Ethanol promotes arteriogenesis and restores perfusion to chronically ischemic myocardium

Endothelial Homeostasis Under the Influence of Alcohol-Relevance to Atherosclerotic Cardiovascular Disease

Alcohol, in the form of ethyl alcohol or ethanol, is a widely consumed substance with significant implications for human health. Research studies indicate multifaceted effects of alcohol on the cardiovascular system with both protective and harmful effects on atherosclerotic cardiovascular disease (ASCVD), depending on the amount involved and the pattern of consumption. Among the critical components of the cardiovascular system are endothelial cells which line blood vessels. These cells are pivotal in maintaining vessel homeostasis, regulating blood flow, and preventing thrombosis. Their compromised function correlates with arterial disease progression and is predictive of cardiovascular events. Here we review research investigating how alcohol exposure affects the endothelium to gain insight into potential mechanisms mediating alcohol's influence on ASCVD underlying heart attacks and strokes. Studies highlight opposite effects of low versus high levels of alcohol on many endothelial functions. In general, low-to-moderate levels of alcohol (~5-25 mM) maintain the endothelium in a non-activated state supporting vascular homeostasis, while higher alcohol levels (≥50 mM) lead to endothelial dysfunction and promotes atherosclerosis. These biphasic endothelial effects of alcohol might underlie the varying impacts of different alcohol consumption patterns on ASCVD.

Association of alcohol consumption with all-cause mortality, new-onset stroke, and coronary heart disease in patients with abnormal glucose metabolism-Findings from a 10-year follow-up of the REACTION study

BACKGROUND

Type 2 diabetes mellitus (T2DM) and diabetic complications threaten human health seriously. Healthy lifestyles can lower the risk of cardiovascular disease (CVD) and long-term complications. However, the relationship between alcohol consumption and CVD mortality is still controversial, and there is a lack of evidence from large-scale longitudinal studies in the Chinese population. Based on the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study), this paper explores the association between alcohol consumption and all-cause mortality, stroke, and coronary heart disease (CHD) in patients with abnormal glucose metabolism during a 10-year follow-up period to provide evidence for lifestyle counselling for these patients.

METHODS

First, baseline data were collected from the REACTION study cohort in Changchun, Jilin Province, China, in 2011-2012. A questionnaire survey was performed among patients with abnormal glucose metabolism aged over 40 years. The frequency of their alcohol intake, the type of alcohol, and the amount of alcohol consumed daily were surveyed. Physical and biochemical examinations were also performed. Then, through the Primary Public Health Service System of Jilin Province, we collected outcomes during the 10-year follow-up up to October 1, 2021, including all-cause mortality, stroke, and CHD. Next, we conducted logistic regression to analyze the relationship between baseline alcohol consumption and 10-year outcomes, and risk ratio (RR) and 95% CI were calculated by adjusting for different clinical indicators. A p value < 0.05 was considered statistically significant.

RESULTS

A total of 4855 patients with T2DM and prediabetes (35.2% men and 64.8% women) were included in the baseline analysis. Outcomes of 3521 patients during the 10-year follow-up were obtained, including 227 deaths, 296 new-onset strokes and 445 new-onset CHD. Occasional drinking (less than once a week) was associated with a reduced 10-year all-cause mortality, with an RR of 0.511 (95% CI [0.266, 0.982]) after adjustment for age, gender, medical history, and lifestyles and an RR of 0.50 (95% CI [0.252, 0.993]) in a fully adjusted model including additional biochemical indicators. In addition, heavy alcohol consumption (≥30 g/day for men and ≥15 g/day for women) was significantly associated with an increased incidence of stroke, with an RR of 2.503 (95% CI [1.138, 5.506]) after the adjustment for age, gender, medical history, lifestyles, and biochemical indicators. No significant association was found between alcohol consumption and new-onset CHD.

CONCLUSIONS

For patients with abnormal glucose metabolism, occasional drinking (less than once a week) reduces the risk of all-cause mortality, while heavy alcohol consumption (≥30 g/day for men and ≥15 g/day for women) significantly increases the risk of new-onset stroke. They should avoid heavy alcohol intake, but light alcohol consumption or occasional drinking is acceptable. Additionally, it is crucial to control blood glucose and blood pressure and keep performing physical activities.

Longitudinal Trajectories of Alcohol Consumption with All-Cause Mortality, Hypertension, and Blood Pressure Change: Results from CHNS Cohort, 1993-2015

BACKGROUND

Previous studies have demonstrated a J-shaped association of alcohol consumption with all-cause mortality and hypertension, but the majority of these studies focus on a single measurement of alcohol intake and were conducted in a Western population. Whether long-term trajectories of alcohol consumption are associated with all-cause mortality, hypertension, and a change in blood pressure remains to be elucidated.

METHODS

In the large, population-based China Health and Nutrition Survey cohort from between 1993 and 2015, group-based trajectory modeling was conducted to identify distinct alcohol-consumption trajectory classes. We investigated their association with all-cause mortality and hypertension using Cox regression and binary logistics regression models. A restricted cubic spline was performed to determine the nonlinear relationships of mean alcohol intake with mortality and hypertension. Multivariate-adjusted generalized linear mixed-effects models were conducted to assess the change in blood pressure among alcohol-consumption trajectory classes.

RESULTS

Among the 5298 participants, 48.4% were women and the mean age was 62.6 years. After 22 years of follow-up, 568 (10.7%) of the participants died and 1284 (24.2%) developed hypertension. Long-term light and moderate drinkers had a lower risk of death than the non-drinkers, and a restricted cubic spline showed a J-shaped relationship between mean alcohol intake and mortality. Although blood pressure increased slower in light and moderate drinkers, a reduced risk of hypertension was only observed in the former. The long-term heavy drinkers had the highest blood pressure and death rate.

CONCLUSIONS

Light alcohol intake might be protective even in the long run, while heavy drinking reversed the beneficial effect. The causality of such a connection needs to be further investigated.

Smoking, alcohol and opioids effect on coronary microcirculation: an update overview

Smoking, heavy alcohol drinking and drug abuse are detrimental lifestyle factors leading to loss of million years of healthy life annually. One of the major health complications caused by these substances is the development of cardiovascular diseases (CVD), which accounts for a significant proportion of substance-induced death. Smoking and excessive alcohol consumption are related to the higher risk of acute myocardial infarction. Similarly, opioid addiction, as one of the most commonly used substances worldwide, is associated with cardiac events such as ischemia and myocardial infarction (MI). As supported by many studies, coronary artery disease (CAD) is considered as a major cause for substance-induced cardiac events. Nonetheless, over the last three decades, a growing body of evidence indicates that a significant proportion of substance-induced cardiac ischemia or MI cases, do not manifest any signs of CAD. In the absence of CAD, the coronary microvascular dysfunction is believed to be the main underlying reason for CVD. To date, comprehensive literature reviews have been published on the clinicopathology of CAD caused by smoking and opioids, as well as macrovascular pathological features of the alcoholic cardiomyopathy. However, to the best of our knowledge there is no review article about the impact of these substances on the coronary microvascular network. Therefore, the present review will focus on the current understanding of the pathophysiological alterations in the coronary microcirculation triggered by smoking, alcohol and opioids.

Effects of chronic moderate alcohol consumption on right ventricle and pulmonary remodelling

NEW FINDINGS

What is the central question of this study? Does the consumption of a moderate amount of alcohol differentially impact the heart ventricles and pulmonary vasculature. What is the main finding and its importance? Moderate alcohol consumption for a short period of time impaired pulmonary vascular cellular renewal through an apoptosis resistance pattern that ultimately affected the right ventricular function and structure. These findings support the need for a deeper understanding of effects of moderate alcohol consumption on the overall cardiovascular and pulmonary systems.

ABSTRACT

Over the past decades, observational studies have supported an association between moderate alcohol consumption and a lower risk of cardiovascular disease and mortality. However, recent and more robust meta-analyses have raised concerns around the robustness of the evidence for the cardioprotective effects of alcohol. Also, studies of the functional, structural and molecular changes promoted by alcohol have focused primarily on the left ventricle, ignoring the fact that the right ventricle could adapt differently. The aim of this study was to evaluate the bi-ventricular impact of daily moderate alcohol intake, during a 4-week period, in a rodent model. Male Wistar rats were allowed to drink water (Control) or a 5.2% ethanol mixture (ETOH) for 4 weeks. At the end of the protocol bi-ventricular haemodynamic recordings were performed and samples collected for further histological and molecular analysis. ETOH ingestion did not impact cardiac function. However, it caused right ventricle hypertrophy, paralleled by an activation of molecular pathways responsible for cell growth (ERK1/2, AKT), proteolysis (MURF-1) and oxidative stress (NOX4, SOD2). Furthermore, ETOH animals also presented remodelling of the pulmonary vasculature with an increase in pulmonary arteries' medial thickness, which was characterized by increased expression of apoptosis-related proteins expression (BCL-XL, BAX and caspases). Moderate alcohol consumption for a short period of time impaired the lungs and the right ventricle early, before any change could be detected on the left ventricle. Right ventricular changes might be secondary to alcohol-induced pulmonary vasculature remodelling.

Alcohol modulates autophagy and apoptosis in pig liver tissue

BACKGROUND

Autophagy serves as a cellular protective mechanism against alcohol-induced tissue injury but excessive autophagy can also be detrimental leading to apoptosis. Our laboratory has previously shown that moderate alcohol consumption alters expression of proteins in the insulin signaling pathway and worsens glucose metabolism in the liver in a swine model of metabolic syndrome. We examined the effect of alcohol consumption on apoptosis and autophagy signaling in the liver in our clinically relevant animal model of chronic hypercholesterolemia.

MATERIAL AND METHODS

Twenty-six Yorkshire swine were fed a high-fat diet for 4 wks and were then split into three groups: hypercholesterolemic diet alone (HCC, n = 9), hypercholesterolemic diet with vodka (hypercholesterolemic vodka [HCV], n = 9), and hypercholesterolemic diet with wine (hypercholesterolemic wine [HCW], n = 8) for 7 wks. Animals underwent euthanasia, and liver tissue samples were harvested for analysis. Liver tissue was analyzed via Western blot analysis. Protein density data were normalized to GAPDH and is reported as fold-change values ± standard error of the mean compared to the high-cholesterol diet control group. A Kruskal-Wallis test with a Dunn's multiple comparison test was used to compare the means among groups.

RESULTS

The HCV group showed significant increases in several proapoptotic proteins (including caspase 3, caspase 8, caspase 9, and cleaved caspase 9) compared with the HCC group. There was a decrease in the proapoptotic protein (BAD) and an increase in anti-apoptotic signal (B-cell lymphoma-2) in the HCW group compared with HCC control. There were increases in pro-survival proteins (AKT, p-AKT, mTOR, p-mTOR) in the HCW and the HCV group compared with control (HCC). There were decreases in autophagy protein LCB-3 in the HCW and HCV compared with the control.

CONCLUSIONS

We found that moderate alcohol consumption altered protein expression related to apoptosis and autophagy signaling in pig liver in the setting of hypercholesterolemia. Interestingly, vodka may induce proapoptotic pathways in liver tissue, whereas wine may induce anti-apoptotic signaling. These results provide a mechanism by which vodka may contribute to alcoholic liver disease and supports the notion that wine, containing resveratrol, may prevent cellular apoptosis in liver tissue in the setting of hypercholesterolemia.

Alcohol and the Heart: A Proteomics Analysis of Pericardium and Myocardium in a Swine Model of Myocardial Ischemia

BACKGROUND

Previous studies have demonstrated that moderate alcohol consumption is cardioprotective and reduces postoperative pericardial adhesions; however, the mechanism is not fully understood. Using proteomic analysis, we sought to objectively investigate the effects of daily moderate alcohol consumption in the pericardium and myocardium in a swine model of chronic myocardial ischemia.

METHODS

Fourteen swine underwent placement of an ameroid constrictor to induce chronic myocardial ischemia. Animals were supplemented with 90 mL of ethanol daily (ETOH) or 80 g of sucrose of equal caloric value (SUC). After 7 weeks, the ischemic myocardium and pericardium were harvested for proteomics analysis.

RESULTS

Pericardial proteomics analysis yielded 397 proteins, of which 23 were unique to SUC and 52 were unique to ETOH. Of the 322 common proteins, 71 were statistically significant and 23 were characterized (p < 0.05). Alcohol supplementation increased structural proteins, and decreased immune protease inhibitors and coagulation proteins in the pericardium (p < 0.01). Myocardial proteomics analysis yielded 576 proteins, of which 32 were unique to SUC and 21 were unique to ETOH. Of the 523 common proteins, 85 were significant, and 32 were characterized (p < 0.05). Alcohol supplementation decreased cardiac remodeling proteins, cell death proteins and motor proteins, and increased metabolic proteins (p < 0.05).

CONCLUSIONS

The results suggest that daily moderate alcohol consumption affects numerous pathways that contribute to cardioprotection, including cardiac remodeling, metabolism, and cell death. Our findings reveal the biosignature of myocardial and pericardial protein expression in the setting of chronic myocardial ischemia and daily moderate alcohol consumption.

Alcoholism: A systemic proinflammatory condition

Excessive ethanol consumption affects virtually any organ, both by indirect and direct mechanisms. Considerable research in the last two decades has widened the knowledge about the paramount importance of proinflammatory cytokines and oxidative damage in the pathogenesis of many of the systemic manifestations of alcoholism. These cytokines derive primarily from activated Kupffer cells exposed to Gram-negative intestinal bacteria, which reach the liver in supra-physiological amounts due to ethanol-mediated increased gut permeability. Reactive oxygen species (ROS) that enhance the inflammatory response are generated both by activation of Kupffer cells and by the direct metabolic effects of ethanol. The effects of this increased cytokine secretion and ROS generation lie far beyond liver damage. In addition to the classic consequences of endotoxemia associated with liver cirrhosis that were described several decades ago, important research in the last ten years has shown that cytokines may also induce damage in remote organs such as brain, bone, muscle, heart, lung, gonads, peripheral nerve, and pancreas. These effects are even seen in alcoholics without significant liver disease. Therefore, alcoholism can be viewed as an inflammatory condition, a concept which opens the possibility of using new therapeutic weapons to treat some of the complications of this devastating and frequent disease. In this review we examine some of the most outstanding consequences of the altered cytokine regulation that occurs in alcoholics in organs other than the liver.

Flk-1/KDR mediates ethanol-stimulated endothelial cell Notch signaling and angiogenic activity

We previously reported that ethanol (EtOH) stimulates endothelial angiogenic activity mediated via a notch- and angiopoietin-1 (Ang-1) pathway. As crosstalk exists between notch and vascular endothelial growth factor (VEGF) signaling, we examined whether the VEGF receptor (VEGFR) Flk-1 (fetal liver kinase 1) mediates EtOH-stimulated notch signaling and angiogenic activity.

METHODS AND RESULTS

Treatment of human coronary artery endothelial cells (HCAECs) with EtOH (1-50 mM, 24 h) dose-dependently increased Flk-1 expression with a maximum increase observed at 25 mM EtOH. Ethanol treatment activated both Flk-1 and Flt-1 (FMS-like tyrosine kinase 1) as indicated by their phosphorylation, and subsequent stimulation of Akt. EtOH activation of Flk-1 was inhibited by the VEGFR inhibitor SU5416. Gene silencing of Flk-1 using small interfering RNA inhibited the EtOH-induced increase in notch receptors 1 and 4 and notch target gene (hairy enhancer of split-related transcription factor 1) mRNA. Knockdown of Flk-1 inhibited EtOH-induced Ang-1/Tie-2 mRNA expression and blocked EtOH-induced HCAEC network formation on Matrigel, a response that was restored by notch ligand, notch ligand delta-like ligand 4, treatment. In vivo, moderate alcohol feeding increased vascular remodeling in mouse ischemic hindlimbs.

CONCLUSIONS

These data demonstrate that EtOH activates Flk-1 and Flt-1 receptors in HCAECs and promotes angiogenic activity via an Flk-1/notch pathway. These effects of EtOH may be relevant to the influence of moderate alcohol consumption on cardiovascular health.

Ethanol promotes new vessel growth in remote nonischemic myocardium

BACKGROUND

Epidemiologic studies have demonstrated that daily low to moderate alcohol consumption is cardioprotective as compared with abstainers and high alcohol consumption. Our group reported that alcohol consumption improves angiogenesis in chronically ischemic myocardium. We developed a clinically relevant follow-up study to assess the effect of moderate alcohol consumption on new vessel growth in normal myocardium remote from an ischemic territory in a swine model.

MATERIALS AND METHODS

Fourteen male Yorkshire swine underwent placement of an ameroid constrictor to induce chronic myocardial ischemia. Postoperatively, animals were supplemented with either 90 mL of ethanol daily (ETOH) or 80 g of sucrose (SUC) of equal caloric value. Seven weeks after ameroid placement, myocardial tissue from a territory remote from the ischemia was harvested for analysis.

RESULTS

Both groups had similar microvascular relaxation to endothelial dependent and endothelium-independent vasodilators. Also, both groups had similar myocardial perfusion at rest and with demand pacing. The ETOH group had significantly increased arteriolar and capillary density in the nonischemic myocardium compared with the SUC group. ETOH supplementation also increased expression of pro-angiogenesis proteins vascular endothelial growth factor and vascular endothelial cadherin, and decreased expression of anti-angiogenesis proteins angiostatin and endostatin.

CONCLUSIONS

ETOH supplementation increased capillary and arteriolar density, upregulated pro-angiogenesis and pro-survival proteins, and downregulated anti-angiogenesis protein expression. These findings suggest that at moderate doses, ETOH directly promotes new vessel growth in the nonischemic myocardium remote from chronic ischemia.

Alcohol consumption mitigates apoptosis and mammalian target of rapamycin signaling in myocardium

BACKGROUND

Epidemiologic studies have shown that individuals who consume low to moderate alcohol have a lower risk of cardiovascular disease developing compared with abstainers. Although experimental studies confirmed this observation, the effect of alcohol on ischemic myocardium is still unclear. We developed a clinically relevant animal model of chronic myocardial ischemia to investigate the effects of moderate alcohol consumption on the myocardium.

STUDY DESIGN

Fourteen Yorkshire swine underwent placement of an ameroid constrictor to induce chronic myocardial ischemia. Postoperatively, one group was supplemented with 90 mL 50% EtOH daily (n = 7) and one group was supplemented with 80 g sucrose daily to normalize caloric intake between groups (n = 7). After 7 weeks, all animals underwent sternotomy, and harvest of the chronically ischemic myocardium and nonischemic myocardium. Tissues were analyzed for protein expression and stained for apoptosis quantification.

RESULTS

In the ischemic myocardium, alcohol down-regulated the following proapoptotic proteins: tumor necrosis factor-α, forkhead box protein 03, BCL2-associated death promoter, and cysteine aspartic acid-specific protease 9; up-regulated the following prosurvival proteins: 5'adenosine monophosphate-activated protein kinase, phosphorylated 5'adenosine monophosphate-activated protein kinase, and phosphorylated forkhead box protein 03; and down-regulated mammalian target of rapamycin (MTOR) signaling by down-regulating MTOR, phosphorylated MTOR, and up-regulating Deptor. In the nonischemic myocardium, alcohol up-regulated prosurvival proteins: protein kinase B, phosphorylated protein kinase B, phosphorylated B-cell CLL/lymphoma 2, 5'adenosine monophosphate-activated protein kinase, phosphorylated BCL2-associated death promoter, phosphorylated forkhead box protein 03, and down-regulated MTOR signaling by down-regulating phosphorylated MTOR and up-regulating Deptor. Alcohol also decreased cell death as measured by terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling staining in the ischemic and nonischemic myocardium.

CONCLUSIONS

Alcohol consumption down-regulates apoptosis and promotes cell survival in the ischemic and nonischemic myocardium. Alcohol also modulates MTOR signaling, which regulates senescence and apoptosis. Perhaps MTOR and apoptosis regulation is another mechanism by which moderate EtOH consumption is cardioprotective.