Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Death receptor-mediated hepatocyte apoptosis is implicated in a wide range of liver diseases including viral hepatitis, alcoholic hepatitis, ischemia/reperfusion injury, fulminant hepatic failure, cholestatic liver injury, and cancer. Our aim was to clarify the protective pathway in death receptor-mediated hepatocyte apoptosis and the significance of apoptosis in liver injury. In vitro: AdIkappaBsr plus tumor necrosis factor (TNF)-alpha/Jo2 rapidly induced apoptosis in mouse hepatocyte, whereas TNF-alpha/Jo2 alone produced little cytotoxicity. The combination of the mitochondrial permeability transition (MPT) inhibitors, cyclosporine A and trifluoperazine, protected AdIkappaBsr-infected hepatocytes from TNF-alpha- but not Fas-mediated apoptosis. The TNF-alpha and Jo2 induced iNOS through NF-kappaB. Nitric oxide donor (S-nitroso-N-acetylpenicillamine) inhibited Bid cleavage, the MPT, and caspase activation and reduced TNF-alpha- and Fas-mediated cell killing. Inhibition of PI3K by LY294,002 and a dominant-negative Akt, which attenuated NF-kappaB activation by TNF-alpha or Jo2, sensitized hepatocytes to TNF- or Jo2. In vivo: apoptosis as well as necrosis may play an important role in hepatic ischemia/reperfusion injury. Adenoviral gene transfer of myrAkt could inhibit apoptotic cell death and subsequent hepatic ischemia/reperfusion injury in the rat, through Bad not NF-kappaB. Bile acids cause liver injury during cholestasis by inducing hepatocyte apoptosis. Hepatocyte apoptosis has a major role in hepatic injury by bile duct ligation. At least, early hepatic injury by bile duct ligation involved Fas-mediated and Bcl-xL insensitive apoptotic pathway. In conclusion, the role of apoptosis in various liver diseases may suggest possible treatments.
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PMID:Tumor necrosis factor signaling in hepatocyte apoptosis. 1756 63

Endoplasmic reticulum stress, initiated by protein overload or malfolding, activates a complex network of interacting and parallel responses that dampen the stress. However, when the protective response is insufficient, a set of responses leads to apoptosis. Coupled with the latter are promotion of lipid synthesis and proinflammatory responses. Evidence has been mounting for an important role of the endoplasmic reticulum (ER) stress response in the pathogenesis of chronic viral hepatitis, insulin resistance and nonalcoholic fatty liver disease, ischemia-reperfusion injury, genetic disorders of protein malfolding, and alcoholic liver disease. In the latter, a key candidate for inducing ER stress is hyperhomocysteinemia. Betaine treatment promotes removal of homocysteine and prevents ER stress, fatty liver, and apoptosis in a mouse model of alcohol-induced liver disease. With increasing interest in the potential role of ER stress in liver disease, greater understanding of pathophysiology, prevention, and treatment of liver disease is anticipated.
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PMID:Endoplasmic reticulum stress and liver injury. 1797 73

Accumulation of unfolded or malfolded proteins induces endoplasmic reticulum (ER) stress which elicits a complex network of interacting and parallel responses that dampen the stress. The ER stress response in the liver is controlled by intrinsic feedback effectors and is initially protective. However, delayed or insufficient responses or interplay with mitochondrial dysfunction may turn physiological mechanisms into pathological consequences including apoptosis, fat accumulation and inflammation all of which have an important role in the pathogenesis of liver disorders such as genetic mutations, viral hepatitis, insulin resistance, ischemia/reperfusion injury, and alcoholic and non-alcoholic steatosis. In both alcohol and non-alcohol-induced ER stress, a common candidate is hyperhomocysteinemia. Betaine supplementation and/or expression of betaine-homocysteine methyltransferase (BHMT) promote removal of homocysteine and alleviate ER stress, fatty accumulation and apoptosis in cultured hepatocytes and mouse models. The rapidity and magnitude of homocysteine-induced activation of each of the main ER resident transmembrane sensors including inositol requiring enzyme 1 (IRE-l alpha), activating transcription factor 6 (ATF-6) and RNA-activated protein kinase (PKR)-like ER kinase (PERK) appear different in different experimental models. Dissection and differentiation of ER stress signaling may reveal clues on the specific importance of the ER stress response in contributing to liver injury and thus provide better strategies on prevention and treatment of liver disease.
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PMID:Dissection of endoplasmic reticulum stress signaling in alcoholic and non-alcoholic liver injury. 1833 57

Platelets play a pivotal role in thrombosis and hemostasis, but an increasing variety of extra-hemostatic functions of platelets are being recognized. This review summarizes recent advances in the understanding of the role of platelets in various pathologies involving the liver. In ischemia/reperfusion injury of the liver, platelets appear to play a dual role. On one hand, platelets bind to the activated sinusoidal endothelium and induce apoptosis of these cells; on the other hand, platelet-derived serotonin assists in repair of the ischemic tissue. Furthermore, platelets are attracted to the liver following systemic inflammatory stimuli, but the significance of this finding is still unclear. Platelets and platelet-derived serotonin appear vital for liver regeneration following a partial liver resection. Finally, platelets and platelet-derived serotonin aggravate viral hepatitis by affecting the microcirculation in the liver.
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PMID:The role of platelets in liver inflammation and regeneration. 2041 32

Mitochondrial dysfunction acts as a common pathogenetic mechanism in several acute and chronic liver diseases, such as Alcoholic and Non-Alcoholic Fatty Liver Disease (NAFLD), drug-induced steatohepatitis, viral hepatitis, biliary cirrhosis, hepatocellular carcinoma, ischemia/reperfusion injury and transplant rejection. In particular mitochondrial uncoupling,has been recently identified to play a determinant role in the pathogenesis of liver diseases by causing decrease of mitochondrial proton motive force and ATP depletion. Damaged mitochondria present defects in lipid homeostasis, bioenergetics impairment and overproduction of Reactive Oxygen Species (ROS), leading to lipid accumulation and oxidative stress. Dysfunctional and/or uncoupled mitochondria enhance the susceptibility of hepatocytes to cell death by necrosis, via ATP depletion, or by apoptosis, via membrane permeabilization. Thus, prevention of mitochondrial alterations promises to be an effective strategy for treatment of liver diseases. However, no therapy has proven to be absolutely effective, whereas those that are beneficial present several side effects. The present review summarizes the recent approaches in mitochondrial drug deliver systems and focuses on mitochondria-targeted molecules application in liver disease. New selective molecules and nanocarriers technology are also considered as potentially effective in the targeting of mitochondrial dysfunction in liver pathology.
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PMID:Targeting mitochondria: a new promising approach for the treatment of liver diseases. 2049 41

Chemotherapy drugs, biological medications that are used to treat cancer, may cause hepatic side effects. Patients with pre-existing viral hepatitis may be more susceptible to exacerbation of their underlying liver disease, and risk of drug-induced hepatotoxicity. We conducted a search on immunosuppression, and its impact on reactivation of viral hepatitis, using the electro-nic medical databases. Before starting chemotherapy, it is recommended to record the past history of liver disease and check for hepatitis B virus (HBV) and hepatitis C virus (HCV) serology. In immunosuppressed patients, radiation toxicity, graft versus host disease, hepatic veno-occlusive disease, acalculous cholecystitis, tumor infiltration, ischemia, other viruses such as CMV and her-pes virus, and systemic infection should also be considered. Transplant recipients with serologic evidence of previous infection with hepatitis B or C, or those who receive organs from a seropositive donor, should have viral load levels monitored before and after transplantation and, may also require treatment. We believe that there is a role for prophylactic use of antiviral treatment in patients at risk for HBV reactivation.
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PMID:Impact of immunosuppression and chemotherapy on reactivation of viral hepatitis. 2058 63

Hepatocellular carcinoma (HCC) is the fifth most common neoplasm in the world, closely correlated with viral hepatitis and liver cirrhosis. The vast majority of HCC patients present at a late stage and are unsuitable for surgery due to limited liver functional reserve. Tumors can involve major vessels or hilar structures, necessitating major liver resection and/or rendering liver resection unfeasible. A series of new technologies have been developed to optimise HCC management. Stem cell therapy improves impaired liver functional reserve prior to liver resection. Intravascular radiofrequency ablation recanalises the portal vein invaded by tumour thrombus and endobiliary radiofrequency ablation restores and extends biliary patency of the bile duct invaded by malignancy. Laparoscopic radiofrequency assisted liver resection minimizes blood loss and avoids liver warm ischemia, while increasing parenchymal sparing. These benefits combined maximize the safety of liver resection.
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PMID:Towards the optimization of management of hepatocellular carcinoma. 2196 8

Since the discovery of the impact of serotonin in liver regeneration, this molecule has gained considerable attention in liver physio-pathology. Platelet-derived serotonin initiates liver regeneration after partial hepatectomy in various rodent models. Serotonin agonism stabilizes the hepatic microcirculation and prevents small-for-size liver graft failure. Similarly, serotonin receptor agonists improve the sinusoidal perfusion of aged liver and restore the deficient liver regeneration in old mice through a pathway dependent on vascular endothelial growth factor. Beside hepatocyte proliferation, cholangiocytes have been shown to be able to deploy serotonin as an autocrine/paracrine signal to regulate regeneration of the biliary tree. Increasing evidence indicates that serotonin is involved in many pathological conditions of the liver. For example, serotonin promotes tissue repair after ischemia/reperfusion injury. Reactive oxygen species generated by serotonin degradation contribute to steatohepatitis in rodent models. Serotonin aggravates viral hepatitis, again through vasoactive effects on the microcirculation, and plays a crucial role in the progression of hepatic fibrosis. Finally, serotonin may facilitate tumor growth of primary liver carcinoma like cholangiocarcinoma and hepatocellular carcinoma. These findings make serotonin both friend and foe for the liver. Whichever, these new data emphasize the potential of serotonin as a pharmacological target in liver disease.
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PMID:Serotonin: a double-edged sword for the liver? 2211 13

Heme oxygenases (HO) are essential enzymes which degrade heme into carbon monoxide (CO), biliverdin and free iron. Due to its anti-inflammatory, anti-apoptotic and, as recently described, anti-viral properties the inducible HO isoform HO-1 is an important molecule which could find its way into therapy of gastrointestinal diseases. Acute and chronic liver injuries including acute liver failure, alcoholic or viral hepatitis, chronic inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma are life threatening diseases and as a consequence might result in the necessity of liver transplantation. HO-1 as well as its reaction products of heme degradation has been linked to cytoprotection. HO-1 induction in rodent models of acute and chronic hepatic inflammation resulted in improvement of liver damage and down-regulation of pro-inflammatory cytokine levels. Furthermore HO-1 induction interfered with fibrosis progression in mice and partially resolved existing fibrosis. Likewise, HO-1 induction interfered with replication of hepatitis viruses B and C, which frequently are the reason for chronic hepatitis and subsequent tumor growth. Liver transplantation is limited by ischemia/reperfusion (I/R) injury, which is characterized by hypoxia and nutrient deficiency resulting in oxidative stress, apoptosis and immune activation. Induction of HO-1 and application predominantly of CO have been shown to interfere with I/R liver injury and to improve recipient and graft survival. On the other hand HO-1 has been shown to be over-expressed in various tumors, including hepatocellular carcinoma (HCC). Due to its anti-apoptotic properties this bears the risk to promote tumor growth. Anti-apoptotic effects are predominantly mediated by CO. This review aims to summarize beneficial as well as detrimental effects of HO-1 and its products within the liver.
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PMID:The multiple functions of heme oxygenase-1 in the liver. 2222 96

Autophagy has emerged as a critical lysosomal pathway that maintains cell function and survival through the degradation of cellular components such as organelles and proteins. Investigations specifically employing the liver or hepatocytes as experimental models have contributed significantly to our current knowledge of autophagic regulation and function. The diverse cellular functions of autophagy, along with unique features of the liver and its principal cell type the hepatocyte, suggest that the liver is highly dependent on autophagy for both normal function and to prevent the development of disease states. However, instances have also been identified in which autophagy promotes pathological changes such as the development of hepatic fibrosis. Considerable evidence has accumulated that alterations in autophagy are an underlying mechanism of a number of common hepatic diseases including toxin-, drug- and ischemia/reperfusion-induced liver injury, fatty liver, viral hepatitis and hepatocellular carcinoma. This review summarizes recent advances in understanding the roles that autophagy plays in normal hepatic physiology and pathophysiology with the intent of furthering the development of autophagy-based therapies for human liver diseases.
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PMID:Functions of autophagy in normal and diseased liver. 2377 82


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