|
1
|
Banerjee T, Goswami AG, Basu S. Biliary microbiome and gallstones: A silent friendship. World J Gastrointest Surg 2024; 16:3395-3399. [PMID: 39649211 PMCID: PMC11622098 DOI: 10.4240/wjgs.v16.i11.3395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 07/18/2024] [Accepted: 07/22/2024] [Indexed: 10/30/2024] Open
Abstract
With increasing evidence, the biliary tract and the gallbladder mucosa are no longer considered sterile environments devoid of bacteria. Rather a profound biofilm of resident bacterial flora is associated with the mucosal surface. The bile too harbors a resident flora. It is when a dysbiotic process ensues, that this bacterial flora either becomes opportunist or is replaced by a pathogenic one that has a strong ability to survive the challenges of the biliary environment. Although once believed a metabolic problem, recent evidence indicates a complex interaction between different species of bacteria and gallbladder mucosa and bile which may culminate in calculus formation. The resident microbiota and its several enzymes dictate the type of gallstone by the mere interplay of the constituting type of bacteria in the biofilm, even without any evidence of infection. Dysbiosis is often mediated by either intestinal dysbiosis or less probably by oral dysbiosis. The gallstones, in turn, provide a haven for the resident microbiota in which they can form their own defined niche enriched with the biofilm that can resist the biliary defense mechanisms and survive the hostile biliary environment in the background of biliary stasis and local infection. However, this process of silent friendship is more complex than said, and further research is needed to define the relationship between the two.
Collapse
Affiliation(s)
- Tuhina Banerjee
- Microbiology, Institute of Medical Sciences, Banaras Hindu University, Uttar Pradesh, Varanasi 221005, India
| | - Aakansha Giri Goswami
- Department of General Surgery, All India Institute of Medical Sciences, Uttarakhand, Rishikesh 249203, India
| | - Somprakas Basu
- Department of General Surgery, All India Institute of Medical Sciences, Uttarakhand, Rishikesh 249203, India
| |
Collapse
|
|
2
|
Cai X, Tacke F, Guillot A, Liu H. Cholangiokines: undervalued modulators in the hepatic microenvironment. Front Immunol 2023; 14:1192840. [PMID: 37261338 PMCID: PMC10229055 DOI: 10.3389/fimmu.2023.1192840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 05/02/2023] [Indexed: 06/02/2023] Open
Abstract
The biliary epithelial cells, also known as cholangiocytes, line the intra- and extrahepatic bile ducts, forming a barrier between intra- and extra-ductal environments. Cholangiocytes are mostly known to modulate bile composition and transportation. In hepatobiliary diseases, bile duct injury leads to drastic alterations in cholangiocyte phenotypes and their release of soluble mediators, which can vary depending on the original insult and cellular states (quiescence, senescence, or proliferation). The cholangiocyte-secreted cytokines (also termed cholangiokines) drive ductular cell proliferation, portal inflammation and fibrosis, and carcinogenesis. Hence, despite the previous consensus that cholangiocytes are bystanders in liver diseases, their diverse secretome plays critical roles in modulating the intrahepatic microenvironment. This review summarizes recent insights into the cholangiokines under both physiological and pathological conditions, especially as they occur during liver injury-regeneration, inflammation, fibrosis and malignant transformation processes.
Collapse
Affiliation(s)
- Xiurong Cai
- Department of Hematology, Oncology and Tumor Immunology, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Frank Tacke
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Adrien Guillot
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Hanyang Liu
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
- Center of Gastrointestinal Diseases, Changzhou Second People's Hospital, Changzhou Medical Center, Nanjing Medical University, Changzhou, China
| |
Collapse
|
|
3
|
Warner JB, Larsen IS, Hardesty JE, Song YL, Warner DR, McClain CJ, Sun R, Deng Z, Jensen BAH, Kirpich IA. Human Beta Defensin 2 Ameliorated Alcohol-Associated Liver Disease in Mice. Front Physiol 2022; 12:812882. [PMID: 35153819 PMCID: PMC8829467 DOI: 10.3389/fphys.2021.812882] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/20/2021] [Indexed: 12/12/2022] Open
Abstract
Alcohol-associated liver disease (ALD) is a prevalent liver disorder and significant global healthcare burden with limited effective therapeutic options. The gut-liver axis is a critical factor contributing to susceptibility to liver injury due to alcohol consumption. In the current study, we tested whether human beta defensin-2 (hBD-2), a small anti-microbial peptide, attenuates experimental chronic ALD. Male C57Bl/6J mice were fed an ethanol (EtOH)-containing diet for 6 weeks with daily administration of hBD-2 (1.2 mg/kg) by oral gavage during the final week. Two independent cohorts of mice with distinct baseline gut microbiota were used. Oral hBD-2 administration attenuated liver injury in both cohorts as determined by decreased plasma ALT activity. Notably, the degree of hBD-2-mediated reduction of EtOH-associated liver steatosis, hepatocellular death, and inflammation was different between cohorts, suggesting microbiota-specific mechanisms underlying the beneficial effects of hBD-2. Indeed, we observed differential mechanisms of hBD-2 between cohorts, which included an induction of hepatic and small intestinal IL-17A and IL-22, as well as an increase in T regulatory cell abundance in the gut and mesenteric lymph nodes. Lastly, hBD-2 modulated the gut microbiota composition in EtOH-fed mice in both cohorts, with significant decreases in multiple genera including Barnesiella, Parabacteroides, Akkermansia, and Alistipes, as well as altered abundance of several bacteria within the family Ruminococcaceae. Collectively, our results demonstrated a protective effect of hBD-2 in experimental ALD associated with immunomodulation and microbiota alteration. These data suggest that while the beneficial effects of hBD-2 on liver injury are uniform, the specific mechanisms of action are associated with baseline microbiota.
Collapse
Affiliation(s)
- Jeffrey B. Warner
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, United States
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, United States
| | - Ida S. Larsen
- Québec Heart and Lung Institute (IUCPQ), Faculty of Medicine, Laval University, Québec city, QC, Canada
| | - Josiah E. Hardesty
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, United States
| | - Ying L. Song
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, United States
| | - Dennis R. Warner
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, United States
| | - Craig J. McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, United States
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, United States
- University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, United States
- University of Louisville Hepatobiology and Toxicology Center, University of Louisville School of Medicine, Louisville, KY, United States
- Robley Rex Veterans Medical Center, Louisville, KY, United States
| | - Rui Sun
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, United States
| | - Zhongbin Deng
- University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, United States
- University of Louisville Hepatobiology and Toxicology Center, University of Louisville School of Medicine, Louisville, KY, United States
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, United States
- Department of Surgery, University of Louisville, Louisville, KY, United States
| | - Benjamin A. H. Jensen
- Québec Heart and Lung Institute (IUCPQ), Faculty of Medicine, Laval University, Québec city, QC, Canada
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Irina A. Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, United States
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, United States
- University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, United States
- University of Louisville Hepatobiology and Toxicology Center, University of Louisville School of Medicine, Louisville, KY, United States
| |
Collapse
|
|
4
|
Massalha H, Bahar Halpern K, Abu‐Gazala S, Jana T, Massasa EE, Moor AE, Buchauer L, Rozenberg M, Pikarsky E, Amit I, Zamir G, Itzkovitz S. A single cell atlas of the human liver tumor microenvironment. Mol Syst Biol 2020; 16:e9682. [PMID: 33332768 PMCID: PMC7746227 DOI: 10.15252/msb.20209682] [Citation(s) in RCA: 115] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 11/11/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
Malignant cell growth is fueled by interactions between tumor cells and the stromal cells composing the tumor microenvironment. The human liver is a major site of tumors and metastases, but molecular identities and intercellular interactions of different cell types have not been resolved in these pathologies. Here, we apply single cell RNA-sequencing and spatial analysis of malignant and adjacent non-malignant liver tissues from five patients with cholangiocarcinoma or liver metastases. We find that stromal cells exhibit recurring, patient-independent expression programs, and reconstruct a ligand-receptor map that highlights recurring tumor-stroma interactions. By combining transcriptomics of laser-capture microdissected regions, we reconstruct a zonation atlas of hepatocytes in the non-malignant sites and characterize the spatial distribution of each cell type across the tumor microenvironment. Our analysis provides a resource for understanding human liver malignancies and may expose potential points of interventions.
Collapse
Affiliation(s)
- Hassan Massalha
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Keren Bahar Halpern
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Samir Abu‐Gazala
- Department of General SurgeryHadassah Hebrew University Medical CenterJerusalemIsrael
- Transplant DivisionDepartment of SurgeryHospital of the University of PennsylvaniaPhiladelphiaPAUSA
| | - Tamar Jana
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Efi E Massasa
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Andreas E Moor
- Department of Biosystems Science and EngineeringETH ZürichBaselSwitzerland
| | - Lisa Buchauer
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Milena Rozenberg
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Eli Pikarsky
- The Lautenberg Center for ImmunologyInstitute for Medical Research Israel‐CanadaHebrew University Medical SchoolJerusalemIsrael
| | - Ido Amit
- Department of ImmunologyWeizmann Institute of ScienceRehovotIsrael
| | - Gideon Zamir
- Department of General SurgeryHadassah Hebrew University Medical CenterJerusalemIsrael
| | - Shalev Itzkovitz
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| |
Collapse
|
|
5
|
Giordano DM, Pinto C, Maroni L, Benedetti A, Marzioni M. Inflammation and the Gut-Liver Axis in the Pathophysiology of Cholangiopathies. Int J Mol Sci 2018; 19:E3003. [PMID: 30275402 PMCID: PMC6213589 DOI: 10.3390/ijms19103003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 09/26/2018] [Accepted: 09/29/2018] [Indexed: 12/11/2022] Open
Abstract
Cholangiocytes, the epithelial cells lining the bile ducts, represent the unique target of a group of progressive diseases known as cholangiopathies whose pathogenesis remain largely unknown. In normal conditions, cholangiocytes are quiescent and participate to the final bile volume and composition. Following exogenous or endogenous stimuli, cholangiocytes undergo extensive modifications of their phenotype. Reactive cholangiocytes actively proliferate and release a set of proinflammatory molecules, which act in autocrine/paracrine manner mediating the cross-talk with other liver cell types and innate and adaptive immune cells. Cholangiocytes themselves activate innate immune responses against gut-derived microorganisms or bacterial products that reach the liver via enterohepatic circulation. Gut microbiota has been implicated in the development and progression of the two most common cholangiopathies, i.e., primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), which have distinctive microbiota composition compared to healthy individuals. The impairment of intestinal barrier functions or gut dysbiosis expose cholangiocytes to an increasing amount of microorganisms and may exacerbate inflammatory responses thus leading to fibrotic remodeling of the organ. The present review focuses on the complex interactions between the activation of innate immune responses in reactive cholangiocytes, dysbiosis, and gut permeability to bacterial products in the pathogenesis of PSC and PBC.
Collapse
Affiliation(s)
- Debora Maria Giordano
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Via Tronto 10, 60126 Ancona, Italy.
| | - Claudio Pinto
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Via Tronto 10, 60126 Ancona, Italy.
| | - Luca Maroni
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Via Tronto 10, 60126 Ancona, Italy.
| | - Antonio Benedetti
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Via Tronto 10, 60126 Ancona, Italy.
| | - Marco Marzioni
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Via Tronto 10, 60126 Ancona, Italy.
| |
Collapse
|
|
6
|
Klag T, Thomas M, Ehmann D, Courth L, Mailänder-Sanchez D, Weiss TS, Dayoub R, Abshagen K, Vollmar B, Thasler WE, Stange EF, Berg CP, Malek NP, Zanger UM, Wehkamp J. β-Defensin 1 Is Prominent in the Liver and Induced During Cholestasis by Bilirubin and Bile Acids via Farnesoid X Receptor and Constitutive Androstane Receptor. Front Immunol 2018; 9:1735. [PMID: 30100908 PMCID: PMC6072844 DOI: 10.3389/fimmu.2018.01735] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 07/13/2018] [Indexed: 12/12/2022] Open
Abstract
Background & aims Knowledge about innate antimicrobial defense of the liver is limited. We investigated hepatic expression and regulation of antimicrobial peptides with focus on the human beta defensin-1 (hBD-1). Methods Radial diffusion assay was used to analyze antimicrobial activity of liver tissue. Different defensins including hBD-1 and its activator thioredoxin-1 (TXN) were analyzed in healthy and cholestatic liver samples by qPCR and immunostaining. Regulation of hBD-1 expression was studied in vitro and in vivo using bile duct-ligated mice. Regulation of hBD-1 via bilirubin and bile acids (BAs) was studied using siRNA. Results We found strong antimicrobial activity of liver tissue against Escherichia coli. As a potential mediator of this antimicrobial activity we detected high expression of hBD-1 and TXN in hepatocytes, whereas other defensins were minimally expressed. Using a specific antibody for the reduced, antimicrobially active form of hBD-1 we found hBD-1 in co-localization with TXN within hepatocytes. hBD-1 was upregulated in cholestasis in a graded fashion. In cholestatic mice hepatic AMP expression (Defb-1 and Hamp) was enhanced. Bilirubin and BAs were able to induce hBD-1 in hepatic cell cultures in vitro. Treatment with siRNA and/or agonists demonstrated that the farnesoid X receptor (FXR) mediates basal expression of hBD-1, whereas both constitutive androstane receptor (CAR) and FXR seem to be responsible for the induction of hBD-1 by bilirubin. Conclusion hBD-1 is prominently expressed in hepatocytes. It is induced during cholestasis through bilirubin and BAs, mediated by CAR and especially FXR. Reduction by TXN activates hBD-1 to a potential key player in innate antimicrobial defense of the liver.
Collapse
Affiliation(s)
- Thomas Klag
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | - Maria Thomas
- Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology, Stuttgart and University of Tuebingen, Tuebingen, Germany
| | - Dirk Ehmann
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | - Lioba Courth
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | | | - Thomas S Weiss
- University Children Hospital (KUNO), Regensburg University Hospital, Regensburg, Germany
| | - Rania Dayoub
- University Children Hospital (KUNO), Regensburg University Hospital, Regensburg, Germany
| | - Kerstin Abshagen
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Rostock, Germany
| | - Brigitte Vollmar
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Rostock, Germany
| | - Wolfgang E Thasler
- Department of Surgery, Grosshadern Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Eduard F Stange
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | - Christoph P Berg
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | - Nisar P Malek
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | - Ulrich M Zanger
- Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology, Stuttgart and University of Tuebingen, Tuebingen, Germany
| | - Jan Wehkamp
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| |
Collapse
|
|
7
|
He ZH, He WR, Li Q, Xiao W, Peng NF, Mo SF, Wei YN. Endoscopic characteristics of bile duct lesions and duodenal papilla in patients with bile duct stones and pneumatosis. Shijie Huaren Xiaohua Zazhi 2018; 26:465-473. [DOI: 10.11569/wcjd.v26.i7.465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the characteristics of biliary pathogenic bacteria, pathological changes of bile ducts, and changes of duodenal papilla in patients with bile duct stones and pneumatosis.
METHODS We analyzed biliary pathogenic bacteria, pathological changes of bile ducts, and characteristics of duodenal papilla in 53 patients with bile duct stones and pneumatosis. The incidence of intestinal juice reflux and recurrent biliary infection and bile duct diameter were compared in each subtype of duodenal papilla.
RESULTS The results of bacterial culture showed that the percentages of Gram positive bacteria, Gram negative bacteria, and fungi were 42.1%, 57.9%, and 1.8%, respectively. The main bacteria were Enterococcus (36.6%), Escherichia coli (19.3%), and Klebsiella pneumoniae (15.8%). Chronic bile duct inflammation, duodenal papillary inflammation, incomplete closure of duodenal papilla, and Oddi sphincter relaxation were common features in patients with bile duct stones and pneumatosis. Chronic inflammation and abnormal hyperplasia of the bile duct mucosa were found in 16 patients, which manifested as intestinal villous change, mucous pits, and reticular pattern. Seven patients had local mass in the bile duct. There was a significant difference in bile duct diameter among each subtype of papilla (P < 0.001). Common bile duct diameter was significantly bigger in IIb and IIc subtypes than in IIa and IId subtypes (P < 0.05), but there was no significant difference between IIb and IIc and between IIa and IId (P > 0.05). The rate of intestinal juice reflux differed significantly among each subtype of papilla (P < 0.05), and the rate of intestinal juice reflux was significantly higher in IIa subtype than in other subtypes. However, the rate of recurrent biliary infection showed no significant difference among each subtype of papilla (P > 0.05).
CONCLUSION Bacterial infection is the main etiology in patients with bile duct stones and pneumatosis, and the percentage of Gram positive bacteria is higher. Chronic bile duct inflammation, duodenal papillary inflammation, incomplete closure of duodenal papilla, and Oddi sphincter relaxation are common features in patients with bile duct stones and pneumatosis. There is a significant difference in bile duct diameter and the rate of intestinal juice reflux among each subtype of duodenal papilla, while there is no significant difference in the rate of recurrent biliary infection.
Collapse
|
|
8
|
Kessler SP, Obery DR, Nickerson KP, Petrey AC, McDonald C, de la Motte CA. Multifunctional Role of 35 Kilodalton Hyaluronan in Promoting Defense of the Intestinal Epithelium. J Histochem Cytochem 2018; 66:273-287. [PMID: 29290146 DOI: 10.1369/0022155417746775] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intestinal epithelium plays a critical role in host defense against orally acquired pathogens. Dysregulation of this protective barrier is a primary driver of inflammatory bowel diseases (Crohn's and ulcerative colitis) and also infant gastrointestinal infections. Previously, our lab reported that hyaluronan (HA) isolated from human milk induces the expression of the antimicrobial peptide β-defensin in vivo and protects against Salmonella Typhimurium infection of epithelial cells in vitro. In addition, we demonstrated that commercially available 35 kDa size HA induces the expression of β-defensin, upregulates the expression of tight junction protein zonula occludens-1 (ZO-1), and attenuates murine Citrobacter rodentium infection in vivo. In this current study, we report that HA35 remains largely intact and biologically active during transit through the digestive tract where it directly induces β-defensin expression upon epithelial cell contact. We also demonstrate HA35 abrogation of murine Salmonella Typhimurium infection as well as downregulation of leaky tight junction protein claudin-2 expression. Taken together, we propose a dual role for HA in host innate immune defense at the epithelial cell surface, acting to induce antimicrobial peptide production and also block pathogen-induced leaky gut. HA35 is therefore a promising therapeutic in the defense against bacterially induced colitis in compromised adults and vulnerable newborns.
Collapse
Affiliation(s)
- Sean P Kessler
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Dana R Obery
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Kourtney P Nickerson
- Division of Pediatric Gastroenterology and Nutrition, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, Massachusetts.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
| | - Aaron C Petrey
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Carol A de la Motte
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
|
9
|
Harada K. Sclerosing and obstructive cholangiopathy in biliary atresia: mechanisms and association with biliary innate immunity. Pediatr Surg Int 2017; 33:1243-1248. [PMID: 29039048 DOI: 10.1007/s00383-017-4154-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/05/2017] [Indexed: 12/13/2022]
Abstract
Biliary atresia (BA) is histologically characterized by a progressive, sclerosing cholangitis and the obstruction of extrahepatic bile ducts. In terms of the etiology and pathogenesis of BA, several viral infections consisting of dsRNA, including Reoviridae, have been implicated. Human biliary epithelial cells (BECs) possess an innate immune system consisting of Toll-like receptors (TLRs). BECs have negative regulatory mechanisms of TLR tolerance to avoid an excessive inflammatory response to lipopolysaccharide (LPS), a TLR4 ligand; however, they lack the tolerance to poly(I:C) (a synthetic analog of viral dsRNA), a TLR3 ligand. Treatment with poly(I:C) induces the expression of the apoptosis-inducer TNF-related apoptosis-inducing ligand (TRAIL), along with the antiviral molecule IFN-β1, and reduces the viability of BECs by enhancing apoptosis. In response, surviving BECs increase their expression of various markers, including basic FGF [an epithelial-mesenchymal transition (EMT)-inducer], S100A4 (a mesenchymal marker), and Snail (a transcriptional factor), and decrease that of epithelial markers such as CK19 and E-cadherin before undergoing EMT. Extrahepatic bile ducts in BA infants frequently show a lack of epithelial markers and an aberrant expression of vimentin, in addition to the enhancement of TRAIL and apoptosis. dsRNA viruses may directly induce apoptosis and EMT in human BECs as a result of the biliary innate immune response, supporting the notion that Reoviridae infections may be directly associated with the pathogenesis of cholangiopathies in BA.
Collapse
Affiliation(s)
- Kenichi Harada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, 920-8640, Japan.
| |
Collapse
|
|
10
|
β-defensin 1 expression in HCV infected liver/liver cancer: an important role in protecting HCV progression and liver cancer development. Sci Rep 2017; 7:13404. [PMID: 29042578 PMCID: PMC5645372 DOI: 10.1038/s41598-017-13332-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/21/2017] [Indexed: 12/14/2022] Open
Abstract
β-defensin family plays a role in host defense against viral infection, however its role in HCV infection is still unknown. In this study, we demonstrated that β-defensin 1 was significantly reduced in HCV-infected liver specimens. Treatment with interferon and ribavirin upregulated β-defensin-1, but not other β-defensin tested, with the extent and duration of upregulation associated with treatment response. We investigated β-defensin family expression in liver cancer in publicly available datasets and found that among all the β-defensins tested, only β-defensin 1 was significantly downregulated, suggesting β-defensin 1 plays a crucial role in liver cancer development. Further analysis identified E-cadherin as the top positive correlated gene, while hepatocyte growth factor-regulated tyrosine kinase substrate as the top negative correlated gene. Expression of two proteoglycans were also positively correlated with that of β-defensin 1. We have also identified small molecules as potential therapeutic agents to reverse β-defensin 1-associated gene signature. Furthermore, the downregulation of β-defensin 1 and E-cadherin, and upregulation of hepatocyte growth factor-regulated tyrosine kinase substrate, were further confirmed in liver cancer and adjacent normal tissue collected from in-house Chinese liver cancer patients. Together, our results suggest β-defensin 1 plays an important role in protecting HCV progression and liver cancer development.
Collapse
|
|
11
|
Strazzabosco M, Fiorotto R, Cadamuro M, Spirli C, Mariotti V, Kaffe E, Scirpo R, Fabris L. Pathophysiologic implications of innate immunity and autoinflammation in the biliary epithelium. Biochim Biophys Acta Mol Basis Dis 2017; 1864:1374-1379. [PMID: 28754453 DOI: 10.1016/j.bbadis.2017.07.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/20/2017] [Accepted: 07/21/2017] [Indexed: 12/12/2022]
Abstract
The most studied physiological function of biliary epithelial cells (cholangiocytes) is to regulate bile flow and composition, in particular the hydration and alkalinity of the primary bile secreted by hepatocytes. After almost three decades of studies it is now become clear that cholangiocytes are also involved in epithelial innate immunity, in inflammation, and in the reparative processes in response to liver damage. An increasing number of evidence highlights the ability of cholangiocyte to undergo changes in phenotype and function in response to liver damage. By participating actively to the immune and inflammatory responses, cholangiocytes represent a first defense line against liver injury from different causes. Indeed, cholangiocytes express a number of receptors able to recognize pathogen- or damage-associated molecular patterns (PAMPs/DAMPs), such as Toll-like receptors (TLR), which modulate their pro-inflammatory behavior. Cholangiocytes can be both the targets and the initiators of the inflammatory process. Derangements of the signals controlling these mechanisms are at the basis of the pathogenesis of different cholangiopathies, both hereditary and acquired, such as cystic fibrosis-related liver disease and sclerosing cholangitis. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.
Collapse
Affiliation(s)
- Mario Strazzabosco
- Digestive Disease Section, Yale University School of Medicine, New Haven, CT, USA; International Center for Digestive Health, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Milan, Italy.
| | - Romina Fiorotto
- Digestive Disease Section, Yale University School of Medicine, New Haven, CT, USA; International Center for Digestive Health, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Milan, Italy
| | - Massimiliano Cadamuro
- International Center for Digestive Health, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Milan, Italy
| | - Carlo Spirli
- Digestive Disease Section, Yale University School of Medicine, New Haven, CT, USA; International Center for Digestive Health, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Milan, Italy
| | - Valeria Mariotti
- Department of Molecular Medicine, University of Padova School of Medicine, Padova, Italy
| | - Eleanna Kaffe
- Department of Molecular Medicine, University of Padova School of Medicine, Padova, Italy
| | - Roberto Scirpo
- Digestive Disease Section, Yale University School of Medicine, New Haven, CT, USA
| | - Luca Fabris
- Digestive Disease Section, Yale University School of Medicine, New Haven, CT, USA; International Center for Digestive Health, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Milan, Italy; Department of Molecular Medicine, University of Padova School of Medicine, Padova, Italy
| |
Collapse
|
|
12
|
Chang C, Lleo A, Kananurak A, Grizzi F, Tsuneyama K, Invernizzi P, Bevins CL, Bowlus CL. Human β-Defensin 2 in Primary Sclerosing Cholangitis. Clin Transl Gastroenterol 2017; 8:e80. [PMID: 28300822 PMCID: PMC5387757 DOI: 10.1038/ctg.2017.8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/05/2017] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVES Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the bile ducts frequently associated with inflammatory bowel disease (IBD), suggesting an important role for the gut-liver axis. Defensins are small (3.5-4.5 kDa) anti-microbial peptides that contribute to innate immunity at mucosal surfaces and have been implicated in IBD. The aim of this study was to investigate copy number variation of the gene (DEFB4) encoding human β-defensin 2 (HBD2) and protein expression of HBD2 in PSC. METHODS US and Italian PSC cases and unaffected controls (US PSC patients n=89, US controls n=87; Italian PSC patients n=46, Italian controls n=84) were used to estimate HBD2 gene copy number by both quantitative real-time PCR and paralog ratio test. Serum levels of HBD2 were measured by enzyme-linked immunosorbent assay and liver expression was analyzed by immunohistochemistry. RESULTS Mean serum levels of HBD2 were significantly greater in PSC (1,086±1,721 ng/μl) compared with primary biliary cholangitis (544±754 ng/μl), ulcerative colitis (417±506 ng/μl), and healthy controls (514±731 ng/μl) (P=0.02). However, no significant differences between the frequencies of high DEFB4 gene copy number, defined by >4 copies, and PSC were found in the US, Italian, or combined cohorts. Importantly, a high number of biliary ducts were found immunopositive in PSC samples compared with controls. CONCLUSIONS Our data show that HBD2 serum levels and tissue expression are increased in PSC subjects, suggesting that this arm of innate immunity may be important in the etiopathogenesis of PSC.
Collapse
Affiliation(s)
- Cindy Chang
- Division of Gastroenterology and Hepatology, University of California Davis Medical Center, Sacramento, California, USA
| | - Ana Lleo
- Liver Unit and Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Anchasa Kananurak
- Department of Microbiology and Immunology, University of California Davis School of Medicine, Davis, California, USA
| | - Fabio Grizzi
- Department of Immunology and Inflammation, Humanitas Clinical and Research Center, Milan, Italy
| | - Koichi Tsuneyama
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Pietro Invernizzi
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California at Davis School of Medicine, Davis, California, USA
- International Center for Digestive Health, Department of Medicine and Surgery, University of Milan-Bicocca, Milan, Italy
| | - Charles L Bevins
- Department of Microbiology and Immunology, University of California Davis School of Medicine, Davis, California, USA
| | - Christopher L Bowlus
- Division of Gastroenterology and Hepatology, University of California Davis Medical Center, Sacramento, California, USA
| |
Collapse
|
|
13
|
Wertenbruch S, Drescher H, Grossarth V, Kroy D, Giebeler A, Erschfeld S, Heinrichs D, Soehnlein O, Trautwein C, Brandenburg LO, Streetz K. The Anti-Microbial Peptide LL-37/CRAMP Is Elevated in Patients with Liver Diseases and Acts as a Protective Factor during Mouse Liver Injury. Digestion 2016; 91:307-17. [PMID: 25998843 DOI: 10.1159/000368304] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 09/11/2014] [Indexed: 02/04/2023]
Abstract
BACKGROUND Antimicrobial peptides (AMP) are an important defense mechanism of the innate immune system and can modulate the course of various diseases. However, their significance during liver pathogenesis is currently not well defined. METHODS Patients with liver diseases were analyzed for LL-37/CRAMP, human beta-defensin-2 (hBD2), and complement 5a (C5a) serum levels. Mice deficient in CRAMP (Cathelicidin-related Antimicrobial Peptide), the mouse homolog for human LL-37, were fed with a methionine- and choline-deficient diet (MCD) and underwent bile-duct ligation (BDL). RESULTS First, serum samples from patients with chronic liver diseases were investigated. Therefore, significantly enhanced levels for LL-37, hBD2, and complement C5a were detected, all of which comprise antimicrobial properties. Next, CRAMP-knockout (CRAMP-KO) mice were investigated, to better define a functional role of LL-37/CRAMP in animal models of liver diseases. MCD feeding and bile-duct ligation of CRAMP-KO mice resulted in an enhanced degree of liver injury during the early treatment phase. MCD feeding in CRAMP-KO mice led to stronger intrahepatic fat accumulation and significantly enhanced matrix remodeling, whereas BDL caused more extensive liver necrosis. At the late 28 days time point, MCD-fed CRAMP-KO mice displayed a higher intrahepatic fat load. Long-term changes in bile-duct-ligated mice included higher collagen content as a sign of enhanced fibrosis progression if CRAMP was absent. CONCLUSION The study shows a clear correlation of antimicrobial peptide serum levels in patients with chronic liver diseases. Furthermore, we were able to demonstrate protective functions of LL-37/CRAMP in two independent mouse models of chronic liver injury.
Collapse
Affiliation(s)
- Svenja Wertenbruch
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
|
14
|
Abstract
Background The biliary system is in continuous contact with the complex microbiota of the intestine. Microbial products have recently been proposed as potential triggers for biliary diseases. Methods The aim of this review is to provide a summary of the current knowledge regarding the role of the biliary and intestinal microbiome in biliary inflammatory diseases. Results Previously, it was suggested that the healthy biliary system is a sterile organ, while acute cholangitis and cholecystitis may occur from ascending infections. Although non-inflammatory biliary colonization by certain bacteria such as Salmonella spp. has been already recognized since several decades, human and animal studies indicated only very recently that the gallbladder harbors a complex microbiota also under non-pathologic conditions. Novel findings suggested that – similar to the situation in the intestine – the biliary mucosa features a chemical, mechanical, and immunological barrier, ensuring immunological tolerance against commensals. However, microbial triggers might influence acute and chronic inflammatory disease of the biliary system and the whole liver. Conclusion Although yet undefined, dysbiosis of the biliary or intestinal microbiota rather than a single microorganism may influence disease progression.
Collapse
Affiliation(s)
- Julien Verdier
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Tom Luedde
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Gernot Sellge
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| |
Collapse
|
|
15
|
Trussoni CE, Tabibian JH, Splinter PL, O’Hara SP. Lipopolysaccharide (LPS)-Induced Biliary Epithelial Cell NRas Activation Requires Epidermal Growth Factor Receptor (EGFR). PLoS One 2015; 10:e0125793. [PMID: 25915403 PMCID: PMC4411066 DOI: 10.1371/journal.pone.0125793] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 03/19/2015] [Indexed: 12/27/2022] Open
Abstract
Cholangiocytes (biliary epithelial cells) actively participate in microbe-induced proinflammatory responses in the liver and contribute to inflammatory and infectious cholangiopathies. We previously demonstrated that cholangiocyte TLR-dependent NRas activation contributes to proinflammatory/ proliferative responses. We test the hypothesis that LPS-induced activation of NRas requires the EGFR. SV40-transformed human cholangiocytes (H69 cells), or low passage normal human cholangiocytes (NHC), were treated with LPS in the presence or absence of EGFR or ADAM metallopeptidase domain 17 (TACE) inhibitors. Ras activation assays, quantitative RT-PCR, and proliferation assays were performed in cells cultured with or without inhibitors or an siRNA to Grb2. Immunofluorescence for phospho-EGFR was performed on LPS-treated mouse samples and specimens from patients with primary sclerosing cholangitis, primary biliary cirrhosis, hepatitis C, and normal livers. LPS-treatment induced an association between the TLR/MyD88 and EGFR/Grb2 signaling apparatus, NRas activation, and EGFR phosphorylation. NRas activation was sensitive to EGFR and TACE inhibitors and correlated with EGFR phosphorylation. The TACE inhibitor and Grb2 depletion prevented LPS-induced IL6 expression (p<0.05) and proliferation (p<0.01). Additionally, cholangiocytes from LPS-treated mouse livers and human primary sclerosing cholangitis (PSC) livers exhibited increased phospho-EGFR (p<0.01). Moreover, LPS-induced mouse cholangiocyte proliferation was inhibited by concurrent treatment with the EGFR inhibitor, Erlotinib. Our results suggest that EGFR is essential for LPS-induced, TLR4/MyD88-mediated NRas activation and induction of a robust proinflammatory cholangiocyte response. These findings have implications not only for revealing the signaling potential of TLRs, but also implicate EGFR as an integral component of cholangiocyte TLR-induced proinflammatory processes.
Collapse
Affiliation(s)
- Christy E. Trussoni
- Division of Gastroenterology and Hepatology, and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, Minnesota, 55905, United States of America
| | - James H. Tabibian
- Division of Gastroenterology and Hepatology, and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, Minnesota, 55905, United States of America
| | - Patrick L. Splinter
- Division of Gastroenterology and Hepatology, and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, Minnesota, 55905, United States of America
| | - Steven P. O’Hara
- Division of Gastroenterology and Hepatology, and the Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, Minnesota, 55905, United States of America
| |
Collapse
|
|
16
|
Toll-like receptor-1 and receptor-2 and Beta-defensin in postcholecystectomy bile duct injury. Gastroenterol Res Pract 2015; 2015:216129. [PMID: 25755667 PMCID: PMC4337755 DOI: 10.1155/2015/216129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 01/11/2015] [Indexed: 11/18/2022] Open
Abstract
Postcholecystectomy bile duct injuries (BDI) produce hepatic cholestasis and cause infection of the biliary tract. The biliary cells participate in secreting cytokines and in expression of immune response receptors. Toll-like receptors (TLRs) conduct signalling and activate the innate and adaptive inflammatory response. The objective was to determine the serum levels of TLR-2 and the expression of TLR-1 and TLR-2 and β-defensin in liver biopsies of postcholecystectomy BDI patients. A transverse, analytical study with 2 groups was done. One group included healthy volunteers (control group) and other included 25 postcholecystectomy BDI patients with complete biliary obstruction. Using the Enzyme-linked Immunosorbent Assay (ELISA) technique, serum levels of TLR-2 were determined, and with immunofluorescence the morphologic analysis of TLR-1 and TLR-2 and β-defensin in liver biopsies of postcholecystectomy BDI patients was performed. The average TLR-2 serum level in the control group was 0.0 pg/mL and in the BDI group, 0.023 ± 0.0045 pg/mL (P < 0.0001, bilateral Mann Whitney U). Immunofluorescence was used to determine the expression in liver biopsies, blood vessels, bile ducts, and hepatic parenchyma where 12 hepatic biopsies were positive for TLR-1 with average of 3213057.74 ± 1071019.25 μm2; and 7 biopsies were positive for β-defensin with an average of 730364.33 ± 210838.02 μm2; and 6 biopsies positive for TLR-2, obtaining an average of 3354364.24 ± 838591.06 μm2. In conclusion, TLR-1 and TLR-2 and β-defensin play an important role in the innate antimicrobial defense of the hepatobiliary system.
Collapse
|
|
17
|
Zhang Q, Yu H, Wu SD. Immune function of biliary epithelial cells. Shijie Huaren Xiaohua Zazhi 2015; 23:925-931. [DOI: 10.11569/wcjd.v23.i6.925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Biliary epithelial cells (BECs) are the epithelial cells lining the bile duct, constituting the biliary system's first line of defense against pathogenic microorganisms. BECs can express many kinds of pathogen recognition receptors, activate intracellular signal transduction pathways, initiate the internal microbial defense system, including the release of pro-inflammatory cytokines and chemokines and antibacterial peptide synthesis, and maintain the integrity of the biliary epithelium. By expressing and releasing adhesion molecules and immune mediators, BECs interact with other cells in the liver, such as lymphocytes and Kupffer's cells. BECs are involved in a complex feedback mechanism of liver cells and thereby regulate the response to microbial infection. BECs actively participate in the biliary duct mucosal immunity and form an important component of liver immunity.
Collapse
|
|
18
|
Abstract
Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by selective destruction of intrahepatic cholangiocytes. Mechanisms underlying the development and progression of the disease are still controversial and largely undefined. Evidence suggests that PBC results from an articulated immunologic response against an immunodominant mitochondrial autoantigen, the E2 component of the pyruvate dehydrogenase complex (PDC-E2); characteristics of the disease are also the presence of disease-specific antimitochondrial autoantibodies (AMAs) and autoreactive CD4 and CD8 T cells. Recent evidence suggests that cholangiocytes show specific immunobiological features that are responsible for the selective targeting of those cells by the immune system. The immune reaction in PBC selectively targets small sized, intrahepatic bile ducts; although a specific reason for that has not been defined yet, it has been established that the biliary epithelium displays a unique heterogeneity, for which the physiological and pathophysiological features of small and large cholangiocytes significantly differ. In this review article, the authors provide a critical overview of the current evidence on the role of cholangiocytes in the immune-mediated destruction of the biliary tree that characterizes PBC.
Collapse
Affiliation(s)
- Ana Lleo
- Liver Unit and Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Rozzano (MI), Italy
| | - Luca Maroni
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy
| | - Shannon Glaser
- Research, Central Texas Veterans Health Care System, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
- Scott & White Digestive Disease Research Center, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
- Department of Medicine, Division Gastroenterology, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
| | - Gianfranco Alpini
- Research, Central Texas Veterans Health Care System, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
- Scott & White Digestive Disease Research Center, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
- Department of Medicine, Division Gastroenterology, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
| | - Marco Marzioni
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy
| |
Collapse
|
|
19
|
The immunophysiology and apoptosis of biliary epithelial cells: primary biliary cirrhosis and primary sclerosing cholangitis. Clin Rev Allergy Immunol 2013; 43:230-41. [PMID: 22689287 DOI: 10.1007/s12016-012-8324-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Biliary epithelial cells (BECs) provide the first line of defense against lumenal microbes in the biliary system. BECs express a variety of pathogen recognition receptors and can activate several intracellular signaling cascades to initiate antimicrobial defenses, including production of several anti-microbial peptides, cytokines, chemokines, and adhesion molecules. BECs also secrete immunoglobulin A and interact with other cells through expression and release of adhesion molecules and immune mediators. Recently, several reports suggest a correlation between apoptosis and autoimmunity through ineffective clearance of self-antigens. Primary biliary cirrhosis (PBC) is a slowly progressive, autoimmune cholestatic liver disease characterized by highly specific antimitochondrial antibodies (AMAs) and the specific immune-mediated destruction of BECs. We have demonstrated that the AMA self-antigen, namely the E2 subunit of the pyruvate dehydrogenase complex, is detectable in its antigenically reactive form within apoptotic blebs from human intrahepatic biliary epithelial cells and activates innate immune responses. Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and the presence of concentric fibrosis of intrahepatic and/or extrahepatic bile ducts, eventually leading to cirrhosis. However, apoptosis does not appear to play a central role in PSC. Despite both diseases involving immune-mediated injury to bile ducts, apoptosis occurs more commonly overall in PBC where it likely plays a unique role.
Collapse
|
|
20
|
Okamura A, Harada K, Nio M, Nakanuma Y. Participation of natural killer cells in the pathogenesis of bile duct lesions in biliary atresia. J Clin Pathol 2012; 66:99-108. [DOI: 10.1136/jclinpath-2012-201097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AimsImmunological disturbances including innate immunity after a suspected viral infection are considered important to the pathogenesis of bile duct lesions in cases of biliary atresia (BA). In this study, we tried to evaluate whether natural killer (NK) cells and CX3CL1 (Fractalkine) and its receptor (CX3CR1) are involved in the bile duct injury.MethodsUsing the section of BA (22 cases) and controls, immunohistochemistry for CD56, CD16, CD68, CX3CL1 and CX3CR1 was performed. Moreover, using cultured biliary epithelial cells (BECs) and NK cells, the production of CX3CL1 in BECs and the migration of NK cells were evaluated.ResultsIt was found that CD56(−)CD16(+)CD68(−) NK cells were increased around the damaged small and large bile ducts in BA and hepatitis C virus-related chronic hepatitis in comparison with other controls. CX3CL1 was strongly expressed on the damaged bile ducts in BA, while this expression was relatively weak or absent in the bile ducts of normal liver. The results suggest the CD56(−)CD16(+) NK cells to be involved in the development of bile duct injuries in BA. These CD16(+) NK cells were positive for CX3CR1, and attracted by CX3CL1 expressed on bile ducts. Further study revealed that stimulation with poly(I:C) (a synthetic analogue of viral dsRNA) increased the expression of CX3CL1 on cultured BECs followed by increased migrational activity of cultured NK cells.ConclusionsCD56(−)CD16(+) NK cells with reduced NK activity may be involved in the bile duct damage in BA, and CD16(+) NK cells expressing CX3CR1 may be attracted by and interact with bile ducts expressing CX3CL1.
Collapse
|
|
21
|
Abstract
Biliary innate immunity is involved in the pathogenesis of cholangiopathies in cases of biliary disease. Cholangiocytes possess Toll-like receptors (TLRs) which recognize pathogen-associated molecular patterns (PAMPs) and play a pivotal role in the innate immune response. Tolerance to bacterial PAMPs such as lipopolysaccharides is also important to maintain homeostasis in the biliary tree, but tolerance to double-stranded RNA (dsRNA) is not found. Moreover, in primary biliary cirrhosis (PBC) and biliary atresia, biliary innate immunity is closely associated with the dysregulation of the periductal cytokine milieu and the induction of biliary apoptosis and epithelial-mesenchymal transition (EMT), forming in disease-specific cholangiopathy. Biliary innate immunity is associated with the pathogenesis of various cholangiopathies in biliary diseases as well as biliary defense systems.
Collapse
|
|
22
|
O'Hara SP, Splinter PL, Trussoni CE, Gajdos GB, Lineswala PN, LaRusso NF. Cholangiocyte N-Ras protein mediates lipopolysaccharide-induced interleukin 6 secretion and proliferation. J Biol Chem 2011; 286:30352-30360. [PMID: 21757746 DOI: 10.1074/jbc.m111.269464] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cholangiocytes, the epithelial cells lining the bile ducts in the liver, are periodically exposed to potentially injurious microbes and/or microbial products. As a result, cholangiocytes actively participate in microbe-associated, hepatic proinflammatory responses. We previously showed that infection of cultured human cholangiocytes with the protozoan parasite, Cryptosporidium parvum, or treatment with gram-negative bacteria-derived LPS, activates NFκB in a myeloid differentiation 88 (MyD88)-dependent manner. Here, we describe a novel signaling pathway initiated by Toll-like receptors (TLRs) involving the small GTPase, Ras, that mediates cholangiocyte proinflammatory cytokine production and induction of cholangiocyte proliferation. Using cultured human cholangiocytes and a Ras activation assay, we found that agonists of plasma membrane TLRs (TLR 1, 2, 4, 5, and 6) rapidly (<10 min) activated N-Ras, but not other p21 Ras isoforms, resulting in the rapid (<15 min) phosphorylation of the downstream Ras effector, ERK1/2. RNA interference-induced depletion of TRAF6, a downstream effector of MyD88 and known activator of MAPK signaling, had no effect on N-Ras activation. Following N-Ras activation the proinflammatory cytokine, IL6, is rapidly secreted. Using a luciferase reporter, we demonstrated that LPS treatment induced IL6 promoter-driven luciferase which was suppressed using MEK/ERK pharmacologic inhibitors (PD98059 or U0126) and RNAi-induced depletion of N-Ras. Finally, we showed that LPS increased cholangiocyte proliferation (1.5-fold), which was inhibited by depletion of N-Ras; TLR agonist-induced proliferation was also inhibited following pretreatment with an IL6 receptor-blocking antibody. Together, our results support a novel signaling axis involving microbial activation of N-Ras likely involved in the cholangiocyte pathogen-induced proinflammatory response.
Collapse
Affiliation(s)
- Steven P O'Hara
- Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905.
| | - Patrick L Splinter
- Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905
| | - Christy E Trussoni
- Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905
| | - Gabriella B Gajdos
- Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905
| | - Pooja N Lineswala
- Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| | - Nicholas F LaRusso
- Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905
| |
Collapse
|
|
23
|
O'Hara SP, Bogert PST, Trussoni CE, Chen X, LaRusso NF. TLR4 promotes Cryptosporidium parvum clearance in a mouse model of biliary cryptosporidiosis. J Parasitol 2011; 97:813-21. [PMID: 21506806 DOI: 10.1645/ge-2703.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cholangiocytes, the epithelial cells lining intrahepatic bile ducts, express multiple toll-like receptors (TLRs) and, thus, have the capacity to recognize and respond to microbial pathogens. In previous work, we demonstrated that TLR4, which is activated by gram-negative lipopolysaccharide (LPS), is upregulated in cholangiocytes in response to infection with Cryptosporidium parvum in vitro and contributes to nuclear factor-kappaB (NF-kB) activation. Here, using an in vivo model of biliary cryptosporidiosis, we addressed the functional role of TLR4 in C. parvum infection dynamics and hepatobiliary pathophysiology. We observed that C57BL mice clear the infection by 3 wk post-infection (PI). In contrast, parasites were detected in bile and stool in TLR4-deficient mice at 4 wk PI. The liver enzymes alanine transaminase (ALT) and aspartate transaminase (AST), and the proinflammatory cytokines tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-6 peaked at 1 to 2 wk PI and normalized by 4 wk in infected C57BL mice. C57BL mice also demonstrated increased cholangiocyte proliferation (PCNA staining) at 1 wk PI that was resolved by 2 wk PI. In contrast, TLR4-deficient mice showed persistently elevated serum ALT and AST, elevated hepatic IL-6 levels, and histological evidence of hepatocyte necrosis, increased inflammatory cell infiltration, and cholangiocyte proliferation through 4 wk PI. These data suggest that a TLR4-mediated response is required for efficient eradication of biliary C. parvum infection in vivo, and lack of this pattern-recognition receptor contributes to an altered inflammatory response and an increase in hepatobiliary pathology.
Collapse
Affiliation(s)
- Steven P O'Hara
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, and Mayo Clinic Center for Cell Signaling, Mayo Clinic, Rochester, Minnesota 55905, USA
| | | | | | | | | |
Collapse
|
|
24
|
Lleo A, Shimoda S, Ishibashi H, Gershwin ME. Primary biliary cirrhosis and autoimmune hepatitis: apotopes and epitopes. J Gastroenterol 2011; 46 Suppl 1:29-38. [PMID: 20798971 DOI: 10.1007/s00535-010-0303-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 07/28/2010] [Indexed: 02/04/2023]
Abstract
Autoimmune liver diseases (ALDs) represent a wide spectrum of chronic inflammatory diseases that are characterized by an immune-mediated attack against either hepatocytes (in the case of autoimmune hepatitis types 1 and 2, AIH-1, 2) or cholangiocytes (in primary biliary cirrhosis, PBC). PBC is considered a model autoimmune disease due to the homogeneity of patients, the high specificity of antimitochondrial antibodies (AMAs), and the specificity of biliary epithelial cell (BEC) destruction. It ensues from a multi-lineage loss of tolerance to the E2 component of the pyruvate dehydrogenase complex (PDC-E2). One of the major unanswered questions in the pathogenesis of PBC is the specificity of small intrahepatic bile duct attack while PDC-E2 is present in mitochondria of nucleated cells. Recent findings suggest that the apoptosis of BECs may be of considerable importance for understanding PBC, and that they are more than simply an innocent victim of an immune attack. Rather, they attract immune attack by virtue of the unique biochemical mechanisms by which they handle PDC-E2. The role of apoptotic cells in AIH is not well defined, but advances in the study of autoreactive T cells stem mostly from AIH type 2, where the main autoantigen (CYP2D6) is known, enabling the characterization of antigen-specific immune responses. This review article is intended to provide a critical overview of current evidence on tissue specificity in ALDs, as well as the characteristics of the relevant epitopes and apotopes and their biological and clinical significance.
Collapse
Affiliation(s)
- Ana Lleo
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California at Davis, Davis, CA 95616, USA
| | | | | | | |
Collapse
|
|
25
|
Jäger S, Stange EF, Wehkamp J. Antimicrobial peptides in gastrointestinal inflammation. Int J Inflam 2010; 2010:910283. [PMID: 21151692 PMCID: PMC2992817 DOI: 10.4061/2010/910283] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 08/18/2010] [Indexed: 12/19/2022] Open
Abstract
Acute and chronic inflammations of mucosal surfaces are complex events in which the effector mechanisms of innate and adaptive immune systems interact with pathogenic and commensal bacteria. The role of constitutive and inducible antimicrobial peptides in intestinal inflammation has been investigated thoroughly over the recent years, and their involvement in various disease states is expanded ever more. Especially in the intestines, a critical balance between luminal bacteria and the antimicrobial peptides is essential, and a breakdown in barrier function by impaired production of defensins is already implicated in Crohn's disease. In this paper, we focus on the role of antimicrobial peptides in inflammatory processes along the gastrointestinal tract, while considering the resident and pathogenic flora encountered at the specific sites. The role of antimicrobial peptides in the primary events of inflammatory bowel diseases receives special attention.
Collapse
Affiliation(s)
- Simon Jäger
- Department of Internal Medicine I, Robert Bosch Hospital, Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376 Stuttgart, Germany
| | | | | |
Collapse
|
|
26
|
Biliary innate immunity: function and modulation. Mediators Inflamm 2010; 2010. [PMID: 20798866 PMCID: PMC2926654 DOI: 10.1155/2010/373878] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 06/22/2010] [Indexed: 12/18/2022] Open
Abstract
Biliary innate immunity is involved in the pathogenesis of cholangiopathies in patients with primary biliary cirrhosis (PBC) and biliary atresia. Biliary epithelial cells possess an innate immune system consisting of the Toll-like receptor (TLR) family and recognize pathogen-associated molecular patterns (PAMPs). Tolerance to bacterial PAMPs such as lipopolysaccharides is also important to maintain homeostasis in the biliary tree, but tolerance to double-stranded RNA (dsRNA) is not found. In PBC, CD4-positive Th17 cells characterized by the secretion of IL-17 are implicated in the chronic inflammation of bile ducts and the presence of Th17 cells around bile ducts is causally associated with the biliary innate immune responses to PAMPs. Moreover, a negative regulator of intracellular TLR signaling, peroxisome proliferator-activated receptor-γ (PPARγ), is involved in the pathogenesis of cholangitis. Immunosuppression using PPARγ ligands may help to attenuate the bile duct damage in PBC patients. In biliary atresia characterized by a progressive, inflammatory, and sclerosing cholangiopathy, dsRNA viruses are speculated to be an etiological agent and to directly induce enhanced biliary apoptosis via the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Moreover, the epithelial-mesenchymal transition (EMT) of biliary epithelial cells is also evoked by the biliary innate immune response to dsRNA.
Collapse
|
|
27
|
O'Hara SP, Splinter PL, Gajdos GB, Trussoni CE, Fernandez-Zapico ME, Chen XM, LaRusso NF. NFkappaB p50-CCAAT/enhancer-binding protein beta (C/EBPbeta)-mediated transcriptional repression of microRNA let-7i following microbial infection. J Biol Chem 2009; 285:216-25. [PMID: 19903813 DOI: 10.1074/jbc.m109.041640] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
MicroRNAs, central players of numerous cellular processes, regulate mRNA stability or translational efficiency. Although these molecular events are established, the mechanisms regulating microRNA function and expression remain largely unknown. The microRNA let-7i regulates Toll-like receptor 4 expression. Here, we identify a novel transcriptional mechanism induced by the protozoan parasite Cryptosporidium parvum and Gram(-) bacteria-derived lipopolysaccharide (LPS) mediating let-7i promoter silencing in human biliary epithelial cells (cholangiocytes). Using cultured cholangiocytes, we show that microbial stimulus decreased let-7i expression, and promoter activity. Analysis of the mechanism revealed that microbial infection promotes the formation of a NFkappaB p50-C/EBPbeta silencer complex in the regulatory sequence. Chromatin immunoprecipitation assays (ChIP) demonstrated that the repressor complex binds to the let-7i promoter following microbial stimulus and promotes histone-H3 deacetylation. Our results provide a novel mechanism of transcriptional regulation of cholangiocyte let-7i expression following microbial insult, a process with potential implications for epithelial innate immune responses in general.
Collapse
Affiliation(s)
- Steven P O'Hara
- Division of Gastroenterology and Hepatology, Miles and Shirley Fiterman Center for Digestive Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA.
| | | | | | | | | | | | | |
Collapse
|
|
28
|
Harada K, Shimoda S, Sato Y, Isse K, Ikeda H, Nakanuma Y. Periductal interleukin-17 production in association with biliary innate immunity contributes to the pathogenesis of cholangiopathy in primary biliary cirrhosis. Clin Exp Immunol 2009; 157:261-70. [PMID: 19604266 DOI: 10.1111/j.1365-2249.2009.03947.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
An innate immune response to bacterial components is speculated to be involved in the pathogenesis of primary biliary cirrhosis (PBC). Recently, CD4-positive T helper type 17 (Th17) cells, characterized by the secretion of interleukin (IL)-17, have been implicated in the pathogenesis of autoimmune diseases. Human Th17 cells are generated from Th0 cells by IL-6 and IL-1 beta and maintained by IL-23. In this study, the role of IL-17 in PBC and its association with biliary innate immunity were examined. Using cultured human biliary epithelial cells (BECs), the expression of Th17-related cytokines and chemokines and changes therein on treatment with pathogen-associated molecular patterns (PAMPs) and IL-17 were examined. Immunohistochemistry for IL-17 and Th17-related cytokines was performed using tissue samples of human liver. Consequently, the expression of IL-6, IL-1 beta, IL-23p19 and IL-23/IL-12p40 mRNAs, and their up-regulation by PAMPs, were found in BECs. Moreover, BECs possessed IL-17-receptors and stimulation with IL-17 induced production of IL-6, IL-1 beta, IL-23p19 and chemokines. Several IL-17-positive cells had infiltrated damaged bile ducts and the expression of IL-6 and IL-1 beta was enhanced in the bile ducts of PBC patients. In conclusion, IL-17-positive cells are associated with the chronic inflammation of bile ducts in PBC which is associated causally with the biliary innate immune responses to PAMPs.
Collapse
Affiliation(s)
- K Harada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | | | | | | | | | | |
Collapse
|
|
29
|
Chuang YH, Lan RY, Gershwin ME. The immunopathology of human biliary cell epithelium. Semin Immunopathol 2009; 31:323-31. [PMID: 19533127 DOI: 10.1007/s00281-009-0172-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Accepted: 06/02/2009] [Indexed: 12/15/2022]
Abstract
Bile ducts lined with biliary epithelial cells, or cholangiocytes, are the main components of the biliary system in liver. Cholangiocytes participate in the production and transport of bile substances, as well as participate in immune responses. Cholangiocytes protect against pathogens by expressing toll-like receptors and anti-microbial peptides; act as antigen-presenting cells by expressing human leukocyte antigen molecules and costimulatory molecules; recruit leukocytes to the target site by expressing adhesion molecules, cytokines, and chemokines; and induce apoptosis of leukocytes to limit the immune responses. Several cholangiopathies result from dysfunctions of the biliary system. They can broadly be divided into autoimmune, genetic, infectious, drug, and ischemic-injury-induced categories. The pathogenesis of many of these cholangiopathies is unclear and treatment is limited. Further understanding of the complexity of the biliary system is critical for medical advancements in this field.
Collapse
Affiliation(s)
- Ya-Hui Chuang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | | | | |
Collapse
|
|
30
|
Abstract
Cholangiocytes, the epithelial cells lining bile ducts, provide the first line of defense against lumenal microbes in the biliary system. Recent advances in biliary immunity indicate that cholangiocytes express a variety of pathogen-recognition receptors and can activate a set of intracellular signaling cascades to initiate a profound antimicrobial defense, including release of proinflammatory cytokines and chemokines, production of antimicrobial peptides and maintenance of biliary epithelial integrity. Cholangiocytes also interact with other cell types in the liver (for example, lymphocytes and Kupffer cells) through expression and release of adhesion molecules and immune mediators. Subsequently, through an intricate feedback mechanism involving both epithelial and other liver cells, a set of intracellular signaling pathways are activated to regulate the functional state of cholangiocyte responses during microbial infection. Thus, cholangiocytes are actively involved in mucosal immunity of the biliary system and represent a fine-tuned, integral component of liver immunity.
Collapse
Affiliation(s)
- Xian-Ming Chen
- Department of Medical Microbiology and Immunology, Creighton University Medical Center, Omaha, NE 68178, USA.
| | | | | |
Collapse
|
|
31
|
Sawada S, Harada K, Isse K, Sato Y, Sasaki M, Kaizaki Y, Nakanuma Y. Involvement of Escherichia coli in pathogenesis of xanthogranulomatous cholecystitis with scavenger receptor class A and CXCL16-CXCR6 interaction. Pathol Int 2007; 57:652-63. [PMID: 17803654 DOI: 10.1111/j.1440-1827.2007.02154.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Xanthogranulomatous cholecystitis (XGC) is characterized by the infiltration of numerous foamy macrophages. Bacterial infection is thought to be involved in the pathogenesis of XGC. Using XGC and cultured murine biliary epithelial cells (BEC), the participation of E. coli and the role of the scavenger receptor class A (SCARA), as well as chemokine(C-X-C motif) ligand 16 (CXCL16) and its receptor chemokine(C-X-C motif) receptor 6 (CXCR6), were examined in the pathogenesis of XGC. E. coli components and genes were detected in XGC on immunohistochemistry and polymerase chain reaction (PCR), respectively. SCARA-recognizing E. coli was found in foamy macrophages aggregated in xanthogranulomatous lesions. CXCL16, which functions as a membrane-bound molecule and soluble chemokine to induce adhesion and migration of CXCR6(+) cells, was detected on gallbladder epithelia, and CXCR6(+)/CD8(+) T cells and CXCR6(+)/CD68(+) macrophages were also accumulated. In cultured BEC, CXCL16 mRNA and secreted soluble CXCL16 were constantly detected and upregulated by treatment with E. coli and lipopolysaccharide through Toll-like receptor 4. These suggest that SCARA in macrophages is involved in the phagocytosis of E. coli followed by foamy changes and that bacterial infection causes the upregulation of CXCL16 in gallbladder epithelia, leading to the chemoattraction of macrophages via CXCL16-CXCR6 interaction and formation of the characteristic histology of XGC.
Collapse
MESH Headings
- Aged
- Aged, 80 and over
- Animals
- Bile Ducts, Intrahepatic/cytology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/pathology
- Cells, Cultured
- Chemokine CXCL16
- Chemokines, CXC/metabolism
- Cholecystitis/metabolism
- Cholecystitis/microbiology
- Cholecystitis/pathology
- Epithelial Cells/cytology
- Epithelial Cells/metabolism
- Escherichia coli/genetics
- Escherichia coli/isolation & purification
- Escherichia coli/pathogenicity
- Female
- Foam Cells/metabolism
- Foam Cells/microbiology
- Genes, Bacterial/genetics
- Granuloma/metabolism
- Granuloma/microbiology
- Granuloma/pathology
- Humans
- Immunohistochemistry
- Male
- Mice
- Middle Aged
- Phagocytosis
- Receptors, CXCR6
- Receptors, Chemokine/metabolism
- Receptors, Scavenger/metabolism
- Receptors, Virus/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Scavenger Receptors, Class A/metabolism
- Up-Regulation
- Xanthomatosis/metabolism
- Xanthomatosis/microbiology
- Xanthomatosis/pathology
Collapse
Affiliation(s)
- Seiko Sawada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | | | | | | | | | | | | |
Collapse
|
|
32
|
Abstract
The intrahepatic biliary tree is a conduit of bile which contains pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS) originated from intestinal flora. Human biliary epithelial cells (BEC) express toll-like receptors (TLR) and intracellular adaptor molecules and secrete antibiotic peptides and (pro)inflammatory cytokines via the activation of nuclear transcription factors. However, although human bile contains several PAMPs in normal as well as diseased livers, PAMPs physiologically do not elicit an inflammatory response in the biliary tree, suggesting that tolerance against commensal PAMPs including LPS (endotoxin tolerance) is important in maintaining the homeostasis of biliary innate immunity. Negative regulators of intracellular TLR signalings, peroxisome proliferator activating receptor-gamma (PPAR-gamma) and IRAK-M, are associated with the endotoxin tolerance in BEC. In vivo, PPAR-gamma and IRAK-M are ubiquitously expressed in intrahepatic biliary epithelium, while the expression of PPAR-gamma is reduced in damaged bile ducts of primary biliary cirrhosis (PBC). In addition to antibiotic peptides, several cytokines andchemokines are also secreted from BEC as an innate immune response and these humoral components participate in attracting immunocytes and modulating peribiliary cytokine milieu. BEC have receptors for several cytokines and the expression of TLR in BEC is affected by cytokines, suggesting that biliary innate immunity is regulated by an acquired immunity. A T-helper (Th)1-type cytokine, interferon-gamma, downregulates PPAR-gamma and upregulates TLR, and consequently increases the susceptibility of biliary innate immunity. Because periductal cytokine milieu in PBC is Th1-dominant, the increased susceptibility to PAMPs may be associated with the development of cholangiopathy in PBC. Biliary innate immunity is speculated to be associated with the pathogenesis of biliary diseases as well as the defense against biliary microbial infection.
Collapse
Affiliation(s)
- Kenichi Harada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | | |
Collapse
|
|
33
|
Chen XM, Splinter PL, O'Hara SP, LaRusso NF. A cellular micro-RNA, let-7i, regulates Toll-like receptor 4 expression and contributes to cholangiocyte immune responses against Cryptosporidium parvum infection. J Biol Chem 2007; 282:28929-28938. [PMID: 17660297 PMCID: PMC2194650 DOI: 10.1074/jbc.m702633200] [Citation(s) in RCA: 373] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptors (TLRs) are important pathogen recognition molecules and are key to epithelial immune responses to microbial infection. However, the molecular mechanisms that regulate TLR expression in epithelia are obscure. Micro-RNAs play important roles in a wide range of biological events through post-transcriptional suppression of target mRNAs. Here we report that human biliary epithelial cells (cholangiocytes) express let-7 family members, micro-RNAs with complementarity to TLR4 mRNA. We found that let-7 regulates TLR4 expression via post-transcriptional suppression in cultured human cholangiocytes. Infection of cultured human cholangiocytes with Cryptosporidium parvum, a parasite that causes intestinal and biliary disease, results in decreased expression of primary let-7i and mature let-7 in a MyD88/NF-kappaB-dependent manner. The decreased let-7 expression is associated with C. parvum-induced up-regulation of TLR4 in infected cells. Moreover, experimentally induced suppression or forced expression of let-7i causes reciprocal alterations in C. parvum-induced TLR4 protein expression, and consequently, infection dynamics of C. parvum in vitro. These results indicate that let-7i regulates TLR4 expression in cholangiocytes and contributes to epithelial immune responses against C. parvum infection. Furthermore, the data raise the possibility that micro-RNA-mediated post-transcriptional pathways may be critical to host-cell regulatory responses to microbial infection in general.
Collapse
Affiliation(s)
- Xian-Ming Chen
- Miles and Shirley Fiterman Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905.
| | - Patrick L Splinter
- Miles and Shirley Fiterman Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Steven P O'Hara
- Miles and Shirley Fiterman Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Nicholas F LaRusso
- Miles and Shirley Fiterman Center for Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905.
| |
Collapse
|
|
34
|
Isse K, Harada K, Nakanuma Y. IL-8 expression by biliary epithelial cells is associated with neutrophilic infiltration and reactive bile ductules. Liver Int 2007; 27:672-80. [PMID: 17498253 DOI: 10.1111/j.1478-3231.2007.01465.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND/AIMS Reactive bile ductule is a non-specific feature of various hepatobiliary diseases, and is not infrequently accompanied by neutrophilic infiltration. Recently, biliary epithelial cells have been shown to secrete cytokines and chemokines and to express components of the mucosal immune system such as Toll-like receptors. METHODS AND RESULTS We examined the expression of a neutrophil chemo-attractant, interluekin (IL)-8, in bile ductular cells to clarify the histogenesis of reactive bile ductules with neutrophilic infiltration using human liver tissues (eight cases of chronic viral hepatitis, seven cases of liver cirrhosis (LC), seven cases of sepsis, 11 cases of extrahepatic biliary obstruction (EBO), three cases of fulminant hepatitis (FH), five cases of primary biliary cirrhosis, and three cases of primary sclerosing cholangitis). Human neutrophil peptides 1-3 (HNP1-3) were used as markers of neutrophils. Immunohistochemically, IL-8 was detected in bile ductules in various diseased livers. HNP1-3-positive neutrophils were significantly dense around IL-8-positive bile ductules compared with IL-8-negative ductules in septic liver, LC, EBO, and FH. Experiments in vitro showed that cultured human biliary epithelial cells expressed and secreted IL-8 in response to lipopolysaccharide and also IL-1beta and tumour necrosis factor-alpha. CONCLUSIONS Neutrophilic infiltration around reactive bile ductules may be related to the IL-8 expressed in bile ductular epithelia, possibly induced by bacterial components and proinflammatory cytokines released locally.
Collapse
Affiliation(s)
- Kumiko Isse
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | | | | |
Collapse
|
|
35
|
Harada K, Isse K, Sato Y, Ozaki S, Nakanuma Y. Endotoxin tolerance in human intrahepatic biliary epithelial cells is induced by upregulation of IRAK-M. Liver Int 2006; 26:935-42. [PMID: 16953833 DOI: 10.1111/j.1478-3231.2006.01325.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND/AIM Biliary epithelial cells possess an innate immune system consisting of Toll-like receptors (TLRs). Although the human bile contains lipopolysaccharide (LPS) in normal as well as diseased livers, LPS physiologically does not elicit an inflammatory response in the biliary tree. This absence of a response to LPS could be due to the 'endotoxin tolerance' speculated to maintain innate immune homeostasis in organs. Our aim here is to clarify the presence and molecular mechanisms of endotoxin tolerance of biliary epithelium. METHODS AND RESULTS In nuclear factor-kappaB (NF-kappaB)-DNA binding assays using three-cultured human intrahepatic biliary epithelial cell (HIBEC) lines, all the cells responded to LPS (TLR4 ligand) by activating NF-kappaB, but pretreatment with LPS for 24 h effectively induced tolerance against any subsequent stimulation with LPS (endotoxin tolerance). This tolerance was also induced by pretreatment with Pam(3)Cys-Ser-(Lys)(4) trihydrochloride (Pam(3)CKS(4), TLR1/2 ligand). Then, real-time polymerase chain treaction and Western blotting revealed that LPS treatment upregulated the expression of IRAK-M (a negative regulator of TLR signaling), but did not affect interleukin-1 receptor-associated kinase-1 (IRAK-1, an essential molecule of TLR signaling), in HIBECs. Moreover, immunohistochemistry revealed that IRAK-M was diffusely expressed in intrahepatic bile ducts. CONCLUSIONS This study showed that the mechanism of endotoxin tolerance exists in the intrahepatic biliary tree and is possibly induced by the expression of IRAK-M in the intrahepatic biliary epithelium, suggesting that the endotoxin tolerance is important in maintaining innate immune biliary homeostasis.
Collapse
Affiliation(s)
- Kenichi Harada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | | | | | | | | |
Collapse
|
|
36
|
Chen XM, O'Hara SP, Nelson JB, Splinter PL, Small AJ, Tietz PS, Limper AH, LaRusso NF. Multiple TLRs are expressed in human cholangiocytes and mediate host epithelial defense responses to Cryptosporidium parvum via activation of NF-kappaB. THE JOURNAL OF IMMUNOLOGY 2006; 175:7447-56. [PMID: 16301652 DOI: 10.4049/jimmunol.175.11.7447] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Infection of epithelial cells by Cryptosporidium parvum triggers a variety of host-cell innate and adaptive immune responses including release of cytokines/chemokines and up-regulation of antimicrobial peptides. The mechanisms that trigger these host-cell responses are unclear. Thus, we evaluated the role of TLRs in host-cell responses during C. parvum infection of cultured human biliary epithelia (i.e., cholangiocytes). We found that normal human cholangiocytes express all known TLRs. C. parvum infection of cultured cholangiocytes induces the selective recruitment of TLR2 and TLR4 to the infection sites. Activation of several downstream effectors of TLRs including IL-1R-associated kinase, p-38, and NF-kappaB was detected in infected cells. Transfection of cholangiocytes with dominant-negative mutants of TLR2 and TLR4, as well as the adaptor molecule myeloid differentiation protein 88 (MyD88), inhibited C. parvum-induced activation of IL-1R-associated kinase, p-38, and NF-kappaB. Short-interfering RNA to TLR2, TLR4, and MyD88 also blocked C. parvum-induced NF-kappaB activation. Moreover, C. parvum selectively up-regulated human beta-defensin-2 in directly infected cells, and inhibition of TLR2 and TLR4 signals or NF-kappaB activation were each associated with a reduction of C. parvum-induced human beta-defensin-2 expression. A significantly higher number of parasites were detected in cells transfected with a MyD88 dominant-negative mutant than in the control cells at 48-96 h after initial exposure to parasites, suggesting MyD88-deficient cells were more susceptible to infection. These findings demonstrate that cholangiocytes express a variety of TLRs, and suggest that TLR2 and TLR4 mediate cholangiocyte defense responses to C. parvum via activation of NF-kappaB.
Collapse
Affiliation(s)
- Xian-Ming Chen
- The Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | | | | | | | | | | | | | | |
Collapse
|