Qiang Geng

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.

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.

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.

Layered Signaling Regulatory Networks Analysis of Gene Expression Involved in Malignant Tumorigenesis of Non-Resolving Ulcerative Colitis via Integration of Cross-Study Microarray Profiles

Background Ulcerative colitis (UC) was the most frequently diagnosed inflammatory bowel disease (IBD) and closely linked to colorectal carcinogenesis. By far, the underlying mechanisms associated with the disease are still unclear. With the increasing accumulation of microarray gene expression profiles, it is profitable to gain a systematic perspective based on gene regulatory networks to better elucidate the roles of genes associated with disorders. However, a major challenge for microarray data analysis is the integration of multiple-studies generated by different groups. Methodology/Principal Findings In this study, firstly, we modeled a signaling regulatory network associated with colorectal cancer (CRC) initiation via integration of cross-study microarray expression data sets using Empirical Bayes (EB) algorithm. Secondly, a manually curated human cancer signaling map was established via comprehensive retrieval of the publicly available repositories. Finally, the co-differently-expressed genes were manually curated to portray the layered signaling regulatory networks. Results Overall, the remodeled signaling regulatory networks were separated into four major layers including extracellular, membrane, cytoplasm and nucleus, which led to the identification of five core biological processes and four signaling pathways associated with colorectal carcinogenesis. As a result, our biological interpretation highlighted the importance of EGF/EGFR signaling pathway, EPO signaling pathway, T cell signal transduction and members of the BCR signaling pathway, which were responsible for the malignant transition of CRC from the benign UC to the aggressive one. Conclusions The present study illustrated a standardized normalization approach for cross-study microarray expression data sets. Our model for signaling networks construction was based on the experimentally-supported interaction and microarray co-expression modeling. Pathway-based signaling regulatory networks analysis sketched a directive insight into colorectal carcinogenesis, which was of significant importance to monitor disease progression and improve therapeutic interventions.

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.

Atheroprotective effects of statins in patients with unstable angina by regulating the blood-borne microRNA network

Experimental studies have demonstrated several effects of statins in acute coronary syndrome (ACS) that may extend their clinical benefit beyond the lipid profile modification itself. However, the precise underlying mechanism remains to be elucidated. microRNAs (miRNAs) serve significant roles in the pathophysiology of atherosclerotic plaque progression. The present study investigated the protective role of statins in patients with unstable angina (UA) by regulating the circulating miRNA network. miRNA array results demonstrated that there were 21 differentially expressed miRNAs in non-statin-treated patients with UA (n=8) compared with non-coronary artery disease controls (n=8), and 33 differentially expressed miRNAs in statin-treated patients with UA (n=8) compared with non-statin patients. TargetScan and miRanda programs were used to predict miRNAs target genes. miRNAs target genes in vascular endothelial cells and monocytes were clustered based on the CGAP SAGE library via the Database for Annotation, Visualization and Integrated Discovery (DAVID) platform, and miRNA target genes in platelets were clustered based on a UP tissue-specific library via the DAVID platform. The PANTHER database via DAVID platform was used to perform signaling pathway analysis. The miRNA-gene/pathway network was visualized by Cytoscape software. Bioinformatic analysis suggested that statin-induced miRNAs functions were primarily enriched in angiogenesis, integrin and platelet derived growth factor signaling pathways in UA patients. In endothelial cells and platelets, statin-induced miRNAs primarily targeted the integrin signaling pathway, and in monocytes primarily targeted cytoskeletal regulation by the Rho GTPase signaling pathway. These results revealed that statins may serve systematic protective roles in UA patients by influencing the circulating miRNA regulatory network. Further studies are required to verify the functions of statin-induced miRNAs in endothelial cells, platelets and monocytes.

The potential inhibitory effects of miR‑19b on vulnerable plaque formation via the suppression of STAT3 transcriptional activity

Atherosclerotic plaque growth requires angiogenesis, and acute coronary syndrome (ACS) is usually triggered by the rupture of unstable atherosclerotic plaques. Previous studies have identified typically circulating microRNA (miRNA/miR) profiles in patients with ACS. miRNAs serve important roles in the pathophysiology of atherosclerotic plaque progression. The present study aimed to investigate the potential role and mechanism of miR-19b in plaque stability. miRNA array data indicated that 28 miRNAs were differentially expressed in the plasma of patients with unstable angina (UA; n=12) compared with in control individuals (n=12), and miR-19b exhibited the most marked upregulation. Circulating miR-19b levels were further validated in another independent cohort, which consisted of 34 patients with UA and 24 controls, by quantitative polymerase chain reaction. Gene Ontology annotations of the predicted target genes of miR-19b suggested that miR-19b may be involved in endothelial cell (EC) proliferation, migration and angiogenesis, which was confirmed by Cell Counting kit-8, wound healing and tube formation assays in the present study. Finally, the present study indicated that miR-19b may suppress signal transducer and activator of transcription 3 (STAT3) tyrosine phosphorylation and transcriptional activity in ECs, as determined by western blot analysis and luciferase reporter assay. In conclusion, the present study revealed that increased miR-19b expression may delay unstable plaque progression in patients with UA by inhibiting EC proliferation, migration and angiogenesis via the suppression of STAT3 transcriptional activity.