Chengfu Cao

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.

TRPV1 activation is involved in the cardioprotection of remote limb ischemic postconditioning in ischemia-reperfusion injury rats.

Limb remote ischemic postconditioning (RIPostC) has been proved to be a safe and effective measurement of cardioprotection against ischemia-reperfusion injury. But what bridges the remote organ insult and the cardioprotective effect in heart remains to be elucidated. This study aimed to found that whether TRPV1 may mediate the cardioprotective effect from remote organ to heart and the role of CGRP and SP in this process. We found that RIPostC effectively ameliorated cardiac ischemia/reperfusion injury in terms of limiting infarct size, lowering CK and cTnI release and improving cardiac function. In addition, these cardioprotective effects could be significantly abolished by inhibition of either CGRP or SP receptors with corresponding antagonists (CGRP8-37 for CGRP and RP-67580 for SP) injected before reperfusion. Besides, RIPostC resulted in significantly increase in the levels of CGRP and SP in plasma and hearts, as well as the levels and mRNA expression of CGRP and SP in DRG. The increase in CGRP and SP levels in plasma and hearts were markedly inhibited by TRPV1 receptor antagonist capsazepine. These findings indicate that limb remote ischemic postconditioning could attenuate cardiac ischemia/reperfusion injury in rats, and the cardioprotective mechanism is via TRPV1-mediated upregulation of CGRP and SP, which could subsequently act on their corresponding receptors in heart tissue.

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.

Circulating microRNAs as potential biomarkers for coronary plaque rupture

Coronary plaque rupture is the most common cause of acute coronary syndrome. However, the timely biomarker-based diagnosis of plaque rupture remains a major unmet clinical challenge. Balloon dilatation and stent implantation during percutaneous coronary intervention (PCI) could cause plaque injury and rupture. Here we aimed to assess the possibility of circulating microRNAs (miRNAs) as biomarkers of acute coronary plaque rupture by virtue of the natural model of PCI-induced plaque rupture. Stable coronary artery disease patients underwent PCI with single stent implantation were recruited and a three-phase approach was conducted in the present study: (i) profiling of plasma miRNAs in a group of patients before (0 h) and after balloon dilatation for 1 h (1 h vs. 0 h), (ii) replication of significant miRNAs in the second group of patients (1 h vs. 0 h), (iii) validation of a multi-miRNAs panel in the third group of patients (0.5 h, 1 h vs. 0 h). Out of 24 miRNAs selected for replication, 6 miRNAs remained significantly associated with plaque rupture. In the validation phase, combinations of miR-483-5p and miR-451a showed the highest area under the receiver-operating-characteristic curve (AUC) (0.982; CI: 0.907-0.999) in patients with plaque rupture for 0.5 h; combinations of miR-483-5p and miR-155-5p showed the highest AUC (0.898; CI: 0.790-0.962) after plaque rupture for 1 h. In conclusion, using a profiling-replication-validation model, we identified 3 miRNAs including miR-155-5p, miR-483-5p and miR-451a, which may be biomarkers for the early identification of plaque rupture.

The changes of gut microbiota after acute myocardial infarction in rats

Recent studies suggested that gut microbiota was involved in the development of coronary artery disease. However, the changes of gut microbiota following acute myocardial infarction (AMI) remain unknown. In this study, a total of 66 male Wistar rats were randomly divided into control, AMI and SHAM groups. The controls (n = 6) were sacrificed after anesthesia. The AMI model was built by ligation of left anterior descending coronary artery. The rats of AMI and SHAM groups were sacrificed at 12 h, 1 d, 3 d, 7 d and 14 d post-operation respectively. Gut microbiota was analyzed by 16S rDNA high throughput sequencing. The gut barrier injuries were evaluated through histopathology, transmission electron microscope and immunohistochemical staining. The richness of gut microbiota was significantly higher in AMI group than SHAM group at 7 d after AMI (P<0.05). Principal coordinate analysis with unweighted UniFrac distances revealed microbial differences between AMI and SHAM groups at 7 d. The gut barrier impairment was also the most significant at 7 d post-AMI. We further identified the differences of microorganisms between AMI and SHAM group at 7 d. The abundance of Synergistetes phylum, Spirochaetes phylum, Lachnospiraceae family, Syntrophomonadaceae family and Tissierella Soehngenia genus was higher in AMI group compared with SHAM group at 7 d post-operation (q<0.05). Our study showed the changes of gut microbiota at day 7 post AMI which was paralleled with intestinal barrier impairment. We also identified the microbial organisms that contribute most.

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.

Total ischemic time and outcomes for patients with ST-elevation myocardial infarction: does time of admission make a difference?

Objective To investigate whether admission time was associated with the delay of reperfusion therapy and in-hospital death in patients with ST-elevation myocardial infarction (STEMI). Methods All patients with STEMI who were admitted to the emergency department and underwent primary percutaneous coronary intervention at Peking University Peoples Hospital between April 2012 and March 2015 were included. We examined differences in clinical characteristics, total ischemic time, and in-hospital death between patients admitted during off-hours and those admitted during regular hours. Multivariate logistic regression was used to estimate the relationship between off-hours admission and clinical outcome. Results The sample comprised 184 and 105 patients with STEMI admitted to hospital during off-hours and regular hours, respectively. Total ischemic and onset-to-door times were significantly shorter in patients admitted during off-hours than among those admitted during regular hours (all P < 0.05). Door-to-balloon (DTB) time, the rate of DTB time ≤ 90 min, and in-hospital death were comparable between groups. Multivariate logistic regression showed that age and creatinine level, but not off-hours admission, were associated independently with increased in-hospital death. Conclusions Off-hours admission did not result in delayed reperfusion therapy or increased in-hospital mortality in patients with STEMI. Further efforts should focus on identifying pivotal factors associated with the pre-hospital and in-hospital delay of reperfusion therapy, and implementing quality improvement initiatives for reperfusion programs.

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.

Predictors and in-hospital prognosis of recurrent acute myocardial infarction.

Objective To investigate the contributing factors and in-hospital prognosis of patients with or without recurrent acute myocardial infarction (AMI). Methods A total of 1686 consecutive AMI patients admitted to Peking University Peoples Hospital from January 2010 to December 2015 were recruited. Their clinical characteristics were retrospectively compared between patients with or without a recurrent AMI. Then multivariable logistic regression was used to estimate the predictors of recurrent myocardial infarction. Results Recurrent AMI patients were older (69.3 ± 11.5 vs. 64.7 ± 12.8 years, P < 0.001) and had a higher prevalence of diabetes mellitus (DM) (52.2% vs. 35.0%, P < 0.001) compared with incident AMI patients, they also had worse heart function at admission, more severe coronary disease and lower reperfusion therapy. Age (OR = 1.03, 95% CI: 1.02–1.05; P < 0.001), DM (OR = 1.86, 95% CI: 1.37–2.52; P < 0.001) and reperfusion therapy (OR = 0.74; 95% CI: 0.52–0.89; P < 0.001) were independent risk factors for recurrent AMI. Recurrent AMI patients had a higher in-hospital death rate (12.1% vs. 7.8%, P = 0.039) than incident AMI patients. Conclusions Recurrent AMI patients presented with more severe coronary artery conditions. Age, DM and reperfusion therapy were independent risk factors for recurrent AMI, and recurrent AMI was related with a high risk of in-hospital death.