Estrogen increases sensitivity of hepatic Kupffer cells to endotoxin

Low-dose alcohol exacerbates hyperdynamic circulation and shunting in non-alcoholic cirrhotic rats

BACKGROUND

Portal hypertension affects hepatic, splanchnic and portosystemic collateral systems. Although alcohol is a well-known risk factor for liver cirrhosis, it also affects vascular contractility. However, the relevant effects on portal hypertension have not been evaluated in non-alcoholic cirrhosis. The present study aimed to investigate the impacts of low-dose alcohol on portal hypertension-related derangements in non-alcoholic cirrhotic rats.

METHODS

Sprague-Dawley rats received bile duct ligation to induce cirrhosis or sham operation as controls. The chronic or acute effects of low-dose alcohol (2.4 g/kg/day, oral gavage, approximately 1.3 drinks/day in humans) were evaluated.

RESULTS

The chronic administration of low-dose alcohol did not precipitate liver fibrosis in the sham or cirrhotic rats; however, it significantly increased splanchnic blood inflow (P=0.034) and portosystemic collaterals (P=0.001). Mesenteric angiogenesis and pro-angiogenic proteins were up-regulated in the alcohol-treated cirrhotic rats, and poorer collateral vasoresponsiveness to vasoconstrictors (P<0.001) was noted. Consistently, acute alcohol administration reduced splenorenal shunt resistance. Collateral vasoresponsiveness to vasoconstrictors also significantly decreased (P=0.003).

CONCLUSIONS

In non-alcoholic cirrhosis rats, a single dose of alcohol adversely affected portosystemic collateral vessels due to vasodilatation. Long-term alcohol use precipitated splanchnic hyperdynamic circulation, in which mesenteric angiogenesis played a role. Further studies are warranted to evaluate the benefits of avoiding low-dose alcohol consumption in patients with non-alcoholic cirrhosis.

Pomegranate-Derived Exosome-Like Nanovesicles Alleviate Binge Alcohol-Induced Leaky Gut and Liver Injury

Alcoholic liver disease (ALD) is damage to the liver and mainly caused by binge alcohol. ALD have decreased junctional protein expression and modulated intestinal permeability. We investigated whether plant-releasing exosome-like nanovesicles can prevent liver damage and leaky gut from binge alcohol. In this study, we characterized the exosome-like nanovesicles from pomegranate juice and confirmed the round shape of a lipid bilayer. After 14 days of pomegranate-derived exosome-like nanovesicle (PNVs) pretreatment, binge alcohol (6 g/kg/dose) was administered to mice three times orally every 12 h. Exposure to binge alcohol increased levels of oxidative and nitric oxide stress marker proteins such as CYP2E1, 3-Nitrotyrosine, and inducible nitric oxide synthase in both liver and gut damage. Also, binge alcohol significantly elevated the plasma endotoxemia, inflammatory fatty liver, and leaky gut. However, PNVs reduced the oxidative stress and apoptosis marker proteins and prevented the leaky gut and endotoxemia. Markedly, PNV treatment significantly prevented a decrease in the amount of intestinal junctional proteins and an increase in leaky gut in mice exposed to alcohol. These results showed that PNVs can prevent leaky gut and liver damage caused by binge alcohol and suggest that it may be useful hepatoprotective or intestinal protective agents for the first time.

Comorbidities and Outcomes among Females with Non-Alcoholic Fatty Liver Disease Compared to Males

Sex-based medicine is an important emerging discipline within medicine. We investigated the clinical characteristics, complications, and outcomes of Nonalcoholic Fatty Liver Disease (NAFLD) in females compared to males. Demographics, comorbidities, malignancy, complications, outcomes, and all-cause mortality of NAFLD patients older than 18 years were analyzed. The data were extracted using the MDClone platform from “Clalit” in Israel. A total of 111,993 (52.8%) of the study subjects were females with an average age of 44.4 ± 14.7 years compared to 39.62 ± 14.9 years in males, p < 0.001. Significantly higher rates of hypertension, diabetes mellitus, obesity, dementia, and thyroid cancer and lower rates of ischemic heart disease (22.3% vs. 27.3%, p < 0.001) were found among females. Females had a higher rate of cirrhosis, 2.3% vs. 1.9%, p < 0.001, and a lower rate of hepatocellular carcinoma, 0.4% vs. 0.5%, p < 0.001. In the multivariate analysis, a relationship between age, diabetes mellitus, and cirrhosis development were found among males and females. A lower age-adjusted mortality rate was found among females, 94.5/1000 vs. 116/1000 among males. In conclusion, older age at diagnosis, higher rates of hypertension, diabetes mellitus, obesity, cirrhosis, and a lower age-adjusted all-cause mortality rate were found among females with NAFLD.

Sex-specific association between alcohol consumption and liver cirrhosis: An updated systematic review and meta-analysis

Different studies have shown that females develop liver diseases at lower levels of alcohol consumption than males. Our aim was to quantify the dose-response relationship between alcohol consumption and the risk of liver cirrhosis by sex and identify the differences between females and males. A systematic review was conducted using PubMed/Medline and Embase to identify longitudinal and case-control studies that analyzed the relationship between the level of alcohol use and liver cirrhosis (LC) incidence, and mortality (ICD-8 and ICD-9 codes 571 and ICD-10 codes K70, K73, K74). Pooled relative risks (RR) were calculated by random effects models. Restricted cubic splines were used to model the dose-response relationship. A total of 24 studies were included in the analysis. There were collectively 2,112,476 females and 924,853 males, and a total of 4,301 and 4,231 cases of LC for females and males, respectively. We identified a non-linear dose-response relationship. Females showed a higher risk for LC compared to males with the same amount of alcohol consumed daily. For instance, drinking 40 g/day showed RRs of 9.35 (95% CI 7.64-11.45) in females and 2.82 (95% CI 2.53-3.14) in males, while drinking 80 g/day presented RRs of 23.32 (95% CI 18.24-29.82) in females and 7.93 (95% CI 7.12-8.83) in males. Additional analyses showed that a higher risk for females was found for morbidity and for mortality. Understanding the influence of sex on the association of alcohol consumption and the risk of LC is needed to develop recommendations and clinical guidelines for prevention and treatment.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022299680, identifier CRD42022299680.

Effect of alcohol on clinical complications of hepatitis virus-induced liver cirrhosis: a consecutive ten-year study

Background and aims

Although coexisting alcohol-induced liver disease and hepatitis B or C virus-induced liver cirrhosis (ALD + HBV or ALD + HCV) has been the center of recent hepatology researches, numerous controversies still persist. This study aimed to showcase the influence of alcohol on the laboratory values and on the clinical outcomes of patients with hepatitis B and C virus-induced liver cirrhosis.

Methods

Patients diagnosed with liver cirrhosis (n = 22,287) from January 2010 to December 2019 were enrolled, and divided into five groups according to the etiology: alcohol-induced liver disease (ALD, 1652 cases), hepatitis B virus (HBV, 18,079 cases), hepatitis C virus (HCV, 682 cases), ALD + HBV (1594 cases) and ALD + HCV (280 cases). Laboratory results and proportion of different liver cirrhosis complications were contrasted between groups.

Results

The proportions of patients with Child Pugh grade C (28.0% vs 18.8%, P < 0.001) or MELD greater than 18 (24.1% vs 18.5%, P < 0.001) in the ALD + HBV group exceeded significantly those in the HBV group. Multivariate logistic regression revealed that the risk of hepatocellular carcinoma (HCC) and that of esophageal gastric variceal bleeding (EGVB) in the ALD + HBV group was respectively 2.01-fold and 1.74-fold that in the HBV group (HCC: OR = 2.01, 95% CI [1.58–2.55]; EGVB: OR = 1.74, 95% CI [1.30–2.33]) after adjusting for potential confounders. Furthermore, a linear-by-linear analysis test showed a decrease in the risk of HCC and EGVB with the duration of alcohol abstinence. Moreover, patients with both antiviral treatment and alcohol abstinence had the lowest risk of HCC and EGVB (HCC: OR = 0.10, 95% CI [0.05–0.20], P < 0.001; EGVB: OR = 0.17, 95% CI [0.06–0.45], P < 0.001) compared to those without any treatment, those with abstinence alone and those with antiviral therapy alone. Similar pattern was noticed while comparing the ALD + HCV group to the HCV group.

Conclusion

Heavy alcohol use increased the severity of liver function impairment and the prevalence of HCC and EGVB in hepatitis virus-induced liver cirrhosis patients. Remarkably, long-term alcohol abstinence coupled with antiviral treatment effectively decreased the risk of HCC and EGVB in these populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02198-w.

Lifestyle and Hepatocellular Carcinoma What Is the Evidence and Prevention Recommendations

Simple Summary

The increasing public health burden of Hepatocellular carcinoma (HCC) emphasizes the importance of defining important modifiable risk factors. In the following review, we will discuss the evidence for the relation of major lifestyle risk factors, mostly from large population-based studies. Generally, it is has been shown that healthy lifestyle habits, including minimizing obesity, eating a healthy diet, avoidance of smoking and alcohol, and increasing physical activity, have the potential to prevent HCC. Dietary composition is important beyond obesity. Consumption of n-3 polyunsaturated fatty acids, as well as fish and poultry, vegetables and fiber, are inversely associated with HCC, while red meat, saturated fat, cholesterol and sugar are related to increased risk. Data from multiple studies clearly show a beneficial effect for physical activity in reducing the risk of HCC. Smoking and alcohol can lead to liver fibrosis and liver cancer and jointly lead to an even greater risk.

Abstract

The increasing burden of hepatocellular carcinoma (HCC) emphasizes the unmet need for primary prevention. Lifestyle measures appear to be important modifiable risk factors for HCC regardless of its etiology. Lifestyle patterns, as a whole and each component separately, are related to HCC risk. Dietary composition is important beyond obesity. Consumption of n-3 polyunsaturated fatty acids, as well as fish and poultry, are inversely associated with HCC, while red meat, saturated fat, and cholesterol are related to increased risk. Sugar consumption is associated with HCC risk, while fiber and vegetable intake is protective. Data from multiple studies clearly show a beneficial effect for physical activity in reducing the risk of HCC. However, the duration, mode and intensity of physical activity needed are yet to be determined. There is evidence that smoking can lead to liver fibrosis and liver cancer and has a synergistic effect with alcohol drinking. On the other hand, an excessive amount of alcohol by itself has been associated with increased risk of HCC directly (carcinogenic effect) or indirectly (liver fibrosis and cirrhosis progression. Large-scale intervention studies testing the effect of comprehensive lifestyle interventions on HCC prevention among diverse cohorts of liver disease patients are greatly warranted.

Estrogen receptor actions in colitis

In recent years, researchers have demonstrated that estrogen and its receptors, aside from their role in regulating several biological functions, contribute to the development and progression/severity of inflammatory bowel diseases (IBDs). IBDs include both ulcerative colitis (UC) and Crohn's disease (CD). Epidemiological data indicate a clear difference in the incidence, severity, and complications of IBDs between sexes. Men present a higher risk of developing colitis than women and a higher risk of developing colorectal cancer, a common complication of this condition. However, fluctuations of estrogen levels have yielded inconsistent data, where oral contraceptives and hormone replacement therapy have been associated with an increased risk of IBDs in premenopausal women but significantly reduce disease activity after menopause. Likewise, improvement of symptoms related to CD has been reported during pregnancy, but not in UC, who often experience worsening symptoms. In the colonic epithelium, estrogen receptor β (ERβ) is the predominant form of the protein expressed, and it helps maintain normal epithelial function and organization. Preclinical data suggest that ER expression and activation via estrogen confers different responses on disease severity depending on the model used to induce colitis, which may reflect what is observed in patients with IBDs. Hence, this review aims to provide an overview of estrogen and its receptors, particularly ERβ, in the pathophysiology of IBDs.

Etiology of Hepatocellular Carcinoma: Special Focus on Fatty Liver Disease

Hepatocellular Carcinoma (HCC) is a highly aggressive cancer with mortality running parallel to its incidence and has limited therapeutic options. Chronic liver inflammation and injury contribute significantly to the development and progression of HCC. Several factors such as gender, age, ethnicity, and demographic regions increase the HCC incidence rates and the major risk factors are chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV), carcinogens (food contaminants, tobacco smoking, and environmental toxins), and inherited diseases. In recent years evidence highlights the association of metabolic syndrome (diabetes and obesity), excessive alcohol consumption (alcoholic fatty liver disease), and high-calorie intake (nonalcoholic fatty liver disease) to be the prime causes for HCC in countries with a westernized sedentary lifestyle. HCC predominantly occurs in the setting of chronic liver disease and cirrhosis (80%), however, 20% of the cases have been known in patients with non-cirrhotic liver. It is widely believed that there exist possible interactions between different etiological agents leading to the involvement of diverse mechanisms in the pathogenesis of HCC. Understanding the molecular mechanisms of HCC development and progression is imperative in developing effective targeted therapies to combat this deadly disease. Noteworthy, a detailed understanding of the risk factors is also critical to improve the screening, early detection, prevention, and management of HCC. Thus, this review recapitulates the etiology of HCC focusing especially on the nonalcoholic fatty liver disease (NAFLD)- and alcoholic fatty liver disease (AFLD)-associated HCC.

Sex specific effect of alcohol on hepatic plasmacytoid dendritic cells

Alcoholic liver disease includes a spectrum of clinical and histological entities. They result from the combined direct effect of alcohol and its metabolites on immune cells and resident tissue cells. In humans and mice, females are more susceptible to alcoholic liver injury than males. Despite being involved in sex specific differences of immune mediated tissue injury, plasmacytoid dendritic cells (pDCs) have not been thoroughly assessed as a cellular target of alcohol in humans or mice. Therefore, Meadows-Cook diet was used to study alcohol effect on hepatic dendritic cells. Alcohol consumption for 12 weeks increased hepatic pDCs in female mice. The expression of the C-C chemokine receptor type 2 (CCR2) increased in hepatic pDC of alcohol-fed female mice. Bone marrow transplant chimera showed CCR2 dependent bone marrow egress of pDCs. Chronic alcohol exposure has a sex specific effect on hepatic pDCs population that may explain sex differences to alcoholic liver disease.

Use of an Animal Model to Evaluate Anxiolytic Effects of Dietary Supplementation with Tilia tomentosa Moench Bud Extracts

Anxiety disorders are common and complex psychiatric syndromes affecting a broad spectrum of patients. On top of that, we know that aging produces an increase in anxiety vulnerability and sedative consumption. Moreover, stress disorders frequently show a clear gender susceptibility. Currently, the approved pharmacological strategies have severe side effects such as hallucinations, addiction, suicide, insomnia, and loss of motor coordination. Dietary integration with supplements represents an intriguing strategy for improving the efficacy and the safety of synthetic anxiolytics. Accordingly, a recent article demonstrated that glyceric bud extracts from Tilia tomentosa Moench (TTBEs) exert effects that are consistent with anxiolytic activity. However, the effects of these compounds in vivo are unknown. To examine this question, we conducted behavioral analysis in mice. A total of 21 days of oral supplements (vehicle and TTBEs) were assessed by Light Dark and Hole Board tests in male and female mice (young, 3 months; old, 24 months). Interestingly, the principal component analysis revealed gender and age-specific behavioral modulations. Moreover, the diet integration with the botanicals did not modify the body weight gain and the daily intake of water. Our results support the use of TTBEs as dietary supplements for anxiolytic purposes and unveil age and gender-dependent responses.

Trends in Premature Deaths From Alcoholic Liver Disease in the U.S., 1999-2018

INTRODUCTION

So-called deaths of despair-those involving drug overdoses, alcohol-related liver disease, and suicide-have been rising in the U.S. among middle-aged white, non-Hispanic adults without a college degree. Premature deaths (ages 25-69) from alcoholic liver disease were examined specifically in this study from 1999 to 2018, by sex, race/Hispanic origin, and age group.

METHODS

Data were drawn from the 1999-2018 Multiple Cause of Death database and bridged-race estimates of the U.S. resident population, including 281,243 alcoholic liver disease deaths or an average of 8 deaths per 100,000 population. Analyses examined alcoholic liver disease death rates for sex differences among 3 age groups (25-49, 50-59, and 60-69 years), by race and Hispanic origin, from 1999 to 2018; age-adjusted and age-specific annual percentage changes (accounted for cohorts); years of potential life lost; and age of death for sociodemographic backgrounds, alcoholic liver disease clinical courses, and comortalities.

RESULTS

White non-Hispanics increasingly experienced greater alcoholic liver disease mortality than black non-Hispanics and Hispanics, confirming the racial and ethnic crossover observed in previous studies. Although men consistently had higher rates of mortality, male-to-female ratios decreased in the past 2 decades and were the lowest among ages 25-49 years and especially among ages 25-34 years. Although women generally had longer life expectancies, women died of alcoholic liver disease on average about 2-3 years earlier than men.

CONCLUSIONS

Prevention and intervention efforts are imperative to address the narrowing sex gap and widening racial disparities in alcoholic liver disease premature deaths.

Non-alcoholic Fatty Liver Disease as a Canonical Example of Metabolic Inflammatory-Based Liver Disease Showing a Sex-Specific Prevalence: Relevance of Estrogen Signaling

There is extensive evidence supporting the interplay between metabolism and immune response, that have evolved in close relationship, sharing regulatory molecules and signaling systems, to support biological functions. Nowadays, the disruption of this interaction in the context of obesity and overnutrition underlies the increasing incidence of many inflammatory-based metabolic diseases, even in a sex-specific fashion. During evolution, the interplay between metabolism and reproduction has reached a degree of complexity particularly high in female mammals, likely to ensure reproduction only under favorable conditions. Several factors may account for differences in the incidence and progression of inflammatory-based metabolic diseases between females and males, thus contributing to age-related disease development and difference in life expectancy between the two sexes. Among these factors, estrogens, acting mainly through Estrogen Receptors (ERs), have been reported to regulate several metabolic pathways and inflammatory processes particularly in the liver, the metabolic organ showing the highest degree of sexual dimorphism. This review aims to investigate on the interaction between metabolism and inflammation in the liver, focusing on the relevance of estrogen signaling in counteracting the development and progression of non-alcoholic fatty liver disease (NAFLD), a canonical example of metabolic inflammatory-based liver disease showing a sex-specific prevalence. Understanding the role of estrogens/ERs in the regulation of hepatic metabolism and inflammation may provide the basis for the development of sex-specific therapeutic strategies for the management of such an inflammatory-based metabolic disease and its cardio-metabolic consequences.

Hydroxysteroid (17β) dehydrogenase 12 is essential for metabolic homeostasis in adult mice

Hydroxysteroid 17β dehydrogenase 12 (HSD17B12) is suggested to be involved in the elongation of very long chain fatty acids. Previously, we have shown a pivotal role for the enzyme during mouse development. In the present study we generated a conditional Hsd17b12 knockout (HSD17B12cKO) mouse model by breeding mice homozygous for a floxed Hsd17b12 allele with mice expressing the tamoxifen-inducible Cre recombinase at the ROSA26 locus. Gene inactivation was induced by administering tamoxifen to adult mice. The gene inactivation led to a 20% loss of body weight within 6 days, associated with drastic reduction in both white (83% males, 75% females) and brown (65% males, 60% females) fat, likely due to markedly reduced food and water intake. Furthermore, the knockout mice showed sickness behavior and signs of liver toxicity, specifically microvesicular hepatic steatosis and increased serum alanine aminotransferase (4.6-fold in males, 7.7-fold in females). The hepatic changes were more pronounced in females than males. Proinflammatory cytokines, such as interleukin-6 (IL-6), IL-17, and granulocyte colony-stimulating factor, were increased in the HSD17B12cKO mice indicating an inflammatory response. Serum lipidomics study showed an increase in the amount of dihydroceramides, despite the dramatic overall loss of lipids. In line with the proposed role for HSD17B12 in fatty acid elongation, we observed accumulation of ceramides, dihydroceramides, hexosylceramides, and lactosylceramides with shorter than 18-carbon fatty acid side chains in the serum. The results indicate that HSD17B12 is essential for proper lipid homeostasis and HSD17B12 deficiency rapidly results in fatal systemic inflammation and lipolysis in adult mice.

Alcohol and Liver Function in Women

Alcohol-related liver disease generally has been ascribed to men because men reportedly consume alcohol at an increased rate and quantity as compared to women. Recent literature has reported, however, that rates of liver disease attributed to alcohol use by women have increased, largely due, in part, to the increased number of women who consume alcohol regularly. This increase is a paramount concern, as women are more susceptible than men to the effects of alcohol-related liver injury. Health care providers should make efforts to counsel women on the risks of excess alcohol consumption to prevent further increase in alcohol-related liver disease and its associated complications.

Inhibition of the Inflammasome Signaling Cascade Reduces Alcohol Consumption in Female But Not Male Mice

BACKGROUND

Alcohol use disorder is a significant societal and medical burden that is associated with both organ pathology and addiction. Excessive alcohol use results in neuroinflammation characterized by activation of the inflammasome, a multiprotein complex, and IL-1β increase in the brain. Recent studies suggest that inflammation could contribute to alcohol addiction. Here, we targeted components of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome cascade, which senses and responds to immunologic stimuli, to determine whether NLRP3 inhibition modulates alcohol consumption.

METHODS

C57BL/6J male and female mice were provided a 2-bottle choice of alcohol at increasing concentrations (3, 6, 9, and 12%, 4 days each) or water, and some were treated with daily injections of an NLRP3 inhibitor (MCC950), a caspase-1 inhibitor (VX765), IL-1 receptor antagonist (IL-1ra; anakinra), or vehicle injection.

RESULTS

Treatment with VX765, MCC950, and IL-1ra significantly reduced alcohol consumption and preference in female mice (p < 0.05). Treatment with MCC950 and IL-1ra reduced alcohol consumption, while IL-1ra reduced alcohol preference in male mice (p < 0.05). VX765 did not affect alcohol consumption or preference in male mice.

CONCLUSIONS

These findings highlight gender differences in alcohol preference and demonstrate that inhibition of different steps in inflammasome signaling can reduce alcohol consumption in females. Inhibition of NLRP3 inflammasome activation and the inflammasome-IL-1β cascade opens novel insights into the development of new therapies to address alcohol use disorder in an era of targeted and precision medicine.

Tannic acid and vitamin E loaded PLGA nanoparticles ameliorate hepatic injury in a chronic alcoholic liver damage model via EGFR-AKT-STAT3 pathway

Aim: Tannic acid and vitamin E loaded-poly D, L-lactide-co-glycolic acid (PLGA) nanoparticles (NP) were developed to achieve hepatoprotection in alcoholic liver disease mice model. Materials & methods: PLGA NPs were formed by emulsion solvent evaporation and characterized and delivered to mice. Histology studies were performed, serum enzyme levels of AST, ALT and inflammatory cytokines were checked using ELISA kits. Confocal microscopy and western blot analysis were utilized to determine protein expression levels, and docking studies were performed for interaction analysis. Results: PLGA NPs provided hepatoprotection by reducing inflammatory load, preventing reactive oxygen species generation and apoptosis, as well as by inhibiting the EGFR-AKT-STAT3 pathway. Conclusion: PLGA NPs of tannic acid and vitamin E could be a future medication for alcoholic liver disease treatment.

Beneficial and Deleterious Effects of Female Sex Hormones, Oral Contraceptives, and Phytoestrogens by Immunomodulation on the Liver

The liver is considered the laboratory of the human body because of its many metabolic processes. It accomplishes diverse activities as a mixed gland and is in continuous cross-talk with the endocrine system. Not only do hormones from the gastrointestinal tract that participate in digestion regulate the liver functions, but the sex hormones also exert a strong influence on this sexually dimorphic organ, via their receptors expressed in liver, in both health and disease. Besides, the liver modifies the actions of sex hormones through their metabolism and transport proteins. Given the anatomical position and physiological importance of liver, this organ is evidenced as an immune vigilante that mediates the systemic immune response, and, in turn, the immune system regulates the hepatic functions. Such feedback is performed by cytokines. Pro-inflammatory and anti-inflammatory cytokines are strongly involved in hepatic homeostasis and in pathological states; indeed, female sex hormones, oral contraceptives, and phytoestrogens have immunomodulatory effects in the liver and the whole organism. To analyze the complex and interesting beneficial or deleterious effects of these drugs by their immunomodulatory actions in the liver can provide the basis for either their pharmacological use in therapeutic treatments or to avoid their intake in some diseases.

Crystallized but not soluble uric acid elicits pro-inflammatory response in short-term whole blood cultures from healthy men

Several epidemiological studies have pointed at serum uric acid (SUA) as an independent risk factor for mortality, diabetes, hypertension, cardiovascular and kidney disease; however, no clear pathogenic pathway is established. Uric acid (UA) crystals show pro-inflammatory properties and can thus create or contribute to the state of chronic low-grade inflammation, a widely accepted pathogenic mechanism in several of the above-mentioned pathologies. On the other hand, soluble uric acid possesses antioxidant properties that might attenuate inflammatory responses. We aimed to explore the net effects of experimentally rising SUA in human whole blood cultures on several mediators of inflammation. Production of TNF-α, IL-1ß, IL-1RA, MCP-1 and IL-8 was assessed upon addition of 200 µM UA, 500 µM UA or monosodium urate (MSU) crystals in the presence or absence of 5 ng/ml lipopolysaccharide (LPS). RT-qPCR and multiplex bead based immunoassay were used to measure mRNA expression and cytokine release at 2 and 4 h of culture, respectively. ¹⁴C labeled UA was used to assess intracellular uptake of UA. We show that crystallized, but not soluble, UA induces production of pro-inflammatory mediators in human whole blood. Soluble UA is internalized in blood cells but does not potentiate or reduce LPS-induced release of cytokines.

Alcoholic Hepatitis: A Review

Alcoholic liver disease (ALD) represents a spectrum of injury, ranging from simple steatosis to alcoholic hepatitis to cirrhosis. Regular alcohol use results in fatty changes in the liver which can develop into inflammation, fibrosis and ultimately cirrhosis with continued, excessive drinking. Alcoholic hepatitis (AH) is an acute hepatic inflammation associated with significant morbidity and mortality that can occur in patients with steatosis or underlying cirrhosis. The pathogenesis of ALD is multifactorial and in addition to genetic factors, alcohol-induced hepatocyte damage, reactive oxygen species, gut-derived microbial components result in steatosis and inflammatory cell (macrophage and neutrophil leukocyte) recruitment and activation in the liver. Continued alcohol and pro-inflammatory cytokines induce stellate cell activation and result in progressive fibrosis. Other than cessation of alcohol use, medical therapy of AH is limited to prednisolone in a subset of patients. Given the high mortality of AH and the progressive nature of ALD, there is a major need for new therapeutic intervention for this underserved patient population.

Alcohol and hepatocellular carcinoma

BACKGROUND

Alcohol is classified as a Group 1 carcinogen by the International Agency for Research on Cancer because it induces hepatocellular carcinoma (among other cancers) in humans. An excessive alcohol intake may result in fatty liver, acute/chronic hepatitis, and cirrhosis and eventually lead to hepatocellular carcinoma. It has been reported that alcohol abuse increases the relative risk of hepatocellular carcinoma by 3- to 10-fold.

AIM AND METHODS

To clarify the known mechanisms of alcohol-related carcinogenesis, we searched Pubmed using the terms alcohol and immune mechanism, alcohol and cancer, and immune mechanism and cancer and summarized the articles as a qualitative review.

RESULTS

From a clinical perspective, it is well known that alcohol interacts with other factors, such as smoking, viral hepatitis, and diabetes, leading to an increased risk of hepatocellular carcinoma. There are several possible mechanisms through which alcohol may induce liver carcinogenicity, including the mutagenic effects of acetaldehyde and the production of ROS due to the excessive hepatic deposition of iron. Furthermore, it has been reported that alcohol accelerates hepatitis C virus-induced liver tumorigenesis through TLR4 signaling. Despite intense investigations to elucidate the mechanisms, they remain poorly understood.

CONCLUSION

This review summarizes the recent findings of clinical and pathological studies that have investigated the carcinogenic effects of alcohol in the liver.

Genetic and Epigenetic Modifiers of Alcoholic Liver Disease

Alcoholic liver disease (ALD), a disorder caused by excessive alcohol consumption is a global health issue. More than two billion people consume alcohol in the world and about 75 million are classified as having alcohol disorders. ALD embraces a wide spectrum of hepatic lesions including steatosis, alcoholic steatohepatitis (ASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). ALD is a complex disease where environmental, genetic, and epigenetic factors contribute to its pathogenesis and progression. The severity of alcohol-induced liver disease depends on the amount, method of usage and duration of alcohol consumption as well as on age, gender, presence of obesity, and genetic susceptibility. Genome-wide association studies and candidate gene studies have identified genetic modifiers of ALD that can be exploited as non-invasive biomarkers, but which do not completely explain the phenotypic variability. Indeed, ALD development and progression is also modulated by epigenetic factors. The premise of this review is to discuss the role of genetic variants and epigenetic modifications, with particular attention being paid to microRNAs, as pathogenic markers, risk predictors, and therapeutic targets in ALD.

The sex specific effect of alcohol consumption on circulating levels of CTRP3

The goal of this project was to establish the effect of alcohol consumption on the circulating levels of the adipose tissue derived protein C1q TNF Related Protein 3 (CTRP3). Adipose tissue secretes several adipokines, such as adiponectin and leptin, which exert a multitude of biological effects important for human health. However, adipose tissue is extremely sensitive to alcohol consumption, leading not only to disrupted fat storage, but also to disruptions in adipokine production. Changes to adipokine secretion could have widespread biological effects and potentially contribute to alcohol-induced ailments, such as alcoholic fatty liver disease (ALD). CTRP3 has been previously demonstrated to attenuate fatty liver disease, and suppression of CTRP3 with alcohol consumption could contribute to development of and progression to alcoholic fatty liver disease. To examine the effect of ethanol consumption on circulating adipokine levels, male and female mice were fed an ethanol containing diet (Lieber-DeCarli 5% (v/v) ethanol diet) for 10-days followed by a single gavage of 5 g/kg ethanol (the NIAAA model), or for 6-weeks with no binge added (chronic model). In female mice, adiponectin levels increased ~2-fold in both models of ethanol feeding, but in male mice increased adiponectin levels were only observed after chronic ethanol feeding. On the other hand, in female mice, circulating CTRP3 levels decreased by ~75% and ~50% in the NIAAA and chronic model, respectively, with no changes observed in the male mice in either feeding model. Leptin levels were unchanged with ethanol feeding regardless of model or sex of mice. Lastly, chronic ethanol feeding led to a significant increase in mortality (~50%) in female mice, with no difference in relative ethanol consumption. These findings indicate that ethanol consumption can dysregulate adipokine secretion, but that the effects vary by sex of animal, method of ethanol consumption, and adipokine examined. These findings also indicate that female mice are more sensitive to the chronic effects of ethanol than male mice. Notably, this is the first study to document the effects of ethanol consumption on the circulating levels of CTRP3. Understanding the impact of excessive alcohol consumption on adipokine production and secretion could identify novel mechanisms of alcohol-induced human disease. However, the mechanism responsible for the increased sensitivity remains elusive.

A Unifying Hypothesis Linking Hepatic Adaptations for Ethanol Metabolism to the Proinflammatory and Profibrotic Events of Alcoholic Liver Disease

The pathogenesis of alcoholic liver disease (ALD) remains poorly understood but is likely a multihit pathophysiological process. Here, we propose a hypothesis of how early mitochondrial adaptations for alcohol metabolism lead to ALD pathogenesis. Acutely, ethanol (EtOH) feeding causes a near doubling of hepatic EtOH metabolism and oxygen consumption within 2 to 3 hours. This swift increase in alcohol metabolism (SIAM) is an adaptive response to hasten metabolic elimination of both EtOH and its more toxic metabolite, acetaldehyde (AcAld). In association with SIAM, EtOH causes widespread hepatic mitochondrial depolarization (mtDepo), which stimulates oxygen consumption. In parallel, voltage-dependent anion channels (VDAC) in the mitochondrial outer membrane close. Together, VDAC closure and respiratory stimulation promote selective and more rapid oxidation of EtOH first to AcAld in the cytosol and then to nontoxic acetate in mitochondria, since membrane-permeant AcAld does not require VDAC to enter mitochondria. VDAC closure also inhibits mitochondrial fatty acid oxidation and ATP release, promoting steatosis and a decrease in cytosolic ATP. After acute EtOH, these changes revert as EtOH is eliminated with little hepatocellular cytolethality. mtDepo also stimulates mitochondrial autophagy (mitophagy). After chronic high EtOH exposure, the capacity to process depolarized mitochondria by mitophagy becomes compromised, leading to intra- and extracellular release of damaged mitochondria, mitophagosomes, and/or autolysosomes containing mitochondrial damage-associated molecular pattern (mtDAMP) molecules. mtDAMPs cause inflammasome activation and promote inflammatory and profibrogenic responses, causing hepatitis and fibrosis. We propose that persistence of mitochondrial responses to EtOH metabolism becomes a tipping point, which links initial adaptive EtOH metabolism to maladaptive changes initiating onset and progression of ALD.

Reduced gut microbiome protects from alcohol-induced neuroinflammation and alters intestinal and brain inflammasome expression

Background

The end-organ effects of alcohol span throughout the entire body, from the gastrointestinal tract to the central nervous system (CNS). In the intestine, alcohol use changes the microbiome composition and increases gut permeability allowing translocation of microbial components into the circulation. Gut-derived pathogen-associated signals initiate inflammatory responses in the liver and possibly elsewhere in the body. Because previous studies showed that the gut microbiome contributes to alcohol-induced liver disease, we hypothesized that antibiotic administration to reduce the gut microbiome would attenuate alcohol-induced inflammation in the brain and small intestine (SI).

Methods

Six- to 8-week-old C57BL/6J female mice were fed alcohol in a liquid diet or a calorie-matched control diet for 10 days with an acute alcohol binge or sugar on the final day (acute-on-chronic alcohol administration). Some mice were treated with oral antibiotics daily to diminish the gut microbiome. We compared serum levels of TNFα, IL-6, and IL-1β by ELISA; expression of cytokines Tnfα, Mcp1, Hmgb1, Il-17, Il-23, Il-6, and Cox2; and inflammasome components Il-1β, Il-18, Casp1, Asc, and Nlrp3 in the CNS and SI by qRT-PCR. Microglial morphology was analyzed using immunohistochemical IBA1 staining in the cortex and hippocampus.

Results

Antibiotics dramatically reduced the gut microbiome load in both alcohol- and pair-fed mice. Alcohol-induced neuroinflammation and increase in SI cytokine expression were attenuated in mice with antibiotic treatment. Acute-on-chronic alcohol did not induce serum TNFα, IL-6, and IL-1β. Alcohol feeding significantly increased the expression of proinflammatory cytokines such as Tnfα, Mcp1, Hmgb1, Il-17, and Il-23 in the brain and intestine. Reduction in the gut bacterial load, as a result of antibiotic treatment, attenuated the expression of all of these alcohol-induced proinflammatory cytokines in both the brain and SI. Alcohol feeding resulted in microglia activation and morphologic changes in the cortex and hippocampus characterized by a reactive phenotype. These alcohol-induced changes were abrogated following an antibiotic-induced reduction in the gut microbiome. Unexpectedly, antibiotic treatment increased the mRNA expression of some inflammasome components in both the brain and intestine.

Conclusions

Our data show for the first time that the acute-on-chronic alcohol administration in mice induces both neuroinflammation and intestinal inflammation and that reduction in the intestinal bacterial load can attenuate alcohol-associated CNS and gut inflammation. Gut microbiome-derived signals contribute to neuroinflammation in acute-on-chronic alcohol exposure.

Bisphenol-A alters microbiota metabolites derived from aromatic amino acids and worsens disease activity during colitis

Inflammatory bowel disease is a complex collection of disorders. Microbial dysbiosis as well as exposure to toxins including xenoestrogens are thought to be risk factors for inflammatory bowel disease development and relapse. Bisphenol-A has been shown to exert estrogenic activity in the colon and alter intestinal function, but the role that xenoestrogens, such as bisphenol-A , play in colonic inflammation has been previously described but with conflicting results. We investigated the ability of bisphenol-A to exacerbate colonic inflammation and alter microbiota metabolites derived from aromatic amino acids in an acute dextran sulfate sodium-induced colitis model. Female C57BL/6 mice were ovariectomized and exposed to bisphenol-A daily for 15 days. Disease activity measures include body weight, fecal consistency, and rectal bleeding. Colons were scored for inflammation, injury, and nodularity. Alterations in the levels of microbiota metabolites derived from aromatic amino acids known to reflect phenotypic changes in the gut microbiome were analyzed. Bisphenol-A exposure increased mortality and worsened disease activity as well as inflammation and nodularity scores in the middle colon region following dextran sulfate sodium exposure. Unique patterns of metabolites were associated with bisphenol-A consumption. Regardless of dextran sulfate sodium treatment, bisphenol-A reduced levels of tryptophan and several metabolites associated with decreased inflammation in the colon. This is the first study to show that bisphenol-A treatment alone can reduce microbiota metabolites derived from aromatic amino acids in the colon which may be associated with increased colonic inflammation and inflammatory bowel disease. Impact statement As rates of inflammatory bowel disease rise, discovery of the mechanisms related to the development of these conditions is important. Environmental exposure is hypothesized to play a role in etiology of the disease, as are alterations in the gut microbiome and the metabolites they produce. This study is the first to show that bisphenol-A alone alters tryptophan and microbiota metabolites derived from aromatic amino acids in a manner consistent with autoimmune diseases, specifically inflammatory bowel diseases, regardless of dextran sulfate sodium treatment. These findings indicate a potential mechanism by which bisphenol-A negatively affects gut physiology to exacerbate inflammation.

Sexual Dimorphism in Alcohol Induced Adipose Inflammation Relates to Liver Injury

Alcoholic liver disease occurs due to chronic, heavy drinking and is driven both by metabolic alterations and immune cell activation. Women are at a higher risk than men for developing alcohol induced liver injury and this dimorphism is reflected in animal models of alcoholic liver disease. The importance of adipose tissue in alcoholic liver disease is emerging. Chronic alcohol consumption causes adipose tissue inflammation, which can influence liver injury. Sex differences in body fat composition are well known. However, it is still unclear if alcohol-induced adipose tissue inflammation occurs in a sex-dependent manner. Here we have employed the clinically relevant NIAAA model of chronic-binge alcohol consumption to investigate this sexual dimorphism. We report that female mice have greater liver injury than male mice despite lower alcohol consumption. Chronic-binge alcohol induces adipose tissue inflammation in vivo in female mice, which is illustrated by increased expression of TNFα, IL-6, and CCL2, compared to only IL-6 induction in male adipose tissue. Further, macrophage activation markers such as CD68 as well as the pro-inflammatory activation markers CD11b and CD11c were higher in female adipose tissue. Interestingly, alcohol induced expression of TLR2, 3, 4, and 9 in female but not male adipose tissue, without affecting the TLR adaptor, MyD88. Higher trends of serum endotoxin in female mice may likely contribute to adipose tissue inflammation. In vitro chronic alcohol-mediated sensitization of macrophages to endotoxin is independent of sex. In summary, we demonstrate for the first time that there is a sexual dimorphism in alcohol-induced adipose tissue inflammation and female mice exhibit a higher degree of inflammation than male mice.

Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity

Chronic obesity is a known risk factor for metabolic syndrome. However, little is known about pathological changes in the small intestine associated with chronic obesity. This study investigated cellular and subcellular level changes in the small intestine of obese mice. In this study, a mouse model of obesity was established by early postnatal administration of monosodium glutamate. Changes in body weight were monitored, and pathological changes in the small intestine were evaluated using hematoxylin-eosin and Nissl staining and light and electron microscopy. Consequently, obese mice were significantly heavier compared with controls from 9 weeks of age. Villi in the small intestine of obese mice were elongated and thinned. There was reduced hematoxylin staining in the epithelium of the small intestine of obese mice. Electron microscopy revealed a significant decrease in and shortening of rough endoplasmic reticulum in epithelial cells of the small intestine of obese mice compared with normal mice. The decrease in rough endoplasmic reticulum in the small intestine epithelial cells of obese mice indicates that obesity starting in childhood influences various functions of the small intestine, such as protein synthesis, and could impair both the defense mechanism against invasion of pathogenic microbes and nutritional absorption.

[Mechanism Analysis and Prevention of Pathogenesis of Nonalcoholic Steatohepatitis]

Nonalcoholic fatty liver disease (NAFLD) is a common disease in humans having a broad spectrum of liver histology from simple fatty liver to mixed inflammatory cell infiltration and fibrosis (nonalcoholic steatohepatitis, NASH), which is a more severe and progressing form. NASH/NAFLD is significantly associated with lifestyle such as diet and exercise, obesity, insulin resistance, type 2 diabetes, dyslipidemia and hypertension. Age and gender are also associated with the development. On the other hand, NAFLD has been found in a high percentage of nonobese individuals in the Asia-Pacific area. Some characteristic animal models of NAFLD/NASH have been developed to clarify the pathogenesis of human NAFLD/NASH. We have recently developed a novel NASH rat model (stroke-prone spontaneously hypertensive rats, SHRSP5/Dmcr), which showed hepatic steatosis and inflammation at 2 weeks, ballooning, macrovesicular steatosis and fibrosis at 8 weeks, and bridging fibrosis at 14 weeks by feeding of high-fat and -cholesterol (HFC) diet alone. This animal model does not have obesity, insulin resistance or diabetes. Therefore, this may be an excellent animal model of human NASH/NAFLD without obesity and diabetes. Sex and strain differences observed in fibrogenesis by the HFC diet in SHRSP5/Dmcr may be associated with the sensitivity to detoxification enzymes in the liver, because the levels of UGP-glucuronosyltransferase and sulfotransferase and their regulating nuclear receptors only decreased in male SHRSP5/Dmcr rats, but not in female and SHRSP rats. This suggests the importance of phase II reactions of drug-metabolizing enzymes in NASH progression. Importantly, SHRSP5/Dmcr rats are spontaneously hypertensive; therefore, when we use the original strain Wistar Kyoto, which has normal blood pressure, the involvement of blood pressure in the development of human NASH/NAFLD may also be clarified.

Biphasic effect of alcohol intake on the development of fatty liver disease

BACKGROUND

Fatty liver is an important clinical feature not only in alcoholic and non-alcoholic fatty liver diseases, but in other chronic liver diseases as well. Our aim was to elucidate the effect and relationship between habitual alcohol intake and obesity in the development of fatty liver disease.

METHODS

We enrolled 8,029 subjects undergoing abdominal ultrasonography with general medical examinations, and analyzed the factors associated with fatty liver based on daily alcohol intake, body mass index (BMI), and waist circumference.

RESULTS

For fatty liver, BMI, waist circumference, total cholesterol, triglycerides, and fasting plasma glucose were significant and independent risk factors. Heavy alcohol intake (50 g/day) was a significant risk factor for fatty liver in women (odds ratio [OR], 3.35). Analysis based on the presence or absence of obesity revealed that moderate alcohol intake was a significant negative risk factor for fatty liver in both male and female obese (BMI ≥25 kg/m(2)) subjects (OR, 0.74 for non-obese and 0.39 for obese patients, respectively). Heavy alcohol intake was also a significant negative risk factor in obese males (0.62). In contrast, heavy alcohol intake was a risk factor in non-obese males (OR, 1.29) and in all females (OR, 2.22 for non-obese and 6.6 for obese patients, respectively).

CONCLUSIONS

The influence of alcohol intake on fatty liver differed depending on the level of alcohol consumption, gender, and the presence of obesity, and showed biphasic effects.

Oestrogen sulfotransferase ablation sensitizes mice to sepsis

Sepsis is the host's deleterious systemic inflammatory response to microbial infections. Here we report an essential role for the oestrogen sulfotransferase (EST or SULT1E1), a conjugating enzyme that sulfonates and deactivates estrogens, in sepsis response. Both the caecal ligation and puncture (CLP) and lipopolysaccharide models of sepsis induce the expression of EST and compromise the activity of oestrogen, an anti-inflammatory hormone. Surprisingly, EST ablation sensitizes mice to sepsis-induced death. Mechanistically, EST ablation attenuates sepsis-induced inflammatory responses due to compromised oestrogen deactivation, leading to increased sepsis lethality. In contrast, transgenic overexpression of EST promotes oestrogen deactivation and sensitizes mice to CLP-induced inflammatory response. The induction of EST by sepsis is NF-κB dependent and EST is a NF-κB-target gene. The reciprocal regulation of inflammation and EST may represent a yet-to-be-explored mechanism of endocrine regulation of inflammation, which has an impact on the clinical outcome of sepsis.

Female mice are more susceptible to nonalcoholic fatty liver disease: sex-specific regulation of the hepatic AMP-activated protein kinase-plasminogen activator inhibitor 1 cascade, but not the hepatic endotoxin response

As significant differences between sexes were found in the susceptibility to alcoholic liver disease in human and animal models, it was the aim of the present study to investigate whether female mice also are more susceptible to the development of non-alcoholic fatty liver disease (NAFLD). Male and female C57BL/6J mice were fed either water or 30% fructose solution ad libitum for 16 wks. Liver damage was evaluated by histological scoring. Portal endotoxin levels and markers of Kupffer cell activation and insulin resistance, plasminogen activator inhibitor 1 (PAI-1) and phosphorylated adenosine monophosphate-activated protein kinase (pAMPK ) were measured in the liver. Adiponectin mRNA expression was determined in adipose tissue. Hepatic steatosis was almost similar between male and female mice; however, inflammation was markedly more pronounced in livers of female mice. Portal endotoxin levels, hepatic levels of myeloid differentiation primary response gene (88) (MyD88) protein and of 4-hydroxynonenal protein adducts were elevated in animals with NAFLD regardless of sex. Expression of insulin receptor substrate 1 and 2 was decreased to a similar extent in livers of male and female mice with NAFLD. The less pronounced susceptibility to liver damage in male mice was associated with a superinduction of hepatic pAMPK in these mice whereas, in livers of female mice with NAFLD, PAI-1 was markedly induced. Expression of adiponectin in visceral fat was significantly lower in female mice with NAFLD but unchanged in male mice compared with respective controls. In conclusion, our data suggest that the sex-specific differences in the susceptibility to NAFLD are associated with differences in the regulation of the adiponectin-AMPK-PAI-1 signaling cascade.

Rodent models of alcoholic liver disease: of mice and men

Alcoholic liver disease (ALD) is a major cause of acute and chronic liver disease worldwide. The progressive nature of ALD is well described; however, the complex interactions under which these pathologies evolve remain to be fully elucidated. Clinically there are no clear biomarkers or universally accepted, effective treatment strategies for ALD. Experimental models of ALD are an important component in identifying underlying mechanisms of alcohol-induced injury to develop better diagnostic markers, predictors of disease progression, and therapeutic targets to manage, halt, or reverse disease progression. Rodents remain the most accessible model for studying ALD pathology. Effective rodent models must mimic the natural history of ALD while allowing examination of complex interactions between multiple hepatic, and non-hepatic, cell types in the setting of altered metabolic or oxidative/nitrosative stress, inflammatory responses, and sensitivity to cytotoxic stress. Additionally, mode and duration of alcohol delivery influence hepatic response and present unique challenges in understanding disease pathology. This review provides an overview of rodent models of ALD, their strengths and weaknesses relative to human disease states, and provides insight of the potential to develop novel rodent models to simulate the course of human ALD.

Identification and characterization of lipopolysaccharide binding protein (LBP) as an estrogen receptor α specific serum biomarker

Estrogen Receptor a (ERα) and Estrogen Receptor β (ERβ) are steroid nuclear receptors that transduce estrogen signaling to control diverse physiological processes linked to reproduction, bone remodeling, behavior, immune response and endocrine-related diseases. In order to differentiate between ERα and ERβ mediated effects in vivo, ER subtype selective biomarkers are essential. We utilized ERα knockout (AERKO) and ERβ knockout (BERKO) mouse liver RNA and genome wide profiling to identify novel ERα selective serum biomarker candidates. Results from the gene array experiments were validated using real-time RT-PCR and subsequent ELISA's to demonstrate changes in serum proteins. Here we present data that Lipopolysacharide Binding Protein (LBP) is a novel liver-derived ERα selective biomarker that can be measured in serum.

Heavy alcohol use and premature death from hepatocellular carcinoma in the United States, 1999-2006

OBJECTIVE

The incidence rate of hepatocellular carcinoma has been rising in the United States during the last 2 decades. Heavy alcohol use has been widely recognized as one of the major etiological factors of hepatocellular carcinoma. This study sought to assess the extent to which heavy alcohol use contributed to premature death from hepatocellular carcinoma on a population scale in the United States.

METHOD

We analyzed the Multiple Cause of Death public-use data sets. Using codes from the International Classification of Diseases, 10th Revision, hepatocellular carcinoma death was defined based on the underlying cause of death, and heavy alcohol use was indicated by the presence of any alcohol-induced medical conditions among the contributing causes of death. During 1999-2006 in the United States, 51,400 hepatocellular carcinoma deaths were identified from 17,727,245 natural deaths of persons age 25 or older. We conducted Poisson regression, life table, and multiple linear regression analyses to compare prevalence ratios, cumulative probabilities, and mean ages of death, respectively, from hepatocellular carcinoma by heavy alcohol use status across sex and race/ethnicity.

RESULTS

Heavy alcohol use decedents had higher prevalence ratios of dying from hepatocellular carcinoma than from non-chronic liver diseases compared with those decedents without heavy alcohol use. Heavy alcohol use was associated with decreased mean ages and increased cumulative probabilities of death among hepatocellular carcinoma decedents across racial/ethnic groups in both sexes. This association was stronger among women than men and stronger among non-Hispanic Whites than non-Hispanic Blacks.

CONCLUSIONS

This study provides mortality-based empirical evidence to further establish heavy alcohol consumption as one of the key risk factors contributing to premature deaths from hepatocellular carcinoma in the United States, and its effect appears more prominent among women and non-Hispanic Whites.

Alcoholic liver injury: Influence of gender and hormones

This article discusses several subjects pertinent to a consideration of the role of gender and hormones in alcoholic liver injury (ALI). Beginning with an overview of factors involved in the pathogenesis of ALI, we review changes in sex hormone metabolism resulting from alcohol ingestion, summarize research that points to estrogen as a cofactor in ALI, consider evidence that gut injury is linked to liver injury in the setting of alcohol, and briefly review the limited evidence regarding sex hormones and gut barrier function. In both women and female animals, most studies reveal a propensity toward greater alcohol-induced liver injury due to female gender, although exact hormonal influences are not yet understood. Thus, women and their physicians should be alert to the dangers of excess alcohol consumption and the increased potential for liver injury in females.

Ghrelin hyporesponsiveness contributes to age-related hyperinflammation in septic shock

OBJECTIVE

To test the hypothesis that hyporesponsiveness to ghrelin due to reduced growth hormone (GH) contributes to the aging-related hyperinflammatory state in sepsis.

SUMMARY BACKGROUND DATA

Sepsis and septic shock are a serious problem, particularly in the geriatric population. Ghrelin is an endogenous ligand for the GH secretagogue receptor 1a (GHSR1a, ie, ghrelin receptor). The decline in GH with age is directly associated with many adverse changes that occur with aging. However, the role of GH, ghrelin, and GHSR1a in the age-associated vulnerability to sepsis remains unknown.

METHODS

Male Fischer 344 rats (young: 3 months; aged: 24 months) were used. Plasma GH levels, ghrelin receptor expression, and neuronal activity in the parasympathostimulatory nuclei of the brain stem in normal young and aged animals were measured. Endotoxemia was induced by intravenous injection of lipopolysaccharide (LPS, 15 mg/kg BW).

RESULTS

While LPS-induced release of proinflammatory cytokines from macrophages isolated from aged rats decreased, LPS injection resulted in an in vivo hyperinflammatory state. GH levels were lower in aged rats, which was associated with lower expression of GHSR1a in the dorsal vagal complex and a decrease in parasympathostimulatory neuronal activity. GHSR1a antagonist elevated LPS-induced cytokine release in young rats. GH increased GHSR-1a expression in the dorsal vagal complex in aged rats. Coadministration of ghrelin and GH, but not ghrelin alone or GH alone, markedly reduced cytokine levels and organ injury after endotoxemia in aged rats, which was associated with significantly elevated parasympathostimulatory neuronal activity.

CONCLUSIONS

These findings suggest that the reduced central (brain) responsiveness to ghrelin due to the decreased GH, plays a major role in producing the hyperinflammatory state, resulting in severe organ injuries and high mortality after endotoxemia in aged animals. Ghrelin and GH can be developed as a novel therapy for sepsis in the geriatric population.

Estrogens augment cell surface TLR4 expression on murine macrophages and regulate sepsis susceptibility in vivo

Gender-based differences exist in infectious disease susceptibility. In general, females generate more robust and potentially protective humoral and cell-mediated immune responses after antigenic challenge than their male counterparts. Furthermore, evidence is accumulating that sex may also influence the early perception of microbial challenges and the generation of inflammatory immune responses such as sepsis. These differences have previously been attributed to the actions of reproductive hormones. Whereas androgens have been shown to suppress acute host immune responses to bacterial endotoxin challenge, estrogens have been found to promote increased resistance to bacterial infections. However, the mechanisms by which estrogens exert immunoprotective effects have not been established. In this study, we investigated the in vivo effects of 17beta-estradiol on endotoxin susceptibility in mice. Importantly, we have examined the actions of this female reproductive hormone on the expression of pattern recognition receptors that recognize bacterial endotoxin by key innate immune sentinel cells. We show that removal of endogenous estrogens decreases both pro- and antiinflammatory cytokine production, with a concomitant reduction in circulating levels of lipopolysaccharide-binding protein and cell surface expression of Toll-like receptor 4 on murine macrophages. Exogenous in vivo replacement of 17beta-estradiol, but not progesterone, significantly elevates sera lipopolysaccharide-binding protein levels and cell surface expression of Toll-like receptor 4 and CD14 on macrophages. Furthermore, this effect corresponds with significantly higher inflammatory cytokine levels after in vivo lipopolysaccharide challenge and a marked increase in endotoxin-associated morbidity. Taken together, these data provide a potential mechanism underlying the immunoenhancing effects of estrogens.

"Second hit" models of alcoholic liver disease

Alcoholic liver disease (ALD) is a lifestyle disease with its pathogenesis and individual predisposition governed by gene-environment interactions. Based on the "second hit" or "multiple hits" hypothesis, patients are predisposed to progressive ALD when a magic combination of gene and environmental interactions exists. Reproduction of second or multiple hits in animal models serves to test a combination and to gain mechanistic insights into synergism achieved by such combination. Numerous environmental factors have been incorporated into animal models, largely classified into nutritional, xenobiotic/pharmacologic, hemodynamic, and viral groups. A loss or gain of function genetic model has become a popular experimental approach to test the role of a gene as a second hit. Future research will need to test more subtle or natural hits combined with excessive alcohol intake to test multiple hits in the genesis of ALD. Additionally, animal models of comorbidities are urgently needed particularly for synergistic liver disease and oncogenesis caused by alcohol, obesity, and hepatitis virus.

Female hepatology: Favorable role of estrogen in chronic liver disease with hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is the most common cause of hepatic fibrosis and hepatocellular carcinoma (HCC), mainly as a result of chronic necroinflammatory liver disease. A characteristic feature of chronic hepatitis B infection, alcoholic liver disease and nonalcoholic fatty liver disease (NAFLD) is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are the primary target cells for inflammatory and oxidative stimuli, and these cells produce extracellular matrix components. Chronic hepatitis B appears to progress more rapidly in males than in females, and NAFLD, cirrhosis and HCC are predominately diseases that tend to occur in men and postmenopausal women. Premenopausal women have lower hepatic iron stores and a decreased production of proinflammatory cytokines. Hepatic steatosis has been observed in aromatase-deficient mice, and has been shown to decrease in animals after estradiol treatment. Estradiol is a potent endogenous antioxidant which suppresses hepatic fibrosis in animal models, and attenuates induction of redox sensitive transcription factors, hepatocyte apoptosis and HSC activation by inhibiting a generation of reactive oxygen species in primary cultures. Variant estrogen receptors are expressed to a greater extent in male patients with chronic liver disease than in females. These lines of evidence suggest that the greater progression of hepatic fibrosis and HCC in men and postmenopausal women may be due, at least in part, to lower production of estradiol and a reduced response to the action of estradiol. A better understanding of the basic mechanisms underlying the sex-associated differences in hepatic fibrogenesis and carciogenesis may open up new avenues for the prevention and treatment of chronic liver disease.

Liver, alcohol and gender

Gender differences in alcohol-induced liver injury have been well described. Females develop alcoholic liver injury more rapidly and have a lower alcohol toxic threshold than men. The mechanism for this difference is poorly characterized, differences in first-pass metabolism in the stomach, or elimination rate, or alcohol distribution volume in the body have been suggested. In addition, estrogen has a major influence on the susceptibility of Kupffer cells to gut-derived LPS resulting in increased proinflammatory cytokine production, which could be a major contributing factor to the increased risk of women to alcohol-induced liver disease.

Is a leaky gut involved in the pathogenesis of intrahepatic cholestasis of pregnancy?

Increased gastrointestinal permeability has been demonstrated in several liver diseases. It may facilitate the absorption of gut-derived endotoxin-stimulating Kupffer cells to release proinflammatory cytokines or other potentially hepatotoxic compounds. We examined gastrointestinal permeability, plasma levels of anti-lipopolysacharides (anti-LPS), and four proinflammatory cytokines in 20 patients with intrahepatic cholestasis of pregnancy (ICP) compared with 22 normal pregnant and 29 non-pregnant women. Urinary excretion of sucrose and the urinary lactulose/mannitol (L/M) ratio after a standard oral load were used to assess gastrointestinal permeability. Anti-LPS (IgA, IgM, and IgG) were measured in peripheral blood by Human EndoCAb test kit; TNF-alpha, IL-1beta, IL-6, and IL-10 by Quantikine HS human immunoassays. Sucrose urinary excretion was similar in the three groups, indicating normal gastric permeability. The urinary L/M ratio was significantly higher in ICP than in the other groups [median (interquartile range): 0.018% (0.011-0.023) in ICP, 0.012% (0.009-0.016) in normal pregnancies, and 0.009% (0.008-0.012) in non-pregnant women, P < .01]. No significant differences were found in anti-LPS or cytokines plasma levels except slightly higher levels of IL-6 in ICP patients than in non-pregnant women (P < .05). Four of five women with abnormal urinary L/M ratio during ICP continued to show abnormalities in tests up to 2 years after delivery. In conclusion, an increased intestinal permeability was detected in ICP patients during and after pregnancy. A "leaky gut" may participate in the pathogenesis of ICP by enhancing the absorption of bacterial endotoxin and the enterohepatic circulation of cholestatic metabolites of sex hormones and bile salts.

Lack of sexual dimorphism in alcohol-induced liver damage (ALD) in rats treated chronically with ethanol-containing low carbohydrate diets: The role of ethanol metabolism and endotoxin

Evidence has been presented suggesting that females are significantly more susceptible to alcohol-induced liver damage (ALD) than males. In the current study, we examined sexual dimorphism in hepatic pathology, metabolism and cytokine profiles using two different rat models of ALD. Male and female Sprague-Dawley or Wistar rats were fed ethanol-containing low-carbohydrate liquid diets using oral or intragastric methods for 42 or 60 days. In both models, ethanol treatment produced similar significant liver hyperplasia accompanied by increases in plasma ALT, steatosis, inflammation and necrosis (p < 0.05). Greater pathology scores were observed in the intragastrically infused rats. Males did not differ significantly from females in serum ALT values or pathology despite greater elevations in TNFalpha and IL-1beta mRNAs in ethanol-treated female rat livers (p < 0.05). Furthermore, there was no sexual dimorphism in blood ethanol concentrations or CYP2E1-induction even though sexually dimorphic alterations in other hepatic cytochrome P450 enzymes were observed. These data do not support previous observations that female rats have a greater susceptibility to ethanol-induced hepatotoxicity than males.

Modulatory effects of estrogen in two murine models of experimental colitis

The association between oral contraceptives or pregnancy and inflammatory bowel disease is unclear. We investigated whether 17beta-estradiol modulates intestinal inflammation in two models of colitis. Female mice were treated with 17beta-estradiol alone or with tamoxifen, tamoxifen alone, 17 alpha-estradiol, or placebo. Dinitrobenzene sulfonic acid (DNB)- or dextran sodium sulfate (DSS)-induced colitis were assessed macroscopically, histologically, and by myeloperoxidase (MPO) activity. Malondialdehyde and mRNA levels of intercellular adhesion molecule-1 (ICAM-1), interferon-gamma (IFN-gamma), and interleukin-13 (IL-13) were determined. In DNB colitis, 17beta-estradiol alone, but not 17beta-estradiol plus tamoxifen, or 17 alpha-estradiol reduced macroscopic and histological scores, MPO activity and malondialdehyde levels. 17beta-Estradiol also decreased the expression of ICAM-1, IFN-gamma, and IL-13 mRNA levels compared with placebo. In contrast, 17beta-Estradiol increased the macroscopic and histological scores compared with placebo in mice with DSS colitis. These results demonstrate anti-inflammatory and proinflammatory effects of 17beta-estradiol in two different models of experimental colitis. The net modulatory effect most likely reflects a combination of estrogen receptor-mediated effects and antioxidant activity and may explain, in part, conflicting results from clinical trials.

Enhanced endotoxin sensitivity in fps/fes-null mice with minimal defects in hematopoietic homeostasis

The fps/fes proto-oncogene encodes a cytoplasmic protein tyrosine kinase implicated in growth factor and cytokine receptor signaling and thought to be essential for the survival and terminal differentiation of myeloid progenitors. Fps/Fes-null mice were healthy and fertile, displayed slightly reduced numbers of bone marrow myeloid progenitors and circulating mature myeloid cells, and were more sensitive to lipopolysaccharide (LPS). These phenotypes were rescued using a fps/fes transgene. This confirmed that Fps/Fes is involved in, but not required for, myelopoiesis and that it plays a role in regulating the innate immune response. Bone marrow-derived Fps/Fes-null macrophages showed no defects in granulocyte-macrophage colony-stimulating factor-, interleukin 6 (IL-6)-, or IL-3-induced activation of signal transducer and activator of transcription 3 (Stat3) and Stat5A or LPS-induced degradation of I kappa B or activation of p38, Jnk, Erk, or Akt.

Increased severity of alcoholic liver injury in female rats: role of oxidative stress, endotoxin, and chemokines

Alcoholic liver injury is more severe and rapidly developing in women than men. To evaluate the reason(s) for these gender-related differences, we determined whether pathogenic mechanisms important in alcoholic liver injury in male rats were further upregulated in female rats. Male and age-matched female rats (7/group) were fed ethanol and a diet containing fish oil for 4 wk by intragastric infusion. Dextrose isocalorically replaced ethanol in control rats. We analyzed liver histopathology, lipid peroxidation, cytochrome P-450 (CYP)2E1 activity, nonheme iron, endotoxin, nuclear factor-kappa B (NF-kappa B) activation, and mRNA levels of cyclooxygenase-1 (COX-1) and COX-2, tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-2 (MIP-2). Alcohol-induced liver injury was more severe in female vs. male rats. Female rats had higher endotoxin, lipid peroxidation, and nonheme iron levels and increased NF-kappa B activation and upregulation of the chemokines MCP-1 and MIP-2. CYP2E1 activity and TNF-alpha and COX-2 levels were similar in male and female rats. Remarkably, female rats fed fish oil and dextrose also showed necrosis and inflammation. Our findings in ethanol-fed rats suggest that increased endotoxemia and lipid peroxidation in females stimulate NF-kappa B activation and chemokine production, enhancing liver injury. TNF-alpha and COX-2 upregulation are probably important in causing liver injury but do not explain gender-related differences.

Lactoferrin protects against development of hepatitis caused by sensitization of Kupffer cells by lipopolysaccharide

BALB/c mice were intravenously injected with lipopolysaccharide (LPS) (0.05 microg/g of body weight) 7 days after being primed with zymosan. Recombinant human lactoferrin (250 microg/g of body weight), intravenously administered 1 day before the injection of LPS, significantly lessened the severity of hepatitis, as assessed by levels of serum alanine transaminase compared to those seen when casein was administered. The transient rise of serum tumor necrosis factor alpha (TNF-alpha) after LPS treatment was also significantly lowered by the intravenous administration of lactoferrin, suggesting that the effect of lactoferrin was due to the suppression of TNF-alpha production. The following results indicate that the sites of action of lactoferrin for the suppression of the development of this type of hepatitis are Kupffer cells. Gadolinium chloride, a substance known to eliminate Kupffer cells, administered 1 day before LPS, inhibited the transient rise of TNF-alpha and protected against the development of hepatitis. Kupffer cells isolated from mice intraperitoneally injected with recombinant human lactoferrin became refractory to LPS. The specific interaction of recombinant human lactoferrin with the Kupffer cells was shown by a binding assay, which revealed two types of binding sites on mouse Kupffer cells. Of the two dissociation constants determined in this way, the lower dissociation constant, 0.47 x 10(-6) M, was within the range of the 50% effective doses for the suppression of TNF-alpha production. These results suggest that recombinant human lactoferrin administered to mice suppresses the production of TNF-alpha by Kupffer cells by directly associating with the binding sites on these cells.

Interleukin-1 receptor signaling rather than that of tumor necrosis factor is critical in protecting the host from the severe consequences of a polymicrobe anaerobic infection

Infection of the dental pulp leads to an osteolytic lesion that results from a polymicrobial infection consisting largely of pathogenic anaerobes. Infection causes significant morbidity and mortality mediated by bacterial factors and in some cases by the up-regulation of inflammatory cytokines. The inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor (TNF), in particular, play a complex and central role in the responses to microbial pathogens. However, relatively little is known about the significance of these cytokines in protecting the host from focal polymicrobial anaerobic infections. To establish the relative importance of IL-1 and TNF in mediating the response to a mixed anaerobic infection, we inoculated the dental pulp of mice with six anaerobic pathogens containing functional deletions of receptors to IL-1 (IL-1R1(-/-)), TNF (TNFRp55(-/-)-p75(-/-)), or both (TNFRp55(-/-)-IL-1RI(-/-)). The results indicate that IL-1 receptor signaling and TNF receptor signaling both play similarly important roles in protecting the host from local tissue damage. However, IL-1 receptor signaling is considerably more important than TNF receptor signaling in preventing the spread of infection into surrounding fascial planes, since IL-1R1(-/-) but not TNFRp55(-/-)-p75(-/-) mice exhibited significantly higher morbidity and mortality. Moreover, all of the fatal infections occurred in male mice, suggesting the importance of gender differences in limiting the impact of these infections.

Gender differences in early alcohol-induced liver injury: role of CD14, NF-kappaB, and TNF-alpha

The purpose of this study was to determine whether early alcohol-induced liver injury (ALI) in females is associated with changes in CD14 on Kupffer cells, activation of hepatic nuclear factor (NF)-kappaB, and expression of tumor necrosis factor (TNF)-alpha mRNA. Male and female rats were given high-fat control or ethanol-containing diets for 4 wk using the intragastric enteral protocol. Physiological parameters were similar in both genders. Ethanol was increased as tolerance developed with higher blood levels than previously observed, resulting in a fourfold increase in aspartate aminotransferase (males 389 +/- 47 IU/l vs. females 727 +/- 66 IU/l). Hepatic pathology developed more rapidly and was nearly twofold greater and endotoxin levels were significantly higher in females after ethanol. Also, expression of CD14 on Kupffer cells was 1.5-fold greater and binding of transcription factor NF-kappaB in hepatic nuclear extracts and TNF-alpha mRNA expression were threefold greater in females. These data are consistent with the hypothesis that elevated endotoxin after ethanol triggers more activation of Kupffer cells via enhanced CD14 expression in females. NF-kappaB is activated in this process, leading to increases in TNF-alpha mRNA expression in the liver and more severe liver injury in females. It is concluded that gender differences in ALI are dependent on endotoxin and a signaling cascade leading to TNF-alpha.