Inhibition of Ceramide Synthesis Attenuates Chronic Ethanol Induced Cardiotoxicity by Restoring Lysosomal Function and Reducing Necroptosis.

AIMS: Chronic alcohol misuse could cause alcoholic cardiomyopathy (ACM), and the specific mechanisms remained largely unknown. In this study, we aimed to explore the effects of endogenous ceramides on chronic ethanol-induced myocardial injury or cell loss (e.g. necroptosis). METHODS: We established chronic alcohol intoxication models in vivo (male C57BL/6 mice) and in vitro (H9c2 cardiomyoblasts). The ceramide profiles were analyzed in mice myocardium and cultured cardiomyocytes. Further research on the role of ceramides and underlying signaling pathways was carried out in H9c2 cells. RESULTS AND CONCLUSIONS: The ceramide profiles analysis revealed increased long and very long-chain ceramides in alcoholic myocardium and ethanol-treated cardiomyocytes. Next, we proved that endogenous ceramide inhibition could reduce necroptosis and alleviate cardiomyocytes injury as suggested by decreased levels of p-RIPK1, p-RIPK3 and p-MLKL proteins and cardiac injury factors expression. Furthermore, we found that lysosomal dysfunction also contributed to alcohol-induced cardiac damage and inhibiting ceramide biosynthesis could repaired this to some extent. Cells studies with exogenous C6 ceramide confirmed the pleotropic roles of ceramide in myocardial damage by causing both necroptosis and lysosomal dysfunction. Finally, our data suggested that lysosomal dysfunction could sensitize cardiomyocytes to induction of necroptosis due to the restriction on degradation of RIPK1/RIPK3 proteins. In conclusion, chronic ethanol treatment boosted myocardial ceramide synthesis in animal hearts and cultured cardiomyocytes. Moreover, ceramides exerted crucial roles in the intrinsic signaling pathways of alcohol-induced cardiotoxicity. Targeting ceramide biosynthesis to simultaneously attenuate necroptosis and lysosomal dysfunction might be a novel strategy for preventing alcoholic cardiotoxicity.

Comprehensive analysis of transcriptomics and metabolomics to understand chronic ethanol induced murine cardiotoxicity.

Alcohol abuse has attracted public attention and long-term alcohol exposure can lead to alcohol-featured non-ischemic dilated cardiomyopathy. However, the precise underlying mechanisms of alcoholic cardiomyopathy remain to be elucidated. This study aimed to comprehensively characterize alcohol abuse-mediated effects on downstream metabolites and genes transcription using a multi-omics strategy. We established chronic ethanol intoxication model in adult male C57BL/6 mice through 8 weeks of 95% alcohol vapor administration and performed metabolomics analysis, mRNA-seq and microRNA-seq analysis with myocardial tissues. Firstly, ethanol markedly induced ejection fraction reductions, cardiomyocyte hypertrophy, and myocardial fibrosis in mice with myocardial oxidative injury. In addition, the omics analysis identified a total of 166 differentially expressed metabolites (DEMs), 241 differentially expressed genes (DEGs) and 19 differentially expressed microRNAs (DEmiRNAs), respectively. The results highlighted that alcohol abuse mainly interfered with endogenous lipids, amino acids and nucleotides production and the relevant genes transcription in mice hearts. Based on KEGG database, the affected signaling pathways are primarily mapped to the antigen processing and presentation, regulation of actin cytoskeleton, AMPK signaling pathway, tyrosine metabolism and PPAR signaling pathway, etc. Furthermore, 9 hub genes related to oxidative stress from DEGs were selected based on function annotation, and potential alcoholic cardiotoxic oxidative stress biomarkers were determined through establishing PPI network and DEmiRNAs-DEGs cross-talk. Altogether, our data strongly supported the conclusion that ethanol abuse characteristically affected amino acid and energy metabolism, nucleotide metabolism and especially lipids metabolism in mice hearts, and underlined the values of lipids signaling and oxidative stress in the treatment strategies.

Diagnostic Value of PICP and PIIINP in Myocardial Fibrosis: A Systematic Review and Meta-analysis.

Myocardial fibrosis is the excessive accumulation of extracellular matrix (ECM) components such as collagen and fibronectin, and its clinical diagnosis is always with limitations. Recently, PICP and PIIINP have been reported by several studies as potential biomarkers for the diagnosis of myocardial fibrosis, however, no meta-analyses focusing on the diagnostic values of these biomarkers have been conducted. So, the present study aimed to investigate the clinical diagnostic value of PICP and PIIINP in myocardial fibrosis patients. Based on the inclusion criteria, 1130 records were identified from four databases, and 12 studies were included eventually after independent screening. All 12 studies were high quality with the Newcastle-Ottawa Quality Assessment Scale (NOS) values ≥7. The results of the present meta-analysis indicated that patients with myocardial fibrosis revealed significantly elevated serum PICP (standard mean difference [SMD] = 0.90, 95% confidence interval [95% CI] = 0.40 to 1.40) and PIIINP (SMD = 0.83, 95% CI = 0.04 to 1.23). Therefore, we believe that PICP and PIIINP could be used as potential auxiliary biomarkers in the clinical diagnosis of myocardial fibrosis. This article is protected by copyright. All rights reserved.

Ethanol potentiates mirtazapine-induced cardiotoxicity by inducing dysfunctional autophagy via HMGB1-dependent Akt/mTOR signaling pathway.

Previous surveys have revealed that mirtazapine (MIR), one of the most commonly prescribed antidepressants, is associated with a higher risk of adverse cardiac events compared with other newer antidepressants. Chronic ethanol (EtOH) abuse could also lead to myocardial injuries. Concerning the common comorbidity of major depression and alcohol dependence, combined consumption of MIR and EtOH might be prevalent in patients with depression, resulting in an additive or synergistic cardiotoxic effect. To this end, the present study evaluated cardiotoxicity induced by MIR-plus-EtOH in vivo (male C57BL/6J mice) and in vitro (H9c2 cardiomyoblasts), Further research on the role of autophagy and underlying signaling pathway were carried out in H9c2 cells. We found that EtOH exacerbated MIR-induced cardiotoxicity both in vivo and in vitro. Furthermore, EtOH significantly potentiated MIR-induced dysfunctional autophagy as reflected by upregulated protein levels of LC3-II, p62, Beclin1 and LAMP-1. Pharmacological inhibition of autophagy by 3-methyladenine alleviated MIR-plus-EtOH-induced myocardial injury. High mobility group box 1 (HMGB1) is a positive regulator of autophagy. In our work, HMGB1 knockdown decreased autophagosome accumulation and boosted viability in H9c2 cells. Additionally, HMGB1 blockage markedly upregulated p-Akt/Akt and p-mTOR/mTOR levels which were suppressed in MIR-plus-EtOH treated cells. In general, the present study demonstrates that EtOH potentiates MIR-induced cardiotoxicity which might be attributed to dysfunctional autophagy via inhibiting Akt/mTOR signaling pathway, while HMGB1 knockdown might contribute to improve autophagy flux.

Abnormally High Blood Acetaldehyde Concentrations Suggest Potential Postmortem Ethanol Generation.

Ethanol is one of the most commonly used and abused substances worldwide. Identifying whether the source of ethanol detected in corpses is antemortem ingestion or postmortem generation is especially important for determining the cause of death, which remains a vibrant field of research. During the synthesis of ethanol in the putrefaction process of corpses, other small molecules such as acetaldehyde and n-propanol could also be produced. According to our prospective statistical analysis based on authentic samples from forensic cases, it is rational to suspect ethanol generation after death when the concentration of acetaldehyde detected in blood exceeds 0.014 g/dL. Through in vitro simulation experiments, in addition to confirming that ethyl glucuronide and ethyl sulfate are the reliable biomarkers of antemortem ingestion of ethanol, we propose that acetaldehyde is far more sensitive than n-propanol as a potential marker in the blood of corpses for postmortem ethanol formation.

Simultaneous Quantification of 38 Psychotropic Drugs and Relevant Metabolites in Blood using LC-MS-MS.

The trend for the concomitant prescription of antidepressants and antipsychotics is increasing. This calls for a veracious screening and quantifying method for forensic and clinical use. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed and validated for the simultaneous determination and quantification of 38 antidepressants, antipsychotics and relevant metabolites in small volumes (200 µL) of human whole blood. Analytes and deuterated internal standards were extracted using liquid-liquid extraction. The separation, determination and quantification of the analytes were performed using an LC-MS-MS system equipped with an ACQUITY UPLC® BEH Phenyl Column under a positive electrospray ionization mode. After validation, the analytical procedure was proved to be highly sensitive, with a limit of detection ranging from 0.0005 to 1 ng/mL and a lower limit of quantification ranging from 0.002 to 2 ng/mL. Bias and within- and between-run precision were within 14.7% for all analytes. Recoveries were reproducible and those of 35 analytes were >50%. Dilution integrity was evaluated to ensure that the therapeutic and toxic blood concentration ranges of target compounds were fully covered. Finally, this method was applied to authentic whole blood samples collected from two forensic cases, which demonstrated its practical usefulness of providing accurate and comprehensive information concerning the previous medication of the deceased.

Spatio-temporal effects of acute alcohol intoxication on endocannabinoid system in rat brain and blood.

The endocannabinoid system (ECS) has been shown to play a critical role in the regulation of alcohol intake and alcohol-related behaviors. However, there are discrepancies between studies examining the interaction of the ECS and alcohol administration due to different experimental procedures. The present study aims at clarifying the time course effects of acute alcohol consumption on the ECS in the peripheral circulatory systems and central nervous systems of the same cohort of subjects. We have closely monitored the critical indicators reflecting changes of the ECS during the entire process from alcohol absorption to its metabolization, after acute alcohol (4.5 g/kg) intake by intragastric administration, including two key endocannabinoids (arachidonoylethanolamide and 2-arachidonoylglycerol) and their hydrolytic enzymes (fatty acid amide hydrolase and monoacylglycerol lipase) in blood and three brain regions, as well as a crucial and abundant receptor (cannabinoid 1 receptor) of the ECS in the three brain regions. Our results indicate that acute alcohol consumption inhibits endocannabinoid (eCB) production in the blood and in the prefrontal cortex of the brain, whereas the reverse was observed in the brain regions of the hippocampus and striatum. The variation between levels of two hydrolytic enzymes in the blood and in the three brain regions failed to reach statistical significance. After acute alcohol consumption, CB1R levels in striatum, hippocampus, and prefrontal cortex showed a similar trend of increasing, while the significant changes occurred at different time points. The present findings reveal different ligand-receptor changing patterns in the blood and in different brain regions, supporting the notion that the ECS plays a vital role in acute alcohol intoxication. Additionally, the temporal effects of alcohol on key elements of the ECS of blood and different brain nuclei were different. Our investigation may lead to a deeper understanding of the effect of acute alcohol consumption on the ECS.

Pharmacological activation of CB2 receptor protects against ethanol-induced myocardial injury related to RIP1/RIP3/MLKL-mediated necroptosis.

Chronic ethanol abuse can lead to harmful consequences for the heart, resulting in systolic dysfunction, variability in the heart rate, arrhythmia, and cardiac remodelling. However, the precise molecular mechanism responsible for ethanol-induced cardiomyopathy is poorly understood. In this regard, the present study aimed to describe the RIP1/RIP3/MLKL-mediated necroptotic cell death that may be involved in ethanol-induced cardiomyopathy and characterize CBR-mediated effects on the signalling pathway and myocardial injury. We performed an ethanol vapour administration experiment to analyse the effects of ethanol on cardiac structure and function in male C57BL/6J mice. Ethanol induced a significant decline in the cardiac structure and function, as evidenced by a decline in ejection fraction and fractional shortening, and an increase in serum Creatine Kinase levels, myocardial collagen content, and inflammatory reaction. Furthermore, ethanol also upregulated the expression levels of necroptosis-related markers such as p-RIP1, p-RIP3, and p-MLKL in the myocardium. Nec-1 treatment exerted significant cardioprotective effects by salvaging the heart tissue, improving the cardiac function, and mitigating inflammation and necroptosis. In addition, ethanol abuse caused an imbalance in the endocannabinoid system and regulated two cannabinoid receptors (CB1R and CB2R) in the myocardium. Treatment with selective CB2R agonists, JWH-133 or AM1241, markedly improved the cardiac dysfunction and reduced the ethanol-induced necroptosis in the myocardium. Altogether, our data provide evidence that ethanol abuse-induced cardiotoxicity can possibly be attributed to the RIP1/RIP3/MLKL-mediated necroptosis. Moreover, pharmacological activation of CB2R may represent a new cardioprotective strategy against ethanol-induced cardiotoxicity.

Cannabinoid 1 Receptor Antagonists Play a Neuroprotective Role in Chronic Alcoholic Hippocampal Injury Related to Pyroptosis Pathway.

BACKGROUND: Alcohol use disorders affect millions of people worldwide, and there is growing evidence that excessive alcohol intake causes severe damage to the brain of both humans and animals. Numerous studies on chronic alcohol exposure in animal models have identified that many functional impairments are associated with the hippocampus, which is a structure exhibiting substantial vulnerability to alcohol exposure. However, the precise mechanisms that lead to structural and functional impairments of the hippocampus are poorly understood. Herein, we report a novel cell death type, namely pyroptosis, which accounts for alcohol neurotoxicity in mice. METHODS: For this study, we used an in vivo model to induce alcohol-related neurotoxicity in the hippocampus. Adult male C57BL/6 mice were treated with 95% alcohol vapor either alone or in combination with selective cannabinoid receptor antagonists or agonists, and VX765 (Belnacasan), which is a selective caspase-1 inhibitor. RESULTS: Alcohol-induced in vivo pyroptosis occurs because of an increase in the levels of pyroptotic proteins such as nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3), caspase-1, gasdermin D (GSDMD), and amplified inflammatory response. Our results indicated that VX765 suppressed the expression of caspase-1 and inhibited the maturation of the proinflammatory cytokines interleukin-1ß (IL-1ß) and IL-18. Additionally, chronic alcohol intake created an imbalance in the endocannabinoid system and regulated 2 cannabinoid receptors (CB1R and CB2R) in the hippocampus. Specific antagonists of CB1R (AM251 and AM281) significantly ameliorated alcohol-induced pyroptosis signaling and inactivated the inflammatory response. CONCLUSIONS: Alcohol induces hippocampal pyroptosis, which leads to neurotoxicity, thereby indicating that pyroptosis may be an essential pathway involved in chronic alcohol-induced hippocampal neurotoxicity. Furthermore, cannabinoid receptors are regulated during this process, which suggests promising therapeutic strategies against alcohol-induced neurotoxicity through pharmacologic inhibition of CB1R.

Proteomic Analysis of Brain Regions Reveals Brain Regional Differences and the Involvement of Multiple Keratins in Chronic Alcohol Neurotoxicity.

AIMS: Alcohol abuse has attracted public attention and chronic alcohol exposure can result in irreversible structural changes in the brain. The molecular mechanisms underlying alcohol neurotoxicity are complex, mandating comprehensive mining of spatial protein expression profile. METHODS: In this study, mice models of chronic alcohol intoxication were established after 95% alcohol vapor administration for 30 consecutive days. On Day 30, striatum (the dorsal and ventral striatum) and hippocampus, the two major brain regions responsible for learning and memorizing while being sensitive to alcohol toxicity, were collected. After that, isobaric tags for relative and absolute quantitation -based quantitative proteomic analysis were carried out for further exploration of the novel mechanisms underlying alcohol neurotoxicity. RESULTS: Proteomic results showed that in the striatum, 29 proteins were significantly up-regulated and 17 proteins were significantly down-regulated. In the hippocampus, 72 proteins were significantly up-regulated, while 2 proteins were significantly down-regulated. Analysis of the overlay proteins revealed that a total of 102 proteins were consistently altered (P < 0.05) in both hippocampus and striatum regions, including multiple keratins such as Krt6a, Krt17 and Krt5. Ingenuity pathway analysis revealed that previously reported diseases/biofunctions such as dermatological diseases and developmental disorders were enriched in those proteins. Interestingly, the glucocorticoid receptor (GR) signaling was among the top enriched pathways in both brain regions, while multiple keratins from the GR signaling such as Krt1 and Krt17 exhibited significantly opposite expression patterns in the two brain nuclei. Moreover, there are several other involved pathways significantly differed between the hippocampus and striatum. CONCLUSIONS: Our data revealed brain regional differences upon alcohol consumption and indicated the critical involvement of keratins from GR signaling in alcohol neurotoxicity. The differences in proteomic results between the striatum and hippocampus suggested a necessity of taking into consideration brain regional differences and intertwined signaling pathways rather than merely focusing on single nuclei or molecule during the study of drug-induced neurotoxicity in the future.