Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptors whose ligands include fatty acids, eicosanoids and the fibrate class of drugs. In humans, fibrates are used to treat dyslipidemias. In rodents, fibrates cause peroxisome proliferation, a change that might explain the observed hepatomegaly. In this study, rats were treated with multiple dose levels of six fibric acid analogs (including fenofibrate) for up to two weeks. Pathological analysis identified hepatocellular hypertrophy as the only sign of hepatotoxicity, and only one compound at the highest dose caused any significant increase in serum ALT or AST activity. RNA profiling revealed that the expression of 1288 genes was related to dose or length of treatment and correlated with hepatocellular hypertrophy. This gene list included expression changes that were consistent with increased mitochondrial and peroxisomal beta-oxidation, increased fatty acid transport, increased hepatic uptake of LDL-cholesterol, decreased hepatic uptake of glucose, decreased gluconeogenesis and decreased glycolysis. These changes are likely linked to many of the clinical benefits of fibrate drugs, including decreased serum triglycerides, decreased serum LDL-cholesterol and increased serum HDL-cholesterol. In light of the fact that all six compounds stimulated similar or identical changes in the expression of this set of 1288 genes, these results indicate that hepatomegaly is due to PPARalpha activation, although signaling through other receptors (e.g. PPARgamma, RXR) or through non-receptor pathways cannot be excluded.
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PMID:Profiling of hepatic gene expression in rats treated with fibric acid analogs. 1512 Sep 67

PTEN is a tumor suppressor gene mutated in many human cancers, and its expression is reduced or absent in almost half of hepatoma patients. We used the Cre-loxP system to generate a hepatocyte-specific null mutation of Pten in mice (AlbCrePten(flox/flox) mice). AlbCrePten(flox/flox) mice showed massive hepatomegaly and steatohepatitis with triglyceride accumulation, a phenotype similar to human nonalcoholic steatohepatitis. Adipocyte-specific genes were induced in mutant hepatocytes, implying adipogenic-like transformation of these cells. Genes involved in lipogenesis and beta-oxidation were also induced, possibly as a result of elevated levels of the transactivating factors PPARgamma and SREBP1c. Importantly, the loss of Pten function in the liver led to tumorigenesis, with 47% of AlbCrePten(flox/flox) livers developing liver cell adenomas by 44 weeks of age. By 74-78 weeks of age, 100% of AlbCrePten(flox/flox) livers showed adenomas and 66% had hepatocellular carcinomas. AlbCrePten(flox/flox) mice also showed insulin hypersensitivity. In vitro, AlbCrePten(flox/flox) hepatocytes were hyperproliferative and showed increased hyperoxidation with abnormal activation of protein kinase B and MAPK. Pten is thus an important regulator of lipogenesis, glucose metabolism, hepatocyte homeostasis, and tumorigenesis in the liver.
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PMID:Hepatocyte-specific Pten deficiency results in steatohepatitis and hepatocellular carcinomas. 1519 12

Amiodarone, an efficacious and widely used antiarrhythmic agent, has been reported to cause hepatotoxicity in some patients. To gain insight into the mechanism of this unwanted effect, mice were administered various doses of amiodarone and examined for changes in hepatic histology and gene regulation. Amiodarone induced hepatomegaly, hepatocyte microvesicular lipid accumulation, and a significant decrease in serum triglycerides and glucose. Northern blot analysis of hepatic RNA revealed a dose-dependent increase in the expression of a number of genes critical for fatty acid oxidation, lipoprotein assembly, and lipid transport. Many of these genes are regulated by the peroxisome proliferator-activated receptor-alpha (PPARalpha), a ligand-activated nuclear hormone receptor transcription factor. The absence of induction of these genes as well as hepatomegaly in PPARalpha knockout [PPARalpha-/-] mice indicated that the effects of amiodarone were dependent upon the presence of a functional PPARalpha gene. Compared to wild-type mice, treatment of PPARalpha-/- mice with amiodarone resulted in an increased rate and extent of total body weight loss. The inability of amiodarone to directly activate either human or mouse PPARalpha transiently expressed in human HepG2 hepatoma cells indicates that the effects of amiodarone on the function of this receptor were indirect. Based upon these results, we conclude that amiodarone disrupts hepatic lipid homeostasis and that the increased expression of PPARalpha target genes is secondary to this toxic effect. These results provide important new mechanistic information regarding the hepatotoxic effects of amiodarone and indicate that PPARalpha protects against amiodarone-induced hepatotoxicity.
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PMID:Disruption of hepatic lipid homeostasis in mice after amiodarone treatment is associated with peroxisome proliferator-activated receptor-alpha target gene activation. 1526 79

A 24-year-old man was admitted to our hospital because of liver dysfunction. He had been diagnosed as having psoriasis vulgaris at 18 years of age. Physical examination demonstrated obesity, general erythema, and hepatomegaly. Laboratory data revealed elevated serum levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and glucose. A histological examination of the liver revealed macrovesicular fatty change and infiltration of inflammatory cells, including lymphocytes and polymorphonuclear cells, within the liver lobules. Pericentral fibrosis and pericellular fibrosis were also recognized. He was diagnosed as having nonalcoholic steatohepatitis (NASH), based on the fact that he had no habit of drinking alcohol, as well as psoriasis vulgaris and diabetes mellitus. We herein report a very rare case of NASH associated with psoriasis vulgaris.
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PMID:Nonalcoholic steatohepatitis associated with psoriasis vulgaris. 1558 Apr 5

Liver diseases are frequently associated with disorders of the carbohydrate metabolism--impaired glucose tolerance, hyperinsulinaemia, insulin resistance. Impaired glucose tolerance is due in particular to impaired glucose uptake in the splanchnic area and periphery. Glucose production by the liver is normal, similarly as insulin secretion. Its reduced clearance leads to hyperinsulinaemia with subsequent down regulation of insulin receptors and the development of insulin resistance. In diabetic subjects hepatomegaly is frequent, most frequently associated with steatosis of the liver. It correlates with the degree of obesity rather than the type of hepatic lesion. It is reversible for a long time and develops into cirrhosis only when combined with other factors, in particular alcoholism or infection with hepatotropic viruses. Cirrhosis of the liver is also more frequent in diabetic subjects. Treatment with antidiabetics is discussed, attention is drawn to new types of biguanides, which may have some advantages. Cholelithiasis is in diabetic subjects three times more frequent and leads more frequently to serious, in particular inflamatory, complications with an adverse course. Therefore cholecystectomy should be contemplated. According to contemporary views it seems that diabetic hepoatopathy proper does not exist. The authors draws practical conclusions for the everyday work of physicians.
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PMID:[Diabetes mellitus and the liver]. 1563 90

The optimal level of energy for critically ill patients who require parenteral nutrition (PN) is unclear. Our objective was to determine whether 50% energy (50%E) restriction due to a reduction in carbohydrate or fat, with provision of adequate protein and micronutrients, ameliorates the detrimental effects of dexamethasone (Dex) on body protein catabolism, insulin resistance, and insulin-like growth factor-I (IGF-I) responses in rats administered PN. The experiment included 6 PN groups, adequate energy (AE) +/- Dex, 50% AE with high carbohydrate (50%E CHO) +/- Dex and 50% AE with high fat (50%E FAT) +/- Dex. There was a significant interaction between energy level and Dex such that the increase in body catabolism due to 50%E from CHO or FAT was reduced by approximately 50%, although the amount of body weight and nitrogen lost over 7 d was significantly greater with 50%E than with AE. AE+Dex induced a 60% increase in liver mass, whereas 50%E+Dex reduced the increase to 26%. AE+Dex induced a 5-fold increase in serum insulin level, whereas 50%E+Dex normalized the insulin to glucose ratio. Serum IGF-I levels were reduced 14-18% by Dex and 30% by 50%E. Hepatic immunoreactive IGF-I was significantly correlated with serum IGF-I and nitrogen balance. 50%E CHO and 50%E FAT had differential effects on hepatic IGF-I mRNA with a 40% decrease in IGF-I mRNA due to 50%E FAT+Dex. In summary,CHO or FAT hypoenergetic PN with adequate protein had similar effects in normalizing hyperinsulinemia, attenuating hepatomegaly, and reducing the increment, but not the total amount of body protein catabolism, induced by glucocorticoid excess.
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PMID:Hypoenergetic high-carbohydrate or high-fat parenteral nutrition induces a similar metabolic response with differential effects on hepatic IGF-I mRNA in dexamethasone-treated rats. 1573 81

Effective therapies for the treatment of obesity, a key element of metabolic syndrome, are urgently needed but currently lacking. Stearoyl-CoA desaturase-1 (SCD1) is the rate-limiting enzyme catalyzing the conversion of saturated long-chain fatty acids into monounsaturated fatty acids, which are major components of triglycerides. In the current study, we tested the efficacy of pharmacological inhibition of SCD1 in controlling lipogenesis and body weight in mice. SCD1-specific antisense oligonucleotide inhibitors (ASOs) reduced SCD1 expression, reduced fatty acid synthesis and secretion, and increased fatty acid oxidization in primary mouse hepatocytes. Treatment of mice with SCD1 ASOs resulted in prevention of diet-induced obesity with concomitant reductions in SCD1 expression and the ratio of oleate to stearoyl-CoA in tissues and plasma. These changes correlated with reduced body adiposity, hepatomegaly and steatosis, and postprandial plasma insulin and glucose levels. Furthermore, SCD1 ASOs reduced de novo fatty acid synthesis, decreased expression of lipogenic genes, and increased expression of genes promoting energy expenditure in liver and adipose tissues. Thus, SCD1 inhibition represents a new target for the treatment of obesity and related metabolic disorders.
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PMID:Prevention of obesity in mice by antisense oligonucleotide inhibitors of stearoyl-CoA desaturase-1. 1674 73

Lipodystrophies represent a group of diseases characterized by altered body fat repartition and major metabolic alterations with insulin resistance. Genetic forms of partial lipodystrophy are currently recognized as two syndromes with subcutaneous lipoatrophy but preserved or increased fat at the level of face and neck (Dunnigan syndrome or FPLD due to LMNA mutations) and/or abdomen (PPARgamma-linked forms) and are both transmitted as dominant diseases. FPLD is further characterized by muscular hypertrophy, hyperandrogenism, acanthosis nigricans, hepatomegaly with steatosis and at the biological level, marked hypertriglyceridaemia, low HDL cholesterol, insulin resistance and altered glucose tolerance or diabetes. These signs occur after puberty and their prevalence and severity are more marked in female than in male patients. At the genetic level, LMNA mutations concern in most cases the type-A lamin C-terminal domain and more than 80% are heterozygous substitutions located at position 482 (R482W/Q/L). The other locations are G465D, K486N, R582H and R584H. The presence of signs evocative of limb-girdle muscular dystrophy has been reported in patients with typical forms of FPLD. In addition, forms presenting with lipodystrophy and myopathy have been reported for patients with mutations at position R28W, R60G, R62G or R527P. In addition, lipodystrophy, either partial or generalized, can be associated with syndromes of premature ageing like Hutchinson-Gilford progeria or acromandibular dysplasia, but also with other phenotypes, as we described in a patient bearing the LMNA R133L heterozygous substitution.
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PMID:A-type lamin-linked lipodystrophies. 1577 53

Severe lipodystrophy is characterized by diminished adipose tissue and hypoleptinemia, leading to ectopic triglyceride accumulation. In the liver, this is associated with steatosis, potentially leading to nonalcoholic steatohepatitis (NASH). We investigated the prevalence of NASH and the effect of leptin replacement in these patients. Ten patients with either generalized lipodystrophy (8 patients) or Dunnigan's partial lipodystrophy (2 patients) were included in this analysis. Paired liver biopsy specimens were obtained at baseline and after treatment with recombinant methionyl human leptin (r-metHuLeptin), mean duration 6.6 months. The extents of portal and parenchymal inflammation, steatosis, ballooning, presence of Mallory bodies, and fibrosis in liver biopsy specimens were scored using a previously validated system developed to assess NASH activity. Histological disease activity was defined as the sum of ballooning, steatosis, and parenchymal inflammation scores. We concurrently tested serum triglycerides and aminotransferases and estimations of liver volume and fat content by magnetic resonance imaging. Eight of 10 patients met histological criteria for NASH at baseline. After treatment with r-metHuLeptin, repeat histological examinations showed significant improvements in steatosis (P = .006) and ballooning injury (P = .005), with a reduction of mean NASH activity by 60% (P = .002). Fibrosis was unchanged. Significant reductions were seen in mean serum triglycerides (1206-->226 mg/dL, P = .002), glucose (220-->144 mg/dL, P = .02), insulin (46.4-->24.8 muIU/mL, P = .004), ALT (54-->24 U/L, P = .02), AST (47-->22 U/L, P = .046), liver volume (3209-->2391 cm(3), P = .007), and liver fat content (31-->11%, P = .006). In conclusion, r-metHuLeptin therapy significantly reduced triglycerides, transaminases, hepatomegaly, and liver fat content. These reductions were associated with significant reductions in steatosis and the hepatocellular ballooning injury seen in NASH.
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PMID:Leptin reverses nonalcoholic steatohepatitis in patients with severe lipodystrophy. 1579 19

Angiopoietin-like protein 4 (ANGPTL4) is a circulating protein predominantly expressed in adipose tissue and liver. Several recent studies demonstrated that ANGPTL4 is the target gene of peroxisome proliferation activators, the agonists of which are widely used as the antidiabetic and lipid-lowering drugs. Here we provide evidence that ANGPTL4 is a blood-borne hormone directly involved in regulating glucose homeostasis, lipid metabolism, and insulin sensitivity. Adenovirus-mediated expression of ANGPTL4 potently decreased blood glucose and improved glucose tolerance, whereas it induced hyperlipidemia, fatty liver, and hepatomegaly in C57 mice. In db/db diabetic mice, ANGPTL4 treatment reduced hyperglycemia to a normal level, and markedly alleviated glucose intolerance and hyperinsulinemia. Ex vivo studies on primary rat hepatocytes revealed that ANGPTL4 significantly decreased hepatic glucose production and enhanced insulin-mediated inhibition of gluconeogenesis. Serum levels of ANGPTL4 in human subjects inversely correlated with plasma glucose concentrations and HOMA IR, the homeostasis model assessment of insulin resistance. In patients with type 2 diabetes, serum levels of ANGPTL4 were significantly lower than those in healthy subjects, suggesting that the decreased ANGPTL4 could be a causative factor of this disease. These results collectively indicate that ANGPTL4 exerts distinct effects on glucose and lipid metabolism, and that its beneficial effect on glucose homeostasis might be useful for the treatment of diabetes.
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PMID:Angiopoietin-like protein 4 decreases blood glucose and improves glucose tolerance but induces hyperlipidemia and hepatic steatosis in mice. 1583 23


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