Cellular and mitochondrial effects of alcohol consumption

Pattern of prescription, dispensation and administration of disulfiram among patients with alcohol use disorder attending a general hospital psychiatry unit in rural India

INTRODUCTION

Disulfiram was the first medication approved to treat alcohol dependence and has been found to be safe and efficacious. This cross sectional, observational, qualitative study was conducted with the aim to assess the pattern of dispensation of disulfiram among patients with alcohol use disorder (AUD).

MATERIAL AND METHODS

Data was collected using a customized questionnaire consisting of 32 questions regarding socio-demographic characteristics, psychiatric history, pattern of dispensation of disulfiram/disulfiram-like product (DLP) and related knowledge. Descriptive statistics and frequency distribution tables were used for analysing the data using Microsoft Excel 2013.

RESULTS

Thirty seven percent (n=100) of the total patients with ADS (n=268) screened had a history of administration of disulfiram/DLP. Tablets were the commonest (60%) formulation of disulfiram/DLP advised by the dispenser, only 4% of whom were psychiatrists. Surreptitious administration was preferred by family members (76%). Majority of the patients (44%) received the medication only once or twice.

LIMITATIONS

The actual product - disulfiram and/or DLP - could not be chemically tested to confirm the identity. Considering the socio-economic and cultural background where the study was conducted, it would be difficult to generalize the findings.

DISCUSSION

Disulfiram/DLP was prescribed by physicians and faith healers alike. They seem to promote surreptitious administration of disulfiram with full agreement of relatives, thereby potentially exposing the patient to life threatening complications. Hence it is recommended that disulfiram prescription should involve stricter guidelines and DLP like kudzu in traditional/herbal products should also be brought under the same purview as disulfiram.

AMP-activated protein kinase: a therapeutic target in intestinal diseases

Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a highly conserved energy sensor, has a crucial role in cardiovascular, neurodegenerative and inflammatory diseases, as well as in cancer and metabolic disorders. Accumulating studies have demonstrated that AMPK activation enhances paracellular junctions, nutrient transporters, autophagy and apoptosis, and suppresses inflammation and carcinogenesis in the intestine, indicating an essential role of AMPK in intestinal health. AMPK inactivation is an aetiological factor in intestinal dysfunctions. This review summarizes the favourable outcomes of AMPK activation on intestinal health, and discusses AMPK as a potential therapeutic target for intestinal diseases.

Free radical production and antioxidant status in brain cortex non-synaptic mitochondria and synaptosomes at alcohol hangover onset

Alcohol hangover (AH) is the pathophysiological state after a binge-like drinking. We have previously demonstrated that AH induced bioenergetics impairments in a total fresh mitochondrial fraction in brain cortex and cerebellum. The aim of this work was to determine free radical production and antioxidant systems in non-synaptic mitochondria and synaptosomes in control and hangover animals. Superoxide production was not modified in non-synaptic mitochondria while a 17.5% increase was observed in synaptosomes. A similar response was observed for cardiolipin content as no changes were evidenced in non-synaptic mitochondria while a 55% decrease in cardiolipin content was found in synaptosomes. Hydrogen peroxide production was 3-fold increased in non-synaptic mitochondria and 4-fold increased in synaptosomes. In the presence of deprenyl, synaptosomal H₂O₂ production was 67% decreased in the AH condition. Hydrogen peroxide generation was not affected by deprenyl addition in non-synaptic mitochondria from AH mice. MAO activity was 57% increased in non-synaptic mitochondria and 3-fold increased in synaptosomes. Catalase activity was 40% and 50% decreased in non-synaptic mitochondria and synaptosomes, respectively. Superoxide dismutase was 60% decreased in non-synaptic mitochondria and 80% increased in synaptosomal fractions. On the other hand, GSH (glutathione) content was 43% and 17% decreased in synaptosomes and cytosol. GSH-related enzymes were mostly affected in synaptosomes fractions by AH condition. Acetylcholinesterase activity in synaptosomes was 11% increased due to AH. The present work reveals that AH provokes an imbalance in the cellular redox homeostasis mainly affecting mitochondria present in synaptic terminals.

Gender-specific predictors of at-risk adolescents' hazardous alcohol use-a cohort study

Background

Previous research has found strong associations between adolescents’ hazardous alcohol use and their perception of peer behavior, as well as own spending money and a range of antisocial behaviors. However, there is insufficient evidence of gender-specific predictors among adolescents with elevated antisocial behavior and alcohol use to design effective selective interventions. The aims of this study were to test short-term predictors of Heavy Episodic Drinking (HED) and risk-use of alcohol among 12-18-year-old females and males with elevated externalizing and delinquent behavior, and alcohol use.

Methods

Eighty-five females, 77 males, and their parents, originally recruited for a parent intervention, were assessed at baseline and 6 months later with several validated instruments measuring externalizing and internalizing behavior, alcohol use, psychosocial distress, and delinquency.

Results

The perception of peer drinking significantly predicted both genders’ HED and risk-use, and also externalizing behavior predicted female risk-use. Rule-breaking behavior and social problems predicted both HED and risk-use among males, while rule-breaking predicted female HED and social problems predicted female risk-use. The parents’ ratings of externalizing behavior predicted only their sons’ risk-use. Lastly, no differences in prediction strength were found to be statistically significant differences between genders.

Conclusions

Females and males shared several predictors of hazardous alcohol use, and perception of peer drinking emerged as a strong predictor. This suggests that interventions may target both genders’ hazardous use of alcohol, and should address peer-resisting skills.

Glutamate contributes to alcohol hepatotoxicity by enhancing oxidative stress in mitochondria

Chronic alcohol intoxication is associated with increased oxidative stress. However, the mechanisms by which ethanol triggers an increase in the production of reactive oxygen species (ROS) and the role of mitochondria in the development of oxidative stress has been insufficiently studied. The biochemical and proteomic data obtained in the present work suggest that one of the main causes of an increase in ROS generation is enhanced oxidation of glutamate in response to long-term alcohol exposure. In the course of glutamate oxidation, liver mitochondria from alcoholic rats generated more superoxide anion and H₂O₂ than in the presence of other substrates and more than control organelles. In mitochondria from alcoholic rats, rates of H₂O₂ production and NAD reduction in the presence of glutamate were almost twice higher than in the control. The proteomic study revealed a higher content of glutamate dehydrogenase in liver mitochondria of rats subjected to chronic alcohol exposure. Simultaneously, the content of mitochondrial catalase decreased compared to control. Each of these factors stimulates the production of ROS in addition to ROS generated by the respiratory chain complex I. The results are consistent with the conclusion that glutamate contributes to alcohol hepatotoxicity by enhancing oxidative stress in mitochondria.

Gene expression profiling in the human alcoholic brain

Long-term alcohol use causes widespread changes in gene expression in the human brain. Aberrant gene expression changes likely contribute to the progression from occasional alcohol use to alcohol use disorder (including alcohol dependence). Transcriptome studies have identified individual gene candidates that are linked to alcohol-dependence phenotypes. The use of bioinformatics techniques to examine expression datasets has provided novel systems-level approaches to transcriptome profiling in human postmortem brain. These analytical advances, along with recent developments in next-generation sequencing technology, have been instrumental in detecting both known and novel coding and non-coding RNAs, alternative splicing events, and cell-type specific changes that may contribute to alcohol-related pathologies. This review offers an integrated perspective on alcohol-responsive transcriptional changes in the human brain underlying the regulatory gene networks that contribute to alcohol dependence. This article is part of the Special Issue entitled "Alcoholism".

Toxicological Implications of Mitochondrial Localization of CYP2E1

Cytochrome P450 2E1 (CYP2E1) metabolizes an extensive array of pollutants, drugs, and other small molecules, often resulting in bioactivation to reactive metabolites. Therefore, it is unsurprising that it has been the subject of decades of research publications and reviews. However, while CYP2E1 has historically been studied in the endoplasmic reticulum (erCYP2E1), active CYP2E1 is also present in mitochondria (mtCYP2E1). Relatively few studies have specifically focused on mtCYP2E1, but there is growing interest in this form of the enzyme as a driver in toxicological mechanisms given its activity and location. Many previous studies have linked total CYP2E1 to conditions that involve mitochondrial dysfunction (fasting, diabetes, non-alcoholic steatohepatitis, and obesity). Furthermore, a large number of reactive metabolites that are formed by CYP2E1 through metabolism of drugs and pollutants have been demonstrated to cause mitochondrial dysfunction. Finally, there appears to be significant inter-individual variability in targeting to the mitochondria, which could constitute a source of variability in individual response to exposures. This review discusses those outcomes, the biochemical properties and toxicological consequences of mtCYP2E1, and highlights important knowledge gaps and future directions. Overall, we feel that this exciting area of research is rich with new and important questions about the relationship between mtCYP2E1, mitochondrial dysfunction, and pathology.

Label-Free Neuroproteomics of the Hippocampal-Accumbal Circuit Reveals Deficits in Neurotransmitter and Neuropeptide Signaling in Mice Lacking Ethanol-Sensitive Adenosine Transporter

The neural circuit of the dorsal hippocampus (dHip) and nucleus accumbens (NAc) contributes to cue-induced learning and addictive behaviors, as demonstrated by the escalation of ethanol-seeking behaviors observed following deletion of the adenosine equilibrative nucleoside transporter 1 (ENT1^-/-) in mice. Here we perform quantitative LC-MS/MS neuroproteomics in the dHip and NAc of ENT1^-/- mice. Using Ingenuity Pathway Analysis, we identified proteins associated with increased long-term potentiation, ARP2/3-mediated actin cytoskeleton signaling and protein expression patterns suggesting deficits in glutamate degradation, GABAergic signaling, as well as significant changes in bioenergetics and energy homeostasis (oxidative phosphorylation, TCA cycle, and glycolysis). These pathways are consistent with previously reported behavioral and biochemical phenotypes that typify mice lacking ENT1. Moreover, we validated decreased expression of the SNARE complex protein VAMP1 (synaptobrevin-1) in the dHip as well as decreased expression of pro-dynorphin (PDYN), neuroendocrine convertase (PCSK1), and Leu-Enkephalin (dynorphin-A) in the NAc. Taken together, our proteomic approach provides novel pathways indicating that ENT1-regulated signaling is essential for neurotransmitter release and neuropeptide processing, both of which underlie learning and reward-seeking behaviors.

Preparation and therapeutic evolution of Ficus benjamina solid lipid nanoparticles against alcohol abuse/antabuse induced hepatotoxicity and cardio-renal injury

Chronic alcoholism destroys the propensity for hepatic detoxification of toxic substances, which further promotes the rapid and intense accumulation of aldehydes in the liver.

Differential Sphingolipid and Phospholipid Profiles in Alcohol and Nicotine-Derived Nitrosamine Ketone-Associated White Matter Degeneration

BACKGROUND

Alcohol-mediated neurodegeneration is associated with white matter (WM) atrophy due to targeting of myelin and oligodendrocytes. However, variability in disease severity suggests cofactors contribute to WM degeneration. We examined the potential cofactor role of the tobacco-specific nitrosamine, nicotine-derived nitrosamine ketone (NNK), because smoking causes WM atrophy and most heavy drinkers consume tobacco products.

METHODS

This 8-week study of Long Evans rats had 4 treatment groups: control; NNK-2 mg/kg, 3×/wk in weeks 3 to 8; ethanol (EtOH) (chronic-26% caloric + binge-2 g/kg, 3×/wk in weeks 7 to 8); and EtOH + NNK. Exposure effects on WM lipid biochemical profiles and in situ distributions were examined using matrix-assisted laser desorption/ionization imaging mass spectrometry and tandem mass spectrometry.

RESULTS

NNK mainly caused WM fiber degeneration and fiber loss, EtOH caused demyelination, and dual exposures had additive effects. EtOH and EtOH + NNK decreased WM (including corpus callosum) and/or gray matter (hypothalamus, cortex, medial temporal) levels of several phosphatidylserine, phosphatidylinositol, and sphingolipid (sulfatide [ST]) species, while NNK increased or had minimal effect on these lipids. EtOH + NNK had broader and larger inhibitory effects on phospholipids and ST than EtOH or NNK alone. Principal component analysis clustered control with NNK, and EtOH with EtOH + NNK groups, highlighting the independent EtOH- rather than NNK-driven responses.

CONCLUSIONS

Chronic EtOH exposures decreased several phospholipid and sphingolipid species in brain, while concomitant NNK exposures exacerbated these effects. These findings support our hypothesis that tobacco smoking is a pathogenic cofactor in alcohol-mediated WM degeneration.

Oxidative stress during acetaminophen hepatotoxicity: Sources, pathophysiological role and therapeutic potential

Acetaminophen (APAP) hepatotoxicity is characterized by an extensive oxidative stress. However, its source, pathophysiological role and possible therapeutic potential if targeted, have been controversially described. Earlier studies argued for cytochrome P450-generated reactive oxygen species (ROS) during APAP metabolism, which resulted in massive lipid peroxidation and subsequent liver injury. However, subsequent studies convincingly challenged this assumption and the current paradigm suggests that mitochondria are the main source of ROS, which impair mitochondrial function and are responsible for cell signaling resulting in cell death. Although immune cells can be a source of ROS in other models, no reliable evidence exists to support a role for immune cell-derived ROS in APAP hepatotoxicity. Recent studies suggest that mitochondrial targeted antioxidants can be viable therapeutic agents against hepatotoxicity induced by APAP overdose, and re-purposing existing drugs to target oxidative stress and other concurrent signaling events can be a promising strategy to increase its potential application in patients with APAP overdose.

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Oxidative stress plays a critical role in acetaminophen hepatotoxicity.

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Mitochondria are the main source of ROS and RNS that are responsible for the toxicity.

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Cytochrome P450 and inflammatory cells are probably not relevant sources of ROS for the toxicity.

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Mitochondrial oxidative stress is a promising therapeutic target against APAP overdose.

Role of Autophagy in HIV Pathogenesis and Drug Abuse

Autophagy is a highly regulated process in which excessive cytoplasmic materials are captured and degraded during deprivation conditions. The unique nature of autophagy that clears invasive microorganisms has made it an important cellular defense mechanism in a variety of clinical situations. In recent years, it has become increasingly clear that autophagy is extensively involved in the pathology of HIV-1. To ensure survival of the virus, HIV-1 viral proteins modulate and utilize the autophagy pathway so that biosynthesis of the virus is maximized. At the same time, the abuse of illicit drugs such as methamphetamine, cocaine, morphine, and alcohol is thought to be a significant risk factor for the acquirement and progression of HIV-1. During drug-induced toxicity, autophagic activity has been proved to be altered in various cell types. Here, we review the current literature on the interaction between autophagy, HIV-1, and drug abuse and discuss the complex role of autophagy during HIV-1 pathogenesis in co-exposure to illicit drugs.

Olive polyphenol effects in a mouse model of chronic ethanol addiction

OBJECTIVES

Alcohol addiction elicits oxidative imbalance and it is well known that polyphenols possess antioxidant properties. We investigated whether or not polyphenols could confer a protective potential against alcohol-induced oxidative stress.

METHODS

We administered (per os) for two months 20 mg/kg of olive polyphenols containing mostly hydroxytyrosol in alcoholic adult male mice. Hydroxytyrosol metabolites as hydroxytyrosol sulfate 1 and hydroxytyrosol sulfate 2 were found in the serum of mice administered with polyphenols with the highest amount in animals treated with both polyphenols and alcohol. Oxidative stress was evaluated by FORT (free oxygen radical test) and FORD (free oxygen radical defense) tests.

RESULTS

Alcoholic mice showed a worse oxidative status than nonalcoholic mice (higher FORT and lower FORD) but polyphenol supplementation partially counteracted the alcohol pro-oxidant effects, as evidenced by FORT.

CONCLUSIONS

A better understanding of the antioxidant protection provided by polyphenols might be of primary interest for drug discovery and dietary-based prevention of the damage associated with chronic alcohol abuse.

Ginsenosides from stems and leaves of ginseng prevent ethanol-induced lipid accumulation in human L02 hepatocytes

OBJECTIVE

To investigate the effect of ginsenosides from stems and leaves of ginseng on ethanol-induced lipid deposition in human L02 hepatocytes.

METHODS

L02 cells were exposed to ethanol for 36 h and treated with or without ginsenosides. The viability of L02 cells was evaluated by methylthiazolyldiphenyl-tetrazolium bromide assay and the triglyceride (TG) content was detected. Lipid droplets were determined by oil red O staining. Intracellular reactive oxygen species (ROS) production and the mitochondrial membrane potential were tested by flow cytometry. The ATP level was measured by reverse phase high performance liquid chromatography. The expression of cytochrome p450 2E1 (CYP2E1) and peroxisome proliferator-activated receptor α (PPARα) was detected by reverse transcriptase-polymerase chain reaction and Western blotting, respectively.

RESULTS

Ethanol exposure resulted in the increase of TG level, lipid accumulation and ROS generation, and the decrease of mitochondrial membrane potential and ATP production in the cells. However, ginsenosides significantly reduced TG content (9.69±0.22 μg/mg protein vs. 4.93±0.49 μg/mg protein, P<0.01), and ROS formation (7254.8±385.7 vs. 5825.2±375.9, P<0.01). Meanwhile, improvements in mitochondrial membrane potential (10655.33±331.34 vs. 11129.52±262.35, P<0.05) and ATP level (1.20±0.18 nmol/mg protein vs. 2.53±0.25 nmol/mg protein, P<0.01) were observed by treatment with ginsenosides. Furthermore, ginsenosides could down-regulate CYP2E1 expression (P<0.01) and upregulate PPARα expression (P<0.01) in ethanol-treated cells.

CONCLUSIONS

Ginsenosides could prevent ethanol-induced hepatocyte steatosis in vitro related to the inhibition of oxidative stress and the improvement of mitochondrial function. In addition, the modulation of CYP2E1 and PPARα expression may also play an important role in the protective effect of ginsenosides against lipid accumulation.

Alcohol consumption decreases lactate clearance in acutely injured patients

INTRODUCTION

Alcohol, a common risk factor for injury, has direct toxic effects on the liver. The use of lactate clearance has been well described as an indicator of the adequacy of resuscitation in injured patients. We investigated whether acutely injured patients with positive blood alcohol content (+BAC) had less lactate clearance than sober patients.

METHODS

We conducted a retrospective cohort study of acutely injured patients treated at an urban Level 1 trauma centre between January 2010 and December 2012. Blood alcohol and venous lactate levels were measured on all patients at the time of arrival. Study subjects were patients transported directly from the scene of injury, who had an elevated lactate concentration on arrival (≥3.0mmol/L) and at least one subsequent lactate measurement within 24h after admission. Lactate clearance ([Lactate1-Lactate2]/Lactate1) was calculated for all patients. Chi-squared tests were used to compare values from sober and intoxicated subjects. Lactate clearance was plotted against alcohol levels and stratified by age and Injury Severity Score (ISS).

RESULTS

Serial lactate concentration measurements were obtained in 3910 patients; 1674 of them had +BAC. Patients with +BAC were younger (mean age: 36.6 [SD 14.7] vs 41.0 [SD 19.9] years [p=0.0001]), were more often male (83.4% vs 75.9% [p=0.0001]), had more minor injuries (ISS<9) (33.8% vs 27.1% [p=0.0001]), had a lower in-hospital mortality rate (1.4% vs 3.9% [p=0.0001]), but also had lower average lactate clearance (37.8% vs 47.6% [p=0.0001]). The lactate clearance of the sober patients (47.6 [SD 33.5]) was twice that of those with +BAC >400 (23.5 [SD 6.5]). Lactate clearance decreased with increasing BAC irrespective of age and ISS.

CONCLUSIONS

In a large group of acutely injured patients, a dose-dependent decrease in lactate clearance was seen in those with elevated BAC. This relationship will cause a falsely elevated lactate reading or prolong lactate clearance and should be taken into account when evaluating patients with +BAC.

An In Vitro Study of the Neurotoxic Effects of N-Benzylpiperazine: A Designer Drug of Abuse

Recently, the number of new psychoactive substances has significantly increased. Despite the systematic introduction of prohibition in trade of medicinal products which mimic the effects of illegal drugs, the problem concerning this group of drugs is still important although knowledge about the mechanism of action of those types of substances is scarce. This study aimed to follow the neurotoxic effect of N-benzylpiperazine (BZP), the central nervous system psychostimulant, using the human cancer LN-18 cell model. The statistically significant elevation of LDH levels, increased mitochondrial membrane potential, decreased ATP and increased ROS production, increased levels of DNA damage marker (8-OHdG) and activation of caspases: -3 and -9 confirmed by Real-Time PCR imply the activation of mitochondrial proapoptotic pathways induced by BZP after 24 h incubation. This study is a novel, preliminary attempt to explain the toxicity of one of the most popular designer drug of abuse at the cellular level.

Evaluation of Hepatoprotective activity of Eriocaulon quinquangulare in vitro using porcine liver slices against ethanol induced liver toxicity and free radical scavenging capacity

BACKGROUND

Production of reactive oxygen species is a common cause in alcohol induced liver diseases. Decoction prepared from the whole plant of Eriocaulon quinquingulare is prescribed to treat liver disorders. The aim of this study was to investigate the hepatoprotective activity and antioxidant capacity of the water extract of E. quinquangulare in vitro.

METHOD

The aqueous extract of the whole plant of E. quinquangulare (AEQ) was investigated for its phytochemical constituents, antioxidant and membrane stabilization properties in-vitro. The antioxidant activities of AEQ were investigated using 1,1-Diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical, nitric oxide scavenging and ferric reducing antioxidant power (FRAP) assays. Membrane stabilizing effect of the extract was determined by hypotonic solution induced human erythrocyte hemolytic assay (HEHA). Further, hepatoprotective activity against ethanol induced hepatotoxicity was carried out using porcine liver slices.

RESULTS

The total phenolics and flavonoids were 10.3 ± 1.6 w/w % gallic acid equivalents and 45.6 ± 3.8 w/w % (-)-epigallocatechin gallate equivalents respectively. The values of EC50 for DPPH, hydroxyl radical and nitric oxide scavenging assays were 37.2 ± 1.7 μg/ml, 170.5 ± 6.6 μg/ml and 31.8 ± 2.2 μg/ml respectively. The reducing capability of AEQ was 6.9 ± 0.2 w/w % L-ascorbic acid equivalents in the FRAP assay. For hypotonic solution induced HEHA, the IC50 was 1.79 ± 0.04 mg/ml. A significant decrease (p < 0.05) was observed in ALT, AST and LDH release from the liver slices treated with AEQ compared to the ethanol treated liver slices. A significant reduction in lipid peroxidation (p < 0.05) was also observed in liver slices treated with the plant extract compared to that of the ethanol treated liver slices.

CONCLUSIONS

The results suggest AEQ possess hepatoprotective activity against ethanol induced liver toxicity of porcine liver slices which can be attributed to antioxidant properties and membrane stabilizing effects caused by the plant material.

Hepato- and neuro-protective effects of watermelon juice on acute ethanol-induced oxidative stress in rats

Chronic and acute alcohol exposure has been extensively reported to cause oxidative stress in hepatic and extra-hepatic tissues. Watermelon (Citrullus lanatus) is known to possess various beneficial properties including; antioxidant, anti-inflammatory, analgesic, anti-diabetic, anti-ulcerogenic effects. However, there is a lack of pertinent information on its importance in acute alcohol-induced hepato- and neuro-toxicity. The present study evaluated the potential protective effects of watermelon juice on ethanol-induced oxidative stress in the liver and brain of male Wistar rats. Rats were pre-treated with the watermelon juice at a dose of 4 ml/kg body weight for a period of fifteen days prior to a single dose of ethanol (50%; 12 ml/kg body weight). Ethanol treatment reduced body weight gain and significantly altered antioxidant status in the liver and brain. This is evidenced by the significant elevation of malondialdehyde (MDA) concentration; depletion in reduced glutathione (GSH) levels and an increased catalase (CAT) activity in the brain and liver. There was no significant difference in the activity of glutathione peroxidase (GPX) in the liver and brain.

Oral administration of watermelon juice for fifteen (15) days prior to ethanol intoxication, significantly reduced the concentration of MDA in the liver and brain of rats. In addition, water melon pre-treatment increased the concentration of GSH and normalized catalase activity in both tissues in comparison to the ethanol control group. Phytochemical analysis revealed the presence of phenol, alkaloids, saponins, tannins and steroids in watermelon juice. Our findings indicate that watermelon juice demonstrate anti-oxidative effects in ethanol-induced oxidation in the liver and brain of rats; which could be associated with the plethora of antioxidant phyto-constituents present there-in.

Alcohol effects on cardiac function

The consumption of ethanol can have both beneficial and detrimental effects on the function of the heart and cardiovascular system, depending on the amount consumed. Low-to-moderate amounts of ethanol intake are associated with improvements in cardiac function and vascular health. On the other hand, ethanol chronically consumed in large amounts acts as a toxin to the heart and vasculature. The cardiac injury produced by chronic alcohol abuse can progress to heart failure and eventual death. Furthermore, alcohol abuse may exacerbate preexisting heart conditions, such as hypertension and cardiomyopathy. This article focuses on the molecular mechanisms and pathophysiology of both the beneficial and detrimental cardiac effects of alcohol.

Lipids and Oxidative Stress Associated with Ethanol-Induced Neurological Damage

The excessive intake of alcohol is a serious public health problem, especially given the severe damage provoked by chronic or prenatal exposure to alcohol that affects many physiological processes, such as memory, motor function, and cognitive abilities. This damage is related to the ethanol oxidation in the brain. The metabolism of ethanol to acetaldehyde and then to acetate is associated with the production of reactive oxygen species that accentuate the oxidative state of cells. This metabolism of ethanol can induce the oxidation of the fatty acids in phospholipids, and the bioactive aldehydes produced are known to be associated with neurotoxicity and neurodegeneration. As such, here we will review the role of lipids in the neuronal damage induced by ethanol-related oxidative stress and the role that lipids play in the related compensatory or defense mechanisms.

Exposure to ethanol during neurodevelopment modifies crucial offspring rat brain enzyme activities in a region-specific manner

The experimental simulation of conditions falling within "the fetal alcohol spectrum disorder" (FASD) requires the maternal exposure to ethanol (EtOH) during crucial neurodevelopmental periods; EtOH has been linked to a number of neurotoxic effects on the fetus, which are dependent upon the extent and the magnitude of the maternal exposure to EtOH and for which very little is known with regard to the exact mechanism(s) involved. The current study has examined the effects of moderate maternal exposure to EtOH (10 % v/v in the drinking water) throughout gestation, or gestation and lactation, on crucial 21-day-old offspring Wistar rat brain parameters, such as the activities of acetylcholinesterase (AChE) and two adenosine triphosphatases (Na(+),K(+)-ATPase and Mg(2+)-ATPase), in major offspring CNS regions (frontal cortex, hippocampus, hypothalamus, cerebellum and pons). The implemented experimental setting has provided a comparative view of the neurotoxic effects of maternal exposure to EtOH between gestation alone and a wider exposure timeframe that better covers the human third trimester-matching CNS neurodevelopment period (gestation and lactation), and has revealed a CNS region-specific susceptibility of the examined crucial neurochemical parameters to the EtOH exposure schemes attempted. Amongst these parameters, of particular importance is the recorded extensive stimulation of Na(+),K(+)-ATPase in the frontal cortex of the EtOH-exposed offspring that seems to be a result of the deleterious effect of EtOH during gestation. Although this stimulation could be inversely related to the observed inhibition of AChE in the same CNS region, its dependency upon the EtOH-induced modulation of other systems of neurotransmission cannot be excluded and must be further clarified in future experimental attempts aiming to simulate and to shed more light on the milder forms of the FASD-related pathophysiology.

Alcohol, Aldehydes, Adducts and Airways

Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA) adduct and hybrid malondialdehyde-acetaldehyde (MAA) protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.

High postnatal susceptibility of hippocampal cytoskeleton in response to ethanol exposure during pregnancy and lactation

Ethanol exposure to offspring during pregnancy and lactation leads to developmental disorders, including central nervous system dysfunction. In the present work, we have studied the effect of chronic ethanol exposure during pregnancy and lactation on the phosphorylating system associated with the astrocytic and neuronal intermediate filament (IF) proteins: glial fibrillary acidic protein (GFAP), and neurofilament (NF) subunits of low, medium, and high molecular weight (NFL, NFM, and NFH, respectively) in 9- and 21-day-old pups. Female rats were fed with 20% ethanol in their drinking water during pregnancy and lactation. The homeostasis of the IF phosphorylation was not altered in the cerebral cortex, cerebellum, or hippocampus of 9-day-old pups. However, GFAP, NFL, and NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. PKA had been activated in the hippocampus, and Ser55 in the N-terminal region of NFL was hyperphosphorylated. In addition, JNK/MAPK was activated and KSP repeats in the C-terminal region of NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. Decreased NFH immunocontent but an unaltered total NFH/phosphoNFH ratio suggested altered stoichiometry of NFs in the hippocampus of ethanol-exposed 21-day-old pups. In contrast to the high susceptibility of hippocampal cytoskeleton in developing rats, the homeostasis of the cytoskeleton of ethanol-fed adult females was not altered. Disruption of the cytoskeletal homeostasis in neural cells supports the view that regions of the brain are differentially vulnerable to alcohol insult during pregnancy and lactation, suggesting that modulation of JNK/MAPK and PKA signaling cascades target the hippocampal cytoskeleton in a window of vulnerability in 21-day-old pups. Our findings are relevant, since disruption of the cytoskeleton in immature hippocampus could contribute to later hippocampal damage associated with ethanol toxicity.

RhoGAP18B Isoforms Act on Distinct Rho-Family GTPases and Regulate Behavioral Responses to Alcohol via Cofilin

Responses to the effects of ethanol are highly conserved across organisms, with reduced responses to the sedating effects of ethanol being predictive of increased risk for human alcohol dependence. Previously, we described that regulators of actin dynamics, such as the Rho-family GTPases Rac1, Rho1, and Cdc42, alter Drosophila's sensitivity to ethanol-induced sedation. The GTPase activating protein RhoGAP18B also affects sensitivity to ethanol. To better understand how different RhoGAP18B isoforms affect ethanol sedation, we examined them for their effects on cell shape, GTP-loading of Rho-family GTPase, activation of the actin-severing cofilin, and actin filamentation. Our results suggest that the RhoGAP18B-PA isoform acts on Cdc42, while PC and PD act via Rac1 and Rho1 to activate cofilin. In vivo, a loss-of-function mutation in the cofilin-encoding gene twinstar leads to reduced ethanol-sensitivity and acts in concert with RhoGAP18B. Different RhoGAP18B isoforms, therefore, act on distinct subsets of Rho-family GTPases to modulate cofilin activity, actin dynamics, and ethanol-induced behaviors.

TLR2 and TLR9 contribute to alcohol-mediated liver injury through induction of CXCL1 and neutrophil infiltration

Although previous studies reported the involvement of the TLR4-TRIF pathway in alcohol-induced liver injury, the role of TLR2 and TLR9 signaling in alcohol-mediated neutrophil infiltration and liver injury has not been elucidated. Since alcohol binge drinking is recognized to induce more severe form of alcohol liver disease, we used a chronic-binge ethanol-feeding model as a mouse model for early stage of alcoholic hepatitis. Whereas a chronic-binge ethanol feeding induced alcohol-mediated liver injury in wild-type mice, TLR2- and TLR9-deficient mice showed reduced liver injury. Induction of neutrophil-recruiting chemokines, including Cxcl1, Cxcl2, and Cxcl5, and hepatic neutrophil infiltration were increased in wild-type mice, but not in TLR2- and TLR9-deficient mice. In vivo depletion of Kupffer cells (KCs) by liposomal clodronate reduced liver injury and the expression of Il1b, but not Cxcl1, Cxcl2, and Cxcl5, suggesting that KCs are partly associated with liver injury, but not neutrophil recruitment, in a chronic-binge ethanol-feeding model. Notably, hepatocytes and hepatic stellate cells (HSCs) produce high amounts of CXCL1 in ethanol-treated mice. The treatment with TLR2 and TLR9 ligands synergistically upregulated CXCL1 expression in hepatocytes. Moreover, the inhibitors for CXCR2, a receptor for CXCL1, and MyD88 suppressed neutrophil infiltration and liver injury induced by chronic-binge ethanol treatment. Consistent with the above findings, hepatic CXCL1 expression was highly upregulated in patients with alcoholic hepatitis. In a chronic-binge ethanol-feeding model, the TLR2 and TLR9-dependent MyD88-dependent pathway mediates CXCL1 production in hepatocytes and HSCs; the CXCL1 then promotes neutrophil infiltration into the liver via CXCR2, resulting in the development of alcohol-mediated liver injury.

Impact of alcohol consumption on the outcome of ischemic stroke and thrombolysis: role of the hepatic clearance of tissue-type plasminogen activator

BACKGROUND AND PURPOSE

Tissue-type plasminogen activator (tPA) is the only acute treatment for ischemic stroke. Unfortunately, the benefit of tPA-driven thrombolysis is not systematic, and understanding the reasons for this is mandatory. The balance between beneficial and detrimental effects of tPA might explain the limited overall efficiency of thrombolysis. Here, we investigated whether this balance could be influenced by excessive alcohol intake.

METHODS

We used a murine model of thromboembolic stroke, coupled to an array of biochemical assays, near-infrared or magnetic resonance imaging scans, 2-photon microscopy, hydrodynamic transfections, and immunohistological techniques.

RESULTS

We found that 6 weeks of alcohol consumption (10% in drinking water) worsens ischemic lesions and cancels the beneficial effects of tPA-induced thrombolysis. We accumulate in vivo and in vitro evidence showing that this aggravation is correlated with a decrease in lipoprotein receptor-related protein 1-mediated hepatic clearance of tPA in alcohol-exposed mice.

CONCLUSIONS

An efficient liver-driven clearance of tPA might influence the safety of thrombolysis after stroke.

Isoaspartate, carbamoyl phosphate synthase-1, and carbonic anhydrase-III as biomarkers of liver injury

We had previously shown that alcohol consumption can induce cellular isoaspartate protein damage via an impairment of the activity of protein isoaspartyl methyltransferase (PIMT), an enzyme that triggers repair of isoaspartate protein damage. To further investigate the mechanism of isoaspartate accumulation, hepatocytes cultured from control or 4-week ethanol-fed rats were incubated in vitro with tubercidin or adenosine. Both these agents, known to elevate intracellular S-adenosylhomocysteine levels, increased cellular isoaspartate damage over that recorded following ethanol consumption in vivo. Increased isoaspartate damage was attenuated by treatment with betaine. To characterize isoaspartate-damaged proteins that accumulate after ethanol administration, rat liver cytosolic proteins were methylated using exogenous PIMT and (3)H-S-adenosylmethionine and proteins resolved by gel electrophoresis. Three major protein bands of ∼ 75-80 kDa, ∼ 95-100 kDa, and ∼ 155-160 kDa were identified by autoradiography. Column chromatography used to enrich isoaspartate-damaged proteins indicated that damaged proteins from ethanol-fed rats were similar to those that accrued in the livers of PIMT knockout (KO) mice. Carbamoyl phosphate synthase-1 (CPS-1) was partially purified and identified as the ∼ 160 kDa protein target of PIMT in ethanol-fed rats and in PIMT KO mice. Analysis of the liver proteome of 4-week ethanol-fed rats and PIMT KO mice demonstrated elevated cytosolic CPS-1 and betaine homocysteine S-methyltransferase-1 when compared to their respective controls, and a significant reduction of carbonic anhydrase-III (CA-III) evident only in ethanol-fed rats. Ethanol feeding of rats for 8 weeks resulted in a larger (∼ 2.3-fold) increase in CPS-1 levels compared to 4-week ethanol feeding indicating that CPS-1 accumulation correlated with the duration of ethanol consumption. Collectively, our results suggest that elevated isoaspartate and CPS-1, and reduced CA-III levels could serve as biomarkers of hepatocellular injury.

Hypolipidaemic and antioxidant effect of Enicostemma littorale Blume

OBJECTIVE

To investigate the hypolipidaemic and antioxidant effects of aqueous leaf extract of Enicostemma littorale (E. littorale) Blume (Ens) against ethanol induced hepatic injury in albino rats.

METHODS

Male albino rats of six numbers in each group were undertaken for study. Hypolipidaemic and antioxidant effect of E. littorale Blume (Ens) aqueous leaf extract at a dosage of 250 mg/kg bw was evaluated.

RESULTS

Levels of serum and tissue cholesterol, triglycerides and free fatty acids were elevated and levels of tissue thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxide were increased in ethanol treated rats. The activity levels of liver antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione-s-transferase (GST) were decreased. After adiminstration of extract of E. littorale Blume, levels of cholesterol, triglycerides and free fatty acids were decreased in serum and liver tissue, levels of TBARS and lipid hydroperoxide were decreased, and liver antioxidant enzymes were increased in liver tissue.

CONCLUSIONS

It can be concluded that the aqueous leaf extract of E. littorale Blume (Ens) has potent restorative effect on hyperlipidaemic and oxidative stress.

Integrative epigenetic profiling analysis identifies DNA methylation changes associated with chronic alcohol consumption

Alcoholism has always been a major public health concern in Taiwan, especially in the aboriginal communities. Emerging evidence supports the association between DNA methylation and alcoholism, though very few studies have examined the effect of chronic alcohol consumption on the epignome. Since 1986, we have been following up on the mental health conditions of four major aboriginal peoples of Taiwan. The 993 aboriginal people who underwent the phase 1 (1986) clinical interviews were followed up through phase 2 (1990-1992), and phase 3 (2003-2009). Selected individuals for the current study included 10 males from the phase 1 normal cohort who remained normal at phase 2 and became dependent on alcohol by phase 3 and 10 control subjects who have not had any drinking problems throughout the study. We profiled the DNA methylation changes in the blood samples collected at phases 2 and 3. Enrichment analyses have identified several biological processes related to immune system responses and aging in the control group. In contrast, differentially methylated genes in the case group were mostly associated with susceptibility to infections, as well as pathways related to muscular contraction and neural degeneration. The methylation levels of six genes were found to correlate with alcohol consumption. These include genes involved in neurogenesis (NPDC1) and inflammation (HERC5), as well as alcoholism-associated genes ADCY9, CKM, and PHOX2A. Given the limited sample size, our approach uncovered genes and disease pathways associated with chronic alcohol consumption at the epigenetic level. The results offer a preliminary methylome map that enhances our understanding of alcohol-induced damages and offers new targets for alcohol injury research.

Mitochondrial toxicity in human pregnancy: an update on clinical and experimental approaches in the last 10 years

Mitochondrial toxicity can be one of the most dreadful consequences of exposure to a wide range of external agents including pathogens, therapeutic agents, abuse drugs, toxic gases and other harmful chemical substances. However, little is known about the effects of mitochondrial toxicity on pregnant women exposed to these agents that may exert transplacental activity and condition fetal remodeling. It has been hypothesized that mitochondrial toxicity may be involved in some adverse obstetric outcomes. In the present study, we investigated the association between exposure to mitochondrial toxic agents and pathologic conditions ranging from fertility defects, detrimental fetal development and impaired newborn health due to intra-uterine exposure. We have reviewed data from studies in human subjects to propose mechanisms of mitochondrial toxicity that could be associated with the symptoms present in both exposed pregnant and fetal patients. Since some therapeutic interventions or accidental exposure cannot be avoided, further research is needed to gain insight into the molecular pathways leading to mitochondrial toxicity during pregnancy. The ultimate objective of these studies should be to reduce the mitochondrial toxicity of these agents and establish biomarkers for gestational monitoring of harmful effects.

Drug abuse and the neurovascular unit

Drug abuse continues to create a major international epidemic affecting society. A great majority of past drug abuse research has focused mostly on the mechanisms of addiction and the specific effects of substance use disorders on brain circuits and pathways that modulate reward, motivation, craving, and decision making. Few studies have focused on the neurobiology of acute and chronic substance abuse as it relates to the neurovascular unit (brain endothelial cell, neuron, astrocyte, microglia, and pericyte). Increasing research indicates that all cellular components of the neurovascular unit play a pivotal role in both the process of addiction and how drug abuse affects the brain response to diseases. This review will focus on the specific effects of opioids, amphetamines, alcohol, and nicotine on the neurovascular unit and its role in addiction and adaption to brain diseases. Elucidation of the role of the neurovascular unit on the neurobiology associated with drug addiction will help to facilitate the development of better therapeutic approaches for drug-dependent individuals.

Impact of chronic low to moderate alcohol consumption on blood lipid and heart energy profile in acetaldehyde dehydrogenase 2-deficient mice

AIM

To investigate the roles of acetaldehyde dehydrogenase 2 (ALDH2), the key enzyme of ethanol metabolism, in chronic low to moderate alcohol consumption-induced heart protective effects in mice.

METHODS

Twenty-one male wild-type (WT) or ALDH2-knockout (KO) mice were used in this study. In each genotype, 14 animals received alcohol (2.5%, 5% and 10% in week 1-3, respectively, and 18% in week 4-7), and 7 received water for 7 weeks. After the treatments, survival rate and general characteristics of the animals were evaluated. Serum ethanol and acetaldehyde levels and blood lipids were measured. Metabolomics was used to characterize the heart and serum metabolism profiles.

RESULTS

Chronic alcohol intake decreased the survival rate of KO mice by 50%, and significantly decreased their body weight, but did not affect those of WT mice. Chronic alcohol intake significantly increased the serum ethanol levels in both WT and KO mice, but KO mice had significantly higher serum acetaldehyde levels than WT mice. Chronic alcohol intake significantly increased the serum HDL cholesterol levels in WT mice, and did not change the serum HDL cholesterol levels in KO mice. After chronic alcohol intake, WT and KO mice showed differential heart and serum metabolism profiles, including the 3 main energy substrate types (lipids, glucose and amino acids) and three carboxylic acid cycles.

CONCLUSION

Low to moderate alcohol consumption increases HDL cholesterol levels and improves heart energy metabolism profile in WT mice but not in ALDH2-KO mice. Thus, preserved ALDH2 function is essential for the protective effect of low to moderate alcohol on the cardiovascular system.

Role of mitochondria ROS generation in ethanol-induced NLRP3 inflammasome activation and cell death in astroglial cells

Toll-like receptors (TLRs) and NOD-like receptors (NLRs) are innate immunity sensors that provide an early/effective response to pathogenic or injury conditions. We have reported that ethanol-induced TLR4 activation triggers signaling inflammatory responses in glial cells, causing neuroinflammation and brain damage. However, it is uncertain if ethanol is able to activate NLRs/inflammasome in astroglial cells, which is the mechanism of activation, and whether there is crosstalk between both immune sensors in glial cells. Here we show that chronic ethanol treatment increases the co-localization of caspase-1 with GFAP⁺ cells, and up-regulates IL-1β and IL-18 in the frontal medial cortex in WT, but not in TLR4 knockout mice. We further show that cultured cortical astrocytes expressed several inflammasomes (NLRP3, AIM2, NLRP1, and IPAF), although NLRP3 mRNA is the predominant form. Ethanol, as ATP and LPS treatments, up-regulates NLRP3 expression, and causes caspase-1 cleavage and the release of IL-1β and IL-18 in astrocytes supernatant. Ethanol-induced NLRP3/caspase-1 activation is mediated by mitochondrial (m) reactive oxygen species (ROS) generation because when using a specific mitochondria ROS scavenger, the mito-TEMPO (500 μM) or NLRP3 blocking peptide (4 μg/ml) or a specific caspase-1 inhibitor, Z-YVAD-FMK (10 μM), abrogates mROS release and reduces the up-regulation of IL-1β and IL-18 induced by ethanol or LPS or ATP. Confocal microscopy studies further confirm that ethanol, ATP or LPS promotes NLRP3/caspase-1 complex recruitment within the mitochondria to promote cell death by caspase-1-mediated pyroptosis, which accounts for ≈73% of total cell death (≈22%) and the remaining (≈25%) die by caspase-3-dependent apoptosis. Suppression of the TLR4 function abrogates most ethanol effects on NLRP3 activation and reduces cell death. These findings suggest that NLRP3 participates, in ethanol-induced neuroinflammation and highlight the NLRP3/TLR4 crosstalk in ethanol-induced brain injury.

Cytotoxicity and metabolic stress induced by acetaldehyde in human intestinal LS174T goblet-like cells

There is compelling evidence indicating that ethanol and its oxidative metabolite acetaldehyde can disrupt intestinal barrier function. Apart from the tight junctions, mucins secreted by goblet cells provide an effective barrier. Ethanol has been shown to induce goblet cell injury associated with alterations in mucin glycosylation. However, effects of its most injurious metabolite acetaldehyde remain largely unknown. This study aimed to assess short-term effects of acetaldehyde (0, 25, 50, 75, 100 μM) on functional characteristics of intestinal goblet-like cells (LS174T). Oxidative stress, mitochondrial function, ATP, and intramitochondrial calcium (Ca(2+)) were assessed by dichlorofluorescein, methyltetrazolium, and bioluminescence, MitoTracker green and rhod-2 double-labeling. Membrane integrity and apoptosis were evaluated by measuring lactate dehydrogenase (LDH), caspase 3/7, and cleavage of cytokeratin 18 (CK18). Expression of mucin 2 (MUC2) was determined by cell-based ELISA. Acetaldehyde significantly increased reactive oxygen species generation and decreased mitochondrial function compared with negative controls (P < 0.05). In addition, acetaldehyde dose-dependently decreased ATP levels and induced intramitochondrial Ca(2+) accumulation compared with negative controls (P < 0.05). Furthermore, acetaldehyde induced LDH release and increased caspase3/7 activity and percentage of cells expressing cleaved CK18 and increased MUC2 protein expression compared with negative controls (P < 0.0001). ATP depletion and LDH release could be largely prevented by the antioxidant N-acetylcysteine, suggesting a pivotal role for oxidative stress. Our data demonstrate that acetaldehyde has distinct oxidant-dependent metabolic and cytotoxic effects on LS174T cells that can lead to induction of cellular apoptosis. These effects may contribute to acetaldehyde-induced intestinal barrier dysfunction and subsequently to liver injury.

Differentially co-expressed genes in postmortem prefrontal cortex of individuals with alcohol use disorders: influence on alcohol metabolism-related pathways

Chronic alcohol consumption may induce gene expression alterations in brain reward regions such as the prefrontal cortex (PFC), modulating the risk of alcohol use disorders (AUDs). Transcriptome profiles of 23 AUD cases and 23 matched controls (16 pairs of males and 7 pairs of females) in postmortem PFC were generated using Illumina's HumanHT-12 v4 Expression BeadChip. Probe-level differentially expressed genes and gene modules in AUD subjects were identified using multiple linear regression and weighted gene co-expression network analyses. The enrichment of differentially co-expressed genes in alcohol dependence-associated genes identified by genome-wide association studies (GWAS) was examined using gene set enrichment analysis. Biological pathways overrepresented by differentially co-expressed genes were uncovered using DAVID bioinformatics resources. Three AUD-associated gene modules in males [Module 1 (561 probes mapping to 505 genes): r = 0.42, P(correlation) = 0.020; Module 2 (815 probes mapping to 713 genes): r = 0.41, P(correlation) = 0.020; Module 3 (1,446 probes mapping to 1,305 genes): r = -0.38, P(correlation) = 0.030] and one AUD-associated gene module in females [Module 4 (683 probes mapping to 652 genes): r = 0.64, P(correlation) = 0.010] were identified. Differentially expressed genes mapped by significant expression probes (P(nominal) ≤ 0.05) clustered in Modules 1 and 2 were enriched in GWAS-identified alcohol dependence-associated genes [Module 1 (134 genes): P = 0.028; Module 2 (243 genes): P = 0.004]. These differentially expressed genes, including ALDH2, ALDH7A1, and ALDH9A1, are involved in cellular functions such as aldehyde detoxification, mitochondrial function, and fatty acid metabolism. Our study revealed differentially co-expressed genes in postmortem PFC of AUD subjects and demonstrated that some of these differentially co-expressed genes participate in alcohol metabolism.

Candida albicans and cancer: Can this yeast induce cancer development or progression?

There is currently increasing concern about the relation between microbial infections and cancer. More and more studies support the view that there is an association, above all, when the causal agents are bacteria or viruses. This review adds to this, summarizing evidence that the opportunistic fungus Candida albicans increases the risk of carcinogenesis and metastasis. Until recent years, Candida spp. had fundamentally been linked to cancerous processes as it is an opportunist pathogen that takes advantage of the immunosuppressed state of patients particularly due to chemotherapy. In contrast, the most recent findings demonstrate that C. albicans is capable of promoting cancer by several mechanisms, as described in the review: production of carcinogenic byproducts, triggering of inflammation, induction of Th17 response and molecular mimicry. We underline the need not only to control this type of infection during cancer treatment, especially given the major role of this yeast species in nosocomial infections, but also to find new therapeutic approaches to avoid the pro-tumor effect of this fungal species.

Multiparameter rodent chronic model for complex evaluation of alcoholism-mediated metabolic violations

BACKGROUND

Despite of the wide spectrum of alcoholism experimental models, the majority of them are very specialized on the short list of investigated parameters and could not provide reproduction of complex metabolic changes in the rats. The aim of the present study was to estimate whether rats selected by high alcohol preference, allowed free access to 15% alcohol for 150 days, develop simultaneous multilevel disturbances of cell macromolecules structure, metabolism and oxidative/nitrosative stress.

METHODS

Wistar albino male rats were divided into groups: I - rats selected by preferences to alcohol were used for chronic alcoholism modeling by replacing water with 15% ethanol (150 days), II - control. Contents of amino acids in serum, liver mRNA CYP2E1 and CYP3A2 expression, DNA fragmentation and lipid peroxidation levels, the reduced glutathione content, superoxide dismutase, catalase, iNOS and cNOS activities were evaluated.

RESULTS

In serum of ethanol-treated rats contents of aspartic acid, serine, glycine, alanine and valine were decreased whereas contents of histidine, methionine and phenylalanine were increased. Liver CYP2E1, CYP3A2 mRNA expression, DNA fragmentation levels significantly elevated. Level of cNOS in ethanol-treated rat's hepatocytes was within the normal limits, whereas iNOS activity was raised 1.6 times. Liver pro- and anti-oxidant system alterations were shown.

CONCLUSIONS

Rats' chronic 15% alcohol consumption (150 days) led solely to complex metabolomic changes at different levels, which simultaneously characterized cell macromolecules structure, metabolism, and oxidative/nitrosative stress. Rodent model of chronic alcoholism in the proposed modification could be an adequate and reasonably priced tool for further preclinical development and testing of pharmacotherapeutic agents.

Alcohol induced mitochondrial oxidative stress and alveolar macrophage dysfunction

An alcohol use disorder increases the risk of invasive and antimicrobial resistant community-acquired pneumonia and tuberculosis. Since the alveolar macrophage (AM) orchestrates the immune response in the alveolar space, understanding the underlying mechanisms by which alcohol suppresses AM phagocytosis is critical to improving clinical outcomes. In the alveolar space, chronic alcohol ingestion causes severe oxidative stress and depletes antioxidants which are critical for AM function. The mitochondrion is important in maintaining cellular redox balance and providing the ATP critical for phagocytosis. The focus of this study was to understand how alcohol triggers mitochondrial reactive oxygen species (ROS), stimulates cellular oxidative stress, and induces AM dysfunction. The current study also investigated the capacity of the mitochondrial targeted antioxidant, mitoTEMPOL (mitoT), in modulating mitochondrial oxidative stress, and AM dysfunction. Using in vitro ethanol exposure and AMs from ethanol-fed mice, ethanol promoted mitochondrial dysfunction including increased mitochondrial ROS, decreased mitochondrial membrane potential, and decreased ATP. Treatment with mitoT reversed these effects. Ethanol-induced decreases in phagocytosis and cell viability were also attenuated with mitoT. Therefore, antioxidants targeted to the mitochondria have the potential to ameliorate ethanol-induced mitochondrial oxidative stress and subsequent decreases in AM phagocytosis and cell viability.

Nuclear receptor-mediated alleviation of alcoholic fatty liver by polyphenols contained in alcoholic beverages

To elucidate the effect of the polyphenols contained in alcoholic beverages on the metabolic stress induced by ethanol consumption, four groups of mice were fed for five weeks on Lieber's diet with or without ethanol, with ethanol plus ellagic acid, and with ethanol plus trans-resveratrol. Alcoholic fatty liver was observed in the group fed the ethanol diet but not in those fed the ethanol plus polyphenol diets. Liver transcriptome analysis revealed that the addition of the polyphenols suppressed the expression of the genes related to cell stress that were up-regulated by ethanol alone. Conversely, the polyphenols up-regulated the genes involved in bile acid synthesis, unsaturated fatty acid elongation, and tetrahydrofolate synthesis that were down-regulated by ethanol alone. Because parts of these genes were known to be regulated by the constitutive androstane receptor (CAR), we performed the same experiment in the CAR-deficient mice. As a result, fatty liver was observed not only in the ethanol group but also with the ethanol plus polyphenol groups. In addition, there was no segregation of the gene expression profiles among these groups. These results provide a molecular basis for the prevention of alcohol-induced stress by the polyphenols in alcoholic beverages.

Alcohol use disorder: pathophysiology, effects, and pharmacologic options for treatment

Alcohol use disorders (AUD) continue to be a concerning health issue worldwide. Harmful alcohol use leads to 2.5 million deaths annually worldwide. Multiple options exist for the management of dependence on alcohol, not all of which are approved by drug-regulating agencies. Current practice in treating AUD does not reflect the diversity of pharmacologic options that have potential to provide benefit, and guidance for clinicians is limited. Few medications are approved for treatment of AUD, and these have exhibited small and/or inconsistent effects in broad patient populations with diverse drinking patterns. The need for continued research into the treatment of this disease is evident in order to provide patients with more specific and effective options. This review describes the neurobiological mechanisms of AUD that are amenable to treatment and drug therapies that target pathophysiological conditions of AUD to reduce drinking. In addition, current literature on pharmacologic (both approved and non-approved) treatment options for AUD offered in the United States and elsewhere are reviewed. The aim is to inform clinicians regarding the options for alcohol abuse treatment, keeping in mind that not all treatments are completely successful in reducing craving or heavy drinking or increasing abstinence.

Alcohol induces mitochondrial redox imbalance in alveolar macrophages

Alcohol abuse suppresses the immune responses of alveolar macrophages (AMs) and increases the risk of a respiratory infection via chronic oxidative stress and depletion of critical antioxidants within alveolar cells and the alveolar lining fluid. Although alcohol-induced mitochondrial oxidative stress has been demonstrated, the oxidation of the mitochondrial thioredoxin redox circuit in response to alcohol has not been examined. In vitro ethanol exposure of a mouse AM cell line and AMs from ethanol-fed mice demonstrated NADPH depletion concomitant with oxidation of mitochondrial glutathione and oxidation of the thioredoxin redox circuit system including thioredoxin 2 (Trx2) and thioredoxin 2 reductase (Trx2R). Mitochondrial peroxiredoxins (Prdx's), which are critical for the reduction of the thioredoxin circuit, were irreversibly hyperoxidized to an inactive form. Ethanol also decreased the mRNAs for Trx2, Trx2R, Prdx3, and Prdx5 plus the mitochondrial thiol-disulfide proteins glutaredoxin 2, glutathione reductase, and glutathione peroxidase 2. Thus, the mitochondrial thioredoxin circuit was highly oxidized by ethanol, thereby compromising the mitochondrial antioxidant capacity and ability to detoxify mitochondrial reactive oxygen species. Oxidation of the mitochondrial thioredoxin redox circuit would further compromise the transient oxidation of thiol groups within specific proteins, the basis of redox signaling, and the processes by which cells respond to oxidants. Impaired mitochondria can then jeopardize cellular function of AMs, such as phagocytosis, which may explain the increased risk of respiratory infection in subjects with an alcohol use disorder.

Short-chain fatty acids activate AMP-activated protein kinase and ameliorate ethanol-induced intestinal barrier dysfunction in Caco-2 cell monolayers

Short-chain fatty acids (SCFAs) have been shown to promote intestinal barrier function, but their protective effects against ethanol-induced intestinal injury and underlying mechanisms remain essentially unknown. The aim of the study was to analyze the influence of SCFAs on ethanol-induced barrier dysfunction and to examine the role of AMP-activated protein kinase (AMPK) as a possible mechanism using Caco-2 monolayers. The monolayers were treated apically with butyrate (2, 10, or 20 mmol/L), propionate (4, 20, or 40 mmol/L), or acetate (8, 40, or 80 mmol/L) for 1 h before ethanol (40 mmol/L) for 3 h. Barrier function was analyzed by measurement of transepithelial resistance and permeation of fluorescein isothiocyanate-labeled dextran. Distribution of the tight junction (TJ) proteins zona occludens-1, occludin, and filamentous-actin (F-actin) was examined by immunofluorescence. Metabolic stress was determined by measuring oxidative stress, mitochondrial function, and ATP using dichlorofluorescein diacetate, dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide, and bioluminescence assay, respectively. AMPK was knocked down by small interfering RNA (siRNA), and its activity was assessed by a cell-based ELISA. Exposure to ethanol significantly impaired barrier function compared with controls (P < 0.0001), disrupted TJ and F-actin cytoskeleton integrity, and induced metabolic stress. However, pretreatment with 2 mmol/L butyrate, 4 mmol/L propionate, and 8 mmol/L acetate significantly alleviated the ethanol-induced barrier dysfunction, TJ and F-actin disruption, and metabolic stress compared with ethanol-exposed monolayers (P < 0.0001). The promoting effects on barrier function were abolished by inhibiting AMPK using either compound C or siRNA. These observations indicate that SCFAs exhibit protective effects against ethanol-induced barrier disruption via AMPK activation, suggesting a potential for SCFAs as prophylactic and/or therapeutic factors against ethanol-induced gut leakiness.