Wnt/beta-Catenin, Foxa2, and CXCR4 Axis Controls Prostate Cancer Progression

DTIC Science & Technology

2014-07-01

NT1 cells that over-expressing Foxa2. The reason we used NT1 cells for the Foxa2 over-expressing experiments is that NT1 is an AR-expressing... cells . We have also established NT1 cells over-expressing a dominant active beta-catenin. We have characterized these cells . Our research found: 1...expression profiles of control NT1 , NT1 /Foxa2, and NT1 /beta-catenin cells Figure 1. We did RT-PCR to examine the expression of key

Dynamic Regulation of FoxA1 by Steroid Receptors | Center for Cancer Research

Cancer.gov

The estrogen receptor (ER) is a key regulator in breast cancer initiation and progression. A widely discussed model proposes that forkhead box protein A1 (FoxA1) acts as a pioneer factor in cancer by binding and penetrating closed chromatin to allow access by transcription factors (TFs), including ER.

Temporal regulation of epithelium formation mediated by FoxA, MKLP1, MgcRacGAP, and PAR-6

PubMed Central

Von Stetina, Stephen E.; Liang, Jennifer; Marnellos, Georgios; Mango, Susan E.

2017-01-01

To establish the animal body plan, embryos link the external epidermis to the internal digestive tract. In Caenorhabditis elegans, this linkage is achieved by the arcade cells, which form an epithelial bridge between the foregut and epidermis, but little is known about how development of these three epithelia is coordinated temporally. The arcade cell epithelium is generated after the epidermis and digestive tract epithelia have matured, ensuring that both organs can withstand the mechanical stress of embryo elongation; mistiming of epithelium formation leads to defects in morphogenesis. Using a combination of genetic, bioinformatic, and imaging approaches, we find that temporal regulation of the arcade cell epithelium is mediated by the pioneer transcription factor and master regulator PHA-4/FoxA, followed by the cytoskeletal regulator and kinesin ZEN-4/MKLP1 and the polarity protein PAR-6. We show that PHA-4 directly activates mRNA expression of a broad cohort of epithelial genes, including junctional factor dlg-1. Accumulation of DLG-1 protein is delayed by ZEN-4, acting in concert with its binding partner CYK-4/MgcRacGAP. Our structure–function analysis suggests that nuclear and kinesin functions are dispensable, whereas binding to CYK-4 is essential, for ZEN-4 function in polarity. Finally, PAR-6 is necessary to localize polarity proteins such as DLG-1 within adherens junctions and at the apical surface, thereby generating arcade cell polarity. Our results reveal that the timing of a landmark event during embryonic morphogenesis is mediated by the concerted action of four proteins that delay the formation of an epithelial bridge until the appropriate time. In addition, we find that mammalian FoxA associates with many epithelial genes, suggesting that direct regulation of epithelial identity may be a conserved feature of FoxA factors and a contributor to FoxA function in development and cancer. PMID:28539408

MicroRNA-99a and 100 mediated upregulation of FOXA1 in bladder cancer

PubMed Central

Drayton, Ross M.; Peter, Stefan; Myers, Katie; Miah, Saiful; Dudziec, Ewa; Bryant, Helen E.; Catto, James W. F.

2014-01-01

Urothelial cell carcinoma of the bladder (UCC) is a common disease often characterized by FGFR3 dysregulation. Whilst upregulation of this oncogene occurs most frequently in low-grade non-invasive tumors, recent data reveal increased FGFR3 expression characterizes a common sub-type of invasive UCC sharing molecular similarities with breast cancer. These similarities include upregulation of the FOXA1 transcription factor and reduced expression of microRNAs-99a/100. We have previously identified direct regulation of FGFR3 by these two microRNAs and now search for further targets. Using a microarray meta-database we find potential FOXA1 regulation by microRNAs-99a/100. We confirm direct targeting of the FOXA1 3′UTR by microRNAs-99a/100 and also potential indirect regulation through microRNA-485-5p/SOX5/JUN-D/FOXL1 and microRNA-486/FOXO1a. In 292 benign and malignant urothelial samples, we find an inverse correlation between the expression of FOXA1 and microRNAs-99a/100 (r=−0.33 to −0.43, p<0.05). As for FGFR3 in UCC, tumors with high FOXA1 expression have lower rates of progression than those with low expression (Log rank p=0.009). Using global gene expression and CpG methylation profiling we find genotypic consequences of FOXA1 upregulation in UCC. Genetic changes are associated with regional hypomethylation, occur near FOXA1 binding sites, and mirror gene expression changes previously reported in FGFR3 mutant-UCC. These include gene silencing through aberrant hypermethylation (e.g. IGFBP3) and affect genes characterizing breast cancer sub-types (e.g. ERBB2). In conclusion, we have identified microRNAs-99a/100 mediate a direct relationship between FGFR3 and FOXA1 and potentially facilitate cross talk between these pathways in UCC. PMID:25071007

MicroRNA-99a and 100 mediated upregulation of FOXA1 in bladder cancer.

PubMed

Drayton, Ross M; Peter, Stefan; Myers, Katie; Miah, Saiful; Dudziec, Ewa; Bryant, Helen E; Catto, James W F

2014-08-15

Urothelial cell carcinoma of the bladder (UCC) is a common disease often characterized by FGFR3 dysregulation. Whilst upregulation of this oncogene occurs most frequently in low-grade non-invasive tumors, recent data reveal increased FGFR3 expression characterizes a common sub-type of invasive UCC sharing molecular similarities with breast cancer. These similarities include upregulation of the FOXA1 transcription factor and reduced expression of microRNAs-99a/100. We have previously identified direct regulation of FGFR3 by these two microRNAs and now search for further targets. Using a microarray meta-database we find potential FOXA1 regulation by microRNAs-99a/100. We confirm direct targeting of the FOXA1 3'UTR by microRNAs-99a/100 and also potential indirect regulation through microRNA-485-5p/SOX5/JUN-D/FOXL1 and microRNA-486/FOXO1a. In 292 benign and malignant urothelial samples, we find an inverse correlation between the expression of FOXA1 and microRNAs-99a/100 (r=-0.33 to -0.43, p<0.05). As for FGFR3 in UCC, tumors with high FOXA1 expression have lower rates of progression than those with low expression (Log rank p=0.009). Using global gene expression and CpG methylation profiling we find genotypic consequences of FOXA1 upregulation in UCC. Genetic changes are associated with regional hypomethylation, occur near FOXA1 binding sites, and mirror gene expression changes previously reported in FGFR3 mutant-UCC. These include gene silencing through aberrant hypermethylation (e.g. IGFBP3) and affect genes characterizing breast cancer sub-types (e.g. ERBB2). In conclusion, we have identified microRNAs-99a/100 mediate a direct relationship between FGFR3 and FOXA1 and potentially facilitate cross talk between these pathways in UCC.

Meta-Analysis of Transcriptome Data Related to Hippocampus Biopsies and iPSC-Derived Neuronal Cells from Alzheimer's Disease Patients Reveals an Association with FOXA1 and FOXA2 Gene Regulatory Networks.

PubMed

Wruck, Wasco; Schröter, Friederike; Adjaye, James

2016-01-01

Although the incidence of Alzheimer's disease (AD) is continuously increasing in the aging population worldwide, effective therapies are not available. The interplay between causative genetic and environmental factors is partially understood. Meta-analyses have been performed on aspects such as polymorphisms, cytokines, and cognitive training. Here, we propose a meta-analysis approach based on hierarchical clustering analysis of a reliable training set of hippocampus biopsies, which is condensed to a gene expression signature. This gene expression signature was applied to various test sets of brain biopsies and iPSC-derived neuronal cell models to demonstrate its ability to distinguish AD samples from control. Thus, our identified AD-gene signature may form the basis for determination of biomarkers that are urgently needed to overcome current diagnostic shortfalls. Intriguingly, the well-described AD-related genes APP and APOE are not within the signature because their gene expression profiles show a lower correlation to the disease phenotype than genes from the signature. This is in line with the differing characteristics of the disease as early-/late-onset or with/without genetic predisposition. To investigate the gene signature's systemic role(s), signaling pathways, gene ontologies, and transcription factors were analyzed which revealed over-representation of response to stress, regulation of cellular metabolic processes, and reactive oxygen species. Additionally, our results clearly point to an important role of FOXA1 and FOXA2 gene regulatory networks in the etiology of AD. This finding is in corroboration with the recently reported major role of the dopaminergic system in the development of AD and its regulation by FOXA1 and FOXA2.

FOXA1 is an essential determinant of ERα expression and mammary ductal morphogenesis

PubMed Central

Bernardo, Gina M.; Lozada, Kristen L.; Miedler, John D.; Harburg, Gwyndolen; Hewitt, Sylvia C.; Mosley, Jonathan D.; Godwin, Andrew K.; Korach, Kenneth S.; Visvader, Jane E.; Kaestner, Klaus H.; Abdul-Karim, Fadi W.; Montano, Monica M.; Keri, Ruth A.

2010-01-01

FOXA1, estrogen receptor α (ERα) and GATA3 independently predict favorable outcome in breast cancer patients, and their expression correlates with a differentiated, luminal tumor subtype. As transcription factors, each functions in the morphogenesis of various organs, with ERα and GATA3 being established regulators of mammary gland development. Interdependency between these three factors in breast cancer and normal mammary development has been suggested, but the specific role for FOXA1 is not known. Herein, we report that Foxa1 deficiency causes a defect in hormone-induced mammary ductal invasion associated with a loss of terminal end bud formation and ERα expression. By contrast, Foxa1 null glands maintain GATA3 expression. Unlike ERα and GATA3 deficiency, Foxa1 null glands form milk-producing alveoli, indicating that the defect is restricted to expansion of the ductal epithelium, further emphasizing the novel role for FOXA1 in mammary morphogenesis. Using breast cancer cell lines, we also demonstrate that FOXA1 regulates ERα expression, but not GATA3. These data reveal that FOXA1 is necessary for hormonal responsiveness in the developing mammary gland and ERα-positive breast cancers, at least in part, through its control of ERα expression. PMID:20501593

Integrated microarray and ChIP analysis identifies multiple Foxa2 dependent target genes in the notochord.

PubMed

Tamplin, Owen J; Cox, Brian J; Rossant, Janet

2011-12-15

The node and notochord are key tissues required for patterning of the vertebrate body plan. Understanding the gene regulatory network that drives their formation and function is therefore important. Foxa2 is a key transcription factor at the top of this genetic hierarchy and finding its targets will help us to better understand node and notochord development. We performed an extensive microarray-based gene expression screen using sorted embryonic notochord cells to identify early notochord-enriched genes. We validated their specificity to the node and notochord by whole mount in situ hybridization. This provides the largest available resource of notochord-expressed genes, and therefore candidate Foxa2 target genes in the notochord. Using existing Foxa2 ChIP-seq data from adult liver, we were able to identify a set of genes expressed in the notochord that had associated regions of Foxa2-bound chromatin. Given that Foxa2 is a pioneer transcription factor, we reasoned that these sites might represent notochord-specific enhancers. Candidate Foxa2-bound regions were tested for notochord specific enhancer function in a zebrafish reporter assay and 7 novel notochord enhancers were identified. Importantly, sequence conservation or predictive models could not have readily identified these regions. Mutation of putative Foxa2 binding elements in two of these novel enhancers abrogated reporter expression and confirmed their Foxa2 dependence. The combination of highly specific gene expression profiling and genome-wide ChIP analysis is a powerful means of understanding developmental pathways, even for small cell populations such as the notochord. Copyright © 2011 Elsevier Inc. All rights reserved.

A novel role for FOXA2 and SHH in organizing midbrain signaling centers.

PubMed

Bayly, Roy D; Brown, Charmaine Y; Agarwala, Seema

2012-09-01

The floor plate (FP) is a midline signaling center, known to direct ventral cell fates and axon guidance in the neural tube. The recent identification of midbrain FP as a source of dopaminergic neurons has renewed interest in its specification and organization, which remain poorly understood. In this study, we have examined the chick midbrain and spinal FP and show that both can be partitioned into medial (MFP) and lateral (LFP) subdivisions. Although Hedgehog (HH) signaling is necessary and sufficient for LFP specification, it is not sufficient for MFP induction. By contrast, the transcription factor FOXA2 can execute the full midbrain and spinal cord FP program via HH-independent and dependent mechanisms. Interestingly, although HH-independent FOXA2 activity is necessary and sufficient for inducing MFP-specific gene expression (e.g., LMX1B, BMP7), it cannot confer ventral identity to midline cells without also turning on Sonic hedgehog (SHH). We also note that the signaling centers of the midbrain, the FP, roof plate (RP) and the midbrain-hindbrain boundary (MHB) are physically contiguous, with each expressing LMX1B and BMP7. Possibly as a result, SHH or FOXA2 misexpression can transform the MHB into FP and also suppress RP induction. Conversely, HH or FOXA2 knockdown expands the endogenous RP and transforms the MFP into a RP and/or MHB fate. Finally, combined HH blockade and FOXA2 misexpression in ventral midbrain induces LMX1B expression, which triggers the specification of the RP, rather than the MFP. Thus we identify HH-independent and dependent roles for FOXA2 in specifying the FP. In addition, we elucidate for the first time, a novel role for SHH in determining whether a midbrain signaling center will become the FP, MHB or RP. Copyright © 2012 Elsevier Inc. All rights reserved.

All-trans retinoic acid regulates hepatic bile acid homeostasis

PubMed Central

Yang, Fan; He, Yuqi; Liu, Hui-Xin; Tsuei, Jessica; Jiang, Xiaoyue; Yang, Li; Wang, Zheng-Tao; Wan, Yu-Jui Yvonne

2014-01-01

Retinoic acid (RA) and bile acids share common roles in regulating lipid homeostasis and insulin sensitivity. In addition, the receptor for RA (retinoid x receptor) is a permissive partner of the receptor for bile acids, farnesoid x receptor (FXR/NR1H4). Thus, RA can activate the FXR-mediated pathway as well. The current study was designed to understand the effect of all-trans RA on bile acid homeostasis. Mice were fed an all-trans RA-supplemented diet and the expression of 46 genes that participate in regulating bile acid homeostasis was studied. The data showed that all-trans RA has a profound effect in regulating genes involved in synthesis and transport of bile acids. All-trans RA treatment reduced the gene expression levels of Cyp7a1, Cyp8b1, and Akr1d1, which are involved in bile acid synthesis. All-trans RA also decreased the hepatic mRNA levels of Lrh-1 (Nr5a2) and Hnf4α (Nr2a1), which positively regulate the gene expression of Cyp7a1 and Cyp8b1. Moreover, all-trans RA induced the gene expression levels of negative regulators of bile acid synthesis including hepatic Fgfr4, Fxr, and Shp (Nr0b2) as well as ileal Fgf15. All-trans RA also decreased the expression of Abcb11 and Slc51b, which have a role in bile acid transport. Consistently, all-trans RA reduced hepatic bile acid levels and the ratio of CA/CDCA, as demonstrated by liquid chromatography-mass spectrometry. The data suggest that all-trans RA-induced SHP may contribute to the inhibition of CYP7A1 and CYP8B1, which in turn reduces bile acid synthesis and affects lipid absorption in the gastrointestinal tract. PMID:25175738

Heterozygous Deletion of FOXA2 Segregates with Disease in a Family with Heterotaxy, Panhypopituitarism, and Biliary Atresia

PubMed Central

Tsai, Ellen A.; Grochowski, Christopher M.; Falsey, Alexandra M.; Rajagopalan, Ramakrishnan; Wendel, Danielle; Devoto, Marcella; Krantz, Ian D.; Loomes, Kathleen M.; Spinner, Nancy B.

2015-01-01

Biliary atresia (BA) is a pediatric cholangiopathy with unknown etiology occurring in isolated and syndromic forms. Laterality defects affecting the cardiovascular and gastrointestinal systems are the most common features present in syndromic BA. Most cases are sporadic, although reports of familial cases have led to the hypothesis of genetic susceptibility in some patients. We identified a child with BA, malrotation, and interrupted inferior vena cava whose father presented with situs inversus, polysplenia, panhypopituitarism, and mildly dysmorphic facial features. Chromosomal microarray analysis demonstrated a 277kb heterozygous deletion on chromosome 20 which included a single gene, FOXA2, in the proband and her father. This deletion was confirmed to be de novo in the father. The proband and her father share a common diagnosis of heterotaxy, but they also each presented with a variety of other issues. Further genetic screening revealed that the proband carried an additional protein-altering polymorphism (rs1904589; p.His165Arg) in the NODAL gene that is not present in the father, and this variant has been shown to decrease expression of the gene. As FOXA2 can be a regulator of NODAL expression, we propose that haploinsufficiency for FOXA2 combined with a decreased expression of NODAL is the likely cause for syndromic BA in this proband. PMID:25765999

Overexpression of FOXA1 inhibits cell proliferation and EMT of human gastric cancer AGS cells.

PubMed

Lin, Mengxin; Pan, Jie; Chen, Qiang; Xu, Zongbin; Lin, Xiaoyan; Shi, Chunmei

2018-02-05

The lack of effective medical treatment for advanced stages of gastric cancer mainly contributes to the high mortality rate. The association of forkhead box protein A1 (FOXA1) with tumor progression has been reported in different human cancers. However, the function of FOXA1 in gastric cancer is largely unknown. In the present study, FOXA1 protein showed a significant reduction in gastric cancer samples comparing with matched control samples. In addition, the higher expression of FOXA1 in transcription level was observed in gastric cancer cell lines as compared with that in normal gastric cell line, while the contrary result was observed in protein level. Then we studied the effects of FOXA1 on gastric cancer cells in vitro and in vivo based on FOXA1-overexpression AGS cells. We found that up-regulation of FOXA1 was notably inhibited the cell proliferation and tumor formation, and induced cell apoptosis. Moreover, overexpression of FOXA1 was able to increase the E-cadherin protein level and decreased the Vimentin protein level, which implicates that FOXA1 probably plays as an inhibitor of epithelial mesenchymal transition. In conclusion, these data suggests that FOXA1 may function as a novel anti-oncogene in gastric cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Induction of hepatocyte-like cells from mouse embryonic stem cells by lentivirus-mediated constitutive expression of Foxa2/Hnf4a.

PubMed

Liu, Tao; Zhang, Shichang; Xiang, Dedong; Wang, Yingjie

2013-11-01

Hepatocytes can be generated from embryonic stem cells (ESCs) using inducers such as chemical compounds and cytokines, but issues related to low differentiation efficiencies remain to be resolved. Recent work has shown that overexpression of lineage-specific transcription factors can directly cause cells phenotypic changes, including differentiation, trans-differentiation, and de-differentiation. We hypothesized that lentivirus-mediated constitutive expression of forkhead box A2 (Foxa2) and hepatocyte nuclear factor 4 alpha (Hnf4a) could promote inducing mouse ESCs to hepatocyte-likes cells. First, ESC lines that stably expressed Foxa2, Hnf4a, or Foxa2/Hnf4a were constructed via lentiviral expression vectors. Second, observations of cell morphology changes were made during the cell culture process, followed by experiments examining teratoma formation. Then, the effects of constitutive expression of Foxa2 and Hnf4a on hepatic differentiation and maturation were determined by measuring the marker gene expression levels of Albumin, α-fetoprotein, Cytokeratin18, and α1-antitrypsin. The results indicate that constitutive expression of Foxa2 and Hnf4a does not affect ESCs culture, teratoma formation, or the expression levels of the specific hepatocyte genes under autonomous differentiation. However, with some assistance from inducing factors, Foxa2 significantly increased the hepatic differentiation of ESCs, whereas the expression of Hnf4a alone or Foxa2/Hnf4a could not. Differentiated CCE-Foxa2 cells were more superior in expressing several liver-specific markers and protein, storing glycogen than differentiated CCE cells. Therefore, our method employing the transduction of Foxa2 would be a valuable tool for the efficient generation of functional hepatocytes derived from ESCs. © 2013 Wiley Periodicals, Inc.

Heterozygous deletion of FOXA2 segregates with disease in a family with heterotaxy, panhypopituitarism, and biliary atresia.

PubMed

Tsai, Ellen A; Grochowski, Christopher M; Falsey, Alexandra M; Rajagopalan, Ramakrishnan; Wendel, Danielle; Devoto, Marcella; Krantz, Ian D; Loomes, Kathleen M; Spinner, Nancy B

2015-06-01

Biliary atresia (BA) is a pediatric cholangiopathy with unknown etiology occurring in isolated and syndromic forms. Laterality defects affecting the cardiovascular and gastrointestinal systems are the most common features present in syndromic BA. Most cases are sporadic, although reports of familial cases have led to the hypothesis of genetic susceptibility in some patients. We identified a child with BA, malrotation, and interrupted inferior vena cava whose father presented with situs inversus, polysplenia, panhypopituitarism, and mildly dysmorphic facial features. Chromosomal microarray analysis demonstrated a 277 kb heterozygous deletion on chromosome 20, which included a single gene, FOXA2, in the proband and her father. This deletion was confirmed to be de novo in the father. The proband and her father share a common diagnosis of heterotaxy, but they also each presented with a variety of other issues. Further genetic screening revealed that the proband carried an additional protein-altering polymorphism (rs1904589; p.His165Arg) in the NODAL gene that is not present in the father, and this variant has been shown to decrease expression of the gene. As FOXA2 can be a regulator of NODAL expression, we propose that haploinsufficiency for FOXA2 combined with a decreased expression of NODAL is the likely cause for syndromic BA in this proband. © 2015 WILEY PERIODICALS, INC.

Differential temporal control of Foxa.a and Zic-r.b specifies brain versus notochord fate in the ascidian embryo.

PubMed

Ikeda, Tatsuro; Satou, Yutaka

2017-01-01

In embryos of an invertebrate chordate, Ciona intestinalis, two transcription factors, Foxa.a and Zic-r.b, are required for specification of the brain and the notochord, which are derived from distinct cell lineages. In the brain lineage, Foxa.a and Zic-r.b are expressed with no temporal overlap. In the notochord lineage, Foxa.a and Zic-r.b are expressed simultaneously. In the present study, we found that the temporally non-overlapping expression of Foxa.a and Zic-r.b in the brain lineage was regulated by three repressors: Prdm1-r.a (formerly called BZ1), Prdm1-r.b (BZ2) and Hes.a. In morphant embryos of these three repressor genes, Foxa.a expression was not terminated at the normal time, and Zic-r.b was precociously expressed. Consequently, Foxa.a and Zic-r.b were expressed simultaneously, which led to ectopic activation of Brachyury and its downstream pathways for notochord differentiation. Thus, temporal controls by transcriptional repressors are essential for specification of the two distinct fates of brain and notochord by Foxa.a and Zic-r.b Such a mechanism might enable the repeated use of a limited repertoire of transcription factors in developmental gene regulatory networks. © 2017. Published by The Company of Biologists Ltd.

Forkhead Box Transcription Factors of the FOXA Class Are Required for Basal Transcription of Angiotensin-Converting Enzyme 2

PubMed Central

Pedersen, Kim Brint; Chodavarapu, Harshita

2017-01-01

Angiotensin-converting enzyme 2 (ACE2) has protective effects on a wide range of morbidities associated with elevated angiotensin-II signaling. Most tissues, including pancreatic islets, express ACE2 mainly from the proximal promoter region. We previously found that hepatocyte nuclear factors 1α and 1β stimulate ACE2 expression from three highly conserved hepatocyte nuclear factor 1 binding motifs in the proximal promoter region. We hypothesized that other highly conserved motifs would also affect ACE2 expression. By systematic mutation of conserved elements, we identified five regions affecting ACE2 expression, of which two regions bound transcriptional activators. One of these is a functional FOXA binding motif. We further identified the main protein binding the FOXA motif in 832/13 insulinoma cells as well as in mouse pancreatic islets as FOXA2. PMID:29082356

Bile acid receptors link nutrient sensing to metabolic regulation

PubMed Central

Li, Jibiao; Li, Tiangang

2017-01-01

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease in Western populations. Non-alcoholic steatohepatitis (NASH) is a more debilitating form of NAFLD characterized by hepatocellular injury and inflammation, which significantly increase the risk of end-stage liver and cardiovascular diseases. Unfortunately, there are no available drug therapies for NASH. Bile acids are physiological detergent molecules that are synthesized from cholesterol exclusively in the hepatocytes. Bile acids circulate between the liver and intestine, where they are required for cholesterol solubilization in the bile and dietary fat emulsification in the gut. Bile acids also act as signaling molecules that regulate metabolic homeostasis and inflammatory processes. Many of these effects are mediated by the bile acid-activated nuclear receptor farnesoid X receptor (FXR) and the G protein-coupled receptor TGR5. Nutrient signaling regulates hepatic bile acid synthesis and circulating plasma bile acid concentrations, which in turn control metabolic homeostasis. The FXR agonist obeticholic acid has had beneficial effects on NASH in recent clinical trials. Preclinical studies have suggested that the TGR5 agonist and the FXR/TGR5 dual agonist are also potential therapies for metabolic liver diseases. Extensive studies in the past few decades have significantly improved our understanding of the metabolic regulatory function of bile acids, which has provided the molecular basis for developing promising bile acid-based therapeutic agents for NASH treatment. PMID:29098111

Integrative analysis identifies targetable CREB1/FoxA1 transcriptional co-regulation as a predictor of prostate cancer recurrence.

PubMed

Sunkel, Benjamin; Wu, Dayong; Chen, Zhong; Wang, Chiou-Miin; Liu, Xiangtao; Ye, Zhenqing; Horning, Aaron M; Liu, Joseph; Mahalingam, Devalingam; Lopez-Nicora, Horacio; Lin, Chun-Lin; Goodfellow, Paul J; Clinton, Steven K; Jin, Victor X; Chen, Chun-Liang; Huang, Tim H-M; Wang, Qianben

2016-05-19

Identifying prostate cancer-driving transcription factors (TFs) in addition to the androgen receptor promises to improve our ability to effectively diagnose and treat this disease. We employed an integrative genomics analysis of master TFs CREB1 and FoxA1 in androgen-dependent prostate cancer (ADPC) and castration-resistant prostate cancer (CRPC) cell lines, primary prostate cancer tissues and circulating tumor cells (CTCs) to investigate their role in defining prostate cancer gene expression profiles. Combining genome-wide binding site and gene expression profiles we define CREB1 as a critical driver of pro-survival, cell cycle and metabolic transcription programs. We show that CREB1 and FoxA1 co-localize and mutually influence each other's binding to define disease-driving transcription profiles associated with advanced prostate cancer. Gene expression analysis in human prostate cancer samples found that CREB1/FoxA1 target gene panels predict prostate cancer recurrence. Finally, we showed that this signaling pathway is sensitive to compounds that inhibit the transcription co-regulatory factor MED1. These findings not only reveal a novel, global transcriptional co-regulatory function of CREB1 and FoxA1, but also suggest CREB1/FoxA1 signaling is a targetable driver of prostate cancer progression and serves as a biomarker of poor clinical outcomes. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

GATA-3 and FOXA1 expression is useful to differentiate breast carcinoma from other carcinomas.

PubMed

Davis, Drew G; Siddiqui, Momin T; Oprea-Ilies, Gabriela; Stevens, Keith; Osunkoya, Adeboye O; Cohen, Cynthia; Li, Xiaoxian Bill

2016-01-01

GATA-3, a member of the GATA family of zinc-finger DNA binding proteins, and FOXA1, a member of the forkhead transcription factor family, are both associated with estrogen receptor expression. Both GATA-3 and FOXA1 are useful markers for breast carcinoma, but their expression in the different breast cancer subtypes and other neoplasms has not been thoroughly evaluated. We examined the expression of GATA-3 and FOXA1 in estrogen receptor-positive, Her2/neu-positive, and triple-negative breast carcinomas as well as in 10 other common carcinomas, including hepatocellular, colonic, pancreatic, gastric, endometrial (endometrioid), lung, prostatic, renal cell, urothelial, and ovarian serous carcinomas. Primary and metastatic melanomas and mesotheliomas were also evaluated. GATA-3 and FOXA1 staining of estrogen receptor-positive breast carcinomas was seen in 96.6% and 96.2%, respectively. In triple-negative breast carcinomas, GATA-3 and FOXA1 staining was seen in 21.6% and 15.9%, respectively. Among the other tumors, GATA-3 staining was only seen in urothelial carcinoma (70.9%) and FOXA1 staining was only seen in prostatic (87.5%), urothelial (5.1%) carcinomas, and mesotheliomas (40.0%). In conclusion, GATA-3 and FOXA1 are excellent breast carcinoma markers; however, their utility is limited in the triple-negative subtype. The utility of FOXA1 in diagnosing prostatic carcinoma and mesothelioma warrants further investigation. Copyright © 2015 Elsevier Inc. All rights reserved.

Organ-specific gene expression: the bHLH protein Sage provides tissue specificity to Drosophila FoxA.

PubMed

Fox, Rebecca M; Vaishnavi, Aria; Maruyama, Rika; Andrew, Deborah J

2013-05-01

FoxA transcription factors play major roles in organ-specific gene expression, regulating, for example, glucagon expression in the pancreas, GLUT2 expression in the liver, and tyrosine hydroxylase expression in dopaminergic neurons. Organ-specific gene regulation by FoxA proteins is achieved through cooperative regulation with a broad array of transcription factors with more limited expression domains. Fork head (Fkh), the sole Drosophila FoxA family member, is required for the development of multiple distinct organs, yet little is known regarding how Fkh regulates tissue-specific gene expression. Here, we characterize Sage, a bHLH transcription factor expressed exclusively in the Drosophila salivary gland (SG). We show that Sage is required for late SG survival and normal tube morphology. We find that many Sage targets, identified by microarray analysis, encode SG-specific secreted cargo, transmembrane proteins, and the enzymes that modify these proteins. We show that both Sage and Fkh are required for the expression of Sage target genes, and that co-expression of Sage and Fkh is sufficient to drive target gene expression in multiple cell types. Sage and Fkh drive expression of the bZip transcription factor Senseless (Sens), which boosts expression of Sage-Fkh targets, and Sage, Fkh and Sens colocalize on SG chromosomes. Importantly, expression of Sage-Fkh target genes appears to simply add to the tissue-specific gene expression programs already established in other cell types, and Sage and Fkh cannot alter the fate of most embryonic cell types even when expressed early and continuously.

Organ-specific gene expression: the bHLH protein Sage provides tissue specificity to Drosophila FoxA

PubMed Central

Fox, Rebecca M.; Vaishnavi, Aria; Maruyama, Rika; Andrew, Deborah J.

2013-01-01

FoxA transcription factors play major roles in organ-specific gene expression, regulating, for example, glucagon expression in the pancreas, GLUT2 expression in the liver, and tyrosine hydroxylase expression in dopaminergic neurons. Organ-specific gene regulation by FoxA proteins is achieved through cooperative regulation with a broad array of transcription factors with more limited expression domains. Fork head (Fkh), the sole Drosophila FoxA family member, is required for the development of multiple distinct organs, yet little is known regarding how Fkh regulates tissue-specific gene expression. Here, we characterize Sage, a bHLH transcription factor expressed exclusively in the Drosophila salivary gland (SG). We show that Sage is required for late SG survival and normal tube morphology. We find that many Sage targets, identified by microarray analysis, encode SG-specific secreted cargo, transmembrane proteins, and the enzymes that modify these proteins. We show that both Sage and Fkh are required for the expression of Sage target genes, and that co-expression of Sage and Fkh is sufficient to drive target gene expression in multiple cell types. Sage and Fkh drive expression of the bZip transcription factor Senseless (Sens), which boosts expression of Sage-Fkh targets, and Sage, Fkh and Sens colocalize on SG chromosomes. Importantly, expression of Sage-Fkh target genes appears to simply add to the tissue-specific gene expression programs already established in other cell types, and Sage and Fkh cannot alter the fate of most embryonic cell types even when expressed early and continuously. PMID:23578928

Association analysis of bovine Foxa2 gene single sequence variant and haplotype combinations with growth traits in Chinese cattle.

PubMed

Liu, Mei; Li, Mijie; Wang, Shaoqiang; Xu, Yao; Lan, Xianyong; Li, Zhuanjian; Lei, Chuzhao; Yang, Dongying; Jia, Yutang; Chen, Hong

2014-02-25

Forkhead box A2 (Foxa2) has been recognized as one of the most potent transcriptional activators that is implicated in the control of feeding behavior and energy homeostasis. However, similar researches about the effects of genetic variations of Foxa2 gene on growth traits are lacking. Therefore, this study detected Foxa2 gene polymorphisms by DNA pool sequencing, PCR-RFLP and PCR-ACRS methods in 822 individuals from three Chinese cattle breeds. The results showed that four sequence variants (SVs) were screened, including two mutations (SV1, g. 7005 C>T and SV2, g. 7044 C>G) in intron 4, one mutation (SV3, g. 8449 A>G) in exon 5 and one mutation (SV4, g. 8537 T>C) in the 3'UTR. Notably, association analysis of the single mutations with growth traits in total individuals (at 24months) revealed that significant statistical difference was found in four SVs, and SV4 locus was highly significantly associated with growth traits throughout all three breeds (P<0.05 or P<0.01). Meanwhile, haplotype combination CCCCAGTC also indicated remarkably associated to better chest girth and body weight in Jiaxian Red cattle (P<0.05). We herein described a comprehensive study on the variability of bovine Foxa2 gene that was predictive of molecular markers in cattle breeding for the first time. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

FoxA4 favours notochord formation by inhibiting contiguous mesodermal fates and restricts anterior neural development in Xenopus embryos.

PubMed

Murgan, Sabrina; Castro Colabianchi, Aitana Manuela; Monti, Renato José; Boyadjián López, Laura Elena; Aguirre, Cecilia E; Stivala, Ernesto González; Carrasco, Andrés E; López, Silvia L

2014-01-01

In vertebrates, the embryonic dorsal midline is a crucial signalling centre that patterns the surrounding tissues during development. Members of the FoxA subfamily of transcription factors are expressed in the structures that compose this centre. Foxa2 is essential for dorsal midline development in mammals, since knock-out mouse embryos lack a definitive node, notochord and floor plate. The related gene foxA4 is only present in amphibians. Expression begins in the blastula -chordin and -noggin expressing centre (BCNE) and is later restricted to the dorsal midline derivatives of the Spemann's organiser. It was suggested that the early functions of mammalian foxa2 are carried out by foxA4 in frogs, but functional experiments were needed to test this hypothesis. Here, we show that some important dorsal midline functions of mammalian foxa2 are exerted by foxA4 in Xenopus. We provide new evidence that the latter prevents the respecification of dorsal midline precursors towards contiguous fates, inhibiting prechordal and paraxial mesoderm development in favour of the notochord. In addition, we show that foxA4 is required for the correct regionalisation and maintenance of the central nervous system. FoxA4 participates in constraining the prospective rostral forebrain territory during neural specification and is necessary for the correct segregation of the most anterior ectodermal derivatives, such as the cement gland and the pituitary anlagen. Moreover, the early expression of foxA4 in the BCNE (which contains precursors of the whole forebrain and most of the midbrain and hindbrain) is directly required to restrict anterior neural development.

Generation of knock-in mice that express nuclear enhanced green fluorescent protein and tamoxifen-inducible Cre recombinase in the notochord from Foxa2 and T loci.

PubMed

Imuta, Yu; Kiyonari, Hiroshi; Jang, Chuan-Wei; Behringer, Richard R; Sasaki, Hiroshi

2013-03-01

The node and the notochord are important embryonic signaling centers that control embryonic pattern formation. Notochord progenitor cells present in the node and later in the posterior end of the notochord move anteriorly to generate the notochord. To understand the dynamics of cell movement during notochord development and the molecular mechanisms controlling this event, analyses of cell movements using time-lapse imaging and conditional manipulation of gene activities are required. To achieve this goal, we generated two knock-in mouse lines that simultaneously express nuclear enhanced green fluorescent protein (EGFP) and tamoxifen-inducible Cre, CreER(T2) , from two notochord gene loci, Foxa2 and T (Brachury). In Foxa2(nEGFP-CreERT2/+) and T(nEGFP-CreERT2/+) embryos, nuclei of the Foxa2 or T-expressing cells, which include the node, notochord, and endoderm (Foxa2) or wide range of posterior mesoderm (T), were labeled with EGFP at intensities that can be used for live imaging. Cre activity was also induced in cells expressing Foxa2 and T 1 day after tamoxifen administration. These mice are expected to be useful tools for analyzing the mechanisms of notochord development. Copyright © 2013 Wiley Periodicals, Inc.

Nuclear factor-E2-related factor 2 is a major determinant of bile acid homeostasis in the liver and intestine

PubMed Central

Weerachayaphorn, Jittima; Mennone, Albert; Soroka, Carol J.; Harry, Kathy; Hagey, Lee R.; Kensler, Thomas W.

2012-01-01

The transcription factor nuclear factor-E2-related factor 2 (Nrf2) is a key regulator for induction of hepatic detoxification and antioxidant mechanisms, as well as for certain hepatobiliary transporters. To examine the role of Nrf2 in bile acid homeostasis and cholestasis, we assessed the determinants of bile secretion and bile acid synthesis and transport before and after bile duct ligation (BDL) in Nrf2−/− mice. Our findings indicate reduced rates of biliary bile acid and GSH excretion, higher levels of intrahepatic bile acids, and decreased expression of regulators of bile acid synthesis, Cyp7a1 and Cyp8b1, in Nrf2−/− compared with wild-type control mice. The mRNA expression of the bile acid transporters bile salt export pump (Bsep) and organic solute transporter (Ostα) were increased in the face of impaired expression of the multidrug resistance-associated proteins Mrp3 and Mrp4. Deletion of Nrf2 also decreased ileal apical sodium-dependent bile acid transporter (Asbt) expression, leading to reduced bile acid reabsorption and increased loss of bile acid in feces. Finally, when cholestasis is induced by BDL, liver injury was not different from that in wild-type BDL mice. These Nrf2−/− mice also had increased pregnane X receptor (Pxr) and Cyp3a11 mRNA expression in association with enhanced hepatic bile acid hydroxylation. In conclusion, this study finds that Nrf2 plays a major role in the regulation of bile acid homeostasis in the liver and intestine. Deletion of Nrf2 results in a cholestatic phenotype but does not augment liver injury following BDL. PMID:22345550

Tyrosine Phosphorylation of the Pioneer Transcription Factor FoxA1 Promotes Activation of Estrogen Signaling.

PubMed

Yamaguchi, Noritaka; Shibazaki, Misato; Yamada, Chiaki; Anzai, Erina; Morii, Mariko; Nakayama, Yuji; Kuga, Takahisa; Hashimoto, Yuuki; Tomonaga, Takeshi; Yamaguchi, Naoto

2017-06-01

The pioneer transcription factor FoxA1 plays an important role in estrogen signaling by opening closed chromatin and promoting recruitment of the estrogen receptor to its target regions in DNA. In this study, we analyzed tyrosine phosphorylation of FoxA1 by the non-receptor-type tyrosine kinase c-Abl. c-Abl was shown to phosphorylate FoxA1 at multiple sites, especially in the N- and C-terminal regions. Tyr429 and Tyr464 were identified as the major phosphorylation sites in the FoxA1 C-terminal region. The phosphomimetic and nonphosphorylatable FoxA1 mutants were generated by glutamic acid and phenylalanine substitutions at these tyrosine residues, respectively. The phosphomimetic FoxA1 promoted the activation of estrogen signaling, whereas the nonphosphorylatable FoxA1 suppressed its activation. Stimulation with the epidermal growth factor, which activates c-Abl, enhanced the activation of estrogen signaling. In contrast, the c-Abl inhibitor imatinib reduced its activation. The phosphomimetic FoxA1 mutant showed a higher affinity toward histone H3 than the wild-type. These results suggest that c-Abl-mediated phosphorylation of FoxA1 promotes the activation of estrogen signaling by inducing its binding to histones. J. Cell. Biochem. 118: 1453-1461, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

[Recombinant hFOXA2 and hPDX1 lentivirus induced dental pulp stem cells from deciduous teeth reprogramming for insulin-producing cells].

PubMed

Shi, Jian-feng; Zhu, Chun-hui; Liu, Jin; Sun, Jun-yi; Rao, Guo-zhou; Li, Ang

2013-12-01

The purpose of this study was to culture and identify dental pulp stem cells(DPSCs) from deciduous teeth in vitro and construct the recombinant hFOXA2 and hPDX1 lentivirus vectors and transfect the DPSCs to induce insulin-producing cells (IPCs). DPSCs were separated and cultured by enzyme digest method, and purified by limited dilution method. Flow cytometry was used to determine the surface marker expression of the DPSCs, and the ability of multiple differentiations was determined by specific staining. hFOXA2 and hPDX1 genes were amplified by PCR, and the recombinant hFOXA2 and hPDX1 lentivirus vectors were reconstructed and transfected into 293T cells by lipofectamine2000 for virus packaging. The viral infection efficiency and titer were determined through fluorescence cell count. The recombinant virus was used to infect the DPSCs cells via multiplicity of infection (MOI) and induce the DPSCs reprogramming for IPCs. Immunofluorescence staining was used to measure the expression of proinsulin, FOXA2 and PDX1. ELISA method was used to detect the insulin secretion. The data was analyzed Using SPSS13.0 software package. DPSCs were isolated and cultured successfully. Cell surface highly expressed STRO-1 (98.01%), CDl46 (98.51%), CD34 (99.54%) and CD45 (24.08%). The multi-lineage differentiation capacity into osteoblasts, chondrocytes, and adipose was achieved. The recombinant hFOXA2 and hPDX1 lentivirus vectors were successfully constructed. Double enzyme digestion and sequencing appraisal showed that the sequence was fully consistent with GenBank retrieval. Virus packing efficiency was (96.15±0.17) % and (95.49±0.21) % respectively, and the infection titer was about 1.80±108 GTU/mL. The best MOI of the virus was 20. After inducing the cells to express proinsulin, FOXA2 and PDX1, insulin secretion volume was about 1.92 μmol/L. Compared with the uninduced group and control group, insulin secretion increased significantly (P<0.01). The recombinant transcription

Ursodeoxycholic acid lowers bile lithogenicity by regulating SCP2 expression in rabbit cholesterol gallstone models

PubMed Central

Cui, Yunfeng; Li, Zhonglian; Zhao, Erpeng; Zhang, Ju; Cui, Naiqiang

2012-01-01

Aims: We designed this study to get insight into the disorder of lipid metabolism during cholesterol gallstone formation and evaluate the effect of ursodeoxycholic acid on the improvement of bile lithogenicity and on expression of lipid related genes. Methods: Rabbit cholesterol gallstone models were induced by high cholesterol diet. Bile, blood and liver tissues were obtained from rabbits after 0, 1, 2, 3, 4 and 5 weeks. Bile and blood lipids were measured enzymatically. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), cytochrome P450, family 7, subfamily A, polypeptide 1 (CYP7A1) and sterol carrier protein 2 (SCP2) mRNA expressions were detected by using quantitative real-time RT-PCR. Cholesterol saturation index (CSI) was calculated by using Carey table to represent the bile lithogenicity. Results: Rates of gallstone formation of the 4 and 5 week treatment groups were 100 %, but that of the ursodeoxycholic acid treatment group was only 33.3 %. Expression of HMGCR and SCP2 mRNA in the 4 week group was upregulated and that of CYP7A1 mRNA decreased as compared with the 0 week group. Ursodeoxycholic acid could significantly extend nucleation time of bile and lower CSI. Ursodeoxycholic acid could reduce the expression of SCP2, but couldn't influence expression of HMGCR and CYP7A1. Conclusions: Abnormal expression of HMGCR, CYP7A1 and SCP2 might lead to high lithogenicity of bile. Ursodeoxycholic acid could improve bile lipids and lower bile lithogenicity, thereby reducing the incidence of gallstones. So it might be a good preventive drug for cholesterol gallstones. PMID:27847447

MicroRNA-1291 targets the FOXA2-AGR2 pathway to suppress pancreatic cancer cell proliferation and tumorigenesis

PubMed Central

Qiu, Jing-Xin; Kim, Edward J.; Yu, Ai-Ming

2016-01-01

Pancreatic cancer is the fourth leading cause of cancer death in the United States. Better understanding of pancreatic cancer biology may help identify new oncotargets towards more effective therapies. This study investigated the mechanistic actions of microRNA-1291 (miR-1291) in the suppression of pancreatic tumorigenesis. Our data showed that miR-1291 was downregulated in a set of clinical pancreatic carcinoma specimens and human pancreatic cancer cell lines. Restoration of miR-1291 expression inhibited pancreatic cancer cell proliferation, which was associated with cell cycle arrest and enhanced apoptosis. Furthermore, miR-1291 sharply suppressed the tumorigenicity of PANC-1 cells in mouse models. A proteomic profiling study revealed 32 proteins altered over 2-fold in miR-1291-expressing PANC-1 cells that could be assembled into multiple critical pathways for cancer. Among them anterior gradient 2 (AGR2) was reduced to the greatest degree. Through computational and experimental studies we further identified that forkhead box protein A2 (FOXA2), a transcription factor governing AGR2 expression, was a direct target of miR-1291. These results connect miR-1291 to the FOXA2-AGR2 regulatory pathway in the suppression of pancreatic cancer cell proliferation and tumorigenesis, providing new insight into the development of miRNA-based therapy to combat pancreatic cancer. PMID:27322206

FOXA1 promotes tumor progression in prostate cancer and represents a novel hallmark of castration-resistant prostate cancer.

PubMed

Gerhardt, Josefine; Montani, Matteo; Wild, Peter; Beer, Marc; Huber, Fabian; Hermanns, Thomas; Müntener, Michael; Kristiansen, Glen

2012-02-01

Forkhead box protein A1 (FOXA1) modulates the transactivation of steroid hormone receptors and thus may influence tumor growth and hormone responsiveness in prostate cancer. We therefore investigated the correlation of FOXA1 expression with clinical parameters, prostate-specific antigen (PSA) relapse-free survival, and hormone receptor expression in a large cohort of prostate cancer patients at different disease stages. FOXA1 expression did not differ significantly between benign glands from the peripheral zone and primary peripheral zone prostate carcinomas. However, FOXA1 was overexpressed in metastases and particularly in castration-resistant cases, but was expressed at lower levels in both normal and neoplastic transitional zone tissues. FOXA1 levels correlated with higher pT stages and Gleason scores, as well as with androgen (AR) and estrogen receptor expression. Moreover, FOXA1 overexpression was associated with faster biochemical disease progression, which was pronounced in patients with low AR levels. Finally, siRNA-based knockdown of FOXA1 induced decreased cell proliferation and migration. Moreover, in vitro tumorigenicity was inducible by ARs only in the presence of FOXA1, substantiating a functional cooperation between FOXA1 and AR. In conclusion, FOXA1 expression is associated with tumor progression, dedifferentiation of prostate cancer cells, and poorer prognosis, as well as with cellular proliferation and migration and with AR signaling. These findings suggest FOXA1 overexpression as a novel mechanism inducing castration resistance in prostate cancer. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Claudin 2 deficiency reduces bile flow and increases susceptibility to cholesterol gallstone disease in mice.

PubMed

Matsumoto, Kengo; Imasato, Mitsunobu; Yamazaki, Yuji; Tanaka, Hiroo; Watanabe, Mitsuhiro; Eguchi, Hidetoshi; Nagano, Hiroaki; Hikita, Hayato; Tatsumi, Tomohide; Takehara, Tetsuo; Tamura, Atsushi; Tsukita, Sachiko

2014-11-01

Bile formation and secretion are essential functions of the hepatobiliary system. Bile flow is generated by transepithelial transport of water and ionic/nonionic solutes via transcellular and paracellular pathways that is mainly driven by osmotic pressure. We examined the role of tight junction-based paracellular transport in bile secretion. Claudins are cell-cell adhesion molecules in tight junctions that create the paracellular barrier. The claudin family has 27 reported members, some of which have paracellular ion- and/or water-channel-like functions. Claudin 2 is a paracellular channel-forming protein that is highly expressed in hepatocytes and cholangiocytes; we examined the hepatobiliary system of claudin 2 knockout (Cldn2(-/-)) mice. We collected liver and biliary tissues from Cldn2(-/-) and Cldn2(+/+) mice and performed histologic, biochemical, and electrophysiologic analyses. We measured osmotic movement of water and/or ions in Cldn2(-/-) and Cldn2(+/+) hepatocytes and bile ducts. Mice were placed on lithogenic diets for 4 weeks and development of gallstone disease was assessed. The rate of bile flow in Cldn2(-/-) mice was half that of Cldn2(+/+) mice, resulting in significantly more concentrated bile in livers of Cldn2(-/-) mice. Consistent with these findings, osmotic gradient-driven water flow was significantly reduced in hepatocyte bile canaliculi and bile ducts isolated from Cldn2(-/-) mice, compared with Cldn2(+/+) mice. After 4 weeks on lithogenic diets, all Cldn2(-/-) mice developed macroscopically visible gallstones; the main component of the gallstones was cholesterol (>98%). In contrast, none of the Cldn2(+/+) mice placed on lithogenic diets developed gallstones. Based on studies of Cldn2(-/-) mice, claudin 2 regulates paracellular ion and water flow required for proper regulation of bile composition and flow. Dysregulation of this process increases susceptibility to cholesterol gallstone disease in mice. Copyright © 2014 AGA Institute

Identification and characterization of a novel PPARα-regulated and 7α-hydroxyl bile acid-preferring cytosolic sulfotransferase mL-STL (Sult2a8)[S

PubMed Central

Feng, Lu; Yuen, Yee-Lok; Xu, Jian; Liu, Xing; Chan, Martin Yan-Chun; Wang, Kai; Fong, Wing-Ping; Cheung, Wing-Tai; Lee, Susanna Sau-Tuen

2017-01-01

PPARα has been known to play a pivotal role in orchestrating lipid, glucose, and amino acid metabolism via transcriptional regulation of its target gene expression during energy deprivation. Recent evidence has also suggested that PPARα is involved in bile acid metabolism, but how PPARα modulates the homeostasis of bile acids during fasting is still not clear. In a mechanistic study aiming to dissect the spectrum of PPARα target genes involved in metabolic response to fasting, we identified a novel mouse gene (herein named mL-STL for mouse liver-sulfotransferase-like) that shared extensive homology with the Sult2a subfamily of a superfamily of cytosolic sulfotransferases, implying its potential function in sulfonation. The mL-STL gene expressed predominantly in liver in fed state, but PPARα was required to sustain its expression during fasting, suggesting a critical role of PPARα in regulating the mL-STL-mediated sulfonation during fasting. Functional studies using recombinant His-tagged mL-STL protein revealed its narrow sulfonating activities toward 7α-hydroxyl primary bile acids, including cholic acid, chenodeoxycholic acid, and α-muricholic acid, and thus suggesting that mL-STL may be the major hepatic bile acid sulfonating enzyme in mice. Together, these studies identified a novel PPARα-dependent gene and uncovered a new role of PPARα as being an essential regulator in bile acid biotransformation via sulfonation during fasting. PMID:28442498

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

Determination of DNA Binding Behavior of FoxA1 Constructs Using a Gold Nanoparticle-Based High Throughput Assay

NASA Astrophysics Data System (ADS)

Aung, Khin Moh Moh; Lim, Michelle Gek Liang; Hong, Shuzhen; Cheung, Edwin; Su, Xiaodi

Forkhead box protein 1 (FoxA1) is a member of the forkhead family of winged-helix transcription factors. It plays crucial roles in the development and differentiation of multiple organs and in the regulation of estrogen-stimulated genes. In this study, in order to determine the regions of FoxA1 necessary for efficient Deoxyribonucleic Acid (DNA) binding, we cloned, expressed and purified a series of FoxA1 constructs that contain either the DNA Binding Domain (DBD), the Transcription Activation Domain (TAD), or both. We determined the DNA binding behavior of these constructs using traditional electrophoretic mobility shift assay (EMSA) and a recently developed gold nanoparticles (AuNPs)-based fast screening method. We conclude that just the DBD region alone is not sufficient for protein-DNA binding activity. Amino acids flanking the upstream of the DBD region are required for maximal DNA binding activity. Through this study, we have also further validated the AuNPs assay for its generality and expanded the existing protocol for comparing the DNA binding behavior of multiple proteins of different charge properties and molecular weights.

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 (OST α ) and OST β increased by 6.4 ± 0.2-fold and 42.9 ± 7.9-fold, respectively. The upregulation of BSEP and OST α and OST β, by OCA reduced the intracellular concentrations of d 8 -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

Circadian regulation of intestinal lipid absorption by apolipoprotein AIV involves forkhead transcription factors A2 and O1 and microsomal triglyceride transfer protein.

PubMed

Pan, Xiaoyue; Munshi, Mohamed Khalid; Iqbal, Jahangir; Queiroz, Joyce; Sirwi, Alaa Ahmed; Shah, Shrenik; Younus, Abdullah; Hussain, M Mahmood

2013-07-12

We have shown previously that Clock, microsomal triglyceride transfer protein (MTP), and nocturnin are involved in the circadian regulation of intestinal lipid absorption. Here, we clarified the role of apolipoprotein AIV (apoAIV) in the diurnal regulation of plasma lipids and intestinal lipid absorption in mice. Plasma triglyceride in apoAIV(-/-) mice showed diurnal variations similar to apoAIV(+/+) mice; however, the increases in plasma triglyceride at night were significantly lower in these mice. ApoAIV(-/-) mice absorbed fewer lipids at night and showed blunted response to daytime feeding. To explain reasons for these lower responses, we measured MTP expression; intestinal MTP was low at night, and its induction after food entrainment was less in apoAIV(-/-) mice. Conversely, apoAIV overexpression increased MTP mRNA in hepatoma cells, indicating transcriptional regulation. Mechanistic studies revealed that sequences between -204/-775 bp in the MTP promoter respond to apoAIV and that apoAIV enhances expression of FoxA2 and FoxO1 transcription factors and their binding to the identified cis elements in the MTP promoter at night. Knockdown of FoxA2 and FoxO1 abolished apoAIV-mediated MTP induction. Similarly, knockdown of apoAIV in differentiated Caco-2 cells reduced MTP, FoxA2, and FoxO1 mRNA levels, cellular MTP activity, and media apoB. Moreover, FoxA2 and FoxO1 expression showed diurnal variations, and their expression was significantly lower in apoAIV(-/-) mice. These data indicate that apoAIV modulates diurnal changes in lipid absorption by regulating forkhead transcription factors and MTP and that inhibition of apoAIV expression might reduce plasma lipids.

Bile Acid Metabolism in Liver Pathobiology

PubMed Central

Chiang, John Y. L.; Ferrell, Jessica M.

2018-01-01

Bile acids facilitate intestinal nutrient absorption and biliary cholesterol secretion to maintain bile acid homeostasis, which is essential for protecting liver and other tissues and cells from cholesterol and bile acid toxicity. Bile acid metabolism is tightly regulated by bile acid synthesis in the liver and bile acid biotransformation in the intestine. Bile acids are endogenous ligands that activate a complex network of nuclear receptor farnesoid X receptor and membrane G protein-coupled bile acid receptor-1 to regulate hepatic lipid and glucose metabolic homeostasis and energy metabolism. The gut-to-liver axis plays a critical role in the regulation of enterohepatic circulation of bile acids, bile acid pool size, and bile acid composition. Bile acids control gut bacteria overgrowth, and gut bacteria metabolize bile acids to regulate host metabolism. Alteration of bile acid metabolism by high-fat diets, sleep disruption, alcohol, and drugs reshapes gut microbiome and causes dysbiosis, obesity, and metabolic disorders. Gender differences in bile acid metabolism, FXR signaling, and gut microbiota have been linked to higher prevalence of fatty liver disease and hepatocellular carcinoma in males. Alteration of bile acid homeostasis contributes to cholestatic liver diseases, inflammatory diseases in the digestive system, obesity, and diabetes. Bile acid-activated receptors are potential therapeutic targets for developing drugs to treat metabolic disorders. PMID:29325602

FoxA and LIPG endothelial lipase control the uptake of extracellular lipids for breast cancer growth

PubMed Central

Slebe, Felipe; Rojo, Federico; Vinaixa, Maria; García-Rocha, Mar; Testoni, Giorgia; Guiu, Marc; Planet, Evarist; Samino, Sara; Arenas, Enrique J.; Beltran, Antoni; Rovira, Ana; Lluch, Ana; Salvatella, Xavier; Yanes, Oscar; Albanell, Joan; Guinovart, Joan J.; Gomis, Roger R.

2016-01-01

The mechanisms that allow breast cancer (BCa) cells to metabolically sustain rapid growth are poorly understood. Here we report that BCa cells are dependent on a mechanism to supply precursors for intracellular lipid production derived from extracellular sources and that the endothelial lipase (LIPG) fulfils this function. LIPG expression allows the import of lipid precursors, thereby contributing to BCa proliferation. LIPG stands out as an essential component of the lipid metabolic adaptations that BCa cells, and not normal tissue, must undergo to support high proliferation rates. LIPG is ubiquitously and highly expressed under the control of FoxA1 or FoxA2 in all BCa subtypes. The downregulation of either LIPG or FoxA in transformed cells results in decreased proliferation and impaired synthesis of intracellular lipids. PMID:27045898

Bile acid regulates c-Jun expression through the orphan nuclear receptor SHP induction in gastric cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Won Il; Park, Min Jung; An, Jin Kwang

2008-05-02

Bile reflux is considered to be one of the most important causative factors in gastric carcinogenesis, due to the attendant inflammatory changes in the gastric mucosa. In this study, we have assessed the molecular mechanisms inherent to the contribution of bile acid to the transcriptional regulation of inflammatory-related genes. In this study, we demonstrated that bile acid induced the expression of the SHP orphan nuclear receptor at the transcriptional level via c-Jun activation. Bile acid also enhanced the protein interaction of NF-{kappa}B and SHP, thereby resulting in an increase in c-Jun expression and the production of the inflammatory cytokine, TNF{alpha}.more » These results indicate that bile acid performs a critical function in the regulation of the induction of inflammatory-related genes in gastric cells, and that bile acid-mediated gene expression provides a pre-clue for the development of gastric cellular malformation.« less

Pinelliae Rhizoma Praeparatum Involved in the Regulation of Bile Acids Metabolism in Hepatic Injury.

PubMed

Guo, Shun; Zhang, Song; Liu, Linna; Yang, Peng; Dang, Xueliang; Wei, Huamei; Hu, Na; Shi, Lei; Zhang, Yan

2018-06-01

Pinelliae Rhizoma Praeparatum (PRP) as traditional Chinese medicine had been used for hepatic diseases in combinative forms. However, the effect of PRP was not clear when used alone. So to explore the hepatoprotective/hepatotoxin of PRP is necessary. The activities of PRP were investigated in acetaminophen-induced hepatic injury mice. Liver function markers, hepatic oxidative stress markers were evaluated. Bile acids metabolic transports and nuclear factor erythroid 2-related factor 2 (Nrf2) were detected. As a drug for the treatment of liver diseases, PRP slightly restored the parameters towards normal in model mice only in low dosage, and also had no antioxidant activity and regulate Nrf2. Cholestasis was significantly elevated in model mice when pretreatment with routine or high dosage of PRP, but had no effect on normal mice. Bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2) in model mice were markedly increased when pretreatment with low dose PRP, but significantly decreased when pretreatment in routine or high dosage. Mrp3 was significantly induced in model mice after pretreatment of PRP. But the adjustment effect to bile acids transporters by PRP was not significant in normal mice. These results reveal that PRP has the different effects on bile acids transporter in hepatic injury mice, and therefore, the dosage of PRP need to be paid attention to when it is used in clinical hepatic injury.

The Hippo signaling functions through the Notch signaling to regulate intrahepatic bile duct development in mammals.

PubMed

Wu, Nan; Nguyen, Quy; Wan, Ying; Zhou, Tiaohao; Venter, Julie; Frampton, Gabriel A; DeMorrow, Sharon; Pan, Duojia; Meng, Fanyin; Glaser, Shannon; Alpini, Gianfranco; Bai, Haibo

2017-07-01

The Hippo signaling pathway and the Notch signaling pathway are evolutionary conserved signaling cascades that have important roles in embryonic development of many organs. In murine liver, disruption of either pathway impairs intrahepatic bile duct development. Recent studies suggested that the Notch signaling receptor Notch2 is a direct transcriptional target of the Hippo signaling pathway effector YAP, and the Notch signaling is a major mediator of the Hippo signaling in maintaining biliary cell characteristics in adult mice. However, it remains to be determined whether the Hippo signaling pathway functions through the Notch signaling in intrahepatic bile duct development. We found that loss of the Hippo signaling pathway tumor suppressor Nf2 resulted in increased expression levels of the Notch signaling pathway receptor Notch2 in cholangiocytes but not in hepatocytes. When knocking down Notch2 on the background of Nf2 deficiency in mouse livers, the excessive bile duct development induced by Nf2 deficiency was suppressed by heterozygous and homozygous deletion of Notch2 in a dose-dependent manner. These results implicated that Notch signaling is one of the downstream effectors of the Hippo signaling pathway in regulating intrahepatic bile duct development.

The Hippo signaling functions through the Notch signaling to regulate intrahepatic bile duct development in mammals

PubMed Central

Wu, Nan; Nguyen, Quy; Wan, Ying; Zhou, Tiaohao; Venter, Julie; Frampton, Gabriel A; DeMorrow, Sharon; Pan, Duojia; Meng, Fanyin; Glaser, Shannon; Alpini, Gianfranco; Bai, Haibo

2018-01-01

The Hippo signaling pathway and the Notch signaling pathway are evolutionary conserved signaling cascades that have important roles in embryonic development of many organs. In murine liver, disruption of either pathway impairs intrahepatic bile duct development. Recent studies suggested that the Notch signaling receptor Notch2 is a direct transcriptional target of the Hippo signaling pathway effector YAP, and the Notch signaling is a major mediator of the Hippo signaling in maintaining biliary cell characteristics in adult mice. However, it remains to be determined whether the Hippo signaling pathway functions through the Notch signaling in intrahepatic bile duct development. We found that loss of the Hippo signaling pathway tumor suppressor Nf2 resulted in increased expression levels of the Notch signaling pathway receptor Notch2 in cholangiocytes but not in hepatocytes. When knocking down Notch2 on the background of Nf2 deficiency in mouse livers, the excessive bile duct development induced by Nf2 deficiency was suppressed by heterozygous and homozygous deletion of Notch2 in a dose-dependent manner. These results implicated that Notch signaling is one of the downstream effectors of the Hippo signaling pathway in regulating intrahepatic bile duct development. PMID:28581486

FOXA1 in HPV associated carcinomas: Its expression in carcinomas of the head and neck and of the uterine cervix.

PubMed

Karpathiou, Georgia; Da Cruz, Vanessa; Casteillo, Francois; Mobarki, Mousa; Dumollard, Jean Marc; Chauleur, Celine; Forest, Fabien; Prades, Jean Michel; Peoc'h, Michel

2017-04-01

FOXA1 is a major transcription factor involved in the action of human papilloma virus (HPV). However, it has been never studied in HPV-associated tumors. To investigate its expression in cervical and head and neck tumors. 63 cervical carcinomas/dysplasias and 152 head and neck squamous cell carcinomas (HNSCC) were immunohistochemically studied for the expression of FOXA1. 63.1% of cervical SCC and 40.7% of endocervical adenocarcinomas strongly expressed FOXA1. Most (90%) pre-invasive lesions (CIN3 and in situ adenocarcinomas) strongly expressed FOXA1 and this difference from invasive lesions was statistically significant (p=0.005). No association with clinicopathological factors was found. 51.3% of HNSCC expressed FOXA1. In these tumors, FOXA1 expression was associated with the non-keratinizing morphology but not with the HPV/p16 status neither other clinicopathological features. Of normal structures, salivary glands, endocervical glands and basal/parabasal cell layer of squamous epithelium of both uterine cervix and head and neck mucosa, all strongly expressed FOXA1. FOXA1 is expressed by basal cells of squamous epithelium, pre-invasion lesions of the uterine cervix and the head/neck and almost half invasive cervical and head/neck carcinomas, supporting its possible implication in HPV pathogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

cGMP stimulates bile acid-independent bile formation and biliary bicarbonate excretion.

PubMed

Myers, N C; Grune, S; Jameson, H L; Sawkat-Anwer, M

1996-03-01

The effect of guanosine 3',5'-cyclic monophosphate (cGMP) on hepatic bile formation was studied in isolated perfused rat livers and rat hepatocytes. Studies in isolated perfused rat livers showed that infusion of 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP, 3 micromol/min or 100 microM) 1) increased bile flow without affecting biliary excretion of simultaneously infused taurocholate, 2) increased biliary concentration and excretion of HCO3(-) but did not affect biliary excretion of glutathione, and 3) increased net perfusate H+ efflux without affecting hepatic O2 uptake. Studies in isolated rat hepatocytes showed that 1) 8-BrcGMP increased intracellular pH in the presence (but not in the absence) of extracellular HCO-3, and effect inhibited by 4,4' -diisothiocyanostilbene-2,2'-disulfonic acid and Na+ replacement, 2) 8-BrcGMP did not affect taurocholate uptake and intracellular [Ca2+], and 3) bile acids, like ursodeoxycholate and cholate, did not increase cellular cGMP. Taken together, these results indicate that cGMP stimulates bile acid-independent bile formation, in part by stimulating biliary HCO3- excretion. cGMP may increase HCO3- excretion by stimulating sinusoidal Na+ - HCO3- cotransport, but not Na+/H+ exchange. cGMP, unlike adenosine 3',5'-cyclic monophosphate, may not regulate hepatic taurocholate transport, and bile acid-induced HCO3- rich choleresis may not be mediated via cGMP.

Regulation of hepatic bile acid transporters Ntcp and Bsep expression.

PubMed

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

2007-12-03

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. 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 (CDCA) increased Bsep mRNA expression. In conclusion, mouse Ntcp and Bsep are regulated by age, gender, cholestyramine, and bile acid, but resistant to induction by most microsomal enzyme inducers.

FOXA1 and SOX9 Expression in the Developing Urogenital Sinus of the Tammar Wallaby (Macropus eugenii).

PubMed

Gamat, Melissa; Chew, Keng Yih; Shaw, Geoffrey; Renfree, Marilyn B

2015-01-01

The mammalian prostate is a compact structure in humans but multi-lobed in mice. In humans and mice, FOXA1 and SOX9 play pivotal roles in prostate morphogenesis, but few other species have been examined. We examined FOXA1 and SOX9 in the marsupial tammar wallaby, Macropus eugenii, which has a segmented prostate more similar to human than to mouse. In males, prostatic budding in the urogenital epithelium (UGE) was initiated by day 24 postpartum (pp), but in the female the UGE remained smooth and had begun forming the marsupial vaginal structures. FOXA1 was upregulated in the male urogenital sinus (UGS) by day 51 pp, whilst in the female UGS FOXA1 remained basal. FOXA1 was localised in the UGE in both sexes between day 20 and 80 pp. SOX9 was upregulated in the male UGS at day 21-30 pp and remained high until day 51-60 pp. SOX9 protein was localised in the distal tips of prostatic buds which were highly proliferative. The persistent upregulation of the transcription factors SOX9 and FOXA1 after the initial peak and fall of androgen levels suggest that in the tammar, as in other mammals, these factors are required to sustain prostate differentiation, development and proliferation as androgen levels return to basal levels. © 2015 S. Karger AG, Basel.

IL-17A Synergistically Enhances Bile Acid–Induced Inflammation during Obstructive Cholestasis

PubMed Central

O'Brien, Kate M.; Allen, Katryn M.; Rockwell, Cheryl E.; Towery, Keara; Luyendyk, James P.; Copple, Bryan L.

2014-01-01

During obstructive cholestasis, increased concentrations of bile acids activate ERK1/2 in hepatocytes, which up-regulates early growth response factor 1, a key regulator of proinflammatory cytokines, such as macrophage inflammatory protein 2 (MIP-2), which, in turn, exacerbates cholestatic liver injury. Recent studies have indicated that IL-17A contributes to hepatic inflammation during obstructive cholestasis, suggesting that bile acids and IL-17A may interact to regulate hepatic inflammatory responses. We treated mice with an IL-17A neutralizing antibody or control IgG and subjected them to bile duct ligation. Neutralization of IL-17A prevented up-regulation of proinflammatory cytokines, hepatic neutrophil accumulation, and liver injury, indicating an important role for IL-17A in neutrophilic inflammation during cholestasis. Treatment of primary mouse hepatocytes with taurocholic acid (TCA) increased the expression of MIP-2. Co-treatment with IL-17A synergistically enhanced up-regulation of MIP-2 by TCA. In contrast to MIP-2, IL-17A did not affect up-regulation of Egr-1 by TCA, indicating that IL-17A does not affect bile acid–induced activation of signaling pathways upstream of early growth response factor 1. In addition, bile acids increased expression of IL-23, a key regulator of IL-17A production in hepatocytes in vitro and in vivo. Collectively, these data identify bile acids as novel triggers of the IL-23/IL-17A axis and suggest that IL-17A promotes hepatic inflammation during cholestasis by synergistically enhancing bile acid–induced production of proinflammatory cytokines by hepatocytes. PMID:24012680

Bile acid disease: the emerging epidemic.

PubMed

Oduyebo, Ibironke; Camilleri, Michael

2017-05-01

Our objective was to review advances in bile acids in health and disease published in the last 2 years. Bile acid diarrhea (BAD) is recognized as a common cause of chronic diarrhea, and its recognition has been facilitated by development of new screening tests. Primary BAD can account for 30% of cases of chronic diarrhea. The mechanisms leading to BAD include inadequate feedback regulation by fibroblast growth factor 19 (FGF-19) from ileal enterocytes, abnormalities in synthesis or degradation of proteins involved in FGF-19 regulation in hepatocytes and variations as a function of the bile acid receptor, TGR5 (GPBAR1). SeHCAT is the most widely used test for diagnosis of BAD. There has been significant validation of fasting serum FGF-19 and 7 α-hydroxy-cholesten-3-one (C4), a surrogate measure of bile acid synthesis. Bile acid sequestrants are the primary treatments for BAD; the farnesoid X-receptor-FGF-19 pathway provides alternative therapeutic targets for BAD. Bile acid-stimulated intestinal mechanisms contribute to the beneficial effects of bariatric surgery on obesity, glycemic control and the treatment of recurrent Clostridium difficile infection. Renewed interest in the role of bile acids is leading to novel management of diverse diseases besides BAD.

Bile acid metabolism and signaling in cholestasis, inflammation and cancer

PubMed Central

Apte, Udayan

2015-01-01

Bile acids are synthesized from cholesterol in the liver. Some cytochrome P450 (CYP) enzymes play key roles in bile acid synthesis. Bile acids are physiological detergent molecules, so are highly cytotoxic. They undergo enterohepatic circulation and play important roles in generating bile flow and facilitating biliary secretion of endogenous metabolites and xenobiotics and intestinal absorption of dietary fats and lipid soluble vitamins. Bile acid synthesis, transport and pool size are therefore tightly regulated under physiological conditions. In cholestasis, impaired bile flow leads to accumulation of bile acids in the liver, causing hepatocyte and biliary injury and inflammation. Chronic cholestasis is associated with fibrosis, cirrhosis and eventually liver failure. Chronic cholestasis also increases the risk of developing hepatocellular or cholangiocellular carcinomas. Extensive research in the last two decades has shown that bile acids act as signaling molecules that regulate various cellular processes. The bile acid-activated nuclear receptors are ligand-activated transcriptional factors that play critical roles in the regulation of bile acid, drug and xenobiotic metabolism. In cholestasis, these bile acid-activated receptors regulate a network of genes involved in bile acid synthesis, conjugation, transport and metabolism to alleviate bile acid-induced inflammation and injury. Additionally, bile acids are known to regulate cell growth and proliferation, and altered bile acid levels in diseased conditions have been implicated in liver injury/regeneration and tumorigenesis. We will cover the mechanisms that regulate bile acid homeostasis and detoxification during cholestasis, and the roles of bile acids in the initiation and regulation of hepatic inflammation, regeneration and carcinogenesis. PMID:26233910

Forced expression of Hnf1b/Foxa3 promotes hepatic fate of embryonic stem cells.

PubMed

Yahoo, Neda; Pournasr, Behshad; Rostamzadeh, Jalal; Hakhamaneshi, Mohammad Saeed; Ebadifar, Asghar; Fathi, Fardin; Baharvand, Hossein

2016-05-20

Embryonic stem (ES) cell-derived hepatocytes have the potential to be used for basic research, regenerative medicine, and drug discovery. Recent reports demonstrated that in addition to conventional differentiation inducers such as chemical compounds and cytokines, overexpression of lineage-specific transcription factors could induce ES cells to differentiate to a hepatic fate. Here, we hypothesized that lentivirus-mediated inducible expression of hepatic lineage transcription factors could enhance mouse ES cells to hepatocyte-like cells. We screened the effects of candidate transcription factors Hnf1b, Hnf1a, Hnf4a, Foxa1, Foxa3 and Hex, and determined that the combination of Hnf1b/Foxa3 promoted expression of several hepatic lineage-specific markers and proteins, in addition to glycogen storage, ICG uptake, and secretion of albumin and urea. The differentiated cells were engraftable and expressed albumin when transplanted into a carbon tetrachloride-injured mouse model. These results demonstrated the crucial role of Hnf1b and Foxa3 in hepatogenesis in vitro and provided a valuable tool for the efficient differentiation of HLCs from ES cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Bile duct epithelial tight junctions and barrier function

PubMed Central

Rao, R.K.; Samak, G.

2013-01-01

Bile ducts play a crucial role in the formation and secretion of bile as well as excretion of circulating xenobiotic substances. In addition to its secretory and excretory functions, bile duct epithelium plays an important role in the formation of a barrier to the diffusion of toxic substances from bile into the hepatic interstitial tissue. Disruption of barrier function and toxic injury to liver cells appear to be involved in the pathogenesis of a variety of liver diseases such as primary sclerosing cholangitis, primary biliary cirrhosis and cholangiocarcinoma. Although the investigations into understanding the structure and regulation of tight junctions in gut, renal and endothelial tissues have expanded rapidly, very little is known about the structure and regulation of tight junctions in the bile duct epithelium. In this article we summarize the current understanding of physiology and pathophysiology of bile duct epithelium, the structure and regulation of tight junctions in canaliculi and bile duct epithelia and different mechanisms involved in the regulation of disruption and protection of bile duct epithelial tight junctions. This article will make a case for the need of future investigations toward our understanding of molecular organization and regulation of canalicular and bile duct epithelial tight junctions. PMID:24665411

The bile acids, deoxycholic acid and ursodeoxycholic acid, regulate colonic epithelial wound healing.

PubMed

Mroz, Magdalena S; Lajczak, Natalia K; Goggins, Bridie J; Keely, Simon; Keely, Stephen J

2018-03-01

The intestinal epithelium constitutes an innate barrier which, upon injury, undergoes self-repair processes known as restitution. Although bile acids are known as important regulators of epithelial function in health and disease, their effects on wound healing processes are not yet clear. Here we set out to investigate the effects of the colonic bile acids, deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA), on epithelial restitution. Wound healing in T 84 cell monolayers grown on transparent, permeable supports was assessed over 48 h with or without bile acids. Cell migration was measured in Boyden chambers. mRNA and protein expression were measured by RT-PCR and Western blotting. DCA (50-150 µM) significantly inhibited wound closure in cultured epithelial monolayers and attenuated cell migration in Boyden chamber assays. DCA also induced nuclear accumulation of the farnesoid X receptor (FXR), whereas an FXR agonist, GW4064 (10 µM), inhibited wound closure. Both DCA and GW4064 attenuated the expression of CFTR Cl - channels, whereas inhibition of CFTR activity with either CFTR- inh -172 (10 µM) or GlyH-101 (25 µM) also prevented wound healing. Promoter/reporter assays revealed that FXR-induced downregulation of CFTR is mediated at the transcriptional level. In contrast, UDCA (50-150 µM) enhanced wound healing in vitro and prevented the effects of DCA. Finally, DCA inhibited and UDCA promoted mucosal healing in an in vivo mouse model. In conclusion, these studies suggest bile acids are important regulators of epithelial wound healing and are therefore good targets for development of new drugs to modulate intestinal barrier function in disease treatment. NEW & NOTEWORTHY The secondary bile acid, deoxycholic acid, inhibits colonic epithelial wound healing, an effect which appears to be mediated by activation of the nuclear bile acid receptor, FXR, with subsequent downregulation of CFTR expression and activity. In contrast, ursodeoxycholic acid promotes

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

Alisol B 23-acetate protects against ANIT-induced hepatotoxity and cholestasis, due to FXR-mediated regulation of transporters and enzymes involved in bile acid homeostasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Qiang; Chen, Xin-li; Wang, Chang-yuan

2015-03-15

Intrahepatic cholestasis is a clinical syndrome with systemic and intrahepatic accumulation of excessive toxic bile acids that ultimately cause hepatobiliary injury. Appropriate regulation of bile acids in hepatocytes is critically important for protection against liver injury. In the present study, we characterized the protective effect of alisol B 23-acetate (AB23A), a natural triterpenoid, on alpha-naphthylisothiocyanate (ANIT)-induced liver injury and intrahepatic cholestasis in mice and further elucidated the mechanisms in vivo and in vitro. AB23A treatment dose-dependently protected against liver injury induced by ANIT through reducing hepatic uptake and increasing efflux of bile acid via down-regulation of hepatic uptake transporters (Ntcp)more » and up-regulation of efflux transporter (Bsep, Mrp2 and Mdr2) expression. Furthermore, AB23A reduced bile acid synthesis through repressing Cyp7a1 and Cyp8b1, increased bile acid conjugation through inducing Bal, Baat and bile acid metabolism through an induction in gene expression of Sult2a1. We further demonstrate the involvement of farnesoid X receptor (FXR) in the hepatoprotective effect of AB23A. The changes in transporters and enzymes, as well as ameliorative liver histology in AB23A-treated mice were abrogated by FXR antagonist guggulsterone in vivo. In vitro evidences also directly demonstrated the effect of AB23A on FXR activation in a dose-dependent manner using luciferase reporter assay in HepG2 cells. In conclusion, AB23A produces protective effect against ANIT-induced hepatotoxity and cholestasis, due to FXR-mediated regulation of transporters and enzymes. - Highlights: • AB23A has at least three roles in protection against ANIT-induced liver injury. • AB23A decreases Ntcp, and increases Bsep, Mrp2 and Mdr2 expression. • AB23A represses Cyp7a1 and Cyp8b1 through inducing Shp and Fgf15 expression. • AB23A increases bile acid metabolism through inducing Sult2a1 expression. • FXR activation is

Interactions Between Nuclear Receptor SHP and FOXA1 Maintain Oscillatory Homocysteine Homeostasis in Mice.

PubMed

Tsuchiya, Hiroyuki; da Costa, Kerry-Ann; Lee, Sangmin; Renga, Barbara; Jaeschke, Hartmut; Yang, Zhihong; Orena, Stephen J; Goedken, Michael J; Zhang, Yuxia; Kong, Bo; Lebofsky, Margitta; Rudraiah, Swetha; Smalling, Rana; Guo, Grace; Fiorucci, Stefano; Zeisel, Steven H; Wang, Li

2015-05-01

Hyperhomocysteinemia is often associated with liver and metabolic diseases. We studied nuclear receptors that mediate oscillatory control of homocysteine homeostasis in mice. We studied mice with disruptions in Nr0b2 (called small heterodimer partner [SHP]-null mice), betaine-homocysteine S-methyltransferase (Bhmt), or both genes (BHMT-null/SHP-null mice), along with mice with wild-type copies of these genes (controls). Hyperhomocysteinemia was induced by feeding mice alcohol (National Institute on Alcohol Abuse and Alcoholism binge model) or chow diets along with water containing 0.18% DL-homocysteine. Some mice were placed on diets containing cholic acid (1%) or cholestyramine (2%) or high-fat diets (60%). Serum and livers were collected during a 24-hour light-dark cycle and analyzed by RNA-seq, metabolomic, and quantitative polymerase chain reaction, immunoblot, and chromatin immunoprecipitation assays. SHP-null mice had altered timing in expression of genes that regulate homocysteine metabolism compared with control mice. Oscillatory production of S-adenosylmethionine, betaine, choline, phosphocholine, glyceophosphocholine, cystathionine, cysteine, hydrogen sulfide, glutathione disulfide, and glutathione, differed between SHP-null mice and control mice. SHP inhibited transcriptional activation of Bhmt and cystathionine γ-lyase by FOXA1. Expression of Bhmt and cystathionine γ-lyase was decreased when mice were fed cholic acid but increased when they were placed on diets containing cholestyramine or high-fat content. Diets containing ethanol or homocysteine induced hyperhomocysteinemia and glucose intolerance in control, but not SHP-null, mice. In BHMT-null and BHMT-null/SHP-null mice fed a control liquid, lipid vacuoles were observed in livers. Ethanol feeding induced accumulation of macrovesicular lipid vacuoles to the greatest extent in BHMT-null and BHMT-null/SHP-null mice. Disruption of Shp in mice alters timing of expression of genes that regulate

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

MicroRNA-132 sensitizes nasopharyngeal carcinoma cells to cisplatin through regulation of forkhead box A1 protein.

PubMed

Li, Yun-Ling; Zhao, Yi-Gang; Chen, Bin; Li, Xiao-Feng

2016-12-01

Chemoresistance in cancer is one of the major hindrances in cisplatin (DPP) treatment for nasopharyngeal carcinoma (NPC). The mechanism of such resistance remains unknown. Therefore, the present study aimed to clarify the mechanism of DDP resistance and attempted to reduce chemoresistance. Here, we found that miR-132, as a tumor suppressor, was poorly expressed in a cisplatin resistant CNE2 cell line (CNE2/DPP) accompanied with a decreased expression of miR-132 and an increased expression of FOXA1 compared with the parental cells CNE2. Exogenous overexpression of miR-132 in CNE2/DPP could sensitize their reaction to the treatment of cisplatin. In addition, FOXA1 knockdown in CNE2/DPP cells increased the chemosensitivity to DPP, suggesting the dependence of FOXA1 regulation in miR-132 activity. Moreover, miR-132 can restore cisplatin treatment response in cisplatin-resistant xenografts in vivo, while FOXA1 protein levels were decreased. In summary, our results provide novel mechanistic insights into the role of miR-132/FOXA1 signaling in the cisplatin resistance of NPC cells. Targeting of miR-132 is a potential therapeutic approach for NPC.

Physiology of bile secretion.

PubMed

Esteller, Alejandro

2008-10-07

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.

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

Fine-Scale Mapping of the FGFR2 Breast Cancer Risk Locus: Putative Functional Variants Differentially Bind FOXA1 and E2F1

PubMed Central

Meyer, Kerstin B.; O’Reilly, Martin; Michailidou, Kyriaki; Carlebur, Saskia; Edwards, Stacey L.; French, Juliet D.; Prathalingham, Radhika; Dennis, Joe; Bolla, Manjeet K.; Wang, Qin; de Santiago, Ines; Hopper, John L.; Tsimiklis, Helen; Apicella, Carmel; Southey, Melissa C.; Schmidt, Marjanka K.; Broeks, Annegien; Van ’t Veer, Laura J.; Hogervorst, Frans B.; Muir, Kenneth; Lophatananon, Artitaya; Stewart-Brown, Sarah; Siriwanarangsan, Pornthep; Fasching, Peter A.; Lux, Michael P.; Ekici, Arif B.; Beckmann, Matthias W.; Peto, Julian; dos Santos Silva, Isabel; Fletcher, Olivia; Johnson, Nichola; Sawyer, Elinor J.; Tomlinson, Ian; Kerin, Michael J.; Miller, Nicola; Marme, Federick; Schneeweiss, Andreas; Sohn, Christof; Burwinkel, Barbara; Guénel, Pascal; Truong, Thérèse; Laurent-Puig, Pierre; Menegaux, Florence; Bojesen, Stig E.; Nordestgaard, Børge G.; Nielsen, Sune F.; Flyger, Henrik; Milne, Roger L.; Zamora, M. Pilar; Arias, Jose I.; Benitez, Javier; Neuhausen, Susan; Anton-Culver, Hoda; Ziogas, Argyrios; Dur, Christina C.; Brenner, Hermann; Müller, Heiko; Arndt, Volker; Stegmaier, Christa; Meindl, Alfons; Schmutzler, Rita K.; Engel, Christoph; Ditsch, Nina; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Nevanlinna, Heli; Muranen, Taru A.; Aittomäki, Kristiina; Blomqvist, Carl; Matsuo, Keitaro; Ito, Hidemi; Iwata, Hiroji; Yatabe, Yasushi; Dörk, Thilo; Helbig, Sonja; Bogdanova, Natalia V.; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Chenevix-Trench, Georgia; Wu, Anna H.; Tseng, Chiu-chen; Van Den Berg, David; Stram, Daniel O.; Lambrechts, Diether; Thienpont, Bernard; Christiaens, Marie-Rose; Smeets, Ann; Chang-Claude, Jenny; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Bonanni, Bernardo; Bernard, Loris; Couch, Fergus J.; Olson, Janet E.; Wang, Xianshu; Purrington, Kristen; Giles, Graham G.; Severi, Gianluca; Baglietto, Laura; McLean, Catriona; Haiman, Christopher A.; Henderson, Brian E.; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Goldberg, Mark S.; Labrèche, France; Dumont, Martine; Teo, Soo-Hwang; Yip, Cheng-Har; Phuah, Sze-Yee; Kristensen, Vessela; Grenaker Alnæs, Grethe; Børresen-Dale, Anne-Lise; Zheng, Wei; Deming-Halverson, Sandra; Shrubsole, Martha; Long, Jirong; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Kauppila, Saila; Andrulis, Irene L.; Knight, Julia A.; Glendon, Gord; Tchatchou, Sandrine; Devilee, Peter; Tollenaar, Robert A.E.M.; Seynaeve, Caroline M.; García-Closas, Montserrat; Figueroa, Jonine; Chanock, Stephen J.; Lissowska, Jolanta; Czene, Kamila; Darabi, Hartef; Eriksson, Kimael; Hooning, Maartje J.; Martens, John W.M.; van den Ouweland, Ans M.W.; van Deurzen, Carolien H.M.; Hall, Per; Li, Jingmei; Liu, Jianjun; Humphreys, Keith; Shu, Xiao-Ou; Lu, Wei; Gao, Yu-Tang; Cai, Hui; Cox, Angela; Reed, Malcolm W.R.; Blot, William; Signorello, Lisa B.; Cai, Qiuyin; Pharoah, Paul D.P.; Ghoussaini, Maya; Harrington, Patricia; Tyrer, Jonathan; Kang, Daehee; Choi, Ji-Yeob; Park, Sue K.; Noh, Dong-Young; Hartman, Mikael; Hui, Miao; Lim, Wei-Yen; Buhari, Shaik A.; Hamann, Ute; Försti, Asta; Rüdiger, Thomas; Ulmer, Hans-Ulrich; Jakubowska, Anna; Lubinski, Jan; Jaworska, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; McKay, James; Vachon, Celine; Slager, Susan; Fostira, Florentia; Pilarski, Robert; Shen, Chen-Yang; Hsiung, Chia-Ni; Wu, Pei-Ei; Hou, Ming-Feng; Swerdlow, Anthony; Ashworth, Alan; Orr, Nick; Schoemaker, Minouk J.; Ponder, Bruce A.J.; Dunning, Alison M.; Easton, Douglas F.

2013-01-01

The 10q26 locus in the second intron of FGFR2 is the locus most strongly associated with estrogen-receptor-positive breast cancer in genome-wide association studies. We conducted fine-scale mapping in case-control studies genotyped with a custom chip (iCOGS), comprising 41 studies (n = 89,050) of European ancestry, 9 Asian ancestry studies (n = 13,983), and 2 African ancestry studies (n = 2,028) from the Breast Cancer Association Consortium. We identified three statistically independent risk signals within the locus. Within risk signals 1 and 3, genetic analysis identified five and two variants, respectively, highly correlated with the most strongly associated SNPs. By using a combination of genetic fine mapping, data on DNase hypersensitivity, and electrophoretic mobility shift assays to study protein-DNA binding, we identified rs35054928, rs2981578, and rs45631563 as putative functional SNPs. Chromatin immunoprecipitation showed that FOXA1 preferentially bound to the risk-associated allele (C) of rs2981578 and was able to recruit ERα to this site in an allele-specific manner, whereas E2F1 preferentially bound the risk variant of rs35054928. The risk alleles were preferentially found in open chromatin and bound by Ser5 phosphorylated RNA polymerase II, suggesting that the risk alleles are associated with changes in transcription. Chromatin conformation capture demonstrated that the risk region was able to interact with the promoter of FGFR2, the likely target gene of this risk region. A role for FOXA1 in mediating breast cancer susceptibility at this locus is consistent with the finding that the FGFR2 risk locus primarily predisposes to estrogen-receptor-positive disease. PMID:24290378

Dissecting the regulation of bile-induced biofilm formation in Staphylococcus aureus.

PubMed

Ulluwishewa, Dulantha; Wang, Liang; Pereira, Callen; Flynn, Stephanie; Cain, Elizabeth; Stick, Stephen; Reen, F Jerry; Ramsay, Joshua P; O'Gara, Fergal

2016-08-01

Aspiration of bile into the cystic fibrosis (CF) lung has emerged as a prognostic factor for reduced microbial lung biodiversity and the establishment of often fatal, chronic pathogen infections. Staphylococcus aureus is one of the earliest pathogens detected in the lungs of children with CF, and once established as a chronic infection, strategies for its eradication become limited. Several lung pathogens are stimulated to produce biofilms in vitro in the presence of bile. In this study, we further investigated the effects of bile on S. aureus biofilm formation. Most clinical S. aureus strains and the laboratory strain RN4220 were stimulated to form biofilms with sub-inhibitory concentrations of bovine bile. Additionally, we observed bile-induced sensitivity to aminoglycosides, which we exploited in a bursa aurealis transposon screen to isolate mutants reduced in aminoglycoside sensitivity and augmented in bile-induced biofilm formation. We identified five mutants that exhibited hypersensitivity to bile with respect to bile-induced biofilm formation, three of which carried transposon insertions within gene clusters involved in wall teichoic acid (WTA) biosynthesis or transport. Strain TM4 carried an insertion between the divergently oriented tagH and tagG genes, which encode the putative WTA membrane translocation apparatus. Ectopic expression of tagG in TM4 restored a wild-type bile-induced biofilm response, suggesting that reduced translocation of WTA in TM4 induced sensitivity to bile and enhanced the bile-induced biofilm formation response. We propose that WTA may be important for protecting S. aureus against exposure to bile and that bile-induced biofilm formation may be an evolved response to protect cells from bile-induced cell lysis.

[Analysis on replacement of traditional Chinese medicine bear bile with bile acids based on drug properties].

PubMed

Yuan, Bin; Ren, Ying-Long; Ma, Li; Gu, Hao; Wang, Yun; Qiao, Yan-Jiang

2014-02-01

To discuss the rationality of the clinical replacement of traditional Chinese medicine (TCM) bear bile with bile acid constituents, and analyze the difference between these constituents and bear bile in drug properties. Summarizing the drug properties of bear bile by reference to medical literatures for drug properties of TCM bear bile and Science of Traditional Chinese Medicine (China Press of Traditional Chinese Medicine, 2007). Analyzing and summarizing the pharmacological effects of main bile acid constituents according to relevant literatures for studies on pharmacological effects of main bile acid constituents in CNKI database. Predicating the drug properties of these bile acid constituents by using the drug property predication model established by the study group according the pharmacological effects of main bile acid constituents in the paper, and compare the prediction results with the drug properties of bear bile. Bile acid constituents in bear bile were mostly cold in property, bitter in taste, and the combination of their drug properties could reflect the combined drug properties of bear bile. All of these bile acid constituents in bear bile could show part of effects of bear bile. Attention shall be given to regulate the medication scheme in clinical application according to actual conditions.

Androgen Receptor and its Splice Variant, AR-V7, Differentially Regulate FOXA1 Sensitive Genes in LNCaP Prostate Cancer Cells

PubMed Central

Krause, William C.; Shafi, Ayesha A.; Nakka, Manjula; Weigel, Nancy L.

2014-01-01

Prostate cancer (PCa) is an androgen-dependent disease, and tumors that are resistant to androgen ablation therapy often remain androgen receptor (AR) dependent. Among the contributors to castration-resistant PCa are AR splice variants that lack the ligand-binding domain (LBD). Instead, they have small amounts of unique sequence derived from cryptic exons or from out of frame translation. The AR-V7 (or AR3) variant is constitutively active and is expressed under conditions consistent with CRPC. AR-V7 is reported to regulate a transcriptional program that is similar but not identical to that of AR. However, it is unknown whether these differences are due to the unique sequence in AR-V7, or simply to loss of the LBD. To examine transcriptional regulation by AR-V7, we have used lentiviruses encoding AR-V7 (amino acids 1-627 of AR with the 16 amino acids unique to the variant) to prepare a derivative of the androgen-dependent LNCaP cells with inducible expression of AR-V7. An additional cell line was generated with regulated expression of AR-NTD (amino acids 1-660 of AR); this mutant lacks the LBD but does not have the AR-V7 specific sequence. We find that AR and AR-V7 have distinct activities on target genes that are co-regulated by FOXA1. Transcripts regulated by AR-V7 were similarly regulated by AR-NTD, indicating that loss of the LBD is sufficient for the observed differences. Differential regulation of target genes correlates with preferential recruitment of AR or AR-V7 to specific cis-regulatory DNA sequences providing an explanation for some of the observed differences in target gene regulation. PMID:25008967

The roles of bile acids and sphingosine-1-phosphate signaling in the hepatobiliary diseases

PubMed Central

Nagahashi, Masayuki; Yuza, Kizuki; Hirose, Yuki; Nakajima, Masato; Ramanathan, Rajesh; Hait, Nitai C.; Hylemon, Phillip B.; Zhou, Huiping; Takabe, Kazuaki; Wakai, Toshifumi

2016-01-01

Based on research carried out over the last decade, it has become increasingly evident that bile acids act not only as detergents, but also as important signaling molecules that exert various biological effects via activation of specific nuclear receptors and cell signaling pathways. Bile acids also regulate the expression of numerous genes encoding enzymes and proteins involved in the synthesis and metabolism of bile acids, glucose, fatty acids, and lipoproteins, as well as energy metabolism. Receptors activated by bile acids include, farnesoid X receptor α, pregnane X receptor, vitamin D receptor, and G protein-coupled receptors, TGR5, muscarinic receptor 2, and sphingosine-1-phosphate receptor (S1PR)2. The ligand of S1PR2, sphingosine-1-phosphate (S1P), is a bioactive lipid mediator that regulates various physiological and pathophysiological cellular processes. We have recently reported that conjugated bile acids, via S1PR2, activate and upregulate nuclear sphingosine kinase 2, increase nuclear S1P, and induce genes encoding enzymes and transporters involved in lipid and sterol metabolism in the liver. Here, we discuss the role of bile acids and S1P signaling in the regulation of hepatic lipid metabolism and in hepatobiliary diseases. PMID:27459945

Bile Acids Down-Regulate Caveolin-1 in Esophageal Epithelial Cells through Sterol Responsive Element-Binding Protein

PubMed Central

Prade, Elke; Tobiasch, Moritz; Hitkova, Ivana; Schäffer, Isabell; Lian, Fan; Xing, Xiangbin; Tänzer, Marc; Rauser, Sandra; Walch, Axel; Feith, Marcus; Post, Stefan; Röcken, Christoph; Schmid, Roland M.; Ebert, Matthias P.A.

2012-01-01

Bile acids are synthesized from cholesterol and are major risk factors for Barrett adenocarcinoma (BAC) of the esophagus. Caveolin-1 (Cav1), a scaffold protein of membrane caveolae, is transcriptionally regulated by cholesterol via sterol-responsive element-binding protein-1 (SREBP1). Cav1 protects squamous epithelia by controlling cell growth and stabilizing cell junctions and matrix adhesion. Cav1 is frequently down-regulated in human cancers; however, the molecular mechanisms that lead to this event are unknown. We show that the basal layer of the nonneoplastic human esophageal squamous epithelium expressed Cav1 mainly at intercellular junctions. In contrast, Cav1 was lost in 95% of tissue specimens from BAC patients (n = 100). A strong cytoplasmic expression of Cav1 correlated with poor survival in a small subgroup (n = 5) of BAC patients, and stable expression of an oncogenic Cav1 variant (Cav1-P132L) in the human BAC cell line OE19 promoted proliferation. Cav1 was also detectable in immortalized human squamous epithelial, Barrett esophagus (CPC), and squamous cell carcinoma cells (OE21), but was low in BAC cell lines (OE19, OE33). Mechanistically, bile acids down-regulated Cav1 expression by inhibition of the proteolytic cleavage of 125-kDa pre-SREBP1 from the endoplasmic reticulum/Golgi apparatus and nuclear translocation of active 68-kDa SREBP1. This block in SREBP1's posttranslational processing impaired transcriptional activation of SREBP1 response elements in the proximal human Cav1 promoter. Cav1 was also down-regulated in esophagi from C57BL/6 mice on a diet enriched with 1% (wt/wt) chenodeoxycholic acid. Mice deficient for Cav1 or the nuclear bile acid receptor farnesoid X receptor showed hyperplasia and hyperkeratosis of the basal cell layer of esophageal epithelia, respectively. These data indicate that bile acid-mediated down-regulation of Cav1 marks early changes in the squamous epithelium, which may contribute to onset of Barrett esophagus

Dietary fish oil regulates gene expression of cholesterol and bile acid transporters in mice.

PubMed

Kamisako, Toshinori; Tanaka, Yuji; Ikeda, Takanori; Yamamoto, Kazuo; Ogawa, Hiroshi

2012-03-01

  Fish oil rich in n-3 polyunsaturated fatty acids is known to affect hepatic lipid metabolism. Several studies have demonstrated that fish oil may affect the bile acid metabolism as well as lipid metabolism, whereas only scarce data are available. The aim of this study was to investigate the effect of fish oil on the gene expression of the transporters and enzymes related to bile acid as well as lipid metabolism in the liver and small intestine.   Seven-week old male C57BL/6 mice were fed diets enriched in 10% soybean oil or 10% fish oil for 4 weeks. After 4 weeks, blood, liver and small intestine were obtained.   Hepatic mRNA expression of lipids (Abcg5/8, multidrug resistance gene product 2) and bile acids transporters (bile salt export pump, multidrug resistance associated protein 2 and 3, organic solute transporter α) was induced in fish oil-fed mice. Hepatic Cyp8b1, Cyp27a1 and bile acid CoA : amino acid N-acyltransferase were increased in fish oil-fed mice compared with soybean-oil fed mice. Besides, intestinal cholesterol (Abcg5/8) and bile acid transporters (multidrug resistance associated protein 2 and organic solute transporter α) were induced in fish oil-fed mice.   Fish oil induced the expression of cholesterol and bile acid transporters not only in liver but in intestine. The upregulation of Abcg5/g8 by fish oil is caused by an increase in cellular 27-HOC through Cyp27a1 induction. The hepatic induction of bile acid synthesis through Cyp27a1 may upregulate expression of bile acid transporters in both organs. © 2012 The Japan Society of Hepatology.

Bile acid-FXRα pathways regulate male sexual maturation in mice

PubMed Central

Vega, Aurélie; Sédes, Lauriane; Rouaisnel, Betty; de Haze, Angélique; Baron, Silvère; Schoonjans, Kristina; Caira, Françoise; Volle, David H.

2016-01-01

The bile acid receptor Farnesol-X-Receptor alpha (FRXα) is a member of the nuclear receptor superfamily. FRXα is expressed in the interstitial compartment of the adult testes, which contain the Leydig cells. In adult, short term treatment (12 hours) with FRXα agonist inhibits the expression of steroidogenic genes via the induction of the Small heterodimer partner (SHP). However the consequences of FRXα activation on testicular pathophysiology have never been evaluated. We demonstrate here that mice fed a diet supplemented with bile acid during pubertal age show increased incidence of infertility. This is associated with altered differentiation and increase apoptosis of germ cells due to lower testosterone levels. At the molecular level, next to the repression of basal steroidogenesis via the induction expression of Shp and Dax-1, two repressors of steroidogenesis, the main action of the BA-FRXα signaling is through lowering the Leydig cell sensitivity to the hypothalamo-pituitary axis, the main regulator of testicular endocrine function. In conclusion, BA-FRXα signaling is a critical actor during sexual maturation. PMID:26848619

Fine-scale mapping of the FGFR2 breast cancer risk locus: putative functional variants differentially bind FOXA1 and E2F1.

PubMed

Meyer, Kerstin B; O'Reilly, Martin; Michailidou, Kyriaki; Carlebur, Saskia; Edwards, Stacey L; French, Juliet D; Prathalingham, Radhika; Dennis, Joe; Bolla, Manjeet K; Wang, Qin; de Santiago, Ines; Hopper, John L; Tsimiklis, Helen; Apicella, Carmel; Southey, Melissa C; Schmidt, Marjanka K; Broeks, Annegien; Van 't Veer, Laura J; Hogervorst, Frans B; Muir, Kenneth; Lophatananon, Artitaya; Stewart-Brown, Sarah; Siriwanarangsan, Pornthep; Fasching, Peter A; Lux, Michael P; Ekici, Arif B; Beckmann, Matthias W; Peto, Julian; Dos Santos Silva, Isabel; Fletcher, Olivia; Johnson, Nichola; Sawyer, Elinor J; Tomlinson, Ian; Kerin, Michael J; Miller, Nicola; Marme, Federick; Schneeweiss, Andreas; Sohn, Christof; Burwinkel, Barbara; Guénel, Pascal; Truong, Thérèse; Laurent-Puig, Pierre; Menegaux, Florence; Bojesen, Stig E; Nordestgaard, Børge G; Nielsen, Sune F; Flyger, Henrik; Milne, Roger L; Zamora, M Pilar; Arias, Jose I; Benitez, Javier; Neuhausen, Susan; Anton-Culver, Hoda; Ziogas, Argyrios; Dur, Christina C; Brenner, Hermann; Müller, Heiko; Arndt, Volker; Stegmaier, Christa; Meindl, Alfons; Schmutzler, Rita K; Engel, Christoph; Ditsch, Nina; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Nevanlinna, Heli; Muranen, Taru A; Aittomäki, Kristiina; Blomqvist, Carl; Matsuo, Keitaro; Ito, Hidemi; Iwata, Hiroji; Yatabe, Yasushi; Dörk, Thilo; Helbig, Sonja; Bogdanova, Natalia V; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M; Chenevix-Trench, Georgia; Wu, Anna H; Tseng, Chiu-Chen; Van Den Berg, David; Stram, Daniel O; Lambrechts, Diether; Thienpont, Bernard; Christiaens, Marie-Rose; Smeets, Ann; Chang-Claude, Jenny; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Bonanni, Bernardo; Bernard, Loris; Couch, Fergus J; Olson, Janet E; Wang, Xianshu; Purrington, Kristen; Giles, Graham G; Severi, Gianluca; Baglietto, Laura; McLean, Catriona; Haiman, Christopher A; Henderson, Brian E; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Goldberg, Mark S; Labrèche, France; Dumont, Martine; Teo, Soo-Hwang; Yip, Cheng-Har; Phuah, Sze-Yee; Kristensen, Vessela; Grenaker Alnæs, Grethe; Børresen-Dale, Anne-Lise; Zheng, Wei; Deming-Halverson, Sandra; Shrubsole, Martha; Long, Jirong; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Kauppila, Saila; Andrulis, Irene L; Knight, Julia A; Glendon, Gord; Tchatchou, Sandrine; Devilee, Peter; Tollenaar, Robert A E M; Seynaeve, Caroline M; García-Closas, Montserrat; Figueroa, Jonine; Chanock, Stephen J; Lissowska, Jolanta; Czene, Kamila; Darabi, Hartef; Eriksson, Kimael; Hooning, Maartje J; Martens, John W M; van den Ouweland, Ans M W; van Deurzen, Carolien H M; Hall, Per; Li, Jingmei; Liu, Jianjun; Humphreys, Keith; Shu, Xiao-Ou; Lu, Wei; Gao, Yu-Tang; Cai, Hui; Cox, Angela; Reed, Malcolm W R; Blot, William; Signorello, Lisa B; Cai, Qiuyin; Pharoah, Paul D P; Ghoussaini, Maya; Harrington, Patricia; Tyrer, Jonathan; Kang, Daehee; Choi, Ji-Yeob; Park, Sue K; Noh, Dong-Young; Hartman, Mikael; Hui, Miao; Lim, Wei-Yen; Buhari, Shaik A; Hamann, Ute; Försti, Asta; Rüdiger, Thomas; Ulmer, Hans-Ulrich; Jakubowska, Anna; Lubinski, Jan; Jaworska, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; McKay, James; Vachon, Celine; Slager, Susan; Fostira, Florentia; Pilarski, Robert; Shen, Chen-Yang; Hsiung, Chia-Ni; Wu, Pei-Ei; Hou, Ming-Feng; Swerdlow, Anthony; Ashworth, Alan; Orr, Nick; Schoemaker, Minouk J; Ponder, Bruce A J; Dunning, Alison M; Easton, Douglas F

2013-12-05

The 10q26 locus in the second intron of FGFR2 is the locus most strongly associated with estrogen-receptor-positive breast cancer in genome-wide association studies. We conducted fine-scale mapping in case-control studies genotyped with a custom chip (iCOGS), comprising 41 studies (n = 89,050) of European ancestry, 9 Asian ancestry studies (n = 13,983), and 2 African ancestry studies (n = 2,028) from the Breast Cancer Association Consortium. We identified three statistically independent risk signals within the locus. Within risk signals 1 and 3, genetic analysis identified five and two variants, respectively, highly correlated with the most strongly associated SNPs. By using a combination of genetic fine mapping, data on DNase hypersensitivity, and electrophoretic mobility shift assays to study protein-DNA binding, we identified rs35054928, rs2981578, and rs45631563 as putative functional SNPs. Chromatin immunoprecipitation showed that FOXA1 preferentially bound to the risk-associated allele (C) of rs2981578 and was able to recruit ERα to this site in an allele-specific manner, whereas E2F1 preferentially bound the risk variant of rs35054928. The risk alleles were preferentially found in open chromatin and bound by Ser5 phosphorylated RNA polymerase II, suggesting that the risk alleles are associated with changes in transcription. Chromatin conformation capture demonstrated that the risk region was able to interact with the promoter of FGFR2, the likely target gene of this risk region. A role for FOXA1 in mediating breast cancer susceptibility at this locus is consistent with the finding that the FGFR2 risk locus primarily predisposes to estrogen-receptor-positive disease. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

The bile acid composition of crane gallbladder bile

USGS Publications Warehouse

Serafin, J.A.

1983-01-01

1. The biliary bile acids of the whooping crane (Grus americana) and the Florida sandhill crane (G. canadensis pratensis) have been examined.2. Cholic acid (CA), chenodeoxycholic acid (CDOCA) and lithocholic acid were found in bile from both species of these North American cranes.3. CDOCA and CA were the primary bile acids in both species, together constituting 70% or more of the bile acids by weight.4. The primary bile acids of cranes appear to be the same as those that have been identified in other avian species.

Calcium carbonate in human gallstones and total CO2 in bile.

PubMed Central

Sutor, D J; Wilkie, L I

1978-01-01

Measurement of total CO2 concentrations in bile from patients undergoing cholecystectomy because of gallstones has shown that the presence of calcium carbonate in the stones can be associated with a raised total CO2 concentration in the common duct bile. In bile from functioning and poorly-functioning gallbladders, total CO2 was nearly always related to pH irrespective of stone composition. PMID:631643

Nuclear receptors in bile acid metabolism

PubMed Central

Li, Tiangang; Chiang, John Y. L.

2013-01-01

Bile acids are signaling molecules that activate nuclear receptors, such as farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, and vitamin D receptor, and play a critical role in the regulation of lipid, glucose, energy, and drug metabolism. These xenobiotic/endobiotic-sensing nuclear receptors regulate phase I oxidation, phase II conjugation, and phase III transport in bile acid and drug metabolism in the digestive system. Integration of bile acid metabolism with drug metabolism controls absorption, transport, and metabolism of nutrients and drugs to maintain metabolic homeostasis and also protects against liver injury, inflammation, and related metabolic diseases, such as nonalcoholic fatty liver disease, diabetes, and obesity. Bile-acid–based drugs targeting nuclear receptors are in clinical trials for treating cholestatic liver diseases and fatty liver disease. PMID:23330546

Bile salt tolerance of Lactococcus lactis is enhanced by expression of bile salt hydrolase thereby producing less bile acid in the cells.

PubMed

Bi, Jie; Liu, Song; Du, Guocheng; Chen, Jian

2016-04-01

Changes of bile salt tolerance, morphology and amount of bile acid within cells were studied to evaluate the exact effects of bile salt hydrolase (BSH) on bile salt tolerance of microorganism. The effect of BSHs on the bile salt tolerance of Lactococcus lactis was examined by expressing two BSHs (BSH1 and BSH2). Growth of L. lactis expressing BSH1 or BSH2 was better under bile salt stress compared to wild-type L. lactis. As indicated by transmission electron microscopy, bile acids released by the action of BSH induced the formation of micelles around the membrane surface of cells subject to conjugated bile salt stress. A similar micelle containing bile acid was observed in the cytoplasm by liquid chromatography-mass spectrometry. BSH1 produced fewer bile acid micelles in the cytoplasm and achieved better cell growth of L. lactis compared to BSH2. Expression of BSH improved bile salt tolerance of L. lactis but excessive production by BSH of bile acid micelles in the cytoplasm inhibited cell growth.

Circadian dysregulation disrupts bile acid homeostasis

USDA-ARS?s Scientific Manuscript database

Bile acids are potentially toxic compounds and their levels of hepatic production, uptake, and export are tightly regulated by many inputs, including circadian rhythm. We tested the impact of disrupting the peripheral circadian clock on integral steps of bile acid homeostasis. Both restricted feedi...

Isolation and characterization of chicken bile matrix metalloproteinase.

PubMed

Packialakshmi, B; Liyanage, R; Rasaputra, K S; Lay, Jackson O; Rath, N C

2014-06-01

Avian bile is rich in matrix metalloproteinases (MMP), the enzymes that cleave extracellular matrix proteins such as collagens and proteoglycans. Changes in bile MMP expression have been correlated with hepatic and gall bladder pathologies, but the significance of their expression in normal, healthy bile is not understood. We hypothesized that the MMP in bile may aid the digestion of native collagens that are resistant to conventional gastric proteases. Hence, the objective of this study was to characterize the bile MMP and check its regulation in association with dietary factors. We used substrate zymography, azocoll protease assay, and gelatin affinity chromatography to identify and purify the MMP from chicken bile. Using zymography and SDS PAGE, 5 bands at 70, 64, 58, 50, and 42 kDa were detected. The bands corresponding to 64, 50, and 42 kDa were identified as MMP2 using trypsin in-gel digestion and matrix-assisted laser desorption time-of-flight mass spectrometry and peptide mass fingerprinting. Chickens fed diets containing gelatin supplements showed higher levels of MMP expression in the bile by both azocoll assay and zymography. We conclude that the bile MMP may be associated with the digestion of collagens and other extracellular matrix proteins in avian diets. Poultry Science Association Inc.

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

Xenobiotic, Bile Acid, and Cholesterol Transporters: Function and Regulation

PubMed Central

Aleksunes, Lauren M.

2010-01-01

Transporters influence the disposition of chemicals within the body by participating in absorption, distribution, and elimination. Transporters of the solute carrier family (SLC) comprise a variety of proteins, including organic cation transporters (OCT) 1 to 3, organic cation/carnitine transporters (OCTN) 1 to 3, organic anion transporters (OAT) 1 to 7, various organic anion transporting polypeptide isoforms, sodium taurocholate cotransporting polypeptide, apical sodium-dependent bile acid transporter, peptide transporters (PEPT) 1 and 2, concentrative nucleoside transporters (CNT) 1 to 3, equilibrative nucleoside transporter (ENT) 1 to 3, and multidrug and toxin extrusion transporters (MATE) 1 and 2, which mediate the uptake (except MATEs) of organic anions and cations as well as peptides and nucleosides. Efflux transporters of the ATP-binding cassette superfamily, such as ATP-binding cassette transporter A1 (ABCA1), multidrug resistance proteins (MDR) 1 and 2, bile salt export pump, multidrug resistance-associated proteins (MRP) 1 to 9, breast cancer resistance protein, and ATP-binding cassette subfamily G members 5 and 8, are responsible for the unidirectional export of endogenous and exogenous substances. Other efflux transporters [ATPase copper-transporting β polypeptide (ATP7B) and ATPase class I type 8B member 1 (ATP8B1) as well as organic solute transporters (OST) α and β] also play major roles in the transport of some endogenous chemicals across biological membranes. This review article provides a comprehensive overview of these transporters (both rodent and human) with regard to tissue distribution, subcellular localization, and substrate preferences. Because uptake and efflux transporters are expressed in multiple cell types, the roles of transporters in a variety of tissues, including the liver, kidneys, intestine, brain, heart, placenta, mammary glands, immune cells, and testes are discussed. Attention is also placed upon a variety of regulatory

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

Bile Stress Response in Listeria monocytogenes LO28: Adaptation, Cross-Protection, and Identification of Genetic Loci Involved in Bile Resistance

PubMed Central

Begley, Máire; Gahan, Cormac G. M.; Hill, Colin

2002-01-01

Bile is one of many barriers that Listeria monocytogenes must overcome in the human gastrointestinal tract in order to infect and cause disease. We demonstrated that stationary-phase cultures of L. monocytogenes LO28 were able to tolerate concentrations of bovine, porcine, and human bile and bile acids well in excess of those encountered in vivo. Strain LO28 was relatively bile resistant compared with other clinical isolates of L. monocytogenes, as well as with Listeria innocua, Salmonella enterica serovar Typhimurium LT2, and Lactobacillus sakei. While exponential-phase L. monocytogenes LO28 cells were exquisitely sensitive to unconjugated bile acids, prior adaptation to sublethal levels of bile acids or heterologous stresses, such as acid, heat, salt, or sodium dodecyl sulfate (SDS), significantly enhanced bile resistance. This adaptive response was independent of protein synthesis, and in the cases of bile and SDS adaptation, occurred in seconds. In order to identify genetic loci involved in the bile tolerance phenotype of L. monocytogenes LO28, transposon (Tn917) and plasmid (pORI19) integration banks were screened for bile-sensitive mutants. The disrupted genes included a homologue of the capA locus required for capsule formation in Bacillus anthracis; a gene encoding the transcriptional regulator ZurR; a homologue of an Escherichia coli gene, lytB, involved in isoprenoid biosynthesis; a gene encoding a homologue of the Bacillus subtilis membrane protein YxiO; and a gene encoding an amino acid transporter with a putative role in pH homeostasis, gadE. Interestingly, all of the identified loci play putative roles in maintenance of the cell envelope or in stress responses. PMID:12450822

A new mechanism for bile acid diarrhea: defective feedback inhibition of bile acid biosynthesis.

PubMed

Walters, Julian R F; Tasleem, Ali M; Omer, Omer S; Brydon, W Gordon; Dew, Tracy; le Roux, Carel W

2009-11-01

Primary (idiopathic) bile acid malabsorption (BAM) is a common, yet underrecognized, chronic diarrheal syndrome. Diagnosis is difficult without selenium homocholic acid taurine (SeHCAT) testing. The diarrhea results from excess colonic bile acids, but the pathogenesis is unclear. Fibroblast growth factor 19 (FGF19), produced in the ileum in response to bile acid absorption, regulates hepatic bile acid synthesis. We proposed that FGF19 is involved in bile acid diarrhea and measured its levels in patients with BAM. Blood was collected from fasting patients with chronic diarrhea; BAM was diagnosed by SeHCAT. Serum FGF19 was measured by enzyme-linked immunosorbent assay. Serum 7alpha-hydroxy-4-cholesten-3-one (C4) was determined using high-performance liquid chromatography, to quantify bile acid synthesis. Data were compared between patients and subjects without diarrhea (controls). Samples were taken repeatedly after meals from several subjects. The median C4 level was significantly higher in patients with primary BAM than in controls (51 vs 18 ng/mL; P < .0001). The median FGF19 level was significantly lower in patients with BAM (120 vs 231 pg/mL; P < .0005). There was a significant inverse relationship between FGF19 and C4 levels (P < .0004). Low levels of FGF19 were also found in patients with postcholecystectomy and secondary bile acid diarrhea. Abnormal patterns of FGF19 levels were observed throughout the day in some patients with primary BAM. Patients with BAM have reduced serum FGF19 which may be useful in diagnosis. We propose a mechanism whereby impaired FGF19 feedback inhibition causes excessive bile acid synthesis that exceeds the normal capacity for ileal reabsorption, producing bile acid diarrhea.

Intestinal transport and metabolism of bile acids

PubMed Central

Dawson, Paul A.; Karpen, Saul J.

2015-01-01

In addition to their classical roles as detergents to aid in the process of digestion, bile acids have been identified as important signaling molecules that function through various nuclear and G protein-coupled receptors to regulate a myriad of cellular and molecular functions across both metabolic and nonmetabolic pathways. Signaling via these pathways will vary depending on the tissue and the concentration and chemical structure of the bile acid species. Important determinants of the size and composition of the bile acid pool are their efficient enterohepatic recirculation, their host and microbial metabolism, and the homeostatic feedback mechanisms connecting hepatocytes, enterocytes, and the luminal microbiota. This review focuses on the mammalian intestine, discussing the physiology of bile acid transport, the metabolism of bile acids in the gut, and new developments in our understanding of how intestinal metabolism, particularly by the gut microbiota, affects bile acid signaling. PMID:25210150

Bile acids: regulation of apoptosis by ursodeoxycholic acid

PubMed Central

Amaral, Joana D.; Viana, Ricardo J. S.; Ramalho, Rita M.; Steer, Clifford J.; Rodrigues, Cecília M. P.

2009-01-01

Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases. PMID:19417220

Bile acids: regulation of apoptosis by ursodeoxycholic acid.

PubMed

Amaral, Joana D; Viana, Ricardo J S; Ramalho, Rita M; Steer, Clifford J; Rodrigues, Cecília M P

2009-09-01

Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases.

Effects of conventional and a novel colonic-release bile acid sequestrant, A3384, on fibroblast growth factor 19 and bile acid metabolism in healthy volunteers and patients with bile acid diarrhoea.

PubMed

Appleby, R N; Bajor, A; Gillberg, P-G; Graffner, H; Simrén, M; Ung, K A; Walters, Jrf

2017-04-01

Primary bile acid diarrhoea (BAD) is associated with increased bile acid synthesis and low fibroblast growth factor 19 (FGF19). Bile acid sequestrants are used as therapy, but are poorly tolerated and may exacerbate FGF19 deficiency. The purpose of this study was to evaluate the pharmacological effects of conventional sequestrants and a colonic-release formulation preparation of colestyramine (A3384) on bile acid metabolism and bowel function in patients with BAD. Patients with seven-day 75 selenium-homocholic acid taurine (SeHCAT) scan retention <10% were randomised in a double-blind protocol to two weeks treatment with twice-daily A3384 250 mg ( n  = 6), 1 g ( n  = 7) or placebo ( n  = 6). Thirteen patients were taking conventional sequestrants at the start of the study. Symptoms were recorded and serum FGF19 and 7α-hydroxy-4-cholesten-3-one (C4) measured. Median serum FGF19 on conventional sequestrant treatment was 28% lower than baseline values in BAD ( p  < 0.05). C4 on conventional sequestrant treatment was 58% higher in BAD ( p  < 0.001). No changes were seen on starting or withdrawing A3384. A3384 improved diarrhoeal symptoms, with a median reduction of 2.2 points on a 0-10 Likert scale compared to placebo, p  < 0.05. Serum FGF19 was suppressed and bile acid production up-regulated on conventional bile acid sequestrants, but not with A3384. This colonic-release formulation of colestyramine produced symptomatic benefit in patients with BAD.

Effects of conventional and a novel colonic-release bile acid sequestrant, A3384, on fibroblast growth factor 19 and bile acid metabolism in healthy volunteers and patients with bile acid diarrhoea

PubMed Central

Bajor, A; Gillberg, P-G; Graffner, H; Simrén, M; Ung, KA; Walters, JRF

2016-01-01

Background Primary bile acid diarrhoea (BAD) is associated with increased bile acid synthesis and low fibroblast growth factor 19 (FGF19). Bile acid sequestrants are used as therapy, but are poorly tolerated and may exacerbate FGF19 deficiency. Aim The purpose of this study was to evaluate the pharmacological effects of conventional sequestrants and a colonic-release formulation preparation of colestyramine (A3384) on bile acid metabolism and bowel function in patients with BAD. Methods Patients with seven-day 75selenium-homocholic acid taurine (SeHCAT) scan retention <10% were randomised in a double-blind protocol to two weeks treatment with twice-daily A3384 250 mg (n = 6), 1 g (n = 7) or placebo (n = 6). Thirteen patients were taking conventional sequestrants at the start of the study. Symptoms were recorded and serum FGF19 and 7α-hydroxy-4-cholesten-3-one (C4) measured. Results Median serum FGF19 on conventional sequestrant treatment was 28% lower than baseline values in BAD (p < 0.05). C4 on conventional sequestrant treatment was 58% higher in BAD (p < 0.001). No changes were seen on starting or withdrawing A3384. A3384 improved diarrhoeal symptoms, with a median reduction of 2.2 points on a 0–10 Likert scale compared to placebo, p < 0.05. Conclusions Serum FGF19 was suppressed and bile acid production up-regulated on conventional bile acid sequestrants, but not with A3384. This colonic-release formulation of colestyramine produced symptomatic benefit in patients with BAD. PMID:28507750

Brachyury, Foxa2 and the cis-Regulatory Origins of the Notochord

PubMed Central

José-Edwards, Diana S.; Oda-Ishii, Izumi; Kugler, Jamie E.; Passamaneck, Yale J.; Katikala, Lavanya; Nibu, Yutaka; Di Gregorio, Anna

2015-01-01

A main challenge of modern biology is to understand how specific constellations of genes are activated to differentiate cells and give rise to distinct tissues. This study focuses on elucidating how gene expression is initiated in the notochord, an axial structure that provides support and patterning signals to embryos of humans and all other chordates. Although numerous notochord genes have been identified, the regulatory DNAs that orchestrate development and propel evolution of this structure by eliciting notochord gene expression remain mostly uncharted, and the information on their configuration and recurrence is still quite fragmentary. Here we used the simple chordate Ciona for a systematic analysis of notochord cis-regulatory modules (CRMs), and investigated their composition, architectural constraints, predictive ability and evolutionary conservation. We found that most Ciona notochord CRMs relied upon variable combinations of binding sites for the transcription factors Brachyury and/or Foxa2, which can act either synergistically or independently from one another. Notably, one of these CRMs contains a Brachyury binding site juxtaposed to an (AC) microsatellite, an unusual arrangement also found in Brachyury-bound regulatory regions in mouse. In contrast, different subsets of CRMs relied upon binding sites for transcription factors of widely diverse families. Surprisingly, we found that neither intra-genomic nor interspecific conservation of binding sites were reliably predictive hallmarks of notochord CRMs. We propose that rather than obeying a rigid sequence-based cis-regulatory code, most notochord CRMs are rather unique. Yet, this study uncovered essential elements recurrently used by divergent chordates as basic building blocks for notochord CRMs. PMID:26684323

Brachyury, Foxa2 and the cis-Regulatory Origins of the Notochord.

PubMed

José-Edwards, Diana S; Oda-Ishii, Izumi; Kugler, Jamie E; Passamaneck, Yale J; Katikala, Lavanya; Nibu, Yutaka; Di Gregorio, Anna

2015-12-01

A main challenge of modern biology is to understand how specific constellations of genes are activated to differentiate cells and give rise to distinct tissues. This study focuses on elucidating how gene expression is initiated in the notochord, an axial structure that provides support and patterning signals to embryos of humans and all other chordates. Although numerous notochord genes have been identified, the regulatory DNAs that orchestrate development and propel evolution of this structure by eliciting notochord gene expression remain mostly uncharted, and the information on their configuration and recurrence is still quite fragmentary. Here we used the simple chordate Ciona for a systematic analysis of notochord cis-regulatory modules (CRMs), and investigated their composition, architectural constraints, predictive ability and evolutionary conservation. We found that most Ciona notochord CRMs relied upon variable combinations of binding sites for the transcription factors Brachyury and/or Foxa2, which can act either synergistically or independently from one another. Notably, one of these CRMs contains a Brachyury binding site juxtaposed to an (AC) microsatellite, an unusual arrangement also found in Brachyury-bound regulatory regions in mouse. In contrast, different subsets of CRMs relied upon binding sites for transcription factors of widely diverse families. Surprisingly, we found that neither intra-genomic nor interspecific conservation of binding sites were reliably predictive hallmarks of notochord CRMs. We propose that rather than obeying a rigid sequence-based cis-regulatory code, most notochord CRMs are rather unique. Yet, this study uncovered essential elements recurrently used by divergent chordates as basic building blocks for notochord CRMs.

Specific bile acids inhibit hepatic fatty acid uptake

PubMed Central

Nie, Biao; Park, Hyo Min; Kazantzis, Melissa; Lin, Min; Henkin, Amy; Ng, Stephanie; Song, Sujin; Chen, Yuli; Tran, Heather; Lai, Robin; Her, Chris; Maher, Jacquelyn J.; Forman, Barry M.; Stahl, Andreas

2012-01-01

Bile acids are known to play important roles as detergents in the absorption of hydrophobic nutrients and as signaling molecules in the regulation of metabolism. Here we tested the novel hypothesis that naturally occurring bile acids interfere with protein-mediated hepatic long chain free fatty acid (LCFA) uptake. To this end stable cell lines expressing fatty acid transporters as well as primary hepatocytes from mouse and human livers were incubated with primary and secondary bile acids to determine their effects on LCFA uptake rates. We identified ursodeoxycholic acid (UDCA) and deoxycholic acid (DCA) as the two most potent inhibitors of the liver-specific fatty acid transport protein 5 (FATP5). Both UDCA and DCA were able to inhibit LCFA uptake by primary hepatocytes in a FATP5-dependent manner. Subsequently, mice were treated with these secondary bile acids in vivo to assess their ability to inhibit diet-induced hepatic triglyceride accumulation. Administration of DCA in vivo via injection or as part of a high-fat diet significantly inhibited hepatic fatty acid uptake and reduced liver triglycerides by more than 50%. In summary, the data demonstrate a novel role for specific bile acids, and the secondary bile acid DCA in particular, in the regulation of hepatic LCFA uptake. The results illuminate a previously unappreciated means by which specific bile acids, such as UDCA and DCA, can impact hepatic triglyceride metabolism and may lead to novel approaches to combat obesity-associated fatty liver disease. PMID:22531947

Bile acids. XLIV, quantitation of bile acids from the bile fistula rat given (4-14C) cholesterol.

PubMed

Siegfried, C M; Doisy, E A; Elliott, W H

1975-01-24

The bile acids derived from [4-14-C]cholesterol administered intracardially to rats with cannulated bile ducts were identified and quantitated. Over a period of 28 days about 90% of the administered 14-C was found in bile of which 73% was retained in the biliary acid fraction. [7beta-3-H]cholic acid, alpha-muri[3beta-3-H]cholic acid, beta-muri[3beta-3-H]cholic acid and litho[3beta-3-H]cholic acid were prepared with specific activities of about 30 muCi/mg by reduction of appropriate ketonic precursors with NaB3H4 and were added to the biliary acid fraction. After separation and purification of the bile acids, cholic, chenodeoxycholic, alpha- and beta-muricholic acids accounted for 70, 16, 7.5 and 6.1%, respectively, of the 14-C in the biliary acid fraction. The specific activities of these isolated 14-C-labeled acids were almost identical. Lithocholic acid accounted for a maximum of 0.2% and ursodeoxycholic acid and 7-oxolithocholic acid could account for no more than 2% of the biliary 14-C. Gas-liquid chromatography on 3% OV-17 of the trimethylsilyl ether derivatives of the methyl esters of the common bile acids of rat bile results in their complete separation and provides a convenient means of estimating the relative proportions of these acids in rat bile. By this method, the relative amounts of the four major acids, cholic, chenodeoxycholic, alpha- and beta-muricholic acids were 63, 20, 8 and 6%, respectively.

Nod2 deficiency protects mice from cholestatic liver disease by increasing renal excretion of bile acids

PubMed Central

Wang, Lirui; Hartmann, Phillipp; Haimerl, Michael; Bathena, Sai P.; Sjöwall, Christopher; Almer, Sven; Alnouti, Yazen; Hofmann, Alan F.; Schnabl, Bernd

2014-01-01

Background & aims Chronic liver disease is characterized by fibrosis that may progress to cirrhosis. Nucleotide oligomerization domain 2 (Nod2), a member of the Nod-like receptor (NLR) family of intracellular immune receptors, plays an important role in the defense against bacterial infection through binding to the ligand muramyl dipeptide (MDP). Here, we investigated the role of Nod2 in the development of liver fibrosis. Methods We studied experimental cholestatic liver disease induced by bile duct ligation or toxic liver disease induced by carbon tetrachloride in wild type and Nod2−/− mice. Results Nod2 deficiency protected mice from cholestatic but not toxin-induced liver injury and fibrosis. Most notably, the hepatic bile acid concentration was lower in Nod2−/− mice than wild type mice following bile duct ligation for 3 weeks. In contrast to wild type mice, Nod2−/− mice had increased urinary excretion of bile acids, including sulfated bile acids, and an upregulation of the bile acid efflux transporters MRP2 and MRP4 in tubular epithelial cells of the kidney. MRP2 and MRP4 were downregulated by IL-1β in a Nod2 dependent fashion. Conclusions Our findings indicate that Nod2 deficiency protects mice from cholestatic liver injury and fibrosis through enhancing renal excretion of bile acids that in turn contributes to decreased concentration of bile acids in the hepatocyte. PMID:24560660

Contribution of Three Bile-Associated Loci, bsh, pva, and btlB, to Gastrointestinal Persistence and Bile Tolerance of Listeria monocytogenes

PubMed Central

Begley, Máire; Sleator, Roy D.; Gahan, Cormac G. M.; Hill, Colin

2005-01-01

Listeria monocytogenes must resist the deleterious actions of bile in order to infect and subsequently colonize the human gastrointestinal tract. The molecular mechanisms used by the bacterium to resist bile and the influence of bile on pathogenesis are as yet largely unexplored. This study describes the analysis of three genes—bsh, pva, and btlB—previously annotated as bile-associated loci in the sequenced L. monocytogenes EGDe genome (lmo2067, lmo0446, and lmo0754, respectively). Analysis of deletion mutants revealed a role for all three genes in resisting the acute toxicity of bile and bile salts, particularly glycoconjugated bile salts at low pH. Mutants were unaffected in the other stress responses examined (acid, salt, and detergents). Bile hydrolysis assays demonstrate that L. monocytogenes possesses only one bile salt hydrolase gene, namely, bsh. Transcriptional analyses and activity assays revealed that, although it is regulated by both PrfA and σB, the latter appears to play the greater role in modulating bsh expression. In addition to being incapable of bile hydrolysis, a sigB mutant was shown to be exquisitely sensitive to bile salts. Furthermore, increased expression of sigB was detected under anaerobic conditions and during murine infection. A gene previously annotated as a possible penicillin V amidase (pva) or bile salt hydrolase was shown to be required for resistance to penicillin V but not penicillin G but did not demonstrate a role in bile hydrolysis. Finally, animal (murine) studies revealed an important role for both bsh and btlB in the intestinal persistence of L. monocytogenes. PMID:15664931

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 structure ofmore » 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

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 and other metals

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

Metformin interferes with bile acid homeostasis through AMPK-FXR crosstalk

PubMed Central

Lien, Fleur; Berthier, Alexandre; Bouchaert, Emmanuel; Gheeraert, Céline; Alexandre, Jeremy; Porez, Geoffrey; Prawitt, Janne; Dehondt, Hélène; Ploton, Maheul; Colin, Sophie; Lucas, Anthony; Patrice, Alexandre; Pattou, François; Diemer, Hélène; Van Dorsselaer, Alain; Rachez, Christophe; Kamilic, Jelena; Groen, Albert K.; Staels, Bart; Lefebvre, Philippe

2014-01-01

The nuclear bile acid receptor farnesoid X receptor (FXR) is an important transcriptional regulator of bile acid, lipid, and glucose metabolism. FXR is highly expressed in the liver and intestine and controls the synthesis and enterohepatic circulation of bile acids. However, little is known about FXR-associated proteins that contribute to metabolic regulation. Here, we performed a mass spectrometry–based search for FXR-interacting proteins in human hepatoma cells and identified AMPK as a coregulator of FXR. FXR interacted with the nutrient-sensitive kinase AMPK in the cytoplasm of target cells and was phosphorylated in its hinge domain. In cultured human and murine hepatocytes and enterocytes, pharmacological activation of AMPK inhibited FXR transcriptional activity and prevented FXR coactivator recruitment to promoters of FXR-regulated genes. Furthermore, treatment with AMPK activators, including the antidiabetic biguanide metformin, inhibited FXR agonist induction of FXR target genes in mouse liver and intestine. In a mouse model of intrahepatic cholestasis, metformin treatment induced FXR phosphorylation, perturbed bile acid homeostasis, and worsened liver injury. Together, our data indicate that AMPK directly phosphorylates and regulates FXR transcriptional activity to precipitate liver injury under conditions favoring cholestasis. PMID:24531544

Bile salt kinetics in cystic fibrosis: influence of pancreatic enzyme replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkins, J.B.; Tercyak, A.M.; Szczepanik, P.

1977-01-01

Bile acid kinetics was investigated by stable isotope dilution technique in 6 children (ages 3/sup 1///sub 2/ months to 4/sup 1///sub 2/ years) with previously untreated cystic fibrosis. All of the patients had clinical and laboratory evidence of malabsorption, normal intestinal mucosal function, as judged by glucose absorption, intestinal histology, disaccharidase levels, and normally functioning gallbladders. The children were maintained on a constant diet throughout the study period; fat intake averaged 4.2 g per kg per day. Before administration of pancreatic enzyme replacement, fat excretion equalled 50 +- 4% (mean +- SE) of intake and was reduced to 20 +-more » 1.0% of intake after therapy. Total bile acid pool size nearly doubled during enzyme replacement from 379 +- 32 ..mu..moles per kg to 620 +- 36 ..mu..moles per kg with secondary bile acids comprising 57% of the total pool before therapy and 40% after therapy. The data indicate that both primary and secondary bile acids are conserved within the enterohepatic circulation during enzyme therapy, and that the mechanism for the regulation of hepatic bile acid synthesis is intact in cystic fibrosis. However, the demonstration that large amounts of bile acid continue to be excreted during therapy suggests that interruption of the enterohepatic circulation continues and that deficiencies of the intraluminal phase may persist during enzyme therapy in this disease.« less

Hepatic artery bridging lessens temporary ischemic injury to bile canaliculi

PubMed Central

Wang, Jia-Zhong; Liu, Yang; Wang, Jin-Long; Lu, Le; Zhang, Ya-Fei; Lu, Hong-Wei; Li, Yi-Ming

2015-01-01

AIM: To study whether transfer of blood between the right gastroepiploic artery and gastroduodenal artery could lessens the damage to bile canaliculi. METHODS: Forty male Bama miniature pigs were divided into four groups as follows: a control group, two hepatic artery ischemia groups (1 h and 2 h), and a hepatic artery bridging group. The hemodynamics of the hepatic artery in the hepatic artery bridging group was measured using color Doppler ultrasound. Morphological changes in the bile canaliculus were observed by transmission electron microscopy. Cofilin, heat shock protein 27 and F-actin expression was detected by immunohistochemistry, Western blot, and real-time polymerase chain reaction. Terminal deoxynucleotidyl transferase-mediated nick end-labeling method was used to evaluate liver injury. RESULTS: The hemodynamics was not changed in the hepatic artery bridging group. The microvilli in the bile canaliculus were impaired in the two hepatic artery ischemia groups. The down-regulation of cofilin and F-actin and up-regulation of heat shock protein 27 were observed in the two hepatic artery ischemia groups, while there were no significant differences between the control group and hepatic artery bridging group. CONCLUSION: Hepatic artery ischemia aggravates damage to bile canaliculi, and this damage can be diminished by a hepatic artery bridging duct. PMID:26401076

Correlation between hepatocarcinogenic effect of estragole and its influence on glucocorticoid induction of liver-specific enzymes and activities of FOXA and HNF4 transcription factors in mouse and rat liver.

PubMed

Kaledin, V I; Pakharukova, M Yu; Pivovarova, E N; Kropachev, K Yu; Baginskaya, N V; Vasilieva, E D; Ilnitskaya, S I; Nikitenko, E V; Kobzev, V F; Merkulova, T I

2009-04-01

It is known that the carcinogenic effect of estragole, a component of essential oils of many spicy plants, is characterized by species, tissue, and sex specificity. It causes mainly liver tumors in female mice but is not carcinogenic for male mice and for rats. In this work, the estragole hepatocarcinogenicity was shown for female mice of previously not studied ICR line. The strict correlation between estragole hepatocarcinogenicity and its ability to decrease the level of glucocorticoid induction of liver-specific enzymes tyrosine aminotransferase (TAT) and tryptophan oxygenase (TO) was found. Inhibition of TAT and TO inducibility by estragole takes place only in female mice but not in male mice and in rats. Studying the estragole effect on DNA-binding activity of transcription factors, present mainly in liver and regulating expression of genes encoding liver-specific proteins, has shown that estragole decreases FOXA and HNF4 activities but not activities of C/EBP and HNF1, and this happens only in female mice, for which this substance is hepatocarcinogen, but not in male mice and in rats. Pentachlorophenol, preventing hepatocarcinogenic effect of estragole, abolishes inhibitory influence of the latter on the TAT and TO glucocorticoid induction and restores DNA-binding activity of FOXA and HNF4. Thus, a correlation was revealed between the estragole hepatocarcinogenic effect and decrease in DNA-binding activity of transcription factors FOXA and HNF4, which might be indicative of the role of these factors in tumor suppression mechanisms in liver.

Bile acids induce necrosis in pancreatic stellate cells dependent on calcium entry and sodium-driven bile uptake.

PubMed

Ferdek, Pawel E; Jakubowska, Monika A; Gerasimenko, Julia V; Gerasimenko, Oleg V; Petersen, Ole H

2016-11-01

Acute biliary pancreatitis is a sudden and severe condition initiated by bile reflux into the pancreas. Bile acids are known to induce Ca 2+ signals and necrosis in isolated pancreatic acinar cells but the effects of bile acids on stellate cells are unexplored. Here we show that cholate and taurocholate elicit more dramatic Ca 2+ signals and necrosis in stellate cells compared to the adjacent acinar cells in pancreatic lobules; whereas taurolithocholic acid 3-sulfate primarily affects acinar cells. Ca 2+ signals and necrosis are strongly dependent on extracellular Ca 2+ as well as Na + ; and Na + -dependent transport plays an important role in the overall bile acid uptake in pancreatic stellate cells. Bile acid-mediated pancreatic damage can be further escalated by bradykinin-induced signals in stellate cells and thus killing of stellate cells by bile acids might have important implications in acute biliary pancreatitis. Acute biliary pancreatitis, caused by bile reflux into the pancreas, is a serious condition characterised by premature activation of digestive enzymes within acinar cells, followed by necrosis and inflammation. Bile acids are known to induce pathological Ca 2+ signals and necrosis in acinar cells. However, bile acid-elicited signalling events in stellate cells remain unexplored. This is the first study to demonstrate the pathophysiological effects of bile acids on stellate cells in two experimental models: ex vivo (mouse pancreatic lobules) and in vitro (human cells). Sodium cholate and taurocholate induced cytosolic Ca 2+ elevations in stellate cells, larger than those elicited simultaneously in the neighbouring acinar cells. In contrast, taurolithocholic acid 3-sulfate (TLC-S), known to induce Ca 2+ oscillations in acinar cells, had only minor effects on stellate cells in lobules. The dependence of the Ca 2+ signals on extracellular Na + and the presence of sodium-taurocholate cotransporting polypeptide (NTCP) indicate a Na + -dependent bile acid

Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor.

PubMed

Inagaki, Takeshi; Moschetta, Antonio; Lee, Youn-Kyoung; Peng, Li; Zhao, Guixiang; Downes, Michael; Yu, Ruth T; Shelton, John M; Richardson, James A; Repa, Joyce J; Mangelsdorf, David J; Kliewer, Steven A

2006-03-07

Obstruction of bile flow results in bacterial proliferation and mucosal injury in the small intestine that can lead to the translocation of bacteria across the epithelial barrier and systemic infection. These adverse effects of biliary obstruction can be inhibited by administration of bile acids. Here we show that the farnesoid X receptor (FXR), a nuclear receptor for bile acids, induces genes involved in enteroprotection and inhibits bacterial overgrowth and mucosal injury in ileum caused by bile duct ligation. Mice lacking FXR have increased ileal levels of bacteria and a compromised epithelial barrier. These findings reveal a central role for FXR in protecting the distal small intestine from bacterial invasion and suggest that FXR agonists may prevent epithelial deterioration and bacterial translocation in patients with impaired bile flow.

Defects in Gallbladder Emptying and Bile Acid Homeostasis in Mice With Cystic Fibrosis Transmembrane Conductance Regulator Deficiencies

PubMed Central

Debray, Dominique; Rainteau, Dominique; Barbu, Véronique; Rouahi, Myriam; Mourabit, Haquima El; Lerondel, Stéphanie; Rey, Colette; Humbert, Lydie; Wendum, Dominique; Cottart, Charles-Henry; Dawson, Paul; Chignard, Nicolas; Housset, Chantal

2013-01-01

Background & Aims Patients with cystic fibrosis (CF) have poorly defined defects in biliary function. We evaluated the effects of cystic fibrosis transmembrane conductance regulator (CFTR) deficiency on the enterohepatic disposition of bile acids (BAs). Methods Bile secretion and BA homeostasis were investigated in Cftrtm1Unc (Cftr−/−) and CftrΔF508 (ΔF508) mice. Results Cftr−/− and ΔF508 mice did not grow to normal size, but did not have liver abnormalities. The gallbladders of Cftr−/− mice were enlarged and had defects in emptying, based on99mtechnetiummebrofenin scintigraphy or post-prandial variationsn gallbladder volume; gallbladder contraction in response to cholecystokinin-8 was normal. Cftr−/− mice had abnormal gallbladder bile and duodenal acidity, and overexpressed the vasoactive intestinal peptide—a myorelaxant factor for the gallbladder. The BA pool was larger in Cftr−/− than wild-type mice, although there were no differences in fecal loss of BAs. Amounts of secondary BAs in portal blood, liver, and bile of Cftr−/− mice were much lower than normal. Expression of genes that are induced by BAs, including fibroblast growth factor-15 and BA transporters, was lower in the ileum but higher in the gallbladders of Cftr−/− mice, compared with wild-type mice, whereas enzymes that synthesize BA were down-regulated in livers of Cftr−/− mice. This indicates that BAs underwent a cholecystohepatic shunt, which was confirmed using cholyl-(Ne-NBD)-lysine as a tracer. In Cftr−/− mice, cholecystectomy reversed most changes in gene expression and partially restored circulating levels of secondary BAs. The ΔF508 mice overexpressed vasoactive intestinal peptide and had defects in gallbladder emptying and in levels of secondary BAs, but these features were less severe than in Cftr−/− mice. Conclusions Cftr−/− and CftrΔF508 mice have defects in gallbladder emptying that disrupt enterohepatic circulation of BAs. These defects

Recent advances in the understanding of bile acid malabsorption.

PubMed

Pattni, Sanjeev; Walters, Julian R F

2009-01-01

Bile acid malabsorption (BAM) is a syndrome of chronic watery diarrhoea with excess faecal bile acids. Disruption of the enterohepatic circulation of bile acids following surgical resection is a common cause of BAM. The condition is easily diagnosed by the selenium homocholic acid taurine (SeHCAT) test and responds to bile acid sequestrants. Idiopathic BAM (IBAM, primary bile acid diarrhoea) is the condition where no definitive cause for low SeHCAT retention can be identified. Review of PubMed and major journals. Evidence is accumulating that BAM is more prevalent than first thought. Management of chronic diarrhoea involves excluding secondary causes. Treatment of the condition is with bile acid binders. SeHCAT testing is not widely performed, limiting awareness of how common this condition can be. The underlying mechanism for IBAM has been unclear. Increasing awareness of the condition is important. Alternative mechanisms of IBAM have been suggested which involve an increased bile acid pool size and reduced negative feedback regulation of bile acid synthesis by FGF19. New sequestrants are available. Further research into the precise mechanism of IBAM is needed. Improvements in the recognition of the condition and optimization of treatment are required.

Bile acids induce necrosis in pancreatic stellate cells dependent on calcium entry and sodium‐driven bile uptake

PubMed Central

Jakubowska, Monika A.; Gerasimenko, Julia V.; Gerasimenko, Oleg V.; Petersen, Ole H.

2016-01-01

Key points Acute biliary pancreatitis is a sudden and severe condition initiated by bile reflux into the pancreas.Bile acids are known to induce Ca2+ signals and necrosis in isolated pancreatic acinar cells but the effects of bile acids on stellate cells are unexplored.Here we show that cholate and taurocholate elicit more dramatic Ca2+ signals and necrosis in stellate cells compared to the adjacent acinar cells in pancreatic lobules; whereas taurolithocholic acid 3‐sulfate primarily affects acinar cells.Ca2+ signals and necrosis are strongly dependent on extracellular Ca2+ as well as Na+; and Na+‐dependent transport plays an important role in the overall bile acid uptake in pancreatic stellate cells.Bile acid‐mediated pancreatic damage can be further escalated by bradykinin‐induced signals in stellate cells and thus killing of stellate cells by bile acids might have important implications in acute biliary pancreatitis. Abstract Acute biliary pancreatitis, caused by bile reflux into the pancreas, is a serious condition characterised by premature activation of digestive enzymes within acinar cells, followed by necrosis and inflammation. Bile acids are known to induce pathological Ca2+ signals and necrosis in acinar cells. However, bile acid‐elicited signalling events in stellate cells remain unexplored. This is the first study to demonstrate the pathophysiological effects of bile acids on stellate cells in two experimental models: ex vivo (mouse pancreatic lobules) and in vitro (human cells). Sodium cholate and taurocholate induced cytosolic Ca2+ elevations in stellate cells, larger than those elicited simultaneously in the neighbouring acinar cells. In contrast, taurolithocholic acid 3‐sulfate (TLC‐S), known to induce Ca2+ oscillations in acinar cells, had only minor effects on stellate cells in lobules. The dependence of the Ca2+ signals on extracellular Na+ and the presence of sodium–taurocholate cotransporting polypeptide (NTCP) indicate a Na

[Effect of vinegar-processed Curcumae Rhizoma on bile metabolism in rats].

PubMed

Gu, Wei; Lu, Tu-Lin; Li, Jin-Ci; Wang, Qiao-Han; Pan, Zi-Hao; Ji, De; Li, Lin; Zhang, Ji; Mao, Chun-Qin

2016-04-01

To explore the effect of vinegar-processed Curcumae Rhizoma on endogenous metabolites in bile by investigating the endogenous metabolites difference in bile before and after Curcumae Rhizoma was processed with vinegar. Alcohol extracts of crude and vinegar-processed Curcumae Rhizoma, as well as normal saline were prepared respectively, which were then given to the rats by intragastric administration for 0.5 h. Then common bile duct intubation drainage was conducted to collect 12 h bile of the rats. UPLC-TOF-MS analysis of bile samples was applied after 1∶3 acetonitrile protein precipitation; unidimensional statistics were combined with multivariate statistics and PeakView software was compared with network database to identify the potential biomarkers. Vinegar-processed Curcumae Rhizoma extracts had significant effects on metabolites spectrum in bile of the rats. With the boundaries of P<0.05, 13 metabolites with significant differences were found in bile of crude and vinegar-processed Curcumae Rhizoma groups, and 8 of them were identified when considering the network database. T-test unidimensional statistical analysis was applied between administration groups and blank group to obtain 7 metabolites with significant differences and identify them as potential biomarkers. 6 of the potential biomarkers were up-regulated in vinegar-processed group, which were related to the metabolism regulation of phospholipid metabolism, fat metabolism, bile acid metabolism, and N-acylethanolamine hydrolysis reaction balance, indicating the mechanism of vinegar-processed Curcumae Rhizoma on endogenous metabolites in bile of the rats. Copyright© by the Chinese Pharmaceutical Association.

Ablating L-FABP in SCP-2/SCP-x null mice impairs bile acid metabolism and biliary HDL-cholesterol secretion.

PubMed

Martin, Gregory G; Atshaves, Barbara P; Landrock, Kerstin K; Landrock, Danilo; Storey, Stephen M; Howles, Philip N; Kier, Ann B; Schroeder, Friedhelm

2014-12-01

On the basis of their abilities to bind bile acids and/or cholesterol, the physiological role(s) of liver fatty acid-binding protein (L-FABP) and sterol carrier protein (SCP) 2/SCP-x (SCP-2/SCP-x) gene products in biliary bile acid and cholesterol formation was examined in gene-ablated male mice. L-FABP (LKO) or L-FABP/SCP-2/SCP-x [triple-knockout (TKO)] ablation markedly decreased hepatic bile acid concentration, while SCP-2/SCP-x [double-knockout (DKO)] ablation alone had no effect. In contrast, LKO increased biliary bile acid, while DKO and TKO had no effect on biliary bile acid levels. LKO and DKO also altered biliary bile acid composition to increase bile acid hydrophobicity. Furthermore, LKO and TKO decreased hepatic uptake and biliary secretion of high-density lipoprotein (HDL)-derived 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol), while DKO alone had no effect. Finally, LKO and, to a lesser extent, DKO decreased most indexes contributing to cholesterol solubility in biliary bile. These results suggest different, but complementary, roles for L-FABP and SCP-2/SCP-x in biliary bile acid and cholesterol formation. L-FABP appears to function more in hepatic retention of bile acids as well as hepatic uptake and biliary secretion of HDL-cholesterol. Conversely, SCP-2/SCP-x may function more in formation and biliary secretion of bile acid, with less impact on hepatic uptake or biliary secretion of HDL-cholesterol. Copyright © 2014 the American Physiological Society.

Ablating L-FABP in SCP-2/SCP-x null mice impairs bile acid metabolism and biliary HDL-cholesterol secretion

PubMed Central

Martin, Gregory G.; Atshaves, Barbara P.; Landrock, Kerstin K.; Landrock, Danilo; Storey, Stephen M.; Howles, Philip N.; Kier, Ann B.

2014-01-01

On the basis of their abilities to bind bile acids and/or cholesterol, the physiological role(s) of liver fatty acid-binding protein (L-FABP) and sterol carrier protein (SCP) 2/SCP-x (SCP-2/SCP-x) gene products in biliary bile acid and cholesterol formation was examined in gene-ablated male mice. L-FABP (LKO) or L-FABP/SCP-2/SCP-x [triple-knockout (TKO)] ablation markedly decreased hepatic bile acid concentration, while SCP-2/SCP-x [double-knockout (DKO)] ablation alone had no effect. In contrast, LKO increased biliary bile acid, while DKO and TKO had no effect on biliary bile acid levels. LKO and DKO also altered biliary bile acid composition to increase bile acid hydrophobicity. Furthermore, LKO and TKO decreased hepatic uptake and biliary secretion of high-density lipoprotein (HDL)-derived 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol), while DKO alone had no effect. Finally, LKO and, to a lesser extent, DKO decreased most indexes contributing to cholesterol solubility in biliary bile. These results suggest different, but complementary, roles for L-FABP and SCP-2/SCP-x in biliary bile acid and cholesterol formation. L-FABP appears to function more in hepatic retention of bile acids as well as hepatic uptake and biliary secretion of HDL-cholesterol. Conversely, SCP-2/SCP-x may function more in formation and biliary secretion of bile acid, with less impact on hepatic uptake or biliary secretion of HDL-cholesterol. PMID:25277800

Ultrasound assisted gene and photodynamic synergistic therapy with multifunctional FOXA1-siRNA loaded porphyrin microbubbles for enhancing therapeutic efficacy for breast cancer.

PubMed

Zhao, Ranran; Liang, Xiaolong; Zhao, Bo; Chen, Min; Liu, Renfa; Sun, Sujuan; Yue, Xiuli; Wang, Shumin

2018-05-03

To improve the non-invasive therapeutic efficacy for ER positive breast cancer (ER+ BC), we fabricated a multifunctional FOXA1 loaded porphyrin microbubble to combine photodynamic therapy (PDT) and gene therapy of FOXA1 knockdown (KD) with ultrasound targeted microbubble destruction (UTMD) technology under the guidance of contrast enhanced ultrasound (CEUS). Cationic porphyrin microbubbles (CpMBs) were firstly fabricated from a porphyrin grafted lipid with two cationic amino groups (PGL-NH2) and fluorocarbon inert gas of C 3 F 8 . Porphyrin group in the CpMBs monolayer could be used as a photosensitizer for PDT, while amino groups could adsorb siRNA through electrostatic interaction for FOXA1 KD, which could inhibit the proliferation of estrogen-dependent ER+ BC. This system showed high photosensitizer and gene loading content. Moreover, CpMBs/siRNA can be converted into nanoparticles with low-frequency pulsed ultrasound (LFUS) exposure, which increase the transfection efficiency of siRNA (∼4 fold) and the porphyrin uptake (∼8 fold) in MCF-7 (a human breast cancer cell line, ER+) by sonoporation effect. In vivo, UTMD was performed under the guidance of CEUS, and the fluorescence intensity of CpMBs/siRNA at the tumour site reached a peak value at 6 h after injection and it was retained in the following 24 h. Furthermore, there was no tumour recurrence during the observation period (21 days) in the group of PDT combined with FXOA1 KD. Compared to the PDT or FOXA1 KD alone group, the combination of these two methods was much more efficient in inhibiting ER+ breast cancer, showing a good synergistic effect. CpMBs/siRNA combined with UTMD dramatically increased the local accumulation of porphyrin and siRNA through ultrasound-induced sonoporation effect under the guidance of CEUS, showing excellent therapeutic effect for estrogen-dependent ER+ breast cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

PubMed

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

2016-07-01

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

INTRACELLULAR SIGNALING BY BILE ACIDS

PubMed Central

Anwer, Mohammed Sawkat

2014-01-01

Bile acids, synthesized from cholesterol, are known to produce beneficial as well as toxic effects in the liver. The beneficial effects include choleresis, immunomodulation, cell survival, while the toxic effects include cholestasis, apoptosis and cellular toxicity. It is believed that bile acids produce many of these effects by activating intracellular signaling pathways. However, it has been a challenge to relate intracellular signaling to specific and at times opposing effects of bile acids. It is becoming evident that bile acids produce different effects by activating different isoforms of phosphoinositide 3-kinase (PI3K), Protein kinase Cs (PKCs), and mitogen activated protein kinases (MAPK). Thus, the apoptotic effect of bile acids may be mediated via PI3K-110γ, while cytoprotection induce by cAMP-GEF pathway involves activation of PI3K-p110α/β isoforms. Atypical PKCζ may mediate beneficial effects and nPKCε may mediate toxic effects, while cPKCα and nPKCδ may be involved in both beneficial and toxic effects of bile acids. The opposing effects of nPKCδ activation may depend on nPKCδ phosphorylation site(s). Activation of ERK1/2 and JNK1/2 pathway appears to mediate beneficial and toxic effects, respectively, of bile acids. Activation of p38α MAPK and p38β MAPK may mediate choleretic and cholestatic effects, respectively, of bile acids. Future studies clarifying the isoform specific effects on bile formation should allow us to define potential therapeutic targets in the treatment of cholestatic disorders. PMID:25378891

Role of the Intestinal Bile Acid Transporters in Bile Acid and Drug Disposition

PubMed Central

Dawson, Paul A.

2011-01-01

Membrane transporters expressed by the hepatocyte and enterocyte play critical roles in maintaining the enterohepatic circulation of bile acids, an effective recycling and conservation mechanism that largely restricts these potentially cytotoxic detergents to the intestinal and hepatobiliary compartments. In doing so, the hepatic and enterocyte transport systems ensure a continuous supply of bile acids to be used repeatedly during the digestion of multiple meals throughout the day. Absorption of bile acids from the intestinal lumen and export into the portal circulation is mediated by a series of transporters expressed on the enterocyte apical and basolateral membranes. The ileal apical sodium-dependent bile acid cotransporter (abbreviated ASBT; gene symbol, SLC10A2) is responsible for the initial uptake of bile acids across the enterocyte brush border membrane. The bile acids are then efficiently shuttled across the cell and exported across the basolateral membrane by the heteromeric Organic Solute Transporter, OSTα-OSTβ. This chapter briefly reviews the tissue expression, physiology, genetics, pathophysiology, and transport properties of the ASBT and OSTα-OSTα. In addition, the chapter discusses the relationship between the intestinal bile acid transporters and drug metabolism, including development of ASBT inhibitors as novel hypocholesterolemic or hepatoprotective agents, prodrug targeting of the ASBT to increase oral bioavailability, and involvement of the intestinal bile acid transporters in drug absorption and drug-drug interactions. PMID:21103970

CYP2E1-dependent elevation of serum cholesterol, triglycerides, and hepatic bile acids by isoniazid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Jie; Krausz, Kristopher W.; Li, Feng

Isoniazid is the first-line medication in the prevention and treatment of tuberculosis. Isoniazid is known to have a biphasic effect on the inhibition–induction of CYP2E1 and is also considered to be involved in isoniazid-induced hepatotoxicity. However, the full extent and mechanism of involvement of CYP2E1 in isoniazid-induced hepatotoxicity remain to be thoroughly investigated. In the current study, isoniazid was administered to wild-type and Cyp2e1-null mice to investigate the potential toxicity of isoniazid in vivo. The results revealed that isoniazid caused no hepatotoxicity in wild-type and Cyp2e1-null mice, but produced elevated serum cholesterol and triglycerides, and hepatic bile acids in wild-typemore » mice, as well as decreased abundance of free fatty acids in wild-type mice and not in Cyp2e1-null mice. Metabolomic analysis demonstrated that production of isoniazid metabolites was elevated in wild-type mice along with a higher abundance of bile acids, bile acid metabolites, carnitine and carnitine derivatives; these were not observed in Cyp2e1-null mice. In addition, the enzymes responsible for bile acid synthesis were decreased and proteins involved in bile acid transport were significantly increased in wild-type mice. Lastly, treatment of targeted isoniazid metabolites to wild-type mice led to similar changes in cholesterol, triglycerides and free fatty acids. These findings suggest that while CYP2E1 is not involved in isoniazid-induced hepatotoxicity, while an isoniazid metabolite might play a role in isoniazid-induced cholestasis through enhancement of bile acid accumulation and mitochondria β-oxidation. -- Highlights: ► Isoniazid metabolites were elevated only in wild-type mice. ► Isoniazid caused no hepatotoxicity in wild-type and Cyp2e1-null mice. ► Isoniazid elevated serum cholesterol and triglycerides, and hepatic bile acids. ► Bile acid transporters were significantly decreased in isoniazid-treated mice.« less

Rapid Determination of Bile Acids in Bile from Various Mammals by Reversed-Phase Ultra-Fast Liquid Chromatography.

PubMed

Si, Gu Leng Ri; Yao, Peng; Shi, Luwen

2015-08-01

A valid and efficient reversed-phase ultra-fast liquid chromatography method was developed for the simultaneous determination of 13 bile acids in the bile of three mammal species, including rat, pig and human gallstone patients. Chromatographic separation was performed with a Shim-pack XR-ODS column, and the mobile phase consisted of acetonitrile and potassium phosphate buffer (pH 2.6) at a flow rate of 0.5 mL min(-1). The linear detection range of most bile acids ranged from 2 to 600 ng µL(-1) with a good correlation coefficient (>0.9995). The precision of each bile acid was <1.8% for intraday and <4.8% for interday. All bile acids were separated in 15 min with satisfactory resolution, and the total analysis time was 18 min, including equilibration. The method was successfully applied in rapid screening of bile samples from the three mammals. Significant metabolic frameworks of bile acids among various species were observed, whereas considerable quantitative variations in both inter- and intraspecies were also observed, especially for gallstone patients. Our results suggest that detecting the change of bile acid profiles could be applied for the diagnosis of gallstone disease. © Crown copyright 2014.

Breast cancer risk-associated SNPs modulate the affinity of chromatin for FOXA1 and alter gene expression

PubMed Central

Cowper-Sal·lari, Richard; Zhang, Xiaoyang; Wright, Jason B.; Bailey, Swneke D.; Cole, Michael D.; Eeckhoute, Jerome; Moore, Jason H.; Lupien, Mathieu

2012-01-01

Genome-wide association studies (GWASs) have identified thousands of single nucleotide polymorphisms (SNPs) associated with human traits and diseases. But because the vast majority of these SNPs are located in the noncoding regions of the genome their risk promoting mechanisms are elusive. Employing a new methodology combining cistromics, epigenomics and genotype imputation we annotate the noncoding regions of the genome in breast cancer cells and systematically identify the functional nature of SNPs associated with breast cancer risk. Our results demonstrate that breast cancer risk-associated SNPs are enriched in the cistromes of FOXA1 and ESR1 and the epigenome of H3K4me1 in a cancer and cell-type-specific manner. Furthermore, the majority of these risk-associated SNPs modulate the affinity of chromatin for FOXA1 at distal regulatory elements, which results in allele-specific gene expression, exemplified by the effect of the rs4784227 SNP on the TOX3 gene found within the 16q12.1 risk locus. PMID:23001124

Biochemical basis for activation of virulence genes by bile salts in Vibrio parahaemolyticus.

PubMed

Rivera-Cancel, Giomar; Orth, Kim

2017-07-04

Bile salts act as a stressor to bacteria that transit the intestinal tract. Enteric pathogens have hijacked bile as an intestinal signal to regulate virulence factors. We recently demonstrated that Vibrio parahemolyticus senses bile salts via a heterodimeric receptor formed by the periplasmic domains of inner-membrane proteins VtrA and VtrC. Crystal structures of the periplasmic complex reveal that VtrA and VtrC form a β-barrel that binds bile salts in its hydrophobic interior to activate the VtrA cytoplasmic DNA-binding domain. Proteins with the same domain arrangement as VtrA and VtrC are widespread in Vibrio and related bacteria, where they are involved in regulating virulence and other unknown functions. Here we discuss our findings and review current knowledge on VtrA and VtrC homologs. We propose that signaling by these membrane-bound transcription factors can be advantageous for the regulation of membrane and secretory proteins.

Biochemical basis for activation of virulence genes by bile salts in Vibrio parahaemolyticus

PubMed Central

2017-01-01

ABSTRACT Bile salts act as a stressor to bacteria that transit the intestinal tract. Enteric pathogens have hijacked bile as an intestinal signal to regulate virulence factors. We recently demonstrated that Vibrio parahemolyticus senses bile salts via a heterodimeric receptor formed by the periplasmic domains of inner-membrane proteins VtrA and VtrC. Crystal structures of the periplasmic complex reveal that VtrA and VtrC form a β-barrel that binds bile salts in its hydrophobic interior to activate the VtrA cytoplasmic DNA-binding domain. Proteins with the same domain arrangement as VtrA and VtrC are widespread in Vibrio and related bacteria, where they are involved in regulating virulence and other unknown functions. Here we discuss our findings and review current knowledge on VtrA and VtrC homologs. We propose that signaling by these membrane-bound transcription factors can be advantageous for the regulation of membrane and secretory proteins. PMID:28129014

Sodium-dependent bile salt transporters of the SCL10A Transporter Family: More than solute transporters

PubMed Central

Anwer, M. Sawkat; Stieger, Bruno

2013-01-01

Summary The SLC10A transporter gene family consists of seven members and substrates transported by three members (SLC10A1, SLC10A2 and SLC10A6) are Na+-dependent. SLC10A1 (sodium taurocholate cotransporting polypeptide or NTCP) and SLC10A2 (apical sodium-dependent bile salt transporter or ASBT) transport bile salts and play an important role in maintaining enterohepatic circulation of bile salts. Solutes other than bile salts are also transported by NTCP. However, ASBT has not been shown to be a transporter for non-bile salt substrates. While the transport function of NTCP can potentially be used as liver function test, interpretation of such a test may be complicated by altered expression of NTCP in diseases and presence of drugs that may inhibit NTCP function. Transport of bile salts by NTCP and ASBT is inhibited by a number of drugs and it appears that ASBT is more permissive to drug inhibition than NTCP. The clinical significance of this inhibition in drug disposition and drug-drug interaction remains to be determined. Both NCTP and ASBT undergo post-translational regulations that involve phosphorylation/dephosphorylation, translocation to and retrieval from the plasma membrane and degradation by the ubiquitin-proteasome system. These posttranslational regulations are mediated via signaling pathways involving cAMP, calcium, nitric oxide, phosphoinositide-3-kinase (PI3K), protein kinase C (PKC) and protein phosphatases. There appears to be species difference in the substrate specificity and the regulation of plasma membrane localization of human and rodent NTCP. These differences should be taken into account when extrapolating rodent data for human clinical relevance and developing novel therapies. NTCP has recently been shown to play an important role in HBV and HDV infection by serving as a receptor for entry of these viruses into hepatocytes. PMID:24196564

[Structure determination of three novel bile acids from bear bile powder].

PubMed

Jian, Long-Hai; Mao, Xiu-Hong; Wang, Ke; Ji, Shen

2013-08-01

A method of LC-QTOF/MS combining with chemical synthesis has been used to determine the structures of three novel bile acids from bear bile powder. Reference substances of tauroursodeoxycholic acid and taurochenodeoxycholic acid were oxidized by pyridinium chlorochromate. The products were analyzed by LC-QTOF/MS. Total 4 products including 3 isomers were predicted and identified according to the PCC oxidation theory and LC-QTOF/MS results. Bear bile powder samples were dissolved by methanol and analyzed by LC-QTOF/MS. Three unknown peaks were found and identified as 2-[[(3beta, 5beta)-3-hydroxy-7, 24-dioxocholan-24-yl]amino]-ethanesulfonic acid, 2-[[(5beta)-3, 7, 24-trioxocholan-24-yl]amino]-ethanesulfonic acid and 2-[[(5beta, 7beta)-7-hydroxy-3, 24-dioxocholan-24-yl]amino]-ethanesulfonic acid, separately, by matching their results with that of oxidation products above.

Direct activation of a notochord cis-regulatory module by Brachyury and FoxA in the ascidian Ciona intestinalis.

PubMed

Passamaneck, Yale J; Katikala, Lavanya; Perrone, Lorena; Dunn, Matthew P; Oda-Ishii, Izumi; Di Gregorio, Anna

2009-11-01

The notochord is a defining feature of the chordate body plan. Experiments in ascidian, frog and mouse embryos have shown that co-expression of Brachyury and FoxA class transcription factors is required for notochord development. However, studies on the cis-regulatory sequences mediating the synergistic effects of these transcription factors are complicated by the limited knowledge of notochord genes and cis-regulatory modules (CRMs) that are directly targeted by both. We have identified an easily testable model for such investigations in a 155-bp notochord-specific CRM from the ascidian Ciona intestinalis. This CRM contains functional binding sites for both Ciona Brachyury (Ci-Bra) and FoxA (Ci-FoxA-a). By combining point mutation analysis and misexpression experiments, we demonstrate that binding of both transcription factors to this CRM is necessary and sufficient to activate transcription. To gain insights into the cis-regulatory criteria controlling its activity, we investigated the organization of the transcription factor binding sites within the 155-bp CRM. The 155-bp sequence contains two Ci-Bra binding sites with identical core sequences but opposite orientations, only one of which is required for enhancer activity. Changes in both orientation and spacing of these sites substantially affect the activity of the CRM, as clusters of identical sites found in the Ciona genome with different arrangements are unable to activate transcription in notochord cells. This work presents the first evidence of a synergistic interaction between Brachyury and FoxA in the activation of an individual notochord CRM, and highlights the importance of transcription factor binding site arrangement for its function.

Review article: bile acid diarrhoea - pathogenesis, diagnosis and management.

PubMed

Mottacki, N; Simrén, M; Bajor, A

2016-04-01

Bile acid diarrhoea results from imbalances in the homoeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease/dysfunction, associated with other GI pathology or can be idiopathic. To summarise the different types of bile acid diarrhoea and discuss the currently available diagnostic methods and treatments. Bile acid diarrhoea is found in up to 40% of patients diagnosed as having functional diarrhoea/IBS-D, and in up to 80% of patients who have undergone ileal resection. It is likely under-diagnosed and under-treated. In idiopathic disease, errors in regulation feedback of fibroblast growth factor 19 contribute to the development of the condition. Clinical therapeutic trials for bile acid diarrhoea have been used to diagnose it, but the 75 SeHCAT test is the primary current method. It is sensitive, specific and widely available, though not in the USA. Other diagnostic methods (such as serum measurement of the bile acid intermediate 7α-hydroxy-4-cholesten-3-one, or C4) have less widespread availability and documentation, and some (such as faecal measurement of bile acids) are significantly more complex and costly. First-line treatment of bile acid diarrhoea is with the bile acid sequestrant cholestyramine, which can be difficult to administer and dose due to gastrointestinal side effects. These side effects are less prominent in newer agents such as colesevelam, which may provide higher efficacy, tolerability and compliance. Bile acid diarrhoea is common, and likely under-diagnosed. Bile acid diarrhoea should be considered relatively early in the differential diagnosis of chronic diarrhoea. © 2016 John Wiley & Sons Ltd.

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

PubMed

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

2014-01-25

Enteric coated oral tablets or capsules can deliver dried live cells directly into the intestine. Previously, we found that a live attenuated bacterial vaccine acquired sensitivity to intestinal bile when dried, raising the possibility that although gastric acid can be bypassed, significant loss of viability might occur on release from an enteric coated oral formulations. Here we demonstrate that some food-grade lyophilised preparations of Lactobacillus casei and Lactobacillus salivarius also show temporary bile sensitivity that can be rapidly reversed by rehydration. To protect dried bacterial cells from temporary bile sensitivity, we propose using bile acid adsorbing resins, such as cholestyramine, which are bile acid binding agents, historically used to lower cholesterol levels. Vcaps™ HPMC capsules alone provided up to 830-fold protection from bile. The inclusion of 50% w/w cholestyramine in Vcaps™ HPMC capsules resulted in release of up to 1700-fold more live Lactobacillus casei into simulated intestinal fluid containing 1% bile, when compared to dried cells added directly to bile. We conclude that delivery of dried live probiotic organisms to the intestine may be improved by providing protection from bile by addition of bile adsorbing resins and the use of HPMC capsules. Copyright © 2013 Elsevier B.V. All rights reserved.

Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis.

PubMed

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

2016-07-29

Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160mg/kg) for 17days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce phosphorylation of JNK and ERK2, which suppresses inflammation, apoptosis and cholangiocyte proliferation during cholestasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Bile Duct Exploration

MedlinePlus

... Patients & Visitors Health Library Institutes & Departments Home / Health Library / Diagnostics & Testing / Bile Duct Exploration Advertising Policy Bile Duct Exploration Common bile duct exploration is ...

Boldine enhances bile production in rats via osmotic and farnesoid X receptor dependent mechanisms.

PubMed

Cermanova, Jolana; Kadova, Zuzana; Zagorova, Marie; Hroch, Milos; Tomsik, Pavel; Nachtigal, Petr; Kudlackova, Zdenka; Pavek, Petr; Dubecka, Michaela; Ceckova, Martina; Staud, Frantisek; Laho, Tomas; Micuda, Stanislav

2015-05-15

Boldine, the major alkaloid from the Chilean Boldo tree, is used in traditional medicine to support bile production, but evidence to support this function is controversial. We analyzed the choleretic potential of boldine, including its molecular background. The acute- and long-term effects of boldine were evaluated in rats either during intravenous infusion or after 28-day oral treatment. Infusion of boldine instantly increased the bile flow 1.4-fold in healthy rats as well as in animals with Mrp2 deficiency or ethinylestradiol induced cholestasis. This effect was not associated with a corresponding increase in bile acid or glutathione biliary excretion, indicating that the effect is not related to stimulation of either bile acid dependent or independent mechanisms of bile formation and points to the osmotic activity of boldine itself. We subsequently analyzed bile production under conditions of changing biliary excretion of boldine after bolus intravenous administration and found strong correlations between both parameters. HPLC analysis showed that bile concentrations of boldine above 10 μM were required for induction of choleresis. Importantly, long-term pretreatment, when the bile collection study was performed 24-h after the last administration of boldine, also accelerated bile formation despite undetectable levels of the compound in bile. The effect paralleled upregulation of the Bsep transporter and increased biliary clearance of its substrates, bile acids. We consequently confirmed the ability of boldine to stimulate the Bsep transcriptional regulator, FXR receptor. In conclusion, our study clarified the mechanisms and circumstances surrounding the choleretic activity of boldine. Copyright © 2015 Elsevier Inc. All rights reserved.

Boldine enhances bile production in rats via osmotic and Farnesoid X receptor dependent mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cermanova, Jolana; Kadova, Zuzana; Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove

Boldine, the major alkaloid from the Chilean Boldo tree, is used in traditional medicine to support bile production, but evidence to support this function is controversial. We analyzed the choleretic potential of boldine, including its molecular background. The acute- and long-term effects of boldine were evaluated in rats either during intravenous infusion or after 28-day oral treatment. Infusion of boldine instantly increased the bile flow 1.4-fold in healthy rats as well as in animals with Mrp2 deficiency or ethinylestradiol induced cholestasis. This effect was not associated with a corresponding increase in bile acid or glutathione biliary excretion, indicating that themore » effect is not related to stimulation of either bile acid dependent or independent mechanisms of bile formation and points to the osmotic activity of boldine itself. We subsequently analyzed bile production under conditions of changing biliary excretion of boldine after bolus intravenous administration and found strong correlations between both parameters. HPLC analysis showed that bile concentrations of boldine above 10 μM were required for induction of choleresis. Importantly, long-term pretreatment, when the bile collection study was performed 24-h after the last administration of boldine, also accelerated bile formation despite undetectable levels of the compound in bile. The effect paralleled upregulation of the Bsep transporter and increased biliary clearance of its substrates, bile acids. We consequently confirmed the ability of boldine to stimulate the Bsep transcriptional regulator, FXR receptor. In conclusion, our study clarified the mechanisms and circumstances surrounding the choleretic activity of boldine. - Highlights: • Boldine may increase bile production by direct as well as indirect mechanisms. • Biliary concentrations of boldine above 10 μM directly stimulate bile production. • Long-term oral boldine administration increases bile acid (BA) biliary secretion. �

Sortilin 1 Loss-of-Function Protects Against Cholestatic Liver Injury by Attenuating Hepatic Bile Acid Accumulation in Bile Duct Ligated Mice.

PubMed

Li, Jibiao; Woolbright, Benjamin L; Zhao, Wen; Wang, Yifeng; Matye, David; Hagenbuch, Bruno; Jaeschke, Hartmut; Li, Tiangang

2018-01-01

Sortilin 1 (Sort1) is an intracellular trafficking receptor that mediates protein sorting in the endocytic or secretory pathways. Recent studies revealed a role of Sort1 in the regulation of cholesterol and bile acid (BA) metabolism. This study further investigated the role of Sort1 in modulating BA detoxification and cholestatic liver injury in bile duct ligated mice. We found that Sort1 knockout (KO) mice had attenuated liver injury 24 h after bile duct ligation (BDL), which was mainly attributed to less bile infarct formation. Sham-operated Sort1 KO mice had about 20% larger BA pool size than sham-operated wildtype (WT) mice, but 24 h after BDL Sort1 KO mice had significantly attenuated hepatic BA accumulation and smaller BA pool size. After 14 days BDL, Sort1 KO mice showed significantly lower hepatic BA concentration and reduced expression of inflammatory and fibrotic marker genes, but similar degree of liver fibrosis compared with WT mice. Unbiased quantitative proteomics revealed that Sort1 KO mice had increased hepatic BA sulfotransferase 2A1, but unaltered phase-I BA metabolizing cytochrome P450s or phase-III BA efflux transporters. Consistently, Sort1 KO mice showed elevated plasma sulfated taurocholate after BDL. Finally, we found that liver Sort1 was repressed after BDL, which may be due to BA activation of farnesoid x receptor. In conclusion, we report a role of Sort1 in the regulation of hepatic BA detoxification and cholestatic liver injury in mice. The mechanisms underlying increased hepatic BA elimination in Sort1 KO mice after BDL require further investigation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Bile acid excess induces cardiomyopathy and metabolic dysfunctions in the heart

PubMed Central

Desai, Moreshwar; Mathur, Bhoomika; Eblimit, Zeena; Vasquez, Hernan; Taegtmeyer, Heinrich; Karpen, Saul; Penny, Daniel J.; Moore, David D.; Anakk, Sayeepriyadarshini

2017-01-01

Cardiac dysfunction in patients with liver cirrhosis is strongly associated with increased serum bile acid concentrations. Here we show that excess bile acids decrease fatty acid oxidation in cardiomyocytes and can cause heart dysfunction, a cardiac syndrome that we term Cholecardia. Fxr; Shp double knockout (DKO) mice, a model for bile acid overload, display cardiac hypertrophy, bradycardia, and exercise intolerance. In addition, DKO mice exhibit an impaired cardiac response to catecholamine challenge. Consistent with this decreased cardiac function, we show that elevated serum bile acids reduce cardiac fatty acid oxidation both in vivo and ex vivo. We find that increased bile acid levels suppress expression of Pgc1α, a key regulator of fatty acid metabolism, and that Pgc1α overexpression in cardiac cells was able to rescue the bile acid-mediated reduction in fatty acid oxidation genes. Importantly, intestinal bile acid sequestration with cholestyramine was sufficient to reverse the observed heart dysfunction in the DKO mice. Conclusions Overall, we propose that decreased Pgc1α expression contributes to the metabolic dysfunction in Cholecardia, and that reducing serum bile acid concentrations will be beneficial against metabolic and pathological changes in the heart. PMID:27774647

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

[Simultaneous determination of eight kinds of conjunct bile acids in human bile by R-HPLC].

PubMed

Dai, Z; Tan, G; Qian, K; Chen, X

1997-01-01

A method for the simultaneous determination of eight kinds of conjunct bile acids in human bile was developed by HPLC. They were separated on a YWG-C18 (3 microns) column at 30 degrees C, with methanol/water (65/35, V/V, pH3.0) as mobile phase, and detection wavelength at UV 210 nm. The linear ranges were 50-1,000 microns.ml-1, the recoveries were 91.2%-108.6%. The biles of 30 cases with cholelithiasis cholecystolithiasis and 20 cases without gallstone were detected by HPLC. The results showed that the constitution of bile acids was different between patients with cholelithiasis cholecystolithiasis and patients without gallstone.

Bile Acid-regulated Peroxisome Proliferator-activated Receptor-α (PPARα) Activity Underlies Circadian Expression of Intestinal Peptide Absorption Transporter PepT1/Slc15a1*

PubMed Central

Okamura, Ayako; Koyanagi, Satoru; Dilxiat, Adila; Kusunose, Naoki; Chen, Jia Jun; Matsunaga, Naoya; Shibata, Shigenobu; Ohdo, Shigehiro

2014-01-01

Digested proteins are mainly absorbed as small peptides composed of two or three amino acids. The intestinal absorption of small peptides is mediated via only one transport system: the proton-coupled peptide transporter-1 (PepT1) encoded from the soluble carrier protein Slc15a1. In mammals, intestinal expression of PepT1/Slc15a1 oscillates during the daily feeding cycle. Although the oscillation in the intestinal expression of PepT1/Slc15a1 is suggested to be controlled by molecular components of circadian clock, we demonstrated here that bile acids regulated the oscillation of PepT1/Slc15a1 expression through modulating the activity of peroxisome proliferator-activated receptor α (PPARα). Nocturnally active mice mainly consumed their food during the dark phase. PPARα activated the intestinal expression of Slc15a1 mRNA during the light period, and protein levels of PepT1 peaked before the start of the dark phase. After food intake, bile acids accumulated in intestinal epithelial cells. Intestinal accumulated bile acids interfered with recruitment of co-transcriptional activator CREB-binding protein/p300 on the promoter region of Slc15a1 gene, thereby suppressing PPARα-mediated transactivation of Slc15a1. The time-dependent suppression of PPARα-mediated transactivation by bile acids caused an oscillation in the intestinal expression of PepT1/Slc15a1 during the daily feeding cycle that led to circadian changes in the intestinal absorption of small peptides. These findings suggest a molecular clock-independent mechanism by which bile acid-regulated PPARα activity governs the circadian expression of intestinal peptide transporter. PMID:25016014

Epigenetic mechanisms of peptidergic regulation of gene expression during aging of human cells.

PubMed

Ashapkin, V V; Linkova, N S; Khavinson, V Kh; Vanyushin, B F

2015-03-01

Expression levels of genes encoding specific transcription factors and other functionally important proteins vary upon aging of pancreatic and bronchial epithelium cell cultures. The peptides KEDW and AEDL tissue-specifically affect gene expression in pancreatic and bronchial cell cultures, respectively. It is established in this work that the DNA methylation patterns of the PDX1, PAX6, NGN3, NKX2-1, and SCGB1A1 gene promoter regions change upon aging in pancreatic and bronchial cell cultures in correlation with variations in their expression levels. Thus, stable changes in gene expression upon aging of cell cultures could be caused by changes in their promoter methylation patterns. The methylation patterns of the PAX4 gene in pancreatic cells as well as those of the FOXA1, SCGB3A2, and SFTPA1 genes in bronchial cells do not change upon aging and are unaffected by peptides, whereas their expression levels change in both cases. The promoter region of the FOXA2 gene in pancreatic cells contains a small number of methylated CpG sites, their methylation levels being affected by cell culture aging and KEDW, though without any correlation with gene expression levels. The promoter region of the FOXA2 gene is completely unmethylated in bronchial cells irrespective of cell culture age and AEDL action. Changes in promoter methylation might be the cause of age- and peptide-induced variations in expression levels of the PDX1, PAX6, and NGN3 genes in pancreatic cells and NKX2-1 and SCGB1A1 genes in bronchial cells. Expression levels of the PAX4 and FOXA2 genes in pancreatic cells and FOXA1, FOXA2, SCGB3A2, and SFTPA1 genes in bronchial cells seem to be controlled by some other mechanisms.

Role of epimorphin in bile duct formation of rat liver epithelial stem-like cells: involvement of small G protein RhoA and C/EBPβ.

PubMed

Jia, Yali; Yao, Hailei; Zhou, Junnian; Chen, Lin; Zeng, Quan; Yuan, Hongfeng; Shi, Lei; Nan, Xue; Wang, Yunfang; Yue, Wen; Pei, Xuetao

2011-11-01

Epimorphin/syntaxin 2 is a high conserved and very abundant protein involved in epithelial morphogenesis in various organs. We have shown recently that epimorphin (EPM), a protein exclusively expressed on the surface of hepatic stellate cells and myofibroblasts of the liver, induces bile duct formation of hepatic stem-like cells (WB-F344 cells) in a putative biophysical way. Therefore, the aim of this study was to present some of the molecular mechanisms by which EPM mediates bile duct formation. We established a biliary differentiation model by co-culture of EPM-overexpressed mesenchymal cells (PT67(EPM)) with WB-F344 cells. Here, we showed that EPM could promote WB-F344 cells differentiation into bile duct-like structures. Biliary differentiation markers were also elevated by EPM including Yp, Cx43, aquaporin-1, CK19, and gamma glutamyl transpeptidase (GGT). Moreover, the signaling pathway of EPM was analyzed by focal adhesion kinase (FAK), extracellular regulated kinase 1/2 (ERK1/2), and RhoA Western blot. Also, a dominant negative (DN) RhoA-WB-F344 cell line (WB(RhoA-DN)) was constructed. We found that the levels of phosphorylation (p) of FAK and ERK1/2 were up-regulated by EPM. Most importantly, we also showed that RhoA is necessary for EPM-induced activation of FAK and ERK1/2 and bile duct formation. In addition, a dual luciferase-reporter assay and CHIP assay was performed to reveal that EPM regulates GGT IV and GGT V expression differentially, possibly mediated by C/EBPβ. Taken together, these data demonstrated that EPM regulates bile duct formation of WB-F344 cells through effects on RhoA and C/EBPβ, implicating a dual aspect of this morphoregulator in bile duct epithelial morphogenesis. Copyright © 2011 Wiley-Liss, Inc.

Rapid analysis of bile acids in different biological matrices using LC-ESI-MS/MS for the investigation of bile acid transformation by mammalian gut bacteria.

PubMed

Wegner, Katrin; Just, Sarah; Gau, Laura; Mueller, Henrike; Gérard, Philippe; Lepage, Patricia; Clavel, Thomas; Rohn, Sascha

2017-02-01

Bile acids are important signaling molecules that regulate cholesterol, glucose, and energy homoeostasis and have thus been implicated in the development of metabolic disorders. Their bioavailability is strongly modulated by the gut microbiota, which contributes to generation of complex individual-specific bile acid profiles. Hence, it is important to have accurate methods at hand for precise measurement of these important metabolites. Here, a rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous identification and quantitation of primary and secondary bile acids as well as their taurine and glycine conjugates was developed and validated. Applicability of the method was demonstrated for mammalian tissues, biofluids, and cell culture media. The analytical approach mainly consists of a simple and rapid liquid-liquid extraction procedure in presence of deuterium-labeled internal standards. Baseline separation of all isobaric bile acid species was achieved and a linear correlation over a broad concentration range was observed. The method showed acceptable accuracy and precision on intra-day (1.42-11.07 %) and inter-day (2.11-12.71 %) analyses and achieved good recovery rates for representative analytes (83.7-107.1 %). As a proof of concept, the analytical method was applied to mouse tissues and biofluids, but especially to samples from in vitro fermentations with gut bacteria of the family Coriobacteriaceae. The developed method revealed that the species Eggerthella lenta and Collinsella aerofaciens possess bile salt hydrolase activity, and for the first time that the species Enterorhabdus mucosicola is able to deconjugate and dehydrogenate primary bile acids in vitro.

Fatty acid bile acid conjugates (FABACs)—New molecules for the prevention of cholesterol crystallisation in bile

PubMed Central

Gilat, T; Somjen, G; Mazur, Y; Leikin-Frenkel, A; Rosenberg, R; Halpern, Z; Konikoff, F.

2001-01-01

BACKGROUND—Cholesterol gall stones are a frequent disease for which at present surgery is the usual therapy. Despite the importance of bile acids it has become evident that phospholipids are the main cholesterol solubilisers in bile. Even phospholipid components, such as fatty acids, have anticrystallising activity.
AIM—To synthesise fatty acid bile acid conjugates (FABACs) and study their effects on cholesterol crystallisation in bile in vitro and in vivo.
METHODS—FABACs were prepared by conjugation of cholic acid at position 3 with saturated fatty acids of variable chain length using an amide bond. Cholesterol crystallisation and its kinetics (crystal observation time, crystal mass) were studied in model bile, pooled enriched human bile, and fresh human bile using FABACs with saturated fatty acids of varying chain length (C-6 to C-22). Absorption of FABACs into blood and bile was tested in hamsters. Prevention of biliary cholesterol crystallisation in vivo was tested in hamsters and inbred mice.
RESULTS—FABACs strongly inhibited cholesterol crystallisation in model as well as native bile. The FABACs with longer acyl chains (C-16 to C-22) were more effective. At a concentration of 5 mM, FABACs almost completely inhibited cholesterol crystallisation in fresh human bile for 21 days. FABACs were absorbed and found in both portal and heart blood of hamsters. Levels in bile were 2-3 times higher than in blood, indicating active secretion. Appreciable levels were found in the systemic circulation 24-48 hours after a single administration. Ingested FABACs completely prevented the formation of cholesterol crystals in the gall bladders of hamsters and mice fed a lithogenic diet.
CONCLUSIONS—FABACs are potent inhibitors of cholesterol crystallisation in bile. They are absorbed and secreted into bile and prevent the earliest step of cholesterol gall stone formation in animals. These compounds may be of potential use in cholesterol gall stone disease in

Fluorescence properties of Schiff base - N,N‧-bis(salicylidene) - 1,2-Phenylenediamine in presence of bile acid host

NASA Astrophysics Data System (ADS)

Roy, Nayan; Paul, Pradip C.; Singh, T. Sanjoy

2015-05-01

Fluorescence properties of Schiff base - N,N‧-bis(salicylidene) - 1,2-phenylenediamine (LH2) is used to study the micelles formed by aggregation of different important bile acids like cholic acid, deoxycholic acid, chenodeoxycholic acid and glycocholic acid by steady state and picosecond time-resolved fluorescence spectroscopy. The fluorescence band intensity was found out to increase with concomitant red shift with gradual addition of different bile acids. Binding constant of the probe with different bile acids as well as critical micelle concentration was obtained from the variation of fluorescence intensity on increasing concentration of bile acids in the medium. The increase in fluorescence quantum yields, fluorescence decay times and substantial decrease in nonradiative decay rate constants in bile acids micellar environment points to the restricted motion of the fluorophore inside the micellar subdomains.

Disulfide bridge regulates ligand-binding site selectivity in liver bile acid-binding proteins.

PubMed

Cogliati, Clelia; Tomaselli, Simona; Assfalg, Michael; Pedò, Massimo; Ferranti, Pasquale; Zetta, Lucia; Molinari, Henriette; Ragona, Laura

2009-10-01

Bile acid-binding proteins (BABPs) are cytosolic lipid chaperones that play central roles in driving bile flow, as well as in the adaptation to various pathological conditions, contributing to the maintenance of bile acid homeostasis and functional distribution within the cell. Understanding the mode of binding of bile acids with their cytoplasmic transporters is a key issue in providing a model for the mechanism of their transfer from the cytoplasm to the nucleus, for delivery to nuclear receptors. A number of factors have been shown to modulate bile salt selectivity, stoichiometry, and affinity of binding to BABPs, e.g. chemistry of the ligand, protein plasticity and, possibly, the formation of disulfide bridges. Here, the effects of the presence of a naturally occurring disulfide bridge on liver BABP ligand-binding properties and backbone dynamics have been investigated by NMR. Interestingly, the disulfide bridge does not modify the protein-binding stoichiometry, but has a key role in modulating recognition at both sites, inducing site selectivity for glycocholic and glycochenodeoxycholic acid. Protein conformational changes following the introduction of a disulfide bridge are small and located around the inner binding site, whereas significant changes in backbone motions are observed for several residues distributed over the entire protein, both in the apo form and in the holo form. Site selectivity appears, therefore, to be dependent on protein mobility rather than being governed by steric factors. The detected properties further establish a parallelism with the behaviour of human ileal BABP, substantiating the proposal that BABPs have parallel functions in hepatocytes and enterocytes.

Bile duct stricture

MedlinePlus

... duct, the tube that moves bile from the liver to the small intestine. Bile is a substance that helps with digestion. ... causes of this condition include: Cancer of the bile duct, liver or pancreas Damage and scarring due to a ...

[Research of conjugated bile acids in gallbladder bile of patients with polypoid lesions of gallbladder].

PubMed

Ge, Chunlin; Sun, Tao; Meng, Jingjuan; Wang, Kun; Huang, Peng

2014-02-01

To investigate the difference in conjugated bile acids in the gallbladder bile between gallbladder cholesterol polyps and adenomatous polyps patients, and screen the differential diagnosis-markers for polypoid lesions of gallbladder (PLG). From January to June 2013, the 20 cholesterol polyps patients, 10 adenomatous polyps patients and 10 patients without gallbladder diseases were enrolled. High performance liquid chromatography assay with ultraviolet detection was used to test 8 conjugated bile acids in gallbladder bile. The 8 conjugated bile acids were completely analyzed in 10 minutes, and the assay was liner in the range 8-500 µg/ml. The correlation coeffients for linear regression was from 0.9996-0.9999 and the detection limits ranged from 3.90-7.81 µg/ml. The level of taurocholic acid (TCA) in adenomatous polyps group ((75 ± 51) µg/ml) was significantly lower than that in the cholesterol polyps ((228 ± 206) µg/ml, q = 3.120, P = 0.014) and control groups ((104 ± 40) µg/ml, q = 2.950, P = 0.027). The level of taurochenodeoxycholic acid (TCDCA) in cholesterol polyps group ((604 ± 444) µg/ml) was significantly higher than that in the adenomatous polyps ((310 ± 182) µg/ml, q = 2.560, P = 0.048) and control groups ((308 ± 21) µg/ml, q = 2.970, P = 0.023). The levels of TCA and TCDCA in the gallbladder biles in cholesterol polyps patients were higher than those in adenomatous polyps patients, which may be the differential diagnosis-markers for PLG.

Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels▿ †

PubMed Central

Fang, Fang; Li, Yin; Bumann, Mario; Raftis, Emma J.; Casey, Pat G.; Cooney, Jakki C.; Walsh, Martin A.; O'Toole, Paul W.

2009-01-01

Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host. PMID:19592587

Correlation between chemical components of billary calculi and bile & sera and bile of gallstone patients.

PubMed

Chandran, Prasheeda; Garg, Pradeep; Pundir, Chandra S

2005-07-01

Total cholesterol, total bilirubin, calcium, oxalate, inorganic phosphate, magnesium, iron, copper, sodium and potassium were analyzed quantitatively in gallstones, bile of gall bladder and sera of 200 patients of cholelithiasis (52 cholesterol, 76 mixed and 72 pigment stone patients) and their contents were correlated between calculi and bile and sera and bile in these three type of stone patients. A significant positive correlation was observed between total cholesterol, total bilirubin of calculi and bile, copper of bile and sera of cholesterol stone patients, copper of calculi and bile, total bilirubin, oxalate, magnesium, potassium of sera and bile of pigment stone patients and oxalate and iron of stone and bile, total bilirubin, oxalate, sodium of sera and bile of mixed stone patients. A significant negative correlation was found between magnesium of serum and bile of cholesterol stone patients, oxalate of calculi and bile of pigment stone patients and magnesium of serum and bile of mixed stone patients.

Analysis of Shigella flexneri Resistance, Biofilm Formation, and Transcriptional Profile in Response to Bile Salts

PubMed Central

Nickerson, Kourtney P.; Chanin, Rachael B.; Sistrunk, Jeticia R.; Fink, Peter J.; Barry, Eileen M.; Nataro, James P.

2017-01-01

ABSTRACT The Shigella species cause millions of cases of watery or bloody diarrhea each year, mostly in children in developing countries. While many aspects of Shigella colonic cell invasion are known, crucial gaps in knowledge regarding how the bacteria survive, transit, and regulate gene expression prior to infection remain. In this study, we define mechanisms of resistance to bile salts and build on previous research highlighting induced virulence in Shigella flexneri strain 2457T following exposure to bile salts. Typical growth patterns were observed within the physiological range of bile salts; however, growth was inhibited at higher concentrations. Interestingly, extended periods of exposure to bile salts led to biofilm formation, a conserved phenotype that we observed among members of the Enterobacteriaceae. Characterization of S. flexneri 2457T biofilms determined that both bile salts and glucose were required for formation, dispersion was dependent upon bile salts depletion, and recovered bacteria displayed induced adherence to HT-29 cells. RNA-sequencing analysis verified an important bile salt transcriptional profile in S. flexneri 2457T, including induced drug resistance and virulence gene expression. Finally, functional mutagenesis identified the importance of the AcrAB efflux pump and lipopolysaccharide O-antigen synthesis for bile salt resistance. Our data demonstrate that S. flexneri 2457T employs multiple mechanisms to survive exposure to bile salts, which may have important implications for multidrug resistance. Furthermore, our work confirms that bile salts are important physiological signals to activate S. flexneri 2457T virulence. This work provides insights into how exposure to bile likely regulates Shigella survival and virulence during host transit and subsequent colonic infection. PMID:28348056

Synthesis, physicochemical properties, and biological activity of bile acids 3-glucuronides: Novel insights into bile acid signalling and detoxification.

PubMed

Mostarda, Serena; Passeri, Daniela; Carotti, Andrea; Cerra, Bruno; Colliva, Carolina; Benicchi, Tiziana; Macchiarulo, Antonio; Pellicciari, Roberto; Gioiello, Antimo

2018-01-20

Glucuronidation is considered an important detoxification pathway of bile acids especially in cholestatic conditions. Glucuronides are less toxic than the parent free forms and are more easily excreted in urine. However, the pathophysiological significance of bile acid glucuronidation is still controversial and debated among the scientific community. Progress in this field has been strongly limited by the lack of appropriate methods for the preparation of pure glucuronides in the amount needed for biological and pharmacological studies. In this work, we have developed a new synthesis of bile acid C3-glucuronides enabling the convenient preparation of gram-scale quantities. The synthesized compounds have been characterized in terms of physicochemical properties and abilities to modulate key nuclear receptors including the farnesoid X receptor (FXR). In particular, we found that C3-glucuronides of chenodeoxycholic acid and lithocholic acid, respectively the most abundant and potentially cytotoxic species formed in patients affected by cholestasis, behave as FXR agonists and positively regulate the gene expression of transporter proteins, the function of which is critical in human conditions related to imbalances of bile acid homeostasis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

IR spectroscopy analysis of pancreatic lipase-related protein 2 interaction with phospholipids: 2. Discriminative recognition of various micellar systems and characterization of PLRP2-DPPC-bile salt complexes.

PubMed

Mateos-Diaz, Eduardo; Sutto-Ortiz, Priscila; Sahaka, Moulay; Byrne, Deborah; Gaussier, Hélène; Carrière, Frédéric

2018-03-01

The interaction of pancreatic lipase-related protein 2 (PLRP2) with various micelles containing phospholipids was investigated using pHstat enzyme activity measurements, differential light scattering, size exclusion chromatography (SEC) and transmission IR spectroscopy. Various micelles of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and lysophosphatidylcholine were prepared with either bile salts (sodium taurodeoxycholate or glycodeoxycholate) or Triton X-100, which are substrate-dispersing agents commonly used for measuring phospholipase activities. PLRP2 displayed a high activity on all phospholipid-bile salt micelles, but was totally inactive on phospholipid-Triton X-100 micelles. These findings clearly differentiate PLRP2 from secreted pancreatic phospholipase A2 which is highly active on both types of micelles. Using an inactive variant of PLRP2, SEC experiments allowed identifying two populations of PLRP2-DPPC-bile salt complexes corresponding to a high molecular weight 1:1 PLRP2-micelle association and to a low molecular weight association of PLRP2 with few monomers of DPPC/bile salts. IR spectroscopy analysis showed how DPPC-bile salt micelles differ from DPPC-Triton X-100 micelles by a higher fluidity of acyl chains and higher hydration/H-bonding of the interfacial carbonyl region. The presence of bile salts allowed observing changes in the IR spectrum of DPPC upon addition of PLRP2 (higher rigidity of acyl chains, dehydration of the interfacial carbonyl region), while no change was observed with Triton X-100. The differences between these surfactants and their impact on substrate recognition by PLRP2 are discussed, as well as the mechanism by which high and low molecular weight PLRP2-DPPC-bile salt complexes may be involved in the overall process of DPPC hydrolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Altered Bile Acid Metabolome in Patients with Nonalcoholic Steatohepatitis.

PubMed

Ferslew, Brian C; Xie, Guoxiang; Johnston, Curtis K; Su, Mingming; Stewart, Paul W; Jia, Wei; Brouwer, Kim L R; Barritt, A Sidney

2015-11-01

The prevalence of nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) is increasing at an alarming rate. The role of bile acids in the development and progression of NAFLD to NASH and cirrhosis is poorly understood. This study aimed to quantify the bile acid metabolome in healthy subjects and patients with non-cirrhotic NASH under fasting conditions and after a standardized meal. Liquid chromatography tandem mass spectroscopy was used to quantify 30 serum and 16 urinary bile acids from 15 healthy volunteers and 7 patients with biopsy-confirmed NASH. Bile acid concentrations were measured at two fasting and four post-prandial time points following a high-fat meal to induce gallbladder contraction and bile acid reabsorption from the intestine. Patients with NASH had significantly higher total serum bile acid concentrations than healthy subjects under fasting conditions (2.2- to 2.4-fold increase in NASH; NASH 2595-3549 µM and healthy 1171-1458 µM) and at all post-prandial time points (1.7- to 2.2-fold increase in NASH; NASH 4444-5898 µM and healthy 2634-2829 µM). These changes were driven by increased taurine- and glycine-conjugated primary and secondary bile acids. Patients with NASH exhibited greater variability in their fasting and post-prandial bile acid profile. Results indicate that patients with NASH have higher fasting and post-prandial exposure to bile acids, including the more hydrophobic and cytotoxic secondary species. Increased bile acid exposure may be involved in liver injury and the pathogenesis of NAFLD and NASH.

Bile Acid Responses in Methane and Non-Methane Producers to Standard Breakfast Meals

USDA-ARS?s Scientific Manuscript database

Bile acids and their conjugates are important regulators of glucose homeostasis. Previous research has revealed the ratio of cholic acid to deoxycholic acid to affect insulin resistance in humans. Bile acid de-conjugation and intestinal metabolism depend on gut microbes which may be affected by hos...

Apolipoprotein A-V is present in bile and its secretion increases with lipid absorption in Sprague-Dawley rats.

PubMed

Zhang, Linda S; Sato, Hirokazu; Yang, Qing; Ryan, Robert O; Wang, David Q-H; Howles, Philip N; Tso, Patrick

2015-12-01

Apolipoprotein (apo) A-V is a protein synthesized only in the liver that dramatically modulates plasma triglyceride levels. Recent studies suggest a novel role for hepatic apoA-V in regulating the absorption of dietary triglycerides, but its mode of action on the gut remains unknown. The aim of this study was to test for apoA-V in bile and to determine whether its secretion is regulated by dietary lipids. After an overnight recovery, adult male Sprague-Dawley bile fistula rats indeed secreted apoA-V into bile at a constant rate under fasting conditions. An intraduodenal bolus of intralipid (n = 12) increased the biliary secretion of apoA-V but not of other apolipoproteins, such as A-I, A-IV, B, and E. The lipid-induced increase of biliary apoA-V was abolished under conditions of poor lymphatic lipid transport, suggesting that the stimulation is regulated by the magnitude of lipids associated with chylomicrons transported into lymph. We also studied the secretion of apoA-V into bile immediately following bile duct cannulation. Biliary apoA-V increased over time (∼6-fold increase at hour 16, n = 8) but the secretions of other apolipoproteins remained constant. Replenishing luminal phosphatidylcholine and taurocholate (n = 9) only enhanced apoA-V secretion in bile, suggesting that the increase was not due to depletion of phospholipids or bile salts. This is the first study to demonstrate that apoA-V is secreted into bile, introducing a potential route of delivery of hepatic apoA-V to the gut lumen. Our study also reveals the uniqueness of apoA-V secretion into bile that is regulated by mechanisms different from other apolipoproteins. Copyright © 2015 the American Physiological Society.

Apolipoprotein A-V is present in bile and its secretion increases with lipid absorption in Sprague-Dawley rats

PubMed Central

Sato, Hirokazu; Yang, Qing; Ryan, Robert O.; Wang, David Q.-H.; Howles, Philip N.; Tso, Patrick

2015-01-01

Apolipoprotein (apo) A-V is a protein synthesized only in the liver that dramatically modulates plasma triglyceride levels. Recent studies suggest a novel role for hepatic apoA-V in regulating the absorption of dietary triglycerides, but its mode of action on the gut remains unknown. The aim of this study was to test for apoA-V in bile and to determine whether its secretion is regulated by dietary lipids. After an overnight recovery, adult male Sprague-Dawley bile fistula rats indeed secreted apoA-V into bile at a constant rate under fasting conditions. An intraduodenal bolus of intralipid (n = 12) increased the biliary secretion of apoA-V but not of other apolipoproteins, such as A-I, A-IV, B, and E. The lipid-induced increase of biliary apoA-V was abolished under conditions of poor lymphatic lipid transport, suggesting that the stimulation is regulated by the magnitude of lipids associated with chylomicrons transported into lymph. We also studied the secretion of apoA-V into bile immediately following bile duct cannulation. Biliary apoA-V increased over time (∼6-fold increase at hour 16, n = 8) but the secretions of other apolipoproteins remained constant. Replenishing luminal phosphatidylcholine and taurocholate (n = 9) only enhanced apoA-V secretion in bile, suggesting that the increase was not due to depletion of phospholipids or bile salts. This is the first study to demonstrate that apoA-V is secreted into bile, introducing a potential route of delivery of hepatic apoA-V to the gut lumen. Our study also reveals the uniqueness of apoA-V secretion into bile that is regulated by mechanisms different from other apolipoproteins. PMID:26505974

Serum bile acid concentrations in dairy cattle with hepatic lipidosis.

PubMed

Garry, F B; Fettman, M J; Curtis, C R; Smith, J A

1994-01-01

This study was designed to evaluate serum bile acid measurements as indicatory, of liver function and/or hepatic fat infiltration in dairy cattle. Serum bile acid concentrations were measured in healthy dairy cattle at different stages of lactation after fasting or feeding. Bile acid concentrations were compared with liver fat content and sulfobromophthalein (BSP) half-life (T 1/2). Serum bile acid concentrations were higher in cows in early lactation and with higher daily milk production. Compared with prefasting values, bile acid concentrations were decreased at 8, 14, and 24 hours of fasting. Blood samples from fed cows at 1- to 2-hour intervals had wide and inconsistent variations in bile acid concentration. Because serum bile acids correlated well with BSP T 1/2, it is suggested that both measurements evaluate a similar aspect of liver function. Neither bile acids nor BSP T 1/2 correlated with differences in liver fat content among cows. Because of large variability in serum bile acid concentrations in fed cows and the lack of correlation of measured values with liver fat content, bile acid determinations do not appear useful for showing changes in hepatic function in fed cows with subclinical hepatic lipidosis nor serve as a screening test for this condition.

Individual bile acids have differential effects on bile acid signaling in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Peizhen, E-mail: songacad@gmail.com; Rockwell, Cheryl E., E-mail: rockwelc@msu.edu; Cui, Julia Yue, E-mail: juliacui@uw.edu

2015-02-15

Bile acids (BAs) are known to regulate BA synthesis and transport by the farnesoid X receptor in the liver (FXR-SHP) and intestine (FXR-Fgf15). However, the relative importance of individual BAs in regulating these processes is not known. Therefore, mice were fed various doses of five individual BAs, including cholic acid (CA), chenodeoxycholic acid (CDCA), deoxoycholic acid (DCA), lithocholic acid (LCA), and ursodeoxycholic acid (UDCA) in their diets at various concentrations for one week to increase the concentration of one BA in the enterohepatic circulation. The mRNA of BA synthesis and transporting genes in liver and ileum were quantified. In themore » liver, the mRNA of SHP, which is the prototypical target gene of FXR, increased in mice fed all concentrations of BAs. In the ileum, the mRNA of the intestinal FXR target gene Fgf15 was increased at lower doses and to a higher extent by CA and DCA than by CDCA and LCA. Cyp7a1, the rate-limiting enzyme in BA synthesis, was decreased more by CA and DCA than CDCA and LCA. Cyp8b1, the enzyme that 12-hydroxylates BAs and is thus responsible for the synthesis of CA, was decreased much more by CA and DCA than CDCA and LCA. Surprisingly, neither a decrease in the conjugated BA uptake transporter (Ntcp) nor increase in BA efflux transporter (Bsep) was observed by FXR activation, but an increase in the cholesterol efflux transporter (Abcg5/Abcg8) was observed with FXR activation. Thus in conclusion, CA and DCA are more potent FXR activators than CDCA and LCA when fed to mice, and thus they are more effective in decreasing the expression of the rate limiting gene in BA synthesis Cyp7a1 and the 12-hydroxylation of BAs Cyp8b1, and are also more effective in increasing the expression of Abcg5/Abcg8, which is responsible for biliary cholesterol excretion. However, feeding BAs do not alter the mRNA or protein levels of Ntcp or Bsep, suggesting that the uptake or efflux of BAs is not regulated by FXR at physiological and

Nutritional Regulation of Bile Acid Metabolism Is Associated with Improved Pathological Characteristics of the Metabolic Syndrome*

PubMed Central

Liaset, Bjørn; Hao, Qin; Jørgensen, Henry; Hallenborg, Philip; Du, Zhen-Yu; Ma, Tao; Marschall, Hanns-Ulrich; Kruhøffer, Mogens; Li, Ruiqiang; Li, Qibin; Yde, Christian Clement; Criales, Gabriel; Bertram, Hanne C.; Mellgren, Gunnar; Øfjord, Erik Snorre; Lock, Erik-Jan; Espe, Marit; Frøyland, Livar; Madsen, Lise; Kristiansen, Karsten

2011-01-01

Bile acids (BAs) are powerful regulators of metabolism, and mice treated orally with cholic acid are protected from diet-induced obesity, hepatic lipid accumulation, and increased plasma triacylglycerol (TAG) and glucose levels. Here, we show that plasma BA concentration in rats was elevated by exchanging the dietary protein source from casein to salmon protein hydrolysate (SPH). Importantly, the SPH-treated rats were resistant to diet-induced obesity. SPH-treated rats had reduced fed state plasma glucose and TAG levels and lower TAG in liver. The elevated plasma BA concentration was associated with induction of genes involved in energy metabolism and uncoupling, Dio2, Pgc-1α, and Ucp1, in interscapular brown adipose tissue. Interestingly, the same transcriptional pattern was found in white adipose tissue depots of both abdominal and subcutaneous origin. Accordingly, rats fed SPH-based diet exhibited increased whole body energy expenditure and heat dissipation. In skeletal muscle, expressions of the peroxisome proliferator-activated receptor β/δ target genes (Cpt-1b, Angptl4, Adrp, and Ucp3) were induced. Pharmacological removal of BAs by inclusion of 0.5 weight % cholestyramine to the high fat SPH diet attenuated the reduction in abdominal obesity, the reduction in liver TAG, and the decrease in nonfasted plasma TAG and glucose levels. Induction of Ucp3 gene expression in muscle by SPH treatment was completely abolished by cholestyramine inclusion. Taken together, our data provide evidence that bile acid metabolism can be modulated by diet and that such modulation may prevent/ameliorate the characteristic features of the metabolic syndrome. PMID:21680746

S-Adenosylmethionine attenuates bile duct early warm ischemia reperfusion injury after rat liver transplantation.

PubMed

Tang, Yong; Chu, Hongpeng; Cao, Guojun; Du, Xiaolong; Min, Xiaobo; Wan, Chidan

2018-03-01

Warm ischemia reperfusion injury (IRI) plays a key role in biliary complication, which is a substantial vulnerability of liver transplantation. The early pathophysiological changes of IRI are characterized by an excessive inflammatory response. S-Adenosylmethionine (SAM) is an important metabolic intermediate that modulates inflammatory reactions; however, its role in bile duct warm IRI is not known. In this study, male rats were treated with or without SAM (170 μmol/kg body weight) after orthotopic autologous liver transplantation. The histopathological observations showed that bile duct injury in the IRI group was more serious than in the SAM group. The alanine aminotransferase (ALT), alkaline phosphatase (ALP) and direct bilirubin (DBIL) levels in the serum of the IRI group were significantly increased compared to the SAM group (P < .05). Simultaneously, SAM effectively improved the survival of the transplant recipients. Furthermore, the H 2 O 2 and malondialdehyde (MDA) of the IRI group were much higher compared to the SAM group (P < .05). The GSH/GSSG ratio in the SAM group was significantly increased by SAM treatment compared to the IRI group (P < .05). SAM administration significantly inhibited macrophage infiltration in liver and bile duct tissues, down-regulated TNF-α levels and up-regulated IL-10 expression in bile duct tissues compared to the IRI group (P < .05). The number of apoptotic biliary epithelial cells and caspase-3-positive cells in IRI rat livers were much higher compared to those in SAM-treated rats at 24 h after liver transplantation (P < .05). These data suggested that SAM protected bile ducts against warm IRI by suppressing oxidative stress, inflammatory reactions and apoptosis of biliary epithelial cells after liver transplantation.α. Copyright © 2018 Elsevier Ltd. All rights reserved.

Colesevelam attenuates cholestatic liver and bile duct injury in Mdr2-/- mice by modulating composition, signalling and excretion of faecal bile acids.

PubMed

Fuchs, Claudia Daniela; Paumgartner, Gustav; Mlitz, Veronika; Kunczer, Victoria; Halilbasic, Emina; Leditznig, Nadja; Wahlström, Annika; Ståhlman, Marcus; Thüringer, Andrea; Kashofer, Karl; Stojakovic, Tatjana; Marschall, Hanns-Ulrich; Trauner, Michael

2018-04-10

Interruption of the enterohepatic circulation of bile acids (BAs) may protect against BA-mediated cholestatic liver and bile duct injury. BA sequestrants are established to treat cholestatic pruritus, but their impact on the underlying cholestasis is still unclear. We aimed to explore the therapeutic effects and mechanisms of the BA sequestrant colesevelam in a mouse model of sclerosing cholangitis. Mdr2 -/- mice received colesevelam for 8 weeks. Gene expression profiles of BA homeostasis, inflammation and fibrosis were explored in liver, intestine and colon. Hepatic and faecal BA profiles and gut microbiome were analysed. Glucagon-like peptide 1 (GLP-1) levels in portal blood were measured by ELISA. Furthermore, Mdr2 -/- mice as well as wild-type 3,5-diethoxy-carbonyl-1,4-dihydrocollidine-fed mice were treated with GLP-1-receptor agonist exendin-4 for 2 weeks prior to analysis. Colesevelam reduced serum liver enzymes, BAs and expression of proinflammatory and profibrogenic markers. Faecal BA profiling revealed increased levels of secondary BAs after resin treatment, while hepatic and biliary BA composition showed a shift towards more hydrophilic BAs. Colonic GLP-1 secretion, portal venous GLP-1 levels and intestinal messenger RNA expression of gut hormone Proglucagon were increased, while ileal Fgf15 expression was abolished by colesevelam. Exendin-4 treatment increased bile duct mass without promoting a reactive cholangiocyte phenotype in mouse models of sclerosing cholangitis. Microbiota analysis showed an increase of the phylum δ-Proteobacteria after colesevelam treatment and a shift within the phyla Firmicutes from Clostridiales to Lactobacillus . Colesevelam increases faecal BA excretion and enhances BA conversion towards secondary BAs, thereby stimulating secretion of GLP-1 from enteroendocrine L-cells and attenuates liver and bile duct injury in Mdr2 -/- mice. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article

Bile Reflux

MedlinePlus

... medications. But there is little evidence pinpointing the effects of bile reflux in people. Unlike acid reflux, bile reflux usually can't be completely controlled by changes in diet or lifestyle. Treatment involves medications or, in severe cases, surgery. ...

Endoscopic management of bile leakage after liver transplantation.

PubMed

Oh, Dong-Wook; Lee, Sung Koo; Song, Tae Jun; Park, Do Hyun; Lee, Sang Soo; Seo, Dong-Wan; Kim, Myung-Hwan

2015-05-23

Endoscopic retrograde cholangiopancreatography (ERCP) can be an effective treatment for bile leakage after liver transplantation. We evaluated the efficacy of endoscopic treatment in liver transplantation in patients who developed bile leaks. Forty-two patients who developed bile leaks after liver transplantation were included in the study. If a bile leak was observed on ERCP, a sphincterotomy was performed, and a nasobiliary catheter was then inserted. If a bile leak was accompanied by a bile duct stricture, either the stricture was dilated with balloons, followed by nasobiliary catheter insertion across the bile duct stricture, or endoscopic retrograde biliary drainage was performed. In the bile leakage alone group (22 patients), endoscopic treatment was technically successful in 19 (86.4%) and clinically successful in 17 (77.3%) cases. Among the 20 patients with bile leaks with bile duct strictures, endoscopic treatment was technically successful in 13 (65.0%) and clinically successful in 10 (50.0%) cases. Among the 42 patients who underwent ERCP, technical success was achieved in 32 (76.2%) cases and clinical success was achieved in 27 (64.3%) cases. ERCP is an effective and safe therapeutic modality for bile leaks after liver transplantation. ERCP should be considered as an initial therapeutic modality in post-liver transplantation patients.

Endoscopic Management of Bile Leakage after Liver Transplantation

PubMed Central

Oh, Dongwook; Lee, Sung Koo; Song, Tae Jun; Park, Do Hyun; Lee, Sang Soo; Seo, Dong-Wan; Kim, Myung-Hwan

2015-01-01

Background/Aims Endoscopic retrograde cholangiopancreatography (ERCP) can be an effective treatment for bile leakage after liver transplantation. We evaluated the efficacy of endoscopic treatment in liver transplantation in patients who developed bile leaks. Methods Forty-two patients who developed bile leaks after liver transplantation were included in the study. If a bile leak was observed on ERCP, a sphincterotomy was performed, and a nasobiliary catheter was then inserted. If a bile leak was accompanied by a bile duct stricture, either the stricture was dilated with balloons, followed by nasobiliary catheter insertion across the bile duct stricture, or endoscopic retrograde biliary drainage was performed. Results In the bile leakage alone group (22 patients), endoscopic treatment was technically successful in 19 (86.4%) and clinically successful in 17 (77.3%) cases. Among the 20 patients with bile leaks with bile duct strictures, endoscopic treatment was technically successful in 13 (65.0%) and clinically successful in 10 (50.0%) cases. Among the 42 patients who underwent ERCP, technical success was achieved in 32 (76.2%) cases and clinical success was achieved in 27 (64.3%) cases. Conclusions ERCP is an effective and safe therapeutic modality for bile leaks after liver transplantation. ERCP should be considered as an initial therapeutic modality in post-liver transplantation patients. PMID:25717048

Technical report: gadoxetate-disodium-enhanced 2D R2* mapping: a novel approach for assessing bile ducts in living donors.

PubMed

Fazeli Dehkordy, Soudabeh; Fowler, Kathryn J; Wolfson, Tanya; Igarashi, Saya; Lamas Constantino, Carolina P; Hooker, Jonathan C; Hong, Cheng W; Mamidipalli, Adrija; Gamst, Anthony C; Hemming, Alan; Sirlin, Claude B

2017-10-31

Gadoxetate-disodium (Gd-EOB-DTPA)-enhanced 3D T1- weighted (T1w) MR cholangiography (MRC) is an efficient method to evaluate biliary anatomy due to T1 shortening of excreted contrast in the bile. A method that exploits both T1 shortening and T2* effects may produce even greater bile duct conspicuity. The aim of our study is to determine feasibility and compare the diagnostic performance of two-dimensional (2D) T1w multi-echo (ME) spoiled gradient-recalled-echo (SPGR) derived R2* maps against T1w MRC for bile duct visualization in living liver donor candidates. Ten potential living liver donor candidates underwent pretransplant 3T MRI and were included in our study. Following injection of Gd-EOBDTPA and a 20-min delay, 3D T1w MRC and 2D T1w ME SPGR images were acquired. 2D R2* maps were generated inline by the scanner assuming exponential decay. The 3D T1w MRC and 2D R2* maps were retrospectively and independently reviewed in two separate sessions by three radiologists. Visualization of eight bile duct segments was scored using a 4-point ordinal scale. The scores were compared using mixed effects regression model. Imaging was tolerated by all donors and R2* maps were successfully generated in all cases. Visualization scores of 2D R2* maps were significantly higher than 3D T1w MRC for right anterior (p = 0.003) and posterior (p = 0.0001), segment 2 (p < 0.0001), segment 3 (p = 0.0001), and segment 4 (p < 0.0001) ducts. Gd-EOB-DTPA-enhanced 2D R2* mapping is a feasible method for evaluating the bile ducts in living donors and may be a valuable addition to the living liver donor MR protocol for delineating intrahepatic biliary anatomy.

Bile acids induce arrhythmias in human atrial myocardium--implications for altered serum bile acid composition in patients with atrial fibrillation.

PubMed

Rainer, Peter P; Primessnig, Uwe; Harenkamp, Sandra; Doleschal, Bernhard; Wallner, Markus; Fauler, Guenter; Stojakovic, Tatjana; Wachter, Rolf; Yates, Ameli; Groschner, Klaus; Trauner, Michael; Pieske, Burkert M; von Lewinski, Dirk

2013-11-01

High bile acid serum concentrations have been implicated in cardiac disease, particularly in arrhythmias. Most data originate from in vitro studies and animal models. We tested the hypotheses that (1) high bile acid concentrations are arrhythmogenic in adult human myocardium, (2) serum bile acid concentrations and composition are altered in patients with atrial fibrillation (AF) and (3) the therapeutically used ursodeoxycholic acid has different effects than other potentially toxic bile acids. Multicellular human atrial preparations ('trabeculae') were exposed to primary bile acids and the incidence of arrhythmic events was assessed. Bile acid concentrations were measured in serum samples from 250 patients and their association with AF and ECG parameters analysed. Additionally, we conducted electrophysiological studies in murine myocytes. Taurocholic acid (TCA) concentration-dependently induced arrhythmias in atrial trabeculae (14/28 at 300 µM TCA, p<0.01) while ursodeoxycholic acid did not. Patients with AF had significantly decreased serum levels of ursodeoxycholic acid conjugates and increased levels of non-ursodeoxycholic bile acids. In isolated myocytes, TCA depolarised the resting membrane potential, enhanced Na(+)/Ca(2+) exchanger (NCX) tail current density and induced afterdepolarisations. Inhibition of NCX prevented arrhythmias in atrial trabeculae. High TCA concentrations induce arrhythmias in adult human atria while ursodeoxycholic acid does not. AF is associated with higher serum levels of non-ursodeoxycholic bile acid conjugates and low levels of ursodeoxycholic acid conjugates. These data suggest that higher levels of toxic (arrhythmogenic) and low levels of protective bile acids create a milieu with a decreased arrhythmic threshold and thus may facilitate arrhythmic events.

Regulation of bile acid homeostasis by the intestinal Diet1–FGF15/19 axis

PubMed Central

Reue, Karen; Lee, Jessica M.; Vergnes, Laurent

2015-01-01

Purpose of review Hepatic bile acid synthesis is controlled, in part, by a complex enterohepatic feedback regulatory mechanism. In this review, we focus on the role of the intestinal FGF15/19 hormone in modulating bile acid levels, and additional metabolic effects on glucose metabolism, non-alcoholic liver disease (NAFLD), and liver regeneration. We also highlight the newly identified intestinal protein, Diet1, which is a modulator of FGF15/19 levels. Recent findings Low FGF19 levels are associated with bile acid diarrhea and NAFLD. In contrast, high FGF19 levels are associated with diabetes remission following Roux-en-Y gastric bypass surgery, suggesting new therapeutic approaches against type 2 diabetes. The effect of FGF15/19 on liver plasticity is a double-edged sword: whereas elevated FGF15/19 levels improve survival of mice after partial hepatectomy, FGF19 mitogenic activity is associated with liver carcinoma. Finally, a recent study has identified Diet1, an intestinal factor that influences FGF15/19 levels in mouse intestine and human enterocytes. Diet1 represents the first factor shown to influence FGF15/19 levels at a post-transcriptional level. Summary The biological effects of FGF15/19 make it an attractive target for treating metabolic dysregulation underlying conditions such as fatty liver and type 2 diabetes. Further elucidation of the role of Diet1 in FGF15/19 secretion may provide a control point for pharmacological modulation of FGF15/19 levels. PMID:24535283

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.

Multidrug resistance-associated protein 4 is a bile transporter of Clonorchis sinensis simulated by in silico docking.

PubMed

Dai, Fuhong; Yoo, Won Gi; Lee, Ji-Yun; Lu, Yanyan; Pak, Jhang Ho; Sohn, Woon-Mok; Hong, Sung-Jong

2017-11-21

Multidrug resistance-associated protein 4 (MRP4) is a member of the C subfamily of the ABC family of ATP-binding cassette (ABC) transporters. MRP4 regulates ATP-dependent efflux of various organic anionic substrates and bile acids out of cells. Since Clonorchis sinensis lives in host's bile duct, accumulation of bile juice can be toxic to the worm's tissues and cells. Therefore, C. sinensis needs bile transporters to reduce accumulation of bile acids within its body. We cloned MRP4 (CsMRP4) from C. sinensis and obtained a cDNA encoding an open reading frame of 1469 amino acids. Phylogenetic analysis revealed that CsMRP4 belonged to the MRP/SUR/CFTR subfamily. A tertiary structure of CsMRP4 was generated by homology modeling based on multiple structures of MRP1 and P-glycoprotein. CsMRP4 had two membrane-spanning domains (MSD1 & 2) and two nucleotide-binding domains (NBD1 & 2) as common structural folds. Docking simulation with nine bile acids showed that CsMRP4 transports bile acids through the inner cavity. Moreover, it was found that CsMRP4 mRNA was more abundant in the metacercariae than in the adults. Mouse immune serum, generated against the CsMRP4-NBD1 (24.9 kDa) fragment, localized CsMRP4 mainly in mesenchymal tissues and oral and ventral suckers of the metacercariae and the adults. Our findings shed new light on MRPs and their homologs and provide a platform for further structural and functional investigations on the bile transporters and parasites' survival.

A comparative proteomic analysis of bile for biomarkers of cholangiocarcinoma.

PubMed

Laohaviroj, Marut; Potriquet, Jeremy; Jia, Xinying; Suttiprapa, Sutas; Chamgramol, Yaovalux; Pairojkul, Chawalit; Sithithaworn, Paiboon; Mulvenna, Jason; Sripa, Banchob

2017-06-01

Cholangiocarcinoma is a primary malignant tumor of the bile duct epithelium. Cholangiocarcinoma is usually detected at an advanced stage when successful treatment is no longer possible. As the tumor originates from the bile duct epithelium, bile is an ideal source of tumor biomarkers for cholangiocarcinoma. In this study, we used a quantitative proteomics approach to identify potential tumor-associated proteins in the bile fluid of six cholangiocarcinoma patients. Three different gross-appearance tumor types were used in the analysis: mass-forming type ( n = 2), periductal infiltrating type ( n = 2), and intraductal growth type ( n = 2). Two bile samples from non-cancerous patients were used as controls. Isobaric labeling, coupled with Tandem mass spectrometry, was used to quantify protein levels in the bile of cholangiocarcinoma and control patients. In all, 63 proteins were significantly increased in cholangiocarcinoma bile compared to normal bile. Alpha-1-antitrypsin was one of the overexpressed proteins that increased in cholangiocarcinoma bile samples. Immunohistochemical analysis revealed that alpha-1-antitrypsin was detected in 177 (50%) of 354 cholangiocarcinoma tissues from our Tissue Bank. Immunoblotting of 54 cholangiocarcinoma bile samples showed that alpha-1-antitrypsin was positive in 38 (70%) samples. Fecal enzyme-linked immunosorbent assay showed that alpha-1-antitrypsin level was able to distinguish cholangiocarcinoma patients from normal individuals. In conclusion, alpha-1-antitrypsin is a potential marker for early diagnosis of cholangiocarcinoma.

Intestinal bile acid malabsorption in cystic fibrosis.

PubMed

O'Brien, S; Mulcahy, H; Fenlon, H; O'Broin, A; Casey, M; Burke, A; FitzGerald, M X; Hegarty, J E

1993-08-01

This study aimed at examining the mechanisms participating in excessive faecal bile acid loss in cystic fibrosis. The study was designed to define the relation between faecal fat and faecal bile acid loss in patients with and without cystic fibrosis related liver disease; to assess terminal ileal bile acid absorption by a seven day whole body retention of selenium labelled homotaurocholic acid (SeHCAT); and to determine if small intestinal bacterial overgrowth contributes to faecal bile acid loss. The study population comprised 40 patients (27 men; median age 18 years) with cystic fibrosis (n = 8) and without (n = 32) liver disease and eight control subjects. Faecal bile acid excretion was significantly higher in cystic fibrosis patients without liver disease compared with control subjects (mean (SEM) 21.5 (2.4) and 7.3 (1.2) micromoles/kg/24 hours respectively; p < 0.01) and patients with liver disease (7.9 (1.3) micromoles/kg/24 hours; p < 0.01). No correlation was found between faecal fat (g fat/24 hours) and faecal bile acid (micromoles 24 hours) excretion. Eight (33%) of cystic fibrosis patients had seven day SeHCAT retention < 10% (normal retention > 20%). SeHCAT retention in cystic fibrosis patients with liver disease was comparable with control subjects (30.0 (SEM) 8.3% v 36.8 (5.9)%; p = NS) while SeHCAT retention in cystic fibrosis patients who did not have liver disease was significantly reduced (19.9 (3.8); p < 0.05). Although evidence of small bowel bacterial overgrowth was present in 40% of patients no relation was found between breath hydrogen excretion, faecal fat, and faecal bile acid loss. The results are consistent with the presence of an abnormality in terminal ideal function in patients with cystic fibrosis who do not have liver disease and that a defect in the ileal absorption of bile acids may be a contributory factor to excessive faecal bile acid loss. Faecal bile acid loss in cystic fibrosis is unrelated to the presence of intraluminal fat

Intestinal bile acid malabsorption in cystic fibrosis.

PubMed Central

O'Brien, S; Mulcahy, H; Fenlon, H; O'Broin, A; Casey, M; Burke, A; FitzGerald, M X; Hegarty, J E

1993-01-01

This study aimed at examining the mechanisms participating in excessive faecal bile acid loss in cystic fibrosis. The study was designed to define the relation between faecal fat and faecal bile acid loss in patients with and without cystic fibrosis related liver disease; to assess terminal ileal bile acid absorption by a seven day whole body retention of selenium labelled homotaurocholic acid (SeHCAT); and to determine if small intestinal bacterial overgrowth contributes to faecal bile acid loss. The study population comprised 40 patients (27 men; median age 18 years) with cystic fibrosis (n = 8) and without (n = 32) liver disease and eight control subjects. Faecal bile acid excretion was significantly higher in cystic fibrosis patients without liver disease compared with control subjects (mean (SEM) 21.5 (2.4) and 7.3 (1.2) micromoles/kg/24 hours respectively; p < 0.01) and patients with liver disease (7.9 (1.3) micromoles/kg/24 hours; p < 0.01). No correlation was found between faecal fat (g fat/24 hours) and faecal bile acid (micromoles 24 hours) excretion. Eight (33%) of cystic fibrosis patients had seven day SeHCAT retention < 10% (normal retention > 20%). SeHCAT retention in cystic fibrosis patients with liver disease was comparable with control subjects (30.0 (SEM) 8.3% v 36.8 (5.9)%; p = NS) while SeHCAT retention in cystic fibrosis patients who did not have liver disease was significantly reduced (19.9 (3.8); p < 0.05). Although evidence of small bowel bacterial overgrowth was present in 40% of patients no relation was found between breath hydrogen excretion, faecal fat, and faecal bile acid loss. The results are consistent with the presence of an abnormality in terminal ideal function in patients with cystic fibrosis who do not have liver disease and that a defect in the ileal absorption of bile acids may be a contributory factor to excessive faecal bile acid loss. Faecal bile acid loss in cystic fibrosis is unrelated to the presence of intraluminal fat

Forkhead box protein A2, a pioneer factor for hepatogenesis, is involved in the expression of hepatic phenotype of alpha-fetoprotein-producing adenocarcinoma.

PubMed

Yamamura, Nobuhisa; Fugo, Kazunori; Kishimoto, Takashi

2017-09-01

Alpha-fetoprotein (AFP)-producing adenocarcinoma is a high-malignant variant of adenocarcinoma with a hepatic or fetal-intestinal phenotype. The number of cases of AFP-producing adenocarcinomas is increasing, but the molecular mechanism underlying the aberrant production of AFP is unclear. Here we sought to assess the role of Forkhead box A (FoxA)2, which is a pioneer transcription factor in the differentiation of hepatoblasts. FoxA2 expression was investigated in five cases of AFP-producing gastric adenocarcinomas by immunohistochemistry, and all cases showed FoxA2 expression. Chromatin immunoprecipitation revealed the DNA binding of FoxA2 on the regulatory element of AFP gene in AFP-producing adenocarcinoma cells. The inhibition of FoxA2 expression with siRNA reduced the mRNA expression of liver-specific proteins, including AFP, albumin, and transferrin. The inhibition of FoxA2 also reduced the expressions of liver-enriched nuclear factors, i.e., hepatocyte nuclear factor (HNF) 4α and HNF6, although the expressions of HNF1α and HNF1β were not affected. The same effect as FoxA2 knockdown in AFP producing adenocarcinoma cells was also observed in hepatocellular carcinoma cells. Our results suggest that FoxA2 plays a key role in the expression of hepatic phenotype of AFP-producing adenocarcinomas. Copyright © 2017 Elsevier GmbH. All rights reserved.

Therapeutic targeting of bile acids

PubMed Central

Gores, Gregory J.

2015-01-01

The first objectives of this article are to review the structure, chemistry, and physiology of bile acids and the types of bile acid malabsorption observed in clinical practice. The second major theme addresses the classical or known properties of bile acids, such as the role of bile acid sequestration in the treatment of hyperlipidemia; the use of ursodeoxycholic acid in therapeutics, from traditional oriental medicine to being, until recently, the drug of choice in cholestatic liver diseases; and the potential for normalizing diverse bowel dysfunctions in irritable bowel syndrome, either by sequestering intraluminal bile acids for diarrhea or by delivering more bile acids to the colon to relieve constipation. The final objective addresses novel concepts and therapeutic opportunities such as the interaction of bile acids and the microbiome to control colonic infections, as in Clostridium difficile-associated colitis, and bile acid targeting of the farnesoid X receptor and G protein-coupled bile acid receptor 1 with consequent effects on energy expenditure, fat metabolism, and glycemic control. PMID:26138466

Plasma lathosterol as a screening test for bile acid malabsorption due to ileal resection: correlation with 75SeHCAT test and faecal bile acid excretion.

PubMed

Färkkilä, M A; Kairemo, K J; Taavitsainen, M J; Strandberg, T A; Miettinen, T A

1996-04-01

1. Plasma lathosterol concentration, known to reflect cholesterol and bile acid synthesis, was evaluated as a screening test for bile acid malabsorption, comparing it with faecal bile acid measurements, SeHCAT test and Schilling test in 22 subjects of whom six were healthy controls and 16 had Crohn's disease with ileal resections of varying length. 2. Plasma lathosterols and other non-cholesterol sterols were determined by GLC. Faecal bile acids were measured by GLC, and SeHCAT retention times by gamma camera. The study subjects were divided into two groups according to the degree of bile acid malabsorption: controls (faecal bile acids < 10 mg day-1 kg-1, n = 9) and bile acid malabsorption (faecal bile acids > 10 mg day-1 kg-1, n = 13). 3. Faecal bile acid excretion was 5.9 +/- 1.0 mg day-1 kg-1 in control subjects and 45.7 +/- 6.1 mg day-1 kg-1 in the bile acid malabsorption group. The biological half-life of 75SeHCAT (T1/2) was 95.6 +/- 16.3 h and 14.1 +/- 4.1 h, respectively. Plasma lathosterol levels were significantly elevated in patients with bile acid malabsorption (742 +/- 84 micrograms/ml compared with 400 +/- 59 micrograms/ml in control subjects) and correlated closely with faecal bile acid levels (r = 0.779, P < 0.001), with 75SeHCAT T1/2 (r = -0.524, P < 0.05) and with Schilling test (r = -0.591, P < 0.05). Significant correlations were also obtained for delta 8-cholestenol with faecal bile acids (r = 0.784, P < 0.001) and 75SeHCAT (r = -0.505, P < 0.05). The biological half-life of SeHCAT correlated with faecal bile acid excretion (r = -0.702, P < 0.001). Using mean+2 SD of lathosterol (In micrograms/ml cholesterol) as a cut-off value and 10 mg day-1 kg-1 as the upper limit for faecal bile acid excretion, the test gives 100% sensitivity and 82% specificity for plasma lathosterol determination to detect bile acid malabsorption. 4. The results indicate that both the 75SeHCAT test and plasma lathosterol detect bile acid malabsorption in patients with

In vivo multiphoton imaging of bile duct ligation

NASA Astrophysics Data System (ADS)

Liu, Yuan; Li, Feng-Chieh; Chen, Hsiao-Chin; Chang, Po-shou; Yang, Shu-Mei; Lee, Hsuan-Shu; Dong, Chen-Yuan

2008-02-01

Bile is the exocrine secretion of liver and synthesized by hepatocytes. It is drained into duodenum for the function of digestion or drained into gallbladder for of storage. Bile duct obstruction is a blockage in the tubes that carry bile to the gallbladder and small intestine. However, Bile duct ligation results in the changes of bile acids in serum, liver, urine, and feces1, 2. In this work, we demonstrate a novel technique to image this pathological condition by using a newly developed in vivo imaging system, which includes multiphoton microscopy and intravital hepatic imaging chamber. The images we acquired demonstrate the uptake, processing of 6-CFDA in hepatocytes and excretion of CF in the bile canaliculi. In addition to imaging, we can also measure kinetics of the green fluorescence intensity.

Normal or increased bile acid uptake in isolated mucosa from patients with bile acid malabsorption.

PubMed

Bajor, Antal; Kilander, Anders; Fae, Anita; Gälman, Cecilia; Jonsson, Olof; Ohman, Lena; Rudling, Mats; Sjövall, Henrik; Stotzer, Per-Ove; Ung, Kjell-Arne

2006-04-01

Bile acid malabsorption as reflected by an abnormal Se-labelled homocholic acid-taurine (SeHCAT) test is associated with diarrhoea, but the mechanisms and cause-and-effect relations are unclear. Primarily, to determine whether there is a reduced active bile acid uptake in the terminal ileum in patients with bile acid malabsorption. Secondarily, to study the linkage between bile acid malabsorption and hepatic bile acid synthesis. Ileal biopsies were taken from patients with diarrhoea and from controls with normal bowel habits. Maximal active bile acid uptake was assessed in ileal biopsies using a previously validated technique based on uptake of C-labelled taurocholate. To monitor the hepatic synthesis, 7alpha-hydroxy-4-cholesten-3-one, a bile acid precursor, was assayed in blood. The SeHCAT-retention test was used to diagnose bile acid malabsorption. The taurocholate uptake in specimens from diarrhoea patients was higher compared with the controls [median, 7.7 (n=53) vs 6.1 micromol/g per min (n=17)] (P<0.01) but no difference was seen between those with bile acid malabsorption (n=18) versus diarrhoea with a normal SeHCAT test (n=23). The SeHCAT values and 7alpha-hydroxy-4-cholesten-3-one were inversely correlated. The data do not support bile acid malabsorption being due to a reduced active bile acid uptake capacity in the terminal ileum.

New insights into bile acid malabsorption.

PubMed

Johnston, Ian; Nolan, Jonathan; Pattni, Sanjeev S; Walters, Julian R F

2011-10-01

Bile acid malabsorption occurs when there is impaired absorption of bile acids in the terminal ileum, so interrupting the normal enterohepatic circulation. The excess bile acids in the colon cause diarrhea, and treatment with bile acid sequestrants is beneficial. The condition can be diagnosed with difficulty by measuring fecal bile acids, or more easily by retention of selenohomocholyltaurine (SeHCAT), where this is available. Chronic diarrhea caused by primary bile acid diarrhea appears to be common, but is under-recognized where SeHCAT testing is not performed. Measuring excessive bile acid synthesis with 7α-hydroxy-4-cholesten-3-one may be an alternative means of diagnosis. It appears that there is no absorption defect in primary bile acid diarrhea but, instead, an overproduction of bile acids. Fibroblast growth factor 19 (FGF19) inhibits hepatic bile acid synthesis. Defective production of FGF19 from the ileum may be the cause of primary bile acid diarrhea.

Eversion Bile Duct Anastomosis: A Safe Alternative for Bile Duct Size Discrepancy in Deceased Donor Liver Transplantation.

PubMed

Leal-Leyte, Pilar; McKenna, Greg J; Ruiz, Richard M; Anthony, Tiffany L; Saracino, Giovanna; Giuliano, Testa; Klintmalm, Goran B; Kim, Peter Tw

2018-04-10

Introduction Bile duct size discrepancy in liver transplantation may increase the risk of biliary complications. The aim of this study was to evaluate the safety and outcomes of the eversion bile duct anastomosis technique in deceased donor liver transplantation (DDLT) with duct to duct anastomosis. Methods A total of 210 patients who received a DDLT with duct to duct anastomosis from 2012 to 2017 were divided into two groups: those who had eversion bile duct anastomosis (N=70) and standard bile duct anastomosis (N=140). Biliary complications rates were compared between the two groups. Results There was no difference in the cumulative incidence of biliary strictures (P=0.20) and leaks (P=0.17) between the two groups. The biliary complication rate in the eversion group was 14.3% and 11.4% in the standard anastomosis group. All the biliary complications in the eversion group were managed with endoscopic stenting. A severe size mismatch (≥3:1 ratio) was associated with a significantly higher incidence of biliary strictures (44.4%) compared to 2:1 ratio (8.2%), (P=0.002). Conclusion The use of the eversion technique is a safe alternative for bile duct discrepancy in deceased donor liver transplantation; however, severe bile duct size mismatch may be a risk factor for biliary strictures with such technique. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Recirculation and reutilization of micellar bile lecithin.

PubMed

Robins, S J

1975-09-01

Bile lecithins, solubilized in micellar bile salt and radiolabeled in the 1-acyl fatty acid, phosphorus, and choline positions, were infused in the small bowel of fasted rats. Absorption of each label was virtually complete after 24 h. However, these lecithins were extensively hydrolyzed in the bowel lumen as well as after absorption, and neither the fatty acid nor phosphorus was significantly retained in the enterohepatic circulation or reutilized for biliary lecithin synthesis. In contrast, while choline was also dissociated from absorbed lecithin, choline was instead retained in the liver, reincorporated into newly synthesized hepatic lecithin, and sercreted in biliary lecithin in 10-fold greater amounts than either the fatty acid or phosphorus. However, the extent of choline incorporation into bile lecithin was limited and was not further increased when free choline was directly injected into the portal vein. The data therefore suggest that although only choline of absorbed lecithin is retained in the enterohepatic circulation and preserved for new biliary lecithin synthesis, exogenous choline utilization is regulated by the size of the available hepatic pool.

Hepatic ischemia-reperfusion injury: roles of Ca2+ and other intracellular mediators of impaired bile flow and hepatocyte damage.

PubMed

Nieuwenhuijs, Vincent B; De Bruijn, Menno T; Padbury, Robert T A; Barritt, Gregory J

2006-06-01

Liver resection and liver transplantation have been successful in the treatment of liver tumors and end-stage liver disease. This success has led to an expansion in the pool of patients potentially treatable by liver surgery and, in the case of transplantation, to a shortage of liver donors. At present, there are significant numbers of potential candidates for liver resection and liver donation who have fatty livers, are aged, or have livers damaged by chemotherapy. All of these are at high risk for ischemic reperfusion (IR) injury. The aims of this review are to assess current knowledge of the clinical effectiveness of ischemic preconditioning and intermittent ischemia in reducing IR damage in liver surgery; to evaluate the use of bile flow as a sensitive indicator of IR liver damage; and to analyze the molecular mechanisms, especially intracellular Ca2+, involved in IR injury and ischemic preconditioning. It is concluded that bile flow is a sensitive indicator of IR injury. Together with reactive oxygen species (ROS) and other extracellular and intracellular signaling molecules, intracellular Ca2+ in hepatocytes plays a key role in the normal regulation of bile flow and in IR-induced injury and cell death. Ischemic preconditioning is an effective strategy to reduce IR injury but there is considerable scope for improvement, especially in patients with fatty and aged livers. The development of effective new strategies to reduce IR injury will depend on improved understanding of the molecular mechanisms involved, especially by gaining a better perspective of the relative importance of the various intrahepatocyte signaling pathways involved.

Increased Renal Clearance of Rocuronium Compensates for Chronic Loss of Bile Excretion, via upregulation of Oatp2.

PubMed

Wang, Long; Zhou, Mai-Tao; Chen, Cai-Yang; Yin, Wen; Wen, Da-Xiang; Cheung, Chi-Wai; Yang, Li-Qun; Yu, Wei-Feng

2017-01-13

Requirement for rocuronium upon surgery changes only minimally in patients with end-stage liver diseases. Our study consisted of both human and rat studies to explore the reason. The reduction rate of rocuronium infusion required to maintain neuromuscular blockade during the anhepatic phase (relative to paleohepatic phase) was examined in 16 children with congenital biliary atresia receiving orthotopic liver transplantation. Pharmacodynamics and pharmacokinetics of rocuronium were studied based on BDL rats. The role of increased Oatp2 and decrease Oatp1 expressions in renal compensation were explored. The reduction of rocuronium requirements significantly decreased in obstructively jaundiced children (24 ± 9 vs. 39 ± 11%). TOF50 in BDL rats was increased by functional removal of the kidneys but not the liver, and the percentage of rocuronium excretion through urine increased (20.3 ± 6.9 vs. 8.6 ± 1.8%), while that decreased through bile in 28d-BDL compared with control group. However, this enhanced renal secretion for rocuronium was eliminated by Oatp2 knock-down, rather than Oatp1 overexpression (28-d BDL vs. Oatp1-ShRNA or Oatp2-ShRNA, 20.3 ± 6.9 vs. 17.0 ± 6.6 or 9.3 ± 3.2%). Upon chronic/sub-chronic loss of bile excretion, rocuronium clearance via the kidneys is enhanced, by Oatp2 up-regulation.

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.

Transcription factor FoxA (HNF3) on a nucleosome at an enhancer complex in liver chromatin.

PubMed

Chaya, D; Hayamizu, T; Bustin, M; Zaret, K S

2001-11-30

Nucleosome-like particles and acetylated histones occur near active promoters and enhancers, and certain transcription factors can recognize their target sites on the surface of a nucleosome in vitro; yet it has been unclear whether transcription factors can occupy target sites on nucleosomes in native chromatin. We developed a method for sequential chromatin immunoprecipitation of distinct nuclear proteins that are simultaneously cross-linked to nucleosome-sized genomic DNA segments. We find that core histone H2A co-occupies, along with the FoxA (hepatocyte nuclear factor-3) transcription factor, DNA for the albumin transcriptional enhancer in native liver chromatin, where the enhancer is active. Because histone H2A on nuclear DNA is only known to exist in nucleosomes, we conclude that transcription factors can form a stable complex on nucleosomes at an active enhancer element in vivo.

Role of bile acids and bile acid binding agents in patients with collagenous colitis.

PubMed

Ung, K A; Gillberg, R; Kilander, A; Abrahamsson, H

2000-02-01

In a retrospective study bile acid malabsorption was observed in patients with collagenous colitis. To study the occurrence of bile acid malabsorption and the effect of bile acid binders prospectively in patients with chronic diarrhoea and collagenous colitis. Over 36 months all patients referred because of chronic diarrhoea completed a diagnostic programme, including gastroscopy with duodenal biopsy, colonoscopy with biopsies, and the (75)Se-homocholic acid taurine ((75)SeHCAT) test for bile acid malabsorption. Treatment with a bile acid binder (cholestyramine in 24, colestipol in three) was given, irrespective of the results of the (75)SeHCAT test. Collagenous colitis was found in 28 patients (six men, 22 women), 27 of whom had persistent symptoms and completed the programme. Four patients had had a previous cholecystectomy or a distal gastric resection. The (75)SeHCAT test was abnormal in 12/27 (44%) of the collagenous colitis patients with (75)SeHCAT values 0.5-9.7%, and normal in 15 patients (56%). Bile acid binding treatment was followed by a rapid, marked, or complete improvement in 21/27 (78%) of the collagenous colitis patients. Rapid improvement occurred in 11/12 (92%) of the patients with bile acid malabsorption compared with 10/15 (67%) of the patients with normal (75)SeHCAT tests. Bile acid malabsorption is common in patients with collagenous colitis and is probably an important pathophysiological factor. Because of a high response rate without serious side effects, bile acid binding treatment should be considered for collagenous colitis, particularly patients with bile acid malabsorption.

Role of bile acids and bile acid binding agents in patients with collagenous colitis

PubMed Central

Ung, K; Gillberg, R; Kilander, A; Abrahamsson, H

2000-01-01

BACKGROUND—In a retrospective study bile acid malabsorption was observed in patients with collagenous colitis.
AIMS—To study the occurrence of bile acid malabsorption and the effect of bile acid binders prospectively in patients with chronic diarrhoea and collagenous colitis.
METHODS—Over 36 months all patients referred because of chronic diarrhoea completed a diagnostic programme, including gastroscopy with duodenal biopsy, colonoscopy with biopsies, and the 75Se-homocholic acid taurine (75SeHCAT) test for bile acid malabsorption. Treatment with a bile acid binder (cholestyramine in 24, colestipol in three) was given, irrespective of the results of the 75SeHCAT test.
RESULTS—Collagenous colitis was found in 28 patients (six men, 22 women), 27 of whom had persistent symptoms and completed the programme. Four patients had had a previous cholecystectomy or a distal gastric resection. The 75SeHCAT test was abnormal in 12/27 (44%) of the collagenous colitis patients with 75SeHCAT values 0.5-9.7%, and normal in 15 patients (56%). Bile acid binding treatment was followed by a rapid, marked, or complete improvement in 21/27 (78%) of the collagenous colitis patients. Rapid improvement occurred in 11/12 (92%) of the patients with bile acid malabsorption compared with 10/15 (67%) of the patients with normal 75SeHCAT tests.
CONCLUSION—Bile acid malabsorption is common in patients with collagenous colitis and is probably an important pathophysiological factor. Because of a high response rate without serious side effects, bile acid binding treatment should be considered for collagenous colitis, particularly patients with bile acid malabsorption.


Keywords: bile acid malabsorption; collagenous colitis; diarrhoea; cholestyramine; colestipol PMID:10644309

Role of cholangiocyte bile Acid transporters in large bile duct injury after rat liver transplantation.

PubMed

Cheng, Long; Zhao, Lijin; Li, Dajiang; Liu, Zipei; Chen, Geng; Tian, Feng; Li, Xiaowu; Wang, Shuguang

2010-07-27

The pathogenesis of nonanastomotic strictures with a patent hepatic artery remains to be investigated. This study focuses on the role of cholangiocyte bile acid transporters in bile duct injury after liver transplantation. Sprague-Dawley rats were divided into three groups (n=20 for each): the sham-operated group (Sham), the transplant group with 1-hr donor liver cold preservation (CP-1h), and the transplant group with 12-hr donor liver cold preservation (CP-12h). Bile was collected for biochemical analysis. The histopathologic evaluation of bile duct injury was performed and the cholangiocyte bile acid transporters apical sodium-dependent bile acid transporter (ASBT), ileal lipid binding protein (ILBP), and Ostalpha/Ostbeta were investigated. RESULTS.: The immunohistochemical assay suggested that ASBT and ILBP were expressed exclusively on large bile duct epithelial cells, whereas Ostalpha and Ostbeta were expressed on both small and large bile ducts. Western blot and quantitative polymerase chain reaction analysis showed that the expression levels of these transporters dramatically decreased after transplantation. It took seven to 14 days for ILBP, Ostalpha, and Ostbeta to recover, whereas ASBT recovered within 3 days and even reached a peak above the normal level seven days after operation. In the CP-12h group, the ratios of the ASBT/ILBP, ASBT/Ostalpha and ASBT/Ostbeta expression levels were correlated with the injury severity scores of large but not small bile ducts. The results suggest that the unparallel alteration of cholangiocyte bile acid transporters may play a potential role in large bile duct injury after liver transplantation with prolonged donor liver preservation.

Determination of Bile Acids in Piglet Bile by Solid Phase Extraction and Liquid Chromatography-Electrospray Tandem Mass Spectrometry.

PubMed

Mi, Si; Lim, David W; Turner, Justine M; Wales, Paul W; Curtis, Jonathan M

2016-03-01

An LC/MS/MS-based method was developed for the determination of individual bile acids (BA) and their conjugates in porcine bile samples. The C18-based solid-phase extraction (SPE) procedure was optimized so that all 19 target BA and their glycine and taurine conjugates were collected with high recoveries for standards (89.1-100.2%). Following this, all 19 compounds were separated and quantified in a single 12 min chromatographic run. The method was validated in terms of linearity, sensitivity, accuracy, precision, and recovery. An LOD in the low ppb range with measured precisions in the range of 0.5-9.3% was achieved. The recoveries for all of the 19 analytes in bile samples were all >80%. The validated method was successfully applied to the profiling of BA and their conjugates in the bile from piglets treated with exogenous glucagon-like peptide-2 (GLP-2) in a preclinical model of neonatal parenteral nutrition-associated liver disease (PNALD). The method developed is rapid and could be easily implemented for routine analysis of BA and their conjugates in other biofluids or tissues.

Bile acid aspiration in suspected ventilator-associated pneumonia.

PubMed

Wu, Yu-Chung; Hsu, Po-Kuei; Su, Kang-Cheng; Liu, Lung-Yu; Tsai, Cheng-Chien; Tsai, Shu-Ho; Hsu, Wen-Hu; Lee, Yu-Chin; Perng, Diahn-Warng

2009-07-01

The aims of this study were to measure the levels of bile acids in patients with suspected ventilator-associated pneumonia (VAP) and provide a possible pathway for neutrophilic inflammation to explain its proinflammatory effect on the airway. Bile acid levels were measured by spectrophotometric enzymatic assay, and liquid chromatography mass spectrometry was used to quantify the major bile acids. Alveolar cells were grown on modified air-liquid interface culture inserts, and bile acids were then employed to stimulate the cells. Reverse transcriptase polymerase chain reaction and Western blots were used to determine the involved gene expression and protein levels. The mean (+/- SE) concentration of total bile acids in tracheal aspirates was 6.2 +/- 2.1 and 1.1 +/- 0.4 mumol/L/g sputum, respectively, for patients with and without VAP (p < 0.05). The interleukin (IL)-8 level was significantly higher in the VAP group (p < 0.05). The major bile acid, chenodeoxycholic acid, stimulated alveolar epithelial cells to increase IL-8 production at both the messenger RNA and protein level through p38 and c-Jun N-terminal kinase (JNK) activation. The selective p38 and JNK inhibitors, as well as dexamethasone, successfully inhibited IL-8 production. These data suggest that early intervention to prevent bile acid aspiration may reduce the intensity of neutrophilic inflammation in intubated and mechanically ventilated patients in the ICU.

Comparison of Salmonella enterica Serovars Typhi and Typhimurium Reveals Typhoidal Serovar-Specific Responses to Bile

PubMed Central

Johnson, Rebecca; Ravenhall, Matt; Pickard, Derek; Dougan, Gordon; Byrne, Alexander

2017-01-01

ABSTRACT Salmonella enterica serovars Typhi and Typhimurium cause typhoid fever and gastroenteritis, respectively. A unique feature of typhoid infection is asymptomatic carriage within the gallbladder, which is linked with S. Typhi transmission. Despite this, S. Typhi responses to bile have been poorly studied. Transcriptome sequencing (RNA-Seq) of S. Typhi Ty2 and a clinical S. Typhi isolate belonging to the globally dominant H58 lineage (strain 129-0238), as well as S. Typhimurium 14028, revealed that 249, 389, and 453 genes, respectively, were differentially expressed in the presence of 3% bile compared to control cultures lacking bile. fad genes, the actP-acs operon, and putative sialic acid uptake and metabolism genes (t1787 to t1790) were upregulated in all strains following bile exposure, which may represent adaptation to the small intestine environment. Genes within the Salmonella pathogenicity island 1 (SPI-1), those encoding a type IIII secretion system (T3SS), and motility genes were significantly upregulated in both S. Typhi strains in bile but downregulated in S. Typhimurium. Western blots of the SPI-1 proteins SipC, SipD, SopB, and SopE validated the gene expression data. Consistent with this, bile significantly increased S. Typhi HeLa cell invasion, while S. Typhimurium invasion was significantly repressed. Protein stability assays demonstrated that in S. Typhi the half-life of HilD, the dominant regulator of SPI-1, is three times longer in the presence of bile; this increase in stability was independent of the acetyltransferase Pat. Overall, we found that S. Typhi exhibits a specific response to bile, especially with regard to virulence gene expression, which could impact pathogenesis and transmission. PMID:29229736

Bile duct hamartomas (von Mayenburg complexes) mimicking liver metastases from bile duct cancer: MRC findings

PubMed Central

Nagano, Yasuhiko; Matsuo, Kenichi; Gorai, Katsuya; Sugimori, Kazuya; Kunisaki, Chikara; Ike, Hideyuki; Tanaka, Katsuaki; Imada, Toshio; Shimada, Hiroshi

2006-01-01

We present a case of a 72-year-old man with a common bile duct cancer, who was initially believed to have multiple liver metastases based on computed tomography findings, and in whom magnetic resonance cholangiography (MRC) revealed a diagnosis of bile duct hamartomas. At exploration for pancreaticoduodenectomy, liver palpation revealed disseminated nodules at the surface of the liver. These nodules showed gray-white nodular lesions of about 0.5 cm in diameter scattered on the surface of both liver lobes, which were looked like multiple liver metastases from bile duct cancer. Frozen section of the liver biopsy disclosed multiple bile ducts with slightly dilated lumens embedded in the collagenous stroma characteristics of multiple bile duct hamartomas (BDHs). Only two reports have described the MRC features of bile duct hamartomas. Of all imaging procedures, MRC provides the most relevant features for the imaging diagnosis of bile duct hamartomas. PMID:16534895

Bile acid metabolism regulated by the gut microbiota promotes non-alcoholic steatohepatitis-associated hepatocellular carcinoma in mice

PubMed Central

Yamada, Shoji; Takashina, Yoko; Watanabe, Mitsuhiro; Nagamine, Ryogo; Saito, Yoshimasa; Kamada, Nobuhiko; Saito, Hidetsugu

2018-01-01

Gut microbiota plays a significant role in the development of hepatocellular carcinoma (HCC) in non-alcoholic steatohepatitis (NASH). However, understanding of the precise mechanism of this process remains incomplete. A new class steatohepatitis-inducing high-fat diet (HFD), namely STHD-01, can promote the development of HCC without the administration of chemical carcinogens. Using this diet, we comprehensively analyzed changes in the gut microbiota and its metabolic functions during the development of HCC in NASH. Mice fed the STHD-01 developed NASH within 9 weeks. NASH further progressed into HCC by 41 weeks. Treatment with antibiotics significantly attenuated liver pathology and suppressed tumor development, indicating the critical role of the gut microbiota in tumor development in this model. Accumulation of cholesterol and bile acids in the liver and feces increased after feeding the mice with STHD-01. Treatment with antibiotics did not reverse these phenotypes. In contrast, accumulation of secondary bile acids was dramatically reduced after the treatment with antibiotics, suggesting the critical role of the gut microbiota in the conversion of primary bile acids to secondary bile acids. Secondary bile acids such as deoxycholic acid activated the mTOR, pathway in hepatocytes. Activation of mTOR was observed in the liver of mice fed STHD-01, and the activation was reduced when mice were treated with antibiotics. Collectively, bile acid metabolism by the gut microbiota promotes HCC development in STHD-01-induced NASH. PMID:29515780

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

Bile Duct Cancer

MedlinePlus

... the liver get rid of toxins and wastes. Bile duct cancer is rare. It can happen in the parts ... Itchy skin Fever Abdominal pain Tests to diagnose bile duct cancer may include a physical exam, imaging tests of ...

1,2-Dibromo-4-(1,2-dibromoethyl)-cyclohexane and tris(methylphenyl) phosphate cause significant effects on development, mRNA expression, and circulating bile acid concentrations in chicken embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crump, Doug, E-mail: doug.crump@ec.gc.ca; Porter, Emily; Egloff, Caroline

1,2-Dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH; formerly abbreviated as TBECH) and tris(methylphenyl) phosphate (TMPP; formerly abbreviated as TCP) are additive flame retardants that are detected in the environment and biota. A recent avian in vitro screening study of 16 flame retardants identified DBE-DBCH and TMPP as important chemicals for follow-up in ovo evaluation based on their effects on cytotoxicity and mRNA expression in avian hepatocytes. In this study, technical mixtures of DBE-DBCH and TMPP were injected into the air cell of chicken embryos at concentrations ranging from 0 to 54,900 ng/g and from 0 to 261,400 ng/g, respectively, to determine effects on pipping success,more » development, hepatic mRNA expression, thyroid hormone levels, and circulating bile acid concentrations. Both compounds were detectable in embryos at pipping and the β-DBE-DBCH isomer was depleted more rapidly than the α-isomer in tissue samples. DBE-DBCH had limited effects on the endpoints measured, with the exception of the up-regulation of two phase I metabolizing enzymes, CYP3A37 and CYP2H1. TMPP exposure caused embryonic deformities, altered growth, increased liver somatic index (LSI) and plasma bile acid concentrations, and altered mRNA expression levels of genes associated with xenobiotic and lipid metabolism and the thyroid hormone pathway. Overall, TMPP elicited more adverse molecular and phenotypic effects than DBE-DBCH albeit at concentrations several orders of magnitude greater than those detected in the environment. The increase in plasma bile acid concentrations was a useful phenotypic anchor as it was associated with a concomitant increase in LSI, discoloration of the liver tissue, and modulation of hepatic genes involved with xenobiotic and lipid metabolism. - Highlights: • DBE-DBCH and TMPP are not embryolethal to chicken embryos. • TMPP caused deformities, morphometric alterations, and increased plasma bile acids. • DBE-DBCH and TMPP altered m

Managing bile acid diarrhoea.

PubMed

Walters, Julian R F; Pattni, Sanjeev S

2010-11-01

Bowel symptoms including diarrhoea can be produced when excess bile acids (BA) are present in the colon. This condition, known as bile acid or bile salt malabsorption, has been under recognized, as the best diagnostic method, the (75)Se-homocholic acid taurine (SeHCAT) test, is not available in many countries and is not fully utilized in others. Reduced SeHCAT retention establishes that this is a complication of many other gastrointestinal diseases. Repeated studies show SeHCAT tests are abnormal in about 30% of patients otherwise diagnosed as diarrhoea-predominant irritable bowel syndrome or functional diarrhoea, with an estimated population prevalence of around 1%. Recent work suggests that the condition previously called idiopathic bile acid malabsorption (BAM) is not in fact due to a defect in absorption, but results from an overproduction of BA because of defective feedback inhibition of hepatic bile acid synthesis, a function of the ileal hormone fibroblast growth factor 19 (FGF19). The approach to treatment currently depends on binding excess BA, to reduce their secretory actions, using colestyramine, colestipol and, most recently, colesevelam. Colesevelam has a number of potential advantages that merit further investigation in trials directed at patients with bile acid diarrhoea.

Predicting Infected Bile Among Patients Undergoing Percutaneous Cholecystostomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beardsley, Shannon L.; Shlansky-Goldberg, Richard D.; Patel, Aalpen

2005-04-15

Purpose. Patients may not achieve a clinical benefit after percutaneous cholecystostomy due to the inherent difficulty in identifying patients who truly have infected gallbladders. We attempted to identify imaging and biochemical parameters which would help to predict which patients have infected gallbladders. Methods. A retrospective review was performed of 52 patients undergoing percutaneous cholecystostomy for clinical suspicion of acute cholecystitis in whom bile culture results were available. Multiple imaging and biochemical variables were examined alone and in combination as predictors of infected bile, using logistic regression. Results. Of the 52 patients, 25 (48%) had infected bile. Organisms cultured included Enterococcus,more » Enterobacter, Klebsiella, Pseudomonas, E. coli, Citrobacter and Candida. No biochemical parameters were significantly predictive of infected bile; white blood cell count >15,000 was weakly associated with greater odds of infected bile (odds ratio 2.0, p = NS). The presence of gallstones, sludge, gallbladder wall thickening and pericholecystic fluid by ultrasound or CT were not predictive of infected bile, alone or in combination, although a trend was observed among patients with CT findings of acute cholecystitis toward a higher 30-day mortality. Radionuclide scans were performed in 31% of patients; all were positive and 66% of these patients had infected bile. Since no patient who underwent a radionuclide scan had a negative study, this variable could not be entered into the regression model due to collinearity. Conclusion. No single CT or ultrasound imaging variable was predictive of infected bile, and only a weak association of white blood cell count with infected bile was seen. No other biochemical parameters had any association with infected bile. The ability of radionuclide scanning to predict infected bile was higher than that of ultrasound or CT. This study illustrates the continued challenge to identify bacterial

Preventive saline irrigation of the bile duct after the endoscopic removal of common bile duct stones.

PubMed

Jang, Sang Eon; Ahn, Dong-Won; Lee, Sang Hyub; Lee, Ban Seok; Jeong, Ji Bong; Hwang, Jin-Hyeok; Ryu, Ji Kon; Kim, Yong-Tae; Lee, Kyoung Ho; Kim, Young Hoon

2013-08-01

Small stone fragments after an endoscopic stone extraction for choledocholithiasis may act as the nidus for recurrent choledocholithiasis. Therefore, efforts to eliminate the nidus might reduce the recurrence of choledocholithiasis and cholangitis related to choledocholithiasis. The purpose of this study was to determine whether an additional preventive saline irrigation of the bile duct after the endoscopic removal of common bile duct stones would decrease residual stones and the recurrence of cholangitis. A retrospective analysis was performed for the consecutively collected data about the patients who underwent the complete endoscopic treatment for common bile duct stone. Among 99 patients, 45 patients underwent saline irrigation. Residual stones were detected in 18 patients (18.2 %). The incidences of residual stones were 8.9 % (4 of 45 patients) in the irrigation group and 25.9 % (14 of 54 patients) in the non-irrigation group (P = 0.037). In multivariate analysis, preventive saline irrigation was found to be the only significant factor for the decrease of residual stones (HR = 0.258, P = 0.039). When analyzing the occurrence of recurrent cholangitis and the procedure related to complications, there were no significant differences according to the performance of preventive saline irrigation of the bile duct. Preventive saline irrigation could reduce the residual common bile duct stones without complications.

Repression of Salmonella enterica phoP Expression by Small Molecules from Physiological Bile

PubMed Central

Antunes, L. Caetano M.; Wang, Melody; Andersen, Sarah K.; Ferreira, Rosana B. R.; Kappelhoff, Reinhild; Han, Jun; Borchers, Christoph H.

2012-01-01

Infection with Salmonella enterica serovar Typhi in humans causes the life-threatening disease typhoid fever. In the laboratory, typhoid fever can be modeled through the inoculation of susceptible mice with Salmonella enterica serovar Typhimurium. Using this murine model, we previously characterized the interactions between Salmonella Typhimurium and host cells in the gallbladder and showed that this pathogen can successfully invade gallbladder epithelial cells and proliferate. Additionally, we showed that Salmonella Typhimurium can use bile phospholipids to grow at high rates. These abilities are likely important for quick colonization of the gallbladder during typhoid fever and further pathogen dissemination through fecal shedding. To further characterize the interactions between Salmonella and the gallbladder environment, we compared the transcriptomes of Salmonella cultures grown in LB broth or physiological murine bile. Our data showed that many genes involved in bacterial central metabolism are affected by bile, with the citric acid cycle being repressed and alternative respiratory systems being activated. Additionally, our study revealed a new aspect of Salmonella interactions with bile through the identification of the global regulator phoP as a bile-responsive gene. Repression of phoP expression could also be achieved using physiological, but not commercial, bovine bile. The biological activity does not involve PhoPQ sensing of a bile component and is not caused by bile acids, the most abundant organic components of bile. Bioactivity-guided purification allowed the identification of a subset of small molecules from bile that can elicit full activity; however, a single compound with phoP inhibitory activity could not be isolated, suggesting that multiple molecules may act in synergy to achieve this effect. Due to the critical role of phoP in Salmonella virulence, further studies in this area will likely reveal aspects of the interaction between Salmonella

Bile Reflux Scintigraphy After Mini-Gastric Bypass.

PubMed

Saarinen, Tuure; Räsänen, Jari; Salo, Jarmo; Loimaala, Antti; Pitkonen, Miia; Leivonen, Marja; Juuti, Anne

2017-08-01

Significant weight-loss and diabetes remission have been reported after mini-gastric bypass (MGB). Concern has been raised regarding postoperative bile reflux (BR), but it has not been demonstrated in previous studies. We set out to find out if BR is evident in hepatobiliary scintigraphy after MGB. Nine consecutive patients, seven with type 2 diabetes, underwent MGB (15 cm gastric tube, 250-275 cm biliary limb) at our institution with a 12-month follow-up, with none lost to follow-up. Then, 10.7 months (8.6-13.0) after MGB, all patients underwent hepatobiliary scintigraphy and a reflux symptom questionnaire (GerdQ) was filled out. A gastroscopy with biopsies was done for all patients with a bile-reflux-positive scintigraphy. Mean age at operation was 56 years (41-65) and preoperative BMI 43.1 kg/m 2 (34.2-54.6). Mean %EWL was 83.9 (49.5-128.3) at 12 months. Four patients reached diabetes remission and two became insulin-independent. Hepatobiliary scintigraphy showed a transient BR into the gastric tube for five patients. Bile tracer was found in the gastric tube at 23-58 min after the tracer injection and highest activity was 8% (1-8%) at 58 min. Bile tracer was not found in the esophagus of any of the patients. One patient with a positive scintigraphy in the gastric tube required re-operation. Two patients with reflux symptoms had a negative scintigraphy. Our results indicate that transient bile reflux is common after MGB in the gastric tube, but not in the esophagus. The clinical relevance of bile reflux needs further studies.

Revising the embryonic origin of thyroid C cells in mice and humans

PubMed Central

Johansson, Ellen; Andersson, Louise; Örnros, Jessica; Carlsson, Therese; Ingeson-Carlsson, Camilla; Liang, Shawn; Dahlberg, Jakob; Jansson, Svante; Parrillo, Luca; Zoppoli, Pietro; Barila, Guillermo O.; Altschuler, Daniel L.; Padula, Daniela; Lickert, Heiko; Fagman, Henrik; Nilsson, Mikael

2015-01-01

Current understanding infers a neural crest origin of thyroid C cells, the major source of calcitonin in mammals and ancestors to neuroendocrine thyroid tumors. The concept is primarily based on investigations in quail–chick chimeras involving fate mapping of neural crest cells to the ultimobranchial glands that regulate Ca2+ homeostasis in birds, reptiles, amphibians and fishes, but whether mammalian C cell development involves a homologous ontogenetic trajectory has not been experimentally verified. With lineage tracing, we now provide direct evidence that Sox17+ anterior endoderm is the only source of differentiated C cells and their progenitors in mice. Like many gut endoderm derivatives, embryonic C cells were found to coexpress pioneer factors forkhead box (Fox) a1 and Foxa2 before neuroendocrine differentiation takes place. In the ultimobranchial body epithelium emerging from pharyngeal pouch endoderm in early organogenesis, differential Foxa1/Foxa2 expression distinguished two spatially separated pools of C cell precursors with different growth properties. A similar expression pattern was recapitulated in medullary thyroid carcinoma cells in vivo, consistent with a growth-promoting role of Foxa1. In contrast to embryonic precursor cells, C cell-derived tumor cells invading the stromal compartment downregulated Foxa2, foregoing epithelial-to-mesenchymal transition designated by loss of E-cadherin; both Foxa2 and E-cadherin were re-expressed at metastatic sites. These findings revise mammalian C cell ontogeny, expand the neuroendocrine repertoire of endoderm and redefine the boundaries of neural crest diversification. The data further underpin distinct functions of Foxa1 and Foxa2 in both embryonic and tumor development. PMID:26395490

Epimorphin regulates bile duct formation via effects on mitosis orientation in rat liver epithelial stem-like cells.

PubMed

Zhou, Junnian; Zhao, Lei; Qin, Lipeng; Wang, Jing; Jia, Yali; Yao, Hailei; Sang, Chen; Hu, Qinghua; Shi, Shuangshuang; Nan, Xue; Yue, Wen; Zhuang, Fengyuan; Yang, Chun; Wang, Yunfang; Pei, Xuetao

2010-03-17

Understanding how hepatic precursor cells can generate differentiated bile ducts is crucial for studies on epithelial morphogenesis and for development of cell therapies for hepatobiliary diseases. Epimorphin (EPM) is a key morphogen for duct morphogenesis in various epithelial organs. The role of EPM in bile duct formation (DF) from hepatic precursor cells, however, is not known. To address this issue, we used WB-F344 rat epithelial stem-like cells as model for bile duct formation. A micropattern and a uniaxial static stretch device was used to investigate the effects of EPM and stress fiber bundles on the mitosis orientation (MO) of WB cells. Immunohistochemistry of liver tissue sections demonstrated high EPM expression around bile ducts in vivo. In vitro, recombinant EPM selectively induced DF through upregulation of CK19 expression and suppression of HNF3alpha and HNF6, with no effects on other hepatocytic genes investigated. Our data provide evidence that EPM guides MO of WB-F344 cells via effects on stress fiber bundles and focal adhesion assembly, as supported by blockade EPM, beta1 integrin, and F-actin assembly. These blockers can also inhibit EPM-induced DF. These results demonstrate a new biophysical action of EPM in bile duct formation, during which determination of MO plays a crucial role.

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.

Effects of taurodihydrofusidate, a bile salt analogue, on bile formation and biliary lipid secretion in the rhesus monkey.

PubMed Central

Beaudoin, M; Carey, M C; Small, D M

1975-01-01

Bile salts play a major role in bile formation and biliary lipid secretion. Sodium taurodihydrofusidate (TDHF), a derivative of the antibiotic fusidic acid, closely resembles bile salts in terms of structure, micellar characteristics, and capacity ot solubilize otherwise insolbule lipids. We have therefore studied the biliary secretion of this bile salt analogue and its influence on bile formation and biliary lipid secretion in primates. Alert, unanesthetized female rhesus monkeys prepared with a total biliary fistula were allowed to reach a steady bile salt secretion rate before each study. In three animals (group I),[14C]TDHF was infused intravenously. Most of the compound was secreted rapidly in bile chemically unchanged. The biliary secretion of this drug produced a twofold increase in bile flow; however, the bile salt output was markedly reduced during the infusion. In spite of this reduction, the phospholipid output remained essentially unchanged whereas the cholesterol output increased almost twofold. In five other animals (group II), the effect of TDHF on the bile salt secretion was further investigated by an intravenous infusion of [14C]taurocholate followed by a combined infusion of [14C]taurocholate and TDHF. When TDHF was added to the infusate, a reduction in the [14C]taurocholate output and a progressive rise in the plasma [14C]taurocholate concentration were observed in each animal. An analysis of the data in both groups indicates that (a) the most likely explanation to account for the decreased bile salt output is that the bile salt analogue, TDHF, interfered with bile salt secretion into the biliary canaliculi; (b) TDHF induces a greater secretion of biliary water than was observed with bile salts, an effect consistent with a stimulation of the bile salt-independent canalicular flow; (c) at similar 3alpha-hydroxysteroid secretion rates TDHF caused a significant increase in cholesterol secretion compared to that induced by bile salt. This finding

Financial Aspects of Bile Duct Injuries.

PubMed

Palaz Alı, Ozgkıour; Ibis, Abdil Cem; Gurtekin, Basak

2017-11-04

BACKGROUND Major bile duct injury is the most worrisome complication of cholecystectomy. There is no detailed data about the incidence or treatment-related costs of bile duct injuries in Turkey. We aimed to determine prevalence and therapeutic costs of patients with major biliary duct injuries managed in our department, and further estimate a projection of these parameters at the national level. MATERIAL AND METHODS All patients admitted due to bile duct injury during cholecystectomy from 2011 to 2014 were included. Healthcare costs were calculated by summing of their all treatment-related costs in Istanbul Medical Faculty. We collected 2014-2015 data on number of patients diagnosed with cholecystitis in Turkey, the number of cholecystectomies, and the number of the interventions performed following these initial surgeries, which were obtained from the Turkish Social Security Institution. RESULTS Forty-nine patients were enrolled and bilioenteric diversion was performed in 39 patients: 20.4% of patients had Bismuth II, 38.8% had Bismuth III, and 40.8% had Bismuth IV biliary stricture. Comparison of stricture types with total costs, days of hospitalization, and outpatient clinic costs revealed significant differences. Mean total cost of corrective surgeries was 9199 TRY. We estimated that 1.5% to 2.4% of patients who underwent cholecystectomy in Turkey have bile duct injury (including 0.3% with major bile duct injury). CONCLUSIONS New preventive strategies should be used to avoid bile duct injuries, which have a huge financial impact on the national economy.

Bile acid patterns in commercially available oxgall powders used for the evaluation of the bile tolerance ability of potential probiotics

PubMed Central

Hu, Peng-Li; Yuan, Ya-Hong; Yue, Tian-Li

2018-01-01

This study aimed to analyze the bile acid patterns in commercially available oxgall powders used for evaluation of the bile tolerance ability of probiotic bacteria. Qxgall powders purchased from Sigma-Aldrich, Oxoid and BD Difco were dissolved in distilled water, and analyzed. Conjugated bile acids were profiled by ion-pair high-performance liquid chromatography (HPLC), free bile acids were detected as their p-bromophenacyl ester derivatives using reversed-phase HPLC after extraction with acetic ether, and total bile acids were analyzed by enzymatic-colorimetric assay. The results showed that 9 individual bile acids (i.e., taurocholic acid, glycocholic acid, taurodeoxycholic acid, glycodeoxycholic acid, taurochenodeoxycholic acid, glycochenodeoxycholic acid, cholic acid, chenodeoxycholic acid, deoxycholic acid) were present in each of the oxgall powders tested. The content of total bile acid among the three oxgall powders was similar; however, the relative contents of the individual bile acids among these oxgall powders were significantly different (P < 0.001). The oxgall powder from Sigma-Aldrich was closer to human bile in the ratios of glycine-conjugated bile acids to taurine-conjugated bile acids, dihydroxy bile acids to trihydroxy bile acids, and free bile acids to conjugated bile acids than the other powders were. It was concluded that the oxgall powder from Sigma-Aldrich should be used instead of those from Oxoid and BD Difco to evaluate the bile tolerance ability of probiotic bacteria as human bile model. PMID:29494656

[Correlations of bile acids in the bile of rats in conditions of alloxan induced diabetes melitus].

PubMed

Danchenko, N M; Vesel'skyĭ, S P; Tsudzevych, B O

2014-01-01

The ratio of bile acids in the bile of rats with alloxan diabetes was investigated using the method of thin-layer chromatography. Changes of coefficients of conjugation and hydroxylation of bile acids were calculated and analyzed in half-hour samples of bile obtained during the 3-hour experiment. It has been found that the processes of conjugation of cholic acid with glycine and taurine are inhibited in alloxan diabetes. At the same time a significant increase of free threehydroxycholic and dixydroxycholic bile acids and conjugates of the latter ones with taurine has been registered. Coefficients of hydroxylation in alloxan diabetes show the domination of "acidic" pathway in bile acid biosynthesis that is tightly connected with the activity of mitochondrial enzymes.

Managing bile acid diarrhoea

PubMed Central

Walters, Julian R. F.; Pattni, Sanjeev S.

2010-01-01

Bowel symptoms including diarrhoea can be produced when excess bile acids (BA) are present in the colon. This condition, known as bile acid or bile salt malabsorption, has been under recognized, as the best diagnostic method, the 75Se-homocholic acid taurine (SeHCAT) test, is not available in many countries and is not fully utilized in others. Reduced SeHCAT retention establishes that this is a complication of many other gastrointestinal diseases. Repeated studies show SeHCAT tests are abnormal in about 30% of patients otherwise diagnosed as diarrhoea-predominant irritable bowel syndrome or functional diarrhoea, with an estimated population prevalence of around 1%. Recent work suggests that the condition previously called idiopathic bile acid malabsorption (BAM) is not in fact due to a defect in absorption, but results from an overproduction of BA because of defective feedback inhibition of hepatic bile acid synthesis, a function of the ileal hormone fibroblast growth factor 19 (FGF19). The approach to treatment currently depends on binding excess BA, to reduce their secretory actions, using colestyramine, colestipol and, most recently, colesevelam. Colesevelam has a number of potential advantages that merit further investigation in trials directed at patients with bile acid diarrhoea. PMID:21180614

Bile leakage test in liver resection: A systematic review and meta-analysis

PubMed Central

Wang, Hai-Qing; Yang, Jian; Yang, Jia-Yin; Yan, Lu-Nan

2013-01-01

AIM: To assess systematically the safety and efficacy of bile leakage test in liver resection. METHODS : Randomized controlled trials and controlled clinical trials involving the bile leakage test were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate postoperative bile leakage, intraoperative positive bile leakage, and complications. We used either the fixed-effects or random-effects model. RESULTS: Eight studies involving a total of 1253 patients were included and they all involved the bile leakage test in liver resection. The bile leakage test group was associated with a significant reduction in bile leakage compared with the non-bile leakage test group (RR = 0.39, 95%CI: 0.23-0.67; I2 = 3%). The white test had superiority for detection of intraoperative bile leakage compared with the saline solution test (RR = 2.38, 95%CI: 1.24-4.56, P = 0.009). No significant intergroup differences were observed in total number of complications, ileus, liver failure, intraperitoneal hemorrhage, pulmonary disorder, abdominal infection, and wound infection. CONCLUSION: The bile leakage test reduced postoperative bile leakage and did not increase incidence of complications. Fat emulsion is the best choice of solution for the test. PMID:24363535

Bile leakage test in liver resection: a systematic review and meta-analysis.

PubMed

Wang, Hai-Qing; Yang, Jian; Yang, Jia-Yin; Yan, Lu-Nan

2013-12-07

To assess systematically the safety and efficacy of bile leakage test in liver resection. Randomized controlled trials and controlled clinical trials involving the bile leakage test were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate postoperative bile leakage, intraoperative positive bile leakage, and complications. We used either the fixed-effects or random-effects model. Eight studies involving a total of 1253 patients were included and they all involved the bile leakage test in liver resection. The bile leakage test group was associated with a significant reduction in bile leakage compared with the non-bile leakage test group (RR = 0.39, 95%CI: 0.23-0.67; I (2) = 3%). The white test had superiority for detection of intraoperative bile leakage compared with the saline solution test (RR = 2.38, 95%CI: 1.24-4.56, P = 0.009). No significant intergroup differences were observed in total number of complications, ileus, liver failure, intraperitoneal hemorrhage, pulmonary disorder, abdominal infection, and wound infection. The bile leakage test reduced postoperative bile leakage and did not increase incidence of complications. Fat emulsion is the best choice of solution for the test. © 2013 Baishideng Publishing Group Co., Limited. All rights reserved.

Inhibition of intestinal bile acid absorption improves cholestatic liver and bile duct injury in a mouse model of sclerosing cholangitis.

PubMed

Baghdasaryan, Anna; Fuchs, Claudia D; Österreicher, Christoph H; Lemberger, Ursula J; Halilbasic, Emina; Påhlman, Ingrid; Graffner, Hans; Krones, Elisabeth; Fickert, Peter; Wahlström, Annika; Ståhlman, Marcus; Paumgartner, Gustav; Marschall, Hanns-Ulrich; Trauner, Michael

2016-03-01

Approximately 95% of bile acids (BAs) excreted into bile are reabsorbed in the gut and circulate back to the liver for further biliary secretion. Therefore, pharmacological inhibition of the ileal apical sodium-dependent BA transporter (ASBT/SLC10A2) may protect against BA-mediated cholestatic liver and bile duct injury. Eight week old Mdr2(-/-) (Abcb4(-/-)) mice (model of cholestatic liver injury and sclerosing cholangitis) received either a diet supplemented with A4250 (0.01% w/w) - a highly potent and selective ASBT inhibitor - or a chow diet. Liver injury was assessed biochemically and histologically after 4weeks of A4250 treatment. Expression profiles of genes involved in BA homeostasis, inflammation and fibrosis were assessed via RT-PCR from liver and ileum homogenates. Intestinal inflammation was assessed by RNA expression profiling and immunohistochemistry. Bile flow and composition, as well as biliary and fecal BA profiles were analyzed after 1week of ASBT inhibitor feeding. A4250 improved sclerosing cholangitis in Mdr2(-/-) mice and significantly reduced serum alanine aminotransferase, alkaline phosphatase and BAs levels, hepatic expression of pro-inflammatory (Tnf-α, Vcam1, Mcp-1) and pro-fibrogenic (Col1a1, Col1a2) genes and bile duct proliferation (mRNA and immunohistochemistry for cytokeratin 19 (CK19)). Furthermore, A4250 significantly reduced bile flow and biliary BA output, which correlated with reduced Bsep transcription, while Ntcp and Cyp7a1 were induced. Importantly A4250 significantly reduced biliary BA secretion but preserved HCO3(-) and biliary phospholipid secretion resulting in an increased HCO3(-)/BA and PL/BA ratio. In addition, A4250 profoundly increased fecal BA excretion without causing diarrhea and altered BA pool composition, resulting in diminished concentrations of primary BAs tauro-β-muricholic acid and taurocholic acid. Pharmacological ASBT inhibition attenuates cholestatic liver and bile duct injury by reducing biliary BA

Ageing sensitized by iPLA2β deficiency induces liver fibrosis and intestinal atrophy involving suppression of homeostatic genes and alteration of intestinal lipids and bile acids.

PubMed

Jiao, Li; Gan-Schreier, Hongying; Zhu, Xingya; Wei, Wang; Tuma-Kellner, Sabine; Liebisch, Gerhard; Stremmel, Wolfgang; Chamulitrat, Walee

2017-12-01

Ageing is a major risk factor for various forms of liver and gastrointestinal (GI) disease and genetic background may contribute to the pathogenesis of these diseases. Group VIA phospholipase A2 or iPLA 2 β is a homeostatic PLA 2 by playing a role in phospholipid metabolism and remodeling. Global iPLA 2 β -/- mice exhibit aged-dependent phenotypes with body weight loss and abnormalities in the bone and brain. We have previously reported the abnormalities in these mutant mice showing susceptibility for chemical-induced liver injury and colitis. We hypothesize that iPLA 2 β deficiency may sensitize with ageing for an induction of GI injury. Male wild-type and iPLA 2 β -/- mice at 4 and 20-22months of age were studied. Aged, but not young, iPLA 2 β -/- mice showed increased hepatic fibrosis and biliary ductular expansion as well as severe intestinal atrophy associated with increased apoptosis, pro-inflammation, disrupted tight junction, and reduced number of mucin-containing globlet cells. This damage was associated with decreased expression of intestinal endoplasmic stress XBP1 and its regulator HNF1α, FATP4, ACSL5, bile-acid transport genes as well as nuclear receptors LXRα and FXR. By LC/MS-MS profiling, iPLA 2 β deficiency in aged mice caused an increase of intestinal arachidonate-containing phospholipids concomitant with a decrease in ceramides. By the suppression of intestinal FXR/FGF-15 signaling, hepatic bile-acid synthesis gene expression was increased leading to an elevation of secondary and hydrophobic bile acids in liver, bile, and intestine. In conclusions, ageing sensitized by iPLA 2 β deficiency caused a decline of key intestinal homeostatic genes resulting in the development of GI disease in a gut-to-liver manner. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

PubMed Central

Sistrunk, Jeticia R.; Nickerson, Kourtney P.; Chanin, Rachael B.; Rasko, David A.

2016-01-01

SUMMARY Bacterial pathogens have coevolved with humans in order to efficiently infect, replicate within, and be transmitted to new hosts to ensure survival and a continual infection cycle. For enteric pathogens, the ability to adapt to numerous host factors under the harsh conditions of the gastrointestinal tract is critical for establishing infection. One such host factor readily encountered by enteric bacteria is bile, an innately antimicrobial detergent-like compound essential for digestion and nutrient absorption. Not only have enteric pathogens evolved to resist the bactericidal conditions of bile, but these bacteria also utilize bile as a signal to enhance virulence regulation for efficient infection. This review provides a comprehensive and up-to-date analysis of bile-related research with enteric pathogens. From common responses to the unique expression of specific virulence factors, each pathogen has overcome significant challenges to establish infection in the gastrointestinal tract. Utilization of bile as a signal to modulate virulence factor expression has led to important insights for our understanding of virulence mechanisms for many pathogens. Further research on enteric pathogens exposed to this in vivo signal will benefit therapeutic and vaccine development and ultimately enhance our success at combating such elite pathogens. PMID:27464994

Percutaneous management of postoperative bile leaks with an ethylene vinyl alcohol copolymer (Onyx).

PubMed

Uller, W; Müller-Wille, R; Loss, M; Hammer, S; Schleder, S; Goessmann, H; Wiggermann, P; Stroszczynski, C; Wohlgemuth, W A

2013-12-01

The management of postoperative bile leakage is challenging especially if the leak rises from the cut surface of the liver and endoscopic treatment fails. Percutaneous transhepatic treatment of bile leaks with biliary drainage is accepted but often requires long-term placement of the drains and is associated with treatment failures. This series evaluates selective embolization of bile ducts with an ethylene vinyl alcohol copolymer (Onyx) in patients with postoperative bile leaks as an alternative treatment option. Between January and September 2012, five consecutive patients with persistent postoperative bile leaks underwent percutaneous transhepatic Onyx application and were analyzed regarding procedural management, complications and success rates. The persistent bile leaks were situated at the cystic stump (after cholecystectomy, n = 2), at the cut surface of the liver (after extended liver resection, n = 2) and at the surface of the liver after surgical exploration and perihepatic abscess (n = 1). Bile drainage alone (endoscopic or percutaneous) failed in all patients and open redo-surgery was deemed potentially harmful. Bilomas were externally drained in all patients before Onyx application. For the closure of bile leaks, Onyx was injected through a microcatheter in a previously built coil nest to keep Onyx in place. All bile leaks were initially closed immediately. In the 2nd week after Onyx embolization, 2 patients showed recurrent small bile leaks without clinical symptoms. In the 4th week after Onyx application, all leaks were closed. No complications occurred. All leaking bile ducts were initially closed immediately after Onyx application. In the 2nd week after Onyx application, 2 patients showed small bile leaks without clinical symptoms. All leaks were closed in the 4th week after Onyx application. © Georg Thieme Verlag KG Stuttgart · New York.

Genetic Predictors of Interindividual Variability in Hepatic CYP3A4 ExpressionS⃞

PubMed Central

Lamba, Vishal; Panetta, John C.; Strom, Stephen

2010-01-01

Variability in hepatic CYP3A4 cannot be explained by common CYP3A4 coding variants. We previously identified polymorphisms in pregnane X receptor (PXR) and ATP-binding cassette subfamily B member 1 (ABCB1) associated with CYP3A4 mRNA levels in small cohorts of human livers. However, the relative contributions of these genetic variations or of polymorphisms in other CYP3A4 regulators to variable CYP3A4 expression were not known. We phenotyped livers from white donors (n = 128) by quantitative real-time polymerase chain reaction for expression of CYP3A4, CYP3A5, and CYP3A7 and nine transcriptional regulators, coactivators, and corepressors. We resequenced hepatic nuclear factor-3-β (HNF3β, FoxA2), HNF4α, HNF3γ (FoxA3), nuclear receptor corepressor 2 (NCoR2), and regions of the CYP3A4 promoter and genotyped informative single-nucleotide polymorphisms in PXR and ABCB1 in the same livers. CYP3A4 mRNA was positively correlated with PXR and FoxA2 and negatively correlated with NCoR2 mRNA. A common silent polymorphism and a polymorphic trinucleotide (CCT) repeat in FoxA2 were associated with CYP3A4 expression. The transcriptional activity of the FoxA2 polymorphic CCT repeat alleles (wild-type, n = 14 and variant, n = 13, 15, and 19) when assayed by luciferase reporter transactivation assays was greatest for the wild-type repeat, with deviations from this number having decreased transcriptional activity. This corresponded with higher expression of FoxA2 mRNA and its targets PXR and CYP3A4 in human livers with (CCT) n = 14 genotypes. Multiple linear regression analysis was used to quantify the contributions of selected genetic polymorphisms to variable CYP3A4 expression. This approach identified sex and polymorphisms in FoxA2, HNF4α, FoxA3, PXR, ABCB1, and the CYP3A4 promoter that together explained as much as 24.6% of the variation in hepatic CYP3A4 expression. PMID:19934400

Simultaneous determination of nine kinds of dominating bile acids in various snake bile by ultrahigh-performance liquid chromatography with triple quadrupole linear iontrap mass spectrometry.

PubMed

Zhang, Jie; Fan, Yeqin; Gong, Yajun; Chen, Xiaoyong; Wan, Luosheng; Zhou, Chenggao; Zhou, Jiewen; Ma, Shuangcheng; Wei, Feng; Chen, Jiachun; Nie, Jing

2017-11-15

Snake bile is one of the most expensive traditional Chinese medicines (TCMs). However, due to the complicated constitutes of snake bile and the poor ultraviolet absorbance of some trace bile acids (BAs), effective analysis methods for snake bile acids were still unavailable, making it difficult to solve adulteration problems. In present study, ultrahigh-performance liquid chromatography with triple quadrupole linear ion trap mass spectrometry (UHPLC-QqQ-MS/MS) was applied to conduct a quantitative analysis on snake BAs. The mass spectrometer was monitored in the negative ion mode, and multiple-reaction monitoring (MRM) program was used to determine the contents of BAs in snake bile. In all, 61 snake bile from 17 commonly used species of three families (Elapidae, Colubridae and Viperidae), along with five batches of commercial snake bile from four companies, were collected and detected. Nine components, Tauro-3α,12α-dihydroxy-7-oxo-5β-cholenoic acid (T1), Tauro-3α,7α,12α,23R-tetrahydroxy-5β-cholenoic acid (T2), taurocholic acid (TCA), glycocholic acid (GCA), taurochenodeoxycholic acid (TCDCA), taurodeoxycholic acid (TDCA), cholic acid (CA), Tauro-3α,7α-dihydroxy-12-oxo-5β-cholenoic acid (T3), and Tauro-3α,7α,9α,16α-tetrahydroxy-5β-cholenoic acid (T4) were simultaneously and rapidly determined for the first time. In these BAs, T1 and T2, self-prepared with purity above 90%, were first reported with their quantitative determination, and the latter two (T3 and T4) were tentatively determined by quantitative analysis multi-components by single marker (QAMS) method for roughly estimating the components without reference. The developed method was validated with acceptable linearity (r 2 ≥0.995), precision (RSD＜6.5%) and recovery (RSD＜7.5%). It turned out that the contents of BAs among different species were also significantly different; T1 was one of the principle bile acids in some common snake bile, and also was the characteristic one in Viperidae

Preference of Conjugated Bile Acids over Unconjugated Bile Acids as Substrates for OATP1B1 and OATP1B3

PubMed Central

Suga, Takahiro; Sato, Toshihiro; Maekawa, Masamitsu; Goto, Junichi; Mano, Nariyasu

2017-01-01

Bile acids, the metabolites of cholesterol, are signaling molecules that play critical role in many physiological functions. They undergo enterohepatic circulation through various transporters expressed in intestine and liver. Human organic anion-transporting polypeptides (OATP) 1B1 and OATP1B3 contribute to hepatic uptake of bile acids such as taurocholic acid. However, the transport properties of individual bile acids are not well understood. Therefore, we selected HEK293 cells overexpressing OATP1B1 and OATP1B3 to evaluate the transport of five major human bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, ursodeoxycholic acid, lithocholic acid) together withtheir glycine and taurine conjugates via OATP1B1 and OATP1B3. The bile acids were quantified by liquid chromatography-tandem mass spectrometry. The present study revealed that cholic acid, chenodeoxyxcholic acid, and deoxycholic acid were transported by OATP1B1 and OATP1B3, while ursodeoxycholic acid and lithocholic acid were not significantly transported by OATPs. However, all the conjugated bile acids were taken up rapidly by OATP1B1 and OATP1B3. Kinetic analyses revealed the involvement of saturable OATP1B1- and OATP1B3-mediated transport of bile acids. The apparent Km values for OATP1B1 and OATP1B3 of the conjugated bile acids were similar (0.74–14.7 μM for OATP1B1 and 0.47–15.3 μM for OATP1B3). They exhibited higher affinity than cholic acid (47.1 μM for OATP1B1 and 42.2 μM for OATP1B3). Our results suggest that conjugated bile acids (glycine and taurine) are preferred to unconjugated bile acids as substrates for OATP1B1 and OATP1B3. PMID:28060902

[Iatrogenic bile duct injuries during the process of laparoscopic cholecystectomy].

PubMed

Qian, G; Wu, M; Zhang, Y

1995-11-01

Twelve patients with iatrogenic bile duct injuries occurred during laparoscopic cholecystectomy (LC) were treated from June 1992 to May 1994. All the patients underwent re-operation and were cured. The causes and characteristics of the injuries were: (1) perforation of the common hepatic or common bile duct caused by dissecting hook (3 cases); (2) necrosis and perforation of the common hepatic duct due to diathermic injury (1 case); (3) clamping of the common hepatic duct by Ti clip (1 case); (4) secondary high bile duct stricture following a failed end-to-end anastomosis or hepatico-cholangio-jejunostomy of the amputated common hepatic duct (5 cases); (5) delayed high bile duct stricture (2 cases). It is emphasized that the severity of bile duct injuries by LC be should not overlooked, and more experience in this field be accumulated to avoid this serious complication.

Reconstruction of Bile Duct Injury and Defect with the Round Ligament.

PubMed

Dokmak, Safi; Aussilhou, Béatrice; Ragot, Emilia; Tantardini, Camille; Cauchy, François; Ponsot, Philippe; Belghiti, Jacques; Sauvanet, Alain; Soubrane, Olivier

2017-09-01

Lateral injury of the bile duct can occur after cholecystectomy, bile duct dissection, or exploration. If direct repair is not possible, conversion to bilioenteric anastomosis can be needed with the risk of long-term bile duct infections and associated complications. We developed a new surgical technique which consist of reconstructing the bile duct with the round ligament. The vascularized round ligament is completely mobilized until its origin and used for lateral reconstruction of the bile duct to cover the defect. T tube was inserted and removed after few months. Patency of the bile duct was assessed by cholangiography, the liver function test and magnetic resonance imaging (MRI). Two patients aged 33 and 59 years old underwent lateral reconstruction of the bile duct for defects secondary to choledocotomy for stone extraction or during dissection for Mirizzi syndrome. The defects measured 2 and 3 cm and occupied half of the bile duct circumference. The postoperative course was marked by low output biliary fistula resolved spontaneously. In one patient, the T tube was removed at 3 months after surgery and MRI at 9 months showed strictly normal aspect of the bile duct with normal liver function test. The second patient is going very well 2 months after surgery and the T tube is closed. Lateral reconstruction of the bile duct can be safely achieved with the vascularized round ligament. We will extend our indications to tubular reconstruction.

Restoration of enterohepatic bile acid pathways in pregnant mice following short term activation of Fxr by GW4064

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moscovitz, Jamie E.; Kong, Bo; Buckley, Kyle

The farnesoid X receptor (Fxr) controls bile acid homeostasis by coordinately regulating the expression of synthesizing enzymes (Cyp7a1, Cyp8b1), conjugating enzymes (Bal, Baat) and transporters in the ileum (Asbt, Ostα/β) and liver (Ntcp, Bsep, Ostβ). Transcriptional regulation by Fxr can be direct, or through the ileal Fgf15/FGF19 and hepatic Shp pathways. Circulating bile acids are increased during pregnancy due to hormone-mediated disruption of Fxr signaling. While this adaptation enhances lipid absorption, elevated bile acids may predispose women to develop maternal cholestasis. The objective of this study was to determine whether short-term treatment of pregnant mice with GW4064 (a potent FXRmore » agonist) restores Fxr signaling to the level observed in virgin mice. Plasma, liver and ilea were collected from virgin and pregnant mice administered vehicle or GW4064 by oral gavage. Treatment of pregnant mice with GW4064 induced ileal Fgf15, Shp and Ostα/β mRNAs, and restored hepatic Shp, Bal, Ntcp, and Bsep back to vehicle-treated virgin levels. Pregnant mice exhibited 2.5-fold increase in Cyp7a1 mRNA compared to virgin controls, which was reduced by GW4064. Similarly treatment of mouse primary hepatocytes with plasma isolated from pregnant mice induced Cyp7a1 mRNA by nearly 3-fold as compared to virgin plasma, which could be attenuated by co-treatment with either GW4064 or recombinant FGF19 protein. Collectively, these data reveal that repressed activity of intestinal and hepatic Fxr in pregnancy, as previously demonstrated, may be restored by pharmacological activation. This study provides the basis for a novel approach to restore bile acid homeostasis in patients with maternal cholestasis. - Highlights: • Ileal bile acid pathways are altered in pregnancy in an Fxr-dependent manner. • Ileal Fxr/Fgf contributes to changes in hepatic bile acid synthesis and transport. • Treatment of pregnant mice with an Fxr agonist restores bile acid homeostasis.« less

Bile alcohols function as the ligands of membrane-type bile acid-activated G protein-coupled receptor

PubMed Central

Iguchi, Yusuke; Yamaguchi, Masafumi; Sato, Hiroyuki; Kihira, Kenji; Nishimaki-Mogami, Tomoko; Une, Mizuho

2010-01-01

TGR5 is a G protein-coupled receptor that is activated by bile acids, resulting in an increase in cAMP levels and the subsequent modulation of energy expenditure in brown adipose tissue and muscle. Therefore, the development of a TGR5-specific agonist could lead to the prevention and treatment of various metabolic disorders related to obesity. In the present study, we evaluated the ability of bile alcohols, which are structurally and physiologically similar to bile acids and are produced as the end products of cholesterol catabolism in evolutionarily primitive vertebrates, to act as TGR5 agonists. In a cell-based reporter assay and a cAMP production assay performed in vitro, most bile alcohols with a side chain containing hydroxyl group(s) were highly efficacious agonists for TGR5 comparable to its most potent ligand in the naturally occurring bile acid, lithocholic acid. However, the abilities of the bile alcohols to activate TGR5 varied with the position and number of the hydroxyl substituent in the side chain. Additionally, the conformation of the steroidal nucleus of bile alcohols is also important for its activity as a TGR5 agonist. Thus, we have provided new insights into the structure-activity relationships of bile alcohols as TGR5 agonists. PMID:20023205

Simple resection of the lesion bile duct branch for treatment of regional hepatic bile duct stones

PubMed Central

Enliang, Li; Rongshou, Wu; Shidai, Shi; Jingling, Zhang; Qian, Feng; Wenjun, Liao; Linquan, Wu

2017-01-01

Abstract To evaluate the effectiveness and safety of simple resections of bile duct branch lesions for the treatment of regional hepatic bile duct stones. A retrospective analysis of the clinical data from patients in our hospital from November 2008 to November 2015, who only underwent a simple resection of the lesion bile duct branch. The patients’ clinical characteristics, surgical features, postoperative complications, stone clear rate, residual stone rate, and recurrence stone rate were analyzed. This study of 32 patients included 13 males and 19 females with intrahepatic bile duct stones confined to the right hepatic bile duct branch. The intraoperative blood loss, operation time, and postoperative hospital stay were 478.0 ± 86.5, 210.7 ± 6.6, and 10.8 ± 3.5, respectively. Postoperative complications occurred in 6 patients (18.8%), all of whom recovered with conservative management. There were no deaths during hospitalization. The intraoperative stone clearance rate was 95.8%. Three patients had a recurrence of stones at a mean of 22 months of follow-up (range, 4–36 months). Simple resection of bile duct branch lesions is safe and feasible for patients who have regional hepatic bile duct stones limited to the right hepatic bile duct branches. PMID:28682899

Conjugated bile acids in gallbladder bile and serum as potential biomarkers for cholesterol polyps and adenomatous polyps.

PubMed

Zhao, Mei-Fen; Huang, Peng; Ge, Chun-Lin; Sun, Tao; Ma, Zhi-Gang; Ye, Fei-Fei

2016-02-28

To identify conjugated bile acids in gallbladder bile and serum as possible biomarkers for cholesterol polyps (CPs) and adenomatous polyps (APs). Gallbladder bile samples and serum samples were collected from 18 patients with CPs (CP group), 9 patients with APs (AP group), and 20 patients with gallstones (control group) from March to November, 2013. High performance liquid chromatography (HPLC) assay with ultraviolent detection was used to detect the concentration of 8 conjugated bile acids (glycocholic acid, GCA; taurocholic acid, TCA; glycochenodeoxycholic acid, GCDCA; taurochenodeoxycholic acid, TCDCA; glycodeoxycholic acid, GDCA; taurodeoxycholic acid, TDCA; taurolithocholic acid, TLCA; tauroursodeoxycholic acid, TUDCA) in bile samples and serum samples. The diagnostic efficacy of serum GCA, GCDCA and TCDCA was evaluated. These 8 conjugated bile acids in gallbladder bile and serum were completely identified within 10 minutes with good linearity (correlation coefficient: R>0.9900; linearity range: 3.91-500 µg/mL). Among these conjugated bile acids, the levels of gallbladder bile GCDCA and TCDCA in the CP group were significantly higher than those in the AP group (p<0.05). Furthermore, serum GCDCA and TCDCA as well as GCA were significantly higher in the AP group than the CP group (p<0.05). Serum GCDCA alone (≤12 µg/mL) had relatively better diagnostic efficacy than the other conjugated bile acids. The levels of serum GCA, GCDCA and TCDCA may be valuable for differentiation of APs and CPs.

Pluronic®-bile salt mixed micelles.

PubMed

Patel, Vijay; Ray, Debes; Bahadur, Anita; Ma, Junhe; Aswal, V K; Bahadur, Pratap

2018-06-01

The present study was aimed to examine the interaction of two bile salts viz. sodium cholate (NaC) and sodium deoxycholate (NaDC) with three ethylene polyoxide-polypropylene polyoxide (PEO-PPO-PEO) triblock copolymers with similar PPO but varying PEO micelles with a focus on the effect of pH on mixed micelles. Mixed micelles of moderately hydrophobic Pluronic ® P123 were examined in the presence of two bile salts and compared with those from very hydrophobic L121 and very hydrophilic F127. Both the bile salts increase the cloud point (CP) of copolymer solution and decreased apparent micelle hydrodynamic diameter (D h ). SANS study revealed that P123 forms small spherical micelles showing a decrease in size on progressive addition of bile salts. The negatively charged mixed micelles contained fewer P123 molecules but progressively rich in bile salt. NaDC being more hydrophobic displays more pronounced effect than NaC. Interestingly, NaC shows micellar growth in acidic media which has been attributed to the formation of bile acids by protonation of carboxylate ion and subsequent solubilization. In contrast, NaDC showed phase separation at higher concentration. Nuclear Overhauser effect spectroscopy (NOESY) experiments provided information on interaction and location of bile salts in micelles. Results are discussed in terms of hydrophobicity of bile salts and Pluronics ® and the site of bile salt in polymer micelles. Proposed molecular interactions are useful to understand more about bile salts which play important role in physiological processes. Copyright © 2018 Elsevier B.V. All rights reserved.

Physiological and molecular biochemical mechanisms of bile formation

PubMed Central

Reshetnyak, Vasiliy Ivanovich

2013-01-01

This review considers the physiological and molecular biochemical mechanisms of bile formation. The composition of bile and structure of a bile canaliculus, biosynthesis and conjugation of bile acids, bile phospholipids, formation of bile micellar structures, and enterohepatic circulation of bile acids are described. In general, the review focuses on the molecular physiology of the transporting systems of the hepatocyte sinusoidal and apical membranes. Knowledge of physiological and biochemical basis of bile formation has implications for understanding the mechanisms of development of pathological processes, associated with diseases of the liver and biliary tract. PMID:24259965

[Endoscopic manometry in the common bile duct].

PubMed

Brandstätter, G; Kratochvil, P; Stupnicki, T; Zenker, G; Justich, E; Resch, M

1982-09-17

Reproducible results were obtained by endoscopic transpapillary pressure measurements with the help of a constantly perfused catheter. Manometric measurements were performed in 51 patients without any premedication. 14 patients with a normal biliary system were compared with 17 patients after cholecystectomy, 14 patients with stones in the common bile duct and 6 patients after papillotomy. Although there were significant differences in the diameter of the common bile duct in the four groups, only the papillotomized patients demonstrated a distinct change of the pressure in the bile duct. In these patients almost no pressure gradient existed between the biliary ducts and the duodenum. On the other hand, there was an increase in intraluminal pressure in the 2 patients with papillary stenosis. Endoscopic manometric measurements in the common bile duct are indicated to obtain reliable data on stenosis of the papilla duodeni, insufficient papillotomy or recurrent stenosis.

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

Efficient and Controlled Generation of 2D and 3D Bile Duct Tissue from Human Pluripotent Stem Cell-Derived Spheroids.

PubMed

Tian, Lipeng; Deshmukh, Abhijeet; Ye, Zhaohui; Jang, Yoon-Young

2016-08-01

While in vitro liver tissue engineering has been increasingly studied during the last several years, presently engineered liver tissues lack the bile duct system. The lack of bile drainage not only hinders essential digestive functions of the liver, but also leads to accumulation of bile that is toxic to hepatocytes and known to cause liver cirrhosis. Clearly, generation of bile duct tissue is essential for engineering functional and healthy liver. Differentiation of human induced pluripotent stem cells (iPSCs) to bile duct tissue requires long and/or complex culture conditions, and has been inefficient so far. Towards generating a fully functional liver containing biliary system, we have developed defined and controlled conditions for efficient 2D and 3D bile duct epithelial tissue generation. A marker for multipotent liver progenitor in both adult human liver and ductal plate in human fetal liver, EpCAM, is highly expressed in hepatic spheroids generated from human iPSCs. The EpCAM high hepatic spheroids can, not only efficiently generate a monolayer of biliary epithelial cells (cholangiocytes), in a 2D differentiation condition, but also form functional ductal structures in a 3D condition. Importantly, this EpCAM high spheroid based biliary tissue generation is significantly faster than other existing methods and does not require cell sorting. In addition, we show that a knock-in CK7 reporter human iPSC line generated by CRISPR/Cas9 genome editing technology greatly facilitates the analysis of biliary differentiation. This new ductal differentiation method will provide a more efficient method of obtaining bile duct cells and tissues, which may facilitate engineering of complete and functional liver tissue in the future.

Identification and differentiation of bear bile used in medicinal products in Taiwan.

PubMed

Lin, D L; Chang, H C; Chang, C P; Chen, C Y

1997-09-01

One hundred eighty-three suspect bear bile used in medicinal products, collected in Taiwan as gall bladders or dried powder forms, were analyzed using FTIR, HPTLC, and HPLC techniques to identify whether they are indeed bear bile. Those confirmed were further examined to determine whether the observed analytical parameters can be reliably used for source inference, i.e., differentiating products among North American black bear, farmed Asiatic black bear, polar bear, etc. Our data suggested that North American and polar bears contain a higher concentration of TC (relative to TUDC and TCDC), whereas the relative concentration of TC in Asiatic bears (wild or farmed) is much lower. Thus, the relative concentration of TC can potentially be used for differentiating Asiatic bear bile from North American and polar bear products, but it cannot be used for the differentiation of wild and farmed bear bile as suggested in an earlier report by Espinoza et al. The origin of the 183 samples analyzed were found to be as follows: 118 (64%), bile salts, or gall bladders were of domestic pig; 56 (31%), bile products of Asiatic bear; 4 (2.2%), Asiatic bear mixed with pig bile salts; 3 (1.6%) goat gall bladders; 1 (0.55%) water buffalo bile salts; and 1 (0.55%), pig bile salts mixed with water buffalo bile salts.

The role of S1PR2 in bile acid-induced cholangiocyte proliferation and cholestasis-induced liver injury in mice

PubMed Central

Wang, Yongqing; Aoki, Hiroaki; Yang, Jing; Peng, Kesong; Liu, Runping; Li, Xiaojiaoyang; Qiang, Xiaoyan; Sun, Lixin; Gurley, Emily C; Lai, Guanhua; Zhang, Luyong; Liang, Guang; Nagahashi, Masayuki; Takabe, Kazuaki; Pandak, William M; Hylemon, Phillip B.; Zhou, Huiping

2017-01-01

Bile duct obstruction is a potent stimulus for cholangiocyte proliferation, especially for large cholangiocytes. Our previous studies reported that conjugated bile acids (CBAs) activate the AKT and ERK1/2 signaling pathways via the sphingosine 1-phosphate receptor 2 (S1PR2) in hepatocytes and cholangiocarcinoma cells. It also has been reported that taurocholate (TCA) promotes large cholangiocyte proliferation and protects cholangiocytes from bile duct ligation (BDL)-induced apoptosis. However, the role of S1PR2 in bile acid-mediated cholangiocyte proliferation and cholestatic liver injury has not been elucidated. Here we report that S1PR2 is the predominant S1PR expressed in cholangiocytes. Both TCA- and S1P-induced activation of ERK1/2 and AKT were inhibited by JTE-013, a specific antagonist of S1PR2, in cholangiocytes. In addition, TCA- and S1P-induced cell proliferation and migration were inhibited by JTE-013 and a specific shRNA of S1PR2 as well as chemical inhibitors of ERK1/2 and AKT in mouse cholangiocytes. In BDL mice, the expression of S1PR2 was upregulated in whole liver and cholangiocytes. S1PR2 deficiency significantly reduced BDL-induced cholangiocyte proliferation and cholestatic injury as indicated by significant reduction of inflammation and liver fibrosis in S1PR2−/− mice. Treatment of BDL mice with JTE-013 significantly reduced total bile acid levels in the serum and cholestatic liver injury. This study suggests that the CBA-induced activation of S1PR2-mediated signaling pathways plays a critical role in obstructive cholestasis and may represent a novel therapeutic target for cholestatic liver diseases. PMID:28120434

Spermine oxidase promotes bile canalicular lumen formation through acrolein production.

PubMed

Uemura, Takeshi; Takasaka, Tomokazu; Igarashi, Kazuei; Ikegaya, Hiroshi

2017-11-01

Spermine oxidase (SMOX) catalyzes oxidation of spermine to generate spermidine, hydrogen peroxide (H 2 O 2 ) and 3-aminopropanal, which is spontaneously converted to acrolein. SMOX is induced by a variety of stimuli including bacterial infection, polyamine analogues and acetaldehyde exposure. However, the physiological functions of SMOX are not yet fully understood. We investigated the physiological role of SMOX in liver cells using human hepatocellular carcinoma cell line HepG2. SMOX localized to the bile canalicular lumen, as determined by F-actin staining. Knockdown of SMOX reduced the formation of bile canalicular lumen. We also found that phospho-Akt (phosphorylated protein kinase B) was localized to canalicular lumen. Treatment with Akt inhibitor significantly reduced the formation of bile canalicular lumen. Acrolein scavenger also inhibited the formation of bile canalicular lumen. PTEN, phosphatase and tensin homolog and an inhibitor of Akt, was alkylated in a SMOX-dependent manner. Our results suggest that SMOX plays a central role in the formation of bile canalicular lumen in liver cells by activating Akt pathway through acrolein production.

Kinetics of the bile acid transporter and hepatitis B virus receptor Na+/taurocholate cotransporting polypeptide (NTCP) in hepatocytes.

PubMed

König, Alexander; Döring, Barbara; Mohr, Christina; Geipel, Andreas; Geyer, Joachim; Glebe, Dieter

2014-10-01

The human liver bile acid transporter Na(+)/taurocholate cotransporting polypeptide (NTCP) has recently been identified as liver-specific receptor for infection of hepatitis B virus (HBV), which attaches via the myristoylated preS1 (myr-preS1) peptide domain of its large surface protein to NTCP. Since binding of the myr-preS1 peptide to NTCP is an initiating step of HBV infection, we investigated if this process interferes with the physiological bile acid transport function of NTCP. HBV infection, myr-preS1 peptide binding, and bile acid transport assays were performed with primary Tupaia belangeri (PTH) and human (PHH) hepatocytes as well as NTCP-transfected human hepatoma HepG2 cells allowing regulated NTCP expression, in the presence of various bile acids, ezetimibe, and myr-preS1 peptides. The myr-preS1 peptide of HBV inhibited bile acid transport in PTH and PHH as well as in NTCP-expressing HEK293 and HepG2 cells. Inversely, HBV infection of PTH, PHH, and NTCP-transfected HepG2 cells was inhibited in a concentration-dependent manner by taurine and glycine conjugates of cholic acid and ursodeoxycholic acid as well as by ezetimibe. In NTCP-HepG2 cells and PTH, NTCP expression, NTCP transport function, myr-preS1 peptide binding, and HBV infection followed comparable kinetics. Myr-preS1 virus binding to NTCP, necessary for productive HBV infection, interferes with the physiological bile acid transport function of NTCP. Therefore, HBV infection via NTCP may be lockable by NTCP substrates and NTCP-inhibiting drugs. This opens a completely new way for an efficient management of HBV infection by the use of NTCP-directed drugs. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

In vitro digestion with bile acids enhances the bioaccessibility of kale polyphenols.

PubMed

Yang, Isabelle; Jayaprakasha, Guddarangavvanahally K; Patil, Bhimanagouda

2018-02-21

Kale (Brassica oleracea) is a leafy green vegetable belonging to the Brassicaceae family, and kale leaves have large amounts of dietary fiber and polyphenolics. Dietary fiber can bind bile acids, thus potentially decreasing cholesterol levels; however, whether the polyphenols from kale contribute to in vitro bile acid binding capacity remains unclear. In the present study, kale was extracted with hexane, acetone, and MeOH : water and the dried extracts, as well as the fiber-rich residue, were tested for their bile acid binding capacity. The fiber-rich residue bound total bile acids in amounts equivalent to that bound by raw kale. The lyophilized acetone extract bound significantly more glycochenodeoxycholate and glycodeoxycholate and less of other bile acids. To test whether bile acid binding enhanced the bioaccessibility of polyphenolic compounds from kale, we used ultra-performance liquid chromatography coupled with electrospray ionization/quadrupole-time-of-flight mass spectrometry to identify chemical constituents and measure their bioaccessibility in an in vitro digestion reaction. This identified 36 phenolic compounds in kale, including 18 kaempferol derivatives, 13 quercetin derivatives, 4 sinapoyl derivatives, and one caffeoylquinic acid. The bioaccessibility of these phenolics was significantly higher (69.4%) in digestions with bile acids. Moreover, bile acids enhanced the bioaccessibility of quercetin by 25 times: only 2.7% of quercetin derivatives were bioaccessible in the digestion without bile acids, but with bile acids, their accessibility increased to 69.5%. Bile acids increased the bioaccessibility of kaempferol from 37.7% to 69.2%. The extractability and biostability of total phenolics in the digested residue increased 1.8 fold in the digestions with bile acids. These results demonstrated the potential use of kale to improve human health.

Profile and predictors of bile infection in patients undergoing laparoscopic cholecystectomy.

PubMed

Mahafzah, Azmi M; Daradkeh, Salam S

2009-08-01

To study the bacteriological profile, and to determine predictors of bile infection and septic complications following laparoscopic cholecystectomy. This cross-sectional study reviewed 1248 laparoscopic cholecystectomy cases performed between January 1994 and December 2007 by one surgical team at the Jordan University Hospital, Amman, Jordan. Bile cultures were performed for all patients and statistical analysis was performed on culture results and postoperative complications as well as, on the possible predictors of bile infection including age, gender, associated diseases, preoperative retrograde cholangiopancreatography (ERCP), and indications for surgery. Uncomplicated gallstone disease was diagnosed in 993 patients (79.6%), 221 patients (17.7%) had acute cholecystitis, and 34 patients (2.7%) had jaundice. Associated morbidities were present in 513 patients (41.1%), preoperative ERCP was performed for 132 patients (10.6%), and postoperative septic complications developed in 25 patients (2%). Bile culture was positive in 250 patients (20%), 134 (53.6%) of whom had gram negative bacteria, 73 (29.2%) had gram positive bacteria, and 43 (17.2%) had mixed cultures. The chi-square test has shown that positive bile culture is significantly associated with age, gender, preoperative ERCP, associated morbidities, and complicated gallbladder disease, whereas multinomial regression analysis has shown that age and preoperative ERCP were the only significant predictors of bile infection. Bile infection commonly complicates gallstone disease, and it can be influenced by age and preoperative endoscopic interventions, but it does not influence the occurrence of postoperative septic complications.

Farnesoid X receptor induces Takeda G-protein receptor 5 cross-talk to regulate bile acid synthesis and hepatic metabolism.

PubMed

Pathak, Preeti; Liu, Hailiang; Boehme, Shannon; Xie, Cen; Krausz, Kristopher W; Gonzalez, Frank; Chiang, John Y L

2017-06-30

The bile acid-activated receptors, nuclear farnesoid X receptor (FXR) and the membrane Takeda G-protein receptor 5 (TGR5), are known to improve glucose and insulin sensitivity in obese and diabetic mice. However, the metabolic roles of these two receptors and the underlying mechanisms are incompletely understood. Here, we studied the effects of the dual FXR and TGR5 agonist INT-767 on hepatic bile acid synthesis and intestinal secretion of glucagon-like peptide-1 (GLP-1) in wild-type, Fxr -/- , and Tgr5 -/- mice. INT-767 efficaciously stimulated intracellular Ca 2+ levels, cAMP activity, and GLP-1 secretion and improved glucose and lipid metabolism more than did the FXR-selective obeticholic acid and TGR5-selective INT-777 agonists. Interestingly, INT-767 reduced expression of the genes in the classic bile acid synthesis pathway but induced those in the alternative pathway, which is consistent with decreased taurocholic acid and increased tauromuricholic acids in bile. Furthermore, FXR activation induced expression of FXR target genes, including fibroblast growth factor 15, and unexpectedly Tgr5 and prohormone convertase 1/3 gene expression in the ileum. We identified an FXR-responsive element on the Tgr5 gene promoter. Fxr -/- and Tgr5 -/- mice exhibited reduced GLP-1 secretion, which was stimulated by INT-767 in the Tgr5 -/- mice but not in the Fxr -/- mice. Our findings uncovered a novel mechanism in which INT-767 activation of FXR induces Tgr5 gene expression and increases Ca 2+ levels and cAMP activity to stimulate GLP-1 secretion and improve hepatic glucose and lipid metabolism in high-fat diet-induced obese mice. Activation of both FXR and TGR5 may therefore represent an effective therapy for managing hepatic steatosis, obesity, and diabetes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Inhibition of NF-κB prevents the acidic bile-induced oncogenic mRNA phenotype, in human hypopharyngeal cells

PubMed Central

Vageli, Dimitra P.; Doukas, Sotirios G.; Sasaki, Clarence T.

2018-01-01

Bile-containing gastro-duodenal reflux has been clinically considered an independent risk factor in hypopharyngeal carcinogenesis. We recently showed that the chronic effect of acidic bile, at pH 4.0, selectively induces NF-κB activation and accelerates the transcriptional levels of genes, linked to head and neck cancer, in normal hypopharyngeal epithelial cells. Here, we hypothesize that NF-κB inhibition is capable of preventing the acidic bile-induced and cancer-related mRNA phenotype, in treated normal human hypopharyngeal cells. In this setting we used BAY 11-7082, a specific and well documented pharmacologic inhibitor of NF-κB, and we observed that BAY 11-7082 effectively inhibits the acidic bile-induced gene expression profiling of the NF-κB signaling pathway (down-regulation of 72 out of 84 analyzed genes). NF-κB inhibition significantly prevents the acidic bile-induced transcriptional activation of NF-κB transcriptional factors, RELA (p65) and c-REL, as well as genes related to and commonly found in established HNSCC cell lines. These include anti-apoptotic bcl-2, oncogenic STAT3, EGFR, ∆Np63, TNF-α and WNT5A, as well as cytokines IL-1β and IL-6. Our findings are consistent with our hypothesis demonstrating that NF-κB inhibition effectively prevents the acidic bile-induced cancer-related mRNA phenotype in normal human hypopharyngeal epithelial cells supporting an understanding that NF-κB may be a critical link between acidic bile and early preneoplastic events in this setting. PMID:29464041

Effect of ursodeoxycholic acid treatment on the altered progesterone and bile acid homeostasis in the mother-placenta-foetus trio during cholestasis of pregnancy

PubMed Central

Estiú, Maria C; Monte, Maria J; Rivas, Laura; Moirón, Maria; Gomez-Rodriguez, Laura; Rodriguez-Bravo, Tomas; Marin, Jose JG; Macias, Rocio IR

2015-01-01

Aim Intrahepatic cholestasis of pregnancy (ICP) is characterized by pruritus and elevated bile acid concentrations in maternal serum. This is accompanied by an enhanced risk of intra-uterine and perinatal complications. High concentrations of sulphated progesterone metabolites (PMS) have been suggested to be involved in the multifactorial aetiopathogenesis of ICP. The aim of this study was to investigate further the mechanism accounting for the beneficial effect of oral administration of ursodeoxycholic acid (UDCA), which is the standard treatment, regarding bile acid and PMS homeostasis in the mother-placenta-foetus trio. Method Using HPLC-MS/MS bile acids and PMS were determined in maternal and foetal serum and placenta. The expression of ABC proteins in placenta was determined by real time quantitative PCR (RT-QPCR) and immunofluorescence. Results In ICP, markedly increased concentrations of bile acids (tauroconjugates > glycoconjugates >> unconjugated), progesterone and PMS in placenta and maternal serum were accompanied by enhanced concentrations in foetal serum of bile acids, but not of PMS. UDCA treatment reduced bile acid accumulation in the mother-placenta-foetus trio, but had no significant effect on progesterone and PMS concentrations. ABCG2 mRNA abundance was increased in placentas from ICP patients vs. controls and remained stable following UDCA treatment, despite an apparent further increase in ABCG2. Conclusion UDCA administration partially reduces ICP-induced bile acid accumulation in mothers and foetuses despite the lack of effect on concentrations of progesterone and PMS in maternal serum. Up-regulation of placental ABCG2 may play an important role in protecting the foetus from high concentrations of bile acids and PMS during ICP. PMID:25099365

Effect of ursodeoxycholic acid treatment on the altered progesterone and bile acid homeostasis in the mother-placenta-foetus trio during cholestasis of pregnancy.

PubMed

Estiú, Maria C; Monte, Maria J; Rivas, Laura; Moirón, Maria; Gomez-Rodriguez, Laura; Rodriguez-Bravo, Tomas; Marin, Jose J G; Macias, Rocio I R

2015-02-01

Intrahepatic cholestasis of pregnancy (ICP) is characterized by pruritus and elevated bile acid concentrations in maternal serum. This is accompanied by an enhanced risk of intra-uterine and perinatal complications. High concentrations of sulphated progesterone metabolites (PMS) have been suggested to be involved in the multifactorial aetiopathogenesis of ICP. The aim of this study was to investigate further the mechanism accounting for the beneficial effect of oral administration of ursodeoxycholic acid (UDCA), which is the standard treatment, regarding bile acid and PMS homeostasis in the mother-placenta-foetus trio. Using HPLC-MS/MS bile acids and PMS were determined in maternal and foetal serum and placenta. The expression of ABC proteins in placenta was determined by real time quantitative PCR (RT-QPCR) and immunofluorescence. In ICP, markedly increased concentrations of bile acids (tauroconjugates > glycoconjugates > unconjugated), progesterone and PMS in placenta and maternal serum were accompanied by enhanced concentrations in foetal serum of bile acids, but not of PMS. UDCA treatment reduced bile acid accumulation in the mother-placenta-foetus trio, but had no significant effect on progesterone and PMS concentrations. ABCG2 mRNA abundance was increased in placentas from ICP patients vs. controls and remained stable following UDCA treatment, despite an apparent further increase in ABCG2. UDCA administration partially reduces ICP-induced bile acid accumulation in mothers and foetuses despite the lack of effect on concentrations of progesterone and PMS in maternal serum. Up-regulation of placental ABCG2 may play an important role in protecting the foetus from high concentrations of bile acids and PMS during ICP. © 2014 The British Pharmacological Society.

Management of Traumatic Liver and Bile Duct Laceration.

PubMed

Tiwari, Charu; Shah, Hemanshi; Waghmare, Mukta; Khedkar, Kiran; Dwivedi, Pankaj

2017-01-01

Posttraumatic major bile leak in children is uncommon, with few cases reported in the literature. These injuries are seen in high-grade liver trauma and are difficult to diagnose and manage. We describe a 7-year-old boy with grade IV hepatic trauma and bile leak following blunt abdominal trauma. The leak was successfully managed by percutaneous drainage and endoscopic retrograde cholangiopancreatography (ERCP) stenting of the injured hepatic duct. How to cite this article: Tiwari C, Shah H, Waghmare M, Khedkar K, Dwivedi P. Management of Traumatic Liver and Bile Duct Laceration. Euroasian J Hepato-Gastroenterol 2017;7(2):188-190.

Acid and bile tolerance of spore-forming lactic acid bacteria.

PubMed

Hyronimus, B; Le Marrec, C; Sassi, A H; Deschamps, A

2000-11-01

Criteria for screening probiotics such as bile tolerance and resistance to acids were studied with 13 spore-forming lactic acid producing bacteria. Different strains of Sporolactobacillus, Bacillus laevolacticus, Bacillus racemilacticus and Bacillus coagulans grown in MRS broth were subjected to low pH conditions (2, 2.5 and 3) and increasing bile concentrations. Among these microorganisms, Bacillus laevolacticus DSM 6475 and all Sporolactobacillus strains tested except Sporolactobacillus racemicus IAM 12395, were resistant to pH 3. Only Bacillus racemilacticus and Bacillus coagulans strains were tolerant to bile concentrations over 0.3% (w/v).

[Advances in studies on bear bile powder].

PubMed

Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

2015-04-01

In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

Association of levels of fasting glucose and insulin with rare variants at the chromosome 11p11.2-MADD locus: Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium Targeted Sequencing Study.

PubMed

Cornes, Belinda K; Brody, Jennifer A; Nikpoor, Naghmeh; Morrison, Alanna C; Chu, Huan; Ahn, Byung Soo; Wang, Shuai; Dauriz, Marco; Barzilay, Joshua I; Dupuis, Josée; Florez, Jose C; Coresh, Josef; Gibbs, Richard A; Kao, W H Linda; Liu, Ching-Ti; McKnight, Barbara; Muzny, Donna; Pankow, James S; Reid, Jeffrey G; White, Charles C; Johnson, Andrew D; Wong, Tien Y; Psaty, Bruce M; Boerwinkle, Eric; Rotter, Jerome I; Siscovick, David S; Sladek, Robert; Meigs, James B

2014-06-01

Common variation at the 11p11.2 locus, encompassing MADD, ACP2, NR1H3, MYBPC3, and SPI1, has been associated in genome-wide association studies with fasting glucose and insulin (FI). In the Cohorts for Heart and Aging Research in Genomic Epidemiology Targeted Sequencing Study, we sequenced 5 gene regions at 11p11.2 to identify rare, potentially functional variants influencing fasting glucose or FI levels. Sequencing (mean depth, 38×) across 16.1 kb in 3566 individuals without diabetes mellitus identified 653 variants, 79.9% of which were rare (minor allele frequency <1%) and novel. We analyzed rare variants in 5 gene regions with FI or fasting glucose using the sequence kernel association test. At NR1H3, 53 rare variants were jointly associated with FI (P=2.73×10(-3)); of these, 7 were predicted to have regulatory function and showed association with FI (P=1.28×10(-3)). Conditioning on 2 previously associated variants at MADD (rs7944584, rs10838687) did not attenuate this association, suggesting that there are >2 independent signals at 11p11.2. One predicted regulatory variant, chr11:47227430 (hg18; minor allele frequency=0.00068), contributed 20.6% to the overall sequence kernel association test score at NR1H3, lies in intron 2 of NR1H3, and is a predicted binding site for forkhead box A1 (FOXA1), a transcription factor associated with insulin regulation. In human HepG2 hepatoma cells, the rare chr11:47227430 A allele disrupted FOXA1 binding and reduced FOXA1-dependent transcriptional activity. Sequencing at 11p11.2-NR1H3 identified rare variation associated with FI. One variant, chr11:47227430, seems to be functional, with the rare A allele reducing transcription factor FOXA1 binding and FOXA1-dependent transcriptional activity. © 2014 American Heart Association, Inc.

Analysis of ileal sodium/bile acid cotransporter and related nuclear receptor genes in a family with multiple cases of idiopathic bile acid malabsorption

PubMed Central

Montagnani, Marco; Abrahamsson, Anna; Gälman, Cecilia; Eggertsen, Gösta; Marschall, Hanns-Ulrich; Ravaioli, Elisa; Einarsson, Curt; Dawson, Paul A

2006-01-01

The etiology of most cases of idiopathic bile acid malabsorption (IBAM) is unknown. In this study, a Swedish family with bile acid malabsorption in three consecutive generations was screened for mutations in the ileal apical sodium-bile acid cotransporter gene (ASBT; gene symbol, SLC10A2) and in the genes for several of the nuclear receptors known to be important for ASBT expression: the farnesoid X receptor (FXR) and peroxisome proliferator activated receptor alpha (PPARα). The patients presented with a clinical history of idiopathic chronic watery diarrhea, which was responsive to cholestyramine treatment and consistent with IBAM. Bile acid absorption was determined using 75Se-homocholic acid taurine (SeHCAT); bile acid synthesis was estimated by measuring the plasma levels of 7α-hydroxy-4-cholesten-3-one (C4). The ASBT, FXR, and PPARα genes in the affected and unaffected family members were analyzed using single stranded conformation polymorphism (SSCP), denaturing HPLC, and direct sequencing. No ASBT mutations were identified and the ASBT gene did not segregate with the bile acid malabsorption phenotype. Similarly, no mutations or polymorphisms were identified in the FXR or PPARα genes associated with the bile acid malabsorption phenotype. These studies indicate that the intestinal bile acid malabsorption in these patients cannot be attributed to defects in ASBT. In the absence of apparent ileal disease, alternative explanations such as accelerated transit through the small intestine may be responsible for the IBAM. PMID:17171805

Ginseng alleviates cyclophosphamide-induced hepatotoxicity via reversing disordered homeostasis of glutathione and bile acid.

PubMed

Zhu, He; Long, Min-Hui; Wu, Jie; Wang, Meng-Meng; Li, Xiu-Yang; Shen, Hong; Xu, Jin-Di; Zhou, Li; Fang, Zhi-Jun; Luo, Yi; Li, Song-Lin

2015-12-02

Cyclophosphamide (CP), a chemotherapeutic agent, is restricted due to its side effects, especially hepatotoxicity. Ginseng has often been clinically used with CP in China, but whether and how ginseng reduces the hepatotoxicity is unknown. In this study, the hepatoprotective effects and mechanisms under the combined usage were investigated. It was found that ginseng could ameliorate CP-induced elevations of ALP, ALT, ALS, MDA and hepatic deterioration, enhance antioxidant enzymes' activities and GSH's level. Metabolomics study revealed that 33 endogenous metabolites were changed by CP, 19 of which were reversed when ginseng was co-administrated via two main pathways, i.e., GSH metabolism and primary bile acids synthesis. Furthermore, ginseng could induce expression of GCLC, GCLM, GS and GST, which associate with the disposition of GSH, and expression of FXR, CYP7A1, NTCP and MRP 3, which play important roles in the synthesis and transport of bile acids. In addition, NRF 2, one of regulatory elements on the expression of GCLC, GCLM, GS, GST, NTCP and MRP3, was up-regulated when ginseng was co-administrated. In conclusion, ginseng could alleviate CP-induced hepatotoxicity via modulating the disordered homeostasis of GSH and bile acid, which might be mediated by inducing the expression of NRF 2 in liver.

Elevated interleukin-8 in bile of patients with primary sclerosing cholangitis.

PubMed

Zweers, Serge J; Shiryaev, Alexey; Komuta, Mina; Vesterhus, Mette; Hov, Johannes R; Perugorria, María J; de Waart, D Rudi; Chang, Jung-Chin; Tol, Shanna; Te Velde, Anje A; de Jonge, Wouter J; Banales, Jesus M; Roskams, Tania; Beuers, Ulrich; Karlsen, Tom H; Jansen, Peter L; Schaap, Frank G

2016-09-01

To better understand the pathogenesis of primary sclerosing cholangitis, anti- and pro-inflammatory factors were studied in bile. Ductal bile of PSC patients (n = 36) and controls (n = 20) was collected by endoscopic retrograde cholangiography. Gallbladder bile was collected at liver transplantation. Bile samples were analysed for cytokines, FGF19 and biliary lipids. Hepatobiliary tissues of PSC and non-PSC patients (n = 8-11 per patient group) were collected at transplantation and were analysed for IL8 and FGF19 mRNA expression and IL8 localization. The effect of IL8 on proliferation of primary human cholangiocytes and expression of pro-fibrotic genes was studied. In PSC patients, median IL8 in ductal bile was 6.6 ng/ml vs. 0.24 ng/ml in controls. Median IL8 in gallbladder bile was 7.6 ng/ml in PSC vs. 2.2 and 0.3 ng/ml in two control groups. IL8 mRNA in PSC gallbladder was increased and bile ducts stained positive for IL8. In vitro, IL8 induced proliferation of primary human cholangiocytes and increased the expression of pro-fibrotic genes. Elevation of IL8 in bile of PSC patients, collected at different stages of disease, indicates an ongoing inflammatory stimulus that drives IL8 production. This challenges the idea that advanced PSC is a burned-out disease, and calls for reconsideration of anti-inflammatory therapy in PSC. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Loss of cellular FLICE-inhibitory protein promotes acute cholestatic liver injury and inflammation from bile duct ligation.

PubMed

Gehrke, Nadine; Nagel, Michael; Straub, Beate K; Wörns, Marcus A; Schuchmann, Marcus; Galle, Peter R; Schattenberg, Jörn M

2018-03-01

Cholestatic liver injury results from impaired bile flow or metabolism and promotes hepatic inflammation and fibrogenesis. Toxic bile acids that accumulate in cholestasis induce apoptosis and contribute to early cholestatic liver injury, which is amplified by accompanying inflammation. The aim of the current study was to evaluate the role of the antiapoptotic caspase 8-homolog cellular FLICE-inhibitory (cFLIP) protein during acute cholestatic liver injury. Transgenic mice exhibiting hepatocyte-specific deletion of cFLIP (cFLIP -/- ) were used for in vivo and in vitro analysis of cholestatic liver injury using bile duct ligation (BDL) and the addition of bile acids ex vivo. Loss of cFLIP in hepatocytes promoted acute cholestatic liver injury early after BDL, which was characterized by a rapid release of proinflammatory and chemotactic cytokines (TNF, IL-6, IL-1β, CCL2, CXCL1, and CXCL2), an increased presence of CD68 + macrophages and an influx of neutrophils in the liver, and resulting apoptotic and necrotic hepatocyte cell death. Mechanistically, liver injury in cFLIP -/- mice was aggravated by reactive oxygen species, and sustained activation of the JNK signaling pathway. In parallel, cytoprotective NF-κB p65, A20, and the MAPK p38 were inhibited. Increased injury in cFLIP -/- mice was accompanied by activation of hepatic stellate cells and profibrogenic regulators. The antagonistic caspase 8-homolog cFLIP is a critical regulator of acute, cholestatic liver injury. NEW & NOTEWORTHY The current paper explores the role of a classical modulator of hepatocellular apoptosis in early, cholestatic liver injury. These include activation of NF-κB and MAPK signaling, production of inflammatory cytokines, and recruitment of neutrophils in response to cholestasis. Because these signaling pathways are currently exploited in clinical trials for the treatment of nonalcoholic steatohepatitis and cirrhosis, the current data will help in the development of novel pharmacological

[Late stage stenoses of bile ducts after iatrogenic bile duct injuries following cholecystectomy].

PubMed

Bektas, H; Winny, M; Schrem, H; Becker, T; Klempnauer, J

2007-12-01

Iatrogenic bile duct injuries represent a severe complication after cholecystectomy. For the attending physician therapy and management of these injuries are a challenge. Inadequate and delayed treatment can lead to stenoses at a late stage, which can necessitate further surgical intervention. In a study data of 74 patients, who were treated in our clinic for bile duct injuries following cholecystectomy, were analysed retrospectively. A total of 8 patients with late stage bile duct strictures following iatrogenic bile duct injury including the subsequent therapy could be identified. The data of these patients were analysed in respect of cause and strategies to prevent late stage stenoses. In 62 patients the bile duct injury occurred following laparoscopic and in 12 patients following open cholecystectomy. In 16 patients the injury was combined with a vascular lesion. The interval between primary intervention and definitive therapy was 11 days in 53 patients and 1-15 years in 21 patients. In 8 patients the reason for the re-operation after a long interval (1-15 years) was a late stage stenosis. A hepatico-jejunostomy was performed subsequently and during follow-up 5 / 8 patients were symptom-free; 7 patients were re-operated due to a stenosed primary biliodigestive anastomosis and 3 patients each due to atrophy of the right liver lobe and recurrent cholangitis. One patient complained of recurrent cholangitis and a further patient of symptoms due to adhesions. If treated inadequately bile duct injuries occurring during cholecystectomy can in the long-term lead to considerable problems such as recurrent cholangitis, late stage stenoses and even to secondary biliary cirrhosis. Therefore, a complex inter-disciplinary therapeutic concept aiming at timely treatment is necessary.

Homologue gene of bile acid transporters ntcp, asbt, and ost-alpha in rainbow trout Oncorhynchus mykiss: tissue expression, effect of fasting, and response to bile acid administration.

PubMed

Murashita, Koji; Yoshiura, Yasutoshi; Chisada, Shin-Ichi; Furuita, Hirofumi; Sugita, Tsuyoshi; Matsunari, Hiroyuki; Iwashita, Yasuro; Yamamoto, Takeshi

2014-04-01

Bile acid transporters belonging to the SLC10A protein family, Na+ taurocholate cotransporting polypeptide (NTCP or SLC10A1), apical sodium-dependent bile salt transporter (ASBT or SLC10A2), and organic solute transporter alpha (Ost-alpha) have been known to play critical roles in the enterohepatic circulation of bile acids in mammals. In this study, ntcp, asbt, and ost-alpha-1/-2 cDNA were cloned, their tissue distributions were characterized, and the effects of fasting and bile acid administration on their expression were examined in rainbow trout Oncorhynchus mykiss. The structural characteristics of Ntcp, Asbt, and Ost-alpha were well conserved in trout, and three-dimensional structure analysis showed that Ntcp and Asbt were similar to each other. Tissue distribution analysis revealed that trout asbt was primarily expressed in the hindgut, while ntcp expression occurred in the brain, and ost-alpha-1/-2 was mainly expressed in the liver or ovary. Although asbt and ost-alpha-1 mRNA levels in the gut increased in response to fasting for 4 days, ost-alpha-1 expression in the liver decreased. Similarly, bile acid administration increased asbt and ost-alpha-1 expression levels in the gut, while those of ntcp and ost-alpha-2 in the liver decreased. These results suggested that the genes asbt, ntcp, and ost-alpha are involved in bile acid transport in rainbow trout.

The hepatic bile acid transporters Ntcp and Mrp2 are downregulated in experimental necrotizing enterocolitis.

PubMed

Cherrington, Nathan J; Estrada, Teresa E; Frisk, Harrison A; Canet, Mark J; Hardwick, Rhiannon N; Dvorak, Bohuslav; Lux, Katie; Halpern, Melissa D

2013-01-01

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of premature infants and is characterized by an extensive hemorrhagic inflammatory necrosis of the distal ileum and proximal colon. We have previously shown that, during the development of experimental NEC, the liver plays an important role in regulating inflammation in the ileum, and accumulation of ileal bile acids (BA) along with dysregulation of ileal BA transporters contributes to ileal damage. Given these findings, we speculated that hepatic BA transporters would also be altered in experimental NEC. Using both rat and mouse models of NEC, levels of Cyp7a1, Cyp27a1, and the hepatic BA transporters Bsep, Ntcp, Oatp2, Oatp4, Mrp2, and Mrp3 were investigated. In addition, levels of hepatic BA transporters were also determined when the proinflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-18, which are both elevated in NEC, are neutralized during disease development. Ntcp and Mrp2 were decreased in NEC, but elevated ileal BA levels were not responsible for these reductions. However, neutralization of TNF-α normalized Ntcp, whereas removal of IL-18 normalized Mrp2 levels. These data show that the hepatic transporters Ntcp and Mrp2 are downregulated, whereas Cyp27a1 is increased in rodent models of NEC. Furthermore, increased levels of TNF-α and IL-18 in experimental NEC may play a role in the regulation of Ntcp and Mrp2, respectively. These data suggest the gut-liver axis should be considered when therapeutic modalities for NEC are developed.

[Bile leakage after liver resection: A retrospective cohort study].

PubMed

Menclová, K; Bělina, F; Pudil, J; Langer, D; Ryska, M

2015-12-01

Many previous reports have focused on bile leakage after liver resection. Despite the improvements in surgical techniques and perioperative care the incidence of this complication rather keeps increasing. A number of predictive factors have been analyzed. There is still no consensus regarding their influence on the formation of bile leakage. The objective of our analysis was to evaluate the incidence of bile leakage, its impact on mortality and duration of hospitalization at our department. At the same time, we conducted an analysis of known predictive factors. The authors present a retrospective review of the set of 146 patients who underwent liver resection at the Department of Surgery of the 2nd Faculty of Medicine of the Charles University and Central Military Hospital Prague, performed between 20102013. We used the current ISGLS (International Study Group of Liver Surgery) classification to evaluate the bile leakage. The severity of this complication was determined according to the Clavien-Dindo classification system. Statistical significance of the predictive factors was determined using Fishers exact test and Students t-test. The incidence of bile leakage was 21%. According to ISGLS classification the A, B, and C rates were 6.5%, 61.2%, and 32.3%, respectively. The severity of bile leakage according to the Clavien-Dindo classification system - I-II, IIIa, IIIb, IV and V rates were 19.3%, 42%, 9.7%, 9.7%, and 19.3%, respectively. We determined the following predictive factors as statistically significant: surgery for malignancy (p<0.001), major hepatic resection (p=0.001), operative time (p<0.001), high intraoperative blood loss (p=0.02), construction of HJA (p=0.005), portal venous embolization/two-stage surgery (p=0.009) and ASA score (p=0.02). Bile leakage significantly prolonged hospitalization time (p<0.001). In the group of patients with bile leakage the perioperative mortality was 23 times higher (p<0.001) than in the group with no leakage. Bile

Water-soluble quercetin modulates the choleresis and bile lipid ratio in rats.

PubMed

Vovkun, Tatiana; Yanchuk, Petro; Shtanova, Lidiya; Veselskiy, Stanislav; Filimonova, Natalia; Shalamay, Anatoly; Vedmid, Volodymyr

2018-01-01

Water-soluble analogue of quercetin, corvitin is used in patients with myocardial infarction as blocker of 5-lipoxygenase. However, its effects on secretion, lipid content and physico-chemical properties of bile have not been understood yet. We investigated the effect of corvitin, applied in different doses, on the level of bile flow, the content of bile free and esterified cholesterol, phospholipids, triacylglycerols, and free fatty acids. In order to determine stability of the bile colloidal system, we examined the relationship between different lipid components. The rats were injected intraportally with a bolus of corvitin. At doses of 2.5, 5, and 10 mg/kg, the latter increased bile flow and concentration of total cholates, as well as free fatty acids. Corvitin (5 mg/kg) elevated phospholipids and cholesterol content, but at a dose of 10 mg/kg it increased the concentration of bile cholesterol esters and triacylglycerols. Corvitin applied at doses of 2.5 and 10 mg/kg increased total cholates/cholesterol ratio, but at a dose of 10 mg/kg, the drug reduced cholesterol / esterified cholesterol ratio. The results suggest that corvitin exerts choleretic effect and improves stability of bile colloidal system.

Biliary Bile Acids in Primary Biliary Cirrhosis: Effect of Ursodeoxycholic Acid

PubMed Central

Combes, Burton; Carithers, Robert L.; Maddrey, Willis C.; Munoz, Santiago; Garcia-Tsao, Guadalupe; Bonner, Gregory F.; Boyer, James L.; Luketic, Velimir A.; Shiffman, Mitchell L.; Peters, Marion G.; White, Heather; Zetterman, Rowen K.; Risser, Richard; Rossi, Stephen S.; Hofmann, Alan F.

2014-01-01

Bile acid composition in fasting duodenal bile was assessed at entry and at 2 years in patients with primary biliary cirrhosis (PBC) enrolled in a randomized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UDCA) (10–12 mg/kg/d) taken as a single bedtime dose. Specimens were analyzed by a high-pressure liquid chromatography method that had been validated against gas chromatography. Percent composition in bile (mean ± SD) for 98 patients at entry for cholic (CA), chenodeoxycholic (CDCA), deoxycholic (DCA), lithocholic (LCA), and ursodeoxycholic (UDCA) acids, respectively, were 57.4 ± 18.6, 31.5 ± 15.5, 8.0 ± 9.3, 0.3 ± 1.0, and 0.6 ± 0.9. Values for CA were increased, whereas those for CDCA, DCA, LCA, and UDCA were decreased when compared with values in normal persons. Bile acid composition of the major bile acids did not change after 2 years on placebo medication. By contrast, in patients receiving UDCA for 2 years, bile became enriched with UDCA on average to 40.1%, and significant decreases were noted for CA (to 32.2%) and CDCA (to 19.5%). No change in percent composition was observed for DCA and LCA. Percent composition at entry and changes in composition after 2 years on UDCA were similar in patients with varying severity of PBC. In patients whose bile was not enriched in UDCA (entry and placebo-treated specimens), CA, CDCA, DCA, and the small amount of UDCA found in some of these specimens were conjugated to a greater extent with glycine (52%–64%) than with taurine (36%–48%). Treatment with UDCA caused the proportion of all endogenous bile acids conjugated with glycine to increase to 69% to 78%, while the proportion conjugated with taurine (22%–31%) fell (P < .05). Administered UDCA was also conjugated predominantly with glycine (87%). PMID:10347103

Comparison of the composition of bile acids in bile of patients with adenocarcinoma of the pancreas and benign disease.

PubMed

Rees, David O; Crick, Peter J; Jenkins, Gareth J; Wang, Yuqin; Griffiths, William J; Brown, Tim H; Al-Sarireh, Bilal

2017-11-01

Bile acids have been implicated in the development of gastrointestinal malignancies. Both the specific nature of individual bile acids and their concentration appear key factors in the carcinogenic potency of bile. Using liquid chromatography mass spectrometry (LC-MS) we performed quantitative profiling of bile extracted directly from the common bile duct in 30 patients (15 patients with pancreatic cancer and 15 patients with benign disease). Separation and detection of bile acids was performed using a 1.7μm particle size reversed-phase C 18 LC column at a flow rate of 200μL/min with negative electrospray ionization MS. A significant difference (p=0.018) was seen in the concentration of unconjugated cholic acid in the malignant group (0.643mmol/L) compared to the benign group (0.022mmol/L), with an overall significant difference (p=0.04) seen in the level of total unconjugated bile acids in the malignant group (1.816mmol/L) compared to the benign group (0.069mmol/L). This finding may offer the possibility of both understanding the biology of cancer development in the pancreas, as well as offering a potential diagnostic avenue to explore. However, a larger study is necessary to confirm the alterations in bile acid profiles reported here and explore factors such as diet and microbial populations on the bile acid profiles of these patient groups. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Structural basis of the alternating-access mechanism in a bile acid transporter

PubMed Central

Zhou, Xiaoming; Levin, Elena J.; Pan, Yaping; McCoy, Jason G.; Sharma, Ruchika; Kloss, Brian; Bruni, Renato; Quick, Matthias; Zhou, Ming

2014-01-01

Bile acids are synthesized from cholesterol in hepatocytes and secreted via the biliary tract into the small intestine, where they aid in absorption of lipids and fat-soluble vitamins. Through a process known as enterohepatic recirculation, more than 90% of secreted bile acids are then retrieved from the intestine and returned to the liver for re-secretion1. In humans, there are two Na+-dependent bile acid transporters involved in enterohepatic recirculation, the Na+-taurocholate co-transporting polypeptide (NTCP or SLC10A1) expressed in hepatocytes, and the apical sodium-dependent bile acid transporter (ASBT or SLC10A2) expressed on enterocytes in the terminal ileum2. In recent years, ASBT has attracted much interest as a potential drug target for treatment of hypercholesterolemia, because inhibition of ASBT reduces reabsorption of bile acids, thus increasing bile acid synthesis and consequently cholesterol consumption3,4. However, a lack of 3-dimensional structures of bile acid transporters hampers our ability to understand the molecular mechanisms of substrate selectivity and transport, and to interpret the wealth of existing functional data2,5-8. The crystal structure of an ASBT homolog from Neisseria meningitidis (ASBTNM) in detergent was reported recently9, showing the protein in an inward-open conformation bound to two Na+ and a taurocholic acid. However, the structural changes that bring bile acid and Na+ across the membrane are difficult to infer from a single structure. To understand better the structural changes associated with the coupled transport of Na+ and bile acids, we crystallized and solved two structures of a ASBT homolog from Yersinia frederiksenii (ASBTYf) in a lipid environment, which reveal that a large rigid-body rotation of a substrate-binding domain gives alternate accessibility to the highly conserved “crossover” region, where two discontinuous transmembrane helices cross each other. This result has implications for the location and

Ca2+-Dependent Cytoprotective Effects of Ursodeoxycholic and Tauroursodeoxycholic Acid on the Biliary Epithelium in a Rat Model of Cholestasis and Loss of Bile Ducts

PubMed Central

Marzioni, Marco; Francis, Heather; Benedetti, Antonio; Ueno, Yoshiyuki; Fava, Giammarco; Venter, Juliet; Reichenbach, Ramona; Mancino, Maria Grazia; Summers, Ryun; Alpini, Gianfranco; Glaser, Shannon

2006-01-01

Chronic cholestatic liver diseases are characterized by impaired balance between proliferation and death of cholangiocytes, as well as vanishing of bile ducts and liver failure. Ursodeoxycholic acid (UDCA) is a bile acid widely used for the therapy of cholangiopathies. However, little is known of the cytoprotective effects of UDCA on cholangiocytes. Therefore, UDCA and its taurine conjugate tauroursodeoxycholic acid (TUDCA) were administered in vivo to rats simultaneously subjected to bile duct ligation and vagotomy, a model that induces cholestasis and loss of bile ducts by apoptosis of cholangiocytes. Because these two bile acids act through Ca2+ signaling, animals were also treated with BAPTA/AM (an intracellular Ca2+ chelator) or Gö6976 (a Ca2+-dependent protein kinase C-α inhibitor). The administration of UDCA or TUDCA prevented the induction of apoptosis and the loss of proliferative and functional responses observed in the bile duct ligation-vagotomized rats. These effects were neutralized by the simultaneous administration of BAPTA/AM or Gö6976. UDCA and TUDCA enhanced intracellular Ca2+ and IP3 levels, together with increased phosphorylation of protein kinase C-α. Parallel changes were observed regarding the activation of the MAPK and PI3K pathways, changes that were abolished by addition of BAPTA/AM or Gö6976. These studies provide information that may improve the response of cholangiopathies to medical therapy. PMID:16436655

Very Long O-antigen Chains Enhance Fitness during Salmonella-induced Colitis by Increasing Bile Resistance

PubMed Central

Crawford, Robert W.; Keestra, A. Marijke; Winter, Sebastian E.; Xavier, Mariana N.; Tsolis, Renée M.; Tolstikov, Vladimir; Bäumler, Andreas J.

2012-01-01

Intestinal inflammation changes the luminal habitat for microbes through mechanisms that have not been fully resolved. We noticed that the FepE regulator of very long O-antigen chain assembly in the enteric pathogen Salmonella enterica serotype Typhimurium (S. Typhimurium) conferred a luminal fitness advantage in the mouse colitis model. However, a fepE mutant was not defective for survival in tissue, resistance to complement or resistance to polymyxin B. We performed metabolite profiling to identify changes in the luminal habitat that accompany S. Typhimurium-induced colitis. This analysis suggested that S. Typhimurium-induced colitis increased the luminal concentrations of total bile acids. A mutation in fepE significantly reduced the minimal inhibitory concentration (MIC) of S. Typhimurium for bile acids in vitro. Oral administration of the bile acid sequestrant cholestyramine resin lowered the concentrations of total bile acids in colon contents during S. Typhimurium infection and significantly reduced the luminal fitness advantage conferred by the fepE gene in the mouse colitis model. Collectively, these data suggested that very long O-antigen chains function in bile acid resistance of S. Typhimurium, a property conferring a fitness advantage during luminal growth in the inflamed intestine. PMID:23028318

Risk of bile duct cancer among printing workers exposed to 1,2-dichloropropane and/or dichloromethane.

PubMed

Sobue, Tomotaka; Utada, Mai; Makiuchi, Takeshi; Ohno, Yuko; Uehara, Shinichiro; Hayashi, Tomoshige; Sato, Kyoko Kogawa; Endo, Ginji

2015-01-01

We conducted a retrospective cohort study to examine the risk of bile duct cancer among current and former workers in the offset color proof printing department at a printing company in Osaka, Japan. Standardized incidence ratios (SIRs) between January 1, 1985, and December 31, 2012, were estimated for the cumulative years of exposure to two chemicals, dichloromethane (DCM) and 1,2-dichloropropane (1,2-DCP), using the national incidence level as a reference. In addition, we examined risk patterns by the calendar year in which observation started. Among 106 workers with a total of 1,452.4 person-years of exposure, 17 bile duct cancer cases were observed, resulting in an estimated overall SIR of 1,132.5 (95% confidence interval (CI): 659.7-1,813.2). The SIR was 1,319.9 (95% CI: 658.9-2,361.7) for those who were exposed to both DCM and 1,2-DCP, and it was 1,002.8 (95% CI: 368.0-2,182.8) for those exposed to 1,2-DCP only. SIRs tended to increase according to years of exposure to 1,2-DCP but not DCM when a 5-year lag time was assumed. The SIRs were higher for the cohorts in which observation started in 1993-2000, particularly in cohorts in which it started in 1996-1999, compared with those in which it started before or after 1993-2000. We observed an extraordinarily high risk of bile duct cancer among the offset color proof printing workers. Elevated risk may be related to cumulative exposure to 1,2-DCP, but there remains some possibility that a portion of the risk is due to other unidentified substances.

Effect of pancreatic polypeptide on gallbladder pressure and hepatic bile secretion.

PubMed

Adrian, T E; Mitchenere, P; Sagor, G; Bloom, S R

1982-09-01

Intraluminal gallbladder pressure, measured by radiotelemetry, and bile output were monitored during infusion of porcine pancreatic polypeptide (PP) at doses of 6, 25, 100, and 400 pmol . kg-1 . h-1 in healthy conscious pigs. Plasma PP concentrations during infusion of the three lower doses, measured by radioimmunoassay, were within the range seen postprandially in these animals. Gallbladder pressure fell in a dose-related manner during PP infusion by 2.2 +/- 0.9, 8.2 +/- 0.4, 11.6 +/- 0.7, and 14.8 +/- 0.8 mmHg, respectively. In addition, a significant reduction in the bile output was observed during infusion of the two higher doses of PP. In a separate series of experiments, using cholecystectomized pigs, PP had no effect on bile output. These findings suggest that the amount of PP released postprandially may be sufficient to influence gallbladder function but not hepatic secretion of bile in the pig.

Clinical score to predict the risk of bile leakage after liver resection.

PubMed

Kajiwara, Takahiro; Midorikawa, Yutaka; Yamazaki, Shintaro; Higaki, Tokio; Nakayama, Hisashi; Moriguchi, Masamichi; Tsuji, Shingo; Takayama, Tadatoshi

2016-05-06

In liver resection, bile leakage remains the most common cause of operative morbidity. In order to predict the risk of this complication on the basis of various factors, we developed a clinical score system to predict the potential risk of bile leakage after liver resection. We analyzed the postoperative course in 518 patients who underwent liver resection for malignancy to identify independent predictors of bile leakage, which was defined as "a drain fluid bilirubin concentration at least three times the serum bilirubin concentration on or after postoperative day 3," as proposed by the International Study Group of Liver Surgery. To confirm the robustness of the risk score system for bile leakage, we analyzed the independent series of 289 patients undergoing liver resection for malignancy. Among 81 (15.6 %) patients with bile leakage, 76 had grade A bile leakage, and five had grade C leakage and underwent reoperation. The median postoperative hospital stay was significantly longer in patients with bile leakage (median, 14 days; range, 8 to 34) than in those without bile leakage (11 days; 5 to 62; P = 0.001). There was no hepatic insufficiency or in-hospital death. The risk score model was based on the four independent predictors of postoperative bile leakage: non-anatomical resection (odds ratio, 3.16; 95 % confidence interval [CI], 1.72 to 6.07; P < 0.001), indocyanine green clearance rate (2.43; 1.32 to 7.76; P = 0.004), albumin level (2.29; 1.23 to 4.22; P = 0.01), and weight of resected specimen (1.97; 1.11 to 3.51; P = 0.02). When this risk score system was used to assign patients to low-, middle-, and high-risk groups, the frequency of bile leakage in the high-risk group was 2.64 (95 % CI, 1.12 to 6.41; P = 0.04) than that in the low-risk group. Among the independent series for validation, 4 (5.7 %), 16 (10.0 %), and 10 (16.6 %) patients in low-, middle, and high-risk groups were given a diagnosis of bile leakage after

Non-targeted metabolomics combined with genetic analyses identifies bile acid synthesis and phospholipid metabolism as being associated with incident type 2 diabetes

PubMed Central

Salihovic, Samira; Brandmaier, Stefan; Nowak, Christoph; Ganna, Andrea; Gustafsson, Stefan; Broeckling, Corey D.; Prenni, Jessica E.; Kastenmüller, Gabi; Peters, Annette; Magnusson, Patrik K.; Wang-Sattler, Rui; Giedraitis, Vilmantas; Berne, Christian; Gieger, Christian; Pedersen, Nancy L.; Ingelsson, Erik; Lind, Lars

2017-01-01

Aims/hypothesis Identification of novel biomarkers for type 2 diabetes and their genetic determinants could lead to improved understanding of causal pathways and improve risk prediction. Methods In this study, we used data from non-targeted metabolomics performed using liquid chromatography coupled with tandem mass spectrometry in three Swedish cohorts (Uppsala Longitudinal Study of Adult Men [ULSAM], n = 1138; Prospective Investigation of the Vasculature in Uppsala Seniors [PIVUS], n = 970; TwinGene, n = 1630). Metabolites associated with impaired fasting glucose (IFG) and/or prevalent type 2 diabetes were assessed for associations with incident type 2 diabetes in the three cohorts followed by replication attempts in the Cooperative Health Research in the Region of Augsburg (KORA) S4 cohort (n = 855). Assessment of the association of metabolite-regulating genetic variants with type 2 diabetes was done using data from a meta-analysis of genome-wide association studies. Results Out of 5961 investigated metabolic features, 1120 were associated with prevalent type 2 diabetes and IFG and 70 were annotated to metabolites and replicated in the three cohorts. Fifteen metabolites were associated with incident type 2 diabetes in the four cohorts combined (358 events) following adjustment for age, sex, BMI, waist circumference and fasting glucose. Novel findings included associations of higher values of the bile acid deoxycholic acid and monoacylglyceride 18:2 and lower concentrations of cortisol with type 2 diabetes risk. However, adding metabolites to an existing risk score improved model fit only marginally. A genetic variant within the CYP7A1 locus, encoding the rate-limiting enzyme in bile acid synthesis, was found to be associated with lower concentrations of deoxycholic acid, higher concentrations of LDL-cholesterol and lower type 2 diabetes risk. Variants in or near SGPP1, GCKR and FADS1/2 were associated with diabetes-associated phospholipids and type 2 diabetes

Bile acids: analysis in biological fluids and tissues

PubMed Central

Griffiths, William J.; Sjövall, Jan

2010-01-01

The formation of bile acids/bile alcohols is of major importance for the maintenance of cholesterol homeostasis. Besides their functions in lipid absorption, bile acids/bile alcohols are regulatory molecules for a number of metabolic processes. Their effects are structure-dependent, and numerous metabolic conversions result in a complex mixture of biologically active and inactive forms. Advanced methods are required to characterize and quantify individual bile acids in these mixtures. A combination of such analyses with analyses of the proteome will be required for a better understanding of mechanisms of action and nature of endogenous ligands. Mass spectrometry is the basic detection technique for effluents from chromatographic columns. Capillary liquid chromatography-mass spectrometry with electrospray ionization provides the highest sensitivity in metabolome analysis. Classical gas chromatography-mass spectrometry is less sensitive but offers extensive structure-dependent fragmentation increasing the specificity in analyses of isobaric isomers of unconjugated bile acids. Depending on the nature of the bile acid/bile alcohol mixture and the range of concentration of individuals, different sample preparation sequences, from simple extractions to group separations and derivatizations, are applicable. We review the methods currently available for the analysis of bile acids in biological fluids and tissues, with emphasis on the combination of liquid and gas phase chromatography with mass spectrometry. PMID:20008121

Ileal absorption of bile acids in patients with chronic cholestasis: SeHCAT test results and effect of ursodeoxycholic acid (UDCA).

PubMed

Chazouillères, O; Marteau, P; Haniche, M; Jian, R; Poupon, R

1996-12-01

The effect of cholestasis on ileal bile acid absorption is controversial in animal models (up- or down-regulation) and unknown in humans. We therefore studied values of the selena homotaurocholic acid (SeHCAT) test before and after long-term administration (>3 months, 13-15 mg/kg/day) of ursodeoxycholic acid (UDCA) in 27 patients with chronic cholestatic liver diseases (24 women, 3 men; mean age, 50 years; 24 primary biliary cirrhosis, 2 secondary biliary cirrhosis, 2 others). The control group consisted of 14 healthy volunteers. Seven-day SeHCAT percentage retention was identical in the 12 untreated cholestatic patients (serum bilirubin, 75+/-42 micromol/L, alkaline phosphatase, 4.2+/-1.0 N; mean+/-SEM) and in the control group (43.6+/-2.9 and 43.8+/-4.2%, respectively). In the 22 patients treated by UDCA for 38+/-8 months, SeHCAT percentage retention was 20.3+/-3.0%. In the seven patients with the SeHCAT test done before and after UDCA treatment (16+/-5 months), SeHCAT percentage retention decreased significantly under UDCA therapy (42.0+/-4.4 vs 19.4+/-4.1%; P < 0.02). We conclude that, in patients with chronic cholestasis (1) SeHCAT percentage retention is not altered-taken together with the known defect of biliary excretion, this lack of increase in SeHCAT percentage retention argues against up-regulation of bile acid ileal transport; and (2) UDCA treatment induces a decrease in the SeHCAT percentage retention-this effect may be related primarily to a decreased bile acid ileal absorption.

NMR studies reveal the role of biomembranes in modulating ligand binding and release by intracellular bile acid binding proteins.

PubMed

Pedò, Massimo; Löhr, Frank; D'Onofrio, Mariapina; Assfalg, Michael; Dötsch, Volker; Molinari, Henriette

2009-12-18

Bile acid molecules are transferred vectorially between basolateral and apical membranes of hepatocytes and enterocytes in the context of the enterohepatic circulation, a process regulating whole body lipid homeostasis. This work addresses the role of the cytosolic lipid binding proteins in the intracellular transfer of bile acids between different membrane compartments. We present nuclear magnetic resonance (NMR) data describing the ternary system composed of the bile acid binding protein, bile acids, and membrane mimetic systems, such as anionic liposomes. This work provides evidence that the investigated liver bile acid binding protein undergoes association with the anionic membrane and binding-induced partial unfolding. The addition of the physiological ligand to the protein-liposome mixture is capable of modulating this interaction, shifting the equilibrium towards the free folded holo protein. An ensemble of NMR titration experiments, based on nitrogen-15 protein and ligand observation, confirm that the membrane and the ligand establish competing binding equilibria, modulating the cytoplasmic permeability of bile acids. These results support a mechanism of ligand binding and release controlled by the onset of a bile salt concentration gradient within the polarized cell. The location of a specific protein region interacting with liposomes is highlighted.

History of hepatic bile formation: old problems, new approaches.

PubMed

Javitt, Norman B

2014-12-01

Studies of hepatic bile formation reported in 1958 established that it was an osmotically generated water flow. Intravenous infusion of sodium taurocholate established a high correlation between hepatic bile flow and bile acid excretion. Secretin, a hormone that stimulates bicarbonate secretion, was also found to increase hepatic bile flow. The sources of the water entering the biliary system with these two stimuli were differentiated by the use of mannitol. An increase in its excretion parallels the increase in bile flow in response to bile acids but not secretin, which led to a quantitative distinction between canalicular and ductular water flow. The finding of aquaglyceroporin-9 in the basolateral surface of the hepatocyte accounted for the rapid entry of mannitol into hepatocytes and its exclusion from water movement in the ductules where aquaporin-1 is present. Electron microscopy demonstrated that bile acids generate the formation of vesicles that contain lecithin and cholesterol after their receptor-mediated canalicular transport. Biophysical studies established that the osmotic effect of bile acids varies with their concentration and also with the proportion of mono-, di-, and trihydroxy bile acids and provides a basis for understanding their physiological effects. Because of the varying osmotic effect of bile acids, it is difficult to quantify bile acid independent flow generated by other solutes, such as glutathione, which enters the biliary system. Monohydroxy bile acids, by markedly increasing aggregation number, severely reduce water flow. Developing biomarkers for the noninvasive assessment of normal hepatic bile flow remains an elusive goal that merits further study. Copyright © 2014 The American Physiological Society.

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.

Bile acid malabsorption in chronic diarrhea: Pathophysiology and treatment

PubMed Central

Barkun, Alan; Love, Jonathan; Gould, Michael; Pluta, Henryk; Steinhart, A Hillary

2013-01-01

BACKGROUND: Bile acid malabsorption (BAM) is a common but frequently under-recognized cause of chronic diarrhea, with an estimated prevalence of 4% to 5%. METHODS: The published literature for the period 1965 to 2012 was examined for articles regarding the pathophysiology and treatment of BAM to provide an overview of the management of BAM in gastroenterology practice. RESULTS: BAM is classified as type 1 (secondary to ileal dysfunction), type 2 (idiopathic) or type 3 (secondary to gastrointestinal disorders not associated with ileal dysfunction). The estimated prevalence of BAM is >90% in patients with resected Crohn disease (CD) and 11% to 52% of unresected CD patients (type 1); 33% in diarrhea-predominant irritable bowel syndrome (type 2); and is a frequent finding postcholecystectomy or postvagotomy (type 3). Investigations include BAM fecal bile acid assay, 23-seleno-25-homo-tauro-cholic acid (SeHCAT) testing and high-performance liquid chromatography of serum 7-α-OH-4-cholesten-3-one (C4), to determine the level of bile acid synthesis. A less time-consuming and expensive alternative in practice is an empirical trial of the bile acid sequestering agent cholestyramine. An estimated 70% to 96% of chronic diarrhea patients with BAM respond to short-course cholestyramine. Adverse effects include constipation, nausea, borborygmi, flatulence, bloating and abdominal pain. Other bile acid sequestering agents, such as colestipol and colesevelam, are currently being investigated for the treatment of BAM-associated diarrhea. CONCLUSIONS: BAM is a common cause of chronic diarrhea presenting in gastroenterology practice. In accordance with current guidelines, an empirical trial of a bile acid sequestering agent is warranted as part of the clinical workup to rule out BAM. PMID:24199211

Bile produced in the liver (image)

MedlinePlus

... duct system that creates, transports, stores, and releases bile into the duodenum for digestion includes the liver, gallbladder, and bile ducts (named the cystic, hepatic, common, and pancreatic ...

Successful endoscopic therapy of traumatic bile leaks.

PubMed

Spinn, Matthew P; Patel, Mihir K; Cotton, Bryan A; Lukens, Frank J

2013-01-01

Traumatic bile leaks often result in high morbidity and prolonged hospital stay that requires multimodality management. Data on endoscopic management of traumatic bile leaks are scarce. Our study objective was to evaluate the efficacy of the endoscopic management of a traumatic bile leak. We performed a retrospective case review of patients who were referred for endoscopic retrograde cholangiopancreatography (ERCP) after traumatic bile duct injury secondary to blunt (motor vehicle accident) or penetrating (gunshot) trauma for management of bile leaks at our tertiary academic referral center. Fourteen patients underwent ERCP for the management of a traumatic bile leak over a 5-year period. The etiology included blunt trauma from motor vehicle accident in 8 patients, motorcycle accident in 3 patients and penetrating injury from a gunshot wound in 3 patients. Liver injuries were grade III in 1 patient, grade IV in 10 patients, and grade V in 3 patients. All patients were treated by biliary stent placement, and the outcome was successful in 14 of 14 cases (100%). The mean duration of follow-up was 85.6 days (range 54-175 days). There were no ERCP-related complications. In our case review, endoscopic management with endobiliary stent placement was found to be successful and resulted in resolution of the bile leak in all 14 patients. Based on our study results, ERCP should be considered as first-line therapy in the management of traumatic bile leaks.

3 alpha-Hydroxylated bile acid profiles in clinically normal cats, cats with severe hepatic lipidosis, and cats with complete extrahepatic bile duct occlusion.

PubMed

Center, S A; Thompson, M; Guida, L

1993-05-01

Concentrations of 3 alpha-hydroxylated bile acids were measured in serum and urine of clinically normal (healthy) cats (n = 6), cats with severe hepatic lipidosis (n = 9), and cats with complete bile duct occlusion (n = 4). Bile acid concentrations were measured by use of a gradient flow high-performance liquid chromatography procedure with an acetonitrile and ammonium phosphate mobile phase and an in-line postanalytic column containing 3 alpha-hydroxy-steroid dehydrogenase and a fluorescence detector. Specific identification of all bile acid peaks was not completed; unidentified moieties were represented in terms of their elution time (in minutes). Significant differences in serum and urine bile acid concentrations, quantitative and proportional, were determined among groups of cats. Cats with hepatic lipidosis and bile duct occlusion had significantly (P > or = 0.05) greater total serum and urine bile acids concentrations than did healthy cats. The proportion of hydrophobic bile acids in serum, those eluting at > or = 400 minutes, was 1.9% for healthy cats, 3.3% for cats with lipidosis, and 5.4% for bile duct-obstructed cats. Both groups of ill cats had a broader spectrum of unidentified late-eluting serum bile acids than did healthy cats; the largest spectrum developed in bile duct-occluded cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Vectorial transport of bile salts across MDCK cells expressing both rat Na+-taurocholate cotransporting polypeptide and rat bile salt export pump.

PubMed

Mita, Sachiko; Suzuki, Hiroshi; Akita, Hidetaka; Stieger, Bruno; Meier, Peter J; Hofmann, Alan F; Sugiyama, Yuichi

2005-01-01

Bile salts are predominantly taken up by hepatocytes via the basolateral Na(+)-taurocholate cotransporting polypeptide (NTCP/SLC10A1) and secreted into the bile by the bile salt export pump (BSEP/ABCB11). In the present study, we transfected rat Ntcp and rat Bsep into polarized Madin-Darby canine kidney cells and characterized the transport properties of these cells for eight bile salts. Immunohistochemical staining demonstrated that Ntcp was expressed at the basolateral domains, whereas Bsep was expressed at the apical domains. Basal-to-apical transport of taurocholate across the monolayer expressing only Ntcp and that coexpressing Ntcp/Bsep was observed, whereas the flux across the monolayer of control and Bsep-expressing cells was symmetrical. Basal-to-apical transport of taurocholate across Ntcp/Bsep-coexpressing monolayers was significantly higher than that across monolayers expressing only Ntcp. Kinetic analysis of this vectorial transport of taurocholate gave an apparent K(m) value of 13.9 +/- 4.7 microM for cells expressing Ntcp alone, which is comparable with 22.2 +/- 4.5 microM for cells expressing both Ntcp and Bsep and V(max) values of 15.8 +/- 4.2 and 60.8 +/- 9.0 pmol.min(-1).mg protein(-1) for Ntcp alone and Ntcp and Bsep-coexpressing cells, respectively. Transcellular transport of cholate, glycocholate, taurochenodeoxycholate, chenodeoxycholate, glycochenodeoxycholate, tauroursodeoxycholate, ursodeoxycholate, and glycoursodeoxycholate, but not that of lithocholate was also observed across the double transfectant. This double-expressing system can be used as a model to clarify vectorial transport of bile salts across hepatocytes under physiological conditions.

Megalin and cubilin expression in gallbladder epithelium and regulation by bile acids.

PubMed

Erranz, Benjamín; Miquel, Juan Francisco; Argraves, W Scott; Barth, Jeremy L; Pimentel, Fernando; Marzolo, María-Paz

2004-12-01

Cholesterol crystal formation in the gallbladder is a key step in gallstone pathogenesis. Gallbladder epithelial cells might prevent luminal gallstone formation through a poorly understood cholesterol absorption process. Genetic studies in mice have highlighted potential gallstone susceptibility alleles, Lith genes, which include the gene for megalin. Megalin, in conjunction with the large peripheral membrane protein cubilin, mediates the endocytosis of numerous ligands, including HDL/apolipoprotein A-I (apoA-I). Although the bile contains apoA-I and several cholesterol-binding megalin ligands, the expression of megalin and cubilin in the gallbladder has not been investigated. Here, we show that both proteins are expressed by human and mouse gallbladder epithelia. In vitro studies using a megalin-expressing cell line showed that lithocholic acid strongly inhibits and cholic and chenodeoxycholic acids increase megalin expression. The effects of bile acids (BAs) were also demonstrated in vivo, analyzing gallbladder levels of megalin and cubilin from mice fed with different BAs. The BA effects could be mediated by the farnesoid X receptor, expressed in the gallbladder. Megalin protein was also strongly increased after feeding a lithogenic diet. These results indicate a physiological role for megalin and cubilin in the gallbladder and provide support for a role for megalin in gallstone pathogenesis.

Risk factors for bile leakage after primary closure following laparoscopic common bile duct exploration: a retrospective cohort study.

PubMed

Liu, Dongbin; Cao, Feng; Liu, Jiafeng; Xu, Dahua; Wang, Yuehua; Li, Fei

2017-01-05

Primary closure following laparoscopic common bile duct exploration (LCBDE) has been widely adopted because of the efficacy and safety in treatment of common bile duct (CBD) stones. However, the risk factors for bile leakage, the most common complication after primary closure, has not been clarified yet. A retrospective cohort study of patients who underwent LCBDE with primary closure after choledochotomy between Feb. 2012 and Jun. 2016 was performed. Risk factors for bile leakage were identified by logistic regression inculding demographic factors, preoperative condition and surgical details. Between Feb. 2012 and Jun. 2016, a total of 265 LCBDE procedures were applied in our hospital and 141 patients with primary closure were included in this study. Bile leakage occurred in 11.3% (16/141) of these patients, and happened more frequently in patients with slender CBD (<1 vs ≥1 cm, 31.6% vs 7.0%, p = 0.04) and those managed by inexperienced surgeons (initial 70 cases vs later cases, 17.1% vs 5.6%, p = 0.04). After multivariable regression, the diameter of CBD [OR 95% CI, 3.799 (1.081-13.349), p = 0.04] and experience of surgeons [OR 95% CI, 4.228 (1.330-13.438), p = 0.03] were significantly related to bile leakage. Slender CBD and inexperienced surgeons were the high risk factors for bile leakage after primary closure following LCBDE.

Interactions between gut bacteria and bile in health and disease.

PubMed

Long, Sarah L; Gahan, Cormac G M; Joyce, Susan A

2017-08-01

Bile acids are synthesized from cholesterol in the liver and released into the intestine to aid the digestion of dietary lipids. The host enzymes that contribute to bile acid synthesis in the liver and the regulatory pathways that influence the composition of the total bile acid pool in the host have been well established. In addition, the gut microbiota provides unique contributions to the diversity of bile acids in the bile acid pool. Gut microbial enzymes contribute significantly to bile acid metabolism through deconjugation and dehydroxylation reactions to generate unconjugated bile acids and secondary bile acids. These microbial enzymes (which include bile salt hydrolase (BSH) and bile acid-inducible (BAI) enzymes) are essential for bile acid homeostasis in the host and represent a vital contribution of the gut microbiome to host health. Perturbation of the gut microbiota in disease states may therefore significantly influence bile acid signatures in the host, especially in the context of gastrointestinal or systemic disease. Given that bile acids are ligands for host cell receptors (including the FXR, TGR5 and Vitamin D Receptor) alterations to microbial enzymes and associated changes to bile acid signatures have significant consequences for the host. In this review we examine the contribution of microbial enzymes to the process of bile acid metabolism in the host and discuss the implications for microbe-host signalling in the context of C. difficile infection, inflammatory bowel disease and other disease states. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Value of MR imaging in the diagnosis of intraductal papillary neoplasm of the bile duct].

PubMed

Song, Fengxiang; Zhou, Jun; Shi, Yuxin; Zeng, Mengsu; Zhou, Kangrong; Ding, Yuqin; Cao, Yingli; Zhou, Jianjun

2015-01-01

To analyze the value of MR imaging in diagnosis of intraductal papillary neoplasm of the bile duct (IPN-B). Fourteen patients with intraductal papillary neoplasms of the bile duct confirmed by surgical pathology were included in this study. The patients underwent MR routine plain scanning and enhancement scanning (including T1WI, T2WI with fat suppression, FALSH T1WI, and three-phase enhancement scanning), diffusion weighted imaging(DWI) and magnetic resonance cholangiopancreatography (MRCP) before operation. The imaging data were reviewed and analyzed retrospectively in comparison with the surgical and pathological results. In these patients, 7 cases had tumors located in the left lobe, 2 cases had tumors in both the left and right lobes, 2 cases in the hepatic hilum, 2 cases in the common bile duct, and 1 case in both the right lobe and the common bile duct. Solitary or multiple intraductal masses could be found in 12 cases, with 11 cases appeared as papillary masses and one case as flat mass. In the other two cases the tumor was not visible (one case had too many stones, and in another case the tumor was too small). The tumors in the 12 cases showed hypointensity on T1WI and hyperintensity on T2WI. On the dynamic contrast-enhanced MRI, 11 cases showed mild and one showed moderate enhancement in arterial phase, and all the cases showed mildly and gradually delayed enhancement. On DWI, the lesion areas showed high signal intensity in all the cases, and the ADC value of the tumor area (1.697×10(-3)mm(2)/s) was significantly lower than that of the normal bile (3.973×10(-3)mm(2)/s) (t = -10.94, P < 0.05). Twelve cases demonstrated filling defects on primary MRCP coronary thin section images. On 3D-reconstruction MRCP images, 7 cases exhibited diffuse bile duct dilatation with the tumor areas more prominent, 3 cases exhibited aneurysmal bile dilatation, while the rest 4 cases exhibited segmental or lobar bile duct dilatation ( including 2 with invisible tumors ). In

Bile pigment pharmacokinetics and absorption in the rat: therapeutic potential for enteral administration

PubMed Central

Bulmer, AC; Coombes, JS; Blanchfield, JT; Toth, I; Fassett, RG; Taylor, SM

2011-01-01

BACKGROUND AND PURPOSE Bilirubin and biliverdin possess antioxidant and anti-inflammatory properties and their exogenous administration protects against the effects of inflammation and trauma in experimental models. Despite the therapeutic potential of bile pigments, little is known about their in vivo parenteral or enteral absorption after exogenous administration. This study investigated the absorption and pharmacokinetics of bile pigments after i.v., i.p. and intraduodenal (i.d.) administration in addition to their metabolism and routes of excretion. EXPERIMENTAL APPROACH Anaesthetized Wistar rats had their bile duct, jugular and portal veins cannulated. Bile pigments were infused and their circulating concentrations/biliary excretion were measured over 180 min. KEY RESULTS After i.v. administration of unconjugated bilirubin, biliverdin and bilirubin ditaurate, their plasma concentrations decreased exponentially over time. Subsequently, native and metabolized compounds appeared in the bile. When administered i.p., their absolute bioavailabilities equalled 14.0, 16.1 and 33.1%, respectively, and correspondingly 38, 28 and 34% of the same bile pigment doses were excreted in the bile. Administration of unconjugated bilirubin and bilirubin ditaurate i.d. increased their portal and systemic concentrations and their systemic bioavailability equalled 1.0 and 2.0%, respectively. Correspondingly, 2.7 and 4.6%, of the doses were excreted in the bile. Biliverdin was rapidly metabolized and these products were absorbed and excreted via the urine and bile. CONCLUSIONS AND IMPLICATIONS Bile pigment absorption from the peritoneal and duodenal cavities demonstrate new routes of administration for the treatment of inflammatory and traumatic pathology. Oral biliverdin administration may lead to the production of active metabolite that protect from inflammation/complement activation. PMID:21486273

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

Novel immunohistochemical markers differentiate intrahepatic cholangiocarcinoma from benign bile duct lesions.

PubMed

Bertram, Stefanie; Padden, Juliet; Kälsch, Julia; Ahrens, Maike; Pott, Leona; Canbay, Ali; Weber, Frank; Fingas, Christian; Hoffmann, Andreas C; Vietor, Antonie; Schlaak, Joerg F; Eisenacher, Martin; Reis, Henning; Sitek, Barbara; Baba, Hideo A

2016-07-01

The distinction between intrahepatic cholangiocarcinoma (ICC) and benign bile duct lesions can be challenging. Using our previously identified potential biomarkers for ICC, we examined whether these are useful for the differential diagnosis of ICC, bile duct adenoma and reactive bile duct proliferations in an immunohistochemical approach and identified a diagnostic marker panel including known biomarkers. Subjects included samples from 77 patients with ICC, 33 patients with bile duct adenoma and 47 patients with ductular reactions in liver cirrhosis. Our previously identified biomarkers (stress-induced phosphoprotein 1 (STIP1), SerpinH1, 14-3-3Sigma) were tested immunohistochemically following comparison with candidates from the literature (cluster of differentiation 56, heat shock protein (HSP)27, HSP70, B-cell-lymphoma2, p53, ki67). The expression of SerpinH1 and 14-3-3Sigma was significantly higher in ICC than in bile duct adenomas and ductular reactions (p<0.05), whereas STIP1 expression was significantly higher (p<0.05) in ICC than in ductular reactions, but the difference to the bile duct adenoma group was not significant. A panel of the biomarker SerpinH1, 14-3-3Sigma and ki67 (≥2 marker positive) showed a high diagnostic accuracy (sensitivity 87.8%, specificity 95.9%, accuracy 91.8%) in the differential diagnosis of ICC versus non-malignant bile duct lesions. This suggests that 14-3-3Sigma and SerpinH1 may be useful in the differential diagnosis of malignant, benign and reactive bile duct lesions in addition to ki67 where a cut-off of >5% might be used for the distinction of malignant and non-malignant lesions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Bile-Esculin Test for Presumptive Identification of Enterococci and Streptococci: Effects of Bile Concentration, Inoculation Technique, and Incubation Time

PubMed Central

Chuard, C.; Reller, L. B.

1998-01-01

The bile-esculin test is used to differentiate enterococci and group D streptococci from non-group D viridans group streptococci. The effects on test performance of the concentration of bile salts, inoculum, and duration of incubation were examined with 110 strains of enterococci, 30 strains of Streptococcus bovis, and 110 strains of non-group D viridans group streptococci. Optimal sensitivity (>99%) and specificity (97%) of the bile-esculin test can be obtained with a bile concentration of 40%, a standardized inoculum of 106 CFU, and incubation for 24 h. PMID:9542954

Bile-esculin test for presumptive identification of enterococci and streptococci: effects of bile concentration, inoculation technique, and incubation time.

PubMed

Chuard, C; Reller, L B

1998-04-01

The bile-esculin test is used to differentiate enterococci and group D streptococci from non-group D viridans group streptococci. The effects on test performance of the concentration of bile salts, inoculum, and duration of incubation were examined with 110 strains of enterococci, 30 strains of Streptococcus bovis, and 110 strains of non-group D viridans group streptococci. Optimal sensitivity (> 99%) and specificity (97%) of the bile-esculin test can be obtained with a bile concentration of 40%, a standardized inoculum of 10(6) CFU, and incubation for 24 h.

Herbert Falk: a vital force in the renaissance of bile acid research and bile acid therapy.

PubMed

Hofmann, Alan F

2011-01-01

Herbert Falk died on August 8, 2008, after a long illness. It was his vision that initiated the Bile Acid Meetings and brought to market chenodeoxycholic acid and ursodeoxycholic acid for the dissolution of cholesterol gallstones as well as the successful treatment of cholestatic liver disease. The 1st Bile Acid Meeting was a small workshop held at the University Hospital of Freiburg in 1970. Great interest in the topic was evident at that small meeting and led to a larger meeting in 1972, whose scope included both the basic and clinical aspects of bile acids. These meetings have continued at biennial intervals, the 2010 meeting being the 21st. The program has always included discussions of the most fundamental aspects of bile acid biosynthesis and metabolism as well as clinical applications of bile acid therapy. The meetings featured brief presentations, ample time for discussion, and imaginative social programs. They have always been flawlessly organized. Social programs usually included a hike through the beautiful countryside of the Black Forest followed by dinner in a rustic restaurant. Herbert Falk took part in these programs, personally welcoming every participant. In the warm glow of the 'Badische' hospitality, friendships developed, and scientific collaborations were often arranged. From a scientific standpoint, there has been enormous progress in understanding the chemistry and biology of bile acids. Herbert Falk established the Windaus Prize in 1978, and the prize has been given to individuals whose contributions moved the field forward. These bile acid meetings have been marvelous, rewarding experiences. We must all be grateful to Herbert Falk's vision in establishing the Falk Foundation that has so generously sponsored these meetings. We also express our gratitude to his widow, Ursula Falk, who continues this worthy tradition. Copyright © 2011 S. Karger AG, Basel.

Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone

PubMed Central

Melia, Tisha; Hao, Pengying; Yilmaz, Feyza

2015-01-01

Long intergenic noncoding RNAs (lincRNAs) are increasingly recognized as key chromatin regulators, yet few studies have characterized lincRNAs in a single tissue under diverse conditions. Here, we analyzed 45 mouse liver RNA sequencing (RNA-Seq) data sets collected under diverse conditions to systematically characterize 4,961 liver lincRNAs, 59% of them novel, with regard to gene structures, species conservation, chromatin accessibility, transcription factor binding, and epigenetic states. To investigate the potential for functionality, we focused on the responses of the liver lincRNAs to growth hormone stimulation, which imparts clinically relevant sex differences to hepatic metabolism and liver disease susceptibility. Sex-biased expression characterized 247 liver lincRNAs, with many being nuclear RNA enriched and regulated by growth hormone. The sex-biased lincRNA genes are enriched for nearby and correspondingly sex-biased accessible chromatin regions, as well as sex-biased binding sites for growth hormone-regulated transcriptional activators (STAT5, hepatocyte nuclear factor 6 [HNF6], FOXA1, and FOXA2) and transcriptional repressors (CUX2 and BCL6). Repression of female-specific lincRNAs in male liver, but not that of male-specific lincRNAs in female liver, was associated with enrichment of H3K27me3-associated inactive states and poised (bivalent) enhancer states. Strikingly, we found that liver-specific lincRNA gene promoters are more highly species conserved and have a significantly higher frequency of proximal binding by liver transcription factors than liver-specific protein-coding gene promoters. Orthologs for many liver lincRNAs were identified in one or more supraprimates, including two rat lincRNAs showing the same growth hormone-regulated, sex-biased expression as their mouse counterparts. This integrative analysis of liver lincRNA chromatin states, transcription factor occupancy, and growth hormone regulation provides novel insights into the

Computer analysis of three-dimensional morphological characteristics of the bile duct

NASA Astrophysics Data System (ADS)

Ma, Jinyuan; Chen, Houjin; Peng, Yahui; Shang, Hua

2017-01-01

In this paper, a computer image-processing algorithm for analyzing the morphological characteristics of bile ducts in Magnetic Resonance Cholangiopancreatography (MRCP) images was proposed. The algorithm consisted of mathematical morphology methods including erosion, closing and skeletonization, and a spline curve fitting method to obtain the length and curvature of the center line of the bile duct. Of 10 cases, the average length of the bile duct was 14.56 cm. The maximum curvature was in the range of 0.111 2.339. These experimental results show that using the computer image-processing algorithm to assess the morphological characteristics of the bile duct is feasible and further research is needed to evaluate its potential clinical values.

Mechanistic insight into nuclear receptor-mediated regulation of bile acid metabolism and lipid homeostasis by grape seed procyanidin extract (GSPE).

PubMed

Downing, Laura E; Edgar, Daniel; Ellison, Patricia A; Ricketts, Marie-Louise

2017-01-01

Dietary procyanidins have emerged as important bioactive components that regulate various metabolic pathways to maintain homeostasis. Grape seed procyanidin extract (GSPE), in particular, has demonstrated regulatory effects on bile acid and lipid metabolism in vivo. While numerous studies in rodent models have shown the potent hypolipidemic action of grape seed extracts, human studies have shown inconsistent results. This review will focus on the molecular mechanisms underlying the hypolipidemic actions of GSPE identified to date, specifically highlighting the effects exerted via nuclear receptors. Such evidence may provide avenues for future research in human subjects with GSPE as a therapeutic treatment for the prevention and amelioration of the metabolic syndrome and cardiovascular disease. Copyright © 2017 John Wiley & Sons, Ltd.

[ENDOSONOGRAPHY IN THE DIFFERENTIAL DIAGNOSIS OF THE COMMON BILE DUCT STENOSIS].

PubMed

Solodinina, E N; Starkov, Y G; Shumkin, L V

2015-01-01

The article states the results of examination and treatment of 57 patients with stenosis of the common bile duct of various genesis. The main aim of the work is criteria definition and evaluation of diagnostic significance of endosonography in the differential diagnosis of benign and malignant common bile duct stenosis. The paper presents a methodology of endoscopic ultrasound and basic criteria for the differential diagnosis of tumors and other lesions of the extrahepatic bile ducts. A comparative analysis of endosonography, ultrasound, CT, MRCP was conducted. The sensitivity of endosonography in determining the nature of the common bile duct stenosis was 97.7%, a specificity 100% and accuracy 98.2%, which is superior to other methods of radiological diagnosis. In comprehensive surgical centers endosonography should be used as a method of specifying the final diagnosis to determine the nature of the common bile duct stenosis, particularly at low constriction location.

Genetic fine-mapping and genomic annotation defines causal mechanisms at type 2 diabetes susceptibility loci

PubMed Central

Mahajan, Anubha; Locke, Adam; Rayner, N William; Robertson, Neil; Scott, Robert A; Prokopenko, Inga; Scott, Laura J; Green, Todd; Sparso, Thomas; Thuillier, Dorothee; Yengo, Loic; Grallert, Harald; Wahl, Simone; Frånberg, Mattias; Strawbridge, Rona J; Kestler, Hans; Chheda, Himanshu; Eisele, Lewin; Gustafsson, Stefan; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Qi, Lu; Karssen, Lennart C; van Leeuwen, Elisabeth M; Willems, Sara M; Li, Man; Chen, Han; Fuchsberger, Christian; Kwan, Phoenix; Ma, Clement; Linderman, Michael; Lu, Yingchang; Thomsen, Soren K; Rundle, Jana K; Beer, Nicola L; van de Bunt, Martijn; Chalisey, Anil; Kang, Hyun Min; Voight, Benjamin F; Abecasis, Goncalo R; Almgren, Peter; Baldassarre, Damiano; Balkau, Beverley; Benediktsson, Rafn; Blüher, Matthias; Boeing, Heiner; Bonnycastle, Lori L; Borringer, Erwin P; Burtt, Noël P; Carey, Jason; Charpentier, Guillaume; Chines, Peter S; Cornelis, Marilyn C; Couper, David J; Crenshaw, Andrew T; van Dam, Rob M; Doney, Alex SF; Dorkhan, Mozhgan; Edkins, Sarah; Eriksson, Johan G; Esko, Tonu; Eury, Elodie; Fadista, João; Flannick, Jason; Fontanillas, Pierre; Fox, Caroline; Franks, Paul W; Gertow, Karl; Gieger, Christian; Gigante, Bruna; Gottesman, Omri; Grant, George B; Grarup, Niels; Groves, Christopher J; Hassinen, Maija; Have, Christian T; Herder, Christian; Holmen, Oddgeir L; Hreidarsson, Astradur B; Humphries, Steve E; Hunter, David J; Jackson, Anne U; Jonsson, Anna; Jørgensen, Marit E; Jørgensen, Torben; Kerrison, Nicola D; Kinnunen, Leena; Klopp, Norman; Kong, Augustine; Kovacs, Peter; Kraft, Peter; Kravic, Jasmina; Langford, Cordelia; Leander, Karin; Liang, Liming; Lichtner, Peter; Lindgren, Cecilia M; Lindholm, Eero; Linneberg, Allan; Liu, Ching-Ti; Lobbens, Stéphane; Luan, Jian’an; Lyssenko, Valeriya; Männistö, Satu; McLeod, Olga; Meyer, Julia; Mihailov, Evelin; Mirza, Ghazala; Mühleisen, Thomas W; Müller-Nurasyid, Martina; Navarro, Carmen; Nöthen, Markus M; Oskolkov, Nikolay N; Owen, Katharine R; Palli, Domenico; Pechlivanis, Sonali; Perry, John RB; Platou, Carl GP; Roden, Michael; Ruderfer, Douglas; Rybin, Denis; van der Schouw, Yvonne T; Sennblad, Bengt; Sigurðsson, Gunnar; Stančáková, Alena; Steinbach, Gerald; Storm, Petter; Strauch, Konstantin; Stringham, Heather M; Sun, Qi; Thorand, Barbara; Tikkanen, Emmi; Tonjes, Anke; Trakalo, Joseph; Tremoli, Elena; Tuomi, Tiinamaija; Wennauer, Roman; Wood, Andrew R; Zeggini, Eleftheria; Dunham, Ian; Birney, Ewan; Pasquali, Lorenzo; Ferrer, Jorge; Loos, Ruth JF; Dupuis, Josée; Florez, Jose C; Boerwinkle, Eric; Pankow, James S; van Duijn, Cornelia; Sijbrands, Eric; Meigs, James B; Hu, Frank B; Thorsteinsdottir, Unnur; Stefansson, Kari; Lakka, Timo A; Rauramaa, Rainer; Stumvoll, Michael; Pedersen, Nancy L; Lind, Lars; Keinanen-Kiukaanniemi, Sirkka M; Korpi-Hyövälti, Eeva; Saaristo, Timo E; Saltevo, Juha; Kuusisto, Johanna; Laakso, Markku; Metspalu, Andres; Erbel, Raimund; Jöckel, Karl-Heinz; Moebus, Susanne; Ripatti, Samuli; Salomaa, Veikko; Ingelsson, Erik; Boehm, Bernhard O; Bergman, Richard N; Collins, Francis S; Mohlke, Karen L; Koistinen, Heikki; Tuomilehto, Jaakko; Hveem, Kristian; Njølstad, Inger; Deloukas, Panagiotis; Donnelly, Peter J; Frayling, Timothy M; Hattersley, Andrew T; de Faire, Ulf; Hamsten, Anders; Illig, Thomas; Peters, Annette; Cauchi, Stephane; Sladek, Rob; Froguel, Philippe; Hansen, Torben; Pedersen, Oluf; Morris, Andrew D; Palmer, Collin NA; Kathiresan, Sekar; Melander, Olle; Nilsson, Peter M; Groop, Leif C; Barroso, Inês; Langenberg, Claudia; Wareham, Nicholas J; O’Callaghan, Christopher A; Gloyn, Anna L; Altshuler, David; Boehnke, Michael; Teslovich, Tanya M; McCarthy, Mark I; Morris, Andrew P

2015-01-01

We performed fine-mapping of 39 established type 2 diabetes (T2D) loci in 27,206 cases and 57,574 controls of European ancestry. We identified 49 distinct association signals at these loci, including five mapping in/near KCNQ1. “Credible sets” of variants most likely to drive each distinct signal mapped predominantly to non-coding sequence, implying that T2D association is mediated through gene regulation. Credible set variants were enriched for overlap with FOXA2 chromatin immunoprecipitation binding sites in human islet and liver cells, including at MTNR1B, where fine-mapping implicated rs10830963 as driving T2D association. We confirmed that this T2D-risk allele increases FOXA2-bound enhancer activity in islet- and liver-derived cells. We observed allele-specific differences in NEUROD1 binding in islet-derived cells, consistent with evidence that the T2D-risk allele increases islet MTNR1B expression. Our study demonstrates how integration of genetic and genomic information can define molecular mechanisms through which variants underlying association signals exert their effects on disease. PMID:26551672

Genetic fine mapping and genomic annotation defines causal mechanisms at type 2 diabetes susceptibility loci.

PubMed

Gaulton, Kyle J; Ferreira, Teresa; Lee, Yeji; Raimondo, Anne; Mägi, Reedik; Reschen, Michael E; Mahajan, Anubha; Locke, Adam; Rayner, N William; Robertson, Neil; Scott, Robert A; Prokopenko, Inga; Scott, Laura J; Green, Todd; Sparso, Thomas; Thuillier, Dorothee; Yengo, Loic; Grallert, Harald; Wahl, Simone; Frånberg, Mattias; Strawbridge, Rona J; Kestler, Hans; Chheda, Himanshu; Eisele, Lewin; Gustafsson, Stefan; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Qi, Lu; Karssen, Lennart C; van Leeuwen, Elisabeth M; Willems, Sara M; Li, Man; Chen, Han; Fuchsberger, Christian; Kwan, Phoenix; Ma, Clement; Linderman, Michael; Lu, Yingchang; Thomsen, Soren K; Rundle, Jana K; Beer, Nicola L; van de Bunt, Martijn; Chalisey, Anil; Kang, Hyun Min; Voight, Benjamin F; Abecasis, Gonçalo R; Almgren, Peter; Baldassarre, Damiano; Balkau, Beverley; Benediktsson, Rafn; Blüher, Matthias; Boeing, Heiner; Bonnycastle, Lori L; Bottinger, Erwin P; Burtt, Noël P; Carey, Jason; Charpentier, Guillaume; Chines, Peter S; Cornelis, Marilyn C; Couper, David J; Crenshaw, Andrew T; van Dam, Rob M; Doney, Alex S F; Dorkhan, Mozhgan; Edkins, Sarah; Eriksson, Johan G; Esko, Tonu; Eury, Elodie; Fadista, João; Flannick, Jason; Fontanillas, Pierre; Fox, Caroline; Franks, Paul W; Gertow, Karl; Gieger, Christian; Gigante, Bruna; Gottesman, Omri; Grant, George B; Grarup, Niels; Groves, Christopher J; Hassinen, Maija; Have, Christian T; Herder, Christian; Holmen, Oddgeir L; Hreidarsson, Astradur B; Humphries, Steve E; Hunter, David J; Jackson, Anne U; Jonsson, Anna; Jørgensen, Marit E; Jørgensen, Torben; Kao, Wen-Hong L; Kerrison, Nicola D; Kinnunen, Leena; Klopp, Norman; Kong, Augustine; Kovacs, Peter; Kraft, Peter; Kravic, Jasmina; Langford, Cordelia; Leander, Karin; Liang, Liming; Lichtner, Peter; Lindgren, Cecilia M; Lindholm, Eero; Linneberg, Allan; Liu, Ching-Ti; Lobbens, Stéphane; Luan, Jian'an; Lyssenko, Valeriya; Männistö, Satu; McLeod, Olga; Meyer, Julia; Mihailov, Evelin; Mirza, Ghazala; Mühleisen, Thomas W; Müller-Nurasyid, Martina; Navarro, Carmen; Nöthen, Markus M; Oskolkov, Nikolay N; Owen, Katharine R; Palli, Domenico; Pechlivanis, Sonali; Peltonen, Leena; Perry, John R B; Platou, Carl G P; Roden, Michael; Ruderfer, Douglas; Rybin, Denis; van der Schouw, Yvonne T; Sennblad, Bengt; Sigurðsson, Gunnar; Stančáková, Alena; Steinbach, Gerald; Storm, Petter; Strauch, Konstantin; Stringham, Heather M; Sun, Qi; Thorand, Barbara; Tikkanen, Emmi; Tonjes, Anke; Trakalo, Joseph; Tremoli, Elena; Tuomi, Tiinamaija; Wennauer, Roman; Wiltshire, Steven; Wood, Andrew R; Zeggini, Eleftheria; Dunham, Ian; Birney, Ewan; Pasquali, Lorenzo; Ferrer, Jorge; Loos, Ruth J F; Dupuis, Josée; Florez, Jose C; Boerwinkle, Eric; Pankow, James S; van Duijn, Cornelia; Sijbrands, Eric; Meigs, James B; Hu, Frank B; Thorsteinsdottir, Unnur; Stefansson, Kari; Lakka, Timo A; Rauramaa, Rainer; Stumvoll, Michael; Pedersen, Nancy L; Lind, Lars; Keinanen-Kiukaanniemi, Sirkka M; Korpi-Hyövälti, Eeva; Saaristo, Timo E; Saltevo, Juha; Kuusisto, Johanna; Laakso, Markku; Metspalu, Andres; Erbel, Raimund; Jöcke, Karl-Heinz; Moebus, Susanne; Ripatti, Samuli; Salomaa, Veikko; Ingelsson, Erik; Boehm, Bernhard O; Bergman, Richard N; Collins, Francis S; Mohlke, Karen L; Koistinen, Heikki; Tuomilehto, Jaakko; Hveem, Kristian; Njølstad, Inger; Deloukas, Panagiotis; Donnelly, Peter J; Frayling, Timothy M; Hattersley, Andrew T; de Faire, Ulf; Hamsten, Anders; Illig, Thomas; Peters, Annette; Cauchi, Stephane; Sladek, Rob; Froguel, Philippe; Hansen, Torben; Pedersen, Oluf; Morris, Andrew D; Palmer, Collin N A; Kathiresan, Sekar; Melander, Olle; Nilsson, Peter M; Groop, Leif C; Barroso, Inês; Langenberg, Claudia; Wareham, Nicholas J; O'Callaghan, Christopher A; Gloyn, Anna L; Altshuler, David; Boehnke, Michael; Teslovich, Tanya M; McCarthy, Mark I; Morris, Andrew P

2015-12-01

We performed fine mapping of 39 established type 2 diabetes (T2D) loci in 27,206 cases and 57,574 controls of European ancestry. We identified 49 distinct association signals at these loci, including five mapping in or near KCNQ1. 'Credible sets' of the variants most likely to drive each distinct signal mapped predominantly to noncoding sequence, implying that association with T2D is mediated through gene regulation. Credible set variants were enriched for overlap with FOXA2 chromatin immunoprecipitation binding sites in human islet and liver cells, including at MTNR1B, where fine mapping implicated rs10830963 as driving T2D association. We confirmed that the T2D risk allele for this SNP increases FOXA2-bound enhancer activity in islet- and liver-derived cells. We observed allele-specific differences in NEUROD1 binding in islet-derived cells, consistent with evidence that the T2D risk allele increases islet MTNR1B expression. Our study demonstrates how integration of genetic and genomic information can define molecular mechanisms through which variants underlying association signals exert their effects on disease.

White gauze test: a novel technique in preventing post-hepatectomy bile leak.

PubMed

Yugasaravanan, K; Affirul, C A; Zamri, Z; Azlanudin, A; Bong, J J

Post-hepatectomy bile leak may lead to undesired morbidity. Multiple methods have been employed to identify this leak but can be inconclusive and taxing. This novel white gauze test is a simple and reliable method. This is a prospective study performed from January 2010 until March 2011. All open hepatic resection were included. Dry white gauze is compressed onto the transected surface and observed for bile staining. The leaking duct is repaired immediately upon detection. The process is repeated until negative. Drain was removed on postoperative day-5. Post-operative bile leak is defined as: 1. Bilirubin concentration of the drain fluid is 3 times or higher than serum; 2. Presence of intra-abdominal bile collection on imaging and upon drainage; 3. Bile leak demonstrated on postoperative cholangiography. 42 patients were recruited. Seven (16.7%) patients were cirrhotic with Child-Pugh A. White gauze test were positive for intra-operative bile leaks in 29 patients (70%), which were primarily repaired. As a result, there was no postoperative bile leak in this series. One mortality was detected in this series due to postoperative pancreatic fistula and multi organ failure. The White Gauze Test is a useful method for the prevention of bile leakage after hepatic resection. It is safe, quick and cheap.

Mechanisms of bile acid mediated inflammation in the liver.

PubMed

Li, Man; Cai, Shi-Ying; Boyer, James L

2017-08-01

Bile acids are synthesized in the liver and are the major component in bile. Impaired bile flow leads to cholestasis that is characterized by elevated levels of bile acid in the liver and serum, followed by hepatocyte and biliary injury. Although the causes of cholestasis have been extensively studied, the molecular mechanisms as to how bile acids initiate liver injury remain controversial. In this chapter, we summarize recent advances in the pathogenesis of bile acid induced liver injury. These include bile acid signaling pathways in hepatocytes as well as the response of cholangiocytes and innate immune cells in the liver in both patients with cholestasis and cholestatic animal models. We focus on how bile acids trigger the production of molecular mediators of neutrophil recruitment and the role of the inflammatory response in this pathological process. These advances point to a number of novel targets where drugs might be judged to be effective therapies for cholestatic liver injury. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolism of Oxo-Bile Acids and Characterization of Recombinant 12α-Hydroxysteroid Dehydrogenases from Bile Acid 7α-Dehydroxylating Human Gut Bacteria.

PubMed

Doden, Heidi; Sallam, Lina A; Devendran, Saravanan; Ly, Lindsey; Doden, Greta; Daniel, Steven L; Alves, João M P; Ridlon, Jason M

2018-05-15

Bile acids are important cholesterol-derived nutrient signaling hormones, synthesized in the liver, that act as detergents to solubilize dietary lipids. Bile acid 7α-dehydroxylating gut bacteria generate the toxic bile acids deoxycholic acid and lithocholic acid from host bile acids. The ability of these bacteria to remove the 7-hydroxyl group is partially dependent on 7α-hydroxysteroid dehydrogenase (HSDH) activity, which reduces 7-oxo-bile acids generated by other gut bacteria. 3α-HSDH has an important enzymatic activity in the bile acid 7α-dehydroxylation pathway. 12α-HSDH activity has been reported for the low-activity bile acid 7α-dehydroxylating bacterium Clostridium leptum ; however, this activity has not been reported for high-activity bile acid 7α-dehydroxylating bacteria, such as Clostridium scindens , Clostridium hylemonae , and Clostridium hiranonis Here, we demonstrate that these strains express bile acid 12α-HSDH. The recombinant enzymes were characterized from each species and shown to preferentially reduce 12-oxolithocholic acid to deoxycholic acid, with low activity against 12-oxochenodeoxycholic acid and reduced activity when bile acids were conjugated to taurine or glycine. Phylogenetic analysis suggests that 12α-HSDH is widespread among Firmicutes , Actinobacteria in the Coriobacteriaceae family, and human gut Archaea IMPORTANCE 12α-HSDH activity has been established in the medically important bile acid 7α-dehydroxylating bacteria C. scindens , C. hiranonis , and C. hylemonae Experiments with recombinant 12α-HSDHs from these strains are consistent with culture-based experiments that show a robust preference for 12-oxolithocholic acid over 12-oxochenodeoxycholic acid. Phylogenetic analysis identified novel members of the gut microbiome encoding 12α-HSDH. Future reengineering of 12α-HSDH enzymes to preferentially oxidize cholic acid may provide a means to industrially produce the therapeutic bile acid ursodeoxycholic acid. In

Transformation of bile acids into iso-bile acids by Clostridium perfringens: possible transport of 3 beta-hydrogen via the coenzyme.

PubMed

Batta, A K; Salen, G; Shefer, S

1985-01-01

We have examined the mechanism for the bacterial transformation of chenodeoxycholic acid and lithocholic acid into the corresponding 3 beta-hydroxy epimers with the use of 3 alpha- and 3 beta-tritiated bile acids. The 3-oxo bile acids were transformed into the 3 alpha- (85%) and 3 beta- (15%) hydroxy bile acids after 20-hr incubation with Clostridium perfringens. Approximately 75% radioactivity was recovered in the aqueous medium when [3 beta-3H]chenodeoxycholic acid or [3 beta-3H]lithocholic acid was incubated with the bacteria, and approximately 15% of radioactivity in the bile acid fraction was associated with the 3 alpha-position of the iso-bile acids. When [3 beta-3H]chenodeoxycholic acid was incubated with unlabeled 3-oxo-5 beta-cholanoic acid, tritiated litho- and iso-lithocholic acids were recovered. These results can be explained only when a 3-oxo intermediate is postulated, and the 3 beta-hydrogen in the bile acids is transferred by the bacterial coenzyme (NAD+ or NADP+) to the 3 alpha-position in the iso-bile acids during the reduction of the 3-oxo compounds.

The role of bile acids in metabolic regulation.

PubMed

Vítek, Libor; Haluzík, Martin

2016-03-01

Bile acids (BA), long believed to only have lipid-digestive functions, have emerged as novel metabolic modulators. They have important endocrine effects through multiple cytoplasmic as well as nuclear receptors in various organs and tissues. BA affect multiple functions to control energy homeostasis, as well as glucose and lipid metabolism, predominantly by activating the nuclear farnesoid X receptor and the cytoplasmic G protein-coupled BA receptor TGR5 in a variety of tissues. However, BA also are aimed at many other cellular targets in a wide array of organs and cell compartments. Their role in the pathogenesis of diabetes, obesity and other 'diseases of civilization' becomes even more clear. They also interact with the gut microbiome, with important clinical implications, further extending the complexity of their biological functions. Therefore, it is not surprising that BA metabolism is substantially modulated by bariatric surgery, a phenomenon contributing favorably to the therapeutic effects of these surgical procedures. Based on these data, several therapeutic approaches to ameliorate obesity and diabetes have been proposed to affect the cellular targets of BA. © 2016 Society for Endocrinology.

New tapered metallic stent for unresectable malignant hilar bile duct obstruction.

PubMed

Sakai, Yuji; Tsuyuguchi, Toshio; Nishikawa, Takao; Sugiyama, Harutoshi; Sasaki, Reina; Sakamoto, Dai; Watanabe, Yuto; Nakamura, Masato; Yasui, Shin; Mikata, Rintaro; Yokosuka, Osamu

2015-10-16

To examine the usefulness of a new tapered metallic stent (MS) in patients with unresectable malignant hilar bile duct obstruction. This new tapered MS was placed in 11 patients with Bismuth II or severer unresectable malignant hilar bile duct obstruction, as a prospective study. The subjects were six patients with bile duct carcinoma, three with gallbladder cancer, and two with metastatic bile duct obstruction. Stenosis morphology was Bismuth II: 7, IIIa: 3, and IV: 1. UMIN Clinical Trial Registry (UMIN000004758). MS placement was 100% (11/11) successful. There were no procedural accidents. The mean patency period was 208.401 d, the median survival period was 142.000 d, and the mean survival period was 193.273 d. Occlusion rate was 36.4% (4/11); the causes of occlusion were ingrowth and overgrowth in 2 patients each, 18.2%, respectively. Patients with occlusion underwent endoscopic treatment one more time and all were treatable. The tapered MS proved useful in patients with unresectable malignant hilar bile duct obstruction because it provided a long patency period, enabled re-treatment by re-intervention, and no procedural accidents occurred.

Diet1, bile acid diarrhea, and FGF15/19: mouse model and human genetic variants.

PubMed

Lee, Jessica M; Ong, Jessica R; Vergnes, Laurent; de Aguiar Vallim, Thomas Q; Nolan, Jonathan; Cantor, Rita M; Walters, Julian R F; Reue, Karen

2018-03-01

Diet1 modulates intestinal production of the hormone, fibroblast growth factor (FGF)15, which signals in liver to regulate bile acid synthesis. C57BL/6ByJ mice with a spontaneous Diet1 -null mutation are resistant to hypercholesterolemia compared with wild-type C57BL/6J mice through enhanced cholesterol conversion to bile acids. To further characterize the role of Diet1 in metabolism, we generated Diet1 -/- mice on the C57BL/6J genetic background. C57BL/6J Diet1 -/- mice had elevated bile acid levels, reduced Fgf15 expression, and increased gastrointestinal motility and intestinal luminal water content, which are symptoms of bile acid diarrhea (BAD) in humans. Natural genetic variation in Diet1 mRNA expression levels across 76 inbred mouse strains correlated positively with Ffg15 mRNA and negatively with serum bile acid levels. This led us to investigate the role of DIET1 genetic variation in primary BAD patients. We identified a DIET1 coding variant ( rs12256835 ) that had skewed prevalence between BAD cases and controls. This variant causes an H1721Q amino acid substitution that increases the levels of FGF19 protein secreted from cultured cells. We propose that genetic variation in DIET1 may be a determinant of FGF19 secretion levels, and may affect bile acid metabolism in both physiological and pathological conditions. Copyright © 2018 by the American Society for Biochemistry and Molecular Biology, Inc.

Identification and Characterization of Post-Translational Modifications on EAF1 and EAF2 in Prostate Cancer

DTIC Science & Technology

2013-04-01

1nM R1881). All samples were normalized to renilla . B) Activity of PSA- luciferase in the presence of FOXA1 when EAF2 is over-expressed. All...samples performed in the presence of 1nM R1881. All samples were normalized to renilla . *=pɘ.05 All experiments were performed in C4-2 cells. FOXA1

History of Hepatic Bile Formation: Old Problems, New Approaches

ERIC Educational Resources Information Center

Javitt, Norman B.

2014-01-01

Studies of hepatic bile formation reported in 1958 established that it was an osmotically generated water flow. Intravenous infusion of sodium taurocholate established a high correlation between hepatic bile flow and bile acid excretion. Secretin, a hormone that stimulates bicarbonate secretion, was also found to increase hepatic bile flow. The…

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

Differentiation of various traditional Chinese medicines derived from animal bile and gallstone: simultaneous determination of bile acids by liquid chromatography coupled with triple quadrupole mass spectrometry.

PubMed

Qiao, Xue; Ye, Min; Pan, De-lin; Miao, Wen-juan; Xiang, Cheng; Han, Jian; Guo, De-an

2011-01-07

Animal biles and gallstones are popularly used in traditional Chinese medicines, and bile acids are their major bioactive constituents. Some of these medicines, like cow-bezoar, are very expensive, and may be adulterated or even replaced by less expensive but similar species. Due to poor ultraviolet absorbance and structural similarity of bile acids, effective technology for species differentiation and quality control of bile-based Chinese medicines is still lacking. In this study, a rapid and reliable method was established for the simultaneous qualitative and quantitative analysis of 18 bile acids, including 6 free steroids (cholic acid, chenodeoxycholic acid, deoxycholic acid, lithocholic acid, hyodeoxycholic acid, and ursodeoxycholic acid) and their corresponding glycine conjugates and taurine conjugates, by using liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). This method was used to analyze six bile-based Chinese medicines: bear bile, cattle bile, pig bile, snake bile, cow-bezoar, and artificial cow-bezoar. Samples were separated on an Atlantis dC₁₈ column and were eluted with methanol-acetonitrile-water containing ammonium acetate. The mass spectrometer was monitored in the negative electrospray ionization mode. Total ion currents of the samples were compared for species differentiation, and the contents of bile acids were determined by monitoring specific ion pairs in a selected reaction monitoring program. All 18 bile acids showed good linearity (r² > 0.993) in a wide dynamic range of up to 2000-fold, using dehydrocholic acid as the internal standard. Different animal biles could be explicitly distinguished by their major characteristic bile acids: tauroursodeoxycholic acid and taurochenodeoxycholic acid for bear bile, glycocholic acid, cholic acid and taurocholic acid for cattle bile, glycohyodeoxycholic acid and glycochenodeoxycholic acid for pig bile, and taurocholic acid for snake bile. Furthermore, cattle bile, cow

Laparoscopic managment of common bile duct stones: our initial experience.

PubMed

Aroori, S; Bell, J C

2002-05-01

The management of choledocholithiasis has changed radically since the introduction of laparoscopic cholecystectomy. However, perceived technical difficulties have deterred many surgeons from treating common bile duct stones laparoscopically at the time of cholecystectomy. This has lead to reliance on endoscopic retrograde cholangiopancreatography followed by endoscopic sphincterotomy to deal with common bile duct stones. We retrospectively reviewed the charts of patients who had laparoscopic common bile duct exploration at Downe Hospital between December 1999 and August 2001. Among 149 laparoscopic cholecystectomies done by our group in this period, 10 patients (6.7%) underwent laparoscopic CBD exploration, three by the transcystic technique and seven by choledochotomy. Three patients (2%) had unsuspected stones found on routine per- operative cholangiogram. The mean operative time was 2.34hrs (range 1.50-3.30hrs). The mean hospital post- operative stay was 3 days (range 1-6 days). Post-operative morbidity was zero. Stone clearance was achieved in all cases. We conclude, laparoscopic exploration of the common bile duct is relatively safe and straightforward method. The key skill required is the ability to perform laparoscopic suturing with confidence.

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

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

PubMed

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.

AP-1 Inhibition by SR 11302 Protects Human Hepatoma HepG2 Cells from Bile Acid-Induced Cytotoxicity by Restoring the NOS-3 Expression

PubMed Central

González-Rubio, Sandra; Linares, Clara I.; Aguilar-Melero, Patricia; Rodríguez-Perálvarez, Manuel; Montero-Álvarez, José L.

2016-01-01

The harmful effects of bile acid accumulation occurring during cholestatic liver diseases have been associated with oxidative stress increase and endothelial nitric oxide synthase (NOS-3) expression decrease in liver cells. We have previously reported that glycochenodeoxycholic acid (GCDCA) down-regulates gene expression by increasing SP1 binding to the NOS-3 promoter in an oxidative stress dependent manner. In the present study, we aimed to investigate the role of transcription factor (TF) AP-1 on the NOS-3 deregulation during GCDCA-induced cholestasis. The cytotoxic response to GCDCA was characterized by 1) the increased expression and activation of TFs cJun and c-Fos; 2) a higher binding capability of these at position -666 of the NOS-3 promoter; 3) a decrease of the transcriptional activity of the promoter and the expression and activity of NOS-3; and 4) the expression increase of cyclin D1. Specific inhibition of AP-1 by the retinoid SR 11302 counteracted the cytotoxic effects induced by GCDCA while promoting NOS-3 expression recovery and cyclin D1 reduction. NOS activity inhibition by L-NAME inhibited the protective effect of SR 11302. Inducible NOS isoform was no detected in this experimental model of cholestasis. Our data provide direct evidence for the involvement of AP-1 in the NOS-3 expression regulation during cholestasis and define a critical role for NOS-3 in regulating the expression of cyclin D1 during the cell damage induced by bile acids. AP-1 appears as a potential therapeutic target in cholestatic liver diseases given its role as a transcriptional repressor of NOS-3. PMID:27490694

Bile salt induced back diffusion of hydrogen ions across gastric mucosa in man. Fact or fiction?

PubMed

Ivey, K J

1981-01-01

We studied the effect of 5.5 mM bile salts, consisting of taurine conjugates in 5 normal subjects. Bile salts caused a significant increase in H+ loss from and Na+ movement into the gastric lumen (controls 1.5 mEq H+, 1.5 mEq Na+; bile salts -3.1 mEq H+ (p less than 0.001), Na+ 2.5 mEq (p less than 0.01) per 15 min.) To determine the effect of acid secretion, studies were repeated after i.v. atropine 2 mg/70 kg b.w. Atropine reduced net H+ flux to -0.2 mEq and Na+ gain to 0.9 mEq. When the bile salt studies were repeated after i.v. atropine, net H+ loss was increased to -5.4 mEq H+, significantly greater than with bile salts alone; corresponding Na+ gain was 3.2 mEq/15 min. The volume of fluid secreted was 25.0 ml in the bile salt study compared with 14.0 ml in the atropine and bile salt study. Even if all the additional volume 'secreted' (14 ml) were bicarbonate from the stomach or pancreatic juice with a concentration of 145 mEq/liter, it could account for a loss of only 2.0 mEq H+. In conclusion, atropine with bile salts is associated with a loss of H+ ions too great to be accounted for by bicarbonate neutralization. We conclude that back diffusion of H+ ions is the most likely explanation of H+ loss after bile salts in man.

Lecithin in mixed micelles attenuates the cytotoxicity of bile salts in Caco-2 cells.

PubMed

Tan, Ya'nan; Qi, Jianping; Lu, Yi; Hu, Fuqiang; Yin, Zongning; Wu, Wei

2013-03-01

This study was designed to investigate the cytotoxicity of bile salt-lecithin mixed micelles on the Caco-2 cell model. Cell viability and proliferation after mixed micelles treatments were evaluated with the MTT assay, and the integrity of Caco-2 cell monolayer was determined by quantitating the transepithelial electrical resistance and the flux of tracer, FITC-dextran 4400. The apoptosis induced by mixed micelles treatments was investigated with the annexin V/PI protocol. The particle size of mixed micelles was all smaller than 100 nm. The mixed micelles with lower than 0.2mM sodium deoxycholate (SDC) had no significant effects on cell viability and proliferation. When the level of SDC was higher than 0.4mM and the lecithin/SDC ratio was lower than 2:1, the mixed micelles caused significant changes in cell viability and proliferation. Furthermore, the mixed micelles affected tight junctions in a composition-dependent manner. Specifically, the tight junctions were transiently opened rather than damaged by the mixed micelles with SDC of between 0.2 and 0.6mM. The mixed micelles with more lecithin also induced less apoptosis. These results demonstrate that relatively higher concentrations of mixed micelles are toxic to Caco-2 cells, while phospholipids can attenuate the toxicity of the bile salts. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Acute bile nephropathy secondary to anabolic steroids.

PubMed

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

2016-02-01

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

Regulation of Epithelial Injury and Bile Duct Obstruction by NLRP3 and IL-1R1 in Experimental Biliary Atresia.

PubMed

Yang, Li; Mizuochi, Tatsuki; Shivakumar, Pranavkumar; Mourya, Reena; Luo, Zhenhua; Gutta, Sridevi; Bezerra, Jorge A

2018-06-07

Biliary atresia (BA) results from a neonatal inflammatory and fibrosing obstruction of bile ducts of unknown etiology. Although the innate immune system has been linked to virus-induced mechanism of disease, the role of the inflammasome-mediated epithelial injury remains largely undefined. Here, we hypothesized that disruption of the inflammasome suppresses the neonatal proinflammatory response and prevents experimental BA. We determined the expression of key inflammasome-related genes in livers from infants at diagnosis of BA and in extrahepatic bile ducts (EHBDs) of neonatal mice after infection with rotavirus (RRV) immediately after birth. Then, we determined the impact of the wholesale inactivation of the genes encoding IL-1R1 (Il1r1 -/- ), NLRP3 (Nlrp3 -/- ) or Caspase-1 (Casp1 -/- ) on epithelial injury and bile duct obstruction. IL1R1, NLRP3 and CASP1 mRNA increased significantly in human livers at the time of diagnosis, and in extrahepatic bile ducts of RRV-infected mice. In Il1r1 -/- mice, the epithelial injury of EHBDs induced by RRV was suppressed, with an inability of dendritic cells (DCs) to activate natural killer (NK) cells. A similar protection was observed in Nlrp3 -/- mice, with decreased injury and inflammation of livers and EHBDs. Long-term survival was also improved. In contrast, the inactivation of the Casp1 gene had no impact on tissue injury, and all mice died. Tissue analyses in Il1r1 -/- and Nlrp3 -/- mice showed decreased population of DC and NK cells and suppressed the expression of type-1 cytokines and chemokines. Inflammasome genes are overexpressed at diagnosis of BA in humans and in the BA mouse model. In the experimental model, the targeted loss of IL-1R1 or NLRP3, but not of Capase-1, protected neonatal mice against RRV-induced bile duct obstruction. Biliary atresia is a severe inflammatory and obstructive disease of bile ducts of infancy. Although the cause is unknown, an activation of the innate and adaptive immune systems injure

Bile Routing Modification Reproduces Key Features of Gastric Bypass in Rat.

PubMed

Goncalves, Daisy; Barataud, Aude; De Vadder, Filipe; Vinera, Jennifer; Zitoun, Carine; Duchampt, Adeline; Mithieux, Gilles

2015-12-01

To evaluate the role of bile routing modification on the beneficial effects of gastric bypass surgery on glucose and energy metabolism. Gastric bypass surgery (GBP) promotes early improvements in glucose and energy homeostasis in obese diabetic patients. A suggested mechanism associates a decrease in hepatic glucose production to an enhanced intestinal gluconeogenesis. Moreover, plasma bile acids are elevated after GBP and bile acids are inhibitors of gluconeogenesis. In male Sprague-Dawley rats, we performed bile diversions from the bile duct to the midjejunum or the mid-ileum to match the modified bile delivery in the gut occurring in GBP. Body weight, food intake, glucose tolerance, insulin sensitivity, and food preference were analyzed. The expression of gluconeogenesis genes was evaluated in both the liver and the intestine. Bile diversions mimicking GBP promote an increase in plasma bile acids and a marked improvement in glucose control. Bile bioavailability modification is causal because a bile acid sequestrant suppresses the beneficial effects of bile diversions on glucose control. In agreement with the inhibitory role of bile acids on gluconeogenesis, bile diversions promote a blunting in hepatic glucose production, whereas intestinal gluconeogenesis is increased in the gut segments devoid of bile. In rats fed a high-fat-high-sucrose diet, bile diversions improve glucose control and dramatically decrease food intake because of an acquired disinterest in fatty food. This study shows that bile routing modification is a key mechanistic feature in the beneficial outcomes of GBP.

Stages of Extrahepatic Bile Duct Cancer

MedlinePlus

... caused by a blocked bile duct and improve quality of life : Biliary bypass : If cancer is blocking the bile ... as palliative treatment to relieve symptoms and improve quality of life . External or internal radiation therapy as palliative treatment ...

Evaluation of bile reflux in HIDA images based on fluid mechanics.

PubMed

Lo, Rong-Chin; Huang, Wen-Lin; Fan, Yu-Ming

2015-05-01

We propose a new method to help physicians assess, using a hepatobiliary iminodiacetic acid scan image, whether or not there is bile reflux into the stomach. The degree of bile reflux is an important index for clinical diagnosis of stomach diseases. The proposed method applies image-processing technology combined with a hydrodynamic model to determine the extent of bile reflux or whether the duodenum is also folded above the stomach. This condition in 2D dynamic images suggests that bile refluxes into the stomach, when endoscopy shows no bile reflux. In this study, we used optical flow to analyze images from Tc99m-diisopropyl iminodiacetic acid cholescintigraphy (Tc99m-DISIDA) to ascertain the direction and velocity of bile passing through the pylorus. In clinical diagnoses, single photon emission computed tomography (SPECT) is the main clinical tool for evaluating functional images of hepatobiliary metabolism. Computed tomography (CT) shows anatomical images of the external contours of the stomach, liver, and biliary extent. By exploiting the functional fusion of the two kinds of medical image, physicians can obtain a more accurate diagnosis. We accordingly reconstructed 3D images from SPECT and CT to help physicians choose which cross sections to fuse with software and to help them more accurately diagnose the extent and quantity of bile reflux. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Digestion of phospholipids after secretion of bile into the duodenum changes the phase behavior of bile components.

PubMed

Birru, Woldeamanuel A; Warren, Dallas B; Ibrahim, Ahmed; Williams, Hywel D; Benameur, Hassan; Porter, Christopher J H; Chalmers, David K; Pouton, Colin W

2014-08-04

Bile components play a significant role in the absorption of dietary fat, by solubilizing the products of fat digestion. The absorption of poorly water-soluble drugs from the gastrointestinal tract is often enhanced by interaction with the pathways of fat digestion and absorption. These processes can enhance drug absorption. Thus, the phase behavior of bile components and digested lipids is of great interest to pharmaceutical scientists who seek to optimize drug solubilization in the gut lumen. This can be achieved by dosing drugs after food or preferably by formulating the drug in a lipid-based delivery system. Phase diagrams of bile salts, lecithin, and water have been available for many years, but here we investigate the association structures that occur in dilute aqueous solution, in concentrations that are present in the gut lumen. More importantly, we have compared these structures with those that would be expected to be present in the intestine soon after secretion of bile. Phosphatidylcholines are rapidly hydrolyzed by pancreatic enzymes to yield equimolar mixtures of their monoacyl equivalents and fatty acids. We constructed phase diagrams that model the association structures formed by the products of digestion of biliary phospholipids. The micelle-vesicle phase boundary was clearly identifiable by dynamic light scattering and nephelometry. These data indicate that a significantly higher molar ratio of lipid to bile salt is required to cause a transition to lamellar phase (i.e., liposomes in dilute solution). Mixed micelles of digested bile have a higher capacity for solubilization of lipids and fat digestion products and can be expected to have a different capacity to solubilize lipophilic drugs. We suggest that mixtures of lysolecithin, fatty acid, and bile salts are a better model of molecular associations in the gut lumen, and such mixtures could be used to better understand the interaction of drugs with the fat digestion and absorption pathway.

Bile Routing Modification Reproduces Key Features of Gastric Bypass in Rat

PubMed Central

Goncalves, Daisy; Barataud, Aude; De Vadder, Filipe; Vinera, Jennifer; Zitoun, Carine; Duchampt, Adeline; Mithieux, Gilles

2015-01-01

STRUCTURED ABSTRACT Objective To evaluate the role of bile routing modification on the beneficial effects of gastric bypass surgery on glucose and energy metabolism. Summary background data Gastric bypass surgery (GBP) promotes early improvements in glucose and energy homeostasis in obese diabetic patients. A suggested mechanism associates a decrease in hepatic glucose production (HGP) to an enhanced intestinal gluconeogenesis (IGN). Moreover, plasma bile acids are elevated after GBP and bile acids are inhibitors of gluconeogenesis. Methods In male Sprague-Dawley rats, we performed bile diversions from the bile duct to the mid-jejunum or the mid-ileum to match the modified bile delivery in the gut occurring in GBP. Body weight, food intake, glucose tolerance, insulin sensitivity and food preference were analyzed. The expression of gluconeogenesis genes was evaluated in both the liver and the intestine. Results Bile diversions mimicking GBP promote an increase in plasma bile acids and a marked improvement in glucose control. Bile bioavailability modification is causal since a bile acid sequestrant suppresses the beneficial effects of bile diversions on glucose control. In agreement with the inhibitory role of bile acids on gluconeogenesis, bile diversions promote a blunting in HGP, whereas IGN is increased in the gut segments devoid of bile. In rats fed a high fat-high sucrose diet, bile diversions improve glucose control and dramatically decrease food intake due to an acquired disinterest in fatty food. Conclusion This study shows that bile routing modification is a key mechanistic feature in the beneficial outcomes of GBP. PMID:25575265

Bile Cast Nephropathy Caused by Obstructive Cholestasis.

PubMed

Aniort, Julien; Poyet, Anaïs; Kemeny, Jean-Louis; Philipponnet, Carole; Heng, Anne-Elisabeth

2017-01-01

Acute kidney injury (AKI) is a major complication in patients with liver disease. Although hepatorenal syndrome is frequently involved, bile cast nephropathy, characterized by tubular bile cast formation, has been scarcely described in the setting of severe liver failure. Few renal histology studies are available in these patients. We describe a case of bile cast nephropathy in a patient with obstructive cholestasis caused by stones in the common bile duct. The kidney biopsy confirmed this diagnosis, with several green casts in tubular lumens, tubular injury, and bilirubin composition of the tubular casts with Hall stain. The patient had no confounding cause of kidney failure, and complete kidney recovery followed removal of the bile duct obstruction. This case shows that severe cholestasis is sufficient to cause AKI, and that AKI can be reversible after treatment of the biliary obstruction. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Comparison of endogenous and radiolabeled bile acid excretion in patients with idiopathic chronic diarrhea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiller, L.R.; Bilhartz, L.E.; Santa Ana, C.A.

Fecal recovery of radioactivity after ingestion of a bolus of radiolabeled bile acid is abnormally high in most patients with idiopathic chronic diarrhea. To evaluate the significance of this malabsorption, concurrent fecal excretion of both exogenous radiolabeled bile acid and endogenous (unlabeled) bile acid were measured in patients with idiopathic chronic diarrhea. Subjects received a 2.5-microCi oral dose of taurocholic acid labeled with 14C in the 24th position of the steroid moiety. Endogenous bile acid excretion was measured by a hydroxysteroid dehydrogenase assay on a concurrent 72-h stool collection. Both radiolabeled and endogenous bile acid excretion were abnormally high inmore » most patients with chronic diarrhea compared with normal subjects, even when equivoluminous diarrhea was induced in normal subjects by ingestion of osmotically active solutions. The correlation between radiolabeled and endogenous bile acid excretion was good. However, neither radiolabeled nor endogenous bile acid excretion was as abnormal as is typically seen in patients with ileal resection, and none of these diarrhea patients responded to treatment with cholestyramine with stool weights less than 200 g. These results suggest (a) that this radiolabeled bile acid excretion test accurately reflects excess endogenous bile acid excretion; (b) that excess endogenous bile acid excretion is not caused by diarrhea per se; (c) that spontaneously occurring idiopathic chronic diarrhea is often associated with increased endogenous bile acid excretion; and (d) that bile acid malabsorption is not likely to be the primary cause of diarrhea in most of these patients.« less

Rethinking the bile acid/gut microbiome axis in cancer

PubMed Central

Phelan, John P.; Reen, F. Jerry; Caparros-Martin, Jose A.; O'Connor, Rosemary; O'Gara, Fergal

2017-01-01

Dietary factors, probiotic agents, aging and antibiotics/medicines impact on gut microbiome composition leading to disturbances in localised microbial populations. The impact can be profound and underlies a plethora of human disorders, including the focus of this review; cancer. Compromised microbiome populations can alter bile acid signalling and produce distinct pathophysiological bile acid profiles. These in turn have been associated with cancer development and progression. Exposure to high levels of bile acids, combined with localised molecular/genome instability leads to the acquisition of bile mediated neoplastic alterations, generating apoptotic resistant proliferation phenotypes. However, in recent years, several studies have emerged advocating the therapeutic benefits of bile acid signalling in suppressing molecular and phenotypic hallmarks of cancer progression. These studies suggest that in some instances, bile acids may reduce cancer phenotypic effects, thereby limiting metastatic potential. In this review, we contextualise the current state of the art to propose that the bile acid/gut microbiome axis can influence cancer progression to the extent that classical in vitro cancer hallmarks of malignancy (cell invasion, cell migration, clonogenicity, and cell adhesion) are significantly reduced. We readily acknowledge the existence of a bile acid/gut microbiome axis in cancer initiation, however, in light of recent advances, we focus exclusively on the role of bile acids as potentially beneficial molecules in suppressing cancer progression. Finally, we theorise that suppressing aggressive malignant phenotypes through bile acid/gut microbiome axis modulation could uncover new and innovative disease management strategies for managing cancers in vulnerable cohorts. PMID:29383197

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.

Effects of endogenous hydrogen peroxide and glutathione on the stability of arsenic metabolites in rat bile.

PubMed

Kobayashi, Yayoi; Hirano, Seishiro

2008-10-01

Trivalent arsenicals such as arsenite (iAs(III)), monomethylarsonous acid (MMA(III)) and dimethylarsinous acid (DMA(III)) are more toxic than analogous pentavalent compounds such as arsenate (iAs(V)), monomethylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)). It has been reported that arsenic-glutathione (As-GSH) complexes such as arsenic triglutathione (ATG) and methylarsenic diglutathione (MADG) are major metabolites in rat bile following intravenous administration of iAs(III). Recently, we have shown that both ATG and MADG are unstable and easily hydrolyzed to iAs(III) and MMA(III), respectively, and that MMA(III) is oxidized to MMA(V) in bile. In the present study we report the effects of H(2)O(2) and GSH on the stability of As-GSH complexes in rat bile. Male SD rats were injected intravenously with saline or iAs(III) at a dose of 0.2 or 2.0 mg As/kg body weight, and bile fluid was collected on ice for 30 min. To estimate the stability of As-GSH complexes in bile, ATG or MADG was added to untreated, heat-treated, catalase-treated, or dialyzed bile, and then incubated at 37 degrees C for 10 min. Concentrations of biliary H(2)O(2) and GSH in the higher dose group were 12.6- and 4.5-times higher than the control value, respectively. Exogenously added trivalent arsenicals were oxidized to pentavalent arsenicals in the bile depending on the biliary concentration of H(2)O(2). Both catalase and dialysis prevented oxidation of trivalent arsenicals to the corresponding pentavalent compounds. Exogenously added GSH stabilized As-GSH complexes in bile. These results suggest that H(2)O(2) converts trivalent arsenicals to less toxic pentavalent arsenicals, whereas GSH prevents hydrolysis of As-GSH complexes and the generation of unconjugated toxic trivalent arsenicals.

H. pylori in the pathogenesis of duodenal ulcer: interaction between duodenal acid load, bile, and H. pylori.

PubMed

Graham, D Y; Osato, M S

2000-01-01

Helicobacter pylori (H. pylori) growth is inhibited by bile yet it can grow in the duodenal bulb and cause ulcer disease. The aim of this study was to test the effect of bile on H. pylori viability and growth and to determine whether acidification of bile reduces its inhibitory activity. Fresh human bile was collected at laparotomy and tested for inhibitory activity of H. pylori using broth dilution assays. Six clinical isolates of H. pylori obtained from patients with duodenal ulcer were used for each experiment. The bile was diluted from 1:3 to 1:192; its inhibitory effect on H. pylori was tested before and after acidification, treatment with cholestyramine, or chloroform. Bile was acidified to a pH of 2-6, centrifuged at 8000 rpm for 20 min to remove precipitated bile acids, and the supernatant pH readjusted. Controls included BHI broth without bile (positive control) and bile that was acidified to pH 2 and neutralized without centrifugation. Human bile inhibited H. pylori growth in a dose dependent manner. Growth of all strains was supported for all strains only at a dilution of 1:192. In contrast, after acidification to pH < or =5 and centrifugation to remove precipitated bile acids, all strains grew at a bile dilution of 1:12. Neither chloroform extraction of lipids, nor acidification without centrifugation removed the inhibitory action of bile. In contrast, cholestyramine sequestration of bile acids completely removed all inhibitory activity. The duodenal acid load may be the critical factor to explain the ability of H. pylori to colonize the duodenal bulb by precipitating glycine-conjugated bile salts. The combination of a high duodenal acid load and H. pylori infection is likely the critical event in the pathogenesis of H. pylori-related duodenal ulcer disease.

Choleperitoneum due to intrahepatic bile duct rupture - case report.

PubMed

Simion, L; Straja, Dn; Prunoiu, Vm; Alecu, M; Brătucu, E

2014-01-01

Non-traumatic perforations of the bile ducts are unfrequently encountered entities, all the more when they affect the intrahepatic bile ducts, exteriorizing their biliary content in the great peritoneal cavity. Reporting such a case has determined the authors to perform a careful overview of the cases present in the literature. An observation that can be made based on these is that the obstruction of the main bile duct due to lithiasis determines, by pressure increase, the dilation of the bile system branches, all on the background of an unknown malformation of the intrahepatic bile ducts. Celsius.

Bile culture

MedlinePlus

Culture - bile ... is placed in a special dish called a culture medium to see if bacteria, viruses, or fungi ... Chernecky CC, Berger BJ. Body fluid - anaerobic culture. In: ... . 6th ed. St Louis, MO: Elsevier Saunders; 2013:225-226. Kim AY, ...

Physical Chemistry of Bile: Detailed Pathogenesis of Cholelithiasis.

PubMed

Itani, Malak; Dubinsky, Theodore J

2017-09-01

Despite the overwhelming prevalence of cholelithiasis, many health care professionals are not familiar with the basic pathophysiology of gallstone formation. This article provides an overview of the biochemical pathways related to bile, with a focus on the physical chemistry of bile. We describe the important factors in bile synthesis and secretion that affect the composition of bile and consequently its liquid state. Within this biochemical background lies the foundation for understanding the clinical and sonographic manifestation of cholelithiasis, including the pathophysiology of cholesterol crystallization, gallbladder sludge, and gallstones. There is a brief discussion of the clinical manifestations of inflammatory and obstructive cholestasis and the impact on bile metabolism and subsequently on liver function tests. Despite being the key modality in diagnosing cholelithiasis, ultrasound has a limited role in the characterization of stone composition.

Organotypic culture of normal, dysplastic and squamous cell carcinoma-derived oral cell lines reveals loss of spatial regulation of CD44 and p75 NTR in malignancy.

PubMed

Dalley, Andrew J; AbdulMajeed, Ahmad A; Upton, Zee; Farah, Camile S

2013-01-01

Oral squamous cell carcinomas (OSCC) often arise from dysplastic lesions. The role of cancer stem cells in tumour initiation is widely accepted, yet the potential existence of pre-cancerous stem cells in dysplastic tissue has received little attention. Cell lines from oral diseases ranging in severity from dysplasia to malignancy provide opportunity to investigate the involvement of stem cells in malignant progression from dysplasia. Stem cells are functionally defined by their ability to generate hierarchical tissue structures in consortium with spatial regulation. Organotypic cultures readily display tissue hierarchy in vitro; hence, in this study, we compared hierarchical expression of stem cell-associated markers in dermis-based organotypic cultures of oral epithelial cells from normal tissue (OKF6-TERT2), mild dysplasia (DOK), severe dysplasia (POE-9n) and OSCC (PE/CA P J15). Expression of CD44, p75(NTR), CD24 and ALDH was studied in monolayers by flow cytometry and in organotypic cultures by immunohistochemistry. Spatial regulation of CD44 and p75(NTR) was evident for organotypic cultures of normal (OKF6-TERT2) and dysplasia (DOK and POE-9n) but was lacking for OSCC (PE/CA PJ15)-derived cells. Spatial regulation of CD24 was not evident. All monolayer cultures exhibited CD44, p75(NTR), CD24 antigens and ALDH activity (ALDEFLUOR(®) assay), with a trend towards loss of population heterogeneity that mirrored disease severity. In monolayer, increased FOXA1 and decreased FOXA2 expression correlated with disease severity, but OCT3/4, Sox2 and NANOG did not. We conclude that dermis-based organotypic cultures give opportunity to investigate the mechanisms that underlie loss of spatial regulation of stem cell markers seen with OSCC-derived cells. © 2012 John Wiley & Sons A/S.

Laparoscopic managment of common bile duct stones: our initial experience.

PubMed Central

Aroori, S.; Bell, J. C.

2002-01-01

The management of choledocholithiasis has changed radically since the introduction of laparoscopic cholecystectomy. However, perceived technical difficulties have deterred many surgeons from treating common bile duct stones laparoscopically at the time of cholecystectomy. This has lead to reliance on endoscopic retrograde cholangiopancreatography followed by endoscopic sphincterotomy to deal with common bile duct stones. We retrospectively reviewed the charts of patients who had laparoscopic common bile duct exploration at Downe Hospital between December 1999 and August 2001. Among 149 laparoscopic cholecystectomies done by our group in this period, 10 patients (6.7%) underwent laparoscopic CBD exploration, three by the transcystic technique and seven by choledochotomy. Three patients (2%) had unsuspected stones found on routine per- operative cholangiogram. The mean operative time was 2.34hrs (range 1.50-3.30hrs). The mean hospital post- operative stay was 3 days (range 1-6 days). Post-operative morbidity was zero. Stone clearance was achieved in all cases. We conclude, laparoscopic exploration of the common bile duct is relatively safe and straightforward method. The key skill required is the ability to perform laparoscopic suturing with confidence. PMID:12137159

A pilot study of bendamustine in advanced bile duct cancer.

PubMed

Schoppmeyer, Konrad; Kreth, Florian; Wiedmann, Marcus; Mössner, Joachim; Preiss, Rainer; Caca, Karel

2007-07-01

We performed a pilot study to evaluate the safety and tolerability of bendamustine in patients with advanced hilar bile duct cancer and impaired liver function. Six patients with histologically proven, unresectable adenocarcinoma of the hilar bile duct were treated with bendamustine 140 mg/m intravenously on day 1 of the first cycle and with bendamustine 100 mg/m on days 1 and 2 of the second to fourth cycle. Treatment cycles were repeated every 21 days. Primary endpoint was the safety and tolerability of the treatment; secondary endpoints were response rate, time to progression and overall survival. Transient lymphopenia grade 3 occurred in all six patients. No other grade 3 or 4 toxicities were present. The most common nonhematologic toxicity was mouth dryness grade 2 in six patients. Three patients had stable disease. No partial or complete responses were observed. Median time to progression was 3.3 months; median overall survival was 6 months. Our study demonstrates that bendamustine can be safely administered in patients with hilar bile duct cancer and impaired liver function. A potential role of bendamustine in combination therapies for bile duct cancer will be a subject of further trials.

Successful treatment of limy bile syndrome extending to the common bile duct by laparoscopic cholecystectomy and common bile duct exploration: A case report and literature review.

PubMed

Masuda, Yuka; Mizuguchi, Yoshiaki; Kanda, Tomohiro; Furuki, Hiroyasu; Mamada, Yasuhiro; Taniai, Nobuhiko; Nakamura, Yoshiharu; Yoshioka, Masato; Matsushita, Akira; Kawano, Yoichi; Shimizu, Tetsuya; Uchida, Eiji

2017-02-01

Limy bile syndrome extending to the common bile duct (CBD) is a rare condition that lacks a standardized treatment. Laparoscopic cholecystectomy with laparoscopic choledocholithotomy by CBD exploration is preferred because it preserves the function of the sphincter of the Vater's papilla and allows treatment of both lesions. A 37-year-old man who was receiving entecavir for chronic hepatitis B developed right upper quadrant pain. Abdominal ultrasonography revealed a calcified shadow in the gallbladder and CBD. Abdominal imaging revealed a liquid-like material identified by a calcified shadow in two phases separated by a fluid-fluid level. Abdominal and 3-D drip infusion cholangiography CT showed stones in the gallbladder and CBD with limy bile. The patient underwent laparoscopic cholecystectomy and choledocholithotomy. Intraoperatively, white-yellow-colored bile and stones were drained from the CBD. A C-tube was placed. Postoperatively, remnant stones and radiopaque materials were absent. The stones comprised of >95% calcium carbonate. © 2016 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)—Health Professional Version

Cancer.gov

Bile duct cancer (also called cholangiocarcinoma) can occur in the bile ducts in the liver (intrahepatic) or outside the liver (perihilar or distal extrahepatic). Learn about the types of bile duct cancer, risk factors, clinical features, staging, and treatment for bile duct cancer in this expert-reviewed summary.

Bile acid signaling in lipid metabolism: Metabolomic and lipidomic analysis of lipid and bile acid markers linked to anti-obesity and anti-diabetes in mice

PubMed Central

Qi, Yunpeng; Jiang, Changtao; Cheng, Jie; Krausz, Kristopher W.; Li, Tiangang; Ferrell, Jessica M.; Gonzalez, Frank J.; Chiang, John Y.L.

2014-01-01

Bile acid synthesis is the major pathway for catabolism of cholesterol. Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme in the bile acid biosynthetic pathway in the liver and plays an important role in regulating lipid, glucose and energy metabolism. Transgenic mice overexpressing CYP7A1 (CYP7A1-tg mice) were resistant to high-fat diet (HFD)-induced obesity, fatty liver, and diabetes. However the mechanism of resistance to HFD-induced obesity of CYP7A1-tg mice has not been determined. In this study, metabolomic and lipidomic profiles of CYP7A1-tg mice were analyzed to explore the metabolic alterations in CYP7A1-tg mice that govern the protection against obesity and insulin resistance by using ultra-performance liquid chromatography-coupled with electrospray ionization quadrupole time-of-flight mass spectrometry combined with multivariate analyses. Lipidomics analysis identified seven lipid markers including lysophosphatidylcholines, phosphatidylcholines, sphingomyelins and ceramides that were significantly decreased in serum of HFD-fed CYP7A1-tg mice. Metabolomics analysis identified 13 metabolites in bile acid synthesis including taurochenodeoxycholic acid, taurodeoxycholic acid, tauroursodeoxycholic acid, taurocholic acid, and tauro-β-muricholic acid (T-β-MCA) that differed between CYP7A1-tg and wild-type mice. Notably, T-β-MCA, an antagonist of the farnesoid X receptor (FXR) was significantly increased in intestine of CYP7A1-tg mice. This study suggests that reducing 12α-hydroxylated bile acids and increasing intestinal T-β-MCA may reduce high fat diet-induced increase of phospholipids, sphingomyelins and ceramides, and ameliorate diabetes and obesity. PMID:24796972

Time course of collagen peak in bile duct-ligated rats.

PubMed

Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

2011-04-28

One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct ligation (BDL) had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats), 14 days later in group 2 (9 rats), 21 days later in group 3(9 rats) and 28 days later in group 4 (9 rats). Eight rats underwent sham-operation (Sham). Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P < 0.001 and P < 0.05). Suprisingly, collagen levels had decreased with the course of time such as at the end of fourth week (P < 0.01 and P < 0.05). We have shown that fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

Albumin expression distinguishes bile duct adenomas from metastatic adenocarcinoma.

PubMed

Moy, Andrea P; Arora, Kshitij; Deshpande, Vikram

2016-09-01

Bile duct adenomas may be difficult to distinguish from metastatic carcinomas, particularly well-differentiated pancreatic ductal adenocarcinoma. Prior studies have evaluated the utility of various immunohistochemical markers, although these markers are notable for low sensitivity and/or specificity. The aim of this study was to investigate the utility of albumin and BRAFV600E expression in distinguishing between metastatic pancreatic adenocarcinoma and bile duct adenoma. We studied 26 bile duct adenomas, three bile duct hamartomas, and 158 pancreatic ductal adenocarcinomas. Branched-chain in-situ hybridization (bISH) for albumin was performed; bISH is based on the branched DNA technology, wherein signal amplification is achieved via a series of sequential steps. Additionally, BRAFV600E immunohistochemistry (IHC) was performed on a subset of cases. Twenty-three of 25 (92%) bile duct adenomas were positive for albumin; 18 (72%) showed diffuse staining, and five showed focal staining (20%), including two challenging examples. Two bile duct hamartomas also stained positively. All pancreatic adenocarcinomas were negative for albumin. Seven of 16 (44%) bile duct adenomas and five of 106 (5%) pancreatic ductal adenocarcinomas were positive for BRAFV600E by IHC. The sensitivity and specificity of expression of albumin, as detected by bISH, for distinguishing bile duct adenomas from metastatic pancreatic adenocarcinomas were 92% and 100%, respectively; the sensitivity and specificity of BRAFV600E IHC for distinguishing bile duct adenomas from metastatic pancreatic adenocarcinomas were 43.8% and 95.3%, respectively. Diagnostically challenging examples of bile duct adenoma may be distinguished from metastatic pancreatic adenocarcinoma by the use of albumin bISH. © 2016 John Wiley & Sons Ltd.

Modification on ursodeoxycholic acid (UDCA) scaffold. discovery of bile acid derivatives as selective agonists of cell-surface G-protein coupled bile acid receptor 1 (GP-BAR1).

PubMed

Sepe, Valentina; Renga, Barbara; Festa, Carmen; D'Amore, Claudio; Masullo, Dario; Cipriani, Sabrina; Di Leva, Francesco Saverio; Monti, Maria Chiara; Novellino, Ettore; Limongelli, Vittorio; Zampella, Angela; Fiorucci, Stefano

2014-09-25

Bile acids are signaling molecules interacting with the nuclear receptor FXR and the G-protein coupled receptor 1 (GP-BAR1/TGR5). GP-BAR1 is a promising pharmacological target for the treatment of steatohepatitis, type 2 diabetes, and obesity. Endogenous bile acids and currently available semisynthetic bile acids are poorly selective toward GP-BAR1 and FXR. Thus, in the present study we have investigated around the structure of UDCA, a clinically used bile acid devoid of FXR agonist activity, to develop a large family of side chain modified 3α,7β-dihydroxyl cholanoids that selectively activate GP-BAR1. In vivo and in vitro pharmacological evaluation demonstrated that administration of compound 16 selectively increases the expression of pro-glucagon 1, a GP-BAR1 target, in the small intestine, while it had no effect on FXR target genes in the liver. Further, compound 16 results in a significant reshaping of bile acid pool in a rodent model of cholestasis. These data demonstrate that UDCA is a useful scaffold to generate novel and selective steroidal ligands for GP-BAR1.

[Clinicopathologic features of drug-induced vanishing bile duct syndrome].

PubMed

Ye, L H; Wang, C K; Zhang, H C; Liu, Z Q; Zheng, H W

2017-04-20

Vanishing bile duct syndrome (VBDS) manifests as progressive destruction and disappearance of the intrahepatic bile duct caused by various factors and cholestasis. VBDS associated with drug-induced liver injury (D-VBDS) is an important etiology of VBDS, and immune disorder or immune imbalance may be the main pathogenesis. According to its clinical symptoms, serological markers, and course of the disease, D-VBDS is classified into major form and minor form, and its clinical features are based on various pathomorphological findings. Its prognosis is associated various factors including regeneration of bile duct cells, number of bile duct injuries, level and range of bile duct injury, bile duct proliferation, and compensatory shunt of bile duct branches. This disease has various clinical outcomes; most patients have good prognosis after drug withdrawal, and some patients may experience cholestatic cirrhosis, liver failure, and even death. Due to the clinical manifestation and biochemical changes are similar to the primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), it need to identify by clinical physician.

Cytoprotection by fructose and other ketohexoses during bile salt-induced apoptosis of hepatocytes.

PubMed

Zeid, I M; Bronk, S F; Fesmier, P J; Gores, G J

1997-01-01

Toxic bile salts cause hepatocyte necrosis at high concentrations and apoptosis at lower concentrations. Although fructose prevents bile salt-induced necrosis, the effect of fructose on bile salt-induced apoptosis is unclear. Our aim was to determine if fructose also protects against bile salt-induced apoptosis. Fructose inhibited glycochenodeoxycholate (GCDC)-induced apoptosis in a concentration-dependent manner with a maximum inhibition of 72% +/- 10% at 10 mmol/L. First, we determined if fructose inhibited apoptosis by decreasing adenosine triphosphate (ATP) and intracellular pH (pHi). Although fructose decreased ATP to <25% of basal values, oligomycin (an ATP synthase inhibitor) did not inhibit apoptosis despite decreasing ATP to similar values. Fructose (10 mmol/L) decreased intracellular pH (pHi) by 0.2 U. However, extracellular acidification (pH 6.8), which decreased hepatocyte pHi 0.35 U and is known to inhibit necrosis, actually potentiated apoptosis 1.6-fold. Fructose cytoprotection also could not be explained by induction of bcl-2 transcription or metal chelation. Because we could not attribute fructose cytoprotection to metabolic effects, alterations in the expression of bcl-2, or metal chelation, we next determined if the poorly metabolized ketohexoses, tagatose and sorbose, also inhibited apoptosis; unexpectedly, both ketohexoses inhibited apoptosis. Because bile salt-induced apoptosis and necrosis are inhibited by fructose, these data suggest that similar processes initiate bile salt-induced hepatocyte necrosis and apoptosis. In contrast, acidosis, which inhibits necrosis, potentiates apoptosis. Thus, ketohexose-sensitive pathways appear to initiate both bile salt-induced cell apoptosis and necrosis, whereas dissimilar, pH-sensitive, effector mechanisms execute these two different cell death processes.

Risk factors, treatment and impact on outcomes of bile leakage after hemihepatectomy.

PubMed

Zheng, Si-Ming; Li, Hong; Li, Gen-Cong; Yu, Dan-Song; Ying, Dong-Jian; Zhang, Bin; Lu, Cai-De; Zhou, Xin-Hua

2017-07-01

Risk factors for bile leakage after hemihepatectomy are unknown. A prospectively maintained database review identified patients undergoing hemihepatectomy between 1 January 2009 and 30 September 2014. Patients were divided into B/C and non-B/C bile leakage groups. Risk factors for bile leakage were predicted and assessments of their impact on patients were made. Bile leakage occurred in 91 of the 297 patients (30.6%); 64 cases were classified as grade B bile leakage (21.5%) and three cases as grade C bile leakage (1.0%). Multivariate analysis confirmed that elevated preoperative alanine transaminase (ALT), positive bile culture during surgery, hilar bile duct plasty, bilioenteric anastomosis and laparoscopic surgery were risk factors for B/C grade bile leakage (P < 0.05). Percutaneous transhepatic biliary drainage (PTBD) and endoscopic nasobiliary drainage (ENBD) were protective factors for B/C grade bile leakage (P < 0.05). PTBD, ENBD and Kehr's T-tube drainage could reduce the drainage volume and duration of drainage after bile leakage (P < 0.05). The incidence of wound infection, abdominal infection, major complications and the Clavien classification system score in the B/C bile leakage group were higher than those in the non-B/C bile leakage group (P < 0.05). Patients in the B/C bile leakage group also required prolonged hospitalization (P < 0.05). The mortality of two groups was similar (P > 0.05). Patient with elevated preoperative ALT, positive bile cultures during surgery, hilar bile duct plasty, bilioenteric anastomosis and laparoscopic surgery are more likely to complicate bile leakage. We should use biliary drainage such as preoperative PTBD, ENBD or intraoperative Kehr's T-tube drainage to reduce and treat bile leakage in patients with high risk of bile leakage. © 2015 Royal Australasian College of Surgeons.

Bear bile: dilemma of traditional medicinal use and animal protection

PubMed Central

Feng, Yibin; Siu, Kayu; Wang, Ning; Ng, Kwan-Ming; Tsao, Sai-Wah; Nagamatsu, Tadashi; Tong, Yao

2009-01-01

Bear bile has been used in Traditional Chinese Medicine (TCM) for thousands of years. Modern investigations showed that it has a wide range of pharmacological actions with little toxicological side effect and the pure compounds have been used for curing hepatic and biliary disorders for decades. However, extensive consumption of bear bile made bears endangered species. In the 1980's, bear farming was established in China to extract bear bile from living bears with "Free-dripping Fistula Technique". Bear farming is extremely inhumane and many bears died of illness such as chronic infections and liver cancer. Efforts are now given by non-governmental organizations, mass media and Chinese government to end bear farming ultimately. At the same time, systematic research has to be done to find an alternative for bear bile. In this review, we focused on the literature, laboratory and clinical results related to bear bile and its substitutes or alternative in English and Chinese databases. We examined the substitutes or alternative of bear bile from three aspects: pure compounds derived from bear bile, biles from other animals and herbs from TCM. We then discussed the strategy for stopping the trading of bear bile and issues of bear bile related to potential alternative candidates, existing problems in alternative research and work to be done in the future. PMID:19138420

Hedgehog-mediated mesenchymal-epithelial interactions modulate hepatic response to bile duct ligation.

PubMed

Omenetti, Alessia; Yang, Liu; Li, Yin-Xiong; McCall, Shannon J; Jung, Youngmi; Sicklick, Jason K; Huang, Jiawen; Choi, Steve; Suzuki, Ayako; Diehl, Anna Mae

2007-05-01

In bile duct-ligated (BDL) rodents, as in humans with chronic cholangiopathies, biliary obstruction triggers proliferation of bile ductular cells that are surrounded by fibrosis produced by adjacent myofibroblastic cells in the hepatic mesenchyme. The proximity of the myofibroblasts and cholangiocytes suggests that mesenchymal-epithelial crosstalk promotes the fibroproliferative response to cholestatic liver injury. Studying BDL mice, we found that bile duct obstruction induces activity of the Hedgehog (Hh) pathway, a system that regulates the viability and differentiation of various progenitors during embryogenesis. After BDL, many bile ductular cells and fibroblastic-appearing cells in the portal stroma express Hh ligands, receptor and/or target genes. Transwell cocultures of an immature cholangiocyte line that expresses the Hh receptor, Patched (Ptc), with liver myofibroblastic cells demonstrated that both cell types produced Hh ligands that enhanced each other's viability and proliferation. Further support for the concept that Hh signaling modulates the response to BDL was generated by studying PtcLacZ mice, which have an impaired ability to constrain Hh signaling due to a heterozygous deficiency of Ptc. After BDL, PtcLacZ mice upregulated fibrosis gene expression earlier than wild-type controls and manifested an unusually intense ductular reaction, more expanded fibrotic portal areas, and a greater number of lobular necrotic foci. Our findings reveal that adult livers resurrect developmental signaling systems, such as the Hh pathway, to guide remodeling of the biliary epithelia and stroma after cholestatic injury.

A retrospective analysis of endoscopic treatment outcomes in patients with postoperative bile leakage.

PubMed

Sayar, Suleyman; Olmez, Sehmus; Avcioglu, Ufuk; Tenlik, Ilyas; Saritas, Bunyamin; Ozdil, Kamil; Altiparmak, Emin; Ozaslan, Ersan

2016-01-01

Bile leakage, while rare, can be a complication seen after cholecystectomy. It may also occur after hepatic or biliary surgical procedures. Etiology may be underlying pathology or surgical complication. Endoscopic retrograde cholangiopancreatography (ERCP) can play major role in diagnosis and treatment of bile leakage. Present study was a retrospective analysis of outcomes of ERCP procedure in patients with bile leakage. Patients who underwent ERCP for bile leakage after surgery between 2008 and 2012 were included in the study. Etiology, clinical and radiological characteristics, and endoscopic treatment outcomes were recorded and analyzed. Total of 31 patients (10 male, 21 female) were included in the study. ERCP was performed for bile leakage after cholecystectomy in 20 patients, after hydatid cyst operation in 10 patients, and after hepatic resection in 1 patient. Clinical signs and symptoms of bile leakage included abdominal pain, bile drainage from percutaneous drain, peritonitis, jaundice, and bilioma. Twelve (60%) patients were treated with endoscopic sphincterotomy (ES) and nasobiliary drainage (NBD) catheter, 7 patients (35%) were treated with ES and biliary stent (BS), and 1 patient (5%) was treated with ES alone. Treatment efficiency was 100% in bile leakage cases after cholecystectomy. Ten (32%) cases of hydatid cyst surgery had subsequent cystobiliary fistula. Of these patients, 7 were treated with ES and NBD, 2 were treated with ES and BS, and 1 patient (8%) with ES alone. Treatment was successful in 90% of these cases. ERCP is an effective method to diagnose and treat bile leakage. Endoscopic treatment of postoperative bile leakage should be individualized based on etiological and other factors, such as accompanying fistula.

A retrospective analysis of endoscopic treatment outcomes in patients with postoperative bile leakage

PubMed Central

Sayar, Suleyman; Olmez, Sehmus; Avcioglu, Ufuk; Tenlik, Ilyas; Saritas, Bunyamin; Ozdil, Kamil; Altiparmak, Emin; Ozaslan, Ersan

2016-01-01

OBJECTIVE: Bile leakage, while rare, can be a complication seen after cholecystectomy. It may also occur after hepatic or biliary surgical procedures. Etiology may be underlying pathology or surgical complication. Endoscopic retrograde cholangiopancreatography (ERCP) can play major role in diagnosis and treatment of bile leakage. Present study was a retrospective analysis of outcomes of ERCP procedure in patients with bile leakage. METHODS: Patients who underwent ERCP for bile leakage after surgery between 2008 and 2012 were included in the study. Etiology, clinical and radiological characteristics, and endoscopic treatment outcomes were recorded and analyzed. RESULTS: Total of 31 patients (10 male, 21 female) were included in the study. ERCP was performed for bile leakage after cholecystectomy in 20 patients, after hydatid cyst operation in 10 patients, and after hepatic resection in 1 patient. Clinical signs and symptoms of bile leakage included abdominal pain, bile drainage from percutaneous drain, peritonitis, jaundice, and bilioma. Twelve (60%) patients were treated with endoscopic sphincterotomy (ES) and nasobiliary drainage (NBD) catheter, 7 patients (35%) were treated with ES and biliary stent (BS), and 1 patient (5%) was treated with ES alone. Treatment efficiency was 100% in bile leakage cases after cholecystectomy. Ten (32%) cases of hydatid cyst surgery had subsequent cystobiliary fistula. Of these patients, 7 were treated with ES and NBD, 2 were treated with ES and BS, and 1 patient (8%) with ES alone. Treatment was successful in 90% of these cases. CONCLUSION: ERCP is an effective method to diagnose and treat bile leakage. Endoscopic treatment of postoperative bile leakage should be individualized based on etiological and other factors, such as accompanying fistula. PMID:28058396

Characterizing Factors Associated With Differences in FGF19 Blood Levels and Synthesis in Patients With Primary Bile Acid Diarrhea.

PubMed

Johnston, Ian M; Nolan, Jonathan D; Pattni, Sanjeev S; Appleby, Richard N; Zhang, Justine H; Kennie, Sarah L; Madhan, Gaganjit K; Jameie-Oskooei, Sina; Pathmasrirengam, Shivani; Lin, Jeremy; Hong, Albert; Dixon, Peter H; Williamson, Catherine; Walters, Julian R F

2016-03-01

Chronic diarrhea caused by primary bile acid diarrhea (PBAD) is a common condition. We have previously shown PBAD is associated with low fasting serum levels of the ileal hormone, fibroblast growth factor 19 (FGF19). FGF19 is a negative regulator of hepatic bile acid synthesis and is stimulated by farnesoid X receptor agonists, which produce symptomatic improvement in PBAD. We aimed to assess possible causes for low serum FGF19 in patients with PBAD. Patients with PBAD, defined by reduced (75)Se-labelled homocholic acid taurine (SeHCAT) retention, and idiopathic diarrhea controls had measurements of fasting lipids and fasting/post-prandial FGF19 serum profiles. Specific functional variants in candidate genes were investigated in exploratory studies. In further groups, basal and bile acid-stimulated transcript expression was determined in ileal biopsies and explant cultures by quantitative PCR. FGF19 profiles in PBAD patients included low fasting and meal-stimulated responses, which were both strongly correlated with SeHCAT. A subgroup of 30% of PBAD patients had fasting hypertriglyceridemia and higher FGF19. No clear significant differences were found for any genetic variant but there were borderline associations with FGFR4 and KLB. SeHCAT retention significantly correlated with the basal ileal transcript expression of FGF19 (rs=0.59, P=0.03) and apical sodium-dependent bile acid transporter (ASBT) (rs=0.49, P=0.04), and also with the degree of stimulation by chenodeoxycholic acid at 6 h for transcripts of FGF19 (median 184-fold, rs=0.50, P=0.02) and ileal bile acid binding protein (IBABP) (median 2.2-fold, rs=0.47, P=0.04). Median stimulation of FGF19 was lower in patients with SeHCAT retention <10% (P=0.01). These studies demonstrate a complex, multifactorial etiology of PBAD, including impairments in ileal FGF19 expression and responsiveness.

Enhancement of bile resistance in Lactobacillus plantarum strains by soy lecithin.

PubMed

Hu, B; Tian, F; Wang, G; Zhang, Q; Zhao, J; Zhang, H; Chen, W

2015-07-01

This study evaluated the effect of soy lecithin on the bile resistance of Lactobacillus plantarum. Six strains were cultured in MRS broth supplemented with soy lecithin at different concentrations. The strains incubated in MRS broth with 1·0% soy lecithin showed no inhibitory effect on cell growth. After culturing in MRS broth with 0·2-1·0% soy lecithin, the survival rate of harvested cells increased significantly (P < 0·05) in the 0·3% bile challenge compared with the no added soy lecithin group. The cells incubated with 0·6% soy lecithin were able to grow in an MRS broth with a higher bile salt content. The surface hydrophobicity and cell leakage in the bile challenge were assessed to reveal the physical changes caused by the addition of soy lecithin. The cell surface hydrophobicity was enhanced and the membrane integrity in the bile challenge increased after culturing with soy lecithin. A shift in the fatty acid composition was also observed, illustrating the cell membrane change in the soy lecithin culture. In this study, we report for the first time the beneficial effect of adding soy lecithin to an MRS broth on subsequent bile tolerance of Lactobacillus plantarum. Soy lecithin had no inhibitory effect on strain viability but significantly enhanced bile resistance. Surface hydrophobicity and cell integrity increased in strains cultured with soy lecithin. The observed shift in the cell fatty acid composition indicated changes to the cell membrane. As soy lecithin is safe for use in the food industry, its protective effects can be harnessed for the development of bile-sensitive strains with health-benefit functions for use in probiotic products. © 2015 The Society for Applied Microbiology.

Bile acid profiling and quantification in biofluids using ultra-performance liquid chromatography tandem mass spectrometry.

PubMed

Sarafian, Magali H; Lewis, Matthew R; Pechlivanis, Alexandros; Ralphs, Simon; McPhail, Mark J W; Patel, Vishal C; Dumas, Marc-Emmanuel; Holmes, Elaine; Nicholson, Jeremy K

2015-10-06

Bile acids are important end products of cholesterol metabolism. While they have been identified as key factors in lipid emulsification and absorption due to their detergent properties, bile acids have also been shown to act as signaling molecules and intermediates between the host and the gut microbiota. To further the investigation of bile acid functions in humans, an advanced platform for high throughput analysis is essential. Herein, we describe the development and application of a 15 min UPLC procedure for the separation of bile acid species from human biofluid samples requiring minimal sample preparation. High resolution time-of-flight mass spectrometry was applied for profiling applications, elucidating rich bile acid profiles in both normal and disease state plasma. In parallel, a second mode of detection was developed utilizing tandem mass spectrometry for sensitive and quantitative targeted analysis of 145 bile acid (BA) species including primary, secondary, and tertiary bile acids. The latter system was validated by testing the linearity (lower limit of quantification, LLOQ, 0.25-10 nM and upper limit of quantification, ULOQ, 2.5-5 μM), precision (≈6.5%), and accuracy (81.2-118.9%) on inter- and intraday analysis achieving good recovery of bile acids (serum/plasma 88% and urine 93%). The ultra performance liquid chromatography-mass spectrometry (UPLC-MS)/MS targeted method was successfully applied to plasma, serum, and urine samples in order to compare the bile acid pool compositional difference between preprandial and postprandial states, demonstrating the utility of such analysis on human biofluids.

Activation of PPARα decreases bile acids in livers of female mice while maintaining bile flow and biliary bile acid excretion.

PubMed

Zhang, Youcai; Lickteig, Andrew J; Csanaky, Iván L; Klaassen, Curtis D

2018-01-01

Fibrates are hypolipidemic drugs that act as activators of peroxisome proliferator-activated receptor α (PPARα). In both humans and rodents, females were reported to be less responsive to fibrates than males. Previous studies on fibrates and PPARα usually involved male mice, but little has been done in females. The present study aimed to provide the first comprehensive analysis of the effects of clofibrate (CLOF) and PPARα on bile acid (BA) homeostasis in female mice. Study in WT male mice showed that a 4-day CLOF treatment increased liver weight, bile flow, and biliary BA excretion, but decreased total BAs in both serum and liver. In contrast, WT female mice were less susceptible to these CLOF-mediated responses observed in males. In WT female mice, CLOF decreased total BAs in the liver, but had little effect on the mRNAs of hepatic BA-related genes. Next, a comparative analysis between WT and PPARα-null female mice showed that lack of PPARα in female mice decreased total BAs in serum, but had little effect on total BAs in liver or bile. However, lack of PPARα in female mice increased mRNAs of BA synthetic enzymes (Cyp7a1, Cyp8b1, Cyp27a1, and Cyp7b1) and transporters (Ntcp, Oatp1a1, Oatp1b2, and Mrp3). Furthermore, the increase of Cyp7a1 in PPARα-null female mice was associated with an increase in liver Fxr-Shp-Lrh-1 signaling. In conclusion, female mice are resistant to CLOF-mediated effects on BA metabolism observed in males, which could be attributed to PPARα-mediated suppression in females on genes involved in BA synthesis and transport. Copyright © 2017 Elsevier Inc. All rights reserved.

Bile sensor: from the lab to the market

NASA Astrophysics Data System (ADS)

Baldini, Francesco

1999-12-01

In 1988 the idea of measuring bile in the stomach and in the oesophagus via optical fibers was conceived and patented in collaboration with physicians from the University of Florence. The working principle is based on the spectrophotometric properties of the bile which contains some pigments with definite absorption properties. Bilirubin is the main pigment and it is characterized by an absorption peak in the blue region: therefore it is possible to detect optically the bile in the stomach by optically detecting bilirubin. The possibility of measuring bile reflux directly measuring the presence of bile represented a winning aspect in comparison with the traditional techniques (pH-metry, cholescintigraphy, bile acid assessment in aspirates); on the contrary the new technique had to overcome the traditional 'cultural' barriers constituted by the conservative attitude of clinicians concerning any innovative technology. The realization of the first laboratory prototype demonstrates the feasibility and validity of the proposed optical method. Then many years were necessary to arrive at the definitive and marketable product. The history of Bilitec 2000 is described, with the purpose to stress how a laboratory prototype is still very far from the market.

Correlation Between Bile Reflux Gastritis and Biliary Excreted Contrast Media in the Stomach.

PubMed

Hyun, Jong Jin; Yeom, Suk Keu; Shim, Euddeum; Cha, Jaehyung; Choi, Inyoung; Lee, Seung Hwa; Chung, Hwan Hoon; Cha, Sang Hoon; Lee, Chang Hee

This study aimed to evaluate the relationship between biliary excreted contrast media in the stomach and the presence of bile reflux gastritis. Consecutive 111 patients who underwent both gadoxetic acid-enhanced magnetic resonance cholangiography (gadoxetic MRC) and gastric endoscopy were included in this study. We performed a review of the gadoxetic-MRC image sets acquired 60 minutes after intravenous injection of contrast media and endoscopic images. We recorded amount of contrast media in the stomach. The sensitivity, specificity, and accuracy of duodenogastric bile reflux diagnosis were evaluated for the gadoxetic MRC. Statistical analysis was performed using the Fisher exact test and the linear-by-linear association test. Among the 111 patients, 39 had 60-minute delayed images showing the presence of contrast media in the stomach. Of these 39 patients, 13 had bile reflux gastritis and 5 showed bile in the stomach without evidence of erythematous gastritis. Of the 72 patients who did not show contrast media in the stomach, none had bile reflux gastritis and 2 patients showed bile staining in the stomach without evidence of erythematous gastritis. Bile reflux gastritis was significantly more frequent in patients with contrast media in the stomach on gadoxetic MRC than in those without. Patients with high-grade extension of contrast media in the stomach had significantly frequent bile reflux gastritis than did those with low-grade extension. Biliary excreted contrast media in the stomach on 60-minute delayed gadoxetic MRC has a correlation with the presence of bile reflux gastritis on endoscopic examination.

Activation of Constitutive Androstane Receptor (CAR) in Mice Results in Maintained Biliary Excretion of Bile Acids Despite a Marked Decrease of Bile Acids in Liver

PubMed Central