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

The farnesoid X receptor (FXR) is a bile acid-activated transcription factor that regulates the expression of genes critical for bile acid and lipid homeostasis. This study was undertaken to investigate the pathological consequences of the loss of FXR function on the risk and severity of atherosclerosis. For this purpose, FXR-deficient (FXR-/-) mice were crossed with apolipoprotein E-deficient (ApoE-/-) mice to generate FXR-/- ApoE-/- mice. Challenging these mice with a high-fat, high-cholesterol (HF/HC) diet resulted in reduced weight gain and decreased survival compared with wild-type, FXR-/-, and ApoE-/- mice. FXR-/- ApoE-/- mice also had the highest total plasma lipids and the most atherogenic lipoprotein profile. Livers from FXR-/- and FXR-/- ApoE-/- mice exhibited marked lipid accumulation, focal necrosis (accompanied by increased levels of plasma aspartate aminotransferase), and increased inflammatory gene expression. Measurement of en face lesion area of HF/HC-challenged mice revealed that although FXR-/- mice did not develop atherosclerosis, FXR-/- ApoE-/- mice had approximately double the lesion area compared with ApoE-/- mice. In conclusion, loss of FXR function is associated with decreased survival, increased severity of defects in lipid metabolism, and more extensive aortic plaque formation in a mouse model of atherosclerotic disease.
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PMID:Loss of functional farnesoid X receptor increases atherosclerotic lesions in apolipoprotein E-deficient mice. 1618 1

The aim of this study was to evaluate the relationship between apolipoprotein E gene polymorphism and nonalcoholic fatty liver disease. The study group consisted of 237 nonalcoholic fatty liver disease patients who were detected by ultrasonography and 201 controls with ultrasonographically normal livers. DNA amplifications were performed by polymerase chain reaction technique and apolipoprotein E genotypes were evaluated after digestion with CfoI restriction enzyme. Serum levels of glucose, lipids, lipoproteins, and apolipoproteins were measured in all subjects. Additionally, viral hepatitis markers, liver enzymes, and body mass index were assessed. Patients were found to have significantly higher triglyceride, glucose, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltransferase levels and lower high-density lipoprotein cholesterol and apolipoprotein (a) levels than controls (P<0.05). There were no statistically significant differences in genotypes and allele frequencies between all patients and controls. Comparing nonobese patients with controls, the frequencies of allele epsilon2 and genotype epsilon2epsilon3 were statistically significantly different in the controls (P=0.04 and P=0.01, respectively). In conclusion, occurrence of the epsilon2 allele and epsilon2epsilon3 genotype may be protective against development of nonalcoholic fatty liver disease.
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PMID:Apolipoprotein E gene polymorphism in nonalcoholic fatty liver disease. 1743 74

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of abnormal hepatic steatosis in the absence of alcohol abuse worldwide. Non-alcoholic steatohepatitis (NASH) is the most progressive form of NAFLD. The aim of this study was to investigate the role of apolipoprotein E (APOE) polymorphisms in the development of NASH. We analysed 57 NASH patients and 245 healthy controls using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a case-control study. The diagnosis of the patients was based on liver biopsy. The serum levels of glucose, lipids, vitamin B12, folic acid, homocysteine, insulin, total biluribin, total protein, albumin, ferritin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were determined in all of the subjects. Body mass index (BMI), waist circumference (WC), AST, ALT, fasting blood sugar (FBS), total cholesterol, triglyceride (TG), low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (VLDL) cholesterol, insulin and ferritin levels were significantly higher in the 57 patients with NASH compared with the 245 healthy controls. The APOE epsilon3 allele was overrepresented in the whole group of NASH patients (epsilon3=97.37% in NASH versus 82.45% in controls). The APOE polymorphism was statistically significantly associated with NASH (chi(2)=15.741; p=0.008). The APOE3/3 genotype (odds ratio [OR]=7.941; p=0.000) was strongly associated with increased risk for NASH in all NASH patients. Consequently, the APOE3/3 genotype may play a role in the aetiopathogenesis of NASH.
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PMID:Association of apolipoprotein E polymorphisms in patients with non-alcoholic steatohepatitis. 1846 45

The contribution of metabolic factors to the severity of liver disease is not completely understood. In this study, apolipoprotein E-deficient (ApoE-/-) mice were evaluated to define potential effects of hypercholesterolemia on the severity of carbon tetrachloride (CCl4)-induced liver injury. Under baseline conditions, hypercholesterolemic ApoE-/- mice showed increased hepatic oxidative stress (SOD activity/4-hydroxy-2-nonenal immunostaining) and higher hepatic TGF-beta1, MCP-1, and TIMP-1 expression than wild-type control mice. After CCl4 challenge, ApoE-/- mice exhibited exacerbated steatosis (Oil Red O staining), necroinflammation (hematoxylin-eosin staining), macrophage infiltration (F4/80 immunohistochemistry), and fibrosis (Sirius red staining and alpha-smooth muscle actin immunohistochemistry) and more severe liver injury [alanine aminotransferase (ALT) and aspartate aminotransferase] than wild-type controls. Direct correlations were identified between serum cholesterol and hepatic steatosis, fibrosis, and ALT levels. These changes did not reflect the usual progression of the disease in ApoE-/- mice, since exacerbated liver injury was not present in untreated age-paired ApoE-/- mice. Moreover, hepatic cytochrome P-450 expression was unchanged in ApoE-/- mice. To explore potential mechanisms, cell types relevant to liver pathophysiology were exposed to selected cholesterol-oxidized products. Incubation of hepatocytes with a mixture of oxysterols representative of those detected by GC-MS in livers from ApoE-/- mice resulted in a concentration-dependent increase in total lipoperoxides and SOD activity. In hepatic stellate cells, oxysterols increased IL-8 secretion through a NF-kappaB-independent mechanism and upregulated TIMP-1 expression. In macrophages, oxysterols increased TGF-beta1 secretion and MCP-1 expression in a concentration-dependent manner. Oxysterols did not compromise cell viability. Taken together, these findings demonstrate that hypercholesterolemic mice are sensitized to liver injury and that cholesterol-derived products (i.e., oxysterols) are able to induce proinflammatory and profibrogenic mechanisms in liver cells.
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PMID:Increased susceptibility to exacerbated liver injury in hypercholesterolemic ApoE-deficient mice: potential involvement of oxysterols. 1913 84

It is documented that hyperhomocysteinemia (HHcy) is an independent risk factor for atherosclerosis, but whether elevated plasma homocysteine contributes to the progression of atherosclerosis in aged animals with hypercholesterolemia is still unknown. HHcy was induced in apolipoprotein E (ApoE) knockout mice (male, 32 weeks old) by feeding 2% methionine/low folate (1 mg/kg) diet for 20 weeks. HHcy induced by methionine feeding significantly increased oxidative stress, as measured by thiobarbituric-reactive substances in livers (P < .05) and genetic expression of Cu,Zn-superoxide dismutase, in methionine-fed animals compared with controls (P < .05). Furthermore, lipoprotein profiles were changed, in that low-density lipoprotein-cholesterol was shifted to very low-density lipoprotein in the methionine-supplemented group. However, nuclear factor kappaB activity, atherosclerotic lesions, hepatic glutathione level, lipid profiles, and activities of aspartate aminotransferase and alanine aminotransferase were not significantly different. These findings suggest that HHcy induced by methionine may promote disturbances in lipid peroxidation and modify lipoprotein metabolism but not contribute to the progression of atherosclerotic lesion in aged ApoE knockout mice.
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PMID:Methionine-induced hyperhomocysteinemia modulates lipoprotein profile and oxidative stress but not progression of atherosclerosis in aged apolipoprotein E knockout mice. 1929 7

Atherosclerosis was previously thought to be a disease that primarily involves lipid accumulation in the arterial wall. In this report, we investigated the effect of Viola mandshurica W. Becker (V. mandshurica) water extract on atherosclerosis in apolipoprotein E deficient (ApoE[Formula: see text]) mice. The administration of V. mandshurica to high-fat diet-fed mice reduced body weight, liver weight, and serum levels of lipids (total cholesterol, low-density lipoprotein-cholesterol, triglycerides), glucose, alanine transaminase, and aspartate transaminase. Histopathologic analyses of the aorta and liver revealed that V. mandshurica attenuated atherosclerotic lesions and reduced lipid accumulation, inflammatory responses and fatty acid synthesis. V. mandshurica also increased phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), thereby reducing acetyl-CoA carboxylase (ACC) in liver tissue and inhibiting sterol regulatory element-binding protein 1c (SREBP-1c). V. mandshurica reduced protein expression levels of adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin) as well as ACC, fatty acid synthase, and SREBP-1c. In addition, quantitative analysis of V. mandshurica by high-performance liquid chromatography revealed the presence of esculetin and scopoletin. Esculetin and scopoletin reduced adhesion molecules in human aortic smooth muscle cells. Our results indicate that the anti-atherosclerotic effects of V. mandshurica may be associated with activation of the AMPK pathway. Therefore, AMPK-dependent phosphorylation of SREBP-1c by V. mandshurica may be an effective therapeutic strategy for combatting atherosclerosis and hepatic steatosis.
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PMID:Effects of Viola mandshurica on Atherosclerosis and Hepatic Steatosis in ApoE[Formula: see text] via the AMPK Pathway. 2851 4

The purpose of the current study was to investigate the mechanism by which fisetin improves atherosclerosis (AS) by regulating lipid metabolism and senescence in apolipoprotein E-deficient (apoE-/-) mice. An AS model was established by feeding apoE-/- mice a high-fat diet. Mice were randomly divided into the model group (n=18), the fisetin group (n=18) and the atorvastatin group (n=18). The control group (n=18) was composed of wild-type C57BL/6 mice of the same age and genetic background. The fisetin and atorvastatin groups were respectively treated with aqueous solutions of fisetin (12.5 mg/kg) and atorvastatin (2 mg/kg) via oral gavage daily for 12 weeks. The pathological morphology, lipid accumulation, collagen deposition of the aortic sinus were observed, serum lipids, superoxide dismutase (SOD) and malondialdehyde (MDA) levels and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were measured in the peripheral blood serum. Additionally, the expressions of proprotein convertase subtilisin/kexin type 9 (PCSK9), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), tumor suppressor protein p53 (p53), cyclin-dependent kinase inhibitor 1A (p21) and multiple tumor suppressor-1 (p16) were analyzed in the aorta. The results of the current study indicated that compared with the control group, a large area of AS plaque in the aortic sinus that contained a large amount of red-stained lipids and decreased collagen fiber content were found in the model group, which exhibited higher total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), oxidized low-density lipoprotein (ox-LDL) and MDA levels; higher ALT and AST activities, lower high-density lipoprotein cholesterol (HDL-C) and SOD levels and increased expression levels of PCSK9, LOX-1, p53, p21 and p16. Fisetin is a phytochemical and bioflavonoid that serves a potential role in chronic diseases including AS, obesity, diabetes and cancer due to its wide biological activities, such as regulating lipid metabolism and anti-aging, anti-oxidation and anti-inflammatory. Atorvastatin is recognized as a first-line treatment drug for AS; therefore it was used as a positive control in the current study. Following fisetin and atorvastatin treatment, both the AS plaque and the lipid accumulation in the aortic sinus were significantly reduced, and the expressions of PCSK9, LOX-1 and aging markers, including p53, p21 and p16 were downregulated.
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PMID:Fisetin ameliorates atherosclerosis by regulating PCSK9 and LOX-1 in apoE-/- mice. 3326 11