MicroRNA-1907 enhances atherosclerosis-associated endothelial cell apoptosis by suppressing Bcl-2.

Injury and endothelial cell apoptosis are hall marks of atherosclerosis (AS). However, the mechanisms underlying its pathogenesis remain ill-defined. Recent evidence of a role for microRNAs in AS-associated endothelial cell apoptosis encouraged us to address this question. Here, AS was developed in ApoE (-/-) mice supplied with a high-fat diet (HFD), compared to ApoE (-/-) mice supplied with a normal diet (ND). Mouse endothelial cells were isolated from the aortic arch using flow cytometry based on their expression of CD31. Human aortic endothelial cells (HAECs) were treated with oxidized low-density lipoprotein (ox-LDL) as an in vitro model for AS. Gene expression was quantified by RT-qPCR and protein levels were analyzed by Western blotting. Apoptosis was evaluated by FITC Annexin V Apoptosis assay and by TUNEL staining. Predicting binding patterns between miRNAs and the 3'-UTR of mRNA from the target gene was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. We found that HFD mice, but not ND mice, developed AS in 12 weeks. A significant reduction in endothelial cells and a significant increase in mesenchymal cells were detected in the aortic arch of the HFD mice, compared to those of ND mice. Endothelial cell apoptosis was significantly higher in HFD mice, seemingly due to functional suppression of protein translation of anti-apoptotic Bcl-2 protein through upregulation of miR-1907, confirmed by in vitro analysis. Moreover, inhibition of miR-1907 abolished the effects of ox-LDL-induced apoptotic cell death on HAECs. Thus, AS-associated endothelial cell apoptosis may partially result from downregulation of Bcl-2, via upregulation of miR-1907 which binds and suppresses the translation of Bcl-2 mRNA.

[Relevance between carotid plaque scores and the severity of coronary atherosclerosis].

OBJECTIVE: To explore the relevance between carotid plaque and the severity of coronary artery disease. METHODS: A total of 207 patients(149 males,58 females) undergoing coronary angiography were definitely diagnosed with coronary heart disease. They were divided into 3 groups of one-vessel disease (1VD, n = 69), two-vessel disease (2VD, n = 57) and three-or-more vessel disease (3VD, n = 81) by the number of involved vessels. Their physical findings, biochemical data and carotid ultrasonographic results were collected. And the scores of Crouse, Gensini and Leaman were calculated to compare the relevance. RESULTS: No significant differences existed among all three groups except for a higher age and the presence of plaque in 2VD and 3VD groups than 1VD group ((63 ± 11) and (60 ± 11) vs (57 ± 10)years old, 82%(n = 47) and 81%(n = 66) vs 65%(n = 45), both P < 0.05) . Crouse had a positive correlation with Gensini (r = 0.455, P < 0.01) and Leaman scores (r = 0.358, P < 0.01) . CONCLUSION: Assessment of plaque scores by carotid ultrasonography is clinically relevant for predicting the severity of coronary artery disease.

[Preliminary study of real-time three-dimensional dobutamine stress echocardiography for coronary artery disease assessment].

OBJECTIVE: To evaluate the efficacy and safety of real-time three-dimensional dobutamine stress echocardiography for coronary artery disease assessment. METHODS: A total of 14 patients suspected of coronary artery disease (CAD) underwent real-time three-dimensional dobutamine stress echocardiography. The initial infusion rate of dobutamine was 5 µg×kg⁻¹ ×min⁻¹, followed by 10 µg×kg⁻¹×min⁻¹ and peak infusion 20 µg×kg⁻¹×min⁻¹ in 3 min stages. At baseline state, stress stages and after the study, the real-time three-dimensional (RT3D) images were captured and assessed by wall motion score index (WMSI) and regional ejection fraction (rEF). And the parameters of these two modalities versus coronary angiography (CAG) were compared and analyzed. Adverse reactions were also observed. RESULTS: All patients completed the stress study uneventfully. As compared with CAG, these two modalities showed no significant difference (P > 0.05) and satisfactory agreement (κ values of 0.704 and 0.759 respectively). The diagnostic parameters of these modalities were: sensitivity (78% vs 89%), specificity (92% vs 88%), positive predictive value (PPV) (88% vs 84%), negative predictive value (NPV) (85% vs 91%) and overall accuracy (86% vs 88%). CONCLUSION: Real-time three-dimensional dobutamine stress echocardiography is an effective, rapid and safe technique of assessing coronary artery disease. It is worthy of wider clinical applications.