Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The endogenous cannabinoid anandamide, a lipid mediator, induces various physiologic events such as vascular relaxation, inhibition of gap-junctions formation, tumor proliferation, neurologic analgesia, and apoptosis. Although increased concentration of anandamide in plasma has been implicated in pathophysiologic states including endotoxin-induced hypotension, the effects of anandamide on hepatocytes still remain unclear. In this study, we present evidence that plasma anandamide concentration is highly increased in severe hepatitis and cirrhosis patients. In addition, concentrations of anandamide within the pathophysiologic range potently induced apoptosis of hepatoma cell line (Hep G2) and primary hepatocytes, suggesting a possible link between increased anandamide level and hepatocyte damage. Anandamide-induced cell death was preceded by G0/G1 cell-cycle arrest, activation of proapoptotic signaling (i.e., p38 MAPK and JNK), and inhibition of antiapoptotic signaling (i.e., PKB/Akt) pathways. Moreover, anandamide increased susceptibility to oxidative stress-induced hepatocyte damage. In this context, methyl-beta-cyclodextrin (MCD), a membrane cholesterol depletor, or mevastatin, an HMG-CoA reductase inhibitor, or N-acetyl cysteine, an antioxidant, potently inhibited the anandamide-induced proapoptotic events and cell death, whereas putative cannabinoid receptor antagonists did not exhibit an inhibitory effect on anandamide-induced cell death. Furthermore, binding assay using polymyxin beads revealed that anandamide could interact with cholesterol. In conclusion, our data suggest that cholesterol present in the cell membrane determines the fate of hepatocytes exposed to anandamide, possibly functioning as an anandamide receptor.
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PMID:Membrane cholesterol but not putative receptors mediates anandamide-induced hepatocyte apoptosis. 1457 55

The clinical significance of phosphatase and tensin homolog deleted on chromosome ten (PTEN) protein expression and the correlation between the expression of PTEN and phosphorylation of protein kinase B (PKB/AKT) in human hepatocellular carcinoma (HCC) were investigated. The expression of PTEN and phospho-AKT was detected by SP immunohistochemical technique and Western blotting in 35 cases of HCC, 15 cases of liver cirrhosis and 8 cases of normal tissues. The correlation between the expression of PTEN and PKB/AKT in HCC was analyzed. The results showed that the positive expression of PTEN in HCC (62.9%, 0.085 +/- 0.021) was significantly lower than that in liver cirrhosis and normal tissues (P < 0. 01). The expression level of PTEN was related to the differentiation degree of HCC and the status of metastasis (P < 0.05). Western blotting revealed a significant inverse correlation between PTEN and phospho-AKT (r = -0.818, P < 0.01). These results demonstrated that down-regulation or loss of PTEN, which may not be able to effectively inhibit the hyper-phosphorylation of PKB/AKT, might play an important role in tumorigenesis and progression of HCC.
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PMID:Correlation between loss of PTEN expression and PKB/AKT phosphorylation in hepatocellular carcinoma. 1593 6

Integrin-linked kinase (ILK) is a multidomain focal adhesion protein implicated in signal transduction between integrins and growth factor receptors. Although its expression is upregulated in pulmonary and renal fibrosis, its role in the development of hepatic fibrosis remains to be determined. Therefore, we considered it important to investigate whether ILK is involved in activation of hepatic stellate cells and thus plays a role in the development of hepatic fibrosis. Immunohistochemical analysis of liver sections obtained from rats with CCl4-induced cirrhosis revealed increased expression and colocalization of ILK and alpha-smooth muscle actin in hepatic stellate cells in perisinusoidal areas. In addition, hepatic stellate cells isolated from fibrotic livers expressed high levels of ILK and alpha-smooth muscle actin, and their expression was sustained in culture. In contrast, hepatic stellate cells (HSCs) isolated from normal rat liver did not express ILK, but its expression was increased when the cells were activated in culture. Our studies also showed that ILK is involved in the phosphorylation of ERK 1/2, p38 MAPK, JNK, and PKB and that selective inhibition of ILK expression by siRNA results in a significant decrease in their phosphorylation. These changes were accompanied by significant inhibition of cell spreading and migration without affecting cell proliferation. In conclusion, ILK plays a key role in HSC activation and could be a possible target for antifibrogenic therapy.
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PMID:Involvement of integrin-linked kinase in carbon tetrachloride-induced hepatic fibrosis in rats. 1694 98

Alpha-lipoic acid (alpha-LA) is an antioxidant used for the treatment of a variety of diseases, including liver cirrhosis, heavy metal poisoining, and diabetic polyneuropathy. In addition to its protective effect against oxidative stress, alpha-LA induces apoptosis in different cancer cells types. However, whether alpha-LA acid induces apoptosis of hepatoma cells is unknown. Herein, we investigated whether alpha-LA induces apoptosis in two different hepatoma cell lines FaO and HepG2. The results showed that alpha-LA inhibits the growth of both cell lines as indicated by the reduction in cell number, the reduced expression of cyclin A and the increased levels of the cyclin/CDKs inhibitors, p27(Kip1) and p21(Cip1). Cell cycle arrest was associated with cell loss, and DNA laddering indicative of apoptosis. Apoptosis was preceded by increased generation of reactive oxygen species, and associated with p53 activation, increased expression of Bax, release of cytochrome c from mitochondria, caspases activation, decreased levels of survivin, induction of pro-apoptotic signaling (i.e JNK) and inhibition of anti-apoptotic signaling (i.e. PKB/Akt) pathways. In conclusion, this study provides evidence that alpha-LA induces apoptosis in hepatoma cells, describes a possible sequence of molecular events underlying its lethal effect, and suggests that it may prove useful in liver cancer therapy.
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PMID:Increased ROS generation and p53 activation in alpha-lipoic acid-induced apoptosis of hepatoma cells. 1713 95

In liver cirrhosis, down-regulation of endothelial nitric oxide synthase (eNOS) has been implicated as a cause of increased intrahepatic resistance. We investigated whether Rho-kinase activation is one of the molecular mechanisms involved in defective eNOS signaling in secondary biliary cirrhosis. Liver cirrhosis was induced by bile duct ligation (BDL). We measured mean arterial pressure (MAP), portal venous pressure (PVP), and hepatic tissue blood flow (HTBF) during intravenous infusion of saline (control), 0.3, 1, or 2 mg/kg/hour fasudil for 60 minutes. In BDL rats, 1 and 2 mg/kg/hour fasudil significantly reduced PVP by 20% compared with controls but had no effect on HTBF. MAP was significantly reduced in response to 2 mg/kg/hour fasudil. In the livers of BDL rats, 1 and 2 mg/kg/hour fasudil significantly suppressed Rho-kinase activity and significantly increased eNOS phosphorylation, compared with controls. Fasudil significantly reduced the binding of serine/threonine Akt/PKB (Akt) to Rho-kinase and increased the binding of Akt to eNOS. These results show in secondary biliary cirrhosis that (1) Rho-kinase activation with resultant eNOS down-regulation is substantially involved in the pathogenesis of portal hypertension and (2) Rho-kinase might interact with Akt and subsequently inhibit the binding of Akt to eNOS.
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PMID:Defective endothelial nitric oxide synthase signaling is mediated by rho-kinase activation in rats with secondary biliary cirrhosis. 1816 63