Tobacco smoke induces ventricular remodeling associated with an increase in NADPH oxidase activity

NADPH-oxidases as potential pharmacological targets for thrombosis and depression comorbidity

There is a complex interrelationship between the nervous system and the cardiovascular system. Comorbidities of cardiovascular diseases (CVD) with mental disorders, and vice versa, are prevalent. Adults with mental disorders such as anxiety and depression have a higher risk of developing CVD, and people with CVD have an increased risk of being diagnosed with mental disorders. Oxidative stress is one of the many pathways associated with the pathophysiology of brain and cardiovascular disease. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is one of the major generators of reactive oxygen species (ROS) in mammalian cells, as it is the enzyme that specifically produces superoxide. This review summarizes recent findings on the consequences of NOX activation in thrombosis and depression. It also discusses the therapeutic effects and pharmacological strategies of NOX inhibitors in CVD and brain disorders. A better comprehension of these processes could facilitate the development of new therapeutic approaches for the prevention and treatment of the comorbidity of thrombosis and depression.

Harmful Impact of Tobacco Smoking and Alcohol Consumption on the Atrial Myocardium

Tobacco smoking and alcohol consumption are widespread exposures that are legal and socially accepted in many societies. Both have been widely recognized as important risk factors for diseases in all vital organ systems including cardiovascular diseases, and with clinical manifestations that are associated with atrial dysfunction, so-called atrial cardiomyopathy, especially atrial fibrillation and stroke. The pathogenesis of atrial cardiomyopathy, atrial fibrillation, and stroke in context with smoking and alcohol consumption is complex and multifactorial, involving pathophysiological mechanisms, environmental, and societal aspects. This narrative review summarizes the current literature regarding alterations in the atrial myocardium that is associated with smoking and alcohol.

Adverse cardiovascular effects of exposure to cadmium and mercury alone and in combination on the cardiac tissue and aorta of Sprague-Dawley rats

The aim of this study was to identify cardiovascular effects of relevant concentrations of Cd and Hg alone and in combination as a mixture in water. This was achieved by administering to male Sprague-Dawley rats via gavage 0.62 mg/kg Cd or 1.23 mg/kg Hg, or a combination of 0.62 mg/kg Cd and 1.23 mg/kg Hg in the co-exposure group for 28 days. Concentrations were the rat equivalence dosages of 1,000 times the World Health Organization's limits of 0.003 mg/L and 0.006 mg/L for Cd and Hg, respectively, for water. With termination, blood levels of the metals were increased. For all metal exposed groups, histological evaluation and transmission electron microscopy of the myocardium revealed myofibrillar necrosis, increased fibrosis, vacuole formation and mitochondrial damage. Cd caused the most mitochondrial damage while Hg to a greater degree induced fibrosis. In the aorta, both Cd and Hg also increased collagen deposition adversely altering the morphology of the fenestrated elastic fibers in the tunica media. Co-exposure resulted in increased cardiotoxicity with increased mitochondrial damage, fibrosis and distortion of the aortic wall as a result of increased collagen deposition, as well as altered elastin deposition, fragmentation and interlink formation. These are typical features of oxidative damage that correlates with a phenotype of premature ageing of the CVS that potentially can lead to hypertension and premature cardiac failure.

The role of glucose metabolism and insulin resistance in cardiac remodelling induced by cigarette smoke exposure

The aim of this study is to evaluate whether the alterations in glucose metabolism and insulin resistance are mechanisms presented in cardiac remodelling induced by the toxicity of cigarette smoke. Male Wistar rats were assigned to the control group (C; n = 12) and the cigarette smoke-exposed group (exposed to cigarette smoke over 2 months) (CS; n = 12). Transthoracic echocardiography, blood pressure assessment, serum biochemical analyses for catecholamines and cotinine, energy metabolism enzymes activities assay; HOMA index (homeostatic model assessment); immunohistochemistry; and Western blot for proteins involved in energy metabolism were performed. The CS group presented concentric hypertrophy, systolic and diastolic dysfunction, and higher oxidative stress. It was observed changes in energy metabolism, characterized by a higher HOMA index, lower concentration of GLUT4 (glucose transporter 4) and lower 3-hydroxyl-CoA dehydrogenase activity, suggesting the presence of insulin resistance. Yet, the cardiac glycogen was depleted, phosphofructokinase (PFK) and lactate dehydrogenase (LDH) increased, with normal pyruvate dehydrogenase (PDH) activity. The activity of citrate synthase, mitochondrial complexes and ATP synthase (adenosine triphosphate synthase) decreased and the expression of Sirtuin 1 (SIRT1) increased. In conclusion, exposure to cigarette smoke induces cardiac remodelling and dysfunction. The mitochondrial dysfunction and heart damage induced by cigarette smoke exposure are associated with insulin resistance and glucose metabolism changes.

Abnormal left ventricular global strain during exercise-test in young healthy smokers

Background. It is unknown how much precociously the cigarette smoking (CS) may compromise the integrity of the cardiovascular (CV) system. Myocardial function can be routinely assessed by conventional echocardiography, but abnormalities are only detected when somewhat a remodelling has already occurred. These limitations could be overcome by strain imaging. Methods. We evaluated whether young smokers with normal left ventricular (LV) geometry, wall motion and ejection fraction may present abnormalities in myocardial deformation, both at rest and during physical effort. We selected 50 young smokers with no additional CV risk factors, and 60 non-smokers to undergo a standardized exercise-test. Consistently, we evaluated the CV adaptation to exercise by both conventional echocardiography and speckle-tracking analysis (2D-STE). Results. We found no difference between smokers and controls regarding baseline characteristics; as expected, smokers presented with lower HDL-cholesterol (p < 0.005), and higher fibrinogen, C-reactive protein (CRP), and interleukin-6 (p < 0.001). Conventional echocardiography parameters were not different between groups, while we detected a different behaviour of global longitudinal strain (GLS), global circumferential strain (GCS) and twist by 2D-STE during exercise-test. Indeed, GLS, GCS and twist behaved differently during exercise test in smokers with respect to controls. We found an association between CS, inflammation and LV mechanics changes uncovered by physical effort, and regression analysis confirmed that the intensity of the exposure to cigarette smoking, together with the inflammatory status (CRP, fibrinogen and Il-6) plasma levels, drive this impairment. Conclusions. We confirm strain imaging (2D-STE) as a very useful tool to identify early changes in cardiac mechanics, as adaptation to exercise; our findings may reflect a very precocious functional abnormality in active smokers, likely long before structural damage occurs.

Correlation between risk factors of cerebrovascular disease and calcified plaque characteristics in patients with atherosclerotic severe carotid stenosis

Objectives: The aim of this study was to evaluate the relationship between the risk factors of cerebral vascular diseases (CVD) and the characteristics of calcified plaques in patients with severe carotid arteriosclerosis stenosis (SCAS).Methods: A total of 402 patients with SCAS who were treated in our hospital between January to December 2016 were included in this study. The patients were divided into calcified plaque group and non-calcified plaque group according to the ultrasonography and computerized tomography angiography (CTA) or digital subtraction angiography (DSA) imaging of SCAS-responsible plaque and the characteristics of calcified plaques evaluated by high-frequency ultrasound.Results: The patients with long-term diabetes mellitus or higher levels of fasting blood glucose were more likely to develop calcified plaques (P = 0.00 and P = 0.021, respectively). In addition, the patients with calcified plaques were mostly smokers (P = 0.016). Their smoking duration and accumulative smoking exposure were higher than those without calcified plaque (P = 0.006 and P = 0.007, respectively). The basal location of calcification (P = 0.004) and the type of patchy calcification (P = 0.00) were both easier to appear in smokers, while non-smokers were more likely to have small granular calcification (P = 0.002). Furthermore, the carotid plaque calcification with mixed-location were more frequently seen in patients with hypertension (P = 0.016). The risk factors independently associated with plaque calcification were significantly associated with smoking status, smoking age, and accumulative smoking exposure, as well as age and diabetes mellitus (all P < 0.05).Conclusion: Smoking, diabetes mellitus and age were independent risk factors for carotid plaque calcification. Smoking and hypertension were associated with specific locations and types of plaque calcification.

Lipid damage is the best marker of oxidative injury during the cardiac remodeling process induced by tobacco smoke

BACKGROUND

Oxidative stress is one potential mechanism that explain the direct effects of smoking on cardiac remodeling process. However, no study has compared different myocardial products of macromolecule oxidation after tobacco smoke exposure. Thus, the aim of this study was to investigate the lipid hydroperoxide (LH) levels, protein carbonyl concentrations and DNA damage in cardiac tissue of rats exposed to tobacco smoke.

METHODS

Male Wistar rats were divided into two groups: group C (control, n = 14) composed of animals not exposed to cigarette smoke; group ETS (exposed to tobacco smoke, n = 14) composed by animals exposed to cigarette smoke. The animals were exposed to 2 month of ETS and morphological, biochemical and functional analyses were performed.

RESULTS

Cardiac cotinine levels were elevated in the ETS group. In addition, the myocyte cross-sectional area was higher in the ETS group. (C = 266.6 ± 23.2 μm2 and ETS = 347.5 ± 15.1 μm2, p <  0.001). Cardiac LH was higher in the ETS group than in group C (C = 196.4 ± 51.5 nmol/g and ETS = 331.9 ± 52.9 nmol/g, p <  0.001). However, there were no between-group differences in cardiac protein carbonyl concentration or DNA damage.

CONCLUSIONS

Therefore, our results suggest that, in this model, lipid damage is a good marker of oxidative damage during the cardiac remodeling process induced by 2 months of exposure to tobacco smoke.

Cardioprotective effects of physical exercise on redox biology in mice exposed to hand-rolled cornhusk cigarette smoke

The present study sought to evaluate the effects of physical training on histological parameters and oxidative stress in the myocardium of mice chronically exposed to hand-rolled cornhusk cigarette (HRCC) smoke. Male Swiss mice (60 days old, 30-35 g) were either exposed to ambient air or passively exposed to the smoke of 12 cigarettes daily over 3 sessions (4 cigarettes per session) for 60 consecutive days with or without physical training for 8 weeks. Forty-eight hours after the last training session, the heart was surgically removed for histological analysis and measurement of oxidative stress parameters. Histological imaging revealed cell disruption, with poorly defined nuclei, in the mice exposed to HRCC smoke, but not in the control group. However, mice exposed to HRCC smoke with physical training displayed signs of tissue repair and improved tissue integrity. Biochemical analysis revealed decreased production of superoxide, 2',7'-dichlorofluorescein (DCF), and nitrite, as well as decreased protein carbonylation, in the physical training groups, likely due to the exercise-induced increase in glutathione peroxidase (GPX) activity and glutathione (GSH) content. Taken together, our results suggest that physical exercise exerts cardioprotective effects by modulating the redox responses in animals exposed to HRCC smoke.

Resveratrol attenuates oxidative stress during experimental periodontitis in rats exposed to cigarette smoke inhalation

OBJECTIVES

This study aimed at investigating the effect of the systemic administration of resveratrol (RESV) on oxidative stress during experimental periodontitis in rats subjected to cigarette smoke inhalation.

MATERIAL AND METHODS

Experimental periodontitis (EP) was induced in 26 male Wistar rats by the insertion of a ligature around one of the first mandibular and maxillary molars. The animals were assigned randomly to the following groups: cigarette smoke inhalation (CSI; 3 times/d, 8 minutes/d) + resveratrol (10 mg/Kg), that is, SMK + RESV (n = 13) and cigarette smoke inhalation + placebo, that is, SMK + PLAC (n = 13). The substances were administered daily for 30 days (19 days prior and 11 days following EP induction), and then, the animals were euthanized. The maxillary specimens were processed for morphometric analysis of bone loss, and the tissue surrounding the first maxillary molars was collected for mRNA quantification of Sirtuin 1 (SIRT1) by real-time PCR. The gingival tissues surrounding the mandibular first molars were collected for quantification of superoxide dismutase 1 (SOD1) and nicotinamide adenine dinucleotide phosphatase oxidase (NADPH) using an ELISA assay.

RESULTS

Reduced bone loss was demonstrated in animals in the SMK + RESV group as compared to those in the SMK + PLAC (P < 0.05) group on the basis of morphometric analysis. Resveratrol promoted higher levels of SIRT and SOD (P < 0.05) as well as reduced levels of NADPH oxidase (P < 0.05) were found in tissues derived from animals in the SMK + RESV group when compared to those in the SMK + PLAC group.

CONCLUSION

Resveratrol is an efficient therapeutic agent that reduces exacerbation of bone loss found in animals with EP that were also exposed to smoke. The results suggest that its effects could be mediated, at least in part, by its antioxidant and anti-inflammatory properties which attenuate the effects of oxidative stress on EP in the presence of cigarette smoke.

Cardiac effects of cigarette tobacco smoking in rat model of diabetes

AIMS

Tobacco smoking is considered a global health issue, contributing to increased risk of cardiovascular disease (CVD) and diabetes (DM). We aimed to assess effects of cigarette smoking on cardiac inflammation, oxidative stress and fibrosis in rat model of streptozotocin (STZ)-induced diabetes.

MAIN METHODS

Adults Wistar rats were assigned into control (fresh air, intraperitoneal injection (i.p) of citrate buffer), cigarette smoking (1 h daily for 4 weeks, i.p citrate buffer), DM (35 STZ mg/kg single i.p, fresh air), and DM + Smoking groups for 4 weeks. Cardiac biomarkers of oxidative stress, inflammation, and fibrosis were evaluated.

KEY FINDINGS

STZ-induced diabetes as documented by the persistent increase in blood glucose. Relative to control, a significant decrease in body weight was observed in diabetic groups paralleled with increased heart to body weight ratio and systolic blood pressure in all groups. Levels of total nitrite, thiobarbituric acid substances, endothelin -1, interleukin-6 and myeloperoxidase were increased in the DM, Smoking and DM + Smoking groups without changes in C-reactive protein. Cardiac levels of GSH were increased in Smoking groups whereas activities of catalase and superoxide dismutase increased in DM, Smoking and DM + Smoking groups. DM but not smoking increased cardiac fibrosis with a parallel increase in transforming growth factor beta. Cardiac levels of matrix metalloproteinase-2 were elevated in Smoking groups and decreased in DM.

SIGNIFICANCE

Exposure to cigarette smoke may increase risk of CVD in DM by increased cardiac oxidative stress and inflammation. Smoking was associated with increased oxidant enzymes and metalloproteinase-2 probably to prevent cardiac fibrosis.

Spondias mombin supplementation attenuated cardiac remodelling process induced by tobacco smoke

The objective of this study was to investigate the influence of Spondias mombin (SM) supplementation on the cardiac remodelling process induced by exposure to tobacco smoke (ETS) in rats. Male Wistar rats were divided into 4 groups: group C (control, n = 20) comprised animals not exposed to cigarette smoke and received standard chow; group ETS (n = 20) comprised animals exposed to cigarette smoke and received standard chow; group ETS100 (n = 20) received standard chow supplemented with 100 mg/kg body weight/d of SM; and group ETS250 (n = 20) received standard chow supplemented with 250 mg/kg body weight/d of SM. The observation period was 2 months. The ETS animals had higher values of left cardiac chamber diameters and of left ventricular mass index. SM supplementation attenuated these changes. In addition, the myocyte cross‐sectional area (CSA) was lower in group C compared with the ETS groups; however, the ETS250 group had lower values of CSA compared with the ETS group. The ETS group also showed higher cardiac levels of lipid hydroperoxide (LH) compared with group C; and, groups ETS100 and ETS250 had lower concentrations of LH compared with the ETS group. Regarding energy metabolism, SM supplementation decreased glycolysis and increased the β‐oxidation and the oxidative phosphorylation. There were no differences in the expression of Nrf‐2, SIRT‐1, NF‐κB, interferon‐gamma and interleukin 10. In conclusion, our results suggest that ETS induced the cardiac remodelling process. In addition, SM supplementation attenuated this process, along with oxidative stress reduction and energy metabolism modulation.

Functional, Cellular, and Molecular Remodeling of the Heart under Influence of Oxidative Cigarette Tobacco Smoke

Passive and active chronic cigarette smoking (CS) remains an international epidemic and a key risk factor for cardiovascular disease (CVD) development. CS-induced cardiac damage is divided into two major and interchangeable mechanisms: (1) direct adverse effects on the myocardium causing smoking cardiomyopathy and (2) indirect effects on the myocardium by fueling comorbidities such as atherosclerotic syndromes and hypertension that eventually damage and remodel the heart. To date, our understanding of cardiac remodeling following acute and chronic smoking exposure is not well elucidated. This manuscript presents for the first time the RIMD (oxidative stress (R), inflammation (I), metabolic impairment (M), and cell death (D)) detrimental cycle concept as a major player in CS-induced CVD risks and direct cardiac injury. Breakthroughs and latest findings in the field with respect to structural, functional, cellular, and molecular cardiac remodeling following chronic smoking exposure are summarized. This review also touches the genetics/epigenetics of smoking as well as the smoker's paradox and highlights the most currently prominent pharmacological venues to mitigate CS-induced adverse cardiac remodeling.

The impact of smoking on the development of diabetes and its complications

Diabetes is one of the most common metabolic disorders and emerges secondary to an interaction between genetic, environmental and lifestyle factors. This work provides an overview of the impact of smoking on the development of vascular complications in this condition and also provides an overview of the potential role of smoking in predisposition to diabetes. There are many studies documenting the impact of smoking on health (not focused on patients with diabetes), suggesting that the health exposure in these individuals is at least comparable to that observed in the general population. Distinct studies of smoking in patients with diabetes have unambiguously confirmed an increased prevalence and a higher risk of early death associated with the development of macrovascular complications. Smoking is also associated with premature development of microvascular complications and may contribute to the pathogenesis of type 2 diabetes. It has been shown that smoking is a predictor of the progression of glucose intolerance at both the transition from normoglycaemia to impaired glucose tolerance status and the increased risk of developing diabetes. The mechanisms explaining the relationship between smoking and the development of diabetes are not fully understood, although a number of hypotheses have been put forward. Current evidence indicates that smoking cessation is not only important to prevent macrovascular complications in diabetes, but also has a role in limiting microvascular disease and may also facilitate glycaemic management in this condition.

Smoking intensity and duration is associated with cardiac structure and function: the ECHOcardiographic Study of Hispanics/Latinos

Objective

Cardiovascular disease is the leading cause of death in smokers and this relationship is complicated by the multiplicity of cardiovascular effects of smoking. However, the relationship between intensity and duration of cigarette smoking and echocardiographic measures of right and left ventricular structure and function has been poorly studied.

Methods

We examined ECHO-SOL (Echocardiographic Study of Hispanics/Latinos) participants, a subset of the Hispanic Community Health Study/Study of Latinos. Participants were administered a detailed tobacco exposure questionnaire and a comprehensive echocardiography exam. Multivariable linear regression models (adjusted for age, sex, obesity, hypertension and diabetes statuses) were performed using sampling weights. Statistical significance was defined at p<0.01.

Results

There were 1818 ECHO-SOL participants (57.4% women, mean age 56.4 years). Among current smokers (n=304), increased duration of smoking, as measured by a younger age of smoking initiation, was significantly associated with higher mean left ventricular mass (LVM) and lower right ventricular (RV) function (lower right ventricular stroke volumes). More cigarettes smoked per day was significantly associated with higher mean LVM, worse diastolic function (higher E/e′ ratio), worse LV geometry (increased relative wall thickness) and worse RV function (decreasing right ventricular stroke volume). Among current smokers, higher mean lifetime pack-years (a combined measure of smoking intensity and duration) was associated with higher LVM, worse LV geometry, worse diastolic function, greater RV dilatation and worse RV function.

Conclusions

There is a dose–response relationship between intensity and duration of cigarette tobacco smoking with unfavourable changes of multiple measures of right-sided and left-sided cardiac structure and function.

The Impact of Environmental Factors in Influencing Epigenetics Related to Oxidative States in the Cardiovascular System

Oxidative states exert a significant influence on a wide range of biological and molecular processes and functions. When their balance is shifted towards enhanced amounts of free radicals, pathological phenomena can occur, as the generation of reactive oxygen species (ROS) in tissue microenvironment or in the systemic circulation can be detrimental. Epidemic chronic diseases of western societies, such as cardiovascular disease, obesity, and diabetes correlate with the imbalance of redox homeostasis. Current advances in our understanding of epigenetics have revealed a parallel scenario showing the influence of oxidative stress as a major regulator of epigenetic gene regulation via modification of DNA methylation, histones, and microRNAs. This has provided both the biological link and a potential molecular explanation between oxidative stress and cardiovascular/metabolic phenomena. Accordingly, in this review, we will provide current insights on the physiological and pathological impact of changes in oxidative states on cardiovascular disorders, by specifically focusing on the influence of epigenetic regulation. A special emphasis will highlight the effect on epigenetic regulation of human's current life habits, external and environmental factors, including food intake, tobacco, air pollution, and antioxidant-based approaches. Additionally, the strategy to quantify oxidative states in humans in order to determine which biological marker could best match a subject's profile will be discussed.

Chronic exposure to water-pipe smoke induces cardiovascular dysfunction in mice

Water-pipe tobacco smoking is becoming prevalent in all over the world including Western countries. There are limited data on the cardiovascular effects of water-pipe smoke (WPS), in particular following chronic exposure. Here, we assessed the chronic cardiovascular effects of nose-only WPS exposure in C57BL/6 mice. The duration of the session was 30 minutes/day, 5 days/week for 6 consecutive months. Control mice were exposed to air. WPS significantly increased systolic blood pressure. The relative heart weight and plasma concentrations of troponin-I and B-type natriuretic peptide were increased in mice exposed to WPS. Arterial blood gas analysis showed that WPS caused a significant decrease in [Formula: see text] and an increase in [Formula: see text] WPS significantly shortened the thrombotic occlusion time in pial arterioles and venules and increased the number of circulating platelet. Cardiac lipid peroxidation, measured as thiobarbituric acid-reactive substances, was significantly increased, while superoxide dismutase activity, total nitric oxide activity, and glutathione concentration were reduced by WPS exposure. Likewise, immunohistochemical analysis of the heart revealed an increase in the expression of inducible nitric oxide synthase and cytochrome c by cardiomyocytes of WPS-exposed mice. Moreover, hearts of WPS-exposed mice showed the presence of focal interstitial fibrosis. WPS exposure significantly increased heart DNA damage assessed by Comet assay. We conclude that chronic nose-only exposure to WPS impairs cardiovascular homeostasis. Our findings provide evidence that long-term exposure to WPS is harmful to the cardiovascular system and supports interventions to control the spread of WPS, particularly amid youths.NEW & NOTEWORTHY No data are available on the chronic cardiovascular effects of water-pipe smoke (WPS). Our findings provide experimental evidence that chronic exposure to WPS increased blood pressure, relative heart weight, troponin I, and B-type natriuretic peptide in plasma and induced hypoxemia, hypercapnia, and thrombosis. Moreover, WPS caused cardiac oxidative stress, DNA damage, and fibrosis.

Pentoxifylline Attenuates Cardiac Remodeling Induced by Tobacco Smoke Exposure

Background

Tobacco smoke exposure is an important risk factor for cardiac remodeling. Under this condition, inflammation, oxidative stress, energy metabolism abnormalities, apoptosis, and hypertrophy are present. Pentoxifylline has anti‑inflammatory, anti-apoptotic, anti-thrombotic and anti-proliferative properties.

Objective

The present study tested the hypothesis that pentoxifylline would attenuate cardiac remodeling induced by smoking.

Methods

Wistar rats were distributed in four groups: Control (C), Pentoxifylline (PX), Tobacco Smoke (TS), and PX-TS. After two months, echocardiography, invasive blood pressure measurement, biochemical, and histological studies were performed. The groups were compared by two-way ANOVA with a significance level of 5%.

Results

TS increased left atrium diameter and area, which was attenuated by PX. In the isolated heart study, TS lowered the positive derivate (+dp/dt), and this was attenuated by PX. The antioxidants enzyme superoxide dismutase and glutathione peroxidase were decreased in the TS group; PX recovered these activities. TS increased lactate dehydrogenase (LDH) and decreased 3-hydroxyacyl Coenzyme A dehydrogenases (OH-DHA) and citrate synthase (CS). PX attenuated LDH, 3-OH-DHA and CS alterations in TS-PX group. TS increased IL-10, ICAM-1, and caspase-3. PX did not influence these variables.

Conclusion

TS induced cardiac remodeling, associated with increased inflammation, oxidative stress, apoptosis, and changed energy metabolism. PX attenuated cardiac remodeling by reducing oxidative stress and improving cardiac bioenergetics, but did not act upon cardiac cytokines and apoptosis.

Higher Plasma Myostatin Levels in Cor Pulmonale Secondary to Chronic Obstructive Pulmonary Disease

Objective

To analyze plasma myostatin levels and investigate their relationship with right ventricular (RV) function in patients with cor pulmonale secondary to chronic obstructive pulmonary disease (COPD).

Methods

The study recruited 81 patients with advanced COPD and 40 age-matched controls. The patients were divided into two groups: those with cor pulmonale and those without. Echocardiography was used to evaluate RV function and morphology, and the value of tricuspid annular plane systolic excursion (TAPSE) less than 16 mm was considered RV dysfunction. Plasma myostatin levels were analyzed by enzyme-linked immunosorbent assay, and B-type natriuretic peptide (BNP) levels were analyzed as a comparison of myostatin.

Results

The data detected cor pulmonale in 39/81 patients, with the mean value of TAPSE of 14.3 mm. Plasma myostatin levels (ng/mL) were significantly higher in patients with cor pulmonale (16.68 ± 2.95) than in those without (13.56 ± 3.09), and much higher than in controls (8.79±2.79), with each p<0.01. Significant differences were also found in plasma BNP levels among the three groups (p<0.05). Multivariate regression analysis suggested that myostatin levels were significantly correlated with the values of TAPSE and RV myocardium performance index among the COPD patients, and that BNP levels were significantly correlated only with systolic pulmonary arterial pressure, with each p<0.05.

Conclusions

Plasma myostatin levels are increased in COPD patients who have cor pulmonale. Stronger correlations of plasma myostatin levels with echocardiographic indexes of the right heart suggest that myostatin might be superior to BNP in the early diagnosis of cor pulmonale in COPD.

Tomato (Lycopersicon esculentum) Supplementation Induces Changes in Cardiac miRNA Expression, Reduces Oxidative Stress and Left Ventricular Mass, and Improves Diastolic Function

The aim of this study was to evaluate the effects of tomato supplementation on the normal rat heart and the role of oxidative stress in this scenario. Male Wistar rats were assigned to two groups: a control group (C; n = 16), in which animals received a control diet + 0.5 mL of corn oil/kg body weight/day, and a tomato group (T; n = 16), in which animals received a control diet supplemented with tomato +0.5 mL of corn oil/kg body weight/day. After three months, morphological, functional, and biochemical analyses were performed. Animals supplemented with tomato had a smaller left atrium diameter and myocyte cross-sectional area (CSA) compared to the control group (C group: 474 (415–539); T group: 273 (258–297) µm²; p = 0.004). Diastolic function was improved in rats supplemented with tomato. In addition, lipid hydroperoxide was lower (C group: 267 ± 46.7; T group: 219 ± 23.0 nmol/g; p = 0.039) in the myocardium of rats supplemented with tomato. Tomato intake was also associated with up-regulation of miR-107 and miR-486 and down-regulation of miR-350 and miR-872. In conclusion, tomato supplementation induces changes in miRNA expression and reduces oxidative stress. In addition, these alterations may be responsible for CSA reduction and diastolic function improvement.

The role of lipotoxicity in smoke cardiomyopathy

Background/Aims

Experimental and clinical studies have shown the direct toxic effects of cigarette smoke (CS) on the myocardium, independent of vascular effects. However, the underlying mechanisms are not well known.

Methods

Wistar rats were allocated to control (C) and cigarette smoke (CS) groups. CS rats were exposed to cigarette smoke for 2 months.

Results

After that morphometric, functional and biochemical parameters were measured. The echocardiographic study showed enlargement of the left atria, increase in the left ventricular systolic volume and reduced systolic function. Within the cardiac metabolism, exposure to CS decreased beta hydroxy acyl coenzyme A dehydrogenases and citrate synthases and increased lactate dehydrogenases. Peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) were expressed similarly in both groups. CS increased serum lipids and myocardial triacylglycerols (TGs). These data suggest that impairment in fatty acid oxidation and the accumulation of cardiac lipids characterize lipotoxicity. CS group exhibited increased oxidative stress and decreased antioxidant defense. Finally, the myocyte cross-sectional area and active Caspase 3 were increased in the CS group.

Conclusion

The cardiac remodeling that was observed in the CS exposure model may be explained by abnormalities in energy metabolism, including lipotoxicity and oxidative stress.

NADPH oxidase and the cardiovascular toxicity associated with smoking

Smoking is one of the most serious but preventable causes of cardiovascular disease (CVD). Key aspects of pathological process associated with smoking include endothelial dysfunction, a prothrombotic state, inflammation, altered lipid metabolism, and hypoxia. Multiple molecular events are involved in smokinginduced CVD. However, the dysregulations of reactive oxygen species (ROS) generation and metabolism mainly contribute to the development of diverse CVDs, and NADPH oxidase (NOX) has been established as a source of ROS responsible for the pathogenesis of CVD. NOX activation and resultant ROS production by cigarette smoke (CS) treatment have been widely observed in isolated blood vessels and cultured vascular cells, including endothelial and smooth muscle cells. NOX-mediated oxidative stress has also been demonstrated in animal studies. Of the various NOX isoforms, NOX2 has been reported to mediate ROS generation by CS, but other isoforms were not tested thoroughly. Of the many CS constituents, nicotine, methyl vinyl ketone, and α,β-unsaturated aldehydes, such as, acrolein and crotonaldehyde, appear to be primarily responsible for NOX-mediated cytotoxicity, but additional validation will be needed. Human epidemiological studies have reported relationships between polymorphisms in the CYBA gene encoding p22phox, a catalytic subunit of NOX and susceptibility to smoking-related CVDs. In particular, G allele carriers of A640G and -930^A/G polymorphisms were found to be vulnerable to smoking-induced cardiovascular toxicity, but results for C242T studies are conflicting. On the whole, evidence implicates the etiological role of NOX in smoking-induced CVD, but the clinical relevance of NOX activation by smoking and its contribution to CVD require further validation in human studies. A detailed understanding of the role of NOX would be helpful to assess the risk of smoking to human health, to define high-risk subgroups, and to develop strategies to prevent or treat smoking-induced CVD.

The -930A>G polymorphism of the CYBA gene is associated with premature coronary artery disease. A case-control study and gene-risk factors interactions

Reactive oxygen species (ROS) are involved in the pathogenesis of atherosclerosis and coronary artery disease (CAD). NADPH oxidases are the main source of ROS in the vasculature. p22phox is a critical component of vascular NADPH oxidases and is encoded by the CYBA (cytochrome b₂₄₅ alpha) gene. The −930A>G CYBA polymorphism (rs9932581:A>G) modulates the activity of the CYBA promoter, and influences CYBA transcriptional activity. The aim of the present study was to analyze a possible association between the −930A>G polymorphism and CAD and to search for gene–traditional risk factors interactions. 480 subjects were studied: 240 patients with premature CAD, 240 age and sex matched blood donors. The −930A>G polymorphism was genotyped using the TaqMan^® Pre-designed SNP Genotyping Assay (Applied Biosystems). The −930G allele carrier state was a risk factor for CAD (OR 2.03, 95 % CI 1.21–3.44, P = 0.007). A synergistic effect of the −930G allele with overweight/obesity (BMI ≥ 25) and cigarette smoking was found. The estimated CAD risk for BMI ≥ 25 and the −930G allele interaction was about 160 % greater than that predicted by assuming additivity of the effects, and about 40 % greater for interaction of cigarette smoking and the −930G allele. Overweight/obesity was a risk factor for CAD only in the −930G allele carriers (P < 10⁻¹⁰) but not in the AA homozygotes (P = 1.00). In conclusion the −930A>G CYBA polymorphism is associated with CAD in the Polish population. The −930G allele carriers are particularly at risk of consequences of obesity and tobacco smoke exposure.

Aldosterone is not involved in the ventricular remodeling process induced by tobacco smoke exposure

BACKGROUND/AIMS

Renin-angiotensin-aldosterone system blockade with a mineralocorticoid-receptor antagonist has not yet been studied in exposure to tobacco smoke (TS) models. Thus, this study investigated the role of spironolactone on cardiac remodeling induced by exposure to tobacco smoke.

METHODS

Male Wistar rats were divided into 4 groups: a control group (group C, n=11); a group with 2 months of cigarette smoke exposure (group TS-C, n=13); a group that received spironolactone 20 mg/kg of diet/day and no cigarette smoke exposure (group TS-S, n=13); and a group with 2 months of cigarette smoke exposure and spironolactone supplementation (group S, n=12). The rats were observed for a period of 60 days, during which morphological, biochemical and functional analyses were performed.

RESULTS

There was no difference in invasive mean arterial pressure among the groups. There were no interactions between tobacco smoke exposure and spironolactone in the morphological and functional analysis. However, in the echocardiographic analysis, the TS groups had left chamber enlargement, higher left ventricular mass index and higher isovolumetric relaxation time corrected by heart rate compared with the non-TS groups. In vitro left ventricular diastolic function also worsened in the TS groups and was not influenced by spironolactone. In addition, there were no differences in myocardial levels of IFN-γ, TNF-α, IL-10, ICAM-1 and GLUT4 [TS: OR 0.52, 95%CI (-0.007; 0.11); Spironolactone: OR -0.01, 95%CI (-0.07;0.05)].

CONCLUSION

Our data do not support the participation of aldosterone in the ventricular remodeling process induced by exposed to cigarette smoke.

Atrophic cardiac remodeling induced by taurine deficiency in Wistar rats

Introduction

Micronutrient deficiency is observed in heart failure patients. Taurine, for example, represents 50% of total free amino acids in the heart, and in vivo studies have linked taurine deficiency with cardiomyopathy.

Methods

Thirty-four male Wistar rats (body weight = 100 g) were weighed and randomly assigned to one of two groups: Control (C) or taurine-deficient (T (-)). Beta-alanine at a concentration of 3% was added to the animals’ water to induce taurine deficiency in the T (-) group. On day 30, the rats were individually submitted to echocardiography; morphometrical and histopathological evaluation and metalloproteinase activity, oxidative stress and inflammation evaluation were performed. Tissue samples were collected to determine the taurine concentration in the heart.

Results

Taurine deficiency led to decreases in: ventricular wall thickness, left ventricle dry weight, myocyte sectional area, left ventricle posterior wall thickness and ventricular geometry. With regard to heart function, the velocity of the A wave, the ratio between the E and A wave, the ejection fraction, fractional shortening and cardiac output values were decreased in T (-) rats, suggesting abnormal diastolic and systolic function. Increased fibrosis, inflammation and increased activation of metalloproteinases were not observed. Oxidative stress was increased in deficient animals.

Conclusions

These data suggest that taurine deficiency promotes structural and functional cardiac alterations with unique characteristics.