Jingyi Ren

Signature of Circulating MicroRNAs as Potential Biomarkers in Vulnerable Coronary Artery Disease

Aims MicroRNAs (miRNAs) play important roles in the pathogenesis of cardiovascular diseases. Circulating miRNAs were recently identified as biomarkers for various physiological and pathological conditions. In this study, we aimed to identify the circulating miRNA fingerprint of vulnerable coronary artery disease (CAD) and explore its potential as a novel biomarker for this disease. Methods and Results The Taqman low-density miRNA array and coexpression network analyses were used to identify distinct miRNA expression profiles in the plasma of patients with typical unstable angina (UA) and angiographically documented CAD (UA group, n = 13) compared to individuals with non-cardiac chest pain (control group, n = 13). Significantly elevated expression levels of miR-106b/25 cluster, miR-17/92a cluster, miR-21/590-5p family, miR-126*, and miR-451 were observed in UA patients compared to controls. These findings were validated by real-time PCR in another 45 UA patients, 31 stable angina patients, and 37 controls. In addition, miR-106b, miR-25, miR-92a, miR-21, miR-590-5p, miR-126* and miR-451 were upregulated in microparticles (MPs) isolated from the plasma of UA patients (n = 5) compared to controls (n = 5). Using flow cytometry and immunolabeling, we further found that Annexin V+ MPs were increased in the plasma samples of UA patients compared to controls, and the majority of the increased MPs in plasma were shown to be Annexin V+ CD31+ MPs. The findings suggest that Annexin V+ CD31+ MPs may contribute to the elevated expression of the selected miRNAs in the circulation of patients with vulnerable CAD. Conclusion The circulating miRNA signature, consisting of the miR-106b/25 cluster, miR-17/92a cluster, miR-21/590-5p family, miR-126* and miR-451, may be used as a novel biomarker for vulnerable CAD. Trial Registration Chinese Clinical Trial Register, ChiCTR-OCH-12002349.

Cardioprotection by ischemic postconditioning is lost in isolated perfused heart from diabetic rats: Involvement of transient receptor potential vanilloid 1, calcitonin gene-related peptide and substance P

We previously found that the expression of transient receptor potential vanilloid 1 (TRPV1) and contents of calcitonin gene-related peptide (CGRP) and substance P (SP), two main neuropeptides released from TRPV1, were decreased in diabetic hearts. This study aimed to test whether decreased TRPV1, CGRP and SP levels were responsible for the loss of cardioprotection by ischemic postconditioning (IPostC) in isolated perfused heart from streptozotocin-induced diabetic rats. IPostC effectively protected non-diabetic hearts against ischemia/reperfusion injury by improving cardiac function and lowering creatine kinase (CK) and cardiac troponin I (cTnI) release, which could be abolished by inhibiting TRPV1, CGRP receptor or SP receptor. However, IPostC had no effect on cardiac function and the release of CK and cTnI in diabetic hearts regardless of whether TRPV1, CGRP receptor or SP receptor were inhibited. CGRP or SP-induced postconditioning significantly prevented both non-diabetic and diabetic hearts from ischemia/reperfusion injury by improving cardiac function and lowering CK and cTnI release. Additionally, IPostC markedly increased CGRP and SP release in non-diabetic hearts, which could be reversed with TRPV1 inhibition, but not CGRP receptor or SP receptor inhibition. However, IPostC failed to affect CGRP and SP release in diabetic hearts in the presence or absence of TRPV1, CGRP receptor or SP receptor inhibition. These results indicate that the loss of cardioprotection by IPostC during diabetes is partly associated with a failure to increase CGRP and SP release, likely due to decreased TRPV1 expression and CGRP and SP contents in diabetic hearts.

MicroRNA-19b functions as potential anti-thrombotic protector in patients with unstable angina by targeting tissue factor.

The activation of a hemostatic system plays a critical role in the incidence of acute coronary events. Hemostatic proteins may be regulated by microRNAs (miRNAs). Microparticles (MPs) are the major carrier of circulating miRNAs. The aim of this study was to determine the potential role of miRNAs in regulating gene expression involved in the hemostatic system in patients with unstable angina (UA). MiRNA expression profiles in the plasma from patients with UA (UA group, n=9) compared with individuals with clinical suspicion of coronary artery disease (CAD) but negative angiography (control group, n=9) showed that among 36 differentially expressed miRNAs, miR-19b was the most obvious one. Using real-time PCR, 5 selected miRNA levels in plasma (UA group, n=20; control group, n=30) and plasma MPs (UA group n=6; control group n=6) were proved to be consistent with the miRNA array. Flow cytometry analysis indicated that the amounts of plasma endothelial microparticles (EMPs) were increased in UA patients (UA group, n=4) compared to controls (control group, n=4). In cultured endothelial cells (ECs), TNF-α increased miR-19b release and expression. Tissue factor (TF) was predicted to be the target of miR-19b by bioinformatics analysis. Luciferase reporter assays demonstrated that miR-19b binds to TF mRNA. Overexpression of miR-19b inhibited TF expression and procoagulant activity. This study indicates that in UA patients, the increase of miR-19b wrapped in EMPs due to endothelial dysfunction may partially contribute to the circulating miR-19b elevation and miR-19b may play an anti-thrombotic role by inhibiting the expression of TF in ECs.

Simvastatin reduces lipoprotein-associated phospholipase A2 in lipopolysaccharide-stimulated human monocyte-derived macrophages through inhibition of the mevalonate-geranylgeranyl pyrophosphate-RhoA-p38 mitogen-activated protein kinase pathway.

Lipoprotein-associated phospholipase A2 (Lp-PLA2), which is produced primarily by macrophages and is predominately found in the blood and in atherosclerotic plaques, represents a potentially promising target for combating atherosclerosis. Although statins are known to decrease the levels and activity of circulating and plaque Lp-PLA2 during atherosclerosis, little is known regarding the mechanisms underlying inhibition of Lp-PLA2 by statins. Therefore, the aim of this study was to explore the molecular mechanisms responsible for inhibition of Lp-PLA2 by statins. Our results showed that treatment with simvastatin inhibited lipopolysaccharide (LPS)-induced increases in Lp-PLA2 expression and secreted activity in human monocyte-derived macrophages in a dose- and time-dependent manner. These effects could be reversed by treatment with mevalonate or geranylgeranyl pyrophosphate (GGPP), but not by treatment with squalene or farnesyl pyrophosphate. Treatment with the Rho inhibitor C3 exoenzyme also inhibited LPS-induced increases in Lp-PLA2 expression and secreted activity, mimicking the effects of simvastatin. In addition, treatment with simvastatin blocked LPS-induced activation of RhoA, which could be abolished by treatment with GGPP. Inhibition of p38 mitogen-activated protein kinase (MAPK), but not extracellular signal regulated kinase 1/2 or Jun N-terminal kinase, suppressed LPS-induced increases in Lp-PLA2 expression and secreted activity, similar to the effects of simvastatin. Treatment of human monocyte-derived macrophages with either simvastatin or C3 exoenzyme prevented LPS-induced activation of p38 MAPK, which could be abolished by treatment with GGPP. Together, these results suggest that simvastatin reduces Lp-PLA2 expression and secreted activity in LPS-stimulated human monocyte-derived macrophages through the inhibition of the mevalonate-GGPP-RhoA-p38 MAPK pathway. These observations provide novel evidence that statins have pleiotropic effects and suggest that inhibition of Lp-PLA2 via this mechanism may account, at least in part, for the clinical benefit of statins in combating atherosclerosis.

Adverse events following statin-fenofibrate therapy versus statin alone: a meta-analysis of randomized controlled trials.

The combination of fenofibrate with statins is a beneficial therapeutic option for patients with mixed dyslipidaemia, but concerns about adverse events (AEs) make physicians reluctant to use this combination therapy. Medline, Embase and the Cochrane Library were searched to identify 13 randomized controlled trials, involving 7712 patients, of statin–fenofibrate therapy versus statin alone for review. There were significant decreases in low‐density lipoprotein–cholesterol, triglycerides and total cholesterol and increases in high‐density lipoprotein–cholesterol in patients receiving combination therapy compared with statin therapy alone. The incidence of aminotransferase elevations in the fenofibrate–statin therapy group was significantly higher than in the statin monotherapy group (odds ratio (OR), 1.66; 95% confidence interval (CI) 1.17–2.37; P < 0.05). The incidence of elevated creatine kinase levels (OR 0.88; 95% CI 0.63–1.23; P > 0.05), muscle‐associated AEs (OR 0.98; 95% CI 0.88–1.09; P > 0.05) and withdrawals attributed to liver and muscle dysfunction did not differ significantly between the two groups. The efficacy of fenofibrate + standard‐dose statin and incidence of AEs in the fenofibrate + standard‐dose statin group were almost identical to those in the fenofibrate–statin group. In conclusion, combination therapy improves the blood lipid profile of patients. Fenofibrate–statin combination therapy appears to be as well tolerated as statin monotherapy. Physicians should consider fenofibrate–statin combination therapy in patients but monitor aminotransferase levels to avoid hepatic complications.

Effects of statin on circulating microRNAome and predicted function regulatory network in patients with unstable angina

BackgroundStatin therapy plays a pivotal role in stabilizing the plaque for unstable angina (UA) patients although its mechanism(s) remains largely unexplored. Here we aim to identify microRNAs (miRNAs) mediating the protective effect of statins in UA patients.MethodsMiRNAs Array was carried out to compare the circulating whole blood miRNA profile of UA patients treated with (n = 10) and without statin (n = 10) and plasma miRNA profile UA patients treated with (n = 5) and without statin (n = 5). 22 whole blood miRNAs and 19 plasma miRNAs were found significantly upregulated in statin group. Targets of these miRNAs were predicted by algoritms: Targetscan, Miranda and Diana microT, then clustered according to functions and cell types by using the Database for Annotation, Visualization and Integrated Discovery (DAVID). To reveal the enriched function pathways in human atherosclerotic plaque, we analyzed microarray data from GEO database, Coronary atherosclerotic plaque (n = 80); macrophages in ruptured plaque (n = 11); carotid atheroma plaque (n = 64); advanced carotid atherosclerotic plaque (n = 29) using Reactome database. Integrated analysis indicated that statin induced miRNAs mainly regulate the signaling pathways of Rho GTPase and hemostasis in human atherosclerotic lesion. In vulnerable plaque, additional immune system signaling was also targeted.ResultsThe data showed target genes regulated by these statin induced miRNAs majorly expressed in i) plaque macrophage and platelet, where they were involved in hemostasis process; ii) in monocyte to regulate NGF apoptosis; iii) and in endothelial cell function in Rho GTPase pathway. Integrate analysis indicated that statin induced miRNAs mainly regulate the signaling pathways of Rho GTPase and hemostasis in human atherosclerotic lesion.ConclusionsOur study suggest that statin induces the expression of multiple miRNAs in the circulation of UA patient, which play important roles by regulating signal pathways critical for the pathogenesis of UA.

Angiotensin-(1-7): new perspectives in atherosclerosis treatment.

Angiotensin (Ang)-(1-7) is recognized as a new bioactive peptide in renin-angiotensin system (RAS). Ang-(1-7) is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular disease. Recent studies have found that Ang-(1-7) played an important role in reducing smooth muscle cell proliferation and migration, improving endothelial function and regulating lipid metabolism, leading to inhibition of atherosclerotic lesions and increase of plaque stability. Although clinical application of Ang-(1-7) is restricted due to its pharmacokinetic properties, identification of stabilized compounds, including more stable analogues and specific delivery compounds, has enabled clinical application of Ang-(1-7). In this review, we discussed recent findings concerning the biological role of Ang-(1-7) and related mechanism during atherosclerosis development. In addition, we highlighted the perspective to develop therapeutic strategies using Ang-(1-7) to treat atherosclerosis.

Adverse events of statin–fenofibric acid versus statin monotherapy: a meta-analysis of randomized controlled trials

Abstract Background: Patients with mixed dyslipidemia can benefit from the combination of fenofibric acid (FA) with statins, but concerns about adverse events make physicians reluctant to prescribe the combination therapy. Objective: In the present study, we performed a meta-analysis of randomized controlled trials (RCTs) to assess the efficacy and adverse events in patients taking statins and FA. Methods: Medline, Embase and the Cochrane Library were searched to identify studies that reported adverse events. Finally, five trials covering 2704 patients were selected in this study. Results: There were significant decreases in TG and increases in HDL-C in patients receiving combination therapy compared with statin monotherapy. The incidence of hepatic toxicity (OR, 3.57; 95% CI, 1.17–10.83; P < 0.05) and increased creatinine (OR, 3.22; 95% CI, 1.28–8.11; P < 0.05) was significantly higher in the FA + low-dose statin group than in the corresponding statin monotherapy. The incidence of CK elevations and muscle-associated AEs was not statistically different between the two groups. The adverse events in the FA + moderate-dose statin group were almost identical to those in the FA + low-dose statin group. Conclusions: In conclusion, combination therapy could improve the blood lipid profile. Addition of FA to statins therapy is more frequently associated with hepatic and renal toxicity than muscle-associated AEs. Therefore patients taking the combination of FA with statins should have liver enzyme and renal function monitored. However, we still need large-scale and long follow-up period RCTs to definitively confirm the adverse events of FA–statin therapy.

Application of next generation sequencing in microRNA detection: Application of next generation sequencing in microRNA detection

MicroRNAs (miRNAs) are a class of ~22nt long non-coding RNAs. They are evolutionarily conserved and play essential roles in the regulation of post-transcriptional gene expression. The rapidly developing next generation sequencing (NGS) has important applications in miRNA detection. This review is focused on the mechanism of three NGS platforms and their applications in miRNA detection. In contrast to traditional methods, NGS has major advantages: high throughput, precise, accurate, and repeatable. Its application includes new miRNAs exploration, detection of miRNA*, miRNA editing, and isomiR and target mRNA detection. As NGS develops, the cost of sequencing is declining which makes it possible for NGS to be widely used in the coming years. Next generation sequencing will greatly promote researches of miRNAs.

Myocardial Injury after Surgery Is a Risk Factor for Weaning Failure from Mechanical Ventilation in Critical Patients Undergoing Major Abdominal Surgery

Background Myocardial injury after noncardiac surgery (MINS) is a newly proposed concept that is common among adults undergoing noncardiac surgery and associated with substantial mortality. We analyzed whether MINS was a risk factor for weaning failure in critical patients who underwent major abdominal surgery. Methods This retrospective study was conducted in the Department of Critical Care Medicine of Peking University Peoples Hospital. The subjects were all critically ill patients who underwent major abdominal surgery between January 2011 and December 2013. Clinical and laboratory parameters during the perioperative period were investigated. Backward stepwise regression analysis was performed to evaluate MINS relative to the rate of weaning failure. Age, hypertension, chronic renal disease, left ventricular ejection fraction before surgery, Acute Physiologic and Chronic Health Evaluation II score, pleural effusion, pneumonia, acute kidney injury, duration of mechanical ventilation before weaning and the level of albumin after surgery were treated as independent variables. Results This study included 381 patients, of whom 274 were successfully weaned. MINS was observed in 42.0% of the patients. The MINS incidence was significantly higher in patients who failed to be weaned compared to patients who were successfully weaned (56.1% versus 36.5%; P<0.001). Independent predictive factors of weaning failure were MINS, age, lower left ventricular ejection fraction before surgery and lower serum albumin level after surgery. The MINS odds ratio was 4.098 (95% confidence interval, 1.07 to 15.6; P = 0.04). The patients who were successfully weaned had shorter hospital stay lengths and a higher survival rate than those who failed to be weaned. Conclusion MINS is a risk factor for weaning failure from mechanical ventilation in critical patients who have undergone major abdominal surgery, independent of age, lower left ventricular ejection fraction before surgery and lower serum albumin levels after surgery.