Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interferon-gamma (IFN-gamma) transgenic mice strongly express IFN-gamma in the liver and develop chronic hepatitis. Furthermore, hepatocyte apoptosis was shown by the TdT-mediated dUTP-biotin nick endlabeling method. In the present study, interleukin-1beta-converting enzyme (ICE) and CPP32-like protease activities in the liver of IFN-gamma transgenic mice were measured, using the synthetic substrates Ac-YVAD-MCA and Ac-DEVD-MCA. Plasma aspartate aminotransferase and alanine aminotransferase activities as well as CPP32-like activity were significantly elevated, while ICE activity was significantly reduced. The addition of the ICE inhibitor Ac-YVAD-CHO to IFN-gamma transgenic mouse liver cell cytosol had no effect on the CPP32 activity, in contrast to a CPP32 inhibitor. The present results indicate that chronic hepatitis in the IFN-gamma transgenic mouse is associated with a decrease in ICE and induction of CPP32-like activity.
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PMID:Chronic hepatitis in interferon-gamma transgenic mice is associated with elevated CPP32-like activity and interleukin-1beta-converting enzyme activity suppression. 1023 Aug 56

Prolonged liver ischemia followed by reperfusion (I/R) causes functional and structural damage to liver cells, resulting in necrosis and apoptosis. c-jun N-terminal kinase 1/stress-activated protein kinase 1 (JNK(1)/SAPK(1)) is activated during I/R and participates in the onset of the apoptosis program. Excessive blood loss during surgery can hinder postoperative recovery. Intermittent portal triad clamping (PTC) is better tolerated than prolonged continuous ischemia. This study was designed to demonstrate that intermittent ischemia could improve postischemic survival rates by a decrease of JNK(1)/SAPK(1) and caspase 3 activation, which were involved in the apoptosis process. Rats were subjected to intermittent 1-hour ischemia (15-minute ischemia/5-minute reperfusion, 4 times), followed by 220-minute reperfusion, or to continuous ischemia (1 hour), followed by 240-minute reperfusion. Mortality rates were assessed on day 7. Serum aspartate transaminase (AST), alanine transaminase (ALT), and lactate dehydrogenase levels (LDH) were measured 6 hours after ischemia. This study was completed in primary cultured isolated rat hepatocytes, subjected to the same continuous or intermittent hypoxic conditions. The activation status of JNK(1)/SAPK(1) was evaluated by immunoprecipitation or Western blotting experiments. Apoptosis was assessed by measuring caspase activation and by terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) reaction. Eighty percent of the intermittent-ischemia group was alive 7 days after surgery and serum enzyme levels were significantly decreased. Intermittent hypoxia or ischemia did not lead to JNK(1)/SAPK(1) activation, but at least 3 hypoxia-reoxygenation (H/R) sets were necessary to inhibit kinase activation. Consequently, caspase 3 activation and apoptosis were dramatically reduced. Intermittent ischemia is a powerful, protective way to reduce I/R damage of the liver, by reduction of JNK(1)/SAPK(1) activation associated with a down-regulation of caspase 3 activity, which leads to inhibition of hepatocyte apoptosis.
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PMID:Intermittent ischemia reduces warm hypoxia-reoxygenation-induced JNK(1)/SAPK(1) activation and apoptosis in rat hepatocytes. 1167 68

Livers can be preserved only for a short period without jeopardizing the transplantation outcome. Heat shock proteins (HSPs) protect against ischemia and reperfusion injury. We studied whether their induction and, in particular, the induction of heme oxygenase 1 (HO-1), improves transplantation survival after an extended time of cold storage. Rats were subjected to heat preconditioning (42 degrees C for 20 minutes). Livers were harvested 24 hours later, preserved in cold University of Wisconsin solution for 44 hours, and transplanted in isogeneic rats (arterialized transplantation). HO-1 was specifically induced and inhibited by cobalt protoporphyrin and tin protoporphyrin, respectively. All animals receiving a graft without preconditioning and subjected to 44 hours of cold preservation died within 3 days, whereas 89% of rats who received a graft exposed to heat survived for 3 weeks (P =.0004). Preconditioning reduced serum aspartate transaminase (AST) and lactate dehydrogenase activities after reperfusion, improved bile flow, and decreased the histologic lesions of reperfusion injury. These significant effects of heat preconditioning were prevented by administration of tin protoporphyrin and could be reproduced by administration of cobalt protoporphyrin. In grafts without preconditioning, only a small fraction (<5%) of hepatocytes were positive with the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) assay, and even less expressed activated caspase 3. Preconditioning tended to reduce the number of positive cells and to stimulate the expression of antiapoptotic Bcl-X(L). In conclusion, heat preconditioning and, specifically, overexpression of HO-1 improve posttransplantation survival and graft function after prolonged cold ischemia preservation. The mechanism underlying these beneficial effects does not appear to be prevention of apoptosis.
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PMID:Extended preservation of rat liver graft by induction of heme oxygenase-1. 1198 58

A hallmark of tumorigenesis is resistance to apoptosis. To explore whether resistance to cell death precedes tumor formation, we have studied the short-term effects of the hepatocarcinogen 2-acetylaminofluorene (AAF) on liver mitochondria, on hepatocytes, and on the response to bacterial endotoxin lipopolysaccharide (LPS) in albino Wistar rats. We show that after as early as two weeks of AAF feeding liver mitochondria developed an increased resistance to opening of the permeability transition pore (PTP), an inner membrane channel that is involved in various forms of cell death. Consistent with a mitochondrial adaptive response in vivo, (i) AAF feeding increased the expression of BCL-2 in mitochondria, and (ii) hepatocytes isolated from AAF-fed rats became resistant to PTP-dependent depolarization, cytochrome c release, and cell death, which were instead observed in hepatocytes from rats fed a control diet. AAF-fed rats were fully protected from the hepatotoxic effects of the injection of 20-30 microg of LPS plus 700 mg of d-galactosamine (d-GalN) x kg-1 of body weight, a treatment that in control rats readily caused a large increase of terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positive cells in liver cryosections and release of alanine and aspartate aminotransferase into the bloodstream. Treatment with LPS and d-GalN triggered cleavage of BID, a BCL-2 family member, in the livers of both control- and AAF-fed animals, whereas caspase 3 was cleaved only in control-fed animals, indicating that the mitochondrial proapoptotic pathway had been selectively suppressed during AAF feeding. Phenotypic reversion was observed after stopping the carcinogenic diet. These results underscore a key role of mitochondria in apoptosis and demonstrate that regulation of the mitochondrial PTP is altered early during AAF carcinogenesis, which matches, and possibly causes, the increased resistance of hepatocytes to death stimuli in vivo. Both events precede tumor formation, suggesting that suppression of apoptosis may contribute to the selection of a resistant phenotype, eventually increasing the probability of cell progression to the transformed state.
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PMID:Early resistance to cell death and to onset of the mitochondrial permeability transition during hepatocarcinogenesis with 2-acetylaminofluorene. 1290 2

In rodents, submandibular salivary glands accumulate a number of biologically active peptides, and release some of them to both saliva and the bloodstream. Surgical removal of these glands (sialoadenectomy) alters the ability of the liver to regenerate after partial hepatectomy. We show here that 5 weeks after surgery, the liver of sialoadenectomized mice contained 40% fewer hepatocytes than the liver of sham-operated mice. We did not obtain evidence of necrotic cell death after surgery. In contrast, sialoadenectomy transiently increased apoptotic hepatocyte death, as revealed by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling (TUNEL) assay. DNA synthesis was determined in vivo by the incorporation of bromo-deoxyuridine (BrdU) into hepatocyte nuclei. BrdU-labeling progressively increased after sialoadenectomy. We conclude that sialoadenectomy induced a transient wave of apoptotic cell death followed by a rise in DNA synthesis but not by cell division. This reduced cell number but increased mean cell volume. In spite of these alterations in cellularity, the liver responded adequately to several stressful conditions, as judged by the lack of any differential effect of sialoadenectomy on liver glycogen and plasma glucose concentration after immobilization, aggressive encounter, or fasting. However, the liver of sialoadenectomized mice was more sensitive to the effect of a non-lethal dose of bacterial lipopolysaccharide (LPS) combined with d-galactosamine, as shown by the enhanced rise in plasma alanine aminotransferase and aspartate aminotransferase, and liver myeloperoxidase (MPO) activities. All these results indicate that a submandibular salivary glands-liver axis is involved in the maintenance of liver structure in mice. A disturbance of this axis induces an adaptive response that preserves the metabolic function of the liver but renders it more sensitive to bacterial endotoxins.
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PMID:Sialoadenectomy alters liver cell turn-over and function in mice. 1458 39

The hepatoprotective effects of Acanthopanax koreanum Nakai (Araliaceae) were evaluated in D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure in mouse. Preparations of Acanthopanax koreanum used were an ethanol extract, a water extract, and the ethanol-soluble and ethanol-insoluble components of the water extract of roots or stems of the plant. Mice were pretreated with various extracts by intraperitoneal injection or orally, 12 and 1 h before intraperitoneal injection of D-galactosamine and lipopolysaccharide (LPS). Intraperitoneal pretreatment with the water extract or the ethanol-insoluble component of the water extract markedly reduced the elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and tumor necrosis factor-alpha (TNF-alpha), reduced the histological changes in the liver, and attenuated hepatocyte apoptosis confirmed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method and DNA fragmentation assay. Oral pretreatment with the ethanol-insoluble component of the water extract also reduced serum AST, ALT, and TNF-alpha levels. The present study shows that the ethanol-insoluble component of a water extract from Acanthopanax koreanum has a protective effect against the induction of fulminant hepatitis in mice by D-galactosamine and lipopolysaccharide.
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PMID:Effect of Acanthopanax koreanum Nakai (Araliaceae) on D-galactosamine and lipopolysaccharide-induced fulminant hepatitis. 1509 51

We studied the effects of cyclosporin A (CsA) administration 1) on the properties of the permeability transition pore (PTP) in mitochondria isolated from the liver and 2) on the susceptibility to hepatotoxicity induced by lipopolysaccharide of Escherichia coli (LPS) plus D-galactosamine (D-GalN) in rats. CsA exerted a marked PTP inhibition ex vivo, with an effect that peaked between 2 and 9 h of drug treatment and decayed with an apparent half-time of about 13 h. Administration of LPS plus D-GalN to naive rats caused the expected increased serum levels of tumor necrosis factor (TNF)-alpha, liver inflammation with BID cleavage, activation of caspase 3, appearance of terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling-positive nuclei, and release of alanine aminotransferase and aspartate aminotransferase into the bloodstream. Treatment with CsA before or within 5 h of the administration of LPS plus D-GalN protected rats from hepatotoxicity despite the normal increase of serum TNF-alpha and BID cleavage. These results indicate that CsA prevents the hepatotoxic effects of TNF-alpha by blocking the mitochondrial proapoptotic pathway through inhibition of the PTP and provides a viable strategy for the treatment of liver diseases that depend on increased production and/or liver sensitization to TNF-alpha.
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PMID:Desensitization of the permeability transition pore by cyclosporin a prevents activation of the mitochondrial apoptotic pathway and liver damage by tumor necrosis factor-alpha. 1520 Dec 76

The aim of this study was to investigate whether Eleutherococcus senticosus stems could attenuate D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure in mice. E. senticosus, known as Siberian ginseng, is a popular folk medicine used as a tonic in Asia. Preparations of E. senticosus used in this study were as follows; (i) 70% ethanol extract (ii) water extract (iii) ethanol-soluble part of the water extract (iv) polysaccharide obtained as an 80% ethanol insoluble of the water extract. Preparations were given by intraperitoneal (300 mg/kg and 50 mg/kg) or oral (300 mg/kg) injection at 12 hr and 1 hr before a D-galactosamine/lipopolysaccharide injection. The intraperitoneal injection of water extract and polysaccharide significantly lowered serum levels of tumour necrosis factor-alpha, aspartate transaminase and alanine transaminase, improved the histologic changes in liver, inhibited hepatocyte apoptosis confirmed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method and DNA fragmentation assay, and suppressed the lethality induced by D-galactosamine/lipopolysaccharide. The oral administration of water extract and polysaccharide also reduced serum aspartate transaminase, alanine transaminase and tumour necrosis factor-alpha levels. In contrast 70% ethanol extract and ethanol-soluble part of the water extract had no protective effect when treated intraperitoneally or orally. These results indicate E. senticosus stems attenuate fulminant hepatic failure induced by D-galactosamine/lipopolysaccharide in mice and the protective effect is due to water-soluble polysaccharides in E. senticosus stems.
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PMID:Water-soluble polysaccharide from Eleutherococcus senticosus stems attenuates fulminant hepatic failure induced by D-galactosamine and lipopolysaccharide in mice. 1522 2

Sixteen barrows (Duroc x Landrace x Yorkshire) were randomly divided into two groups, each consisting eight pigs. The groups received the same basal diet supplemented with 0 and 400 mg/kg fluoride, respectively. Histological examinations, including in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), Haematoxylin and Eosin staining (HE) and transmission electron microscopy observation, found apoptotic hepatocytes 50 days after additional 400 mg/kg fluoride treatment. The obvious DNA ladder and the significantly increased both hepatic caspase-9 and caspase-3 activity indicated that fluoride induced caspase-dependent apoptosis in vivo. In addition, serum glutamate pyruvate transaminase (GPT) activity and hepatic lipid peroxides (LPO) concentration was significantly increased. The activity of serum glutamate oxaloacetate transaminase (GOT) showed an increased trend. The results suggest that fluoride induces apoptosis by elevating the oxidative stress-induced lipid peroxidation, causing mitochondrial dysfunction and further activating caspase-9 and caspase-3.
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PMID:Evaluation of caspase-dependent apoptosis during fluoride-induced liver lesion in pigs. 1613 39

Most acute respiratory distress syndrome studies have been focused on the lung injury. Little is known about other organs during the development of acute respiratory distress syndrome. Herein, we investigated the injury and cell death in multiple organs after intestinal ischemia-reperfusion (IIR) in C57BL/6 mice. Terminal transferase dUTP nick end labeling staining was used as a marker of cell death. Caspase 3 and cathepsin B activation as markers of caspase-dependent and caspase-independent apoptosis, respectively, and electron microscopy for ultimate characterization of cell death were used. In comparison with control and sham-operated mice, the IIR group showed interstitial inflammatory infiltrates in the lung and significant increases of lung injury parameters and plasma lactate dehydrogenase and aspartate aminotransferase levels. Terminal transferase dUTP nick end labeling-positive cells and immunostaining for hemeoxygenase 1, an enzyme induced by inflammatory stimuli, were increased in the lung, heart, and kidney, but not in the liver. The number of hemeoxygenase 1-positive cells positively and significantly correlated to the number of terminal transferase dUTP nick end labeling-positive cells. Cell death was not associated with caspase 3 or cathepsin B activation. Electron microscopy showed morphological features compatible with oncotic rather than apoptotic cell death or necrosis, including mitochondrial swelling and cytoplasm disorganization in pulmonary and renal epithelial cells, lung and cardiac endothelial cells, and myocytes. These results indicate that, although lung injury is the most significant manifestation after IIR, oncotic cell death occurs in the lung, heart, and kidney, which may be related to ischemia and inflammation.
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PMID:Intestinal ischemia-reperfusion-induced acute lung injury and oncotic cell death in multiple organs. 1766 44


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