Hispidol Regulates Behavioral Responses to Ethanol through Modulation of BK Channels: A Novel Candidate for the Treatment of Alcohol Use Disorder.

Alcohol use disorder (AUD) is the most common substance use disorder and poses a significant global health challenge. Despite pharmacological advances, no single drug effectively treats all AUD patients. This study explores the protective potential of hispidol, a 6,4'-dihydroxyaurone, for AUD using the Caenorhabditis elegans model system. Our findings demonstrate that hispidol-fed worms exhibited more pronounced impairments in thrashes, locomotory speed, and bending amplitude, indicating that hispidol exacerbated the detrimental effects of acute ethanol exposure. However, hispidol significantly improved ethanol withdrawal behaviors, such as locomotory speed and chemotaxis performance. These beneficial effects were absent in slo-1 worms (the ortholog of mammalian α-subunit of BK channel) but were restored with the slo-1(+) or hslo(+) transgene, suggesting the involvement of BK channel activity. Additionally, hispidol increased fluorescence intensity and puncta in the motor neurons of slo-1::mCherry-tagged worms, indicating enhanced BK channel expression and clustering. Notably, hispidol did not alter internal ethanol concentrations, suggesting that its action is independent of ethanol metabolism. In the mouse models, hispidol treatment also demonstrated anxiolytic activity against ethanol withdrawal. Overall, these findings suggest hispidol as a promising candidate for targeting the BK channel in AUD treatment.

Preexisting risk-avoidance and enhanced alcohol relief are driven by imbalance of the striatal dopamine receptors in mice.

Alcohol use disorder (AUD) is frequently comorbid with anxiety disorders, yet whether alcohol abuse precedes or follows the expression of anxiety remains unclear. Rodents offer control over the first drink, an advantage when testing the causal link between anxiety and AUD. Here, we utilized a risk-avoidance task to determine anxiety-like behaviors before and after alcohol exposure. We found that alcohol's anxiolytic efficacy varied among inbred mice and mice with high risk-avoidance showed heightened alcohol relief. While dopamine D1 receptors in the striatum are required for alcohol's relief, their levels alone were not correlated with relief. Rather, the ratio between striatal D1 and D2 receptors was a determinant factor for risk-avoidance and alcohol relief. We show that increasing striatal D1 to D2 receptor ratio was sufficient to promote risk-avoidance and enhance alcohol relief, even at initial exposure. Mice with high D1 to D2 receptor ratio were more prone to continue drinking despite adverse effects, a hallmark of AUD. These findings suggest that an anxiety phenotype may be a predisposing factor for AUD.

Reduced GABA Levels in the ACC of Actively Drinking High Risk Individuals Compared to Recently Detoxified Alcohol-Dependent Patients.

BACKGROUND: Acute gamma-aminobutyric acid (GABAergic) effects of alcohol consumption are well-known, whereas prior research has yielded inconsistent findings regarding on adaptations of the GABAergic neurotransmitter system to chronic alcohol use. Previous studies indicate either elevated or reduced GABA levels in cortical regions such as the anterior cingulate cortex (ACC) in persons with alcohol use disorder (AUD). We tested the hypothesis that active alcohol consumption compared to abstinence contributes to GABA levels as observed in prior research on chronic alcohol use. METHODS: We investigated GABA levels in the ACC of 31 healthy controls (low risk, LR), 38 high risk individuals providing an active drinking pattern (high risk, HR) and 27 recently detoxified alcohol-dependent (AD) subjects via proton magnetic resonance spectroscopy (1H-MRS). RESULTS: GABA levels in the ACC were significantly lower in HR compared with AD, but did neither differ between LR and AD nor between LR and HR. Also, we observed a quadratic effect indicating a distribution of GABA levels in the ACC as follows: LR > HR < AD. GABA levels were not associated with abstinence duration in AD. CONCLUSIONS: This study suggests that the GABAergic neurotransmitter system is blunted in AUD. More precisely GABA levels in the ACC seem to be higher in recently detoxified AD patients than in individuals at high risk which might suggest that GABA levels may increase after abstinence. No correlation was found between GABA levels and abstinence duration. Longitudinal studies are required to investigate alterations in the GABAergic system throughout the development and maintenance of AUD. CLINICAL TRIAL REGISTRATION: No: NCT02094196. Registered 20 March 2014, https://clinicaltrials.gov/study/NCT02094196.

Transcriptional Patterns in Stages of Alzheimer's Disease Are Cell-Type-Specific and Partially Converge with the Effects of Alcohol Use Disorder in Humans.

Advances in single-cell technologies have led to the discovery and characterization of new brain cell types, which in turn lead to a better understanding of the pathogenesis of Alzheimer's disease (AD). Here, we present a detailed analysis of single-nucleus (sn)RNA-seq data for three stages of AD from middle temporal gyrus and compare it with snRNA-seq data from the prefrontal cortices from individuals with alcohol use disorder (AUD). We observed a significant decrease in both inhibitory and excitatory neurons, in general agreement with previous reports. We observed several cell-type-specific gene expressions and pathway dysregulations that delineate AD stages. Endothelial and vascular leptomeningeal cells showed the greatest degree of gene expression changes. Cell-type-specific evidence of neurodegeneration was seen in multiple neuronal cell types particularly in somatostatin and Layer 5 extratelencephalic neurons, among others. Evidence of inflammatory responses was seen in non-neuronal cells, particularly in intermediate and advanced AD. We observed common perturbations in AD and AUD, particularly in pathways, like transcription, translation, apoptosis, autophagy, calcium signaling, neuroinflammation, and phosphorylation, that imply shared transcriptional pathogenic mechanisms and support the role of excessive alcohol intake in AD progression. Major AUD gene markers form and perturb a network of genes significantly associated with intermediate and advanced AD. Master regulator analysis from AUD gene markers revealed significant correlation with advanced AD of transcription factors that have implications in intellectual disability, neuroinflammation, and other neurodegenerative conditions, further suggesting a shared nexus of transcriptional changes between AD and AUD.

Alcohol use disorder disrupts BDNF maturation via the PAI-1 pathway which could be reversible with abstinence.

The plasminogen activator inhibitor-1 (PAI-1)→mature brain-derived neurotrophic factor (mBDNF) pathway plays a pivotal role in the conversion of probrain-BDNF (ProBDNF) to mBDNF, but its clinical relevance in patients with alcohol use disorder (AUD) remains unknown. Enzyme-linked immunosorbent assays were used to examine the relevant protein levels of components of the PAI-1→mBDNF pathway in plasma samples from three groups of subjects, and statistical analysis was performed using analysis of variance (ANOVA) and one-way repeated-measures ANOVA. Our findings revealed significant alterations induced by alcohol. (1) AUD was associated with significant decreases in tissue plasminogen activator (tPA), mBDNF, and tropomyosin receptor kinase B (TrkB); significant increases in PAI-1, ProBDNF, and P75 neurotrophin receptor (P75NTR); and inhibited conversion of ProBDNF to mBDNF. (2) Following abstinence, the levels of tPA, mBDNF, and TrkB in the AUD group significantly increased, whereas the levels of PAI-1, ProBDNF, and P75NTR significantly decreased, promoting the conversion of ProBDNF to mBDNF. These clinical outcomes collectively suggest that AUD inhibits the conversion of ProBDNF to mBDNF and that abstinence reverses this process. The PAI-1→mBDNF cleavage pathway is hypothesized to be associated with AUD and abstinence treatment.

THE INFLUENCE OF CHANGES IN CARBOHYDRATE METABOLISM INDICATORS IN PATIENTS WITH POLYTRAUMA COMPLICATED BY ALCOHOLIC DELIRIUM ON THE CHOICE OF THE SEDATION METHOD.

Topicality: Providing assistance to patients with polytrauma, in a state of alcohol intoxication, complicated by alcoholic delirium, is a serious problem when providing anesthesia care and, in particular, choosing drugs for sedation. Considering the severity of mechanical damage, complications associated with alcohol intoxication and serious biochemical disorders of the body, namely carbohydrate, lipid metabolism, electrolyte changes, on which the activity of all systems depends, it is necessary to study the influence on the course of these processes, depending on the choice of their medicinal corrections. PURPOSE: The purpose of the work is to choose a sedation method to improve the results of treatment of patients with polytrauma and alcohol withdrawal, based on the study of changes in carbohydrate metabolism indicator. MATERIALS AND METHODS: The paper analyzes the results of a study of 80 patients with polytrauma and chronic alcohol intoxication with a state of alcohol withdrawal, complicated by alcoholic delirium, who received intensive therapy in the 12-bed department of anesthesiology and intensive therapy for patients with combined trauma of the KNP «Kharkiv City Clinical Hospital of Emergency Medical Care¼ named after Prof. O. I. Meschaninov¼ KhMR. All patients were diagnosed with polytrauma (thoracic and/or abdominal trauma: rib fractures, hemo-, pneumothorax, hematomas of the liver or spleen, fracture of the bones of the waist, and/or upper and/or lower limbs, fracture of the pelvis). In the course of the research, to achieve the goal, the main indicators of carbohydrate metabolism were determined, which were evaluated by the content of key metabolites: glucose, pyruvic acid, lactate. The study was conducted on the 1st, 3rd and 7th day of hospitalization of the patients. RESULTS AND DISCUSSION: In all traumatized patients with alcohol withdrawal syndrome and alcoholic delirium with the use of dexmedetomidine for sedation (group 1) and in patients who were used as sedatives, diazepam and haloperidol (group 2), changes in these parameters were observed in the blood, compared to healthy people of the control group. As for the glucose content in the blood of the patients of the 1st group, on the first day, persistent hyperglycemia was observed in them 1.7 times higher than this indicator in healthy people. Next, patients' blood glucose levels were determined on the 3rd and 7th day after hospitalization. Glucose content on the 3rd day decreased by 9.4% compared to the level determined on the first day. On the 7th day, the content of glucose in the blood decreased to normal values, which is 26.5% lower compared to the content of glucose in the blood on the first day. In the 2nd group of patients, where diazepam and haloperidol were used on the first day, hyperglycemia was also observed - 1.9 times higher than this indicator in the control group of healthy individuals. On the third day, the level of glucose in the blood decreased by 6%. And on the 7th day, it decreased by 20.5%. Thus, hyperglycemia was observed in the blood of victims with alcohol withdrawal syndrome, complicated by delirium during hospitalization, on the 3rd day of hospitalization (first and second groups) and on the 7th day in patients of the second group, which indicates violation of carbohydrate metabolism and the development of hypoxia, with impaired liver and pancreas function. In accordance with the aim and objectives of the study, the blood content of the main metabolites of glucose metabolism - pyruvate and lactate - was also studied upon admission to the hospital and one week after treatment, which made it possible to comprehensively assess possible carbohydrate metabolism disorders and characterize the features of the body's energy supply in the combination of polytrauma and withdrawal alcohol, complicated by alcoholic delirium. According to the results of the research, there is an increase in the content of lactate and pyruvate in patients with polytrauma against the background of chronic alcoholism compared to healthy people. When analyzing the content of lactate in the blood of patients with polytrauma and alcohol withdrawal syndrome, complicated by alcoholic delirium upon admission to the intensive care unit, a significant increase of this indicator was observed by 97.1% and 113.0%, respectively, in patients of the first and second groups. One week after the intensive therapy, the patients of the 1st group had a significant decrease in the lactate content in the blood - by 13% (Р<0.0001) compared to the content of this indicator at the time of admission to the hospital. In the blood of the patients of the 2nd group, on the 7th day, the lactate content remained unchanged, and by 106.3% it exceeded this biochemical indicator in the blood of the control group. Hyperpyruvatemia was also observed - when entering the hospital in patients of the 2nd group, the content was 55.4% higher compared to healthy people, remained elevated after a week of treatment - by 30.1%, and did not return to normal values. In the patients of the first group, upon admission to the hospital, the pyruvate content in the blood was 53.0% higher compared to the control group, and on the 7th day it significantly decreased by 18.9%, but did not reach the values of the control group (remained at 24, 1% higher compared to the control). The cause of hyperpyruvatemia and hyperlactatemia in patients may also be a violation of their enzymatic transformation into decay products. Lactate is the final product of anaerobic oxidation of glucose, it is formed due to the transformation of pyruvate, under the conditions of action of the lactate dehydrogenase enzyme in conditions of hypoxia. An important indicator of the state of carbohydrate metabolism, namely the balance of anaerobic and aerobic processes in the body, is the lactate / pyruvate ratio, which in the control group was 14.33 [13.82; 14.49]. In the patients of the first group, an increase in this ratio was observed - and it was 18.46 [18.3; 20.59] and 19.81 [18.96; 21,17] upon admission to the intensive care unit and one week after treatment, respectively. Practically the same value of this ratio was observed in patients of the second group - 19.65 [18.97; 22.3] and 22.73 [21.32 23.91], respectively, according to the time of intensive therapy. The latest figures indicate the restructuring of the energy supply of body tissues during the stay of patients in the intensive care unit. CONCLUSIONS: Thus, in patients with polytrauma and alcohol withdrawal syndrome, complicated by alcoholic delirium, there is an intensification of the processes of anaerobic glycolysis, which is evidenced by an increase in the content of pyruvate, lactate, the lactate/pyruvate ratio, and is accompanied by a hypoxic state. When comparing the terms of stay in the intensive care unit, it was determined that the use of dexmedetomidine for the treatment of alcoholic delirium compared to benzodiazepines allows reducing the time of intensive care by 34 hours. Thus, in group 2, the duration of intensive therapy for alcoholic delirium was 89 [82-96.2] hours, while in group 1 it was reduced to 55 [52.2-59.8] (p=0.020427). In addition, it was found that the consumption of drugs by patients was different. During the first day, it was 20 [20-30] mg in group 1, and 40 [40-50] mg in group 2. The groups also differed significantly in terms of the total dose of the drug during intensive therapy, so in patients of group 1, the total consumption was 30 [30-40] mg, in group 2 - 80 [80-90] mg (p=0.033011).

Pro-atherogenic medical conditions are associated with widespread regional brain metabolite abnormalities in those with alcohol use disorder.

AIMS: Widespread brain metabolite abnormalities in those with alcohol use disorder (AUD) were reported in numerous studies, but the effects of the pro-atherogenic conditions of hypertension, type 2 diabetes mellitus, hepatitis C seropositivity, and hyperlipidemia on metabolite levels were not considered. These conditions were associated with brain metabolite abnormalities in those without AUD. We predicted treatment-seeking individuals with AUD and pro-atherogenic conditions (Atherogenic+) demonstrate lower regional metabolite markers of neuronal viability [N-acetylaspartate (NAA)] and cell membrane turnover/synthesis [choline-containing compounds (Cho)], compared with those with AUD without pro-atherogenic conditions (Atherogenic-) and healthy controls (CON). METHODS: Atherogenic+ (n = 59) and Atherogenic- (n = 51) and CON (n = 49) completed a 1.5 T proton magnetic resonance spectroscopic imaging study. Groups were compared on NAA, Cho, total creatine, and myoinositol in cortical gray matter (GM), white matter (WM), and select subcortical regions. RESULTS: Atherogenic+ had lower frontal GM and temporal WM NAA than CON. Atherogenic+ showed lower parietal GM, frontal, parietal and occipital WM and lenticular nuclei NAA level than Atherogenic- and CON. Atherogenic- showed lower frontal GM and WM NAA than CON. Atherogenic+ had lower Cho level than CON in the frontal GM, parietal WM, and thalamus. Atherogenic+ showed lower frontal WM and cerebellar vermis Cho than Atherogenic- and CON. CONCLUSIONS: Findings suggest proatherogenic conditions in those with AUD were associated with increased compromise of neuronal integrity and cell membrane turnover/synthesis. The greater metabolite abnormalities observed in Atherogenic+ may relate to increased oxidative stress-related compromise of neuronal and glial cell structure and/or impaired arterial vasoreactivity/lumen viability.

Kappa-opioid receptor antagonism in the nucleus accumbens shell distinguishes escalated alcohol consumption and negative affective-like behavior from physiological withdrawal in alcohol-dependence.

Alcohol use disorder (AUD) is a chronic relapsing disease that is deleterious at individual, familial, and societal levels. Although AUD is one of the highest preventable causes of death in the USA, therapies for the treatment of AUD are not sufficient given the heterogeneity of the disorder and the limited number of approved medications. To provide better pharmacological strategies, it is important to understand the neurological underpinnings of AUD. Evidence implicates the endogenous dynorphin (DYN)/κ-opioid receptor (KOR) system recruitment in dysphoric and negative emotional states in AUD to promote maladaptive behavioral regulation. The nucleus accumbens shell (AcbSh), mediating motivational and emotional processes that is a component of the mesolimbic dopamine system and the extended amygdala, is an important site related to alcohol's reinforcing actions (both positive and negative) and neuroadaptations in the AcbSh DYN/KOR system have been documented to induce maladaptive symptoms in AUD. We have previously shown that in other nodes of the extended amygdala, site-specific KOR antagonism can distinguish different symptoms of alcohol dependence and withdrawal. In the current study, we examined the role of the KOR signaling in the AcbSh of male Wistar rats in operant alcohol self-administration, measures of negative affective-like behavior, and physiological symptoms during acute alcohol withdrawal in alcohol-dependence. To induce alcohol dependence, rats were exposed to chronic intermittent ethanol vapor for 14 h/day for three months, during which stable escalation of alcohol self-administration was achieved and pharmacological AcbSh KOR antagonism ensued. The results showed that AcbSh KOR antagonism significantly reduced escalated alcohol intake and negative affective-like states but did not alter somatic symptoms of withdrawal. Understanding the relative contribution of these different drivers is important to understand and inform therapeutic efficacy approaches in alcohol dependence and further emphasis the importance of the KOR/DYN system as a target for AUD therapeutics.

Unveiling the power of optimism: Exploring behavioral and neuromolecular correlates of alcohol seeking and drinking in rats with biased judgement.

Alcohol use disorder (AUD) is a common psychiatric condition with substantial global mortality. Despite extensive research into its pathophysiology, the cognitive predispositions driving alcohol dependence are less understood. This study explores whether biased cognition, specifically traits of optimism and pessimism, predicts susceptibility to alcohol-seeking behaviors using an animal model. Rats were initially tested for judgement bias through Ambiguous Cue Interpretation tests. Those identified as 'optimistic' or 'pessimistic' were further examined for their tendency to escalate alcohol intake using the intermittent access 2-bottle choice (2BC) paradigm. Additionally, we assessed how judgement bias influenced the development of compulsive alcohol-seeking behavior in a Seeking-Taking (ST) and Seeking-Taking Punishment tasks, alcohol-seeking motivation in the Progressive Ratio Schedule of Reinforcement paradigm, the speed of extinction, and reinstatement after abstinence. Neurochemical analyses were conducted to investigate trait-specific differences in neurotransmitter-related gene expression and receptor densities in the brain. We used TaqMan Gene Expression Array Cards to analyze expression levels of genes linked to serotonergic, dopaminergic, glutamatergic, and GABAergic pathways, and alcohol metabolism in various brain regions. Receptor densities for 5-HT1A, 5-HT2A, and D2 were measured using autoradiography analysis. Behaviorally, 'optimistic' rats showed significantly lower alcohol consumption in the 2BC paradigm compared to 'pessimistic' rats. This lowered intake correlated with decreased monoamine oxidase-A (Maoa) expression in the medial prefrontal cortex (mPFC) and increased metabotropic glutamate receptor 2 (Grm2) expression in the amygdala (Amy). Additionally, we observed significant interactions between judgement bias and alcohol intake in the expression of several genes in the mPFC, nucleus accumbens (Nacc), orbitofrontal cortex (OFC), and Amy, as well as in 5-HT2A receptor binding in the Nacc. Overall, these results suggest that optimism is linked to lower alcohol consumption and related neurochemical changes, indicating a potential cognitive mechanism in AUD risk.

Brain lncRNA-mRNA co-expression regulatory networks and alcohol use disorder.

Prolonged alcohol consumption can disturb the expression of both coding and noncoding genes in the brain. These dysregulated genes may co-express in modules and interact within networks, consequently influencing the susceptibility to developing alcohol use disorder (AUD). In the present study, we performed an RNA-seq analysis of the expression of both long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) in 192 postmortem tissue samples collected from eight brain regions (amygdala, caudate nucleus, cerebellum, hippocampus, nucleus accumbens, prefrontal cortex, putamen, and ventral tegmental area) of 12 AUD and 12 control subjects of European ancestry. Applying the limma-voom method, we detected a total of 57 lncRNAs and 51 mRNAs exhibiting significant differential expression (Padj < 0.05 and fold-change ≥2) across at least one of the eight brain regions investigated. Machine learning analysis further confirmed the potential of these top genes in predicting AUD. Through Weighted Gene Co-expression Network Analysis (WGCNA), we identified distinct lncRNA-mRNA co-expression modules associated with AUD in each of the eight brain regions. Additionally, lncRNA-mRNA co-expression networks were constructed for each brain region using Cytoscape to reveal gene regulatory interactions implicated in AUD. Hub genes within these networks were found to be enriched in several key KEGG pathways, including Axon Guidance, MAPK Signaling, p53 Signaling, Adherens Junction, and Neurodegeneration. Our results underscore the significance of networks involving AUD-associated lncRNAs and mRNAs in modulating neuroplasticity in response to alcohol exposure. Further elucidating these molecular mechanisms holds promise for the development of targeted therapeutic interventions for AUD.

Withdrawal from chronic alcohol impairs the serotonin-mediated modulation of GABAergic transmission in the infralimbic cortex in male rats.

The infralimbic cortex (IL) is part of the medial prefrontal cortex (mPFC), exerting top-down control over structures that are critically involved in the development of alcohol use disorder (AUD). Activity of the IL is tightly controlled by γ-aminobutyric acid (GABA) transmission, which is susceptible to chronic alcohol exposure and withdrawal. This inhibitory control is regulated by various neuromodulators, including 5-hydroxytryptamine (5-HT; serotonin). We used chronic intermittent ethanol vapor inhalation exposure, a model of AUD, in male Sprague-Dawley rats to induce alcohol dependence (Dep) followed by protracted withdrawal (WD; 2 weeks) and performed ex vivo electrophysiology using whole-cell patch clamp to study GABAergic transmission in layer V of IL pyramidal neurons. We found that WD increased frequencies of spontaneous inhibitory postsynaptic currents (sIPSCs), whereas miniature IPSCs (mIPSCs; recorded in the presence of tetrodotoxin) were unaffected by either Dep or WD. The application of 5-HT (50 µM) increased sIPSC frequencies and amplitudes in naive and Dep rats but reduced sIPSC frequencies in WD rats. Additionally, 5-HT2A receptor antagonist M100907 and 5-HT2C receptor antagonist SB242084 reduced basal GABA release in all groups to a similar extent. The blockage of either 5-HT2A or 5-HT2C receptors in WD rats restored the impaired response to 5-HT, which then resembled responses in naive rats. Our findings expand our understanding of synaptic inhibition in the IL in AUD, indicating that antagonism of 5-HT2A and 5-HT2C receptors may restore GABAergic control over IL pyramidal neurons. SIGNIFICANCE STATEMENT: Impairment in the serotonergic modulation of GABAergic inhibition in the medial prefrontal cortex contributes to alcohol use disorder (AUD). We used a well-established rat model of AUD and ex vivo whole-cell patch-clamp electrophysiology to characterize the serotonin modulation of GABAergic transmission in layer V infralimbic (IL) pyramidal neurons in ethanol-naive, ethanol-dependent (Dep), and ethanol-withdrawn (WD) male rats. We found increased basal inhibition following WD from chronic alcohol and altered serotonin modulation. Exogenous serotonin enhanced GABAergic transmission in naive and Dep rats but reduced it in WD rats. 5-HT2A and 5-HT2C receptor blockage in WD rats restored the typical serotonin-mediated enhancement of GABAergic inhibition. Our findings expand our understanding of synaptic inhibition in the infralimbic neurons in AUD.

Synaptic Mechanisms of Ethanol Tolerance and Neuroplasticity: Insights from Invertebrate Models.

Alcohol tolerance is a neuroadaptive response that leads to a reduction in the effects of alcohol caused by previous exposure. Tolerance plays a critical role in the development of alcohol use disorder (AUD) because it leads to the escalation of drinking and dependence. Understanding the molecular mechanisms underlying alcohol tolerance is therefore important for the development of effective therapeutics and for understanding addiction in general. This review explores the molecular basis of alcohol tolerance in invertebrate models, Drosophila and C. elegans, focusing on synaptic transmission. Both organisms exhibit biphasic responses to ethanol and develop tolerance similar to that of mammals. Furthermore, the availability of several genetic tools makes them a great candidate to study the molecular basis of ethanol response. Studies in invertebrate models show that tolerance involves conserved changes in the neurotransmitter systems, ion channels, and synaptic proteins. These neuroadaptive changes lead to a change in neuronal excitability, most likely to compensate for the enhanced inhibition by ethanol.

Chronic Alcohol Intake Compromises Lung Immunity by Altering Immunometabolism in Humans and Mouse Models.

Chronic alcohol consumption disrupts lung immunity and host defense mechanisms, rendering individuals with alcohol use disorder more susceptible to developing inflammatory lung conditions with poor prognoses. Here, we focused on investigating the molecular and cellular effects of alcohol ingestion on lung immunity in male and female subjects using population-based human lung transcriptomics analysis and an experimental mouse model of chronic alcohol drinking using the National Institute on Alcohol Abuse and Alcoholism alcohol feeding model. Flow cytometry and transcriptomics analyses in lungs revealed a sexually dimorphic effect of chronic alcohol drinking on lung immunity in both human and mouse. Male lungs were more sensitive to chronic alcohol drinking-induced dysregulation of lung immunity compared with female lungs. Furthermore, comparative transcriptomics analysis using lungs and liver samples from matched human and mouse subjects demonstrated that lungs were more sensitive than liver to the effects of alcohol in downregulating immune-related genes and pathways. Furthermore, the transcriptomics analysis provided evidence that immunometabolic change is a central driver in lung alteration by downregulating the immune pathways and upregulating metabolic pathways. Chronic alcohol consumption resulted in reduced mTOR signaling and decreased immune cell populations. The mTOR signaling axis may serve as an upstream regulator of alcohol-induced dysregulation in lung immunity.

Benefits of exercise on cognitive impairment in alcohol use disorder following alcohol withdrawal.

Although most cognitive impairments induced by prolonged alcohol consumption tend to improve within the initial months of abstinence, there is evidence suggesting certain cognitive deficits may persist. This study aimed to investigate the impact of aerobic exercise on learning and memory in alcohol use disorder (AUD) mice following a period of abstinence from alcohol. We also sought to assess the levels of monoamine neurotransmitters in the hippocampus. To this end, we established an AUD mouse model through a two-bottle choice (sucrose fading mode and normal mode) and chronic intermittent alcohol vapor (combined with intraperitoneal injection) and randomly allocated mice into exercise groups to undergo treadmill training. Learning and memory abilities were assessed through the Morris water maze test and spontaneous activity was evaluated using the open field test. The levels of dopamine, norepinephrine, serotonin, and brain-derived neurotrophic factor in the hippocampus were quantified using enzyme-linked immunoassay (ELISA) kits. The findings reveal that after cessation of alcohol consumption, learning and memory abilities in AUD mice did not completely return to normal levels. The observed enhancement of cognitive functions in AUD mice through aerobic exercise may be attributed to restoring levels of monoamine neurotransmitters in the hippocampus, boosting brain-derived neurotrophic factor (BDNF) concentrations, and facilitating an increase in hippocampal mass. These results offer empirical evidence to support aerobic exercise as a viable therapeutic strategy to alleviate cognitive deficits associated with AUD.

Emerging GPCR targets for AUD: Insights from preclinical studies.

G protein-coupled receptors (GPCRs) are the largest group of membrane receptors in the central nervous system and one of the key proteins for signal transduction between cells. Currently, many drugs available on the market act via GPCRs and these receptors remain attractive targets for the treatment of brain disorders, including alcohol use disorder (AUD). Here, we describe the most recent literature, with a primary focus on the past 5 years, on GPCR targets with the potential for reducing behaviours associated with excessive alcohol intake. Specifically, we focus on preclinical evidence of compounds with attractive pharmacological profiles and potential for future clinical investigation for the treatment of AUD.

Coordinated action of a gut-liver pathway drives alcohol detoxification and consumption.

Alcohol use disorder (AUD) affects millions of people worldwide, causing extensive morbidity and mortality with limited pharmacological treatments. The liver is considered as the principal site for the detoxification of ethanol metabolite, acetaldehyde (AcH), by aldehyde dehydrogenase 2 (ALDH2) and as a target for AUD treatment, however, our recent data indicate that the liver only plays a partial role in clearing systemic AcH. Here we show that a liver-gut axis, rather than liver alone, synergistically drives systemic AcH clearance and voluntary alcohol drinking. Mechanistically, we find that after ethanol intake, a substantial proportion of AcH generated in the liver is excreted via the bile into the gastrointestinal tract where AcH is further metabolized by gut ALDH2. Modulating bile flow significantly affects serum AcH level and drinking behaviour. Thus, combined targeting of liver and gut ALDH2, and manipulation of bile flow and secretion are potential therapeutic strategies to treat AUD.

JNK Signaling Positively Regulates Acute Ethanol Tolerance in C. elegans.

Alcohol use disorder (AUD) is a chronic neurobehavioral condition characterized by a cycle of tolerance development, increased consumption, and reinstated craving and seeking behaviors during withdrawal. Understanding the intricate mechanisms of AUD necessitates reliable animal models reflecting its key features. Caenorhabditis elegans (C. elegans), with its conserved nervous system and genetic tractability, has emerged as a valuable model organism to study AUD. Here, we employ an ethanol vapor exposure model in Caenorhabditis elegans, recapitulating AUD features while maintaining high-throughput scalability. We demonstrate that ethanol vapor exposure induces intoxication-like behaviors, acute tolerance, and ethanol preference, akin to mammalian AUD traits. Leveraging this model, we elucidate the conserved role of c-jun N-terminal kinase (JNK) signaling in mediating acute ethanol tolerance. Mutants lacking JNK signaling components exhibit impaired tolerance development, highlighting JNK's positive regulation. Furthermore, we detect ethanol-induced JNK activation in C. elegans. Our findings underscore the utility of C. elegans with ethanol vapor exposure for studying AUD and offer novel insights into the molecular mechanisms underlying acute ethanol tolerance through JNK signaling.

Correlation of striatal dopamine D2/3 receptor availability with GABA level in the anterior cingulate cortex in healthy controls but not in alcohol-dependent subjects and individuals at high risk: A multimodal magnetic resonance spectroscopy and positron emission tomography study.

BACKGROUND: The association of impaired dopaminergic neurotransmission with the development and maintenance of alcohol use disorder is well known. More specifically, reduced dopamine D2/3 receptors in the striatum of subjects with alcohol dependence (AD) compared to healthy controls have been found in previous studies. Furthermore, alterations of gamma-aminobutyric acid (GABA) and glutamate (Glu) levels in the anterior cingulate cortex (ACC) of AD subjects have been documented in several studies. However, the interaction between cortical Glu levels and striatal dopamine D2/3 receptors has not been investigated in AD thus far. METHODS: This study investigated dopamine D2/3 receptor availability via 18F-fallypride positron emission tomography (PET) and GABA as well as Glu levels via magnetic resonance spectroscopy (MRS) in 19 detoxified AD subjects, 18 healthy controls (low risk, LR) controls and 19 individuals at high risk (HR) for developing AD, carefully matched for sex, age and smoking status. RESULTS: We found a significant negative correlation between GABA levels in the ACC and dopamine D2/3 receptor availability in the associative striatum of LR but not in AD or HR individuals. Contrary to our expectations, we did not observe a correlation between Glu concentrations in the ACC and striatal D2/3 receptor availability. CONCLUSIONS: The results may reflect potential regulatory cortical mechanisms on mesolimbic dopamine receptors and their disruption in AD and individuals at high risk, mirroring complex neurotransmitter interactions associated with the pathogenesis of addiction. This is the first study combining 18F-fallypride PET and MRS in AD subjects and individuals at high risk.

Evaluation of plasma-derived extracellular vesicles miRNAs and their connection with hippocampal mRNAs in alcohol use disorder.

Alcohol use disorder (AUD) is a common mental illness with high morbidity and disability. The discovery of laboratory biomarkers has progressed slowly, resulting in suboptimal diagnosis and treatment of AUD. This study aimed to identify promising biomarkers, as well as the potential miRNA-mRNA networks associated with AUD pathogenesis. RNA sequencing was performed on plasma-derived small extracellular vesicles (sEVs) from AUD patients and healthy controls (HCs) to harvest miRNAs expression profiles. Machine learning (ML) models were built to screen characteristic miRNAs, whose target mRNAs were analyzed using TargetScan, miRanda and miRDB databases. Gene Expression Omnibus (GEO) datasets (GSE181804 and GSE180722) providing postmortem hippocampal gene expression profiles of AUD subjects were mined. A total of 247 differentially expressed (DE) plasma-derived sEVs miRNAs and 122 DE hippocampal mRNAs were obtained. Then, 22 overlapping sEVs miRNAs with high importance scores were gained by intersecting 5 ML models. As a result, we established a putative sEVs miRNA-hippocampal mRNA network that can effectively distinguish AUD patients from HCs. In conclusion, we proposed 5 AUD-representative sEVs miRNAs (hsa-miR-144-5p, hsa-miR-182-5p, hsa-miR-142-5p, hsa-miR-7-5p, and hsa-miR-15b-5p) that may participate in the pathogenesis of AUD by modulating downstream target hippocampal genes. These findings may provide novel insights into the diagnosis and treatment of AUD.

Gut microbial diversity and functional characterization in people with alcohol use disorder: A case-control study.

Individuals with Alcohol Use Disorder (AUD) typically have comorbid chronic health conditions, including anxiety and depression disorders, increased sleep disruption, and poor nutrition status, along with gut microbial dysbiosis. To better understand the effects of gut dysbiosis previously shown in individuals with AUD, gut microbiome and metabolome were investigated between three cohorts. Two groups of individuals with AUD included treatment-seeking newly abstinent for at least six weeks (AB: N = 10) and non-treatment-seeking currently drinking (CD: N = 9) individuals. The third group was age, gender, and BMI-matched healthy controls (HC: N = 12). Deep phenotyping during two weeks of outpatient National Institutes of Health Clinical Center visits was performed, including clinical, psychological, medical, metabolic, dietary, and experimental assessments. Alpha and beta diversity and differential microbial taxa and metabolite abundance of the gut microbiome were examined across the three groups. Metabolites derived from the lipid super-pathway were identified to be more abundant in the AB group compared to CD and HC groups. The AB individuals appeared to be most clinically different from CD and HC individuals with respect to their gut microbiome and metabolome. These findings highlight the potential long-term effects of chronic alcohol use in individuals with AUD, even during short-term abstinence.