title: Nlrp3 Activation Induces Il-18 Synthesis and Affects the Epithelial Barrier Function in Reactive Cholangiocytes.
abstract: Microbial products are thought to influence the progression of cholangiopathies, in particular primary sclerosing cholangitis (PSC). Inflammasomes are molecular platforms that respond to microbial products through the synthesis of proinflammatory cytokines. We investigated the role of inflammasome activation in cholangiocyte response to injury. Nucleotide-binding oligomerization domain (NOD)-like receptor family, pyrin domain-containing protein 3 (Nlrp3) expression was tested in cholangiocytes of normal and cholestatic livers. Effects of Nlrp3 activation induced by incubation with lipopolysaccharide and ATP was studied in vitro in normal and siRNA-Nlrp3 knocked-down cholangiocytes. Wild-type and Nlrp3 knockout (Nlrp3-/-) mice were fed 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC; a model of sclerosing cholangitis) for 4 weeks. Nlrp3 and its components were overexpressed in cholangiocytes of mice subjected to DDC and in patients affected by PSC. In vitro, Nlrp3 activation stimulated expression of Il-18 but not of Il-1β and Il-6. Nlrp3 activation had no effect on cholangiocyte proliferation but significantly decreased the expression of Zonulin-1 and E-cadherin, whereas Nlrp3 knockdown increased the permeability of cholangiocyte monolayers. In vivo, the DDC-stimulated number of cytokeratin-19-positive cells in the liver of wild-type animals was slightly reduced in Nlrp3-/-mice, and expression of E-cadherin was reestablished. In conclusion, Nlrp3 is expressed in reactive cholangiocytes, in both murine models and patients with PSC. Activation of Nlrp3 leads to synthesis of proinflammatory cytokines and influences epithelial integrity of cholangiocytes.
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy. Electronic address: luca.maroni@live.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Maroni
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Agostinelli
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Saccomanno
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Pinto
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Debora M
authors.initials: DM
authors.lastname: Giordano
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Rychlicki
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Samuele
authors.initials: S
authors.lastname: De Minicis
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Trozzi
authors.affiliation: Department of Liver and Gastrointestinal Diseases, Biodonostia Health Research Institute-Donostia University Hospital, Ikerbasque, CIBERehd, University of the Basque Country (UPV/EHU), San Sebastian, Spain.
authors.forename: Jesus M
authors.initials: JM
authors.lastname: Banales
authors.affiliation: Division of Surgery, Inflammatory Medicine and Transplantation, Norwegian PSC Research Center, Oslo University Hospital, Rikshospitalet, Oslo, Norway; K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Division of Surgery, Inflammatory Medicine and Transplantation, Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Melum
authors.affiliation: Division of Surgery, Inflammatory Medicine and Transplantation, Norwegian PSC Research Center, Oslo University Hospital, Rikshospitalet, Oslo, Norway; K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Division of Surgery, Inflammatory Medicine and Transplantation, Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Tom H
authors.initials: TH
authors.lastname: Karlsen
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Benedetti
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Gianluca Svegliati
authors.initials: GS
authors.lastname: Baroni
authors.affiliation: Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Marzioni
mesh_terms: D000818:Animals; D015209:Cholangitis, Sclerosing / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D015151:Immunoblotting; D058847:Inflammasomes / Q000378:metabolism; D020382:Interleukin-18 / Q000096:biosynthesis*; D051379:Mice; D018345:Mice, Knockout; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D058847:Inflammasomes; D020382:Interleukin-18; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein