Plasma tumor necrosis factor alpha predicts decreased long-term survival in severe alcoholic hepatitis

Inflammation in Alcohol-Associated Hepatitis: Pathogenesis and Therapeutic Targets

Alcohol-associated hepatitis (AH) is an acute-on-chronic liver injury that occurs in patients with chronic alcohol-associated liver disease (ALD). Patients with severe AH have high short-term mortality and lack effective pharmacologic therapies. Inflammation is believed to be one of the key factors promoting AH progression and has been actively investigated as therapeutic targets over the last several decades, but no effective inflammatory targets have been identified so far. In this review, we discuss how inflammatory cells and the inflammatory mediators produced by these cells contribute to the development and progression of AH, with focus on neutrophils and macrophages. The crosstalk between inflammatory cells and liver nonparenchymal cells in the pathogenesis of AH is elaborated. We also deliberate the application of recent cutting-edge technologies in characterizing liver inflammation in AH. Finally, the potential therapeutic targets of inflammatory mediators for AH are briefly summarized.

Therapeutic modulation of the liver immune microenvironment

Inflammation is a hallmark of progressive liver diseases such as chronic viral or immune-mediated hepatitis, alcohol-associated liver disease, and NAFLD. Preclinical and clinical studies have provided robust evidence that cytokines and related cellular stress sensors in innate and adaptive immunity orchestrate hepatic disease processes. Unresolved inflammation and liver injury result in hepatic scarring, fibrosis, and cirrhosis, which may culminate in HCC. Liver diseases are accompanied by gut dysbiosis and a bloom of pathobionts, fueling hepatic inflammation. Anti-inflammatory strategies are extensively used to treat human immune-mediated conditions beyond the liver, while evidence for immunomodulatory therapies and cell therapy-based strategies in liver diseases is only emerging. The development and establishment of novel immunomodulatory therapies for chronic liver diseases has been dampened by several clinical challenges, such as invasive monitoring of therapeutic efficacy with liver biopsy in clinical trials and risk of DILI in several studies. Such aspects prevented advancements of novel medical therapies for chronic inflammatory liver diseases. New concepts modulating the liver immune environment are studied and eagerly awaited to improve the management of chronic liver diseases in the future.

Mean platelet volume and mortality in patients with alcohol use disorder

Several recent studies have pointed out the relationship of platelet size with increased mortality or adverse clinical course. Most studies show that increased mean platelet volume (MPV) may be associated with a deleterious outcome in different settings such as sepsis or neoplasia, whereas other researchers have found the opposite. In inflammatory conditions there is an altered secretion of several cytokines, some of them exerting a marked influence on platelet biogenesis and/or on platelet activation and aggregation. Alcohol use disorder is a chronic situation characterized by a protracted low-grade inflammation. In this study we analyze the relationship between proinflammatory cytokines and MPV and their relationships with mortality in patients with alcohol abuse. We determined serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 and routine laboratory variables among 184 patients with alcohol use disorder admitted to our hospital and followed-up for a median of 42 months. We found that MPV was inversely related to TNF-α (ρ=-0.34), and directly to IL-8 (ρ=0.32, p<0.001 in both cases) and to IL-6 (ρ=0.15; p = 0.046). Reduced MPV was related both with short-term (<6 months) and long-term mortality. Conclusion: These results suggest that inflammatory cytokines are strongly related to MPV. A low MPV is associated with a poor prognosis among patients with alcohol use disorder.

Patterns of IgA Autoantibody Generation, Inflammatory Responses and Extracellular Matrix Metabolism in Patients with Alcohol Use Disorder

Recent data have emphasized the role of inflammation and intestinal immunoglobulin A (IgA) responses in the pathogenesis of alcoholic liver disease (ALD). In order to further explore such associations, we compared IgA titers against antigens targeted to ethanol metabolites and tissue transglutaminase with pro- and anti-inflammatory mediators of inflammation, markers of liver status, transferrin protein desialylation and extracellular matrix metabolism in alcohol-dependent patients with or without liver disease and in healthy controls. Serum IgAs against protein adducts with acetaldehyde (HbAch-IgA), the first metabolite of ethanol, and tissue transglutaminase (tTG-IgA), desialylated transferrin (CDT), pro- and anti-inflammatory cytokines, markers of liver status (GT, ALP) and extracellular matrix metabolism (PIIINP, PINP, hyaluronic acid, ICTP and CTx) were measured in alcohol-dependent patients with (n = 83) or without (n = 105) liver disease and 88 healthy controls representing either moderate drinkers or abstainers. In ALD patients, both tTG-IgA and HbAch-IgA titers were significantly higher than those in the alcoholics without liver disease (p < 0.0005 for tTG-IgA, p = 0.006 for Hb-Ach-IgA) or in healthy controls (p < 0.0005 for both comparisons). The HbAch-IgA levels in the alcoholics without liver disease also exceeded those found in healthy controls (p = 0.0008). In ROC analyses, anti-tTG-antibodies showed an excellent discriminative value in differentiating between ALD patients and healthy controls (AUC = 0.95, p < 0.0005). Significant correlations emerged between tTG-IgAs and HbAch-IgAs (rs = 0.462, p < 0.0005), CDT (rs = 0.413, p < 0.0001), GT (rs = 0.487, p < 0.0001), alkaline phosphatase (rs = 0.466, p < 0.0001), serum markers of fibrogenesis: PIIINP (rs = 0.634, p < 0.0001), hyaluronic acid (rs = 0.575, p < 0.0001), ICTP (rs = 0.482, p < 0.0001), pro-inflammatory cytokines IL-6 (rs = 0.581, p < 0.0001), IL-8 (rs = 0.535, p < 0.0001) and TNF-α (rs = 0.591, p < 0.0001), whereas significant inverse correlations were observed with serum TGF-β (rs = -0.366, p < 0.0001) and CTx, a marker of collagen degradation (rs = -0.495, p < 0.0001). The data indicate that the induction of IgA immune responses toward ethanol metabolites and tissue transglutaminaseis a characteristic feature of patients with AUD and coincides with the activation of inflammation, extracellular matrix remodeling and the generation of aberrantly glycosylated proteins. These processes appear to work in concert in the sequence of events leading from heavy drinking to ALD.

AMPK-Regulated Autophagy Contributes to Ursolic Acid Supplementation-Alleviated Hepatic Steatosis and Liver Injury in Chronic Alcohol-Fed Mice

Alcoholic liver disease (ALD) is a chronic liver disease caused by long-term heavy consumption of alcohol. The pathogenesis of ALD is complex, and there is no effective clinical treatment at present. Ursolic acid (UA), a general triterpenoid with multiple biological roles, is widely distributed in plants. This study aims to explore the therapeutic effect and potential mechanisms of UA that protect against liver injury and hepatic steatosis in an ALD mouse model. In this study, we analyzed the lipid accumulation and the effect of UA treatment in a mouse model of ALD; AML12 and HepG2 cells were used to study the biological effect and potential mechanisms of UA on ethanol-induced hepatotoxicity. The morphologic and histological detections showed that UA significantly reduced alcohol-induced liver injury and hepatic steatosis. In addition, UA dramatically ameliorated alcohol-induced metabolic disorders, oxidative stress, and inflammation. Furthermore, UA treatment activated autophagy via the AMPK-ACC pathway to protect hepatocytes from lipotoxicity. Thus, these findings demonstrate that UA treatment alleviates alcoholic-induced liver injury by activating autophagy through the AMPK-ACC pathway. Therefore, UA may represent a promising candidate for the treatment of ALD.

IL-1 receptor antagonist plus pentoxifylline and zinc for severe alcohol-associated hepatitis

BACKGROUND AND AIMS

Patients with severe alcohol-associated hepatitis (AH) have high mortality. Corticosteroids improve survival only for 30 days. We targeted inflammation, cellular injury, and gut leakiness in a randomized clinical trial comparing combination therapy to corticosteroids on 180-day survival.

APPROACH AND RESULTS

Subjects with a clinical diagnosis of severe AH (Model for End-Stage Liver Disease [MELD] >20, Maddrey discriminant function [MDF] >32) were randomized to receive methylprednisolone (PRED; 28 days) or a combination of anakinra (14 days) plus pentoxifylline (28 days) plus zinc (COMB; 180 days). The primary endpoint was survival at 180 days. The study was designed in 2013, initiated in October 2014, and completed in March 2018. Five hundred patients were screened to randomize 104 subjects with a clinical diagnosis of AH with a MELD score >20. Fifty-three patients were randomized into the COMB and 50 to the PRED treatment; 1 dropped out of the study before randomization. Mean age was 45.3 ± 10.4 years; 60.6% were males, 92.3% White, and mean MELD 25.7 ± 3.9. Kaplan-Meier survival estimate at 180 days was 67.9% in COMB and 56% in PRED (HR = 0.69; p = 0.3001). Survival curves separated by 90 days (COMB, 69.8%; PRED, 58.0%; HR = 0.69; p = 0.28). Survival at 28 days was similar between the COMB (83.4%) and PRED groups (81.2%; HR = 0.91; p = 0.85). There were no unexpected serious adverse events, and incidence of infection was comparable between groups. MELD 20-25 and MELD >26 strata showed nonsignificant treatment effects in favor of COMB.

CONCLUSIONS

A combination of anakinra, pentoxifylline plus zinc provides similar survival benefits compared to corticosteroid therapy in severe AH.

Effects of TNF-α deletion on iNKT cell development, activation, and maturation in the steady-state and chronic alcohol-consuming mice

Cytokines play critical roles in regulating iNKT cell development, activation, and maturation. TNF-α co-occurs with iNKT cells in steady-state and many disease conditions. How TNF-α affects iNKT cell function has not been thoroughly investigated. It was found that chronic alcohol consumption enhanced iNKT cell activation and maturation. The underlying mechanism is not known. Herein, a TNF-α KO mouse model was used to address these issues. It was found that the depletion of TNF-α mitigated alcohol consumption-enhanced iNKT cell activation and maturation. In steady-state, depletion of TNF-α did not affect the frequency of iNKT cells in the thymus and spleen but decreased iNKT cells in the liver and increased liver iNKT cell apoptosis. The portion of stage-2 immature iNKT cells increased, stage-3 mature iNKT cells decreased in the thymus of TNF-α KO mice, suggesting that depletion of TNF-α impairs iNKT cell development and maturation. The percentage of CD69⁺ iNKT cells was significantly lower in the thymus, spleen, and liver of TNF-α KO mice compared to their wild-type littermates, suggesting that depletion of TNF-α inhibits iNKT cell activation. Moreover, the percentage of splenic IL-4- and IFN-γ-producing iNKT cells was significantly lower in TNF-α KO mice than in their wild-type littermates. The depletion of TNF-α increased PLZF⁺ iNKT cells in the thymus and down-regulated the expression of CD122 on iNKT cells. Collectively, these results support that TNF-α plays a vital role in the regulation of iNKT cell development, activation, and maturation, and alcohol consumption enhances iNKT cell activation and maturation through TNF-α.

Tumour Necrosis Factor in Neuroplasticity, Neurogenesis and Alcohol Use Disorder

Alcohol use disorder is a pervasive and detrimental condition that involves changes in neuroplasticity and neurogenesis. Alcohol activates the neuroimmune system and alters the inflammatory status of the brain. Tumour necrosis factor (TNF) is a well characterised neuroimmune signal but its involvement in alcohol use disorder is unknown. In this review, we discuss the variable findings of TNF's effect on neuroplasticity and neurogenesis. Acute ethanol exposure reduces TNF release while chronic alcohol intake generally increases TNF levels. Evidence suggests TNF potentiates excitatory transmission, promotes anxiety during alcohol withdrawal and is involved in drug use in rodents. An association between craving for alcohol and TNF is apparent during withdrawal in humans. While anti-inflammatory therapies show efficacy in reversing neurogenic deficit after alcohol exposure, there is no evidence for TNF's essential involvement in alcohol's effect on neurogenesis. Overall, defining TNF's role in alcohol use disorder is complicated by poor understanding of its variable effects on synaptic transmission and neurogenesis. While TNF may be of relevance during withdrawal, the neuroimmune system likely acts through a larger group of inflammatory cytokines to alter neuroplasticity and neurogenesis. Understanding the individual relevance of TNF in alcohol use disorder awaits a more comprehensive understanding of TNF's effects within the brain.

Phosphodiesterase 4 Inhibition as a Therapeutic Target for Alcoholic Liver Disease: From Bedside to Bench

Alcoholic liver disease (ALD) is a major cause of liver-related mortality. There is still no US Food and Drug Administration-approved therapy for ALD, and therefore, identifying therapeutic targets is needed. Our previous work demonstrated that ethanol exposure leads to up-regulation of cAMP-degrading phosphodiesterase 4 (PDE4) expression, which compromises normal cAMP signaling in monocytes/macrophages and hepatocytes. This effect of ethanol on cAMP signaling contributes to dysregulated inflammatory response and altered lipid metabolism. It is unknown whether chronic alcohol consumption in humans alters hepatic PDE4 expression and cAMP signaling and whether inadequate cAMP signaling plays a pathogenic role in alcohol-induced liver injury. Our present work shows that expression of the PDE4 subfamily of enzymes is significantly up-regulated and cAMP levels are markedly decreased in hepatic tissues of patients with severe ALD. We also demonstrate the anti-inflammatory efficacy of roflumilast, a clinically available PDE4 inhibitor, on endotoxin-inducible proinflammatory cytokine production ex vivo in whole blood of patients with alcoholic hepatitis. Moreover, we demonstrate that ethanol-mediated changes in hepatic PDE4 and cAMP levels play a causal role in liver injury in in vivo and in vitro models of ALD. This study employs a drug delivery system that specifically delivers the PDE4 inhibitor rolipram to the liver to avoid central nervous system side effects associated with this drug. Our results show that PDE4 inhibition significantly attenuates ethanol-induced hepatic steatosis and injury through multiple mechanisms, including reduced oxidative and endoplasmic reticulum stress both in vivo and in vitro. Conclusion: Increased PDE4 plays a pathogenic role in the development of ALD; hence, directed interventions aimed at inhibiting PDE4 might be an effective treatment for ALD.

Safety and Efficacy of Infliximab in Severe Alcoholic Hepatitis: A Systematic Review

Severe alcoholic hepatitis (SAH) is associated with significant morbidity and mortality, yet the treatment options available are very limited. Past studies have evaluated the efficacy of infliximab in such patients; however, they were limited by sample size. Our aim was to perform a systematic review of these studies to assess the role of infliximab in patients with SAH.

We conducted a literature search using electronic database engines including Ovid, PubMed, Scopus, MEDLINE and Cochrane Library from inception to October 2018 to identify published articles addressing outcomes in patients treated for alcoholic hepatitis with infliximab. The primary outcome reviewed was one-month mortality. Secondary outcomes included rate and type of infection; cause of mortality; levels of aspartate aminotransferase, alanine aminotransferase, bilirubin and tumor necrosis factor-α; and Maddrey discriminant function.

Five studies including two randomized controlled trials and three case series were included in our analysis with a total sample size of 70 patients. One-month mortality ranged from 10% to 17% in patients who received a single dose of infliximab with or without prednisone compared to 38% in patients who received three doses of infliximab in combination with prednisone. A single dose of infliximab was associated with an infection rate of 10% to 26% in contrast to an 89% rate with three doses of infliximab.

Infliximab, when used in a single dose, could potentially be an alternative agent for the management of SAH in a large group of patients who have contraindications such as gastrointestinal bleeding, uncontrolled diabetes or an active hepatitis infection. It might also have a role in the prevention of hepatorenal syndrome. There is a need for larger trials to evaluate the role of infliximab in a cohort of patients who are not candidates for prednisolone therapy.

Time course of microglia activation and brain and blood cytokine/chemokine levels following chronic ethanol exposure and protracted withdrawal in rats

Alcohol produces complex effects on the immune system. Moderate alcohol use (1-2 drinks per day) has been shown to produce anti-inflammatory responses in human blood monocytes, whereas, the post mortem brains of severe alcoholics show increased immune gene expression and activated microglial markers. The present study was conducted to evaluate the time course of alcohol effects during exposure and after withdrawal, and to determine the relationship between microglial and cytokine responses in brain and blood. Forty-eight adult, male Wistar rats were exposed to chronic ethanol vapors, or air control, for 5 weeks. Following ethanol/air exposure blood and brains were collected at three time points: 1) while intoxicated, following 35 days of air/vapor exposure; 2) following 24 h of withdrawal from exposure, and 3) 28 days after withdrawal. One hemisphere of the brain was flash-frozen for cytokine analysis, and the other was fixed for immunohistochemical analysis. The ionized calcium-binding adapter molecule 1 (Iba-1) was used to evaluate microglia activation at the three time points, and rat cytokine/chemokine Magnetic Bead Panels (Millipore) were used to analyze frontal cortex tissue lysate and serum. Ethanol induced a significant increase in Iba-1 that peaked at day 35, remained significant after 1 day of withdrawal, and was elevated at day 28 in frontal cortex, amygdala, and substantia nigra. Ethanol exposure was associated with a transient reduction of the serum level of the major pro- and anti-inflammatory cytokines and chemokines and a transient increase of effectors of sterile inflammation. Little or no changes in these molecules were seen in the frontal cortex except for HMG1 and fractalkine that were reduced and elevated, respectively, at day 28 following withdrawal. These data show that ethanol exposure produces robust microglial activation; however, measures of inflammation in the blood differ from those in the brain over a protracted time course.

Role of cAMP and phosphodiesterase signaling in liver health and disease

Liver disease is a significant health problem worldwide with mortality reaching around 2 million deaths a year. Non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are the major causes of chronic liver disease. Pathologically, NAFLD and ALD share similar patterns of hepatic disorders ranging from simple steatosis to steatohepatitis, fibrosis and cirrhosis. It is becoming increasingly important to identify new pharmacological targets, given that there is no FDA-approved therapy yet for either NAFLD or ALD. Since the evolution of liver diseases is a multifactorial process, several mechanisms involving parenchymal and non-parenchymal hepatic cells contribute to the initiation and progression of liver pathologies. Moreover, certain protective molecular pathways become repressed during liver injury including signaling pathways such as the cyclic adenosine monophosphate (cAMP) pathway. cAMP, a key second messenger molecule, regulates various cellular functions including lipid metabolism, inflammation, cell differentiation and injury by affecting gene/protein expression and function. This review addresses the current understanding of the role of cAMP metabolism and consequent cAMP signaling pathway(s) in the context of liver health and disease. The cAMP pathway is extremely sophisticated and complex with specific cellular functions dictated by numerous factors such abundance, localization and degradation by phosphodiesterases (PDEs). Furthermore, because of the distinct yet divergent roles of both of its effector molecules, the cAMP pathway is extensively targeted in liver injury to modify its role from physiological to therapeutic, depending on the hepatic condition. This review also examines the behavior of the cAMP-dependent pathway in NAFLD, ALD and in other liver diseases and focuses on PDE inhibition as an excellent therapeutic target in these conditions.

Effects of treatment with Maraviroc a CCR5 inhibitor on a human hepatic stellate cell line

After an acute liver damage, tissue regeneration repairs lesions with degradation of deposed fibrotic material, while mechanisms of tissue restoration are persistently activated following several repeated injuries, inducing deposition of extracellular matrix. (ECM). Factors responsible for ECM remodeling have been identified in a pathway involving a family of zinc-dependent enzyme matrix metalloproteinases (MMPs), together with tissue inhibitor of metalloproteinases (TIMPs). Recent experimental models suggested a role of CCR5 receptor in the genesis of liver fibrosis. Drawing from these background we decided to evaluate the effects of the treatment with the CCR5 inhibitor Maraviroc on LX-2, a human hepatic stellate cell line (HSC). Treatment with Maraviroc resulted in a block in S phase of LX-2 cells with increased expression levels of cyclin D1 and p21 while the expression of p53 was reduced. Treatment with Maraviroc was also able to block the accumulation of fibrillar collagens and extracellular matrix proteins (ECM), as demonstrated by the decrease of specific markers as Collagen type I, α-SMA, and TGF-β1. In addition we observed a down regulation of both metalloproteins (MMP-2, MMP-9), used for the degradation of the extracellular matrix and their inhibitors (TIMP-1, TIMP-2). The identification of a compound that may modulate the dynamic of liver fibrosis could be crucial in all chronic liver diseases. Maraviroc could play an important role because, in addition to its own anti-HIV activity, it could reduce the release of pro-inflammatory citokynes implicated in liver fibrogenesis.

Optimizing therapy of liver diseases not associated with viral infection

The review demonstrated results and prospects of non-pharmacological and drug therapy patients with liver disease, not associated with a viral infection. The presented data emphasize the relevance of studying the problem of effective therapy of diseases of the liver and its role in improving the course and outcomes of liver disease.

Danshen protects against early-stage alcoholic liver disease in mice via inducing PPARα activation and subsequent 4-HNE degradation

Alcoholic liver disease (ALD) is a type of chronic liver disease caused by long-term heavy ethanol consumption. Danshen is one of the most commonly used substances in traditional Chinese medicine and has been widely used for the treatment of various diseases, and most frequently, the ALD. The current study aims to determine the potential beneficial effect of Danshen administration on ALD and to clarify the underlying molecular mechanisms. Danshen administration improved liver pathologies of ALD, attenuated alcohol-induced increment of hepatic 4-Hydroxynonenal (4-HNE) formation, and prevented hepatic Peroxisome proliferators activated receptor alpha (PPARα) suppression in response to chronic alcohol consumption. Cell culture studies revealed that both hepatoprotective effect and increased intracellular 4-HNE clearance instigated by Danshen supplementation are PPARα-dependent. In conclusion, Danshen administration can protect against ALD via inducing PPARα activation and subsequent 4-HNE degradation.

Intestinal Alkaline Phosphatase Attenuates Alcohol-Induced Hepatosteatosis in Mice

BACKGROUND AND AIMS

Bacterially derived factors from the gut play a major role in the activation of inflammatory pathways in the liver and in the pathogenesis of alcoholic liver disease. The intestinal brush-border enzyme intestinal alkaline phosphatase (IAP) detoxifies a variety of bacterial pro-inflammatory factors and also functions to preserve gut barrier function. The aim of this study was to investigate whether oral IAP supplementation could protect against alcohol-induced liver disease.

METHODS

Mice underwent acute binge or chronic ethanol exposure to induce alcoholic liver injury and steatosis ± IAP supplementation. Liver tissue was assessed for biochemical, inflammatory, and histopathological changes. An ex vivo co-culture system was used to examine the effects of alcohol and IAP treatment in regard to the activation of hepatic stellate cells and their role in the development of alcoholic liver disease.

RESULTS

Pretreatment with IAP resulted in significantly lower serum alanine aminotransferase compared to the ethanol alone group in the acute binge model. IAP treatment attenuated the development of alcohol-induced fatty liver, lowered hepatic pro-inflammatory cytokine and serum LPS levels, and prevented alcohol-induced gut barrier dysfunction. Finally, IAP ameliorated the activation of hepatic stellate cells and prevented their lipogenic effect on hepatocytes.

CONCLUSIONS

IAP treatment protected mice from alcohol-induced hepatotoxicity and steatosis. Oral IAP supplementation could represent a novel therapy to prevent alcoholic-related liver disease in humans.

Impact of Alcohol Dependency on Oral Health - A Cross-sectional Comparative Study

INTRODUCTION

Alcoholism is a chronic and progressive psychiatric illness characterised by a loss of control over alcohol consumption. Consumption of alcohol inevitably affects the oral cavity, oral mucosa and teeth. Literature indicates that alcohol dependents may have increased risk of dental caries, probing pocket depth and mucosal lesions.

AIM

To assess the impact of alcohol dependency on oral health status among alcoholics in comparison with non alcoholics.

MATERIALS AND METHODS

A total 76 alcoholic patients visiting Psychiatric Department were compared with matched non alcoholics. Subjects were categorised as alcohol dependents based on American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnostic criteria. Non alcoholic subjects were selected by controlling for potentially confounding variables such as for cigarette, smoking and age. Data was collected by interview and clinical examination. Oral health status of subjects was assessed using a modified WHO proforma and salivary pH and plaque pH were assessed. Chi-square test was used for assessing socio demographic details and Mann-whitney U test was used for prevalence of dental caries and periodontal diseases, Unpaired t-test was used for plaque and salivary pH.

RESULTS

There was no statistically significant difference noted among alcoholic and nonalcoholic control group with respect to socio demographic details. Prevalence of dental caries was higher in alcohol dependent subjects with a mean DMFT of 5.92 compared to nonalcoholic subjects (4.51). Prevalence of periodontitis was higher (89.61%) in alcohol dependent subjects compared to controls (78.67%). Prevalence of mucosal lesions among alcohol dependent subjects was 31.5% which was higher than the controls (25%). Subjects who were categorised as alcoholics showed a lower plaque and salivary pH compared to non alcoholics.

CONCLUSION

Subjects categorised as alcohol dependent subjects had slightly lower mean plaque and salivary pH and a higher prevalence of dental caries, periodontitis and mucosal lesions compared with non alcoholic subjects.

Pathogenesis of alcoholic liver disease

Alcoholic liver disease (ALD) has become one of the most critical health problems in many countries, including Japan. Liver injury in ALD ranges from steatosis and steatohepatitis to fibrosis, cirrhosis, and hepatocellular carcinoma. Many factors are thought to contribute to the development and progression of ALD, particularly insulin resistance, generation of reactive oxygen species during alcohol metabolism, adipokines from visceral adipose tissue, and endotoxin derived from the gut. Although the pathogenesis of ALD has been widely investigated, the precise mechanisms are yet to be elucidated and many questions remain. This article reviews the possible mechanisms for the development of ALD identified to date.

Medical Management of Severe Alcoholic Hepatitis: Expert Review from the Clinical Practice Updates Committee of the AGA Institute

The purpose of this clinical practice update is to review diagnostic criteria for severe acute alcoholic hepatitis and to determine the current best practices for this life-threatening condition. The best practices in this review are based on clinical trials, systematic reviews including meta-analysis and expert opinion to develop an approach to diagnosis and management. Best Practice Advice 1: Abstinence from drinking alcohol is the cornerstone of treatment for alcohol hepatitis (AH). Best Practice Advice 2: Patients with jaundice and suspected AH should have cultures of blood, urine, and ascites, if present, to determine the presence of bacterial infections regardless of whether they have fever. Best Practice Advice 3: Patients with AH who have jaundice should be admitted to the hospital to encourage abstinence, restore adequate nutrition, and exclude serious infections. Best Practice Advice 4: Imaging of the liver is warranted as part of the evaluation, but caution should be used in administering iodinated contrast dye, as it increases the risk of acute kidney injury (AKI). Best Practice Advice 5: Patients with AH require a diet with 1-1.5 g protein and 30-40 kcal/kg body weight for adequate recovery. If the patient is unable to eat because of anorexia or altered mental status, a feeding tube should be considered for enteral feeding. Parenteral nutrition alone is inadequate. Best Practice Advice 6: Severity and prognosis of AH should be evaluated using Maddrey Discriminant Function (MDF), Model for End-Stage Liver Disease (MELD), age, bilirubin, international normalized ratio, and creatinine (ABIC), or Glasgow scoring systems. Current treatments are based on this assessment. Best Practice Advice 7: Presence of systemic inflammatory response syndrome (SIRS) on admission is associated with an increased risk of multi-organ failure (MOF) syndrome. Development of MOF, usually due to infections developing after initial diagnosis of AH, is associated with a very high mortality rate. Best Practice Advice 8: Nephrotoxic drugs, including diuretics, should be avoided or used sparingly in patients with AH, since AKI is an early manifestation of MOF. Best Practice Advice 9: Patients with MDF > 32 or MELD score > 20 without a contraindication to glucocorticoid, such as hepatitis B viral infection, tuberculosis, or other serious infectious diseases, may be treated with methylprednisolone 32 mg daily, but the appropriate duration of treatment remains a subject of controversy. Methylprednisolone does not improve survival beyond 28 days, and the benefits for < 28 days are modest. Best Practice Advice 10: Patients with a contraindication to glucocorticoids may be treated with pentoxifylline 400 mg three times daily with meals. Data regarding the efficacy are conflicting. Best Practice Advice 11: Patients with severe AH, particularly those with a MELD score > 26 with good insight into their alcohol use disorder and good social support should be referred for evaluation for liver transplantation, as the 90-day mortality rate is very high. Best Practice Advice 12: Patients with mild to moderate AH defined by a MELD score < 20 and MDF < 32 should be referred for abstinence counseling and prescribed a high protein diet supplemented with B vitamins and folic acid.

Alcoholic Hepatitis: Risk Factors, Pathogenesis, and Approach to Treatment

BACKGROUND

Alcoholic hepatitis (AH) is an inflammatory disorder of the liver characterized clinically by jaundice, hepatomegaly, and abdominal pain, and histologically by macrovesicular steatosis and necroinflammation.

METHODS

This clinical review will cover what is known about the pathogenesis, clinical presentation, current treatments, and novel therapies for AH.

RESULTS

The pathogenesis and treatment of AH remain areas of active research. Although abstinence is the cornerstone of therapy for all stages of alcoholic liver disease, corticosteroids have shown modest short-term benefits in treatment of severe AH.

CONCLUSIONS

Improved understanding of the pathogenesis of AH has expanded the range of potential treatments for this devastating disease. Several novel therapies are also currently in various stages of testing through clinical trials.

Ethanol and High Cholesterol Diet Causes Severe Steatohepatitis and Early Liver Fibrosis in Mice

Background and Aim

Because ethanol consumption is commonly associated with a high cholesterol diet, we examined whether combined consumption of ethanol and high cholesterol increases liver injury and fibrosis.

Methods

Male C57BL/6J mice were fed diets containing: 1) 35% of calories from corn oil (CTR), 2) CTR plus 0.5% (w/v) cholesterol (Chol), 3) CTR plus ethanol (27% of calories) (EtOH), or 4) EtOH+Chol for 3 months.

Results

In mice fed Chol or EtOH alone, ALT increased to ~160 U/L, moderate hepatic steatosis occurred, and leukocyte infiltration, necrosis, and apoptosis increased modestly, but no observable fibrosis developed. By contrast in mice fed EtOH+Chol, ALT increased to ~270 U/L, steatosis was more extensive and mostly macrovesicular, and expression of proinflammatory molecules (HMGB-1, TLR4, TNFα, ICAM-1) and leukocyte infiltration increased substantially. Necrosis and apoptosis also increased. Trichrome staining and second harmonic generation microscopy revealed hepatic fibrosis. Fibrosis was mostly sinusoidal and/or perivenular, but in some mice bridging fibrosis occurred. Expression of smooth muscle α-actin and TGF-β1 increased slightly by Chol, moderately by EtOH, and markedly by EtOH+Chol. TGF-β pseudoreceptor BAMBI increased slightly by Chol, remained unchanged by EtOH and decreased by EtOH+Chol. MicroRNA-33a, which enhances TGF-β fibrotic effects, and phospho-Smad2/3, the down-stream signal of TGF-β, also increased more greatly by EtOH+Chol than Chol or EtOH. Metalloproteinase-2 and -9 were decreased only by EtOH+Chol.

Conclusion

High dietary cholesterol and chronic ethanol consumption synergistically increase liver injury, inflammation, and profibrotic responses and suppress antifibrotic responses, leading to severe steatohepatitis and early fibrosis in mice.

Current Management of Alcoholic Hepatitis and Future Therapies

Alcohol is one of the most common etiologies of liver disease, and alcoholic liver disease overall is the second most common indication for liver transplantation in the United States. It encompasses a spectrum of disease, including fatty liver disease, alcoholic hepatitis (AH), and alcoholic cirrhosis. AH can range from mild to severe disease, with severe disease being defined as: Discriminant Function (DF) ≥ 32, or Model for End-stage Liver Disease (MELD) ≥ 21, or presence of hepatic encephalopathy. Management of the mild disease consists mainly of abstinence and supportive care. Severe AH is associated with significant mortality. Currently, there is no ideal medical treatment for this condition. Besides alcohol cessation, corticosteroids have been used with conflicting results and are associated with an inherent risk of infection. Overall steroids have shown short term benefit when compared to placebo, but they have no obvious long term benefits. Pentoxifylline does not improve survival in patients with severe AH and is no longer recommended based on the results of the STOPAH (Steroid Or Pentoxifylline for Alcoholic Hepatitis) trial. Anti-tumor necrosis factor (TNF) agents are associated with increased risk of life threatening infections and death. Currently, early stage trials are underway, mainly targeting novel pathways based on disease pathogenesis, including modulation of innate immune system, inhibition of gut-liver axis and cell death pathways, and activation of transcription factor farnesyl X receptor (FXR). Future treatment may lie in human induced pluripotent stem cell (iPSC) technology, which is currently under investigation for the study of pathogenesis, drug discovery, and stem cell transplantation. Liver transplantation has been reported with good results in highly selected patients but is controversial due to limited organ supply.

Alcohol Consumption and Periodontitis: Quantification of Periodontal Pathogens and Cytokines

BACKGROUND

There are few studies on periodontal status related to microbiologic and immunologic profiles among individuals not or occasionally using alcohol and those with alcohol dependence. The aim of this study is to determine the effect of alcohol consumption on the levels of subgingival periodontal pathogens and proinflammatory cytokines (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) in the gingival fluid among individuals with and without periodontitis.

METHODS

This observational analytic study includes 88 volunteers allocated in four groups (n = 22): individuals with alcohol dependence and periodontitis (ADP), individuals with alcohol dependence and without periodontitis (ADNP), individuals not or occasionally using alcohol with periodontitis (NAP), and individuals not or occasionally using alcohol without periodontitis (NANP). Levels of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Eikenella corrodens, and Fusobacterium nucleatum were determined by real-time polymerase chain reaction on the basis of the subgingival biofilm, and IL-1β and TNF-α were quantified by enzyme-linked immunosorbent assay in gingival fluid samples.

RESULTS

Individuals with alcohol dependence showed worse periodontal status and higher levels of P. intermedia, E. corrodens, F. nucleatum, and IL-1β than non-users. No significant correlations between TNF-α and bacterial levels were observed. However, in the ADP group, higher levels of E. corrodens were correlated with higher levels of IL-1β.

CONCLUSION

A negative influence of alcohol consumption was observed on clinical and microbiologic periodontal parameters, as well as a slight influence on immunologic parameters, signaling the need for additional studies.

Pathogenesis of alcoholic liver disease: Role of oxidative metabolism

Alcohol consumption is a predominant etiological factor in the pathogenesis of chronic liver diseases, resulting in fatty liver, alcoholic hepatitis, fibrosis/cirrhosis, and hepatocellular carcinoma (HCC). Although the pathogenesis of alcoholic liver disease (ALD) involves complex and still unclear biological processes, the oxidative metabolites of ethanol such as acetaldehyde and reactive oxygen species (ROS) play a preeminent role in the clinical and pathological spectrum of ALD. Ethanol oxidative metabolism influences intracellular signaling pathways and deranges the transcriptional control of several genes, leading to fat accumulation, fibrogenesis and activation of innate and adaptive immunity. Acetaldehyde is known to be toxic to the liver and alters lipid homeostasis, decreasing peroxisome proliferator-activated receptors and increasing sterol regulatory element binding protein activity via an AMP-activated protein kinase (AMPK)-dependent mechanism. AMPK activation by ROS modulates autophagy, which has an important role in removing lipid droplets. Acetaldehyde and aldehydes generated from lipid peroxidation induce collagen synthesis by their ability to form protein adducts that activate transforming-growth-factor-β-dependent and independent profibrogenic pathways in activated hepatic stellate cells (HSCs). Furthermore, activation of innate and adaptive immunity in response to ethanol metabolism plays a key role in the development and progression of ALD. Acetaldehyde alters the intestinal barrier and promote lipopolysaccharide (LPS) translocation by disrupting tight and adherent junctions in human colonic mucosa. Acetaldehyde and LPS induce Kupffer cells to release ROS and proinflammatory cytokines and chemokines that contribute to neutrophils infiltration. In addition, alcohol consumption inhibits natural killer cells that are cytotoxic to HSCs and thus have an important antifibrotic function in the liver. Ethanol metabolism may also interfere with cell-mediated adaptive immunity by impairing proteasome function in macrophages and dendritic cells, and consequently alters allogenic antigen presentation. Finally, acetaldehyde and ROS have a role in alcohol-related carcinogenesis because they can form DNA adducts that are prone to mutagenesis, and they interfere with methylation, synthesis and repair of DNA, thereby increasing HCC susceptibility.

Toll-like receptor-mediated signaling cascade as a regulator of the inflammation network during alcoholic liver disease

Chronic abuse of alcohol leads to various histological abnormalities in the liver. These are conditions collectively known as alcoholic liver disease (ALD). Currently, ALD is considered to be one of the major causes of death worldwide. An impaired intestinal barrier with related endotoxemia is among the various pathogenetic factors. This is mainly characterized by circulating levels of lipopolysaccharide (LPS), considered critical for the onset of intra-hepatic inflammation. This in turn promotes hepatocellular damage and fibrosis in ALD. Elevated levels of LPS exert their effects by binding to Toll-like receptors (TLRs) which are expressed by all liver-resident cells. The activation of TLR signaling triggers an overproduction and release of some cytokines, which promote an autocatalytic cascade of other pro-inflammatory signals. In this review, we provide an overview of the mechanisms that sustain LPS-mediated activation of TLR signaling, reporting current experimental and clinical evidence of its role during inflammation in ALD.

Elevation of serum cytokines preceding elevation of liver enzymes in a case of drug-induced liver injury

A 50-year-old man who was being treated for both pneumonia and type 2 diabetes mellitus complained of abdominal distention on the 16th hospital day. Liver enzyme elevation without symptoms was detected on the 17th hospital day. Based on a Roussel Uclaf Causality Assessment Method score of 10 and a Japan Digestive Disease Week score of 9, we diagnosed the patient as having drug-induced liver injury (DILI). Simultaneous assays of the levels of cytokines revealed that the elevation of the levels of interleukin (IL)-1β, IL-10, IL-12, IL-13 and tumor necrosis factor-α preceded the elevation of the serum liver enzymes. This case suggests that some cytokines or related molecules are potentially useful as early-phase biomarkers for DILI.

Biomarkers of liver cell death

Hepatocyte cell death during liver injury was classically viewed to occur by either programmed (apoptosis), or accidental, uncontrolled cell death (necrosis). Growing evidence from our increasing understanding of the biochemical and molecular mechanisms involved in cell demise has provided an expanding view of various modes of cell death that can be triggered during both acute and chronic liver damage such as necroptosis, pyroptosis, and autophagic cell death. The complexity of non-invasively assessing the predominant mode of cell death during a specific liver insult in either experimental in vivo models or in humans is highlighted by the fact that in many instances there is significant crosstalk and overlap between the different cell death pathways. Nevertheless, the realization that during cell demise triggered by a specific mode of cell death certain intracellular molecules such as proteins, newly generated protein fragments, or MicroRNAs are released from hepatocytes into the extracellular space and may appear in circulation have spurred a significant interest in the development of non-invasive markers to monitor liver cell death. This review focuses on some of the most promising markers, and their potential role in assessing the presence and severity of liver damage in humans.

Alcohol enhances Acinetobacter baumannii-associated pneumonia and systemic dissemination by impairing neutrophil antimicrobial activity in a murine model of infection

Acinetobacter baumannii (Ab) is a common cause of community-acquired pneumonia (CAP) in chronic alcoholics in tropical and sub-tropical climates and associated with a >50% mortality rate. Using a murine model of alcohol (EtOH) administration, we demonstrated that EtOH enhances Ab-mediated pneumonia leading to systemic infection. Although EtOH did not affect neutrophil recruitment to the lungs of treated mice, it decreased phagocytosis and killing of bacteria by these leukocytes leading to increased microbial burden and severity of disease. Moreover, we determined that mice that received EtOH prior to Ab infection were immunologically impaired, which was reflected in increased pulmonary inflammation, sequential dissemination to the liver and kidneys, and decreased survival. Furthermore, immunosuppression by EtOH was associated with deregulation of cytokine production in the organs of infected mice. This study establishes that EtOH impairs immunity in vivo exacerbating Ab infection and disease progression. The ability of Ab to cause disease in alcoholics warrants the study of its virulence mechanisms and host interactions.

Hepatic Fibrosis Inhibitory Effect of Peptides Isolated from Navicula incerta on TGF-β1 Induced Activation of LX-2 Human Hepatic Stellate Cells

In this study, novel peptides (NIPP-1, NIPP-2) derived from Navicula incerta (microalgae) protein hydrolysate were explored for their inhibitory effects on collagen release in hepatic fibrosis with the investigation of its underlying mechanism of action. TGF-β1 activated fibrosis in LX-2 cells was examined in the presence or absence of purified peptides NIPP-1 and NIPP-2. Besides the mechanisms of liver cell injury, protective effects of NIPP-1 and NIPP-2 were studied to show the protective mechanism against TGF-β1 stimulated fibrogenesis. Our results showed that the core protein of NIPP-1 peptide prevented fibril formation of type I collagen, elevated the MMP level and inhibited TIMP production in a dose-dependent manner. The treatment of NIPP-1 and NIPP-2 on TGF-β1 induced LX-2 cells alleviated hepatic fibrosis. Moreover, α-SMA, TIMPs, collagen and PDGF in the NIPP-1 treated groups were significantly decreased. Therefore, it could be suggested that NIPP-1 has potential to be used in anti-fibrosis treatment.

Interleukin-17A plays a pivotal role in cholestatic liver fibrosis in mice

BACKGROUND

It was recently reported that serum interleukin (IL)-17 levels increased in liver fibrosis associated with human alcoholic liver disease. However, the role of IL-17 in liver fibrosis has not yet been elucidated. Therefore, the aim of this study was to evaluate the role of IL-17 on cholestatic liver fibrosis.

MATERIALS AND METHODS

IL-17A knockout (KO) and wild-type (WT) mice were subjected to bile duct ligation. Animals were sacrificed at designated times, and serum and liver tissues were collected. The mRNA expression of hepatic fibrotic markers was assessed, and distribution of activated hepatic stellate cells (HSCs) was determined by immunohistochemical staining. In an in vitro study, Kupffer cells (KCs) and HSCs were isolated from WT mice. KCs were cultured with IL-17A or IL-17F, and production of tumor necrosis factor α (TNF-α) and transforming growth factor β1 (TGF-β1) was measured. HSCs were cultured with IL-17A or IL-17F, and morphologic changes were assessed by immunohistochemical staining.

RESULTS

Liver damage observed in the WT mice was significantly improved in the KO mice. Serum TNF-α and TGF-β1 levels were significantly decreased in the KO compared with the WT mice. The hepatic mRNA expression of TNF-α, TGF-β1, and collagen 1α1, which increased in the WT mice, also significantly decreased in the KO mice. Increased hepatic fibrosis in the WT mice was significantly improved in the KO mice. Cytokine production was increased in IL-17A-treated KCs. The most remarkable myofibroblast-like changes were observed in isolated HSCs in the presence of IL-17A.

CONCLUSIONS

IL-17A was involved in the pathogenesis of cholestatic liver fibrosis by activation of both the KCs and HSCs.

Alcohol, liver, systemic inflammation and skin: a focus on patients with psoriasis

Emerging evidence suggests that excessive alcohol consumption is associated with psoriasis. In alcoholics, antipsoriatic treatments are less efficient, but more toxic and an additional challenge is poor therapeutic compliance. There is a correlation between excess alcohol intake and increased risk of infections, but on the other hand alcohol and its metabolites can trigger a persistent systemic inflammation, mediated by pro-inflammatory cytokines released from activated Kupffer cells in the liver and from monocytes in the circulation. Ethanol and its metabolites can also enhance lymphocyte and keratinocyte activation and proliferation and can increase the mRNA levels of genes characteristic for proliferating keratinocytes. In this review, we discuss the mechanisms by which alcohol contributes to psoriasis development focusing on liver, systemic inflammation and skin.

Impact of altered methylation in cytokine signaling and proteasome function in alcohol and viral-mediated diseases

Data from several laboratories have shown that ethanol (EtOH) feeding impairs many essential methylation reactions that contribute to alcoholic liver disease (ALD). EtOH is also a comorbid factor in the severity of hepatitis C virus-induced liver injury. The presence of viral proteins further exacerbates the methylation defects to disrupt multiple pathways that promote the pathogenesis of liver disease. This review is a compilation of presentations that linked the methylation reaction defects with proteasome inhibition, decreased antigen presentation, and impaired interferon (IFN) signaling in the hepatocytes and dysregulated TNFα expression in macrophages. Two therapeutic modalities, betaine and S-adenosylmethionine, can correct methylation defects to attenuate many EtOH-induced liver changes, as well as improve IFN signaling pathways, thereby overcoming viral treatment resistance.

TNF-dependent signaling pathways in liver cancer: promising targets for therapeutic strategies?

Liver cancer represents a growing health burden worldwide, and treatment options are still limited. Hepatocellular carcinoma (HCC), the most frequent primary hepatic malignancy, arises in most instances in chronically inflamed and fibrotic livers. However, current systemic molecular therapies against HCC are mainly focusing on tyrosine kinases involved in angiogenic and oncogenic signaling pathways, whereas the knowledge on the unique association between inflammation and carcinogenesis in the liver has not yet translated into preventive or therapeutic concepts against HCC. Tumor necrosis factor (TNF) is a cytokine derived from monocytes and various other immunological and parenchymal cells. Upon binding to its receptors, TNF activates different signaling cascades including the pro-apoptotic caspase cascade as well as inflammatory and stress-related pathways such as the NF-ĸB, p38MAPK, and Jun-(N)-terminal kinase (JNK) pathways. The role of TNF in cancer is controversial, since it was attributed both pro- and anti-carcinogenic functions. Its potential function in hepatocarcinogenesis has lately been investigated using genetically modified mouse models. These studies have highlighted that the various TNF-dependent signaling pathways withhold distinct functions in hepatocarcinogenesis, which are in part controversial and strongly depend on the experimental model system. Nevertheless, careful interpretation of findings in mouse models and critical consideration of their limitations might result in a new understanding of this complex pathway in hepatocarcinogenesis and thus might help identify the most promising targets in the TNF pathway and the appropriate clinical settings for future chemo-preventive or therapeutic strategies against HCC.

Molecular targets in the treatment of alcoholic hepatitis

Alcohol related costs to health and society are high. One of the most serious complications of alcohol misuse to the individual is the development of alcoholic hepatitis (AH), a clinical syndrome of jaundice and progressive inflammatory liver injury in patients with a history of recent heavy alcohol use. It has a poor outcome and few existing successful therapies. The use of glucocorticoids in patients with severe AH is still controversial and there remains a group of patients with glucocorticoid-resistant disease. However, as our understanding of the pathogenesis of the condition improves there are opportunities to develop new targeted therapies with specific actions to control liver inflammation without having a detrimental effect on the immune system as a whole. In this article we review the molecular mechanisms of AH concentrating on the activation of the innate and adaptive immune response. We consider existing treatments including glucocorticoids, anti-tumor necrosis factor therapy and pentoxifylline and their limitations. Using our knowledge of the disease pathogenesis we discuss possible novel therapeutic approaches. New targets include pro-inflammatory cytokines such as interleukin (IL)-17, chemokines and their receptors (for example IL-8, CXCL9 and CXCR3) and augmentation of anti-inflammatory molecules such as IL-10 and IL-22. And there is also future potential to consider combination therapy to selectively modulate the immune response and gain control of disease.

Inhibition of NF-κB activation by 4-hydroxynonenal contributes to liver injury in a mouse model of alcoholic liver disease

Long-term alcohol exposure sensitizes hepatocytes to tumor necrosis factor-α (TNF) cytotoxicity. 4-Hydroxynonenal (4-HNE) is one of the most abundant and reactive lipid peroxides. Increased hepatic 4-HNE contents present in both human alcoholics and alcohol-fed animals. In the present study, we investigated the effects of intracellular 4-HNE accumulation on TNF-induced hepatotoxicity and its potential implication in the pathogenesis of alcoholic liver disease. Male C57BL/6 mice were fed an ethanol-containing or a control diet for 5 weeks. Long-term alcohol exposure increased hepatic 4-HNE and TNF levels. Cell culture studies revealed that 4-HNE, at nontoxic concentrations, sensitized hepatocytes to TNF killing, which was associated with suppressed NF-κB transactivity. Further investigation demonstrated that 4-HNE prevented TNF-induced inhibitor of κBα phosphorylation without affecting upstream IκB kinase activity. An immunoprecipitation assay revealed that increased 4-HNE content was associated with increased formation of 4-HNE-inhibitor of κBα adduction in both 4-HNE-treated hepatocytes and in the livers of alcohol-fed mice. Prevention of intracellular 4-HNE accumulation by bezafibrate, a peroxisome proliferator-activated receptor-α agonist, protected hepatocytes from TNF killing via NF-κB activation. Supplementation of N-acetylcysteine, a glutathione precursor, conferred a protective effect on alcohol-induced liver injury in mice, was associated with decreased hepatic 4-HNE formation, and improved hepatic NF-κB activity. In conclusion, increased 4-HNE accumulation represents a potent and clinically relevant sensitizer to TNF-induced hepatotoxicity. These data support the notion that removal of intracellular 4-HNE can serve as a potential therapeutic option for alcoholic liver disease.

Biochemical and immunological basis of silymarin effect, a milk thistle (Silybum marianum) against ethanol-induced oxidative damage

Ethanol metabolism induces generation of excessive amount of reactive oxygen species (ROS) which results in immune dysfunction. We examined the efficacy of silymarin on ethanol-induced oxidative stress, immunomodulatory activity, and vascular function in mice blood. Effectiveness of silymarin was compared with potent antioxidant ascorbic acid. In the present study, 8- to 10-week-old male BALB/c mice (20-30 g) were divided into the four groups of six each. One group were fed with ethanol (1.6 g/kg body weight), while second group were fed with ethanol (1.6 g/kg body weight) and silybin (250 mg/kg body weight), and the third group were exposed to ethanol (250 mg/kg body weight) and ascorbic acid (250 mg/kg body weight) per day for 12 weeks. The control group was fed with isocaloric glucose solution instead of ethanol. Ethanol exposure significantly increased thiobarbituric acid reactive substance (TBARS) and nitrite levels besides glutathione-S-transferase (GST) activity, and significantly decreased reduced glutathione (GSH) content and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GPx) in whole blood hemolyzate, while silymarin treatment significantly normalized these altered parameters. Silymarin significantly prevented ethanol-induced, elevated activities of interleukin (IL)-10, tumor necrosis factor (TNF)-α, γ interferon (IFN-γ), vascular endothelial growth factor (VEGF)-A, and transforming growth factor (TGF)-β1, as well as decreased IL-4 activity in mice blood. These results were comparable with the activity of ascorbic acid.

Antioxidant peptides from protein hydrolysate of microalgae Navicula incerta and their protective effects in HepG2/CYP2E1 cells induced by ethanol

Marine microalgae have been reported as valuable new sources of pharmacologically active compounds and there are now numerous commercial applications of microalgae. Hence, in this study we evaluated the protective effects of peptides purified from marine microalgae, Navicula incerta, against alcohol-induced damage in HepG2/CYP2E1 cells. To obtain bioactive peptides from microalgae, N. incerta was hydrolysed using various enzymes (alcalase, α-chymotrypsin, neutrase, papain, pepsin, pronase-E and trypsin), and the hydrolysates were evaluated for cytoprotective activity. Among them, papain-derived hydrolysate exhibited higher antioxidant activities than those of other enzymes. Therefore, papain hydrolysate was purified in order to obtain potent antihepatotoxic and antioxidative peptides. The amino acid sequences of the purified peptides were analysed as; NIPP-1 (Pro-Gly-Trp-Asn-Gln-Trp-Phe-Leu) with molecular mass 1 171 Da, and NIPP-2 (Val-Glu-Val-Leu-Pro-Pro-Ala-Glu-Leu) with molecular mass 1108 Da. Furthermore, this study demonstrated that NIPP-1 and NIPP-2 peptides inhibited ethanol-induced cytotoxicity in HepG2/CYP2E1 cells.

Reduction in hyperammonaemia by ornithine phenylacetate prevents lipopolysaccharide-induced brain edema and coma in cirrhotic rats

OBJECTIVE

In liver failure, inflammation synergistically exacerbates the deleterious cerebral effects of ammonia. The aims were to test whether treatment with the ammonia-lowering agent ornithine phenylacetate (OP) and/or anti-TNF-α (infliximab) prevent the deleterious brain consequences of lipopolysaccharide (LPS) in cirrhotic rats.

DESIGN

Rats 4 weeks following bile duct-ligation (BDL), sham-operation (sham) and/or 7 days hyperammonemic feed (HD), were randomized to receive LPS (1 mg/kg) or saline, and treatment with either 3 days intraperitoneal injections of OP (0.6 g/kg) and/or infliximab, 10 mg/kg. Animals were sacrificed at coma stages or at 3 h.

RESULTS

In sham rats, both HD and LPS increased brain water, with an increase in ammonia in the former and brain cytokines in the latter but with no effect on consciousness. BDL + HD rats caused significantly higher plasma ammonia, TNF-α and IL-6 levels compared to sham. LPS significantly worsened coma stage, increased brain water and plasma and brain TNF-α. OP significantly delayed LPS-induced progression to coma stages (P < 0.009), reduced arterial ammonia and brain water (P < 0.001 and P < 0.01 respectively), which was associated with a significant reduction in cytokines. Infliximab significantly reduced plasma and brain cytokines, but not brain water. OP + infliximab attenuated increase in brain water and delayed occurrence of coma, which was not different to OP alone. In BDL rats, OP reduced the expression of brain iNOS and NFκB.

CONCLUSION

Reduction in ammonia with OP in cirrhotic rats prevents LPS-induced brain edema and delays coma, suggesting that ammonia may prime the brain to the deleterious effect of LPS, possibly through effects on iNOS and NFκB related mechanisms.

Cytokines in alcoholic liver disease

Alcoholic liver disease (ALD) is associated with a spectrum of liver injury ranging from steatosis and steatohepatitis to fibrosis and cirrhosis. While multifactorial pathogenesis plays a role in the disease progression, enhanced inflammation in the liver during ethanol exposure is a major feature of ALD. Dysregulated cytokine metabolism and activity are crucial to the initiation of alcohol-induced liver injury. The pro-inflammatory cytokine tumor necrosis factor (TNF-α) has been demonstrated to be one of the key factors in the various aspects of pathophysiology of ALD. The immunomodulatory cytokines such as interleukin 10 and interleukin 6 play roles in exerting hepatic protective effects. Adiponectin is an adipose tissue-derived hormone, which displays protective actions on ethanol-induced liver injury. Treatment for mice with adiponectin decreases TNF-α expression, steatosis and prevents alcohol-induced liver injury. Adiponectin exerts its anti-inflammatory effects via suppression of TNF-α expression and induction of anti-inflammatory cytokines such as IL-10. Adiponectin attenuates alcoholic liver injury by the complex network of multiple signaling pathways in the liver, leading to enhanced fatty acid oxidation and reduced steatosis. Interactions between pro- and anti-inflammatory cytokines such as TNFα and adiponectin and other cytokines are likely to play important roles in the development and progression of alcoholic liver disease.

Controversies in the management of alcoholic liver disease

Alcohol is a risk factor for chronic disease burden in developed countries. Alcoholic liver disease affects 1% of the North American population and is the second most frequent indication for liver transplantation in the United States. It is a spectrum that ranges from simple hepatic steatosis to alcoholic hepatitis to steatohepatitis and eventually cirrhosis. The clinical spectrum of alcoholic hepatitis is wide and ranges from the asymptomatic patient to overt liver failure and death. Liver biopsy as a means of prognostication in alcoholic hepatitis has mostly been replaced with less invasive scoring systems. The management of alcoholic liver disease is challenging. Abstinence is the cornerstone of therapy and should include rehabilitation with a multidisciplinary approach. No specific treatment is required in mild to moderate alcoholic hepatitis. In patients with severe hepatitis, there appears to be a moderate survival benefit from the use of either corticosteroids or pentoxifylline in the absence of contraindications to their use. Nonresponders should have steroid therapy withdrawn by day 7, as persistence with therapy is not beneficial. Orthotopic liver transplantation remains the definitive therapy for decompensated alcoholic cirrhosis despite alcohol abstinence. More studies are needed to define the optimal timing of orthotopic liver transplantation and patients at risk of alcohol relapse post-transplant. Mt Sinai J Med 76:484-498, 2009. (c) 2009 Mount Sinai School of Medicine.

Treatment of alcoholic liver disease

Alcoholic liver disease (ALD) remains a major cause of liver-related mortality in the US and worldwide. The correct diagnosis of ALD can usually be made on a clinical basis in conjunction with blood tests, and a liver biopsy is not usually required. Abstinence is the hallmark of therapy for ALD, and nutritional therapy is the first line of therapeutic intervention. The role of steroids in patients with moderate to severe alcoholic hepatitis is gaining increasing acceptance, with the caveat that patients be evaluated for the effectiveness of therapy at 1 week. Pentoxifylline appears to be especially effective in ALD patients with renal dysfunction/hepatorenal syndrome. Biologics such as specific anti-TNFs have been disappointing and should probably not be used outside of the clinical trial setting. Transplantation is effective in patients with end-stage ALD who have stopped drinking (usually for ≥6 months), and both long-term graft and patient survival are excellent.

Lack of association between tumour necrosis factor receptor types 1 and 2 gene polymorphism and severe acute alcoholic hepatitis

BACKGROUND/AIMS

Tumour necrosis factor-alpha (TNF-alpha) is involved in the physiopathology of severe acute alcoholic hepatitis (AAH) binding with TNF receptor types TNFR1 and TNFR2, whose serum concentrations are elevated. We studied the role of TNFR1 and TNFR2 gene polymorphism in AAH patients.

METHODS

One hundred and ninety-two patients (58 AAH with Maddrey score >or=32, 44 non-AAH cirrhoses, 90 healthy individuals) were genotyped for A36G TNFR1 and T676G TNFR2 using polymerase chain reaction-restriction fragment length polymorphism technique. Serum sTNFR1 and sTNFR2 were assayed.

RESULTS

The AAH and two control groups did not differ for genotype distribution. In three groups, A (36 TNFR1) and T (676 TNFR2) allelic frequencies were similar, at 0.47, 0.47, 0.44 and 0.78, 0.81, 0.80, respectively. The 36 TNFR1, 676 TFNR2 genotypes did not influence on prognostic scores (Maddrey, Child-Pugh), nor in response to corticosteroids or 6-month survival. sTNFR1 levels were higher in AAH than healthy group (3.07+/-1.14 vs. 1.17+/-0.27 ng/ml, P<0.001) and sTNFR2 levels were higher in AAH than cirrhosis (3.6+/-1.02 vs. 3.1+/-1.03, P<0.05) and healthy groups (3.6+/-1.02 vs. 1.91+/-0.54, P<0.001). However, sTNFR1 and sTNFR2 levels did not vary significantly according to genotypes.

CONCLUSION

These results did not support an association between 36 TNFR1, 676 TNFR2 gene polymorphisms and AAH.

NFkappaB, cytokines, TLR 3 and 7 expression in human end-stage HCV and alcoholic liver disease

BACKGROUND/AIMS

Conflicting observations exist concerning the role of nuclear factor kappa B (NFjB) in alcoholic liver disease (ALD) in animal models. To date no studies have examined this aspect in human liver tissue. We here assessed cytokines and toll-like receptors (TLRs) expressions in conjunction with NFkappaB activation in non-active end-stage human ALD compared with normal livers and hepatitis C virus (HCV) related end-stage disease.

METHODS

mRNA and protein expression were examined by quantitative PCR and Western blotting, DNA-binding by electrophoretic mobility shift assays and NFkappaB sub-cellular localization by immunofluorescent staining of livers.

RESULTS

NFkappaB mRNA and protein expression as well as strong DNA-binding were preserved in ALD but significantly down-regulated in HCV compared with normal livers. P50 immunofluorescence was found in hepatocytes and bile ducts in ALD and normal livers, whereas a shift was observed in p65 staining from non-parenchymal cells in normal livers to hepatocytes in ALD. NFkappaB responsive genes mRNA levels IkBalpha and interleukin 6 were significantly higher in ALD compared with HCV. Tumour necrosis factor alpha (TNFalpha), TLRs 3 and 7 mRNA were up-regulated in ALD and HCV compared with normal liver with TNFalpha and TLR7 being the highest in HCV. Strong induction of interferon beta was found in HCV but not in ALD or normal liver tissue.

CONCLUSIONS

Persistent NFkappaB activation together with high pro-inflammatory cytokine expression and upregulation of TLR3 and TLR7 is associated with end-stage ALD in humans and could contribute to disease progression even in absence of alcohol intake.

Pentoxifylline does not decrease short-term mortality but does reduce complications in patients with advanced cirrhosis

BACKGROUND & AIMS

Pentoxifylline, an inhibitor of tumor necrosis factor-alpha, is given to patients with liver diseases, but its effects in patients with advanced cirrhosis are unknown. We performed a randomized, placebo-controlled, double-blind trial of its effects in patients with cirrhosis.

METHODS

A total of 335 patients with cirrhosis (Child-Pugh class C) were assigned to groups given either pentoxifylline (400 mg, orally, 3 times daily; n = 164) or placebo (n = 171) for 6 months. The primary end point was mortality at 2 months. Secondary end points were mortality at 6 months and development of liver-related complications.

RESULTS

By 2 months, 28 patients in the pentoxifylline group (16.5%) and 31 in the placebo group (18.2%) had died (P = .84). At 6 months, 50 patients in the pentoxifylline group (30.0%) and 54 in the placebo group (31.5%) had died (P = .75). The proportions of patients without complications (eg, bacterial infection, renal insufficiency, hepatic encephalopathy, or gastrointestinal hemorrhage) were higher in the pentoxifylline group than in the placebo group at 2 months (78.6% vs 63.4%; P = .006) and 6 months (66.8% vs 49.7%; P = .002). The probability of survival without complications was higher in the pentoxifylline group than in the placebo group at 2 and 6 months (P = .04). In multivariate analysis, the factors associated with death were age, the Model for End-Stage Liver Disease score, and presence of early-stage carcinoma. Treatment with pentoxifylline was the only factor associated with liver-related complications.

CONCLUSIONS

Although pentoxifylline does not decrease short-term mortality in patients with advanced cirrhosis, it does reduce the risk of complications.

Granulocytapheresis in the treatment of severe alcoholic hepatitis: a case series

OBJECTIVES

The management of alcoholic hepatitis remains controversial. Anti-tumour necrosis factor treatments have been studied recently. We piloted the use of granulocytapheresis (GCAP) in the management of severe alcoholic hepatitis.

METHODS

GCAP was performed on six patients with severe alcoholic hepatitis. Their clinical and laboratory progress was reviewed retrospectively.

RESULTS

Six of the patients underwent at least one session of GCAP. Three of the patients had coexistent renal failure and five of the six patients were corticosteroid nonresponders. All patients tolerated the procedure. However, three of the patients died during their hospital admission within 4 days of GCAP treatment. These three patients suffered from torrential variceal haemorrhage, multiorgan failure and pneumonia, respectively. Two patients died 18 and 25 days after their GCAP treatment, both with multiorgan failure. The survivor was the sole corticosteroid responder of the group. There was a trend towards a fall in serum bilirubin level after GCAP, but this did not reach significance.

CONCLUSION

GCAP is tolerated in severe alcoholic hepatitis; however, we have no evidence of survival advantage with this treatment.

Circulating cytokines as biomarkers of alcohol abuse and alcoholism

There are currently no consistent objective biochemical markers of alcohol abuse and alcoholism. Development of reliable diagnostic biomarkers that permit accurate assessment of alcohol intake and patterns of drinking is of prime importance to treatment and research fields. Diagnostic biomarker development in other diseases has demonstrated the utility of both open, systems biology, screening for biomarkers and more rational focused efforts on specific biomolecules or families of biomolecules. Long-term alcohol consumption leads to altered inflammatory cell and adaptive immune responses with associated pathologies and increased incidence of infections. This has led researchers to focus attention on identifying cytokine biomarkers in models of alcohol abuse. Alcohol is known to alter cytokine levels in plasma and a variety of tissues including lung, liver, and very importantly brain. A number of cytokine biomarker candidates have been identified, including: tumor necrosis factor-alpha, interleukin (IL)-1-alpha, IL-1-beta, IL-6, IL-8, IL-12, and monocyte chemoattractant protein-1. This is an emerging and potentially exciting avenue of research in that circulating cytokines may contribute to diagnostic biomarker panels, and a combination of multiple biomarkers may significantly increase the sensitivity and specificity of the biochemical tests aiding reliable and accurate detection of excessive alcohol intake.

"Hypothesis of seven balances": molecular mechanisms behind alcoholic liver diseases and association with PPARalpha

OBJECTIVES

The purpose of this review to collate current leading scientific advances of molecular mechanisms in alcoholic liver diseases and to propose a working "hypothesis of seven balances" in relation to peroxisome proliferator activated receptor alpha (PPARalpha), which has important roles in fatty acid oxidation, oxidative stress, inflammatory responses, and possibly liver fibrosis.

METHODS

We conducted an extensive literature review of over a hundred publications and collated the findings with evidence generated in our laboratory.

RESULTS

Our research points to a working hypothesis of seven balances for alcoholic liver diseases consisting of: 1) ethanol oxidation balance in hepatocytes; 2) PPAR alpha activities in liver; 3) fatty acid metabolism balance in hepatic mitochondria; 4) gastrointestinal response to ethanol, acetaldehyde and lipopolysaccharide (LPS); 5) Kupffer cells response to LPS, oxidative stress and inflammatory cytokines; 6) adiponectin levels in plasma interchangeably regulated by tumor necrosis factor-alpha (TNF-alpha); and 7) stellate cells response to all of the above promoting hepatic fibrosis. Cellular mechanisms behind alcoholic liver diseases reveal close temporal associations of PPARalpha, adiponectin, TNF-alpha, cellular inflammation, proliferation, and potentially fibrosis as illustrated in "the hypothesis of seven balances."

CONCLUSIONS

The regulation and adjustment of PPARalpha activation underlying the balance of molecular cascades might resolve the progression of alcoholic liver diseases by reducing oxidative stress and inflammatory effects induced by nuclear factor-kappaB as well as the associated adiponectin pathway. Further elucidation of these pathways would reveal exciting new prospects for treating alcoholic liver diseases and other related liver disorders.

Protein array technology to investigate cytokine production by monocytes from patients with advanced alcoholic cirrhosis: An ex vivo pilot study

AIM

In patients with advanced cirrhosis, little is known about the ability of peripheral blood monocytes to spontaneously produce signaling proteins such as cytokines. The aim of this ex vivo study was to evaluate cytokine production under baseline conditions and after stimulation by lipopolysaccharide (LPS), a toll-like receptor (TLR) agonist.

METHODS

Peripheral blood monocytes were isolated from patients with advanced alcoholic cirrhosis (without ongoing bacterial infections) and normal subjects. Cells were left unstimulated or were stimulated with LPS. The abundance of 24 cytokines was measured using a filter-based, arrayed sandwich enzyme-linked immunosorbent assay (ELISA) in the supernatant of cultured monocytes.

RESULTS

Cirrhotic monocytes spontaneously produced six proteins (TNF-alpha, IL-6, IL-8, MCP-1, RANTES and Gro), whereas normal monocytes produced only small amounts of IL-8 and RANTES. Analyses with the online gene set analysis toolkit WebGestalt (http://bioinfo.vanderbilt.edu/webgestalt) found enrichment for the six proteins in the human gene ontology subcategory (http://www.geneontology.org), Kyoto Encyclopedia of Genes and Genome pathways (http://www.genome.ad.jp/kegg/) and BioCarta pathways (http://www.biocarta.com/genes/index.asp) consistent with a proinflammatory phenotype of cirrhotic monocytes resulting from activated TLR signaling. Interestingly, LPS-elicited TLR engagement further increased the production of the six proteins and did not induce the secretion of any others, in particular the anti-inflammatory cytokine IL-10. LPS-stimulated normal monocytes produced TNF-alpha, IL-6, IL-8, MCP-1, RANTES, Gro and IL-10.

CONCLUSION

In patients with advanced cirrhosis, peripheral blood monocytes spontaneously produce proinflammatory cytokines, presumably in response to unrestricted TLR signaling.