Mechanisms of alcohol-induced hepatic fibrosis: a summary of the Ron Thurman Symposium

Oxidative stress in alcoholic liver disease: role of NADPH oxidase complex

Alcohol is a well-known risk factor for liver damage and is one of the major causes of liver disease worldwide. Chronic intake of alcohol, over a certain limit, inevitably leads to hepatic steatosis. If the injury persists, steatosis with concomitant tumor necrosis factor-alpha and other cytokines, progresses to steatohepatitis, fibrosis and finally cirrhosis. Among the multiple factors involved in the process of alcohol-induced liver injury, a crucial role is played by oxidative stress. Several mechanisms during ethanol metabolism result in reactive oxygen species (ROS) production. Although the main site of ethanol metabolism is hepatocytes, other mechanisms are involved in alcohol-induced liver injury. Specifically, in the ROS production activity, an important role is played by the NADPH oxidase complex. NADPH oxidase is expressed in hepatocytes, hepatic stellate cells and Kupffer cells in the liver. Studying NADPH oxidase gives new insights into alcohol-induced liver damage and provides new direction for future therapeutic strategies.

CYP2E1 and oxidative liver injury by alcohol

Ethanol-induced oxidative stress seems to play a major role in mechanisms by which ethanol causes liver injury. Many pathways have been suggested to contribute to the ability of ethanol to induce a state of oxidative stress. One central pathway seems to be the induction of cytochrome P450 2E1 (CYP2E1) by ethanol. CYP2E1 metabolizes and activates many toxicological substrates, including ethanol, to more reactive, toxic products. Levels of CYP2E1 are elevated under a variety of physiological and pathophysiological conditions and after acute and chronic alcohol treatment. CYP2E1 is also an effective generator of reactive oxygen species such as the superoxide anion radical and hydrogen peroxide and, in the presence of iron catalysts, produces powerful oxidants such as the hydroxyl radical. This review article summarizes some of the biochemical and toxicological properties of CYP2E1 and briefly describes the use of cell lines developed to constitutively express CYP2E1 and CYP2E1 knockout mice in assessing the actions of CYP2E1. Possible therapeutic implications for treatment of alcoholic liver injury by inhibition of CYP2E1 or CYP2E1-dependent oxidative stress will be discussed, followed by some future directions which may help us to understand the actions of CYP2E1 and its role in alcoholic liver injury.

Molecular phenotypic descriptors of Dupuytren's disease defined using informatics analysis of the transcriptome

PURPOSE

Dupuytren's disease (DD) is a fibroproliferative disorder of unknown etiopathogenesis, which may cause progressive, permanent contracture of digits. Previous studies provide compelling evidence that genetic alterations play an important role. Macroscopically affected areas demonstrate phenotypic differences between the two structurally distinct fibrotic elements in DD (ie, the nodule and the cord). In this study, we set out to (1) compare gene expression profiles between DD and transverse carpal fascia of control subjects (external control); (2) profile DD cords and nodules from the palm against the unaffected transverse palmar fascia (internal control); and (3) identify biologically important candidate genes from the transcriptome profiles.

METHODS

RNA samples from DD nodules (n = 4), cords (n = 4), and internal control (n = 4) as well as external control (n = 4) from unaffected individuals were subjected to differential gene expression profile analysis. Changes of more than 2-fold in DD groups and controls were recorded. Quantitative reverse transcriptase-polymerase chain reactions were performed to validate 16 implicated genes, which included developmental control genes, matrix metalloproteinases, and apoptotic genes.

RESULTS

Several genes associated with DD formation were common across all 6 pairwise analyses. Genes markedly upregulated shared common expression levels across all pairwise analysis studies. Pairs involving the DD nodule arrays were notably distinguishable from all other permutations. The majority of genes dysregulated in the DD cords demonstrated an increase in fold change when compared with the DD nodule tissues. Key collagens, collagenases, metalloproteinases, and inhibitors were identified. Genes involved in cytoskeleton development and lipid metabolism were markedly dysregulated. Confirmations of these alterations were obtained in quantitative reverse transcriptase-polymerase chain reaction.

CONCLUSIONS

These data demonstrate a gradation in expression of certain genes in DD tissue phenotypes compared with control fascia. Transcriptome profiling is predictive not only of disease but also of disease phenotype. These results indicate a number of important candidate genes associated with DD formation, which may provide clues for molecular mechanisms involved in DD pathogenesis.

Chronic ethanol intake promotes double gluthatione S-transferase/transforming growth factor-alpha-positive hepatocellular lesions in male Wistar rats

The chronic ethanol intake influence on the gluthatione S-transferase (GST-P) and transforming growth factor alpha (TGF-alpha) expression in remodeling/persistent preneoplastic lesions (PNLs) was evaluated in the resistant hepatocyte model. Male Wistar rats were allocated into five groups: G1, non-treated, fed water and chow ad libitum; G2, non-treated and pair-fed chow (restricted to match that of G3 group) and a maltodextrin (MD) solution in tap water (matched ethanol-derived calories); G3, fed 5% ethanol in drinking water and chow ad libitum; G4, diethylnitrosamine (DEN, 200 mg/kg, body weight) plus 200 parts per million of 2-acetylaminofluorene (2-AAF) for 3 weeks and pair-fed chow (restricted to match that of G5 group) and an MD solution in tap water (matched ethanol-derived calories); G5, DEN/2-AAF treatment, fed ethanol 5% and chow ad libitum. All animals were subjected to 70% partial hepatectomy at week 3 and sacrificed at weeks 12 or 22, respectively. Liver samples were collected for histological analysis or immunohistochemical expression of GST-P, TGF-alpha and proliferating cell nuclear antigen or zymography for matrix metalloproteinases-2 and -9. At the end of ethanol treatment, there was a significant increase in the percentage of liver area occupied by persistent GST-P-positive PNLs, the number of TGF-alpha-positive PNLs and the development of liver tumors in ethanol-fed and DEN/2-AAF-treated groups (G5 versus G4, P < 0.001). In addition, ethanol feeding led to a significant increase in cell proliferation mainly in remodeling and persistent PNLs with immunoreactivity for TGF-alpha at week 22 (P < 0.001). Gelatinase activities were not altered by ethanol treatment. The results demonstrated that ethanol enhances the selective growth of PNL with double expression of TGF-alpha and GST-P markers.

Oxidative stress, plasminogen activator inhibitor 1, and lung fibrosis

Fibrosis is characterized by excessive accumulation of extracellular matrix (ECM) in basement membranes and interstitial tissues, resulting from increased synthesis or decreased degradation of ECM or both. The plasminogen activator/plasmin system plays an important role in ECM degradation, whereas the plasminogen activator inhibitor 1 (PAI-1) is a physiologic inhibitor of plasminogen activators. PAI-1 expression is increased in the lung fibrotic diseases and in experimental fibrosis models. The deletion of the PAI-1 gene reduces, whereas the overexpression of PAI-1 enhances, the susceptibility of animals to lung fibrosis induced by different stimuli, indicating an important role of PAI-1 in the development of lung fibrosis. Many growth factors, including transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha), as well as other chemicals/agents, induce PAI-1 expression in cultured cells and in vivo. Reactive oxygen and nitrogen species (ROS/RNS) have been shown to mediate the induction of PAI-1 by many of these stimuli. This review summarizes some recent findings that help us to understand the role of PAI-1 in the development of lung fibrosis and ROS/RNS in the regulation of PAI-1 expression during fibrogenesis.

Abrogation of the antifibrotic effects of natural killer cells/interferon-gamma contributes to alcohol acceleration of liver fibrosis

BACKGROUND & AIMS

Chronic alcohol drinking accelerates liver fibrosis in patients with viral hepatitis that cannot be fully explained by ethanol-enhanced liver damage. Here, we identified a novel mechanism by which alcohol accelerates liver fibrosis: inhibition of the antifibrotic effects of natural killer (NK) cells and interferon-gamma (IFN-gamma).

METHODS

Alcohol administration was achieved by feeding mice with a liquid diet containing 5% ethanol for 8 weeks. Liver fibrosis was induced by administration of carbon tetrachloride (CCl(4)) for 2 weeks. Hepatic stellate cells (HSCs) were also isolated and cultured for in vitro studies.

RESULTS

CCl(4) treatment induced greater fibrosis and less apoptosis of HSCs in ethanol-fed mice compared with pair-fed mice. Polyinosinic-polycytidylic acid (Poly I:C) or IFN-gamma treatment inhibited liver fibrosis in pair-fed but not in ethanol-fed mice. Poly I:C activation of NK cell cytotoxicity against HSCs was attenuated in ethanol-fed mice compared with pair-fed mice, which was due to reduced natural killer group 2 member D (NKG2D), tumor necrosis factor-related apoptosis-inducing ligand, and IFN-gamma expression on NK cells from ethanol-fed mice. In vitro, HSCs from ethanol-fed mice were resistant to IFN-gamma-induced cell cycle arrest and apoptosis compared with pair-fed mice. Such resistance was due to diminished IFN-gamma activation of signal transducer and activator of transcription 1 (STAT1) in HSCs from ethanol-fed mice caused by the induction of suppressors of cytokine signaling proteins and the production of oxidative stress. Finally, HSCs from ethanol-fed mice were resistant to NK cell killing, which can be reversed by transforming growth factor-beta1 (TGF-beta1) neutralizing antibody.

CONCLUSIONS

Chronic ethanol consumption attenuates the antifibrotic effects of NK/IFN-gamma/STAT1 in the liver, representing new and different therapeutic targets with which to treat alcoholic liver fibrosis.

Age, alcohol metabolism and liver disease

PURPOSE OF REVIEW

Alcohol consumption among the elderly has increased. Alcohol metabolism changes with age and the elderly are more sensitive to the toxic effects; this increased consumption is therefore of great clinical relevance.

RECENT FINDINGS

Metabolism of ethanol changes with advancing age because activity of the enzymes involved, such as alcohol and acetaldehyde dehydrogenase and cytochrome P-4502E1, diminish with age. The water distribution volume also decreases with age. Both lead to increased blood concentrations of ethanol. Also, elderly people take more drugs, and ethanol and these drugs may interact; therefore, alcohol consumption can modify serum drug concentrations and their toxicity. Finally, elderly people may suffer more frequently from other types of liver disease, and alcohol may exacerbate these.

SUMMARY

Over recent decades alcohol consumption has increased among those who are older than 65 years. Alcohol is more toxic in the ageing organism because of changes in its metabolism, distribution and elimination, which lead to central nervous system effects at lower levels of intake; also, ageing organs such as brain and liver are more sensitive to the toxicity of alcohol. For these reasons, alcohol should be used in moderation, especially among those of older age.

Neuroprotective effects of emodin-8-O-β-d-glucoside in vivo and in vitro

Emodin-8-O-beta-D-glucoside extracted from the traditional Chinese medicinal herb Polygonum cuspidatum Sieb. et Zucc is widely used to treat acute hepatitis possibly by antioxidative mechanisms. The present study was designed to investigate whether emodin-8-O-beta-D-glucoside exerted neuroprotective effects on the focal cerebral injury induced by ischemia and reperfusion in vivo and on the neuronal damage induced by glutamate in vitro, and to study the possible mechanisms. Male Wistar rats were used to establish the model of ischemia and reperfusion. The behavioral test was performed and the cerebral infarction area was assessed in the brain slices stained with 2% 2,3,5-triphenyl tetrazolium chloride to evaluate the neuroprotective effects of emodin-8-O-beta-D-glucoside. Superoxide dismutase (SOD) activity, total antioxidative capability and malondialdehyde (MDA) level in the brain tissue were determined with spectrophotometrical methods to probe the primary mechanisms of emodin-8-O-beta-D-glucoside. In vitro, the neuroprotective effects of emodin-8-O-beta-D-glucoside were tested in the cultured cortical cells of fetal rats exposed to glutamate. Emodin-8-O-beta-D-glucoside concentration in plasma and brain tissue was also measured to examine distribution of emodin-8-O-beta-D-glucoside in the brain. The results showed that the treatment of rats with emodin-8-O-beta-D-glucoside reduced the neurological deficit score and the cerebral infarction area, increased SOD activity and total antioxidative capability, and decreased MDA level in the brain tissue in dose-dependent way. Emodin-8-O-beta-D-glucoside also inhibited the neuronal damage induced by glutamate. Besides, emodin-8-O-beta-D-glucoside was able to penetrate blood-brain barrier and distribute in the brain tissue. These findings demonstrate that emodin-8-O-beta-D-glucoside is able to provide neuroprotection against cerebral ischemia-reperfused injury and glutamate induced neuronal damage through exerting antioxidative effects and inhibiting glutamate neurotoxicity.

Changes in the expression of genes related to apoptosis and fibrosis pathways in CCl4-treated rats

Chronic liver diseases are accompanied by changes in the biochemical pathways related to the regulation of apoptosis and extra-cellular matrix deposition. The present study was designed to investigate, using low density arrays, changes in the hepatic gene expression together with hepatic biochemical and histological alterations in rats that had liver impairment induced by chronic exposure to CCl(4). Further, we examined the possible recovery of genetic and pathological changes following the cessation of the hepatotoxic injury. Experimental fibrosis was induced in male Wistar rats by CCl(4) administration. Animals were subdivided into two groups. One group was given CCl(4 )and animals were killed at 8 and 12 weeks of treatment. The other group was treated with CCl(4) for 6 weeks, the CCl(4 )was then stopped and, subsequently, subgroups of animals were killed after 1 and 2 weeks of recovery. CCl(4) administration over 12 weeks was associated with significant changes in B-cell leukemia/lymphoma 2, procollagen type I alpha 2, matrix metalloproteinases 3 and 8, tissue inhibitors of metalloproteinases 1, 2, and 3 and the inhibitor of apoptosis 4 gene expressions. Recovery after CCl(4) cessation was associated with changes in procollagen type I alpha 2, matrix metalloproteinase 7, tissue inhibitors of metalloproteinases 1 and 2, inhibitor of apoptosis 4, and survivin gene expressions. This study shows an association between changes in the expression of several genes regulating hepatic cell apoptosis, the fibrosis process, and the recovery of the hepatic function after removal of the toxic injury.

Myofibroblast - like cells and liver fibrogenesis: Emerging concepts in a rapidly moving scenario

Fibrotic progression of chronic liver diseases of different aetiology to the common advanced-stage of cirrhosis can be envisaged as a dynamic and highly integrated cellular response to chronic liver injury. Liver fibrosis is accompanied by perpetuation of liver injury, chronic hepatitis and persisting activation of tissue repair mechanisms, leading eventually to excess deposition of ECM components. Liver fibrogenesis (i.e., the process) is sustained by populations of highly proliferative, pro-fibrogenic and contractile MFs that, according to current literature, originate by a process of activation involving perisinusoidal HSC, portal fibroblasts and even bone marrow-derived MSC. In this short review emerging concepts in hepatic fibrogenesis and related molecular mechanisms, as provided by recent experimental and clinical studies, are presented.

Protective effects of estradiol on ethanol-induced bone loss involve inhibition of reactive oxygen species generation in osteoblasts and downstream activation of the extracellular signal-regulated kinase/signal transducer and activator of transcription 3/receptor activator of nuclear factor-kappaB ligand signaling cascade

Bone loss occurs following chronic ethanol (EtOH) consumption in males and cycling females in part as a result of increased bone resorption. We have demonstrated in vivo that estradiol treatment can reverse this effect. Using osteoclast precursors from bone marrow and osteoblast/preosteoclast coculture, we found that EtOH-induced receptor activator of nuclear factor-kappaB ligand (RANKL) expression in osteoblasts was able to promote osteoclastogenesis. These effects were blocked by pretreatment of cells with either 17beta-estradiol (E(2)) or the anti-oxidant N-acetyl cysteine (NAC). EtOH treatment of stromal osteoblasts increased the intracellular level of reactive oxygen species (ROS). This was associated with induction of NADPH oxidase (NOX) and a downstream signaling cascade involving sustained activation of extracellular signal-regulated kinase (ERK) and activation of signal transducer and activator of transcription 3, resulting in increased gene expression of RANKL. In the presence of EtOH, sustained nuclear ERK translocation >24 h was observed in calvarial osteoblasts and UMR-106 cells transfected with green fluorescent protein-ERK2 plasmid. This was abolished by pretreatment with either E(2) or NAC. NOX subtypes 1, 2, and 4, but not 3, were expressed in stromal osteoblasts. Chemical inhibition of NOX by diphenylene iodonium also reversed the ability of EtOH to phosphorylate ERK and induce RANKL mRNA expression. Down-regulation of EtOH-induced ROS generation in osteoblasts was also observed after treatment with E(2) or NAC. These data suggest that the molecular mechanisms whereby E(2) prevents EtOH-induced bone loss involve interference with ROS generation and cytoplasmic kinase activation.

Retinoic acid signaling sensitizes hepatic stellate cells to NK cell killing via upregulation of NK cell activating ligand RAE1

Hepatic stellate cells (HSCs) store 75% of the body's supply of vitamin A (retinol) and play a key role in liver fibrogenesis. During liver injury, HSCs become activated and susceptible to natural killer (NK) cell killing due to increased expression of the NK cell activating ligand retinoic acid early inducible gene 1 (RAE-1). To study the mechanism by which RAE-1 is upregulated in HSCs during activation, an in vitro model of cultured mouse HSCs was employed. RAE-1 was detected at low levels in quiescent HSCs but upregulated in 4- and 7-day cultured HSCs (early activated HSCs), whereas 21-day cultured HSCs (fully activated HSCs) lost RAE-1 expression. High levels of RAE-1 in 4- and 7-day cultured HSCs correlated with their susceptibility to NK cell killing, which was diminished by treatment with RAE-1 neutralizing antibody. Furthermore, retinoic acid (RA) and retinal dehydrogenase (Raldh) levels were upregulated in early activated HSCs compared with quiescent or fully activated HSCs. Blocking RA synthesis by the Raldh inhibitor or blocking RA signaling by the retinoic acid receptor antagonist abolished upregulation of RAE-1 whereas treatment with RA induced RAE-1 expression in HSCs. In conclusion, during activation, HSCs lose retinol, which is either secreted out or oxidized into RA; the latter stimulates RAE-1 expression and sensitizes early activated HSCs to NK cell killing. In contrast, fully activated HSCs become resistant to NK cell killing because of lack of RAE1 expression, leading to chronic liver fibrosis and disease.

Redox regulation of hepatitis C in nonalcoholic and alcoholic liver

Hepatitis C virus (HCV) is an RNA virus of the Flaviviridae family that is estimated to have infected 170 million people worldwide. HCV can cause serious liver disease in humans, such as cirrhosis, steatosis, and hepatocellular carcinoma. HCV induces a state of oxidative/nitrosative stress in patients through multiple mechanisms, and this redox perturbation has been recognized as a key player in HCV-induced pathogenesis. Studies have shown that alcohol synergizes with HCV in the pathogenesis of liver disease, and part of these effects may be mediated by reactive species that are generated during hepatic metabolism of alcohol. Furthermore, reactive species and alcohol may influence HCV replication and the outcome of interferon therapy. Alcohol consumption has also been associated with increased sequence heterogeneity of the HCV RNA sequences, suggesting multiple modes of interaction between alcohol and HCV. This review summarizes the current understanding of oxidative and nitrosative stress during HCV infection and possible combined effects of HCV, alcohol, and reactive species in the pathogenesis of liver disease.

Molecular mechanisms of alcohol-mediated carcinogenesis

Approximately 3.6% of cancers worldwide derive from chronic alcohol drinking, including those of the upper aerodigestive tract, the liver, the colorectum and the breast. Although the mechanisms for alcohol-associated carcinogenesis are not completely understood, most recent research has focused on acetaldehyde, the first and most toxic ethanol metabolite, as a cancer-causing agent. Ethanol may also stimulate carcinogenesis by inhibiting DNA methylation and by interacting with retinoid metabolism. Alcohol-related carcinogenesis may interact with other factors such as smoking, diet and comorbidities, and depends on genetic susceptibility.

Alcohol dehydrogenase 1B genotype and fetal alcohol syndrome: a HuGE minireview

Fetal alcohol syndrome (FAS), 1 of the most common developmental disabilities in the United States, occurs at a rate of 0.5-2.0:1000 live births. Animal model, family, and twin studies suggest a genetic component to FAS susceptibility. Alcohol dehydrogenases (ADHs) catalyze the rate-limiting step in alcohol metabolism. Studies of genetic associations with FAS have focused on the alcohol dehydrogenase 1B (ADH1B) gene, comparing mothers and children with the alleles ADH1B*2 or ADH1B*3, associated with faster ethanol metabolism, with those homozygous for ADH1B*1. While most studies have found a protective effect for genotypes containing ADH1B*2 or ADH1B*3, results have been conflicting, and further investigation into the association between the ADH1B genotype and FAS is needed. Whether increased alcohol intake accounts for the elevated risk reported for the ADH1B*1/ADH1B*1 genotype should be addressed, and future studies would benefit from consistent case definitions, enhanced exposure measurements, larger sample sizes, and careful study design.

Liver regeneration is suppressed in alcoholic cirrhosis: correlation with decreased STAT3 activation

Liver regeneration is suppressed in alcoholic patients; however, the underlying mechanisms are not fully understood. We examined liver regeneration and signal transducer and activator of transcription 3 (STAT3) activation (an important signal for liver regeneration) in cirrhotic livers from alcoholics, hepatitis C virus (HCV) infection, and alcoholic plus HCV infection. Liver regeneration and STAT3 activation were determined by immunohistochemistry analysis of Ki67 and STAT3 phosphorylation, respectively, in 20 alcoholic cirrhosis, 13 HCV cirrhosis, 13 alcoholic+HCV cirrhosis. Alcoholic or alcoholic plus HCV cirrhotic livers had significantly lower Ki67+ and phospho-STAT3+ (pSTAT3+) hepatocytes and bile duct cells than HCV cirrhotic livers. The pSTAT3 positive staining did not correlate with liver injury (elevation of serum levels of aspartate transaminase [AST] and alkaline phosphatase [ALP]) but correlated positively with cell proliferation (Ki67 positive staining).

IN CONCLUSION

liver regeneration is suppressed in alcoholic cirrhotic livers, which may be partly due to decreased STAT3 activation.

NOX in liver fibrosis

NADPH oxidase is a multi-protein complex producing reactive oxygen species (ROS) both in phagocytic cells, being essential in host defense, and in non-phagocytic cells, regulating intracellular signalling. In the liver, NADPH oxidase plays a central role in fibrogenesis. A functionally active form of the NADPH oxidase is expressed not only in Kupffer cells (phagocytic cell type) but also in hepatic stellate cells (HSCs) (non-phagocytic cell type), suggesting a role of the non-phagocytic NADPH oxidase in HSC activation. Consistent with this concept, profibrogenic agonists such as Angiotensin II (Ang II) and platelet derived growth factor (PDGF), or apoptotic bodies exert their activity through NADPH oxidase-activation in HSCs. Both pharmacological inhibition with DPI and genetic studies using p47(phox) knockout mice provided evidence for a central role of NADPH oxidase in the regulation of HSC-activity and liver fibrosis. In addition to the p47(phox) component, only Rac1 has been identified as a functional active component of the NADPH oxidase complex in HSCs.

Hepatobiliary pathology

PURPOSE OF REVIEW

Recent papers on disorders of the liver and biliary tract which clarify their pathogenesis and attendant morphologic changes are highlighted.

RECENT FINDINGS

The concept of 'bystander hepatitis' was cited in studies showing hepatic infiltration of CD8-positive T cells in the setting of extrahepatic infections such as influenza virus and severe acute respiratory syndrome. Diabetic liver lesions include glycogenic hepatopathy (in which poor diabetic control leads to swollen, glycogen-filled hepatocytes without fat, steatohepatitis or fibrosis) and diabetic hepatosclerosis in which there is diffuse perisinusoidal fibrosis (type IV collagen) without zonal predilection. Ground-glass hepatocellular inclusions (positive with periodic acid-Schiff stain for glycogen) were reported in three separate series of patients who were hepatitis B virus-negative, often transplant recipients, immunosuppressed and on multiple medications. A Banff consensus paper expertly compared and contrasted the histologic features which characterize the various causes of late liver allograft dysfunction.

SUMMARY

Informative papers emerged this past year concerning collateral damage to the liver in extrahepatic infections, diabetic lesions and causes of liver dysfunction after transplantation, among other topics.

Fenugreek seed (Trigonella foenum graecum) polyphenols inhibit ethanol-induced collagen and lipid accumulation in rat liver

Chronic alcoholism is associated with fatty liver and fibrosis characterized by collagen accumulation. Seeds of fenugreek, an annual herb, are reported to possess hepatoprotective activity. The study aims to investigate the effects of fenugreek seed polyphenol extract (FPEt) on liver lipids and collagen in experimental hepatotoxic rats. Hepatotoxicity was induced in male albino Wistar rats by administrating ethanol (6 g/kg per day) for 30 days. Control rats were given isocaloric glucose solution. FPEt was co-administered with ethanol at a dose of 200 mg/kg per day for the next 30 days. Silymarin was used as a positive control. Ethanol treatment caused increase in plasma and liver lipids, together with alterations in collagen content and properties. Administration of FPEt to alcohol-fed rats significantly improved lipid profile and reduced collagen content, crosslinking, aldehyde content and peroxidation. The effects were comparable with that of silymarin. FPEt administration had a positive influence on both lipid profile and on the quantitative and qualitative properties of collagen in alcoholic liver disease. The protective effect is presumably due to the bioactive phytochemicals in fenugreek seeds.

Adult stem cells in progression and therapy of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most aggressive solid tumours associated with poor prognosis. Despite its significance, there is only an elemental understanding of the mechanisms that drive disease pathogenesis, and there are just limited therapy options. The medical community is currently experiencing a wave of enthusiasm for clinical trials, in which adult stem/progenitor cells are used for liver regeneration. This is based on promising results in animal models and encouraging reports from some initial clinical studies. On the other hand, several essential precautions are not being fully addressed. Stem cells may contribute to fibrosis or give rise to hepatic cancer stem cells as a source of hepatocellular carcinoma. This review outlines the current state of knowledge in progression of liver disease and highlights the function of adult stem cells in disease and therapy.

Role of ethanol in the regulation of hepatic stellate cell Function

Evidence has accumulated to suggest an important role of ethanol and/or its metabolites in the pathogenesis of alcohol-related liver disease. In this review, the fibrogenic effects of ethanol and its metabolites on hepatic stellate cells (HSCs) are discussed. In brief, ethanol interferes with retinoid metabolism and its signaling, induces the release of fibrogenic cytokines such as transforming growth factor β-1 (TGFβ-1) from HSCs, up-regulates the gene expression of collagen I and enhances type I collagen protein production by HSCs. Ethanol further perpetuates an activated HSC phenotype through extracellular matrix remodeling. The underlying pathophysiologic mechanisms by which ethanol exerts these pro-fibrogenic effects on HSCs are reviewed.

Anabolic-androgenic steroids for alcoholic liver disease

BACKGROUND

Alcohol is one of the most common causes of liver disease in the Western World. Randomised clinical trials have examined the effects of anabolic-androgenic steroids for alcoholic liver disease.

OBJECTIVES

To assess the beneficial and harmful effects of anabolic-androgenic steroids for patients with alcoholic liver disease based on the results of randomised clinical trials.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Controlled Trials Register in The Cochrane Library, MEDLINE, EMBASE, LILACS, and Science Citation Index Expanded until June 2006. Electronic searches were combined with full text searches. Manufacturers and researchers in the field were also contacted.

SELECTION CRITERIA

Randomised clinical trials studying patients with alcoholic steatosis, alcoholic fibrosis, alcoholic hepatitis, and/or alcoholic cirrhosis were included. Interventions encompassed anabolic-androgenic steroids at any dose or duration versus placebo or no intervention. The trials could be double blind, single blind, or unblinded. The trials could be unpublished or published, and no language limitations were applied.

DATA COLLECTION AND ANALYSIS

Outcomes are assessed at maximal follow-up. All analyses were performed according to the intention-to-treat method. The statistical package RevMan Analyses was used. The methodological quality of the randomised clinical trials was assessed.

MAIN RESULTS

Combining the results of five randomised clinical trials randomising 499 patients with alcoholic hepatitis and/or cirrhosis demonstrated no significant effects of anabolic-androgenic steroids on mortality (relative risk (RR) 1.01, 95% confidence interval (CI) 0.79 to 1.29), liver-related mortality (RR 0.83, 95% CI 0.60 to 1.15), complications of liver disease (RR 1.25, 95% CI 0.74 to 2.10), and liver histology. Anabolic-androgenic steroids did not significantly affect a number of other outcome measures, including sexual function and liver biochemistry. Anabolic-androgenic steroids were not associated with a significantly increased risk of non-serious adverse events (RR 1.14, 95% CI 0.50 to 2.59) or with serious adverse events (RR 4.54, 95% CI 0.57 to 36.30).

AUTHORS' CONCLUSIONS

This systematic review could not demonstrate any significant beneficial effects of anabolic-androgenic steroids on any clinically important outcomes (mortality, liver-related mortality, liver complications, and histology) of patients with alcoholic liver disease.

N/A

N/A