Alcohol-induced Damage Research Articles

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

This study reveals a novel IRAKM-Mincle axis that contributes to the pathogenesis of ethanol-induced liver injury. (Hepatology 2016;64:1978-1993).

Nephro-protective action of P. santalinus against alcohol-induced biochemical alterations and oxidative damage in rats.

The present study investigated the antioxidant potential of P. santalinus heartwood methanolic extract (PSE) against alcohol-induced nephro-toxicity. The results indicated an increase in the concentration of kidney damage plasma markers, urea and creatinine with a concomitant decrease in the concentration of uric acid in alcohol-administered rats. A significant decrease in plasma electrolytes and mineral levels with increased kidney thiobarbituric acid reactive substances (TBARS) and nitric oxide (NOx) levels was also observed. PSE treatment to alcohol-administered rats effectively prevented the elevation in TBARS and NOx levels. Decreased activity of Na+/K+-ATPase in alcohol administered rats was brought to near normal levels with treatment of PSE. Chronic alcohol consumption affects antioxidant enzymatic activity and reabsorption function of the kidney which is evident from the decreased level of GSH as well as the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione s-transferase (GST). However, treatment with PSE to alcohol-administered rats significantly enhanced these enzymatic activities and reduced glutathione (GSH) content close to normal level. Alcohol-induced organ damage was evident from morphological changes in the kidney. Nevertheless, administration of PSE effectively restored these morphological changes to normal. The flavonoid and tannoid compounds might have protective activity against alcohol-induced oxidative/nitrosative stress mediated kidney damage.

Modulatory role of Pterocarpus santalinus against alcohol-induced liver oxidative/nitrosative damage in rats

Pterocarpus santalinus, a traditional medicinal plant has shown protective mechanisms against various complications. The aim of the present study is to evaluate therapeutic efficacy of P. santalinus heartwood methanolic extract (PSE) against alcohol-induced oxidative/nitrosative stress leading to hepatotoxicity. In-vitro studies revealed that PSE possess strong DPPH (1,1-diphenyl-2-picryl hydrazyl) and nitric oxide radical scavenging activity. For in vivo studies male albino Wistar rats were treated with 20% alcohol (5g/kg b.wt/day) and PSE (250mg/kg b.wt/day) for 60days. Results showed that alcohol administration significantly altered plasma lipid profile with marked increase in the levels of plasma transaminases (ALT and AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (γGT). Moreover, lipid peroxides, nitric oxide (NOx) levels in plasma and liver were increased with increased iNOS protein expression in liver was noticed in alcohol administered rats and these levels were significantly brought back close to normal level by PSE administration except iNOS protein expression. Alcohol administration also decreased the content of reduced glutathione (GSH) and activities of glutathione peroxidase (GPx), glutathione-s transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) in liver, which were significantly enhanced by administration of PSE. The active compounds pterostilbene, lignan and lupeols present in PSE might have shown protection against alcohol-induced hepatic damage by possibly reducing the rate of lipid peroxidation, NOx levels and increasing the antioxidant defence mechanism in alcohol administered rats. Both biochemical and histopathological results in the alcohol-induced liver damage model emphasize beneficial action of PSE as a hepatoprotective agent.

The Relationship Between XRCC1 Arg399Gln Polymorphism, Alcohol Consumption and Colorectal Cancer: One of the Alcohol Forbidding Reasons in Islam

Cancers start when cells in the body begin uncontrolled growth. Cancers are one of the major reasons of morbidity and death universally, and can spread to other organs of the body. colorectal cancer (CRC) is a type of cancer that starts in the colon or rectum. It has the third rank in occurrence of cancer and mortality in the US (1, 2). It is a very serious and dangerous problem worldwide (3). On the other hand, X-Ray repair cross-complementing protein 1 (XRCC1) plays an important role in the repair of DNA damage, and this repair implementation is via base lesions excision repair (BER) pathway (4). Free radical intermediates may generate DNA base lesions that should be removed via the BER. It should be noted that the reduced repair capacity due to XRCC1 polymorphisms is a venturesome factor for body’s health; Lunn et al. showed that the XRCC1 Arg399Gln polymorphism could cause defective DNA repair (5, 6). XRCC1 Arg399Gln polymorphism can result in lung cancer, leukemia, lymphoma, breast cancer and hepatocellular carcinoma (7-10). Our goal was to detect the relationship between XRCC1 Arg399Gln polymorphism and CRC and also to determine the efficacy of alcohol consumption on this relationship. Regarding the relationship between XRCC1 Arg399Gln polymorphism and CRC, some studies have shown that XRCC1 Arg399Gln polymorphism could cause CRC occurrence (11, 12). In Wu’s study, it was suggested that this polymorphism has a potential to increase CRC susceptibility (13). Similarly, Chang-Jiang Qin et al. detected the association between the polymorphism of XRCC1 Arg399Gln and CRC (14). Also two meta-analyses confirmed that XRCC1 Arg399Gln polymorphism is a predisposing factor for the development of CRC (15, 16). On the other hand, researchers also evaluated the interaction between three polymorphic sites of XRCC1 gene and drinking habit; the idea was based on the role of reactive oxygen species as relevant genotoxins that might account for the effects of alcohol; and they indicated a higher risk in people with Arg399Gln allele and alcohol drinking. Also, they suggested that chronic alcohol consumption could reduce XRCC1 protein activity (13). In addition, scholars found that the effect of high alcohol intake that increased the risk of CRC was more remarkable in carriers of the XRCC1 codons 194 Trp allele or 399 Gln allele (17-19), and as mentioned above, XRCC1 polymorphisms are repair capacity reducers, so in alcoholism, XRCC1 can’t become involved in the BER of alcohol-induced DNA damage. In conclusion, CRC is seriously and significantly associated with XRCC1 Arg399Gln polymorphism. The findings demonstrate that alcoholic drinks possess adverse effects on the colon and rectum because these drinks are associated with problems linked to XRCC1 Arg399Gln polymorphism in creation and development of CRC. Also, it should be noted that according to the Holy Quran, consumption of anything that causes drunkenness is forbidden such as alcoholic drinks (20). Finally, alcoholic drinks are hazardous factors in relation to CRC and this is one of the detected alcohol forbidding reasons in Islam. So via adherence to preachments of Islam about lack of alcohol consumption, one can promote their social and personal health.

Decreased subcortical volumes in alcohol dependent individuals: effect of polysubstance use disorder.

Chronic alcohol use has widespread effects on brain morphometry. Alcohol dependent individuals are often diagnosed with comorbid substance use disorders. Alterations in brain morphometry may be different in individuals that are dependent on alcohol alone and individuals dependent on alcohol and other substances. We examined subcortical brain volumes in 37 individuals with alcohol dependence only (ADO), 37 individuals with polysubstance use disorder (PS) and 37 healthy control participants (HC). Participants underwent a structural MR scan and a model-based segmentation tool was used to measure the volume of 14 subcortical regions (bilateral thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala and nucleus accumbens). Compared to HC, ADO had smaller volume in the bilateral hippocampus, right nucleus accumbens and right thalamus. PS only had volume reductions in the bilateral thalamus compared to HC. PS had a larger right caudate compared to ADO. Subcortical volume was negatively associated with drinking measures only in the ADO group. This study confirms the association between alcohol dependence and reductions in subcortical brain volume. It also suggests that polysubstance use interacts with alcohol use to produce limited subcortical volume reduction and at least one region of subcortical volume increase. These findings indicate that additional substance use may mask damage through inflammation or may function in a protective manner, shielding subcortical regions from alcohol-induced damage.

Profile of Class I Histone Deacetylases (HDAC) by Human Dendritic Cells after Alcohol Consumption and In Vitro Alcohol Treatment and Their Implication in Oxidative Stress: Role of HDAC Inhibitors Trichostatin A and Mocetinostat.

Epigenetic mechanisms have been shown to play a role in alcohol use disorders (AUDs) and may prove to be valuable therapeutic targets. However, the involvement of histone deacetylases (HDACs) on alcohol-induced oxidative stress of human primary monocyte-derived dendritic cells (MDDCs) has not been elucidated. In the current study, we took a novel approach combining ex vivo, in vitro and in silico analyses to elucidate the mechanisms of alcohol-induced oxidative stress and role of HDACs in the periphery. ex vivo and in vitro analyses of alcohol-modulation of class I HDACs and activity by MDDCs from self-reported alcohol users and non-alcohol users was performed. Additionally, MDDCs treated with alcohol were assessed using qRT-PCR, western blot, and fluorometric assay. The functional effects of alcohol-induce oxidative stress were measured in vitro using PCR array and in silico using gene expression network analysis. Our findings show, for the first time, that MDDCs from self-reported alcohol users have higher levels of class I HDACs compare to controls and alcohol treatment in vitro differentially modulates HDACs expression. Further, HDAC inhibitors (HDACi) blocked alcohol-induction of class I HDACs and modulated alcohol-induced oxidative stress related genes expressed by MDDCs. In silico analysis revealed new target genes and pathways on the mode of action of alcohol and HDACi. Findings elucidating the ability of alcohol to modulate class I HDACs may be useful for the treatment of alcohol-induced oxidative damage and may delineate new potential immune-modulatory mechanisms.

Extracellular ATP protects pancreatic duct epithelial cells from alcohol-induced damage through P2Y1 receptor-cAMP signal pathway.

Extracellular adenosine-5'-triphosphate (ATP) regulates cell death and survival of neighboring cells. The detailed effects are diverse depending on cell types and extracellular ATP concentration. We addressed the effect of ATP on ethanol-induced cytotoxicity in epithelial cells, the cell type that experiences the highest concentrations of alcohol. Using pancreatic duct epithelial cells (PDEC), we found that a micromolar range of ATP reverses all intracellular toxicity mechanisms triggered by exceptionally high doses of ethanol and, thus, improves cell viability dramatically. Out of the many purinergic receptors expressed in PDEC, the P2Y1 receptor was identified to mediate the protective effect, based on pharmacological and siRNA assays. Activation of P2Y1 receptors increased intracellular cyclic adenosine monophosphate (cAMP). The protective effect of ATP was mimicked by forskolin and 8-Br-cAMP but inhibited by a protein kinase A (PKA) inhibitor, H-89. Finally, ATP reverted leakiness of PDEC monolayers induced by ethanol and helped to maintain epithelial integrity. We suggest that purinergic receptors reduce extreme alcohol-induced cell damage via the cAMP signal pathway in PDEC and some other types of cells.

Physiological basis of the pathogenesis of alcohol-induced skeletal muscle injury

Alcohol-induced muscle damage (AIMD) is an umbrella term that includes all forms of alcoholic myopathy developing in acute or chronic alcohol intoxication. The most common form of destruction of skeletal muscles in alcoholism is chronic alcoholic myopathy, which develops independently of other alcohol-induced disorders, such as polyneuropathy, the malabsorption syndrome, and liver damage, but may be combined with them. The atrophy of muscle fibers underlies skeletal muscle destruction in chronic AIMD. Type II muscle fibers are affected to a greater degree than type I muscle fibers. To date, the pathogenesis of chronic alcoholic myopathy has been studied insufficiently. The imbalance between protein synthesis and proteolysis, as well as increased apoptosis rate, is discussed.

Increased levels of the acetaldehyde-derived DNA adduct N 2-ethyldeoxyguanosine in oral mucosa DNA from Rhesus monkeys exposed to alcohol.

Alcohol is a human carcinogen. A causal link has been established between alcohol drinking and cancers of the upper aerodigestive tract, colon, liver and breast. Despite this established association, the underlying mechanisms of alcohol-induced carcinogenesis remain unclear. Various mechanisms may come into play depending on the type of cancer; however, convincing evidence supports the concept that ethanol's major metabolite acetaldehyde may play a major role. Acetaldehyde can react with DNA forming adducts which can serve as biomarkers of carcinogen exposure and potentially of cancer risk. The major DNA adduct formed from this reaction is N (2)-ethylidenedeoxyguanosine, which can be quantified as its reduced form N (2)-ethyl-dG by LC-ESI-MS/MS. To investigate the potential use of N (2)-ethyl-dG as a biomarker of alcohol-induced DNA damage, we quantified this adduct in DNA from the oral, oesophageal and mammary gland tissues from rhesus monkeys exposed to alcohol drinking over their lifetimes and compared it to controls. N (2)-Ethyl-dG levels were significantly higher in the oral mucosa DNA of the exposed animals. Levels of the DNA adduct measured in the oesophageal mucosa of exposed animals were not significantly different from controls. A correlation between the levels measured in the oral and oesophageal DNA, however, was observed, suggesting a common source of formation of the DNA adducts. N (2) -Ethyl-dG was measured in mammary gland DNA from a small cohort of female animals, but no difference was observed between exposed animals and controls. These results support the hypothesis that acetaldehyde induces DNA damage in the oral mucosa of alcohol-exposed animals and that it may play role in the alcohol-induced carcinogenic process. The decrease of N (2)-ethyl-dG levels in exposed tissues further removed from the mouth also suggests a role of alcohol metabolism in the oral cavity, which may be considered separately from ethanol liver metabolism in the investigation of ethanol-related cancer risk.

Sex differences in substance use disorders: focus on side effects.

Although sex differences in several aspects of substance use disorders (SUDs) have been identified, less is known about the importance of possible sex differences in side effects induced by substances of abuse or by medications used to treat SUDs. In the SUD field, the perception of certain subjective effects are actively sought, while all other manifestations might operationally be considered side effects. This article was aimed at reviewing sex differences in side effects induced by alcohol, nicotine, heroin, marijuana and cocaine and by medications approved for alcohol, nicotine and heroin use disorders. A large body of evidence suggests that women are at higher risk of alcohol-induced injury, liver disease, cardiomyopathy, myopathy, brain damages and mortality. The risk of tobacco-induced coronary heart disease, lung disease and health problems is higher for women than for men. Women also experience greater exposure to side effects induced by heroin, marijuana and cocaine. In addition, women appear to be more vulnerable to the side effects induced by medications used to treat SUDs. Patients with SUDs should be advised that the risk of developing health problems may be higher for women than for men after consumption of the same amount of substances of abuse. Doses of medications for SUD women should be adjusted at least according to body weight. The sex differences observed also indicate an urgent need to recruit adequate numbers of female subjects in pre-clinical and clinical studies to improve our knowledge about SUDs in women.

Beneficial effects of chlorogenic acid on alcohol-induced damage in PC12 cells.

As one of the most commonly abused psychotropic substances, ethanol exposure has deleterious effects on the central nervous system (CNS). The most detrimental results of ethanol exposure during development are the loss of neurons in brain regions such as the hippocampus and neocortex, which may be related to the apoptosis and necrosis mediated by oxidative stress. Recent studies indicated that a number of natural drugs from plants play an important role in protection of nerve cells from damage. Among these, it has been reported that chlorogenic acid (CA) has neuroprotective effects against oxidative stress. Thus, it may play some beneficial effects on ethanol-induced neurotoxicity. However, the effects of CA on ethanol-induced nerve damage remain unclear. In order to investigate the protective effects of CA on alcohol-induced apoptosis in rat pheochromocytoma PC12 cells, in the present study, cell viability and the optimal dosage of CA were first quantified by MTT assay. Then, the cell apoptosis and cell cycle were respectively investigated by Hoechst 33258 staining and flow cytometer (FCM). To further clarify the possible mechanism, followed with the test of mitochondria transmembrane potential with Rhodamine 123 (Rho 123) staining, the expression of Bcl-2, Capase-3 and growth associated protein-43 (GAP-43) were analyzed by immunofluorescence assay separately. The results showed that treatment with 500 mM alcohol decreased the cell viability and then significantly induced apoptosis in PC12 cells. However, when pretreated with different concentrations of CA (1, 5, 10, 50 μM), cell viability increased in different degree. Comparatively, CA with the concentration of 10 μM most effectively promoted the proliferation of damaged cells, increased the distribution ratio of the cells at the G2/M and S phases, and enhanced mitochondria transmembrane potential. This appears to be in agreement with up-regulation of the expression of Bcl-2 and GAP-43, and down-regulation of the expression of Capsae-3. Taken together, CA can increase cell viability and promote cell differentiation by preventing alcohol-induced cell from apoptosis. The mechanism may be related to the enhancement of the expression of GAP-43 and the inhibition of mitochondrial apoptotic pathway including promotion of mitochondria transmembrane potential, up-regulation of the expression of Bcl-2, and down-regulation of the expression of Capsae-3.

Fisetin protects liver from binge alcohol-induced toxicity by mechanisms including inhibition of matrix metalloproteinases (MMPs) and oxidative stress

Alcohol consumption is an addictive disorder causing hepatic steatosis, fibrosis and cirrhosis. The protective effect of fisetin, a bioflavonoid, present in foods like strawberries, apples, persimmons, grapes and onions was studied on murine model of acute alcohol-induced hepatotoxicity. Five doses of 50% ethanol p.o. (10 ml/kg body weight) every 12 hours was used to induce hepatotoxicity in mice. Liver function, oxidative stress, histological changes, mitochondrial function, pro-inflammatory markers, collagen content, and matrix metalloproteinases were assessed. Alcohol treatment produced a significant increase in the oxidative stress markers, disturbed the mitochondrial function, matrix metalloproteinases activities and also induced histological changes in liver tissue. Pre-treatment with fisetin (5 and 10 mg/kg) restored the alcohol-induced alterations in liver function, antioxidant defence, histological changes, mitochondrial respiratory enzymes and matrix metalloproteinases activities. Thus, fisetin has the potential to ameliorate alcohol-induced hepatic damage and may be used as an adjuvant in the treatment of alcohol-induced hepatotoxicity.

Analysis of alcohol-induced DNA damage in Escherichia coli by visualizing single genomic DNA molecules.

Consumption of alcohol injures DNA, and such damage is considered to be a primary cause for the development of cancer and many other diseases essentially due to reactive oxygen species generated from alcohol. To sensitively detect alcohol-induced DNA lesions in a biological system, we introduced a novel analytical platform for visualization of single genomic DNA molecules using E. coli. By fluorescently labelling the DNA lesions, our approach demonstrated, with the highest sensitivity, that we could count the number of DNA lesions induced by alcohol metabolism in a single bacterial cell. Moreover, our results showed a linear relationship between ethanol concentration and the number of DNA lesions: 0.88 lesions per 1% ethanol. Using this approach, we quantitatively analysed the DNA damage induced by exposure to alcoholic beverages such as beer (5% ethanol), rice wine (13%), soju (20%), and whisky (40%).

Alcohol and the Intestine.

Alcohol abuse is a significant contributor to the global burden of disease and can lead to tissue damage and organ dysfunction in a subset of alcoholics. However, a subset of alcoholics without any of these predisposing factors can develop alcohol-mediated organ injury. The gastrointestinal tract (GI) could be an important source of inflammation in alcohol-mediated organ damage. The purpose of review was to evaluate mechanisms of alcohol-induced endotoxemia (including dysbiosis and gut leakiness), and highlight the predisposing factors for alcohol-induced dysbiosis and gut leakiness to endotoxins. Barriers, including immunologic, physical, and biochemical can regulate the passage of toxins into the portal and systemic circulation. In addition, a host of environmental interactions including those influenced by circadian rhythms can impact alcohol-induced organ pathology. There appears to be a role for therapeutic measures to mitigate alcohol-induced organ damage by normalizing intestinal dysbiosis and/or improving intestinal barrier integrity. Ultimately, the inflammatory process that drives progression into organ damage from alcohol appears to be multifactorial. Understanding the role of the intestine in the pathogenesis of alcoholic liver disease can pose further avenues for pathogenic and treatment approaches.

Transient and 2-Dimensional Shear-Wave Elastography Provide Comparable Assessment of Alcoholic Liver Fibrosis and Cirrhosis

Alcohol abuse causes half of all deaths from cirrhosis in the West, but few tools are available for noninvasive diagnosis of alcoholic liver disease. We evaluated 2 elastography techniques for diagnosis of alcoholic fibrosis and cirrhosis; liver biopsy with Ishak score and collagen-proportionate area were used as reference. We performed a prospective study of 199 consecutive patients with ongoing or prior alcohol abuse, but without known liver disease. One group of patients had a high pretest probability of cirrhosis because they were identified at hospital liver clinics (in Southern Denmark). The second, lower-risk group, was recruited from municipal alcohol rehabilitation centers and the Danish national public health portal. All subjects underwent same-day transient elastography (FibroScan), 2-dimensional shear wave elastography (Supersonic Aixplorer), and liver biopsy after an overnight fast. Transient elastography and 2-dimensional shear wave elastography identified subjects in each group with significant fibrosis (Ishak score ≥3) and cirrhosis (Ishak score ≥5) with high accuracy (area under the curve ≥0.92). There was no difference in diagnostic accuracy between techniques. The cutoff values for optimal identification of significant fibrosis by transient elastography and 2-dimensional shear wave elastography were 9.6 kPa and 10.2 kPa, and for cirrhosis 19.7 kPa and 16.4 kPa. Negative predictive values were high for both groups, but the positive predictive value for cirrhosis was >66% in the high-risk group vs approximately 50% in the low-risk group. Evidence of alcohol-induced damage to cholangiocytes, but not ongoing alcohol abuse, affected liver stiffness. The collagen-proportionate area correlated with Ishak grades and accurately identified individuals with significant fibrosis and cirrhosis. In a prospective study of individuals at risk for liver fibrosis due to alcohol consumption, we found elastography to be an excellent tool for diagnosing liver fibrosis and for excluding (ruling out rather than ruling in) cirrhosis.

Potential Role of the Gut/Liver/Lung Axis in Alcohol-Induced Tissue Pathology.

Both Alcoholic Liver Disease (ALD) and alcohol-related susceptibility to acute lung injury are estimated to account for the highest morbidity and mortality related to chronic alcohol abuse and, thus, represent a focus of intense investigation. In general, alcohol-induced derangements to both organs are considered to be independent and are often evaluated separately. However, the liver and lung share many general responses to damage, and specific responses to alcohol exposure. For example, both organs possess resident macrophages that play key roles in mediating the immune/inflammatory response. Additionally, alcohol-induced damage to both organs appears to involve oxidative stress that favors tissue injury. Another mechanism that appears to be shared between the organs is that inflammatory injury to both organs is enhanced by alcohol exposure. Lastly, altered extracellular matrix (ECM) deposition appears to be a key step in disease progression in both organs. Indeed, recent studies suggest that early subtle changes in the ECM may predispose the target organ to an inflammatory insult. The purpose of this chapter is to review the parallel mechanisms of liver and lung injury in response to alcohol consumption. This chapter will also explore the potential that these mechanisms are interdependent, as part of a gut-liver-lung axis.

Assessing the aftermath of an alcohol-fueled weekend: Alcohol-induced DNA damage and faulty repairs may raise the risk of certain cancers, but resveratrol could provide some relief.

Assessing the aftermath of an alcohol-fueled weekend: Alcohol-induced DNA damage and faulty repairs may raise the risk of certain cancers, but resveratrol could provide some relief.

Protection of Gastrointestinal Mucosa from Acute Heavy Alcohol Consumption: The Effect of Berberine and Its Correlation with TLR2, 4/IL1β-TNFα Signaling.

The purpose of the present study is to confirm the protective effect of berberine (BBR) on gastrointestinal injury caused by acute heavy alcohol exposure, an effect that has not been reported previously. Our research details how BBR protects against gastrointestinal injuries from acute alcohol exposure using both in vivo and in vitro experiments. Acute high alcohol concentrations lead to obvious damage to the gastrointestinal mucosa, resulting in necrosis of the intestinal mucosa. Oral administration of BBR was able to significantly reduce this alcohol-induced damage, inhibit increases of alcohol-induced TNFα and IL-1β expression in gastrointestinal mucosa as well as their upstream signals TLR2 and TLR4, and regulate cytokines that modulate tight junctions. Alcohol consumption is a popular human social behavior worldwide, and the present study reports a comprehensive mechanism by which BBR protects against gastrointestinal injuries from alcohol stress, providing people with a novel application of BBR.

Parkin regulates mitophagy and mitochondrial function to protect against alcohol-induced liver injury and steatosis in mice.

Alcoholic liver disease claims two million lives per year. We previously reported that autophagy protected against alcohol-induced liver injury and steatosis by removing damaged mitochondria. However, the mechanisms for removal of these mitochondria are unknown. Parkin is an evolutionarily conserved E3 ligase that is recruited to damaged mitochondria to initiate ubiquitination of mitochondrial outer membrane proteins and subsequent mitochondrial degradation by mitophagy. In addition to its role in mitophagy, Parkin has been shown to have other roles in maintaining mitochondrial function. We investigated whether Parkin protected against alcohol-induced liver injury and steatosis using wild-type (WT) and Parkin knockout (KO) mice treated with alcohol by the acute-binge and Gao-binge (chronic plus acute-binge) models. We found that Parkin protected against liver injury in both alcohol models, likely because of Parkin's role in maintaining a population of healthy mitochondria. Alcohol caused greater mitochondrial damage and oxidative stress in Parkin KO livers compared with WT livers. After alcohol treatment, Parkin KO mice had severely swollen and damaged mitochondria that lacked cristae, which were not seen in WT mice. Furthermore, Parkin KO mice had decreased mitophagy, β-oxidation, mitochondrial respiration, and cytochrome c oxidase activity after acute alcohol treatment compared with WT mice. Interestingly, liver mitochondria seemed able to adapt to alcohol treatment, but Parkin KO mouse liver mitochondria had less capacity to adapt to Gao-binge treatment compared with WT mouse liver mitochondria. Overall, our findings indicate that Parkin is an important mediator of protection against alcohol-induced mitochondrial damage, steatosis, and liver injury.

Chronic ethanol exposure combined with high fat diet up-regulates P2X7 receptors that parallels neuroinflammation and neuronal loss in C57BL/6J mice

The present investigation tested the role of ATP-activated P2X7 receptors (P2X7Rs) in alcohol-induced brain damage using a model that combines intragastric (iG) ethanol feeding and high fat diet in C57BL/6J mice (Hybrid). The Hybrid paradigm caused increased levels of pro-inflammatory markers, changes in microglia and astrocytes, reduced levels of neuronal marker NeuN and increased P2X7R expression in ethanol-sensitive brain regions. Observed changes in P2X7R and NeuN expression were more pronounced in Hybrid paradigm with inclusion of additional weekly binges. In addition, high fat diet during Hybrid exposure aggravated the increase in P2X7R expression and activation of glial cells.