TGR5 is essential for bile acid-dependent cholangiocyte proliferation in vivo and in vitro
| Autor: | Annika Sommerfeld, Ertan Mayatepek, Caroline Klindt, K Deutschmann, Diran Herebian, Verena Keitel, Stefanie Kluge, M Reich, Wolfram T. Knoefel, Ralf Kubitz, Dieter Häussinger, Christoph Ullmer |
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| Rok vydání: | 2015 |
| Předmět: |
Male
0301 basic medicine MAPK/ERK pathway medicine.medical_specialty Cholangiocyte proliferation Apoptosis Receptors G-Protein-Coupled Bile Acids and Salts Cholangiocarcinoma Mice 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Cell Line Tumor Internal medicine medicine Animals Humans Epidermal growth factor receptor Ligation Cell Proliferation Common Bile Duct Mice Knockout biology Cell growth Gastroenterology Fas receptor G protein-coupled bile acid receptor Cell biology 030104 developmental biology Endocrinology Bile Duct Neoplasms chemistry biology.protein 030211 gastroenterology & hepatology Taurolithocholic acid |
| Zdroj: | Gut. 65:487-501 |
| ISSN: | 1468-3288 0017-5749 |
| DOI: | 10.1136/gutjnl-2015-309458 |
| Popis: | Objective Cholestatic liver diseases in humans as well as bile acid (BA)-feeding and common bile duct ligation (CBDL) in rodents trigger hyperplasia of cholangiocytes within the portal fields. Furthermore, elevation of BA levels enhances proliferation and invasiveness of cholangiocarcinoma (CCA) cells in animal models, thus promoting tumour progression. TGR5 is a G-protein coupled BA receptor, which is highly expressed in cholangiocytes and postulated to mediate the proliferative effects of BA. Design BA-dependent cholangiocyte proliferation was examined in TGR5-knockout and wild type mice following cholic acid (CA)-feeding and CBDL. TGR5-dependent proliferation and protection from apoptosis was studied in isolated cholangiocytes and CCA cell lines following stimulation with TGR5 ligands and kinase inhibitors. TGR5 expression was analysed in human CCA tissue. Results Cholangiocyte proliferation was significantly reduced in TGR5-knockout mice in response to CA-feeding and CBDL. Taurolithocholic acid and TGR5-selective agonists induced cholangiocyte proliferation through elevation of reactive oxygen species and cSrc mediated epidermal growth factor receptor transactivation and subsequent Erk1/2 phosphorylation only in wild type but not in TGR5-knockout-derived cells. In human CCA tissue TGR5 was overexpressed and the pathway of TGR5-dependent proliferation via epidermal growth factor receptor and extracellular signal-regulated kinase (ERK)1/2 activation also translated to CCA cell lines. Furthermore, apoptosis was inhibited by TGR5-dependent CD95 receptor serine phosphorylation. Conclusions TGR5 is an important mediator of BA-induced cholangiocyte proliferation in vivo and in vitro. Furthermore, TGR5 protects cholangiocytes from death receptor-mediated apoptosis. These mechanisms may protect cholangiocytes from BA toxicity under cholestatic conditions, however, they may trigger proliferation and apoptosis resistance in malignantly transformed cholangiocytes, thus promoting CCA progression. |
| Databáze: | OpenAIRE |
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