Binge Alcohol Exposure in Adolescence Impairs Normal Heart Growth

Simvastatin Significantly Reduced Alcohol-Induced Cardiac Damage in Adolescent Mice

Alcohol abuse by adolescents is becoming a serious health concern as they often progress to becoming alcoholics later in life which may lead to heart problems. Chronic alcohol use alters the cardiac function and structure, such as haemodynamic changes, weakening and loss of cardiomyocytes, myocardial fibrosis, and inflammation. Simvastatin is a commonly used drug for the treatment and management of various cardiovascular problems but information on its protective effects against alcohol-induced cardiomyocyte hypertrophy, fibrosis, and inflammation is lacking in the literature. Four-week-old male (n = 5) and female (n = 5) C57BL/6 J mice were assigned to each experimental group: (I) NT-no administration of alcohol or Simvastatin; (II) ALC-2.5 g/Kg/day of 20% alcohol via intraperitoneal injection (i.p.); (III) SIM-5 mg/Kg/day of Simvastatin via oral gavage; (iv) ALC + SIM5-5 mg/Kg/day of Simvastatin via oral gavage followed by 2.5 g/Kg/day of 20% alcohol via i.p.; and (v) ALC + SIM15-15 mg/Kg/day Simvastatin via oral gavage followed by 2.5 g/Kg/day of 20% alcohol via i.p. After the 28-day treatment period, the heart was removed and processed for H&E, Masson's trichrome, or TNF-α immunolabelling. The area and diameter of cardiomyocytes were measured on the H&E-stained sections. The distribution of collagen or TNF-α expression was quantified using the deconvolution tool of ImageJ software. The results confirmed alcohol-induced toxicity on the cardiomyocytes and Simvastatin reduced alcohol-induced cardiomyocyte hypertrophy, fibrosis, and inflammation in both sexes. This study demonstrated that Simvastatin, an FDA approved and easily accessible drug, may be beneficial in lowering the prevalence of alcohol-induced cardiovascular diseases (especially in adolescents) which will have a huge financial implication on health systems worldwide.

Abstinence Restores Cardiac Function in Mice with Established Alcohol-Induced Cardiomyopathy

Alcohol-induced cardiomyopathy (ACM) has a poor prognosis with up to a 50% chance of death within four years of diagnosis. There are limited studies investigating the potential of abstinence for promoting repair after alcohol-induced cardiac damage, particularly in a controlled preclinical study design. Here, we developed an exposure protocol that led to significant decreases in cardiac function in C57BL6/J mice within 30 days; dP/dt max decreased in the mice fed alcohol for 30 days (8054 ± 664.5 mmHg/s compared to control mice: 11,188 ± 724.2 mmHg/s, p < 0.01), and the dP/dt min decreased, as well (-7711 ± 561 mmHg/s compared to control mice: -10,147 ± 448.2 mmHg/s, p < 0.01). Quantitative PCR was used to investigate inflammatory and fibrotic biomarkers, while histology was used to depict overt changes in cardiac fibrosis. We observed a complete recovery of function after abstinence (dP/dt max increased from 8054 ± 664 mmHg/s at 30 days to 11,967 ± 449 mmHg/s after abstinence, p < 0.01); further, both inflammatory and fibrotic biomarkers decreased after abstinence. These results lay the groundwork for future investigation of the molecular mechanisms underlying recovery from alcohol-induced damage in the heart.

Adipose tissue homeostasis orchestrates the oxidative, energetic, metabolic and endocrine disruption induced by binge drinking in adolescent rats

Binge drinking (BD) is the most common alcohol consumption model for adolescents, and has recently been related to the generation of high oxidation and insulin resistance (IR). White adipose tissue (WAT) is a target organ for insulin action that regulates whole-body metabolism by secreting adipokines. The present study aimed to analyse the oxidative, inflammatory, energetic and endocrine profile in the WAT of BD-exposed adolescent rats, to obtain an integrative view of insulin secretion and WAT in IR progression. Two groups of male adolescent rats were used: control (n = 8) and BD (n = 8). An intermittent i.p. BD model (20% v/v) was used during 3 consecutive weeks. BD exposure led to a pancreatic oxidative imbalance, which was joint to high insulin secretion by augmenting deacetylase sirtuin-1 (SIRT-1) pancreatic expression and serum adipsin levels. However, BD rats had hyperglycaemia and high homeostasis model assessment of insulin resistance value (HOMA-IR). BD exposure in WAT increased lipid oxidation, as well as decreased insulin receptor substrate 1 (IRS-1) and AKT expression, sterol regulatory element-binding protein 1 (SREBP1), forkhead box O3A (FOXO3a) and peroxisome proliferator-activated receptor γ (PPARγ), and adipocyte size. BD also affected the expression of proteins related to energy balance, such as SIRT-1 and AMP activated protein kinase (AMPK), affecting the adipokine secretion profile (increasing resistin/adiponectin ratio). BD altered the entire serum lipid profile, increasing the concentration of free fatty acids. In conclusion, BD led to an oxidative imbalance and IR process in WAT, which modified the energy balance in this tissue, decreasing the WAT lipogenic/lipolytic ratio, affecting adipokine secretion and the systemic lipid profile, and contributing to the progression of IR. Therefore, WAT is key in the generation of metabolic and endocrine disruption after BD exposure during adolescence in rats. KEY POINTS: Adolescent rat binge drinking (BD) exposure leads to hepatic and systemic oxidative stress (OS) via reactive oxygen species generation, causing hepatic insulin resistance (IR) and altered energy metabolism. In the present study, BD exposure in adolescent rats induces OS in the pancreas, with increased insulin secretion despite hyperglycaemia, indicating a role for IR in white adipose tissue (WAT) homeostasis. In WAT, BD produces IR and an oxidative and energetic imbalance, triggering an intense lipolysis where the serum lipid profile is altered and free fatty acids are increased, consistent with liver lipid accumulation and steatosis. BD exposure heightens inflammation in WAT, elevating pro-inflammatory and reducing anti-inflammatory adipokines, favouring cardiovascular damage. This research provides a comprehensive view of how adolescent BD in rats impacts liver, WAT and pancreas homeostasis, posing a risk for future cardiometabolic complications in adulthood.

Binge drinking leads to an oxidative and metabolic imbalance in skeletal muscle during adolescence in rats: endocrine repercussion

Binge drinking (BD) is an especially pro-oxidant model of alcohol consumption, mainly used by adolescents. It has recently been related to the hepatic IR-process. Skeletal muscle is known to be involved in insulin action and modulation through myokine secretion. However, there is no information on muscle metabolism and myokine secretion after BD exposure in adolescents. Two experimental groups of adolescent rats have been used: control and BD-exposed one. Oxidative balance, energy status and lipid, and protein metabolism have been analyzed in muscle, together with myokine serum levels (IL-6, myostatin, LIF, IL-5, fractalkine, FGF21, irisin, BDNF, FSTL1, apelin, FABP3, osteocrin, osteonectin (SPARC), and oncostatin). In muscle, BD affects the antioxidant enzyme balance leading to lipid and protein oxidation. Besides, it also increases the activation of AMPK and thus contributes to decrease SREBP1 and pmTOR and to increase FOXO3a expressions, promoting lipid and protein degradation. These alterations deeply affect the myokine secretion pattern. This is the first study to examine a general myokine response after exposure to BD. BD not only caused a detrimental imbalance in myokines related to muscle turnover, decreased those contributing to increase IR-process, decreased FST-1 and apelin and their cardioprotective function but also reduced the neuroprotective BDNF. Consequently, BD leads to an important metabolic and energetic disequilibrium in skeletal muscle, which contributes to exacerbate a general IR-process.

Binge drinking during the adolescence period causes oxidative damage-induced cardiometabolic disorders: A possible ameliorative approach with selenium supplementation

Binge drinking (BD) is the most common alcohol consumption model among adolescents. BD exposure during adolescence disrupts the nervous system function, being involved in the major mortality causes at this age: motor vehicle accidents, homicides and suicides. Recent studies have also shown that BD consumption during adolescence affects liver, renal and cardiovascular physiology, predisposing adolescents to future adult cardiometabolic damage. BD is a particularly pro-oxidant alcohol consumption pattern, because it leads to the production of a great source of reactive oxygen species (ROS) via the microsomal ethanol oxidizing system, also decreasing the antioxidant activity of glutathione peroxidase (GPx). Selenium (Se) is a mineral which plays a pivotal role against oxidation; it forms part of the catalytic center of different antioxidant selenoproteins such as GPxs (GPx1, GPx4, GPx3) and selenoprotein P (SelP). Specifically, GPx4 has an essential role in mitochondria, preventing their oxidation, apoptosis and NFkB-inflamative response, being this function even more relevant in heart's tissue. Se serum levels are decreased in acute and chronic alcoholic adult patients, being correlated to the severity of oxidation, liver damage and metabolic profile. Experimental studies have described that Se supplementation to alcohol exposed mice clearly decreases oxidative and liver damage. However, clinical BD effects on Se homeostasis and selenoproteins' tissue distribution related to oxidation during adolescence are not yet studied. In this narrative review we will describe the use of sodium selenite supplementation as an antioxidant therapy in adolescent BD rats in order to analyze Se homeostasis implication during BD exposure, oxidative balance, apoptosis and inflammation, mainly in liver, kidney, and heart. These biomolecular changes and the cardiovascular function will be analyzed. Se supplementation therapies could be a good strategy to prevent the oxidation, inflammation and apoptosis generated in tissues by BD during adolescence, such as liver, kidney and heart, improving cardiovascular functioning.

Epigenetic modification in alcohol use disorder and alcoholic cardiomyopathy: From pathophysiology to therapeutic opportunities

Alcohol consumption prompts detrimental psychological, pathophysiological and health issues, representing one of the major causes of death worldwide. Alcohol use disorder (AUD), which is characterized by compulsive alcohol intake and loss of control over alcohol usage, arises from a complex interplay between genetic and environmental factors. More importantly, long-term abuse of alcohol is often tied with unfavorable cardiac remodeling and contractile alterations, a cadre of cardiac responses collectively known as alcoholic cardiomyopathy (ACM). Recent evidence has denoted a pivotal role for ethanol-triggered epigenetic modifications, the interface between genome and environmental cues, in the organismal and cellular responses to ethanol exposure. To-date, three major epigenetic mechanisms (DNA methylation, histone modifications, and RNA-based mechanisms) have been identified for the onset and development of AUD and ACM. Importantly, these epigenetic changes induced by alcohol may be detectable in the blood, thus offering diagnostic, therapeutic, and prognostic promises of epigenetic markers for AUD and alcoholic complications. In addition, several epigenetic drugs have shown efficacies in the management of alcohol abuse, loss of control for alcohol usage, relapse, drinking-related anxiety and behavior in withdrawal. In this context, medications targeting epigenetic modifications may hold promises for pharmaceutical management of AUD and ACM.

Binge Alcohol Exposure in Adolescence Impairs Normal Heart Growth

Background

Approximately 1 in 6 adolescents report regular binge alcohol consumption, and we hypothesize it affects heart growth during this period.

Methods and Results

Adolescent, genetically diverse, male Wistar rats were gavaged with water or ethanol once per day for 6 days. In vivo structure and function were assessed before and after exposure. Binge alcohol exposure in adolescence significantly impaired normal cardiac growth but did not affect whole‐body growth during adolescence, therefore this pathology was specific to the heart. Binge rats also exhibited signs of accelerated pathological growth (concentric cellular hypertrophy and thickening of the myocardial wall), suggesting a global reorientation from physiologic to pathologic growth. Binge rats compensated for their smaller filling volumes by increasing systolic function and sympathetic stimulation. Consequently, binge alcohol exposure increased PKA (protein kinase A) phosphorylation of troponin I, inducing myofilament calcium desensitization. Binge alcohol also impaired in vivo relaxation and increased titin‐based cellular stiffness due to titin phosphorylation by PKCα (protein kinase C α). Mechanistically, alcohol inhibited extracellular signal‐related kinase activity, a nodal signaling kinase activating physiology hypertrophy. Thus, binge alcohol exposure depressed genes involved in growth. These cardiac structural alterations from binge alcohol exposure persisted through adolescence even after cessation of ethanol exposure.

Conclusions

Alcohol negatively impacts function in the adult heart, but the adolescent heart is substantially more sensitive to its effects. This difference is likely because adolescent binge alcohol impedes the normal rapid physiological growth and reorients it towards pathological hypertrophy. Many adolescents regularly binge alcohol, and here we report a novel pathological consequence as well as mechanisms involved.