Model Of Hepatic Failure Research Articles

Hepatoprotective Effect Of Ethilendiaminotetracetic Acid And Sodium Selenate In A Chronic Hepatic Failure Model In Mice

Oxidative stress and serum iron levels are important in the development of hepatic fibrosis and low serum selenium levels in some hepatic diseases. The objective was to determine the hepatoprotector effect of EDTA (ethilendiaminotetracetic acid) as a chelating agent and SeNa(sodium selenate) in a chronic hepatic failure model in mice. Iron chelating therapy with deferoxamine is more expensive than EDTA representing an economic alternative. This is an experimental controlled trial with heterocigotes adult mice grouped in 4 experimental groups. Group I received no treatment, groups II and III each treatment separately, and group IV combined treatment. Group I revealed chronic hepatic injury (p<0.05); groups II and III revealed similar findings; however initial low damage was observed in 60% with turbid and vacuolar degeneration (p<0.05). Group IV revealed 25-75% of the subjects without histopathology degeneration and 50-100% did not present necrosis (p<0.01). This was the only group with normal enzymatic values obtaining 65.3% of hepatic protection. Conclusion: using a chronic hepatic failure model with thioacetamide, the combination of EDTA and SeNa produce a better hepatoprotection response in contrast with monotherapy group in the reduction of the progression and severity of hepatic damage.

On the Protective Effects of IMOD and Silymarin Combination in a Rat Model of Acute Hepatic Failure Through Anti Oxidative Stress Mechanisms

On the Protective Effects of IMOD and Silymarin Combination in a Rat Model of Acute Hepatic Failure Through Anti Oxidative Stress Mechanisms

Heme Oxygenase-1 Alleviates Mouse Hepatic Failure through Suppression of Adaptive Immune Responses

Heme oxygenase-1 (HO-1) has protective effects on liver damage induced by noxious stimuli. The mechanism of action of HO-1 is not well understood. In the present study, we investigate the effect of HO-1 in a model of fulminant hepatic failure induced by Propionibacterium acnes and lipopolysaccharide (LPS). The expression of HO-1 mRNA and protein in the liver was increased after repeated administration of the HO-1 inducer cobalt protoporphyrin IX. We found that HO-1 protected mice from acute liver damage induced by P. acnes/LPS and prolonged survival. On the contrary, administration of the HO-1 inhibitor zinc protoporphyrin IX increased liver damage induced by P. acnes/LPS. Subsequently, to investigate the underlying mechanisms of HO-1 in the acute liver injury model, we primed mice with P. acnes only. We found that the expression of HO-1 mRNA and protein in dendritic cells (DCs) was increased after the administration of cobalt protoporphyrin IX. HO-1 decreased the mature markers major histocompatibility complex II and CD80 on liver DCs. The expression of CCR7, CCL2, and CCL22 mRNA, which are expressed by mature DCs, was also reduced. These liver DCs could not efficiently stimulate CD4+ T cell activation and proliferation. Consequently, HO-1 inhibited the activation, proliferation, and T helper 1 polarization of liver-infiltrating CD4+ T cells and reduced the production of serum alanine aminotransferase and proinflammatory cytokines such as interferon-γ and tumor necrosis factor-α. Taken together, our data suggest that HO-1 alleviates P. acnes/LPS-induced fulminant hepatic failure, probably by inhibiting DC-induced adaptive responses.

The nuclear receptor FXR regulates hepatic transport and metabolism of glutamine and glutamate

Hepatic transport and metabolism of glutamate and glutamine are regulated by intervention of several proteins. Glutamine is taken up by periportal hepatocytes and is the major source of ammonia for urea synthesis and glutamate for N-acetylglutamate (NAG) synthesis, which is catalyzed by the N-acetylglutamate synthase (NAGS). Glutamate is taken up by perivenous hepatocytes and is the main source for the synthesis of glutamine, catalyzed by glutamine synthase (GS). Accumulation of glutamate and ammonia is a common feature of chronic liver failure, but mechanism that leads to failure of the urea cycle in this setting is unknown. The Farnesoid X Receptor (FXR) is a bile acid sensor in hepatocytes. Here, we have investigated its role in the regulation of the metabolism of both glutamine and glutamate. In vitro studies in primary cultures of hepatocytes from wild type and FXR −/− mice and HepG2 cells, and in vivo studies, in FXR −/− mice as well as in a rodent model of hepatic liver failure induced by carbon tetrachloride (CCl 4), demonstrate a role for FXR in regulating this metabolism. Further on, promoter analysis studies demonstrate that both human and mouse NAGS promoters contain a putative FXRE, an ER8 sequence. EMSA, ChIP and luciferase experiments carried out to investigate the functionality of this sequence demonstrate that FXR is essential to induce the expression of NAGS. In conclusion, FXR activation regulates glutamine and glutamate metabolism and FXR ligands might have utility in the treatment of hyperammonemia states.

Neuromonitoring in a porcine model of acute hepatic failure

Cerebral oedema has been noted to occur frequently in patients dying of fulminant hepatic failure. Therefore, in the present study, multimodal neuromonitoring was evaluated in an animal model of hepatectomy. Acute liver failure was surgically induced in swine by complete hepatectomy (n = 8). Intracranial pressure monitoring via a ventricular drainage system, electroencephalogram and recording of visually evoked potentials were used to establish a continuous neuromonitoring system. Measurements of liquor and serum ammonia (NH(3)) levels were taken at later stages of the trial in an approach to widen monitoring. Serial monitoring of the electroencephalogram revealed progressive slowing of the frequency with decreasing amplitude. Monitoring of the intracranial pressure with a subdural pressure transducer demonstrated a progressive and reproducible elevation. Increase in blood NH(3) was observed. Anaesthesia was terminal. In all cases death was caused by cardiocirculatory insufficiency, confirmed by autopsy. At autopsy, brain tissue of the animals was found to be swollen showing flattened cortical gyri. In conclusion, the technique of extended neuromonitoring offers an advanced option for monitoring animal models of fulminant hepatic failure for further developments and investigations.

OL-032 Expression of mRNA and protein of Fas associated death domain protein in fulminant hepatic failure model and the relationship of hepatocytes apoptosis

OL-032 Expression of mRNA and protein of Fas associated death domain protein in fulminant hepatic failure model and the relationship of hepatocytes apoptosis

Bioartificial liver system based on choanoid fluidized bed bioreactor improve the survival time of fulminant hepatic failure pigs

Bioartificial liver (BAL) support system has been proposed as potential treatment method for end-stage liver diseases. We described an improved BAL system based on a choanoid fluidized bed bioreactor containing alginate-chitosan encapsulated primary porcine hepatocytes. The feasibility, safety, and efficiency of this device were estimated using an allogeneic fulminant hepatic failure (FHF) model. FHF was induced with intravenous administration of D-galactosamine. Thirty FHF pigs were divided into three groups: (1) an FHF group which was only given intensive care; (2) a sham BAL group which was treated with the BAL system with empty encapsulation, and (3) a BAL group which was treated with the BAL system containing encapsulated freshly isolated primary porcine hepatocytes. The survival times and biochemical parameters of these animals were measured, and properties of the encapsulations and hepatocytes before and after perfusion were also evaluated. Compared to the two control groups, the BAL-treated group had prolonged the survival time and decreased the blood lactate levels, blood glucose, and amino acids remained stable. No obvious ruptured beads or statistical decline in viability or function of encapsulated hepatocytes were observed. This new fluidized bed BAL system is safe and efficient. It may represent a feasible alternative in the treatment of liver failure.

Melatonin prevents the decreased activity of antioxidant enzymes and activates nuclear erythroid 2-related factor 2 signaling in an animal model of fulminant hepatic failure of viral origin

This work was undertaken to investigate whether treatment with melatonin prevents oxidative stress and changes in the expression and activity of factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant enzymes in an animal model of fulminant hepatic failure of viral origin. Rabbits were experimentally infected with 2 x 10(4) hemagglutination units of a rabbit hemorrhagic disease virus (RHDV) isolate and received melatonin at two concentrations of 10 mg/kg and 20 mg/kg at 0, 12 and 24 hr postinfection. Blood transaminases, blood lactate dehydrogenase, liver concentration of thiobarbituric reactive acid substances and the liver oxidized to reduced glutathione ratio significantly increased at 36 hr postinfection in infected animals. Significant decreases were found in the mRNA levels and in the liver activities of Mn-superoxide dismutase, glutathione peroxidase and glutathione-S-transferase in infected rabbits. These effects were prevented by melatonin administration in a concentration-dependent manner. Melatonin treatment was not accompanied by changes in protein levels of Kelch-like ECH-associating protein 1 (Keap1) but resulted in an increased protein expression of Nrf2 in the cytoplasm and the nucleus, which was confirmed by the results of Nrf2 immunostaining. Nuclear extracts from livers of melatonin-treated rats displayed an enhanced antioxidant responsive element (ARE)-binding activity of Nrf2. Our results suggest a potential hepatoprotective role of melatonin in fulminant hepatic failure, partially mediated through the abrogation of oxidative stress and the prevention of the decreased activity of antioxidant enzymes via the Nrf2 pathways.

A new experimental model for acute hepatic failure in rats

To develop a reliable surgical model of acute hepatic failure and hyperammonemia in rats that avoids porto-systemic shunt and bile duct ligation, applicable to hepatic encephalopathy research. The pedicles of right lateral and caudate lobes were exposed and clamped. One hour later, the animal was reopened, clamps were released and anterior subtotal hepatectomy (resection of median and left lateral lobes) was performed, comprising 75% of liver removal. Four hours after hepatectomy, blood samples and liver tissues were collected from ALF and control groups. Differences between ALF and control groups were significant for ALT, AST, total and direct bilirubin, sodium, potassium, alkaline phosphatasis, gamma-glutamyltransferase and most important, ammonia. Histologically, significant differences were noticed between groups. The model is useful for the study of specific aspects of ALF and the development of new therapeutic approaches.

Salvage effect of E5564, Toll‐like receptor 4 antagonist on d‐galactosamine and lipopolysaccharide‐induced acute liver failure in rats

The transmembrane protein Toll-like receptor 4 (TLR4), which exists mainly in macrophages such as Kupffer cells of the liver, plays an important role in recognizing and mediating macrophage activation and pro-inflammatory cytokine release. Activation of the pro-inflammatory cytokine cascade, including tumor necrosis factor-alpha (TNF-alpha), has a pivotal role in the progression of severe liver injury. D-galactosamine (GalN) and lipopolysaccharide (LPS)-induced liver injury in rats is an experimental model of fulminant hepatic failure, where TNF-alpha plays a central role in the progression of liver injury. E5564, a synthetic analogue of the lipid A component of endotoxin, inhibits endotoxin-stimulated inflammation and is under study for patients with sepsis. In the present study, we sought to explore the salvage effect of TLR4 antagonist E5564 on GalN+LPS-induced acute liver failure (ALF) in rats. ALF was induced in male Wistar rats by the intraperitoneal injection of GalN (500 mg/kg) and LPS (50 microg/kg). Immediately after GalN+LPS injection, rats were treated with intravenous injection of E5564 (3 mg/kg). The cumulative survival rates of GalN+LPS-induced ALF rats were compared between those with and without E5564 treatment. The intravenous injection of E5564 reduced the elevation of serum total bilirubin, aspartate aminotransferase, alanine aminotransferase and TNF-alpha levels in rats at 3 h after GalN+LPS injection, and improved the survival rate of GalN+LPS-induced ALF rats at 24 h (8% vs 43%). TLR4 antagonist E5564 reduced GalN+LPS-induced acute liver injury in rats and improved the overall survival rate of GalN+LPS-induced ALF rats. It may contribute to the treatment of ALF through blocking endotoxin-induced TNF-alpha overproduction of macrophages.

T1955 Overexpression of Brain GLUT-1 but Not Glt-1/GFAP in a New Model of Hepatic Acute Liver Failure in Rats

T1955 Overexpression of Brain GLUT-1 but Not Glt-1/GFAP in a New Model of Hepatic Acute Liver Failure in Rats

832 SERUM HIGH-MOBILITY GROUP BOX 1 LEVEL IN THE PATIENTS WITH FULMINANT HEPATIC FAILURE AND ITS BLOCKADE EFFECT IN RAT MODEL

832 SERUM HIGH-MOBILITY GROUP BOX 1 LEVEL IN THE PATIENTS WITH FULMINANT HEPATIC FAILURE AND ITS BLOCKADE EFFECT IN RAT MODEL G. Oshima, M. Shinoda, M. Tanabe, A. Takayanagi, T. Miyasho, S. Yamada, H. Ebinuma, K. Takano, Taizo Hibi, K. Suda, H. Obara, H. Takeuchi, S. Kawachi, K. Fukunaga, Toshifumi Hibi, I. Maruyama, Y. Kitagawa. Surgery, School of Medicine, Keio University, Molecular Biology, School of Medicine, Keio University, Tokyo, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, Central Institute, Shino-Test Corporation, Kanagawa, Internal Medicine, School of Medicine, Keio University, Tokyo, Department of Laboratory and Molecular Medicine, Kagoshima University, Kagoshima, Japan E-mail: oshgo@hotmail.com

MRI of magnetically labeled mesenchymal stem cells in hepatic failure model

To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure. Human MSCs labeled with FDA-approved SPIO particles (Feridex) were transplanted via the mesenteric vein into rabbits (n = 16) with carbon tetrachloride-induced hepatic failure. Magnetic resonance (MR) examinations were performed with a 3.0 T clinical scanner immediately before and 2 h and 1, 3, and 7 d after transplantation. Signal intensity (SI) changes on T2*-weighted MRI were measured, and correlation between MR findings and histomorphologic findings was also investigated. SI on T2*-weighted MRI decreased significantly in the liver 2 h after injection of human MSCs and returned gradually to the levels found before injection in 7 d. Changes in SI in the liver at 2 h, 1, 3, and 7 d were 41.87% ± 9.63%, 10.42% ± 4.3%, 5.12% ± 1.9%, 3.75% ± 1.2%, respectively (P < 0.001). Histologic analyses confirmed the presence of MSCs in the liver, localized mainly in the sinusoids in early period (2 h and 1 d) and concentrated to the border zone in late period (3 and 7 d). The number of iron-positive cells in the liver at 2 h and on 1, 3 and 7 d after transplantation was 29.2 ± 4.8, 10.1 ± 3.7, 6.7 ± 2.2, and 5.8 ± 2.1, respectively (P = 0.013). Intravascularly injected SPIO-labeled MSCs in an experimental rabbit model of hepatic failure can be detected and followed with MRI.

The approaches for making acute-on-chronic liver failure in rat

To study the approaches for making acute-on-chronic hepatic failure model in rat. SD rats were intraperitoneally injected with 50% CCl4 (Carbon tetrachloride) olive solution every three days for 6 or 10 weeks. Then they were divided into two groups randomly and injected with D-galactosamine (D-gal) at a dose of 2 g/kg, lipopolysaccharide (LPS) at a dose of 100 pg/kg and D-gal at a dose of 0.5 g/kg BW respectively. The levels of serum ALT, AST and TBil were detected,and histopathological changes were observed to evaluate these two models. After injection of 50% CCl4 olive solution intraperitoneally for 6 weeks, liver fibrosis happened in SD rats, 10 weeks, cirrhosis happened. Pelleta necrosis and massive or submassive necrosis was seen administration of two reagents mentioned above. By injecting of 50% CCl4 olive solution intraperitoneally, acute-on-chronic liver failure model could be induced by D-gal, LPS/D-gal in rats.

Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure

Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-κB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 × 104 hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-α from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-κB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF.

Effects of endotoxin on liver smac apoptosis channel

To study the effect of endotoxin on liver apoptosis, L02 liver cells were cultured and passaged in vitro, and then stimulated by endotoxin at 10 mg/mL for 4, 8, 16 and 24 h respectively. Liver apoptosis was flow cytometrically and fluorescently detected. Immunohistochemistry was used to detect the delivery of smac and caspase9. The delivery of liver cell smac and the activity of caspase3 were measured by caspase3 assay kit. The hepatic failure models of rats were established by using D-galactosamine. The blood serum and liver tissues were collected for the detection of the liver function, the level of endotoxin and the activity of caspase3 by using chromogenic substrate limulus amebocyte lysate method (LAL) and caspase3 active assay kit. The expression of smac and caspase9 in liver cells was detected by Western blotting. With in vitro study, the L02 cells stimulated by LPS condensed into conglobation and formed apoptotic bodies. After those cells were stained by hoechst, the apoptotic cells displayed blue color under the fluorescent microscope. The apoptosis rate was increased over time and the apoptosis was mainly of advanced stage. Meanwhile, the rate of smac delivery and activity of caspase9 and caspase3 were increased on L02 cell membrane. In vivo, hepatic failure and obvious endotoxemia were induced by injection of more than 200 mg/kg D-GalN. Hepatic mitochondria smac was reduced with dosage of D-GalN and, on the contrary, the activity of caspase3 was increased. D-GalN at 200 mg/kg increased Caspase9 while D-GalN at 300 mg/kg decreased caspase9. Mitochondria signal channel plays an important role in the endotoxin-induced apoptosis of hepatic cells by promoting the release of smac from mitochondria to cytoplasm and activating caspase9 and caspase3 in its low-level channel.

Plasma Exchange‐based Plasma Recycling Dialysis System as an Artificial Liver Support

We developed a plasma recycling dialysis (PRD) system based on plasma exchange (PE). In this system, rapid reduction of toxic substances and restitution of deficient essential substances are performed by PE and subsequent blood purification is performed by dialysis between separated plasma recycled over a purification device and the patient's blood across the membrane of a plasma separator. To demonstrate the safety and efficacy of this system, we used a pig model of fulminant hepatic failure (FHF) and anion exchange resin, activated charcoal and hemodialysis for the purification device. FHF was induced by intraportal administration of alpha-amanitine (0.1 mg/kg) and lipopolysaccharides (1 microg/kg) in pigs. Three groups of animals were studied: group 1, diseased controls (N = 4); group 2, PE group (N = 4), 16 h after drug infusion the pigs underwent PE of approximately 1.2 L for 2 h; and group 3, PE + PRD group (N = 4), the pigs underwent PE followed by PRD for 6 h. The hemodynamic status of all animals was stable during the procedure. In group 3, the values of ammonia, total bile acid and total bilirubin continuously decreased and were significantly lower than those of the animals in group 2 24 h after the induction of FHF. The Fischer ratio was significantly higher than in group 2 after 24 h. Group 3 pigs maintained a higher level of consciousness and survived longer than group 2 pigs. Safety of this PE-based PRD system was demonstrated and the removal of toxic substances was significant. This study confirmed the clinical utility of this system as an artificial liver support.

76. Endothelial Progenitor Cells Therapy Increase Survival and Induce Hepatoprotection in a Murine Model of Fulminant Hepatic Failure Mediated by Adenovirus Encoding CD40L

76. Endothelial Progenitor Cells Therapy Increase Survival and Induce Hepatoprotection in a Murine Model of Fulminant Hepatic Failure Mediated by Adenovirus Encoding CD40L

The way to safer liver resection in cirrhotic patients: is Cardiotrophin‐1 the future miracle drug?

The way to safer liver resection in cirrhotic patients: is Cardiotrophin‐1 the future miracle drug?

793 An Increased Serum Level of High-Mobility Group Box 1 in the Pig Fulminant Hepatic Failure Model

793 An Increased Serum Level of High-Mobility Group Box 1 in the Pig Fulminant Hepatic Failure Model