Vulnerable Atherosclerosis Plaques Research Articles

Aiming at early-stage vulnerable plaques: A nanoplatform with dual-mode imaging and lipid-inflammation integrated regulation for atherosclerotic theranostics

The vulnerable plaques in atherosclerosis can cause severe outcome with great danger of acute cardiovascular events. Thus, timely diagnosis and treatment of vulnerable plaques in early stage can effectively benefit the clinical management of atherosclerosis. In this work, a targeting theranostic strategy on early-stage vulnerable plaques in atherosclerosis is realized by a LAID nanoplatform with X-CT and fluorescent dual-mode imaging and lipid-inflammation integrated regulation abilities. The iodinated contrast agents (ICA), phenylboronic acid modified astaxanthin and oxidized-dextran (oxDEX) jointly construct the nanoparticles loaded with the lipid-specific probe LFP. LAID indicates an active targeting to plaques along with the dual-responsive disassembly in oxidative stress and acidic microenvironment of atherosclerosis. The X-CT signals of ICA execute the location of early-stage plaques, while the LFP combines with lipid cores and realizes the recognition of vulnerable plaques. Meanwhile, the treatment based on astaxanthin is performed for restraining the progression of plaques. Transcriptome sequencing suggests that LAID can inhibit the lipid uptake and block NF-κB pathway, which synergistically demonstrates a lipid-inflammation integrated regulation to suppression the plaques growing. The in vivo investigations suggest that LAID delivers a favorable theranostics to the early-stage vulnerable plaques, which provides an impressive prospect for reducing the adverse prognosis of atherosclerosis.

Osteopontin targeted non-invasive nanoprobes with amplified surface plasmon resonance for photothermally enhanced multimodal precision imaging of vulnerable atherosclerotic plaques

Effective strategies for accurate differentiation of the vulnerable atherosclerosis (AS) plaques at molecular level for clinical diagnosis have yet been developed. Herein, a versatile SAmOCP nanoprobe, is constructed by sealing up the multinuclear gold self-assembled nanospheres by hollow mesoporous silicon shell and then decorating the surfaces with Chlorine e6 (Ce6)-conjugated osteopontin antibody (OPN Ab), followed by filling the internal cavity with perfluoropentane (PFP) for precise in vivo targeting and multi-modal imaging of the vulnerable AS plaques. SAmOCP nanoprobes actively recognize the foam cells and specifically target the vulnerable AS plaques in vivo. Relying on the exceptional photo-to-heat conversion properties resulting from enhanced localized surface plasmon resonance (LSPR) effects of Au self-assembled particles, the encapsulated liquid PFP could transform into abundant microbubbles when AS plaque-rich regions were overheated by 808-nm laser irradiation, enabling hyperthermia-enhanced microbubbles generation, thereby endowing nanoprobes with significantly enhanced ultrasonic imaging capacity. SAmOCP nanoprobes exhibit a triple-modality diagnostic efficacy of ultrasound/fluorescence/photothermal imaging for in vivo precise detection of vulnerable AS plaques at molecular level. Together, SAmOCP nanoprobes overcome the difficulty in identifying the vulnerable AS plaque for clinic practice, holding great promise for vulnerable AS diagnosis.

Sodium Danshensu stabilizes atherosclerotic vulnerable plaques by targeting IKKβ mediated inflammation in macrophages

BackgroundThe primary cause of acute cardiovascular events with high mortality is the rupture of atherosclerotic plaque followed by thrombosis. Sodium Danshensu (SDSS) has shown potential in inhibiting the inflammatory response in macrophages and preventing early plaque formation in atherosclerotic mice. However, the specific targets and detailed mechanism of action of SDSS are still unclear. ObjectiveThis study aims to investigate the efficacy and mechanism of SDSS in inhibiting inflammation in macrophages and stabilizing vulnerable plaques in atherosclerosis (AS). Materials and MethodsThe efficacy of SDSS in stabilizing vulnerable plaques was demonstrated using various techniques such as ultrasound, Oil Red O staining, HE staining, Masson staining, immunohistochemistry, and lipid analysis in ApoE-/- mice. Subsequently, IKKβ was identified as a potential target of SDSS through protein microarray, network pharmacology analysis, and molecular docking. Additionally, ELISA, RT-qPCR, Western blotting, and immunofluorescence were employed to measure the levels of inflammatory cytokines, IKKβ, and NF-κB pathway-related targets, thereby confirming the mechanism of SDSS in treating AS both in vivo and in vitro. Finally, the impact of SDSS was observed in the presence of an IKKβ-specific inhibitor. ResultsInitially, the administration of SDSS led to a decrease in the formation and area of aortic plaque, while also stabilizing vulnerable plaques in ApoE-/- mice. Furthermore, it was identified that IKKβ serves as the primary binding target of SDSS. Additionally, both in vivo and in vitro experiments demonstrated that SDSS effectively inhibits the NF-κB pathway by targeting IKKβ. Lastly, the combined use of the IKKβ-specific inhibitor IMD-0354 further enhanced the beneficial effects of SDSS. ConclusionsSDSS stabilized vulnerable plaques and suppressed inflammatory responses by inhibiting the NF-κB pathway through its targeting of IKKβ.

CD40-targeting magnetic nanoparticles for MRI/optical dual-modality molecular imaging of vulnerable atherosclerotic plaques

Background and aimsAcute coronary syndrome caused by vulnerable plaque rupture or erosion is a leading cause of death worldwide. CD40 has been reported to be highly expressed in atherosclerotic plaques and closely related to plaque stability. Therefore, CD40 is expected to be a potential target for the molecular imaging of vulnerable plaques in atherosclerosis. We aimed to design a CD40-targeted magnetic resonance imaging (MRI)/optical multimodal molecular imaging probe and explore its ability to detect and target vulnerable atherosclerotic plaques. MethodsCD40-Cy5.5 superparamagnetic iron oxide nanoparticles (CD40-Cy5.5-SPIONs), which comprise a CD40-targeting multimodal imaging contrast agent, were constructed by conjugating CD40 antibody and Cy5.5-N-hydroxysuccinimide ester with SPIONs. During this in vitro study, we observed the binding ability of CD40-Cy5.5-SPIONs with RAW 264.7 cells and mouse aortic vascular smooth muscle cells (MOVAS) after different treatments, using confocal fluorescence microscopy and Prussian blue staining. An in vivo study involving ApoE−/− mice fed a high-fat diet for 24–28 weeks was performed.24 h after intravenous injection of CD40-Cy5.5-SPIONs, fluorescence imaging and MRI were performed. ResultsCD40-Cy5.5-SPIONs bind specifically to tumor necrosis factor (TNF)-α-treated macrophages and smooth muscle cells. Fluorescence imaging results showed that, compared with the control group and the atherosclerosis group injected with non-specific bovine serum albumin (BSA)-Cy5.5-SPIONs, the atherosclerotic group injected with CD40-Cy5.5-SPIONs had a stronger fluorescence signal. T2-weighted images showed that the carotid arteries of atherosclerotic mice injected with CD40-Cy5.5-SPIONs had a significant substantial T2 contrast enhancement effect. ConclusionsCD40-Cy5.5-SPIONs could potentially serve as an effective MRI/optical probe for vulnerable atherosclerotic plaques during non-invasive detection.

Cerium fluoride nanoparticles as a theranostic material for optical imaging of vulnerable atherosclerosis plaques

AbstractAtherosclerosis (AS) is a chronic progressive vascular disease, which can bring on a threat against the health. The eruption of unstable arteriosclerosis plaques has been linked to heart attacks and strokes. The accumulation of foamy macrophages initiates and evolves atherosclerotic plaques, which can be a good target for identifying vulnerable plaques. CD36 and OPN overexpress in foamy macrophages surface, which have a preferable relation with plaque disruption. Furthermore, we choose Yb ions and Tm ions as doping ions and Ce fluoride as matrix of luminescent materials and prepare upconversion luminescent nanoparticles. With the modification of CD36 antibody and OPN antibody, this material can target macrophages in arteriosclerosis plaques. As‐prepared nanoparticles (CeF3:Yb,Tm@SiO2–CD36/OPN) can be excited by near‐infrared light with deep tissue penetration, while emitting strong blue light to image arteriosclerosis plaques. In brief, this study provides a new upconversion luminescent material for the identification and detection of vulnerable atherosclerosis plaques.

Targeted Therapy of Atherosclerosis Vulnerable Plaque by ROS-Scavenging Nanoparticles and MR/Fluorescence Dual-Modality Imaging Tracing.

Early diagnosis and treatment of atherosclerosis (AS) vulnerable plaque has important clinical significance for the prognosis of patients. In this work, the integrated diagnosis and treatment nanoparticles based on Gd-doped Prussian blue (GPB) were constructed for the fluorescence/MR dual-mode imaging and anti-ROS treatment of vulnerable AS plaques in vitro and in vivo. To fabricate the theranostic NPs, GPB was modified with water-soluble polymer polyethyleneimine (PEI), fluorescence molecule rhodamine (Rd), and targeted molecule dextran sulfate (DS) step by step via electrostatic adsorption to construct GPRD NPs. The fluorescence/MR imaging ability and various nano-enzymes activity of GPRD NPs were detected, and the biocompatibility and safety of GPRD were also evaluated. Subsequently, RAW264.7 cells and ApoE -/- model mice were used to evaluate the effect of GPRD NPs on the targeted dual-mode imaging and anti-ROS treatment of vulnerable plaque in vitro and in vivo. The experimental results showed that our fabricated GPRD NPs not only displayed excellent MR/fluorescence dual-modality imaging of vulnerable plaque in vivo but also effectively utilized the nano-enzyme activity of GPB to inhibit the AS progress by ROS scavenging and the following reduction of inflammation, apoptosis, and foam cells' formation, providing a new avenue for the diagnosis and treatment of AS vulnerable plaque. The fabricated multimodal imaging nanoparticles with ROS-scavenging ability provided a new avenue for the diagnosis and treatment of AS vulnerable plaques.

Advanced targeted nanomedicines for vulnerable atherosclerosis plaque imaging and their potential clinical implications.

Atherosclerosis plaques caused by cerebrovascular and coronary artery disease have been the leading cause of death and morbidity worldwide. Precise assessment of the degree of atherosclerotic plaque is critical for predicting the risk of atherosclerosis plaques and monitoring postinterventional outcomes. However, traditional imaging techniques to predict cardiocerebrovascular events mainly depend on quantifying the percentage reduction in luminal diameter, which would immensely underestimate non-stenotic high-risk plaque. Identifying the degree of atherosclerosis plaques still remains highly limited. vNanomedicine-based imaging techniques present unique advantages over conventional techniques due to the superior properties intrinsic to nanoscope, which possess enormous potential for characterization and detection of the features of atherosclerosis plaque vulnerability. Here, we review recent advancements in the development of targeted nanomedicine-based approaches and their applications to atherosclerosis plaque imaging and risk stratification. Finally, the challenges and opportunities regarding the future development and clinical translation of the targeted nanomedicine in related fields are discussed.

Status of biomarkers for the identification of stable or vulnerable plaques in atherosclerosis.

Atherosclerosis is a systemic inflammation of the arteries characterized by atherosclerotic plaque due to the accumulation of lipids, inflammatory cells, apoptotic cells, calcium and extracellular matrix (ECM) proteins. Stable plaques present a chronic inflammatory infiltration, whereas vulnerable plaques present an 'active' inflammation involved in the thinning of the fibrous cap that predisposes to plaque rupture. Several complex biological cellular processes lead plaques to evolve from stable to vulnerable predisposing them to rupture and thrombosis. In this review, we analyze some emerging circulating biomarkers related to inflammation, ECM and lipid infiltration, angiogenesis, metalloproteinases and microRNA (miRNA), as possible diagnostic and prognostic indicators of plaque vulnerability.

Acute coronary syndrome: Uncommon presentation of multiple endocrine neoplasia.

IntroductionMyocardial infarction is usually due to thrombotic occlusion of a coronary vessel caused by rupture of a vulnerable atherosclerosis plaque. There is also the acute myocardial infarction with no evidence of relevant stenosis of the coronary artery, known as myocardial infarction with non-obstructive coronary arteries (MINOCA) such as Takotsubo, myocarditis and catecholamine induced cardiomyopathy. Pheochromocytoma is one of the causes of MINOCA. This association is rare but it may delay diagnosis and must be known in order to provide the best chance at early detection.This work has been reported in the line with the SCARE criteria.Presentation of the caseWe report a case of a 49 year-old man, admitted to our department for a recurrence of myocardial infarction with angiographically normal coronary arteries. During his hospitalization the patient complained of intestinal haemorrhage. The abdominal Computed tomographic scan revealed bilateral adrenal mass. The diagnosis of pheochromocytoma was made and confirmed by a high level of normetanephirnes and metanephrines.DiscussionThe coexistence of multiple endocrine neoplasia type 2 and myocardial infarction appears to be a rare association rather than a coincidence.ConclusionIn this case we highlight the importance of thorough history taking and investigation for the determining the aetiology of MINOCA. As a reversible cause of myocardial dysfunction, catecholamine-induced cardiomyopathy can occur as a feature of multiple endocrine neoplasia. The prognosis depends greatly on early diagnosis and prompt medical and surgical treatment, which are unfortunately often delayed because of the challenging diagnosis in many cases.

Analysis of genes and underlying mechanisms involved in foam cells formation and atherosclerosis development.

BackgroundFoam cells (FCs) play crucial roles in the process of all stages of atherosclerosis. Smooth muscle cells (SMCs) and macrophages are the major sources of FCs. This study aimed to identify the common molecular mechanism in these two types of FCs.Methods GSE28829, GSE43292, GSE68021, and GSE54666 were included to identify the differentially expressed genes (DEGs) associated with FCs derived from SMCs and macrophages. Gene Ontology biological process (GO-BP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed by using the DAVID database. The co-regulated genes associated with the two origins of FCs were validated (GSE9874), and their expression in vulnerable atherosclerosis plaques (GSE120521 and GSE41571) was assessed.ResultsA total of 432 genes associated with FCs derived from SMCs (SMC-FCs) and 81 genes associated with FCs derived from macrophages (M-FCs) were identified, and they were mainly involved in lipid metabolism, inflammation, cell cycle/apoptosis. Furthermore, three co-regulated genes associated with FCs were identified: GLRX, RNF13, and ABCA1. These three common genes showed an increased tendency in unstable or ruptured plaques, although in some cases, no statistically significant difference was found.ConclusionsDEGs related to FCs derived from SMCs and macrophages have contributed to the understanding of the molecular mechanism underlying the formation of FCs and atherosclerosis. GLRX, RNF13, and ABCA1 might be potential targets for atherosclerosis treatment.

MicroRNA Let-7g and Atherosclerosis Plaque Stabilization

Vascular atherosclerotic vulnerable plaque rupture is the primary cause of acute myocardial infarctions and strokes. Thus, stabilization of vulnerable plaques is of important clinical endeavor to decrease the fatal risk of atherosclerosis. Inflammatory infiltration, apoptosis of endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), destruction of extracellular matrix (ECM) or collagen, and neovascularization all contribute to the formation and stability of plaque. Let-7g, one miRNA of let-7 family, is related to retardation of the progress of vulnerable atherosclerosis plaque. First of all, let-7g induced preservation on vascular diseases through regulating on the intracellular Ca2+- activated protein kinase C-oxLDL-LOX-1 pathway, which resulted in reduced leukocyte adhesion to and migration across endothelium. Over expression of let-7g negatively regulated apoptosis in the ECs by targeting lectin-like oxidized LDL receptor-1(LOX-1)/CASP3 expression, therefore made the fibrous cap of plaque integrated and thick, increased the density of vascular atherosclerotic plaque. In addition, let-7g might stabilize the atherosclerotic plaque through other aspects. In this review, we focus on current and potential importance of let-7g on the stabilization of atherosclerosis plaque which might lead to the future development of an alternative strategy of CAD.

Gold nanoparticles-based SPECT/CT imaging probe targeting for vulnerable atherosclerosis plaques.

In order to realize accurate localization and precise evaluation of vulnerability of atherosclerotic plaques via dual-modal imaging, gold nanoparticles (GNPs) were firstly caped with a thin amino-PEGs cover and then conjugated with the targeting molecular Annexin V and radionuclide Tc-99m simultaneously to form SPECT/CT imaging probe targeting apoptotic macrophages. The as-synthesized (99m)Tc-GNPs-Annexin V was with uniform size (30.2±2.9nm) and high labeling rate (98.9±0.5%) and stability. Targeting ability of Annexin V for apoptotic macrophages was kept and enhanced. For macrophages with 30% apoptosis, cellular uptakes of 3.52±0.35% for (99m)Tc-GNPs-Annexin V, 2.41±0.53% for (99m)Tc-GNPs and 1.68±0.36% for (99m)Tc-Annexin V were achieved after 2h incubation. ApoE knock out mice with high fat diet-induced atherosclerosis were scanned via (99m)Tc-GNPs-Annexin V SPECT/CT. With the introduction of targeting molecules, imaging probe was more efficient in accumulating in apoptotic macrophages. In practical evaluation, CT helps to restrict the lesions depiction more accurately, meanwhile, SPECT imaging intensity correlated with pathological changes tightly. In conclusion, Annexin V-modified hybrid gold nanoparticles were successfully synthesized, and this imaging system helped to better localize and diagnose those vulnerable AS plaques via specific targeting the apoptotic macrophages.

Ex Vivo Porcine Arterial and Chorioallantoic Membrane Acoustic Angiography Using Dual-Frequency Intravascular Ultrasound Probes

The presence of blood vessels within a developing atherosclerotic plaque has been found to be correlated with increased plaque vulnerability and ensuing cardiac events, however, detection of coronary intraplaque neovascularization poses a significant challenge in the clinic. We describe here a new in vivo intravascular ultrasound imaging method using a dual-frequency transducer to visualize contrast flow in microvessels with high specificity. This method uses a specialized transducer capable of exciting contrast agents at a low frequency (5.5 MHz) while detecting their nonlinear superhamonics at a much higher frequency (37 MHz). In vitro evaluation of the approach was performed in a microvascular phantom to produce 3-D renderings of simulated vessel patterns and to determine image quality metrics as a function of depth. Furthermore, we describe the ability of the system to detect microvessels both ex vivo using porcine arteries and in vivo using the chorioallantoic membrane of a developing chicken embryo with optical confirmation. Dual-frequency contrast-specific imaging was able to resolve vessels similar in size to those found in vulnerable atherosclerotic plaques at clinically relevant depths. The results of this study add to the support for further evaluation and translation of contrast-specific imaging in intravascular ultrasound for the detection of vulnerable plaques in atherosclerosis.

Beyond Cholesterol - New Cardiovascular Biomarkers.

Atherosclerosis (AS) is the primary pathological result of obesity. Vulnerable AS plaques cause fatal clinical end points such as myocardial infarction and stroke. To prevent this, improvements in early diagnosis and treatment are essential. Because vulnerable AS plaques are frequently nonstenotic, they are preclinically undetectable using conventional imaging. Levels of blood lipids, C-reactive protein, and interleukin-6 are increased, but are insufficient to indicate the process of critical perpetuation before the end points present. More specific biomarkers (e.g. troponin, copetin, natriuretic peptides, growth differentiation factor-15, or soluble ST2) indicate the acute coronary syndrome or cardiac insufficiency, but not a critical destabilization of AS lesions in coronary or carotid arteries. Thus, valuable time (months to years) that could be used to treat the patient is wasted. An improved management of this dilemma may involve better detection of variations in degrees of immune inflammation in plaques by using new biomarkers in blood and/or within the lesion (molecular imaging). Macrophage and T-cell polarization, and innate and adaptive immune responses (e.g. Toll-like receptors) are involved in this critical process. New biomarkers in these mechanisms include pentraxin 3, calprotectins S100A8/S100A9, myeloperoxidase, adiponectin, interleukins, and chemokines. These proteins may also be candidates for molecular imaging using nuclear (magnetic resonance) imaging tools. Nevertheless, the main challenge remains: which asymptomatic individual should be screened? At which time interval? Intense interdisciplinary research in laboratory medicine (biomarkers), nanomedicine (nanoparticle development), and radiology (molecular imaging) will hopefully address these questions.

Converting Molecular Vibration to Mechanical Wave for Bond-Selective Imaging of Deep Tissue

As an emerging label-free imaging modality with chemical selectivity and millimeter-depth resolvability, vibrational photoacoustic imaging provides a new avenue to map chemical content in biological tissue. It heralds the potential for detection of white matter loss and regeneration, assessment of breast tumor margin, and clinical diagnosis of vulnerable plaques in atherosclerosis. In this work, we provide an overview of the development of bond-selective photoacoustic imaging and various biomedical applications enabled by this new technology.

FOXO3A elicits vascular smooth muscle cell apoptosis through release of MMP-13 and subsequent degradation of the extracellular matrix

s / Atherosclerosis 241 (2015) e32ee71 e57 apolipoprotein B100 modification in MGmin-LDL.A computed structural model predicted that methylglyoxal modification of apolipoprotein B100 induces distortion, increasing exposure of the N-terminal proteoglycan binding domain on the surface of LDL. Conclusion: Methylglyoxal modification of LDL forms small, dense LDL with increased atherogenicity. This non-oxidative process may explain escalation of cardiovascular risk in diabetes and renal failure, and resistance of early stage atherosclerosis to antioxidant therapy. Quantitation of methylglyoxal-modified LDL may improvecardiovascular disease risk models and therapeutics to decrease methylglyoxal may improve preventive treatment of cardiovascular disease. EAS-0611. FOXO3A ELICITS VASCULAR SMOOTH MUSCLE CELL APOPTOSIS THROUGH RELEASE OF MMP-13 AND SUBSEQUENT DEGRADATION OF THE EXTRACELLULAR MATRIX A. Fellows, Z. Yang, M.R. Bennett, H. Yu. Department of Cardiovascular Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom Aims: Vulnerable atherosclerotic plaques are characterised by heightened vascular smooth muscle cell (VSMC) apoptosis and degradation of the extracellular matrix (ECM) within the fibrous cap. The ECM can be degraded by matrix metalloproteinase enzymes (MMPs), thereby promoting VSMC apoptosis. We have previously found that VSMCs in human atherosclerotic plaques show impaired inhibition of the pro-apoptotic transcription factor FOXO3a and we investigated the precise mechanisms underlying this VSMC apoptosis. Methods: We generated rat VSMCs that stably express an inducible mutant of FOXO3a (FOXO3aA3ER) which cannot be inhibited by Akt. We usedmicroarrays, qPCR andWestern blots to identify FOXO3a target genes, flow cytometry and MTT assay to determine cell death, and in situ fluorescence gelatin zymography to assay MMP activity. Results: FOXO3a activation induced profound cell death in FOXO3aA3ER cells (48.0±9.0% vs. 11.8±3.7% control, p<0.01). In addition to known pro-apoptotic genes such as BIM (6.24-fold), FOXO3a potently increased mRNA expression of MMP-13 (371-fold) and potentiated the expression and cleavage of MMP-13 protein, indicating greater release as well as activation. FOXO3a-induced MMP-13 secretion triggered significant enzymatic digestion of fluorescent gelatin surrounding VSMCs, and supplementation of gelatin provided substantial protection against FOXO3a-mediated apoptosis (19.3% vs. 68.0%). Finally, apoptosis of FOXO3aER cells was rescued by MMP-13-selective small molecule inhibitors, and to a greater extent than the broad-spectrum MMP inhibitor GM6001. Conclusions: FOXO3a induces VSMC apoptosis both directly and via MMP13-mediated degradation of the protective ECM.We predict that FOXO3a is a potent inducer of vulnerable plaques in atherosclerosis through this mechanism. EAS-0804. EFFECT OF ENGINEERED NANOPARTICLES ON PLATELET ACTIVATION AND THROMBUS FORMATION IN MAN J.B. Raftis , R. Duffin , A. Hunter , N. Joshi , A. Lucking , S. Alam, D.E. Newby , K. Donaldson , N.L. Mills . Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom; Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom Aims: Engineered nanoparticles, developed to facilitate imaging of atherosclerosis and as a drug delivery tool, share properties with combustion-derived particles in air pollution that have been associated with thrombosis and acute myocardial infarction. We hypothesize that engineered nanoparticles will exert similar pro-thrombotic effects in man. Methods: We assessed the effects of ultra-small superparamagnetic iron oxide nanoparticles (USPIO) nanoparticles on platelet activation, aggregation, and thrombus formation using flowcytometric techniques and the Badimon chamber (an ex vivo model of thrombosis). In a randomised, double-blind, cross-over study 12 healthy volunteers received saline control or USPIO (150 mg/mL & 300 mg/mL) added to whole blood in the extra-corporeal circuit of the Badimon chamber. In 8 patients with abdominal aortic aneurysms platelet activation and thrombus formation were measured both before and 1-hour after intravenous USPIO (4 mg/kg) bolus injection. Results: In healthy volunteers extra-corporeal infusion of USPIO at 300mg/mL increased thrombus area compared to saline control (16,916 ± 1,766 mm2, versus 11,678 ± 1,045 mm2; P1⁄40.001), but not at 150 mg/mL. In patients, intravenous bolus injection of USPIO increased thrombus formation compared to baseline (27,670 ± 709 mm2 versus 12,156 ± 1156 mm2; P1⁄40.006), and increased platelet p-selectin and CD36 expression (P Conclusions: We demonstrate that engineered nanoparticles cause platelet activation and have prothrombotic effects in the circulation of healthy persons and patients with vascular disease. The clinical consequences of these findings are unknown but warrant further investigation. Nutrition, nutraceuticals and cardiovascular disease in diabetes, myocardial infarction and chronic renal disease EAS-0083. FOOD SUPPLEMENTATION WITH RICE BRAN ENZYMATIC EXTRACT PREVENTS VASCULAR SENESCENCE AND ATHEROGENESIS IN APOE-/MICE C. Perez Ternero , C. Werner , J. Parrado , M. Alvarez de Sotomayor , M.D. Herrera , U. Laufs . Departamento de Farmacologia, Universidad de Sevilla, Sevilla, Spain; Klinik fur Innere Medizin III (Kardiologie Angiologie und Internistische Intensivmedizin), Universit€ atsklinikum des Saarlandes, Homburg, Germany; Departamento de Bioquimica y Biologia Molecular, Universidad de Sevilla, Sevilla, Spain We aimed to evaluate the effects of g-oryzanol-, phytosteroland tocolrich rice bran enzymatic extract (RBEE) on apoptosis and telomere shortening in aorta and spleen-derived mononuclear cells (MNC) in relation to macrophage infiltration and atherosclerotic plaque development in the ApoE-/model of high fat diet (HFD)-induced atherogenesis. Male ApoE-/mice were fed HFD or isocaloric HFD supplemented with 5% (w/w) RBEE for 30 weeks. C57BL6/J wild-type mice (WT) were kept as healthy controls under standard chow diet for the same period. Diet supplementation with RBEE improved serum lipid profile showing lower total cholesterol (744±63 vs 947±66 mg/dL) and triglycerides (97±16 vs 155±20 mg/dL) and higher HDL-cholesterol (69±8 vs 35±8 mg/ dL). Compared to WT, ApoE-/mice on HFD were characterized by significant telomere shortening in aorta (11±2%) and MNC (73±7%), which was reduced by co-treatment with RBEE (aorta: 40±7%; MNC: 105±10%). While telomerase activity and expression of TERT remained unchanged, expression of telomere repeat-binding factor 2 was increased in RBEE mice. In the aorta, RBEE treatment reduced expression of apoptosis markers (p16, p53 and bax/bcl2-ratio) and apoptosis of aortic endothelial cells (38±38% of ApoE-/HFD animals; hairpin oligonucleotide assay). In contrast, MNC of RBEE-fed mice exhibited enhanced apoptosis with increased expression of p53 and bax/bcl2. Importantly, plaque development in the aortic sinus was potently attenuated (7,737±836 vs 12,040±1,001 mm2) and macrophage infiltration was reduced by 52±5% by RBEE treatment. In conclusion, treatment of ApoE-/on high fat diet with rice bran enzymatic extract prevented atherogenesis involving mechanisms related to vascular apoptosis and senescence.

Detection of Vulnerable Atherosclerosis Plaques with a Dual-Modal Single-Photon-Emission Computed Tomography/Magnetic Resonance Imaging Probe Targeting Apoptotic Macrophages

Atherosclerosis (AS), especially the vulnerable AS plaque rupture-induced acute obstructive vascular disease, is a leading cause of death. Accordingly, there is a need for an effective method to draw accurate predictions about AS progression and plaque vulnerability. Herein we report on an approach to constructing a hybrid nanoparticle system using a single-photon-emission computed tomography (SPECT)/magnetic resonance imaging (MRI) multimodal probe, aiming for a comprehensive evaluation of AS progression by achieving high sensitivity along with high resolution. Ultrasmall superparamagnetic iron oxide (USPIO) was covered by aminated poly(ethylene glycol) (PEG) and carboxylated PEG simultaneously and then functionalized with diethylenetriaminepentacetate acid for (99m)Tc coordination and subsequently Annexin V for targeting apoptotic macrophages abundant in vulnerable plaques. The in vivo accumulations of imaging probe reflected by SPECT and MRI were consistent and accurate in highlighting lesions. Intense radioactive signals detected by SPECT facilitated focus recognization and quantification, while USPIO-based T2-weighted MRI improved the focal localization and volumetry of AS plaques. For subsequent ex vivo planar images, targeting effects were further confirmed by immunohistochemistry, including CD-68 and TUNEL staining; meanwhile, the degree of concentration was proven to be statistically correlated with the Oil Red O staining results. In conclusion, these results indicated that the Annexin V-modified hybrid nanoparticle system specifically targeted the vulnerable AS plaques containing apoptotic macrophages and could be of great value in the invasively accurate detection of vulnerable plaques.

Progress of Molecular Imaging in Vulnerable Atherosclerosis Plaque

Progress of Molecular Imaging in Vulnerable Atherosclerosis Plaque

Receptor-targeted iron oxide nanoparticles for molecular MR imaging of inflamed atherosclerotic plaques

In a number of literature reports iron oxide nanoparticles have been investigated for use in imaging atherosclerotic plaques and found to accumulate in plaques via uptake by macrophages, which are critical in the process of atheroma initiation, propagation, and rupture. However, the uptake of these agents is non-specific; thus the labeling efficiency for plaques in vivo is not ideal. We have developed targeted agents to improve the efficiency for labeling macrophage-laden plaques. These probes are based on iron oxide nanoparticles coated with dextran sulfate, a ligand of macrophage scavenger receptor type A (SR-A). We have sulfated dextran-coated iron oxide nanoparticles (DIO) with sulfur trioxide, thereby targeting our nanoparticle imaging agents to SR-A. The sulfated DIO (SDIO) remained mono-dispersed and had an average hydrodynamic diameter of 62 nm, an r 1 relaxivity of 18.1 mM −1 s −1, and an r 2 relaxivity of 95.8 mM −1 s −1 (37 °C, 1.4 T). Cell studies confirmed that these nanoparticles were nontoxic and specifically targeted to macrophages. In vivo MRI after intravenous injection of the contrast agent into an atherosclerotic mouse injury model showed substantial signal loss on the injured carotid at 4 and 24 h post-injection of SDIO. No discernable signal decrease was seen at the control carotid and only mild signal loss was observed for the injured carotid post-injection of non-sulfated DIO, indicating preferential uptake of the SDIO particles at the site of atherosclerotic plaque. These results indicate that SDIO can facilitate MRI detection and diagnosis of vulnerable plaques in atherosclerosis.

Synthesis and evaluation of a tri-tyrosine decorated dextran MR contrast agent for vulnerable plaque detection

This communication reports the synthesis, characterization and in vivo evaluation in mice of a new tri-tyrosine conjugated MR contrast agent, which may help to identify vulnerable plaques in atherosclerosis by targeting the lipid core.