Interaction between high-fat diet and alcohol dehydrogenase on ethanol-elicited cardiac depression in murine myocytes

Elevated levels of alcohol dehydrogenase aggravate ethanol-evoked cardiac remodeling and contractile anomalies through FKBP5-yap-mediated regulation of ferroptosis and ER stress

Alcohol intake provokes severe organ injuries including alcoholic cardiomyopathy with hallmarks of cardiac remodeling and contractile defects. This study examined the toxicity of facilitated ethanol metabolism in alcoholism-evoked changes in myocardial morphology and contractile function, insulin signaling and various cell death domains using cardiac-selective overexpression of alcohol dehydrogenase (ADH). WT and ADH mice were offered an alcohol liquid diet for 12 weeks prior to assessment of cardiac geometry, function, ER stress, apoptosis and ferroptosis. Alcohol intake provoked pronounced glucose intolerance, cardiac remodeling and contractile anomalies with apoptosis, ER stress, and ferroptosis, the effects were accentuated by ADH with the exception of global glucose intolerance. Hearts from alcohol ingesting mice displayed dampened insulin-stimulated phosphorylation of insulin receptor (tyr1146) and IRS-1 (tyrosine) along with elevated IRS-1 serine phosphorylation, the effect was augmented by ADH. Alcohol challenge dampened phosphorylation of Akt and GSK-3β, and increased phosphorylation of c-Jun and JNK, the effects were accentuated by ADH. Alcohol challenge promoted ER stress, FK506 binding protein 5 (FKBP5), YAP, apoptosis and ferroptosis, the effects were exaggerated by ADH. Using a short-term ethanol challenge model (3 g/kg, i.p., twice in three days), we found that inhibition of FKBP5-YAP signaling or facilitated ethanol detoxification by Alda-1 alleviated ethanol cardiotoxicity. In vitro study revealed that the ethanol metabolite acetaldehyde evoked cardiac contractile anomalies, lipid peroxidation, and apoptosis, the effects of which were mitigated by Alda-1, inhibition of ER stress, FKBP5 and YAP. These data suggest that facilitated ethanol metabolism via ADH exacerbates alcohol-evoked myocardial remodeling, functional defects, and insulin insensitivity possibly through a FKBP5-YAP-associated regulation of ER stress and ferroptosis.

High Adherence to a Mediterranean Alcohol-Drinking Pattern and Mediterranean Diet Can Mitigate the Harmful Effect of Alcohol on Mortality Risk

BACKGROUND

Alcohol is a psychoactive substance with deleterious effects on human health and mortality. This study aims to investigate the joint associations between the Mediterranean Diet (MedDiet), alcohol- consumption patterns and mortality from the following: all causes, cardiovascular, neoplastic, the digestive system, and other causes.

METHODS

A sample of 3411 alcohol consumers aged ≥18 years was selected from two prospective cohort studies: the MICOL and NUTRIHEP Study. Cohorts were enrolled in 2005-2006, and followed up until December 2022, capturing data on alcohol consumption, diet, and mortality. Adherence to the MedDiet was measured by the relative Mediterranean score (rMED), and alcohol consumption by the Mediterranean Alcohol-drinking Pattern index (MADP). Statistical analyses included flexible parametric survival models and subdistribution hazard ratios, to consider different causes of death.

RESULTS

a significant increase in digestive-system (SHR 2.77, 95% CI 1.16; 63) and cancer mortality risk (SHR 2.25, 95% CI 1.08; 4.70) was observed among individuals with low adherence to the MADP. Low adherence to the Mediterranean pattern of alcohol consumption, combined with low adherence to the MedDiet, was associated with higher overall mortality (HR 2.29, 95% CI 1.04, 5.04), and, in particular, with higher mortality from digestive system diseases (SHR 4.38, 95% CI 1.22, 15.8).

CONCLUSIONS

This study suggests that deleterious effects of alcohol on mortality vary, depending on alcohol consumption patterns and dietary context. Higher adherence to the MedDiet appears to mitigate the adverse effects of moderate alcohol consumption, particularly for wine drinkers.

High-Fat Diet Augments the Effect of Alcohol on Skeletal Muscle Mitochondrial Dysfunction in Mice

Previous studies have shown that chronic heavy alcohol consumption and consumption of a high-fat (HF) diet can independently contribute to skeletal muscle oxidative stress and mitochondrial dysfunction, yet the concurrent effect of these risk factors remains unclear. We aimed to assess the effect of alcohol and different dietary compositions on mitochondrial activity and oxidative stress markers. Male and female mice were randomized to an alcohol (EtOH)-free HF diet, a HF + EtOH diet, or a low-Fat (LF) + EtOH diet for 6 weeks. At the end of the study, electron transport chain complex activity and expression as well as antioxidant activity and expression, were measured in skeletal muscles. Complex I and III activity were diminished in muscles of mice fed a HF + EtOH diet relative to the EtOH-free HF diet. Lipid peroxidation was elevated, and antioxidant activity was diminished, in muscles of mice fed a HF + EtOH diet as well. Consumption of a HF diet may exacerbate the negative effects of alcohol on skeletal muscle mitochondrial health and oxidative stress.

Deletion of the E3 ubiquitin ligase, Parkin, exacerbates chronic alcohol intake-induced cardiomyopathy through an Ambra1-dependent mechanism

BACKGROUND AND PURPOSE

Chronic alcohol consumption contributes to contractile dysfunction and unfavourable geometric changes in myocardium, accompanied by altered autophagy and disturbed mitochondrial homeostasis. The E3 ubiquitin ligase Parkin encoded by PARK2 gene maintains a fundamental role in regulating mitophagy and mitochondrial homeostasis, although little is known of its role in the aetiology of alcoholic cardiomyopathy. Here we assessed the effects of Parkin deletion in chronic alcohol-evoked cardiotoxicity.

EXPERIMENTAL APPROACH

Following alcohol (4%) or control diet intake for 8 weeks, adult male wild-type (WT) and PARK2 knockout (Parkin^-/- ) mice were examined using echocardiography. Cardiomyocyte mechanical properties, morphology of myocardium, and mitochondrial damage were also evaluated. Autophagy and mitophagy levels were assessed by LC3B and GFP-LC3 puncta, and lysosome-dependent autophagic flux was scrutinized using GFP-mRFP-LC3 puncta and Bafilomycin A1 treatment.

KEY RESULTS

Chronic alcohol exposure provoked unfavourable geometric changes in myocardium and led to mitochondrial dysfunction and cardiac contractile defects, effects further exacerbated by Parkin knockout. Chronic alcohol exposure provoked autophagy and PINK1/Parkin-mediated mitophagy without affecting lysosome-dependent autophagic flux, the effects of which were diminished by Parkin deletion. Parkin adenovirus infection in neonatal rat cardiomyocytes further increased autophagy and protected against alcohol-induced myocardial injury, effects blocked by siRNA for Ambra1 (Autophagy and Beclin1 regulator 1). Immunofluorescence staining and co-immunoprecipitation assays showed interactions between Parkin and Ambra1.

CONCLUSIONS AND IMPLICATIONS

Parkin was essential for cardiac homeostasis in alcohol challenge, accompanied by increased autophagy/mitophagy and maintenance of mitochondrial integrity through its interaction with Ambra1.

Alcohol-Mediated Organ Damages: Heart and Brain

Alcohol is one of the most commonly abused substances in the United States. Chronic consumption of ethanol has been responsible for numerous chronic diseases and conditions globally. The underlying mechanism of liver injury has been studied in depth, however, far fewer studies have examined other organs especially the heart and the central nervous system (CNS). The authors conducted a narrative review on the relationship of alcohol with heart disease and dementia. With that in mind, a complex relationship between inflammation and cardiovascular disease and dementia has been long proposed but inflammatory biomarkers have gained more attention lately. In this review we examine some of the consequences of the altered cytokine regulation that occurs in alcoholics in organs other than the liver. The article reviews the potential role of inflammatory markers such as TNF-α in predicting dementia and/or cardiovascular disease. It was found that TNF-α could promote and accelerate local inflammation and damage through autocrine/paracrine mechanisms. Unraveling the mechanisms linking chronic alcohol consumption with proinflammatory cytokine production and subsequent inflammatory signaling pathways activation in the heart and CNS, is essential to improve our understanding of the disease and hopefully facilitate the development of new remedies.

Antihypertensive effect of radix paeoniae alba in spontaneously hypertensive rats and excessive alcohol intake and high fat diet induced hypertensive rats

Radix Paeoniae Alba (Baishao, RPA) has long been used in traditional Chinese medicine formulation to treat hypertension by repression the hyperfunction of liver. However, whether the RPA itself has the antihypertensive effect or not is seldom studied. This study was to evaluate the protective effect of RPA on hypertensive rats. Alcohol in conjunction with a high fat diet- (ACHFD-) induced hypertensive rats and spontaneously hypertensive rats (SHR) was constantly received either RPA extract (25 or 75 mg/kg) or captopril (15 mg/kg) all along the experiments. As a result, RPA extract (75 mg/kg) could significantly reduce systolic blood pressure of both ACHFD-induced hypertensive rats and SHR after 9-week or 4-week treatment. In ACHFD-induced hypertensive rats, the blood pressure was significantly increased and the lipid profiles in serum including triglyceride, total cholesterol, LDL-cholesterol, and HDL-cholesterol were significantly deteriorated. Also, hepatic damage was manifested by a significant increase in alanine transaminase (ALT) and aspartate transaminase (AST) in serum. The RPA extract significantly reversed these parameters, which revealed that it could alleviate the liver damage of rats. In SHR, our result suggested that the antihypertensive active of RPA extract may be related to its effect on regulating serum nitric oxide (NO) and endothelin (ET) levels.

DNA damage and neurotoxicity of chronic alcohol abuse

Chronic alcohol abuse results in a variety of pathological effects including damage to the brain. The causes of alcohol-induced brain pathology are presently unclear. Several mechanisms of pathogenicity of chronic alcoholism have been proposed, including accumulation of DNA damage in the absence of repair, resulting in genomic instability and death of neurons. Genomic instability is a unified genetic mechanism leading to a variety of neurodegenerative disorders. Ethanol also likely interacts with various metabolic pathways, including one-carbon metabolism (OCM). OCM is critical for the synthesis of DNA precursors, essential for DNA repair, and as a methyl donor for various methylation events, including DNA methylation. Both DNA repair and DNA methylation are critical for maintaining genomic stability. In this review, we outline the role of DNA damage and DNA repair dysfunction in chronic alcohol-induced neurodegeneration.

Alcohol and the heart: an ounce of prevention

OPINION STATEMENT

Moderate alcohol intake is beneficial to the heart and cardiovascular system. A J- or U-shaped response has been shown in the majority of studies examining alcohol's effect on cardiovascular mortality and downstream cardio-metabolic effects, with heavy alcohol intake associated with worse outcomes. These effects apply to individuals with and without underlying coronary artery disease. However, care must be taken in defining "moderate" intake between the sexes. Males appear to have a wider therapeutic window and can afford 2 to 3 drinks per day whereas women should limit intake to 1 to 2 drinks per day (a "drink" being classified as 10 to 14 grams of alcohol). More than half of alcohol's cardioprotective effects can be attributed to its effect on lipoproteins, specifically an increase in high-density lipoprotein. Interestingly, the risk of cardiovascular mortality in former heavy drinkers has been shown to ultimately approach the risk seen in lifelong abstainers.

Aldehyde dehydrogenase 2 knockout accentuates ethanol-induced cardiac depression: role of protein phosphatases

Alcohol consumption leads to myocardial contractile dysfunction possibly due to the toxicity of ethanol and its major metabolite acetaldehyde. This study was designed to examine the influence of mitochondrial aldehyde dehydrogenase-2 (ALDH2) knockout (KO) on acute ethanol exposure-induced cardiomyocyte dysfunction. Wild-type (WT) and ALDH2 KO mice were subjected to acute ethanol (3g/kg, i.p.) challenge and cardiomyocyte contractile function was assessed 24h later using an IonOptix edge detection system. Western blot analysis was performed to evaluate ALDH2, protein phosphatase 2A (PP2A), phosphorylation of Akt, and glycogen synthase kinase-3beta (GSK-3beta). ALDH2 KO accentuated ethanol-induced elevation in cardiac acetaldehyde levels. Ethanol exposure depressed cardiomyocyte contractile function including decreased cell shortening amplitude and maximal velocity of shortening/relengthening as well as prolonged relengthening duration and a greater decline in peak shortening in response to increasing stimulus frequency, the effect of which was significantly exaggerated by ALDH2 KO. ALDH2 KO also unmasked an ethanol-induced prolongation of shortening duration. In addition, short-term in vitro incubation of ethanol-induced cardiomyocyte mechanical defects was exacerbated by the ALDH inhibitor cyanamide. Ethanol treatment dampened phosphorylation of Akt and GSK-3beta associated with upregulated PP2A, which was accentuated by ALDH2 KO. ALDH2 KO aggravated ethanol-induced decrease in mitochondrial membrane potential. These results suggested that ALDH2 deficiency led to worsened ethanol-induced cardiomyocyte function, possibly due to upregulated expression of protein phosphatase, depressed Akt activation, and subsequently impaired mitochondrial function. These findings depict a critical role of ALDH2 in the pathogenesis of alcoholic cardiomyopathy.

Cisplatin compromises myocardial contractile function and mitochondrial ultrastructure: role of endoplasmic reticulum stress

1. Cisplatin is a potent chemotherapeutic agent with broad-spectrum antineoplastic activity against various types of tumours. However, a major factor limiting treatment with cisplatin is its acute and cumulative cardiotoxicity. The aim of the present study was to explore the effect of cisplatin on myocardial contractile function and the possible underlying cellular mechanisms. 2. C57 mice were treated with cisplatin (10 mg/kg per day, i.v.) or vehicle (0.9% NaCl) for 1 week and myocardial function was assessed using the Langendorff and cardiomyocyte edge-detection systems. Transmission electron microscopy, mitochondrial membrane potential, indices of endoplasmic reticulum (ER) stress and caspase 3 activity were evaluated. 3. Cisplatin-treated mice developed myocardial contractile dysfunction, as evidenced by a reduction in left ventricular developed pressure (LVDP) and the first derivative of LVDP (+/-dP/dt). Cisplatin treatment significantly prolonged time to 90% relengthening, depressed peak shortening, maximal velocity of shortening/relengthening (+/-dL/dt) and augmented the frequency-elicited depression in peak shortening. The JC-1 fluorescent assay demonstrated that cispatin-induced cardiac dysfunction was associated with mitochondrial membrane depolarization. Transmission electron microscopy revealed that cisplatin induces ultrastructural abnormalities of the mitochondria. Following cisplatin treatment, cardiomyocytes show activation of the ER stress response, increased caspase 3 activity and increased terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) staining. 4. The data indicate that cisplatin is cardiotoxic and may lead to left ventricular dysfunction and depressed cardiomyocyte contraction associated with mitochondrial abnormalities, enhanced ER stress and apoptosis. This work should shed some light on the management of cisplatin-induced cardiac injury.

Aldehyde dehydrogenase-2 transgene ameliorates chronic alcohol ingestion-induced apoptosis in cerebral cortex

Chronic intake of alcohol results in multiple organ damage including brain. This study was designed to examine the impact of facilitated acetaldehyde breakdown via transgenic overexpression of mitochondrial aldehyde dehydrogenase-2 (ALDH2) on alcohol-induced cerebral cortical injury. ALDH2 transgenic mice were produced using the chicken beta-actin promoter. Wild-type FVB and ALDH2 mice were placed on a 4% alcohol or control diet for 12 weeks. Protein damage and apoptosis were evaluated with carbonyl formation, caspase and TUNEL assays. Western blot was performed to examine expression (or its activation) of ALDH2, the pro- and anti-apoptotic proteins caspase-8, Bax, Bcl-2, Omi/HtrA2, apoptosis repressor with caspase recruitment domain (ARC), FLICE-like inhibitory protein (FLIP), X-linked inhibitor of apoptosis protein (XIAP), Akt, glycogen synthase kinase-3beta (GSK-3beta), p38, c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). Chronic alcohol intake led to elevated apoptosis in the absence of overt protein damage, the effect of which was ablated by the overexpression of ALDH2 transgene. Consistently, ALDH2 transgene significantly attenuated alcohol-induced upregulation of Bax, Omi/HtrA2 and XIAP as well as downregulation of Bcl-2 and ARC without affecting alcohol-induced increase of FLIP in cerebral cortex. Phosphorylation of Akt and GSK-3beta was dampened while total/phosphorylated JNK and p38 phosphorylation were elevated following chronic alcohol intake, the effects of which were abrogated by ALDH2 transgene. Expression of total Akt, GSK-3beta, p38 and ERK (total or phosphorylated) was not affected by either chronic alcohol intake or ALDH2 transgene. Our results suggested that transgenic overexpression of ALDH2 rescues chronic alcoholism-elicited cerebral injury possibly via a mechanism associated with Akt, GSK-3beta, p38 and JNK signaling.

Overexpression of aldehyde dehydrogenase-2 attenuates chronic alcohol exposure-induced apoptosis, change in Akt and Pim signalling in liver

1. The liver, the main site of ethanol oxidation, is extremely vulnerable to the toxic effects of alcohol. Chronic alcohol intake has been shown to result in alcoholic liver disease, although the precise mechanism of action remains poorly understood. 2. The present study was designed to examine the impact of facilitated acetaldehyde metabolism via overexpression of aldehyde dehydrogenase-2 (ALDH2) on chronic alcohol ingestion-induced hepatic damage. Mice (wild-type Friend Virus B (FVB) and ALDH2 transgenic mice) were placed on a 4% alcohol or control diet for 12 weeks. Pro- and anti-apoptotic proteins, including p53, Omi/HtrA2, Bcl-2, Bax, X-linked inhibitor of apoptosis protein (XIAP), Akt, phosphorylated (p) Akt, the Akt downstream signalling molecule Pim and pPim, were examined using immunoblot analysis. Apoptosis and protein damage were assessed using the caspase 3 assay and protein carbonyl formation, respectively. 3. The data revealed that alcohol intake enhanced expression of p53, Omi/HtrA2, Bcl-2 and Bax without affecting XIAP expression or the Bcl-2/Bax ratio. Total Akt and pPim were downregulated in response to alcohol, whereas total Pim was upregulated in conjunction with unchanged pAkt. As a result, the pAkt : Akt and pPim : Pim ratios were elevated and reduced, respectively, in response to alcohol. All these effects that resulted from alcohol exposure were attenuated or ablated by ALDH2. 4. Collectively, the results suggest that ALDH2 may effectively ameliorate alcohol-induced hepatic apoptosis and changes in Akt as well as Pim signalling.