessitates the need to develop valid alternatives to maintain productivity and sustainability of food animals. Previous studies suggest inhibition of bile salt hydrolase (BSH), an intestinal bacteria-produced enzyme that exerts negative impact on host fat digestion and utilization, is a promising approach to promote animal growth performance. To achieve the long term goal of developing novel alternatives to AGPs, in this study, a rapid and convenient high-throughput screening (HTS) system was developed and successfully used for identification of BSH inhibitors. With the aid of a high-purity BSH from a chicken Lactobacillus salivarius strain, we optimized various screening conditions (e.g. BSH concentration, reaction buffer pH, incubation temperature and length, substrate type and concentration) and establish a precipitation-based screening approach to identify BSH inhibitors using 96-well or 384-well microplates. A pilot HTS was performed using a small compound library comprised of 2,240 biologically active and structurally diverse compounds. Among the 107 hits, several promising and potent BSH inhibitors (e.g. riboflavin and phenethyl caffeate) were selected and validated by standard BSH activity assay. Interestingly, the HTS also identified a panel of antibiotics as BSH inhibitor; in particular, various tetracycline antibiotics and roxarsone, the widely used AGP, have been demonstrated to display potent inhibitory effect on BSH. Together, this study developed an efficient HTS system and identified several BSH inhibitors with potential as alternatives to AGP. In addition, the findings from this study also suggest a new mode of action of AGP for promoting animal growth. PMID:24454844

  8. Discovery of bile salt hydrolase inhibitors using an efficient high-throughput screening system.

    PubMed

    Smith, Katie; Zeng, Ximin; Lin, Jun

    2014-01-01

    The global trend of restricting the use of antibiotic growth promoters (AGP) in animal production necessitates the need to develop valid alternatives to maintain productivity and sustainability of food animals. Previous studies suggest inhibition of bile salt hydrolase (BSH), an intestinal bacteria-produced enzyme that exerts negative impact on host fat digestion and utilization, is a promising approach to promote animal growth performance. To achieve the long term goal of developing novel alternatives to AGPs, in this study, a rapid and convenient high-throughput screening (HTS) system was developed and successfully used for identification of BSH inhibitors. With the aid of a high-purity BSH from a chicken Lactobacillus salivarius strain, we optimized various screening conditions (e.g. BSH concentration, reaction buffer pH, incubation temperature and length, substrate type and concentration) and establish a precipitation-based screening approach to identify BSH inhibitors using 96-well or 384-well microplates. A pilot HTS was performed using a small compound library comprised of 2,240 biologically active and structurally diverse compounds. Among the 107 hits, several promising and potent BSH inhibitors (e.g. riboflavin and phenethyl caffeate) were selected and validated by standard BSH activity assay. Interestingly, the HTS also identified a panel of antibiotics as BSH inhibitor; in particular, various tetracycline antibiotics and roxarsone, the widely used AGP, have been demonstrated to display potent inhibitory effect on BSH. Together, this study developed an efficient HTS system and identified several BSH inhibitors with potential as alternatives to AGP. In addition, the findings from this study also suggest a new mode of action of AGP for promoting animal growth.

  9. The human microbiome and bile acid metabolism: dysbiosis, dysmetabolism, disease and intervention.

    PubMed

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

    2014-04-01

    Recent evidence indicates that the human gut microbiome plays a significant role in health and disease. Dysbiosis, defined as a pathological imbalance in a microbial community, is becoming increasingly appreciated as a 'central environmental factor' that is both associated with complex phenotypes and affected by host genetics, diet and antibiotic use. More recently, a link has been established between the dysmetabolism of bile acids (BAs) in the gut to dysbiosis. BAs, which are transformed by the gut microbiota, have been shown to regulate intestinal homeostasis and are recognized as signaling molecules in a wide range of metabolic processes. This review will examine the connection between BA metabolism as it relates to the gut microbiome and its implication in health and disease. A disrupted gut microbiome, including a reduction of bile salt hydrolase (BSH)-active bacteria, can significantly impair the metabolism of BAs and may result in an inability to maintain glucose homeostasis as well as normal cholesterol breakdown and excretion. To better understand the link between dysbiosis, BA dysmetabolism and chronic degenerative disease, large-scale metagenomic sequencing studies, metatranscriptomics, metaproteomics and metabolomics should continue to catalog functional diversity in the gastrointestinal tract of both healthy and diseased populations. Further, BSH-active probiotics should continue to be explored as treatment options to help restore metabolic levels.

  10. Favorable effect of 4-phenylacetate on liver functions attributable to enhanced bile salt export pump expression in ornithine transcarbamylase-deficient children.

    PubMed

    Nagasaka, Hironori; Yorifuji, Tohru; Kobayashi, Kunihiko; Takikawa, Hajime; Komatsu, Haruki; Inui, Ayano; Fujisawa, Tomoo; Miida, Takashi; Tsukahara, Hirokazu; Takatani, Tomozumi; Hayashi, Hisamitsu

    2010-06-01

    4-Phenylbutyrate (4-PB) acting against hyperammonemia has been administered to patients with urea cycle defects. Results of our recent experiments using animals and cultured cells strongly suggest that this agent enhances the function of bile salt export pump/ATP binding cassette B11 (BSEP/ABCB11) promoting bile acid excretion from hepatocytes to bile canaliculi, although it has not been confirmed in humans. Considering that 4-PB is converted easily into 4-phenylacetate (4-PA) in the liver, such an effect of 4-PB might occur through 4-PA. We performed retrospective analyzes of the effects of 4-PA on the liver functions of three ornithine transcarbamylase (OTC)-deficient female children receiving 4-PA. Two of the three received intravenous administration of 4-PA only at episodic periods of hyperammonemia; the remaining one received it orally at intercurrent periods. Soon after 4-PA administration, the serum total bile acid level was decreased to one-half or one-third of pre-treatment levels, but it returned to the basal levels within one month after 4-PA discontinuation. Other serum parameters for cholestasis such as gamma-glutamyl transferase also decreased markedly. Concomitantly, alanine aminotransferase and aspartate amino transferase levels decreased significantly. Western blot analyzes of the liver samples revealed that the 4-PA administration enhanced BSEP/ABCB11 protein expressions in the membranous fraction of liver cells, although the liver BSEP/ABCB11 messenger RNA level remained unchanged. These results suggest that 4-PA enhanced liver BSEP/ABCB11 function and thereby improved liver functions in OTC-deficient children. For treatment of liver disorders requiring enhancement of BSEP function, 4-PA might be a candidate.

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

    PubMed

    Stieger, Bruno; Geier, Andreas

    2011-04-01

    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. This article provides an introduction into the physiology of bile formation followed by a summary of the current knowledge on the key bile salt transporters, namely, the sodium-taurocholate co-transporting polypeptide NTCP, the organic anion transporting polypeptides (OATPs), BSEP and the multi-drug resistance protein 3. The pathophysiologic consequences of altered functions of these transporters, with an emphasis on molecular and genetic aspects, are then discussed. Knowledge of the role of hepatocellullar transporters, especially BSEP, in acquired cholestasis is continuously increasing. A common variant of BSEP (p.V444A) is now a well-established susceptibility factor for acquired cholestasis and recent evidence suggests that the same variant also influences the therapeutic response and disease progression of viral hepatitis C. Studies in large independent cohorts are now needed to confirm the relevance of p.V444A. Genome-wide association studies should lead to the identification of additional genetic factors underlying cholestatic liver disease.

  12. Interaction of Bile Salts with β-Cyclodextrins Reveals Nonclassical Hydrophobic Effect and Enthalpy-Entropy Compensation.

    PubMed

    Paul, Bijan K; Ghosh, Narayani; Mukherjee, Saptarshi

    2016-04-28

    Herein, we present an endeavor toward exploring the lacuna underlying the host:guest chemistry of inclusion complex formation between bile salt(s) and β-cyclodextrin(s) (βCDs). An extensive thermodynamic investigation based on isothermal titration calorimetry (ITC) demonstrates a dominant contribution from exothermic enthalpy change (ΔH < 0) accompanying the phenomenon of inclusion complex formation, along with a relatively smaller contribution to total free energy change from the entropic component. However, the negative heat capacity change (ΔCp < 0) displays the hallmark for a pivotal role of hydrophobic effect underlying the interaction. Contrary to the classical hydrophobic effect, such apparently paradoxical thermodynamic signature has been adequately described under the notion of "nonclassical hydrophobic effect". On the basis of our results, the displacement of disordered water from hydrophobic binding sites has been argued to mark the enthalpic signature and the key role of such interaction forces is further corroborated from enthalpy-entropy compensation behavior showing indication for almost complete compensation. To this end, we have quantified the interaction of two bile salt molecules (namely, sodium deoxycholate and sodium glycocholate) with a series of varying chemical substituents on the host counterpart, namely, βCD, (2-hydroxypropyl)-βCD, and methyl βCD.

  13. Identification and characterization of a bile salt hydrolase from Lactobacillus salivarius for development of novel alternatives to antibiotic growth promoters.

    PubMed

    Wang, Zhong; Zeng, Ximin; Mo, Yiming; Smith, Katie; Guo, Yuming; Lin, Jun

    2012-12-01

    Antibiotic growth promoters (AGPs) have been used as feed additives to improve average body weight gain and feed efficiency in food animals for more than 5 decades. However, there is a worldwide trend to limit AGP use to protect food safety and public health, which raises an urgent need to discover effective alternatives to AGPs. The growth-promoting effect of AGPs has been shown to be highly correlated with the decreased activity of intestinal bile salt hydrolase (BSH), an enzyme that is produced by various gut microflora and involved in host lipid metabolism. Thus, BSH inhibitors are likely promising feed additives to AGPs to improve animal growth performance. In this study, the genome of Lactobacillus salivarius NRRL B-30514, a BSH-producing strain isolated from chicken, was sequenced by a 454 GS FLX sequencer. A BSH gene identified by genome analysis was cloned and expressed in an Escherichia coli expression system for enzymatic analyses. The BSH displayed efficient hydrolysis activity for both glycoconjugated and tauroconjugated bile salts, with slightly higher catalytic efficiencies (k(cat)/K(m)) on glycoconjugated bile salts. The optimal pH and temperature for the BSH activity were 5.5 and 41°C, respectively. Examination of a panel of dietary compounds using the purified BSH identified some potent BSH inhibitors, in which copper and zinc have been recently demonstrated to promote feed digestion and body weight gain in different food animals. In sum, this study identified and characterized a BSH with broad substrate specificity from a chicken L. salivarius strain and established a solid platform for us to discover novel BSH inhibitors, the promising feed additives to replace AGPs for enhancing the productivity and sustainability of food animals.

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

    PubMed

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

    2016-08-05

    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

  15. Effect of jaundiced sera and bile salts on cultured beating rat heart cells

    SciTech Connect

    Bogin, E.; Better, O.; Harary, I.

    1980-01-01

    Jaundiced serum, from common bile duct ligated rats, added to cultured heart cells decreased the beating rate and caused an early cessation of beating. Similarly it produced higher levels of lactate in the media. Deoxychloic acid but not cholic acid which are the main bile acids in jaundiced serum caused similar effects, thus suggesting that deoxychloic acid is the toxic substance responsible for heart function alterations seen in severe jaundiced patients.

  16. Influence of bile salt on vitamin E derived vesicles involving a surface active ionic liquid and conventional cationic micelle.

    PubMed

    Roy, Arpita; Kundu, Sangita; Dutta, Rupam; Sarkar, Nilmoni

    2017-09-01

    This study has been actually performed with the aim to develop vitamin E derived vesicles individually from a surface active ionic liquid (1-Hexadecyl-3-Methylimidazolium chloride ([C16mim]Cl)) and a common cationic amphiphile (benzyldimethylhexadecylammonium chloride (BHDC)) and also to investigate their consequent breakdown in presence of bile salt molecule. From this study, it is revealed that the rotational motion of coumarin 153 (C153) molecule is hindered as the vitamin E content is increased in the individual micellar solution of [C16mim]Cl and BHDC. The extent of enhancement in rotational relaxation time is more pronounced in case of [C16mim]Cl-vitamin E solutions than in the BHDC-vitamin E vesicular aggregates which confirms the greater rigidity of the former vesicular system than the later one. Moreover, the effect of bile salt in the vitamin E forming vesicular assemblies have also been unravelled. It is found that the large area occupancy by the steroidal backbone of the bile salt plays a crucial role towards the enlargement of the average surfactant head group area. This results in disintegration of the vesicles composed of vitamin E and consequently, vesicles are transformed into mixed micellar aggregates. From the anisotropy measurement it is found that the rotational motion of C153 is more hindered in the [C16mim]Cl/BHDC-NaCh mixed micelles compared to that inside the individual vesicles. The fluorescence correlation spectroscopic (FCS) study also confirms that the mixed micelles have a more compact structure than that of the [C16mim]Cl-vitamin E and BHDC-vitamin E vesicles. Altogether, the micelle to vesicle transition involving any vitamin and their disruption by bile salt would be an interesting investigation both from the view point of basic colloidal chemistry and towards the generation of new drug delivery vehicle due to their unique microenvironment. Therefore, in future, these systems can be utilised as vehicle for the transport and as well

  17. IS30-related transposon mediated insertional inactivation of bile salt hydrolase (bsh1) gene of Lactobacillus plantarum strain Lp20.

    PubMed

    Kumar, Rajesh; Grover, Sunita; Kaushik, Jai K; Batish, Virender Kumar

    2014-01-01

    Lactobacillus plantarum is a flexible and versatile microorganism that inhabits a variety of niches, and its genome may express up to four bsh genes to maximize its survival in the mammalian gut. However, the ecological significance of multiple bsh genes in L. plantarum is still not clearly understood. Hence, this study demonstrated the disruption of bile salt hydrolase (bsh1) gene due to the insertion of a transposable element in L. plantarum Lp20 - a wild strain of human fecal origin. Surprisingly, L. plantarum strain Lp20 produced a ∼2.0 kb bsh1 amplicon against the normal size (∼1.0 kb) bsh1 amplicon of Bsh(+)L. plantarum Lp21. Strain Lp20 exhibited minimal Bsh activity in spite of having intact bsh2, bsh3 and bsh4 genes in its genome and hence had a Bsh(-) phenotype. Cloning and sequence characterization of Lp20 bsh1 gene predicted four individual open reading frames (ORFs) within this region. BLAST analysis of ORF1 and ORF2 revealed significant sequence similarity to the L. plantarum bsh1 gene while ORF3 and ORF4 showed high sequence homology to IS30-family transposases. Since, IS30-related transposon element was inserted within Lp20 bsh1 gene in reverse orientation (3'-5'), it introduced several stop codons and disrupted the protein reading frames of both Bsh1 and transposase. Inverted terminal repeats (GGCAGATTG) of transposon, mediated its insertion at 255-263 nt and 1301-1309 nt positions of Lp20 bsh1 gene. In conclusion, insertion of IS30 related-transposon within the bsh1 gene sequence of L. plantarum strain Lp20 demolished the integrity and functionality of Bsh1 enzyme. Additionally, this transposon DNA sequence remains active among various Lactobacillus spp. and hence harbors the potential to be explored in the development of efficient insertion mutagenesis system.

  18. Oral immunization against hepatitis B using bile salt stabilized vesicles (bilosomes).

    PubMed

    Shukla, Anshuman; Khatri, Kapil; Gupta, Prem N; Goyal, Amit K; Mehta, Abhinav; Vyas, Suresh P

    2008-01-01

    Most of the presently available vaccines including hepatitis B vaccines administered through parenteral route, fail to induce a mucosal antibody response. Therefore, oral immunization appears to be an effective and attractive alternative to parenteral immunization. However, the problem of degradation of antigen in the harsh and hostile environment of the gastrointestinal tract consequently requires larger doses and more frequent dosing of antigen. Furthermore, much larger doses can induce antigen tolerance. Therefore the purpose of the present study was firstly to overcome these problems by the use of bile salt stabilized vesicles (bilosomes) and HBsAg as the model antigen,which could provide both protection to the antigen as well as enable transmucosal uptake and subsequent immunization. Another purpose of this study was to determine the dose that could produce serum antibody titres against hepatitis B via the oral route compared to those following intramuscular immunization. In the present study bilosomes containing recombinant hepatitis B surface antigen were prepared by a lipid cast film method. HBsAg loaded bilosomeswere characterized in vitro for their shape, size, percent antigen entrapment and stability. Fluorescence microscopy was carried out to confirm the uptake of bilosomes by gut associated lymphoid tissues (GALT). The in vivo part of the study comprised estimation of anti-HBsAg IgG response in serum and anti-HBsAg sIgA in various body secretions using specific ELISA techniques following oral immunization with low dose loaded bilosomes (B1, 10 microg), intermediate dose loaded bilosomes (B2, 20 microg) and high dose loaded bilosomes (B3, 50 microg) in BALB/c mice. Fluorescence microscopy suggested that there was an increase in fluorescence intensity following the uptake of bilosomes entrapped FITC-BSA in gut associated lymphoid tissues. The high dose HBsAg bilosomes (B3, 50 microg) produced comparable anti-HBsAg IgG levels in serum to those observed in

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

    PubMed

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

    2016-05-14

    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

  20. Use of a simple enzymatic assay for cholesterol analysis in human bile.

    PubMed

    Fromm, H; Amin, P; Klein, H; Kupke, I

    1980-02-01

    An enzymatic technique for cholesterol analysis in serum was applied to human bile. The analytical yield was very satisfactory in experiments in which known amounts of cholesterol were added to untreated, as well as Millipore-filtered, samples of human bile. The analytical results of the enzymatic test agreed closely with those of a method utilizing the Liebermann-Burchard reaction. The enzymatic assay of cholesterol in bile proved to be sensitive and precise. In comparison to other methods of biliary cholesterol determination, it has the advantage of being rapid and simple.

  1. Enhanced bioavailability of the poorly water-soluble drug fenofibrate by using liposomes containing a bile salt.

    PubMed

    Chen, Yaping; Lu, Yi; Chen, Jianming; Lai, Jie; Sun, Jing; Hu, Fuqiang; Wu, Wei

    2009-07-06

    The main purpose of this study was to evaluate oral bioavailability of the poorly water-soluble drug fenofibrate when liposomes containing a bile salt were used as oral drug delivery systems. Liposomes composed of soybean phosphotidylcholine (SPC) and sodium deoxycholate (SDC) were prepared by a dry-film dispersing method coupled with sonication and homogenization. Several properties of the liposomes, including particle size, entrapment efficiency and membrane fluidity, were extensively characterized. In vitro release experiments indicated that no more than 20% of total fenofibrate was released from SPC/cholesterol (CL) and SPC/SDC liposomes at 2 h, in contrast with near complete release for micronized fenofibrate capsules. Strikingly, in vivo measurements of pharmacokinetics and bioavailability demonstrated higher rates of fenofibrate absorption from both SPC/SDC and SPC/CL liposomes than micronized fenofibrate. The bioavailability of SPC/SDC and SPC/CL liposomes was 5.13- and 3.28-fold higher, respectively, than that of the micronized fenofibrate. The disparity between oral bioavailability and in vitro release for liposomes strongly suggests alternative absorption mechanisms rather than enhanced release. Importantly, SPC/SDC liposomes exhibited a 1.57-fold increase in bioavailability relative to SPC/CL liposomes, indicating that liposomes containing bile salts may be used to enhance oral bioavailability of poorly water-soluble drugs.

  2. Importance of two Enterococcus faecium loci encoding Gls-like proteins for in vitro bile salts stress response and virulence.

    PubMed

    Choudhury, Tina; Singh, Kavindra V; Sillanpää, Jouko; Nallapareddy, Sreedhar R; Murray, Barbara E

    2011-04-15

    General stress proteins, Gls24 and GlsB, were previously shown to be involved in bile salts resistance of Enterococcus faecalis and in virulence. Here, we identified 2 gene clusters in Enterococcus faecium each encoding a homolog of Gls24 (Gls33 and Gls20; designated on the basis of their predicted sizes) and of GlsB (GlsB and GlsB1). The sequences of the gls33 and gls20 gene clusters from available genomes indicate distinct lineages, with those of hospital-associated CC17 isolates differing from non-CC17 by ∼7% and ∼3.5%, respectively. Deletion of an individual locus did not have a significant effect on virulence in a mouse peritonitis model, whereas a double-deletion mutant was highly attenuated (P<.004) versus wild-type. However, mutants lacking either gls33-glsB, gls20-glsB1, or both all exhibited increased sensitivity to bile salts. These results suggest that gls-encoded loci may be important for adaptation to the intestinal environment, in addition to being important for virulence functions.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25392597

  4. Interaction of a dietary fiber (pectin) with gastrointestinal components (bile salts, calcium, and lipase): a calorimetry, electrophoresis, and turbidity study.

    PubMed

    Espinal-Ruiz, Mauricio; Parada-Alfonso, Fabián; Restrepo-Sánchez, Luz-Patricia; Narváez-Cuenca, Carlos-Eduardo; McClements, David Julian

    2014-12-31

    An in vitro gastrointestinal model consisting of oral, gastric, and intestinal phases was used to elucidate the impact of pectin on the digestion of emulsified lipids. Pectin reduced the extent of lipid digestion, which was attributed to its binding interactions with specific gastrointestinal components. The interaction of pectin with bile salts, lipase, CaCl2, and NaCl was therefore investigated by turbidity, microstructure, electrophoresis, and isothermal titration calorimetry (ITC) at pH 7.0 and 37 °C. ITC showed that the interaction of pectin was endothermic with bile salts, but exothermic with CaCl2, NaCl, and lipase. Electrophoresis, microstructure, and turbidity measurements showed that anionic pectin formed electrostatic complexes with calcium ions, which may have decreased lipid digestion due to increased lipid flocculation or microgel formation because this would reduce the surface area of lipid exposed to the lipase. This research provides valuable insights into the physicochemical and molecular mechanisms of the interaction of pectin with gastrointestinal components that may affect the rate and extent of lipid digestion.

  5. Molecular Mechanism of Taurocholate Transport by the Bile Salt Export Pump, an ABC Transporter Associated with Intrahepatic Cholestasis.

    PubMed

    Sohail, Muhammad Imran; Schmid, Diethart; Wlcek, Katrin; Spork, Matthias; Szakács, Gergely; Trauner, Michael; Stockner, Thomas; Chiba, Peter

    2017-10-01

    The bile salt export pump (BSEP/ABCB11) transports bile salts from hepatocytes into bile canaliculi. Its malfunction is associated with severe liver disease. One reason for functional impairment of BSEP is systemic administration of drugs, which as a side effect inhibit the transporter. Therefore, drug candidates are routinely screened for potential interaction with this transporter. Hence, understanding the functional biology of BSEP is of key importance. In this study, we engineered the transporter to dissect interdomain communication paths. We introduced mutations in noncanonical and in conserved residues of either of the two nucleotide binding domains and determined the effect on BSEP basal and substrate-stimulated ATPase activity as well as on taurocholate transport. Replacement of the noncanonical methionine residue M584 (Walker B sequence of nucleotide binding site 1) by glutamate imparted hydrolysis competency to this site. Importantly, this mutation was able to sustain 15% of wild-type transport activity, when the catalytic glutamate of the canonical nucleotide binding site 2 was mutated to glutamine. Kinetic modeling of experimental results for the ensuing M584E/E1244Q mutant suggests that a transfer of hydrolytic capacity from the canonical to the noncanonical nucleotide binding site results in loss of active and adoption of facilitative characteristics. This facilitative transport is ATP-gated. To the best of our knowledge, this result is unprecedented in ATP-binding cassette proteins with one noncanonical nucleotide binding site. Our study promotes an understanding of the domain interplay in BSEP as a basis for exploration of drug interactions with this transporter. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  6. Generation of a bile salt export pump deficiency model using patient-specific induced pluripotent stem cell-derived hepatocyte-like cells

    PubMed Central

    Imagawa, Kazuo; Takayama, Kazuo; Isoyama, Shigemi; Tanikawa, Ken; Shinkai, Masato; Harada, Kazuo; Tachibana, Masashi; Sakurai, Fuminori; Noguchi, Emiko; Hirata, Kazumasa; Kage, Masayoshi; Kawabata, Kenji; Sumazaki, Ryo; Mizuguchi, Hiroyuki

    2017-01-01

    Bile salt export pump (BSEP) plays an important role in hepatic secretion of bile acids and its deficiency results in severe cholestasis and liver failure. Mutation of the ABCB11 gene encoding BSEP induces BSEP deficiency and progressive familial intrahepatic cholestasis type 2 (PFIC2). Because liver transplantation remains standard treatment for PFIC2, the development of a novel therapeutic option is desired. However, a well reproducible model, which is essential for the new drug development for PFIC2, has not been established. Therefore, we attempted to establish a PFIC2 model by using iPSC technology. Human iPSCs were generated from patients with BSEP-deficiency (BD-iPSC), and were differentiated into hepatocyte-like cells (HLCs). In the BD-iPSC derived HLCs (BD-HLCs), BSEP was not expressed on the cell surface and the biliary excretion capacity was significantly impaired. We also identified a novel mutation in the 5′-untranslated region of the ABCB11 gene that led to aberrant RNA splicing in BD-HLCs. Furthermore, to evaluate the drug efficacy, BD-HLCs were treated with 4-phenylbutyrate (4PBA). The membrane BSEP expression level and the biliary excretion capacity in BD-HLCs were rescued by 4PBA treatment. In summary, we succeeded in establishing a PFIC2 model, which may be useful for its pathophysiological analysis and drug development. PMID:28150711

  7. Generation of a bile salt export pump deficiency model using patient-specific induced pluripotent stem cell-derived hepatocyte-like cells.

    PubMed

    Imagawa, Kazuo; Takayama, Kazuo; Isoyama, Shigemi; Tanikawa, Ken; Shinkai, Masato; Harada, Kazuo; Tachibana, Masashi; Sakurai, Fuminori; Noguchi, Emiko; Hirata, Kazumasa; Kage, Masayoshi; Kawabata, Kenji; Sumazaki, Ryo; Mizuguchi, Hiroyuki

    2017-02-02

    Bile salt export pump (BSEP) plays an important role in hepatic secretion of bile acids and its deficiency results in severe cholestasis and liver failure. Mutation of the ABCB11 gene encoding BSEP induces BSEP deficiency and progressive familial intrahepatic cholestasis type 2 (PFIC2). Because liver transplantation remains standard treatment for PFIC2, the development of a novel therapeutic option is desired. However, a well reproducible model, which is essential for the new drug development for PFIC2, has not been established. Therefore, we attempted to establish a PFIC2 model by using iPSC technology. Human iPSCs were generated from patients with BSEP-deficiency (BD-iPSC), and were differentiated into hepatocyte-like cells (HLCs). In the BD-iPSC derived HLCs (BD-HLCs), BSEP was not expressed on the cell surface and the biliary excretion capacity was significantly impaired. We also identified a novel mutation in the 5'-untranslated region of the ABCB11 gene that led to aberrant RNA splicing in BD-HLCs. Furthermore, to evaluate the drug efficacy, BD-HLCs were treated with 4-phenylbutyrate (4PBA). The membrane BSEP expression level and the biliary excretion capacity in BD-HLCs were rescued by 4PBA treatment. In summary, we succeeded in establishing a PFIC2 model, which may be useful for its pathophysiological analysis and drug development.

  8. Characterization of a small vesicular cholesterol carrier in human gallbladder bile.

    PubMed Central

    Ahrendt, S A; Fox-Talbot, M K; Kaufman, H S; Lillemoe, K D; Lipsett, P A; Pitt, H A

    1994-01-01

    OBJECTIVE: Cholesterol phospholipid vesicles play an important role in the nucleation of cholesterol in bile. Recent studies have identified an additional vesicle population in human bile. In this study, the role of these small vesicles as cholesterol carriers was examined. METHODS: Gallbladder bile was obtained from 60 patients at cholecystectomy. Large vesicles, small vesicles, lamellae, and mixed micelles were separated using gel filtration chromatography. RESULTS: Small vesicles were present in bile from the majority of patients both with and without cholesterol gallstones, whereas the void volume vesicle fraction was found almost exclusively in bile from patients with cholesterol gallstones. Both large vesicular and small vesicular cholesterol increased as total bile cholesterol concentration increased; however, the cholesterol-phospholipid ratio in the large vesicle fraction from patients with cholesterol stones was significantly greater than the ratio in small vesicles (1.6 +/- 0.3 vs. 1.0 < or = 0.1, p < 0.05). Whole bile cholesterol crystal appearance time was correlated significantly with the percentage of cholesterol transported by large vesicles (r = 0.63, p < 0.001) but not with the percentage of cholesterol present in small vesicles. Finally, large vesicles isolated by gel filtration chromatography formed cholesterol crystals faster than small vesicles (5.3 +/- 2 vs. 17.4 +/- 4 days, p < 0.01). CONCLUSIONS: These data suggest that a heterogenous population of vesicles is present in human gallbladder bile. As bile becomes saturated with cholesterol, it increasingly is solubilized by both small and large vesicles. The small vesicles have relatively less cholesterol and are more stable than the larger variety, from which cholesterol is most likely to precipitate. Images Figure 2. PMID:7979611

  9. Enhancement by sodium chloride of the selectivity of thiosulfate citrate bile salts sucrose agar for isolating Vibrio cholerae biotype El Tor.

    PubMed Central

    Morris, G K; DeWitt, W E; Gangarosa, E J; McCormack, W M

    1976-01-01

    In this study we utilized the salt-tolerant characteristics of vibrios to develop a more selective medium by addition of NaCl to thiosulfate citrate bile salts sucrose (TCBS) agar. The effect of adding salt to TCBS agar varied greatly among brands of TCBS agar and between lots of the same brand. The addition of salt at concentrations as high as 1.5% (2.5% total NaCl) caused the inhibition of growth of three species of commonly encountered normal bowel flora and one strain of classical Vibrio cholerae but did not compromise the use of TCBS agar for isolation of V. cholerae biotype El Tor. PMID:965476

  10. Adsorption of bile acid by chitosan salts prepared with cinnamic acid and analogue compounds.

    PubMed

    Murata, Yoshifumi; Nagaki, Kumiko; Kofuji, Kyouko; Sanae, Fujiko; Kontani, Hitoshi; Kawashima, Susumu

    2006-01-01

    A chitosan (CS) powder treated with cinnamic acid and an analogue compound (CN) was prepared as CS-CN. Using it, bile acid adsorption by CS-CN and the release of CN were investigated in vitro. When CS-CN was soaked in a taurocholate solution, it released CN and simultaneously adsorbed the bile acid. For CS-CN prepared with cinnamic acid, the amount of CN released was 0.286 +/- 0.001 mmol/g CS-CN; the amount of taurocholate adsorbed was 0.284 +/- 0.003 mmol/g CS-CN. These two functions were recognized on alginate or pectin gel beads containing CS-CN. The amount of released CN was altered extensively by the species of CN used for gel-bead preparation. Results suggest that CS-CN is a candidate for complementary medicine to prevent lifestyle-related diseases.

  11. The Vibrio cholerae Mrp system: cation/proton antiport properties and enhancement of bile salt resistance in a heterologous host.

    PubMed

    Dzioba-Winogrodzki, Judith; Winogrodzki, Olga; Krulwich, Terry A; Boin, Markus A; Häse, Claudia C; Dibrov, Pavel

    2009-01-01

    The mrp operon from Vibrio cholerae encoding a putative multisubunit Na(+)/H(+) antiporter was cloned and functionally expressed in the antiporter-deficient strain of Escherichia coli EP432. Cells of EP432 expressing Vc-Mrp exhibited resistance to Na(+) and Li(+) as well as to natural bile salts such as sodium cholate and taurocholate. When assayed in everted membrane vesicles of the E. coli EP432 host, Vc-Mrp had sufficiently high antiport activity to facilitate the first extensive analysis of Mrp system from a Gram-negative bacterium encoded by a group 2 mrp operon. Vc-Mrp was found to exchange protons for Li(+), Na(+), and K(+) ions in pH-dependent manner with maximal activity at pH 9.0-9.5. Exchange was electrogenic (more than one H(+) translocated per cation moved in opposite direction). The apparent K(m) at pH 9.0 was 1.08, 1.30, and 68.5 mM for Li(+), Na(+), and K(+), respectively. Kinetic analyses suggested that Vc-Mrp operates in a binding exchange mode with all cations and protons competing for binding to the antiporter. The robust ion antiport activity of Vc-Mrp in sub-bacterial vesicles and its effect on bile resistance of the heterologous host make Vc-Mrp an attractive experimental model for the further studies of biochemistry and physiology of Mrp systems.

  12. Bipolar and Related Disorders Induced by Sodium 4-Phenylbutyrate in a Male Adolescent with Bile Salt Export Pump Deficiency Disease

    PubMed Central

    Simonetti, Giulia; Pirillo, Martina; Taruschio, Gianfranco; Andreone, Pietro

    2016-01-01

    Bile Salt Export Pump (BSEP) Deficiency disease, including Progressive Familial Intrahepatic Cholestasis type 2 (PFIC2), is a rare disease, usually leading within the first ten years to portal hypertension, liver failure, hepatocellular carcinoma. Often liver transplantation is needed. Sodium 4-phenylbutyrate (4-PB) seems to be a potential therapeutic compound for PFIC2. Psychiatric side effects in the adolescent population are little known and little studied since the drug used to treat children and infants. So we described a case of Caucasian boy, suffering from a late onset PFIC2, listed for a liver transplant when he was sixteen and treated with 4-FB (200 mg per kilogram of body weight per day). The drug was discontinued for the onset of bipolar and related disorders. This case illustrates possible psychiatric side effects of the drug. PMID:27757140

  13. Bipolar and Related Disorders Induced by Sodium 4-Phenylbutyrate in a Male Adolescent with Bile Salt Export Pump Deficiency Disease.

    PubMed

    Vitale, Giovanni; Simonetti, Giulia; Pirillo, Martina; Taruschio, Gianfranco; Andreone, Pietro

    2016-09-01

    Bile Salt Export Pump (BSEP) Deficiency disease, including Progressive Familial Intrahepatic Cholestasis type 2 (PFIC2), is a rare disease, usually leading within the first ten years to portal hypertension, liver failure, hepatocellular carcinoma. Often liver transplantation is needed. Sodium 4-phenylbutyrate (4-PB) seems to be a potential therapeutic compound for PFIC2. Psychiatric side effects in the adolescent population are little known and little studied since the drug used to treat children and infants. So we described a case of Caucasian boy, suffering from a late onset PFIC2, listed for a liver transplant when he was sixteen and treated with 4-FB (200 mg per kilogram of body weight per day). The drug was discontinued for the onset of bipolar and related disorders. This case illustrates possible psychiatric side effects of the drug.

  14. Molecular Switch Controlling the Binding of Anionic Bile Acid Conjugates to Human Apical Sodium-dependent Bile Acid Transporter

    PubMed Central

    Rais, Rana; Acharya, Chayan; Tririya, Gasirat; MacKerell, Alexander D.; Polli, James E.

    2010-01-01

    The human apical sodium-dependent bile acid transporter (hASBT) may serve as a prodrug target for oral drug absorption. Synthetic, biological, NMR and computational approaches identified the structure-activity relationships of mono- and dianionic bile acid conjugates for hASBT binding. Experimental data combined with a conformationally-sampled pharmacophore/QSAR modeling approach (CSP-SAR) predicted that dianionic substituents with intramolecular hydrogen bonding between hydroxyls on the cholane skeleton and the acid group on the conjugate's aromatic ring increased conjugate hydrophobicity and improved binding affinity. Notably, the model predicted the presence of a conformational molecular switch, where shifting the carboxylate substituent on an aromatic ring by a single position controlled binding affinity. Model validation was performed by effectively shifting the spatial location of the carboxylate by inserting a methylene adjacent to the aromatic ring, resulting in the predicted alteration in binding affinity. This work illustrates conformation as a determinant of ligand binding affinity to a biological transporter. PMID:20504026

  15. The human gut sterolbiome: bile acid-microbiome endocrine aspects and therapeutics

    PubMed Central

    Ridlon, Jason M.; Bajaj, Jasmohan S.

    2015-01-01

    The human body is now viewed as a complex ecosystem that on a cellular and gene level is mainly prokaryotic. The mammalian liver synthesizes and secretes hydrophilic primary bile acids, some of which enter the colon during the enterohepatic circulation, and are converted into numerous hydrophobic metabolites which are capable of entering the portal circulation, returned to the liver, and in humans, accumulating in the biliary pool. Bile acids are hormones that regulate their own synthesis, transport, in addition to glucose and lipid homeostasis, and energy balance. The gut microbial community through their capacity to produce bile acid metabolites distinct from the liver can be thought of as an “endocrine organ” with potential to alter host physiology, perhaps to their own favor. We propose the term “sterolbiome” to describe the genetic potential of the gut microbiome to produce endocrine molecules from endogenous and exogenous steroids in the mammalian gut. The affinity of secondary bile acid metabolites to host nuclear receptors is described, the potential of secondary bile acids to promote tumors, and the potential of bile acids to serve as therapeutic agents are discussed. PMID:26579434

  16. Functional human induced hepatocytes (hiHeps) with bile acid synthesis and transport capacities: A novel in vitro cholestatic model

    PubMed Central

    Ni, Xuan; Gao, Yimeng; Wu, Zhitao; Ma, Leilei; Chen, Chen; Wang, Le; Lin, Yunfei; Hui, Lijian; Pan, Guoyu

    2016-01-01

    Drug-induced cholestasis is a leading cause of drug withdrawal. However, the use of primary human hepatocytes (PHHs), the gold standard for predicting cholestasis in vitro, is limited by their high cost and batch-to-batch variability. Mature hepatocyte characteristics have been observed in human induced hepatocytes (hiHeps) derived from human fibroblast transdifferentiation. Here, we evaluated whether hiHeps could biosynthesize and excrete bile acids (BAs) and their potential as PHH alternatives for cholestasis investigations. Quantitative real-time PCR (qRT-PCR) and western blotting indicated that hiHeps highly expressed BA synthases and functional transporters. Liquid chromatography tandem mass spectrometry (LC-MS/MS) showed that hiHeps produced normal intercellular unconjugated BAs but fewer conjugated BAs than human hepatocytes. When incubated with representative cholestatic agents, hiHeps exhibited sensitive drug-induced bile salt export pump (BSEP) dysfunction, and their response to cholestatic agent-mediated cytotoxicity correlated well with that of PHHs (r2 = 0.8032). Deoxycholic acid (DCA)-induced hepatotoxicity in hiHeps was verified by elevated aspartate aminotransferase (AST) and γ-glutamyl-transferase (γ-GT) levels. Mitochondrial damage and cell death suggested DCA-induced toxicity in hiHeps, which were attenuated by hepatoprotective drugs, as in PHHs. For the first time, hiHeps were reported to biosynthesize and excrete BAs, which could facilitate predicting cholestatic hepatotoxicity and screening potential therapeutic drugs against cholestasis. PMID:27934920

  17. Effects of Bile Salt Sodium Glycodeoxycholate on the Self-Assembly of PEO-PPO-PEO Triblock Copolymer P123 in Aqueous Solution.

    PubMed

    Bayati, Solmaz; Galantini, Luciano; Knudsen, Kenneth D; Schillén, Karin

    2015-12-22

    A comprehensive experimental study on the interaction between the PEO-PPO-PEO block copolymer P123 (EO20PO68EO20) and the anionic bile salt sodium glycodeoxycholate (NaGDC) in water has been performed. The work was aimed at investigating the suitability of using P123 as bile salt sequestrant beside the fundamental aspects of PEO-PPO-PEO block copolymer-bile salt interactions. Various experimental techniques including dynamic and static light scattering, small-angle X-ray scattering, and differential scanning calorimetry (DSC) were employed in combination with electrophoretic mobility measurements. The system was investigated at a constant P123 concentration of 1.74 mM and with varying bile salt concentrations up to approximately 250 mM NaGDC (or a molar ratio n(NaGDC)/n(P123) = 144). In the mixed P123-NaGDC solutions, the endothermic process related to the self-assembly of P123 was observed to gradually decrease in enthalpy and shift to higher temperatures upon progressive addition of NaGDC. To explain this effect, the formation of NaGDC micelles carrying partly dehydrated P123 unimers was proposed and translated into a stoichiometric model, which was able to fit the experimental DSC data. In the mixtures at low molar ratios, NaGDC monomers associated with the P123 micelle forming a charged "P123 micelle-NaGDC" complex with a dehydrated PPO core. These complexes disintegrated upon increasing NaGDC concentration to form small "NaGDC-P123" complexes visualized as bile salt micelles including one or a few P123 copolymer chains.

  18. Effect of sodium taurolithocholate on bile flow and bile acid excretion

    PubMed Central

    Javitt, Norman B.; Emerman, Sidney

    1968-01-01

    Sodium taurolithocholate and sodium taurocholenate were infused intravenously into rats and hamsters. Each bile acid salt was given alone or in combination with varying amounts of a primary bile salt, either sodium taurocholate or sodium taurochenodeoxycholate. Bile flow, total bile acid salt excretion, and the excretion of sodium taurolithocholate were quantitatively determined. In addition, mannitol excretion in bile was determined at various flow rates. Sodium taurolithocholate was found to be rapidly excreted in bile in concentrations greater than its aqueous solubility. When the endogenous excretion rate of bile salt or the infusion of primary bile salt was less than the molar amount of administered sodium taurolithocholate, cholestasis always occurred. Increasing molar amounts of primary bile salt prevented cholestasis and enhanced the excretion rate of sodium taurolithocholate. Infusion of sodium taurocholenate, a nonhemolytic bile salt, caused an effect on bile flow and bile acid salt excretion qualitatively similar to sodium taurolithocholate. The induction of cholestasis can be attributed to the physical properties of these poorly water soluble bile salts. The reduction in bile flow could not be shown to be related to water reabsorption from the biliary tree since there was no increase in mannitol concentration in bile during cholestasis. Reduction in bile flow may be related to obstruction of segments of the biliary tree by precipitates of sodium taurolithocholate and possibly to a decrease in water entry into the biliary tree during infusion of this bile acid salt. PMID:5645847

  19. Relative gene expression of bile salt hydrolase and surface proteins in two putative indigenous Lactobacillus plantarum strains under in vitro gut conditions.

    PubMed

    Duary, Raj Kumar; Batish, Virender Kumar; Grover, Sunita

    2012-03-01

    Probiotic bacteria must overcome the toxicity of bile salts secreted in the gut and adhere to the epithelial cells to enable their better colonization with extended transit time. Expression of bile salt hydrolase and other proteins on the surface of probiotic bacteria can help in better survivability and optimal functionality in the gut. Two putative Lactobacillus plantarum isolates i.e., Lp9 and Lp91 along with standard strain CSCC5276 were used. A battery of six housekeeping genes viz. gapB, dnaG, gyrA, ldhD, rpoD and 16S rRNA were evaluated by using geNorm 3.4 excel based application for normalizing the expression of bile salt hydrolase (bsh), mucus-binding protein (mub), mucus adhesion promoting protein (mapA), and elongation factor thermo unstable (EF-Tu) in Lp9 and Lp91. The maximal level of relative bsh gene expression was recorded in Lp91 with 2.89 ± 0.14, 4.57 ± 0.37 and 6.38 ± 0.19 fold increase at 2% bile salt concentration after 1, 2 and 3 h, respectively. Similarly, mub and mapA genes were maximally expressed in Lp9 at the level of 20.07 ± 1.28 and 30.92 ± 1.51 fold, when MRS was supplemented with 0.05% mucin and 1% each of bile and pancreatin (pH 6.5). However, in case of EF-Tu, the maximal expression of 42.84 ± 5.64 fold was recorded in Lp91 in the presence of mucin alone (0.05%). Hence, the expression of bsh, mub, mapA and EF-Tu could be considered as prospective biomarkers for screening of novel probiotic lactobacillus strains for optimal functionality in the gut.

  20. The effects of endogenous energy, type of diet, and addition of bile salts on true metabolizable energy values in young chicks.

    PubMed

    Kussaibati, R; Guillaume, J; Leclercq, B

    1982-11-01

    A trial was carried out using 3-week-old chickens of a commercial breed to study the effects of either a fat-free diet or a diet containing 150 g/kg of animal fat on the endogenous energy losses measured with starved birds. The effects of the addition of different levels of bile salts to such diets and the accuracy of true metabolizable energy (TME) with respect to the other modes of expression of metabolizable energy were also examined. The excreted endogenous energy values were shown to vary not only according to the type of diet (P less than .01) but also in relation to the dietary intake level (P less than .01). Because it is directly related to endogenous energy, TME proved to be an inaccurate parameter in young chicks unless values were corrected for N-balance. If the values of both apparent metabolizable energy (AME) and TME are corrected for N-balance, they are normally comparable and independent of the dietary intake level if the diet contains virtually no added fat. These findings indicate that most of the endogenous excreta are composed of nitrogenous metabolites. However, neither AME nor TME values of fat-rich diets are independent of dietary intake. The addition of bile salts had no effect on the metabolizable energy values of the fat-free diet. However, in the case of the diet rich in saturated fats, they compensated either for insufficient bile secretion or for endogenous bile salts degraded by the intestinal microflora. Thus, the digestive utilization of dietary fat, especially that of the saturated fatty acids, palmitic and stearic acids, was increased. In addition, metabolizable energy was significantly improved (P less than .01) by the addition of bile salts when the dietary intake level increased to the ad libitum level.

  1. Bile-salt-stimulated lipase and mucins from milk of ‘secretor’ mothers inhibit the binding of Norwalk virus capsids to their carbohydrate ligands

    PubMed Central

    2005-01-01

    Breast-feeding-associated protection against calicivirus diarrhoea is associated with the presence of high levels of 2-linked oligosaccharides in mother's milk, and human calicivirus strains including the NV (Norwalk virus) use gut 2-linked fucosylated glycans as receptors, suggesting the presence of decoy receptors in milk. Our aim was to analyse the ability of human milk to inhibit the attachment of rNV VLPs (recombinant NV-like particles) to their carbohydrate ligands and to characterize potential inhibitors found in milk. Milk from women with the secretor phenotype was strongly inhibitory, unlike milk from women that are non-secretors, which is devoid of 2-linked fucosylated structures. At least two fractions in human milk acted as inhibitors for the NV capsid attachment. The first fraction corresponded to BSSL (bile-salt-stimulated lipase) and the second to associated mucins MUC1 and MUC4. These proteins present tandem repeat O-glycosylated sequences that should act as decoy receptors for the NV, depending on the combined mother/child secretor status. PMID:16266293

  2. Bile Formation and Secretion

    PubMed Central

    Boyer, James L.

    2014-01-01

    Bile is a unique and vital aqueous secretion of the liver that is formed by the hepatocyte and modified down stream by absorptive and secretory properties of the bile duct epithelium. Approximately 5% of bile consists of organic and inorganic solutes of considerable complexity. The bile-secretory unit consists of a canalicular network which is formed by the apical membrane of adjacent hepatocytes and sealed by tight junctions. The bile canaliculi (~1 μm in diameter) conduct the flow of bile countercurrent to the direction of portal blood flow and connect with the canal of Hering and bile ducts which progressively increase in diameter and complexity prior to the entry of bile into the gallbladder, common bile duct, and intestine. Canalicular bile secretion is determined by both bile salt-dependent and independent transport systems which are localized at the apical membrane of the hepatocyte and largely consist of a series of adenosine triphosphate-binding cassette transport proteins that function as export pumps for bile salts and other organic solutes. These transporters create osmotic gradients within the bile canalicular lumen that provide the driving force for movement of fluid into the lumen via aquaporins. Species vary with respect to the relative amounts of bile salt-dependent and independent canalicular flow and cholangiocyte secretion which is highly regulated by hormones, second messengers, and signal transduction pathways. Most determinants of bile secretion are now characterized at the molecular level in animal models and in man. Genetic mutations serve to illuminate many of their functions. PMID:23897680

  3. Laxative treatment with polyethylene glycol decreases microbial primary bile salt dehydroxylation and lipid metabolism in the intestine of rats.

    PubMed

    van der Wulp, Mariëtte Y M; Derrien, Muriel; Stellaard, Frans; Wolters, Henk; Kleerebezem, Michiel; Dekker, Jan; Rings, Edmond H H M; Groen, Albert K; Verkade, Henkjan J

    2013-10-01

    Polyethylene glycol (PEG) is a frequently used osmotic laxative that accelerates gastrointestinal transit. It has remained unclear, however, whether PEG affects intestinal functions. We aimed to determine the effect of PEG treatment on intestinal sterol metabolism. Rats were treated with PEG in drinking water (7%) for 2 wk or left untreated (controls). We studied the enterohepatic circulation of the major bile salt (BS) cholate with a plasma stable isotope dilution technique and determined BS profiles and concentrations in bile, intestinal lumen contents, and feces. We determined the fecal excretion of cholesterol plus its intestinally formed metabolites. Finally, we determined the cytolytic activity of fecal water (a surrogate marker of colorectal cancer risk) and the amount and composition of fecal microbiota. Compared with control rats, PEG treatment increased the pool size (+51%; P < 0.01) and decreased the fractional turnover of cholate (-32%; P < 0.01). PEG did not affect the cholate synthesis rate, corresponding with an unaffected fecal primary BS excretion. PEG reduced fecal excretion of secondary BS and of cholesterol metabolites (each P < 0.01). PEG decreased the cytolytic activity of fecal water [54 (46-62) vs. 87 (85-92)% erythrocyte potassium release in PEG-treated and control rats, respectively; P < 0.01]. PEG treatment increased the contribution of Verrucomicrobia (P < 0.01) and decreased that of Firmicutes (P < 0.01) in fecal flora. We concluded that PEG treatment changes the intestinal bacterial composition, decreases the bacterial dehydroxylation of primary BS and the metabolism of cholesterol, and increases the pool size of the primary BS cholate in rats.

  4. Postprandial concentrations of free and conjugated bile acids down the length of the normal human small intestine

    PubMed Central

    Northfield, T. C.; McColl, I.

    1973-01-01

    Small intestinal samples were obtained by intubation from multiple sites along the small intestine in 11 subjects with no known gastrointestinal disease eating a normal diet and at laparotomy in a further three subjects. Free (unconjugated) bile acids were consistently demonstrated in ileal samples, and occasionally in lower jejunal samples, by thin-layer chromatography, supplemented in some cases by gas/liquid chromatography and by infrared spectroscopy. The free bile acid concentration, measured enzymically following thin-layer chromatography, reached a maximum (1 mM) in the lower ileum, where it represented half the total bile acid concentration. Following ampicillin, the concentration of free bile acids decreased markedly, suggesting that they resulted from bacterial deconjugation; at the same time the total bile acid concentration increased, suggesting impaired absorption due to the reduced concentration of the more rapidly absorbed free bile acids. Our results indicate that the presence of free bile acids in lower jejunal and ileal samples is a normal finding, and cannot be taken as evidence of abnormal bacterial overgrowth. They also suggest that bacterial deconjugation at these sites may be a factor contributing to the remarkable efficiency of bile salt reabsorption. ImagesFig 2 PMID:4729918

  5. Structure and rheology of cationic molecular hydrogels of quinuclidine grafted bile salts. Influence of the ionic strength and counter-ion type.

    PubMed

    Terech, P; Dourdain, S; Maitra, U; Bhat, S

    2009-04-09

    Quinuclidine grafted cationic bile salts are forming salted hydrogels. An extensive investigation of the effect of the electrolyte and counterions on the gelation has been envisaged. The special interest of the quinuclidine grafted bile salt is due to its broader experimental range of gelation to study the effect of electrolyte. Rheological features of the hydrogels are typical of enthalpic networks exhibiting a scaling law of the elastic shear modulus with the concentration (scaling exponent 2.2) modeling cellular solids in which the bending modulus is the dominant parameter. The addition of monovalent salt (NaCl) favors the formation of gels in a first range (0.00117 g cm(-3) (0.02 M) < T(NaCl) < 0.04675 g cm(-3) (0.8 M)). At larger salt concentrations, the gels become more heterogeneous with nodal zones in the micron scale. Small-angle neutron scattering experiments have been used to characterize the rigid fibers ( approximately 68 A) and the nodal zones. Stress sweep and creep-recovery measurements are used to relate the lack of linear viscoelastic domain to a mechanism of disentanglement of the fibers from their associations into fagots. The electrostatic interactions can be screened by addition of salt to induce a progressive evolution toward flocculation. SEM, UV absorbance, and SAXS study of the Bragg peak at large Q-values complete the investigation.

  6. Catalytic Interactions and Molecular Docking of Bile Salt Hydrolase (BSH) from L. plantarum RYPR1 and Its Prebiotic Utilization

    PubMed Central

    Yadav, Ruby; Singh, Puneet K.; Puniya, Anil K.; Shukla, Pratyoosh

    2017-01-01

    Prebiotics are the non-digestible carbohydrate, which passes through the small intestine into unmetabolized form, reaches the large intestine and undergoes fermentation by the colonic bacteria thus; prebiotics stimulate the growth of probiotic bacteria. Further, bile salt hydrolase (BSH) is an enzyme that catalyses the deconjugation of bile salt, so it has enormous potential toward utilizing such capability of Lactobacillus plantarum RYPR1 toward detoxifying through BSH enzyme activity. In the present study, six isolates of Lactobacillus were evaluated for the co-aggregation assay and the isolate Lactobacillus plantarum RYPR1 was further selected for studies of prebiotic utilization, catalytic interactions and molecular docking. The prebiotic utilization ability was assessed by using commercially available prebiotics lactulose, inulin, xylitol, raffinose, and oligofructose P95. The results obtained revealed that RYPR1 is able to utilize these probiotics, maximum with lactulose by showing an increase in viable cell count (7.33 ± 0.02 to 8.18 ± 0.08). In addition, the molecular docking of BSH from Lactobacillus plantarum RYPR1 was performed which revealed the binding energy –4.42 and 7.03 KJ/mol. This proves a considerably good interactions among BSH and its substrates like Taurocholic acid (–4.42 KJ/mol) and Glycocholic acid (–7.03 KJ/mol). These results from this study establishes that Lactobacillus plantarum RYPR1 possesses good probiotic effects so it could be used for such applications. Further, molecular dynamics simulations were used to analyze the dynamic stability of the of modeled protein to stabilize it for further protein ligand docking and it was observed that residues Asn12, Ile8, and Leu6 were interacting among BSH and its substrates, i.e., Taurocholic acid and Lys88 and Asp126 were interacting with Glycocholic acid. These residues were interacting when the docking was carried out with stabilized BSH protein structure, thus, these residues may

  7. Catalytic Interactions and Molecular Docking of Bile Salt Hydrolase (BSH) from L. plantarum RYPR1 and Its Prebiotic Utilization.

    PubMed

    Yadav, Ruby; Singh, Puneet K; Puniya, Anil K; Shukla, Pratyoosh

    2016-01-01

    Prebiotics are the non-digestible carbohydrate, which passes through the small intestine into unmetabolized form, reaches the large intestine and undergoes fermentation by the colonic bacteria thus; prebiotics stimulate the growth of probiotic bacteria. Further, bile salt hydrolase (BSH) is an enzyme that catalyses the deconjugation of bile salt, so it has enormous potential toward utilizing such capability of Lactobacillus plantarum RYPR1 toward detoxifying through BSH enzyme activity. In the present study, six isolates of Lactobacillus were evaluated for the co-aggregation assay and the isolate Lactobacillus plantarum RYPR1 was further selected for studies of prebiotic utilization, catalytic interactions and molecular docking. The prebiotic utilization ability was assessed by using commercially available prebiotics lactulose, inulin, xylitol, raffinose, and oligofructose P95. The results obtained revealed that RYPR1 is able to utilize these probiotics, maximum with lactulose by showing an increase in viable cell count (7.33 ± 0.02 to 8.18 ± 0.08). In addition, the molecular docking of BSH from Lactobacillus plantarum RYPR1 was performed which revealed the binding energy -4.42 and 7.03 KJ/mol. This proves a considerably good interactions among BSH and its substrates like Taurocholic acid (-4.42 KJ/mol) and Glycocholic acid (-7.03 KJ/mol). These results from this study establishes that Lactobacillus plantarum RYPR1 possesses good probiotic effects so it could be used for such applications. Further, molecular dynamics simulations were used to analyze the dynamic stability of the of modeled protein to stabilize it for further protein ligand docking and it was observed that residues Asn12, Ile8, and Leu6 were interacting among BSH and its substrates, i.e., Taurocholic acid and Lys88 and Asp126 were interacting with Glycocholic acid. These residues were interacting when the docking was carried out with stabilized BSH protein structure, thus, these residues may have a

  8. Enhanced Permeation of an Antiemetic Drug from Buccoadhesive Tablets by Using Bile Salts as Permeation Enhancers: Formulation Characterization, In Vitro, and Ex Vivo Studies

    PubMed Central

    Jain, C. P.; Joshi, Garima; Kataria, Udichi; Patel, Komal

    2016-01-01

    Buccal bioadhesive bilayer tablets of prochlorperazine maleate were designed and formulated by using buccoadhesive polymers such as hydroxypropylmethyl cellulose, Carbopol 934P, and sodium alginate. Physicochemical characteristics like the uniformity of weight, hardness, thickness, surface pH, drug content, swelling index, microenvironment pH, in vitro drug release, and in vivo buccoadhesion time of the prepared tablets were found to be dependent on the type and composition of the buccoadhesive materials used. The effect of bile salts on the permeation was studied through porcine buccal mucosa and it was found that out of three bile salts incorporated (sodium glycholate, sodium taurocholate, and sodium deoxycholate), sodium glycholate enhanced the permeation rate of prochlorperazine maleate by an enhancement factor of 1.37. PMID:27222611

  9. Role of the bile salt surfactant sodium cholate in enhancing the aqueous dispersion stability of single-walled carbon nanotubes: a molecular dynamics simulation study.

    PubMed

    Lin, Shangchao; Blankschtein, Daniel

    2010-12-02

    Very recently, bile salt biosurfactants have been utilized extensively to disperse individual single-walled carbon nanotubes (SWNTs) in aqueous solution with high weight fractions, as well as to sort SWNTs according to their electronic properties with the aid of ultracentrifugation. To help elucidate the role of bile salts in the SWNT dispersion process, we report the first detailed large-scale all-atomistic molecular dynamics (MD) simulation study of the adsorption and surface self-assembly of a common bile salt surfactant, sodium cholate (SC), on a SWNT in aqueous solution. We find that the cholate ions wrap around the SWNT like a ring and have a small tendency to orient perpendicular to the cylindrical axis of the SWNT, a unique feature that has not been observed for conventional linear surfactants such as sodium dodecyl sulfate (SDS). In addition, we carry out a series of simulations to compute the potential of mean force (PMF) between two parallel SC-covered SWNTs as a function of the intertube separation. By comparing our simulated PMF profile of SC with the PMF profile of SDS reported in the literature, we found that, at the saturated surface coverages, SC is a better stabilizer than SDS, a finding that is consistent with the widespread use of SC to disperse SWNTs in aqueous media. Indeed, the superior dispersion-induced stability of SC over SDS results from a higher repulsive energy barrier and a shallower attractive energy well induced by SC in the PMF profile. In particular, we found that the shallower attractive energy well induced by SC is due to the rigid, bean-like structure of SC which allows this bile salt surfactant to more effectively accommodate the intertube gap.

  10. CYP7A1 promoter polymorphism -203A>C affects bile salt synthesis rate in patients after ileal resection.

    PubMed

    Lenícek, Martin; Komárek, Viktor; Zimolová, Miluse; Kovár, Jan; Jirsa, Milan; Lukás, Milan; Vítek, Libor

    2008-12-01

    Cholesterol 7alpha-hydroxylase (CYP7A1) plays a crucial role in cholesterol metabolism and has been implicated in genetic susceptibility to atherosclerosis. Thus, an understanding of its transcriptional regulation is of considerable importance. We evaluated the effect of a common -203A>C polymorphism in the CYP7A1 promoter region on the activity of CYP7A1, estimated as the ratios of serum 7alpha-hydroxycholest-4-en-3-one (C4) to either total or non-HDL-cholesterol. The study was performed on patients after resection of the distal ileum, leading to upregulation of CYP7A1 activity (n = 65). Healthy volunteers served as the control group (n = 66). Whereas higher CYP7A1 activity was associated with the -203A allele in the patient group (C4/cholesterol ratio, 29.0 vs. 14.8 microg/mmol, P = 0.032; C4/non-HDL-cholesterol ratio, 53.3 vs. 21.3 microg/mmol in -203AA and -203CC, P = 0.017, respectively), no differences were observed in the healthy controls. We conclude that under physiological conditions, the -203A>C polymorphism in the CYP7A1 gene promoter region does not seem to have any clinically relevant effect. However, in patients with severe bile salt malabsorption, this polymorphism markedly affects CYP7A1 activity.

  11. Fluorescence probe studies of mixed micellar and lyotropic phases formed between an anionic bile salt and a cationic detergent

    SciTech Connect

    Wu, K.; McGown, L.B. )

    1994-01-27

    Fluorescent probes, including pyrene, benzo[ghi]perylene (BgP), and perylene, were used to study organized media formed between the anionic trihydroxy bile salt sodium taurocholate (NaTC) and the cationic detergent octyltrimethylammonium bromide (CTAB), over a wide concentration range that includes micellar and lyotropic phases. Solutions of the individual amphiphiles were studied as well. The location of a probe in the mixed micelles was found to depend on the solubility and size of the probe. The microenvironment of pyrene is dominated by NaTC in the mixed micelles, whereas the larger and less soluble perylene and BgP probes interact more favorably with the hydrophobic tails of the CTAB molecules. The photophysical responses of the probes reflect their different locations, providing different perspectives on the transitions in micellar structure. Bromide counterion at the micellar surfaces was found to be an important factor in the photophysical responses, along with accessibility to bulk solution. A scheme for mixed micellization is proposed that extends from large excesses of one amphiphile to large excesses of the other, over a wide range of total amphiphile concentration. Interestingly, the lyotropic phases formed between NaTC and CTAB have high bulk viscosity, but the probe microenvironment is less viscous than in the mixed micellar phases. 43 refs., 9 figs., 2 tabs.

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

    PubMed

    Aburahma, Mona Hassan

    2016-07-01

    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.

  13. Cl- secretion induced by bile salts. A study of the mechanism of action based on a cultured colonic epithelial cell line.

    PubMed Central

    Dharmsathaphorn, K; Huott, P A; Vongkovit, P; Beuerlein, G; Pandol, S J; Ammon, H V

    1989-01-01

    When applied to the basolateral (serosal) side of the T84 colonic epithelial monolayer, taurodeoxycholate caused net Cl- secretion in a dose-dependent manner with a threshold effect observed at 0.2 mM. In contrast, when applied to the apical (luminal) surface, concentrations of taurodeoxycholate below 1 mM had little or no effect. Only when the concentration of taurodeoxycholate present on the apical side was greater than or equal to 1 mM did apical addition results in an electrolyte transport effect. This apical effect on electrolyte transport was associated with an abrupt increase in the permeability of the monolayer. Cyclic AMP and cyclic GMP in the T84 monolayers were not increased by the bile salt, but in the presence of extracellular Ca2+, free cytosolic Ca2+ increased with a graded dose effect and time course that corresponded approximately to the changes in short circuit current (Isc). The results suggest that luminal bile salts at a relatively high concentration (greater than or equal to 1 mM) increase tight junction permeability. Once tight junction permeability increases, luminal bile salts could reach the basolateral membrane of the epithelial cells where they act to increase free cytosolic Ca2+ from extracellular sources. The resulting increases in free cytosolic Ca2+, rather than in cyclic nucleotides, appear to be involved in transcellular Cl- secretion. PMID:2547841

  14. Effects of heat, cold, acid and bile salt adaptations on the stress tolerance and protein expression of kefir-isolated probiotic Lactobacillus kefiranofaciens M1.

    PubMed

    Chen, Ming-Ju; Tang, Hsin-Yu; Chiang, Ming-Lun

    2017-09-01

    Lactobacillus kefiranofaciens M1 is a probiotic strain isolated from Taiwanese kefir grains. The present study evaluated the effects of heat, cold, acid and bile salt adaptations on the stress tolerance of L. kefiranofaciens M1. The regulation of protein expression of L. kefiranofaciens M1 under these adaptation conditions was also investigated. The results showed that adaptation of L. kefiranofaciens M1 to heat, cold, acid and bile salts induced homologous tolerance and cross-protection against heterologous challenge. The extent of induced tolerance varied depending on the type and condition of stress. Proteomic analysis revealed that 27 proteins exhibited differences in expression between non-adapted and stress-adapted L. kefiranofaciens M1 cells. Among these proteins, three proteins involved in carbohydrate metabolism (triosephosphate isomerase, enolase and NAD-dependent glycerol-3-phosphate dehydrogenase), two proteins involved in pH homeostasis (ATP synthase subunits AtpA and AtpB), two stress response proteins (chaperones DnaK and GroEL) and one translation-related protein (30S ribosomal protein S2) were up-regulated by three of the four adaptation treatments examined. The increased synthesis of these stress proteins might play a critical protective role in the cellular defense against heat, cold, acid and bile salt stresses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Increased paracellular absorption by bile salts and P-glycoprotein stimulated efflux of otilonium bromide in Caco-2 cells monolayers as a model of intestinal barrier.

    PubMed

    Catalioto, Rose-Marie; Triolo, Antonio; Giuliani, Sandro; Altamura, Maria; Evangelista, Stefano; Maggi, Carlo Alberto

    2008-09-01

    The present study investigates the intestinal permeability of otilonium bromide, a spasmolytic drug used to treat irritable bowel syndrome, across Caco-2 cell monolayers. The amount of otilonium bromide transported was determined by high-performance liquid chromatography-mass spectrometry. Epithelial barrier integrity was estimated by measuring transepithelial electrical resistance and the transport of reference compounds, P-glycoprotein activity by measuring rhodamine 123 efflux. Results showed that the apparent permeability of otilonium bromide was comparable to that of our zero permeability marker, inulin, in the apical-to-basal direction and similar to that of rhodamine 123 in the basal-to-apical direction. The P-glycoprotein substrate, verapamil, prevented otilonium bromide efflux and, conversely, otilonium bromide inhibited P-glycoprotein activity. Bile salts induced a transient opening of tight junctions, as measured by selective increase of paracellular transport, and significantly enhanced the absorption of otilonium bromide. In turn otilonium bromide potentiates the effect of bile salts on tight junctions without modifying their critical micellar concentration or altering cell viability. In conclusion, otilonium bromide is a paracellularly transported drug whose absorption, in amounts sufficient to exert a spasmolytic effect, is favoured by bile salts. P-glycoprotein, by stimulating efflux, contributes to remove excess compound, restraining its distribution and site of action to the intestinal wall.

  16. 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.

    PubMed

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

    2015-09-01

    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.

  17. Bile salt-stimulated lipase and pancreatic lipase-related protein 2 are the dominating lipases in neonatal fat digestion in mice and rats.

    PubMed

    Li, Xiaonan; Lindquist, Susanne; Lowe, Mark; Noppa, Laila; Hernell, Olle

    2007-11-01

    During infancy, the basic conditions for digestion of dietary fat differ from later in life. The bile salt-stimulated lipase (BSSL) is an enzyme expressed in the exocrine pancreas and in some species (including human) also in the lactating mammary gland and secreted with the milk. The aim of this study was to compare the ontogeny of four pancreatic lipases [BSSL, pancreatic triglyceride lipase (PL), pancreatic lipase-related protein 2 (PLRP2), and phospholipase A2 (PLA2)] in one species that supplies BSSL with milk (the mouse) and one that does not (the rat). We followed expression of the four pancreatic lipases from postnatal d 1 until after weaning in both species. We found that BSSL and PLRP2, two lipases with broad substrate specificity, dominated. It was not until weaning that significant expression of PL and PLA2 were induced. Thus, BSSL and PLRP2 seem to be responsible for fat digestion as long as milk is the main food. Moreover, the early temporal pattern of BSSL expression differed between species. We speculate that the milk-borne BSSL is able to compensate for a slower ontogeny of pancreatic BSSL expression in the mouse.

  18. Decreased hepatotoxic bile acid composition and altered synthesis in progressive human nonalcoholic fatty liver disease

    SciTech Connect

    Lake, April D.; Novak, Petr; Shipkova, Petia; Aranibar, Nelly; Robertson, Donald; Reily, Michael D.; Lu, Zhenqiang; Lehman-McKeeman, Lois D.; Cherrington, Nathan J.

    2013-04-15

    Bile acids (BAs) have many physiological roles and exhibit both toxic and protective influences within the liver. Alterations in the BA profile may be the result of disease induced liver injury. Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of chronic liver disease characterized by the pathophysiological progression from simple steatosis to nonalcoholic steatohepatitis (NASH). The hypothesis of this study is that the ‘classical’ (neutral) and ‘alternative’ (acidic) BA synthesis pathways are altered together with hepatic BA composition during progression of human NAFLD. This study employed the use of transcriptomic and metabolomic assays to study the hepatic toxicologic BA profile in progressive human NAFLD. Individual human liver samples diagnosed as normal, steatosis, and NASH were utilized in the assays. The transcriptomic analysis of 70 BA genes revealed an enrichment of downregulated BA metabolism and transcription factor/receptor genes in livers diagnosed as NASH. Increased mRNA expression of BAAT and CYP7B1 was observed in contrast to decreased CYP8B1 expression in NASH samples. The BA metabolomic profile of NASH livers exhibited an increase in taurine together with elevated levels of conjugated BA species, taurocholic acid (TCA) and taurodeoxycholic acid (TDCA). Conversely, cholic acid (CA) and glycodeoxycholic acid (GDCA) were decreased in NASH liver. These findings reveal a potential shift toward the alternative pathway of BA synthesis during NASH, mediated by increased mRNA and protein expression of CYP7B1. Overall, the transcriptomic changes of BA synthesis pathway enzymes together with altered hepatic BA composition signify an attempt by the liver to reduce hepatotoxicity during disease progression to NASH. - Highlights: ► Altered hepatic bile acid composition is observed in progressive NAFLD. ► Bile acid synthesis enzymes are transcriptionally altered in NASH livers. ► Increased levels of taurine and conjugated bile acids

  19. [The effect of aspirin, antacids, alcohol, and bile acids on transmural potential difference of the human stomach (author's transl)].

    PubMed

    Caspary, W F

    1975-06-06

    The effect of orally administered buffered and unbuffered aspirin, antacids, alcohol and bile salts on functional changes in the gastric mucosal barrier was assessed by measuring gastric transmural potential differences (PD) in healthy subjects. In contrast to buffered aspirin, unbuffered aspirin caused a marked decrease in transmural PD due to its known effect of enhancing H+ back-diffusion. Simultaneous administration of antacids prevented the aspirin-induced drop of transmural PD. Ethanol (20% w/v), whisky (45% w/v), wine (6-7% ethanol), bile salts and ox-bile reduced transmural PD in healthy subjects. The measurement of transmural PD is a simple and sensitive method for detecting functional changes in the gastric mucosal barrier induced by drugs known to alter mucosal permeability.

  20. Effects of bile acids on human airway epithelial cells: implications for aerodigestive diseases

    PubMed Central

    Aldhahrani, Adil; Verdon, Bernard; Pearson, Jeffery

    2017-01-01

    Gastro-oesophageal reflux and aspiration have been associated with chronic and end-stage lung disease and with allograft injury following lung transplantation. This raises the possibility that bile acids may cause lung injury by damaging airway epithelium. The aim of this study was to investigate the effect of bile acid challenge using the immortalised human bronchial epithelial cell line (BEAS-2B). The immortalised human bronchial epithelial cell line (BEAS-2B) was cultured. A 48-h challenge evaluated the effect of individual primary and secondary bile acids. Post-challenge concentrations of interleukin (IL)-8, IL-6 and granulocyte−macrophage colony-stimulating factor were measured using commercial ELISA kits. The viability of the BEAS-2B cells was measured using CellTiter-Blue and MTT assays. Lithocholic acid, deoxycholic acid, chenodeoxycholic acid and cholic acid were successfully used to stimulate cultured BEAS-2B cells at different concentrations. A concentration of lithocholic acid above 10 μmol·L−1 causes cell death, whereas deoxycholic acid, chenodeoxycholic acid and cholic acid above 30 μmol·L−1 was required for cell death. Challenge with bile acids at physiological levels also led to a significant increase in the release of IL-8 and IL6 from BEAS-2B. Aspiration of bile acids could potentially cause cell damage, cell death and inflammation in vivo. This is relevant to an integrated gastrointestinal and lung physiological paradigm of chronic lung disease, where reflux and aspiration are described in both chronic lung diseases and allograft injury. PMID:28344983

  1. Bile Reflux

    MedlinePlus

    ... bile can wash back into the esophagus. What leads to bile reflux? Bile reflux may be caused ... it should. Stagnant food in the stomach can lead to increased gastric pressure and allow bile and ...

  2. A novel bile salts-lipase polymeric film-infused minitablet system for enhanced oral delivery of cholecalciferol.

    PubMed

    Braithwaite, Miles C; Choonara, Yahya E; Kumar, Pradeep; Tomar, Lomas K; Du Toit, Lisa C; Pillay, Viness

    2016-11-01

    Few researchers have investigated the use of multiple physiological enhancers combined with synthetic carriers to augment delivery of nutraceuticals. The current work describes the development of an oral delivery system termed a bioactive association platform (BAP) capable of delivering nutraceutical actives from a formulation framework specifically for enhancing the in vitro and in vivo performance of model vitamin, cholecalciferol (Vitamin D3). Synthesis of a novel triple vitamin minitablet and an optimized bile salt/lipase alginate-glycerin film provided unique oral components for inclusion in a BAP capsule. Component validation and physicochemical characterizations included comparative ex vivo permeability, chemical structure mapping, thermodynamic analysis and magnetic resonance imaging. In vitro dissolution studies of the BAP produced an area under the dissolution curve (AUC) for cholecalciferol release that was 28% greater than a conventional comparator product. A total of 84.01% of cholecalciferol was released from the BAP within 3 h versus only 59% from a comparator. Ex vivo permeation studies revealed superior cholecalciferol membrane diffusion from the triple vitamin minitablet BAP component. In vivo performance showed a greater mean change from baseline cholecalciferol to peak plasma levels (Cmax) from the BAP compared to the comparator (55.66 versus 46.05 ng/mL). Cholecalciferol bioavailability was improved in vivo with an AUC0-inf from the BAP that was 3.2× greater than the conventional product. The BAP was also superior at improving and maintaining serum levels of the main metabolite, 25-hydroxyvitamin D3, compared to the conventional system. In vitro and in vivo results thus confirmed improvements in cholecalciferol dissolution, membrane permeability and plasma drug levels. The study results position the BAP as an ideal oral vehicle for enhanced delivery of cholecalciferol.

  3. Epidemiology of Klebsiella oxytoca-associated diarrhea detected by Simmons citrate agar supplemented with inositol, tryptophan, and bile salts.

    PubMed

    Cheng, Vincent C C; Yam, Wing-Cheong; Tsang, Lee-Lee; Yau, Miranda C Y; Siu, Gilman K H; Wong, Sally C Y; Chan, Jasper F W; To, Kelvin K W; Tse, Herman; Hung, Ivan F N; Tai, Josepha W M; Ho, Pak-Leung; Yuen, Kwok-Yung

    2012-05-01

    We studied the clinical and epidemiological characteristics of Klebsiella oxytoca-associated diarrhea in hospitalized patients in Hong Kong. Between 1 November 2009 and 30 April 2011, all inositol-fermenting colonies found on Simmons citrate agar supplemented with inositol, tryptophan, and bile salts (SCITB agar) used for the culturing of diarrheal stool samples were screened by a spot indole test for K. oxytoca. The overall sensitivity of SCITB agar plus the spot indole test (93.3%) for the detection of K. oxytoca in stool samples was superior to that of MacConkey agar (63.3%), while the specificities were 100% and 60.4%, respectively. The former achieved a 23-fold reduction in the workload and cost of subsequent standard biochemical identifications. Cytotoxin production and the clonality of K. oxytoca were determined by a cell culture cytotoxicity neutralization assay using HEp-2 cells and pulsed-field gel electrophoresis (PFGE), respectively. Of 5,581 stool samples from 3,537 patients, K. oxytoca was cultured from 117/5,581 (2.1%) stool samples from 104/3,537 (2.9%) patients. Seventy-six of 104 (73.1%) patients with K. oxytoca had no copathogens in their diarrheal stool samples. Twenty-four (31.6%) of 76 patients carried cytotoxin-producing strains, which were significantly associated with antibiotic therapy after hospital admission (50% versus 21.2%; P = 0.01). Health care-associated diarrhea was found in 44 (42%) of 104 patients with K. oxytoca, but there was no epidemiological linkage suggestive of a nosocomial outbreak, and PFGE showed a diverse pattern. None of the patients with cytotoxin-producing K. oxytoca developed antibiotic-associated hemorrhagic colitis, suggesting that K. oxytoca can cause a mild disease manifesting as uncomplicated antibiotic-associated diarrhea with winter seasonality.

  4. Interaction of Bile Salts with Model Membranes Mimicking the Gastrointestinal Epithelium: A Study by Isothermal Titration Calorimetry.

    PubMed

    Coreta-Gomes, Filipe M; Martins, Patrícia A T; Velazquez-Campoy, Adrián; Vaz, Winchil L C; Geraldes, Carlos F G; Moreno, Maria João

    2015-08-25

    Bile salts (BS) are biosurfactants synthesized in the liver and secreted into the intestinal lumen where they solubilize cholesterol and other hydrophobic compounds facilitating their gastrointestinal absorption. Partition of BS toward biomembranes is an important step in both processes. Depending on the loading of the secreted BS micelles with endogeneous cholesterol and on the amount of cholesterol from diet, this may lead to the excretion or absorption of cholesterol, from cholesterol-saturated membranes in the liver or to gastrointestinal membranes, respectively. The partition of BS toward the gastrointestinal membranes may also affect the barrier properties of those membranes affecting the permeability for hydrophobic and amphiphilic compounds. Two important parameters in the interaction of the distinct BS with biomembranes are their partition coefficient and the rate of diffusion through the membrane. Altogether, they allow the calculation of BS local concentrations in the membrane as well as their asymmetry in both membrane leaflets. The local concentration and, most importantly, its asymmetric distribution in the bilayer are a measure of induced membrane perturbation, which is expected to significantly affect its properties as a cholesterol donor and hydrophobic barrier. In this work we have characterized the partition of several BS, nonconjugated and conjugated with glycine, to large unilamellar vesicles (LUVs) in the liquid-disordered phase and with liquid-ordered/liquid-disordered phase coexistence, using isothermal titration calorimetry (ITC). The partition into the liquid-disordered bilayer was characterized by large partition coefficients and favored by enthalpy, while association with the more ordered membrane was weak and driven only by the hydrophobic effect. The trihydroxy BS partitions less efficiently toward the membranes but shows faster translocation rates, in agreement with a membrane protective effect of those BS. The rate of translocation

  5. Hydration Differences Explain the Large Variations in the Complexation Thermodynamics of Modified γ-Cyclodextrins with Bile Salts.

    PubMed

    Køhler, Jonatan; Schönbeck, Christian; Westh, Peter; Holm, René

    2016-01-28

    The structure and thermodynamics of inclusion complexes of seven different γ-cyclodextrins (γCDs) and three biologically relevant bile salts (BS) were investigated in the present study. Natural γCD and six modified γCDs [two methyl-γCDs, one sulfobutyl ether-γCD (SBEγCD), and three 2-hydroxypropyl-γCDs (HPγCD)] and their complexes with BS were investigated by isothermal titration calorimetry, NMR, and molecular dynamics simulations. With the exception of the fully methylated γCD, which did not bind the BSs investigated, all of the γCDs formed 1:1 complexes with the BS, and the structures were similar to those with natural γCD; i.e., the modifications of the γCD had limited structural impact on the formation of complexes. Isothermal titration calorimetry was carried out over in the temperature interval 5-55 °C to enable the calculation of the stability constant (K) and the thermodynamic parameters enthalpy (ΔH°), entropy (ΔS°), and heat capacity (ΔCp°). The stability constants decreased with an increased degree of substitution (DS), with methyl substituents having a lower effect on the stability constant than the sulfobutyl ether and hydroxypropyl substituents on the stability constants. Enthalpy-entropy compensation was observed, since both enthalpy and entropy increased with the degree of substitution, which may reflect dehydration of the hydrophobic surface on both CD and BS. Calculations based on ΔCp° data suggested that each of the substituents dehydrated 10-20 (hydroxypropyl), 22-33 (sulfobutyl ether), and 10-15 Å(2) (methyl) of the BS surface area, in reasonable agreement with estimates from the molecular dynamics simulations. Combined with earlier investigations on modified βCDs, these results indicate general trends of the substituents on the thermodynamics of complex formation.

  6. A multimedia CD-ROM tool to improve student understanding of bile salts and bilirubin metabolism: evaluation of its use in a medical hybrid PBL course.

    PubMed

    Azer, Samy A

    2005-03-01

    Over the last 35 years our understanding of bile salts, bilirubin metabolism, and hepatobiliary transport has progressively increased. From 1965 to the end of 2002, 3,610 articles and review papers have been published on hepatobiliary and enterocyte transport of bile salts. However, there is a lack of information in the content of current textbooks about hepatobiliary physiology, bile salt transporters, bile formation, mechanisms underlying cholestasis, and drug-induced liver injury. The use of an integrated multimedia program on the liver covering these gaps in textbooks may be useful to student learning. This study aims to 1) assess student views on a multimedia CD-ROM ("The Liver") integrating basic and clinical sciences related to the liver, bile salts, and bilirubin metabolism, 2) assess the usefulness of problem-based learning (PBL) cases included in the multimedia CD-ROM, and 3) assess student learning before and after use of the multimedia CD-ROM. A total of 106 first-year medical students (27 with and 79 without a prior university degree) at the University of Melbourne participated in this study. Students were tested on the liver, bile salts, and bilirubin metabolism before and after using the multimedia CD-ROM. After completing the multimedia CD-ROM, each student filled out a 5-point Likert scale questionnaire evaluating the features of the program and its usefulness to their learning. Results show that the aims of the package were clear to participants, the contents were logically organized and clear, the key concepts were easy to identify, the contents were pitched to an appropriate level, and the package was interactive and encouraged participants to reflect on their learning. Students also agreed that the assessment tools used in the program and the feedback provided were meaningful and helpful to their learning. No differences were found when responses were compared on the basis of academic background, gender, citizenship, or first language of

  7. The method of polarization selection of laser images in diagnostics of polycrystalline structure of human bile layers

    NASA Astrophysics Data System (ADS)

    Ivashchuk, I. O.; Marchuk, Yu. F.; Fediv, O. I.; Andriychuk, D. R.

    2011-09-01

    In this paper the possibility of polarization correlometry complex distributions of azimuth and ellipticity of laser images polarization of layers of human bile. Were found new approach of comparative analysis of polarization of different points in the far field. The principles of optical model of human bile polycrystalline structure are described. The results of investigating the interrelation between the values of statistical, correlation and fractal parameters are presented. They characterize the coordinate distributions of mutual polarization degree of the points of laser images of bile smears of cholelithiasis patients in combination with other pathologies. The diagnostic criteria of the cholelithiasis nascency and its severity degree differentiation are determined.

  8. The method of polarization selection of laser images in diagnostics of polycrystalline structure of human bile layers

    NASA Astrophysics Data System (ADS)

    Ivashchuk, I. O.; Marchuk, Yu. F.; Fediv, O. I.; Andriychuk, D. R.

    2012-01-01

    In this paper the possibility of polarization correlometry complex distributions of azimuth and ellipticity of laser images polarization of layers of human bile. Were found new approach of comparative analysis of polarization of different points in the far field. The principles of optical model of human bile polycrystalline structure are described. The results of investigating the interrelation between the values of statistical, correlation and fractal parameters are presented. They characterize the coordinate distributions of mutual polarization degree of the points of laser images of bile smears of cholelithiasis patients in combination with other pathologies. The diagnostic criteria of the cholelithiasis nascency and its severity degree differentiation are determined.

  9. Gamma-glutamyltransferase fractions in human plasma and bile: characteristic and biogenesis.

    PubMed

    Fornaciari, Irene; Fierabracci, Vanna; Corti, Alessandro; Aziz Elawadi, Hassan; Lorenzini, Evelina; Emdin, Michele; Paolicchi, Aldo; Franzini, Maria

    2014-01-01

    Total plasma gamma-glutamyltransferase (GGT) activity is a sensitive, non-specific marker of liver dysfunction. Four GGT fractions (b-, m-, s-, f-GGT) were described in plasma and their differential specificity in the diagnosis of liver diseases was suggested. Nevertheless fractional GGT properties have not been investigated yet. The aim of this study was to characterize the molecular nature of fractional GGT in both human plasma and bile. Plasma was obtained from healthy volunteers; whereas bile was collected from patients undergoing liver transplantation. Molecular weight (MW), density, distribution by centrifugal sedimentation and sensitivity to both detergent (deoxycholic acid) and protease (papain) were evaluated. A partial purification of b-GGT was obtained by ultracentrifugation. Plasma b-GGT fraction showed a MW of 2000 kDa and a density between 1.063-1.210 g/ml. Detergent converted b-GGT into s-GGT, whereas papain alone did not produce any effect. Plasma m-GGT and s-GGT showed a MW of 1,000 and 200 kDa, and densities between 1.006-1.063 g/ml and 1.063-1.210 g/ml respectively. Both fractions were unaffected by deoxycholic acid, while GGT activity was recovered into f-GGT peak after papain treatment. Plasma f-GGT showed a MW of 70 kDa and a density higher than 1.21 g/ml. We identified only two chromatographic peaks, in bile, showing similar characteristics as plasma b- and f-GGT fractions. These evidences, together with centrifugal sedimentation properties and immunogold electronic microscopy data, indicate that b-GGT is constituted of membrane microvesicles in both bile and plasma, m-GGT and s-GGT might be constituted of bile-acid micelles, while f-GGT represents the free-soluble form of the enzyme.

  10. Gamma-Glutamyltransferase Fractions in Human Plasma and Bile: Characteristic and Biogenesis

    PubMed Central

    Fornaciari, Irene; Fierabracci, Vanna; Corti, Alessandro; Aziz Elawadi, Hassan; Lorenzini, Evelina; Emdin, Michele; Paolicchi, Aldo; Franzini, Maria

    2014-01-01

    Total plasma gamma-glutamyltransferase (GGT) activity is a sensitive, non-specific marker of liver dysfunction. Four GGT fractions (b-, m-, s-, f-GGT) were described in plasma and their differential specificity in the diagnosis of liver diseases was suggested. Nevertheless fractional GGT properties have not been investigated yet. The aim of this study was to characterize the molecular nature of fractional GGT in both human plasma and bile. Plasma was obtained from healthy volunteers; whereas bile was collected from patients undergoing liver transplantation. Molecular weight (MW), density, distribution by centrifugal sedimentation and sensitivity to both detergent (deoxycholic acid) and protease (papain) were evaluated. A partial purification of b-GGT was obtained by ultracentrifugation. Plasma b-GGT fraction showed a MW of 2000 kDa and a density between 1.063–1.210 g/ml. Detergent converted b-GGT into s-GGT, whereas papain alone did not produce any effect. Plasma m-GGT and s-GGT showed a MW of 1,000 and 200 kDa, and densities between 1.006-1.063 g/ml and 1.063–1.210 g/ml respectively. Both fractions were unaffected by deoxycholic acid, while GGT activity was recovered into f-GGT peak after papain treatment. Plasma f-GGT showed a MW of 70 kDa and a density higher than 1.21 g/ml. We identified only two chromatographic peaks, in bile, showing similar characteristics as plasma b- and f-GGT fractions. These evidences, together with centrifugal sedimentation properties and immunogold electronic microscopy data, indicate that b-GGT is constituted of membrane microvesicles in both bile and plasma, m-GGT and s-GGT might be constituted of bile-acid micelles, while f-GGT represents the free-soluble form of the enzyme. PMID:24533101

  11. Characterization of AQPs in Mouse, Rat, and Human Colon and Their Selective Regulation by Bile Acids

    PubMed Central

    Yde, Jonathan; Keely, Stephen; Wu, Qi; Borg, Johan F.; Lajczak, Natalia; O’Dwyer, Aoife; Dalsgaard, Peter; Fenton, Robert A.; Moeller, Hanne B.

    2016-01-01

    In normal individuals, the epithelium of the colon absorbs 1.5–2 l of water a day to generate dehydrated feces. However, in the condition of bile acid malabsorption (BAM), an excess of bile acids in the colon results in diarrhea. Several studies have attempted to address the mechanisms contributing to BAM induced by various bile acids. However, none have addressed a potential dysregulation of aquaporin (AQP) water channels, which are responsible for the majority of transcellular water transport in epithelial cells, as a contributing factor to the onset of diarrhea and the pathogenesis of BAM. In this study, we aimed to systematically analyze the expression of AQPs in colonic epithelia from rat, mouse, and human and determine whether their expression is altered in a rat model of BAM. Mass spectrometry-based proteomics, RT-PCR, and western blotting identified various AQPs in isolated colonic epithelial cells from rats (AQP1, 3, 4, 7, 8) and mice (AQP1, 4, 8). Several AQPs were also detected in human colon (AQP1, 3, 4, 7–9). Immunohistochemistry localized AQP1 to the apical plasma membrane of epithelial cells in the bottom of the crypts, whereas AQP3 (rat, human) and AQP4 (mice, human) were localized predominantly in the basolateral plasma membrane. AQP8 was localized intracellularly and at the apical plasma membrane of epithelial cells. Rats fed sodium cholate for 72 h had significantly increased fecal water content, suggesting development of BAM-associated diarrhea. Colonic epithelial cells isolated from this model had significantly altered levels of AQP3, 7, and 8, suggesting that these AQPs may be involved in the pathogenesis of bile acid-induced diarrhea. PMID:27777930

  12. Na+/Taurocholate Cotransporting Polypeptide and Apical Sodium-Dependent Bile Acid Transporter Are Involved in the Disposition of Perfluoroalkyl Sulfonates in Humans and Rats

    PubMed Central

    Zhao, Wen; Zitzow, Jeremiah D.; Ehresman, David J.; Chang, Shu-Ching; Butenhoff, John L.; Forster, Jameson; Hagenbuch, Bruno

    2015-01-01

    Among the perfluoroalkyl sulfonates (PFASs), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) have half-lives of several years in humans, mainly due to slow renal clearance and potential hepatic accumulation. Both compounds undergo enterohepatic circulation. To determine whether transporters involved in the enterohepatic circulation of bile acids are also involved in the disposition of PFASs, uptake of perfluorobutane sulfonate (PFBS), PFHxS, and PFOS was measured using freshly isolated human and rat hepatocytes in the absence or presence of sodium. The results demonstrated sodium-dependent uptake for all 3 PFASs. Given that the Na+/taurocholate cotransporting polypeptide (NTCP) and the apical sodium-dependent bile salt transporter (ASBT) are essential for the enterohepatic circulation of bile acids, transport of PFASs was investigated in stable CHO Flp-In cells for human NTCP or HEK293 cells transiently expressing rat NTCP, human ASBT, and rat ASBT. The results demonstrated that both human and rat NTCP can transport PFBS, PFHxS, and PFOS. Kinetics with human NTCP revealed Km values of 39.6, 112, and 130 µM for PFBS, PFHxS, and PFOS, respectively. For rat NTCP Km values were 76.2 and 294 µM for PFBS and PFHxS, respectively. Only PFOS was transported by human ASBT whereas rat ASBT did not transport any of the tested PFASs. Human OSTα/β was also able to transport all 3 PFASs. In conclusion, these results suggest that the long half-live and the hepatic accumulation of PFOS in humans are at least, in part, due to transport by NTCP and ASBT. PMID:26001962

  13. Bile acid transporters

    PubMed Central

    Dawson, Paul A.; Lan, Tian; Rao, Anuradha

    2009-01-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na+ taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTα-OSTβ. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers. PMID:19498215

  14. Bile acid transporters.

    PubMed

    Dawson, Paul A; Lan, Tian; Rao, Anuradha

    2009-12-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na(+) taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTalpha-OSTbeta. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26543366

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

    PubMed

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

    2015-01-01

    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.

  17. Image-guided intervention in the human bile duct using scanning fiber endoscope system

    NASA Astrophysics Data System (ADS)

    Seibel, Eric J.; Jo, Javier A.; Melville, C. David; Johnston, Richard S.; Naumann, Christopher R.; Saunders, Michael D.

    2012-01-01

    Bile duct cancers are increasing in frequency while being difficult to diagnose. Currently available endoscopic imaging devices used in the biliary tree are low resolution with poor image quality, leading to inadequate evaluation of indeterminate biliary strictures. However, a new ultrathin and flexible cholangioscope system has been successfully demonstrated in a human subject. This mini-cholangioscope system uses a scanning fiber endoscope (SFE) as a forward-imaging guidewire, dimensions of 1.2-mm diameter and 3-m length. Full color video (500-line resolution at 30Hz) is the standard SFE imaging mode using spiral scanning of red, green, and blue laser light at low power. Image-guided operation of the biopsy forceps was demonstrated in healthy human bile ducts with and without saline flushing. The laser-based video imaging can be switched to various modes to enhance tissue markers of disease, such as widefield fluorescence and enhanced spectral imaging. In parallel work, biochemical discrimination of tissue health in pig bile duct has been accomplished using fiberoptic delivery of pulsed UV illumination and time-resolved autofluorescence spectroscopic measurements. Implementation of time-resolved fluorescence spectroscopy for biochemical assessment of the bile duct wall is being done through a secondary endoscopic channel. Preliminary results indicate that adequate SNR levels (> 30 dB) can be achieved through a 50 micron fiber, which could serve as an optical biopsy probe. The SFE is an ideal mini-cholangioscope for integration of both tissue and molecular specific image contrast in the future. This will provide the physician with unprecedented abilities to target biopsy locations and perform endoscopically-guided therapies.

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

    SciTech Connect

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

    2012-10-25

    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.

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

    PubMed Central

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

    2011-01-01

    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 α3 and α7, with concomitant movement in the orientation of helix α7 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. PMID:22423359

  20. The protective effect of hydrophilic bile acids on bile acid hepatotoxicity in the rat.

    PubMed

    Kitani, K

    1995-09-01

    Taurochenodeoxycholate (TCDC) (or taurocholate, TC) excessively i.v. infused in rats causes an acute cholestasis accompanied by an excessive excretion of various proteins (lactate dehydrogenase, LDH, albumin, etc.) into the bile. This cholestasis was initially found to be effectively prevented by a simultaneous infusion of tauroursodeoxycholate (TUDC). Later this property was found to be shared by glycoursodeoxycholate (GUDC) and tauro (and glyco) alpha and beta-muricholate (MC) all known to be relatively hydrophilic. The extent of the preventative effect appears to be comparable for taurine and glycine conjugates of all three bile salts (UDC, alpha-MC and beta-MC). An albumin leakage into the bile enhanced by TCDC infusion appears to be mainly from albumin in the serum, since i.v. injected 125I-human serum albumin excretion into the bile paralled the rat albumin excretion. Despite very drastic biochemical abnormalities induced by TCDC infusion, morphological correlates in the liver are scarce both from light and electron microscopic examinations, the only correlate with biochemical parameters being a sporadic necrosis of hepatocytes, especially in the periportal areas. Although there is not sufficient morphological evidence, it appears that TCDC infusion causes a direct communication between serum and bile leading to a rapid leakage of large molecules such as albumin and even gamma-globulin. Conjugates of hydrophilic bile salts such as UDC, alpha-MC and beta-MC efficiently prevent such bile abnormalities but their hydrophilicity is not the sole determinant of this property since a more hydrophilic bile salt such as taurodehydrocholate does not possess this property. The underlying mechanism(s) for this protective property remains uncertain.

  1. 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.

    PubMed

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

    2015-02-24

    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.

  2. 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

    PubMed Central

    Lin, Pei-Pei; Hsieh, You-Miin; Zhang, Zi-yi; Wu, Hui-Ching; Huang, Chun-Chih

    2014-01-01

    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. PMID:25538960

  3. Function of the liver and bile ducts in humans exposed to lead.

    PubMed

    Kasperczyk, A; Dziwisz, M; Ostałowska, A; Swietochowska, E; Birkner, E

    2013-08-01

    Lead is very common in the environment, and it is therefore important to characterize its possible adverse health effects. The aim of this study was to evaluate the impact of lead exposure on selected functions of the liver and bile ducts in people who are chronically exposed to the metal because of their occupations. To provide this information, the activity of specific enzymes and the bilirubin concentration were determined in blood serum, and morphological parameters of the liver and bile ducts were evaluated using the ultrasonic imaging method. Healthy male employees of a lead-zinc processing facility (n = 145) who were occupationally exposed to lead were divided into two subgroups as a function of the lead concentrations in blood (PbB): low lead exposure (PbB = 20-35 μg/dl; n = 57) and high lead exposure (PbB = 35-60 μg/dl; n = 88). Human exposure to lead compounds was found to cause liver enlargement and to activate inflammatory reactions with the characteristics of moderate cholestasis within the bile ducts, while no characteristics of necrotic damage of hepatic cells were noted. It seems that lipid peroxidation can be one of the toxic mechanisms of lead which induce moderate cholestasis. The effects depend on the extent of the lead exposure and were greater in subjects with higher exposure levels, particularly subjects with PbB values greater than 35 μg/dl.

  4. Effects of encapsulation on the viability of potential probiotic Lactobacillus plantarum exposed to high acidity condition and presence of bile salts.

    PubMed

    Tee, W F; Nazaruddin, R; Tan, Y N; Ayob, M K

    2014-09-01

    This study investigated the survival of encapsulated potential probiotic Lactobacillus plantarum which isolated from fermented cocoa beans. κ-Carrageenan was used to encapsulate the probiotic. Encapsulation techniques such as emulsification, freeze-drying or extrusion were adopted to encapsulate the probiotic. Freeze-drying and extrusion methods showed higher (p < 0.05) efficiency (89.48 ± 3.21 and 92.26 ± 1.45%, respectively) in encapsulating the probiotic compared to the emulsification method (82.19 ± 0.71% efficiency). Freeze-dried encapsulated probiotic L. plantarum was selected for further survival analysis as greater amount of beads were produced compared to the extrusion method. Freeze-dried probiotic was found to have significantly (p < 0.05) higher tolerance to acid at pH 2 with higher survival percentage compared to non-encapsulated probiotic. However, freeze-drying encapsulation was proven not to enhance the resistance of the probiotic to bile salt as evidenced by the one log colony reduction as for the non-encapsulated probiotic. Further modification of freeze-drying encapsulation technique is needed to enhance the survival of the encapsulated potential probiotic L. plantarum toward bile salt in the future. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  5. Isolation, Identification, and Evaluation of New Lactic Acid Bacteria Strains with Both Cellular Antioxidant and Bile Salt Hydrolase Activities In Vitro.

    PubMed

    Xu, Shuang; Liu, Taigang; Radji, Chiraz Akorede Ibinke; Yang, Jing; Chen, Lanming

    2016-11-01

    In this study, we analyzed Chinese traditional fermented food to isolate and identify new lactic acid bacteria (LAB) strains with novel functional properties and to evaluate their cellular antioxidant and bile salt hydrolase (BSH) activities in vitro. A sequential screening strategy was developed to efficiently isolate and obtain 261 LAB strains tolerant of bile salt, acid, and H2O2 from nine Chinese traditional fermented foods. Among these strains, 70 were identified as having 2,2-diphenyl-1-picrylhydrazyl radical scavenging and/or BSH activity. These strains belonged to eight species: Enterococcus faecium (33% of the strains), Lactobacillus plantarum (26%), Leuconostoc mesenteroides (14%), Pediococcus pentosaceus (6%), Enterococcus durans (9%), Lactobacillus brevis (9%), Pediococcus ethanolidurans (3%), and Lactobacillus casei (1%). The pulsed-field gel electrophoresis genome fingerprinting profiles of these strains revealed 38 distinct pulsotypes, indicating a high level of genomic diversity among the tested strains. Twenty strains were further evaluated for hydroxyl radical scavenging activity, reducing power, and ferrous ion chelating activity exerted by both viable intact cells and/or intracellular cell-free extracts. Some strains, such as L. plantarum D28 and E. faecium B28, had high levels of both cellular antioxidant and BSH activities in vitro. These strains are promising probiotic components for health-promoting functional foods.

  6. A comparative study of microstructural development in paired human hepatic and gallbladder biles.

    PubMed

    Weihs, Daphne; Schmidt, Judith; Danino, Dganit; Goldiner, Ilana; Leikin-Gobbi, Diana; Eitan, Arieh; Rubin, Moshe; Talmon, Yeshayahu; Konikoff, Fred M

    2007-10-01

    Cholesterol gallstones usually develop in the gallbladder and rarely form in bile ducts even in patients with highly lithogenic bile. Bile concentration and proteins (e.g. mucin) may affect crystallization, but the exact nature of this effect, especially in relation to crystallization pathways and microstructural evolution remains unclear. We examined lipid microstructures in paired hepatic and gallbladder biles to reveal ones that are essential for crystallization. Combining digital light microscopy with cryogenic-temperature transmission electron microscopy we are able to directly visualize and compare the time evolution of lipid microstructures in paired hepatic, gallbladder and diluted gallbladder biles of gallstone patients and controls, without drying or separating. Gallbladder bile exhibited several multilamellar vesicles and spheroidal micelles preceding and throughout crystallization. Vesicle morphology changed before crystallization was observed. In contrast, hepatic bile revealed almost no crystallization and while a variety of unilamellar vesicles and spheroidal micelles existed throughout the examination, multilamellar vesicles were rare. Diluted gallbladder bile was different from native gallbladder bile, as well as the paired hepatic bile, yielding occasional crystallization. Our findings suggest that maturing multilamellar vesicles precede (and at least partially initiate) crystallization in gallbladder bile. Although microstructural development seems to be concentration dependent, dilution of gallbladder bile to hepatic bile concentrations neither makes it identical to hepatic bile, nor prevents crystallization.

  7. Human liver class I alcohol dehydrogenase gammagamma isozyme: the sole cytosolic 3beta-hydroxysteroid dehydrogenase of iso bile acids.

    PubMed

    Marschall, H U; Oppermann, U C; Svensson, S; Nordling, E; Persson, B; Höög, J O; Jörnvall, H

    2000-04-01

    3beta-Hydroxy (iso) bile acids are formed during enterohepatic circulation from 3alpha-hydroxy bile acids and constitute normal compounds in plasma but are virtually absent in bile. Isoursodeoxycholic acid (isoUDCA) is a major metabolite of UDCA. In a recent study it was found that after administration of isoUDCA, UDCA became the major acid in bile. Thus, epimerization of the 3beta-hydroxy to a 3alpha-hydroxy group, catalyzed by 3beta-hydroxysteroid dehydrogenases (HSD) and 3-oxo-reductases must occur. The present study aims to characterize the human liver bile acid 3beta-HSD. Human liver cytosol and recombinant alcohol dehydrogenase (ADH) betabeta and gammagamma isozymes were subjected to native polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing. Activity staining with oxidized nicotinamide adenine dinucleotide (NAD(+)) or oxidized nicotinamide adenine dinucleotide phosphate (NADP(+)) as cofactors and various iso bile acids as substrates was used to screen for 3beta-HSD activity. Reaction products were identified and quantified by gas chromotography/mass spectrometry (GC/MS). Computer-assisted substrate docking of isoUDCA to the active site of a 3-dimensional model of human class I gammagamma ADH was performed. ADH gammagamma isozyme was identified as the iso bile acid 3beta-HSD present in human liver cytosol, with NAD(+) as a cofactor. Values for k(cat)/K(m) were in the rank order isodeoxycholic acid (isoDCA), isochenodeoxycholic acid (isoCDCA), isoUDCA, and isolithocholic acid (isoLCA) (0.10, 0.09, 0.08, and 0. 05 min(-1) x micromol/L(-1), respectively). IsoUDCA fits as substrate to the 3-dimensional model of the active-site of ADH gammagamma. ADH gammagamma isozyme was defined as the only bile acid 3beta-HSD in human liver cytosol. Hydroxysteroid dehydrogenases are candidates for the binding and transport of 3alpha-hydroxy bile acids. We assume that ADH gammagamma isozyme is involved in cytosolic bile acid binding and transport processes as well.

  8. Identification of lactic acid bacteria isolated from the fecal samples of healthy humans and patients with dyspepsia, and determination of their ph, bile, and antibiotic tolerance properties.

    PubMed

    Kiliç, Gülden Başyiğit; Karahan, Aynur Gül

    2010-01-01

    The research of novel probiotic strains is important in order to satisfy the increasing request of the market and to obtain functional products in which the probiotic cultures are more active and have better probiotic characteristics than those already on the market. In this study, the probiotic potential of Lactobacillus and Enterococcus strains isolated from human feces was investigated. One hundred seven strains of lactic acid bacteria were isolated from the fecal samples of 19 adult volunteers with stomach problems and the fecal samples of 12 healthy adult volunteers. The strains were identified by 16S rRNA analysis and examined for resistance to gastric acidity (pH 3.5) and bile salts (0.3% bile salt). The antibiotic susceptibility of the strains was also determined. The counts of lactic acid bacteria in the fecal samples ranged from 1.7 x 10(7) to 3.1 x 10(10) CFU/g. The species present in those samples were found to be Lactobacillusplantarum, L. fermentum, Enterococcus faecium and E. durans. Results indicated that L. plantarum (AA1-2, AA17-73, AC18-88, AK4-11, and AK7-28), L. fermentum (AB5-18, BB16-75, and AK4-180), E. faecium (AB20-98 and BK11-50) and E. durans (AK4-14 and BK9-40) showed good pH and bile tolerance. These strains are potentially good candidates for use as health-promoting bacteria.

  9. Potent stimulation of fibroblast growth factor 19 expression in the human ileum by bile acids.

    PubMed

    Zhang, Justine H; Nolan, Jonathan D; Kennie, Sarah L; Johnston, Ian M; Dew, Tracy; Dixon, Peter H; Williamson, Catherine; Walters, Julian R F

    2013-05-15

    Fibroblast growth factor 19 (FGF19) is proposed to be a negative feedback regulator of hepatic bile acid (BA) synthesis. We aimed to clarify the distribution of FGF19 expression in human intestine and to investigate induction in a novel explant system. Ileal and colonic mucosal biopsies were obtained at endoscopy and analyzed for FGF19 transcript expression. Primary explants were incubated with physiological concentrations of various BA for up to 6 h, and expression of FGF19 and other genes was determined. FGF19 transcripts were detected in ileum but were unquantifiable in colon. No loss of FGF19 mRNA occurred as a consequence of the explant system. Ileal FGF19 transcript expression was induced 350-fold by 50 μM chenodeoxycholate (CDCA, n = 24, P < 0.0001) and 161-fold by 50 μM glycochenodeoxycholate (GCDCA, n = 12, P = 0.0005). The responses of other genes to CDCA or GCDCA (50 μM) were smaller: median increases of ileal bile acid binding protein, organic solute transporter-α and -β, and short heterodimer partner were 2.4- to 4.0-fold; apical membrane sodium bile acid transporter and farnesoid X receptor (FXR) showed little change. The EC50 for FGF19 transcript induction by CDCA was 20 μM. FGF19 protein concentrations were significantly higher in the culture fluid from BA-stimulated explants. FGF19 induction with cholate was 81% of that found with CDCA, but deoxycholate (40%) and lithocholate (4%) were significantly less potent. The synthetic FXR agonist obeticholic acid was much more potent than CDCA with a 70-fold FGF19 stimulation at 1 μM. We concluded that FGF19 expression in human ileum is very highly responsive to BA. Changes in FGF19 induction are a potential mechanism involved in disorders of BA homeostasis.

  10. Potent stimulation of fibroblast growth factor 19 expression in the human ileum by bile acids

    PubMed Central

    Zhang, Justine H.; Nolan, Jonathan D.; Kennie, Sarah L.; Johnston, Ian M.; Dew, Tracy; Dixon, Peter H.; Williamson, Catherine

    2013-01-01

    Fibroblast growth factor 19 (FGF19) is proposed to be a negative feedback regulator of hepatic bile acid (BA) synthesis. We aimed to clarify the distribution of FGF19 expression in human intestine and to investigate induction in a novel explant system. Ileal and colonic mucosal biopsies were obtained at endoscopy and analyzed for FGF19 transcript expression. Primary explants were incubated with physiological concentrations of various BA for up to 6 h, and expression of FGF19 and other genes was determined. FGF19 transcripts were detected in ileum but were unquantifiable in colon. No loss of FGF19 mRNA occurred as a consequence of the explant system. Ileal FGF19 transcript expression was induced 350-fold by 50 μM chenodeoxycholate (CDCA, n = 24, P < 0.0001) and 161-fold by 50 μM glycochenodeoxycholate (GCDCA, n = 12, P = 0.0005). The responses of other genes to CDCA or GCDCA (50 μM) were smaller: median increases of ileal bile acid binding protein, organic solute transporter-α and -β, and short heterodimer partner were 2.4- to 4.0-fold; apical membrane sodium bile acid transporter and farnesoid X receptor (FXR) showed little change. The EC50 for FGF19 transcript induction by CDCA was 20 μM. FGF19 protein concentrations were significantly higher in the culture fluid from BA-stimulated explants. FGF19 induction with cholate was 81% of that found with CDCA, but deoxycholate (40%) and lithocholate (4%) were significantly less potent. The synthetic FXR agonist obeticholic acid was much more potent than CDCA with a 70-fold FGF19 stimulation at 1 μM. We concluded that FGF19 expression in human ileum is very highly responsive to BA. Changes in FGF19 induction are a potential mechanism involved in disorders of BA homeostasis. PMID:23518683

  11. Influence of acid and bile acid on ERK activity, PPARγ expression and cell proliferation in normal human esophageal epithelial cells

    PubMed Central

    Jiang, Zhi-Ru; Gong, Jun; Zhang, Zhen-Ni; Qiao, Zhe

    2006-01-01

    AIM: To observe the effects of acid and bile acid exposure on cell proliferation and the expression of extracellular signal-regulated protein kinase (ERK) and peroxisome proliferator-activated receptor γ (PPARγ) in normal human esophageal epithelial cells in vitro. METHODS: In vitro cultured normal human esophageal epithelial cells were exposed to acidic media (pH 4.0 - 6.5), media containing different bile acid (250 μmol/L), media containing acid and bile acid, respectively. Cell proliferation was assessed using MTT and flow cytometry. The expressions of phosphorylated ERK1/2 and PPARγ protein were determined by the immunoblotting technique. RESULTS: Acid-exposed (3 min) esophageal cells exhibited a significant increase in proliferation ratio, S phase of the cell cycle (P < 0.05) and the level of phosphorylated ERK1/2 protein. When the acid-exposure period exceeded 6 min, we observed a decrease in proliferation ratio and S phase of the cell cycle, with an increased apoptosis ratio (P < 0.05). Bile acid exposure (3-12 min) also produced an increase in proliferation ratio, S phase of the cell cycle (P < 0.05) and phosphorylated ERK1/2 expression. On the contrary, deoxycholic acid (DCA) exposure (> 20 min) decreased proliferation ratio. Compared with bile acid exposure (pH 7.4), bile acid exposure (pH 6.5, 4) significantly decreased proliferation ratio (P < 0.05). There was no expression of PPARγ in normal human esophageal epithelial cells. CONCLUSION: The rapid stimuli of acid or bile acid increase proliferation in normal human esophageal epithelial cells by activating the ERK pathway. PMID:16688842

  12. Profiling serum bile acid glucuronides in humans: gender divergences, genetic determinants and response to fenofibrate

    PubMed Central

    Trottier, Jocelyn; Perreault, Martin; Rudkowska, Iwona; Levy, Cynthia; Dallaire-Theroux, Amélie; Verreault, Mélanie; Caron, Patrick; Staels, Bart; Vohl, Marie-Claude; Straka, Robert J.; Barbier, Olivier

    2014-01-01

    Glucuronidation, catalyzed by UDP-glucuronosyltransferase (UGT) enzymes detoxifies cholestatic bile acids (BAs). We aimed at i) characterizing the circulating BA-glucuronide (-G) pool composition in humans, ii) evaluating how sex and UGT polymorphisms influence this composition, and iii) analyzing the effects of lipid-lowering drug fenofibrate on the circulating BA-G profile in 300 volunteers and 5 cholestatic patients. Eleven BA-Gs were determined in pre- and post-fenofibrate samples. Men exhibited higher BA-G concentrations, and various genotype/BA-G associations were discovered in relevant UGT genes. The chenodeoxycholic acid-3G concentration was associated with the UGT2B7 802C>T polymorphism. Glucuronidation assays confirmed the predominant role of UGT2B7 and UGT1A4 in CDCA-3G formation. Fenofibrate exposure increased the serum levels of 5 BA-G species, including CDCA-3G, and up-regulated expression of UGT1A4, but not UGT2B7, in hepatic cells. This study demonstrates that fenofibrate stimulates BA glucuronidation in humans, and thus reduces bile acid toxicity in the liver. PMID:23756370

  13. Oxysterols from human bile induce apoptosis of canine gallbladder epithelial cells in monolayer culture.

    PubMed

    Seo, Dong Wan; Choi, Ho-Soon; Lee, Sum P; Kuver, Rahul

    2004-12-01

    Oxysterols have been detected in various mammalian organs and blood. Biliary epithelium is exposed to high concentrations of cholesterol, and we have identified three keto-oxysterols (cholest-4-en-3-one, cholesta-4,6-dien-3-one, cholesta-3,5-dien-7-one) in human bile and gallstones. Because the effects of oxysterols on biliary physiology are not well defined, we investigated their biological effects on dog gallbladder epithelial cells. Enriched medium (culture medium containing taurocholate and lecithin and cholesterol +/- various oxysterols) was applied to confluent monolayers of dog gallbladder epithelial cells in culture. Cytotoxicity and apoptosis were studied by morphological analysis and flow cytometry. Oxysterols in the mitochondrial fraction were identified by gas chromatography/mass spectrometry, whereas release of cytochrome c from mitochondria was assayed by spectrophotometry and Western blot analysis. Compared with cells treated with culture medium or with enriched medium containing cholesterol, oxysterol-treated cells showed significantly increased apoptosis (P < 0.05). Exogenously applied oxysterols were recovered from the mitochondrial fraction. Cytochrome c release from mitochondria was increased significantly by cholest-4-en-3-one, cholesta-4,6-dien-3-one, and 5beta-cholestan-3-one (all P < 0.05). Thus oxysterols recovered from human bile and gallstones induce apoptosis of biliary epithelium via a mitochondrial-dependent pathway and may play a role in the pathogenesis of chronic inflammation and carcinogenesis in the gallbladder.

  14. Transport across Caco-2 cell monolayer and sensitivity to hydrolysis of two anxiolytic peptides from αs1-casein, α-casozepine, and αs1-casein-f91-97: effect of bile salts.

    PubMed

    Cakir-Kiefer, Céline; Miclo, Laurent; Balandras, Frédérique; Dary, Annie; Soligot, Claire; Le Roux, Yves

    2011-11-23

    α-Casozepine and f91-97, peptides from α(s1)-casein, display anxiolytic activity in rats and may have to cross the intestinal epithelium to exert this central effect. We evaluated their resistance to hydrolysis by the peptidases of Caco-2 cells and their ability to cross the cell monolayer. To mimic physiological conditions, two preparations of bile salts were used in noncytotoxic concentrations: porcine bile extract and an equimolar mixture of taurocholate, cholate, and deoxycholate. The presence and composition of bile salts appeared to modulate the peptidase activities of the Caco-2 cells involved (i) in the hydrolysis of α-casozepine, leading to much higher formation of fragments f91-99, f91-98, and f91-97, and (ii) in the hydrolysis of f91-97, leading to lower degradation of this peptide. Transport of α-casozepine across Caco-2 monolayer increased significantly, in the presence of bile extract, and of fragment f91-97, in the presence of bile salts.

  15. Computational models for drug inhibition of the human apical sodium-dependent bile acid transporter.

    PubMed

    Zheng, Xiaowan; Ekins, Sean; Raufman, Jean-Pierre; Polli, James E

    2009-01-01

    The human apical sodium-dependent bile acid transporter (ASBT; SLC10A2) is the primary mechanism for intestinal bile acid reabsorption. In the colon, secondary bile acids increase the risk of cancer. Therefore, drugs that inhibit ASBT have the potential to increase the risk of colon cancer. The objectives of this study were to identify FDA-approved drugs that inhibit ASBT and to derive computational models for ASBT inhibition. Inhibition was evaluated using ASBT-MDCK monolayers and taurocholate as the model substrate. Computational modeling employed a HipHop qualitative approach, a Hypogen quantitative approach, and a modified Laplacian Bayesian modeling method using 2D descriptors. Initially, 30 compounds were screened for ASBT inhibition. A qualitative pharmacophore was developed using the most potent 11 compounds and applied to search a drug database, yielding 58 hits. Additional compounds were tested, and their K(i) values were measured. A 3D-QSAR and a Bayesian model were developed using 38 molecules. The quantitative pharmacophore consisted of one hydrogen bond acceptor, three hydrophobic features, and five excluded volumes. Each model was further validated with two external test sets of 30 and 19 molecules. Validation analysis showed both models exhibited good predictability in determining whether a drug is a potent or nonpotent ASBT inhibitor. The Bayesian model correctly ranked the most active compounds. In summary, using a combined in vitro and computational approach, we found that many FDA-approved drugs from diverse classes, such as the dihydropyridine calcium channel blockers and HMG CoA-reductase inhibitors, are ASBT inhibitors.

  16. Computational Models for Drug Inhibition of the Human Apical Sodium-dependent Bile Acid Transporter

    PubMed Central

    Zheng, Xiaowan; Ekins, Sean; Raufman, Jean-Pierre; Polli, James E.

    2009-01-01

    The human apical sodium-dependent bile acid transporter (ASBT; SLC10A2) is the primary mechanism for intestinal bile acid re-absorption. In the colon, secondary bile acids increase the risk of cancer. Therefore, drugs that inhibit ASBT have the potential to increase the risk of colon cancer. The objectives of this study were to identify FDA-approved drugs that inhibit ASBT and to derive computational models for ASBT inhibition. Inhibition was evaluated using ASBT-MDCK monolayers and taurocholate as the model substrate. Computational modeling employed a HipHop qualitative approach, a Hypogen quantitative approach, as well as a modified Laplacian Bayesian modeling method using 2D descriptors. Initially, 30 compounds were screened for ASBT inhibition. A qualitative pharmacophore was developed using the most potent 11 compounds and applied to search a drug database, yielding 58 hits. Additional compounds were tested and their Ki values were measured. A 3D-QSAR and a Bayesian model were developed using 38 molecules. The quantitative pharmacophore consisted of one hydrogen bond acceptor, three hydrophobic features, and five excluded volumes. Each model was further validated with two external test sets of 30 and 19 molecules. Validation analysis showed both models exhibited good predictability in determining whether a drug is a potent or non-potent ASBT inhibitor. The Bayesian model correctly ranked the most active compounds. In summary, using a combined in vitro and computational approach, we found that many FDA-approved drugs from diverse classes, such as the dihydropyridine calcium channel blockers and HMG CoA-reductase inhibitors, are ASBT inhibitors. PMID:19673539

  17. Overexpression of the Transcriptional Regulator WOR1 Increases Susceptibility to Bile Salts and Adhesion to the Mouse Gut Mucosa in Candida albicans

    PubMed Central

    Prieto, Daniel; Román, Elvira; Alonso-Monge, Rebeca; Pla, Jesús

    2017-01-01

    The transcriptional regulator Wor1 has been shown to induce the GUT transition, an environmentally triggered process that increases the fitness of Candida albicans in the mouse gastrointestinal tract. We have developed strains where the expression of this gene is driven from the strong and tightly regulated tetracycline promoter. These cells retain the main characteristics reported for GUT cells albeit they show defects in the initial stages of colonization. They also show a differential colonization along the gastrointestinal tract compared to isogenic strains, which is probably caused by their susceptibility to bile salts. We also show that WOR1 overexpressing cells have an altered metabolic activity, as revealed by a different susceptibility to inhibitors of respiration, and an enhanced adhesion to the mouse mucosa. We propose that this may contribute to their long-term favored ability to colonize the gastrointestinal tract. PMID:28955659

  18. Apoptosis of human cholangiocarcinoma cells induced by ESC-3 from Crocodylus siamensis bile

    PubMed Central

    Song, Wei; Shen, Dong-Yan; Kang, Jin-He; Li, Shan-Shan; Zhan, Hui-Wang; Shi, Yan; Xiong, You-Xiong; Liang, Ge; Chen, Qing-Xi

    2012-01-01

    AIM: To investigate the effects of ESC-3 isolated from crocodile bile on the growth and apoptosis induction of human cholangiocarcinoma cells. METHODS: ESC-3 was isolated from crocodile bile by Sephadex LH-20 and RP-18 reversed-phase column. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was conducted to determine the effects of ESC-3 on the proliferation of human cholangiocarcinoma cell lines (QBC939, Sk-ChA-1 and MZ-ChA-1). Giemsa staining, Hoechst 33258 and acridine orange/ethidium bromide staining showed the morphological changes of Mz-ChA-1 cells exposed to ESC-3 at different concentrations. Flow cytometry with regular propidium iodide (PI) staining was performed to analyze the cell cycle distribution of Mz-ChA-1 cells and to assess apoptosis by annexin v-fluorescein isothiocyanate (V-FITC)/PI staining. Rh123 staining was used to detect the alteration of mitochondrial membrane potential (ΔΨm). The protein levels of Bax, Bcl-2, Cdk2, cytochrome c and caspase-3 were further confirmed by Western blotting. RESULTS: ESC-3 significantly inhibited the growth of three human cholangiocarcinoma cell lines and arrested Mz-ChA-1 cell cycle at G0/G1 phase. Mz-ChA-1 cells showed typical apoptotic morphological changes after treated with ESC-3 (10 μg/mL) for 48 h. Cell death assay indicated that Mz-ChA-1 cells underwent apoptosis in a dose-dependent manner induced by ESC-3. In addition, ESC-3 treatment could downregulate the protein level of Bcl-2 and upregulate the Bax, leading to the increase in the ratio of Bax to Bcl-2 in Mz-ChA-1 cells. Meanwhile, cytochrome c was released from the mitochondria into the cytosol, which subsequently initiated the activation of caspase-3. All these events were associated with the collapse of the mitochondrial membrane potential. CONCLUSION: ESC-3, the active ingredient of crocodile bile, induced apoptosis in Mz-ChA-1 cells through the mitochondria-dependent pathway and may be a potential chemotherapeutic drug for

  19. Apoptosis of human cholangiocarcinoma cells induced by ESC-3 from Crocodylus siamensis bile.

    PubMed

    Song, Wei; Shen, Dong-Yan; Kang, Jin-He; Li, Shan-Shan; Zhan, Hui-Wang; Shi, Yan; Xiong, You-Xiong; Liang, Ge; Chen, Qing-Xi

    2012-02-21

    To investigate the effects of ESC-3 isolated from crocodile bile on the growth and apoptosis induction of human cholangiocarcinoma cells. ESC-3 was isolated from crocodile bile by Sephadex LH-20 and RP-18 reversed-phase column. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was conducted to determine the effects of ESC-3 on the proliferation of human cholangiocarcinoma cell lines (QBC939, Sk-ChA-1 and MZ-ChA-1). Giemsa staining, Hoechst 33258 and acridine orange/ethidium bromide staining showed the morphological changes of Mz-ChA-1 cells exposed to ESC-3 at different concentrations. Flow cytometry with regular propidium iodide (PI) staining was performed to analyze the cell cycle distribution of Mz-ChA-1 cells and to assess apoptosis by annexin v-fluorescein isothiocyanate (V-FITC)/PI staining. Rh123 staining was used to detect the alteration of mitochondrial membrane potential (ΔΨm). The protein levels of Bax, Bcl-2, Cdk2, cytochrome c and caspase-3 were further confirmed by Western blotting. ESC-3 significantly inhibited the growth of three human cholangiocarcinoma cell lines and arrested Mz-ChA-1 cell cycle at G0/G1 phase. Mz-ChA-1 cells showed typical apoptotic morphological changes after treated with ESC-3 (10 μg/mL) for 48 h. Cell death assay indicated that Mz-ChA-1 cells underwent apoptosis in a dose-dependent manner induced by ESC-3. In addition, ESC-3 treatment could downregulate the protein level of Bcl-2 and upregulate the Bax, leading to the increase in the ratio of Bax to Bcl-2 in Mz-ChA-1 cells. Meanwhile, cytochrome c was released from the mitochondria into the cytosol, which subsequently initiated the activation of caspase-3. All these events were associated with the collapse of the mitochondrial membrane potential. ESC-3, the active ingredient of crocodile bile, induced apoptosis in Mz-ChA-1 cells through the mitochondria-dependent pathway and may be a potential chemotherapeutic drug for the treatment of cholangiocarcinoma.

  20. Downregulation of peroxiredoxin-3 by hydrophobic bile acid induces mitochondrial dysfunction and cellular senescence in human trophoblasts

    PubMed Central

    Wu, Wei-Bin; Menon, Ramkumar; Xu, Yue-Ying; Zhao, Jiu-Ru; Wang, Yan-Lin; Liu, Yuan; Zhang, Hui-Juan

    2016-01-01

    Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific disorder characterised by raised bile acids in foetal-maternal circulation, which threatens perinatal health. During the progression of ICP, the effect of oxidative stress is underscored. Peroxiredoxin-3 (PRDX3) is a mitochondrial antioxidant enzyme that is crucial to balance intracellular oxidative stress. However, the role of PRDX3 in placental trophoblast cells under ICP is not fully understood. We demonstrated that the level of PRDX3 was downregulated in ICP placentas as well as bile acids–treated trophoblast cells and villous explant in vitro. Toxic levels of bile acids and PRDX3 knockdown induced oxidative stress and mitochondrial dysfunction in trophoblast cells. Moreover, silencing of PRDX3 in trophoblast cell line HTR8/SVneo induced growth arrest and cellular senescence via activation of p38-mitogen-activated protein kinase (MAPK) and induction of p21WAF1/CIP and p16INK4A. Additionally, enhanced cellular senescence, determined by senescence-associated beta-galactosidase staining, was obviously attenuated by p38-MAPK inhibitor SB203580. Our data determined that exposure to bile acid decreased PRDX3 level in human trophoblasts. PRDX3 protected trophoblast cells against mitochondrial dysfunction and cellular senescence induced by oxidative stress. Our results suggest that decreased PRDX3 by excessive bile acids in trophoblasts plays a critical role in the pathogenesis and progression of ICP. PMID:27958341

  1. Centuries of Human-Driven Change in Salt Marsh Ecosystems

    NASA Astrophysics Data System (ADS)

    Gedan, K. Bromberg; Silliman, B. R.; Bertness, M. D.

    2009-01-01

    Salt marshes are among the most abundant, fertile, and accessible coastal habitats on earth, and they provide more ecosystem services to coastal populations than any other environment. Since the Middle Ages, humans have manipulated salt marshes at a grand scale, altering species composition, distribution, and ecosystem function. Here, we review historic and contemporary human activities in marsh ecosystems—exploitation of plant products; conversion to farmland, salt works, and urban land; introduction of non-native species; alteration of coastal hydrology; and metal and nutrient pollution. Unexpectedly, diverse types of impacts can have a similar consequence, turning salt marsh food webs upside down, dramatically increasing top down control. Of the various impacts, invasive species, runaway consumer effects, and sea level rise represent the greatest threats to salt marsh ecosystems. We conclude that the best way to protect salt marshes and the services they provide is through the integrated approach of ecosystem-based management.

  2. Centuries of human-driven change in salt marsh ecosystems.

    PubMed

    Gedan, K Bromberg; Silliman, B R; Bertness, M D

    2009-01-01

    Salt marshes are among the most abundant, fertile, and accessible coastal habitats on earth, and they provide more ecosystem services to coastal populations than any other environment. Since the Middle Ages, humans have manipulated salt marshes at a grand scale, altering species composition, distribution, and ecosystem function. Here, we review historic and contemporary human activities in marsh ecosystems--exploitation of plant products; conversion to farmland, salt works, and urban land; introduction of non-native species; alteration of coastal hydrology; and metal and nutrient pollution. Unexpectedly, diverse types of impacts can have a similar consequence, turning salt marsh food webs upside down, dramatically increasing top down control. Of the various impacts, invasive species, runaway consumer effects, and sea level rise represent the greatest threats to salt marsh ecosystems. We conclude that the best way to protect salt marshes and the services they provide is through the integrated approach of ecosystem-based management.

  3. Bilirubin conjugates of human bile. Nuclear-magnetic-resonance, infrared and optical spectra of model compounds

    PubMed Central

    Kuenzle, Clive C.

    1970-01-01

    N.m.r., i.r. and optical spectra of model compounds were recorded. These were to help in elucidating the structures of the phenylazo derivatives of bilirubin conjugates isolated from human bile. Model compounds included commercial and human bile bilirubin, mesobilirubin, bilirubin dimethyl ester, dimethoxybilirubin dimethyl ester and the corresponding phenylazo derivatives. The phenylazo derivative of vinylneoxanthobilirubinic acid was also investigated. All compounds were of the type IXα, and no other isomer could be detected with the spectroscopic methods employed. The compounds crystallize as the lactams, except for dimethoxybilirubin dimethyl ester and its phenylazo derivative, which are held in the lactim ether configuration. With all other compounds no tautomeric forms other than the lactams could be detected, although small proportions of bilirubin must exist as the lactim. Bilirubin does not form a betaine, a structure that has been proposed by von Dobeneck & Brunner (1965) to explain the bathochromic shift of its optical spectrum as compared with the expected position of the absorption maximum at 420nm. However, this shift to 453nm can be explained on the basis of internal hydrogen bonds occurring between the carboxylic protons and the pyrrole rings of bilirubin, as proposed by Fog & Jellum (1963), and new evidence for such a bonding has been accumulated. The bilirubin sulphate described by Watson (1958), which is formed by treatment of bilirubin with concentrated sulphuric acid and acetic anhydride, was also investigated. The main product of this reaction was isolated as its phenylazo derivative, and was shown to be 3,18-di(ethylidene sulphate)-2,7,13,17-tetramethylbiladiene-ac-8,12-dipropionic acid. The reaction leading to this compound is an addition of sulphuric acid to the vinyl side chains of bilirubin according to Markownikoff's rule. PMID:5500301

  4. Expression of β-catenin and c-myc during human common bile duct development: a possible role in the morphogenesis of the common bile duct

    PubMed Central

    Guo, W.L.; Zhang, Q.; Wang, J.

    2014-01-01

    β-catenin and c-myc play important roles in the development of tissues and organs. However, little is known about their expression patterns during the development of the human common bile duct. Immunohistochemistry was used to detect β-catenin and c-myc expression in common bile duct samples from postmortem tissues of 14 premature infants and 6 spontaneously aborted fetuses. The expression of β-catenin and c-myc was also analyzed by Western blot. The samples were divided into four groups based on the stage of human fetal development: 12, 13-27, 28-37, and >37 weeks. The Image-Pro Plus v. 6.0 image analysis software was used to calculate the mean qualifying score (MQS). At fetal stages 12, 13-27, 28-37, and >37 weeks, MQS of β-catenin were 612.52±262.13, 818.38±311.73, 706.33±157.19, and 350.69±110.19, respectively. There was a significant difference in MQS among the four groups (ANOVA, P=0.0155) and between the scores at >37 and 13-27 weeks (Student-Newman-Keuls, P<0.05). At fetal stages 12, 13-27, 28-37, and >37 weeks, the MQS of c-myc were 1376.64±330.04, 1224.18±171.66, 1270.24±320.75, and 741.04±219.19, respectively. There was a significant difference in MQS among the four groups (ANOVA, P=0.0087) and between the scores at >37 and 12 weeks, >37 and 13-27 weeks, and >37 and 28-37 weeks (all P<0.05, Student-Newman-Keuls). Western blots showed that β-catenin and c-myc expression were significantly higher in fetal than in postnatal control duct tissue (P<0.05). c-myc and β-catenin are involved in the normal development of the human common bile duct. PMID:25003633

  5. Bile culture

    MedlinePlus

    ... these risks. Alternative Names Culture - bile Images Bile culture References Hall GS, Woods GL. Medical bacteriology. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 22nd ed. Philadelphia, PA: Elsevier ...

  6. Salt, blood pressure, and human health.

    PubMed

    Alderman, M H

    2000-11-01

    The positive relation of sodium intake and blood pressure, first recognized a century ago, has been well established in ecological, epidemiological, and experimental human studies. Equally well established is the association of increasing blood pressure and cardiovascular morbidity and mortality. Indeed, the pharmacological capacity to reduce blood pressure has produced one of the great public health accomplishments of the 20th century. These two facts-the positive relation of blood pressure to strokes and heat attacks and the positive association of sodium intake to blood pressure-underlie the hypothesis that a reduction in sodium intake, by virtue of its hypotensive effect, might prevent strokes and heart attacks. Moreover, even if the effect on blood pressure were in the range of a 1- to 2-mm Hg decline in blood pressure for every 75- to 100-mmol difference in sodium intake, the impact of such a change, applied to the whole population, would be enormous. The problem with this appealing possibility is that a reduction in salt consumption of this magnitude has other-and sometimes adverse-health consequences. The question, therefore, is whether the beneficial hypotensive effects of sodium restriction will outweigh its hazards. Unfortunately, few data link sodium intake to health outcomes, and that which is available is inconsistent. Without knowledge of the sum of the multiple effects of a reduced sodium diet, no single universal prescription for sodium intake can be scientifically justified.

  7. Inside the adaptation process of Lactobacillus delbrueckii subsp. lactis to bile.

    PubMed

    Burns, Patricia; Sánchez, Borja; Vinderola, Gabriel; Ruas-Madiedo, Patricia; Ruiz, Lorena; Margolles, Abelardo; Reinheimer, Jorge; de los Reyes-Gavilán, Clara G

    2010-08-15

    Progressive adaptation to bile might render some lactobacilli able to withstand physiological bile salt concentrations. In this work, the adaptation to bile was evaluated on previously isolated dairy strains of Lactobacillus delbrueckii subsp. lactis 200 and L. delbrueckii subsp. lactis 200+, a strain derived thereof with stable bile-resistant phenotype. The adaptation to bile was obtained by comparing cytosolic proteomes of both strains grown in the presence or absence of bile. Proteomics were complemented with physiological studies on both strains focusing on glycolytic end-products, the ability to adhere to the human intestinal epithelial cell line HT29-MTX and survival to simulated gastrointestinal conditions. Protein pattern comparison of strains grown with and without bile allowed us to identify 9 different proteins whose production was regulated by bile in both strains, and 17 proteins that showed differences in their levels between the parental and the bile-resistant derivative. These included general stress response chaperones, proteins involved in transcription and translation, in peptidoglycan/exopolysaccharide biosynthesis, in the lipid and nucleotide metabolism and several glycolytic and pyruvate catabolism enzymes. Differences in the level of metabolic end-products of the sugar catabolism were found between the strains 200 and 200+. A decrease in the adhesion of both strains to the intestinal cell line was detected in the presence of bile. In simulated gastric and intestinal juices, a protective effect was exerted by milk improving the survival of both microorganisms. These results indicate that bile tolerance in L. delbrueckii subsp. lactis involves several mechanisms responding to the deleterious impact of bile salts on bacterial physiology.

  8. Structural requirements of the human sodium-dependent bile acid transporter (hASBT): Role of 3- and 7-OH moieties on binding and translocation of bile acids

    PubMed Central

    González, Pablo M.; Lagos, Carlos F.; Ward, Weslyn C.; Polli, James E.

    2014-01-01

    Bile acids (BAs) are the end products of cholesterol metabolism. One of the critical steps in their biosynthesis involves the isomerization of the 3β-hydroxyl (-OH) group on the cholestane ring to the common 3α-configuration on BAs. BAs are actively recaptured from the small intestine by the human Apical Sodium-dependent Bile Acid Transporter (hASBT) with high affinity and capacity. Previous studies have suggested that no particular hydroxyl group on BAs is critical for binding or transport by hASBT, even though 3β-hydroxylated BAs were not examined. The aim of this study was to elucidate the role of the 3α-OH group on BAs binding and translocation by hASBT. Ten 3β-hydroxylated BAs (Iso-bile acids, iBAs) were synthesized, characterized, and subjected to hASBT inhibition and uptake studies. hASBT inhibition and uptake kinetics of iBAs were compared to that of native 3α-OH BAs. Glycine conjugates of native and isomeric BAs were subjected to molecular dynamics simulations in order to identify topological descriptors related to binding and translocation by hASBT. Iso-BAs bound to hASBT with lower affinity and exhibited reduced translocation than their respective 3α-epimers. Kinetic data suggests that, in contrast to native BAs where hASBT binding is the rate-limiting step, iBAs transport was rate-limited by translocation and not binding. Remarkably, 7-dehydroxylated iBAs were not hASBT substrates, highlighting the critical role of 7-OH group on BA translocation by hASBT, especially for iBAs. Conformational analysis of gly-iBAs and native BAs identified topological features for optimal binding as: concave steroidal nucleus, 3-OH “on-” or below-steroidal plane, 7-OH below-plane, and 12-OH moiety towards-plane. Our results emphasize the relevance of the 3α-OH group on BAs for proper hASBT binding and transport and revealed the critical role of 7-OH group on BA translocation, particularly in the absence of a 3α-OH group. Results have implications for BA

  9. Bile Acids and the Gut Microbiome

    PubMed Central

    Ridlon, Jason M.; Kang, Dae Joong; Hylemon, Phillip B.; Bajaj, Jasmohan S.

    2014-01-01

    Purpose of the review We examine the latest research on the emerging bile acid-gut microbiome axis and its role in health and disease. Our focus revolves around two key microbial pathways for degrading bile salts, and the impact of bile acid composition in the gut on the gut microbiome and host physiology. Recent findings Bile acid pool size has recently been shown to be a function of microbial metabolism of bile acids in the intestines. Recent studies have shown potential mechanisms explaining how perturbations in the microbiome affect bile acid pool size and composition. Bile acids are emerging as regulators of the gut microbiome at the highest taxomic levels. The role of bile acids as hormones and potentiators of liver cancer are also emerging. Summary The host and microbiome appear to regulate bile acid pool size. The host produces a large, conjugated hydrophilic bile acid pool, maintained through positive-feedback antagonism of FXR in intestine and liver. Members of the microbiome utilize bile acids and their conjugates resulting in agonism of FXR in intestine and liver resulting in a smaller, unconjugated hydrophobic bile acid pool. Hydrophilicity of the bile acid pool is associated with disease states. Reduced bile acid levels in the gut are associated with bacterial overgrowth and inflammation. Diet, antibiotic therapy, and disease states affect the balance of the microbiome-bile acid pool. PMID:24625896

  10. Consumer control of salt marshes driven by human disturbance.

    PubMed

    Bertness, Mark D; Silliman, Brian R

    2008-06-01

    Salt marsh ecosystems are widely considered to be controlled exclusively by bottom-up forces, but there is mounting evidence that human disturbances are triggering consumer control in western Atlantic salt marshes, often with catastrophic consequences. In other marine ecosystems, human disturbances routinely dampen (e.g., coral reefs, sea grass beds) and strengthen (e.g., kelps) consumer control, but current marsh theory predicts little potential interaction between humans and marsh consumers. Thus, human modification of top-down control in salt marshes was not anticipated and was even discounted in current marsh theory, despite loud warnings about the potential for cascading human impacts from work in other marine ecosystems. In spite of recent experiments that have challenged established marsh dogma and demonstrated consumer-driven die-off of salt marsh ecosystems, government agencies and nongovernmental organizations continue to manage marsh die-offs under the old theoretical framework and only consider bottom-up forces as causal agents. This intellectual dependency of many coastal ecologists and managers on system-specific theory (i.e., marsh bottom-up theory) has the potential to have grave repercussions for coastal ecosystem management and conservation in the face of increasing human threats. We stress that marine vascular plant communities (salt marshes, sea grass beds, mangroves) are likely more vulnerable to runaway grazing and consumer-driven collapse than is currently recognized by theory, particularly in low-diversity ecosystems like Atlantic salt marshes.

  11. Profiling serum bile acid glucuronides in humans: gender divergences, genetic determinants, and response to fenofibrate.

    PubMed

    Trottier, J; Perreault, M; Rudkowska, I; Levy, C; Dallaire-Theroux, A; Verreault, M; Caron, P; Staels, B; Vohl, M-C; Straka, R J; Barbier, O

    2013-10-01

    Glucuronidation, catalyzed by uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, detoxifies cholestatic bile acids (BAs). We aimed to (i) characterize the circulating BA-glucuronide (BA-G) pool composition in humans, (ii) determine how sex and UGT polymorphisms influence this composition, and (iii) analyze the effects of the lipid-lowering drug fenofibrate on the circulating BA-G profile in 300 volunteers and 5 cholestatic patients. Eleven BA-Gs were determined in pre- and postfenofibrate samples. Men exhibited higher BA-G concentrations, and various genotype/BA-G associations were discovered in relevant UGT genes. The chenodeoxycholic acid-3G (CDCA-3G) concentration was associated with the UGT2B7 802C>T polymorphism. Glucuronidation assays confirmed the predominant role of UGT2B7 and UGT1A4 in CDCA-3G formation. Fenofibrate exposure increased the serum levels of five BA-G species, including CDCA-3G, and upregulated expression of UGT1A4, but not UGT2B7, in hepatic cells. This study demonstrated that fenofibrate stimulates BA glucuronidation in humans and thus reduces BA toxicity in the liver.

  12. Bile acids: regulation of synthesis.

    PubMed

    Chiang, John Y L

    2009-10-01

    Bile acids are physiological detergents that generate bile flow and facilitate intestinal absorption and transport of lipids, nutrients, and vitamins. Bile acids also are signaling molecules and inflammatory agents that rapidly activate nuclear receptors and cell signaling pathways that regulate lipid, glucose, and energy metabolism. The enterohepatic circulation of bile acids exerts important physiological functions not only in feedback inhibition of bile acid synthesis but also in control of whole-body lipid homeostasis. In the liver, bile acids activate a nuclear receptor, farnesoid X receptor (FXR), that induces an atypical nuclear receptor small heterodimer partner, which subsequently inhibits nuclear receptors, liver-related homolog-1, and hepatocyte nuclear factor 4alpha and results in inhibiting transcription of the critical regulatory gene in bile acid synthesis, cholesterol 7alpha-hydroxylase (CYP7A1). In the intestine, FXR induces an intestinal hormone, fibroblast growth factor 15 (FGF15; or FGF19 in human), which activates hepatic FGF receptor 4 (FGFR4) signaling to inhibit bile acid synthesis. However, the mechanism by which FXR/FGF19/FGFR4 signaling inhibits CYP7A1 remains unknown. Bile acids are able to induce FGF19 in human hepatocytes, and the FGF19 autocrine pathway may exist in the human livers. Bile acids and bile acid receptors are therapeutic targets for development of drugs for treatment of cholestatic liver diseases, fatty liver diseases, diabetes, obesity, and metabolic syndrome.

  13. The CJIE1 prophage of Campylobacter jejuni affects protein expression in growth media with and without bile salts

    PubMed Central

    2014-01-01

    Background The presence of Campylobacter jejuni temperate bacteriophages has increasingly been associated with specific biological effects. It has recently been demonstrated that the presence of the prophage CJIE1 is associated with increased adherence and invasion of C. jejuni isolates in cell culture assays. Results Quantitative comparative proteomics experiments were undertaken using three closely related isolates with CJIE1 and one isolate without CJIE1 to determine whether there was a corresponding difference in protein expression levels. Initial experiments indicated that about 2% of the total proteins characterized were expressed at different levels in isolates with or without the prophage. Some of these proteins regulated by the presence of CJIE1 were associated with virulence or regulatory functions. Additional experiments were conducted using C. jejuni isolates with and without CJIE1 grown on four different media: Mueller Hinton (MH) media containing blood; MH media containing 0.1% sodium deoxycholate, which is thought to result in increased expression of virulence proteins; MH media containing 2.5% Oxgall; and MHwithout additives. These experiments provided further evidence that CJIE1 affected protein expression, including virulence-associated proteins. They also demonstrated a general bile response involving a majority of the proteome and clearly showed the induction of almost all proteins known to be involved with iron acquisition. The data have been deposited to the ProteomeXchange with identifiers PXD000798, PXD000799, PXD000800, and PXD000801. Conclusion The presence of the CJIE1 prophage was associated with differences in protein expression levels under different conditions. Further work is required to determine what genes are involved in causing this phenomenon. PMID:24641125

  14. Kinetics for the synthetic bile acid 75-selenohomocholic acid-taurine in humans: comparison with (/sup 14/C)taurocholate

    SciTech Connect

    Jazrawi, R.P.; Ferraris, R.; Bridges, C.; Northfield, T.C.

    1988-07-01

    The apparent fractional turnover rate of the gamma-labeled bile acid analogue 75-selenohomocholic acid-taurine (75-SeHCAT) was assessed from decline in radioactivity over the gallbladder area on 4 successive days using a gamma-camera, and was compared in the same subjects with the fractional turnover rate of the corresponding natural bile acid, cholic acid-taurine, labeled with 14C ((14C)CAT) using the classical Lindstedt technique. Very similar results were obtained in 5 healthy individuals (coefficient of variation 4.8%, medians 0.35 and 0.34, respectively). By contrast, the fractional deconjugation rate assessed from zonal scanning of glycine- and taurine-conjugated bile acids on thin-layer chromatography was much less for 75-SeHCAT than for (14C)CAT (0.02 and 0.13, respectively; p less than 0.05). The fractional rate for deconjugation plus dehydroxylation was also determined by zonal scanning, and gave lower values for 75-SeHCAT than for (14C)CAT (0.02 and 0.12, respectively; p less than 0.05). There was a striking similarity between the fractional rate for deconjugation alone and that for deconjugation plus dehydroxylation for both bile acids in individual samples (r = 0.999, p less than 0.001), suggesting that these two processes might occur simultaneously and probably involve the same bacteria. We conclude that our scintiscanning technique provides an accurate, noninvasive method of measuring fractional turnover rate of a bile acid in humans, and that the finding that 75SeHCAT remains conjugated with taurine during enterohepatic recycling means that absorption should be specific for the ileal active transport site, thus rendering it an ideal substance for assessing ileal function.

  15. Proliposomes containing a bile salt for oral delivery of Ginkgo biloba extract: Formulation optimization, characterization, oral bioavailability and tissue distribution in rats.

    PubMed

    Zheng, Bin; Teng, Lirong; Xing, Gaoyang; Bi, Ye; Yang, Shuang; Hao, Fei; Yan, Guodong; Wang, Xinmei; Lee, Robert J; Teng, Lesheng; Xie, Jing

    2015-09-18

    Proliposomes containing a bile salt were developed to improve the oral bioavailability of Ginkgo biloba extract (GbE). GbE loaded proliposomes (P-GbE) were successfully prepared by spray drying method. The formulation was optimized using the response surface methodology. FE-SEM, DSC, and FT-IR were used to study the surface morphology and molecular state of proliposomes, and demonstrated key interactions between the formulation ingredients. In vitro studies showed delayed release and enhanced dissolution of Ginkgo flavonoids and terpene lactones from GbE proliposomes. Proliposomes significantly enhanced GbE absorption in the gastrointestinal tract and decreased its elimination. The bioavailabilities of quercetin, kaempferol, isorhmnetin, ginkgolide A, ginkgolide B and ginkgolide C from proliposomes relative to the control were 245%, 211%, 264%, 203%, 333%, and 294%, respectively. Proliposomes were shown to selectively deliver GbE to critical target tissues. In conclusion, development of proliposomes formulation for GbE solved the problem of its poor oral bioavailability, prolonged its duration of action, and increased drug distribution in critical tissues, especially in the brain, therefore, warrant further investigation.

  16. Cloning of the bile salt hydrolase (bsh) gene from Enterococcus faecium FAIR-E 345 and chromosomal location of bsh genes in food enterococci.

    PubMed

    Wijaya, Agus; Hermann, Anette; Abriouel, Hikmate; Specht, Ingrid; Yousif, Nuha M K; Holzapfel, Wilhelm H; Franz, Charles M A P

    2004-12-01

    Enterococcus faecium strain FAIR-E 345 isolated from food was shown to possess bile salt hydrolase (Bsh) activity in a plate screening assay and by high-performance liquid chromatography analysis. The bsh gene was cloned and sequenced. DNA sequence analysis revealed that it encoded a protein of 324 amino acids, with pI 4.877. A bsh gene probe was prepared from the cloned bsh gene and was used for probing plasmid and total genomic DNA of Bsh-positive enterococci isolated from food to determine the genomic location of their bsh genes. This probe was able to detect the bsh gene among total genomic DNA preparations but not from plasmid preparations of 10 plasmid-bearing Enterococcus strains. However, the probe could detect the bsh gene from total genomic DNA preparations of 12 Enterococcus strains that did not contain detectable plasmid DNA. In no cases did the probe hybridize with plasmid DNA preparations, suggesting that the bsh gene among enterococci is probably generally chromosomally encoded. This presumptive chromosomal location of bsh genes among food enterococci suggests that transfer of this trait by conjugative plasmids is unlikely.

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

    PubMed Central

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

    2016-01-01

    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

  18. Investigation of solubilising effects of bile salts on an active pharmaceutical ingredient with unusual pH dependent solubility by NMR spectroscopy.

    PubMed

    Vogtherr, M; Marx, A; Mieden, A-C; Saal, C

    2015-05-01

    The interaction between an ampholytic and amphiphilic Active Pharmaceutical Ingredient (API) showing unusual pH dependent solubility and Fasted State Simulated Intestinal Fluid (FaSSIF) was studied by NMR spectroscopy. Solubility in FaSSIF was drastically increased, about 30 fold, compared to simulated gastrointestinal fluid without bile salts. Our studies aimed at understanding the mechanisms that lead to this drastic enhancement. All species present in solution at various concentrations of API were characterised by Diffusion Ordered Spectroscopy (DOSY) NMR measurements. These indicated the presence of mixed taurocholate-lecithin and pure taurocholate micelles in pure FaSSIF, and formation of mixed taurocholate-API micelles after addition of API. The formation of taurocholate-API micelles was also supported by Nuclear Overhauser Effect/Enhancement (NOE) contacts between taurocholate and the API. Formation of mixed taurocholate-API micelles took place at the expense of pure taurocholate micelles, whereas mixed taurocholate-lecithin micelles remained uninfluenced by the presence of API. Our results showed that the increase in solubility was due to similar amphiphilic properties of the API and taurocholate which enabled formation of mixed taurocholate-API micelles. From results of determination of solubility as well as NMR experiments a phase diagram comprising several micellar species was derived.

  19. Preparation of Pluronic/Bile salt/Phospholipid Mixed Micelles as Drug Solubility Enhancer and Study the Effect of the PPO Block Size on the Solubility of Pyrene.

    PubMed

    Wang, Li; Peng, Min; Zhu, Yuan; Tong, Shan-Shan; Cao, Xia; Xu, Xi-Ming; Yu, Jiang-Nan

    2014-01-01

    Pluronic/bile salt/phospholipid mixed micelles (Pluronic/BS/PS-MM) drug carrier system for solubilization hydrophobic drugs was developed. A typical hydrophobic compound, pyrene, was selected as a representative hydrophobic compound to model the hydrophobic drugs. Five Pluronics, F68, F88, F98, F108, and F127 with different PPO chain length were studied. CMC data and solubilization capacities were obtained from a pyrene solubilization method. A closed association model was used to obtain the thermodynamic parameters: Gibbs free energy (ΔG°), enthalpy, (ΔH°) and entropy (ΔS°) of micellization. The results obtained from these experiments suggest that the mixed micelles was more stable and solubilize more pyrene than single one; and the solubilization of pyrene was strong effected by the PPO block size, thus accentuating synergistic interaction mechanism in Pluronic/BS/PS-MM. The study generated an important dataset so as to compare the effect of different Pluronics on solubility capacity of Pluronic/BS/PS-MM.

  20. Does bile protect or damage interstitial Cajal-like cells in the human gallbladder?

    PubMed

    Pasternak, Artur; Szura, Miroslaw; Matyja, Maciej; Tomaszewski, Krzysztof A; Matyja, Andrzej

    2013-01-01

    the etiology of gallstone disease is considered to be multifactorial, including biliary cholesterol hypersecretion, supersaturation and crystallization, stone formation, bile stasis and mucus hypersecretion and gel formation. Gallbladder hypomotility seems to be a key process that triggers the precipitation of cholesterol microcrystals from supersaturated lithogenic bile. the purpose of the current study was to determine whether ICLCs in the gallbladder were influenced by lithogenic bile. Gallbladder specimens were collected from 30 patients (8 males and 22 females) who underwent elective laparoscopic cholecystectomy for symptomatic gallstone disease. The control group consisted of 25 consecutive patients (11 males and 14 females) who received elective treatment for pancreatic head tumors. ICLCs were visualized in paraffin sections of gallbladders using double immunofluorescence protocol with monoclonal c-kit antibodies and mast cell tryptase. Cholesterol, phospholipid and bile acid concentrations were measured in bile samples obtained by needle aspiration from the gallbladder at the time of surgery. The number of ICLCs in the gallbladder wall was significantly lower in the study group than in the control group (3.35 ± 1.23 vs. 7.06 ± 1.82 cell/FOV in the muscularis propria, P < 0.001) and correlated with a significant increase in the cholesterol saturation index. The glycocholic and taurocholic acid levels were significantly elevated in the control subjects compared with the study group. The results suggest that bile composition may play an important role in the reduction of ICLC density in the gallbladder.

  1. Bile acid transport in sister of P-glycoprotein (ABCB11) knockout mice.

    PubMed

    Lam, Ping; Wang, Renxue; Ling, Victor

    2005-09-20

    In vertebrates, bile flow is essential for movement of water and solutes across liver canalicular membranes. In recent years, the molecular motor of canalicular bile acid secretion has been identified as a member of the ATP binding cassette transporter (ABC) superfamily, known as sister of P-glycoprotein (Spgp) or bile salt export pump (Bsep, ABCB11). In humans, mutations in the BSEP gene are associated with a very low level of bile acid secretion and severe cholestasis. However, as reported previously, because the spgp(-)(/)(-) knockout mice do not express severe cholestasis and have substantial bile acid secretion, we investigated the "alternative transport system" that allows these mice to be physiologically relatively normal. We examined the expression levels of several ABC transporters in spgp(-)(/)(-) mice and found that the level of multidrug resistance Mdr1 (P-glycoprotein) was strikingly increased while those of Mdr2, Mrp2, and Mrp3 were increased to only a moderate extent. We hypothesize that an elevated level of Mdr1 in the spgp(-)(/)(-) knockout mice functions as an alternative pathway to transport bile acids and protects hepatocytes from bile acid-induced cholestasis. In support of this hypothesis, we showed that plasma membrane vesicles isolated from a drug resistant cell line expressing high levels of P-glycoprotein were capable of transporting bile acids, albeit with a 5-fold lower affinity compared to Spgp. This finding is the first direct evidence that P-glycoprotein (Mdr1) is capable of transporting bile acids.

  2. SALT, Human Rights and Foreign Policy.

    DTIC Science & Technology

    1980-06-30

    achievements. Political, economic and psychological considerations overshadow military ones. Arms control is one approach to managing this potential for...York Times , December 4, 1978, pp. Al, DII; Christoph Bertram, "Arms Control and Technological Change," Adelphi Papers Number 146; Edgar Ulsmer...He concludes that a concern forhuman rights is a vital component of the long-term solution to the problem which SALT seeks to manage in the short term

  3. Metabolism of Cholesterol and Bile Acids by the Gut Microbiota

    PubMed Central

    Gérard, Philippe

    2013-01-01

    The human gastro-intestinal tract hosts a complex and diverse microbial community, whose collective genetic coding capacity vastly exceeds that of the human genome. As a consequence, the gut microbiota produces metabolites from a large range of molecules that host's enzymes are not able to convert. Among these molecules, two main classes of steroids, cholesterol and bile acids, denote two different examples of bacterial metabolism in the gut. Therefore, cholesterol is mainly converted into coprostanol, a non absorbable sterol which is excreted in the feces. Moreover, this conversion occurs in a part of the human population only. Conversely, the primary bile acids (cholic and chenodeoxycholic acids) are converted to over twenty different secondary bile acid metabolites by the gut microbiota. The main bile salt conversions, which appear in the gut of the whole human population, include deconjugation, oxidation and epimerization of hydroxyl groups at C3, C7 and C12, 7-dehydroxylation, esterification and desulfatation. If the metabolisms of cholesterol and bile acids by the gut microbiota are known for decades, their consequences on human health and disease are poorly understood and only start to be considered. PMID:25437605

  4. Metabolism of cholesterol and bile acids by the gut microbiota.

    PubMed

    Gérard, Philippe

    2013-12-30

    The human gastro-intestinal tract hosts a complex and diverse microbial community, whose collective genetic coding capacity vastly exceeds that of the human genome. As a consequence, the gut microbiota produces metabolites from a large range of molecules that host's enzymes are not able to convert. Among these molecules, two main classes of steroids, cholesterol and bile acids, denote two different examples of bacterial metabolism in the gut. Therefore, cholesterol is mainly converted into coprostanol, a non absorbable sterol which is excreted in the feces. Moreover, this conversion occurs in a part of the human population only. Conversely, the primary bile acids (cholic and chenodeoxycholic acids) are converted to over twenty different secondary bile acid metabolites by the gut microbiota. The main bile salt conversions, which appear in the gut of the whole human population, include deconjugation, oxidation and epimerization of hydroxyl groups at C3, C7 and C12, 7-dehydroxylation, esterification and desulfatation. If the metabolisms of cholesterol and bile acids by the gut microbiota are known for decades, their consequences on human health and disease are poorly understood and only start to be considered.

  5. Effects of bile salt deconjugation by probiotic strains on the survival of antibiotic-resistant foodborne pathogens under simulated gastric conditions.

    PubMed

    He, Xinlong; Zou, Yunyun; Cho, Youngjae; Ahn, Juhee

    2012-06-01

    This study was designed to evaluate the effects of bile acid deconjugation by probiotic strains on the antibiotic susceptibility of antibiotic-sensitive and multiple antibiotic-resistant Salmonella Typhimurium and Staphylococcus aureus. Eight probiotic strains, Bifidobacterium longum B6, Lactobacillus acidophilus ADH, Lactobacillus brevis KACC 10553, Lactobacillus casei KACC 12413, Lactobacillus paracasei ATCC 25598, Lactobacillus rhamnosus GG, Leuconostoc mesenteroides KACC 12312, and Pediococcus acidilactici KACC 12307, were used to examine bile acid tolerance. The ability to deconjugate bile acids was evaluated using both thin-layer chromatography and high-performance liquid chromatography. The antibiotic susceptibility testing was carried out to determine the synergistic inhibitory activity of deconjugated bile acids. L. acidophilus, L. brevis, and P. acidilactici showed the most tolerance to the conjugated bile acids. P. acidilactici deconjugated glycocholic acid and glycodeoxycholate from 3.18 and 3.09 mM to the detection limits, respectively. The antibiotic susceptibility of selected foodborne pathogens was increased by increasing the concentration of deconjugated bile acids. The study results are useful for understanding the relationship between bile acid deconjugation by probiotic strains and antibiotic susceptibility in the presence of deconjugated bile acids, and they may be useful for designing new probiotic-antibiotic combination therapy based on bile acid deconjugation.

  6. Measurement of transport activities of bile acids in human multidrug resistance-associated protein 3 using liquid chromatography-tandem mass spectrometry.

    PubMed

    Yamaguchi, Kana; Murai, Tsuyoshi; Yabuuchi, Hikaru; Kurosawa, Takao

    2010-01-01

    A method has been developed for the measurement of transport activities in membrane vesicles obtained from human multidrug resistance-associated protein 3-expressing Sf9 cells for 1beta-hydroxy-, 6alpha-hydroxy- and unsaturated bile acids by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Calibration curves for the bile acids were linear over the range of 10 to 2000 pmol/mL, and the detection limit was less than 2 pmol/mL for all bile acids using selected reaction monitoring analysis. The method was applied to measurements of adenosine triphosphate-dependent transport activities of the membrane vesicles for the above-mentioned hydroxylated and unsaturated bile acids. The present study demonstrated that the human multidrug resistance-associated protein 3 vesicles accepted 1beta-, 6alpha-hydroxylated and unsaturated bile acids along with common bile acids, such as glycocholic acid and taurolithocholic acid 3-sulfate. The developed method is useful for measurements of bile acid transport activities.

  7. The "Hemolysis Model" for the Study of Cyto-Toxicity and Cyto-Protection by Bile Salts and Phospholipids

    NASA Astrophysics Data System (ADS)

    Portincasa, Piero; Moschetta, Antonio; Petruzzelli, Michele; Vacca, Michele; Krawczyk, Marcin; Minerva, Francesco; Palmieri, Vincenzo O.; Palasciano, Giuseppe

    The hemolysis of human erythrocytes can be proposed as a valuable in vitro model to study the interaction of different molecules with the plasma membrane: given its simplicity and versatility, this method provides a reliable tool to screen potentially damaging or protective compounds like drugs, nutrients and endogenous molecules, with relevance to the pathophysiology and treatment of human diseases.

  8. Direct measurement of first-pass ileal clearance of a bile acid in humans

    SciTech Connect

    Galatola, G.; Jazrawi, R.P.; Bridges, C.; Joseph, A.E.; Northfield, T.C. )

    1991-04-01

    The purpose of this study was to develop and validate a method of directly measuring ileal bile acid absorption efficiency during a single enterohepatic cycle (first-pass ileal clearance). This has become feasible for the first time because of the availability of the synthetic gamma-labeled bile acid 75Selena-homocholic acid-taurine (75SeHCAT). Together with the corresponding natural bile acid cholic acid-taurine (labeled with 14C), SeHCAT was infused distal to an occluding balloon situated beyond the ampulla of Vater in six healthy subjects. Completion of a single enterohepatic cycle was assessed by obtaining a plateau for 75SeHCAT activity proximal to the occluding balloon, which prevented further cycles. Unabsorbed 75SeHCAT was collected after total gut washout, which was administered distal to the occluding balloon. 75SeHCAT activity in the rectal effluent measured by gamma counter was compared with that of absorbed 75SeHCAT level measured by gamma camera and was used to calculate first-pass ileal clearance. This was very efficient (mean value, 96%) and showed very little variation in the six subjects studied (range, 95%-97%). A parallel time-activity course in hepatic bile for 14C and 75Se during a single enterohepatic cycle, together with a ratio of unity for 14C/75Se in samples obtained at different time intervals, suggests that 75SeHCAT is handled by the ileum like the natural bile acid cholic acid-taurine. Extrapolation of 75SeHCAT first-pass ileal clearance to that of the natural bile acid therefore seems justifiable. In a subsidiary experiment, ileal absorption efficiency per day for 75SeHCAT was also measured by scanning the gallbladder area on 5 successive days after the measurement of first-pass ileal clearance. In contrast with absorption efficiency per cycle, absorption efficiency per day varied widely (49%-86%).

  9. GC-FID determination of cocaine and its metabolites in human bile and vitreous humor.

    PubMed

    Fernández, P; Aldonza, M; Bouzas, A; Lema, M; Bermejo, A M; Tabernero, M J

    2006-01-01

    Gas chromatography was used in combination with flame ionization detection (GC-FID) to develop a method for determining cocaine and its two metabolites, benzoylecgonine (BEG) and ecgonine methyl ester (EME), in bile and vitreous humor. The method used a 12 m x 0.2 mm i.d. column of 0.33 microm film thickness packed with 5% phenylmethylsiloxane, and proadifen as a reference compound. Drug-free bile and vitreous humor samples were used to prepare solutions of the target compounds at concentrations over the range 0.1-4 microg ml(-1) that were subjected to solid-phase extraction through Bond Elut Certify columns and derivatized with 99:1 (v/v) N,O-bis-trimethylsilyltrifluoroacetamide (BSTFA)/trimethylchlorosilane (TMCS). Calibration graphs were highly linear, with correlation coefficients above 0.99 in all instances. Also, the precision of the method was found to be quite acceptable, with coefficients of variation less than 5% for bile and less than 7% for vitreous humor. The average extraction yields ranged from 73.6% to 91.2% for bile and from 71.5% to 92.2% for vitreous humor. The proposed method was used to analyse 26 samples of bile and as many of vitreous humor from individuals fatally poisoned by cocaine, whether alone or in combination with other drugs. The mean drug levels found were 0.75 and 1.54 microg ml(-1) for cocaine in bile and vitreous humor, respectively, 6.35 and 0.94 microg ml(-1) for BEG, and 2.18 and 0.61 microg ml(-1) for EME.

  10. Integrated transcriptomic and proteomic analysis of the bile stress response in a centenarian-originated probiotic Bifidobacterium longum BBMN68.

    PubMed

    An, Haoran; Douillard, François P; Wang, Guohong; Zhai, Zhengyuan; Yang, Jin; Song, Shuhui; Cui, Jianyun; Ren, Fazheng; Luo, Yunbo; Zhang, Bing; Hao, Yanling

    2014-10-01

    Bifidobacteria are natural inhabitants of the human gastrointestinal tract and well known for their health-promoting effects. Tolerance to bile stress is crucial for bifidobacteria to survive in the colon and to exert their beneficial actions. In this work, RNA-Seq transcriptomic analysis complemented with proteomic analysis was used to investigate the cellular response to bile in Bifidobacterium longum BBMN68. The transcript levels of 236 genes were significantly changed (≥ threefold, p < 0.001) and 44 proteins were differentially abundant (≥1.6-fold, p < 0.01) in B. longum BBMN68 when exposed to 0.75 g l(-1) ox-bile. The hemolysin-like protein and bile efflux systems were significantly over produced, which might prevent bile adsorption and exclude bile, respectively. The cell membrane composition was modified probably by an increase of cyclopropane fatty acid and a decrease of transmembrane proteins, resulting in a cell membrane more impermeable to bile salts. Our hypothesis was later confirmed by surface hydrophobicity assay. The transcription of genes related to xylose utilization and bifid shunt were up-regulated, which increased the production of ATP and reducing equivalents to cope with bile-induced damages in a xylan-rich colon environment. Bile salts signal the B. longum BBMN68 to gut entrance and enhance the expression of esterase and sortase associated with adhesion and colonization in intestinal tract, which was supported by a fivefold increased adhesion ability to HT-29 cells by BBMN68 upon bile exposure. Notably, bacterial one-hybrid and EMSA assay revealed that the two-component system senX3-regX3 controlled the expression of pstS in bifidobacteria and the role of this target gene in bile resistance was further verified by heterologous expression in Lactococcus lactis. Taken altogether, this study established a model for global response mechanisms in B. longum to bile. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Mixed Micelles Loaded with Bile Salt: An Approach to Enhance Intestinal Transport of the BCS Class III Drug Cefotaxime in Rats.

    PubMed

    Arafat, Mosab; Kirchhoefer, Cathrin; Mikov, Momir

    2017-08-01

    Cefotaxime is a class III drug according to the Biopharmaceutical Classification System due to low intestinal permeability based on poor oral bioavailability. Bile salt compounds have been shown to be effective additive for drug permeation through several biological membranes. The main purpose of this study was to investigate the ability of a mixed micelles made of phosphatidylcholine, sodium deoxycholate, and loaded with a cefotaxime-3α,7α-dihydroxy-12-keto-5β-cholanate complex to enhance the oral bioavailability of cefotaxime in rats. Thin-film hydration method was used to prepare cefotaxime-loaded mixed micelles using different bile salt concentrations (0.87-25 mM of sodium deoxycholate). Overall, micelle sizes ranging from 86.9 to 155.6 nm were produced with negative zeta potential values from -15.9 to -19.5 mV and drug loading from 10.5 to 18.9 %. The oral bioavailability of cefotaxime in mixed micellar formulation was assessed and the pharmacokinetic parameters were compared with cefotaxime-3α,7α-dihydroxy-12-keto-5β-cholanate complex and cefotaxime aqueous solution. 24 Male Wistar rats were randomly allocated into four groups (n = 6, per group) to receive the following: (1) a single intravenous dose of cefotaxime (25 mg/kg) in sterilized normal saline solution for injection; (2) a single oral dose of mixed micelles (100 mg/kg of cefotaxime) in phosphate buffered saline administered by oral gavage; (3) a single oral dose of cefotaxime-3α,7α-dihydroxy-12-keto-5β-cholanate complex (100 mg/kg of cefotaxime) in phosphate buffered saline administered by oral gavage; (4) a single oral dose of free cefotaxime (100 mg/kg) in aqueous solution administered by oral gavage. Blood samples were collected for up to 24 h and cefotaxime analyzed using a validated HPLC assay. Pharmacokinetic data showed that the oral bioavailability of cefotaxime in mixed micelles was found to be 4.91 % higher compared to the cefotaxime in aqueous solution (1.30

  12. A novel class of apical sodium--dependent bile salt transporter inhibitors: 1-(2,4-bifluorophenyl)-7-dialkylamino-1,8-naphthyridine-3-carboxamides.

    PubMed

    Liu, Hongtao; Pang, Guoxun; Ren, Jinfeng; Zhao, Yue; Wang, Juxian

    2017-03-01

    The apical sodium--dependent bile acid transporter (ASBT) is the main transporter to promote re-absorption of bile acids from the intestinal tract into the enterohepatic circulation. Inhibition of ASBT could increase the excretion of bile acids, thus increasing bile acid synthesis and consequently cholesterol consumption. Therefore, ASBT is an attractive target for developing new cholesterol-lowering drugs. In this report, a series of 1-(2,4-bifluorophenyl)-7-dialkylamino-1,8-naphthyridine-3-carboxamides were designed as inhibitors of ASBT. Most of them demonstrated potency against ASBT transport of bile acids. In particular, compound 4a1 was found to have the best activity, resulting in 80.1% inhibition of ASBT at 10 μmol/L.

  13. In vivo 1H MRS of human gallbladder bile at 3 T in one and two dimensions: detection and quantification of major biliary lipids.

    PubMed

    Mohajeri, Sanaz; Ijare, Omkar B; Bezabeh, Tedros; King, Scott B; Thomas, M Albert; Minuk, Gerald; Lipschitz, Jeremy; Kirkpatrick, Iain; Smith, Mike; Smith, Ian C P

    2014-10-01

    In vitro (1)H MRS of human bile has shown potential in the diagnosis of various hepatopancreatobiliary (HPB) diseases. Previously, in vivo (1)H MRS of human bile in gallbladder using a 1.5 T scanner demonstrated the possibility of quantification of choline-containing phospholipids (chol-PLs). However, other lipid components such as bile acids play an important role in the pathophysiology of the HPB system. We have employed a higher magnetic field strength (3 T), and a custom-built receive array coil, to improve the quality of in vivo (1)H MRS of human bile in the gallbladder. We obtained significant improvement in the quality of 1D spectra (17 healthy volunteers) using a respiratory-gated PRESS sequence with well distinguished signals for total bile acids (TBAs) plus cholesterol resonating at 0.66 ppm, taurine-conjugated bile acids (TCBAs) at 3.08 ppm, chol-PLs at 3.22 ppm, glycine-conjugated bile acids (GCBAs) at 3.74 ppm, and the amide proton (-NH) arising from GCBAs and TCBAs in the region 7.76-8.05 ppm. The peak areas of these signals were measured by deconvolution, and subsequently the molar concentrations of metabolites were estimated with good accuracy, except for that of TBAs plus cholesterol. The concentration of TBAs plus cholesterol was overestimated in some cases, which could be due to lipid contamination. In addition, we report the first 2D L-COSY spectra of human gallbladder bile in vivo (obtained in 15 healthy volunteers). 2D L-COSY spectra will be helpful in differentiating various biliary chol-PLs in pathological conditions of the HPB system.

  14. The effects of 405 nm light on bacterial membrane integrity determined by salt and bile tolerance assays, leakage of UV-absorbing material and SYTOX green labelling.

    PubMed

    McKenzie, Karen; Maclean, Michelle; Grant, M Helen; Ramakrishnan, Praveen; MacGregor, Scott J; Anderson, John G

    2016-09-01

    Bacterial inactivation by 405 nm light is accredited to the photoexcitation of intracellular porphyrin molecules resulting in energy transfer and the generation of reactive oxygen species that impart cellular oxidative damage. The specific mechanism of cellular damage, however, is not fully understood. Previous work has suggested that destruction of nucleic acids may be responsible for inactivation; however, microscopic imaging has suggested membrane damage as a major constituent of cellular inactivation. This study investigates the membrane integrity of Escherichia coli and Staphylococcus aureus exposed to 405 nm light. Results indicated membrane damage to both species, with loss of salt and bile tolerance by S. aureus and E. coli, respectively, consistent with reduced membrane integrity. Increased nucleic acid release was also demonstrated in 405 nm light-exposed cells, with up to 50 % increase in DNA concentration into the extracellular media in the case of both organisms. SYTOX green fluorometric analysis, however, demonstrated contradictory results between the two test species. With E. coli, increasing permeation of SYTOX green was observed following increased exposure, with >500 % increase in fluorescence, whereas no increase was observed with S. aureus. Overall, this study has provided good evidence that 405 nm light exposure causes loss of bacterial membrane integrity in E. coli, but the results with S. aureus are more difficult to explain. Further work is required to gain greater understanding of the inactivation mechanism in different bacterial species, as there are likely to be other targets within the cell that are also impaired by the oxidative damage from photo-generated reactive oxygen species.

  15. Bile salt-induced pro-oxidant liver damage promotes transplanted cell proliferation for correcting Wilson disease in the Long-Evans Cinnamon rat model.

    PubMed

    Joseph, Brigid; Kapoor, Sorabh; Schilsky, Michael L; Gupta, Sanjeev

    2009-05-01

    Insights into disease-specific mechanisms for liver repopulation are needed for cell therapy. To understand the efficacy of pro-oxidant hepatic perturbations in Wilson disease, we studied Long-Evans Cinnamon (LEC) rats with copper toxicosis under several conditions. Hepatocytes from healthy Long-Evans Agouti (LEA) rats were transplanted intrasplenically into the liver. A cure was defined as lowering of copper to below 250 microg/g liver, presence of ATPase, Cu++ transporting, beta polypeptide (atp7b) messenger RNA (mRNA) in the liver and improvement in liver histology. Treatment of animals with the hydrophobic bile salt, cholic acid, or liver radiation before cell transplantation produced cure rates of 14% and 33%, respectively; whereas liver radiation plus partial hepatectomy followed by cell transplantation proved more effective, with cure in 55%, P < 0.01; and liver radiation plus cholic acid followed by cell transplantation was most effective, with cure in 75%, P < 0.001. As a group, cell therapy cures in rats preconditioned with liver radiation plus cholic acid resulted in less hepatic copper, indicating greater extent of liver repopulation. We observed increased hepatic catalase and superoxide dismutase activities in LEC rats, suggesting chronic oxidative stress. After liver radiation or cholic acid, hepatic lipid peroxidation levels increased, indicating further oxidative injury, although we did not observe overt additional cytotoxicity. This contrasted with healthy animals in which liver radiation and cholic acid produced hepatic steatosis and loss of injured hepatocytes. We concluded that pro-oxidant perturbations were uniquely effective for cell therapy in Wilson disease because of the nature of preexisting hepatic damage.

  16. Differential roles of ubiquitination in the degradation mechanism of cell surface-resident bile salt export pump and multidrug resistance-associated protein 2.

    PubMed

    Aida, Kensuke; Hayashi, Hisamitsu; Inamura, Kaori; Mizuno, Tadahaya; Sugiyama, Yuichi

    2014-03-01

    We previously showed that ubiquitination, a reversible post-translational modification, facilitates degradation of cell surface-resident bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2), ABC transporters that are expressed at the canalicular membrane (CM) of hepatocytes. In the current study, its underlying mechanism was investigated by evaluating the role of ubiquitination in the processes of internalization and subsequent degradation of cell surface-resident BSEP and MRP2. Cell surface biotinylation analysis using Flp-In T-REx 293 cells showed that ectopic expression of Ub(Δ)(GG), which is ubiquitin (Ub) lacking the two C-terminal glycines essential for the Ub conjugation reaction, inhibited the internalization of 3× FLAG-BSEP, but not of MRP2, and the degradation of the internalized MRP2, but not of the internalized 3× FLAG-BSEP. Its inhibitory effect on BSEP internalization was also indicated by a time-lapse imaging analysis using the rat hepatoma cell line McA-RH7777 in which Ub(Δ)(GG) delayed the loss of fluorescence from photoactivated Dronpa-BSEP on the CM. The effect of Ub(Δ)(GG) on BSEP internalization in these experiments was abrogated by treatment with chlorpromazine, an inhibitor of clathrin-mediated endocytosis, and the introduction of a Y1311A mutation into BSEP. This mutation eliminates the ability of BSEP to interact with the AP2 adaptor complex, an adaptor protein required for cargo selection in clathrin-mediated endocytosis. In conclusion, our data suggest that ubiquitination facilitates clathrin-mediated endocytosis of BSEP and the degradation of internalized MRP2, leading to the degradation of the cell surface-resident form of both transporters.

  17. Conformational Changes in IpaD from Shigella flexneri Upon Binding Bile Salts Provide Insight into the Second Step of Type III Secretion†

    PubMed Central

    Dickenson, Nicholas E.; Zhang, Lingling; Epler, Chelsea R.; Adam, Philip R.; Picking, Wendy L.; Picking, William D.

    2011-01-01

    Shigella flexneri uses its type III secretion apparatus (TTSA) to inject host-altering proteins into targeted eukaryotic cells. The TTSA is composed of a basal body and an exposed needle with invasion plasmid antigen D (IpaD) forming a tip complex that controls secretion. The bile salt deoxycholate (DOC) stimulates recruitment of the translocator protein IpaB into the maturing TTSA needle tip complex. This process appears to be triggered by a direct interaction between DOC and IpaD. Fluorescence spectroscopy and NMR spectroscopy are used here to confirm the DOC-IpaD interaction and to reveal that IpaD conformational changes upon DOC binding trigger the appearance of IpaB at the needle tip. Förster resonance energy transfer between specific sites on IpaD was used here to identify changes in distances between IpaD domains as a result of DOC binding. To further explore the effects of DOC binding on IpaD structure, NMR chemical shift mapping was employed. The environments of residues within the proposed DOC binding site and additional residues within the “distal” globular domain were perturbed upon DOC binding, further indicating that conformational changes occur within IpaD upon DOC binding. These events are proposed to be responsible for the recruitment of IpaB at the TTSA needle tip. Mutation analyses combined with additional spectroscopic analyses confirms that conformational changes in IpaD induced by DOC binding contribute to the recruitment of IpaB to the S. flexneri TTSA needle tip. These findings lay the foundation for determining how environmental factors promote TTSA needle tip maturation prior to host cell contact. PMID:21126091

  18. Organochloride pesticides modulated gut microbiota and influenced bile acid metabolism in mice.

    PubMed

    Liu, Qian; Shao, Wentao; Zhang, Chunlan; Xu, Cheng; Wang, Qihan; Liu, Hui; Sun, Haidong; Jiang, Zhaoyan; Gu, Aihua

    2017-07-01

    Organochlorine pesticides (OCPs) can persistently accumulate in body and threaten human health. Bile acids and intestinal microbial metabolism have emerged as important signaling molecules in the host. However, knowledge on which intestinal microbiota and bile acids are modified by OCPs remains unclear. In this study, adult male C57BL/6 mice were exposed to p, p'-dichlorodiphenyldichloroethylene (p, p'-DDE) and β-hexachlorocyclohexane (β-HCH) for 8 weeks. The relative abundance and composition of various bacterial species were analyzed by 16S rRNA gene sequencing. Bile acid composition was analyzed by metabolomic analysis using UPLC-MS. The expression of genes involved in hepatic and enteric bile acids metabolism was measured by real-time PCR. Expression of genes in bile acids synthesis and transportation were measured in HepG2 cells incubated with p, p'-DDE and β-HCH. Our findings showed OCPs changed relative abundance and composition of intestinal microbiota, especially in enhanced Lactobacillus with bile salt hydrolase (BSH) activity. OCPs affected bile acid composition, enhanced hydrophobicity, decreased expression of genes on bile acid reabsorption in the terminal ileum and compensatory increased expression of genes on synthesis of bile acids in the liver. We demonstrated that chronic exposure of OCPs could impair intestinal microbiota; as a result, hepatic and enteric bile acid profiles and metabolism were influenced. The findings in this study draw our attention to the hazards of chronic OCPs exposure in modulating bile acid metabolism that might cause metabolic disorders and their potential to cause related diseases in human. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Bile Acid Metabolism and Signaling

    PubMed Central

    Chiang, John Y. L.

    2015-01-01

    Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684

  20. [Experimental study of relationship of bile composition imbalance with bile duct injury].

    PubMed

    Chen, Geng; Zhang, Yu-Jun; Yang, Cheng; Li, Kun; Li, Xiao-Wu; Wang, Shu-Guang; Dong, Jia-Hong

    2008-02-01

    To investigate the change of bile composition and its role in bile duct injury after orthotopic liver transplantation (OLT). Rats were randomly divided into 3 groups: group A (sham surgery), group B (OLT with 1 h cold preservation), group C (OLT with 12 h cold preservation). The arterialized rat liver transplantation model with biliary extra-drainage was used in group B and C. Animals were sacrificed at posttransplant 1, 3, 5, 7, 10 and 14 day. Routine bile chemistry and pathological assays were performed. Cold preservation/reperfusion injury (CPRI) could repress the secretion of bile salts and phospholipid. However, in contrast with a rapid increase of bile salt secretion, the biliary secretion of phospholipid recovered more slowly, leading to an abnormal high bile salts/phospholipid ratio early after transplantation. Further analysis suggested that the secretion of bile salts correlated strongly with biochemical and histopathological signs of bile duct injury. CPRI can lead to great changes of graft bile composition, which plays a role in the pathogenesis of bile duct injury following liver transplantation.

  1. Sulfasalazine reduces bile acid induced apoptosis in human hepatoma cells and perfused rat livers

    PubMed Central

    Rust, C; Bauchmuller, K; Bernt, C; Vennegeerts, T; Fickert, P; Fuchsbichler, A; Beuers, U

    2006-01-01

    Background Bile acid induced apoptosis in hepatocytes can be antagonised by nuclear factor κB (NFκB) dependent survival pathways. Sulfasalazine modulates NFκB in different cell types. We aimed to determine the effects of sulfasalazine and its metabolites sulfapyridine and 5‐aminosalicylic acid (5‐ASA) on bile acid induced apoptosis in hepatocytes. Methods Apoptosis was determined by caspase assays and immunoblotting, NFκB activation by electrophoretic mobility shift assay and reporter gene assays, generation of reactive oxygen species (ROS) fluorometrically, bile secretion gravimetrically, and bile acid uptake radiochemically and by gas chromatography in HepG2‐Ntcp cells and isolated perfused rat livers. Results Glycochenodeoxycholic acid (GCDCA 75 µmol/l) induced apoptosis was reduced by sulfasalazine dose dependently (1–1000 µmol/l) in HepG2‐Ntcp cells whereas its metabolites 5‐ASA and sulfapyridine had no effect. Sulfasalazine significantly reduced GCDCA induced activation of caspases 9 and 3. In addition, sulfasalazine activated NFκB and decreased GCDCA induced generation of ROS. Bile acid uptake was competitively inhibited by sulfasalazine. In perfused rat livers, GCDCA (25 µmol/l) induced liver injury and extensive hepatocyte apoptosis were significantly reduced by simultaneous administration of 100 µmol/l sulfasalazine: lactate dehydrogenase and glutamate‐pyruvate transaminase activities were reduced by 82% and 87%, respectively, and apoptotic hepatocytes were observed only occasionally. GCDCA uptake was reduced by 45 (5)% when sulfasalazine was coadministered. However, when 50% of GCDCA (12.5 µmol/l) was administered alone, marked hepatocyte apoptosis and liver injury were again observed, questioning the impact of reduced GCDCA uptake for the antiapoptotic effect of sulfasalazine. Conclusion Sulfasalazine is a potent inhibitor of GCDCA induced hepatocyte apoptosis in vitro and in the intact liver. PMID:16322111

  2. Bile resistance mechanisms in Lactobacillus and Bifidobacterium

    PubMed Central

    Ruiz, Lorena; Margolles, Abelardo; Sánchez, Borja

    2013-01-01

    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

  3. A solid phospholipid-bile salts-mixed micelles based on the fast dissolving oral films to improve the oral bioavailability of poorly water-soluble drugs

    NASA Astrophysics Data System (ADS)

    Lv, Qing-yuan; Li, Xian-yi; Shen, Bao-de; Dai, Ling; Xu, He; Shen, Cheng-ying; Yuan, Hai-long; Han, Jin

    2014-06-01

    The phospholipid-bile salts-mixed micelles (PL-BS-MMs) are potent carriers used for oral absorption of drugs that are poorly soluble in water; however, there are many limitations associated with liquid formulations. In the current study, the feasibility of preparing the fast dissolving oral films (FDOFs) containing PL-BS-MMs was examined. FDOFs incorporated with Cucurbitacin B (Cu B)-loaded PL-sodium deoxycholate (SDC)-MMs have been developed and characterized. To prepare the MMs and to serve as the micellar carrier, a weight ratio of 1:0.8 and total concentration of 54 mg/mL was selected for the PL/SDC based on the size, size distribution, zeta potential, encapsulation efficiency, and morphology. The concentration of Cu B was determined to be 5 mg/mL. Results showed that a narrow size distributed nanomicelles with a mean particle size of 86.21 ± 6.11 nm and a zeta potential of -31.21 ± 1.17 mV was obtained in our optimized Cu B-PL/SDC-MMs formulation. FDOFs were produced by solvent casting method and the formulation with 50 mg/mL of pullulan and 40 mg/mL of PEG 400 were deemed based on the physico-mechanical properties. The FDOFs containing Cu B-PL/SDC-MMs were easily reconstituted in a transparent and clear solution giving back a colloidal system with spherical micelles in the submicron range. In the in vitro dissolution test, the FDOFs containing Cu B-PL/SDC-MMs showed an increased dissolution velocity markedly. The pharmacokinetics study showed that the FDOFs containing PL-SDC-MMs not only kept the absorption properties as same as the PL-SDC-MMs, but also significantly increased the oral bioavailability of Cu B compared to the Cu B suspension ( p < 0.05). This study showed that the FDOFs containing Cu B-PL/SDC-MMs could represent a novel platform for the delivery of poorly water-soluble drugs via oral administration. Furthermore, the integration with the FDOFs could also provide a simple and cost-effective manner for the solidification of PL-SDC-MMs.

  4. Influence of human serum albumin on the bile acid-mediated inhibition of liver microsomal type 1 11β-hydroxysteroid dehydrogenase.

    PubMed

    Maeda, Yorio; Funagayama, Mayumi; Shinohara, Akio; Koshimoto, Chihiro; Furusawa, Hidemi; Nakahara, Hiroshi; Yamaguchi, Yukiko; Saitoh, Tomokazu; Yamamoto, Takashi; Komaki, Kansei

    2014-09-01

    The influence of human serum albumin (HSA) on the bile acid-mediated inhibition of liver microsomal type 1 11β-hydroxysteroid dehydrogenase (11β-HSD1) was studied in vitro. A rat liver microsomal fraction was prepared, and the 11β-HSD1 enzyme activity in the presence of various concentrations of bile acids and HSA was determined using hydrocortisone as the substrate. The products of the reaction were extracted and analyzed using high-performance liquid chromatography. The magnitude of the inhibition decreased with the addition of HSA in a dose-dependent manner. Four percent human albumin decreased the inhibitory effects of 100 μM chenodeoxycholic acid and lithocholic acid from 89.9 ± 5.6 to 54.5 ± 6.1% and from 83.8 ± 4.8 to 20.8 ± 4.2%, respectively. In contrast, ursodeoxycholic acid and deoxycholic acid showed no inhibitory effect on the enzyme activity in the presence of 4% human serum albumin, and the addition of 1% γ-globulin to the assay mixture in the presence of bile acids did not affect the enzyme activity. Our in vitro study showed that the addition of HSA ameliorated the inhibition of 11β-HSD1 and that the magnitude of the change is dependent on the species of bile acid, presumably based on the numbers of hydroxyl groups. These results suggest that HSA seems to protect the bile acid-mediated inhibition of 11β-HSD1 in the healthy subject. On the other hand, in the patients with obstructive biliary diseases, not only elevated serum bile acid but also the accompanying hypoalbuminemia is important to evaluate the pathophysiology of the bile acid-mediated inhibition of 11β-HSD1 of the disease.

  5. Structural elucidation of the hormonal inhibition mechanism of the bile acid cholate on human carbonic anhydrase II

    SciTech Connect

    Boone, Christopher D.; Tu, Chingkuang; McKenna, Robert

    2014-06-01

    The structure of human carbonic anhydrase II in complex with cholate has been determined to 1.54 Å resolution. Elucidation of the novel inhibition mechanism of cholate will aid in the development of a nonsulfur-containing, isoform-specific therapeutic agent. The carbonic anhydrases (CAs) are a family of mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO{sub 2} into bicarbonate and a proton. Human isoform CA II (HCA II) is abundant in the surface epithelial cells of the gastric mucosa, where it serves an important role in cytoprotection through bicarbonate secretion. Physiological inhibition of HCA II via the bile acids contributes to mucosal injury in ulcerogenic conditions. This study details the weak biophysical interactions associated with the binding of a primary bile acid, cholate, to HCA II. The X-ray crystallographic structure determined to 1.54 Å resolution revealed that cholate does not make any direct hydrogen-bond interactions with HCA II, but instead reconfigures the well ordered water network within the active site to promote indirect binding to the enzyme. Structural knowledge of the binding interactions of this nonsulfur-containing inhibitor with HCA II could provide the template design for high-affinity, isoform-specific therapeutic agents for a variety of diseases/pathological states, including cancer, glaucoma, epilepsy and osteoporosis.

  6. Bile Duct Diseases

    MedlinePlus

    ... gallbladder pushes the bile into tubes called bile ducts. They carry the bile to your small intestine. ... and wastes. Different diseases can block the bile ducts and cause a problem with the flow of ...

  7. Confocal imaging with a fluorescent bile acid analogue closely mimicking hepatic taurocholate disposition.

    PubMed

    De Bruyn, Tom; Sempels, Wouter; Snoeys, Jan; Holmstock, Nico; Chatterjee, Sagnik; Stieger, Bruno; Augustijns, Patrick; Hofkens, Johan; Mizuno, Hideaki; Annaert, Pieter

    2014-06-01

    This study aimed to characterize the in vitro hepatic transport mechanisms in primary rat and human hepatocytes of the fluorescent bile acid derivative N-(24-[7-(4-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole)]amino-3α,7α,12α-trihydroxy-27-nor-5β-cholestan-26-oyl)-2'-aminoethanesulfonate (tauro-nor-THCA-24-DBD), previously synthesized to study the activity of the bile salt export pump (BSEP). The fluorescent bile acid derivative exhibited saturable uptake kinetics in suspended rat hepatocytes. Hepatic uptake was inhibited in the presence of substrates/inhibitors of the organic anion transporting polypeptide (Oatp) family and Na(+) -taurocholate cotransporting peptide (Ntcp). Concentration-dependent uptake of the fluorescent bile acid was also saturable in Chinese hamster ovary cells transfected with rNtcp, hNTCP, OATP1B1, or OATP1B3. The fluorescent bile acid derivative was actively excreted in the bile canaliculi of sandwich-cultured rat and human hepatocytes (SCRH and SCHH), with a biliary excretion index (BEI) of 26% and 32%, respectively. In SCRH, cyclosporin A significantly decreased the BEI to 5%. Quantification by real-time confocal imaging further confirmed canalicular transport of the fluorescent bile acid derivative (BEI = 75%). We conclude that tauro-nor-THCA-24-DBD is a useful probe to study interference of drugs with NTCP/Ntcp- and BSEP/Bsep-mediated transport in fluorescence-based in vitro assays.

  8. Effects of long-term ingestion of difructose anhydride III (DFA III) on intestinal bacteria and bile acid metabolism in humans.

    PubMed

    Minamida, Kimiko; Asakawa, Chikako; Sujaya, I Nengah; Kaneko, Maki; Abe, Ayumi; Sone, Teruo; Hara, Hiroshi; Asano, Kozo; Tomita, Fusao

    2006-02-01

    Changes in the intestinal microbiota of 10 human subjects with long-term ingestion of 3 g/d difructose anhydride III (DFA III; 4 persons, 2 months; 3 persons, 6 months; and 3 persons, 12 months) were examined by denaturing gradient gel electrophoresis (DGGE). According to the answers to questionnaires, the subjects were divided into two groups (constipated and normal). The DGGE profile was different for every individual and each subject had unique profiles of intestinal microbiota. In the DGGE profiles of constipated subjects, the intensities of bands related to Bacteroides spp. increased. Moreover, the DFA III-assimilating bacteria, Ruminococcus sp. were isolated from subjects who ingested DFA III for 12 months. These strains showed 95% similarity of their 16S rDNA sequences with that of Ruminococcus obeum ATCC 29174(T) (X85101) and produced large amounts of acetic acid. DFA III ingestion for 2 months tended to increase total organic acids in feces, and tended to decrease fecal pH and the secondary bile acid (SBA) ratio in total bile acids. The SBA ratio in total bile acids corresponded to fecal pH. The production of SBA was decreased by low pH in vitro. These results indicated that DFA III ingestion in humans tended to lower intestinal pH, inhibited bile acid 7alpha-dehydroxylation activities and also tended to decrease the SBA ratios in total bile acids. Moreover, as another cause for the decrease in the SBA ratio in total bile acids, it was suggested that the number of bile acid 7alpha-dehydroxylating bacteria were decreased by DFA III ingestion.

  9. Transport of bile acids in multidrug-resistance-protein 3-overexpressing cells co-transfected with the ileal Na+-dependent bile-acid transporter.

    PubMed Central

    Zelcer, Noam; Saeki, Tohru; Bot, Ilse; Kuil, Annemieke; Borst, Piet

    2003-01-01

    Many of the transporters involved in the transport of bile acids in the enterohepatic circulation have been characterized. The basolateral bile-acid transporter of ileocytes and cholangiocytes remains an exception. It has been suggested that rat multidrug resistance protein 3 (Mrp3) fulfills this function. Here we analyse bile-salt transport by human MRP3. Membrane vesicles from insect ( Spodoptera frugiperda ) cells expressing MRP3 show time-dependent uptake of glycocholate and taurocholate. Furthermore, sulphated bile salts were high-affinity competitive inhibitors of etoposide glucuronide transport by MRP3 (IC50 approximately 10 microM). Taurochenodeoxycholate, taurocholate and glycocholate inhibited transport at higher concentrations (IC50 approximately 100, 250 and 500 microM respectively). We used mouse fibroblast-like cell lines derived from mice with disrupted Mdr1a, Mdr1b and Mrp1 genes to generate transfectants that express the murine apical Na+-dependent bile-salt transporter (Asbt) and MRP3. Uptake of glycocholate by these cells is Na+-dependent, with a K(m) and V(max) of 29+/-7 microM and 660 +/- 63 pmol/min per mg of protein respectively and is inhibited by several organic-aniontransport inhibitors. Expression of MRP3 in these cells limits the accumulation of glycocholate and increases the efflux from cells preloaded with taurocholate or glycocholate. In conclusion, we find that MRP3 transports both taurocholate and glycocholate, albeit with low affinity, in contrast with the high-affinity transport by rat Mrp3. Our results suggest that MRP3 is unlikely to be the principal basolateral bile-acid transporter of ileocytes and cholangiocytes, but that it may have a role in the removal of bile acids from the liver in cholestasis. PMID:12220224

  10. Probiotics--interactions with bile acids and impact on cholesterol metabolism.

    PubMed

    Pavlović, Nebojša; Stankov, Karmen; Mikov, Momir

    2012-12-01

    The use of probiotics, alone or in interaction with bile acids, is a modern strategy in the prevention and treatment of hypercholesterolemia. Numerous mechanisms for hypocholesterolemic effect of probiotics have been hypothesized, based mostly on in vitro evidence. Interaction with bile acids through reaction of deconjugation catalyzed by bile salt hydrolase enzymes (BSH) is considered as the main mechanism of cholesterol-lowering effects of probiotic bacteria, but it has been reported that microbial BSH activity could be potentially detrimental to the human host. There are several approaches for prevention of possible side effects associated with BSH activity, which at the same time increase the viability of probiotics in the intestines and also in food matrices. The aim of our study was to summarize present knowledge of probiotics-bile acids interactions, with special reference to cholesterol-lowering mechanisms of probiotics, and to report novel biotechnological approaches for increasing the pharmacological benefits of probiotics.

  11. Phenolic composition and antioxidant effect of aqueous extract of Arisaema cum Bile, the Oriental Herb Medicine, in human fibroblast cells.

    PubMed

    Ahn, Chang-Bum; Shin, Tai-Sun; Seo, Hye Kyoung; Je, Jae-Young

    2012-08-01

    Phenolic composition and antioxidant activities of the aqueous extract of Arisaema cum Bile, which is widely used as a folk medicine in Korea, were determined. Phenolic composition profile revealed that the aqueous extract is rich in sinapic acid (13.14 mg/100 g extract), catechin (9.88 mg/100 g extract), neohesperidin (7.38 mg/100 g extract), and chlorogenic acid (3.64 mg/100 g extract). The aqueous extract effectively scavenged toward 2,2-diphenyl-1-picrylhydrazyl (90.63%), hydrogen peroxide (98.13%), and hydroxyl radical (59.62%) at 2.0 mg/mL, and also showed high reducing power. In cytotoxic evaluation, the aqueous extract exhibited no significant cytotoxicity in human fibroblast, and it also exhibited appreciable suppression of intracellular reactive oxygen species and inhibition of lipid peroxidation. In addition, the aqueous extract upregulated the level of glutathione in a dose-dependent manner. Taken together, the aqueous extract of Arisaema cum Bile could be considered as a potential natural source that may be useful for curing diseases arising from oxidative deterioration.

  12. Bile salt export pump deficiency: A de novo mutation in a child compound heterozygous for ABCB11. Laboratory investigation to study pathogenic role and transmission of two novel ABCB11 mutations.

    PubMed

    Francalanci, Paola; Giovannoni, Isabella; Candusso, Manila; Bellacchio, Emanuele; Callea, Francesco

    2013-03-01

    Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomal disorders. PFIC type 2 is due to mutation in ABCB11, the gene encoding the bile salt export pump (BSEP) protein. The aim of the study was to describe a child with a de novo mutation in a compound heterozygous for ABCB11 gene. We report a 1.7-year-old girl who presented with pruritus, jaundice and liver dysfunction of PFIC type 2. Immunohistochemistry and molecular analysis are described. Liver biopsy showed micronodular cirrhosis and immunohistochemical staining for BSEP, the protein encoded by ABCB11, displayed a patchy and faint reactivity. Molecular analysis revealed two novel mutations of ABCB11. We give details that one mutation is transmitted by the mother while the second one appears a de novo mutation as mutations or a potential mosaicism were ruled out in the natural father. We further speculate that the ABCB11 mutations do not prevent BSEP glycoprotein to be expressed at the canalicular pole of hepatocytes, but interfere with its ability to export bile salts. As in most instances, mutational analysis is performed following the histochemical demonstration of an undetectable BSEP on liver biopsy specimen. This case stresses that clinical PFIC with an attenuated rather than absent BSEP immunostaining can still be due to ABCB11 mutations presumably encoding a functionally deficient protein.

  13. Bile Acids, Obesity, and the Metabolic Syndrome

    PubMed Central

    Ma, Huijuan; Patti, Mary Elizabeth

    2014-01-01

    Bile acids are increasingly recognized as key regulators of systemic metabolism. While bile acids have long been known to play important and direct roles in nutrient absorption, bile acids also serve as signaling molecules. Bile acid interactions with the nuclear hormone receptor farnesoid X receptor (FXR) and the membrane receptor G-protein-coupled bile acid receptor 5 (TGR5) can regulate incretin hormone and fibroblast growth factor 19 (FGF19) secretion, cholesterol metabolism, and systemic energy expenditure. Bile acid levels and distribution are altered in type 2 diabetes and increased following bariatric procedures, in parallel with reduced body weight and improved insulin sensitivity and glycemic control. Thus, modulation of bile acid levels and signaling, using bile acid binding resins, TGR5 agonists, and FXR agonists, may serve as a potent therapeutic approach for the treatment of obesity, type 2 diabetes, and other components of the metabolic syndrome in humans. PMID:25194176

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

    PubMed Central

    Wang, David Q-H; Carey, Martin C

    2014-01-01

    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-20th 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. Therapeutic uses of animal biles in traditional Chinese medicine: an ethnopharmacological, biophysical chemical and medicinal review.

    PubMed

    Wang, David Q-H; Carey, Martin C

    2014-08-07

    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

  16. The ulcerogenic effect of bile and bile acid in rats during immobilization stress

    NASA Technical Reports Server (NTRS)

    Weisener, J.

    1980-01-01

    The effect of different concentrations of oxen bile and individual bile acids or their sodium salts on the gastric mucosa of rats was investigated in combination with immobilization stress. A statistically significant higher frequency of ulcers was only determined in the application of 10% oxen bile. Dosages on 10% sodium glycocholic acid demonstrated strong toxic damage with atonic dilation of the stomach and extensive mucosal bleeding.

  17. Influence of various bile acids on the metabolism of glycyrrhizin and glycyrrhetic acid by Ruminococcus sp. PO1-3 of human intestinal bacteria.

    PubMed

    Akao, T

    1999-08-01

    Ruminococcus sp. PO1-3, an intestinal bacterium isolated from human feces, metabolized glycyrrhizin (GL) to glycyrrhetic acid (GA) and GA to 3-oxo-glycyrrhetic acid (3-oxo-GA) and possessed GL beta-D-glucuronidase and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) involved in the metabolism of GL. This bacterial growth was enhanced by GL at a concentration of 0.4 mm and was suppressed by GA at concentration of 1.0 mM. Chenodeoxycholic acid, deoxycholic acid and lithocholic acid among the bile acids added to this bacterium suppressed the growth and GL beta-D-glucuronidase activity and 3beta-HSD activity incident to it at a concentration of 1.0 mM, while cholic acid, hyodeoxycholic acid and glycine and taurin conjugates of cholic acid, chenodeoxycholic acid, deoxycholic acid and lithocholic acid had almost no effect on this bacterium at a concentration of 0.2 to 1.0 mm. However, these enzyme activities of this sonicated bacteria were inhibited by all of these bile acids. Although each bile acid and GL added to bacteria at the same time suppressed the growth and the amount of metabolite GA by all bile acids used except cholic acid, taurocholic acid and taurodeoxycholic acid with GL, a combination of each bile acid and GA eased the growth inhibition caused by GA at a concentration of 0.2 mM and enhanced the amount of metabolite 3-oxo-GA by the glycine conjugate of bile acids with GA. GL or GA added after 6 h culture with each of these bile acids and bacteria was metabolized to a relatively large amount of GA by chenodeoxycholic acid and lithocholic acid and their glycine and taurine conjugates, glycocholic acid and taurodeoxycholic acid, or had almost no effect on the amount of metabolite 3-oxo-GA, respectively. These results showed that although GL added after the exposure to bile acid and GA and bile acid added at the same time as bacteria had different bile acid action, these conditions enhanced the amount of metabolite GA from GL and metabolite 3-oxo-GA from GA.

  18. Bile acids and cytokines inhibit the human cholesterol 7 alpha-hydroxylase gene via the JNK/c-jun pathway in human liver cells.

    PubMed

    Li, Tiangang; Jahan, Asmeen; Chiang, John Y L

    2006-06-01

    Cholesterol 7 alpha-hydroxylase (CYP7A1) of the bile acid biosynthesis pathway is suppressed by bile acids and inflammatory cytokines. Bile acids are known to induce inflammatory cytokines to activate the mitogen-activated protein kinase/c-Jun N-terminal kinase (JNK) signaling pathway that inhibits CYP7A1 gene transcription. c-Jun has been postulated to mediate bile acid inhibition of CYP7A1. However, the c-Jun target involved in the regulation of CYP7A1 is unknown. Human primary hepatocytes and HepG2 cells were used as models to study chenodeoxycholic acid (CDCA) and interleukin-1 beta (IL-1 beta) regulation of human CYP7A1 gene expression via real-time polymerase chain reaction, reporter assays, co-immunoprecipitation and chromatin immunocipitation (ChIP) assays. IL-1 beta and CDCA reduced CYP7A1 but induced c-Jun messenger RNA expression in human primary hepatocytes. IL-1beta inhibited human CYP7A1 reporter activity via the HNF4 alpha binding site. A JNK-specific inhibitor blocked the inhibitory effect of IL-1 beta on HNF4 alpha expression and CYP7A1 reporter activity. c-Jun inhibited HNF4 alpha and PPARgamma coactivator-1 alpha (PGC-1 alpha) coactivation of CYP7A1 reporter activity, whereas a dominant negative c-Jun did not. Co-immunoprecipitation and ChIP assays revealed that IL-1 beta and CDCA reduced HNF4 alpha bound to the CYP7A1 chromatin, and that c-Jun interacted with HNF4 alpha and blocked HNF4 alpha recruitment of PGC-1 alpha to the CYP7A1 chromatin. In conclusion, IL-1 beta and CDCA inhibit HNF4 alpha but induce c-Jun, which in turn blocks HNF 4 alpha recruitment of PGC-1 alpha to the CYP7A1 chromatin and results in inhibition of CYP7A1 gene transcription. The JNK/c-Jun signaling pathway inhibits bile acid synthesis and protects hepatocytes against the toxic effect of inflammatory agents.

  19. Adaptation and Preadaptation of Salmonella enterica to Bile

    PubMed Central

    Hernández, Sara B.; Cota, Ignacio; Ducret, Adrien; Aussel, Laurent; Casadesús, Josep

    2012-01-01

    Bile possesses antibacterial activity because bile salts disrupt membranes, denature proteins, and damage DNA. This study describes mechanisms employed by the bacterium Salmonella enterica to survive bile. Sublethal concentrations of the bile salt sodium deoxycholate (DOC) adapt Salmonella to survive lethal concentrations of bile. Adaptation seems to be associated to multiple changes in gene expression, which include upregulation of the RpoS-dependent general stress response and other stress responses. The crucial role of the general stress response in adaptation to bile is supported by the observation that RpoS− mutants are bile-sensitive. While adaptation to bile involves a response by the bacterial population, individual cells can become bile-resistant without adaptation: plating of a non-adapted S. enterica culture on medium containing a lethal concentration of bile yields bile-resistant colonies at frequencies between 10−6 and 10−7 per cell and generation. Fluctuation analysis indicates that such colonies derive from bile-resistant cells present in the previous culture. A fraction of such isolates are stable, indicating that bile resistance can be acquired by mutation. Full genome sequencing of bile-resistant mutants shows that alteration of the lipopolysaccharide transport machinery is a frequent cause of mutational bile resistance. However, selection on lethal concentrations of bile also provides bile-resistant isolates that are not mutants. We propose that such isolates derive from rare cells whose physiological state permitted survival upon encountering bile. This view is supported by single cell analysis of gene expression using a microscope fluidic system: batch cultures of Salmonella contain cells that activate stress response genes in the absence of DOC. This phenomenon underscores the existence of phenotypic heterogeneity in clonal populations of bacteria and may illustrate the adaptive value of gene expression fluctuations. PMID:22275872

  20. Gender, but not CYP7A1 or SLCO1B1 polymorphism, affects the fasting plasma concentrations of bile acids in human beings.

    PubMed

    Xiang, Xiaoqiang; Backman, Janne T; Neuvonen, Pertti J; Niemi, Mikko

    2012-03-01

    Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme of bile acid production in human beings, and organic anion-transporting polypeptide 1B1 (OATP1B1) may influence bile acid hepatic uptake and cholesterol and bile acid synthesis rate. Our purpose was to investigate the effects of gender and CYP7A1 and SLCO1B1 polymorphisms on the fasting plasma concentrations of bile acids, bile acid synthesis marker and total cholesterol in a Finnish population. Fasting plasma concentrations of 16 endogenous bile acids, their synthesis marker (7α-hydroxy-4-cholesten-3-one) and total cholesterol were measured in 243 samples from 143 healthy volunteers. The volunteers were genotyped for 6 haplotype-tagging single-nucleotide polymorphisms (SNPs) of CYP7A1 and two functionally relevant SNPs in SLCO1B1. The mean plasma concentrations of chenodeoxycholic acid, glycochenodeoxycholic acid, ursodeoxycholic acid and glycoursodeoxycholic acid were 61-111% higher in men than in women (P ≤ 0.001). Accordingly, the mean concentration of total bile acids was 51% higher in men than in women (P = 0.001). The CYP7A1 rs8192879 and rs1023652 SNPs were associated with deoxycholic acid and hyodeoxycholic acid concentrations, respectively, but the associations were not significant after correction for multiple testing. None of the six CYP7A1 SNPs was associated with the plasma concentrations of cholesterol or 7α-hydroxy-4-cholesten-3-one. SLCO1B1 genotype was associated with total plasma cholesterol concentration only, but the association was not significant after correction for multiple testing. In general, the gender contributes substantially more to variation in fasting plasma bile acid concentrations than CYP7A1 or SLCO1B1 polymorphism do. Common genetic variability in CYP7A1 is unlikely to play a significant role in cholesterol metabolism and bile acid homeostasis under normal physiological conditions. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011

  1. Real-time PCR-based analysis of the human bile microRNAome identifies miR-9 as a potential diagnostic biomarker for biliary tract cancer.

    PubMed

    Shigehara, Kengo; Yokomuro, Shigeki; Ishibashi, Osamu; Mizuguchi, Yoshiaki; Arima, Yasuo; Kawahigashi, Yutaka; Kanda, Tomohiro; Akagi, Ichiro; Tajiri, Takashi; Yoshida, Hiroshi; Takizawa, Toshihiro; Uchida, Eiji

    2011-01-01

    Biliary tract cancer (BTC) is often difficult to diagnose definitively, even through histological examination. MicroRNAs (miRNAs) regulate a variety of physiological processes. In recent years, it has been suggested that profiles for circulating miRNAs, as well as those for tissue miRNAs, have the potential to be used as diagnostic biomarkers for cancer. The aim of this study was to confirm the existence of miRNAs in human bile and to assess their potential as clinical biomarkers for BTC. We sampled bile from patients who underwent biliary drainage for biliary diseases such as BTC and choledocholithiasis. PCR-based miRNA detection and miRNA cloning were performed to identify bile miRNAs. Using high-throughput real-time PCR-based miRNA microarrays, the expression profiles of 667 miRNAs were compared in patients with malignant disease (n = 9) and age-matched patients with the benign disease choledocholithiasis (n = 9). We subsequently characterized bile miRNAs in terms of stability and localization. Through cloning and using PCR methods, we confirmed that miRNAs exist in bile. Differential analysis of bile miRNAs demonstrated that 10 of the 667 miRNAs were significantly more highly expressed in the malignant group than in the benign group at P<0.0005. Setting the specificity threshold to 100% showed that some miRNAs (miR-9, miR-302c*, miR-199a-3p and miR-222*) had a sensitivity level of 88.9%, and receiver-operating characteristic analysis demonstrated that miR-9 and miR-145* could be useful diagnostic markers for BTC. Moreover, we verified the long-term stability of miRNAs in bile, a characteristic that makes them suitable for diagnostic use in clinical settings. We also confirmed that bile miRNAs are localized to the malignant/benign biliary epithelia. These findings suggest that bile miRNAs could be informative biomarkers for hepatobiliary disease and that some miRNAs, particularly miR-9, may be helpful in the diagnosis and clinical management of BTC.

  2. Real-Time PCR-Based Analysis of the Human Bile MicroRNAome Identifies miR-9 as a Potential Diagnostic Biomarker for Biliary Tract Cancer

    PubMed Central

    Shigehara, Kengo; Yokomuro, Shigeki; Ishibashi, Osamu; Mizuguchi, Yoshiaki; Arima, Yasuo; Kawahigashi, Yutaka; Kanda, Tomohiro; Akagi, Ichiro; Tajiri, Takashi; Yoshida, Hiroshi; Takizawa, Toshihiro; Uchida, Eiji

    2011-01-01

    Biliary tract cancer (BTC) is often difficult to diagnose definitively, even through histological examination. MicroRNAs (miRNAs) regulate a variety of physiological processes. In recent years, it has been suggested that profiles for circulating miRNAs, as well as those for tissue miRNAs, have the potential to be used as diagnostic biomarkers for cancer. The aim of this study was to confirm the existence of miRNAs in human bile and to assess their potential as clinical biomarkers for BTC. We sampled bile from patients who underwent biliary drainage for biliary diseases such as BTC and choledocholithiasis. PCR-based miRNA detection and miRNA cloning were performed to identify bile miRNAs. Using high-throughput real-time PCR-based miRNA microarrays, the expression profiles of 667 miRNAs were compared in patients with malignant disease (n = 9) and age-matched patients with the benign disease choledocholithiasis (n = 9). We subsequently characterized bile miRNAs in terms of stability and localization. Through cloning and using PCR methods, we confirmed that miRNAs exist in bile. Differential analysis of bile miRNAs demonstrated that 10 of the 667 miRNAs were significantly more highly expressed in the malignant group than in the benign group at P<0.0005. Setting the specificity threshold to 100% showed that some miRNAs (miR-9, miR-302c*, miR-199a-3p and miR-222*) had a sensitivity level of 88.9%, and receiver-operating characteristic analysis demonstrated that miR-9 and miR-145* could be useful diagnostic markers for BTC. Moreover, we verified the long-term stability of miRNAs in bile, a characteristic that makes them suitable for diagnostic use in clinical settings. We also confirmed that bile miRNAs are localized to the malignant/benign biliary epithelia. These findings suggest that bile miRNAs could be informative biomarkers for hepatobiliary disease and that some miRNAs, particularly miR-9, may be helpful in the diagnosis and clinical management of BTC. PMID

  3. Bile acids potentiate proton-activated currents in Xenopus laevis oocytes expressing human acid-sensing ion channel (ASIC1a).

    PubMed

    Ilyaskin, Alexandr V; Diakov, Alexei; Korbmacher, Christoph; Haerteis, Silke

    2017-02-01

    Acid-sensing ion channels (ASICs) are nonvoltage-gated sodium channels transiently activated by extracellular protons and belong to the epithelial sodium channel (ENaC)/Degenerin (DEG) family of ion channels. Bile acids have been shown to activate two members of this family, the bile acid-sensitive ion channel (BASIC) and ENaC. To investigate whether bile acids also modulate ASIC function, human ASIC1a was heterologously expressed in Xenopus laevis oocytes. Exposing oocytes to tauro-conjugated cholic (t-CA), deoxycholic (t-DCA), and chenodeoxycholic (t-CDCA) acid at pH 7.4 did not activate ASIC1a-mediated whole-cell currents. However, in ASIC1a expressing oocytes the whole-cell currents elicited by pH 5.5 were significantly increased in the presence of these bile acids. Single-channel recordings in outside-out patches confirmed that t-DCA enhanced the stimulatory effect of pH 5.5 on ASIC1a channel activity. Interestingly, t-DCA reduced single-channel current amplitude by ~15% which suggests an interaction of t-DCA with a region close to the channel pore. Molecular docking predicted binding of bile acids to the pore region near the degenerin site (G433) in the open conformation of the channel. Site-directed mutagenesis demonstrated that the amino acid residue G433 is critically involved in the potentiating effect of bile acids on ASIC1a activation by protons.

  4. Tissue-specific bioaccumulation of human and veterinary antibiotics in bile, plasma, liver and muscle tissues of wild fish from a highly urbanized region.

    PubMed

    Zhao, Jian-Liang; Liu, You-Sheng; Liu, Wang-Rong; Jiang, Yu-Xia; Su, Hao-Chang; Zhang, Qian-Qian; Chen, Xiao-Wen; Yang, Yuan-Yuan; Chen, Jun; Liu, Shuang-Shuang; Pan, Chang-Gui; Huang, Guo-Yong; Ying, Guang-Guo

    2015-03-01

    We investigated the bioaccumulation of antibiotics in bile, plasma, liver and muscle tissues of wild fish from four rivers in the Pearl River Delta region. In total, 12 antibiotics were present in at least one type of fish tissues from nine wild fish species in the four rivers. The mean values of log bioaccumulation factors (log BAFs) for the detected antibiotics in fish bile, plasma, liver, and muscle tissues were at the range of 2.06-4.08, 1.85-3.47, 1.41-3.51, and 0.48-2.70, respectively. As the digestion tissues, fish bile, plasma, and liver showed strong bioaccumulation ability for some antibiotics, indicating a different bioaccumulation pattern from hydrophobic organic contaminants. Human health risk assessment based on potential fish consumption indicates that these antibiotics do not appear to pose an appreciable risk to human health. To the best of our knowledge, this is first report of bioaccumulation patterns of antibiotics in wild fish bile and plasma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Bile Duct Cancer (Cholangiocarcinoma)

    MedlinePlus

    ... Types of Cancer > Bile Duct Cancer (Cholangiocarcinoma) Bile Duct Cancer (Cholangiocarcinoma) This is Cancer.Net’s Guide to Bile Duct Cancer (Cholangiocarcinoma). Use the menu below to choose ...

  6. Metabolic Activation of Cholestatic Drug-Induced Bile Acid-Dependent Toxicity in Human Sandwich-Cultured Hepatocytes.

    PubMed

    Ogimura, Eiichiro; Tokizono, Mayuko; Sekine, Shuichi; Nakagawa, Tetsuya; Bando, Kiyoko; Ito, Kousei

    2017-09-01

    We previously reported a cell-based toxicity assay using sandwich-cultured hepatocytes in combination with a titrated amount of human bile acid (BA) species. In this assay, test compound-induced inhibition of BA efflux from sandwich-cultured hepatocytes leads to BA-dependent cell toxicity (BAtox, i.e., cell death due to the accumulation of BAs). Using this assay, we investigated whether 1-aminobenzotriazole (1-ABT; a nonselective cytochrome P450 inhibitor) enhanced or suppressed test compound-induced BAtox. There was a tendency that BAtox of many compounds was enhanced by 1-ABT in human hepatocytes; in contrast, such a tendency was not observed in rat hepatocytes. In particular, 1-ABT tended to enhance BAtox of several compounds (clopidogrel, ticlopidine, everolimus, etc.) in human, whereas 1-ABT tended to enhance BAtox of only ticlopidine in rat. These results indicate that this system can be used to evaluate BAtox while taking into account drug metabolism and the existence of an interspecies difference in the effect of 1-ABT treatment on BAtox. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  7. Thermodynamic and molecular basis for dissimilar cholesterol-solubilizing capacities by micellar solutions of bile salts: cases of sodium chenodeoxycholate and sodium ursodeoxycholate and their glycine and taurine conjugates.

    PubMed

    Carey, M C; Montet, J C; Phillips, M C; Armstrong, M J; Mazer, N A

    1981-06-09

    The bile salts chenodeoxycholate (CDC) and its 7 beta-hydroxy epimer ursodeoxycholate (UDC) are administered therapeutically (as acids) to dissolve cholesterol gallstones in man. Since their micellarr solutions and those of their physiological conjugates differ strikingly in their capacities to solubilize cholesterol, we studied the interfacial and micellar properties of the epimers by a number of complimentary physical--chemical methods and correlated these with their solubilizing capacities. The critical micella concentrations (cmc) estimated by surface tension, dye titration, and turbidimetry were similar (1-5 mM), varying slightly with the bile salt species, the method employed, NaCl concentration (0-1 M), and temperature (10-50 degrees C). The weight-average aggregation number (number of monomers per micelle, nw) at the cmc, derived from Debye plots of conventional light-scattering data and from the mean hydrodynamic radii of the micelles obtained by quasi-elastic light-scattering spectroscopy, revealed no appreciable differences between the UDC-CDC epimers or between their conjugates. From the mean hydrodynamic radii, the taurine conjugates were found to form larger micelles (nw = 15-17) than the glycine conjugates (nw = 13) which in turn were larger than the free species (n w = 5), respectively. Consistent with previous experimental deductions, free and conjugated CDC micelles grew slightly in size with increases in total lipid concentration, but UDC micelles did not. With solubilization of cholesterol monohydrate, the mean sizes of UDC (13.4 A) and of CDC (13 A) micelles in 10 g/dL solutions did not change appreciably, even as the cholesterol saturation limit was reached. At the air-5 M NaCl (pH 2) interface, the glycine conjugates formed more expanded monomolecular films than the free acid, and both UDC and its glycine conjugate collapsed at surface pressures that were 10-20 mN m-1 lower than the collapse pressures of monolayers of CDC and its glycine

  8. Enzymic sulfation of bile salts. Partial purification and characterization of an enzyme from the liver of the shark Heterodontus portusjacksoni that catalyses the sulfation of the shark bile steroid 5 beta-scymnol.

    PubMed

    Macrides, T A; Faktor, D A; Kalafatis, N; Amiet, R G

    1994-03-01

    An enzyme system which catalyses the transfer of the sulfate group from 3'-phosphoadenosine-5'-phosphosulfate to the bile steroid 5 beta-scymnol has been isolated and characterized from the liver of the shark Heterodontus portusjacksoni (Meyer 1793). The enzyme is present in the cytosol fraction of liver cells. It was partially purified by hydroxylapatite chromatography, molecular sizing by G100-Sephadex and isoelectrofocusing electrophoresis. The apparent Km value for 3'-phosphoadenosine-5'-phosphosulfate was 4 microM and that for 5 beta-scymnol, 14 microM. The enzyme activity is inhibited by iodoacetate and p-chloromercuribenzoate indicating the possible requirement of a sulfhydryl group for activity. The molecular weight of the enzyme was estimated to be 40 kDa by gel filtration. This was verified by running the partially purified material on a native gel and electrophoretically separating two major bands corresponding to molecular weights of 40 and 45 kDa, respectively. Isoelectric focusing of the purified material resulted in two major bands with pI values of 5.0 and 5.85. Enzymatic activity was found to be optimal at a pH of 6.5 with little activity recorded at pH 5.0 and 8.0.

  9. 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.

    PubMed

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

    2015-11-10

    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.

  10. Unconjugated Bile Acids Influence Expression of Circadian Genes: A Potential Mechanism for Microbe-Host Crosstalk

    PubMed Central

    Govindarajan, Kalaimathi; MacSharry, John; Casey, Patrick G.; Shanahan, Fergus

    2016-01-01

    Disruptions to circadian rhythm in mice and humans have been associated with an increased risk of obesity and metabolic syndrome. The gut microbiota is known to be essential for the maintenance of circadian rhythm in the host suggesting a role for microbe-host interactions in the regulation of the peripheral circadian clock. Previous work suggested a role for gut bacterial bile salt hydrolase (BSH) activity in the regulation of host circadian gene expression. Here we demonstrate that unconjugated bile acids, known to be generated through the BSH activity of the gut microbiota, are potentially chronobiological regulators of host circadian gene expression. We utilised a synchronised Caco-2 epithelial colorectal cell model and demonstrated that unconjugated bile acids, but not the equivalent tauro-conjugated bile salts, enhance the expression levels of genes involved in circadian rhythm. In addition oral administration of mice with unconjugated bile acids significantly altered expression levels of circadian clock genes in the ileum and colon as well as the liver with significant changes to expression of hepatic regulators of circadian rhythm (including Dbp) and associated genes (Per2, Per3 and Cry2). The data demonstrate a potential mechanism for microbe-host crosstalk that significantly impacts upon host circadian gene expression. PMID:27907092

  11. Unconjugated Bile Acids Influence Expression of Circadian Genes: A Potential Mechanism for Microbe-Host Crosstalk.

    PubMed

    Govindarajan, Kalaimathi; MacSharry, John; Casey, Patrick G; Shanahan, Fergus; Joyce, Susan A; Gahan, Cormac G M

    2016-01-01

    Disruptions to circadian rhythm in mice and humans have been associated with an increased risk of obesity and metabolic syndrome. The gut microbiota is known to be essential for the maintenance of circadian rhythm in the host suggesting a role for microbe-host interactions in the regulation of the peripheral circadian clock. Previous work suggested a role for gut bacterial bile salt hydrolase (BSH) activity in the regulation of host circadian gene expression. Here we demonstrate that unconjugated bile acids, known to be generated through the BSH activity of the gut microbiota, are potentially chronobiological regulators of host circadian gene expression. We utilised a synchronised Caco-2 epithelial colorectal cell model and demonstrated that unconjugated bile acids, but not the equivalent tauro-conjugated bile salts, enhance the expression levels of genes involved in circadian rhythm. In addition oral administration of mice with unconjugated bile acids significantly altered expression levels of circadian clock genes in the ileum and colon as well as the liver with significant changes to expression of hepatic regulators of circadian rhythm (including Dbp) and associated genes (Per2, Per3 and Cry2). The data demonstrate a potential mechanism for microbe-host crosstalk that significantly impacts upon host circadian gene expression.

  12. Bile salt–dependent lipase interacts with platelet CXCR4 and modulates thrombus formation in mice and humans

    PubMed Central

    Panicot-Dubois, Laurence; Thomas, Grace M.; Furie, Barbara C.; Furie, Bruce; Lombardo, Dominique; Dubois, Christophe

    2007-01-01

    Bile salt–dependent lipase (BSDL) is an enzyme involved in the duodenal hydrolysis and absorption of cholesteryl esters. Although some BSDL is transported to blood, the role of circulating BSDL is unknown. Here, we demonstrate that BSDL is stored in platelets and released upon platelet activation. Because BSDL contains a region that is structurally homologous to the V3 loop of HIV-1, which binds to CXC chemokine receptor 4 (CXCR4), we hypothesized that BSDL might bind to CXCR4 present on platelets. In human platelets in vitro, both BSDL and a peptide corresponding to its V3-like loop induced calcium mobilization and enhanced thrombin-mediated platelet aggregation, spreading, and activated αIIbβ3 levels. These effects were abolished by CXCR4 inhibition. BSDL also increased the production of prostacyclin by human endothelial cells. In a mouse thrombosis model, BSDL accumulated at sites of vessel wall injury. When CXCR4 was antagonized, the accumulation of BSDL was inhibited and thrombus size was reduced. In BSDL–/– mice, calcium mobilization in platelets and thrombus formation were attenuated and tail bleeding times were increased in comparison with those of wild-type mice. We conclude that BSDL plays a role in optimal platelet activation and thrombus formation by interacting with CXCR4 on platelets. PMID:18037996

  13. Bile salt receptor TGR5 is highly expressed in esophageal adenocarcinoma and precancerous lesions with significantly worse overall survival and gender differences

    PubMed Central

    Pang, Chunhong; LaLonde, Amy; Godfrey, Tony E; Que, Jianwen; Sun, Jun; Wu, Tong Tong; Zhou, Zhongren

    2017-01-01

    Bile acid reflux in the esophagus plays an important role in the carcinogenesis of esophageal adenocarcinoma (EAC). The G-protein coupled bile acid receptor (TGR5) has been associated with the development of gastrointestinal cancer. However, little is known regarding the role of TGR5 in esophageal carcinoma and precancerous lesions. We analyzed genomic DNA from 116 EACs for copy number aberrations via Affymetrix SNP6.0 microarrays. The TGR5 gene locus was amplified in 12.7% (14/116) of the EACs. The TGR5 protein expression was also assessed using immunohistochemistry from tissue microarrays, including Barrett’s esophagus (BE), low-(LGD) and high-grade dysplasia (HGD), columnar cell metaplasia (CM), squamous epithelium (SE), EAC and squamous cell carcinoma. The TGR5 protein was highly expressed in 71% of EAC (75/106), 100% of HGD (11/11), 72% of LGD (13/18), 66% of BE (23/35), 84% of CM (52/62), and 36% of SE (30/83). The patients with high expression of TGR5 exhibited significantly worse overall survival compared to the patients with nonhigh expression. TGR5 high expression was significantly increased in the males compared to the females in all cases with an odds ratio of 1.9 times. The vitamin D receptor (VDR) was significantly correlated with TGR5 expression. Our findings indicated that TGR5 may play an important role in the development and prognosis of EAC through a bile acid ligand. Gender differences in TGR5 and VDR expression may explain why males have a higher incidence of EAC compared to females. PMID:28223834

  14. Effect of Maillard reacted peptides on human salt taste and the amiloride-insensitive salt taste receptor (TRPV1t).

    PubMed

    Katsumata, Tadayoshi; Nakakuki, Hiroko; Tokunaga, Chikara; Fujii, Noboru; Egi, Makoto; Phan, Tam-Hao T; Mummalaneni, Shobha; DeSimone, John A; Lyall, Vijay

    2008-09-01

    Maillard reacted peptides (MRPs) were synthesized by conjugating a peptide fraction (1000-5000 Da) purified from soy protein hydrolyzate with galacturonic acid, glucosamine, xylose, fructose, or glucose. The effect of MRPs was investigated on human salt taste and on the chorda tympani (CT) taste nerve responses to NaCl in Sprague-Dawley rats, wild-type, and transient receptor potential vanilloid 1 (TRPV1) knockout mice. MRPs produced a biphasic effect on human salt taste perception and on the CT responses in rats and wild-type mice in the presence of NaCl + benzamil (Bz, a blocker of epithelial Na+ channels), enhancing the NaCl response at low concentrations and suppressing it at high concentrations. The effectiveness of MRPs as salt taste enhancers varied with the conjugated sugar moiety: galacturonic acid = glucosamine > xylose > fructose > glucose. The concentrations at which MRPs enhanced human salt taste were significantly lower than the concentrations of MRPs that produced increase in the NaCl CT response. Elevated temperature, resiniferatoxin, capsaicin, and ethanol produced additive effects on the NaCl CT responses in the presence of MRPs. Elevated temperature and ethanol also enhanced human salt taste perception. N-(3-methoxyphenyl)-4-chlorocinnamid (a blocker of TRPV1t) inhibited the Bz-insensitive NaCl CT responses in the absence and presence of MRPs. TRPV1 knockout mice demonstrated no Bz-insensitive NaCl CT response in the absence or presence of MRPs. The results suggest that MRPs modulate human salt taste and the NaCl + Bz CT responses by interacting with TRPV1t.

  15. The susceptibility of Streptococcus thermophilus 14085 to organic acid, simulated gastric juice, bile salt and disinfectant as influenced by cold shock treatment.

    PubMed

    Fang, Shiu-Hui; Lai, Ying-Jang; Chou, Cheng-Chun

    2013-02-01

    Streptococcus thermophilus is a thermophilic lactic acid bacterium which is used as the starter organism for the fermentation of yoghurt and some cheese. In the present study, S. thermophilus BCRC 14085 was subjected to cold shock treatment by exposure at 10 °C for 2 h. The effect of cold shock on the susceptibility of S. thermophilus in subsequent lethal stress environments such as simulated gastric juice (pH 2.0-3.0), bile solution (2.0%) and various organic acids (0.75 M, pH 3.5) including propionic, lactic, acetic, citric and tartaric acid was investigated. In addition, the survival of cold-shocked and non-shocked S. thermophilus exposed to disinfectants, Clidox-S and Quatricide, were compared. Results revealed that cold shock enhanced the tolerance of S. thermophilus in the presence of simulated gastric juice (pH 2.5 and 2.8), while in bile solution, the population increase of cold-shocked cells is higher than that of non-shocked cells after 12 h of incubation. Furthermore, the susceptibility of S. thermophilus, regardless of cold shock, to organic acid varied with the kinds of organic acid examined. The cold-shocked S. thermophilus showed a significantly less survival (P < 0.05) than that of the non-shocked cells when exposed to lactic or acetic acid. Furthermore, cold shock reduced the survival of S. thermophilus when exposed to Quatricide but not Clidox-S.

  16. Hematopoietic stem cell markers are expressed by ductal plate and bile duct cells in developing human liver.

    PubMed

    Blakolmer, K; Jaskiewicz, K; Dunsford, H A; Robson, S C

    1995-06-01

    The identification of ductal plate cells as likely progenitors for bile duct epithelium and hepatocytes and their possible reappearance as oval cells in the regenerating liver have generated much interest in their pluripotential capacities. We have examined the distribution of three hematopoietic stem cell markers, c-kit, CD34, and CD33 in addition to laminin, the standard cytokeratin markers CAM 5.2, CK 18, and CK 7 and the oval cell marker OV-6 in fetal liver during various stages of development. Hematopoietic stem cell markers were expressed in ductal plate cells in a pattern similar to the early cytokeratin markers CAM 5.2 and CK 18. Cells stained strongly for these early cytokeratin markers until 22 weeks. Thereafter, the expression of these markers decreased while positivity for CK 7 increased. Bile duct cells showed a distribution of hematopoietic and cytokeratin markers resembling that of ductal plate cells. Both ductal plate cells and bile duct cells expressed OV-6 strongly throughout development. This study showed similarity between hepatic and bile duct precursors and bone marrow stem cells. The comparable distribution of markers in bile duct epithelium and ductal plate cells may imply fewer transitional stages between ductal plate cells and bile duct epithelium than between the putative stem cells and hepatocytes.

  17. Antiproliferation and apoptosis induced by tamoxifen in human bile duct carcinoma QBC939 cells via upregulated p53 expression

    SciTech Connect

    Han, Peng; Kang, Jin-He; Li, Hua-Liang; Hu, Su-Xian; Lian, Hui-Hui; Qiu, Ping-Ping; Zhang, Jian; Li, Wen-Gang; Chen, Qing-Xi

    2009-07-24

    Tamoxifen (TAM) is a nonsteroidal antiestrogen that has been used in the treatment of breast cancer for over 30 years. Recently, it was shown that TAM also has efficacy on gastrointestinal neoplasms such as hepatocarcinoma and pancreatic carcinoma, and that the chemopreventive activities of TAM might be due to its abilities to inhibit cell growth and induce apoptosis. In the present study, we investigated the effects of tamoxifen on growth and apoptosis in the human bile duct carcinoma (BDC) cell line QBC939 using MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, classic DNA fragmentation agarose gel electrophoresis assay, PI single- and FITC/PI double-staining flow cytometry, and Western blotting. Our data revealed that TAM could significantly inhibit growth and induce apoptosis in QBC939 cells. Increased expression of p53 was observed in TAM-treated cells, indicating that p53 might play an important role in TAM-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of TAM on BDC.

  18. Vibrio cholerae leuO Transcription Is Positively Regulated by ToxR and Contributes to Bile Resistance.

    PubMed

    Ante, Vanessa M; Bina, X Renee; Howard, Mondraya F; Sayeed, Sameera; Taylor, Dawn L; Bina, James E

    2015-11-01

    Vibrio cholerae is an aquatic organism and facultative human pathogen that colonizes the small intestine. In the small intestine, V. cholerae is exposed to a variety of antimicrobial compounds, including bile. V. cholerae resistance to bile is multifactorial and includes alterations in the membrane permeability barrier that are mediated by ToxR, a membrane-associated transcription factor. ToxR has also been shown to be required for activation of the LysR family transcription factor leuO in response to cyclic dipeptides. LeuO has been implicated in the regulation of multiple V. cholerae phenotypes, including biofilm production and virulence. In this study, we investigated the effects of bile on leuO expression. We show that leuO transcription increased in response to bile and bile salts but not in response to other detergents. The bile-dependent increase in leuO expression was dependent on ToxR, which was found to bind directly to the leuO promoter. The periplasmic domain of ToxR was required for basal leuO expression and for the bile-dependent induction of both leuO and ompU transcription. V. cholerae mutants that did not express leuO exhibited increased bile susceptibility, suggesting that LeuO contributes to bile resistance. Our collective results demonstrate that ToxR activates leuO expression in response to bile and that LeuO is a component of the ToxR-dependent responses that contribute to bile resistance. The success of Vibrio cholerae as a human pathogen is dependent upon its ability to rapidly adapt to changes in its growth environment. Growth in the human gastrointestinal tract requires the expression of genes that provide resistance to host antimicrobial compounds, including bile. In this work, we show for the first time that the LysR family regulator LeuO mediates responses in V. cholerae that contribute to bile resistance. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. Binding of bile acids by pastry products containing bioactive substances during in vitro digestion.

    PubMed

    Dziedzic, Krzysztof; Górecka, Danuta; Szwengiel, Artur; Smoczyńska, Paulina; Czaczyk, Katarzyna; Komolka, Patrycja

    2015-03-01

    The modern day consumer tends to choose products with health enhancing properties, enriched in bioactive substances. One such bioactive food component is dietary fibre, which shows a number of physiological properties including the binding of bile acids. Dietary fibre should be contained in everyday, easily accessible food products. Therefore, the aim of this study was to determine sorption capacities of primary bile acid (cholic acid - CA) and secondary bile acids (deoxycholic - DCA and lithocholic acids - LCA) by muffins (BM) and cookies (BC) with bioactive substances and control muffins (CM) and cookies (CC) in two sections of the in vitro gastrointestinal tract. Variations in gut flora were also analysed in the process of in vitro digestion of pastry products in a bioreactor. Enzymes: pepsin, pancreatin and bile salts: cholic acid, deoxycholic acid and lithocholic acid were added to the culture. Faecal bacteria, isolated from human large intestine, were added in the section of large intestine. The influence of dietary fibre content in cookies and concentration of bile acids in two stages of digestion were analysed. Generally, pastry goods with bioactive substances were characterized by a higher content of total fibre compared with the control samples. These products also differ in the profile of dietary fibre fractions. Principal Component Analysis (PCA) showed that the bile acid profile after two stages of digestion depends on the quality and quantity of fibre. The bile acid profile after digestion of BM and BC forms one cluster, and with the CM and CC forms a separate cluster. High concentration of H (hemicellulose) is positively correlated with LCA (low binding effect) and negatively correlated with CA and DCA contents. The relative content of bile acids in the second stage of digestion was in some cases above the content in the control sample, particularly LCA. This means that the bacteria introduced in the 2nd stage of digestion synthesize the LCA.

  20. Bile acids deoxycholic acid and ursodeoxycholic acid differentially regulate human β-defensin-1 and -2 secretion by colonic epithelial cells.

    PubMed

    Lajczak, Natalia K; Saint-Criq, Vinciane; O'Dwyer, Aoife M; Perino, Alessia; Adorini, Luciano; Schoonjans, Kristina; Keely, Stephen J

    2017-09-01

    Bile acids and epithelial-derived human β-defensins (HβDs) are known to be important factors in the regulation of colonic mucosal barrier function and inflammation. We hypothesized that bile acids regulate colonic HβD expression and aimed to test this by investigating the effects of deoxycholic acid (DCA) and ursodeoxycholic acid on the expression and release of HβD1 and HβD2 from colonic epithelial cells and mucosal tissues. DCA (10-150 µM) stimulated the release of both HβD1 and HβD2 from epithelial cell monolayers and human colonic mucosal tissue in vitro In contrast, ursodeoxycholic acid (50-200 µM) inhibited both basal and DCA-induced defensin release. Effects of DCA were mimicked by the Takeda GPCR 5 agonist, INT-777 (50 μM), but not by the farnesoid X receptor agonist, GW4064 (10 μM). INT-777 also stimulated colonic HβD1 and HβD2 release from wild-type, but not Takeda GPCR 5(-/-), mice. DCA stimulated phosphorylation of the p65 subunit of NF-κB, an effect that was attenuated by ursodeoxycholic acid, whereas an NF-κB inhibitor, BMS-345541 (25 μM), inhibited DCA-induced HβD2, but not HβD1, release. We conclude that bile acids can differentially regulate colonic epithelial HβD expression and secretion and discuss the implications of our findings for intestinal health and disease.-Lajczak, N. K., Saint-Criq, V., O'Dwyer, A. M., Perino, A., Adorini, L., Schoonjans, K., Keely, S. J. Bile acids deoxycholic acid and ursodeoxycholic acid differentially regulate human β-defensin-1 and -2 secretion by colonic epithelial cells. © FASEB.

  1. The Helicobacter pylori L-form: formation and isolation in the human bile cultures in vitro and in the gallbladders of patients with biliary diseases.

    PubMed

    Wang, Dan N; Ding, Wen J; Pan, Yao Z; Tang, Ke L; Wang, Tao; She, Xiao L; Wang, He

    2015-04-01

    The Helicobacter pylori is considered the important causative agent causing biliary diseases, but the H. pylori can be isolated from very few gallbladder specimens with diseases. We studied the formation of H. pylori L-forms in bile in vitro and isolated the H. pylori L-forms from gallbladder of patients with biliary diseases. We inoculated the H. pylori into the human bile to induce the L-form in vitro. The gallbladder specimens were collected from patients with biliary diseases to isolate the bacterial L-forms by the nonhigh osmotic isolation technique, and the H. pylori L-forms in the L-form isolates were identified by the gene assay for the H. pylori-specific genes 16S rRNA and UreA. The H. Pylori cannot be isolated from the bile-induced cultures, but the H. pylori L-form can be isolated from the H. pylori-negative bile-induced cultures. The L-form isolates of bile-induced cultures showed a positive reaction of the H. pylori-specific genes by PCR, and the coincidence ratio of the nucleotide sequences between the L-forms and the H. pylori is 99%. The isolation rate of bacteria L-form is 93.2% in the gallbladder specimens with bacteria-negative isolation culture by the nonhigh osmotic isolation technique, and the positive rate of the H. pylori-specific genes in the L-form isolates is 7.1% in the bacterial L-form-positive isolation cultures by the PCR. H. pylori can be rapidly induced into the L-form in the human bile; the L-form, as the latent bacteria, can live in the host gallbladder for a long times, and they made the host became a latent carrier of the H. pylori L-form. The H. pylori L-form can be isolated by the nonhigh osmotic isolation technique, and the variant can be identified by the gene assay for the H. pylori-specific genes 16S rRNA and reA. © 2014 John Wiley & Sons Ltd.

  2. Glucagon and cAMP inhibit cholesterol 7alpha-hydroxylase (CYP7A1) gene expression in human hepatocytes: discordant regulation of bile acid synthesis and gluconeogenesis.

    PubMed

    Song, Kwang-Hoon; Chiang, John Y L

    2006-01-01

    The gene encoding cholesterol 7alpha-hydroxylase (CYP7A1) is tightly regulated to control bile acid synthesis and maintain lipid homeostasis. Recent studies in mice suggest that bile acid synthesis is regulated by the fasted-to-fed cycle, and fasting induces CYP7A1 gene expression in parallel to the induction of peroxisome proliferators-activated receptor gamma co-activator 1alpha (PGC-1alpha) and phosphoenolpyruvate carboxykinase (PEPCK). How glucagon regulates CYP7A1 gene expression in the human liver is not clear. Here we show that glucagon and cyclic adenosine monophosphate (cAMP) strongly repressed CYP7A1 mRNA expression in human primary hepatocytes. Reporter assays confirmed that cAMP and protein kinase A (PKA) inhibited human CYP7A1 gene transcription, in contrast to their stimulation of the PEPCK gene. Mutagenesis analysis identified a PKA-responsive region located within the previously identified HNF4alpha binding site in the human CYP7A1 promoter. Glucagon and cAMP increased HNF4alpha phosphorylation and reduced the amount of HNF4alpha present in CYP7A1 chromatin. Our findings suggest that glucagon inhibited CYP7A1 gene expression via PKA phosphorylation of HNF4alpha, which lost its ability to bind the CYP7A1 gene and resulted in inhibition of human CYP7A1 gene transcription. In conclusion, this study unveils a species difference in nutrient regulation of the human and mouse CYP7A1 gene and suggests a discordant regulation of bile acid synthesis and gluconeogenesis by glucagon in human livers during fasting.

  3. An integrated approach for comparative proteomic analysis of human bile reveals overexpressed cancer-associated proteins in malignant biliary stenosis.

    PubMed

    Lukic, Natalija; Visentin, Rémy; Delhaye, Myriam; Frossard, Jean-Louis; Lescuyer, Pierre; Dumonceau, Jean-Marc; Farina, Annarita

    2014-05-01

    Proteomics is a key tool in the identification of new bile biomarkers for differentiating malignant and nonmalignant biliary stenoses. Unfortunately, the complexity of bile and the presence of molecules interfering with protein analysis represent an obstacle for quantitative proteomic studies in bile samples. The simultaneous need to introduce purification steps and minimize the use of pre-fractionation methods inevitably leads to protein loss and limited quantifications. This dramatically reduces the chance of identifying new potential biomarkers. In the present study, we included differential centrifugation as a preliminary step in a quantitative proteomic workflow involving iTRAQ labeling, peptide fractionation by OFFGEL electrophoresis and LC-MS/MS, to compare protein expression in bile samples collected from patients with malignant or nonmalignant biliary stenoses. A total of 1267 proteins were identified, including a set of 322 newly described bile proteins, mainly belonging to high-density cellular fractions. The subsequent comparative analysis led to a 5-fold increase in the number of quantified proteins over previously published studies and highlighted 104 proteins overexpressed in malignant samples. Finally, immunoblot verifications performed on a cohort of 8 malignant (pancreatic adenocarcinoma, n=4; cholangiocarcinoma, n=4) and 5 nonmalignant samples (chronic pancreatitis, n=3; biliary stones, n=2) confirmed the results of proteomic analysis for three proteins: olfactomedin-4, syntenin-2 and Ras-related C3 botulinum toxin substrate 1. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge.

  4. Effect of organo and inorganic lithium salt on human blood plasma glutathione- A comparative study.

    PubMed

    Ullah, Hashmat; Khan, Muhammad Farid; Jan, Syed Umer; Hashmat, Farwa

    2016-03-01

    Investigation of toxicological effect of various metals is the field of interest for toxicological scientists since four to five decades and especially the toxicological effect of those drugs containing metals and there use is common because there is no other choice except to use these metal containing drugs. Inorganic as well as organic salts of lithium are commonly used in prophylaxis and treatments of many psychiatric disorders. The aim of the present study was to see the difference between the effect of organic and inorganic salt of lithium commonly used in psychiatric disorders on the GSH of human blood plasma. It is the scientific fact that ionic dissociation of organic and inorganic salts of any metal is always quite different hence to prove this fact, the effect of lithium citrate (organic salt of lithium) and lithium carbonate (inorganic salt of lithium) was investigated on human blood plasma GSH to find the difference between the effect of two. Ellman's method was used for the quantification of glutathione contents in plasma. It was found that lithium citrate decrease plasma GSH contents less than lithium carbonate indicating that organic salts of lithium are safe than inorganic salts of lithium when are used in psychiatric disorders. Further to analyze the effect of organic and inorganic salt of lithium on blood plasma GSH with the increase in incubation time was also evaluated and was found that both concentration and time dependent effect of organic salt of lithium shows that this salt has decreased plasma GSH contents of human blood less than inorganic salt of lithium either by promoting oxidation of GSH into GSSG or by lithium glutathione complex formation. These results suggest the physicians that the use of organic lithium salts is much safer than inorganic salts of lithium in terms of depletion of blood plasma GSH contents.

  5. Structural and Functional Characterization of BaiA, An Enzyme Involved in Secondary Bile Acid Synthesis in Human Gut Microbe

    PubMed Central

    Bhowmik, Shiva; Jones, David H.; Chiu, Hsien-Po; Park, In-Hee; Chiu, Hsiu-Ju; Axelrod, Herbert L.; Farr, Carol L.; Tien, Henry J.; Agarwalla, Sanjay; Lesley, Scott A.

    2014-01-01

    Despite significant influence of secondary bile acids on human health and disease, limited structural and biochemical information is available for the key gut microbial enzymes catalyzing its synthesis. Herein, we report apo- and co-factor bound crystal structures of BaiA2, a short chain dehydrogenase/reductase from Clostridium scindens VPI 12708 that represent the first protein structure of this pathway. The structures elucidated the basis of co-factor specificity and mechanism of proton relay. A conformational restriction involving Glu42 located in the co-factor binding site seems crucial in determining co-factor specificity. Limited flexibility of Glu42 results in imminent steric and electrostatic hindrance with 2′-phosphate group of NADP(H). Consistent with crystal structures, steady-state kinetic characterization performed with both BaiA2 and BaiA1, a close homolog with 92% sequence identity, revealed specificity constant (kcat/KM) of NADP+ at least an order of magnitude lower than NAD+. Substitution of Glu42 with Ala improved specificity towards NADP+ by 10- fold compared to wild type. The co-factor bound structure uncovered a novel nicotinamide-hydroxyl ion (NAD+-OH−) adduct contraposing previously reported adducts. The OH− of the adduct in BaiA2 is distal to C4 atom of nicotinamide and proximal to 2′-hydroxyl group of the ribose moiety. Moreover, it is located at intermediary distances between terminal functional groups of active site residues Tyr157 (2.7 Å) and Lys161 (4.5 Å). Based on these observations we propose an involvement of NAD+-OH− adduct in proton relay instead of hydride transfer as noted for previous adducts. PMID:23836456

  6. Gardenia jasminoides attenuates hepatocellular injury and fibrosis in bile duct-ligated rats and human hepatic stellate cells

    PubMed Central

    Chen, Ying-Hua; Lan, Tian; Li, Jing; Qiu, Chun-Hui; Wu, Teng; Gou, Hong-Ju; Lu, Min-Qiang

    2012-01-01

    AIM: To investigate the anti-hepatofibrotic effects of Gardenia jasminoides in liver fibrosis. METHODS: Male Sprague-Dawley rats underwent common bile duct ligation (BDL) for 14 d and were treated with Gardenia jasminoides by gavage. The effects of Gardenia jasminoides on liver fibrosis and the detailed molecular mechanisms were also assessed in human hepatic stellate cells (LX-2) in vitro. RESULTS: Treatment with Gardenia jasminoides decreased serum alanine aminotransferase (BDL vs BDL + 100 mg/kg Gardenia jasminoides, 146.6 ± 15 U/L vs 77 ± 6.5 U/L, P = 0.0007) and aspartate aminotransferase (BDL vs BDL + 100 mg/kg Gardenia jasminoides, 188 ± 35.2 U/L vs 128 ± 19 U/L, P = 0.005) as well as hydroxyproline (BDL vs BDL + 100 mg/kg Gardenia jasminoides, 438 ± 40.2 μg/g vs 228 ± 10.3 μg/g liver tissue, P = 0.004) after BDL. Furthermore, Gardenia jasminoides significantly reduced liver mRNA and/or protein expression of transforming growth factor β1 (TGF-β1), collagen type I (Col I) and α-smooth muscle actin (α-SMA). Gardenia jasminoides significantly suppressed the upregulation of TGF-β1, Col I and α-SMA in LX-2 exposed to recombinant TGF-β1. Moreover, Gardenia jasminoides inhibited TGF-β1-induced Smad2 phosphorylation in LX-2 cells. CONCLUSION: Gardenia jasminoides exerts antifibrotic effects in the liver fibrosis and may represent a novel antifibrotic agent. PMID:23326120

  7. Mueller-matrix invariants of optical anisotropy of the bile polycrystalline films in the diagnosis of human liver pathologies

    NASA Astrophysics Data System (ADS)

    Ushenko, V. O.; Prysyazhnyuk, V. P.; Dubolazov, O. V.; Savich, O. V.; Novakovska, O. Y.; Olar, O. V.

    2015-09-01

    The model of Mueller-matrix description of mechanisms of optical anisotropy typical for polycrystalline films of bile - optical activity, birefringence, as well as linear and circular dichroism - is suggested. Within the statistical analysis of such distributions the objective criteria of differentiation of films of bile from the dead you people different times were determined. From the point of view of probative medicine the operational characteristics (sensitivity, specificity and accuracy) of the method of Muellermatrix reconstruction of optical anisotropy parameters were found and its efficiency in another task - diagnostics of diseases of internal organs of rats was demonstrated.

  8. Effects of the lipid environment, cholesterol and bile acids on the function of the purified and reconstituted human ABCG2 protein.

    PubMed

    Telbisz, Ágnes; Özvegy-Laczka, Csilla; Hegedűs, Tamás; Váradi, András; Sarkadi, Balázs

    2013-03-01

    The human ABCG2 multidrug transporter actively extrudes a wide range of hydrophobic drugs and xenobiotics recognized by the transporter in the membrane phase. In order to examine the molecular nature of the transporter and its effects on the lipid environment, we have established an efficient protocol for the purification and reconstitution of the functional protein. We found that the drug-stimulated ATPase and the transport activity of ABCG2 are fully preserved by applying excess lipids and mild detergents during solubilization, whereas a detergent-induced dissociation of the ABCG2 dimer causes an irreversible inactivation. By using the purified and reconstituted protein we demonstrate that cholesterol is an essential activator, whereas bile acids are important modulators of ABCG2 activity. Both wild-type ABCG2 and its R482G mutant variant require cholesterol for full activity, although they exhibit different cholesterol sensitivities. Bile acids strongly decrease the basal ABCG2-ATPase activity both in the wild-type ABCG2 and in the mutant variant. These data reinforce the results for the modulatory effects of cholesterol and bile acids of ABCG2 investigated in a complex cell membrane environment. Moreover, these experiments open the possibility to perform functional and structural studies with a purified, reconstituted and highly active ABCG2 multidrug transporter.

  9. Absorption of Bile Pigments by the Gall Bladder*

    PubMed Central

    Ostrow, J. Donald

    1967-01-01

    A technique is described for preparation in the guinea pig of an in situ, isolated, vascularized gall bladder that exhibits normal absorptive functions. Absorption of labeled bile pigments from the gall bladder was determined by the subsequent excretion of radioactivity in hepatic bile. Over a wide range of concentrations, unconjugated bilirubin-14C was well absorbed, whereas transfer of conjugated bilirubin proceeded slowly. Mesobilirubinogen-3H was absorbed poorly from whole bile, but was absorbed as rapidly as unconjugated bilirubin from a solution of pure conjugated bile salt. Bilirubin absorption was not impaired by iodoacetamide, 1.5 mM, or dinitrophenol, 1.0 mM, even though water transport was affected. This indicated that absorption of bilirubin was not dependent upon water transport, nor upon energy-dependent processes. The linear relationship between absorption and concentration of pigment at low concentrations in bile salt solutions suggested that pigment was transferred by passive diffusion. At higher pigment concentrations or in whole bile, this simple relationship was modified by interactions of pigment with bile salts and other constituents of bile. These interactions did not necessarily involve binding of bilirubin in micelles. The slow absorption of the more polar conjugates and photo-oxidative derivatives of bilirubin suggested that bilirubin was absorbed principally by nonionic, and partially, by ionic diffusion. Concentrations of pure conjugated bile salts above 3.5 mM were found to be injurious to the gall bladder mucosa. This mucosal injury did not affect the kinetics of bilirubin absorption. During in vitro incubation of bile at 37°C, decay of bilirubin and hydrolysis of the conjugate proceeded as first-order reactions. The effects of these processes on the kinetics of bilirubin absorption, and their possible role in the formation of “white bile” and in the demonstrated appearance of unconjugated bilirubin in hepatic bile, are discussed

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

    PubMed

    Berman, Marvin D; Carey, Martin C

    2015-01-01

    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. Copyright © 2015 the American Physiological Society.

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

    PubMed Central

    Berman, Marvin D.

    2014-01-01

    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

  12. Regulation of the Function of the Human ABCG2 Multidrug Transporter by Cholesterol and Bile Acids: Effects of Mutations in Potential Substrate and Steroid Binding Sites

    PubMed Central

    Telbisz, Ágnes; Hegedüs, Csilla; Váradi, András; Sarkadi, Balázs

    2014-01-01

    ABCG2 (ATP-binding cassette, subfamily G, member 2) is a plasma membrane glycoprotein that actively extrudes xenobiotics and endobiotics from the cells and causes multidrug resistance in cancer. In the liver, ABCG2 is expressed in the canalicular membrane of hepatocytes and excretes its substrates into the bile. ABCG2 is known to require high membrane cholesterol content for maximal activity, and by examining purified ABCG2 reconstituted in proteoliposomes we have recently shown that cholesterol is an essential activator, while bile acids significantly modify the activity of this protein. In the present work, by using isolated insect cell membrane preparations expressing human ABCG2 and its mutant variants, we have analyzed whether certain regions in this protein are involved in sterol recognition. We found that replacing ABCG2-R482 with large amino acids does not affect cholesterol dependence, but changes to small amino acids cause altered cholesterol sensitivity. When leucines in the potential steroid-binding element (SBE, aa 555–558) of ABCG2 were replaced by alanines, cholesterol dependence of ABCG2 activity was strongly reduced, although the L558A mutant variant when purified and reconstituted still required cholesterol for full activity. Regarding the effect of bile acids in isolated membranes, we found that these compounds decreased ABCG2-ATPase in the absence of drug substrates, which did not significantly affect substrate-stimulated ATPase activity. These ABCG2 mutant variants also altered bile acid sensitivity, although cholic acid and glycocholate were not transported by the protein. We suggest that the aforementioned two regions in ABCG2 are important for sterol sensing and may represent potential targets for pharmacologic modulation of ABCG2 function. PMID:24384916

  13. Pharmacological activity of Kaempferia parviflora extract against human bile duct cancer cell lines.

    PubMed

    Leardkamolkarn, Vijittra; Tiamyuyen, Sunida; Sripanidkulchai, Bung-orn

    2009-01-01

    A crude ethanol extract of Kaemperia parviflora Wall. Ex Baker and a purified compound, 5,7,4-trimethoxyflavone (KP.8.10), were evaluated for pharmacological effects on human cholangiocarcinoma cell lines (HuCCA-1 and RMCCA-1). The cells were incubated with various concentrations of extract for various time periods and metabolic activity (MTT assay) was assessed for cell viability. The results showed a dose-dependent effect of both crude ethanol extract and the pure compound. CC50s for the crude extract on HuCCA-1 and RMCCA-1 cells were 46.1 microg/ml and 62.0 microg/ml, respectively. Values for the pure compound could not be determined because of solubility problems. Interestingly, K. parviflora ethanol extract and KP.8.10 at low concentrations (10-20 microg/ml and 2.5-5 microg/ml, respectively) markedly reduced rhHGF-induced invasion by HuCCA-1 and RMCCA-1 cells across matrix-coated transwell plates. Higher concentrations of K. parviflora ethanol extract (60 and 80 microg/ml) and KP.8.10 (20 microg /ml) dramatically changed the cellular morphology and caused death in both cell types. KP.8.10 further exhibited progressive action via caspase-3 mitochondrial enzyme activation, enhancing cellular toxicity in a time-dose dependent fashion. Therefore, 5,7,4-trimethoxyflavone appeared to be a bioactive component of K. parviflora extract capable of exerting anti-cancer action. The results suggested a benefit of this edible plant in prevention and treatment of cholangiocarcinoma.

  14. Salt Promotes Passive Overconsumption of Dietary Fat in Humans.

    PubMed

    Bolhuis, Dieuwerke P; Costanzo, Andrew; Newman, Lisa P; Keast, Russell Sj

    2016-04-01

    Excess fat consumption has been linked to the development of obesity. Fat and salt are a common and appetitive combination in food; however, the effect of either on food intake is unclear. Fat taste sensitivity has been negatively associated with dietary fat intake, but how fat taste sensitivity influences the intake of fat within a meal has, to our knowledge, not yet been investigated. Our objectives were, first, to investigate the effects of both fat and salt on ad libitum food intake and, second, to investigate the effects of fat taste sensitivity on satiation responses to fat and whether this was affected by salt. Forty-eight healthy adults [16 men and 32 women, aged 18-54 y, body mass index (kg/m(2)): 17.8-34.4] were recruited and their fat taste sensitivity was measured by determination of the detection threshold of oleic acid (18:1n-6). In a randomized 2 × 2 crossover design, participants attended 4 lunchtime sessions after a standardized breakfast. Meals consisted of elbow macaroni (56%) with sauce (44%); sauces were manipulated to be1) low-fat (0.02% fat, wt:wt)/low-salt (0.06% NaCl, wt:wt),2) low-fat/high-salt (0.5% NaCl, wt:wt),3) high-fat (34% fat, wt:/wt)/low-salt, or4) high-fat/high-salt. Ad libitum intake (primary outcome) and eating rate, pleasantness, and subjective ratings of hunger and fullness (secondary outcomes) were measured. Salt increased food and energy intakes by 11%, independent of fat concentration (P= 0.022). There was no effect of fat on food intake (P= 0.6), but high-fat meals increased energy intake by 60% (P< 0.001). A sex × fat interaction was found (P= 0.006), with women consuming 15% less by weight of the high-fat meals than the low-fat meals. Fat taste sensitivity was negatively associated with the intake of high-fat meals but only in the presence of low salt (fat taste × salt interaction on delta intake of high-fat - low-fat meals;P= 0.012). The results suggest that salt promotes passive overconsumption of energy in adults

  15. Bile Duct Cancer

    MedlinePlus

    ... to diagnose bile duct cancer may include a physical exam, imaging tests of the liver and bile ducts, blood tests, and a biopsy. Treatments include surgery, radiation therapy, and chemotherapy. NIH: National Cancer Institute

  16. Bile duct stricture

    MedlinePlus

    ... occur after surgery to remove the gallbladder. Other causes of this condition include: Cancer of the bile duct, liver or pancreas Damage and scarring due to a gallstone in the bile duct Damage or scarring after ...

  17. The Human UDP-glucuronosyltransferase UGT2A1 and UGT2A2 enzymes are highly active in bile acid glucuronidation.

    PubMed

    Perreault, Martin; Gauthier-Landry, Louis; Trottier, Jocelyn; Verreault, Mélanie; Caron, Patrick; Finel, Moshe; Barbier, Olivier

    2013-09-01

    Bile acids (BA) are essential modulators of lipid, glucose, and cholesterol homeostasis, but they exert cytotoxic effects in the cholestatic liver. Glucuronidation, catalyzed by the UDP-glucuronosyltransferase (UGT) enzymes is a pharmacologically relevant BA detoxification process. The present study characterized the BA-conjugating activity of the little-studied human UGTs of subfamily 2A: UGT2A1, 2A2, and 2A3. Recombinant UGT2As, expressed in baculovirus-infected insect cells, were assayed for the glucuronidation of six major bile acids: chenodeoxycholic acid (CDCA), cholic acid (CA), lithocholic acid (LCA), deoxycholic acid (DCA), hyocholic acid (HCA) and hyodeoxycholic acid (HDCA). UGT2A3 exhibited detectable but very low activity with all the tested BA substrates. UGT2A1 was highly efficient in forming LCA-3 and LCA-24G, CDCA-24, DCA-24, HCA-24, and HDCA-24G, whereas UGT2A2 was the most active enzyme for CA-24G and CDCA-24G formation and also was able to generate HDCA-6G, HDCA-24G, LCA-24G, and HCA-24G. The Km values of UGT2A1 varied between 102.2 ± 14.3 µM and 2.4 ± 1.2 mM. With the exception of CA-24G, a low affinity substrate for UGT2A2, all the Km values for UGT2A2 were in the 100 to 400 µM range. We demonstrate the high reactivity of the human UGT2A1 and UGT2A2 for bile acid glucuronidation. The physiologic importance of these reactions to BA disposition remains, however, to be clarified in vivo.

  18. The human UDP-glucuronosyltransferase UGT2A1 and UGT2A2 enzymes are highly active in bile acid glucuronidation

    PubMed Central

    Perreault, Martin; Gauthier-Landry, Louis; Trottier, Jocelyn; Verreault, Mélanie; Caron, Patrick; Finel, Moshe; Barbier, Olivier

    2013-01-01

    Bile acids (BA) are essential modulators of lipid, glucose and cholesterol homeostasis, but exert cytotoxic effects in the cholestatic liver. Glucuronidation, catalyzed by the UDP-glucuronosyltransferase (UGT) enzymes is a pharmacologically-relevant BA detoxification process. The present study aimed at characterizing the BA-conjugating activity of the little-studied human UGTs of subfamily 2A, UGT2A1, 2A2 and 2A3. Recombinant UGT2As, expressed in baculovirus-infected insect cells, were assayed for the glucuronidation of 6 major bile acids, chenodeoxycholic (CDCA), cholic (CA), lithocholic (LCA), deoxycholic (DCA), hyocholic (HCA) and hyodeoxycholic (HDCA) acids. UGT2A3 exhibited detectable, but very low, activity with all the tested BAs substrates. UGT2A1 was highly efficient in forming LCA-3 and -24G, CDCA-24, DCA-24, HCA-24 and HDCA-24G, while UGT2A2 was the most active enzyme for CA-24G and CDCA-24G formation, and was also able to generate HDCA-6G, HDCA-24G, LCA-24G and HCA-24G. The Km values of UGT2A1 varied between 102.2 ± 14.3 μM and 2.4 ± 1.2 mM. With the exception of CA-24G, a low affinity substrate for UGT2A2, all the Km values for UGT2A2 were in the 100 to 400 μM range. In conclusion, the present study demonstrates the high reactivity of the human UGT2A1 and UGT2A2 for bile acid glucuronidation. The physiological importance of these reactions to BA disposition remains, however, to be clarified in vivo. PMID:23756265

  19. Survival of O157:H7 and non-o157 serogroups of Escherichia coli in bovine rumen fluid and bile salts

    USDA-ARS?s Scientific Manuscript database

    Escherichia coli are gram negative, facultative anaerobic bacteria that colonize within the intestines of animals and humans. Enterohemorragic strains of E. coli (EHEC) pose a serious health risk to humans yet reside asymptomatically within ruminants. In particular, bovine serve as the major reser...

  20. Bile is essential for lipid assimilation in Leach's storm petrel, Oceanodroma leucorhoa.

    PubMed

    Place, A R

    1992-08-01

    A tritium-labeled glycerol triether was tested as a non-absorbable lipid marker for studies of neutral lipid absorption in normal and cholestryamine-induced steatorrhic chicks of Leach's storm petrel (Oceanodroma leucorhoa). Absorption of triacylglycerol and wax ester (96 +/- 4.2 and 94 +/- 2.1%, respectively) in normal chicks was indistinguishable. Absorption of neutral lipids decreased with increasing quantities of resin, and with the highest dosage (14% wt/wt) less than 30% of dietary lipids were assimilated. The concentration of bile salts (greater than 500 mM) in the gallbladder of Leach's storm petrel is among the highest recorded. The bile salts are predominantly taurine conjugates of chenodeoxycholate and cholate. Biliary cholesterol levels are within the range observed in humans although biliary phospholipid levels are lower and triglyceride levels are higher. Extensive retrograde movement of duodenal contents and biliary secretions to the gizzard and proventriculus were found. Although similarities in fat and bile salt assimilation exist between seabirds and mammals, there do exist differences that make non-polar lipid assimilation (i.e., wax esters) more efficient in seabirds.

  1. Increased renal oxidative stress in salt-sensitive human GRK4γ486V transgenic mice.

    PubMed

    Diao, Zhenyu; Asico, Laureano D; Villar, Van Anthony M; Zheng, Xiaoxu; Cuevas, Santiago; Armando, Ines; Jose, Pedro A; Wang, Xiaoyan

    2017-05-01

    We tested the hypothesis that salt-sensitive hypertension is caused by renal oxidative stress by measuring the blood pressure and reactive oxygen species-related proteins in the kidneys of human G protein-coupled receptor kinase 4γ (hGRK4γ) 486V transgenic mice and non-transgenic (Non-T) littermates on normal and high salt diets. High salt diet increased the blood pressure, associated with impaired sodium excretion, in hGRK4γ486V mice. Renal expressions of NOX isoforms were similar in both strains on normal salt diet but NOX2 was decreased by high salt diet to a greater extent in Non-T than hGRK4γ486V mice. Renal HO-2, but not HO-1, protein was greater in hGRK4γ486V than Non-T mice on normal salt diet and normalized by high salt diet. On normal salt diet, renal CuZnSOD and ECSOD proteins were similar but renal MnSOD was lower in hGRK4γ486V than Non-T mice and remained low on high salt diet. High salt diet decreased renal CuZnSOD in hGRK4γ486V but not Non-T mice and decreased renal ECSOD to a greater extent in hGRK4γ486V than Non-T mice. Renal SOD activity, superoxide production, and NOS3 protein were similar in two strains on normal salt diet. However, high salt diet decreased SOD activity and NOS3 protein and increased superoxide production in hGRK4γ486V mice but not in Non-T mice. High salt diet also increased urinary 8-isoprostane and 8-hydroxydeoxyguanosine to a greater extent in hGRK4γ486V than Non-T mice. hGRK4γwild-type mice were normotensive and hGRK4γ142V mice were hypertensive but both were salt-resistant and in normal redox balance. Chronic tempol treatment partially prevented the salt-sensitivity of hGRK4γ486V mice. Thus, hGRK4γ486V causes salt-sensitive hypertension due, in part, to defective renal antioxidant mechanisms.

  2. Preliminary analyses of scenarios for potential human interference for repositories in three salt formations

    SciTech Connect

    Not Available

    1985-10-01

    Preliminary analyses of scenarios for human interference with the performance of a radioactive waste repository in a deep salt formation are presented. The following scenarios are analyzed: (1) the U-Tube Connection Scenario involving multiple connections between the repository and the overlying aquifer system; (2) the Single Borehole Intrusion Scenario involving penetration of the repository by an exploratory borehole that simultaneously connects the repository with overlying and underlying aquifers; and (3) the Pressure Release Scenario involving inflow of water to saturate any void space in the repository prior to creep closure with subsequent release under near lithostatic pressures following creep closure. The methodology to evaluate repository performance in these scenarios is described and this methodology is applied to reference systems in three candidate formations: bedded salt in the Palo Duro Basin, Texas; bedded salt in the Paradox Basin, Utah; and the Richton Salt Dome, Mississippi, of the Gulf Coast Salt Dome Basin.

  3. Bile Acid-Activated Receptors, Intestinal Microbiota, and the Treatment of Metabolic Disorders.

    PubMed

    Fiorucci, Stefano; Distrutti, Eleonora

    2015-11-01

    The composition of the bile acid pool is a function of the microbial metabolism of bile acids in the intestine. Perturbations of the microbiota shape the bile acid pool and modulate the activity of bile acid-activated receptors (BARs) even beyond the gastrointestinal tract, triggering various metabolic axes and altering host metabolism. Bile acids, in turn, can also regulate the composition of the gut microbiome at the highest taxonomic levels. Primary bile acids from the host are preferential ligands for the farnesoid X receptor (FXR), while secondary bile acids from the microbiota are ligands for G-protein-coupled bile acid receptor 1 (GPBAR1). In this review, we examine the role of bile acid signaling in the regulation of intestinal microbiota and how changes in bile acid composition affect human metabolism. Bile acids may offer novel therapeutic modalities in inflammation, obesity, and diabetes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Physiology of bile secretion

    PubMed Central

    Esteller, Alejandro

    2008-01-01

    The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology. PMID:18837079

  5. Composition of gallbladder bile in healthy individuals and patients with gallstone disease from north and South India.

    PubMed

    Jayanthi, V; Sarika, S; Varghese, Joy; Vaithiswaran, V; Sharma, Malay; Reddy, Mettu Srinivas; Srinivasan, Vijaya; Reddy, G M M; Rela, Mohamed; Kalkura, S

    2016-09-01

    Gallstones (GS) in south India (SI) are predominantly pure pigment or mixed, while in North India (NI), these are either pure cholesterol or mixed. While cholesterol rich gallbladder (GB) bile predicts cholesterol GS, constituent of bile in primary pigment GS is not known. We compared the composition of GB bile from healthy liver donors and patients with GS from north and south India. Gallbladder bile from healthy liver donors from north (10) and south India (8) served as controls. Cases were patients from north (21) and south India (17) who underwent cholecystectomy for GS disease. Gallbladder bile from both cases and controls was analyzed for cholesterol, lecithin (phospholipid), and bile salts. Gallstones were classified as cholesterol, mixed, and pigment based on morphology and biochemical analysis. The median cholesterol concentration in control bile from north was significantly high compared to south (p<0.001) with no difference in lecithin and bile salts (p NS). Except for one sample each from north and south, the cholesterol solubility of controls was within the critical micellar zone. Mixed GS were most frequent in north India (61.9 %) while pigment GS dominated in south (61.9 %). The median cholesterol concentration in bile samples of cholecystectomy patients from north India was significantly high GS (p < 0.00001) with significant lowering of bile salts and lecithin (p < 0.00001). In south India, patients with mixed GS had high cholesterol content in bile compared to controls and patients with pigment GS; bile in latter had significantly higher concentration of bile salt compared to controls and mixed GS. The ternary plot confirmed the composition of GB bile from north and south India. Gallbladder bile in controls and patients with GS from north India had significantly high cholesterol concentration. In south India, patients with mixed GS had cholesterol rich bile while pigment GS had higher concentrations of bile salts.

  6. Cholesterol reduces the effects of dihydroxy bile acids and fatty acids on water and solute transport in the human jejunum.

    PubMed Central

    Broor, S L; Slota, T; Ammon, H V

    1980-01-01

    Jejunal perfusion studies were performed in 16 healthy volunteers to test the hypothesis that intraluminal cholesterol can mitigate the fluid secretion induced by dihydroxy bile acids and fatty acids. Fluid secretion in the presence of 5 mM taurodeoxycholate was somewhat reduced by 4 mM mono-olein which was used for the solubilization of cholesterol. Addition of 0.8 mM cholesterol reduced fluid secretion further (P less than 0.05). Fluid secretion induced by 4 mM oleic acid was changed to net absorption in a linear fashion with increasing cholesterol concentration in the perfusion solutions. 1 mM cholesterol reduced fluid secretion induced by 6 mM oleic acid (P less than 0.005), but had no effect on fluid secretion induced by 6 mM linolenic acid. Glucose absorption was generally affected in a similar manner as water transport. In vitro, 1 mM cholesterol reduced monomer activity of 6 mM oleic acid to 72.3 +/- 0.9% of control and that of linolenic acid to 81.1 +/- 1.7% of control. Although statistically significant (P less than 0.001), the difference in the effects of cholesterol on monomer activities of the two fatty acids was rather small and it is unlikely that changes in monomer concentration of fatty acids and bile acids account for the protective effect of cholesterol. The in vivo observations point to a new physiological role for biliary cholesterol: the modification of the response of the small intestine to the effects of dihydroxy bile acids and fatty acids. PMID:7358850

  7. Estimated human health risks of disposing of nonhazardous oil field waste in salt caverns

    SciTech Connect

    Tomasko, D.; Elcock, D.; Veil, J.

    1997-09-01

    Argonne National Laboratory (ANL) has completed an evaluation of the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from nonhazardous oil field wastes (NOW) disposed in domal salt caverns. In this assessment, several steps were used to evaluate potential human health risks: identifying potential contaminants of concern, determining how humans could be exposed to these contaminants, assessing the contaminants` toxicities, estimating contaminant intakes, and, finally, calculating human cancer and noncancer risks.

  8. The role of lithocholic acid in the regulation of bile acid detoxication, synthesis, and transport proteins in rat and human intestine and liver slices.

    PubMed

    Khan, Ansar A; Chow, Edwin C Y; Porte, Robert J; Pang, K Sandy; Groothuis, Geny M M

    2011-02-01

    The effects of the secondary bile acid, lithocholic acid (LCA), a VDR, FXR and PXR ligand, on the regulation of bile acid metabolism (CYP3A isozymes), synthesis (CYP7A1), and transporter proteins (MRP3, MRP2, BSEP, NTCP) as well as nuclear receptors (FXR, PXR, LXRα, HNF1α, HNF4α and SHP) were studied in rat and human precision-cut intestine and liver slices at the mRNA level. Changes due to 5 to 10 μM of LCA were compared to those of other prototype ligands for VDR, FXR, PXR and GR. LCA induced rCYP3A1 and rCYP3A9 in the rat jejunum, ileum and colon, rCYP3A2 only in the ileum, rCYP3A9 expression in the liver, and CYP3A4 in the human ileum but not in liver. LCA induced the expression of rMRP2 in the colon but not in the jejunum and ileum but did not affect rMRP3 expression along the length of the rat intestine. In human ileum slices, LCA induced hMRP3 and hMRP2 expression. In rat liver slices, LCA decreased rCYP7A1, rLXRα and rHNF4α expression, induced rSHP expression, but did not affect rBSEP or rNTCP expression; whereas in the human liver, a small but significant decrease was found for hHNF1α expression. These data suggests profound species differences in the effects of LCA on bile acid transport, synthesis and detoxification. An examination of the effects of prototype VDR, PXR, GR and FXR ligands showed that these pathways are all intact in precision cut slices and that LCA exerted VDR, PXR and FXR effects. The LCA-induced altered enzymes and transporter expressions in the intestine and liver would affect the disposition of drugs.

  9. Suppressed hepatic bile acid signalling despite elevated production of primary and secondary bile acids in NAFLD.

    PubMed

    Jiao, Na; Baker, Susan S; Chapa-Rodriguez, Adrian; Liu, Wensheng; Nugent, Colleen A; Tsompana, Maria; Mastrandrea, Lucy; Buck, Michael J; Baker, Robert D; Genco, Robert J; Zhu, Ruixin; Zhu, Lixin

    2017-08-03

    Bile acids are regulators of lipid and glucose metabolism, and modulate inflammation in the liver and other tissues. Primary bile acids such as cholic acid and chenodeoxycholic acid (CDCA) are produced in the liver, and converted into secondary bile acids such as deoxycholic acid (DCA) and lithocholic acid by gut microbiota. Here we investigated the possible roles of bile acids in non-alcoholic fatty liver disease (NAFLD) pathogenesis and the impact of the gut microbiome on bile acid signalling in NAFLD. Serum bile acid levels and fibroblast growth factor 19 (FGF19), liver gene expression profiles and gut microbiome compositions were determined in patients with NAFLD, high-fat diet-fed rats and their controls. Serum concentrations of primary and secondary bile acids were increased in patients with NAFLD. In per cent, the farnesoid X receptor (FXR) antagonistic DCA was increased, while the agonistic CDCA was decreased in NAFLD. Increased mRNA expression for cytochrome P450 7A1, Na(+)-taurocholate cotransporting polypeptide and paraoxonase 1, no change in mRNA expression for small heterodimer partner and bile salt export pump, and reduced serum FGF19 were evidence of impaired FXR and fibroblast growth factor receptor 4 (FGFR4)-mediated signalling in NAFLD. Taurine and glycine metabolising bacteria were increased in the gut of patients with NAFLD, reflecting increased secondary bile acid production. Similar changes in liver gene expression and the gut microbiome were observed in high-fat diet-fed rats. The serum bile acid profile, the hepatic gene expression pattern and the gut microbiome composition consistently support an elevated bile acid production in NAFLD. The increased proportion of FXR antagonistic bile acid explains, at least in part, the suppression of hepatic FXR-mediated and FGFR4-mediated signalling. Our study suggests that future NAFLD intervention may target the components of FXR signalling, including the bile acid converting gut microbiome. © Article

  10. Transport and biological activities of bile acids.

    PubMed

    Zwicker, Brittnee L; Agellon, Luis B

    2013-07-01

    Bile acids have emerged as important biological molecules that support the solubilization of various lipids and lipid-soluble compounds in the gut, and the regulation of gene expression and cellular function. Bile acids are synthesized from cholesterol in the liver and eventually released into the small intestine. The majority of bile acids are recovered in the distal end of the small intestine and then returned to the liver for reuse. The components of the mechanism responsible for the recycling of bile acids within the enterohepatic circulation have been identified whereas the mechanism for intracellular transport is less understood. Recently, the ileal lipid binding protein (ILBP; human gene symbol FABP6) was shown to be needed for the efficient transport of bile acids from the apical side to the basolateral side of enterocytes in the distal intestine. This review presents an overview of the transport of bile acids between the liver and the gut as well as within hepatocytes and enterocytes. A variety of pathologies is associated with the malfunction of the bile acid transport system.

  11. STUDIES ON THE TOTAL BILE

    PubMed Central

    Broun, G. O.; McMaster, Philip D.; Rous, Peyton

    1923-01-01

    In dogs fed the green bile or the liver tissue of herbivora, the bile later secreted frequently becomes green, changing from the previous yellow-brown. When they are fed sheep bile that contains cholohematin, their bile comes to contain this pigment. When they are fed dog bile in quantity a well marked increase in the output of bilirubin by the liver frequently follows. Taken together, these facts indicate the existence of an enterohepatic circulation of bile pigment. PMID:19868754

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

    PubMed Central

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

    2009-01-01

    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 at parturition. After birth, mouse Ntcp and Bsep mRNA decreased by more than 50%, and then gradually increased to adult levels by day 30. Expression of mouse Ntcp mRNA and protein exhibit higher levels in female than male livers, which is consistent with the trend of human NTCP mRNA expression between men and women. No gender difference exists in BSEP/Bsep expression in human and mouse livers. Hormone replacements conducted in gonadectomized, hypophysectomized, and lit/lit mice indicate that female-predominant Ntcp expression in mouse liver is due to the inhibitory effect of male-pattern GH secretion, but not sex hormones. Ntcp and Bsep expression are in general resistant to induction by a large battery of microsomal enzyme inducers. Administration of cholestyramine increased Ntcp, whereas chenodeoxycholic acid increased Bsep mRNA expression. In silico analysis indicates that female-predominant mouse and human Ntcp/NTCP expression may be due to GH. In conclusion, mouse Ntcp and Bsep are regulated by age, gender, cholestyramine, and bile acid, but resistant to induction by most microsomal enzyme inducers. PMID:17897632

  13. Bile Acid Signaling in Metabolic Disease and Drug Therapy

    PubMed Central

    Li, Tiangang

    2014-01-01

    Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates hepatobiliary secretion of lipids, lipophilic metabolites, and xenobiotics. In the intestine, bile acids are essential for the absorption, transport, and metabolism of dietary fats and lipid-soluble vitamins. Extensive research in the last 2 decades has unveiled new functions of bile acids as signaling molecules and metabolic integrators. The bile acid–activated nuclear receptors farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, vitamin D receptor, and G protein–coupled bile acid receptor play critical roles in the regulation of lipid, glucose, and energy metabolism, inflammation, and drug metabolism and detoxification. Bile acid synthesis exhibits a strong diurnal rhythm, which is entrained by fasting and refeeding as well as nutrient status and plays an important role for maintaining metabolic homeostasis. Recent research revealed an interaction of liver bile acids and gut microbiota in the regulation of liver metabolism. Circadian disturbance and altered gut microbiota contribute to the pathogenesis of liver diseases, inflammatory bowel diseases, nonalcoholic fatty liver disease, diabetes, and obesity. Bile acids and their derivatives are potential therapeutic agents for treating metabolic diseases of the liver. PMID:25073467

  14. Bile acid signaling in metabolic disease and drug therapy.

    PubMed

    Li, Tiangang; Chiang, John Y L

    2014-10-01

    Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates hepatobiliary secretion of lipids, lipophilic metabolites, and xenobiotics. In the intestine, bile acids are essential for the absorption, transport, and metabolism of dietary fats and lipid-soluble vitamins. Extensive research in the last 2 decades has unveiled new functions of bile acids as signaling molecules and metabolic integrators. The bile acid-activated nuclear receptors farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, vitamin D receptor, and G protein-coupled bile acid receptor play critical roles in the regulation of lipid, glucose, and energy metabolism, inflammation, and drug metabolism and detoxification. Bile acid synthesis exhibits a strong diurnal rhythm, which is entrained by fasting and refeeding as well as nutrient status and plays an important role for maintaining metabolic homeostasis. Recent research revealed an interaction of liver bile acids and gut microbiota in the regulation of liver metabolism. Circadian disturbance and altered gut microbiota contribute to the pathogenesis of liver diseases, inflammatory bowel diseases, nonalcoholic fatty liver disease, diabetes, and obesity. Bile acids and their derivatives are potential therapeutic agents for treating metabolic diseases of the liver.

  15. The impact of reduced gastric acid secretion on dissolution of salts of weak bases in the fasted upper gastrointestinal lumen: Data in biorelevant media and in human aspirates.

    PubMed

    Litou, Chara; Vertzoni, Maria; Xu, Wei; Kesisoglou, Filippos; Reppas, Christos

    2017-06-01

    To propose media for simulating the intragastric environment under reduced gastric acid secretion in the fasted state at three levels of simulation of the gastric environment and evaluate their usefulness in evaluating the intragastric dissolution of salts of weak bases. To evaluate the importance of bicarbonate buffer in biorelevant in vitro dissolution testing when using Level II biorelevant media simulating the environment in the fasted upper small intestine, regardless of gastric acid secretions. Media for simulating the hypochlorhydric and achlorhydric conditions in stomach were proposed using phosphates, maleates and bicarbonates buffers. The impact of bicarbonates in Level II biorelevant media simulating the environment in upper small intestine was evaluated so that pH and bulk buffer capacity were maintained. Dissolution data were collected using two model compounds, pioglitazone hydrochloride and semifumarate cocrystal of Compound B, and the mini-paddle dissolution apparatus in biorelevant media and in human aspirates. Simulated gastric fluids proposed in this study were in line with pH, buffer capacity, pepsin content, total bile salt/lecithin content and osmolality of the fasted stomach under partial and under complete inhibition of gastric acid secretion. Fluids simulating the conditions under partial inhibition of acid secretion were useful in simulating concentrations of both model compounds in gastric aspirates. Bicarbonates in Level III biorelevant gastric media and in Level II biorelevant media simulating the composition in the upper intestinal lumen did not improve simulation of concentrations in human aspirates. Level III biorelevant media for simulating the intragastric environment under hypochlorhydric conditions were proposed and their usefulness in the evaluation of concentrations of two model salts of weak bases in gastric aspirates was shown. Level II biorelevant media for simulating the environment in upper intestinal lumen led to

  16. A salt bridge in intracellular loop 2 is essential for folding of human p-glycoprotein.

    PubMed

    Loo, Tip W; Clarke, David M

    2013-05-14

    There is no high-resolution structure of the human P-glycoprotein (P-gp, ABCB1) drug pump. Homology models based on the crystal structures of mouse and Caenorhabditis elegans P-gps show extensive contacts between intracellular loop 2 (ICL2, in the first transmembrane domain) and the second nucleotide-binding domain. Human P-gp modeled on these P-gp structures yields different ICL2 structures. Only the model based on the C. elegans P-gp structure predicts the presence of a salt bridge. We show that the Glu256-Arg276 salt bridge was critical for P-gp folding.

  17. Antimutagenic activity and in vitro anticancer effects of bamboo salt on HepG2 human hepatoma cells.

    PubMed

    Zhao, Xin; Ju, Jaehyun; Kim, Hyung-Min; Park, Kun-Young

    2013-01-01

    Bamboo salt is a traditional Korean baked solar salt processed by packing the solar salt in bamboo joint cases and heating it several times to high temperatures. The antimutagenic activity and in vitro anticancer effects of bamboo salt on HepG2 human hepatoma cells were investigated and compared to those of other salt samples. Although solar salt and purified salt exhibited comutagenicity with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the Salmonella typhimurium TA100 strain, bamboo salt was associated with a lower degree of comutagenicity or antimutagenic activity. Bamboo salt baked nine times (9×) showed a greater increase in antimutagenic activity than salts baked once (1×) or three times (3×). At a concentration of 1%, the growth rate of HepG2 cells treated with 9× bamboo salt determined by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MIT) assay was reduced by 65%; this rate of inhibition was higher than that achieved with 1× baked bamboo salt (40%). Purified and solar salts had relatively lower inhibitory effects on growth rate (25% and 29%, respectively). Compared to the other salt samples, 9× bamboo salt significantly (p<0.05) induced apoptosis as determined by 4,6-diamidino-2-phenylindole (DAPI) staining and flow cytometry analysis. It also upregulated the expression of Bax, caspase-9 and caspase-3; and downregulated Bcl-2 expression. The bamboo salts, especially 9× bamboo salt, also significantly (p<0.05) downregulated the expression of inflammation-related NF-κB, iNOS, and COX-2, and upregulated the gene expression of IκB-α compared to the other salt sample.

  18. CCAAT/Enhancer-binding protein beta regulates expression of human T1R3 taste receptor gene in the bile duct carcinoma cell line, HuCCT1.

    PubMed

    Toyono, Takashi; Seta, Yuji; Kataoka, Shinji; Toyoshima, Kuniaki

    2007-01-01

    The T1R family (T1R1, T1R2 and T1R3 receptors) has a role in the detection of umami and sweet tastes in taste buds. Although T1R3 is also expressed in the intrahepatic bile duct, the expression patterns of T1R1 and T1R2 in this region have not been determined. In addition, the mechanisms of transcriptional regulation of the human T1R3 gene (Tas1r3) have not been elucidated. In this study, we determined the expression patterns of T1R2 and T1R3 in human liver and the function of C/EBPbeta in Tas1r3 promoter activity. Immunohistochemistry showed that T1R2 and T1R3 were expressed in the intrahepatic bile duct. 5'-RACE analysis revealed that the transcriptional start sites of Tas1r3 were located 67 bp and 176 bp upstream of the ATG. Promoter analysis of Tas1r3 was performed using the luciferase reporter assay and EMSA in the Tas1r3-expressing cell line, HuCCT1. The 226-bp region upstream of the ATG had promoter activity, and C/EBPbeta activated the Tas1r3 promoter activity in HuCCT1 cells. These results show that T1R2 and T1R3 receptors, in addition to their role in taste perception, may also have a role in intrahepatic cholangiocytes. C/EBPbeta was identified as the transcription factor regulating Tas1r3 promoter activity in HuCCT1 cells.

  19. Prognostic roles of tetrahydroxy bile acids in infantile intrahepatic cholestasis.

    PubMed

    Lee, Chee-Seng; Kimura, Akihiko; Wu, Jia-Feng; Ni, Yen-Hsuan; Hsu, Hong-Yuan; Chang, Mei-Hwei; Nittono, Hiroshi; Chen, Huey-Ling

    2017-03-01

    Tetrahydroxy bile acids (THBAs) are hydrophilic and are present at minimal or undetectable levels in healthy human adults, but are present at high levels in bile salt export pump (abcb11)-knockout mice. The roles of THBAs in human cholestatic diseases are unclear. We aimed to investigate the presence of THBAs in patients with infantile intrahepatic cholestasis and its correlation with outcome. Urinary bile acids (BAs) were analyzed by GC-MS. Data were compared between good (n = 21) (disease-free before 1 year old) and poor prognosis groups (n = 19). Good prognosis patients had a higher urinary THBA proportion than poor prognosis patients [25.89% (3.45-76.73%) vs. 1.93% (0.05-48.90%)]. A urinary THBA proportion >7.23% predicted good prognosis with high sensitivity (95.24%), specificity (84.21%), and area under the curve (0.91) (P < 0.0001). A THBA proportion 7.23% was an independent factor for decreased transplant-free survival (hazard ratio = 7.16, confidence interval: 1.24-41.31, P = 0.028). Patients with a confirmed ABCB11 or tight junction protein 2 gene mutation (n = 7) had a minimally detectable THBA proportion (0.23-2.99% of total BAs). Three patients with an ATP8B1 mutation had an elevated THBA proportion (7.51-37.26%). In conclusion, in addition to disease entity as a major determinant of outcome, a high THBA level was associated with good outcome in the infantile intrahepatic cholestasis patients.

  20. The bile acid receptor GPBAR1 (TGR5) is expressed in human gastric cancers and promotes epithelial-mesenchymal transition in gastric cancer cell lines

    PubMed Central

    Cipriani, Sabrina; Marchianò, Silvia; Marino, Elisabetta; Zampella, Angela; Rende, Mario; Mosci, Paolo; Distrutti, Eleonora; Donini, Annibale; Fiorucci, Stefano

    2016-01-01

    GPBAR1 (also known as TGR5) is a bile acid activated receptor expressed in several adenocarcinomas and its activation by secondary bile acids increases intestinal cell proliferation. Here, we have examined the expression of GPBAR1 in human gastric adenocarcinomas and investigated whether its activation promotes the acquisition of a pro-metastatic phenotype. By immunohistochemistry and RT-PCR analysis we found that expression of GPBAR1 associates with advanced gastric cancers (Stage III-IV). GPBAR1 expression in tumors correlates with the expression of N-cadherin, a markers of epithelial-mesenchymal transition (EMT) (r=0.52; P<0.01). Expression of GPBAR1, mRNA and protein, was detected in cancer cell lines, with MKN 45 having the higher expression. Exposure of MKN45 cells to GPBAR1 ligands, TLCA, oleanolic acid or 6-ECDCA (a dual FXR and GPBAR1 ligand) increased the expression of genes associated with EMT including KDKN2A, HRAS, IGB3, MMP10 and MMP13 and downregulated the expression of CD44 and FAT1 (P<0.01 versus control cells). GPBAR1 activation in MKN45 cells associated with EGF-R and ERK1 phosphorylation. These effects were inhibited by DFN406,