Cigarette smoking, endothelial injury and cardiovascular disease

The prevalence and correlates of subclinical atherosclerosis among adults with low-density lipoprotein cholesterol <70 mg/dL: The Multi-Ethnic Study of Atherosclerosis (MESA) and Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND AND AIMS

The prevalence and correlates of subclinical atherosclerosis when low-density lipoprotein cholesterol (LDL-C) levels are low remain unclear. Therefore, we examined the association of cardiovascular risk factors and subclinical atherosclerosis among individuals with untreated LDL-C <70 mg/dL.

METHODS

We included participants from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohorts. To optimize accuracy, LDL-C was calculated by the validated Martin/Hopkins equation that uses an adjustable factor for the ratio of triglycerides to very low-density lipoprotein cholesterol. We defined subclinical atherosclerosis as a coronary artery calcium (CAC) score >0 in the combined cohort or common carotid intima media thickness (cIMT) in the 4^th quartile, using cohort-specific cIMT distributions at baseline. Logistic regression models examined the cross-sectional associations of cardiovascular risk factors and subclinical atherosclerosis.

RESULTS

Among 9411 participants not on lipid lowering therapy, 263 (3%) had LDL-C <70 mg/dL (MESA: 206, ELSA: 57). Mean age in this population was 58 (SD 12) years, with 43% men, and 41% Black. The prevalence of CAC >0 in those with untreated LDL-C<70 mg/dL was 30%, and 18% were in 4th quartile of cIMT. In demographically adjusted models, only ever smoking was significantly associated with both CAC and cIMT. Similar results were obtained in risk factor-adjusted models (smoking: OR, 2.29; 95% CI, 1.10-4.80 and OR, 3.44; 95% CI, 1.41-8.37 for CAC and cIMT, respectively).

CONCLUSIONS

Among middle-aged to older individuals with untreated LDL-C <70 mg/dL, subclinical atherosclerosis remains moderately common and is associated with cigarette smoking.

Crocin attenuates cigarette smoke-induced lung injury and cardiac dysfunction by anti-oxidative effects: the role of Nrf2 antioxidant system in preventing oxidative stress

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has been emerging as a great health problem in world. Cigarette smoke is known to cause oxidative stress and deplete glutathione (GSH) levels. Nuclear erythroid-related factor 2 (Nrf2) is involved in transcriptional regulation of glutamate-cysteine ligase catalytic subunit (GCLc). Antioxidant compounds may be of therapeutic value in monitoring disease progression. Crocin demonstrates antioxidant and anti-inflammatory functions. The aim of this study was to investigate the protective role of crocin against CSE-mediated oxidative stress, inflammatory process, Nrf2 modifications and impairment of cardiac function in rats with COPD.

METHODS

Eighty rats were divided into four groups: Control, Cigarette smoke exposure (CSE), Crocin, Crocin+CS. Each group was divided into the two parts: 1) to evaluate lung inflammatory and oxidative process, 2) to evaluate the effect of Cigarette smoke induced-lung injuries on cardiac electrocardiogram (such as heart rate and QRS complex) and hemodynamic parameters (such as perfusion pressure and left ventricular developed pressure).

RESULTS

CSE rats showed a significant increase in cotinine concentration (17.24 ng/ml), and inflammatory parameters and a decrease in PO2 (75.87 mmHg) and expression of PKC (0.86 fold), PI3K (0.79 fold), MAPK (0.87 fold), Nrf2 (0.8 fold) and GCLc (0.75 fold) genes, antioxidant activity, and finally cardiac abnormalities in electrocardiogram and hemodynamic parameters. Co-treatment whit crocin could restore all these values to normal levels.

CONCLUSIONS

CS induced-COPD in rat model provides evidence that chronic CS exposure leads to lung injury and mediated cardiac dysfunction. Crocin co-treatment by modulating of Nrf2 pathway protected lung injury caused by COPD and its related cardiac dysfunction. In this study, we showed the importance of Nrf2 activators as a therapeutic target for the development of novel therapy for lung oxidative injuries.

Didymin prevents hyperglycemia-induced human umbilical endothelial cells dysfunction and death

Although didymin, a flavonoid-O-glycosides compound naturally found in the citrus fruits, has been reported to be a potent anticancer agent in the prevention of various cancers, its role in the prevention of cardiovascular complications is unclear. Most importantly, its effect in the prevention of endothelial dysfunction, a pathological process involved in the atherogenesis, is unknown. We have examined the efficacy of didymin in preventing the high glucose (HG; 25 mM)-induced human umbilical vein endothelial cells (HUVECs) dysfunction. Our results indicate that incubation of HUVECs with HG resulted in the loss of cell viability, and pre-incubation of didymin prevented it. Further, didymin prevented the HG-induced generation of reactive oxygen species (ROS) as well as lipid peroxidation product, malondialdehyde. Pretreatment of HUVECs with didymin also prevented the HG-induced decrease in eNOS and increase in iNOS expressions. Further, didymin prevented the HG-induced monocytes cell adhesion to endothelial cells, expressions of ICAM-1 and VCAM-1 and activation of NF-κB. Didymin also prevented the release of various inflammatory cytokines and chemokines in HG-treated HUVECs. In conclusion, our results demonstrate that didymin with its anti-oxidative and anti-inflammatory actions prevents hyperglycemia-induced endothelial dysfunction and death. Thus, it could be developed as a potential natural therapeutic agent for the prevention of cardiovascular complications in diabetes.

COPD as an endothelial disorder: endothelial injury linking lesions in the lungs and other organs? (2017 Grover Conference Series)

Chronic obstructive pulmonary disease (COPD) is characterized by chronic expiratory airflow obstruction that is not fully reversible. COPD patients develop varying degrees of emphysema, small and large airway disease, and various co-morbidities. It has not been clear whether these co-morbidities share common underlying pathogenic processes with the pulmonary lesions. Early research into the pathogenesis of COPD focused on the contributions of injury to the extracellular matrix and pulmonary epithelial cells. More recently, cigarette smoke-induced endothelial dysfunction/injury have been linked to the pulmonary lesions in COPD (especially emphysema) and systemic co-morbidities including atherosclerosis, pulmonary hypertension, and chronic renal injury. Herein, we review the evidence linking endothelial injury to COPD, and the pathways underlying endothelial injury and the "vascular COPD phenotype" including: (1) direct toxic effects of cigarette smoke on endothelial cells; (2) generation of auto-antibodies directed against endothelial cells; (3) vascular inflammation; (4) increased oxidative stress levels in vessels inducing increases in lipid peroxidation and increased activation of the receptor for advanced glycation end-products (RAGE); (5) reduced activation of the anti-oxidant pathways in endothelial cells; (6) increased endothelial cell release of mediators with vasoconstrictor, pro-inflammatory, and remodeling activities (endothelin-1) and reduced endothelial cell expression of mediators that promote vasodilation and homeostasis of endothelial cells (nitric oxide synthase and prostacyclin); and (7) increased endoplasmic reticular stress and the unfolded protein response in endothelial cells. We also review the literature on studies of drugs that inhibit RAGE signaling in other diseases (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), or vasodilators developed for idiopathic pulmonary arterial hypertension that have been tested on cell culture systems, animal models of COPD, and/or smokers and COPD patients.

Cigarette Smoke Extract Inhibits Platelet Aggregation by Suppressing Cyclooxygenase Activity

The results of studies that were performed to determine whether cigarette smoking affects platelet function have been controversial, and the effects of nicotine- and tar-free cigarette smoke extract (CSE) on platelet function remain to be determined. The aim of this study was to determine the effect of CSE on platelet aggregation and to clarify the mechanism by which CSE affects platelet function. CSE inhibited murine platelet aggregation induced by 9,11-dideoxy-9α,11α-methanoepoxy-prosta-5Z,13E-dien-1-oic acid (U-46619), a thromboxane (TX) A ₂ receptor agonist, and that induced by collagen with respective IC ₅₀ values of 1.05 ± 0.14% and 1.34 ± 0.19%. A similar inhibitory action of CSE was also observed in human platelets. CSE inhibited arachidonic acid–induced TXA ₂ production in murine platelets with an IC ₅₀ value of 7.32 ± 2.00%. Accordingly, the inhibitory effect of CSE on collagen-induced aggregation was significantly blunted in platelets lacking the TXA ₂ receptor compared with the inhibitory effect in control platelets. In contrast, the antiplatelet effects of CSE in platelets lacking each inhibitory prostanoid receptor, prostaglandin (PG) I ₂ receptor and PGE ₂ receptor subtypes EP ₂ and EP ₄ , were not significantly different from the effects in respective control platelets. Among the enzymes responsible for TXA ₂ production in platelets, the activity of cyclooxygenase (COX)-1 was inhibited by CSE with an IC ₅₀ value of 1.07 ± 0.15% in an uncompetitive manner. In contrast, the activity of TX synthase was enhanced by CSE. The results indicate that CSE inhibits COX-1 activity and thereby decreases TXA ₂ production in platelets, leading to inhibition of platelet aggregation.

Impact of commercial cigarette smoke condensate on brain tissue co-cultured with astrocytes and blood-brain barrier endothelial cells

The purpose of the current study was to investigate the effect of two commercial cigarette smoke condensates (CCSC) on oxidative stress and cell cytotoxicity in human brain (T98G) or astrocytes (U-373 MG) in the presence of human brain microvascular endothelial cells (HBMEC). Cell viability of mono-culture of T98G or U-373 MG was markedly decreased in a concentration-dependent manner, and T98G was more susceptible than U-373 MG to CCSC exposure. Cytotoxicity was less prominent when T98G was co-cultured with HBMEC than when T98G was co-cultured with U-373 MG. Significant reduction in trans-epithelial electric resistance (TEER), a biomarker of cellular integrity was noted in HBMEC co-cultured with T98G (HBMEC-T98G co-culture) and U-373 MG co-cultured with T98G (U-373 MG-T98G co-culture) after 24 or 48 hr CCSC exposure, respectively. TEER value of U-373 MG co-cultured with T98G (79-84%) was higher than HBMEC co-cultured with T98G (62-63%) within 120-hr incubation with CCSC. Reactive oxygen species (ROS) generated by CCSC in mono-culture of T98G and U-373 MG reached highest levels at 4 and 16 mg/ml, respectively. ROS production by T98G fell when co-cultured with HBMEC or U-373MG. These findings suggest that adverse consequences of CCSC treatment on brain cells may be protected by blood-brain barrier or astrocytes, but with chronic exposure toxicity may be worsened due to destruction of cellular integrity.

The impact of passive and active smoking on inflammation, lipid profile and the risk of myocardial infarction

Objective

To investigate the effect of passive smoking, active smoking and smoking cessation on inflammation, lipid profile and the risk of myocardial infarction (MI).

Methods

A total of 423 cases with a first MI and 465 population controls from the Maltese Acute Myocardial Infarction (MAMI) Study were analysed. Data were collected through an interviewer-led questionnaire, and morning fasting blood samples were obtained. ORs adjusted for the conventional risk factors of MI (aORs) were calculated as an estimate of the relative risk of MI. The influence of smoking on biochemical parameters was determined among controls.

Results

Current smokers had a 2.7-fold (95% CI 1.7 to 4.2) and ex-smokers a 1.6-fold (95% CI 1.0 to 2.4) increased risk of MI. Risk increased with increasing pack-years and was accompanied by an increase in high-sensitivity C reactive protein levels and an abnormal lipid profile. Smoking cessation was associated with lower triglyceride levels. Exposure to passive smoking increased the risk of MI (aOR 3.2 (95% CI 1.7 to 6.3)), with the OR being higher for individuals exposed to passive smoking in a home rather than in a public setting (aOR 2.0 (95% CI 0.7 to 5.6) vs aOR 1.2 (95% CI 0.7 to 2.0)). Passive smoke exposure was associated with higher levels of total cholesterol, triglycerides and total cholesterol:high-density lipoprotein cholesterol ratio compared with individuals not exposed to passive smoking.

Conclusions

Both active and passive smoking are strong risk factors for MI. This risk increased with increasing pack-years and decreased with smoking cessation. Such effects may be partly mediated through the influence of smoking on inflammation and lipid metabolism.

An endothelial link between the benefits of physical exercise in dementia

The current absence of a disease-modifying treatment for Alzheimer's disease (AD) and vascular cognitive impairment and dementia (VCID) highlights the necessity for investigating the benefits of non-pharmacological approaches such as physical exercise (PE). Although evidence exists to support an association between regular PE and higher scores on cognitive function tests, and a slower rate of cognitive decline, there is no clear consensus on the underlying molecular mechanisms of the advantages of PE. This review seeks to summarize the positive effects of PE in human and animal studies while highlighting the vascular link between these benefits. Lifestyle factors such as cardiovascular diseases, metabolic syndrome, and sleep apnea will be addressed in relation to the risk they pose in developing AD and VCID, as will molecular factors known to have an impact on either the initiation or the progression of AD and/or VCID. This will include amyloid-beta clearance, oxidative stress, inflammatory responses, neurogenesis, angiogenesis, glucose metabolism, and white matter integrity. Particularly, this review will address how engaging in PE can counter factors that contribute to disease pathogenesis, and how these alterations are linked to endothelial cell function.

Incidental extravascular findings in computed tomographic angiography for planning or monitoring endovascular aortic aneurysm repair: Smoker patients, increased lung cancer prevalence?

AIM

To validate the feasibility of high resolution computed tomography (HRCT) of the lung prior to computed tomography angiography (CTA) in assessing incidental thoracic findings during endovascular aortic aneurysm repair (EVAR) planning or follow-up.

METHODS

We conducted a retrospective study among 181 patients (143 men, mean age 71 years, range 50-94) referred to our centre for CTA EVAR planning or follow-up. HRCT and CTA were performed before or after 1 or 12 mo respectively to EVAR in all patients. All HRCT examinations were reviewed by two radiologists with 15 and 8 years’ experience in thoracic imaging. The results were compared with histology, bronchoscopy or follow-up HRCT in 12, 8 and 82 nodules respectively.

RESULTS

There were a total of 102 suspected nodules in 92 HRCT examinations, with a mean of 1.79 nodules per patient and an average diameter of 9.2 mm (range 4-56 mm). Eighty-nine out of 181 HRCTs resulted negative for the presence of suspected nodules with a mean smoking history of 10 pack-years (p-y, range 5-18 p-y). Eighty-two out of 102 (76.4%) of the nodules met criteria for computed tomography follow-up, to exclude the malignant evolution. Of the remaining 20 nodules, 10 out of 20 (50%) nodules, suspected for malignancy, underwent biopsy and then surgical intervention that confirmed the neoplastic nature: 4 (20%) adenocarcinomas, 4 (20%) squamous cell carcinomas, 1 (5%) small cell lung cancer and 1 (5%) breast cancer metastasis); 8 out of 20 (40%) underwent bronchoscopy (8 pneumonia) and 2 out of 20 (10%) underwent biopsy with the diagnosis of sarcoidosis.

CONCLUSION

HRCT in EVAR planning and follow-up allows to correctly identify patients requiring additional treatments, especially in case of lung cancer.

Cigarette Smoking-Associated Alterations in Serotonin/Adrenalin Signaling Pathways of Platelets

Background

Cigarette smoking plays a major role in cardiovascular diseases. The acute effects of cigarette smoking produce central nervous system–mediated activation of the sympathetic nervous system. The overactive sympathetic nervous system stimulates the secretion of serotonin (5‐HT) and catecholamine into blood at supraphysiological levels. The correlation between these pathological conditions induced by smoking and the increased risk of thrombosis has not been thoroughly investigated. The goal of our study was to explore cigarette smoking–associated changes in platelet biology mediated by elevated 5‐HT and catecholamine levels in blood plasma.

Methods and Results

Using blood samples collected from healthy nonsmokers and smokers (15 minutes after smoking), we determined that cigarette smoking increased the plasma 5‐HT/catecholamine concentration by several fold and the percent aggregation of platelets 2‐fold. Liquid chromatography–tandem mass spectrometry analysis of proteins eluted from platelet plasma membranes of smokers and nonsmokers demonstrated that GTPase‐activating proteins and proteins participating in the actin cytoskeletal network were differentially and significantly elevated in smokers' platelet membranes compared with those of nonsmokers. Interestingly, Matrix‐assisted laser desorption/ionization–mass spectrometry analyses of the glycans eluted from platelet plasma membranes of the smokers demonstrated that the level and structures of glycans are different from the nonsmokers' platelet surface glycans. Pharmacological blockade of 5‐HT or catecholamine receptors counteracted the 5‐HT/catecholamine‐mediated aggregation and altered the level and composition of glycan on platelet surfaces.

Conclusions

Based on our findings, we propose that smoking‐associated 5‐HT/catecholamine signaling accelerates the trafficking dynamics of platelets, and this remodels the surface proteins and glycans and predisposes platelets to hyperactive levels. Smokers' platelets also had correspondingly higher resting concentrations of intracellular calcium and transglutaminase activity. These findings suggest a link among smoking, platelet 5‐HT, catecholamine signaling, and their downstream effectors—including phospholipase C and inositol‐1,4,5‐triphosphate pathways—resulting in an increased tonic level of platelet activation in smokers.

Progressive fingertip necrosis after nail avulsion injury in a patient with ulnar artery hypoplasia: A case report

RATIONALE

Slowly progressive hand ischemia is mostly associated with medical illness such as vasculitis, and in patients with smoking history, Buerger disease is often considered first. However, despite the very low incidence of vascular anatomical anomalies, they can lead to hand ischemia. And if there is no consideration for them, proper treatment cannot be selected.

PATIENT CONCERNS

A 42-year-old male smoker presented with a slowly progressing 5th fingertip necrosis following blunt trauma.

DIAGNOSES

Angiography revealed congenital hypoplasia of ulnar artery, and excluded Buerger disease or hypothenar hammer syndrome.

INTERVENTIONS AND OUTCOMES

We reconstructed the necrotic fingertip using a 2nd toe pulp free flap to reflect the patient's need.

LESSONS

In this case report, the authors emphasize that the possibility of anatomical anomaly should be considered as a cause of the ischemia. Vascular imaging should be undertaken to investigate the cause of ischemia of the hand.

Subclinical Carotid Atherosclerosis in Asymptomatic Subjects With Type 2 Diabetes Mellitus

BACKGROUND

Subjects with type 2 diabetes mellitus are considered to be at high risk for cardiovascular disease. The identification of carotid atherosclerosis is a validated surrogate marker of cardiovascular disease. Nurses are key professionals in the improvement and intensification of cardiovascular preventive strategies.

AIMS

The aim is to study the presence of carotid atherosclerosis in a group of asymptomatic subjects with type 2 diabetes mellitus and no previous clinical cardiovascular disease.

METHODS

A total of 187 patients with type 2 diabetes mellitus and 187 age- and sex-matched subjects without type 2 diabetes mellitus were studied in this cross-sectional, observational, cohort study. Standard operational procedures were applied by the nursing team regarding physical examination and carotid ultrasound assessment. Common, bulb, and internal carotid arteries were explored by measuring intima-media thickness and identifying atherosclerotic plaques.

RESULTS

Carotid intima-media thickness (c-IMT) and carotid plaque prevalence were significantly greater in diabetic subjects than in the control group. Carotid plaques and c-IMT were more frequent in men than in women and increased with increasing age. In the multivariate analysis, age, gender, waist circumference, systolic blood pressure, and hypercholesterolemia were positively associated with c-IMT, whereas age, gender, and weight were positively associated with carotid plaque.

CONCLUSION

The current nurse-led study shows that subjects with type 2 diabetes mellitus have a high prevalence of subclinical atherosclerosis that is associated with cardiovascular risk factors.

Are healthy smokers really healthy?

Cigarette smoke contains more than 4500 chemicals which have toxic, mutagenic and carcinogenic effects. Strong evidences have shown that current smokers take a significantly higher risk of cardiovascular diseases, chronic obstructive pulmonary disease (COPD) and lung cancer than nonsmokers. However, less attention has been paid to the smoking induced abnormalities in the individuals defined as healthy smokers who are normal with spirometry, radiographic images, routine physical exam and categorized as healthy control group in many researches. Actually, ‘healthy smokers’ are not healthy. This narrative review focuses on the smoking related pathophysiologic changes mainly in the respiratory system of healthy smokers, including inflammation and immune changes, genetic alterations, structural changes and pulmonary dysfunction.

Cardiovascular disease risk factors in relation to smoking behaviour and history: a population-based cohort study

Objective

To investigate how individual risk factors for cardiovascular disease (CVD) (blood pressure, lipid levels, body mass index, waist and hip circumference, use of antihypertensive or hypolipidemic medication, and diagnosed diabetes) differ in people aged 46 years with different smoking behaviour and history.

Methods

This population-based cohort study is based on longitudinal data from the Northern Finland Birth Cohort 1966 project. Data were collected at the 31-year and 46-year follow-ups, when a total of 5038 and 5974 individuals participated in clinical examinations and questionnaires. Data from both follow-ups were available for 3548 participants. In addition to individual CVD risk factors, Framingham and Systematic Coronary Risk Evaluation (SCORE) algorithms were used to assess the absolute risk of a CVD event within the next decade.

Results

The differences in individual risk factors for CVD reached statistical significance for some groups, but the differences were not consistent or clinically significant. There were no clinically significant differences in CVD risk as measured by Framingham or SCORE algorithms between never smokers, recent quitters and former smokers (7.5%, 7.4%, 8.1% for men; 3.3%, 3.0%, 3.2% for women; p<0.001).

Conclusions

The effect of past or present smoking on individual CVD risk parameters such as blood pressure and cholesterol seems to be of clinically minor significance in people aged 46 years. In other words, smoking seems to be above all an independent risk factor for CVD in the working-age population. Quitting smoking in working age may thus reduce calculated CVD risk nearly to the same level with people who have never smoked.

Protection from cigarette smoke-induced vascular injury by recombinant human relaxin-2 (serelaxin)

Smoking is regarded as a major risk factor for the development of cardiovascular diseases (CVD). This study investigates whether serelaxin (RLX, recombinant human relaxin-2) endowed with promising therapeutic properties in CVD, can be credited of a protective effect against cigarette smoke (CS)-induced vascular damage and dysfunction. Guinea pigs exposed daily to CS for 8 weeks were treated with vehicle or RLX, delivered by osmotic pumps at daily doses of 1 or 10 μg. Controls were non-smoking animals. Other studies were performed on primary guinea pig aortic endothelial (GPAE) cells, challenged with CS extracts (CSE) in the absence and presence of 100 ng/ml (17 nmol/l) RLX. In aortic specimens from CS-exposed guinea pigs, both the contractile and the relaxant responses to phenylephrine and acetylcholine, respectively, were significantly reduced in amplitude and delayed, in keeping with the observed adverse remodelling of the aortic wall, endothelial injury and endothelial nitric oxide synthase (eNOS) down-regulation. RLX at both doses maintained the aortic contractile and relaxant responses to a control-like pattern and counteracted aortic wall remodelling and endothelial derangement. The experiments with GPAE cells showed that CSE significantly decreased cell viability and eNOS expression and promoted apoptosis by sparkling oxygen free radical-related cytotoxicity, while RLX counterbalanced the adverse effects of CSE. These findings demonstrate that RLX is capable of counteracting CS-mediated vascular damage and dysfunction by reducing oxidative stress, thus adding a tile to the growing mosaic of the beneficial effects of RLX in CVD.

Flow cytometric analysis of platelets type 2 diabetes mellitus reveals 'angry' platelets

Background

The function of platelets have extended way beyond the horizon of haemostasis and thrombosis, and are recognised as active participants in vascular inflammation, as well as in prothrombotic complications of cardiovascular diseases. We describe and compare platelet function in type II diabetes (with and without cardiovascular manifestation) and healthy individuals using scanning electron microscopy and flow cytometry.

Methods

Thirty subjects were recruited per group and informed consent was obtained from all participants. Diabetic patients were recruited from the diabetic clinic of the Steve Biko Academic Hospital (South Africa). Blood samples were drawn from all participants so that platelet specific antigens were analyzed in citrated whole blood. The platelet parameters used in the study were platelet identifiers (CD41 and CD42) and markers of platelet activation (CD62 and CD63).

Results

Results show that, compared to healthy individuals, both diabetic groups showed a significant difference in both platelet identifiers (CD41-PE, CD42b-PE) as well as markers indicating platelet activation (CD62P-PE and CD63-PE).

Interpretation

The flow cytometric data shows that the platelet surface receptors and platelet activation are statistically elevated. This is suggestive of enhanced platelet activation and it appears as if platelets are displaying ‘angry’ behaviour. The lysosomal granules may play a significant role in diabetes with cardiovascular complications. These results were confirmed by ultrastructural analysis.

Sex-Related Differences Between Patients With Symptomatic Acute Aortic Dissection

We designed a retrospective cohort study to assess sex-related differences in clinical manifestations, incidence, and outcomes of patients with symptomatic acute aortic dissection (AAD). We collected clinical data from 2010 to 2015 of 400 patients with AAD. Patients' clinical characteristics, treatment, and outcomes were analyzed as a function of sex. Among 400 patients with AAD, the ratio of men to women was 3.18:1; the incidence of atherosclerosis was higher in women (P = 0.02). Dysphoria (P = 0.01), focal neurological deficits (P = 0.04), and pulse deficits (P = 0.03) were more frequent in men. Imaging findings revealed that pleural effusion (P < 0.01), celiac trunk involvement (P < 0.01), and superior mesenteric artery involvement (P = 0.02) were more frequent in men. Dissection-related pneumonia (P = 0.02), pulmonary atelectasis (P = 0.01), aortic intramural hematoma (P < 0.01), ischemic electrocardiographic changes (P = 0.03), and in-hospital complications such as myocardial ischemia (P = 0.03), hypoxemia (P < 0.01), cardiac tamponade (P = 0.01) occurred more frequently in women. Women with type A dissection had higher in-hospital mortality than men (P < 0.01). The presentation of AAD varies with a patient's sex. Women with AAD had clinical features different from men as follows: higher age of onset, more frequent inpatient complications, and higher in-hospital mortality. These findings may lead to a better understanding of aortic dissection in women that will improve their outcomes.

Association of smoking status with health-related outcomes after percutaneous coronary intervention

BACKGROUND

Patients who smoke at the time of percutaneous coronary intervention (PCI) would ideally have a strong incentive to quit, but most do not. We sought to compare the health status outcomes of those who did and did not quit smoking after PCI with those who were not smoking before PCI.

METHODS AND RESULTS

A cohort of 2765 PCI patients from 10 US centers were categorized into never, past (smoked in the past but had quit before PCI), quitters (smoked at time of PCI but then quit), and persistent smokers. Health status was measured with the disease-specific Seattle Angina Questionnaire and the EuroQol 5 dimensions, adjusted for baseline characteristics. In unadjusted analyses, persistent smokers had worse disease-specific and overall health status when compared with other groups. In fully adjusted analyses, persistent smokers showed significantly worse health-related quality of life when compared with never smokers. Importantly, of those who smoked at the time of PCI, quitters had significantly better adjusted Seattle Angina Questionnaire angina frequency scores (mean difference, 2.73; 95% confidence interval, 0.13-5.33) and trends toward higher disease specific (Seattle Angina Questionnaire quality of life mean difference, 1.97; 95% confidence interval, -1.24 to 5.18), and overall (EuroQol 5 dimension visual analog scale scores mean difference, 2.45; 95% confidence interval, -0.58 to 5.49) quality of life when compared with persistent smokers at 12 months.

CONCLUSIONS

Smokers at the time of PCI have worse health status at 1 year than those who never smoked, whereas smokers who quit after PCI have less angina at 1 year than those who continue smoking.

Atherogenesis: hyperhomocysteinemia interactions with LDL, macrophage function, paraoxonase 1, and exercise

Despite great strides in understanding the atherogenesis process, the mechanisms are not entirely known. In addition to diet, cigarette smoking, genetic predisposition, and hypertension, hyperhomocysteinemia (HHcy), an accumulation of the noncoding sulfur-containing amino acid homocysteine (Hcy), is a significant contributor to atherogenesis. Although exercise decreases HHcy and increases longevity, the complete mechanism is unclear. In light of recent evidence, in this review, we focus on the effects of HHcy on macrophage function, differentiation, and polarization. Though there is need for further evidence, it is most likely that HHcy-mediated alterations in macrophage function are important contributors to atherogenesis, and HHcy-countering strategies, such as nutrition and exercise, should be included in the combinatorial regimens for effective prevention and regression of atherosclerotic plaques. Therefore, we also included a discussion on the effects of exercise on the HHcy-mediated atherogenic process.

A Review of Epigenetic Markers of Tobacco and Alcohol Consumption

Over the past two decades, advances in genetic technologies have posed unexpected challenges to the ethical and legal framework guiding the application of the most recent advances in healthcare technologies. By and large, these challenges have been successfully met by the introduction by statutes such as the Genetic Information Nondiscrimination Act (GINA). However, over the past several years, these advances in the ability to measure genetic (or heritable) contributions to medical illness have been joined by advances in epigenetic (or acquired) contributions to common medical illnesses. Unfortunately, the moral and legal framework for the use of these epigenetic technologies, which can objectively determine the presence of medical illnesses such as diabetes or the consumption of substances of abuse, is not as well developed. This communication provides an introduction to the fundamentals of epigenetics and then reviews how some of the latest advances in this technology can now be used to assess the consumption of alcohol and tobacco. Next, the possible mechanisms through which these tools could be employed clinically are discussed. Finally, the authors outline the potential for misuse of this technology and suggest that well-informed policy could play a critical role in shaping the optimal implementation of epigenetic technologies.

Human adipose-derived stem cells ameliorate cigarette smoke-induced murine myelosuppression via secretion of TSG-6

OBJECTIVE

Bone marrow-derived hematopoietic stem and progenitor cells (HSC/HPC) are critical to homeostasis and tissue repair. The aims of this study were to delineate the myelotoxicity of cigarette smoking (CS) in a murine model, to explore human adipose-derived stem cells (hASC) as a novel approach to mitigate this toxicity, and to identify key mediating factors for ASC activities.

METHODS

C57BL/6 mice were exposed to CS with or without i.v. injection of regular or siRNA-transfected hASC. For in vitro experiments, cigarette smoke extract was used to mimic the toxicity of CS exposure. Analysis of bone marrow HPC was performed both by flow cytometry and colony-forming unit assays.

RESULTS

In this study, we demonstrate that as few as 3 days of CS exposure results in marked cycling arrest and diminished clonogenic capacity of HPC, followed by depletion of phenotypically defined HSC/HPC. Intravenous injection of hASC substantially ameliorated both acute and chronic CS-induced myelosuppression. This effect was specifically dependent on the anti-inflammatory factor TSG-6, which is induced from xenografted hASC, primarily located in the lung and capable of responding to host inflammatory signals. Gene expression analysis within bone marrow HSC/HPC revealed several specific signaling molecules altered by CS and normalized by hASC.

CONCLUSION

Our results suggest that systemic administration of hASC or TSG-6 may be novel approaches to reverse CS-induced myelosuppression.

Protection of coronary endothelial cells from cigarette smoke-induced oxidative stress by a new Mn(II)-containing polyamine-polycarboxilate scavenger of superoxide anion

Oxidative stress plays a major role in cardiovascular injury and dysfunction induced by cigarette smoke. Smoke-borne pro-oxidants impair endothelial function and predispose to thrombosis, inflammation and atherosclerosis. This in vitro study evaluates whether Mn(II)(4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate).2H2O (Mn(II)(Me2DO2A)), a polyamine-polycarboxilate, Mn(II)-containing O2(-) scavenger, has a direct protective action on guinea pig coronary endothelial (GPCE) cells exposed to cigarette smoke extracts (CSE). Mn(II)(Me2DO2A) (1-10μmol/l) was added to the culture medium together with CSE and maintained for 4h. In parallel experiments, the inactive congener Zn(II)(Me2DO2A), in which Zn(II) replaced the functional Mn(II) center in the same organic scaffold, was used as negative control. Mn(II)(Me2DO2A), mostly at the higher doses (5 and 10μmol/l), significantly increased GPCE cell viability (trypan blue assay), improved mitochondrial activity (MTT test, mitochondrial membrane potential Δψ), reduced cellular apoptosis (mPTP, caspase-3 activity, TUNEL assay), decreased intracellular ROS levels (H2DCFDA), lipoperoxidation (BODIPY 581/591) and decreased protein nitrosylation. Of note, Zn(II)(Me2DO2A) did not preserve cell viability. These findings suggest that Mn(II)(Me2DO2A) is a promising O2(-) scavenging compound able to protect from cigarette smoke-induced oxidative cell injury. In perspective, should its efficacy be confirmed in future in vivo studies, this molecule might represent a therapeutic or preventive drug to counteract cigarette smoke toxicity.

Relationship between increase of serum homocysteine caused by smoking and oxidative damage in elderly patients with cardiovascular disease

BACKGROUND

To investigate the mechanism of smoking on cardiovascular diseases.

MATERIAL AND METHODS

576 elderly patients with cardiovascular diseases in stable condition were consecutive recruited, asked about the living habits and smoking history in a way of face to face.

RESULTS

Of all the enrolled patients, current smoking rate was 34.8% for males and 3.4% for females. Average smoking quantity was 17 cigarettes per day and incidence of hyperhomocysteinemia was 38.0%. The homocysteine level in current smokers was significantly higher than that in never smokers (P = 0.004); while the serum folic acid and serum superoxide dismutase (SOD) level were significantly lower those in never smokers (P = 0.012; P = 0.004). The daily smoking consumption and the pack-years of smoking were significantly positively correlated with total homocysteine (tHcy) level (P = 0.020; P = 0.003). The reduced serum SOD level might be associated with increased risk of hypertension (P = 0.023), coronary heart disease (P = 0.018), and stroke (P = 0.035). However, the elevated serum tHcy level was not correlated with increased risk of hypertension and coronary heart disease, while may increase the risk of ischemic stroke (P = 0.075).

CONCLUSIONS

Smoking status is still prevalent among Chinese elderly patients with cardiovascular diseases, which causes the increase of serum tHcy and the decrease of serum folate as well as SOD; smoking consumption per day and pack-years of smoking have indirect effects on tHcy. And decrease of serum SOD is a risk factor for cardiovascular diseases, increase of serum tHcy may be associated with changes of metabolism caused by oxidative damage.

Induction of Covalently Crosslinked p62 Oligomers with Reduced Binding to Polyubiquitinated Proteins by the Autophagy Inhibitor Verteporfin

Autophagy is a cellular catabolic process responsible for the degradation of cytoplasmic constituents, including organelles and long-lived proteins, that helps maintain cellular homeostasis and protect against various cellular stresses. Verteporfin is a benzoporphyrin derivative used clinically in photodynamic therapy to treat macular degeneration. Verteporfin was recently found to inhibit autophagosome formation by an unknown mechanism that does not require exposure to light. We report that verteporfin directly targets and modifies p62, a scaffold and adaptor protein that binds both polyubiquitinated proteins destined for degradation and LC3 on autophagosomal membranes. Western blotting experiments revealed that exposure of cells or purified p62 to verteporfin causes the formation of covalently crosslinked p62 oligomers by a mechanism involving low-level singlet oxygen production. Rose bengal, a singlet oxygen producer structurally unrelated to verteporfin, also produced crosslinked p62 oligomers and inhibited autophagosome formation. Co-immunoprecipitation experiments demonstrated that crosslinked p62 oligomers retain their ability to bind to LC3 but show defective binding to polyubiquitinated proteins. Mutations in the p62 PB1 domain that abolish self-oligomerization also abolished crosslinked oligomer formation. Interestingly, small amounts of crosslinked p62 oligomers were detected in untreated cells, and other groups noted the accumulation of p62 forms with reduced SDS-PAGE mobility in cellular and animal models of oxidative stress and aging. These data indicate that p62 is particularly susceptible to oxidative crosslinking and lead us to propose a model whereby oxidized crosslinked p62 oligomers generated rapidly by drugs like verteporfin or over time during the aging process interfere with autophagy.

Influence of genetic polymorphism on t,t-MA/S-PMA ratio in 301 benzene exposed subjects

This study investigated the effect of polymorphic genes GSTT1, GSTM1, GSTA1, EHPX1, NQO1, CYP2E1, CYP1A and MPO on the urinary concentrations and ratio (R) of the benzene metabolites trans,trans-muconic acid (t,t-MA) and S-phenyl mercapturic acid (S-PMA) in 301 oil refinery workers. The metabolites' concentrations are lower and R is higher (100.66) in non-smokers (n=184) than in smokers (n=117, R=36.54). Non-smokers have lower S-PMA and a higher R in GSTT1 null genotypes than in positive, and a higher S-PMA and a lower R in GSTA1 wild type genotypes. In smokers the GSTT1 null genotype effect on both S-PMA and R is confirmed, and is also shown in GSTM1 null, but not in GSTA1 wild type genotypes. GSTT1 null polymorphism reduces the conjugation rate of benzene epoxide with GSH, and to a lesser extent also GSTTA1 mutant, GSTM1 null and NQO1 mutant genotypes. The activity of one GST is compensated by another in GSTM1 and GSTA1 defective subjects, but not in GSTT1 null genotypes, whose average S-PMA excretion is about 50% with respect to the positive ones, for the same benzene exposure. R showed to be a more sensitive marker for these effects than the metabolite levels.

Nicotine: A Double-Edged Sword in Atherosclerotic Disease

Chronic cigarette smoking is well-known to damage vascular endothelium, which initiates atherosclerosis by first manifesting as endothelial dysfunction and later progressing to cardiovascular diseases (CVD). Nicotine, a major component of tobacco smoke, is traditionally thought to be responsible for increased cardiovascular events through stimulation of the sympathetic nervous system, increased myocardial metabolic demand, impaired lipid metabolism, and activated platelet function. However, recent studies have demonstrated that nicotine, at lower doses, may be beneficial to the cardiovascular system. With binding to specific nicotinic acetylcholine receptors, nicotine can induce migration and proliferation of vascular cells, and hence enhances angiogenesis. Therefore, these seemingly inconsistent properties of nicotine may in fact give rise to novel and efficacious management strategies of CVD.

KEY WORDS

Angiogenesis; Atherosclerosis; nicotinic acetylcholine receptors (nAChRs); Nicotine.

Effect of smoking on common carotid artery wall elasticity evaluated by echo tracking technique

The aim of this study was to examine the applicability of echo tracking to evaluation of common carotid artery wall elasticity in smokers and the effects of hypertension, hyperlipidemia and hyperglycemia on common carotid artery wall elasticity in smokers. Subjects were divided into three groups based on smoking status and presence of complications: group A (healthy control group), group B1 (simple smoking group) and group B2 (smoking with complications group). Complications included one or several symptoms of hypertension, hyperlipidemia and hyperglycemia. Intima-media thickness (IMT) of the common carotid artery was measured with ultrasound, and wall stiffness index(β), pressure-strain elasticity modulus (Ep), arterial compliance, augmentation index and local pulse wave velocity (PWVβ) were measured with echo tracking. We also determined the systolic (Ds) and diastolic (Dd) lumen diameters of the common carotid artery and systolic (Ps) and diastolic (Pd) pressures. The differences in β, Ep and PWVβ among the three groups in this study were statistically significant (p < 0.05). Augmentation index was increased in group B2 compared with groups B1 and A, with the differences being statistically significant (p < 0.05). Differences in augmentation index between groups B1 and A, differences in arterial compliance among the three groups and differences in intima-media thickness among the three groups were not statistically significant (p > 0.05), but differences in Ds and Dd among the three groups were statistically significant (p < 0.05). Differences in Ps and Pd between groups A and B1 were not statistically significant (p > 0.05), whereas those between groups B1 and B2 were statistically significant (p < 0.05). Echo tracking can be used to quantitatively evaluate the effect of smoking on common carotid artery wall elasticity and the effects of hypertension, hyperlipidemia and hyperglycemia on common carotid artery wall elasticity in smokers.

Concurrent relations among cigarette smoking status, resting heart rate variability, and erectile response

INTRODUCTION

Heart rate variability (HRV) is a marker of sympathovagal balance; it has been implicated in erectile function and is also altered by tobacco use. Furthermore, smoking and erectile health are strongly related, given that smokers are at increased risk for erectile dysfunction. Few studies have explored the interrelationships between smoking, HRV, and erectile function concurrently.

AIM

The aim of this study was to examine potential mechanisms underlying tobacco's effects on penile hemodynamics by exploring the mediating role of HRV.

METHODS

The sample comprised 119 men (smokers = 64; nonsmokers = 55) (mean age 28.90 years; standard deviation (SD) 11.68; range 18-58) selected from the control conditions of three previously published experiments. Participants were free from a history of cardiovascular disease, myocardial infarct, and/or cardiac/cardiovascular medication use. During a laboratory visit, self-report, anthropometric, cardiovascular, and electrocardiographic data were assessed, as well as sexual arousal responses elicited from viewing an erotic film.

MAIN OUTCOME MEASURES

Objective sexual arousal indices (circumferential change via penile plethysmography), self-reported erectile function (per the erectile function domain score of the International Index of Erectile Function [IIEF-EF]), and time- (SD of beat-to-beat intervals) and frequency-domain parameters of HRV (ratio of low-frequency [LF] power to high-frequency [HF] power [LF/HF ratio]) were assessed.

RESULTS

Being a current long-term cigarette smoker was associated with dysregulated sympathovagal balance (higher LF/HF ratios, indicative of sympathetic nervous system dominance), which in turn showed inverse relations with magnitude of erectile tumescence. HRV did not mediate relations between tobacco use and either IIEF-EF scores or resting penile circumference.

CONCLUSIONS

Findings suggest that dysfunctional cardiac autonomic tone may be an underlying mechanism by which tobacco exerts its deleterious effects on erectile health. Further research is necessary to determine whether this relationship is mechanistic in nature, or whether it is better explained by other health factors.

Expression analysis of intercellular adhesion molecule-2 (ICAM-2) in the context of classical cardiovascular risk factors in acute coronary syndrome patients

INTRODUCTION

Cardiopulmonary diseases are the most common cause of hospitalization and death. Often the basic problem is endothelial dysfunction leading to elevated expression of adhesion proteins as well as increased adhesion and aggregation of blood cells. The goal of the study was to assess expression level of intercellular adhesive molecule-2 (ICAM-2) in patients with acute coronary syndrome (ACS).

MATERIAL AND METHODS

The obtained data were analysed in the context of the occurrence of classical cardiovascular risk factors. The two studied groups consisted of 60 ACS patients and 20 healthy individuals who both were qualified based on electrocardiography (ECG), transthoracic echocardiography and biochemical tests. The ACS patients additionally had coronary angiography performed. The number of ICAM-2 gene mRNA molecules was evaluated on the basis of QRT-PCR reaction kinetics. To compare the results the Mann-Whitney U test was used. Results were judged statistically significant if p < 0.05.

RESULTS

Analysis of the results showed a significantly higher number of ICAM-2 gene mRNA copies in ACS patients compared to healthy subjects (140920 ±105207 and 15023 ±14325, respectively). Furthermore, our results indicate a correlation between obesity (p = 0.012) and positive burdening family history (p = 0.041) and increased ICAM-2 levels in patients with ACS.

CONCLUSIONS

Increased ICAM-2 gene expression in ACS patients is probably symptomatic of endothelium dysfunction and may be responsible for intensified adhesion and aggregation processes as well as for appearance of acute coronary syndrome. These results indicate a correlation between obesity and burdening family history on the one hand, and increased ICAM-2 levels in patients with ACS, on the other.

Associations of smoking with alterations in renal hemodynamics may depend on sex--investigations in potential kidney donors

BACKGROUND/AIMS

Cigarette smoking is a risk factor for renal damage, but little is known about subclinical effects of smoking on renal hemodynamics and parameters of renal function in humans. We examined the associations of smoking with systemic and renal hemodynamics and renal function parameters in healthy individuals.

METHODS

Data from 196 potential living kidney donors were analysed retrospectively. Mean arterial blood pressure (MAP), effective renal plasma flow (ERPF) and creatinine clearance had been measured. We additionally calculated parameters of renal hemodynamics. Data were analyzed for the effects of smoking and sex dependent on age and MAP.

RESULTS

Systemic and renal hemodynamic parameters did not differ between smokers and non-smokers. In non-smokers of both sexes MAP was negatively correlated with ERPF, and higher MAP was associated with increased renal vascular resistance and with afferent arteriolar resistance, with glomerular pressure (PG) remaining constant. However, in male, but not in female smokers, ERPF and PG increased with MAP. A correlation of age with a steeper decline in ERPF in male smokers was lost in multiple regression analysis.

CONCLUSIONS

As compared to women, smoking men may exhibit an increased glomerular hydrostatic pressure, which is a known promoter of kidney damage.

Effects of tobacco on cytokine expression from human endothelial cells

OBJECTIVE

To investigate the effects of nicotine and cigarette smoke condensate (CSC) exposure on cytokine expression from human endothelial cells in order to identify one possible mechanism that smoking plays in the pathogenesis of both periodontal disease (PDD) and cardiovascular disease (CVD).

METHODS

Human endothelial cells (HUVECs) were exposed to different concentrations of nicotine and CSC to examine the effects that they have on cell proliferation and cytotoxicity. Non-toxic levels were then used to examine cytokine expression using cytokine protein arrays.

RESULTS

Exposure to nicotine caused significant down-regulation in the expression of IL-10 (P = 0.046), growth-regulated oncogene (GRO)α (P = 0.036), MCP-1 (P = 0.046), and GMCSF (P = 0.004) compared with the control untreated HUVECs. Exposure to CSC caused significant down-regulation in the expression of GRO (P = 0.04), GROα (P = 0.01), IL-6 (P = 0.03), and MCP-1 (P = 0.04) compared with the control untreated HUVECs.

CONCLUSIONS

Exposure of HUVECs to nicotine or CSC affects the levels of cytokine expression including reduction in anti-inflammatory and chemoattractant cytokines. This may subsequently affect the host defensive mechanisms of the tissues. The action of toxic chemicals in tobacco smoke on endothelial cells is a potential pathogenic mechanism that may in part explain the association between tobacco, PDD, and CVD.

Effect of tobacco smoking and smoking cessation on plasma lipoproteins and associated major cardiovascular risk factors: a narrative review

Cigarette smoking, active or passive, kills about 6 million people each year worldwide. Cardiovascular disease (CVD) is responsible for 40% of all smoking-related deaths, lung cancer accounts for 20% of all smoking-related deaths, and chronic obstructive pulmonary disease is related to another 20% of deaths. In this narrative review we consider the relationship between cigarette smoking and CVD. We discuss disease states and/or CVD risk factors related to smoking, such as dyslipidaemia, vascular inflammation, endothelial dysfunction, arterial stiffness, insulin resistance, type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD), and non-alcoholic fatty liver disease (NAFLD) as well as their complex interrelations. Smoking cessation can correct abnormalities related to smoking; however, success rates are relatively low. In cases of inability to quit, measures to minimize the adverse effects of smoking specifically related to CVD should be taken. Smokers should receive best practice treatment, according to guidelines, as for non-smokers.

Smoking counteracts the favorable effect of exercise training on endothelial function in patients with type 2 diabetes

Background

Exercise training can improve endothelial function in patients with diabetes. We hypothesized that the favorable effect of exercise training on endothelial function in patients with diabetes is counteracted by cigarette smoking.

Purpose:

To assess whether there is a difference in the effect of exercise on endothelial function in smokers and non-smokers with type 2 diabetes.

Methods:

We performed a 3-month controlled trial in 27 never-smoking and 17 smoking individuals with type 2 diabetes who participated in a home-based walking program. The percentage decrease in post-exercise ankle-brachial pressure index (ABI), which is an index of endothelial function, was assessed at baseline and after 3 months.

Results:

Compared to the smoking group, the never-smoking group showed a more significant improvement in post exercise ABI during the 3 months of home-based training (interaction, P < 0.01).

Conclusions:

These results indicate that smoking may counteract the favorable effects of exercise training on endothelial function. Endothelial function plays an important role in the prevention of cardiovascular disease among patients with diabetes. Therefore, a Certified Diabetes Educator should strongly advise diabetic patients not to smoke.

Nicotine induces the expression of C-reactive protein via MAPK-dependent signal pathway in U937 macrophages

Atherosclerosis is an inflammatory disease in the vessel wall. Nicotine, a major component of cigarette smoke, is an independent risk factor for cardiovascular diseases including atherosclerosis. As an inflammatory molecule, C- reactive protein (CRP) participates in atherogenesis. Although it has been confirmed that CRP level in smoking patient is significantly higher than non-smokers and cigarette withdrawal, it is unknown whether nicotine induces CRP expression in macrophages. The present study was to observe effect of nicotine on CRP production and the related signal pathway in U937 macrophages. The results showed that nicotine significantly increased mRNA and protein expression of CRP in U937 macrophages in time- and concentration-dependent ways. Nicotinic acetylcholine receptor (nAChR) blocker hexamethonium, MEK1/2 inhibitor PD98059, p38 MAPK inhibitor SB203580 and NF-κB inhibitor PDTC almost completely abolished nicotineinduced CRP expression in mRNA and protein levels in U937 macrophages. The further study indicated that hexamethonium, PD98059, and SB203580 significantly inhibited ERK1/2 and p38 MAPK phosphorylation. These demonstrate that nicotine has ability to induce CRP expression in macrophages through nAChR-ERK1/2/p38 MAPK-NF-κB signal pathway, which contributes to better understanding of the pro-inflammatory and pro-atherosclerotic effects of nicotine in cigarette smokers.

The effect of cigarette smoke extract on thrombomodulin-thrombin binding: an atomic force microscopy study

Cigarette smoking is a well-known risk factor for cardiovascular disease. Smoking can cause vascular endothelial dysfunction and consequently trigger haemostatic activation and thrombosis. However, the mechanism of how smoking promotes thrombosis is not fully understood. Thrombosis is associated with the imbalance of the coagulant system due to endothelial dysfunction. As a vital anticoagulation cofactor, thrombomodulin (TM) located on the endothelial cell surface is able to regulate intravascular coagulation by binding to thrombin, and the binding results in thrombosis inhibition. This work focused on the effects of cigarette smoke extract (CSE) on TM-thrombin binding by atomic force microscopy (AFM) based single-molecule force spectroscopy. The results from both in vitro and live-cell experiments indicated that CSE could notably reduce the binding probability of TM and thrombin. This study provided a new approach and new evidence for studying the mechanism of thrombosis triggered by cigarette smoking.

Nicotinic acetylcholine receptor signaling in atherogenesis

Smoking is a major risk factor for the development of atherosclerosis, stroke and myocardial infarction. Cigarette smoke consists of a complex mixture of about 4000 compounds. Out of these, polycyclic hydrocarbons, tobacco-specific nitrosamines, oxidizing agents and carbon monoxide have been implicated in the development of atherosclerosis. Recent studies have shown that nicotine (the addictive component of cigarettes) binds to high affinity cell-surface receptors and accelerates the atherogenic process. These receptors are called nicotinic acetylcholine receptors (nAChRs) and are expressed ubiquitously in almost all cells existing in the blood vessels. The present review summarizes the pro-atherogenic effects of nAChR ligands such as nicotine and tobacco nitrosamines. The contribution of different nAChR subunits in plaque growth, progression and neovascularization are discussed in detail. The signaling pathways underlying the actions of the nAChRs ligands in blood vessels are also described. Finally, the feasibility of nAChR ligands as therapeutic targets for atherosclerosis is summarized. We believe that the information presented in this review is relevant for atherosclerosis patients who are active smokers, exposed to environmental tobacco smoke or use nicotine patches or gums for smoking cessation.

Impact of low-and high-density lipoprotein cholesterol levels on carotid intima-media thickness differs by smoking status in middle-aged men

AIM

Cigarette smoking is a strong risk factor for atherosclerotic disease; however, it remains unclear whether the impact of other risk factors differs by smoking status. The aim of this study was to investigate this issue, especially with regard to low-density and high-density lipoprotein (LDL/HDL) levels.

METHODS

In total, 448 healthy, middle-aged men (aged 37 to 61) participated in this study. Smoking habits were recorded, carotid intima-media thickness (IMT) was measured by B-mode ultrasound, and serum lipids and other biochemical parameters were determined from fasted blood samples.

RESULTS

Among the overall subjects, multivariate regression analyses showed that IMT was significantly associated with age (p < 0.0001 for mean IMT, p= 0.002 for max IMT), body mass index (BMI, mean IMT, p= 0.028), LDL-C levels (mean/max IMT, p= 0.001), HDL-C levels (max IMT, p= 0.022) and current smoking habit (mean IMT, p=0.012). Subgroup analyses according to smoking status revealed that LDL-C levels were significantly associated with mean/max IMT in current smokers (p=0.001) but not in ex- or nonsmokers (never smoked subjects). After adjusting for age, BMI, systolic blood pressure, hemoglobin A1c and serum lipids, mean IMT respectively increased and decreased progressively across LDL-C and HDL-C quartiles (p= 0.004 and 0.045) in the overall subjects. These associations were observed in current smokers (p= 0.01) but not in ex- or nonsmokers for LDL-C, and were observed in ex- and nonsmokers (p= 0.025, 0.017, respectively) but not in current smokers for HDL-C.

CONCLUSION

The impact of LDL-C/HDL-C levels on carotid IMT differs by smoking status. These observations imply that distinct mechanisms are involved in the (anti) atherogenesis of LDL/HDL according to smoking status.

Evaluation of Salivary Antioxidant Enzymes among Smokers and Nonsmokers

Background

Cigarette smoke contains various oxygen-free radicals which are considered as the main causes of damage to biomolecules when exposed to cigarette smoke. Saliva is the first biological fluid that encounters inhaled cigarette smoke (CS) and has an antioxidant defense system able to counter toxic activities of free radical species. So, the aim of this study was to compare the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in saliva of smokers and nonsmokers.

Materials and methods

Unstimulated saliva of 200 males (100 smokers and 100 nonsmokers) was collected. The saliva was centrifuged and the activity of salivary superoxide dismutase and glutathione peroxidase was measured according to a specific assay.

Results

The mean value of superoxide dismutase activity was significantly higher in the smoking group than in the nonsmoker group, while the levels of GSH-Px activity was significantly higher in the nonsmoking group than in the smoking group.

Conclusion

Cigarette smoke leads to an alteration in salivary antioxidant activity. Evaluating the variations in the level of antioxidant enzymes (SOD and GSH-Px) in smoker's saliva might be useful for estimating the level of oxidative stress caused by cigarette smoke. Thus, it may help in patient's education regarding the ill-effects of smoking and determining the evolution and progress of various oral diseases.

How to cite this article

Saggu TK, Masthan KMK, Dudanakar MP, Nisa SUI, Patil S. Evaluation of Salivary Antioxidant Enzymes among Smokers and Nonsmokers. World J Dent 2012;3(1):18-21.

Recruitment of α7 nicotinic acetylcholine receptor to caveolin-1-enriched lipid rafts is required for nicotine-enhanced Escherichia coli K1 entry into brain endothelial cells

AIM

We investigate how the α7 nicotinic acetylcholine receptor (α7 nAChR), an essential regulator of inflammation, contributes to the α7 agonist nicotine-enhanced Escherichia coli K1 invasion of human brain microvascular endothelial cells (HBMECs) through lipid rafts/caveolae-mediated signaling.

MATERIALS & METHODS

α7 nAChR-mediated signaling and bacterial invasion were defined by lipid raft fractionation, immunofluorescence microscopy and siRNA knockdown.

RESULTS

Nicotine-enhanced bacterial invasion was dose-dependently inhibited by two raft-disrupting agents, nystatin and filipin. Significant accumulation of the lipid raft marker GM3 was observed in HBMEC induced by E. coli K1 and nicotine. The recruitment of α7 nAChR and related signaling molecules, including vimentin, and Erk1/2, to caveolin-1 enriched lipid rafts was increased upon treatment with E44 or E44 plus nicotine. Erk1/2 activation (phosphorylation), which is required for α7 nAChR-mediated signaling and E44 invasion, was associated with lipid rafts and nicotine-enhanced bacterial infection. Furthermore, E44 invasion, E44/nicotine-induced activation of Erk1/2 and clustering of α7 nAChR and caveolin-1 was specifically blocked by both siRNAs.

CONCLUSION

α7 nAChR-mediated signaling through lipid rafts/caveolae is required for nicotine-enhanced E. coli K1 invasion of HBMEC.

The research on endothelial function in women and men at risk for cardiovascular disease (REWARD) study: methodology

Background

Endothelial function has been shown to be a highly sensitive marker for the overall cardiovascular risk of an individual. Furthermore, there is evidence of important sex differences in endothelial function that may underlie the differential presentation of cardiovascular disease (CVD) in women relative to men. As such, measuring endothelial function may have sex-specific prognostic value for the prediction of CVD events, thus improving risk stratification for the overall prediction of CVD in both men and women. The primary objective of this study is to assess the clinical utility of the forearm hyperaemic reactivity (FHR) test (a proxy measure of endothelial function) for the prediction of CVD events in men vs. women using a novel, noninvasive nuclear medicine -based approach. It is hypothesised that: 1) endothelial dysfunction will be a significant predictor of 5-year CVD events independent of baseline stress test results, clinical, demographic, and psychological variables in both men and women; and 2) endothelial dysfunction will be a better predictor of 5-year CVD events in women compared to men.

Methods/Design

A total of 1972 patients (812 men and 1160 women) undergoing a dipyridamole stress testing were recruited. Medical history, CVD risk factors, health behaviours, psychological status, and gender identity were assessed via structured interview or self-report questionnaires at baseline. In addition, FHR was assessed, as well as levels of sex hormones via blood draw. Patients will be followed for 5 years to assess major CVD events (cardiac mortality, non-fatal MI, revascularization procedures, and cerebrovascular events).

Discussion

This is the first study to determine the extent and nature of any sex differences in the ability of endothelial function to predict CVD events. We believe the results of this study will provide data that will better inform the choice of diagnostic tests in men and women and bring the quality of risk stratification in women on par with that of men.

Circulating endothelial-coagulative activation markers after smoking cessation: a 12-month observational study

BACKGROUND

Cigarette smoking is associated with cardiovascular morbidity and mortality. Exposure to cigarette smoke can cause endothelial dysfunction with impaired endothelium-dependent vasodilation and 'endothelial activation', which predispose to atherothrombosis. The effects of continued smoking and smoking cessation on the level of endothelial, platelet and clotting activation have not been described previously. Here, we prospectively monitored changes in circulating endothelial-coagulative activation markers in smokers undertaking smoking cessation.

METHOD

This 12-month prospective study of 174 smokers with no commonly acquired atherothrombotic risk factors underwent an intensive smoking-cessation programme investigating the effect of quitting on circulating levels of von Willebrand's Factor Antigen (vWF:Ag), soluble Thrombomodulin (sTM), d-Dimer (d-D), prothrombin fragment F1+2 (F1+2), platelet factor-4 (PF4) and β-Thromboglobulin (β-TG). Blood samples and study measures were collected and compared at baseline and at 2, 6 and 12months after smoking cessation from quitters and relapsers'.

RESULTS

No significant differences in demographic or laboratory parameters at baseline were observed between the study groups. Significant changes in von Willebrand's Factor activity were observed at 2months after smoking cessation, with levels decreasing from 141·8% to 113·6%. Substantial modifications in d-Dimer, prothrombin fragment F1 +2, platelet factor-4 and β-thromboglobulin concentrations were observed only at 6 and 12months after smoking cessation. Positive associations between baseline levels of these biomarkers and number of pack per years have been demonstrated.

CONCLUSIONS

Chronic exposure to cigarette smoke sustains the activation of the endothelial-coagulative system and abstinence may result in the improvement of several endothelial-coagulative abnormalities in regular smokers. This may translate into an overall decline in cardiovascular risk.

Effect of Cigarette Smoking on Platelet Aggregation

Background: Cigarette smoking may increase platelet aggregation and cause atherothrombotic cardiovascular events. We aimed to investigate the impact of cigarette smoking on platelet function in patients with ischemic coronary heart disease (CHD).Methods: Twenty patients with ischemic stable CHD under aspirin therapy (300 mg/d), who continue to smoking despite all warnings, and 20 nonsmokers with CHD are enrolled in the study. Platelet function is studied at the morning, before and 15 minutes after the first cigarette, by the Platelet Function Analyzer (PFA)-100, with collagen and epinephrine and collagen and adenosine diphosphate cartridges. Post aspirin platelet hyperactivity is defined as having a closure time (CT) shorter than 186 seconds despite regular aspirin intake. Serial CT measurements are analyzed by paired samples t test.Results: Persistent platelet activity was present in 4 smoker (20%) and 3 nonsmoker (15%) patients at the beginning. Platelet activity measured by the PFA-100 is been increased significantly after cigarette smoking ( P = .004). Shorter CTs were determined after smoking in all patients with and without baseline persistent platelet activity, and 4 more participants became aspirin nonresponder ( P = .004). No significant differences in demographic, hematological, and biochemical parameters were determined between aspirin responders and nonresponders.Conclusions: We determined that cigarette smoking may increase platelet aggregation in patients with ischemic CHD in an aspirin nonresponsive manner. Our results emphasize the importance of quitting cigarette smoking in patients with CHD.

Effect of cigarette smoking on plasma homocysteine concentrations

BACKGROUND

Cigarette smoking has been recognized as a major risk factor for cardiovascular disease, while the role of homocysteine is still not clear. This study investigated the effects of smoking on plasma homocysteine concentration and determined the correlation between this parameter and biological markers of tobacco use, such as plasma thiocyanate and urine cotinine.

METHODS

Folate, vitamin B12 and homocysteine were measured in 300 subjects: 138 non-smokers and 162 smokers using immunoassay methods. Cotinine was measured using an enzymatic colorimetric method and thiocyanate by a selective electrode.

RESULTS

In smokers, we found a significant increase in homocysteine and a decrease in folate and vitamin B12 levels compared to non-smokers. Homocysteine was strongly correlated with the duration of use and the number of cigarettes consumed. Folate and vitamin B12 were significantly reduced in subjects smoking for more than 20 years compared to those who smoked less than 5 years. Among smokers, we noted a positive correlation between homocysteine and both plasma thiocyanates and cotininuria, and a negative-correlation between cotininuria and plasma folate.

CONCLUSIONS

Cigarette smoking increases homocysteine, which is strongly correlated with cotininuria and plasma thiocyanates. Moreover, smokers had tendency to develop hypofolatemia and hypovitamin B12, particularly when the duration of consumption exceeded 20 years.

Chronic cigarette smoking: implications for neurocognition and brain neurobiology

Compared to the substantial volume of research on the general health consequences associated with chronic smoking, little research has been specifically devoted to the investigation of its effects on human neurobiology and neurocognition. This review summarizes the peer-reviewed literature on the neurocognitive and neurobiological implications of chronic cigarette smoking in cohorts that were not seeking treatment for substance use or psychiatric disorders. Studies that specifically assessed the neurocognitive or neurobiological (with emphasis on computed tomography and magnetic resonance-based neuroimaging studies) consequences of chronic smoking are highlighted. Chronic cigarette smoking appears to be associated with deficiencies in executive functions, cognitive flexibility, general intellectual abilities, learning and/or memory processing speed, and working memory. Chronic smoking is related to global brain atrophy and to structural and biochemical abnormalities in anterior frontal regions, subcortical nuclei and commissural white matter. Chronic smoking may also be associated with an increased risk for various forms of neurodegenerative diseases. The existing literature is limited by inconsistent accounting for potentially confounding biomedical and psychiatric conditions, focus on cross-sectional studies with middle aged and older adults and the absence of studies concurrently assessing neurocognitive, neurobiological and genetic factors in the same cohort. Consequently, the mechanisms promoting the neurocognitive and neurobiological abnormalities reported in chronic smokers are unclear. Longitudinal studies are needed to determine if the smoking-related neurobiological and neurocognitive abnormalities increase over time and/or show recovery with sustained smoking cessation.