GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Dordrecht :Springer Netherlands,
    Keywords: Liver-Growth-Molecular aspects. ; Electronic books.
    Type of Medium: Online Resource
    Pages: 1 online resource (681 pages)
    Edition: 1st ed.
    ISBN: 9789401149327
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 20 (2004), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background : Insulin sensitizing agents may be useful in treatment of non-alcoholic fatty liver disease.Aim : A pilot study to evaluate the efficacy and safety of metformin in non-alcoholic fatty liver disease.Methods : In an open labelled study, patients with histologically confirmed non-alcoholic fatty liver disease were given metformin (20 mg/kg) for 1 year. Insulin resistance (by log homeostasis assessment model analysis for insulin resistance and Quantitative Insulin Sensitivity Check Index) and post-treatment hepatic histology were compared with pre-treatment histology.Results : Fifteen patients completed 1 year of treatment. During the initial 3 months, there was improvement in alanine aminotransferase and aspartate aminotransferase (P-value 0.01 and 0.02, respectively) along with improvement in insulin sensitivity. However, after 3 months, there was no further improvement in insulin sensitivity and there was gradual rise in aspartate aminotransferase and alanine aminotransferase back to pre-treatment levels. Among the 10 patients with post-treatment biopsy, three (33%), showed improvement in steatosis, two (20%) showed improvement in inflammation score and one (10%) showed improvement in fibrosis.Conclusion : Metformin treatment was associated with only a transient improvement in liver chemistries. A progressive, sustainable reduction in insulin sensitivity was not noted during treatment.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2013-12-16
    Description: The outcome of liver injury is determined by the success of repair. Liver repair involves replacement of damaged liver tissue with healthy liver epithelial cells (including both hepatocytes and cholangiocytes) and reconstruction of normal liver structure and function. Current dogma posits that replication of surviving mature hepatocytes and cholangiocytes drives the regeneration of liver epithelium after injury, whereas failure of liver repair commonly leads to fibrosis, a scarring condition in which hepatic stellate cells, the main liver-resident mesenchymal cells, play the major role. The present review discusses other mechanisms that might be responsible for the regeneration of new liver epithelial cells and outgrowth of matrix-producing mesenchymal cells during hepatic injury. This theory proposes that, during liver injury, some epithelial cells undergo epithelial-to-mesenchymal transition (EMT), acquire myofibroblastic phenotypes/features, and contribute to fibrogenesis, whereas certain mesenchymal cells (namely hepatic stellate cells and stellate cell-derived myofibroblasts) undergo mesenchymal-to-epithelial transition (MET), revert to epithelial cells, and ultimately differentiate into either hepatocytes or cholangiocytes. Although this theory is highly controversial, it suggests that the balance between EMT and MET modulates the outcome of liver injury. This review summarizes recent advances that support or refute the concept that certain types of liver cells are capable of phenotype transition (i.e., EMT and MET) during both culture conditions and chronic liver injury.
    Print ISSN: 0193-1857
    Electronic ISSN: 1522-1547
    Topics: Medicine
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2016-03-10
    Description: Objective The ductular reaction (DR) involves mobilisation of reactive-appearing duct-like cells (RDC) along canals of Hering, and myofibroblastic (MF) differentiation of hepatic stellate cells (HSC) in the space of Disse. Perivascular cells in stem cell niches produce pleiotrophin (PTN) to inactivate the PTN receptor, protein tyrosine phosphatase receptor zeta-1 (PTPRZ1), thereby augmenting phosphoprotein-dependent signalling. We hypothesised that the DR is regulated by PTN/PTPRZ1 signalling. Design PTN-GFP, PTN-knockout (KO), PTPRZ1-KO, and wild type (WT) mice were examined before and after bile duct ligation (BDL) for PTN, PTPRZ1 and the DR. RDC and HSC from WT, PTN-KO, and PTPRZ1-KO mice were also treated with PTN to determine effects on downstream signaling phosphoproteins, gene expression, growth, and migration. Liver biopsies from patients with DRs were also interrogated. Results Although quiescent HSC and RDC lines expressed PTN and PTPRZ1 mRNAs, neither PTN nor PTPRZ1 protein was demonstrated in healthy liver. BDL induced PTN in MF-HSC and increased PTPRZ1 in MF-HSC and RDC. In WT mice, BDL triggered a DR characterised by periportal accumulation of collagen, RDC and MF-HSC. All aspects of this DR were increased in PTN-KO mice and suppresse d in PTPRZ1-KO mice. In vitro studies revealed PTN-dependent accumulation of phosphoproteins that control cell-cell adhesion and migration, with resultant inhibition of cell migration. PTPRZ1-positive cells were prominent in the DRs of patients with ductal plate defects and adult cholestatic diseases. Conclusions PTN, and its receptor, PTPRZ1, regulate the DR to liver injury by controlling the migration of resident cells in adult liver progenitor niches.
    Keywords: Pancreas and biliary tract, Open access
    Print ISSN: 0017-5749
    Electronic ISSN: 1468-3288
    Topics: Medicine
    Published by BMJ Publishing Group
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2012-08-14
    Description: Objective Immune responses are important in dictating non-alcoholic steatohepatitis (NASH) outcome. We previously reported that upregulation of hedgehog (Hh) and osteopontin (OPN) occurs in NASH, that Hh-regulated accumulation of natural killer T (NKT) cells promotes hepatic stellate cell (HSC) activation, and that cirrhotic livers harbour large numbers of NKT cells. Design The hypothesis that activated NKT cells drive fibrogenesis during NASH was evaluated by assessing if NKT depletion protects against NASH fibrosis; identifying the NKT-associated fibrogenic factors; and correlating plasma levels of the NKT cell-associated factor OPN with fibrosis severity in mice and humans. Results When fed methionine-choline-deficient (MCD) diets for 8 weeks, wild type (WT) mice exhibited Hh pathway activation, enhanced OPN expression, and NASH-fibrosis. Ja18-/- and CD1d-/- mice which lack NKT cells had significantly attenuated Hh and OPN expression and dramatically less fibrosis. Liver mononuclear cells (LMNCs) from MCD diet fed WT mice contained activated NKT cells, generated Hh and OPN, and stimulated HSCs to become myofibroblasts; neutralising these factors abrogated the fibrogenic actions of WT LMNCs. LMNCs from NKT-cell-deficient mice were deficient in fibrogenic factors, failing to activate collagen gene expression in HSCs. Human NASH livers with advanced fibrosis contained more OPN and Hh protein than those with early fibrosis. Plasma levels of OPN mirrored hepatic OPN expression and correlated with fibrosis severity. Conclusion Hepatic NKT cells drive production of OPN and Hh ligands that promote fibrogenesis during NASH. Associated increases in plasma levels of OPN may provide a biomarker of NASH fibrosis.
    Keywords: Nonalcoholic steatosis, Editor's choice
    Print ISSN: 0017-5749
    Electronic ISSN: 1468-3288
    Topics: Medicine
    Published by BMJ Publishing Group
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2014-07-09
    Description: Objective Smoothened (SMO), a coreceptor of the Hedgehog (Hh) pathway, promotes fibrogenic repair of chronic liver injury. We investigated the roles of SMO+ myofibroblast (MF) in liver regeneration by conditional deletion of SMO in α smooth muscle actin (αSMA)+ cells after partial hepatectomy (PH). Design αSMA-Cre-ER T2 x SMO/flox mice were treated with vehicle (VEH) or tamoxifen (TMX), and sacrificed 24–96 h post-PH. Regenerating livers were analysed for proliferation, progenitors and fibrosis by qRT-PCR and quantitative immunohistochemistry (IHC). Results were normalised to liver segments resected at PH. For lineage-tracing studies, αSMA-Cre-ER T2 x ROSA-Stop-flox-yellow fluorescent protein (YFP) mice were treated with VEH or TMX; livers were stained for YFP, and hepatocytes isolated 48 and 72 h post-PH were analysed for YFP by flow cytometric analysis (FACS). Results Post-PH, VEH-αSMA-SMO mice increased expression of Hh-genes, transiently accumulated MF, fibrosis and liver progenitors, and ultimately exhibited proliferation of hepatocytes and cholangiocytes. In contrast, TMX-αSMA-SMO mice showed loss of whole liver SMO expression, repression of Hh-genes, enhanced accumulation of quiescent HSC but reduced accumulation of MF, fibrosis and progenitors, as well as inhibition of hepatocyte and cholangiocyte proliferation, and reduced recovery of liver weight. In TMX-αSMA-YFP mice, many progenitors, cholangiocytes and up to 25% of hepatocytes were YFP+ by 48–72 h after PH, indicating that liver epithelial cells were derived from αSMA-YFP+ cells. Conclusions Hh signalling promotes transition of quiescent hepatic stellate cells to fibrogenic MF, some of which become progenitors that regenerate the liver epithelial compartment after PH. Hence, scarring is a component of successful liver regeneration.
    Print ISSN: 0017-5749
    Electronic ISSN: 1468-3288
    Topics: Medicine
    Published by BMJ Publishing Group
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2013-12-16
    Description: Recent studies indicate that metabolic oxidative stress, autophagy, and inflammation are hallmarks of nonalcoholic steatohepatitis (NASH) progression. However, the molecular mechanisms that link these important events in NASH remain unclear. In this study, we investigated the mechanistic role of purinergic receptor X7 (P2X7) in modulating autophagy and resultant inflammation in NASH in response to metabolic oxidative stress. The study uses two rodent models of NASH. In one of them, a CYP2E1 substrate bromodichloromethane is used to induce metabolic oxidative stress and NASH. Methyl choline-deficient diet feeding is used for the other NASH model. CYP2E1 and P2X7 receptor gene-deleted mice are used to establish their roles in regulating metabolic oxidative stress and autophagy. Autophagy gene expression, protein levels, confocal microscopy based-immunolocalization of lysosome-associated membrane protein (LAMP)2A and histopathological analysis were performed. CYP2E1-dependent metabolic oxidative stress induced increases in P2X7 receptor expression and chaperone-mediated autophagy markers LAMP2A and heat shock cognate 70 but caused depletion of light chain 3 isoform B (LC3B) protein levels. P2X7 receptor gene deletion significantly decreased LAMP2A and inflammatory indicators while significantly increasing LC3B protein levels compared with wild-type mice treated with bromodichloromethane. P2X7 receptor-deleted mice were also protected from NASH pathology as evidenced by decreased inflammation and fibrosis. Our studies establish that P2X7 receptor is a key regulator of autophagy induced by metabolic oxidative stress in NASH, thereby modulating hepatic inflammation. Furthermore, our findings presented here form a basis for P2X7 receptor as a potential therapeutic target in the treatment for NASH.
    Print ISSN: 0193-1857
    Electronic ISSN: 1522-1547
    Topics: Medicine
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2013-01-05
    Description: Objective Vascular remodelling during liver damage involves loss of healthy liver sinusoidal endothelial cell (LSEC) phenotype via capillarisation. Hedgehog (Hh) signalling regulates vascular development and increases during liver injury. This study therefore examined its role in capillarisation. Design Primary LSEC were cultured for 5 days to induce capillarisation. Pharmacological, antibody-mediated and genetic approaches were used to manipulate Hh signalling. Effects on mRNA and protein expression of Hh-regulated genes and capillarisation markers were evaluated by quantitative reverse transcription PCR and immunoblot. Changes in LSEC function were assessed by migration and tube forming assay, and gain/loss of fenestrae was examined by electron microscopy. Mice with acute or chronic liver injury were treated with Hh inhibitors; effects on capillarisation were assessed by immunohistochemistry. Results Freshly isolated LSEC expressed Hh ligands, Hh receptors and Hh ligand antagonist Hhip. Capillarisation was accompanied by repression of Hhip and increased expression of Hh-regulated genes. Treatment with Hh agonist further induced expression of Hh ligands and Hh-regulated genes, and upregulated capillarisation-associated genes; whereas Hh signalling antagonist or Hh ligand neutralising antibody each repressed expression of Hh target genes and capillarisation markers. LSEC isolated from Smo loxP/loxP transgenic mice that had been infected with adenovirus expressing Cre-recombinase to delete Smoothened showed over 75% knockdown of Smoothened. During culture, Smoothened-deficient LSEC had inhibited Hh signalling, less induction of capillarisation-associated genes and retention of fenestrae. In mice with injured livers, inhibiting Hh signalling prevented capillarisation. Conclusions LSEC produce and respond to Hh ligands, and use Hh signalling to regulate complex phenotypic changes that occur during capillarisation.
    Print ISSN: 0017-5749
    Electronic ISSN: 1468-3288
    Topics: Medicine
    Published by BMJ Publishing Group
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2012-11-16
    Description: The hepatitis B virus (HBV) encoded X protein (HBx) contributes centrally to the pathogenesis of hepatocellular carcinoma (HCC). Aberrant activation of the Hedgehog (Hh) pathway has been linked to many tumor types including HCC. Thus, experiments were designed to test the hypothesis that HBx promotes HCC via activation of Hh signaling. HBx expression correlated with an upregulation of Hh markers in human liver cancer cell lines, in liver samples from HBV infected patients with HCC, and in the livers of HBx transgenic mice (HBxTg) that develop hepatitis, steatosis, and dysplasia, culminating in the appearance of HCC. The findings in human samples provide clinical validation for the in vitro results and those in the HBxTg. Blockade of Hh signaling inhibited HBx stimulation of cell migration, anchorage-independent growth, tumor development in HBxTg, and xenograft growth in nude mice. Results suggest that the ability of HBx to promote cancer is at least partially dependent upon the activation of the Hh pathway. This study provides biologic evidence for the role of Hh signaling in the pathogenesis of HBV-mediated HCC and suggests cause and effect for the first time. The observation that inhibition of Hh signaling partially blocked the ability of HBx to promote growth and migration in vitro and tumorigenesis in two animal models implies that Hh signaling may represent an “oncogene addiction” pathway for HBV-associated HCC. This work could be central to designing specific treatments that target early development and progression of HBx-mediated HCC. Cancer Res; 72(22); 5912–20. ©2012 AACR.
    Print ISSN: 0008-5472
    Electronic ISSN: 1538-7445
    Topics: Medicine
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2013-04-02
    Description: Choline metabolism is important for very low-density lipoprotein secretion, making this nutritional pathway an important contributor to hepatic lipid balance. The purpose of this study was to assess whether the cumulative effects of multiple single nucleotide polymorphisms (SNPs) across genes of choline/1-carbon metabolism and functionally related pathways increase susceptibility to developing hepatic steatosis. In biopsy-characterized cases of nonalcoholic fatty liver disease and controls, we assessed 260 SNPs across 21 genes in choline/1-carbon metabolism. When SNPs were examined individually, using logistic regression, we only identified a single SNP ( PNPLA3 rs738409) that was significantly associated with severity of hepatic steatosis after adjusting for confounders and multiple comparisons ( P =0.02). However, when groupings of SNPs in similar metabolic pathways were defined using unsupervised hierarchical clustering, we identified groups of subjects with shared SNP signatures that were significantly correlated with steatosis burden ( P =0.0002). The lowest and highest steatosis clusters could also be differentiated by ethnicity. However, unique SNP patterns defined steatosis burden irrespective of ethnicity. Our results suggest that analysis of SNP patterns in genes of choline/1-carbon metabolism may be useful for prediction of severity of steatosis in specific subsets of people, and the metabolic inefficiencies caused by these SNPs should be examined further.—Corbin, K. D., Abdelmalek, M. F., Spencer, M. D., da Costa, K.-A., Galanko, J. A., Sha, W., Suzuki, A., Guy, C. D., Cardona, D. M., Torquati, A., Diehl, A. M., Zeisel, S. H. Genetic signatures in choline and 1-carbon metabolism are associated with the severity of hepatic steatosis.
    Print ISSN: 0892-6638
    Electronic ISSN: 1530-6860
    Topics: Biology
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...