Association between Coronary Artery Spasm and the risk of incident Diabetes: A Nationwide population-based Cohort Study.

Background: Non-diabetic coronary artery spasm (CAS) without obstructive coronary artery disease increases insulin resistance. We investigated the risk of incident type 2 diabetes (diabetes) associated with CAS. Methods: Patient records were retrospectively collected from the Taiwan National Health Insurance Research Database during the period 2000-2012. The matched cohorts consisted of 12,413 patients with CAS and 94,721 patients in the control group. Results: During the entire follow-up, the incidence of newly-diagnosed diabetes was 22.2 events per 1000 person-years in the CAS group and 13.9 events per 1000 person-years in the control group. The increased risk of CAS-related incident diabetes was observed regardless of sex and length of follow-up. The median time to incident diabetes was 2.9 and 3.5 years in the CAS and the control group (P <0.001), respectively, regardless of sex. Although age did not affect the risk of CAS-related incident diabetes, the risk was less apparent in the subgroups of male, dyslipidemia, chronic obstructive pulmonary disease, stroke, gout and medicated hypertension. However, CAS patients aged <50 years compared with patients ≥50 years had a greater risk of incident diabetes in females but not in males. Older CAS patients developed diabetes in a shorter length of time than younger patients. Conclusion: CAS is a risk factor for incident diabetes regardless of sex. However, females aged <50 years have a more apparent risk for CAS-related diabetes than old females, which is not observed in males. The median time of 2.9 years to incident diabetes warrants close follow-up.

Coronary Artery Spasm as Related to Anxiety and Depression: A Nationwide Population-Based Study.

OBJECTIVE: Anxiety and depression are risk factors for obstructive coronary artery disease (CAD), but their effects on coronary artery spasm (CAS) remain unestablished. METHODS: Patient records in this population-based study were retrospectively collected from the Taiwan National Health Insurance Research Database. Using propensity score matching, we used 1:1:1 ratio stratification into a control group of 10,325 individuals without CAS or CAD, a CAS group comprising 10,473 patients, and a CAD group comprising 10,473 patients during 2000-2012. RESULTS: The prevalence of CAS and CAD was 0.067% and 8.7%, respectively, in the general population. The prevalence of anxiety and depression diagnoses was significantly higher in patients with new-onset CAS than in those with new-onset CAD and controls without CAS/CAD, even after propensity score matching. Compared with CAD, anxiety and depression diagnoses conferred a higher risk of developing CAS (odds ratio [OR] = 2.29, 95% confidence interval [CI], 2.14-2.45, p < .001, and OR = 1.34, 95% CI, 1.08-1.66, p = .007, respectively). The association was even stronger when comparing CAS with the control group without CAD or CAS (OR = 5.20, 95% CI, 4.72-5.74, p < .001, and OR = 1.98, 95% CI, 1.50-2.62, p < .001, respectively). The increased risk of new-onset CAS as related to previous anxiety and depression diagnoses was comparable between males and females. CONCLUSIONS: Compared with CAD or the general population, anxiety and depression diagnoses confer a higher risk of developing CAS. No sex differences are found for the association of anxiety and depression with CAS.

Nicorandil regulates the macrophage skewing and ameliorates myofibroblasts by inhibition of RhoA/Rho-kinase signalling in infarcted rats.

We have demonstrated that ATP-sensitive potassium (KATP ) channel agonists attenuated fibrosis; however, the mechanism remained unclear. Since RhoA has been identified as a mediator of cardiac fibrosis, we sought to determine whether the anti-fibrotic effects of KATP channel agonists were mediated via regulating macrophage phenotype and fibroblast differentiation by a RhoA/RhoA-kinase-dependent pathway. Wistar male rats after induction of myocardial infarction were randomized to either vehicle, nicorandil, an antagonist of KATP channel glibenclamide, an antagonist of ROCK fasudil, or a combination of nicorandil and glibenclamide or fasudil and glibenclamide starting 24 hrs after infarction. There were similar infarct sizes among the infarcted groups. At day 3 after infarction, post-infarction was associated with increased RhoA/ROCK activation, which can be inhibited by administering nicorandil. Nicorandil significantly increased myocardial IL-10 levels and the percentage of regulatory M2 macrophages assessed by immunohistochemical staining, Western blot, and RT-PCR compared with vehicle. An IL-10 receptor antibody increased myofibroblast infiltration compared with nicorandil alone. At day 28 after infarction, nicorandil was associated with attenuated cardiac fibrosis. These effects of nicorandil were functionally translated in improved echocardiographically derived cardiac performance. Fasudil showed similarly increased expression of M2 macrophages as nicorandil. The beneficial effects of nicorandil on fibroblast differentiation were blocked by adding glibenclamide. However, glibenclamide cannot abolish the attenuated fibrosis of fasudil, implying that RhoA/RhoA-kinase is a downstream effector of KATP channel activation. Nicorandil polarized macrophages into M2 phenotype by inhibiting RhoA/RhoA-kinase pathway, which leads to attenuated myofibroblast-induced cardiac fibrosis after myocardial infarction.

Norcantharidin, a clinical used chemotherapeutic agent, acts as a powerful inhibitor by interfering with fibrinogen-integrin αIIb ß3 binding in human platelets.

During platelet activation, fibrinogen binds to its specific platelet receptor, integrin αIIb ß3 , thus completing the final common pathway for platelet aggregation. Norcantharidin (NCTD) is a promising anticancer agent in China from medicinal insect blister beetle. In this study, we provided the evidence to demonstrate NCTD (0.1-1.0 µM) possesses very powerful antiplatelet activity in human platelets; nevertheless, it had no effects on surface P-selectin expression and only slight inhibition on ATP-release reaction in activated platelets. Moreover, NCTD markedly hindered integrin αIIb ß3 activation by interfering with the binding of FITC-labelled PAC-1. It also markedly reduced the number of adherent platelets and the single platelet spreading area on immobilized fibrinogen as well as clot retraction. Additionally, NCTD attenuated phosphorylation of proteins such as integrin ß3 , Src and FAK in platelets spreading on immobilized fibrinogen. These results indicate that NCTD restricts integrin αIIb ß3 -mediated outside-in signalling in human platelets. Besides, NCTD substantially prolonged the closure time in human whole blood and increased the occlusion time of thrombotic platelet plug formation and prolonged the bleeding time in mice. In conclusion, NCTD has dual activities, it can be a chemotherapeutic agent for cancer treatment, and the other side it possesses powerful antiplatelet activity for treating thromboembolic disorders.

Inhibition of infarction-induced sympathetic innervation with endothelin receptor antagonism via a PI3K/GSK-3ß-dependent pathway.

Although endothelin (ET)-1 has been shown to upregulate nerve growth factor (NGF) expression, the molecular mechanisms are largely unknown. Phosphatidylinositol 3-kinase (PI3K)/Akt/glycogen synthase kinase (GSK)-3ß signal has been implicated in the regulation of NGF. We investigated whether selective ET receptor blockers attenuated cardiac sympathetic reinnervation through restoring PI3K/Akt/GSK-3ß activity. After ligation of the left anterior descending artery, male Wistar rats were randomized to either vehicle, atrasentan (an ETA receptor antagonist) or A-192621 (an ETB receptor antagonist) for 4 weeks. Sympathetic hyperinnervation after infarction was confirmed by myocardial norepinephrine measurement and immunofluorescent analysis. Post infarction was associated with increased reactive oxygen species (ROS), as measured by myocardial superoxide levels and dihydroethidine fluorescence staining. This was paralleled by a significant upregulation of NGF expression on mRNA and protein levels in the vehicle-treated rats, which reduced after administering atrasentan, not A-192621. Arrhythmic scores in the vehicle-treated rats were significantly higher than those treated with atrasentan. In an in vivo study atrasentan-induced decreased NGF was associated with activation of PI3K/Akt signaling pathway, which was further confirmed by the ex vivo study showing the restoration of NGF levels after coadministration of PI3K inhibitors (wortmannin and LY294002). Lithium chloride, an inhibitor of GSK-3ß, did not provide additional attenuated NGF levels compared with atrasentan alone. Finally, atrasentan-attenuated NGF levels were reversed in the presence of peroxynitrite generator. ETA receptor antagonism is a mediator to attenuate sympathetic hyperinnervation probably through restoration of PI3K/Akt/GSK-3ß/ROS signaling pathway, a potential pharmacological target for arrhythmias after infarction.

Effects of urate-lowering agents on arrhythmia vulnerability in post-infarcted rat hearts.

Hyperuricemia has been shown to be associated with ventricular arrhythmias. However, the mechanisms remained unknown. We assessed whether different urate-lowering agents can attenuate arrhythmias through lowering urate itself or inhibiting xanthenes oxidize (XO) activity in infarcted rats. Male Wistar rats after ligating coronary artery were randomized to either allopurinol, or febuxostat, chemically unrelated inhibitors of XO, benzbromarone or vehicle for 4 weeks. Post-infarction was associated with increased oxidant stress, as measured by myocardial superoxide, isoprostane, XO activity and dihydroethidine fluorescence staining. Measurement of myocardial norepinephrine levels revealed a significant elevation in vehicle-treated infarcted rats compared with sham-operated rats. Sympathetic hyperinnervation was blunted after administering both XO inhibitors, assessed by immunofluorescent analysis, Western blotting and real-time quantitative RT-PCR. Besides, the XO inhibitors-attenuated nerve growth factor levels were reversed in the presence of peroxynitrite generator. Arrhythmic scores in the XO inhibitors-treated infarcted rats were significantly lower than that in vehicle. For similar levels of urate lowering, the uricosuric agent benzbromarone had no beneficial effects on oxidative stress, sympathetic hyperinnervation or arrhythmia vulnerability. Chronic use of XO inhibitors, but not uricosuric agent, down-regulated sympathetic innervation probably through a superoxide-dependent pathway and plays a role in the beneficial effect on arrhythmogenic response.

Effect of Feedback Signal on Blood Pressure Self-regulation Capability in Individuals With Prehypertension or Stage I Hypertension: A Randomized Controlled Study.

OBJECTIVES: We aimed to determine the efficacy of an 8-week direct blood pressure (BP) biofeedback training program for prehypertensive or stage I hypertensive patients with a particular focus on the impact of the authenticity of feedback signals on the efficacy of BP regulation. DESIGNS: This study has a randomized, double-blind, parallel-group design. PARTICIPANTS AND METHODS: Fifty-nine individuals with ages from 18 to 64 years and who met the criteria for the diagnosis of prehypertenion or stage 1 hypertension participated in this study. The participants were referrals from physicians or community-dwelling volunteers. No participants had taken antihypertensive medication within the previous 2 months prior to enrollment. The participants were randomly assigned to the biofeedback group (n = 31) trained with real-time BP feedback signals or the control group (n = 28) trained with pseudofeedback signals. The primary outcome measures were systolic BP (SBP) and diastolic BP (DBP). Systolic BP and DBP were assessed at baseline, 1 week after training (week 9), and 8 weeks after training (week 16) in both groups. Only 54 participants had week 16 data. RESULTS: The changes in SBP and DBP from baseline to week 9, from baseline to week 16, and from week 9 to week 16 were not significantly different between the groups (All P > 0.05). Both groups were able to significantly decrease BP after completing the training. A percentage of 45.2% of the participants in the biofeedback group and 63.0% of the participants in the control group lowered their SBP by 5 mm Hg or more at week 9. The SBP-lowering effects were also maintained for at least 8 weeks after the completion of training. CONCLUSIONS: The equivalent magnitude of BP reduction between the 2 study groups suggests that repeated practice in BP self-regulation was more likely responsible for the efficacy of direct BP biofeedback training than was the type of feedback signals.

Sitagliptin attenuates sympathetic innervation via modulating reactive oxygen species and interstitial adenosine in infarcted rat hearts.

We investigated whether sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, attenuates arrhythmias through inhibiting nerve growth factor (NGF) expression in post-infarcted normoglycemic rats, focusing on adenosine and reactive oxygen species production. DPP-4 bound adenosine deaminase has been shown to catalyse extracellular adenosine to inosine. DPP-4 inhibitors increased adenosine levels by inhibiting the complex formation. Normoglycemic male Wistar rats were subjected to coronary ligation and then randomized to either saline or sitagliptin in in vivo and ex vivo studies. Post-infarction was associated with increased oxidative stress, as measured by myocardial superoxide, nitrotyrosine and dihydroethidium fluorescent staining. Measurement of myocardial norepinephrine levels revealed a significant elevation in vehicle-treated infarcted rats compared with sham. Compared with vehicle, infarcted rats treated with sitagliptin significantly increased interstitial adenosine levels and attenuated oxidative stress. Sympathetic hyperinnervation was blunted after administering sitagliptin, as assessed by immunofluorescent analysis and western blotting and real-time quantitative RT-PCR of NGF. Arrhythmic scores in the sitagliptin-treated infarcted rats were significantly lower than those in vehicle. Ex vivo studies showed a similar effect of erythro-9-(2-hydroxy-3-nonyl) adenine (an adenosine deaminase inhibitor) to sitagliptin on attenuated levels of superoxide and NGF. Furthermore, the beneficial effects of sitagliptin on superoxide anion production and NGF levels can be reversed by 8-cyclopentyl-1,3-dipropulxanthine (adenosine A1 receptor antagonist) and exogenous hypoxanthine. Sitagliptin protects ventricular arrhythmias by attenuating sympathetic innervation via adenosine A1 receptor and xanthine oxidase-dependent pathways, which converge through the attenuated formation of superoxide in the non-diabetic infarcted rats.

Comparative decline of the protein profiles of nebulin in response to denervation in skeletal muscle.

The sliding filament model of the sarcomere was developed more than half a century ago. This model, consisting only of thin and thick filaments, has been efficacious in elucidating many, but not all, features of skeletal muscle. Work during the 1980s revealed the existence of two additional filaments: the giant filamentous proteins titin and nebulin. Nebulin, a giant myofibrillar protein, acts as a protein ruler to maintain the lattice arrays of thin filaments and plays a role in signal transduction and contractile regulation. However, the change of nebulin and its effect on thin filaments in denervation-induced atrophic muscle remains unclear. The purpose of this study is to examine the content and pattern of nebulin, myosin heavy chain (MHC), actin, and titin in innervated and denervated tibialis anterior (TA) muscles of rats using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), densitometry and electron microscopic (EM) analyses. The results revealed that denervation induced muscle atrophy is accompanied by decreased nebulin content in a time-dependent manner. For instant, the levels of nebulin in denervated muscles were markedly (P < 0.05) decreased, about 24.6% and 40.2% in comparison with innervated muscle after denervation of 28 and 56 days, respectively. The nebulin/MHC, nebulin/actin, and nebulin/titin ratios were decreased, suggesting a concomitant reduction of nebulin in denervated muscle. Moreover, a western blotting assay proved that nebulin declined faster than titin on 28 and 56 days of denervated muscle. In addition, EM study revealed that the disturbed arrangements of myofilaments and a disorganized contractile apparatus were also observed in denervated muscle. Overall, the present study provides evidence that nebulin is more sensitive to the effect of denervation than MHC, actin, and titin. Nebulin decline indeed resulted in disintegrate of thin filaments and shortening of sarcomeres.

Dipeptidyl peptidase-4 inhibition attenuates arrhythmias via a protein kinase A-dependent pathway in infarcted hearts.

BACKGROUND: The effect of dipeptidyl peptidase-4 (DPP-4) inhibitors on arrhythmias remains unknown. The aim of this study was to investigate whether sitagliptin attenuates arrhythmias through inhibiting nerve growth factor (NGF) expression, focusing on cyclic adenosine monophosphate (cAMP) downstream signaling such as protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac). METHODS AND RESULTS: Male Wistar rats were randomized to either vehicle or sitagliptin for 4 weeks starting 24 h after ligating the coronary artery. Post-infarction was associated with increased oxidative stress. Measurement of myocardial norepinephrine levels revealed a significant elevation in vehicle-treated rats compared with sham. Compared with the vehicle, infarcted rats treated with sitagliptin had significantly increased cAMP levels, decreased DPP-4 activity, oxidative stress, NGF levels and immunofluorescence-stained sympathetic hyperinnervation. Arrhythmic scores were significantly lower in the sitagliptin-treated infarcted rats than in vehicle. Ex vivo studies showed that sitagliptin increased the phosphorylated cAMP response element-binding protein (CREB), which can be reversed by H-89 (a PKA inhibitor), not brefeldin A (an Epac inhibitor).Heme oxygenase-1(HO-1) expression was increased by a PKA agonist but not by an Epac agonist.HO-1expression was attenuated in KG-501 (a CREB inhibitor)-treated infarcted rats in the presence of a PKA agonist. CONCLUSIONS: Sitagliptin protects ventricular arrhythmias by attenuating NGF-induced sympathetic innervation via upregulation ofHO-1expression in a cAMP/PKA/CREB-dependent antioxidant pathway in non-diabetic infarcted rats.

Arterial Stiffness Index and Coronary Artery Plaques in Patients with Subclinical Coronary Atherosclerosis.

BACKGROUND: Arterial stiffness is a physiologic quantitative value used to measure arterial compliance. It is predictive of coronary atherosclerosis in patients with intermediate to high cardiovascular risk. However, a correlation between arterial stiffness and subclinical coronary atherosclerosis has yet to be established. Therefore, the purpose of this study was to evaluate arterial stiffness using an arterial stiffness index (ASI) and investigate its association with coronary artery plaque in patients with subclinical coronary atherosclerosis. METHODS: Our study enrolled 156 consecutive subjects who underwent health screening using a 64-slice cardiac computed tomography angiography (CCTA). Their arterial stiffness index was assessed noninvasively by CardioVision(®) MS-2000. The atheroma on the coronary vessel walls was analyzed. RESULTS: Of the 156 patients, 53 displayed at least one > 50% stenotic lesion over the coronary arteries in CCTA images. The patients with at least one > 50% coronary stenotic plaque were older and had higher systolic blood pressure and ASI values than patients without > 50% coronary stenotic plaque. After dividing the study population into 2 groups by those patients over and under 50 years of age, the ASI positively correlated with the presentation of at least one > 50% coronary stenotic plaque in patients aged ≥ 50 years (odds ratio = 1.02, 95% confidence interval: 1.00-1.04, p = 0.03). CONCLUSIONS: The ASI could play a role in risk stratification systems for coronary artery disease in patients with subclinical coronary atherosclerosis, and is a useful clinical marker for the correlation of early coronary plaque. KEY WORDS: Arterial stiffness; Arterial stiffness index; Atherosclerosis; Coronary artery plaque.

Both GPER and membrane oestrogen receptor-α activation protect ventricular remodelling in 17ß oestradiol-treated ovariectomized infarcted rats.

Clinical and experimental studies have established that gender is a factor in the development of ventricular hypertrophy. We investigated whether the attenuated hypertrophic effect of oestradiol was via activation of phosphatidylinositol 3-kinase (PI3K)/Akt/endothelial nitric oxide synthase (eNOS) through non-genomic action. Twenty-four hours after coronary ligation, female Wistar rats were randomized into control, subcutaneous oestradiol treatment or a G-protein coupled oestrogen receptor (GPER) agonist, G-1 and treated for 4 weeks starting from 2 weeks after bilateral ovariectomy. Ventricular hypertrophy assessed by cardiomyocyte size after infarction was similarly attenuated by oestradiol or G-1 in infarcted rats. The phosphorylation of Akt and eNOS was significantly decreased in infarcted rats and restored by oestradiol and G-1, implying the GPER pathway in this process. Oestradiol-induced Akt phosphorylation was not abrogated by G-15 (a GPER blocker). Akt activation was not inhibited by actinomycin D. When a membrane-impermeable oestrogen-albumin construct was applied, similar responses in terms of eNOS activation to those of oestradiol were achieved. Furthermore, PPT, an ERα receptor agonist, activated the phosphorylation of Akt and eNOS. Thus, membrane ERα receptor played a role in mediating the phosphorylation of Akt and eNOS. The specific PI3K inhibitor, LY290042, completely abolished Akt activation and eNOS phosphorylation in infarcted hearts treated with either oestradiol or oestradiol + G-15. These data support the conclusions that oestradiol improves ventricular remodelling by both GPER- and membrane-bound ERα-dependent mechanisms that converge into the PI3K/Akt/eNOS pathway, unveiling a novel mechanism by which oestradiol regulates pathological cardiomyocyte growth after infarction.

Differential effect of phosphodiesterase-3 inhibitors on sympathetic hyperinnervation in healed rat infarcts.

BACKGROUND: The effect of phosphodiesterase-3 (PDE-3) inhibitors on arrhythmia remains controversial, so the purpose of this study was to determine their differential effects on sympathetic hyperinnervation and the involved mechanisms in a rat model of myocardial infarction. METHODS AND RESULTS: After ligating the coronary artery, male Wistar rats were randomized to cilostazol or milrinone, chemically unrelated inhibitors of PDE-3, or vehicle for 4 weeks. The postinfarction period was associated with increased myocardial norepinephrine levels and oxidant release, as measured by myocardial superoxide level and dihydroethidine fluorescence staining. Infarcted rats in the milrinone- and cilostazol-treated groups had favorable ventricular remodeling with similar potency. Compared with milrinone, cilostazol significantly increased interstitial adenosine levels and reduced the production of myocardial cAMP and superoxide. Cilostazol significantly blunted sympathetic hyperinnervation, as assessed by immunofluorescent analysis of sympathetic innervation, and western blotting and real-time quantitative RT-PCR of nerve growth factor. Furthermore, the inhibitory effect of cilostazol on nerve growth factor was reversed by 8-cyclopentyl-1,3-dipropylxanthine, a selective A1 receptor antagonist, and enhanced by tempol administration. In spite of similar arrhythmic vulnerability during programmed stimulation in both the vehicle-and cilostazol-treated groups, cilostazol did not have proarrhythmic effects compared with milrinone. CONCLUSIONS: Unlike milrinone, cilostazol has therapeutic neutrality in arrhythmias because of adenosine uptake inhibition, which antagonizes the PDE-3-induced increase of sympathetic reinnervation via mediation of an adenosine A1 receptor-mediated antioxidation.

Assessment of elevation of and rapid change in left ventricular filling pressure using a novel global strain imaging diastolic index.

BACKGROUND: The aim of this study was to determine whether global strain imaging diastolic index (SIDI) obtained using 2-D speckle tracking imaging (2DSI) could predict elevation in and rapid change of LV filling pressure. METHODS AND RESULTS: Patients (n=126) underwent echocardiography and 2DSI during simultaneous cardiac catheterization. There were 60 patients in whom the same measurements were repeated 5min after i.v. glyceryl trinitrate. LV pre-atrial contraction pressure (pre-A) was measured as a surrogate of LV filling pressure. SIDI was defined as the change of LV longitudinal strain measured using 2DSI during the first one-third of diastole. Then, longitudinal global SIDI (L-global SIDI) was calculated as the mean SIDI of 18 LV segments. Mitral inflow and tissue Doppler imaging were also assessed. Among 126 patients, 93 patients had LV pre-A ≥15mmHg. L-global SIDI had a better correlation with LV pre-A (P<0.001, r=-0.56) than E/e' (P<0.01, r=0.35). On receiver operating characteristic curve analysis, L-global SIDI <0.48 was the optimum cut-off to predict LV pre-A ≥15mmHg (sensitivity, 82%; specificity, 68%). In addition, the ratio of L-global SIDI (after nitrate/before nitrate) was correlated with the ratio of LV pre-A (after nitrate/before nitrate; P=0.02, r=-0.34). CONCLUSIONS: A novel L-global SIDI derived from 2DSI may reflect elevated LV filling pressure and its rapid change better than conventional diastolic parameters.

Sanguis draconis, a dragon's blood resin, attenuates high glucose-induced oxidative stress and endothelial dysfunction in human umbilical vein endothelial cells.

Hyperglycaemia, a characteristic feature of diabetes mellitus, induces endothelial dysfunction and vascular complications by limiting the proliferative potential of these cells. Here we aimed to investigate the effect of an ethanolic extract of Sanguis draconis (SD), a kind of dragon's blood resin that is obtained from Daemonorops draco (Palmae), on human umbilical vein endothelial cells (HUVEC) under high-glucose (HG) stimulation and its underlying mechanism. Concentration-dependent (0-50 µg/mL) assessment of cell viability showed that SD does not affect cell viability with a similar trend up to 48 h. Remarkably, SD (10-50 µg/mL) significantly attenuated the high-glucose (25 and 50 mM) induced cell toxicity in a concentration-dependent manner. SD inhibited high glucose-induced nitrite (NO) and lipid peroxidation (MDA) production and reactive oxygen species (ROS) formation in HUVEC. Western blot analysis revealed that SD treatments abolished HG-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK 1/2), nuclear transcription factor, κB (NF-κB), VCAM-1, and E-selectin, and it also blocked the breakdown of PARP-116 kDa protein in a dose-dependent manner. Furthermore, we found that SD increased the expression of Bcl-2 and decreased Bax protein expression in HG-stimulated HUVEC. Thus, these results of this study demonstrate for the first time that SD inhibits glucose induced oxidative stress and vascular inflammation in HUVEC by inhibiting the ERK/NF-κB/PARP-1/Bax signaling cascade followed by suppressing the activation of VCAM-1 and E-selectin. These data suggest that SD may have a therapeutic potential in vascular inflammation due to the decreased levels of oxidative stress, apoptosis, and PARP-1 activation.

Moderate to high concentrations of high-density lipoprotein from healthy subjects paradoxically impair human endothelial progenitor cells and related angiogenesis by activating Rho-associated kinase pathways.

OBJECTIVE: Recent clinical evidence has failed to demonstrate the benefits of elevation of serum high-density lipoprotein (HDL), suggesting potential loss of protective effects of HDL at high concentrations. This study aimed to investigate the concentration-related effects of HDL on in vitro and in vivo functions of human endothelial progenitor cells (EPCs) and related angiogenesis. METHODS AND RESULTS: Early and late outgrowth EPCs were generated from human circulating mononuclear cells. Oxidized low-density lipoprotein reduced viability of late outgrowth EPCs, which was reversed dose dependently by HDL. In the absence of oxidized low-density lipoprotein, HDL at low concentrations (5-50 µg/mL, equal to 0.5-5 mg/dL in human) enhanced EPC tube formation by activating phosphatidylinositol-3 kinase/Akt/endothelial NO synthase pathways. Moderate to high concentrations (400-800 µg/mL) of HDL paradoxically enhanced EPC senescence and impaired tube formation by activating Rho-associated kinase (ROCK) and inhibiting phosphatidylinositol-3 kinase/Akt and p38 mitogen-activated protein kinase pathways. Rho-associated kinase inhibitors, either Y27632 or statins, prevented high HDL-induced EPC senescence and improved in vitro tube formation, as well as in vivo capacity of angiogenesis of EPCs. CONCLUSIONS: While protecting EPCs from the injury of oxidized low-density lipoprotein, moderate to high concentrations of HDL paradoxically impaired EPCs and related angiogenesis in the absence of oxidized low-density lipoprotein by activating Rho-associated kinase pathways, providing mechanistic evidence of potential hazard effects of HDL.

GroEL1, a heat shock protein 60 of Chlamydia pneumoniae, induces lectin-like oxidized low-density lipoprotein receptor 1 expression in endothelial cells and enhances atherogenesis in hypercholesterolemic rabbits.

Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) plays a major role in oxidized low-density lipoprotein-induced vascular inflammation. Chlamydia pneumoniae has been found in atherosclerotic lesions and is related to atherosclerotic pathogenesis, although its specific mechanism remains unknown. This study was conducted to investigate the mechanisms of LOX-1 expression in GroEL1 (a heat shock protein from C. pneumoniae)-administered human coronary artery endothelial cells (HCAECs) and atherogenesis in hypercholesterolemic rabbits. We demonstrated that in the hypercholesterolemic rabbit model, GroEL1 administration enhanced fatty streak and macrophage infiltration in atherosclerotic lesions, which may be mediated by elevated LOX-1 expression. In in vitro study using HCAECs, stimulation with GroEL1 increased TLR4 and LOX-1 expression. Increased LOX-1 expression was downregulated by Akt activation and PI3K-mediated endothelial NO synthase activation. PI3K inhibitor and NO synthase inhibitor induced LOX-1 mRNA production, whereas the NO donor ameliorated the increasing effect of LOX-1 mRNA in GroEL1-stimulated HCAECs. LOX-1 expression was regulated by NADPH oxidase, which mediates reactive oxygen species production and intracellular MAPK signaling pathway in GroEL1-stimulated HCAECs. Treatment with polyethylene-glycol-conjugated superoxide dismutase, apocynin, or diphenylene iodonium significantly decreased GroEL1-induced LOX-1 expression, as did the knockdown of Rac1 gene expression by RNA interference. In conclusion, the GroEL1 protein may induce LOX-1 expression in endothelial cells and atherogenesis in hypercholesterolemic rabbits. The elevated level of LOX-1 in vitro may be mediated by the PI3K-Akt signaling pathway, endothelial NO synthase activation, NADPH oxidase-mediated reactive oxygen species production, and MAPK activation in GroEL1-stimulated HCAECs. The GroEL1 protein of C. pneumoniae may contribute to vascular inflammation and cardiovascular disorders.

Gender-specific prognosis and risk impact of C-reactive protein, hemoglobin and platelet in the development of coronary spasm.

BACKGROUND: Scarce data are available on hemoglobin and platelet in relation to coronary artery spasm (CAS) development. We sought to determine the roles that high-sensitivity C-reactive protein (hs-CRP), hemoglobin and platelet play in CAS patients. METHODS: Patients (337 women and 532 men) undergoing coronary angiography with or without CAS but without obstructive coronary artery disease were evaluated during a 12-year period. RESULTS: Among women with high hemoglobin levels, the odds ratios (OR) from the lowest (<1 mg/l) to the highest tertiles (>3 mg/l) of hs-CRP were 1.21, 2.15, and 5.93 (p=0.009). In women with low hemoglobin levels, an elevated risk was found from the middle to the highest tertiles of hs-CRP (OR 0.59 to 3.85) (p=0.004). This relationship was not observed in men. In men, platelet count was the most significant risk factor for CAS (p=0.004). The highest likelihood of developing CAS was found among women with the highest hs-CRP tertile and low platelet counts (OR 8.77; 95% confidence interval [CI] 2.20-35.01) and among men with the highest hs-CRP tertile and high platelet counts (OR 4.58; 95% CI 0.48-43.97). Neither hemoglobin level nor platelet count was associated with frequent recurrent angina in both genders with CAS whereas death and myocardial infarction were rare. CONCLUSIONS: There are positive interactions among hs-CRP, hemoglobin and platelet in women with this disease, but not in men. While hemoglobin is a modifier in CAS development in women, platelet count is an independent risk factor for men. Both women and men have good prognosis of CAS.

Combined Framingham Risk Score and Coronary Artery Calcium Score Predict Subclinical Coronary Plaque Assessed by Coronary Computed Tomography Angiogram in Asymptomatic Taiwanese Population.

BACKGROUND: We sought to determine the predictive value of the combined traditional Framingham risk score (FRS) and coronary artery calcium score (CACS) for subclinical coronary plaque detected by computed tomography coronary angiogram (CTCA) in asymptomatic subjects. METHOD: We evaluated 167 asymptomatic Taiwanese subjects (mean age, 57 ± 11.2 years), who underwent CTCA as part of a health evaluation. We examined the associations between FRS, CACS, serum biomarkers, and coronary plaque assessed by CTCA. RESULTS: Out of 167 subjects in the study, 95 had coronary artery atheroma. Of those possible predictors for coronary atherosclerosis, both FRS and CACS were independent predictors for the presence of coronary plaque [relative risk (RR): 1.29, 95% confidence interval (CI): 1.07-1.54, p = 0.006 and RR: 1.42, 95% CI: 1.16-1.75, p = 0.001, respectively]. Receiver operating characteristics curve analysis revealed that CACS and FRS were indicators of the presence of coronary plaque. The area under the curve for FRS and CACS was 0.729 and 0.889, respectively (p < 0.001). Furthermore, the area under the curve for combination of FRS and CACS was 0.936 (95% CI: 0.887-0.969, p < 0.001), and this combination provided a better diagnostic advantage than either FRS or CACS alone (p < 0.001 and p = 0.012 by C-statistic, respectively). CONCLUSIONS: In asymptomatic Taiwanese subjects with low to intermediate cardiovascular risk, both FRS and CACS were independently related to subclinical atherosclerosis. A combined FRS and CACS evaluation improved the efficacy of prediction for atherosclerotic plaque burden. KEY WORDS: Atherosclerosis; Computed coronary tomography angiogram; Coronary artery calcium score; Framingham risk score; Subclinical coronary plaque.

Cardiac sympathetic hyperinnervation in deoxycorticosterone acetate-salt hypertensive rats.

Sympathetic activities are elevated in the central SNSs (sympathetic nervous systems) of hypertensive animals, but it is not known whether sympathetic innervation is also elevated in the heart. Sympathetic hyper-responsiveness in hypertension may result from oxidative stress. The aim of the present study was to investigate sympathetic hyperinnervation in DOCA (deoxycorticosterone acetate)-salt hypertensive rats with established hypertension. At 4 weeks after the start of DOCA-salt treatment and uninephrectomization, male Wistar rats were randomized into three groups for 8 weeks: vehicle, NAC (N-acetylcysteine) and triple therapy (hydralazine, hydrochlorothiazide and reserpine). DOCA-salt was associated with increased oxidant release. DOCA-salt produced concentric left ventricular hypertrophy and cardiomyocyte hypertrophy. Sympathetic hyperinnervation was observed in DOCA-salt rats, as assessed by myocardial noradrenaline levels, immunofluorescent analysis of tyrosine hydroxylase, growth-associated factor 43 and neurofilament and Western blotting and real-time quantitative RT-PCR (reverse transcription-PCR) of NGF (nerve growth factor). Arrhythmic scores during programmed stimulation in DOCA-salt rats were significantly higher than those in the control rats. Triple therapy, despite being effective on BP (blood pressure), offered neither attenuated cardiomyocyte hypertrophy nor anti-arrhythmia. The effects of DOCA-salt treatment on NGF expression, sympathetic hyperinnervation and arrhythmias were attenuated by NAC. Furthermore, the effects of NAC on NGF were abolished by administering BSO (L-buthionine sulfoximine), an inhibitor of glutamate-cysteine ligase. In conclusion, DOCA-salt treatment contributes to up-regulation of NGF proteins probably through a free radical-dependent pathway in a BP-independent manner. DOCA-salt rats treated with NAC attenuate sympathetic hyperinnervation and thus show a beneficial effect on arrhythmogenic response to programmed electrical stimulation.