Oral administration of PEGylated TLR7 ligand ameliorates alcohol-associated liver disease via the induction of IL-22.

Effective therapies for alcohol-associated liver disease (ALD) are limited; therefore, the discovery of new therapeutic agents is greatly warranted. Toll-like receptor 7 (TLR7) is a pattern recognition receptor for single-stranded RNA, and its activation prevents liver fibrosis. We examined liver and intestinal damage in Tlr7-/- mice to determine the role of TLR7 in ALD pathogenesis. In an alcoholic hepatitis (AH) mouse model, hepatic steatosis, injury, and inflammation were induced by chronic binge ethanol feeding in mice, and Tlr7 deficiency exacerbated these effects. Because these results demonstrated that endogenous TLR7 signaling activation is protective in the AH mouse model, we hypothesized that TLR7 activation may be an effective therapeutic strategy for ALD. Therefore, we investigated the therapeutic effect of TLR7 agonistic agent, 1Z1, in the AH mouse model. Oral administration of 1Z1 was well tolerated and prevented intestinal barrier disruption and bacterial translocation, which thus suppressed ethanol-induced hepatic injury, steatosis, and inflammation. Furthermore, 1Z1 treatment up-regulated the expression of antimicrobial peptides, Reg3b and Reg3g, in the intestinal epithelium, which modulated the microbiome by decreasing and increasing the amount of Bacteroides and Lactobacillus, respectively. Additionally, 1Z1 up-regulated intestinal interleukin (IL)-22 expression. IL-22 deficiency abolished the protective effects of 1Z1 in ethanol-induced liver and intestinal damage, suggesting intestinal IL-22 as a crucial mediator for 1Z1-mediated protection in the AH mouse model. Collectively, our results indicate that TLR7 signaling exerts protective effects in the AH mouse model and that a TLR7 ligand, 1Z1, holds therapeutic potential for the treatment of AH.

Ductular reaction promotes intrahepatic angiogenesis through Slit2-Roundabout 1 signaling.

BACKGROUND AND AIMS: Ductular reaction (DR) expands in chronic liver diseases and correlates with disease severity. Besides its potential role in liver regeneration, DR plays a role in the wound-healing response of the liver, promoting periductular fibrosis and inflammatory cell recruitment. However, there is no information regarding its role in intrahepatic angiogenesis. In the current study we investigated the potential contribution of DR cells to hepatic vascular remodeling during chronic liver disease. APPROACH AND RESULTS: In mouse models of liver injury, DR cells express genes involved in angiogenesis. Among angiogenesis-related genes, the expression of Slit2 and its receptor Roundabout 1 (Robo1) was localized in DR cells and neoangiogenic vessels, respectively. The angiogenic role of the Slit2-Robo1 pathway in chronic liver disease was confirmed in ROBO1/2-/+ mice treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine, which displayed reduced intrahepatic neovascular density compared to wild-type mice. However, ROBO1/2 deficiency did not affect angiogenesis in partial hepatectomy. In patients with advanced alcohol-associated disease, angiogenesis was associated with DR, and up-regulation of SLIT2-ROBO1 correlated with DR and disease severity. In vitro, human liver-derived organoids produced SLIT2 and induced tube formation of endothelial cells. CONCLUSIONS: Overall, our data indicate that DR expansion promotes angiogenesis through the Slit2-Robo1 pathway and recognize DR cells as key players in the liver wound-healing response.

Palliative care needs among patients with advanced illnesses in Bhutan.

BACKGROUND: Palliative care improves the quality of lives of patients and families affected by advanced illnesses through the prevention and relief of suffering. While palliative care is well established in developed countries, it is inadequate or non-existent in most developing countries. Palliative care is an emerging concept in Bhutan, a tiny Himalayan Kingdom. A small community palliative care service is available in the national referral hospital with three dedicated inpatient palliative care beds. This study explored the needs for palliative care among patients diagnosed with advanced illnesses and is a component of a larger project aimed to inform a suitable palliative care model for the country. METHODS: This is a cross-sectional descriptive study. A survey, using a structured questionnaire including the EORTC QLQ-C30, was carried out among patients with advanced illness in hospitals, primary care units and communities across the country. Purposeful and snowball sampling strategies were used to recruit study participants. RESULTS: Seventy (76%), out of 93 eligible patients, agreed to participate in the survey. Participants reported low to moderate scores on physical, role, emotional, cognitive and social functioning, a moderate score for the global health/ quality of life scale and moderately high (worse) scores in symptoms including fatigue, pain, insomnia, loss of appetite and the financial impact from the disease. CONCLUSIONS: The symptom burden experienced by patients affected by advanced illnesses demonstrates the need for palliative care in Bhutan. These findings will help inform the development of a public health-focused palliative care model, modified to the Bhutanese context, as recommended by the World Health Organization.

Dysregulated Autophagy and Lysosome Function Are Linked to Exosome Production by Micro-RNA 155 in Alcoholic Liver Disease.

Cellular homeostais, that is normally maintained through autophagy, is disrupted in alcoholic liver disease (ALD). Because autophagy and exosome biogenesis share common elements, we hypothesized that increased exosome production in ALD may be linked to disruption of autophagic function. We found impaired autophagy both in ALD and alcoholic hepatitis (AH) mouse models and human livers with ALD as indicated by increased hepatic p62 and LC3-II levels. Alcohol reduced autophagy flux in vivo in chloroquine-treated mice as well as in vitro in hepatocytes and macrophages treated with bafilomycin A. Our results revealed that alcohol targets multiple steps in the autophagy pathway. Alcohol-related decrease in mechanistic target of rapamycin (mTOR) and Ras homolog enriched in brain (Rheb), that initiate autophagy, correlated with increased Beclin1 and autophagy-related protein 7 (Atg7), proteins involved in phagophore-autophagosome formation, in ALD. We found that alcohol disrupted autophagy function at the lysosomal level through decreased lysosomal-associated membrane protein 1 (LAMP1) and lysosomal-associated membrane protein 2 (LAMP2) in livers with ALD. We identified that micro-RNA 155 (miR-155), that is increased by alcohol, targets mTOR, Rheb, LAMP1, and LAMP2 in the authophagy pathway. Consistent with this, miR-155-deficient mice were protected from alcohol-induced disruption of autophagy and showed attenuated exosome production. Mechanistically, down-regulation of LAMP1 or LAMP2 increased exosome release in hepatocytes and macrophages in the presence and absence of alcohol. These results suggested that the alcohol-induced increase in exosome production was linked to disruption of autophagy and impaired autophagosome and lysosome function. Conclusion: Alcohol affects multiple genes in the autophagy pathway and impairs autophagic flux at the lysosome level in ALD. Inhibition of LAMP1 and LAMP2 promotes exosome release in ALD. We identified miR-155 as a mediator of alcohol-related regulation of autophagy and exosome production in hepatocytes and macrophages.

Differential Metabolic Pathways and Metabolites in a C57BL/6J Mouse Model of Alcoholic Liver Disease.

BACKGROUND Alcoholic liver disease (ALD), an important cause of acute or chronic liver injury, results from binge drinking or long-term alcohol consumption. To date, there is no well-established mouse model with a comprehensive metabolic profile that mimics ALD in humans. This study aimed to explore the differential metabolic pathways and related differential metabolites in the liver of an ALD mouse model. MATERIAL AND METHODS A C57BL/6J mouse model of ALD was induced by alcohol feeding for 10 days plus binge alcohol feeding. The metabolomic profiles in the liver of the ALD mouse model was detected through ultra-high-pressure liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF-MS). RESULTS A total 35 metabolites were significantly altered during the development of ALD. These metabolites were correlated to multiple metabolic pathways, including purine metabolism, the pentose phosphate pathway, cysteine and methionine metabolism, D-glutamine and D-glutamate metabolism, pyrimidine metabolism, and vitamin B6 metabolism. CONCLUSIONS The findings of the present study reveal potential biomarkers of ALD, and provide further insights into the pathogenesis of ALD.

Alcohol-related liver disease: Areas of consensus, unmet needs and opportunities for further study.

A joint meeting of the European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases (AASLD) was held in London on September 30 and October 1, 2017. The goals of the meeting were to identify areas of broad agreement and disagreement, develop consensus, and determine future directions to ultimately reduce the burden, morbidity, and mortality of alcohol-related liver disease (previously termed alcoholic liver disease). The specific aims of the meeting were to identify unmet needs and areas for future investigation, in order to reduce alcohol consumption, develop markers for diagnosis and prognosis of disease, and create a framework to test novel pharmacological agents with pre-specified treatment endpoints.

Alcohol or Gut Microbiota: Who Is the Guilty?

Alcoholic liver disease (ALD), a disorder caused by excessive alcohol intake represents a global health care burden. ALD encompasses a broad spectrum of hepatic injuries including asymptomatic steatosis, alcoholic steatohepatitis (ASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The susceptibility of alcoholic patients to develop ALD is highly variable and its progression to more advanced stages is strongly influenced by several hits (i.e., amount and duration of alcohol abuse). Among them, the intestinal microbiota and its metabolites have been recently identified as paramount in ALD pathophysiology. Ethanol abuse triggers qualitative and quantitative modifications in intestinal flora taxonomic composition, mucosal inflammation, and intestinal barrier derangement. Intestinal hypermeability results in the translocation of viable pathogenic bacteria, Gram-negative microbial products, and pro-inflammatory luminal metabolites into the bloodstream, further corroborating the alcohol-induced liver damage. Thus, the premise of this review is to discuss the beneficial effect of gut microbiota modulation as a novel therapeutic approach in ALD management.

Is moderate alcohol use in nonalcoholic fatty liver disease good or bad? A critical review.

Moderate alcohol consumption in patients with nonalcoholic fatty liver disease (NAFLD) is common, yet the effects on cardiovascular and liver health are unclear. Moderate alcohol use is associated with improved insulin sensitivity and decreased cardiovascular mortality in the general population, but whether similar benefits would be observed in persons with NAFLD remains largely unstudied. There is significant overlap in the pathogenesis of alcoholic liver disease (ALD) and NAFLD, although studies of ALD have focused on pathological alcohol intake and few mechanistic studies of moderate alcohol use in NAFLD exist. We undertook a critical review of the effect of moderate alcohol use on cardiovascular and liver disease in patients with NAFLD. A total of seven observational studies met the criteria for inclusion (one for cardiovascular endpoints and six for liver endpoints). Insufficient studies have assessed the association of moderate alcohol use with cardiovascular outcomes. There was a positive association between moderate alcohol use and decreased NASH and fibrosis; however, heavy episodic drinking may accelerate fibrosis progression and moderate alcohol use may increase the risk of hepatocellular carcinoma in patients with advanced fibrosis. Significant methodological limitations were present, including incomplete adjustment for confounding factors and failure to measure lifetime use or the pattern of alcohol intake. Thus, a strong recommendation of benefit of moderate alcohol use in NAFLD cannot be made. There remains a need for additional high-quality longitudinal studies that evaluate both cardiovascular and liver outcomes among NAFLD patients with moderate or lesser degrees of alcohol use. (Hepatology 2017;65:2090-2099).

Galectin-9: Diverse roles in hepatic immune homeostasis and inflammation.

Glycan-binding proteins, which include galectins, are involved at all stages of immunity and inflammation, from initiation through resolution. Galectin-9 (Gal-9) is highly expressed in the liver and has a wide variety of biological functions in innate and adaptive immunity that are instrumental in the maintenance of hepatic homeostasis. In the setting of viral hepatitis, increased expression of Gal-9 drives the expansion of regulatory T cells and contraction of effector T cells, thereby favoring viral persistence. The dichotomous nature of Gal-9 is evident in hepatocellular carcinoma, where loss of expression in hepatocytes promotes tumor growth and metastasis, whereas overexpression by Kupffer cells and endothelial cells inhibits the antitumor immune response. In nonalcoholic fatty liver disease, Gal-9 is involved indirectly in the expansion of protective natural killer T-cell populations. In ischemic liver injury, hepatocyte-derived Gal-9 is both diagnostic and cytoprotective. In drug-induced acute liver failure, plasma levels correlate with outcome. Here, we offer a synthesis of recent and emerging findings on Gal-9 in the regulation of hepatic inflammation. Ongoing studies are warranted to better elucidate the pathophysiology of hepatic immune-mediated diseases and to develop new therapeutic interventions using glycan-binding proteins. (Hepatology 2017;66:271-279).

Intestinal dysbiosis and permeability: the yin and yang in alcohol dependence and alcoholic liver disease.

Alcohol dependence and alcoholic liver disease represent a major public health problem with substantial morbidity and mortality. By yet incompletely understood mechanisms, chronic alcohol abuse is associated with increased intestinal permeability and alterations of the gut microbiota composition, allowing bacterial components, bacteria, and metabolites to reach the portal and the systemic circulation. These gut-derived bacterial products are recognized by immune cells circulating in the blood or residing in remote organs such as the liver leading to the release of pro-inflammatory cytokines which are considered important mediators of the liver-gut-brain communication. Although circulating cytokines are likely not the sole factors involved, they can induce liver inflammation/damage and reach the central nervous system where they favor neuroinflammation which is associated with change in mood, cognition, and drinking behavior. In this review, the authors focus on the current evidence describing the changes that occur in the intestinal microbiota with chronic alcohol consumption in conjunction with intestinal barrier breakdown and inflammatory changes sustaining the concept of a gut-liver-brain axis in the pathophysiology of alcohol dependence and alcoholic liver disease.

Cellular Abnormalities and Emerging Biomarkers in Alcohol-Associated Liver Disease.

Alcohol-associated liver disease (AALD) is the third most common preventable cause for disease burden and mortality in the US. AALD, including alcoholic hepatitis (AH), contributes to half of admissions from decompensated liver disease and 20% of all liver transplants in the US. Peripheral blood cells contribute to systemic inflammation, oxidative stress, mitochondrial dysfunction, and fibrosis in AALD and AH. Alcohol dysregulates function of lymphocytes, neutrophils, monocytes, and tissue macrophages of the innate immune system. These alterations in turn can modulate adaptive immune responses. In this review, we describe these disruptive effects of alcohol on cells of the innate and adaptive immune system and focus on cellular-based emerging biomarkers on diagnosis and prognosis of patients with AALD and AH.

Predicting Pre-transplant Abstinence in Patients with Alcohol-Induced Liver Disease.

BACKGROUND: Some patients with alcohol-induced liver failure will succumb to their disease prior to demonstrating compliance with the six months abstinence rule for liver transplantation. PURPOSE: The purpose of this study was to determine whether a patient's self-reported, longest period of abstinence predicts subsequent abstinence. METHODS: Adult patients (n=63) with alcohol-induced liver disease were asked to recall their longest period of abstinence prior to their initial hepatology visit. Compliance with instructions to remain abstinent was then documented. RESULTS: Nineteen patients (30%) achieved abstinence and 44 (70%) relapsed within six months of seeing their hepatologist. Relapses were more common in patients who self-reported previous periods of abstinence exceeding six months (19/44, 43%) compared with 2/19 (11%) in those with periods of less than six months (p=0.01). Serum albumin levels were lower in relapsers but other tests of liver function (bilirubin level and international ratio of prothrombin time) and predictors of post-transplant recidivism did not associate with relapses. On multivariate analysis, self-reported abstinence (OR: 0.11, 95% CI: 0.02-0.57, p=0.008) and serum albumin levels (regression coefficient 0.113, p=0.02) predicted relapses. CONCLUSIONS: A self-reported period of abstinence in excess of six months was associated with an increased risk of subsequent relapse following a hepatologist's instructions to remain abstinent. These counter-intuitive findings should be confirmed by larger, prospective studies.

Sepsis in alcohol-related liver disease.

Alcohol-related liver disease (ALD) remains the most important cause of death due to alcohol. Infections, particularly bacterial infections, are one of the most frequent and severe complications of advanced ALDs, such as alcoholic cirrhosis and severe alcoholic hepatitis (sAH). The specific mechanisms responsible for this altered host defence are yet to be deciphered. The aim of the present study is to review the current knowledge of infectious complications in ALD and its pathophysiological mechanisms, distinguishing the role of alcohol consumption and the contribution of different forms of ALD. To date, corticosteroids are the only treatment with proven efficacy in sAH, but their impact on the occurrence of infections remains controversial. The combination of an altered host defence and corticosteroid treatment in sAH has been suggested as a cause of opportunistic fungal and viral infections. A high level of suspicion with systematic screening and prompt, adequate treatment are warranted to improve outcomes in these patients. Prophylactic or preemptive strategies in this high-risk population might be a preferable option, because of the high short-term mortality rate despite adequate therapies. However, these strategies should be assessed in well-designed trials before clinical implementation.

Linking Pathogenic Mechanisms of Alcoholic Liver Disease With Clinical Phenotypes.

Alcoholic liver disease (ALD) develops in approximately 20% of alcoholic patients, with a higher prevalence in females. ALD progression is marked by fatty liver and hepatocyte necrosis, as well as apoptosis, inflammation, regenerating nodules, fibrosis, and cirrhosis.(1) ALD develops via a complex process involving parenchymal and nonparenchymal cells, as well as recruitment of other cell types to the liver in response to damage and inflammation. Hepatocytes are damaged by ethanol, via generation of reactive oxygen species and induction of endoplasmic reticulum stress and mitochondrial dysfunction. Hepatocyte cell death via apoptosis and necrosis are markers of ethanol-induced liver injury. We review the mechanisms by which alcohol injures hepatocytes and the response of hepatic sinusoidal cells to alcohol-induced injury. We also discuss how recent insights into the pathogenesis of ALD will affect the treatment and management of patients.

IRAKM-Mincle axis links cell death to inflammation: Pathophysiological implications for chronic alcoholic liver disease.

Lipopolysaccharide (LPS)-mediated activation of Toll-like receptors (TLRs) in hepatic macrophages and injury to hepatocytes are major contributors to the pathogenesis of alcoholic liver disease. However, the mechanisms by which TLR-dependent inflammatory responses and alcohol-induced hepatocellular damage coordinately lead to alcoholic liver disease are not completely understood. In this study, we found that mice deficient in interleukin-1 receptor-associated kinase M (IRAKM), a proximal TLR pathway molecule typically associated with inhibition of TLR signaling, were actually protected from chronic ethanol-induced liver injury. In bone marrow-derived macrophages challenged with low concentrations of LPS, which reflect the relevant pathophysiological levels of LPS in both alcoholic patients and ethanol-fed mice, the IRAKM Myddosome was preferentially formed. Further, the IRAKM Myddosome mediated the up-regulation of Mincle, a sensor for cell death. Mincle-deficient mice were also protected from ethanol-induced liver injury. The endogenous Mincle ligand spliceosome-associated protein 130 (SAP130) is a danger signal released by damaged cells; culture of hepatocytes with ethanol increased the release of SAP130. Ex vivo studies in bone marrow-derived macrophages suggested that SAP130 and LPS synergistically activated inflammatory responses, including inflammasome activation. CONCLUSION: This study reveals a novel IRAKM-Mincle axis that contributes to the pathogenesis of ethanol-induced liver injury. (Hepatology 2016;64:1978-1993).

Fecal microbiota transplantation for gastrointestinal disorders.

PURPOSE OF REVIEW: The importance of the gut microbiome in human health is being increasingly recognized. The purpose of this review is to examine the existing literature pertaining to alterations in the gut microbiome and the utility of microbiome restoration therapies in gastrointestinal disorders. RECENT FINDINGS: Imbalance and maladaptation of the microbiome, termed dysbiosis, has been associated with several disease states such as irritable bowel syndrome, Clostridium difficile infection, inflammatory bowel diseases, nonalcoholic fatty liver disease, and obesity among others. The possibility of restoration of normal microbiota has become an attractive concept for diseases in which the normal microbiome is perturbed. The rationale of using fecal microbiota transplantation to treat disease has been validated by its successful use in treating recurrent Clostridium difficile infection, which occurs as a result of decreased microbial diversity in the gut, most often in the setting of recent antibiotic treatment. Similar strategies may be applicable to other disorders. SUMMARY: Alterations in the gut microbiome are associated with several disorders, and microbiome restoration based therapies such as fecal microbiota transplantation may be an adjunct to conventional treatments but more investigation is needed.

Animal Models of Alcoholic Liver Disease: Pathogenesis and Clinical Relevance.

Alcoholic liver disease (ALD), a leading cause of chronic liver injury worldwide, comprises a range of disorders including simple steatosis, steatohepatitis, cirrhosis, and hepatocellular carcinoma. Over the last five decades, many animal models for the study of ALD pathogenesis have been developed. Recently, a chronic-plus-binge ethanol feeding model was reported. This model induces significant steatosis, hepatic neutrophil infiltration, and liver injury. A clinically relevant model of high-fat diet feeding plus binge ethanol was also developed, which highlights the risk of excessive binge drinking in obese/overweight individuals. All of these models recapitulate some features of the different stages of ALD and have been widely used by many investigators to study the pathogenesis of ALD and to test for therapeutic drugs/components. However, these models are somewhat variable, depending on mouse genetic background, ethanol dose, and animal facility environment. This review focuses on these models and discusses these variations and some methods to improve the feeding protocol. The pathogenesis, clinical relevance, and translational studies of these models are also discussed.

Lifetime drinking history in patients with alcoholic liver disease and patients with alcohol use disorder without liver disease.

OBJECTIVE: To determine the differences in lifetime alcohol intake (LAI) and drinking patterns between patients with alcoholic liver disease (ALD) and alcohol use disorder (AUD) without notable liver injury and between males and females with ALD. METHODS: Alcohol drinking patterns were assessed using the Lifetime Drinking History (LDH) a validated questionnaire, during an outpatient visit. Patients with AUD, currently in addiction treatment, were matched for gender and age (±5 years) with the ALD group. RESULTS: A total of 39 patients with ALD (26 males and 13 females; median age 58) and equal number of AUD patients were included (median age 56 years). The onset age for alcohol drinking and duration of alcohol consumption was similar in ALD and AUD. The number of drinking days was higher in women with ALD than in women with AUD: 4075 [(3224-6504) versus 2092 (1296-3661), p = .0253]. The LAI and drinks per drinking day (DDD) were not significantly different between patients with ALD and AUD. Females with ALD had lower LAI than males with ALD: 32,934 (3224-6504) versus 50,923 (30,360-82,195), p = .0385, fewer DDD (p = .0112), and lower proportion of binge drinking as compared to males with ALD (p = .0274). CONCLUSIONS: The total LAI was similar in patients with ALD and AUD. The number of drinking days over the lifetime was associated with the development of ALD in females. Females with ALD had significantly lower alcohol consumption than men with ALD despite similar duration in years of alcohol intake which supports the concept of female propensity of ALD.

More Alcohol, More Liver Injury: Not Always True.

An animal model of alcoholic liver disease (ALD) that recapitulates human disease is an unmet need. An alcohol-preferring strain and WT mice were fed alcohol by different techniques and with different diet compositions. Interestingly, the greatest alcohol consumers did not develop the worst ALD. This editorial highlights how diet and the gut microbiome/metabolome may influence the development/severity of ALD.