Suppression of microRNA-323-3p restrains vascular endothelial cell apoptosis via promoting sirtuin-1 expression in coronary heart disease.

AIMS: Coronary heart disease (CHD), a chronic inflammatory condition of vascular endothelial cells (VECs), poses a serious threat to human health. Previous studies have found that microRNAs (miRNAs) are closely related to the occurrence and development of cardiac diseases. Therefore, this study focused on the regulation by miR-323-3p on the progression of CHD. METHODS: Initially, we employed microarray-based gene expression profiling of CHD to identify differentially expressed miRNAs. Next, the expression of miR-323-3p and SIRT1 was detected by RT-qPCR in a rat model of CHD generated by feeding with a high-fat diet. The interaction between miR-323-3p and SIRT1 was identified using bioinformatics analysis and dual luciferase reporter gene assay. The expressions of miR-323-3p and SIRT1 were altered in CHD rats and vascular endothelial cells (VECs) to examine the specific effects on CHD. RESULTS: miR-323-3p was observed to be highly-expressed in blood samples from patients with CHD or with mild atherosclerosis and in the rat model of CHD. SIRT1 was a target gene of miR-323-3p, which could downregulate SIRT1 expression. miR-323-3p overexpression or SIRT1 inhibition resulted in increased apoptosis of VECs, elevated ac-p65 protein expression and ratio of ac-p65/p65, and upregulated expression of NF-κB signaling pathway-related proteins. Besides, miR-323-3p inhibition or SIRT1 upregulation in the CHD rat model was found to significantly alleviate symptoms and decrease levels of proteins related to the ac-p65 and NF-κB signaling pathways. CONCLUSION: Overall, the experimental data provide evidence that miR-323-3p suppression may restrain VEC apoptosis and prevent the resultant CHD progression via SIRT1-inactivatedNF-κB signaling pathway.

microRNA-132 inhibits cardiomyocyte apoptosis and myocardial remodeling in myocardial infarction by targeting IL-1ß.

The patients suffering from myocardial infarction (MI) undergo cardiac remodeling with the features of expanded myocardial infarct size and dilated left ventricle. Multiple microRNAs (miRNAs) are emerged as crucial modulators to participate in the remodeling process. This study is mainly intended to clarify the regulatory mechanism of miR-132 in the MI-induced myocardial remodeling. miR-132 low expression, while interleukin-1ß (IL-1ß) high expression was determined in MI by reverse-transcription quantitative polymerase chain reaction and ELISA assays. MI rats showed decreased cardiac function and increased cardiomyocyte apoptosis. Moreover, miR-132 and IL-1ß levels were altered in cardiomyocytes to explore their role in MI, with levels of proapoptotic or antiapoptotic proteins in MI together with cardiac function indexes observed. In addition, upregulation of miR-132, decreased levels of Bax and Cleaved Caspase-3, increased left ventricular ejection fraction, left ventricular fractional shortening, the maximum rate of rise or decrease of left ventricular pressure (±dp/dtmax ), and Bcl-2 level, which could be reversed by overexpressing IL-1ß. All in all, miR-132 inhibits cardiomyocyte apoptosis so as to ameliorate myocardial remodeling in rats with MI through IL-1ß downregulation. Thus, miR-132 is a potential candidate for the MI treatment.

LncRNA DYNLRB2-2 inhibits THP-1 macrophage foam cell formation by enhancing autophagy.

The aim of this study was to investigate whether long non-coding RNA (lncRNA) DYNLRB2-2 can inhibit foam cell formation by activating autophagy. The location of DYNLRB2-2 in THP-1-derived macrophages was analyzed by fluorescence in situ hybridization (FISH). Oxidized-low-density lipoprotein (ox-LDL) was used to induce the formation of foam cells, Oil Red O (ORO) staining and high-performance liquid chromatography (HPLC) were performed to detect accumulation of lipid droplets and the level of cholesterol concentration, respectively. The mRNA and protein level of ATP-binding cassette transporter A1 (ABCA1) were examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. Relative protein levels of (p-) liver kinase B1 (LKB1), (p-) AMP-activated protein kinase (AMPK), (p-) the mammalian target of rapamycin (mTOR) and autophagy markers (LC3 II, Beclin-1 and p62) in THP-1 macrophage-derived foam cells were analyzed by Western blotting. The levels of inflammatory factors [tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1ß] in THP-1 macrophage-derived foam cells were detected by enzyme-linked immunosorbent assay (ELISA). 3-MA and compound C were used to block autophagy. Our data show that DYNLRB2-2 inhibited the formation of THP-1 macrophage-derived foam cells and promotes cholesterol efflux (CE) by activating autophagy. DYNLRB2-2 caused autophagy by activating the signaling pathway of LKB1/AMPK/mTOR in foam cells. DYNLRB2-2 activated the LKB1/AMPK/mTOR signaling pathway via the miR-298/Sirtuin 3 (SIRT3) axis. Our data indicated that DYNLRB2-2 enhanced CE by regulating the LKB1/AMPK/mTOR autophagy signaling pathway through the miR-298/SIRT3 axis, thereby blocking the formation of foam cells from THP-1 macrophages.

Comparative efficacy and safety of lipid-lowering agents in patients with hypercholesterolemia: A frequentist network meta-analysis.

BACKGROUND: The comparative efficacy and safety of PCSK9 inhibitors, statins, and ezetimibe to lower lipid levels in patients with hypercholesterolemia remain unknown. We aimed to investigate the benefits and harms of the lipid-lowering agents in these patients. METHODS: PubMed, Embase, and the Cochrane Library were searched from January 1, 2000 to June 1, 2018 for relevant randomized controlled trials (RCTs). Frequentist network meta-analysis was used to pool all estimates. Ranking probabilities were used to rank the comparative effects of all drugs against placebo. RESULTS: Eighty-four RCTs enrolled 246,706 patients were included. Most of the included were assessed as low risk of bias. The probabilities of PCSK9 inhibitors that ranked first in improving lipid outcomes were all 100%. The probability of statins that ranked first in reducing the risk of cardiovascular (CV) events was 60.6%, and the probability of PCSK9 inhibitor was 37.1%, while no significant difference of efficacy in reducing CV events was observed between the 2 agents (odds ratios [OR] 0.98, 95% CI 0.87-1.11). Statin ranked first in reducing all-cause and CV death. Compared with placebo, statins were associated with reduced risks of all-cause (OR 0.90, 95% CI 0.85-0.96) and CV death (OR 0.83, 95% CI 0.75-0.91) while PCSK9 inhibitors and ezetimibe were not. No agents caused adverse events (including neurocognitive events), except that statins therapy significantly increases the levels of alanine aminotransferase (ALT) (OR 1.89, 95% CI 1.42-2.51) and creatine kinase (CK) (OR 1.45, 95% CI 1.09-1.93) and the incidence of diabetes (OR 1.13, 95% CI 1.02-1.26). CONCLUSIONS: PCSK9 inhibitors were the most effective lipid-lowering agents in improving lipid levels. Furthermore, PCSK9 inhibitors achieved similar CV benefits like statins, while PCSK9 inhibitors were not associated with any increased risk of statin-related side-effects. Thus, PCSK9 inhibitors may also be recommended as promisingly first-line lipid-lowering treatment for patients with hypercholesterolemia, especially for these with statins intolerance or resistance.

Folate-conjugated nanobubbles selectively target and kill cancer cells via ultrasound-triggered intracellular explosion.

With the rapid development of cancer-targeted nanotechnology, a variety of nanoparticle-based drug delivery systems have clinically been employed in cancer therapy. However, multidrug resistance significantly impacts the therapeutic efficacy. Physical non-drug therapy has emerged as a new and promising strategy. This study aimed to determine whether novel folate-nanobubbles (F-NBs), combined with therapeutic ultrasound (US), could act as a safe and effective physical targeted cancer therapy. Using folate-conjugated N-palmitoyl chitosan (F-PLCS), we developed novel F-NBs and characterised their physicochemical properties, internalization mechanism, targeting ability, therapeutic effects, and killing mechanism. The results showed that the novel F-NBs selectively accumulated in FR-positive endothelial cells and tumour cells via FR coupled with clathrin- and caveolin-mediated endocytosis in vitro and in vivo. In addition, the F-NBs killed target cells by an intracellular explosion under US irradiation. Hoechst/PI staining demonstrated that apoptosis and necrosis accounted for a large proportion of cell death in vivo. F-NBs combined with US therapy significantly inhibited tumour growth and improved the overall survival of tumour-bearing mice. Under US irradiation, the novel F-NBs selectively killed FR-positive tumour cells in vitro and in vivo via intracellular explosion and therefore is a promising alternative for targeted cancer treatment.

Toll-like receptor 2 downregulates the cholesterol efflux by activating the nuclear factor-κB pathway in macrophages and may be a potential therapeutic target for the prevention of atherosclerosis.

Atherosclerosis is a chronic inflammatory disease, which is triggered by lipid retention. Toll-like receptor 2 (TLR2) is a novel target for therapeutic intervention in atherosclerosis. In addition, nuclear factor-κB (NF-κB) serves important roles in stress response and inflammation. The present study investigated whether TLR2 is involved in the activation of cholesterol efflux in macrophages by regulating the NF-κB pathway. The human monocytic THP-1 cell line and murine macrophage RAW264.7 cell line were treated with 50 µg/ml oxidized low-density lipoprotein (ox-LDL) for 48 h in order to obtain macrophage foam cells. The cholesterol efflux of the cell lines under exogenous TLR2 treatment was assessed by liquid scintillation counting. Furthermore, the protein and mRNA expression levels of ATP binding cassette transporter A1 (ABCA1), ABCG1 and scavenger receptor B1 (SR-B1) were examined by western blot and quantitative polymerase chain reaction assays, respectively. To detect the effect of NF-κB on cholesterol efflux, the cells were divided into three groups, including the control, 10 ng/ml lipopolysaccharides (LPS; 24 h) and 10 ng/ml LPS + 50 µM pyrrolidinedithiocarbamate (PDTC; 24 h) groups. The results indicated that ox-LDL induced foam cell formation in the THP-1 and RAW264.7 cells, while TLR2 significantly decreased the cholesterol efflux in dose- and time-dependent manners. Accordingly, TLR2 reduced ABCA1, ABCG1 and SR-B1 expression at the transcriptional and translational levels in a dose-dependent manner. In addition, application of PDTC (an NF-κB specific inhibitor) markedly suppressed the LPS-induced downregulation of cholesterol efflux. These data revealed that TLR2 may be involved in the activation of cholesterol efflux in macrophages by regulating the NF-κB signaling pathway.

LincRNA DYN-LRB2-2 upregulates cholesterol efflux by decreasing TLR2 expression in macrophages.

This study is designed to determine whether lincRNA-DYNLRB2-2 could promote cholesterol efflux through regulating the expression of TLR2. THP-1 and RAW264.7 cells were incubated with oxLDL for 48 h to induce the formation of foam cells, and ORO staining was performed and intracellular cholesterol contents were measured by HPLC assay. qRT-PCR and Western blotting were performed to detect mRNA and protein expression levels, respectively. Lentiviral vector LV-DYNLRB2-2 and lincRNA-DYNLRB2-2 siRNA was constructed to explore its potential role. The cholesterol efflux was assessed by liquid scintillation counting. The effects of TRL2 were determined in apoE-/- mice that fed a high fat diet and were randomly divided into three groups and infected with LV-Mock, LV-Sh-TRL2, or LV-TRL2. Atherosclerosis was observed in the aortic sinus and the levels of cytokines and serum biochemical parameters were measured. Ox-LDL induced foam cell formation in the THP-1 and RAW264.7 cells. LincRNA DYN-LRB2-2 was upregulated in oxLDL-treated THP-1 and Raw264.7 cells. LincRNA-DYNLRB2-2 plays important role in regulating the cholesterol efflux, ABCA1 expression level and anti-inflammatory processes in THP-1 and RAW264.7 cells. Further study indicated that lincRNA-DYNLRB2-2 negatively regulated TRL2 expression and TRL2 overexpression reversed the effects of lincRNA-DYNLRB2-2 on cholesterol efflux and ABCA1 expression level in THP-1 and RAW264.7 cells. Besides, we found TRL2 plays important role in lipid accumulation, plaque formation and regulating serum inflammatory cytokines level in apoE-/- mice with a high fat diet. LincRNA DYN-LRB2-2 upregulates cholesterol efflux by decreasing TLR2 expression in macrophages.

Ultrasound-targeted microbubble destruction enhances delayed BMC delivery and attenuates post-infarction cardiac remodelling by inducing engraftment signals.

Delayed administration of bone marrow cells (BMCs) at 2-4 weeks after successful reperfusion in patients with acute myocardial infarction (MI) does not improve cardiac function. The reduction in engraftment signals observed following this time interval might impair the effects of delayed BMC treatment. In the present study, we aimed to determine whether ultrasound-targeted microbubble destruction (UTMD) treatment could increase engraftment signals, enhance the delivery of delayed BMCs and subsequently attenuate post-infarction cardiac remodelling. A myocardial ischaemia/reperfusion (I/R) model was induced in Wistar rats via left coronary ligation for 45 min followed by reperfusion. Western blotting revealed that engraftment signals peaked at 7 days post-I/R and were dramatically lower at 14 days post-I/R. The lower engraftment signals at 14 days post-I/R could be triggered by UTMD treatment at a mechanical index of 1.0-1.9. The troponin I levels in the 1.9 mechanical index group were higher than in the other groups. Simultaneous haematoxylin and eosin staining and fluorescence revealed that the number of engrafted BMCs in the ischaemic zone was greater in the group treated with both UTMD and delayed BMC transplantation than in the control groups (P<0.05). Both UTMD and delayed BMC transplantation improved cardiac function and decreased cardiac fibrosis at 4 weeks after treatment, as compared with control groups (both P<0.05). Histopathology demonstrated that UTMD combined with delayed BMC transplantation increased capillary density, myocardial cell proliferation and c-kit+ cell proliferation. These findings indicated that UTMD treatment could induce engraftment signals and enhance homing of delayed BMCs to ischaemic myocardium, attenuating post-infarction cardiac remodelling by promoting neovascularization, cardiomyogenesis and expansion of cardiac c-kit+ cells.

Intensity of Left Atrial Spontaneous Echo Contrast as a Correlate for Stroke Risk Stratification in Patients with Nonvalvular Atrial Fibrillation.

The intensity of left atrial spontaneous echo contrast (LASEC) by transesophageal echocardiography (TEE) has been proposed as an important variable in the stratification of thromboembolic risk, particularly in patients with nonvalvular atrial fibrillation (NVAF). We hypothesized that the quantification of LASEC by ultrasound will improve its utility in predicting subsequent stroke events in patients with NVAF. Patients (n = 206) with definite NVAF receiving TEE were included for this prospective cohort study. Baseline clinical risk factors of stroke, CHADS2 score and CHA2DS2-Vasc, left atrial thrombus (LAT), the five-grades of LASEC and video intensity (VI) value of LASEC were measured. During 2 years follow-up, 20 patients (9.7%) developed stroke. VI value of LASEC in the patients with stroke was higher compared to patients without stroke (25.30 ± 3.61 vs. 8.65 ± 0.81, p < 0.001). On logistic regression analysis, LAT, qualitative LASEC, graded LASEC, VI value of LASEC and CHADS2 and CHA2DS2-Vasc score were independent predictors of stroke. Among them, the highest area under the curve of receiver operating characteristic (ROC) in predicting stroke was VI value of LASEC (p < 0.05). These results show that quantification of LASEC by VI value is the most favorable predictor of stroke in patients with NVAF, and calls for improving the utility of LASEC in predicting subsequent stroke events.

Microbubble-Mediated Sonothrombolysis Improves Outcome After Thrombotic Microembolism-Induced Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Microthrombi originating from disintegrated clots or formed in situ may account for the poor clinical improvement of acute ischemic stroke after recanalization therapy. We attempted to determine whether microbubble-mediated sonothrombolysis could dissolve platelet-rich and erythrocyte-rich microthrombi, thereby reducing their brain injury-causing potential. METHODS: Platelet- and erythrocyte-rich microthrombosis were induced by periadventitial application of 5% ferric chloride or thrombin to mesenteric microvessels in 75 Sprague-Dawley rats. Acute ischemic stroke was induced by intracarotid injection of platelet- or erythrocyte-rich microthrombi in another 50 rats. Rats were randomly divided into control (CON), ultrasound (US), ultrasound and microbubble (US+MB), recombinant tissue-type plasminogen activator (r-tPA), and US+MB+r-tPA groups. The post-treatment mesenteric microvessel recanalization rates, cerebral infarct volumes, and neurological scores were determined. RESULTS: The recanalization rates of platelet- and erythrocyte-rich microthrombi in mesenteric microvessels were higher (P<0.05), and the cerebral infarct volumes and neurological scores of rats with either microthrombi were lower in the US+MB group than in the CON group (P<0.01). The infarct volumes and neurological scores were greater in the r-tPA group than in the US+MB and US+MB+r-tPA groups after treatment of rats with platelet-rich microthrombi (P<0.05). In contrast, after treatment of rats with erythrocyte-rich microthrombi, the infarct volumes and neurological scores were similar in the r-tPA and US+MB groups, but smaller in the US+MB+r-tPA group (P<0.05). CONCLUSIONS: Microbubble-mediated sonothrombolysis improved the outcomes of microthrombi-induced acute ischemic stroke. Thus, this method may serve as an attractive adjunct to recanalization therapy for acute ischemic stroke.

Loss of CEACAM1, a Tumor-Associated Factor, Attenuates Post-infarction Cardiac Remodeling by Inhibiting Apoptosis.

Carcinoembryonic antigen-related cell adhesion molecule1 (CEACAM1) is a tumor-associated factor that is known to be involved in apoptosis, but the role of CEACAM1 in cardiovascular disease is unclear. We aims to investigate whether CEACAM1 influences cardiac remodeling in mice with myocardial infarction (MI) and hypoxia-induced cardiomyocyte injury. Both serum in patients and myocardial CEACAM1 levels in mice were significantly increased in response to MI, while levels were elevated in neonatal rat cardiomyocytes (NRCs) exposed to hypoxia. Eight weeks after MI, a lower mortality rate, improved cardiac function, and less cardiac remodeling in CEACAM1 knock-out (KO) mice than in their wild-type (WT) littermates were observed. Moreover, myocardial expression of mitochondrial Bax, cytosolic cytochrome C, and cleaved caspase-3 was significantly lower in CEACAM1 KO mice than in WT mice. In cultured NRCs exposed to hypoxia, recombinant human CEACAM1 (rhCEACAM1) reduced mitochondrial membrane potential, upregulated mitochondrial Bax, increased cytosolic cytochrome C and cleaved caspase-3, and consequently increased apoptosis. RhCEACAM1 also increased the levels of GRP78 and CHOP in NRCs with hypoxia. All of these effects were abolished by silencing CEACAM1. Our study indicates that CEACAM1 exacerbates hypoxic cardiomyocyte injury and post-infarction cardiac remodeling by enhancing cardiomyocyte mitochondrial dysfunction and endoplasmic reticulum stress-induced apoptosis.

[Temporal variation of serum interleukin-37 and its relation with C-reactive protein in patients with acute ST-segment elevation myocardial infarction].

OBJECTIVE: To investigate the temporal changes of serum interleukin-37 (IL-37) concentration following acute ST-segment elevation myocardial infarction (ASTEMI) and the relationship between IL-37 and C-reactive protein (CRP) in patients with ASTEMI. METHODS: This analysis was conducted in a cohort of 20 patients with an established diagnosis of ASTEMI and 26 patients admitted for chest pain but with normal findings in coronary angiography (control) between June 2012 and December 2013. Venous blood was collected at days 1, 3, 5, and 7 after myocardial infarction for measurement of serum IL-37 and CRP levels using enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with the control group, the patients in ASTEMI group showed a significant acute elevation of IL-37 level on day 1 following myocardial infarction; IL-37 level reached the peak on day 3 and began to decrease on day 5, followed by a significant decrease on day 7. The time course of post-infarction CRP changes was consistent with that of IL-37 variations and showed a positive correlation the latter (r=0.63, P<0.05). CONCLUSION: IL-37 may participate in the inflammatory responses in ASTEMI.

Effect of cardiac resynchronization therapy on patients with heart failure and narrow QRS complexes: a meta-analysis of five randomized controlled trials.

PURPOSE: Although cardiac resynchronization therapy (CRT) has been demonstrated extensively to benefit heart failure (HF) patients with wide QRS complexes, the effect of CRT in patients with narrow QRS complexes remains unclear. This meta-analysis aimed to determine whether HF patients with narrow QRS complexes may benefit from CRT. METHODS: A search of MEDLINE, EMBASE, and Cochrane databases was performed to identify randomized controlled trials (RCTs) that investigated the effect of CRT in HF patients with narrow QRS complexes (< 130 ms). Outcomes included all-cause mortality, heart failure-related death or hospitalization, 6-min walk distance, quality of life ejection fraction, end-systolic volume, and end-diastolic volume. RESULTS: A total of five RCTs involving 1246 HF patients with narrow QRS complexes were included. The frequency of all-cause mortality for patients receiving CRT versus the control group was 10 versus 7 % (relative risk [RR] 1.45, 95 % confidence interval [CI] 1.002 to 2.091, P = 0.049). CRT did not reduce heart failure-related mortality (RR 0.89; 95 % CI 0.52 to 1.54; P = 0.69) or hospitalization (RR 0.99, 95 % CI 0.79 to 1.23, P = 0.91). In addition, CRT did not improve average 6-min walk distance (weighted mean difference [WMD] 39.28 m, 95 % CI -71.04 to 149.61 m, P = 0.49), QOL scores (WMD 0.64 points, 95 % CI -2.15.10 to 3.43 points, P = 0.65), or ejection fraction (WMD 0.90 %, 95 % CI -0.71 to 2.51 %, P = 0.28). CONCLUSIONS: In HF patients with reduced left ventricular ejection fraction (≤ 35 %) and narrow QRS complexes (< 130 ms), CRT did not improve clinical or functional outcomes and may actually increase all-cause mortality.

Selective depletion of tumor neovasculature by microbubble destruction with appropriate ultrasound pressure.

Low-intensity ultrasound-microbubble (LIUS-MB) treatment is a promising antivascular therapy for tumors. We sought to determine whether LIUS-MB treatment with an appropriate ultrasound pressure could achieve substantial and persistent cessation of tumor perfusion without having significant effects on normal tissue. Further, we investigated the mechanisms underlying this treatment. Murine S-180 sarcomas, thigh muscles, and skin tissue from 60 tumor-bearing mice were subjected to sham therapy, an ultrasound application combined with microbubbles in four different ultrasound pressures (0.5, 1.5, 3.0, 5.0 MPa), or ultrasound at 5.0 MPa alone. Subsequently, contrast-enhanced ultrasonic imaging and histological studies were performed. Tumor microvessels, tumor cell necrosis, apoptosis, tumor growth, and survival were evaluated in 85 mice after treatment with the selected ultrasound pressure. We found that twenty-four hours after LIUS-MB treatment at 3.0 MPa, blood perfusion and microvessel density of the tumor had substantially decreased by 84 ± 8% and 84%, respectively (p < 0.01). Similar reductions were not observed in the muscle or skin. Additionally, an extreme reduction in the number of immature vessels was observed in the tumor (reduced by 90%, p < 0.01), while the decrease in mature vessels was not significant. Further, LIUS-MB treatment at 3.0 MPa promoted tumor cell necrosis and apoptosis, delayed tumor growth, and increased the survival rate of tumor-bearing mice (p < 0.01). These findings indicate that LIUS-MB treatment with an appropriate ultrasound pressure could selectively and persistently reduce tumor perfusion by depleting the neovasculature. Therefore, LIUS-MB treatment offers great promise for clinical applications in antivascular therapy for solid tumors.

Detection of high-risk atherosclerotic plaques with ultrasound molecular imaging of glycoprotein IIb/IIIa receptor on activated platelets.

OBJECTIVE: Ultrasound molecular imaging (UMI) of glycoprotein (GP) IIb/IIIa receptor on activated platelets offers a unique means of identifying high-risk atherosclerosis. We hypothesized that contrast-enhanced ultrasound with microbubbles (MBs) targeted to GP IIb/IIIa could be used to detect and quantify activated platelets on the surface of advanced plaques. METHODS AND RESULTS: A mouse model of advanced atherosclerosis was generated by maintaining apolipoprotein E-deficient (ApoE(-/-)) mice on a hypercholesterolemic diet (HCD). The three other experimental groups consisted of ApoE(-/-) and wild-type (C57BL/6) mice fed a normal chow diet and C57BL/6 mice on an HCD diet. Plaque formation was confirmed by histological and immunohistochemical methods using light, fluorescence, and electron microscopy. Mice were injected with a lipid MB-conjugated cyclic Arg-Gly-Asp peptide or nonspecific control peptide, and the abdominal aorta was examined by UMI. The accumulation of GP IIb/IIIa and activated platelets on the surface of atherosclerotic plaques was highest in the ApoE(-/-)+HCD group, followed by ApoE(-/-)+chow, C57BL/6+HCD, and C57BL/6+chow groups (P<0.05). Notably, GP IIb/IIIa expression was associated with the vulnerability index and necrotic center/fiber cap ratio (P<0.05), and contrast video intensity from adhered cyclic Arg-Gly-Asp-modified MBs (MB-cRGDs) was correlated with GP IIb/IIIa expression on the plaque surface (P<0.05). CONCLUSION: GP IIb/IIIa of activated platelets on the atherosclerotic endothelium is a biomarker for high-risk plaques that can be quantified by UMI using MB-cRGDs, providing a noninvasive means for detecting high-risk plaques and preventing acute cardiovascular events.

Impact of etiology on the outcomes in heart failure patients treated with cardiac resynchronization therapy: a meta-analysis.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been extensively demonstrated to benefit heart failure patients, but the role of underlying heart failure etiology in the outcomes was not consistently proven. This meta-analysis aimed to determine whether efficacy and effectiveness of CRT is affected by underlying heart failure etiology. METHODS AND RESULTS: Searches of MEDLINE, EMBASE and Cochrane databases were conducted to identify RCTs and observational studies that reported clinical and functional outcomes of CRT in ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) patients. Efficacy of CRT was assessed in 7 randomized controlled trials (RCTs) with 7072 patients and effectiveness of CRT was evaluated in 14 observational studies with 3463 patients In the pooled analysis of RCTs, we found that CRT decreased mortality or heart failure hospitalization by 29% in ICM patients (95% confidence interval [CI], 21% to 35%), and by 28% (95% CI, 18% to 37%) in NICM patients. No significant difference was observed between the 2 etiology groups (P = 0.55). In the pooled analysis of observational studies, however, we found that ICM patients had a 54% greater risk for mortality or HF hospitalization than NICM patients (relative risk: 1.54; 95% CI: 1.30-1.83; P<0.001). Both RCTs and observational studies demonstrated that NICM patients had greater echocardiographic improvements in the left ventricular ejection fraction and end-systolic volume, as compared with ICM patients (both P<0.001). CONCLUSION: CRT might reduce mortality or heart failure hospitalization in both ICM and NICM patients similarly. The improvement of the left ventricular function and remodeling is greater in NICM patients.

In vivo ultrasound molecular imaging of inflammatory thrombosis in arteries with cyclic Arg-Gly-Asp-modified microbubbles targeted to glycoprotein IIb/IIIa.

OBJECTIVE: Ultrasound molecular imaging has the potential to detect activated platelets, thus identifying atherosclerotic plaque instability before onset of serious clinical events. However, it has not been well defined in inflammatory arterial thrombosis. We hypothesized that microbubbles (MBs) target glycoprotein IIb/IIIa (GP IIb/IIIa) could achieve a noninvasive in vivo detection of inflammatory thrombosis in large arteries through contrast-enhanced ultrasound (CEU) imaging. MATERIALS AND METHODS: Lipid shell-based gas-filled MBs were modified covalently with a cyclic Arg-Gly-Asp (RGD) peptide (MB-cRGD) targeted to activated GP IIb/IIIa or a negative control peptide (MB-CON) via thiol-maleimide coupling. Adherence of MB-cRGD and MB-CON to GP IIb/IIIa was determined in vitro by using a parallel plate flow chamber at variable shear stress (0.5-8 dynes/cm2). Inflammatory platelet thrombosis was induced by periadvential application of arachidonic acid (AA) to one of the bilateral carotids of C57BL/6 mice (n = 20) and confirmed through intravital fluorescence microscopy. Attachment of MBs was determined in vivo with CEU imaging of bilateral carotids in the AA application mice with (n = 10) or without (n = 10) pretreatment of GP IIb/IIIa antagonist. The expression of integrin GP IIb/IIIa was assessed through immunohistochemistry. RESULTS: Microbubble-cRGD but not MB-CON had excellent affinity to GP IIb/IIIa under all shear stress conditions. Successful inflammatory platelet activation and thrombosis in AA application carotids were noted through intravital fluorescence microscopy. Contrast video intensity from adhered MB-cRGD in the thrombi was significantly higher than that from MB-CON (P < 0.05). Video intensity of MB-cRGD in the thrombi was suppressed significantly by preblocking with GP IIb/IIIa antagonist (P < 0.05) but not for MB-CON. Immunohistochemical finding demonstrates that expression of integrin GP IIb/IIIa in the thrombi was abundant; it was inhibited significantly through pretreatment with GP IIb/IIIa antagonist (P < 0.05). CONCLUSIONS: Cyclic RGD-modified MBs targeted to GP IIb/IIIa with CEU are capable of detecting inflammation-activated platelets and thrombosis in large arteries, thus providing a potential tool for identification of vulnerable atherosclerotic plaques.