Smooth muscle cell fate decisions decipher a high-resolution heterogeneity within atherosclerosis molecular subtypes.

BACKGROUND: Mounting evidence has revealed the dynamic variations in the cellular status and phenotype of the smooth muscle cell (SMC) are vital for shaping the atherosclerotic plaque microenvironment and ultimately mapping onto heterogeneous clinical outcomes in coronary artery disease. Currently, the underlying clinical significance of SMC evolutions remains unexplored in atherosclerosis. METHODS: The dissociated cells from diseased segments within the right coronary artery of four cardiac transplant recipients and 1070 bulk samples with atherosclerosis from six bulk cohorts were retrieved. Following the SMC fate trajectory reconstruction, the MOVICS algorithm integrating the nearest template prediction was used to develop a stable and robust molecular classification. Subsequently, multi-dimensional potential biological implications, molecular features, and cell landscape heterogeneity among distinct clusters were decoded. RESULTS: We proposed an SMC cell fate decision signature (SCFDS)-based atherosclerosis stratification system and identified three SCFDS subtypes (C1-C3) with distinguishing features: (i) C1 (DNA-damage repair type), elevated base excision repair (BER), DNA replication, as well as oxidative phosphorylation status. (ii) C2 (immune-activated type), stronger immune activation, hyper-inflammatory state, the complex as well as varied lesion microenvironment, advanced stage, the most severe degree of coronary stenosis severity. (iii) C3 (stromal-rich type), abundant fibrous content, stronger ECM metabolism, immune-suppressed microenvironment. CONCLUSIONS: This study uncovered atherosclerosis complex cellular heterogeneity and a differentiated hierarchy of cell populations underlying SMC. The novel high-resolution stratification system could improve clinical outcomes and facilitate individualized management.

Protective Effect of miR-204 on Doxorubicin-Induced Cardiomyocyte Injury via HMGB1.

The toxicity of doxorubicin (DOX) limits its clinical application. Nevertheless, at present, there is no effective drug to prevent DOX-induced cardiac injury. miR-204 is a newly discovered miRNA with many protective effects on cardiovascular diseases. However, little research has been done on the effects of miR-204 on DOX-induced cardiac injury. Our study is aimed at investigating the effect of miR-204 on DOX-induced myocardial injury. An adenoassociated virus system was used to achieve cardiac-specific overexpression of miR-204. Two weeks later, the mice were intraperitoneally injected with DOX (15 mg/kg) to induce cardiac injury. H9c2 myocardial cells were used to validate the role of miR-204 in vitro. Our study showed that miR-204 expression was decreased in DOX-treated hearts. miR-204 overexpression improved cardiac function and alleviated cardiac inflammation, apoptosis, and autophagy induced by DOX. In addition, our results showed that miR-204 prevented DOX-induced injury in cardiomyocytes by directly decreasing HMGB1 expression. Moreover, the overexpression of HMGB1 could offset the protective effects of miR-204 against DOX-induced cardiac injury. In summary, our study showed that miR-204 protected against DOX-induced cardiac injury via the inhibition of HMGB1, and increasing miR-204 expression may be a new treatment option for patients with DOX-induced cardiac injury.

Downregulation of microRNA­34b is responsible for the elevation of blood pressure in spontaneously hypertensive rats.

The present study aimed to identify the microRNA (miRNA) responsible for the development of primary hypertension, and examine the downstream signaling pathway, which mediates the effect of the miRNA. Reverse transcription­quantitative polymerase chain reaction analysis was performed to identify which miRNA may be involved in the pathogenesis of hypertension. In silico analysis and a luciferase assay were used to validate the target of the selected miRNA, and miRNA mimics and small interfering (si)RNA of the target were transfected into smooth muscle cells to examine its effect on the biological activity of the cells. miR­34b was found to be upregulated in spontaneously hypertensive rats (SHRs), compared with Wistar Kyoto (WKY) rats. Therefore, the present study used online miRNA target prediction tools to predict the candidate target genes of miR­34b in the database, and consequently identified cyclin G1 (CCNG1) and cyclin­dependent kinase 6 (CDK6) as its possible target genes. CDK6 subsequently identified to be the direct target gene of miR­34b using a luciferase reporter assay in vascular smooth muscle cells (VSMCs). The present study also established the possible negative regulatory association between miR­34b and CDK6 via investigating the mRNA and protein expression levels of CDK6 and CCNG1 in VSMCs collected from the SHRs and WKY rats, respectively. To investigate the signaling pathways between miR­34b and CDK6, the mRNA and protein expression levels of CDK6, and the proliferation rates were compared in VSMCs transfected with CDK6 siRNA or miR­34b mimics, the results of which indicated that the miR­34b mimics exerted the same effects on the expression of CDK6 and cell proliferation as CDK6 siRNA. The negative regulatory association between miR­34b and its target, CDK6, was confirmed, which may offer potential as a novel therapeutic target in the treatment of hypertension.

Association between polymorphisms of platelet membrane glycoprotein Ibα and risk of coronary heart disease in Han Chinese, Henan, China.

OBJECTIVE: To study the relationship between human platelet alloantigens-2 (HPA-2) polymorphism, Kozak sequence polymorphism, macroglycopeptide region variable number of tandem repeats (VNTR) polymorphism of GPIbα and coronary heart disease (CHD). METHODS: In the present study, blood obtained from 403 patients with CHD and 500 healthy controls was detected by PCR or PCR-RFLP methods to analyze the genotypes of HPA-2, Kozak sequence and VNTR. RESULTS: About HPA-2 polymorphism, there were significant differences between CHD group and control group in TM+MM genotype (13.15% vs. 8.60%, P<0.05; OR 1.609; 95% CI 1.051 to 2.463) and M alleles distributions (6.58% vs. 4.40%, P<0.05; OR 1.645; 95% CI 1.090 to 2.482). For Kozak sequence polymorphism, between control group and CHD group, the difference of CC genotype distribution is statistic significance (3.20% vs. 7.69%, P<0.05; OR 2.000; 95% CI 1.076 to 3.718). The genotype analysis of VNTR in Han People of Henan (AC, BC, BD, CC, CD and DD) proved that no association between any genotypes or alleles and CHD. There weren't any significant differences about haplotypes of these genes between control group and CHD group (P>0.05). CONCLUSIONS: The M allele of HPA-2 could be an important risk factor for CHD; the CC genotype of Kozak sequence would be a biomarker of genetic susceptibility about CHD; and each genotype of VNTR is no associated with CHD. No significant differences between control group and CHD group about haplotypes of these genes.

Validation of the fully automated Pangao PG-800B68 upper-arm device according to the European Society of Hypertension International Protocol revision 2010.

OBJECTIVE: This study aimed to validate the fully automated Pangao PG-800B68 upper-arm device according to the European Society of Hypertension International Protocol (ESH-IP) revision 2010. MATERIALS AND METHODS: Sequential measurements of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were obtained in 33 participants using the standard mercury sphygmomanometer and the test device. The ESH-IP revision 2010 was followed precisely and 99 pairings of test device and reference blood pressure measurements were obtained for analysis. RESULTS: The number of blood pressure differences within 5, 10, and 15 mmHg was 76, 95, and 98, respectively, for SBP and 79, 96, and 99, respectively, for DBP. The device achieved all the required criteria of the ESH-IP revision 2010 with a device-observer difference of -0.03±4.64 mmHg for SBP and -0.64±4.50 mmHg for DBP. CONCLUSION: According to the validation results on the basis of the ESH-IP revision 2010, the Pangao PG-800B68 can be recommended for clinical use and self-measurement in adults.

Feasibility and effect of para-right bundle branch pacing in patients with atrial fibrillation and complete atrioventricular block.

BACKGROUND: Chronic right ventricular apex (RVA) pacing can induce negative clinical effects. The aim of the present study was to compare RVA pacing with para-right bundle branch (para-RBB) pacing in terms of electrocardiogram (ECG) and echocardiographic (ECHO) features. METHODS: Forty-one consecutive persistent atrial fibrillation patients with an indication for permanent pacing treatment due to complete atrioventricular block were randomly assigned to receive a screw-in lead either in the RVA (n = 22) or at the para-RBB (n = 19). Para-RBB pacing leads were located according to the RBB potential recorded by electrophysiology catheter. ECG was recorded before and after implantation. All patients underwent the pacemaker programming at 1 day, 6 months, 12 months and 24 months after implantation. ECHO examination was performed during follow-up at 6, 12 and 24 months after implantation to assess the heart function and synchronism. RESULTS: There was no significant difference in pacing lead parameters between para-RBB pacing group and RVA pacing group. Compared with RVA pacing group, the para-RBB pacing group obtained a narrower QRS complex, more synchronic ventricular systole, and less negative effect on heart function (p < 0.05). CONCLUSIONS: Para-RBB pacing has potential clinical benefits and may be a physiological pacing site.

Red blood cell distribution width and long-term outcome in patients undergoing percutaneous coronary intervention in the drug-eluting stenting era: a two-year cohort study.

BACKGROUND: Previous studies suggest the higher the red blood cell distribution width (RDW) the greater the risk of mortality in patients with coronary artery disease (CAD). However, the relationship between RDW and long-term outcome in CAD patients undergoing percutaneous coronary intervention (PCI) with a drug-eluting stent (DES) remains unclear. This study was designed to evaluate the long-term effect of RDW in patients treated with drug-eluting stent for CAD. METHODS: In total of 2169 non-anemic patients (1468 men, mean age 60.2 ± 10.9 years) with CAD who had undergone successful PCI and had at least one drug-eluting stent were included in this study. Patients were grouped according to their baseline RDW: Quartile 1 (RDW<12.27%), Quartile 2 (12.27% ≤ RDW <13%), Quartile 3 (13% ≤ RDW<13.5%), and Quartile 4 (RDW ≥ 13.5). RESULTS: The incidence of in-hospital mortality and death or myocardial infarction was significantly higher in Quartiles 3 and 4 compared with Quartile 1 (P<0.05). After a follow-up of 29 months, the incidence of all-cause death and stent thrombosis in Quartile 4 was higher than in Quartiles 1, 2, and 3 (P<0.05). The incidence of death/myocardial infarction/stroke and cardiac death in Quartile 4 was higher than in Quartiles 1 and 2 (P<0.05). Multivariate Cox regression analysis showed that RDW was an independent predictor of all-cause death (hazard ratio (HR) = 1.37, 95% confidence interval (CI) = 1.15-1.62, P<0.001) and outcomes of death/myocardial infarction/stroke (HR = 1.21, 95% CI = 1.04-1.39, P = 0.013). The cumulative survival rate of Quartile 4 was lower than that of Quartiles 1, 2, and 3 (P<0.05). CONCLUSION: High RDW is an independent predictor of long-term adverse clinical outcomes in non-anemic patients with CAD treated with DES.

Plaque characteristics and serum pregnancy-associated plasma protein A levels predict the no-reflow phenomenon after percutaneous coronary intervention.

OBJECTIVES: To investigate the relationship between serum plasma pregnancy-associated plasma protein A (PAPP-A) and coronary plaque characteristics, and their prognostic value for coronary no-reflow after percutaneous coronary intervention (PCI). METHODS: Patients with unstable angina undergoing PCI were divided into a normal reflow group and a no-reflow group after stent deployment. Coronary blood flow was measured angiographically; plaque components were detected by virtual histology intravascular ultrasound. Serum PAPP-A and high-sensitivity C-reactive protein (hsCRP) were measured before PCI. Cardiac troponin T (cTnT) was measured before and 24 h after PCI. RESULTS: A total of 166 patients with unstable angina undergoing PCI were included: normal reflow group (n = 145) and no-reflow group (n = 21), after stent deployment. Baseline coronary blood flow was similar in the two groups. The no-reflow group had plaques with less-fibrotic tissue and a larger necrotic core, more thin-cap fibroatheromas and plaque ruptures, and higher serum PAPP-A, hsCRP and post-PCI cTnT levels than the normal reflow group. Serum PAPP-A was correlated negatively with plaque fibrotic area and positively with necrotic core area. CONCLUSION: High serum PAPP-A and plaque lesions with a large necrotic core are associated with the no-reflow phenomenon after PCI, in patients with unstable angina.

Effect of the composition of atherosclerotic plaques and rate of platelet aggregation on elevation of serum levels of cardiac troponin T after percutaneous coronary interventions.

PURPOSE: Elevation of the levels of myocardial biomarkers after percutaneous coronary intervention (PCI) has prognostic value in patients with coronary heart disease. We explored the relationship between elevation of the serum level of cardiac troponin T (cTnT) after PCI and platelet aggregation rate and coronary plaque composition. METHODS: Eighty patients with unstable angina pectoris underwent PCI and were divided into two groups according to serum cTnT level 24 hours after PCI: group I (cTnT ≥2 times the normal level) and group II (cTnT <2 times the normal level). Coronary plaque composition was measured with virtual histology-intravascular ultrasound. Platelet aggregation rate was detected immediately before and 24 hours after PCI. RESULTS: Compared with the patients in group II, patients in group I showed more unstable plaques, a larger necrotic core area (20.88 ± 8.04% vs. 15.31 ± 5.48%, P < 0.05), higher platelet aggregation rate (51.47 ± 12.72% vs. 44.78 ± 13.29%, P < 0.05), and longer stents. The serum cTnT level 24 hours after PCI was positively correlated with the necrotic core area. CONCLUSIONS: In patients with unstable angina pectoris, a large necrotic core, high rate of platelet aggregation, and stent length are predictors of cTnT elevation after PCI.

[Mesenchymal stem cells implantation increases the myofibroblasts congregating in infarct region in a rat model of myocardial infarction].

OBJECTIVE: To investigate the modulation effects of mesenchymal stem cells (MSC) implantation on the myofibroblasts congregating in the infarct region after myocardial infarction (MI). METHODS: MI was induced in SD rats by left anterior descending coronary artery ligation, and the experimental animals were assigned randomly into the sham group, MI + PBS group and MI + MSC group (myocardial injection of 0.1 ml 2×10(7)/ml in four locations in the infarct region). Echocardiography, hemodynamic examinations and Masson trichrome staining were performed. Implanted MSC differentiation and myofibroblasts congregating in infarct region were investigated by immunofluorescence staining. TGF-ß(1)-Smad2 signaling pathway was examined by real-time RT-PCR and Western blot. RESULTS: (1) Four weeks late, heart-weight/body-weight ratio [(3.04 ± 0.16) mg/g vs. (3.34 ± 0.14) mg/g, P < 0.01] and myocardial infarction size [(38.72 ± 2.38)% vs. (46.36 ± 2.81)%, P < 0.01] were significantly reduced in MI + MSC group than in MI + PBS group, while scar thickness of infarct region was thicker [(0.93 ± 0.17) mm vs. (0.65 ± 0.16) mm, P = 0.01], and LVEF was higher [LVEF: (32.5 ± 5.9)% vs. (26.5 ± 4.5)%, P = 0.03] in MI + MSC group than in MI + PBS group. (2) Myofibroblasts congregating in the infarct region was significantly enhanced in MI + MSC group compared with MI + PBS group [(196 ± 20) cells/mm(2) vs. (89 ± 25) cells/mm(2), P < 0.01], and part of implanted MSC expressed α-SMA(+). (3) TGF-ß(1) expression and the phosphorylating of Smad2 in the infarct region were significantly upregulated in MI + MSC group compared with MI + PBS group (all P < 0.05). CONCLUSIONS: MSC could improve myocardial function and promote myofibroblasts congregating in the infarct region via activating the TGF-ß(1)-Smad2 signaling pathway in this model.

The altered expression of inflammation-related microRNAs with microRNA-155 expression correlates with Th17 differentiation in patients with acute coronary syndrome.

MicroRNAs (miRNAs) are a novel class of small, non-coding RNAs that play a significant role in both inflammatory and cardiovascular diseases. Immune cells, especially T helper (Th) cells, are critical in the development of atherosclerosis and the onset of acute coronary syndrome (ACS). To assess whether inflammation-related miRNAs (such as miR-155, 146a, 21, 125a-5p, 125b, 31) are involved in the imbalance of Th cell subsets in patients with ACS, we measured the expression of related miRNAs in patients with acute myocardial infarction (AMI), unstable angina (UA), stable angina (SA) and chest pain syndrome (CPS); analyzed the relationship between miRNA expression and the frequency of Th cell subsets; and observed the co-expression of miR-155 and IL-17A in peripheral blood mononuclear cells (PBMCs) of patients with ACS. The results showed that the expression of miR-155 in the PBMCs of patients with ACS was decreased by approximately 60%, while the expression of both miR-21 and miR-146a was increased by approximately twofold. The expression patterns of miRNAs in plasma correlated with those in PBMCs, except for miR-21, which was increased by approximately sixfold in the AMI group and showed no significant difference between the UA group and the CPS group. We also found that the expression of miR-155 inversely correlated with the frequency of Th17 cells (r=-0.896, P<0.01) and that miR-155 was co-expressed with IL-17A in patients with ACS. In conclusion, our study revealed the expression patterns of inflammation-related miRNAs in patients with ACS and found that miR-155 may be associated with Th17 cell differentiation.

[Dural modulation effects of mesenchymal stem cells implantation on myocardial collagen remodeling in a rat model of myocardial infarction].

OBJECTIVE: To investigate the modulation effects of mesenchymal stem cells (MSCs) implantation on the collagen remodeling in myocardial infarction. METHODS: Acute myocardial infarction (AMI) was induced in SD rats by left anterior descending coronary artery ligation, and the animals were assigned randomly into the Sham group, MI + PBS group and MI + MSCs group. Echocardiography and hemodynamic examinations were performed to evaluate the cardiac function. HE staining and Masson trichrome staining were used to evaluate the myocardial infarction size. Infarcted area and infarcted expansion index were calculated. The expression of collagens in infarcted hearts was evaluated by immunohistochemistry, RT-PCR and Western blot. RESULTS: (1) Infarct area was significantly reduced post MSCs transplantation [MI + MSCs vs. MI + PBS: (38.27 ± 2.70)% vs. (46.20 ± 3.17)%, P < 0.001]. (2) Cardiac function was significantly improved post MSCs transplantation [MI + MSCs vs. MI + PBS: FS(%): 29.98 ± 4.50 vs. 23.43 ± 3.34, P = 0.005; LVSP (mm Hg, 1 mm Hg = 0.133 kPa): 113.63 ± 10.81 vs. 99.25 ± 16.76, P < 0.05; LVEDP (mm Hg): 12.10 ± 4.28 vs. 20.08 ± 4.26, P < 0.05; +dp/dtmax (mm Hg/s): 4616.63 ± 363.34 vs. 3912.75 ± 248.79, P < 0.05; -dp/dtmax (mm Hg/s): 4254.63 ± 324.34 vs. 3530.88 ± 309.71, P < 0.05]. (3) Collagen synthesis was enhanced in infarcted area and decreased in non-infarcted area post MSCs transplantation (P < 0.05). CONCLUSIONS: MSCs transplantation could enhance the collagen synthesis in infarcted area while decrease the deposition of collagen in non-infarcted area in this MI model. This may be one of the mechanisms by which ventricular remodeling is attenuated post MSCs transplantation.