Diagnostic value and method of soluble transferrin receptor for suspected coronary artery disease: a case-control study.

Background: Many studies have pointed out that iron overload in the body is a risk factor for coronary atherosclerosis (AS), while there are also studies that show that iron deficiency is associated with coronary AS. There is still no consensus on how iron metabolism affects coronary artery disease (CAD). This study aimed to analyze the relationship between iron metabolism indexes and CAD, investigate the diagnostic value of soluble transferrin receptor (sTfR) in suspected CAD, and establish a diagnostic model. Methods: This was a retrospective study. A total of 268 people with CAD-like symptoms who underwent coronary angiography in the Department of Cardiovascular Medicine, The Second Affiliated Hospital of Anhui Medical University from September 2022 to May 2023 without other chronic diseases or related medication history were included in the study and formed a continuous series including 188 CAD patients and 80 control subjects. Each iron metabolism index was divided into a grade variable according to tertile. The comparison of CAD morbidity between the tertiles and nonlinear correlation test was conducted to investigate the relationship between iron metabolism indexes and CAD risk. We used restricted cubic spline (RCS) to plot the relationship curve between sTfR and CAD risk and to determine the sTfR value corresponding to the minimal odds, according to which we divided the total sample into the "sTfR low level" subgroup and the "sTfR high level" subgroup. Logistic regression analyses were used to establish diagnostic models in both subgroups. The diagnostic efficiency of the indexes and models was compared by receiver operating characteristic (ROC) analysis. Results: There is a "J" shape correlation between sTfR and CAD risk. Age/sTfR ratio [area under the curve (AUC) =0.690, 95% confidence interval (CI): 0.598-0.782, specificity 0.488 and sensitivity 0.842] has the best diagnostic efficiency in the "sTfR low level" subgroup. The diagnostic efficiency of sTfR (AUC =0.701, 95% CI: 0.598-0.803, specificity 0.541 and sensitivity 0.797) in the "sTfR high level" subgroup was higher than that of cardiac troponin I (cTnI) (AUC =0.674, 95% CI: 0.564-0.784, specificity 0.719 and sensitivity 0.653). The specific diagnostic methods were as follows: (I) When sTfR ≤1.087 mg/L, calculate the age/sTfR ratio, which indicates the diagnosis of CAD when the result is >58.595; (II) We can directly make a preliminary clinical diagnosis of CAD when sTfR >1.205 mg/L. Except for the above 2 cases, we can initially rule out a diagnosis of CAD. Conclusions: The iron metabolism index sTfR correlates with CAD morbidity in a "J" shape. With superior diagnostic efficacy than cTnI, sTfR can assist in diagnosing CAD in patients with CAD-like symptoms. In addition, sTfR can provide guidance for the management of body iron levels in CAD patients.

Evaluation of changes in atrial fibrillation predictors(P wave parameters and left atrial diameter) in morbidly obese patients undergoing bariatric surgery.

BACKGROUND: Bariatric surgery has been associated with reduced cardiovascular event in obese patients.In this study, we aimed to investigate the changes between pre-operation and post-operation atrial fibrillation predictors(p-wave parameters and left atrial diameter)in morbidly obese patients who underwent bariatric surgery. METHODS: 176 obese patients undergoing bariatric surgery were enrolled. Heart rate, PR, P-wave max, P-wave min,P-wave dispersion (PWdis), average P-axis, P-wave peak time (PWPT) of lead II and lead V1, terminal force of lead V1 (PWTF V1), partial interatrial block (p-IAB), advanced interatrial block(a-IAB), and left atrial diamete were measured both before operation and 8 months post-operation. RESULTS: Heart rate, PR, PW max, PW min, PWdis, mean P-axis, PWPT II, PWPT V1, and PWTF V1 were near their upper limits before operation. Left atrial diameter was larger than the upper limit before operation. All parameters showed statistically significant decrease at 8 months post-operation. The most significant changes were observed in PWPT II (55.69 ± 6.87 ms vs 50.43 ± 7.48 ms, p < 0.001), PWPT V1(54.21 ± 7.01 ms vs 48.02 ± 7.13 ms, p < 0.001), PWTF V1(74 [42.0%] vs 41 [23.3%], p < 0.001),p-IAB(41[23.2%]vs11[6.2%],p < 0.001),a-IAB(6[3.4%]vs2[1.1%], p < 0.001), and left atrial diameter(43.25 ± 9.23 mm vs 34.27 ± 6.21 mm,p < 0.001). CONCLUSIONS: The results of our study showed that bariatric surgery had a positive effect on the regression of P wave parameters and left atrial diameter which are predictors of atrial fibrillation.

IVABRADINE-INDUCED HEART RATE REDUCTION INCREASES THE SEVERITY OF POSTRESUSCITATION MYOCARDIAL DYSFUNCTION IN A RAT MODEL OF CARDIOPULMONARY RESUSCITATION.

ABSTRACT: Aims: A rapid heart rate (HR) that occurs after cardiopulmonary resuscitation (CPR) is a short-term compensatory mechanism preserving cardiac output. However, if of long duration, it is unfavorable for myocardial function postresuscitation because of disrupted balance between myocardial oxygen supply and demand. This raises the assumption that such a sustained fast HR should be regulated. The present study aimed to investigate the follow-on effect of ivabradine (a specific inhibitor of the I f current of the sinoatrial node)-induced HR reduction (HRR) on postresuscitation myocardial function in a rat model of CPR. Methods and results: Six minutes of ventricular fibrillation and 8 min of CPR were performed on Sprague-Dawley rats. All 32 resuscitated animals were then randomized into saline and ivabradine groups, each group having nonsurvival and survival subgroups (n = 8 each). Saline or ivabradine (0.5 mL/kg) was administered at 1 h postresuscitation. Heart rate, myocardial function as expressed by cardiac output, ejection fraction, and myocardial performance index were assessed at baseline and hourly from 1 to 5 h postresuscitation. Heart rate variability was analyzed at baseline and at 1, 3, and 5 h postresuscitation. Serum epinephrine and cardiac troponin I at baseline and at 1, 3, and 5 h postresuscitation in nonsurvival subgroup were measured. Survival duration in the survival subgroup was observed. The baseline HR was approximately 390 beats/min (bpm). After resuscitation, an average increase of Δ ≈ +15 bpm (relative ratio ≈ +3.8%) with a resultant HR of 405 bpm lasting more than 5 h occurred. Ivabradine group achieved a steady HRR of Δ ≈ -30 bpm (relative ratio ≈ -7.4%) as compared with saline group ( P < 0.01). Postresuscitation myocardial function was significantly worse in the ivabradine group (all P < 0.01). Heart rate variability was significantly impaired in the ivabradine group (all P < 0.05). Serum cardiac troponin I and epinephrine concentration were significantly higher in the ivabradine group (all P < ?0.01). Survival duration was significantly shortened in the ivabradine group as compared with the saline group (388 vs. 526 min, P < ?0.01). Conclusions: Ivabradine-induced HRR increases the severity of postresuscitation myocardial dysfunction and shortens survival duration in a rat model of CPR.

Bivalirudin vs. heparin on a background of ticagrelor and aspirin in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: A multicenter prospective cohort study.

Objective: Current guidelines recommend potent P2Y12 inhibitors such as ticagrelor over clopidogrel as part of the dual antiplatelet therapy (DAPT) after ST-segment elevation myocardial infarction (STEMI), irrespective of final management strategy. The aim of this multicenter prospective cohort study was to examine the efficacy and safety of bivalirudin with background ticagrelor and aspirin therapy in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI). Methods: A total of 800 patients with STEMI who were undergoing PPCI and receiving treatment with aspirin and ticagrelor from three Hospitals between April 2019 and September 2021 were included in this study. The patients were assigned, according to the perioperative anticoagulant, to the bivalirudin group (n = 456) or the heparin group (n = 344). In this study, the primary endpoint was 30-day net adverse clinical events (NACEs), a composite of major adverse cardiac or cerebral events (MACCEs, a composite of cardiac death, recurrent myocardial infarction, ischemia-driven target vessel revascularization, or stroke), or any bleeding as defined by the Bleeding Academic Research Consortium (BARC) definition (grades 1-5). Results: The patients were followed up for 30 days after PPCI. The incidence of NACE was significantly lower in the bivalirudin group than in the heparin group (11.2 vs. 16.0%, P = 0.042), and this significance was mainly a consequence of the reduction in BARC 1 bleeding events in the bivalirudin group compared to the heparin group (3.2 vs. 7.1%, P = 0.010). Results from multivariate Cox regression analysis showed that bivalirudin significantly reduced 30-day NACE (HR: 0.676, 95% CI: 0.462-0.990, P = 0.042) and BARC1 bleeding events (HR: 0.429, 95% CI: 0.222-0.830, P = 0.010). No significant between-group differences were observed for MACCE, all-cause mortality, cardiac death, recurrent myocardial infarction, stroke, target vessel revascularization, stent thrombosis, and BARC2-5 bleeding events at 30 days. Conclusion: In patients with STEMI who were undergoing primary PCI and receiving treatment with aspirin and ticagrelor, bivalirudin was associated with decreased rates in NACE and minimal bleeding events without significant differences in the rates of MACCE or stent thrombosis when compared with heparin. Nevertheless, large randomized trials are warranted to confirm these observations. Clinical trial registration: The trial was registered at the Chinese Clinical Trial Registry (ChiCTR, http://www.chictr.org.cn; identifier [ChiCTR1900022529]). Registered on 15 April 2019. Registration title: Effect of bivalirudin combined with ticagrelor in patients with ST-segment elevation myocardial infarction during primary percutaneous coronary intervention.

Causal associations between blood pressure and the risk of myocardial infarction: A bidirectional Mendelian randomization study.

Introduction: Many observational studies imply elevated blood pressure (BP) as a leading risk factor for incident myocardial infarction (MI), but whether this relationship is causal remains unknown. In this study, we used bidirectional Mendelian randomization (MR) to investigate the potential causal association of BP levels with the risk of MI. Methods: Genetic variants associated with BP and MI traits were retrieved from the International Consortium of Blood Pressure (N = 7,57,601) and UKB (N = 3,61,194), obtaining 1,26,40,541 variants. We used two-sample MR (TSMR) analyses to examine the potential bidirectional causal association of systolic BP (SBP), diastolic BP (DBP) and pulse pressure (PP) with MI. Results: The forward MR analysis identified a potentially causal association between MI and BP except PP[odds ratio (OR) SBP: 1.0008, P = 1.911 × 10-22; ORDBP: 1.0014, P = 1.788 × 10-28;odds ratio (OR)pp: 1.0092, P = 0.179]. However, the reverse analysis suggested no causal relation (betaSBP: 5.469, P = 0.763; betaDBP: 3.624, P = 0.588; betaPP: -0.074, P = 0.912). These findings were robust in sensitivity analyses such as the MR-Egger method, the maximum likelihood method and the MR pleiotropy residual sum and outlier test (MR-PRESSO). No horizontal pleiotropy (p = 0.869 for SBP, p = 0.109 for DBP and p = 0.978 for PP in the forward results and p = 0.168 for SBP, P = 0.892 for DBP and p = 0.989 for PP in the reverse results) was observed. Conclusions: Elevated SBP or DBP levels increase the risk of MI, but there is no causal relationship between MI and changes in BP including PP. Independent of other risk factors, optimal BP control might represent an important therapeutic target for MI prevention in the general population.

Procedural Efficiency, Efficacy, and Safety of High-Power, Short-Duration Radiofrequency Ablation Delivered by STSF Catheter for Paroxysmal Atrial Fibrillation.

Objectives: To investigate the procedural efficiency, efficacy, and safety of high-power, short-term radiofrequency ablation delivered by the SmartTouch Surround Flow (STSF) catheter for paroxysmal atrial fibrillation (AF). Methods: We retrospectively analyzed a total of 72 patients who were admitted with paroxysmal AF, and who underwent radiofrequency catheter ablation (RFCA) for the first time. Of these patients, 36 cases underwent low-power, long-duration (LPLD, (30-35 W/20-40 s) pulmonary vein isolation (PVI) delivered by an SmartTouch (ST) catheter (control group), and the other 36 cases underwent high-power, short-duration (HPSD, (45-50 W/10-20 s) PVI delivered by a STSF catheter (study group). The baseline data, duration of PVI, procedural time, fluoroscopy time, the rate of first-pass isolation, irrigation perfusion, eschar and steam pop occurrences, intraoperative complications, and the rate of stable sinus rhythm maintenance following a blanking period of three months were analyzed between the two groups. Results: The isolation time of bilateral PVI and procedural time in the study group were markedly less than in controls (p < 0.01). The rate of first-pass isolation in the study group was significantly higher than in the control group (95.8% vs. 84.7%, p = 0.023), while the fluid perfusion in the study group was approximately 20% less than that in the control group (767 ± 171 vs. 966 ± 227 ml, p < 0.001). We observed no severe complications in any patients. The rate of freedom from AF recurrences following a blanking period of three months showed a tendency to be higher than in controls (93.9% vs. 87.1%, p = 0.348). Conclusions: The HPSD strategy delivered by the STSF catheter was superior to conventional LPLD ablation through the ST catheter with respect to efficiency, acute procedural effectiveness, short-term safety, and the risk of heart failure in patients with paroxysmal AF.

LncRNA HOXA11-AS promotes vascular endothelial cell injury in atherosclerosis by regulating the miR-515-5p/ROCK1 axis.

AIMS: Long non-coding RNA HOXA11-AS participated in heart disease. In this study, we aim to evaluate the potential roles of HOXA11-AS in atherosclerosis and its underlying mechanisms. METHODS AND RESULTS: The expression levels of HOXA11-AS in ox-LDL-treated HUVECs and arch tissues of high-fat diet-fed ApoE-/- mice (n = 10) were assessed by qRT-PCR. The effects of HOXA11-AS knockdown on the development of atherosclerosis were evaluated using in vitro and in vivo models. Luciferase reporter and RNA immunoprecipitation (RIP) assays verified the potential relationships between HOXA11-AS or ROCK1 and miR-515-5p. The interactive roles between HOXA11-AS and miR-515-5p and between miR-515-5p and ROCK1 were further characterized in ox-LDL-treated HUVECs. Our data showed that HOXA11-AS was significantly up-regulated (P < 0.001), whereas miR-515-5p was dramatically down-regulated in AS mice tissues (P < 0.001) and ox-LDL-treated HUVECs (P < 0.01). Ox-LDL could induce endothelial injuries by inhibiting cell proliferation (P < 0.001) and SOD synthesis (P < 0.001), promoting apoptosis (P < 0.01), ROS (P < 0.001), and MDA production (P < 0.001), increasing Bax (P < 0.001) and cleaved Caspase-3 (P < 0.001), and decreasing Bcl-2 (P < 0.001) and phosphorylated eNOS (P < 0.01). HOXA11-AS knockdown attenuated endothelial injuries via increasing eNOS phosphorylation. Luciferase assay and RIP results confirmed that miR-515-5p is directly bound to HOXA11-AS and ROCK1. HOXA11-AS promoted ox-LDL-induced HUVECs injury by directly inhibiting miR-515-5p from increasing ROCK1 expression and subsequently decreasing the expression and phosphorylation of eNOS. MiR-515-5p mimics could partially reverse the effects of HOXA11-AS knockdown. CONCLUSIONS: HOXA11-AS contributed to atherosclerotic injuries by directly regulating the miR-515-5p/ROCK1 axis. This study provided new evidence that HOXA11-AS might be a candidate for atherosclerosis therapy.

LncRNA LINC00461 exacerbates myocardial ischemia-reperfusion injury via microRNA-185-3p/Myd88.

OBJECTIVE: Long non-coding RNAs (lncRNAs) play critically in the pathogenesis of myocardial ischemia-reperfusion (I/R) injury. Thus, it was proposed to investigate the mechanism of LINC00461 in the disease through mediating microRNA-185-3p (miR-185-3p)/myeloid differentiation primary response gene 88 (Myd88) axis. METHODS: miR-185-3p, LINC00461 and Myd88 expression in mice with I/R injury was measured. Mice with I/R injury were injected with the gene expression-modified vectors, after which cardiac function, hemodynamics, myocardial enzyme, oxidative stress, and cardiomyocyte apoptosis were analyzed. RESULTS: I/R mice showed LINC00461 and Myd88 up-regulation and miR-185-3p down-regulation. Down-regulating LINC00461 or up-regulating miR-185-3p recovered cardiac function, reduced myocardial enzyme levels, and attenuated oxidative stress and cardiomyocyte apoptosis in mice with I/R. miR-185-3p overexpression rescued the promoting effect of LINC00461 upregulation on myocardial injury in I/R mice. CONCLUSION: LINC00461 knockdown attenuates myocardial I/R injury via elevating miR-185-3p expression to suppress Myd88 expression.

Inhibition of MicroRNA-92 alleviates atherogenesis by regulation of macrophage polarization through targeting KLF4.

BACKGROUND: Atherosclerosis is a chronic inflammatory disease in which macrophage polarization plays an important role in contribution to atherosclerotic plaque formation and stability. Here we tested the effect of miR-92 regulation on the development of atherosclerosis beyond tumorigenesis and explored the potential mechanism. METHODS AND RESULTS: In the present study, bone marrow derived macrophages (BMDMs), mouse peritoneal macrophages (MPMs), and human macrophages were used to test the expression of miR-92. Here we noticed miR-92 levels were enhanced in classic M1 macrophage but decreased in alternative M2 macrophage, respectively. In vitro, we demonstrated that macrophages transfected with miR-92 inhibitor attenuated proinflammatory cytokine secretion represented by polarized M1 markers but promoted anti-inflammatory state that was indicative of an M2 phenotype. Mechanistically, miR-92 was found to directly interact with KLF4 and we further identified a requirement role of KLF4 in mediating the effect of miR-92 silencing macrophage polarization. Concomitantly, miR-92 inhibition treated ApoE-/- mice promoted macrophage polarization toward alternative M2 macrophage, thus protecting against atherosclerotic plaque formation and preventing a vulnerable phenotype. CONCLUSION: miR-92 inhibition promoted alternative macrophage activation and attenuated atherosclerosis regression partially regulated in a KLF4-dependent manner, which indicated that miR-92/KLF4 axis may serve as a promising strategy for prevention of atherosclerotic diseases.

Uric acid aggravates myocardial ischemia-reperfusion injury via ROS/NLRP3 pyroptosis pathway.

BACKGROUND: The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome activation-mediated pyroptosis pathway has been linked to myocardial ischemia-reperfusion (MI/R) injury. This study explored whether uric acid (UA) aggravates MI/R injury through NLRP3 inflammasome-mediated pyroptosis. METHODS: In vivo, a mouse MI/R model was established by ligating the left coronary artery, and a mouse hyperuricemia model was created by intraperitoneal injection of potassium oxonate (PO). Then, the myocardial infarction (MI) size; terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) immunofluorescence; and serum levels of lactate dehydrogenase (LDH), creatine kinase isoenzyme (CK-MB), and UA, as well as the expression level of pyroptosis-related protein and caspase-3 in heart tissues, were measured. Separately, primary mouse cardiomyocytes were cultured in vitro to create a hypoxia/reoxygenation (H/R) model. We then compared cardiomyocytes viability, TUNEL immunofluorescence, and the levels of LDH, reactive oxygen species (ROS), and pyroptosis-related protein and caspase-3 in cardiomyocytes. RESULTS: In vivo, the MI area, levels of CK-MB and LDH, rate of cell death, and pyroptosis-related protein and the expression of caspase-3 were significantly higher in the MI/R group than in the sham group, and high UA levels worsened these changes. In vitro, cardiomyocytes viability was significantly downregulated, and the levels of ROS, LDH, pyroptosis-related protein, caspase-3, and the rate of cardiomyocyte death were significantly higher in the H/R + UA group compared with the HR group. Administration of an NLRP3 inflammasome inhibitor and ROS scavenger reversed these effects. CONCLUSION: UA aggravates MI/R-induced activation of the NLRP3 inflammatory cascade and pyroptosis by promoting ROS generation, while inflammasome inhibitors and ROS scavengers partly reverse the injury.

Trajectories of Waist-to-Hip Ratio and Adverse Outcomes in Heart Failure with Mid-Range Ejection Fraction.

BACKGROUND: Waist-to-hip ratio (WHR) is a strong predictor of mortality in patients with heart failure (HF). However, common WHR trajectories are not well established in HF with mid-range ejection fraction (HFmrEF) persons, and their relationship to clinical outcomes remains uncertain. METHOD: We prospectively enrolled 1,396 participants with HFmrEF (left ventricular ejection fraction 40-49%) from April 2013 through April 2017. The waist and hip circumferences of the subjects were measured at regular intervals, and the WHR was calculated as waist circumference divided by hip circumference. Latent mixture modeling was performed to identify WHR trajectories. We then used Cox proportional-hazard models to examine the association between WHR trajectory patterns and incident HF, incident cardiovascular disease (CVD), and all-cause mortality. RESULTS: We identified four distinct WHR trajectory patterns: lean-moderate increase (9.2%), medium-stable/increase (32.7%), heavy-stable/increase (48.0%), and heavy-moderate decrease (10.1%). After multivariable adjustment, the heavy-stable/increase and heavy-moderate decrease patterns were associated with an increased all-cause mortality risk (heavy-stable/increase: adjusted hazard ratio [HR] 3.18, 95% confidence interval [CI] 2.75-4.62; heavy-moderate decrease: adjusted HR 2.32, 95% CI 1.71-3.04), incident CVD risk (heavy-stable/increase: adjusted HR 4.03, 95% CI 2.39-4.91; heavy-moderate decrease: adjusted HR 3.05, 95% CI 2.34-4.09), and incident HF risk (heavy-stable/increase: adjusted HR 2.72, 95% CI 2.05-3.28; heavy-moderate decrease: adjusted HR 2.39, 95% CI 1.80-3.03) with reference to the lean-moderate increase pattern. CONCLUSION: Among patients with HFmrEF, the trajectories of WHR gain are associated with poor outcomes. These findings highlight the importance of abdominal fat accumulation management during the progression of HFmrEF.

Resveratrol pretreatment alleviates myocardial ischemia/reperfusion injury by inhibiting STIM1-mediated intracellular calcium accumulation.

Previous studies have shown that stromal interaction molecule1 (STIM1)-mediated store-operated Ca2+ entry (SOCE) contributes to intracellular Ca2+ accumulation in H9C2 cells subjected to hypoxia/reoxygenation(H/R) injury. The aim of the present study was to investigate the effect of resveratrol on STIM1-mediated intracellular Ca2+ accumulation and subsequent cell death in the context of myocardial ischemia/reperfusion (I/R) injury. C57 BL/6 mice were fed with either saline or resveratrol (50 mg/kg daily for 2 weeks) and then subjected to myocardial I/R injury. TTC/Evans Blue staining and TUNEL assay were performed to quantify the infarct size and apoptosis index. The cardiac function was evaluated by echocardiography. Neonatal rat ventricular cardiomyocytes (NRVCs) underwent hypoxia/reoxygenation (H/R) to establish the in vitro model. To achieve over-expression, NRVCs were transfected with STIM1-adenovirus vector. Apoptosis was analyzed by TUNEL assay. Cell viability was measured using MTS assay and cell necrosis was determined by LDH release assay. Intracellular Ca2+ concentration was detected by laser scanning confocal microscopy using a Fluo-3AM probe. Resveratrol significantly reduced apoptosis, decreased infarct size, and improved cardiac function in mice subjected to myocardial I/R injury. In NRVCs, resveratrol also downregulated STIM1 expression accompanied by decreased intracellular Ca2+ accumulation elicited by H/R injury. In addition, resveratrol reduced cell apoptosis, upregulated the Bcl-2, decreased Bax, and cleaved caspase-3 expression. Furthermore, the effects of resveratrol on STIM1-mediated intracellular Ca2+ accumulation, apoptotic proteins, and H/R-induced cell injury were exacerbated by STIM1 over-expression and were partly abolished by SOCE inhibitor SKF96365 in NRVCs in vitro. Our findings demonstrate that resveratrol exerts anti-apoptotic activity and improves cardiac functional recovery following myocardial I/R by inhibiting STIM1-induced intracellular Ca2+ accumulation.

MicroRNA-449a Inhibition Protects H9C2 Cells Against Hypoxia/Reoxygenation-Induced Injury by Targeting the Notch-1 Signaling Pathway.

BACKGROUND/AIMS: The present study aimed to detect the expression of miR-449a and investigate the effect of miR-449a on cell injury in cardiomyocytes subjected to hypoxia/ reoxygenation (H/R) and its underlying mechanisms. METHODS: The expression of miR-449a was determined using reverse transcription-polymerase chain reaction in both neonatal rat ventricular myocytes and H9C2 cells. For gain-of-function and loss-of-function studies, H9C2 cells were transfected with either miR-449a mimics or miR-449a inhibitor. The target gene of miR-449a was confirmed by a dual-luciferase reporter assay. Apoptosis was analyzed by both flow cytometry using Annexin V and propidium iodide and transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL). Necrosis was confirmed by the detection of lactate dehydrogenase release. The cell viability was measured using the methylthiotetrazole method. The protein levels of Notch-1, Notch-1 intracellular domain, hairy and enhancer of split-1 (Hes-1), and apoptosis-related genes were measured by Western blot analysis. RESULTS: MiR-449a was significantly upregulated in both neonatal rat ventricular myocytes and H9C2 cells subjected to H/R. However, H/R-induced cell apoptosis and necrosis were markedly reduced by miR-449a inhibition. By targeting Notch-1, miR-449a regulated the Notch-1/ Hes-1 signaling pathway. The blockade of the Notch signaling pathway partly abolished the protective effect of miR-449a suppression against H/R injury, whereas the overexpression of Notch-1 intracellular domain partly reversed the effect of miR-449a overexpression on H/R-induced cell injury. CONCLUSIONS: The present study suggested that miR-449a inhibition protected H9C2 cells against H/R-induced cell injury by targeting the Notch-1 signaling pathway, providing a novel insight into the molecular basis of myocardial ischemia-reperfusion injury and a potential therapeutic target.

Suppression of Stim1 reduced intracellular calcium concentration and attenuated hypoxia/reoxygenation induced apoptosis in H9C2 cells.

OBJECTIVE: Previous studies have demonstrated Stromal interaction molecule 1 (STIM1)-mediated store-operated Ca2+ entry (SOCE) contributes to intracellular Ca2+ accumulation. The present study aimed to investigate the expression of STIM1 and its downstream molecules Orai1/TRPC1 in the context of myocardial ischemia/reperfusion injury (MIRI) and the effect of STIM1 inhibition on Ca2+ accumulation and apoptosis in H9c2 cardiomyocytes subjected to hypoxia/reoxygenation (H/R). METHODS: Expression of STIM1/Orai1/TRPC1 was determined by RT-PCR and Western blot in mice subjected to MIRI and H9C2 cardiomyocytes subjected to H/R. To knock-down STIM1, H9C2 cardiomyocytes was transfected with Stealth SiRNA. Apoptosis was analyzed by both flow cytometry and TUNEL assay. Cell viability was measured by MTT assay. Intracellular Ca2+ concentration was detected by laser scanning confocal microscopy using Fluo-3/AM probe. Furthermore, the opening of mitochondrial permeability transition pore (mPTP) was assessed by coloading with calcein AM and CoCl2, while ROS generation was evaluated using the dye DCFH-DA in H9C2 cardiomyocytes. RESULTS: Expression of STIM1/Orai1/TRPC1 significantly increased in transcript and translation level after MIRI in vivo and H/R in vitro In H9C2 cardiomyocytes subjected to H/R, intracellular Ca2+ accumulation significantly increased compared with control group, along with enhanced mPTP opening and elevated ROS generation. However, suppression of STIM1 by SiRNA significantly decreased apoptosis and intracellular Ca2+ accumulation induced by H/R in H9C2 cardiomyocytes, accompanied by attenuated mPTP opening and decreased ROS generation. In addition, suppression of STIM1 increased the Bcl-2/Bax ratio, decreased Orai1/TRPC1, and cleaved caspase-3 expression. CONCLUSION: Suppression of STIM1 reduced intracellular calcium level and attenuated hypoxia/reoxygenation induced apoptosis in H9C2 cardiomyocytes. Our findings provide a new perspective in understanding STIM1-mediated calcium overload in the setting of MIRI.

Association of Soluble Fibrinogen-like Protein 2 with the Severity of Coronary Artery Disease.

Objective The purpose of this study was to investigate the relationship between circulating soluble fibrinogen-like protein 2 (sFGL2) concentrations and the severity of coronary artery disease (CAD) in patients who underwent first-time angiography for suspected CAD. Methods Serum sFGL2 concentrations were measured in 102 consecutive patients by an enzyme-linked immunosorbent assay (ELISA). The number of circulating CD4(+)CD25(+)CD127(low) T regulatory cells (Tregs) was determined by flow cytometry and effecter cytokines, including transforming growth factor-ß1 and interleukin-10 (IL-10), were also evaluated by an ELISA. Associations between sFGL2 and Tregs with angiographic indexes of the severity of CAD (i.e., number of diseased vessels and the modified Gensini score) were estimated. Results The sFGL2 levels in patients with angiographically confirmed CAD were significantly lower than those in patients with normal coronary arteries (26.95±8.53 vs. 9.88±5.46 ng/mL, p<0.001). Significant correlations were observed between the serum sFGL2 level and number of diseased vessels (r=-0.860, p<0.001) and modified Gensini score (r=-0.833, p<0.001). Using a multivariate analysis, the serum sFGL2 level was independently associated with the presence and severity of CAD. Conclusion The serum sFGL2 levels are significantly lower in the presence of CAD and correlate with the severity of the disease. Further clinical studies are needed to confirm the use of sFGL2 as a biomarker for the detection and extent of CAD.

Methylophiopogonanone A suppresses ischemia/reperfusion-induced myocardial apoptosis in mice via activating PI3K/Akt/eNOS signaling pathway.

AIM: The dried tuber root of Ophiopogon japonicus has been used in the traditional Chinese medicine for treatment of myocardial ischemia and thrombosis. In this study we investigated the effects of methylophiopogonanone A (MO-A), a major homoisoflavonoid in Ophiopogon japonicus, on myocardial ischemia/reperfusion (I/R) injury. METHODS: Mice were pretreated with MO-A (10 mg·kg(-1)·d(-1), po) for 2 weeks and then subjected to transient occlusion of the left anterior descending coronary artery. Cardiac function was evaluated, and the infarct size and apoptosis index were assessed. The mechanisms underlying the cardio-protection of MO-A were analyzed in H9C2 rat cardiomyocytes subjected to hypoxia/reoxygenation (H/R). The cell viability and apoptosis were evaluated; apoptotic and relevant signaling proteins were analyzed. NO levels in the culture medium were assessed. RESULTS: In I/R mice, pretreatment with MO-A significantly reduced the infarct size (by 60.7%) and myocardial apoptosis (by 56.8%), and improved cardiac function. In H9C2 cells subjected to H/R, pretreatment with MO-A (10 µmol/L) significantly decreased apoptosis and cleaved caspase-3 expression, elevated the Bcl-2/Bax ratio and restored NO production. Furthermore, pretreatment with MO-A markedly increased the activation of PI3K/Akt/eNOS pathway in H9C2 cells subjected to H/R, and the protective effects of MO-A were abolished in the presence of the PI3K inhibitor wortmannin (100 nmol/L). CONCLUSION: MO-A attenuates I/R-induced myocardial apoptosis in mice via activating the PI3K/Akt/eNOS signaling pathway.

Total cholesterol content of erythrocyte membranes levels are associated with the presence of acute coronary syndrome and high sensitivity C-reactive protein.

In this study we assessed whether total cholesterol content of erythrocyte membranes (CEM) was associated with the presence of acute coronary syndrome (ACS) and high sensitivity C-reactive protein (hs-CRP). Consecutive angina patients were assessed; 98 had ACS and 45 had stable angina pectoris (SAP). CEM in the ACS group was significantly higher compared with the SAP group (p< 0.05). Multiple logistic regression analyses revealed a significant independent relation between CEM and the presence of ACS (OR 24.990, p<0.001). CEM was positively correlated with serum hs-CRP levels (r=0.328, p<0.001). These findings suggest a potential role of CEM as a marker of vulnerable plaque.