Jun Jin

C-reactive protein down-regulates endothelial nitric oxide synthase expression and promotes apoptosis in endothelial progenitor cells through receptor for advanced glycation end-products.

OBJECTIVE C-reactive protein (CRP), the prototypic marker of inflammation, has been shown to be an independent predictor of atherosclerosis. CRP can regulate receptor for advanced glycation end-products (RAGE) expression in endothelial progenitor cells (EPCs). Endothelial nitric oxide synthase (eNOS) deficiency is a pivotal event in atherogenesis. It is believed that decreased eNOS bioactivity occurs early in atherogenesis. Therefore, we tested the hypothesis that CRP can alter eNOS expression and promote apoptosis in EPCs through RAGE. METHODS AND RESULTS EPCs, isolated from bone marrow, were cultured in the presence or absence of LPS-free CRP (5, 10, 15, 20, and50μg/ml). RAGE protein expression and siRNA were measured by flow cytometric analysis. PCR was used to detect eNOS mRNA expression. eNOS protein expression was measured by Western blot analysis. A spectrophotometer was used to assess eNOS activity. A modified Boydens chamber was used to assess the migration of EPCs and the number of recultured EPCs was counted to measure adhesiveness. A MTT assay was used to determine proliferation. Apoptosis was evaluated by annexin V immunostaining and TUNEL staining. Co-culturing with CRP caused a significant down-regulation of eNOS expression, inhibited the proliferation, migration, and adhesion of EPCs, and induced EPC apoptosis. In addition, these effects were attenuated during RAGE protein expression blockade by siRNA. CONCLUSIONS CRP, at concentrations known to predict cardiovascular event, directly quenches the expression of eNOS and diminishes NO production, and may serve to impair EPC function and promote EPC apoptosis through RAGE. These data further support a direct role of CRP in the development and/or progression of atherosclerosis and indicate a new pathophysiologic mechanism of disturbed vascular adaptation in atherosclerosis.

Over-expression of hepatocyte growth factor in smooth muscle cells regulates endothelial progenitor cells differentiation, migration and proliferation

BACKGROUND Endothelial repair is one of key events after vascular injury. The mechanisms by which hepatocyte growth factor (HGF) and endothelial progenitor cells (EPCs) may be responsible for re-endothelialization of injured blood vessel wall are poorly understood. METHODS Primary culture SMCs were transfected with pcDNA3.0-HGF followed by G418 selection, one of G418-resistant colonies in well was picked, propagated and used as donor cells for further experiments. HGF and VEGF expression in SMCs were detected with western blot and enzyme linked immunosorbent assays (ELISA). Rat EPCs were cultured in untreated, pcDNA3.0 and pcDNA3.0-HGF transfected SMCs conditioned medium with or without anti-VEGF or exogenous recombinant HGF addition. eNOS, KDR and CD31 expression in EPCs was determined by real-time quantitative polymerase chain reaction (RT-qPCR) or flow cytometry; EPCs migration and proliferation were measured by using a modified Boyden chambers and MTT assay respectively. RESULTS Abundant and stable expression of HGF was found in G418-resistant colony-derived SMCs. VEGF expression significantly increased in HGF transfected SMCs. Exogenous recombinant HGF (rHGF) markedly up-regulated eNOS mRNA expression in EPCs and promoted EPCs migration and proliferation, but no significant changes were found in KDR and CD31 mRNA expression. HGF transfection in SMCs was more effective than exogenous HGF for EPCs differentiation, proliferation and migration. CONCLUSIONS Over-expression of HGF in SMCs can be helpful for promoting EPCs differentiation, increasing EPCs migration and proliferation. It may be responsible for angiogenesis of arteriosclerosis lesions and useful for blood vessel tissue engineering.

Tailored antiplatelet therapy and clinical adverse outcomes

Objective The clinical evidence regarding the influence of tailored antiplatelet strategy on adverse outcomes has been controversial. The aim of the study was to evaluate the significance of tailored antiplatelet therapy with respect to clinical adverse events in antiplatelet-resistant patients. Methods Randomised studies that assess clinical relevance of personalised antiplatelet treatment in antiplatelet-resistant patients were identified through a literature search: PubMed, EMBASE, Web of Science and the Cochrane Library. The primary endpoint was the composite of death from any cause and stent thrombosis. All total clinical adverse events and bleeding complications were evaluated. Results Data were combined across seven randomised studies comprising 12 048 subjects, of whom 3738 (31.0%) were found to be antiplatelet-resistant. Antiplatelet-resistant patients provided with tailored antiplatelet therapy showed less risk of death or stent thrombosis than those assigned conventional antiplatelet treatment (0.5% vs 2.2%; OR (95% CI) 0.25 (0.13 to 0.49), p<0.0001). A significant benefit in terms of total adverse event risk reduction was observed during follow-up for tailored vs conventional antiplatelet therapy (5.5% vs 10.0%; OR (95% CI) 0.40 (0.20 to 0.77), p=0.006). No statistical difference in bleeding complications was observed between these two groups (p=0.08). Conclusions In the study, personalised antiplatelet treatment for antiplatelet resistance was found to be associated with less occurrence of death or stent thrombosis and the less risk of total clinical adverse events than conventional treatment, without increasing the risk of bleeding complications.

Bivalirudin Anticoagulant Therapy With or Without Platelet Glycoprotein IIb/IIIa Inhibitors During Transcatheter Coronary Interventional Procedures: A Meta-Analysis

AbstractThe safety and effectiveness of using the direct thrombin inhibitor bivalirudin during transcatheter coronary interventional procedures remains uncertain.This study aimed to systematically assess anticoagulation with bivalirudin alone or bivalirudin plus glycoprotein (GP) IIb/IIIa inhibitors (bivalirudin-based anticoagulant therapy) in patients undergoing percutaneous coronary intervention (PCI) procedures by a meta-analysis of randomized controlled trials (RCTs).Systematical searches of the MEDLINE, EMBASE, and Cochrane databases were conducted. RCTs comparing bivalirudin-based anticoagulant therapy with a comparable heparin therapy in patients undergoing PCI were eligible. Risk ratios (RRs) with 95% confidence intervals (CIs) served as summary statistics.A total of 38,096 patients from 17 RCTs were randomized to the bivalirudin group (n = 18,878) or heparin group (n = 19,218) in the meta-analysis. No significant differences in death, myocardial infarction or reinfarction, ischemia-driven revascularization, or in-stent thrombosis were observed between the 2 groups (all P > 0.05). Notably, bivalirudin-based therapy showed a highly significant 34% decrease in the incidence of major bleeding (RR = 0.66; 95% CI 0.54–0.81; P < 0.001) and a 28% reduction in the need for blood transfusion (RR = 0.72; 95% CI 0.56–0.91; P < 0.01). Meta-regression analyses demonstrated that additional administration of GP IIb/IIIa receptor inhibitors (P = 0.01), especially eptifibatide (P = 0.001) and tirofiban (P = 0.002), was likely to increase the major bleeding risk associated with bivalirudin.Bivalirudin, in comparison to heparin, is associated with a markedly lower risk of major bleeding, and the additional use of GP IIb/IIIa inhibitors may weaken this benefit.

Principal Component Analysis and Risk Factors for Acute Mountain Sickness upon Acute Exposure at 3700 m.

Objective We aimed to describe the heterogeneity in the clinical presentation of acute mountain sickness (AMS) and to identify its primary risk factors. Methods The participants (n = 163) received case report form questionnaires, and their heart rate (HR), oxygen saturation (SpO2), echocardiographic and transcranial Doppler variables, ability to perform mental and physical work, mood and psychological factors were assessed within 18 to 22 hours after arriving at 3700 m from sea level (500 m) by plane. First, we examined the differences in all variables between the AMS-positive and the AMS-negative groups. Second, an adjusted regression analysis was performed after correlation and principal component analyses. Results The AMS patients had a higher diastolic vertebral artery velocity (Vd; p = 0.018), a higher HR (p = 0.006) and a lower SpO2. The AMS subjects also experienced poorer sleep quality, as quantified using the Athens Insomnia Scale (AIS). Moreover, the AMS population exhibited more negative mood states, including anxiety, depression, hostility, fatigue and confusion. Five principal components focused on diverse aspects were also found to be significant. Additionally, more advanced age (p = 0.007), a higher HR (p = 0.034), a higher Vd (p = 0.014), a higher AIS score (p = 0.030), a decreased pursuit aiming capacity (p = 0.035) and decreased vigor (p = 0.015) were risk factors for AMS. Conclusions Mood states play critical roles in the development of AMS. Furthermore, an elevated HR and Vd, advanced age, elevated AIS sores, insufficient vigor and decreased mental work capacity are independent risk factors for AMS.

Value of Myocardial Regional Perfusion on Long-Term Function in Collateral-Dependent Myocardium

Background: Collateral circulation is considered key for left ventricular (LV) function recovery in patients with chronic total occlusion (CTO). However, there are conflicting reports about the influence of collaterals on LV recovery after revascularization. Methods: Echocardiographic assessment of regional myocardial perfusion, wall motion score (WMS), and left ventricular ejection fraction (LVEF) were performed in patients with angiographically visible collateral circulation of grades 2 and 3. Results: The WMS and LVEF of group B (with presence of myocardial regional perfusion) were significantly improved at one month and six months compared to those of group A (with absence of myocardial regional perfusion). The correlation between myocardial regional blood flow and changes in WMS and LVEF was significant at 6 months in patients with angiographically visible collateral circulation of grade 2 and 3. Similar correlations were observed on myocardial contrast echocardiography (MCE) score index. Conclusion: Myocardial function recovery in patients with CTO is determined by myocardial regional perfusion. MCE has important value for prognosis and risk stratification in patients with CTO undergoing cardiac catheterization.

Physiological and psychological factors associated with onset of high-altitude headache in Chinese men upon acute high-altitude exposure at 3700 m.

Aim We aimed to identify clinical characteristics and risk factors associated with onset of high-altitude headache (HAH) after acute exposure at 3700 m. Method In two hours, 163 individuals ascended by plane to 3700 m. Demographic information, physiological and psychological measurements, cognitive function, physical work capacity tests and profile of mood states within one week prior to the departure and within 24 hours after arrival were examined. Results HAH patients featured significantly higher vertebral artery diastolic velocity (Vd), heart rate (HR) and pulmonary artery diameter. HAH was also associated with a more negative mood state, including scores for tension anxiety, depression, hostility, fatigue and confusion, as well as lower vigor (all p values <0.05). Furthermore, negative emotions were positively related to HAH severity. HAH slightly decreased cognitive functioning. HR, Vd, lack of vigor, confusion and self-reported anxiety (all p values <0.05) were independent risk factors for HAH. We have identified three independent baseline predictors for HAH including internal diameter of the left ventricle (LVD), Athens Insomnia Scale (AIS) and confusion score. Conclusions Higher HR, Vd, confusion and self-reported anxiety and insufficient vigor were independent risk factors for HAH. Furthermore, higher baseline LVD, AIS and confusion score are independent predictors of HAH.

Copper sulfide-functionalized molybdenum disulfide nanohybrids as nanoenzyme mimics for electrochemical immunoassay of myoglobin in cardiovascular disease

Myoglobin is one of the most commonly used cardiac biomarkers for the clinical diagnosis of acute myocardial infarction, which is the leading cause of mortality worldwide. Herein, we report a novel ‘signal-on’ electrochemical immunosensing system for the quantitative detection of myoglobin without the need for natural enzymes and additional electron mediators. The assay was readily carried out on a monoclonal mouse anti-human myoglobin capture antibody-modified carbon fiber microelectrode using copper sulfide–molybdenum disulfide (CuS–MoS2) hybrid nanostructures conjugated with polyclonal rabbit anti-human myoglobin detection antibody. Upon introduction of target myoglobin into the detection system, sandwiched immunocomplexes were formed on the electrode between the capture antibody and the detection antibody accompanying the CuS–MoS2 nanohybrids. The carried CuS–MoS2 nanohybrids acted as nanoenzyme mimics to electrochemically oxidize the glucose substrate, thereby resulting in the increment of the anodic current. Under optimal conditions, the detectable currents exhibited a ‘signal-on’ response relative to myoglobin concentrations within a dynamic linear range of 0.005–20 ng mL−1, with a limit of detection (LOD) as low as 1.2 pg mL−1. In addition, the electrochemical immunosensing platform displayed high specificity, good precision and reproducibility, and acceptable method accuracy for determining human serum specimens from cardiovascular disease patients with consistent results obtained from the referenced enzyme-linked immunosorbent assay (ELISA) method.

The ubiquitin-activating enzyme E1 as a novel therapeutic target for the treatment of restenosis

AIMS The ubiquitin-activating enzyme E1 (UBA1, E1), the apex of the ubiquitin proteasome pathway, plays a critical role in protein degradation and in pathological processes. Whether UBA1 participates the development of vascular restenosis remains unknown. This study aims to determine the role of UBA1 in the development of balloon injury induced neointimal formation. METHODS AND RESULTS Immunostaining and western blots were used to examine the expression of the ubiquitinated protein in the injured carotid after angioplasty. Higher levels of ubiquitinated protein were observed in the neointima. Local delivery of potent chemical UBA1 inhibitor PYR-41 (100 μM) and UBA1 shRNA lentivirus both resulted in a substantial decrease in intimal hyperplasia at 2 weeks and 4 weeks after balloon injury. UBA1 inhibition also reduced Ki-67 positive cell percentage and inflammatory response in the carotid artery wall. We further determined that in vitro UBA1 inhibition was able to ameliorate TNF-α-induced nuclear factor-kappa B (NF-κB) activation by reducing IκB degradation in vascular smooth muscle cells (VSMCs). UBA1 inhibition also led to the accumulation of short-lived proteins such as p53, p21 and c-jun, which may account for the UBA1 inhibition-induced cell cycle delay. Thus, VSMCs proliferation was blocked. CONCLUSIONS UBA1 inhibition effectively suppresses neointimal thickening through its anti-proliferative and anti-inflammatory effects. Our results provide further evidence that the ubiquitin-proteasome system is a potential new target for the prevention of vascular restenosis.

Left Ventricular Function during Acute High-Altitude Exposure in a Large Group of Healthy Young Chinese Men

Objective The purpose of this study was to observe left ventricular function during acute high-altitude exposure in a large group of healthy young males. Methods A prospective trial was conducted in Szechwan and Tibet from June to August, 2012. By Doppler echocardiography, left ventricular function was examined in 139 healthy young Chinese men at sea level; within 24 hours after arrival in Lhasa, Tibet, at 3700 m; and on day 7 following an ascent to Yangbajing at 4400 m after 7 days of acclimatization at 3700 m. The resting oxygen saturation (SaO2), heart rate (HR) and blood pressure (BP) were also measured at the above mentioned three time points. Results Within 24 hours of arrival at 3700 m, the HR, ejection fraction (EF), fractional shortening (FS), stroke volume (SV), cardiac output (CO), and left ventricular (LV) Tei index were significantly increased, but the LV end-systolic dimension (ESD), end-systolic volume (ESV), SaO2, E/A ratio, and ejection time (ET) were significantly decreased compared to the baseline levels in all subjects. On day 7 at 4400 m, the SV and CO were significantly decreased; the EF and FS Tei were not decreased compared with the values at 3700 m; the HR was further elevated; and the SaO2, ESV, ESD, and ET were further reduced. Additionally, the E/A ratio was significantly increased on day 7 but was still lower than it was at low altitude. Conclusion Upon acute high-altitude exposure, left ventricular systolic function was elevated with increased stroke volume, but diastolic function was decreased in healthy young males. With higher altitude exposure and prolonged acclimatization, the left ventricular systolic function was preserved with reduced stroke volume and improved diastolic function.