Theodore Cooper Memorial Lecture. Hypertension and the pathogenesis of atherosclerosis. Oxidative stress and the mediation of arterial inflammatory response: a new perspective

In vitro validation of measurement of volume elastic modulus using photoplethysmography

Arterial stiffness (AS) is one of the earliest detectable symptoms of cardiovascular diseases and their progression. Current AS measurement methods provide an indirect and qualitative estimation of AS. The purpose of this study is to explore the utilisation of Photoplethysmography (PPG) as a measure of volumetric strain in providing a direct quantification of the Volume Elastic modulus (E_v). An in vitro experimental setup was designed using an arterial model to simulate the human circulation in health (Model 2) and disease (Model 1). Flow, pressure, and PPG signals were recorded continuously under varied conditions of flow dynamics. The obtained E_v values were validated with the gold standard mechanical testing techniques. Values obtained from both methods had no significant difference for both models with a percent error of 0.26% and 1.9% for Model 1 and Model 2, respectively. This study shows that PPG and pressure signals can provide a direct measure of AS in an in vitro setup. With emerging noninvasive pressure measurement methods, this research paves the way for the direct quantification of AS in vivo.

HIV infection and stroke

The landscape of human immunodeficiency virus (HIV) infection is changing with the increasing coverage of antiretroviral therapy (ART). Patients are living longer but continually exposed to a virologically suppressed HIV infection. This has resulted in a decrease in acquired immune deficiency syndrome (AIDS)-related complications such as opportunistic infections, and an increase in non-AIDS complications such as stroke. In this era, stroke is perhaps the most important neurologic complication of HIV infection. Furthermore, stroke is more of a heterogeneous disease in people living with HIV infection and therefore needs to be approached systematically. Many of the etiologies are treatable. HIV-associated vasculopathy is perhaps the most common etiology in this population and our understanding of this is still evolving. Moreover, the treatment of HIV infection may contribute to an excess risk of stroke and interact with stroke therapies.

Levothyroxine Replacement Improves Oxidative Status in Primary Hypothyroidism

Objective: Although hypothyroidism has been linked to oxidative stress, data regarding the relationship between thyroid hormone levels and oxidative stress is still inconsistent. This study was designed to evaluate the effect of levothyroxine replacement on oxidative stress in women with primary hypothyroidism. Design: A total of 25 female patients with primary hypothyroidism were included. Oxidative stress markers were measured before and after levothyroxine replacement treatment in all patients. Methods: Oxidative stress was evaluated through the measurement of oxidants (thiobarbituric acid reactive substances [TBARS] and nitrite/nitrate levels), and antioxidants (superoxide dismutase and catalase activity). Results: Antioxidant catalase activity (63.77 ± 23.8 vs. 50.12 ±12.75 atv/min; p = 0.03) was significantly increased and the levels of TBARS (3.02 ± 0.86 vs. 3.55 ± 0.87 μM; p = 0.03) were significantly decreased in the state of euthyroidism after levothyroxine replacement compared to the hypothyroidism before levothyroxine treatment. No significant change in neither nitrite/nitrate concentration (p = 0.18) nor in superoxide dismutase activity (p = 0.93) after L-T4 adjustment was found. Conclusions: Our data demonstrate that levothyroxine replacement improved oxidative status in patients with primary hypothyroidism, indexed by the significantly decreased levels of malonaldehyde (MDA) and increased catalase (CAT) activity.

Experimental research of hypotensive and hypolipidemic effects with Modified Sanhuang Xiexin Decoction ()

OBJECTIVE

To investigate the hypotensive and hypolipidemic effects of Modified Sanhuang Xiexin Decoction (, HVC1), a herbal prescription for the vascular diseases in Chinese medicine and evaluate the acute and subchronic oral toxicities.

METHODS

Fifty-six spontaneous hypertensive rats (SHRs) were used to investigate the hypotensive and hypolipidemic effect of HVC1. Rats in the normal group (n=8) were fed with normal diet. The rats in the other groups (n=48) were fed with high fat and cholesterol diet for inducing hyperlipidemia models. Forty-eight rats were randomly divided into 6 groups [model, positive control (amlodipine, simvastain), 50, 250, and 1,000 mg/(kg•d) HVC1 groups] with 8 animals in each group. Normal and model groups were treated with distilled water [1 mL/(kg•d)], the positive control group was treated with amlodipine [5 mg/(kg•d)] or simvastatin [10 mg/(kg•d)], and the HVC1 groups were treated with HVC1 [50, 250, or 1,000 mg/(kg•d)] for 8 weeks, respectively. Blood pressure (BP) of the rats was measured using a non-invasive tail cuff system. On the last day of the experiment, serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels were measured. To investigate the safety of HVC1, acute and subchronic toxicity studies were conducted on Sprague-Dawley rats. In toxicity studies, the body weight, food and water consumption of rats were measured and clinical signs observation, ophthalmologic examinations, urinalysis, hematological analysis, and serum biochemical analysis were performed.

RESULTS

A dose of 50 and 250 mg/(kg•d) HVC1 lowered systolic and diastolic BP (P<0.05). HVC1 at 1,000 mg/(kg•d) decreased TC, LDL-C and TG levels, respectively (P<0.01 or P<0.05) and 250 mg/(kg•d) HVC1 decreased TG levels on hyperlipidemic SHRs (P<0.05). In the acute toxicity study, oral administration of HVC1 did not show any toxicity effect, and the median lethal dose value of HVC1 was greater than 5,000 mg/kg. In the subchronic toxicity study, oral administration of HVC1 for 4 weeks also did not show any toxicity effect, and the no-observedadverse-effect-level of HVC1 was established as 2,000 mg/(kg•d).

CONCLUSION

These results could be used as preclinical data for clinical trials that develop HVC1 as a herbal medicine for treating or preventing hypertension and hyperlipidemia.

Age-Related Diseases and Clinical and Public Health Implications for the 85 Years Old and Over Population

By 2050, the American 85 years old and over population will triple. Clinicians and the public health community need to develop a culture of sensitivity to the needs of this population and its subgroups. Sensory changes, cognitive changes, and weakness may be subtle or may be severe in the heterogeneous population of people over age 85. Falls, cardiovascular disease, and difficulty with activities of daily living are common but not universal. This paper reviews relevant changes of normal aging, diseases, and syndromes common in people over age 85, cognitive and psychological changes, social and environmental changes, and then reviews common discussions which clinicians routinely have with these patients and their families. Some hearing and vision loss are a part of normal aging as is decline in immune function. Cardiovascular disease and osteoporosis and dementia are common chronic conditions at age 85. Osteoarthritis, diabetes, and related mobility disability will increase in prevalence as the population ages and becomes more overweight. These population changes have considerable public health importance. Caregiver support, services in the home, assistive technologies, and promotion of home exercise programs as well as consideration of transportation and housing policies are recommended. For clinicians, judicious prescribing and ordering of tests includes a consideration of life expectancy, lag time to benefit, and patient goals. Furthermore, healthy behaviors starting in early childhood can optimize quality of life among the oldest-old.

Cytochrome P450 eicosanoids in cerebrovascular function and disease

Cytochrome P450 eicosanoids play important roles in brain function and disease through their complementary actions on cell-cell communications within the neurovascular unit (NVU) and mechanisms of brain injury. Epoxy- and hydroxyeicosanoids, respectively formed by cytochrome P450 epoxygenases and ω-hydroxylases, play opposing roles in cerebrovascular function and in pathological processes underlying neural injury, including ischemia, neuroinflammation and oxidative injury. P450 eicosanoids also contribute to cerebrovascular disease risk factors, including hypertension and diabetes. We summarize studies investigating the roles P450 eicosanoids in cerebrovascular physiology and disease to highlight the existing balance between these important lipid signaling molecules, as well as their roles in maintaining neurovascular homeostasis and in acute and chronic neurovascular and neurodegenerative disorders.

Associations of urinary sodium and sodium to potassium ratio with hypertension prevalence and the risk of cardiovascular events in patients with prehypertension

The aim of this study was to investigate the effects of urinary sodium and sodium to potassium ratio on inflammatory cytokines, hypertension, and cardiovascular disease in patients with prehypertension. The authors observed 627 patients with prehypertension in the General Hospital of Shenyang Military Region. Rank correlation analysis revealed that interleukin 6 expression exhibited significant positive correlations with urinary sodium (R = .13) and sodium to potassium ratio (R = .13). The multivariate-adjusted hazard ratio of 24-hour urinary sodium was 1.01 (95% confidence interval, 1.00 - 1.01) for hypertension and 1.01 (95% confidence interval, 1.00 - 1.02) for cardiovascular disease, whereas the hazard ratio for 24-hour urinary sodium to potassium ratio was 1.13 (95% confidence interval, 1.08 - 1.19) for hypertension and 1.10 (95% confidence interval, 1.04 - 1.17) for cardiovascular disease. The study suggests that a high-salt diet may lead to increased interleukin 6 levels and may contribute to hypertension. In addition, a high sodium to potassium ratio and high sodium levels are associated with increased risks of cardiovascular disease and hypertension in patients with prehypertension.

Study of carotid intimal medial thickness in essential hypertension with or without left ventricular hypertrophy

Introduction:

Hypertension and atherosclerosis though separate entities, are interrelated as hypertension plays an important role in the pathogenesis of atherosclerosis. This study was undertaken to study the association of carotid intimal medial thickness with left ventricular hypertrophy (LVH) in hypertensive patients.

Materials and Methods:

Hundred hypertensives (JNC-7, Stage 1 and 2) between 30 and 55 years were enrolled in this prospective observational study conducted at a tertiary care teaching institute of Punjab, India. Electrocardiogram, Carotid Doppler, and Echocardiography were carried out in addition to routine biochemical investigations.

Results:

Increased carotid intimal medial thickness (CIMT) had statistically significant association with age, duration of hypertension, high systolic and diastolic blood pressure (BP), left ventricular hypertrophy and left ventricular mass index but was not associated with body mass index, low-density lipoproteins, and total cholesterol.

Conclusions:

LVH and arterial wall changes occur concurrently, and therefore, management of hypertension should not be limited just to control of BP but should also include therapy for carotid plaques and increased CIMT.

Influence of Erythrocyte Membrane Stability in Atherosclerosis

PURPOSE OF REVIEW

The purpose of this study is to show how an excess of cholesterol in the erythrocyte membrane contributes stochastically to the progression of atherosclerosis, leading to damage in blood rheology and O₂ transport, deposition of cholesterol (from trapped erythrocytes) in an area of intraplaque hemorrhage, and local exacerbation of oxidative stress.

RECENT FINDINGS

Cholesterol contained in the membrane of erythrocytes trapped in an intraplaque hemorrhage contributes to the growth of the necrotic nucleus. There is even a relationship between the amount of cholesterol in the erythrocyte membrane and the severity of atherosclerosis. In addition, the volume variability among erythrocytes, measured by RDW, is predictive of a worsening of this disease. Erythrocytes contribute to the development of atherosclerosis in several ways, especially when trapped in intraplate hemorrhage. These erythrocytes are oxidized and phagocytosed by macrophages. The cholesterol present in the membrane of these erythrocytes subsequently contributes to the growth of the atheroma plaque. In addition, when they rupture, erythrocytes release hemoglobin, which leads to the generation of free radicals. Finally, increased RDW may predict the worsening of atherosclerosis, due to the effects of inflammation and oxidative stress on erythropoiesis and erythrocyte volume. A better understanding of erythrocyte participation in atherosclerosis may contribute to the improvement of the prevention and treatment strategies of this disease.

Prediction Model for Hemorrhagic Complications after Laparoscopic Sleeve Gastrectomy: Development of SLEEVE BLEED Calculator

Introduction

Laparoscopic sleeve gastrectomy (LSG) is one of the most frequently performed bariatric procedures. Hemorrhagic complications (HC) after surgery are common and require surgical revision. Accurate estimation of the risk of postoperative HC can improve surgical decision-making process and minimize the risk of reoperation. The aim of the present study was to develop a predictive model for HC after LSG.

Material and Methods

The retrospective analysis of 522 patients after primary LSG was performed. Patients underwent surgery from January 2013 to February 2015. The primary outcome was defined as a surgical revision due to hemorrhagic complications. Multiple regression analysis was performed.

Results

The rate of hemorrhagic complications was 4 %. The mean age of patients was 41.0 (±11.6) years and mean BMI was 47.3 (±7.3) kg/m². Of the 12 examined variables, four were associated with risk of HC. Protective factors for HC were no history of obstructive sleep apnea (odds ratio [OR] 0.22; 95 % CI 0.05–0.94) and no history of hypertension (OR 0.38; 95 % CI 0.14–1.05). The low level of expertise in bariatric surgery (OR 2.85; 95 % CI 1.08–7.53) and no staple line reinforcement (OR 3.34; 95 % CI 1.21–9.21) were associated with higher risk of HC.

Conclusions

The result revealed the association between hemorrhagic complications and the following factors: obstructive sleep apnea, hypertension, level of expertise in bariatric surgery, and reinforcement of the staple line. The risk assessment model for hemorrhagic complications after LSG can contribute to surgical decision-making process.

Endothelial dysfunction in human essential hypertension

Although the endothelium has a number of important functions, the term endothelial dysfunction is commonly used to describe impairment in its vasodilatory capacity. It is increasingly recognized that this is related to hypertension, although whether it predates essential hypertension or is a consequence of it is still unknown. In this review, we explore the mechanisms of endothelial dysfunction in essential hypertension, its prognostic significance and methods of pharmacological reversal.

Hydrogen Peroxide and Lipopolysaccharide Differentially Affect the Expression of MicroRNAs 10a, 33a, 21, 221 in Endothelial Cells Before and After Coculture With Monocytes

Inflammation and oxidative stress are important risk factors affecting various cells in the formation of atherosclerosis. MicroRNAs (miRs) are regulators of inflammation and atherogenesis. The expressions of endothelial cell (EC)-specific miR-10a and miR-21 and monocyte-specific miR-33a and miR-221 were investigated using coculture of the ECs and monocytes upon exposure to H₂O₂ as an oxidative stressor, and endotoxin/lipopolysaccharide (LPS) as a microbial stressor. Human umbilical endothelial cells (HUVECs) and peripheral blood mononuclear cells (or monocytes) were cocultured in M199 complete medium and were incubated with LPS (20 ng/mL) or H₂O₂ (1%) for 8 hours at 37°C. The HUVECs and monocytes were then separated from the cellular mix using a magnetic bead negative selection technique. The relative expression of miRs was determined by real-time polymerase chain reaction. In both cell types, H₂O₂ induced miR10a ( P = 0.05) and LPS induced miR21 ( P = 0.0003) compared to the untreated controls. Coculture increased miR-10a and miR-21 expression in monocytes ( P = 0.0008 and <0.0001); however when cultured alone, HUVECs expressed higher levels of miR-10a and miR-21 ( P < 0.0001 and <0.0001). Coculture decreased the expression of miR-33a in monocytes ( P < 0.0001) while increasing miR221 in HUVECs and monocytes ( P < 0.0001 and <0.0001). The expression pattern of miRs in HUVECs and monocytes changes in the coculture compared to culturing alone in response to oxidative and microbial toxic compounds. Moreover, different cellular stressors induce different athero-miRs, which may affect the course of inflammation.

Oxidized low-density lipoprotein, lipid and calcium aggregates reveal oxidative stress and inflammation in the conjunctiva of glaucoma patients

PURPOSE

Conjunctival specimens from primary open-angle glaucoma (POAG), exfoliation glaucoma (ExG) patients and controls were histologically analysed for oxidized low-density lipoprotein (ox-LDL), lipid and calcium aggregates. Our goal was to use them as biomarkers of oxidative stress and inflammation and to evaluate their correlation with glaucoma and impact on surgical outcome.

METHODS

Conjunctival samples were obtained from POAG (n = 14) and ExG (n = 17) patients and from control subjects (n = 11) operated for macular hole, retinal detachment or strabismus. Immunohistochemistry was performed using the antibody against ox-LDL. Lipids and calcium were analysed by histochemical stainings with Nile red and Alizarin red S, respectively.

RESULTS

Immunoreaction for ox-LDL was significantly increased in POAG (p = 0.049) and the number of lipid aggregates was significantly higher in ExG (p = 0.009) when compared to control. When POAG and ExG patients were grouped according to the outcome of deep sclerectomy (DS) surgery, the number of lipid (p < 0.001) and calcium aggregates (p = 0.014) were significantly higher in the conjunctival stroma of patients whose surgery failed within a three-year follow-up period.

CONCLUSIONS

The lipid-mediated alterations suggested the presence of oxidative stress and inflammation in the conjunctiva of glaucoma patients. The present data further support the role of oxidative stress and inflammation in the wound healing process leading to excessive scarring and failure in DS surgery.

A mechanistic model for atherosclerosis and its application to the cohort of Mayak workers

We propose a stochastic model for use in epidemiological analysis, describing the age-dependent development of atherosclerosis with adequate simplification. The model features the uptake of monocytes into the arterial wall, their proliferation and transition into foam cells. The number of foam cells is assumed to determine the health risk for clinically relevant events such as stroke. In a simulation study, the model was checked against the age-dependent prevalence of atherosclerotic lesions. Next, the model was applied to incidence of atherosclerotic stroke in the cohort of male workers from the Mayak nuclear facility in the Southern Urals. It describes the data as well as standard epidemiological models. Based on goodness-of-fit criteria the risk factors smoking, hypertension and radiation exposure were tested for their effect on disease development. Hypertension was identified to affect disease progression mainly in the late stage of atherosclerosis. Fitting mechanistic models to incidence data allows to integrate biological evidence on disease progression into epidemiological studies. The mechanistic approach adds to an understanding of pathogenic processes, whereas standard epidemiological methods mainly explore the statistical association between risk factors and disease outcome. Due to a more comprehensive scientific foundation, risk estimates from mechanistic models can be deemed more reliable. To the best of our knowledge, such models are applied to epidemiological data on cardiovascular diseases for the first time.

Anti-atherogenic properties of resveratrol: 4-week resveratrol administration associated with serum concentrations of SIRT1, adiponectin, S100A8/A9 and VSMCs contractility in a rat model

Resveratrol (3, 4', 5-trihydroxy-trans-stilbene) is a natural, non-flavonoid polyphenol that exerts protective properties against atherosclerosis-associated endothelial dysfunction and senescence. The present study aimed to assess the influence of resveratrol on vascular contractility and molecular factors including sirtuin-1 (SIRT1), adiponectin and calprotectin (S100A8/A9) that are considered to be important elements of atherogenesis. A total of 17 male rats were divided into a control and treatment group and administered resveratrol or a placebo. Pharmacometrics were performed on an isolated and perfused tail artery. Serum SIRT1, adiponectin and S100A8/A9 levels were quantified using an ELISA assay. The level of SIRT1 in the control and treatment groups at time 0 was 4.26 and 4.45 ng/ml, respectively. SIRT1 in the control and treatment groups following 2 weeks of treatment was 4.59 and 6.86 ng/ml, respectively (P<0.05) and following 4 weeks of treatment was 4.15 and 6.38 ng/ml, respectively (P<0.05). The level of adiponectin in the control and treatment groups at time 0 was 1.24 and 1.21 ng/ml, respectively. Following 2 weeks of treatment, the level of adiponectin in the control and treatment groups was 1.22 and 1.2 ng/ml, respectively (P>0.05) and following 4 weeks of treatment was 1.26 and 1.58 ng/ml, respectively (P<0.05). The S100A8/A9 level in control and treatment groups at time 0 was 0.39 and 0.33 ng/ml, respectively. The level of S100A8/A9 in control and treatment groups following 2 weeks of treatment was 0.37 and 0.35 ng/ml, respectively (P>0.05) and following 4 weeks of treatment was 0.34 and 0.32 ng/ml, respectively (P>0.05). EC₅₀ values obtained for phenylephrine in resveratrol-pretreated arteries were significantly higher than controls in the presence and absence of A7-hydrochloride (P<0.05). The results of the present study indicate a significant increase in the concentration of SIRT1 and adiponectin in the resveratrol-pretreated group (P<0.05). S100A8/A9 serum concentrations remained unchanged. Reactivity of resistant arteries was significantly reduced for resveratrol-pretreated vessels and this effect was partially independent of phosphodiesterase (PDE1). Additionally, there was a synergistic interaction observed between resveratrol and the PDE1 inhibitor.

Cyclic Strain and Hypertension Increase Osteopontin Expression in the Aorta

Hypertension has a direct impact on vascular hypertrophy and is a known risk factor for the development of atherosclerosis. Osteopontin (OPN) has emerged as an important protein mediator of inflammation and remodeling of large arteries. However, its role and mechanism of regulation in the setting of hypertension is still unknown. Our objectives for this study were therefore to investigate the role of OPN in hypertension-induced vascular remodeling and inflammation. OPN Knockout (KO) and wild type (WT) mice were made hypertensive with angiotensin II (Ang II) infusion for seven days. We observed that OPN KO aortas were protected against Ang II-induced medial hypertrophy and inflammation, despite comparable increases in systolic blood pressure (SBP) in both groups. OPN expression was increased in WT aortas from hypertensive mice (induced by either Ang II or norepinephrine). OPN expression was increased in aortic smooth muscle cells (SMCs) subjected to cyclic mechanical strain suggesting that mechanical deformation of the aortic wall is responsible in part for the increased OPN expression induced by hypertension. Finally, we utilized hypertensive transgenic smooth muscle cell-specific catalase overexpressing (Tg^SMC-Cat) mice to determine the role of H₂O₂ in mediating hypertension-induced increases in OPN expression. We also found that the hypertension-induced increase in OPN expression was inhibited in transgenic smooth muscle cell-specific catalase overexpressing (Tg^SMC-Cat) mice, suggesting that H₂O₂, plays a vital role in mediating the hypertension-induced increase in OPN expression. Taken together, these results define a potentially important role for OPN in the pathophysiology of hypertension.

Imbalanced Production of Reactive Oxygen Species and Mitochondrial Antioxidant SOD2 in Fabry Disease-Specific Human Induced Pluripotent Stem Cell-Differentiated Vascular Endothelial Cells

Fabry disease (FD) is an X-linked inherited lysosomal storage disease caused by α-galactosidase A (GLA) deficiency. Progressive intracellular accumulation of globotriaosylceramide (Gb3) is considered to be pathogenically responsible for the phenotype variability of FD that causes cardiovascular dysfunction; however, molecular mechanisms underlying the impairment of FD-associated cardiovascular tissues remain unclear. In this study, we reprogrammed human induced pluripotent stem cells (hiPSCs) from peripheral blood cells of patients with FD (FD-iPSCs); subsequently differentiated them into vascular endothelial-like cells (FD-ECs) expressing CD31, VE-cadherin, and vWF; and investigated their ability to form vascular tube-like structures. FD-ECs recapitulated the FD pathophysiological phenotype exhibiting intracellular Gb3 accumulation under a transmission electron microscope. Moreover, compared with healthy control iPSC-derived endothelial cells (NC-ECs), reactive oxygen species (ROS) production considerably increased in FD-ECs. Microarray analysis was performed to explore the possible mechanism underlying Gb3 accumulation-induced ROS production in FD-ECs. Our results revealed that superoxide dismutase 2 (SOD2), a mitochondrial antioxidant, was significantly downregulated in FD-ECs. Compared with NC-ECs, AMPK activity was significantly enhanced in FD-ECs. Furthermore, to investigate the role of Gb3 in these effects, human umbilical vein endothelial cells (HUVECs) were treated with Gb3. After Gb3 treatment, we observed that SOD2 expression was suppressed and AMPK activity was enhanced in a dose-dependent manner. Collectively, our results indicate that excess accumulation of Gb3 suppressed SOD2 expression, increased ROS production, enhanced AMPK activation, and finally caused vascular endothelial dysfunction. Our findings suggest that dysregulated mitochondrial ROS may be a potential target for treating FD.

A Shearing-Stretching Device That Can Apply Physiological Fluid Shear Stress and Cyclic Stretch Concurrently to Endothelial Cells

Endothelial cell (EC) morphology and functions can be highly impacted by the mechanical stresses that the cells experience in vivo. In most areas in the vasculature, ECs are continuously exposed to unsteady blood flow-induced shear stress and vasodilation-contraction-induced tensile stress/strain simultaneously. Investigations on how ECs respond to combined shear stress and tensile strain will help us to better understand how an altered mechanical environment affects EC mechanotransduction, dysfunction, and associated cardiovascular disease development. In the present study, a programmable shearing and stretching device that can apply dynamic fluid shear stress and cyclic tensile strain simultaneously to cultured ECs was developed. Flow and stress/strain conditions in the device were simulated using a fluid structure interaction (FSI) model. To characterize the performance of this device and the effect of combined shear stress-tensile strain on EC morphology, human coronary artery ECs (HCAECs) were exposed to concurrent shear stress and cyclic tensile strain in the device. Changes in EC morphology were evaluated through cell elongation, cell alignment, and cell junctional actin accumulation. Results obtained from the numerical simulation indicated that in the "in-plane" area of the device, both fluid shear stress and biaxial tensile strain were uniform. Results obtained from the in vitro experiments demonstrated that shear stress, alone or combined with cyclic tensile strain, induced significant cell elongation. While biaxial tensile strain alone did not induce any appreciable change in EC elongation. Fluid shear stress and cyclic tensile strain had different effects on EC actin filament alignment and accumulation. By combining various fluid shear stress and cyclic tensile strain conditions, this device can provide a physiologically relevant mechanical environment to study EC responses to physiological and pathological mechanical stimulation.

Consumption of nattokinase is associated with reduced blood pressure and von Willebrand factor, a cardiovascular risk marker: results from a randomized, double-blind, placebo-controlled, multicenter North American clinical trial

OBJECTIVE

The objective of this study is to evaluate the effects of consumption of nattokinase on hypertension in a North American hypertensive population with associated genetic, dietary, and lifestyle factors. This is in extension of, and contrast to, previous studies on Asian populations.

MATERIALS AND METHODS

A randomized, double-blind, placebo-controlled, parallel-arm clinical study was performed to evaluate nattokinase (NSK-SD), a fermented soy extract nattō from which vitamin K2 has been removed. Based on the results from previous studies on Asian populations, 79 subjects were enrolled upon screening for elevated blood pressure (BP; systolic BP ≥130 or diastolic BP ≥90 mmHg) who consumed placebo or 100 mg nattokinase/d for the 8-week study duration. Blood collections were performed at baseline and 8 weeks for testing plasma renin activity, von Willebrand factor (vWF), and platelet factor-4. Seventy-four people completed the study with good compliance.

RESULTS

Consumption of nattokinase was associated with a reduction in both systolic and diastolic BP. The reduction in systolic BP was seen for both sexes but was more robust in males consuming nattokinase. The average reduction in diastolic BP in the nattokinase group from 87 mmHg to 84 mmHg was statistically significant when compared to that in the group consuming placebo, where the average diastolic BP remained constant at 87 mmHg (P<0.05), and reached a high level of significance for males consuming nattokinase, where the average diastolic BP dropped from 86 mmHg to 81 mmHg (P<0.006). A decrease in vWF was seen in the female population consuming nattokinase (P<0.1). In the subpopulation with low plasma renin activity levels at baseline (<0.29 ng/mL/h), an increase was seen for 66% of the people after 8-week consumption of nattokinase (P<0.1), in contrast to only 8% in the placebo group.

CONCLUSION

The data suggest that nattokinase consumption in a North American population is associated with beneficial changes to BP in a hypertensive population, indicating sex-specific mechanisms of action of nattokinase's effect on vWF and hypertension.

Genetic factors associated with endothelial dysfunction affect the early onset of coronary artery disease in Korean males

The maintenance of balance between nitric oxide (NO) and the superoxide anion is required for proper functioning of the endothelium. To investigate the relationship between genetic factors associated with endothelial function and the development of coronary artery disease (CAD), endothelial nitric oxide synthase ( ecNOS) gene a/b polymorphism and NADH/NADPH oxidase p22 phox gene C242T polymorphism were examined in 305 Korean male CAD patients and 215 healthy male control subjects. The β-fibrinogen gene H1/H2 polymorphism was also analyzed. Both ecNOS a/b and p22 phox C242T polymorphisms were found to be associated with the development of CAD in the study population ( p = 0.020 and 0.011, respectively). When the association was analyzed by age, statistical significance was retained only in those <51 years ( p = 0.021 and 0.025 for the a/b and the C242T polymorphism, respectively) and not in those >51 years of age ( p =0.155 and 0.278 respectively). However, the distribution of the β-fibrinogen H1/H2 genotypes was not found to be associated with the development of CAD in either the ≤50 ( p = 0.611) or >50 groups ( p = 0.188). The ecNOS gene a/b polymorphism and the NADH/NADPH oxidase p22 phox gene C242T polymorphism were found to be significantly associated with the development of CAD in Korean male patients less than 51 years old.

Hospitalizations from Hypertensive Diseases, Diabetes, and Arrhythmia in Relation to Low and High Temperatures: Population-Based Study

Little is known about the extent to which ambient temperatures contribute to the burden of hospitalizations from hypertensive diseases, diabetes, and arrhythmia. To fill this knowledge gap, we conducted a time-series study comprising entire population of Ontario, Canada during 1996–2013. A distributed lag non-linear model was developed to estimate the cumulative effect of temperatures over a 21-day lag period. We computed the burden of hospitalizations attributable to cold and heat. Furthermore, we separated the burden into components related to mild and extreme temperatures. Compared to the temperature with minimum risk of morbidity, cold temperatures (1^st percentile) were associated with a 37% (95% confidence interval: 5%, 78%) increase in hypertension-related hospitalizations whereas no significant association with hot temperatures (99^th percentile) was observed. Cold and hot temperatures were also associated with a 12% (1%, 24%) and a 30% (6%, 58%) increase in diabetes-related hospitalizations, respectively. Arrhythmia was not linked to temperatures. These estimates translate into ~10% of hypertension-related hospitalizations attributable to total cold, and ~9% from mild cold. Similarly, ~11% of diabetes-related hospitalizations were due to total heat, virtually all of which were from mild heat. In conclusion, ambient temperatures, especially in moderate ranges, contribute to excess hospitalizations from hypertension and diabetes.

The effect of angiotensin II microinjection into the bed nucleus of the stria terminalis on serum lipid peroxidation and nitric oxide metabolite levels

BACKGROUND

Overactivity of renin-angiotensin system is involved in the pathophysiology of renal and cardiovascular diseases. It is suggested that endothelial cells can release nitric oxide (NO) and reactive oxygen species in response to angiotensin II (Ang II). Angiotensin type 1 (AT1) receptor of Ang II has been found in the bed nucleus of the stria terminalis (BST). BST is involved in autonomic function. This study was performed to find the role of central Ang II in serum lipid peroxidation product and in releasing NO into circulation.

MATERIALS AND METHODS

Twenty-one catheterized rats were placed in stereotaxic instrument. A hole was drilled above BST. In the control group, saline 0.9% (100 nl) was microinjected into the BST. In the second group, Ang II (100 μM, 100-150 nl) was microinjected into the BST. In the third group losartan (an AT1 antagonist) was microinjected (100 μM, 200 nl) before Ang II into the BST. Systolic blood pressure was recorded. The NO metabolite (nitrite) and malondialdehyde (MDA) were measured in the rat's serum.

RESULTS

The data indicated that microinjection of Ang II into the BST produced a pressor response (P < 0.0001). It also increased MDA and nitrite levels of the serum significantly (P < 0.001, P < 0.0001). Pretreatment with losartan before Ang II microinjection attenuated serum's levels of MDA and nitrite (P < 0.001, P < 0.0001).

CONCLUSION

Our findings suggest that central effect of Ang II on blood pressure is accompanied with increased levels of MDA and nitrite in the circulation.

Macrophage Superoxide Anion Production in Essential Hypertension: Associations With Biological and Psychological Cardiovascular Risk Factors

OBJECTIVE

Essential hypertension is an important risk factor for coronary artery disease and its underlying process atherosclerosis, but involved mechanisms are not fully understood. Both macrophages and superoxide anions have been proposed to play a major role in the pathogenesis of atherosclerosis. In the present study, we investigated whether macrophages of individuals with hypertension show higher nicotinamide adenine dinucleotide phosphate oxidase-derived superoxide anion production compared with normotensive individuals. Furthermore, we examined associations between macrophage superoxide anion production and the psychological factors depression and chronic stress independent from hypertension status.

METHODS

We studied 30 hypertensive (mean [standard deviation] = 48.7 [2.4] years) and 30 age-matched normotensive men (mean [standard deviation] = 48.6 [2.4] years). We assessed macrophage superoxide anion production using the WST-1 assay. The assay is based on the chemical reduction of the cell-impermeative tetrazolium salt WST-1 by superoxide anions that are produced by activated human ex vivo isolated monocyte-derived macrophages. We further evaluated whether chronic stress or depressive symptom severity was associated with macrophage superoxide anion production. All analyses were adjusted for potential confounders.

RESULTS

Individuals with hypertension showed higher superoxide anion production compared with normotensive individuals (F(1,58) = 11.56, p = .001). Complementary analyses using mean arterial blood pressure as a continuous measure revealed that higher mean arterial pressure correlated significantly with higher WST-1 reduction (ß = .38, p = .003, ΔR = .145). These results remained significant when controlling for potential confounding influences. Chronic stress was related to higher WST-1 reduction scores, but this association was not statistically significant (ß = .24, p = .067, ΔR = .053); depression levels were not significantly associated with WST-1 reduction scores (p = .24).

CONCLUSIONS

Our results indicate higher macrophage superoxide anion production in individuals with hypertension compared with normotensive individuals. This may suggest a mechanism underlying cardiovascular risk with hypertension.

RhoA/Rho-Kinase in the Cardiovascular System

Twenty years ago, Rho-kinase was identified as an important downstream effector of the small GTP-binding protein, RhoA. Thereafter, a series of studies demonstrated the important roles of Rho-kinase in the cardiovascular system. The RhoA/Rho-kinase pathway is now widely known to play important roles in many cellular functions, including contraction, motility, proliferation, and apoptosis, and its excessive activity induces oxidative stress and promotes the development of cardiovascular diseases. Furthermore, the important role of Rho-kinase has been demonstrated in the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, and heart failure. Cyclophilin A is secreted by vascular smooth muscle cells and inflammatory cells and activated platelets in a Rho-kinase-dependent manner, playing important roles in a wide range of cardiovascular diseases. Thus, the RhoA/Rho-kinase pathway plays crucial roles under both physiological and pathological conditions and is an important therapeutic target in cardiovascular medicine. Recently, functional differences between ROCK1 and ROCK2 have been reported in vitro. ROCK1 is specifically cleaved by caspase-3, whereas granzyme B cleaves ROCK2. However, limited information is available on the functional differences and interactions between ROCK1 and ROCK2 in the cardiovascular system in vivo. Herein, we will review the recent advances about the importance of RhoA/Rho-kinase in the cardiovascular system.

Comparison of Triggering and Nontriggering Factors in ST-Segment Elevation Myocardial Infarction and Extent of Coronary Arterial Narrowing

Various physical, emotional, and extrinsic triggers have been attributed to acute coronary syndrome. Whether a correlation can be drawn between identifiable ischemic triggers and the nature of coronary artery disease (CAD) still remains unclear. In the present study, we evaluated the correlation between triggered versus nontriggered ischemic symptoms and the extent of CAD in patients with ST-segment elevation myocardial infarction (STEMI). We conducted a retrospective, single-center observational study including 1,345 consecutive patients with STEMI, treated with primary percutaneous coronary intervention. Acute physical and emotional triggers were identified in patients' historical data. Independent predictors of multivessel CAD were determined using a logistic regression model. A potential trigger was identified in 37% of patients. Physical exertion was found to be the most dominant trigger (65%) followed by psychological stress (16%) and acute illness (12%). Patients with nontriggered STEMI tended to be older and more likely to have co-morbidities. Patients with nontriggered STEMI showed a higher rate of multivessel CAD (73% vs 30%, p <0.001). In a multivariate regression model, nontriggered symptoms emerged as an independent predictor of multivessel CAD (odds ratio 8.33, 95% CI 5.74 to 12.5, p = 0.001). No specific trigger was found to predict independently the extent of CAD. In conclusion, symptoms onset without a recognizable trigger is associated with multivessel CAD in STEMI. Further studies will be required to elucidate the putative mechanisms underlying ischemic triggering.

An Early-Stage Atherosclerosis Research Model Based on Microfluidics

The arterial microenvironment plays a vital role in the pathology of atherosclerosis (AS). However, the interplay between the arterial microenvironment and atherogenesis remains unclear, partially due to the gap between cell culture and animal experiments. Addressing this problem, the present study reports a microfluidic AS model reconstituting early-stage AS. Physiological or AS-prone hemodynamic conditions are recapitulated on the model. The on-chip model recaptures the atherogenic responses of endothelial cells (ECs) in ways that the Petri dish could not. Significant cytotoxicity of a clinical anti-atherosclerotic drug probucol is discovered on the model, which does not appear on Petri dish but is supported by previous clinical evidence. Moreover, the anti-AS efficiency of platinum-nanoparticles (Pt-NPs) on the model shows excellent consistency with animal experiments. The early-stage AS model shows an excellent connection between Petri dish and animal experiments and highlights its promising role in bridging fundamental AS research, drug screening, and clinical trials.

Shared Risk Factors in Cardiovascular Disease and Cancer

Cardiovascular disease (CVD) and cancer are the 2 leading causes of death worldwide. Although commonly thought of as 2 separate disease entities, CVD and cancer possess various similarities and possible interactions, including a number of similar risk factors (eg, obesity, diabetes mellitus), suggesting a shared biology for which there is emerging evidence. Although chronic inflammation is an indispensable feature of the pathogenesis and progression of both CVD and cancer, additional mechanisms can be found at their intersection. Therapeutic advances, despite improving longevity, have increased the overlap between these diseases, with millions of cancer survivors now at risk of developing CVD. Cardiac risk factors have a major impact on subsequent treatment-related cardiotoxicity. In this review, we explore the risk factors common to both CVD and cancer, highlighting the major epidemiological studies and potential biological mechanisms that account for them.

Understanding the mechanisms of angiotensin II signaling involved in hypertension and its long-term sequelae: insights from Bartter's and Gitelman's syndromes, human models of endogenous angiotensin II signaling antagonism

Angiotensin II (Ang II) plays a key role in hypertension, renal and cardiovascular pathophysiology via intracellular pathways that involve the activation of a multiplicity of signaling mechanisms. Although experimental and genetic animal models have been developed and used to explore Ang II signaling's role in hypertension, a complete understanding of the processes mediating Ang II signaling in hypertension in humans remains elusive. One impediment is that these animal models do not exhibit all the traits of human hypertension, making it impossible to extrapolate from them to humans. To overcome this issue, we have used patients with Bartter's and Gitelman's syndromes, a human model of endogenously blunted and blocked Ang II signaling that presents a constellation of clinical findings which manifest themselves as the opposite of hypertension. This article reviews the aspects of the pathophysiology of human hypertension and its short and long term sequelae, and uses the results of our studies in Bartter's and Gitelman's syndromes along with those of others to gain better insight and understanding of the role of Ang II signaling in these processes.

Association of increased lipid peroxide levels in the aorta in comparison to the pulmonary artery with the presence of coronary artery disease

Atherosclerosis predominantly affects systemic arteries as compared to pulmonary arteries; however, the reasons for this differential predilection are not clear. Oxidative damage caused by free radicals is a key initiating event in atherogenesis and the lungs are able to produce large quantities of free radicals even under physiological conditions. The present study investigated whether pulmonary venous blood reaching the aorta contained greater quantities of lipid peroxides, a marker of oxidative stress, compared to the pulmonary artery. Aortic and pulmonary artery blood samples were collected at the time of cardiac catheterization from 45 consecutive patients (38% female) without acute coronary event and free of other medical disorders, who were scheduled to undergo coronary angiography for anginal chest pain. Lipid peroxides were measured in terms of malondialdehyde (MDA). MDA levels were significantly higher in the aorta compared to the pulmonary artery (4.93±1.97 vs. 3.36±1.14 nmol/ml; P<0.001); the difference was significant in patients with angiographic coronary artery disease (CAD) (P<0.001) compared to the patients without CAD (P=0.071). Higher aortic MDA levels were associated with the presence of CAD even following adjustment for major risk factors. The results of the present study demonstrate that aortic blood contains significantly greater levels of lipid peroxides compared to pulmonary artery. This differential oxidative stress between systemic and pulmonary arteries could provide a mechanistic explanation for their difference in the propensity to develop atherosclerosis.

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.

Metabolic Syndrome Components Are Associated with Intervertebral Disc Degeneration: The Wakayama Spine Study

OBJECTIVE

The objective of the present study was to examine the associations between metabolic syndrome (MS) components, such as overweight (OW), hypertension (HT), dyslipidemia (DL), and impaired glucose tolerance (IGT), and intervertebral disc degeneration (DD).

DESIGN

The present study included 928 participants (308 men, 620 women) of the 1,011 participants in the Wakayama Spine Study. DD on magnetic resonance imaging was classified according to the Pfirrmann system. OW, HT, DL, and IGT were assessed using the criteria of the Examination Committee of Criteria for MS in Japan.

RESULTS

Multivariable logistic regression analysis revealed that OW was significantly associated with cervical, thoracic, and lumbar DD (cervical: odds ratio [OR], 1.28; 95% confidence interval [CI], 0.92-1.78; thoracic: OR, 1.75; 95% CI, 1.24-2.51; lumbar: OR, 1.87; 95% CI, 1.06-3.48). HT and IGT were significantly associated with thoracic DD (HT: OR, 1.54; 95% CI, 1.09-2.18; IGT: OR, 1.65; 95% CI, 1.12-2.48). Furthermore, subjects with 1 or more MS components had a higher OR for thoracic DD compared with those without MS components (vs. no component; 1 component: OR, 1.58; 95% CI, 1.03-2.42; 2 components: OR, 2.60; 95% CI, 1.62-4.20; ≥3 components: OR, 2.62; 95% CI, 1.42-5.00).

CONCLUSION

MS components were significantly associated with thoracic DD. Furthermore, accumulation of MS components significantly increased the OR for thoracic DD. These findings support the need for further studies of the effects of metabolic abnormality on DD.

Effects of Acute Stroke Serum on Non-Ischemic Cerebral and Mesenteric Vascular Function

We investigated the effects of circulating factors in serum obtained from patients in the acute phase of different subtypes of ischemic stroke on non-ischemic cerebral and mesenteric arteries, as a potential mechanism involved in influencing regional perfusion and thus clinical evolution. Posterior cerebral arteries (PCAs) and mesentery arteries (MAs) isolated from Wistar Kyoto rats were perfused with serum from acute stroke patients with large vessel disease without (LVD) or with hypertension (LVD + HTN), cardioembolism with hypertension (CE + HTN), or physiologic saline as controls. Myogenic activity and nitric oxide-dependent vasorelaxation were assessed after 2 h of intraluminal exposure to serum. Vascular function was differentially affected by sera. Exposure to LVD serum increased myogenic tone and produced endothelial dysfunction in both PCAs and MAs. However, CE + HTN serum increased tone and decreased smooth muscle sensitivity to NO in vessels from both vascular beds. LVD + HTN serum was associated with reduced smooth muscle sensitivity to NO in vessels from both vascular beds but increased tone only in PCAs. Inflammation and oxidative stress, determined by measurement of high sensitivity C-reactive protein, uric acid, and free 8-isoprostane, were enhanced in all the serum groups. These results demonstrate vasoactive properties of acute stroke serum related to stroke subtypes that could potentially contribute to the pathogenesis of early hemodynamic-based clinical events.

Protocatechuic aldehyde inhibits TNF-α-induced fibronectin expression in human umbilical vein endothelial cells via a c-Jun N-terminal kinase dependent pathway

Fibronectin (FN) is one of the most important extracellular matrix proteins and plays an important role in the pathogenesis of atherosclerosis (AS). The aim of the present study was to evaluate the effect of a potent, water-soluble antioxidant, protocatechuic aldehyde (PA), which is derived from the Chinese herb Salvia miltiorrhiza, on the expression of FN in human umbilical vein endothelial cells (HUVECs) stimulated with tumor necrosis factor-α (TNF-α). The pharmacological effects of PA on the production of FN were investigated using ELISA and western blot analysis. In addition, ELISA and western blot analysis were used to examine the activation and suppression of the mitogen-activated protein kinase (MAPK) pathways and nuclear factor (NF)-κB in TNF-α-stimulated HUVECs, in order to explore the underlying pharmacological mechanism of PA. The inhibitory effect of PA on the total generation of reactive oxygen species (ROS) in TNF-α-stimulated HUVECs was assessed using 2',7'-dichlorofluorescein diacetate. Pretreatment of HUVECs with PA (0.15, 0.45 and 1.35 mM) for 18 h markedly attenuated the TNF-α-stimulated FN surface expression and secretion in a dose-dependent manner. Intracellular ROS generation and the expression of extracellular signal-regulated kinase 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 MAPK (p38) were significantly induced by TNF-α (2 ng/ml) in HUVECs. TNF-α-induced ROS generation and JNK activation were inhibited by PA in a concentration-dependent manner. By contrast, ERK1/2 and p38 activation was not significantly affected by PA. Pretreatment of HUVECs with PA for 18 h markedly attenuated TNF-α-stimulated NF-κB activation. In conclusion, the present findings suggest that PA inhibits TNF-α-induced FN expression in HUVECs through a mechanism that involves ROS/JNK and NF-κB.

L-Carnitine intake and high trimethylamine N-oxide plasma levels correlate with low aortic lesions in ApoE(-/-) transgenic mice expressing CETP

OBJECTIVE

Dietary l-carnitine can be metabolized by intestinal microbiota to trimethylamine, which is absorbed by the gut and further oxidized to trimethylamine N-oxide (TMAO) in the liver. TMAO plasma levels have been associated with atherosclerosis development in ApoE(-/-) mice. To better understand the mechanisms behind this association, we conducted in vitro and in vivo studies looking at the effect of TMAO on different steps of atherosclerotic disease progression.

METHODS

J774 mouse macrophage cells were used to evaluate the effect of TMAO on foam cell formation. Male ApoE(-/-) mice transfected with human cholesteryl ester transfer protein (hCETP) were fed l-carnitine and/or methimazole, a flavin monooxygenase 3 (FMO3) inhibitor that prevents the formation of TMAO. Following 12 week treatment, l-carnitine and TMAO plasma levels, aortic lesion development, and lipid profiles were determined.

RESULTS

TMAO at concentrations up to 10-fold the Cmax reported in humans did not affect in vitro foam cell formation. In ApoE(-/-)mice expressing hCETP, high doses of l-carnitine resulted in a significant increase in plasma TMAO levels. Surprisingly, and independently from treatment group, TMAO levels inversely correlated with aortic lesion size in both aortic root and thoracic aorta. High TMAO levels were found to significantly correlate with smaller aortic lesion area. Plasma lipid and lipoprotein levels did not change with treatment nor with TMAO levels, suggesting that the observed effects on lesion area were independent from lipid changes.

CONCLUSION

These findings suggest that TMAO slows aortic lesion formation in this mouse model and may have a protective effect against atherosclerosis development in humans.

Expression pattern and function of tyrosine receptor kinase B isoforms in rat mesenteric arterial smooth muscle cells

Tyrosine receptor kinaseB (TrkB) is a high affinity receptor for brain-derived neurotrophic factor (BDNF). TrkB isoforms involve full length TrkB (TrkB FL) and truncated TrkB type1 (TrkB T1) and type 2 (TrkB T2) in rats. The aim of present study was to explore their expression pattern and function in mesenteric arterial smooth muscle cells (MASMCs). The expression of TrkB isoform protein and mRNA was examined by Western blotting, immunofluorescence and quantitative RT-PCR analyses. Cell proliferation was measured by a bromodeoxyuridine (BrdU) incorporation assay. Cell migration was measured by a Boyden chamber assay. Cell morphology was observed with a phase-contrast microscope. Protein and mRNA expression of BDNF and TrkB isoforms was confirmed in MASMCs. Expression level of TrkB FL was less, while that of TrkB T1 was the highest in MASMCs. Although BDNF increased phosphorylation of ERK, it had no influence on migration and proliferation of MASMCs. TrkB T1 gene knockdown by a RNA interference induced morphological changes and reduced expression level of α-smooth muscle actin (α-SMA) in MASMCs. Similar morphological changes and reduced α-SMA expression were induced in MASMCs by a Rho kinase inhibitor, Y-27632. In conclusion, we for the first time demonstrate that TrkB T1 expressed highly in MASMCs contributes to maintain normal cell morphology possibly via regulation of Rho activity. This study firstly defined expression level of TrkB isoforms and partly revealed their functions in peripheral vascular cells.

Antihypertensive effect of Korean Red Ginseng by enrichment of ginsenoside Rg3 and arginine-fructose

Background

Ginsenoside Rg3 and arginine–fructose (Arg-Fru) are known as the hypotensive compounds of Panax ginseng; however, their efficacy on antihypertension has not been reported yet to our best knowledge. Thus, hypotensive components-enriched fraction of red ginseng (HCEF-RG) was prepared from fine root concentrate (FR) and their antihypertensive effects were investigated in spontaneously hypertensive rats (SHR).

Methods

Male SHRs were divided into six groups: control (Wistar Kyoto, SHR); FR 500; FR 1,000; HCEF-RG 500; and HCEF-RG 1,000; samples (mg/kg body weight) were orally administered every day for 8 wk. Blood pressure was monitored at 1 wk, 2 wk, 3 wk, 4 wk, 6 wk, and 8 wk by tail cuff method. At 8 wk after samples administration, mice were killed for the measurement of renin activity (RA), angiotensin-I converting enzyme inhibition, angiotensin II, and nitric oxide (NO) levels in plasma.

Results

HCEF-RG with four-fold more Rg3 and 24-fold more Arg-Fru contents was successfully prepared from reacted mixtures of FR and persimmon vinegar (12 times against FR, v/v) at 80°C for 18 h. Both FR 1,000 and HCEF-RG 1,000 showed lowered systolic blood pressure than SHR control group and HCEF-RG 1,000 group exhibited a significant decrease in diastolic blood pressure. RA was significantly lowered in all treated groups, while angiotensin II did not affect by FR and HCEF-RG treatment. However, angiotensin-I converting enzyme inhibition and NO in FR 1,000 and HCEF-RG 1,000 were significantly increased compared with SHR control group.

Conclusion

HCEF-RG is more effective and useful for alleviating hypertension than FR, implying the health benefit of Rg3 and Arg-Fru.

Prevention of cardiac hypertrophy by the use of a glycosphingolipid synthesis inhibitor in ApoE-/- mice

ApoE-/- mice fed a high fat and high cholesterol (HFHC) diet (20% fat and 1.25% cholesterol) from 12 weeks of age to 36 weeks revealed an age-dependent increase in the left ventricular mass (LV mass) and decline in fractional shortening (FS%), which worsened with HFHC diet. These traits are indicative of maladaptive pathological cardiac hypertrophy and dysfunction. This was accompanied by loading of glycosphingolipids and increased gene expression of ANP, BNP in myocardial tissue. Masson's trichrome staining revealed a significant increase in cardiomyocyte size and fibrosis. In contrast, treatment with 5 and 10 μM D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), an inhibitor of glucosylceramide synthase and lactosylceramide synthase, dose-dependently decreased the load of glycosphingolipids and preserved fractional shortening and maintained left ventricular mass to normal 12-week-old control levels over a 6 month treatment period. Our mechanistic studies showed that D-PDMP inhibited cardiac hypertrophy by inhibiting the phosphorylation of mitogen-activated protein kinase (MAPK). We propose that associating increased glycosphingolipid synthesis with cardiac hypertrophy could serve as a novel approach to prevent this phenotype in experimental animal models of diet -induced atherosclerotic heart disease.

Nox4-dependent activation of cofilin mediates VSMC reorientation in response to cyclic stretching

Vascular smooth muscle cells (VSMCs) are subjected to various types of mechanical forces within the vessel wall. Although it is known that VSMCs undergo cell body reorientation in response to mechanical stimulation, how this mechanical stretch is transduced within the cell into biochemical signals causing cytoskeleton reorganization remains unclear. Cofilin, a protein that controls actin dynamics, is activated by Slingshot phosphatase-dependent serine 3 dephosphorylation by redox-dependent mechanisms. Nox4 is a main source of reactive oxygen species (ROS) in the vessel wall that localizes in association with the cytoskeleton. Therefore, we hypothesize that Nox4 mediates redox-dependent activation of cofilin, which is required for cytoskeletal reorganization and cell reorientation after mechanical stimulation. In this study, we found that mechanical stretch stimulates ROS production in VSMCs and that the signaling that leads to cell reorientation requires hydrogen peroxide but not superoxide. Indeed, mechanical stretch induces cofilin activation and stretch-induced cytoskeletal reorganization, and cell reorientation is inhibited in cells where cofilin activity has been downregulated. Importantly, Nox4-deficient cells fail to activate cofilin and to undergo cell reorientation, a phenotype rescued by the expression of a constitutively active cofilin mutant. Our results demonstrate that in VSMCs mechanical stimulation activates cofilin by a Nox4-dependent mechanism and that this pathway is required for cytoskeleton reorganization and cell reorientation.

Antioxidants in Cardiovascular Therapy: Panacea or False Hope?

Oxidative stress is a key feature of the atherothrombotic process involved in the etiology of heart attacks, ischemic strokes, and peripheral arterial disease. It stands to reason that antioxidants represent a credible therapeutic option to prevent disease progression and thereby improve outcome, but despite positive findings from in vitro studies, clinical trials have failed to consistently show benefit. The aim of this review is to re-appraise the concept of antioxidants in the prevention and management of cardiovascular disease. In particular, the review will explore the reasons behind failed antioxidant strategies with vitamin supplements and will evaluate how flavonoids might improve cardiovascular function despite bioavailability that is not sufficiently high to directly influence antioxidant capacity. As well as reaching conclusions relating to those antioxidant strategies that might hold merit, the major myths, limitations, and pitfalls associated with this research field are explored.