Huiling Huang

The oxidation ratio of LDL: a predictor for coronary artery disease.

Objective: Oxidized LDL cholesterol (ox-LDL-C) is considered to be a key factor of initiating and accelerating atherosclerosis (AS). The purpose of this study is to elucidate the sensitivity and specificity of ox-LDL and oxidation ratio of LDL in the diagnosis of coronary artery disease (CAD). For the first time, we investigated the ratio of ox-LDL to ALB(ox-LDL/ALB). Methods and results: Blood ox-LDL, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglyceride (TG) and albumin (ALB) were measured in patients with acute myocardial infarction (AMI, n = 80), unstable angina pectoris (UAP, n = 80), stable angina pectoris (SAP, n = 80), normal control (n = 60), and dyslipidemia control (n = 60). Ox-LDL was measured by competitive ELISA. The level of ox-LDL and oxidation ratio of LDL(ox-LDL/TC, ox-LDL/HDL-C, ox-LDL/ LDL-C and ox-LDL/ALB) were significantly higher in each diseased group than controls (P < 0.001). In CAD group, ox-LDL and oxidation ratio of LDL in subjects complicated with hypertension (HT) and/or diabetes mellitus (DM) increased further (P < 0.001). Ox-LDL/ALB in the AMI group was 7 times higher than normal control group (0.068 ± 0.017 vs 0.009 ± 0.007, P < 0.001). The area under the curve (AUC) of receiver operating characteristic curve (ROC curve) is a criterium to evaluate the accuracy of diagnosing a disease. The AUC of ROC curve of ox-LDL/TC, ox-LDL/HDL-C, ox-LDL, ox-LDL/ALB and ox-LDL/ LDL-C for diagnosing CAD were 0.975, 0.975, 0.966, 0.966, 0.957 respectively (P < 0.001). When ox-LDL/TC = 0.175, the sensitivity and specificity of diagnosing CAD were 0.917 and 0.925, which were almost equal to each other, indicating that the rates of missed diagnosis and misdiagnosis for CAD were the lowest. Conclusions: The level of ox-LDL and the ratio of ox-LDL/TC, ox-LDL/LDL-C, ox-LDL/HDL-C and ox-LDL/ALB are better biomarkers than TC, TG, HDL-C and LDL-C for discriminating between patients with coronary artery disease and healthy subjects. And patients who have a high ratio of ox-LDL /TC may have a higher risk for CAD.

Plasma oxidized low-density lipoprotein is an independent risk factor in young patients with coronary artery disease

Objectives: Oxidized low-density lipoprotein (ox-LDL) is considered to be a key factor of initiating and accelerating atherosclerosis. The objective of this study was to investigate the role of ox-LDL in young patients with coronary artery disease (CAD). Methods: 128 consecutive angiographically proven young CAD patients (aged ≤ 55 years) were enrolled, and 132 age-matched non-CAD individuals (coronary angiography normal or negative finding by coronary ultrafast CT) were set as control group. Conventional risk factors (hypertension, dyslipidemia, diabetes mellitus, obesity, smoking) were evaluated in the two groups. Ox-LDL was measured by competitive ELISA. Framingham risk score (FRS) and absolute 10-year CAD events risk were calculated for each individual. Results: Male sex was more prevalent in group CAD than in control (87.5% vs. 62.1%; P < 0.01). There were significant differences in smoking history (P < 0.01) and triglyeride (TG) and ratio of apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) (both P < 0.05) but no remarkable difference in other conventional risk factors (all P > 0.05) between group CAD and control. Level of ox-LDL was significantly higher in group CAD than in control (P < 0.01). Multivariate logistic regression showed that male sex (OR, 4.54; 95%CI, 1.76–9.77), smoking quantity (OR, 2.78; 95%CI, 1.34–4.25), TG (OR, 1.42; 95%CI, 1.18–2.83), ApoB/ApoA1 (OR, 1.73; 95%CI, 1.32–4.23), and ox-LDL (OR, 2.15; 95%CI, 1.37–6.95) were independently correlated with CAD in young patients. Area under the curve (AUC) of receiver operating characteristic (ROC) curve of TG, ApoB/ApoA1, and ox-LDL was 0.831, 0.866, and 0.935, respectively (P < 0.001). Conclusions: Ox-LDL is an important independent risk factor for CAD in young patients after adjusting other risk factors such as smoking, TG, and ApoB/ApoA1.

The critical role of Sestrin 1 in regulating the proliferation of cardiac fibroblasts

The proliferation of cardiac fibroblasts is pivotal in the development of cardiac fibrosis. Sestrin 1, which functions as antioxidant, plays diverse roles in the regulation of proliferation and cellular injury that is induced by oxidative stress. However, little is known regarding the impact of Sestrin 1 on the proliferation of cardiac fibroblasts. In the present study, with knockdown of Sestrin 1 by siRNA, we surveyed the effect of Sestrin 1 on cardiac fibroblast proliferation. Downregulation of Sestrin 1 promotes Ang II-induced proliferation of cardiac fibroblasts, leading to increased DNA synthesis and collagen production. Moreover, in the absence of Ang II, a similar phenotype to the basal condition was detected with silencing of Sestrin 1. Further analysis of the pro-proliferating signals revealed that knockdown of Sestrin 1 significantly activated ERK1/2 and mTOR, meanwhile, downregulation of Sestrin 1 also enhanced the expression of collagen type I and CTGF, which play important role in the cardiac fibrosis. Consistent with the antioxidant property of Sestrin 1, we determined that the proliferation induced by silence of Sestrin 1 was accompanied by a remarkably enhanced production of reactive oxygen species (ROS). However, diminishing ROS by NAC, a potent antioxidant, could only partly repress the pro-proliferative effect of Sestrin 1-downregulation. Consequently, our study demonstrated that Sestrin 1 plays an important role in the proliferation of cardiac fibroblasts, and the effect could be partly mediated by decreased oxidative stress.

Oxidized low-density lipoprotein cholesterol and the ratio in the diagnosis and evaluation of therapeutic effect in patients with coronary artery disease

Objective: The purpose of the present study was to investigate the value of ox-LDL and oxidation ratio of LDL (ox-LDL/TC, ox-LDL/HDL-C and ox-LDL/LDL-C) in diagnosis and prognosis evaluation in CAD patients. Also, we aimed to observe the effect of statins on reducing level of ox-LDL and oxidation ratio of LDL, and explore whether statins still have similar effect on ox-LDL in a short period of therapy (within 2 weeks). Methods: Blood ox-LDL, TC, HDL-C, LDL-C, and TG were measured in cases with acute myocardial infarction (AMI, n = 177), unstable angina pectoris (UAP, n = 195), stable angina pectoris (SAP, n = 228), normal control (n = 120), and high risk control (n = 140). Results: Mean value of ox-LDL and oxidation ratio of LDL was significantly higher in the CAD group than in the two control groups. The AUC of ROC curve of ox-LDL, ox-LDL/TC, ox-LDL/HDL-C, ox-LDL/LDL-C and apoA1/apoB were more than 0.50 (P < 0.001). Multivariate logistic regression analysis showed that age and ox-LDL/LDL-C related with short-term, while ox-LDL/LDL-C and ox-LDL/TC related with long-term prognosis (P < 0.05). Furthermore, after treatment with statins for 2 weeks, TC, LDL-C, ox-LDL, ox-LDL/TC, ox-LDL/HDL-C and ox-LDL/LDL-C decreased by 22%, 28%, 38%, 29%, 23% and 25% respectively. And the reduction of ox-LDL by statins is independent of lowering of LDL-C and TC. Conclusions: Ox-LDL and oxidation ratio of LDL are closely related with AS, and they are better biomarkers for discriminating between patients with coronary artery disease and healthy subjects. In addition, statins can decrease level of ox-LDL significantly, which is independent of lowering of LDL-C and TC.

AMPK attenuates ventricular remodeling and dysfunction following aortic banding in mice via the Sirt3/Oxidative stress pathway

ABSTRACT Although recent findings have suggested that AMP‐activated protein kinase (AMPK) exerts inhibitory effects on cardiac remodeling secondary to hypertension, the mechanism and optimal duration of treatment remain unknown. Mice with descending aortic banding (AB) or subjected to sham operation received subcutaneous injection of either AICAR (0.5 mg g‐1 day‐1) or vehicle over 4 week periods. At the end of 4 week treatment, left ventricular (LV) remodeling and function were evaluated with histological analysis and echocardiography. Collagen deposition within the LV myocardium was detected with Massons trichrome staining. Collagen I, Collagen III, Smad 2, Smad 3, NOX2, NOX4 and Sirt3 (an important antioxidant factor) within the LV tissue were also evaluated. Compared with the sham group, the vehicle‐treated AB group exhibited significant elevations in cardiac remodeling and heart failure, characterized by an increase in LV weight relative to body weight, an increase in the area of collagen deposition, an increase in LV end‐diastolic diameter, an increase in mitral E inflow velocity to mitral A inflow velocity and increases in the gene expressions of the fibrosis markers Collagen I, III and Smad 2, 3 mRNA and decreases in EF and fractional shortening. AMPK attenuate the cardiac remodeling parameters and improve cardiac function. Moreover, the expressions of NOX2, NOX4 were significantly elevated in vehicle‐treated AB group. AMPK was able to significantly inhibit NOX2, NOX4 expression, while activate Sirt3 expression. AMPK significantly attenuated hypertension‐induced Ventricular remodeling and dysfunction, which may be mediated by the Sirt3/Oxidative stress signaling pathway.

Effects of Long-Term Statin Therapy in Coronary Artery Disease Patients with or without Chronic Kidney Disease.

Introduction. The effect of long-term statin therapy is essential for secondary prevention of adverse clinical outcomes of coronary artery disease (CAD) patients. No study has compared the effects of long-term statin treatment in CAD patients with or without chronic kidney disease (CKD) and CKD only patients. Methods. We compared the effects of long-term statin therapy (average follow-up time 5.79 years) in terms of major adverse cardiovascular events (MACE), all-cause death, and cardiac death among 570 CAD patients with or without CKD and 147 CKD only patients. Results. The all-cause death and cardiac death of the patients with CAD and CKD (24.4% and 20.4%) doubled those of CAD only patients (10.7% and 9.1%) (P < 0.001). Long-term statin therapy dramatically reduced the rates of both MACE and all-cause death/cardiac death (by 20.5% and 28.6%/27.7%, resp.) in CAD and CKD patients. CKD only patients had no significant adverse clinical outcomes and were not responsive to long-term statin therapy. Conclusion. Chinese CAD patients with CKD had dramatically high rates of adverse clinical outcomes; for them, long-term statin therapies were exceptionally effective in improving morbidity and mortality. CKD patients who had no cardiovascular disease initially can prognose good clinical outcomes and do not require statin treatment.

Fisetin inhibits cardiac hypertrophy by suppressing oxidative stress

Cardiac hypertrophy is a pathophysiological response to various pathological stresses and ultimately leads to heart failure. Oxidative stress is one of the critical processes involved in hypertrophy development. Fisetin, a small molecular flavonoid, has been shown to have anti-oxidative, anti-proliferative and anti-inflammatory properties. However, the effect of fisetin on cardiac hypertrophy remains unknown. In our present study, we showed that fisetin inhibited pressure overload-induced cardiac hypertrophy, improved cardiac function in vivo and suppressed phenylephrine (PE)-induced cardiomyocyte hypertrophy in vitro. Reactive oxygen species (ROS) levels were markedly decreased by fisetin treatment in both hypertrophic hearts and cardiomyocytes. Moreover, fisetin significantly up-regulated the expression of antioxidative genes, including catalase (CAT), superoxide dismutase 1 (SOD1) and heme oxygenase 1 (HO-1). Furthermore, co-treatment with N-acetylcysteine (NAC; ROS scavenger) and fisetin did not have synergistic inhibitory effects on PE-induced cardiomyocyte hypertrophy, indicating that the anti-hypertrophic effects of fisetin are mainly associated with the blockade of oxidative stress. Finally, the pro-hypertrophic signaling pathways, mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) kinase, were found to be suppressed by fisetin after pressure overload and PE treatment. In conclusion, our study revealed that fisetin protects against cardiac hypertrophy and that oxidative stress inhibition may be one of the pivotal mechanisms involved.

Prognostic Significance of Serum Cysteine-Rich Protein 61 in Patients with Acute Heart Failure

Background/Aims: Cyr61-cysteine-rich protein 61 (CCN1/CYR61) is a multifunctional matricellular protein involved in the regulation of fibrogenesis. Animal experiments have demonstrated that CCN1 can inhibit cardiac fibrosis in cardiac hypertrophy. However, no study has been conducted to assess the relation between serum CCN1 and prognosis of acute heart failure (AHF). Methods: We measured the serum CCN1 levels of 183 patients with AHF, and the patients were followed up for 6 months. The associations between CCN1 levels and some clinical covariates, especially left ventricular ejection fraction (LVEF), estimated glomerular filtration rate (eGFR), atrial fibrillation and age, were estimated. The AHF patients were followed up for 6 months. The endpoint was all-cause mortality. Kaplan-Meier curve analysis and multivariable Cox proportional hazards analysis were employed to evaluate the prognostic ability of CCN1. We used calibration, discrimination and reclassification to assess the mortality risk prediction of adding CCN1. Results: Serum CCN1 concentrations in AHF patients were significantly increased compared with those in individuals without AHF (237 pg/ml vs. 124.8 pg/ml, p< 0.001). CCN1 level was associated with the level of NT-proBNP (r=0.349, p< 0.001) and was not affected by LVEF, eGFR, age or atrial fibrillation in AHF patients. Importantly, Kaplan-Meier curve analysis illustrated that the AHF patients with serum CCN1 level > 260 pg/ ml had a lower survival rate (p< 0.001). Multivariate Cox hazard analysis suggests that CCN1 functions as an independent predictor of mortality for AHF patients (LgCCN1, hazard ratio 5.825, 95% confidence interval: 1.828-18.566, p=0.003). In addition, the inclusion of CCN1 in the model with NT-proBNP significantly improved the C-statistic for predicting death (0.758, p< 0.001). The integrated discrimination index was 0.019 (p< 0.001), and the net reclassification index increased significantly after addition of CCN1 (23.9%, p=0.0179). Conclusions: CCN1 is strongly predictive of 6-month mortality in patients with AHF, suggesting serum CCN1 as a promising candidate prognostic biomarker for AHF patients.

The Role of Angiopoietin-like Protein 4 in Phenylephrine-induced Cardiomyocyte Hypertrophy

Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional secreted protein that can be induced by fasting, hypoxia and glucocorticoids. ANGPTL4 has been associated with a variety of diseases; however, the role of ANGPTL4 in cardiac hypertrophy remains poorly understood. In our study, we aimed to explore the effect of ANGPTL4 on phenylephrine-induced cardiomyocyte hypertrophy. Our results showed that knockdown of ANGPTL4 expression significantly exacerbated cardiomyocyte hypertrophy, as demonstrated by increased hypertrophic marker expression, including ANP and cell surface area. Moreover, significantly reduced fatty acid oxidation, as featured by decreased CPT-1 levels, was observed in hypertrophic cardiomyocytes following ANGPTL4 down-regulation. Furthermore, knockdown of ANGPLT4 led to down-regulated expression of peroxisome proliferator-activated receptor α (PPARα), which is the key regulator of cardiac fatty acid oxidation. In addition, ANGPTL4 silencing promoted the activation of JNK1/2, and JNK1/2 signaling blockade could restore the level of PPARα and significantly ameliorate the ANGPTL4 knockdown-induced cardiomyocyte hypertrophy. Therefore, our study demonstrated that ANGPTL4 regulates PPARα through JNK1/2 signaling and is required for the inhibition of cardiomyocyte hypertrophy.

GW24-e2463 Relationship between resting heart rate reduction and progression of coronary atherosclerosis in established coronary artery disease patients

Objectives β-block can reduce the rate of progression of atherosclerosis caused by increased sympathetic activity. However, the percentage reduction in resting heart rate (RHR) in relation to the progression of coronary atherosclerosis in patients with established coronary artery disease (CAD) remains uncertain. Methods We performed retrospective chart review of 318 patients with established CAD who underwent 2 coronary angiographies (CAG). Progression of coronary atherosclerosis was defined as in-stent restenosis, or increasing stenosis of 20% or more in luminal diameter than baseline. Results After a median follow-up of 24 months between coronary angiographies, 147(46.2%) patients developed progressive coronary atherosclerosis. There were no significant differences in baseline RHR (74.71 ± 10.67 vs 76.21 ± 10.74, p = 0.211) among patients with and without progression of coronary atherosclerosis. The use of beta-blockers, statins, aspirin, clopidogrel, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers were also similar between two groups from baseline to follow-up. However, RHR was significantly higher in patients with progressive disease than those in the non-progressive group (74.75 ± 11.04 vs 71.99 ± 9.39, p = 0.017) in the second CAG, and there was significant difference in the changes between two RHR between two groups (-0.041 ± 12.30 vs 4.14 ± 11.73, p<0.001). After multivariate adjustment accounting for age, gender, smoking, number of diseased vessels, stent implantation, serum LDL-C level, LDL-C reduction and RHR reduction, et al, achieving RHR reduction of 20% or more showed significantly reduced progression of coronary atherosclerosis (Odds ratio [OR] 0.352, 95% confidence interval [CI], 0.139-0.894, p = 0.028). Conclusions The current study suggests that the benefit of β-block therapy in progression of coronary atherosclerosis is in proportion to the reduction in RHR. More than 20% reduce in RHR may bring more benefit for the prevention of coronary atherosclerosis progress.