Effect of PlGF-inhibition on survival in mice with hepatocellular carcinoma

Background: Inhibition of angiogenesis is currently hot topic in the search for an effective treatment for hepatocellular carcinoma (HCC). Up till recently, the focus was mainly on VEGF, an important regulator in the pathologic and physiologic angiogenesis. Although promising results are seen by inhibiting the VEGF-pathway, patients often suffer from major side effects. Placental growth factor (PlGF) is a VEGF analogue only involved in pathologic angiogenesis and its inhibition has the potential to restrain tumour growth, without affecting healthy organs. Therefore, we assessed whether administration of PlGF-antibodies could serve as a potential therapy for HCC in mice. Methods: 5-week-old male mice (sv129) received intraperitoneal (ip) injections once per week with N-nitrosodiethylamine (35 mg/kg bodyweight) or saline , which gives rise to HCC after 25W in WT. PlGF-knock-out mice (PlGF-/-) received weekly ip DEN-injections and were compared with their WT counterparts. At 26W, WT mice were treated with twice a week with murine monoclonal PlGF-antibodies (20 mg/kg anti-PlGF) or IgG for 5W and 10W. Results: By 25 weeks of DEN treatment, 29% of the WT mice but none of the PlGF-/- mice had succumbed to the disease (p = 0,056). Also, treatment of DEN-injected HCC mice from 25 weeks for 5 weeks with 5D11D4 (ThromboGenics N.V.) or IgG showed a significant difference in mortality. While 45% died in the control IgG group, only 23% mortality was observed in the anti-PlGF group (N=48; P < 0.05). Also, the liver/body weight ratio was 0.057 ± 0.003 in the control group versus 0.042 ± 0.004 in the 5D11D4 group (N=19; P < 0,05). After 10W treatment 90% died in the control IgG group, while only 41 % mortality was observed in the anti-PlGF group (N = 11, P < 0,05). No mortality was observed in mice injected with saline instead of DEN, followed by 5 wks of treatment with anti-PlGF or IgG. The liver/body weight ratio was 0.038 ± 0.001 in the saline and IgG group versus 0.041 ± 0.002 in the anti-PlGF group (N=12, P = 0,27). Figure 1: left: Mean survival of IgG and aPlGF treated mice ; right: mean survival of PlGF knock out mice and WT’s during DEN-induction Conclusion: Our study showed that administration of 20 mg/kg anti-PlGF twice a week, has a positive effect on survival in mice with HCC. The liver/bodyweight ratio of anti-PlGF treated mice was significantly lower than in the control IgG group, showing a specific effect on liver tumours. Treatment of anti-PlGF in healthy mice did not induce negative side effects. Therefore, treatment with PlGF antibodies might serve as a promising systemic treatment in hepatocellular carcinoma patients

The impact of elevation of total bilirubin level and etiology of the liver disease on serum N-glycosylation patterns in mice and men

The GlycoFibroTest and GlycoCirrhoTest are noninvasive alternatives for liver biopsy that can be used as a follow-up tool for fibrosis patients and to diagnose cirrhotic patients, respectively. These tests are based on the altered N-glycosylation of total serum protein. Our aim was to investigate the impact of etiology on the alteration of N-glycosylation and whether other characteristics of liver patients could have an influence on N-glycosylation. In human liver patients, no specific alteration could be found to make a distinction according to etiological factor, although alcoholic patients had a significant higher mean value for the GlycoCirrhoTest. Undergalactosylation did not show a significantly different quantitative alteration in the cirrhotic and non-cirrhotic population of all etiologies. Importantly, patients with an elevation of total bilirubin level (>2 mg/dl) had a strong increase of glycans modified with alpha 1-6 fucose. The fucosylation index was therefore significantly higher in fibrosis/cirrhosis and hepatocellular carcinoma patients with elevated total bilirubin levels irrespective of etiology. Furthermore, in a multiple linear regression analysis, only markers for cholestasis significantly correlated with the fucosylation index. In mouse models of chronic liver disease, the fucosylation index was uniquely significantly increased in mice that were induced with a common bile duct ligation. Mice that were chronically injected with CCl4 did not show this increase. Apart from this difference, common changes characteristic to fibrosis development in mice were observed. Finally, mice induced with a partial portal vein ligation did not show biological relevant changes indicating that portal hypertension does not contribute to the alteration of N-glycosylation

Modulation of the unfolded protein response by tauroursodeoxycholic acid counteracts apoptotic cell death and fibrosis in a mouse model for secondary biliary liver fibrosis

The role of endoplasmic reticulum stress and the unfolded protein response (UPR) in cholestatic liver disease and fibrosis is not fully unraveled. Tauroursodeoxycholic acid (TUDCA), a hydrophilic bile acid, has been shown to reduce endoplasmic reticulum (ER) stress and counteract apoptosis in different pathologies. We aimed to investigate the therapeutic potential of TUDCA in experimental secondary biliary liver fibrosis in mice, induced by common bile duct ligation. The kinetics of the hepatic UPR and apoptosis during the development of biliary fibrosis was studied by measuring markers at six different timepoints post-surgery by qPCR and Western blot. Next, we investigated the therapeutic potential of TUDCA, 10 mg/kg/day in drinking water, on liver damage (AST/ALT levels) and fibrosis (Sirius red-staining), in both a preventive and therapeutic setting. Common bile duct ligation resulted in the increased protein expression of CCAAT/enhancer-binding protein homologous protein (CHOP) at all timepoints, along with upregulation of pro-apoptotic caspase 3 and 12, tumor necrosis factor receptor superfamily, member 1A (TNFRsf1a) and Fas-Associated protein with Death Domain (FADD) expression. Treatment with TUDCA led to a significant reduction of liver fibrosis, accompanied by a slight reduction of liver damage, decreased hepatic protein expression of CHOP and reduced gene and protein expression of pro-apoptotic markers. These data indicate that TUDCA exerts a beneficial effect on liver fibrosis in a model of cholestatic liver disease, and suggest that this effect might, at least in part, be attributed to decreased hepatic UPR signaling and apoptotic cell death

Angiogenesis in liver disease

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Liver transplantation for alcoholic liver disease: a retrospective analysis of recidivism, survival and risk factors predisposing to alcohol relapse

Background and study aims : Alcoholic liver disease (ALD) is the second most common indication for liver transplantation. The aim of this study was to evaluate the alcohol relapse rate and long-term survival after liver transplantation for ALD and to identify risk factors predisposing to alcohol relapse. Patients and methods : Between 2000 and 2007, 108 patients transplanted for ALD in the Ghent University Hospital were included in this retrospective analysis. Relapse was defined as any drinking after transplantation, problem drinking as more than 2 units/day for women and 3 units/day for men. A wide range of variables was obtained from a questionnaire and medical records. Results : The mean follow-up was 55 months. Relapse was observed in 29%, 16% in problem drinking. The one-and five-year survival was 87% and 74% respectively. No significant difference in survival was found between non-relapsers, occasional drinkers and problem drinkers. The following risk factors were found to be significantly associated with relapse into problem drinking in an univariate analysis : a shorter pre-transplant abstinence period, the presence of a first degree relative with alcohol abuse and a higher number of prior attempts to quit. In multivariable analysis, the presence of a first degree relative with alcohol abuse was found associated with relapse into problem drinking. Conclusions : The presence of a first degree relative with alcohol abuse is a valuable pre-transplant variable evaluating an ALD patient's eligibility for liver transplantation. Other variables are also helpful to outline the broader context of the drinking behavior of the patient

Effectiveness and tolerability of pegylated interferon alfa-2b in combination with ribavirin for treatment of chronic hepatitis C: the PegIntrust Study

Background and study aims : Large international clinical trials conducted in the past 5 years rapidly improved the treatment of chronic hepatitis C; however, it is unclear whether the advances seen in clinical trials are being paralleled by similar improvements in routine clinical practice. PegIntrust is a Belgian community-based trial evaluating the sustained virological response. Patients and Methods : Observational study of 219 patients receiving pegylated interferon alfa-2b (1.5 mu g/kg/wk) and weight. based ribavirin (800-1200 mg/day) for 48 weeks. Primary study end point was sustained virological response (SVR), defined as undetectable HCV RNA 6 months after the completion of treatment. Results : In total, 108 patients (49.3 %) had undetectable HCV RNA at the end of therapy, 91(41.6%) attaining SVR. Of the 111 patients without an end-of-treatment response, 28 were non-responders, and 21 had virological breakthrough. In total, 134 patients attained early virological response (EVR); 88 (65.7%) of those patients attained SVR. In contrast, 82 (96.5 %) of the 85 patients who did not attain EVR also did not attain SVR. Age, fibrosis score and baseline viral load were identified as important predictors of treatment outcome. The most frequently reported serious adverse events resulting in treatment discontinuation were anemia (n = 10), fatigue/asthenia/malaise (n = 6) and fever (n = 3). Conclusion : Our data indicate that treatment of chronic hepatitis C with PEG-IFN alfa-2b plus weight-based ribavirin results in favourable treatment outcomes in a Belgian cohort of patients treated in community-based clinical practice. (Ada gastroenterol. belg., 2010, 73, 5-11)

A novel “humanized mouse” model for autoimmune hepatitis and the association of gut microbiota with liver inflammation:Association of Gut Microbiota With Liver Inflammation

BACKGROUND: Autoimmune hepatitis (AIH) in humans is a severe inflammatory liver disease, characterized by interface hepatitis, the presence of circulating autoantibodies and hyper-gammaglobulinemia. There are two types of AIH, type-1 (AIH-1) and type-2 (AIH-2) characterized by distinct autoimmune serology. Patients with AIH-1 are positive for anti-smooth muscle and/or anti-nuclear (SMA/ANA) autoantibodies whereas patients with AIH-2 have anti-liver kidney microsomal type 1 (anti-LKM1) and/or anti-liver cytosol type 1 (anti-LC1) autoantibodies. Cytochrome P4502D6 (CYP2D6) is the antigenic target of anti-LKM1 and formiminotransferase cyclodeaminase (FTCD) is the antigenic target of anti-LC1. It is known that AIH, both type-1 and type-2, is strongly linked to the Human Leukocyte Antigen (HLA) alleles -DR3, -DR4 and -DR7. However, the direct evidence of the association of HLA with AIH is lacking. METHODS: We developed a novel mouse model of AIH using the HLA-DR3 transgenic mouse on the non-obese diabetic (NOD) background (HLA-DR3 NOD) by immunization of HLA-DR3(−) and HLA-DR3(+) NOD mice with a DNA plasmid, coding for human CYP2D6/FTCD fusion protein. RESULTS: Immunization with CYP2D6/FTCD leads to a sustained elevation of alanine aminotransferase (ALT), development of ANA and anti-LKM1/anti-LC1 autoantibodies, chronic immune cell infiltration and parenchymal fibrosis on liver histology in HLA-DR3(+) mice. Immunized mice also showed an enhanced Th1 immune response and paucity of the frequency of regulatory T-cell (Treg) in the liver. Moreover, HLA-DR3(+) mice with exacerbated AIH showed reduced diversity and total load of gut bacteria. CONCLUSION: Our humanized animal model has provided a novel experimental tool to further elucidate the pathogenesis of AIH and to evaluate the efficacy and safety of immunoregulatory therapeutic interventions in vivo