Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Fas ligand (FasL), a member of the tumor necrosis factor family, induces apoptosis in Fas-expressing cells. A matrix metalloproteinase-like enzyme cleaves the membrane-bound FasL to produce the soluble FasL (sFasL). Since FasL has been reported to play a pivotal role in the development of hepatitis, we evaluated clinical significance of serum sFasL in acute liver injury including acute self-limited and fulminant hepatitis. Serum sFasL in 19 patients including 12 with acute self-limited hepatitis and 7 with fulminant hepatitis was measured by an enzyme-linked immunosorbent assay (ELISA). The clinical data consisted of 18 indices including age, sex, liver function tests, hepatocyte growth factor (HGF), outcome and sFasL. Serum sFasL in fulminant hepatitis is 0.06+/-0.01 ng/ml, being identical to that in acute self-limited hepatitis, Serum sFasL is positively correlated with AST and ALT (p<0.0001 and p<0.0001). The factors associated with outcome of the patients were HGF, albumin, prothrombin time, platelet count, cholinesterase and leukocyte count in this order. Serum sFasL serves as an indicator of liver injury in acute self-limited and fulminant hepatitis.
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PMID:Clinical significance of serum soluble Fas ligand in patients with acute self-limited and fulminant hepatitis. 975 39

Administration of a methionine and choline deficient (MCD) diet to rodents causes progressive fibrosing steatohepatitis pathologically similar to human metabolic steatohepatitis. We have previously shown that the peroxisome proliferator-activated receptor-alpha (PPARalpha) agonist, Wy-14,643, prevented the development of MCD diet-induced steatohepatitis. We have now tested whether Wy-14,643 ameliorates established steatohepatitis and fibrosis. Male C57BL6 mice were fed the MCD diet for 51 days to induce severe steatohepatitis. They were then treated with Wy-14,643 together with the MCD diet for 5 or 12 days; positive controls continued on the MCD diet for 5 or 12 days. After 5 days of Wy-14,643 treatment, alanine aminotransferase (ALT) levels were significantly decreased, steatohepatitis less severe, and hepatic lipoperoxides significantly reduced. After 12 days, hepatic triglycerides were normalized and there was near resolution of histological changes. MCD dietary feeding was associated with increased expression of vascular cell adhesion molecule (VCAM)-1, and increased numbers of activated macrophages in the liver. Treatment with Wy-14,643 reduced VCAM-1 expression and macrophage numbers. MCD diet-fed mice developed hepatic fibrosis with increased hepatic collagen alpha1(I), tissue inhibitor of metalloproteinases (TIMP)-1, TIMP-2, and matrix metalloproteinase (MMP)-13 mRNA levels. After treatment with Wy-14,643, expression of these genes was reduced in a manner that paralleled the reduction in activated hepatic stellate cells and near resolution of liver fibrosis. In conclusion, the present study shows that MCD diet-induced fibrosing steatohepatitis can be reversed by treatment with Wy-14,643. It is likely that activation of PPARalpha reverses fibrosis indirectly by reducing stimuli, such as lipid peroxides, and activation of cells responsible for promoting hepatic fibrosis.
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PMID:Administration of the potent PPARalpha agonist, Wy-14,643, reverses nutritional fibrosis and steatohepatitis in mice. 1512 57

Liver biopsy is thought mandatory for management in patients with hepatitis C virus infection (HCV) especially for histopathological grading and staging of the disease to assess suitability for treatment and monitoring disease progression. However, tracking of liver disease progression can't rely on repeated biopsies. The study aimed to evaluate two significant items, we try to develop and validate a non-invasive predictive tool to assess hepatic necro-inflammation and fibrosis. Also, to determine factors that associate severity of hepatic pathology in HCV infected Egyptian patients particularly at Sharkia G. The study included 109 patients with detectable HCV by Real Time-PCR. The patients were classified into three different pathological stages and grades according to the new concept of histopathoglical staging and grading. The different clinical, biochemical, virological and ultra-sonographic parameters were assessed and analyzed and the variables that showed significant association with histopathological staging and grading were included in multivariate logistic regression analysis. The regression model revealed that, platelet count, matrix metalloproteinase-9 (MMP-9), portal vein diameter, splenic longitudinal axis, alanine transaminase, aspartate transaminase and viral load were the factors that add significance to the model in decreasing order of significance. From these findings we generate a new score ranged from 0-9. The score model was applied to our patients to assess its validity where it proved to be accurate in discriminating patients with mild inflammation and fibrosis (sensitivity 81.8%, specificity 80.5% and accuracy 80.7%) and more accurate in detecting patients with cirrhosis (specificity 96.6%, sensitivity 80% & accuracy 93.6%) but less accurate in detecting patients with moderate to severe fibrosis (specificity 66.7%, sensitivity 68.7% & accuracy 67.9%). Also the results revealed that, co-infection with schistosomiasis, old age > or = 45 years and positive history of blood transfusion as a source of infection was significantly associated with severe hepatic pathology. It is concluded that, the score model can't completely replace liver biopsy but at least it could be used to substantially reduce the number of liver biopsies done in patients with HCV infection in assessing disease progression during follow up. Also, it can be used to make decisions about treatment in patients who have contraindications to or who refused liver biopsy. Co-infection with schistosomiasis, age > or = 45 and positive history of blood transfusion in patients with HCV warrant special attention with more intensive follow up. These factors may play a major role in forecasting the course of HCV as well as in determining the therapeutic approach in each case.
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PMID:Non-invasive markers and predictors of severity of hepatic fibrosis in HCV patients at Sharkia Governorate, Egypt. 1512 53

As chronic liver disease progresses, an imbalance occurs between synthesis and breakdown of extracellular matrix (ECM). Matrix metalloproteinases (MMPs) are involved in degrading ECM while tissue inhibitors of metalloproteinases (TIMPs) prevent their fibrolytic action. In the present study, serum levels of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were investigated as non-invasive parameters for the diagnosis of hepatic fibrosis in patients with HCV related chronic liver disease. Their diagnostic potential was evaluated in comparison to hepatic histology and standard liver function tests. A sandwich enzyme immunoassay technique was used to study circulating values of MMP-2 and TIMP-1 in forty-one patients with HCV antibodies in their sera (27 patients with biopsy ascertained chronic hepatitis C and 14 patients with histologically proven liver cirrhosis. Hepatic histology was evaluated using the hepatitis-activity-index according to Ishak et al. (1995), quantifying separately inflammatory activity and fibrosis. Ten healthy individuals were also included in the study as controls. Serum levels of MMP-2 were similar in controls and in chronic hepatitis C patients with (n = 15) and without (n = 12) fibrosis, but increased significantly in cirrhosis. TIMP-1 serum values showed a steady increase from normal controls to chronic hepatitis C without fibrosis, hepatitis C with fibrosis, and cirrhosis. The diagnostic potential of MMP-2 to detect fibrosis was low with a sensitivity of 7% and a diagnostic efficiency of 56%. The diagnostic potential of circulating MMP-2 to detect cirrhosis was higher with a sensitivity of 83% and a specificity of 96% resulting in a diagnostic efficiency of 92%. Serum TIMP-1 values detected fibrosis with a sensitivity of 67% and a specificity of 69% resulting in an efficiency rate of 70%. TIMP-1 values detected cirrhosis with 100% sensitivity but only 75% specificity. The diagnostic potential of circulating TIMP-1 was higher than that of serum ALT, AST or albumin values. In conclusion, serum values of MMP-2 and TIMP-1 are able to detect cirrhosis with a high sensitivity. Moreover, TIMP-1 values can detect fibrosis with comparable efficiency. Regular determinations of both TIMP-1 and MMP-2 in patients with chronic hepatitis C may be used as indicators of increasing fibrosis and the development of cirrhosis.
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PMID:Diagnostic potential of serum matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 as non-invasive markers of hepatic fibrosis in patients with HCV related chronic liver disease. 1571 20

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear transcription factor that comprises the primary molecular target for thiazolidinedione (TZD) insulin-sensitizing drugs. Whilst expressed in many tissues in humans, its abundant expression in adipose tissue is believed to be the focal point through which TZDs regulate genes involved in glucose and lipid metabolism and via which these agents ultimately improve the hyperglycemia of type 2 diabetes. However, TZDs exhibit many additional properties, not least an array of effects which suggest a broad attack on the inflammatory process. Thus, TZDs have been shown to reduce plasma levels of the chemokine, monocyte chemotactic protein-1 (MCP-1), the anti-fibrinolytic protein, plasminogen activator inhibitor-1 (PAI-1), the endothelial cell adhesion molecules, e-selectin and inter-cellular adhesion molecule-1 (ICAM-1), the leucocyte-activating molecule, CD40L, and the tissue-remodeling enzyme, matrix metalloproteinase-9 (MMP-9). Further tangible evidence of a reduction by TZDs of systemic inflammation in patients with the classical metabolic syndrome stems from falls in the white blood cell count, P-selectin-positive platelets and in the acute-phase inflammatory proteins, C-reactive protein, serum amyloid A and fibrinogen. At the tissue level, TZDs improve vascular endothelial function, and reduce the rate of progression of intimal-medial thickening of the carotid artery and the microalbuminuria of type 2 diabetes. Further, TZDs have been shown to be efficacious in inflammatory diseases as wide-ranging as psoriasis, ulcerative colitis and non-alcoholic steatohepatitis (NASH). In the case of the latter, a broad spectrum of TZD-related properties is visible. Here, these drugs improve insulin sensitivity for glucose metabolism, reduce hyperinsulinemia, hepatic steatosis, inflammation and fibrosis, and lower the circulating levels of liver transaminases (ALT, AST), alkaline phosphatase and gamma glutamyl transferase. These effects in humans are also well-supported by investigative animal and in vitro studies. The ameliorative effects on liver fibrosis are of particular interest since they suggest that TZDs are able to activate a program of corrective tissue-remodeling. The basis for this action may be partly an ability to inhibit matrix protein secretion by hepatic stellate cells. An analogous action has also been seen in kidney mesangial cells. In conclusion, TZDs are important new drugs, presently indicated for the treatment of type 2 diabetes but with a spectrum of properties which suggests their potential for treating a number of degenerative inflammatory diseases, including NASH. However, full-scale, long-term clinical trials are needed with TZDs to test their potential to treat NASH, not least because of the (hepatotoxic) legacy of the prototype TZD, troglitazone, but also in view of the escalating burden of liver disease which is accompanying the increasing global prevalence of clinical obesity and type 2 diabetes.
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PMID:Thiazolidinediones: Pleiotropic drugs with potent anti-inflammatory properties for tissue protection. 1619 19

Piper betel leaves (PBL) are used in Chinese folk medicine for the treatment of various disorders. PBL has the biological capabilities of detoxication, antioxidation, and antimutation. In this study, we evaluated the antihepatotoxic effect of PBL extract on the carbon tetrachloride (CCl(4))-induced liver injury in a rat model. Fibrosis and hepatic damage, as reveled by histology and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were induced in rats by an administration of CCl(4) (8%, 1 ml/kg body weight) thrice a week for 4 weeks. PBL extract significantly inhibited the elevated AST and ALT activities caused by CCl(4) intoxication. It also attenuated total glutathione S-transferase (GST) activity and GST alpha isoform activity, and on the other hand, enhanced superoxide dismutase (SOD) and catalase (CAT) activities. The histological examination showed the PBL extract protected liver from the damage induced by CCl(4) by decreasing alpha-smooth muscle actin (alpha-sma) expression, inducing active matrix metalloproteinase-2 (MMP2) expression though Ras/Erk pathway, and inhibiting TIMP2 level that consequently attenuated the fibrosis of liver. The data of this study support a chemopreventive potential of PBL against liver fibrosis.
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PMID:Protection effect of piper betel leaf extract against carbon tetrachloride-induced liver fibrosis in rats. 1667 62

The aim of the study was to examine the effects of epigallocatechin-3-gallate (EGCG) on hepatic fibrogenesis and on cultured hepatic stellate cells (HSCs). The rat model of carbon tetrachloride (CCl(4))-induced hepatic fibrosis was used to assess the effect of daily intraperitoneal injections of EGCG on the indexes of fibrosis. Histological and hepatic hydroxyproline examination revealed that EGCG significantly arrested progression of hepatic fibrosis. EGCG caused significant amelioration of liver injury (reduced activities of serum alanine aminotransferase and aspartate aminotransferase). The development of CCl(4)-induced hepatic fibrosis altered the redox state with a decreased hepatic glutathione and increased the formation of lipid peroxidative products, which were partially normalized by treatment with EGCG, respectively. Moreover, EGCG markedly attenuated HSC activation as well as matrix metalloproteinase (MMP)-2 activity. In cultured stellate cell, the expression of MMP-2 mRNA and protein were substantially reduced by EGCG treatment. Concanavalin A-induced activation of secreted MMP-2 was inhibited by EGCG through the influence of membrane type 1-MMP activity. These results demonstrate that administration of EGCG may be useful in the treatment and prevention of hepatic fibrosis.
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PMID:Green tea polyphenol epigallocatechin-3-gallate inhibits oxidative damage and preventive effects on carbon tetrachloride-induced hepatic fibrosis. 1748 82

In the course of the investigation of effects of newly synthesized matrix metalloproteinase inhibitors (MMPIs), FYK-1388, FYK-1352 and F61-1008, which have strong and broad matrix metalloproteinase (MMP) inhibitory activity, on wound healing in streptozotocin (STZ)-induced diabetic rats, strong reducing effects on serum triacylglycerol (TG) have been found. Namely, when examined using breaking wound strength as an index, MMPIs did not significantly facilitate wound healing in STZ-induced diabetic rats. Unexpectedly, however, the treatment of STZ-induced diabetic rats with MMPIs markedly lowered the serum level of TG without changing the blood glucose level. Among these compounds tested, FYK-1388 was the most effective, and the compound reduced serum concentrations of TG and cholesterol and levels of very low-density lipoprotein (VLDL)-TG and low density lipoprotein (LDL)-cholesterol in a dose-dependent manner. FYK-1388 did not affect serum levels of free fatty acids, high-density lipoprotein (HDL)-cholesterol, aspartate aminotransferase and alanine aminotransferase, mass of body fat, liver weights, and hepatic contents of TG and cholesterol. Moreover, treatment of Zucker fa/fa rats with FYK-1388 lowered serum levels of TG and cholesterol without changing blood levels of glucose and insulin. Since the structures of these MMPIs markedly differ from those of the hypotriglyceridemic drugs that are used clinically, it seems plausible that these MMPIs could be used as a new type of hypotriglyceridemic drug.
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PMID:Reducing effect of matrix metalloproteinase inhibitors on serum triacylglycerol in streptozotocin-induced diabetic rats and Zucker fa/fa rats. 1766 4

Glycyrrhizin, a biological active compound isolated from the liquorice root, has been used as a treatment for chronic hepatitis. We have examined the involvement of matrix metalloproteinase (MMP)9 in the development of lipopolysaccharide (LPS) and D-galactosamine (GalN)-induced liver injury in mice. We also investigated the effect of glycyrrhizin on expression of MMP-9 in this model. Levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased after LPS/ GalN treatment. Expression of MMP-9 mRNA and protein was markedly up-regulated in liver tissues 6-8 h after LPS/GalN treatment. Pretreatment with glycyrrhizin (50 mg kg(-1)) and the MMP inhibitor (5 mg kg(-1)) suppressed increases in serum levels of ALT and AST in mice treated with LPS/GalN. Furthermore, glycyrrhizin inhibited levels of both mRNA and protein for MMP-9. Immunohistochemical reaction for MMP-9 was observed in macrophages/monocytes infiltrated in the inflammatory area of liver injury. Glycyrrhizin reduced the infiltration of inflammatory cells and immunoreactive MMP- 9 in liver injury. The results indicated that MMP-9 played a role in the development of LPS/GalN- induced mouse liver injury, and suggested that an inhibition by glycyrrhizin of the acute liver injury may have been due to a down-regulation of MMP-9.
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PMID:Glycyrrhizin prevents of lipopolysaccharide/D-galactosamine-induced liver injury through down-regulation of matrix metalloproteinase-9 in mice. 1825 Oct 86

The pathophysiological mechanisms of thioacetamide (TAA)-induced hepatic fibrogenesis are not yet fully understood. In particular, the role of hepatic stellate cells (HSCs) remains unclear. We therefore examined proliferation and transdifferentiation of HSC as well as the underlying molecular mechanisms in TAA-induced fibrosis. Hepatic fibrogenesis was induced in mice by addition of TAA to drinking water. Liver damage was determined by assessment of alanine aminotransferase and aspartate aminotransferase levels, and measurement of collagen deposition. Additionally, expression patterns of alpha-smooth muscle actin, glial fibrillary acidic protein (GFAP, specific hepatic biomarker for HSC), cysteine- and glycine-rich protein 2 (CRP2, specific marker of HSC transdifferentiation), tissue inhibitor of metalloproteinases-1, matrix metalloproteinase-9 (MMP-9), interleukins (IL-1beta, IL-6), platelet-derived growth factors (PDGF-B, PDGF-D) , tumor necrosis factor (TNF)-alpha, and (transforming growth factor (TGF)-beta1 were assessed by real-time PCR. Transcription of GFAP and CRP2 were transiently upregulated during TAA-induced fibrogenesis (punctum maxima (p.m.) week 10 for GFAP and week 14 for CRP2). Similar transient expression patterns were demonstrated for IL-1beta, IL-6, TGF-beta1, and PDGF-B (p.m. week 12) whereas TNF-alpha and PDGF-D continuously increased with ongoing liver injury. In particular, not only neutrophil granulocytes, but also macrophages and leukocytes served as a major source for MMP-9 expression. GFAP and CRP2 expression patterns demonstrated transiently increased HSC-activation during TAA-induced hepatic fibrogenesis. The rate of increase of transcription of GFAP correlated best with PDGF-B, whereas CRP2 levels correlated with PDGF-B, PDGF-D, and IL-1beta expression. This study demonstrates for the first time that transiently increased activation patterns of HSC are observed in toxically induced hepatic fibrosis. Thus, TAA in drinking water is an effective and elegant model to induce reproducible states of liver fibrosis without parenchymal damage in mice.
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PMID:Activation of hepatic stellate cells is associated with cytokine expression in thioacetamide-induced hepatic fibrosis in mice. 1879 50


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