Acute alcohol consumption attenuates interleukin-8 (IL-8) and monocyte chemoattractant peptide-1 (MCP-1) induction in response to ex vivo stimulation

Circulating Immune and Endocrine Markers in Currently Drinking and Abstinent Individuals With Alcohol Use Disorder and Controls

Alcohol use disorder (AUD) is associated with changes in endocrine and immune system function. This study is a secondary analysis aimed at investigating changes in circulating immune and endocrine biomarkers in blood samples from three groups: (1) healthy controls (HC, N = 12), (2) AUD-currently drinking, nontreatment seeking (CD, N = 9), and (3) AUD-abstinent, treatment-seeking (AB, N = 10; abstinent for at least 6 weeks). We hypothesized that both immune and endocrine biomarker concentrations would be different in AUD groups compared to healthy controls. Immune biomarkers included IL-8, IL-18, CCL2, TNF-α, IL-1RA, IL-6, and IL-10. Endocrine biomarkers included brain-derived neurotrophic factor (BDNF), glucagon-like peptide 1 (GLP-1), ghrelin, gastric inhibitory peptide (GIP), growth hormone, leptin, and insulin. Biomarker concentrations were compared between the three groups while controlling for age and sex, and associations between biomarker concentrations and behavioral measures were explored. IL-8 concentrations were elevated in AB compared to CD and HC (F(2,29) = 6.33, p = 0.006, ƞp 2 = 0.318). BDNF concentrations were lower in AB compared to HC (F(2,30) = 4.34, p = 0.02, ƞp 2 = 0.266). GLP-1 concentrations were higher in AB compared to HC (F(2,25) = 4.22, p = 0.03, ƞp 2 = 0.287). Exploratory analyses in combined groups showed that measures of past drinking, AUD severity, and anxiety/depression positively correlated with IL-18 and TNF-α and negatively correlated with BDNF. These results demonstrate that circulating concentrations of both immune and endocrine proteins are altered in abstinent individuals with a history of severe AUD (AB group) compared to healthy controls. In contrast, no group differences were observed for any biomarker between the nontreatment seeking, currently drinking people with AUD and the HC group. Our findings highlight the importance of accounting for AUD severity, comorbidities, and treatment-seeking status, especially when studying alcohol-related biomarkers.

To Eat or Not to Eat?-Food Safety Aspects of Essential Metals in Seafood

The popularity of seafoods is high due to their superb dietary properties and healthy composition. However, it is crucial to understand whether they adequately contribute to our essential nutritional needs. Small amounts of essential metals are indispensable in the human body to proper physiological functioning; their deficiency can manifest in various sets of symptoms that can only be eliminated with their intake during treatment or nutrition. However, the excessive consumption of metals can induce undesirable effects, or even toxicosis. Shellfish, oyster, and squid samples were collected directly from a fish market. After sample preparation, the concentration of essential metals (cobalt, chromium, copper, manganese, molybdenum, nickel, and zinc) was detected by Inductively Coupled Plasma Optical Emission Spectrometry. The results were analyzed statistically using ANOVA and two-sample t-tests. The average concentration of the investigated essential elements and the calculated burden based on the consumption were below the Recommended Dietary Allowances and Tolerable Upper Intake Levels. Based on these results, the trace element contents of the investigated seafoods do not cover the necessary recommended daily intake of them, but their consumption poses no health hazard due to their low levels.

Production performance, egg quality and some blood parameters of heat-stressed laying hens as affected by dietary supplemental Vit B6, Mg and Zn

OBJECTIVES

The effects of dietary supplements, including magnesium sulfate (Mg), zinc oxide (Zn) and vitamin B6 (Vit B6), on the performance of laying hens reared under normal (NC) and heat-stress (HSC) conditions were investigated.

MATERIAL AND METHODS

A total of 288 30-week-old Lohmann LSL-Lite laying hens were randomly divided into 48 cages and assigned to receive one of the eight diets with six replicates and six hens per replicate, based on a 2 × 2 × 2 factorial arrangement of treatments. Dietary supplements, including two levels (0 & 600 mg/kg) of Mg, two levels (0 & 30 mg/kg) of Zn and two levels (0 & 8 mg/kg) of Vit B6, in normal and heat-stress conditions, were tested at 30-40 and 41-45 weeks of age, respectively.

RESULTS

In the Vit B6 group, a decrease in feed intake (FI), egg production (EP), albumin, Zn, Fe and Mg, and an increase in triglyceride and insulin in HSC were observed, in addition to a decrease in cholesterol and an increase in egg weight (EW) in NC. Supplemental Mg decreased EP, blood triglycerides and copper in NC, and Zn, Fe and Mg in HSC as well. Feeding Zn, increased egg shape index, total protein and copper in addition to yolk index in NC and Fe in HSC. EWs were higher in hens supplemented with Vit B6+Mg in HSC. Increased insulin and decreased glutathione peroxidase activity were detected with the Vit B6+Zn compared to feeding either Vit B6 or Zn in HSC.

CONCLUSIONS

The results indicated Vit B6 could improve EWs and suppress blood cholesterol in NC. Zn improved the egg shape index in NC.

Immune Response to an Acute Moderate Dose of Alcohol in Healthy Young Adults

Prior research on alcohol and the immune system has tended to focus on binge doses or chronic heavy drinking. The aim of this single-session preliminary study was to characterize immune response to moderate alcohol (0.60 g alcohol per kilogram body weight) in healthy, nonchronic drinkers. The sample (N = 11) averaged 26.6 years of age and was balanced in gender. Plasma samples were collected at baseline and 1, 2 and 3 hours postconsumption. Markers of microbial translocation [lipopolysaccharide (LPS)] and innate immune response [LPS-binding protein (LBP), soluble cluster of differentiation 14 (sCD14), and selected cytokines] were measured using immunoassays. Participants completed self-report questionnaires on subjective alcohol response and craving. Linear mixed models were used to assess changes in biomarkers and self-report measures. Breath alcohol concentration peaked at 0.069 ± 0.008% 1 hour postconsumption. LPS showed a significant linear decrease. LBP and sCD14 showed significant, nonlinear (U-shaped) trajectories wherein levels decreased at 1 hour then rebounded by 3 hours. Of nine cytokines tested, only MCP-1 and IL-8 were detectable in ≥50% of samples. IL-8 did not change significantly. MCP-1 showed a significant linear decrease and also accounted for significant variance in alcohol craving, with higher levels associated with stronger craving. Results offer novel evidence on acute immune response to moderate alcohol. Changes in LBP and sCD14, relative to LPS, may reflect their role in LPS clearance. Results also support further investigation into the role of MCP-1 in alcohol craving. Limitations include small sample size and lack of a placebo condition.

Evaluation of nutritional value and antioxidant activity of root and leaf of Samarakhai (Byttneria herbacea Roxb.): An extra pharmacopoeial herb

Background

Samarakhai (Byttneria herbacea Roxb.), family Sterculiaceae, is one of the reputed folklore medicinal herbs, found in many parts of India. Although consumed as a vegetable since long time, its root and leaves are not yet reported for its nutritive value and antioxidant activities.

Aim

The aim of this study was to evaluate nutritional value and antioxidant potential of root and leaf of B. herbacea Roxb.

Materials and methods

Nutritional parameters such as carbohydrate, fat, protein, energy value, calcium, iron, zinc, manganese, phosphorus and vitamin C were evaluated. Antioxidant activity was evaluated through three test methods, i.e., 1,1-diphenyl-2-picrylhydrazyl, ferric-reducing antioxidant power (FRAP) and phosphomolybdenum assay.

Results

B. herbacea roots and leaves showed the presence of total carbohydrate 46.39 g/100 g and 40.12 g/100 g, total fat 0.63 g/100 g and 1.20 g/100 g, true protein 11.46 g/100 g and 10.49 g/100 g, energy content 237.07 kcal/100 g and 213.24 kcal/100 g, iron 821.10 ppm and 889.64 ppm, zinc 9.2 ppm and 47.98 ppm, manganese 329.86 ppm and 474.59 ppm, phosphorus 0.40 ppm and 0.10 ppm and calcium 4856.84 ppm and 14964.49 ppm, respectively. The half-maximal inhibitory concentration values of the methanol extract of root, leaf and ascorbic acid were found to be 217.25 µg/ml, 131.42 µg/ml and 178.88 µg/ml, respectively. In FRAP assay, antioxidant activity of methanol extract of leaf (129.15 µM) was found to be more than root (73.13 µM).

Conclusion

B. herbacea root contains high amount of true protein, carbohydrate and energy value, while micronutrients such as iron, zinc, manganese and calcium are more in its leaf. Both roots and leaves exhibited potent antioxidant activity where the leaves possess more values than the roots.

Binge alcohol consumption 18 h after induction of sepsis in a mouse model causes rapid overgrowth of bacteria, a cytokine storm, and decreased survival

Alcohol abuse increases vulnerability to infections and infection-related mortality. In previous studies, we found that acute alcohol abuse in a binge-drinking model in mice decreased resistance to bacterial sepsis when alcohol was administered near the time of bacterial challenge. In the present study, we investigated the effects of alcohol administered later in the course of sepsis (18 h after injection of Escherichia coli). Our working hypothesis was that decreased production of cytokines caused by alcohol at this time would actually improve survival, because overproduction of pro-inflammatory mediators is thought to be the proximate cause of mortality in sepsis. Unexpectedly, administration of alcohol late in the course of sepsis led to a rapid increase in the number of viable bacteria in the peritoneal cavity. Significant increases in the concentrations of several cytokines and chemokines coincided with the increased number of bacteria in alcohol-treated mice and decreased survival time. These results demonstrated our working hypothesis to be incorrect, and reiterated the complexity of sepsis. Hypothermia is a consistent feature in this model of sepsis. In control mice (E. coli only), body temperature was near normal by 18 h or 21 h after administration of E. coli, but in mice treated with alcohol 18 h after E. coli, hypothermia was significant 3 h later and ultimately mortality was significantly increased. However, counteracting the hypothermic effect of alcohol by external warming of mice led to earlier mortality, demonstrating that hypothermia was not the major cause of mortality. These results, along with previous results from studies in which alcohol was given before initiation of sepsis, suggest that decreased cytokine and chemokine production may not be the key effect of alcohol that decreases resistance to sepsis. It seems more likely that suppression of mechanisms by which macrophages and neutrophils kill bacteria is critical, and this can occur even in the presence of high levels of cytokines and chemokines.

Effects of chronic alcohol exposure on ischemia-reperfusion-induced acute kidney injury in mice: the role of β-arrestin 2 and glycogen synthase kinase 3

Little is known about the effects of chronic alcohol intake on the outcome of acute kidney injury (AKI). Hence, we examined the effects of chronic alcohol intake on the development of renal fibrosis following AKI in an animal model of bilateral renal ischemia–reperfusion (IR) injury. We first found that chronic alcohol exposure exacerbated bilateral IR-induced renal fibrosis and renal function impairment. This phenomenon was associated with increased bilateral IR-induced extracellular matrix deposition and an increased myofibroblast population as well as increased bilateral IR-induced expression of fibrosis-related genes in the kidneys. To explore the mechanisms underlying this phenomenon, we showed that chronic alcohol exposure enhanced β-arrestin 2 (Arrb2) expression and Akt and glycogen synthase kinase-3 (GSK3)β activation in the kidneys. Importantly, pharmacological GSK3 inhibition alleviated bilateral IR-induced renal fibrosis and renal function impairment. Furthermore, we demonstrated that Arrb2^−/− mice exhibited resistance to IR-induced renal fibrosis and renal function impairment following chronic alcohol exposure, and these effects were associated with attenuated GSK3β activation in the kidneys. Taken together, our results suggest that chronic alcohol exposure may potentiate AKI via β-arrestin 2/Akt/GSK3β-mediated signaling in the kidney.

Effect of alcohol after muscle-damaging resistance exercise on muscular performance recovery and inflammatory capacity in women

PURPOSE

To investigate the effect of acute alcohol consumption on muscular performance recovery, assessed by maximal torque production, and on inflammatory capacity, assessed by lipopolysaccharide (LPS)-stimulated cytokine production, following muscle-damaging resistance exercise in women.

METHODS

Thirteen recreationally resistance-trained women completed two identical exercise bouts (300 maximal single-leg eccentric leg extensions) followed by alcohol (1.09 g ethanol kg^-1 fat-free body mass) or placebo ingestion. Blood was collected before (PRE), and 5 (5 h-POST), 24 (24 h-POST), and 48 (48 h-POST) hours after exercise and analyzed for LPS-stimulated cytokine production (TNF-α, IL-1β, IL-6, and IL-8 and IL-10). Maximal torque production (concentric, eccentric, isometric) was measured for each leg at PRE, 24 h-POST, and 48 h-POST.

RESULTS

Although the exercise bout increased LPS-stimulated production of TNF-α (%change from PRE: 5 h-POST 109%; 24 h-POST 49%; 48 h-POST 40%) and decreased LPS-stimulated production of IL-8 (5 h-POST -40%; 24 h-POST -50%; 48 h-POST: -43%) and IL-10 (5 h-POST: -37%; 24 h-POST -32%; 48 h-POST -31%), consuming alcohol after exercise did not affect this response. Regardless of drink condition, concentric, eccentric, and isometric torque produced by the exercised leg were lower at 24 h-POST (concentric 106 ± 6 Nm, eccentric 144 ± 9 Nm, isometric 128 ± 8 Nm; M ± SE) compared to PRE (concentric 127 ± 7 Nm, eccentric 175 ± 11 Nm, isometric 148 ± 8 Nm). Eccentric torque production was partially recovered and isometric torque production was fully recovered by 48 h-POST.

CONCLUSIONS

Alcohol consumed after muscle-damaging resistance exercise does not appear to affect inflammatory capacity or muscular performance recovery in resistance-trained women. Combined with previous findings in men, these results suggest a gender difference regarding effects of alcohol on exercise recovery.

The effect of post‑resistance exercise alcohol ingestion on lipopolysaccharide‑stimulated cytokines

PURPOSE

To examine the effect of post-resistance exercise alcohol ingestion on lipopolysaccharide (LPS)-stimulated production of IFNγ, TNF-α, IL-1β, IL-6, IL-8, and IL-10.

METHODS

Recreationally resistance-trained men (n = 10, 25 ± 3 year, 177 ± 7 cm, 83.8 ± 15.7 kg, 14.8 ± 8.5% body fat) and women (n = 8, 23 ± 2 year, 161 ± 3 cm, 59.5 ± 6.0 kg, 26.5 ± 3.0% body fat) completed two identical heavy back squat sessions (6 × 10 at 80% 1 repetition maximum) followed by ingestion of either an alcohol (ALC; 1.09 g ethanol · kg fat-free mass(-1)) or water (PLA) drink. Blood samples were collected before exercise (PRE), and at 3 h (3 h), and 5 h (5 h) after exercise, stimulated with LPS, and analyzed for IFNγ, TNF-α, IL-1β, IL-6, IL-8, and IL-10 concentrations.

RESULTS

There were no drink conditions by time effects for IFNγ, TNF-α, IL-1β, or IL-10. Regardless of condition, resistance exercise induce an increase in IFNγ, TNF-α, and IL-1β at 5 h compared to PRE but a decrease in IL-10 at 3 and 5 h compared to PRE. For ALC, IL-8 was reduced at 5 h compared to PLA. From PRE to 3 h, IL-6 was reduced for ALC but increased for PLA; resistance exercise induced an increase in IL-6 for both conditions at 5 h.

CONCLUSIONS

Heavy resistance exercise increased production of IFNγ, TNF-α, IL-1β, and Il-6 and decreased production of IL-10. Alcohol ingestion after resistance exercise affected aspects of inflammatory capacity (IL-6 and IL-8 production). It appears that some of the effects previously observed for alcohol ingestion alone on the LPS-stimulated cytokine production were overwhelmed by the response to resistance exercise.

Ethanol Inhibits High-Affinity Immunoglobulin E Receptor (FcεRI) Signaling in Mast Cells by Suppressing the Function of FcεRI-Cholesterol Signalosome

Ethanol has multiple effects on biochemical events in a variety of cell types, including the high-affinity immunoglobulin E receptor (FcεRI) signaling in antigen-activated mast cells. However, the underlying molecular mechanism remains unknown. To get better understanding of the effect of ethanol on FcεRI-mediated signaling we examined the effect of short-term treatment with non-toxic concentrations of ethanol on FcεRI signaling events in mouse bone marrow-derived mast cells. We found that 15 min exposure to ethanol inhibited antigen-induced degranulation, calcium mobilization, expression of proinflammatory cytokine genes (tumor necrosis factor-α, interleukin-6, and interleukin-13), and formation of reactive oxygen species in a dose-dependent manner. Removal of cellular cholesterol with methyl-β-cyclodextrin had a similar effect and potentiated some of the inhibitory effects of ethanol. In contrast, exposure of the cells to cholesterol-saturated methyl-β-cyclodextrin abolished in part the inhibitory effect of ethanol on calcium response and production of reactive oxygen species, supporting lipid-centric theories of ethanol action on the earliest stages of mast cell signaling. Further studies showed that exposure to ethanol and/or removal of cholesterol inhibited early FcεRI activation events, including tyrosine phosphorylation of the FcεRI β and γ subunits, SYK kinases, LAT adaptor protein, phospholipase Cγ, STAT5, and AKT and internalization of aggregated FcεRI. Interestingly, ethanol alone, and particularly in combination with methyl-β-cyclodextrin, enhanced phosphorylation of negative regulatory tyrosine 507 of LYN kinase. Finally, we found that ethanol reduced passive cutaneous anaphylactic reaction in mice, suggesting that ethanol also inhibits FcεRI signaling under in vivo conditions. The combined data indicate that ethanol interferes with early antigen-induced signaling events in mast cells by suppressing the function of FcεRI-cholesterol signalosomes at the plasma membrane.

Acute immunomodulatory effects of binge alcohol ingestion

BACKGROUND

Blood alcohol is present in a third of trauma patients and has been associated with organ dysfunction. In both human studies and in animal models, it is clear that alcohol intoxication exerts immunomodulatory effects several hours to days after exposure, when blood alcohol is no longer detectable. The early immunomodulatory effects of alcohol while blood alcohol is still elevated are not well understood.

METHODS

Human volunteers achieved binge alcohol intoxication after high-dose alcohol consumption. Blood was collected for analysis prior to alcohol ingestion, and 20 min, 2 h, and 5 h after alcohol ingestion. Flow cytometry was performed on isolated peripheral blood mononuclear cells, and cytokine generation in whole blood was measured by enzyme-linked immunosorbent assay (ELISA) after 24-h stimulation with lipopolysaccharide (LPS) and phytohemagglutinin-M (PHA) stimulation.

RESULTS

An early pro-inflammatory state was evident at 20 min when blood alcohol levels were ∼130 mg/dL, which was characterized by an increase in total circulating leukocytes, monocytes, and natural killer cells. During this time, a transient increase in LPS-induced tumor necrosis factor (TNF)-α levels and enhanced LPS sensitivity occurred. At 2 and 5 h post-alcohol binge, an anti-inflammatory state was shown with reduced numbers of circulating monocytes and natural killer cells, attenuated LPS-induced interleukin (IL)-1β levels, and a trend toward increased interleukin (IL)-10 levels.

CONCLUSIONS

A single episode of binge alcohol intoxication exerted effects on the immune system that caused an early and transient pro-inflammatory state followed by an anti-inflammatory state.

Chronic alcohol exposure exacerbates inflammation and triggers pancreatic acinar-to-ductal metaplasia through PI3K/Akt/IKK

Pancreatic acinar-to-ductal metaplasia (ADM) has been identified as an initiating event that can progress to pancreatic intraepithelial neoplasia (PanIN) or pancreatic ductal adenocarcinoma (PDAC). Acini transdifferentiation can be induced by persistent inflammation. Notably, compelling evidence has emerged that chronic alcohol exposure may trigger an inflammatory response of macrophages/monocytes stimulated by endotoxins. In the present study, we aimed to evaluate the role of inflammation induced by chronic alcohol and lipopolysaccharide (LPS) exposure in the progression of pancreatic ADM, as well as to elucidate the possible mechanisms involved. For this purpose, cultured macrophages were exposed to varying doses of alcohol for 1 week prior to stimulation with LPS. Tumor necrosis factor-α (TNF-α) and regulated upon activation, normal T cell expression and secreted (RANTES) expression were upregulated in the intoxicated macrophages with activated nuclear factor-κB (NF-κB). Following treatment with the supernatant of intoxicated macrophages, ADM of primary acinar cells was induced. Furthermore, the expression of TNF-α and RANTES, as well as the phosphatidylinositol-3-kinase (PI3K)/protein kinase B(Akt)/inhibitory κB kinase (IKK) signaling pathway have been proven to be involved in the ADM of acinar cells. Moreover, Sprague-Dawley (SD) rats were employed to further explore the induction of pancreatic ADM by chronic alcohol and LPS exposure in vivo. At the end of the treatment period, a number of physiological parameters, such as body weight, liver weight and pancreatic weight were reduced in the exposed rats. Plasma alcohol concentrations and oxidative stress levels in the serum, as well as TNF-α and RANTES expression in monocytes were also induced following chronic alcohol and LPS exposure. In addition, pancreatic ADM was induced through the PI3K/Akt/IKK signaling pathway by the augmented TNF-α and RANTES expression levels in the exposed rats. Overall, we characterized the link between inflammation induced by chronic alcohol and LPS exposure and pancreatic ADM. However, the mechanisms behind the induction of pancreatic ADM warrant further investigation.

Moderate alcohol induces stress proteins HSF1 and hsp70 and inhibits proinflammatory cytokines resulting in endotoxin tolerance

Binge or moderate alcohol exposure impairs host defense and increases susceptibility to infection because of compromised innate immune responses. However, there is a lack of consensus on the molecular mechanism by which alcohol mediates this immunosuppression. In this study, we show that cellular stress proteins HSF1 and hsp70 play a mechanistic role in alcohol-mediated inhibition of the TLR4/MyD88 pathway. Alcohol exposure induced transcription factor HSF1 mRNA expression and DNA binding activity in primary human monocytes and murine macrophages. Furthermore, HSF1 target gene hsp70 mRNA and protein are upregulated by alcohol in monocytes. In vitro pre-exposure to moderate alcohol reduced subsequent LPS-induced NF-κB promoter activity and downstream TNF-α, IL-6 and IL-1β production in monocytes and macrophages, exhibiting endotoxin tolerance. Mechanistic analysis demonstrates that alcohol-induced HSF1 binds to the TNF-α promoter in macrophages at early time points, exerting transrepression and decreased TNF-α expression. Furthermore, association of hsp70 with NF-κB subunit p50 in alcohol-treated macrophages correlates with reduced NF-κB activation at later time points. Hsp70 overexpression in macrophages was sufficient to block LPS-induced NF-κB promoter activity, suggesting alcohol-mediated immunosuppression by hsp70. The direct crosstalk of hsp70 and HSF1 was further confirmed by the loss of alcohol-mediated endotoxin tolerance in hsp70- and HSF1-silenced macrophages. Our data suggest that alcohol-mediated activation of HSF1 and induction of hsp70 inhibit TLR4-MyD88 signaling and are required for alcohol-induced endotoxin tolerance. Using stress proteins as direct drug targets would be clinically relevant in alcohol abuse treatment and may serve to provide a better understanding of alcohol-mediated immunosuppression.

Health-related behaviors and effectiveness of trivalent inactivated versus live attenuated influenza vaccine in preventing influenza-like illness among young adults

BACKGROUND

Vaccination is the preferred preventive strategy against influenza. Though health behaviors are known to affect immunity and vaccine delivery modes utilize different immune processes, data regarding the preferred influenza vaccine type among adults endorsing specific health-related behaviors (alcohol use, tobacco use, and exercise level) are limited.

METHODS

The relative effectiveness of two currently available influenza vaccines were compared for prevention of influenza-like illness during 2 well-matched influenza seasons (2006/2007, 2008/2009) among US military personnel aged 18-49 years. Relative vaccine effectiveness was compared between those self-reporting and not reporting recent smoking history and potential alcohol problem, and by exercise level using Cox proportional hazard modeling adjusted for sociodemographic and military factors, geographic area, and other health behaviors.

RESULTS

28,929 vaccination events and 3936 influenza-like illness events over both influenza seasons were studied. Of subjects, 27.5% were smokers, 7.7% had a potential alcohol-related problem, 10.5% reported minimal exercise, and 4.4% reported high exercise levels. Overall, the risk of influenza-like illness did not significantly differ between live attenuated and trivalent inactivated influenza vaccine recipients (hazard ratio, 0.98; 95% confidence interval, 0.90-1.06). In the final adjusted model, the relative effectiveness of the 2 vaccine types did not differ by smoking status (p = 0.10), alcohol status (p = 0.21), or activity level (p = 0.11).

CONCLUSIONS

Live attenuated and trivalent inactivated influenza vaccines were similarly effective in preventing influenza-like illness among young adults and did not differ by health-related behavior status. Influenza vaccine efforts should continue to focus simply on delivering vaccine.

Effects of acute ethanol gavage on intestinal integrity after hemorrhage/resuscitation

BACKGROUND

In hemorrhagic shock with subsequent resuscitation (H/R), increased pro-inflammatory changes contribute to tissue injury and mortality in rodent models. Ethanol (EtOH) is assumed to modulate the inflammatory response and the subsequent organ injury after H/R. Therefore, we determined the contribution of acute ethanol gavage on intestinal inflammation and injury as well as survival after H/R in rats.

METHODS

Fourteen hours before H/R, female LEWIS rats were gavaged with single dose of EtOH or saline (5 g/kg, 30% EtOH, H/R_EtOH group or H/R_ctrl group). Then, rats were hemorrhaged to a mean arterial blood pressure of 30 ± 2 mmHg for 60 min and resuscitated. Control groups underwent surgical procedures and gavage without H/R (sham_ctrl group and sham_EtOH group). Tissue was harvested 2 h after resuscitation. Mortality was assessed 72 h after H/R.

RESULTS

Ethanol gavage increased survival after H/R from 20% to 80%, but amplified plasma alanineaminotransferase (ALT) release compared to saline gavage (2847 ± 406 vs. 1159 ± 200 IU/L, p < 0.05). Intestinal mucosal damage index, intestinal permeability, ileal myeloperoxidase levels as indicators of polymorphonuclear leukocyte (PMNL) infiltration and systemic IL-6 levels as well as ileal IL-6 and TNF gene expressions after H/R were reduced and partly restored after ethanol gavage when compared to the saline gavaged group after H/R.

CONCLUSIONS

Taken together, we propose that acute ethanol gavage prior to H/R 1) did not enhance intestinal mucosa injury after H/R and 2) suppressed the H/R-induced inflammatory response. Both findings seem to contribute to the ethanol-induced survival benefit after H/R in our model.

Acute alcohol intoxication reduces mortality, inflammatory responses and hepatic injury after haemorrhage and resuscitation in vivo

BACKGROUND AND PURPOSE

Haemorrhagic shock and resuscitation (H/R) induces hepatic injury, strong inflammatory changes and death. Alcohol intoxication is assumed to worsen pathophysiological derangements after H/R. Here, we studied the effects of acute alcohol intoxication on survival, liver injury and inflammation after H/R, in rats.

EXPERIMENTAL APPROACH

Rats were given a single oral dose of ethanol (5 g·kg(-1) , 30%) or saline (control), 12 h before they were haemorrhaged for 60 min and resuscitated (H/R). Sham groups received the same procedures without H/R. Measurements were made 2, 24 and 72 h after resuscitation. Survival was assessed 72 h after H/R.

KEY RESULTS

Ethanol increased survival after H/R three-fold and also induced fatty changes in the liver. H/R-induced liver injury was amplified by ethanol at 2 h but inhibited 24 h after H/R. Elevated serum IL-6 levels as well as hepatic IL-6 and TNF-α gene expression 2 h after H/R were reduced by ethanol. Ethanol enhanced serum IL-1β at 2 h, but did not affect increased hepatic IL-1β expression at 72 h after H/R. Local inflammatory markers, hepatic infiltration with polymorphonuclear leukocytes and intercellular adhesion molecule 1 expression decreased after ethanol compared with saline, following H/R. Ethanol reduced H/R-induced IκBα activation 2 h after H/R, and NF-κB-dependent gene expression of MMP9.

CONCLUSIONS AND IMPLICATIONS

Ethanol reduced H/R-induced mortality at 72 h, accompanied by a suppression of proinflammatory changes after H/R in ethanol-treated animals. Binge-like ethanol exposure modulated the inflammatory response after H/R, an effect that was associated with NF-κB activity.

Acute ethanol gavage attenuates hemorrhage/resuscitation-induced hepatic oxidative stress in rats

Acute ethanol intoxication increases the production of reactive oxygen species (ROS). Hemorrhagic shock with subsequent resuscitation (H/R) also induces ROS resulting in cellular and hepatic damage in vivo. We examined the role of acute ethanol intoxication upon oxidative stress and subsequent hepatic cell death after H/R. 14 h before H/R, rats were gavaged with single dose of ethanol or saline (5 g/kg, EtOH and ctrl; H/R_EtOH or H/R_ctrl, resp.). Then, rats were hemorrhaged to a mean arterial blood pressure of 30 ± 2 mmHg for 60 min and resuscitated. Two control groups underwent surgical procedures without H/R (sham_ctrl and sham_EtOH, resp.). Liver tissues were harvested at 2, 24, and 72 h after resuscitation. EtOH-gavage induced histological picture of acute fatty liver. Hepatic oxidative (4-hydroxynonenal, 4-HNE) and nitrosative (3-nitrotyrosine, 3-NT) stress were significantly reduced in EtOH-gavaged rats compared to controls after H/R. Proapoptotic caspase-8 and Bax expressions were markedly diminished in EtOH-gavaged animals compared with controls 2 h after resuscitation. EtOH-gavage increased antiapoptotic Bcl-2 gene expression compared with controls 2 h after resuscitation. iNOS protein expression increased following H/R but was attenuated in EtOH-gavaged animals after H/R. Taken together, the data suggest that acute EtOH-gavage may attenuate H/R-induced oxidative stress thereby reducing cellular injury in rat liver.

Role of acute ethanol exposure and TLR4 in early events of sepsis in a mouse model

Sepsis is a major cause of death worldwide. The associated risks and mortality are known to significantly increase on exposure to alcohol (chronic or acute). The underlying mechanisms of the association of acute ethanol ingestion and poor prognosis of sepsis are largely unknown. The study described here was designed to determine in detail the role of ethanol and TLR4 in the pathogenesis of the sepsis syndrome. The effects of acute ethanol exposure and TLR4 on bacterial clearance, spleen cell numbers, peritoneal macrophage numbers, and cytokine production were evaluated using wild-type and TLR4 hyporesponsive mice treated with ethanol and then challenged with a nonpathogenic strain of Escherichia coli. Ethanol-treated mice exhibited a decreased clearance of bacteria and produced lesser amounts of most pro-inflammatory cytokines in both strains of mice at 2h after challenge. Neither ethanol treatment nor a hyporesponsive TLR4 had significant effects on the cell numbers in the peritoneal cavity and spleen 2h postinfection. The suppressive effect of acute ethanol exposure on cytokine and chemokine production was more pronounced in the wild-type mice, but the untreated hyporesponsive mice produced less of most cytokines than untreated wild-type mice. The major conclusion of this study is that acute ethanol exposure suppresses pro-inflammatory cytokine production and that a hyporesponsive TLR4 (in C3H/HeJ mice) decreases pro-inflammatory cytokine levels, but the cytokines and other mediators induced through other receptors are sufficient to ultimately clear the infection but not enough to induce lethal septic shock. In addition, results reported here demonstrate previously unknown effects of acute ethanol exposure on leukemia inhibitory factor and eotaxin, and provide the first evidence that interleukin (IL)-9 is induced through TLR4 in vivo.

Exposure to ethanol during the last trimester of pregnancy alters the maturation and immunity of the fetal lung

The effects of ethanol exposure on fetal lungs remain under investigation. Previously, we demonstrated that lambs exposed to ethanol during gestation had impaired expression of pulmonary surfactant protein A, a crucial component of lung immunity. In this study, we investigated the effects of in utero exposure to ethanol on maturation and immunity of the fetal lung. Pregnant ewes were surgically implanted with an abomasal cannula and administered 1g ethanol/kg (n=8) or water (n=8) during the last trimester of pregnancy. Lambs were delivered prematurely or naturally. Neonatal lungs were assessed for maturation markers (hypoxia-inducible factor-1α [HIF-1α], HIF-2α, HIF-3α, vascular endothelial growth factor-A [VEGF-A], VEGFR-1, VEGFR-2, glycogen, and lung protein levels) and immunity (cytokines and chemokines). Preterm animals exposed to ethanol had significantly reduced VEGF-A mRNA (P=.066) and protein levels, HIF-1α (P=.055), HIF-2α (P=.019), VEGFR-1 (P=.088), and VEGFR-2 (P=.067) mRNA levels but no changes in HIF-3α mRNA. No significant changes occurred in full-term animals exposed to ethanol. Glycogen levels were significantly higher in preterm animals exposed to ethanol (P=.006) but not in full-term animals. Ethanol exposure was associated with significantly lower lung protein levels in preterm (P=.03) but not full-term animals. Preterm animals exposed to ethanol had significantly reduced TNF-α (P=.05), IL-10 (P=.03), chemokine (C-C motif) ligand 5 (CCL5) (P=.017), and monocyte chemotactic protein-1 (MCP-1) (P=.0004) mRNA. In full-term animals exposed to ethanol, the immune alterations were either sustained (TNF-α, P=.009; IL-10, P=.03) or returned to near baseline levels (CCL5 and MCP-1). The ethanol-mediated alterations in fetal lung maturation and immunity may explain the increased incidence of respiratory infections in neonates exposed to ethanol in utero.

Glycogen synthase kinase 3 involvement in the excessive proinflammatory response to LPS in patients with decompensated cirrhosis

BACKGROUND & AIMS

In decompensated cirrhosis, the early innate immune response to the Toll-like receptor 4 (TLR4) agonist, lipopolysaccharides (LPS), is characterized by a hyper-production of pro-inflammatory cytokines and hypo-production of the anti-inflammatory cytokine IL-10. In LPS-stimulated non-cirrhotic immune cells, the constitutively active glycogen synthase kinase (GSK) 3 favors pro- vs. anti-inflammatory cytokines, by acting on gene induction. However, in these cells, TLR4 dampens its own pro-inflammatory response by inducing early (within minutes) AKT-mediated phosphorylation of GSK3β (one of two GSK3 isoforms) on Ser9. Phosphorylation of GSK3β (Ser9) inhibits its activity, decreases pro-inflammatory cytokines, and increases IL-10. Thus, we investigated the role of GSK3 in LPS-induced cytokine production by peripheral blood mononuclear cells (PBMCs) or monocytes from patients with advanced cirrhosis and normal subjects.

METHODS

Cells were pre-incubated with or without GSK3 inhibitor (SB216763 or lithium chloride) for 1h and then stimulated with LPS. Cytokine production was assessed at mRNA and secreted proteins levels, by real-time RT-PCR at 1h and ELISA at 20 h, respectively. GSK3β phosphorylation was assessed using Western blotting.

RESULTS

In cirrhotic and normal PBMCs pretreated with GSK3 inhibitors, LPS-induced production of pro-inflammatory proteins TNF-α and IL-12p40 was significantly decreased while that of IL-10 was increased. LPS-induced, AKT-mediated phosphorylation of GSK3β on Ser9 found in normal monocytes, was abolished in cirrhotic cells.

CONCLUSIONS

GSK3 is involved in the early TLR4-mediated pro-inflammatory response in patients with decompensated cirrhosis. This was associated with a defect in AKT-mediated GSK3β phosphorylation resulting in unrestricted 'pro-inflammatory' activity of the enzyme.

A low dose of alcohol does not impact skeletal muscle performance after exercise-induced muscle damage

Moderate, acute alcohol consumption after eccentric exercise has been shown to magnify the muscular weakness that is typically associated with exercise-induced muscle damage (EIMD). As it is not known whether this effect is dose-dependent, the aim of this study was to investigate the effect of a low dose of alcohol on EIMD-related losses in muscular performance. Ten healthy males performed 300 maximal eccentric contractions of the quadriceps muscles of one leg on an isokinetic dynamometer. They then consumed either a beverage containing 0.5 g of alcohol per kg bodyweight (as vodka and orange juice) or an isocaloric, isovolumetric non-alcoholic beverage. At least 2 weeks later, they performed an equivalent bout of eccentric exercise on the contralateral leg after which they consumed the other beverage. Measurement of peak and average peak isokinetic (concentric and eccentric) and isometric torque produced by the quadriceps was made before and 36 and 60 h post-exercise. Significant decreases in all measures of muscular performance were observed over time under both conditions (all P < 0.05); however, no difference between treatments was evident at any of the measured time points (all P > 0.05). Therefore, consumption of a low dose of alcohol after damaging exercise appears to have no effect on the loss of force associated with strenuous eccentric exercise.

Innate immunity and inflammation in sepsis: mechanisms of suppressed host resistance in mice treated with ethanol in a binge-drinking model

Sepsis is a major cause of mortality worldwide. Acute or chonic ethanol exposure typically suppresses innate immunity and inflammation and increases the risk of mortality in patients with sepsis. The study described here was designed to address the mechanism(s) by which acute ethanol exposure alters the course of sepsis. Ethanol administered to mice shortly before Escherichia coli (injected ip to produce sepsis) decreased production of proinflammatory cytokines and chemokines for several hours. Bacteria in the peritoneal cavity decreased over time in control mice and were mostly cleared by 21 h, but in ethanol-treated mice, bacteria increased over time to more than 2 × 10(8) at 21 h. Killing of bacteria in macrophages and neutrophils was apparently compromised by ethanol, as the percentage of these cells that had cleared phagocytosed bacteria increased over time in control mice but not in ethanol-treated mice. The roles of TLR4, MyD88, and myeloperoxidase (MPO) were evaluated using mutant or knockout mice, and these experiments indicated that mice with hyporesponsive TLR4 survived better than those with normal TLR4. Lack of MyD88 or MPO did not significantly alter survival in the presence or absence of ethanol. Ethanol decreased survival in all groups. This indicates that the antimicrobial activities induced though TLR4 are dispensable for survival but contribute to lethality late in the course of sepsis. Thus, the effects of ethanol responsible for lethal outcome in sepsis are not dependent on inhibition of TLR4 signaling, as we and others had previously suspected.

Alcohol abuse and pulmonary disease

ARDS is a severe form of lung injury characterized by increased permeability of the alveolar capillary membrane, diffuse alveolar damage, the accumulation of proteinaceous interstitial and intra-alveolar edema, and the presence of hyaline membranes. These pathological changes are accompanied by physiological alterations, including severe hypoxemia, an increase in pulmonary dead space, and decreased pulmonary compliance. Approximately 200,000 individuals develop ARDS in the United States each year, and nearly 50% of these patients have a history of alcohol abuse. We have identified alcohol abuse as an independent risk factor for the development of ARDS, and more recent studies have validated these findings in patients following lung resection and blood transfusion. In ARDS survivors, alcohol abuse is also associated with an increased duration of mechanical ventilation and prolonged ICU length of stay. Despite studies aimed at improving outcomes in patients with ARDS, the mortality remains high at > 40%]. For those who abuse alcohol, the mortality is even higher, at 65%. In this review, we will discuss the relationship between alcohol abuse and ARDS, the effects of alcohol abuse on pulmonary function, and future directions and potential therapeutic targets for patients at risk for ARDS as a result of alcohol abuse, which impairs immune function, decreases pulmonary antioxidant capacity, decreases alveolar epithelial cell function, alters activation of the renin angiotensin system, and impairs GM-CSF signaling. These pathways represent potential therapeutic targets for patients at risk for ARDS as a result of alcohol abuse.

The opposite effects of acute and chronic alcohol on lipopolysaccharide-induced inflammation are linked to IRAK-M in human monocytes

Impaired host defense after alcohol use is linked to altered cytokine production, however, acute and chronic alcohol differently modulate monocyte/macrophage activation. We hypothesized that in human monocytes, acute alcohol induces hyporesponsiveness to LPS, resulting in decreased TNF-alpha, whereas chronic alcohol increases TNF-alpha by sensitization to LPS. We found that acute alcohol increased IL-1R-associated kinase-monocyte (IRAK-M), a negative regulator of IRAK-1, in human monocytes. This was associated with decreased IkappaB alpha kinase activity, NFkappaB DNA binding, and NFkappaB-driven reporter activity after LPS stimulation. In contrast, chronic alcohol decreased IRAK-M expression but increased IRAK-1 and IKK kinase activities, NFkappaB DNA binding, and NFkappaB-reporter activity. Inhibition of IRAK-M in acute alcohol-exposed monocytes using small interfering RNA restored the LPS-induced TNF-alpha production whereas over-expression of IRAK-M in chronic alcohol macrophages prevented the increase in TNF-alpha production. Addition of inhibitors of alcohol metabolism did not alter LPS signaling and TNF-alpha production during chronic alcohol exposure. IRAK-1 activation induces MAPKs that play an important role in TNF-alpha induction. We determined that acute alcohol decreased but chronic alcohol increased activation of ERK in monocytes and ERK inhibitor, PD98059, prevented the chronic alcohol-induced increase in TNF-alpha. In summary, inhibition of LPS-induced NFkappaB and ERK activation by acute alcohol leads to hyporesponsiveness of monocytes to LPS due to increased IRAK-M. In contrast, chronic alcohol sensitizes monocytes to LPS through decreased IRAK-M expression and activation of NFkappaB and ERK kinases. Our data indicate that IRAK-M is a central player in the opposite regulation of LPS signaling by different lengths of alcohol exposure in monocytes.

A recent perspective on alcohol, immunity, and host defense

BACKGROUND

Multiple line of clinical and experimental evidence demonstrates that both acute, moderate, and chronic, excessive alcohol use result in various abnormalities in the functions of the immune system.

METHODS

Medline and PubMed databases were used to identify published reports with particular interest in the period of 2000-2008 in the subject of alcohol use, infection, inflammation, innate, and adaptive immunity.

RESULTS

This review article summarizes recent findings relevant to acute or chronic alcohol use-induced immunomodulation and its consequences on host defense against microbial pathogens and tissue injury. Studies with in vivo and in vitro alcohol administration are both discussed. The effects of alcohol on lung infections, trauma and burn injury, liver, pancreas, and cardiovascular diseases are evaluated with respect to the role of immune cells. Specific changes in innate immune response and abnormalities in adaptive immunity caused by alcohol intake are detailed.

CONCLUSION

Altered inflammatory cell and adaptive immune responses after alcohol consumption result in increased incidence and poor outcome of infections and other organ-specific immune-mediated effects.

Ethanol exerts anti-inflammatory effects in human adipose tissue in vitro

Moderate alcohol consumption is suggested to be associated with reduced inflammation and morbidity. Human adipose tissue (AT) and obesity is characterised by low-grade inflammation, so the present study wanted to investigate the effects of ethanol on inflammation in human AT in vitro. Subcutaneous human AT was incubated with ethanol [11-88 mM] under non- or LPS-stimulated [50mg/mL] conditions. Protein and mRNA levels of adiponectin, IL-6, IL-8, TNF-alpha, MCP-1, and CD68 were assessed using ELISA and real-time RT-PCR, respectively. Non-stimulated, ethanol incubations up to 24h increased adiponectin release and mRNA expression (p<0.01) and decreased IL-6 release in both short-term [1.5h] (p<0.05) and long-term [24h] (p<0.01) incubations. Ethanol decreased LPS-stimulated IL-6, IL-8, TNF-alpha, and MCP-1 dose-dependently (all p<0.01). Ethanol decreased CD68 mRNA (p<0.001), which correlated with the investigated adipokines (p<0.05) but not adiponectin (p>0.05). In conclusion, ethanol exerts anti-inflammatory effects in human AT, suggesting that ethanol may attenuate whole-body inflammation.

Acute alcohol intake induces SOCS1 and SOCS3 and inhibits cytokine-induced STAT1 and STAT3 signaling in human monocytes

BACKGROUND

Acute alcohol consumption is associated with induction of immuno-inhibitory cytokines and down-regulation of pro-inflammatory responses to various pathogens. We previously reported that alcohol activates janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling leading to IL-10 induction. The JAK-STAT pathway also activates its own negative regulators, suppressors of cytokine signaling (SOCS) 1 and SOCS3. SOCS proteins are inducible inhibitors that negatively regulate STAT3/STAT1 signaling pathways induced by cytokines, IL-6 or IFNs. Here we aimed to explore the effect of acute alcohol on induction of SOCS1/SOCS3 and regulation of STAT3/STAT1 pathways induced by IL-6 or IFNs in human monocytes.

METHODS

Blood samples from normal volunteers were collected before and 24 hours after consumption of 2 ml vodka/kg body weight. For in vitro experiments human monocytes were pretreated with ethanol (EtOH) followed by stimulation with cytokines; proteins were analyzed by Western blot, nuclear protein binding to DNA by EMSA, and RNA by real time PCR.

RESULTS

Acute in vivo or in vitro alcohol treatment increased both SOCS1 and SOCS3 RNA expression in monocytes. Alcohol treatment resulted in increased STAT3 and STAT1 DNA binding capacity. Activation of both STAT1 and STAT3 has been shown to induce SOCS1/3. We hypothesized that induction of SOCS proteins by alcohol in turn may lead to modulation of cytokine signaling through STAT1 and STAT3. Indeed, we observed significant down-regulation of IL-6-, IFNalpha- and IFNgamma-induced STAT1 DNA binding as well as inhibition of IL-6- and IFNgamma-induced STAT3 when alcohol was added to monocytes 3 hours prior to the cytokine stimulation. Consistent with inhibition of IL-6-induced STAT3 DNA binding in alcohol-pretreated cells, the levels of IL-6-dependent genes, MCP-1 and ICAM-1, was reduced after IL-6 stimulation. Similar to EtOH alone, combined EtOH+IL-6 simulation resulted in increased expression of both SOCS3 and SOCS1 genes.

CONCLUSION

While acute alcohol treatment alone activates STAT1/3 signaling pathways and induces SOCS3 and SOCS1 levels in monocytes, alcohol also leads to down-regulation of IL-6-, IFNalpha-, and IFNgamma-induced signaling via STAT1/STAT3 pathways, likely through excessive SOCS activation.

RETRACTED: Effects of ethanol on monosodium urate crystal-induced inflammation

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Image duplication has been observed within Figure 3. The corresponding author has been asked to provide an acceptable explanation for this duplication but has not been able to do so, neither have the original source files been supplied.

Neuroimmunity, drugs of abuse, and neuroAIDS

It has long been postulated that drugs of abuse may represent significant cofactors in the progression of human immunodeficiency virus (HIV)-induced disease. Both HIV infection and drugs of abuse have significant effect on the immune system as well as on the nervous system. In HIV infection, abnormalities in these systems intersect to lead to a constellation of symptoms known as neuroAIDS. Drugs of abuse may synergize with such damage, acting on immune and/or neural cells. However, definitive epidemiological evidence for such an interaction is lacking. Here we review such studies as well as the use of the nonhuman primate/simian immunodeficiency virus system to investigate the interaction of neuroAIDS with drugs of abuse. Furthermore, recent findings on mechanisms of actions of selected drugs reveal the possibility of protective as well as detrimental effects on the central nervous system damage induced by HIV.

Effect of ethanol on inflammatory responses. Implications for pancreatitis

BACKGROUND/AIMS

Alcohol use alters inflammatory cell responses. While alcohol has direct effects on pancreatic acinar cells, activation of inflammatory cells is a major component of the pathology of alcoholic pancreatitis.

METHODS

The effects of acute or chronic alcohol exposure were evaluated in human monocytes on the production of TNFalpha or IL-10 production, pro-inflammatory gene and nuclear factor-kappaB (NF-kappaB) activation.

RESULTS

Moderate, acute alcohol consumption or equivalent doses of alcohol in vitro had anti-inflammatory effects on monocyte activation via inhibition of pro-inflammatory genes and NF-kappaB activation, inhibition of TNFalpha production and augmentation of the anti-inflammatory cytokine, IL-10. In contrast, acute alcohol treatment augmented NF-kappaB activation and TNFalpha production and inhibited IL-10 levels in the presence of complex stimulation with combined TLR2 and TLR4 ligands. Prolonged alcohol exposure also resulted in an increase in NF-kappaB and TNFalpha production in response to TLR4 stimulation with LPS.

CONCLUSION

These results suggest that alcohol can either attenuate or promote inflammatory responses that are critical in pancreatitis. Our results support the hypothesis that both acute alcohol intake in the presence of complex stimuli (such as necrotic cells) and chronic alcohol exposure result in hyper-responsiveness of monocytes to inflammatory signals and may contribute to increased inflammation in pancreatitis.

TLR4, ethanol, and lipid rafts: a new mechanism of ethanol action with implications for other receptor-mediated effects

Ethanol (EtOH) is the most widely abused substance in the United States, and it contributes to well-documented harmful (at high dosages) and beneficial (at low dosages) changes in inflammatory and immune responses. Lipid rafts have been implicated in the regulation and activation of several important receptor complexes in the immune system, including the TLR4 complex. Many questions remain about the precise mechanisms by which rafts regulate the assembly of these receptor complexes. Results summarized in this review indicate that EtOH acts by altering the LPS-induced redistribution of components of the TLR4 complex within the lipid raft and that this is related to changes in actin cytoskeleton rearrangement, receptor clustering, and subsequent signaling. EtOH provides an example of an immunomodulatory drug that acts at least in part by modifying lipid rafts, and it could represent a model to probe the relationships between rafts, receptor complexes, and signaling.

Chronic alcohol consumption is associated with changes in the distribution, immunophenotype, and the inflammatory cytokine secretion profile of circulating dendritic cells

BACKGROUND

Alcoholism is frequently associated with altered immune responses, limited information being available on its effects on dendritic cells (DC). In the present study we analyze the effects of chronic alcoholism on circulating DC.

METHODS

For the first time we studied the numerical distribution of DC in peripheral blood (PB), their immunophenotype, and their ex vivo pattern of spontaneous cytokine secretion, in chronic alcoholic patients without liver disease (AWLD group; n=17) and active ethanol (EtOH) intake, as well as in subjects with alcohol liver cirrhosis (ALC group; n=21).

RESULTS

A significantly decreased HLADR expression and an increased reactivity for CD123 was observed on PB DC from AWLD patients; additionally, increased secretion of interleukin (IL) 1beta, IL6, IL12, and tumor necrosis factor-alpha (TNFalpha) by DC was also noted in this group. Conversely, patients with ALC and at least 1 year of alcohol withdrawal (ALCAW group) showed a decreased number of total circulating DC, whereas ALC patients with active EtOH intake (ALCET group) had an abnormally low production of IL1beta and TNFalpha by PB DC.

CONCLUSION

Chronic alcoholism in the absence of liver disease is associated with an increased secretion of inflammatory cytokines by PB DC, whereas ALCAW and ALCET patients show decreased numbers of circulating DC and reduced secretion of these cytokines, respectively.

Modulation of non-alcoholic steatohepatitis by pattern recognition receptors in mice: the role of toll-like receptors 2 and 4

Toll-like receptors (TLR) recognize pathogen-derived molecules and induce downstream activation of inflammatory pathways. Fatty liver has been shown to result in increased sensitivity to lipopolysaccharide (LPS), a TLR4 ligand. In this study, we investigated the roles of TLR2 and TLR4 in liver damage and on cytokine induction in a methionine-choline deficient (MCD) diet-induced model of nonalcoholic steatohepatitis. We found that mice with nonalcoholic fatty liver had increased liver injury and inflammatory cytokine induction after challenge with a TLR4 but not with a TLR2 ligand. TLR2 deficient mice were not protected against the development of steatohepatitis after MCD diet feeding. On the contrary, TLR2 mice had significantly higher levels of serum ALT and greater TNF-alpha levels after LPS challenge suggesting increased liver injury. This was associated with reduced production of IL-6, a cytokine with hepatoprotective effects in fatty liver. Increased liver injury in the MCD diet-fed TLR2 mice was associated with reduced baseline and LPS-induced NF-kB and PPRE binding compared to MCS controls. These results demonstrate that TLR2 deficiency results in increased liver injury in association with nonalcoholic steatohepatitis and may suggest a protective role for TLR2-mediated signals in liver injury.

Increased lipopolysaccharide sensitivity in alcoholic fatty livers is independent of leptin deficiency and toll-like receptor 4 (TLR4) or TLR2 mRNA expression

BACKGROUND

Both alcoholic (AFL) and nonalcoholic (NAFL) fatty livers show increased sensitivity to endotoxin-induced injury. Lipopolysaccharide (LPS) is recognized by toll-like receptor 4 (TLR4), whereas lipopeptide triggers TLR2 to induce common downstream activation of nuclear factor (NF)-kappaB and pro-inflammatory pathways that are activated in AFL and NAFL.

METHODS

Serum alanine aminotransferase (ALT), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 levels; hepatic NF-kappaB activity; and expression of TLR2, TLR4, inducible nitric oxide synthase (iNOS), and heme oxygenase (HO)-1 mRNAs were investigated in lean and leptin-deficient ob/ob mice after LPS challenge in combination with acute or chronic alcohol feeding.

RESULTS

Increased LPS sensitivity in AFL and NAFL was characterized by elevated serum TNF-alpha and IL-6 induction. However, there was no difference in TLR2 and TLR4 mRNA levels between lean and ob/ob livers at baseline and after acute or chronic alcohol treatment. LPS increased TLR2, but not TLR4, mRNA levels in all groups. Chronic alcohol feeding and LPS increased serum ALT and TNF-alpha levels in lean but not in ob/ob mice compared with pair-fed controls. Hepatic NF-kappaB activation was increased in both ob/ob and lean mice after chronic alcohol feeding compared with pair-fed controls. Expression of iNOS, an inducer of oxidative stress, and HO-1, a cytoprotective protein, were higher in ob/ob compared with lean mice after chronic alcohol feeding. However, LPS-induced HO-1, but not iNOS, expression was attenuated in ob/ob compared with lean mice.

CONCLUSION

These results imply that the increased sensitivity of AFL to LPS occurs without up-regulation of TLR2 or TLR4 genes and may be related to an imbalance of pro-inflammatory/oxidative and cytoprotective mechanisms.

Ethanol inhibits monocyte chemotactic protein-1 expression in interleukin-1{beta}-activated human endothelial cells

The aim of this study was to determine the effect of ethanol (EtOH) on endothelial monocyte chemotactic protein-1 (MCP-1) expression. IL-1beta increased the production of MCP-1 by human umbilical vein endothelial cells from undetectable levels to approximately 900 pg/ml at 24 h. EtOH dose-dependently inhibited IL-1beta-stimulated MCP-1 secretion as determined by ELISA: 25 +/- 1%, 35 +/- 7%, and 65 +/- 5% inhibition for 1, 10, and 100 mM EtOH, respectively, concomitant with inhibition of monocyte adhesion to activated endothelial cells. Similarly, EtOH dose-dependently inhibited IL-1beta-stimulated MCP-1 mRNA expression. Experiments with actinomycin D demonstrated that EtOH decreased the stability of MCP-1 mRNA. In addition, EtOH significantly reduced NF-kappaB and AP-1 binding activity induced by IL-1beta and inhibited MCP-1 gene transcription. Binding of (125)I-labeled MCP-1 to its receptor (CCR2) on THP-1 human monocytic cells was not affected by EtOH treatment. Modulation of the expression of MCP-1 represents a mechanism whereby EtOH could inhibit atherogenesis by blocking the crucial early step of monocyte adhesion and subsequent recruitment to the subendothelial space. These actions of EtOH may underlie, in part, its cardiovascular protective effects in vivo.

Acute alcohol consumption inhibits accessory cell function of monocytes and dendritic cells

BACKGROUND

Alcohol affects both innate and acquired immune responses. Chronic alcoholics have reduced delayed-type hypersensitivity response and increased susceptibility to infections. In contrast, recent studies suggest that acute, moderate alcohol consumption has protective effects on mortality. Monocytes and dendritic cells (DC) play a central role in coordination of innate and adaptive immune responses and are pivotal in activation of T lymphocytes in an antigen-specific manner. In this study, we investigated the effects of acute, moderate alcohol consumption on antigen presenting cell function of blood monocytes and monocyte-derived myeloid dendritic cells.

METHODS

Accessory cell function of human blood monocytes was tested before and after acute alcohol intake (2 ml vodka/kg body weight) by measuring T cell activation with alloantigen (mixed lymphocyte reaction, MLR), superantigen (staphylococcal enterotoxin B) and recall antigen (tetanus toxoid). Myeloid DCs were generated in vitro from monocytes obtained from these individuals using IL-4 and GM-CSF and their allostimulatory function was tested in an MLR.

RESULTS

We found significantly reduced T cell proliferation in the presence of monocytes obtained 2 or 18 hr after alcohol consumption whether alloantigen, superantigen, or recall antigen was the stimuli (p < 0.01). The reduced T cell proliferation was due to the effects of acute alcohol on monocytes rather than on T cells as we found decreased proliferation only in the presence of alcohol-exposed accessory cells but not when T cells were exposed to alcohol. In addition, monocyte-derived dendritic cells showed significantly reduced allostimulatory capacity after alcohol consumption (p < 0.005).

CONCLUSION

Acute alcohol consumption inhibits accessory cell function of both monocytes and myeloid dendritic cells. Impaired function of these key antigen-presenting cells may contribute to reduced adaptive immune responses and increased susceptibility to infections when acute alcohol intake coincides with exposure to pathogens.

Diverse regulation of NF-kappaB and peroxisome proliferator-activated receptors in murine nonalcoholic fatty liver

Fatty liver is highly sensitive to inflammatory activation. Peroxisome proliferator-activated receptors (PPAR) have anti-inflammatory effects and regulate lipid metabolism in the fatty liver. We hypothesized that fatty liver leads to endotoxin sensitivity through an imbalance between pro- and anti-inflammatory signals. Leptin-deficient, ob/ob mice and their lean littermates were challenged with single or double insults and pro- and anti-inflammatory pathways were tested on cytokine production and activation of nuclear regulatory factors NF-kappaB and peroxisome proliferator receptor element (PPRE). Ob/ob mice produced significantly higher serum tumor necrosis factor alpha (TNF-alpha) and interleukin (IL) 6 and showed increased hepatic NF-kappaB activation compared to lean littermates after stimulation with a single dose of lipopolysaccharide (LPS) or alcohol. In ob/ob mice, double insults with alcohol and LPS augmented proinflammatory responses mediated by increased degradation of inhibitory kappaB (IkappaB)-alpha and IkappaB-beta and preferential induction of the p65/p50 NF-kappaB heterodimer. In lean mice, in contrast, acute alcohol attenuated LPS-induced TNF-alpha, IL-6 production, and NF-kappaB activation through reduced IkappaB-alpha degradation and induction of p50/p50 homodimers. PPRE binding was increased in fatty but not in lean livers after alcohol or LPS stimulation. However, cotreatment with alcohol and LPS reduced both PPRE binding and nuclear levels of PPAR-alpha in fatty livers but increased those in lean livers. In conclusion, our results show opposite PPRE and NF-kappaB activation in fatty and lean livers. PPAR activation may represent an anti-inflammatory mechanism that fails in the fatty liver on increased proinflammatory pressure. Thus, an imbalance between PPAR-mediated anti-inflammatory and NF-kappaB-mediated proinflammatory signals may contribute to increased inflammation in the fatty liver.

Alcohol-induced suppression of lung chemokine production and the host defense response to Streptococcus pneumoniae

BACKGROUND

Acute alcohol intoxication impairs neutrophil migration in response to intrapulmonary infection with Streptococcus pneumoniae, the most common bacterial cause of pneumonia. Many of the same host defense functions that are impaired in the alcohol-intoxicated host are mechanistically associated with chemokines, a group of proinflammatory molecules that enhance neutrophil adhesion and direct neutrophil migration to sites of inflammation. The purpose of this study was to determine whether alcohol-induced chemokine suppression is responsible for impaired neutrophil recruitment into the lung during infection of the alcohol-intoxicated host.

METHODS

S. pneumoniae was administered (107 colony-forming units) intratracheally 30 min after intraperitoneal injection of 20% alcohol (5.5 g/kg) or saline. Four hours after bacterial challenge, bronchoalveolar lavage fluid (BALF) was collected, and the ability of BALF to induce neutrophil chemotaxis and adhesion molecule expression was measured by using chemotactic and flow cytometric assays. In another experiment, intratracheal challenge was performed by using recombinant macrophage inflammatory protein-2 (MIP-2), and BALF neutrophils were measured.

RESULTS

BALF MIP-2 and cytokine-induced neutrophil chemoattractant were decreased by alcohol, and BALF from alcohol-intoxicated animals had decreased chemotactic activity for neutrophils, as well as a decreased ability to up-regulate neutrophil adhesion molecule expression, compared with controls. This decreased chemotactic activity was significantly increased in the alcohol group by repletion of chemokines to control levels. Alcohol also suppressed neutrophil recruitment after intrapulmonary challenge with MIP-2, suggesting that mechanisms other than chemokine suppression contribute to the alcohol-induced effect.

CONCLUSIONS

At least two mechanisms, suppressed chemokine production and impaired neutrophil adhesion molecule expression, likely work in concert in the alcohol-intoxicated host to impair neutrophil adhesion and migration into the lung during pneumococcal infection. These alterations in neutrophil function likely increase the susceptibility of alcohol-consuming hosts to pneumonia.

Activated natural killer T cells induce liver injury by Fas and tumor necrosis factor-alpha during alcohol consumption

BACKGROUND & AIMS

Chronic alcohol abuse induces liver injury and increases the severity of viral hepatitis, but the precise mechanisms responsible are not well understood. In particular, little is known about the role of natural killer T cells in alcohol-induced liver injury. Natural killer T cells are mediators of important regulator and effector functions making use of Fas and tumor necrosis factor (TNF)-alpha in apoptosis induction. This report analyzes the role of natural killer T cells, Fas, and TNF-alpha in a model of chronic alcohol consumption.

METHODS

Mice fed alcohol by intragastric tube were assayed for serum alanine aminotransferase values, liver histology, and liver mononuclear cells before and after activation of natural killer T cells by ligand alpha-galactosylceramide.

RESULTS

In alcohol-consuming animals, liver natural killer T cells increase, and further activation by alpha-galactosylceramide causes lethal liver injury. This is explained by alcohol-induced hepatocyte sensitization to cell-mediated lysis, which develops concomitant to increased cytolytic activity of natural killer T cells. Natural killer T cell-mediated apoptosis proceeds by the Fas pathway, and Fas is essential for alcohol-associated liver injury. TNF-alpha plays an additional role as a defect in TNF receptor-1 inhibits alcohol-associated liver injury. Alcohol-fed natural killer T cell-deficient Jalpha281(-/-) mice express a delay in alcohol-induced liver injury.

CONCLUSIONS

Alcohol consumption induces an increase of natural killer T cells in the liver and a high sensitivity of hepatocytes to cell-mediated lysis. Stimulation of natural killer T cells during alcohol consumption induces serious liver injury by a mechanism that involves concomitant signals by Fas and tumor necrosis factor receptor-1 on alcohol-stressed hepatocytes.

Acute ethanol binge followed by withdrawal regulates production of reactive oxygen species and cytokine-induced neutrophil chemoattractant and liver injury during reperfusion after hepatic ischemia

This work tests the hypothesis that withdrawal from an acute ethanol binge regulates the production of reactive oxygen species (ROS) and chemokines by Kupffer cells, and as a result compromises or protects the liver from injury. Male Sprague-Dawley rats received an intravenous ethanol bolus (1.75 g/kg), followed by an intravenous infusion of 200-300 mg/kg/h for 12 h. At 12 h, ethanol infusion was stopped and replaced by saline. At 18 h, rats were subjected to 45 min of partial hepatic ischemia, followed by 0-24 h of reperfusion (I/R). At specific time points, Kupffer cells were isolated for superoxide anion assay and CINC (cytokine-induced neutrophil chemoattractant) and MIP-2 (macrophage inflammatory protein-2) production in vitro. Alanine transferase (ALT) activity, endotoxin, CINC, and MIP-2 were measured in serum samples taken at appropriate intervals. Results show that at 3 h post reperfusion, serum ALT was significantly elevated in the ethanol-treated group + I/R, compared with the saline + I/R group. ROS production by Kupffer cells at this time was also significantly increased compared with the saline + I/R group. However, ethanol withdrawal + I/R did not significantly alter CINC and MIP-2 production at 3 h of reperfusion. After 24 h, serum ALT was lower in the ethanol + I/R group than in the saline + I/R group. Superoxide anion and MIP-2 releases by Kupffer cells were not statistically significantly different between these two groups at this time. CINC production by Kupffer cells from the ethanol-treated + I/R group was significantly lower than in the saline + I/R group. Concomitantly, CINC and nuclear factor-kappaB (NF-kappaB) mRNAs and NF-kappaB translocation and binding in Kupffer cells in this treatment group were down-regulated. Moreover, the number of polymorphonuclear neutrophils (PMNs) sequestered in the liver was significantly lower in the ethanol + I/R group than in the saline-treated group. ROS and chemokine productions in sham animals with or without ethanol were lower than in the I/R group. These data suggest that acute ethanol binge followed by withdrawal may compromise the liver to injury during the early phase, whereas in the later phase it may be protective. Furthermore, these results support the notion that Kupffer cells are involved in hepatic injury in the early phase, whereas PMNs participate more actively during the later phase of reperfusion.

Dual mechanisms for ethanol-induced inhibition of monocyte chemotactic protein-3 mRNA expression in activated glial cells

The differential display of mRNA technique was used to screen the expressed genes in control and 50 mM chronic ethanol-treated rat C6 glial cells, with and without activation by lipopolysaccharide (LPS) combined with phorbol 12-myristate 13-acetate (PMA). One differentially expressed transcript was identified as that corresponding to the chemokine monocyte chemotactic protein (MCP)-3. MCP-3 is a broadly active chemokine that functions in chemoattraction and activation of monocytes, T lymphocytes, eosinophils, basophils, natural killer cells, and dendritic cells. Steady-state MCP-3 mRNA levels were elevated 6-fold after 24-h stimulation of control cells but less than 3-fold after stimulation of 9-day chronic ethanol-exposed cells. One- and 5-day exposures to 50 mM ethanol were not effective at reducing steady-state MCP-3 mRNA levels in stimulated cells, whereas 1-day exposure to >150 mM ethanol was effective. Stimulation with tumor necrosis factor-alpha elevated MCP-3 mRNA in C6 glial cells to a lesser extent than with LPS plus PMA, but the effects of ethanol were consistent. To gain insight into possible mechanisms for ethanol-induced reductions in steady-state MCP-3 mRNA, additional studies examined nuclear MCP-3 RNA levels and MCP-3 mRNA degradation. MCP-3 RNA content was greatly reduced in isolated nuclei from acute and chronic ethanol-exposed cells, suggesting transcriptional inhibition. On the other hand, acute ethanol exposure enhanced degradation of preexisting MCP-3 mRNA, indicating message destabilization. Thus, the results are consistent with a dual mechanism for ethanol-induced reductions in steady-state MCP-3 mRNA levels.

Acute ethanol administration downregulates human immunodeficiency virus-1 glycoprotein 120-induced KC and RANTES production by murine Kupffer cells and splenocytes

Glycoprotein 120 from HIV-1, HIV-2 and SIV is known to stimulate secretion of chemokines by mononuclear cells. Thus, this work tests the hypothesis that acute ethanol intoxication suppresses HIV-1 gp120-induced chemokine production by murine Kupffer cells and splenocytes. Male Balb/c mice were given ethanol (1.70 g/Kg) by intragastric gavage in 0.1 ml volume of saline. Five minutes after ethanol administration, mice received an intravenous injection of HIV-1 gp120 (5 microg/Kg). After 24 hr, serum samples, splenocytes and Kupffer cells were obtained. Isolated cells were cultured in DMEM for 24 hr to determine production of chemokines and cytokines in vitro. Chemokines (MIP-2, KC, RANTES, MIP-1 alpha and MCP-1) and cytokines (IL-1 beta, TNF alpha, IL-10, gamma-IFN) were measured by ELISA. M-RNA abundance of these mediators was determined by RT-PCR. Results show that HIV-1 gp120 treatment was associated with significant elevations in serum KC and RANTES. No changes were observed with regard to other chemokines and cytokines. Oral administration of ethanol significantly suppressed HIV-1gp120-induced KC and RANTES release. KC and RANTES-mRNA expression and protein release by splenocytes and Kupffer cells were up-regulated by HIV-1 gp120. Such up-regulation was attenuated by ethanol treatment. These data show that acute ethanol administration attenuates HIV-1 gp120-induced chemokine release in vivo by isolated splenocytes and Kupffer cells. Through this mechanism, previous in vivo ethanol use may compromise the ability of HIV-1 gp120 to induce chemokine-mediated inhibition of HIV-1 entry into target cells.