Time filter

Source Type

Schrumpf E.,University of Oslo | Jiang X.,University of Oslo | Zeissig S.,TU Dresden | Pollheimer M.J.,Research Unit for Experimental and Molecular Hepatology | And 8 more authors.
Physiological Reports | Year: 2017

Natural killer T (NKT) cells are activated by lipid antigens presented by CD1d molecules and represent a major lymphocyte subset of the liver. NOD.c3c4 mice spontaneously develop biliary inflammation in extra- and intrahepatic bile ducts. We demonstrated by flow cytometry that invariant NKT (iNKT) cells were more abundant in the thymus, spleen, and liver of NOD.c3c4 mice compared to NOD mice. iNKT cells in NOD.c3c4 mice displayed an activated phenotype. Further, NOD and NOD.Cd1d-/- mice were irradiated and injected with NOD.c3c4 bone marrow, and injection of NOD.c3c4 bone marrow resulted in biliary infiltrates independently of CD1d expression in recipient mice. Activation or blocking of NKT cells with α-galactosylceramide or anti-CD1d antibody injections did not affect the biliary phenotype of NOD.c3c4 mice. NOD.c3c4.Cd1d-/- mice were generated by crossing NOD.Cd1d-/- mice onto a NOD.c3c4 background. NOD.c3c4.Cd1d-/- and NOD.c3c4 mice developed the same extent of biliary disease. This study demonstrates that iNKT cells are more abundant and activated in the NOD.c3c4 model. The portal inflammation of NOD.c3c4 mice can be transferred to irradiated recipients, which suggests an immune-driven disease. Our findings imply that NKT cells can potentially participate in the biliary inflammation, but are not the primary drivers of disease in NOD.c3c4 mice. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.


Pollheimer M.J.,Research Unit for Experimental and Molecular Hepatology | Pollheimer M.J.,Medical University of Graz | Fickert P.,Research Unit for Experimental and Molecular Hepatology | Fickert P.,Medical University of Graz
Clinical Reviews in Allergy and Immunology | Year: 2015

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are immune-mediated cholangiopathies with enigmatic etiology and pathogenesis. They have distinct clinical, laboratory, immunological, and histomorphological characteristics. Well-characterized animal models for PBC and PSC are utterly needed to develop novel pathogenetic concepts and to study innovative treatment strategies. The aim of the current paper is to outline the characteristics of ideal PBC and PSC animal models and to contrast this with a real-life up-to-date overview of currently available mouse models. Although some of this models show several individual characteristics of PBC and PSC, it is obvious that all of them have substantial and important limitations. Nevertheless, some may be beneficial to study certain pathophysiological aspects. Potential cholangiopathy animal models should be systematically investigated in regard to elevated serum alkaline phosphatase, bilirubin, and bile acid levels; immunological abnormalities; and longitudinal studies in regard to their liver phenotype. We herein propose a common systematic workup for potential models based on the fact that there are some intriguing disease combinations in specific genetically modified mice and recommend a stepwise process in regard to model characterization with methodical harvesting and screening of numerous organs for potential concomitant diseases. Due to the complex nature of both cholangiopathies, it seems to be very likely that no single perfect PBC or PSC model will ever be generated. The models outlined herein will certainly help to clarify specific pathogenetic aspects and even more important may turn out to be suitable to test potential drugs for treatment. © 2014, Springer Science+Business Media New York.


Reiter F.P.,Ludwig Maximilians University of Munich | Wimmer R.,Ludwig Maximilians University of Munich | Wottke L.,Ludwig Maximilians University of Munich | Artmann R.,Ludwig Maximilians University of Munich | And 9 more authors.
World Journal of Hepatology | Year: 2016

AIM: To study the interleukin-1 (IL-1) pathway as a therapeutic target for liver fibrosis in vitro and in vivo using the ATP-binding cassette transporter b4-/- (Abcb4-/-) mouse model. METHODS: Female and male Abcb4-/- mice from 6 to 13 mo of age were analysed for the degree of cholestasis (liver serum tests), extent of liver fibrosis (hydroxyproline content and Sirius red staining) and tissue-specific activation of signalling pathways such as the IL-1 pathway [quantitative polymerase chain reaction (qPCR)]. For in vivo experiments, murine hepatic stellate cells (HSCs) were isolated via pronasecollagenase perfusion followed by density gradient centrifugation using female mice. Murine HSCs were stimulated with up to 1 ng/mL IL-1β with or without 2.5 μg/mL Anakinra, an IL-1 receptor antagonist, respectively. The proliferation of murine HSCs was assessed via the BrdU assay. The toxicity of Anakinra was evaluated via the fluorescein diacetate hydrolysis (FDH) assay. In vivo 8-wk-old Abcb4-/- mice with an already fully established hepatic phenotype were treated with Anakinra (1 mg/kg body-weight daily intraperitoneally) or vehicle and liver injury and liver fibrosis were evaluated via serum tests, qPCR, hydroxyproline content and Sirius red staining. RESULTS: Liver fibrosis was less pronounced in males than in female Abcb4-/- animals as defined by a lower hydroxyproline content (274 ± 64 μg/g vs 436 ± 80 μg/g liver, respectively; n = 13-15; P < 0.001; Mann- Whitney U -test) and lower mRNA expression of the profibrogenic tissue inhibitor of metalloproteinase-1 (TIMP) (1 ± 0.41 vs 0.66 ± 0.33 fold, respectively; n = 13-15; P < 0.05; Mann-Whitney U -test). Reduced liver fibrosis was associated with significantly lower levels of F4/80 mRNA expression (1 ± 0.28 vs 0.71 ± 0.41 fold, respectively; n = 12-15; P < 0.05; Mann-Whitney U -test) and significantly lower IL-1β mRNA expression levels (1 ± 0.38 vs 0.44 ± 0.26 fold, respectively; n = 13-15; P < 0.001; Mann-Whitney U -test). No gender differences in the serum liver parameters [bilirubin; alanine aminotransferase (ALT); aspartate aminotransferase and alkaline phosphatase (AP)] were found. In vitro , the administration of IL-1β resulted in a significant increase in HSC proliferation [0.94 ± 0.72 arbitrary units (A.U.) in untreated controls, 1.12 ± 0.80 A.U. at an IL-1β concentration of 0.1 ng/mL and 1.18 ± 0.73 A.U. at an IL-1β concentration of 1 ng/mL in samples from n = 6 donor animals; P < 0.001; analyses of variance (ANOVA)]. Proliferation was reduced significantly by the addition of 2.5 μg/mL Anakinra (0.81 ± 0.60 A.U. in untreated controls, 0.92 ± 0.68 A.U. at an IL-1β concentration of 0.1 ng/mL, and 0.91 ± 0.69 A.U. at an IL-1β concentration of 1 ng/mL; in samples from n = 6 donor animals; P < 0.001; ANOVA) suggesting an anti-proliferative effect of this clinically approved IL-1 receptor antagonist. The FDH assay showed this dose to be non-toxic in HSCs. In vivo , Anakinra had no effect on the hepatic hydroxyproline content, liver serum tests (ALT and AP) and profibrotic (collagen 1α1, collagen 1α2, transforming growth factor-β, and TIMP-1) and anti-fibrotic [matrix metalloproteinase 2 (MMP2 ), MMP9 and MMP13 ] gene expression after 4 wk of treatment. Furthermore, the hepatic IL-1β and F4/80 mRNA expression levels were unaffected by Anakinra treatment. CONCLUSION: IL-1β expression is associated with the degree of liver fibrosis in Abcb4-/- mice and promotes HSC proliferation. IL-1 antagonism shows antifibrotic effects in vitro but not in Abcb4-/- mice. © The Author(s) 2016.


Krones E.,Research Unit for Experimental and Molecular Hepatology | Wagner M.,Research Unit for Experimental and Molecular Hepatology | Eller K.,Medical University of Graz | Rosenkranz A.R.,Medical University of Graz | And 2 more authors.
Digestive Diseases | Year: 2014

Kidney injury in deeply jaundiced patients became known as cholemic nephropathy. This umbrella term covers impaired renal function in cholestatic patients with characteristic histomorphological changes including intratubular cast formation and tubular epithelial cell injury. Cholemic nephropathy represents a widely underestimated but important cause of kidney dysfunction in patients with cholestasis and advanced liver disease. However, the nomenclature is inconsistent since there are numerous synonyms used; the underlying mechanisms of cholemic nephropathy are not entirely clear, and widely accepted diagnostic criteria are still missing. Consequently, the current article aims to summarize the present knowledge on the clinical and morphological characteristics, available preclinical models, derived potential pathomechanisms, and future diagnostic and therapeutic strategies in cholemic nephropathy. Furthermore, we provide a potential research agenda for this evolving field. © 2015 S. Karger AG, Basel.


PubMed | Research Unit for Experimental and Molecular Hepatology
Type: Journal Article | Journal: Clinical reviews in allergy & immunology | Year: 2015

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are immune-mediated cholangiopathies with enigmatic etiology and pathogenesis. They have distinct clinical, laboratory, immunological, and histomorphological characteristics. Well-characterized animal models for PBC and PSC are utterly needed to develop novel pathogenetic concepts and to study innovative treatment strategies. The aim of the current paper is to outline the characteristics of ideal PBC and PSC animal models and to contrast this with a real-life up-to-date overview of currently available mouse models. Although some of this models show several individual characteristics of PBC and PSC, it is obvious that all of them have substantial and important limitations. Nevertheless, some may be beneficial to study certain pathophysiological aspects. Potential cholangiopathy animal models should be systematically investigated in regard to elevated serum alkaline phosphatase, bilirubin, and bile acid levels; immunological abnormalities; and longitudinal studies in regard to their liver phenotype. We herein propose a common systematic workup for potential models based on the fact that there are some intriguing disease combinations in specific genetically modified mice and recommend a stepwise process in regard to model characterization with methodical harvesting and screening of numerous organs for potential concomitant diseases. Due to the complex nature of both cholangiopathies, it seems to be very likely that no single perfect PBC or PSC model will ever be generated. The models outlined herein will certainly help to clarify specific pathogenetic aspects and even more important may turn out to be suitable to test potential drugs for treatment.

Loading Research Unit for Experimental and Molecular Hepatology collaborators
Loading Research Unit for Experimental and Molecular Hepatology collaborators