Andree Zibert

Universitätsklinikum Münster, Muenster, North Rhine-Westphalia, Germany

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Publications (27)96.67 Total impact


  • No preview · Article · Dec 2015 · Zeitschrift für Gastroenterologie

  • No preview · Article · Apr 2015 · Journal of Hepatology

  • No preview · Article · Apr 2015 · Journal of Hepatology
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    Preview · Article · Nov 2014
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    ABSTRACT: Background Wilson disease (WD) is caused by accumulation of excess copper (Cu) due to a mutation in the gene encoding the liver Cu transporter ATP7B, and is characterized by acute liver failure or cirrhosis and neuronal cell death. We investigated the effect of OSIP108, a plant derived decapeptide that prevents Cu-induced apoptosis in yeast and human cells, on Cu-induced toxicity in various mammalian in vitro models relevant for WD and in a Cu-toxicity zebrafish larvae model applicable to WD. Methods The effect of OSIP108 was evaluated on viability of various cell lines in presence of excess Cu, on liver morphology of a Cu-treated zebrafish larvae strain that expresses a fluorescent reporter in hepatocytes, and on oxidative stress levels in wild type AB zebrafish larvae. Results OSIP108 increased viability of Cu-treated CHO cells transgenically expressing ATP7B and the common WD-causing mutant ATP7BH1069Q, but also viability of Cu-treated human glioblastoma U87 cells. Aberrancies in liver morphology of Cu-treated zebrafish larvae were observed, which were further confirmed as Cu-induced hepatotoxicity by liver histology. Injections of OSIP108 into Cu-treated zebrafish larvae significantly increased the amount of larvae with normal liver morphology, and decreased Cu-induced production of reactive oxygen species. Conclusions OSIP108 prevents Cu-induced toxicity in in vitro models and in a Cu-toxicity zebrafish larvae model applicable to WD. General significance All the above data indicate the potential of OSIP108 as a drug lead for further development as a novel WD treatment.
    Full-text · Article · Oct 2014 · Toxicology and Applied Pharmacology
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    ABSTRACT: Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophies affecting approximately 1:3500 male live births. Deletion of the dystrophin gene accounts for approximately 65% of mutations, duplications occur in 6–10% while the remaining 20–30% are point mutations, small deletion/insertions, or splicing mutations. Aim To study non-deletion mutations in a sample of Egyptian patients with DMD as most previous studies focused on deletion mutations. Patients and methods The study included 25 patients with DMD from 18 different families from the genetics clinic, Children’s Hospital, Ain Shams University. Diagnosis was made based on typical clinical findings, high CPK and EMG result. Molecular analysis included Polymerase Chain Reaction (PCR) followed by multiplex ligation-dependent probe amplification (MLPA) to those patients with no deletion by PCR. Direct sequencing of the whole dystrophin gene was done to those patients who had no deletion or duplication by the previous 2 methods. Results Non-deletion mutation included duplications (5 families (27.8%)) which are higher than previously reported and point mutation (c.583C>T) in only one family. Deletion mutations were found in 9 families (50%) and no mutation found in 3 families (16.7%). Interestingly, 60% of the duplications were located in the distal region of the dystrophin gene. A frame shift mutation was identified in most patients (93%) except one with duplication of exons 50–51 who had an unexpected severe disease with an early age of onset. Also, an intragenic deletion involving the 5′ end of the dystrophin gene (deletion of muscle protomor and exon 1) was found in another patient with severe disease without cardiac involvement. Conclusion The relative higher frequency of duplication mutations in Egyptian patients with DMD may indicate that MLPA and not PCR should be preferred for molecular testing of Egyptian patients with DMD.
    Full-text · Article · Jul 2014 · Egyptian Journal of Medical Human Genetics
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    ABSTRACT: We previously identified the Arabidopsis thaliana–derived decapeptide OSIP108, which increases tolerance of plants and yeast cells to oxidative stress. As excess copper (Cu) is known to induce oxidative stress and apoptosis, and is characteristic for the human pathology Wilson disease, we investigated the effect of OSIP108 on Cu-induced toxicity in yeast. We found that OSIP108 increased yeast viability in presence of toxic Cu concentrations, and decreased the prevalence of Cu-induced apoptotic markers. Next, we translated these results to the human hepatoma HepG2 cell line, demonstrating anti-apoptotic activity of OSIP108 in this cell line. In addition, we found that OSIP108 did not affect intracellular Cu levels in HepG2 cells, but preserved HepG2 mitochondrial ultrastructure. As Cu is known to induce acid sphingomyelinase activity of HepG2 cells, we performed a sphingolipidomic analysis of OSIP108-treated HepG2 cells. We demonstrated that OSIP108 decreased the levels of several sphingoid bases and ceramide species. Moreover, exogenous addition of the sphingoid base dihydrosphingosine abolished the protective effect of OSIP108 against Cu-induced cell death in yeast. These findings indicate the potential of OSIP108 to prevent Cu-induced apoptosis, possibly via its effects on sphingolipid homeostasis.
    Full-text · Article · Jun 2014 · Biochimica et Biophysica Acta (BBA) - Molecular Cell Research

  • No preview · Article · Nov 2013 · Transplant International
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    ABSTRACT: Wilson disease (WD) is an autosomal recessive disorder resulting from mutations in the ATP7B gene, with over 600 mutations described. Identification of mutations has made genetic diagnosis of WD feasible in many countries. The heterogeneity of ATP7B mutants is, however, yet to be identified in the Indian population. We analyzed the mutational pattern of WD in a large region of Western India. We studied patients (n = 52) for ATP7B gene mutations in a cohort of families with WD and also in first-degree relatives (n = 126). All 21 exon-intron boundaries of the WD gene were amplified and directly sequenced. We identified 36 different disease-causing mutations (31 exonic and five intronic splice site variants). Fourteen novel mutations were identified. Exons 2, 8, 13, 14, and 18 accounted for the majority of mutations (86.4%). A previously recognized mutation, p.C271*, and the novel mutation p.E122fs, were the most common mutations with allelic frequencies of 20.2% and 10.6%, respectively. Frequent homozygous mutations (58.9%) and disease severity assessments allowed analysis of genotype-phenotype correlations. Our study significantly adds to the emerging data from other parts of India suggesting that p.C271* may be the most frequent mutation across India, and may harbor a moderate to severely disabling phenotype with limited variability.
    Full-text · Article · Apr 2013 · Annals of Human Genetics
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    Full-text · Article · Apr 2013
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    ABSTRACT: Non-alcoholic fatty liver disease (NAFLD) is a common problem with a wide variety of phenotypes. While its pathogenesis is still not fully understood, several risk factors for disease progression have been identified. Therefore, defining adequate animal models may serve to unreveal the pathogenesis in NAFLD. We studied Lewis and Sprague-Dawley rats of both genders (n = 6) fed standard (Std) or high-fat (HF) diet for three weeks. Disease stage was assessed by haematoxylin-eosin, Azan Heidenheim and Oil-Red staining, apoptosis by single-stranded DNA (ssDNA) detection and liver regeneration by Ki-67 staining. Serum markers of liver injury and lipid metabolism including adipocytokines were analysed. Livers of both strains and genders fed with HF diet demonstrated evidence of steatosis. Lewis rats developed microvesicular steatosis whereas Sprague-Dawley rats presented macrovesicular steatosis accompanied by pronounced fibrosis. Female gender of both strains was associated with lower steatosis grade and higher proliferation rate (P < 0.05). Gender-specific differences were most prominent in Lewis rats on a HF diet, where females showed lower alkaline phosphatase, cholesterol, triglyceride and leptin levels and a more favourable low-density lipoprotein/high-density lipoprotein ratio than males (P < 0.05). Reverse transcriptase-polymerase chain reaction analysis was performed to demonstrate changes in expression of various genes important for liver regeneration, fibrosis and steatosis. HF diet induced downregulation of proangiogenic genes such as vascular endothelial growth factor receptor 1 and 2 (P < 0.05) in males was not present in females. In conclusion, strain and gender served major roles in disease progression. These differences should be considered when designing studies and may offer new ways to advance therapeutic strategies.
    No preview · Article · Mar 2013 · Laboratory Animals
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    Ramsi Siaj · Andree Zibert · Hartmut H-J Schmidt

    Full-text · Dataset · Oct 2012
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    ABSTRACT: AIM: To investigate the impact of dietary copper given at different time points on the onset of fulminant hepatitis. METHODS: The Long-Evans cinnamon (LEC) rat model of Wilson’s disease (WD) was used to study the impact of high dietary copper (hCu) on the induction of fulminant hepatitis at early or late time points of life. High Cu diet was started in rat pups or in adults (month 5) for three months. Animals that received reduced dietary copper (rCu) throughout their lifetime served as a control. Hepatitis-associated serum markers (alanine aminotransferase, aspartate transaminase, bilirubin) were analyzed in animal groups receiving hCu or rCu. Liver copper content and liver histology were revealed at sacrifice. A set of 5 marker genes previously found to be affected in injured liver and which are related to angiogenesis (Vegfa ), fat metabolism (Srebf1 ), extracellular matrix (Timp1 ), oxidative stress (Hmox1 ), and the cell cycle (Cdkn1a ) were analyzed by real-time polymerase chain reaction. RESULTS: Regardless of the time point when hCu was started, LEC rats (35/36) developed fulminant hepatitis and died. Animals receiving rCu (36/36) remained healthy, did not develop hepatitis, and survived long term without symptoms of overt disease, although liver copper accumulated in adult animals (477 ± 75 μg/g). With regard to start of hCu, onset of fulminant hepatitis was significantly (P < 0.001) earlier in adults (35 ± 9 d) that showed pre-accumulation of liver copper as compared to the pup group (77 ± 15 d). Hepatitis-associated serum markers, liver copper and liver histology, as well as gene expression, were affected in LEC rats receiving hCu. However, except for early and rapid onset of hepatitis, biochemical and molecular markers were similar at the early and late time points of disease. CONCLUSION: Rapid onset of fulminant hepatitis in asymptomatic LEC rats with elevated liver copper suggests that there is a critical threshold of liver copper which is important to trigger the course of WD.
    Full-text · Article · Oct 2012 · World Journal of Gastroenterology
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    ABSTRACT: Purpose MicroRNA-122 (miR-122) has recently been shown to represent a novel biomarker of liver disease. However, the presence of serum miR-122 after liver injury was mostly studied at singular time points. The course of serum miR-122 was determined at consecutive time points during the onset of disease. Methods Fulminant hepatitis was induced by a high-copper diet in Long-Evans Cinnamon (LEC) rats that were used as models for Wilson’s disease (WD). Levels of serum miR-122, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and liver histology were determined. Results Toxic copper given to isolated hepatocytes induced release of miR-122 into the tissue culture medium. Levels of serum miR-122 were highly elevated (21.9 ± 5) in LEC rats after high-copper diet in fulminant hepatitis, whereas healthy rats showed low (<0.6) baseline levels of miR-122. Levels of miR-122 in the serum of LEC rats after high-copper diet continuously increased for about 4 weeks prior to the onset of fulminant hepatitis. In most of the animals (77.8%), significantly increased levels of miR-122 were detected about 2 weeks (13.7 ± 2 days) earlier as compared to hepatitis-associated serum markers ALT, AST, and bilirubin. Analysis of miR-122 in survivors after cell-based therapy of WD demonstrated a rapid decrease of miR-122 levels following hepatocyte transplantation. miR-122 expression in the serum was normalized to baseline levels in most of the (4/5) survivors. Conclusion Our results suggest that longitudinal analysis of miR-122 allows detection of severe liver disease at an early stage and might be excellently suited to monitor therapy, at least when severe liver disease can be restored as observed after cell-based therapy of WD.
    Full-text · Article · Oct 2012 · Hepatology International

  • No preview · Article · Apr 2012 · Journal of Hepatology

  • No preview · Article · Apr 2012 · Journal of Hepatology

  • No preview · Article · Apr 2012 · Journal of Hepatology
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    ABSTRACT: The outcome of consecutive hepatocyte transplants was explored in a rat model of Wilson's disease before the onset of fulminant hepatitis without preconditioning regimens. Rats received a high-copper diet in order to induce a rapid induction of liver failure. Sham-operated rats (15/15) developed jaundice and fulminant hepatitis, and they died within 4 weeks of first transplantation. Despite the continuation of a high dietary copper challenge, long-term survival was observed for a notable proportion of the transplanted animals (7/18). All survivors displayed normalized levels of hepatitis-associated serum markers and ceruloplasmin oxidase activity by posttransplant days 50 and 98, respectively. The liver copper concentrations, the liver histology, and the expression of marker genes were significantly restored within 4 months of transplantation in comparison with the control group. The high expression of a copper transporter gene (ATPase Cu++ transporting beta polypeptide) in the livers of the survivors indicated a high rate of repopulation by donor hepatocytes. Our data suggest that repeated cell transplantation can overcome the limitations of a single therapy session in rats with severe hepatic disease by functionally restoring the host liver without preconditioning.
    Full-text · Article · Feb 2012 · Liver Transplantation
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    ABSTRACT: The regeneration capacity of cirrhotic livers might be affected by angiotensin-1 (AT1) receptors located on hepatic stellate cells (HSC). The effect of AT1 receptor blockade on microcirculation, fibrosis and liver regeneration was investigated. In 112 Lewis rats, cirrhosis was induced by repetitive intraperitoneal injections of CCl(4) . Six hours, 3, 7 and 14 days after partial hepatectomy or sham operation, rats were sacrificed for analysis. Animals were treated with either vehicle or 5 mg/kg body weight losartan pre-operatively and once daily after surgery by gavage. Microcirculation and portal vein flow were investigated at 6 h. The degree of cirrhosis was assessed by Azan Heidenhein staining, activation of HSC by desmin staining, apoptosis by ssDNA detection and liver regeneration by Ki-67 staining. Changes in expression of various genes important for liver regeneration and fibrosis were analysed at 6 h and 3 days. Haemodynamic parameters and liver enzymes were monitored. Losartan treatment increased sinusoidal diameter, sinusoidal blood flow and portal vein flow after partial hepatectomy (P<0.05), but not after sham operation. AT1 receptor blockade resulted in increased apoptosis early after resection. HSC activation was reduced and after 7 days, a significantly lower degree of cirrhosis in resected animals was observed. Losartan increased the proliferation of hepatocytes at late time-points and of non-parenchymal cells early after partial hepatectomy (P<0.05). Tumour necrosis factor (TNF)-α was significantly upregulated at 6 h and stem cell growth factor (SCF) was downregulated at 3 days (P<0.05). Losartan increased hepatic blood flow, reduced HSC activation and liver fibrosis, but interfered with hepatocyte proliferation after partial hepatectomy in cirrhotic livers.
    No preview · Article · May 2011 · Liver international: official journal of the International Association for the Study of the Liver

  • No preview · Article · Jan 2011 · Zeitschrift für Gastroenterologie