Atherosclerotic plaque biomarkers: beyond the horizon of the vulnerable plaque

Association between Endodontic Infection, Its Treatment and Systemic Health: A Narrative Review

The ‘Focal Infection Era in Dentistry’ in the late 19th and early 20th century resulted in widespread implementation of tooth extraction and limited the progress of endodontics. The theory proposed that bacteria and toxins entrapped in dentinal tubules could disseminate systemically to remote body parts, resulting in many types of degenerative systemic diseases. This theory was eventually refuted due to anecdotal evidence. However, lately there has been increased interest in investigating whether endodontic disease could have an impact on general health. There are reviews that have previously been carried out on this subject, but as new data have emerged since then, this review aims to appraise the available literature investigating the dynamic associations between apical periodontitis, endodontic treatment, and systemic health. The available evidence regarding focal infection theory, bacteraemia and inflammatory markers was appraised. The review also collated the available research arguing the associations of apical periodontitis with cardiovascular diseases, diabetes mellitus, adverse pregnancy outcome and autoimmune disorders, along with the effect of statins and immunomodulators on apical periodontitis prevalence and endodontic treatment prognosis. There is emerging evidence that bacteraemia and low-grade systemic inflammation associated with apical periodontitis may negatively impact systemic health, e.g., development of cardiovascular diseases, adverse pregnancy outcomes, and diabetic metabolic dyscontrol. However, there is limited information supporting the effect of diabetes mellitus or autoimmune disorders on the prevalence and prognosis post endodontic treatment. Furthermore, convincing evidence supports that successful root canal treatment has a beneficial impact on systemic health by reducing the inflammatory burden, thereby dismissing the misconceptions of focal infection theory. Although compelling evidence regarding the association between apical periodontitis and systemic health is present, further high-quality research is required to support and establish the benefits of endodontic treatment on systemic health.

Significantly Altered Serum Levels of NAD, AGE, RAGE, CRP, and Elastin as Potential Biomarkers of Psoriasis and Aging—A Case-Control Study

Background: This study aims to investigate potential markers of psoriasis and aging, and to elucidate possible connections between these two processes. Methods: The serum samples of 60 psoriatic patients and 100 controls were analysed, and the levels of four selected parameters (AGEs, RAGE, NAD, and elastin) were determined using commercial ELISA kits. Serum C-reactive protein was assayed using an immune-nephelometry method. Findings: Among the patients, the levels of CRP, AGEs, and RAGE were all increased, while the levels of NAD were reduced when compared to the control group. A negative correlation between the levels of AGEs and NAD was found. A negative correlation between age and the NAD levels among the control group was observed, however among the patients the relationship was diminished. While there was no difference in the levels of native elastin between the patients and the controls, a positive correlation between the levels of native elastin and age and a negative correlation between the levels of native elastin and the severity of psoriasis were found. Conclusions: The results of our study support the notion of psoriasis and possibly other immune-mediated diseases accelerating the aging process through sustained systemic damage. The serum levels of CRP, NAD, AGEs, and RAGE appear to be promising potential biomarkers of psoriasis. The decrease in the serum levels of NAD is associated with (pro)inflammatory states. Our analysis indicates that the levels of native elastin might strongly reflect both the severity of psoriasis and the aging process.

The Circulating Biomarker Fractalkine and Platelet-Derived Growth Factor BB are Correlated with Carotid Plaque Vulnerability Assessed by Computed Tomography Angiography

OBJECTIVES

Although studies have demonstrated that inflammatory and lipid/ lipoproteins-related biomarkers, genetic mutations, and epigenetic mechanisms could be candidates for diagnosis and prognosis of ischemic stroke, there is still no consensus on how to identify vulnerable plaques based on circulating biomarkers.

MATERIALS AND METHODS

Histological and immunohistochemical staining were performed in the aorta sections of ApoE^-/^- and WT mice. Eighty-nine patients who underwent CTA were included in this study. The degree of carotid stenosis and the wall features of plaque components were quantitatively analyzed. And the serum concentration of FKN and PDGF-BB were measured.

RESULTS

(1) The type V vulnerable atherosclerotic plaques deposited on the aortas of ApoE^-/^- mice after feeding with western diet for 16 weeks. And the expression of CX3CR1 and PDGFR-β increased in the areas of atherosclerotic plaques, especially inside the fibrous cap of plaque. (2) Patients with symptomatic carotid stenosis showed larger LNRC, smaller calcified plaques and more plaque ulceration detected by CTA than asymptomatic stenosis patients. Plaque ulceration and size of LNRC were high risk factors for stroke while plaque calcification was less frequently associated with cerebrovascular ischemia. (3) The serum concentration of FKN was lower and of PDGF-BB was higher in the patients with carotid artery stenosis. Correlation analysis suggested that FKN and PDGF-BB correlated positively with carotid plaque calcification and LNRC respectively.

CONCLUSIONS

For prediction it is recommended to combine circulating biomarkers (FKN and PDGF-BB) and imaging biomarkersfor comprehensive diagnosis and risk stratification in carotid atherosclerotic stroke.

Synopsis of Biomarkers of Atheromatous Plaque Formation, Rupture and Thrombosis in the Diagnosis of Acute Coronary Syndromes

Acute coronary syndrome is the main cause of mortality and morbidity worldwide and early diagnosis is a challenge for clinicians. Though cardiac Troponin, the most commonly used biomarker, is the gold standard for myocardial necrosis, it is blind for ischemia without necrosis. Therefore, ideal biomarkers are essential in the care of patients presenting with symptoms suggestive of cardiac ischemia. The ideal biomarker or group of biomarkers of atheromatous plaque formation, rupture and thrombosis for timely and accurate diagnosis of acute coronary syndrome is a current need. Therefore, we discuss the existing understanding and future of biomarkers of atheromatous plaque formation, rupture and thrombosis of acute coronary syndrome in this review. Keywords were searched from Medline, ISI, IBSS and Google Scholar databases. Further, the authors conducted a manual search of other relevant journals and reference lists of primary articles. The development of high-sensitivity troponin assays facilitates earlier exclusion of acute coronary syndrome, contributing to a reduced length of stay at the emergency department, and earlier treatment resulting in better outcomes. Although researchers have investigated biomarkers of atheromatous plaque formation, rupture and thrombosis to help early diagnosis of cardiac ischemia, most of them necessitate validation from further analysis. Among these biomarkers, pregnancy-associated plasma protein-A, intercellular adhesion molecule-1, and endothelial cell-specific molecule- 1(endocan) have shown promising results in the early diagnosis of acute coronary syndrome but need further evaluation. However, the use of a combination of biomarkers representing varying pathophysiological mechanisms of cardiac ischemia will support risk assessment, diagnosis and prognosis in these patients and this is the way forward.

Nanomaterial-based aptasensors as an efficient substitute for cardiovascular disease diagnosis: Future of smart biosensors

As a major cause of deaths in developed countries, cardiovascular disease (CVD) has been a big burden for human health systems. Its early and rapid detection is crucial to efficiently apply appropriate on time therapy and to ultimately reduce the associated mortality rate. Aptamers, known as single-stranded DNA/RNA or oligonucleotides containing receptors and/or catalytic properties, have been widely employed in biodetection platforms due to their beneficial properties. Like antibodies, aptamers have served as artificial target receptors in affinity biosensors. Currently, advanced biosensors with improved sensitivity and specificity are fabricated by the synergistic combination of aptamers and diverse nanomaterials. Herein, we review the current development and applications of nanomaterial-based aptasensors for the recognition of CVD biomarkers with special emphasis on electrochemical and optical technologies. The performance of aptasensors has been assessed further in terms of key quality assurance metrics along with discussions on recent technologies developed for the amplification of signals with enhanced portability.

Enzyme-activated probes in optical imaging: a focus on atherosclerosis

Enzyme-activated probes enable complex biological processes to be studied in real-time. A wide range of enzymes are modulated in diseases, including cancer, inflammatory diseases and cardiovascular disease, and have the potential to act as vital diagnostic and prognostic biomarkers to monitor and report on disease progression. In this perspective article, we discuss suitable design characteristics of enzyme-activated fluorescent probes for ex vivo and in vivo optical imaging applications. With a particular focus on atherosclerosis imaging, we highlight recent approaches to report on the activity of cathepsins (K and B), matrix metalloproteinases (MMP-2 and MMP-9), thrombin, heme oxygenase-1 (HO-1) and myeloperoxidase (MPO).

Circulating Biomarkers Reflecting Destabilization Mechanisms of Coronary Artery Plaques: Are We Looking for the Impossible?

Despite significant strides to mitigate the complications of acute coronary syndrome (ACS), this clinical entity still represents a major global health burden. It has so far been well-established that most of the plaques leading to ACS are not a result of gradual narrowing of the vessel lumen, but rather a result of sudden disruption of vulnerable atherosclerotic plaques. As most of the developed imaging modalities for vulnerable plaque detection are invasive, multiple biomarkers were proposed to identify their presence. Owing to the pivotal role of lipids and inflammation in the pathophysiology of atherosclerosis, most of the biomarkers originated from one of those processes, whereas recent advancements in molecular sciences shed light on the use of microRNAs. Yet, at present there are no clinically implemented biomarkers or any other method for that matter that could non-invasively, yet reliably, diagnose the vulnerable plaque. Hence, in this review we summarized the available knowledge regarding the pathophysiology of plaque instability, the current evidence on potential biomarkers associated with plaque destabilization and finally, we discussed if search for biomarkers could one day bring us to non-invasive, cost-effective, yet valid way of diagnosing the vulnerable, rupture-prone coronary artery plaques.

CC Chemokine Receptor 5 Targeted Nanoparticles Imaging the Progression and Regression of Atherosclerosis Using Positron Emission Tomography/Computed Tomography

Chemokines and chemokine receptors play an important role in the initiation and progression of atherosclerosis by mediating the trafficking of inflammatory cells. Chemokine receptor 5 (CCR5) has major implications in promoting the development of plaques to advanced stage and related vulnerability. CCR5 antagonist has demonstrated the effective inhibition of atherosclerotic progression in mice, making it a potential biomarker for atherosclerosis management. To accurately determine CCR5 in vivo, we synthesized CCR5 targeted Comb nanoparticles through a modular design and construction strategy with control over the physiochemical properties and functionalization of CCR5 targeting peptide d-Ala-peptide T-amide (DAPTA-Comb). In vivo pharmacokinetic evaluation through 64Cu radiolabeling showed extended blood circulation of 64Cu-DAPTA-Combs conjugated with 10%, 25%, and 40% DAPTA. The different organ distribution profiles of the three nanoparticles demonstrated the effect of DAPTA on not only physicochemical properties but also targeting efficiency. In vivo positron emission tomography/computed tomography (PET/CT) imaging in an apolipoprotein E knockout mouse atherosclerosis model (ApoE-/-) showed that the three 64Cu-DAPTA-Combs could sensitively and specifically detect CCR5 along the progression of atherosclerotic lesions. In an ApoE-encoding adenoviral vector (AAV) induced plaque regression ApoE-/- mouse model, decreased monocyte recruitment, CD68+ macrophages, CCR5 expression, and plaque size were all associated with reduced PET signals, which not only further confirmed the targeting efficiency of 64Cu-DAPTA-Combs but also highlighted the potential of these targeted nanoparticles for atherosclerosis imaging. Moreover, the up-regulation of CCR5 and colocalization with CD68+ macrophages in the necrotic core of ex vivo human plaque specimens warrant further investigation for atherosclerosis prognosis.

Intracranial Atherosclerotic Stenoses: Pathophysiology, Epidemiology, Risk Factors and Current Therapy Options

Intracranial atherosclerotic stenoses (ICAS) are one of the most common causes of first and recurrent cerebrovascular ischaemic events worldwide, with highest prevalence in Asian, Hispanic and African populations. Clinical trials have improved the understanding of epidemiology, risk factors and imaging characteristics of patients with ICAS. Current therapeutic approaches concerning these patients include management of risk factors, best medical therapy, potentially endovascular and rarely surgical therapy. In our review, we elucidate the current epidemiology and evidence in evaluation of risk factors and therapeutic options for providing favourable outcome for patients with ICAS.

Molecular signatures of atherosclerotic plaques: An up-dated panel of protein related markers

Atherosclerosis remains the leading cause of ischemic syndromes such as myocardial infarction or brain stroke, mainly promoted by plaque rupture and subsequent arterial blockade. Identification of vulnerable or high-risk plaques constitutes a major challenge, being necessary to identify patients at risk of occlusive events in order to provide them with appropriate therapies. Clinical imaging tools have allowed the identification of certain structural indicators of prone-rupture plaques, including a necrotic lipidic core, intimal and adventitial inflammation, extracellular matrix dysregulation, and smooth muscle cell depletion and micro-calcification. Additionally, alternative approaches focused on identifying molecular biomarkers of atherosclerosis have also been applied. Among them, proteomics has provided numerous protein markers currently investigated in clinical practice. In this regard, it is quite uncertain that a single molecule can describe plaque rupture, due to the complexity of the process itself. Therefore, it should be more accurate to consider a set of markers to define plaques at risk. Herein, we propose a selection of 76 proteins, from classical inflammatory to recently related markers, all of them identified in at least two proteomic studies analyzing unstable atherosclerotic plaques. Such panel could be used as a prognostic signature of plaque instability.

Inhibition of Vascular Calcification

Objective- Vascular calcification is a major risk factor for rupture of atherosclerotic plaques. High expression of BMP2 (bone morphogenetic protein 2) in lesions suggests its importance in vascular calcification during atherosclerosis. Teniposide is a Topo II (DNA topoisomerase II) inhibitor and is used for cancer treatment. Previously, we reported that teniposide activated macrophage ABCA1 (ATP-binding cassette transporter A1) expression and free cholesterol efflux indicating Topo II inhibitors may demonstrate antiatherogenic properties. Herein, we investigated the effects of teniposide on the development of atherosclerosis and vascular calcification in apoE^-/- (apoE deficient) mice. Approach and Results- apoE^-/- mice were fed high-fat diet containing teniposide for 16 weeks, or prefed high-fat diet for 12 weeks followed by high-fat diet containing teniposide for 4 weeks. Atherosclerosis and vascular calcification were determined. Human aortic smooth muscle cells were used to determine the mechanisms for teniposide-inhibited vascular calcification. Teniposide reduced atherosclerotic lesions. It also substantially reduced vascular calcification without affecting bone structure. Mechanistically, teniposide reduced vascular calcification by inactivating BMP2/(pi-Smad1/5/8 [mothers against decapentaplegic homolog 1, 5, and 8])/RUNX2 (runt-related transcription factor 2) axis in a p53-dependent manner. Furthermore, activated miR-203-3p by teniposide functioned as a link between activated p53 expression and inhibited BMP2 expression in inhibition of calcification. Conclusions- Our study demonstrates that teniposide reduces vascular calcification by regulating p53-(miR-203-3p)-BMP2 signaling pathway, which contributes to the antiatherogenic properties of Topo II inhibitors.

Residential Exposure to PM2.5 and Ozone and Progression of Subclinical Atherosclerosis Among Women Transitioning Through Menopause: The Study of Women's Health Across the Nation

Objective: This article aims to examine the association between long-term ambient air pollution and progression of subclinical atherosclerosis with 2-year follow-up among midlife women from the Study of Women's Health Across the Nation (SWAN). Materials and Methods: Carotid duplex ultrasonography was performed in participants from a SWAN ancillary study carried out at the Pittsburgh and Chicago sites. Mean and maximum carotid intima-media thickness (CIMT) and plaque burden were assessed throughout the common, bulb, and internal carotid artery. The yearly mean exposure to PM2.5 (particulate matter) and ozone was generated based on monitors within 20 km of the participants' home. The effect of air pollutants during follow-up on progression of CIMT was estimated using linear mixed-effects models, and the effect on progression of plaque presence and plaque index, a measure of extent of plaque, was evaluated using logistic regression. Results: This study included 417 (257 White and 160 Black) women with a mean age of 51 years at baseline. A 1 μg/m3 higher yearly mean exposure to PM2.5 during follow-up was associated with a 4.28 (95% confidence interval [CI]: 0.02-8.54) μm/year increase in maximum CIMT, after adjusting for socioeconomic and traditional cardiovascular disease (CVD) risk factors. Exposure to PM2.5 contributed to a 30% (95% CI: 3%-65%) higher odds of plaque index progression adjusting for socioeconomic factors only. Conclusions: PM2.5 independently contributed to progression of subclinical atherosclerosis, among women transitioning through menopause, a time of increasing CVD risk. Yet no significant associations between ozone and subclinical atherosclerosis were observed.

Recent advances in designing nanomaterial based biointerfaces for electrochemical biosensing cardiovascular biomarkers

Early diagnosis of cardiovascular disease (CVD) is critically important for successful treatment and recovery of patients. At present, detection of CVD at early stages of its progression becomes a major issue for world health. The nanoscale electrochemical biosensors exhibit diverse outstanding properties, rendering them extremely suitable for the determination of CVD biomarkers at very low concentrations in biological fluids. The unique advantages offered by electrochemical biosensors in terms of sensitivity and stability imparted by nanostructuring the electrode surface together with high affinity and selectivity of bioreceptors have led to the development of new electrochemical biosensing strategies that have introduced as interesting alternatives to conventional methodologies for clinical diagnostics of CVD. This review provides an updated overview of selected examples during the period 2005-2018 involving electrochemical biosensing approaches and signal amplification strategies based on nanomaterials, which have been applied for determination of CVD biomarkers. The studied CVD biomarkers include AXL receptor tyrosine kinase, apolipoproteins, cholesterol, C-reactive protein (CRP), D-dimer, fibrinogen (Fib), glucose, insulin, interleukins, lipoproteins, myoglobin, N-terminal pro-B-type natriuretic peptide (BNP), tumor necrosis factor alpha (TNF-α) and troponins (Tns) on electrochemical transduction format. Identification of new specific CVD biomarkers, multiplex bioassay for the simultaneous determination of biomarkers, emergence of microfluidic biosensors, real-time analysis of biomarkers and point of care validation with high sensitivity and selectivity are the major challenges for future research.

Pathological Characteristics

Within the intracranial vasculature, atherosclerosis occurs in two distinctive patterns: (1) in Western populations who have severe extracranial and systemic atherosclerosis, the severity of intracranial involvement is consistently less than that within extracranial arteries; and (2) in Asians, Africans, and Hispanics, who often have isolated intracranial arterial disease that is found to be more often accompanied by brain infarction than comparable extracranial atherosclerotic disease. Compared to coronary and extracranial carotid atherosclerosis, intracranial atherosclerosis has distinct pathological characteristics compared to that of extracranial arteries. Intracranial atherosclerosis (ICAS) had been understudied due to the relative inaccessibility of cerebral artery specimens under current treatment strategies. Acquiring post-mortem cerebral vessel specimens for histology processing is the most direct method to analyze the pathological characteristics of ICAS, in order to analyze both lumen stenosis and plaque components contributing to brain infarctions. The developments in high resolution magnetic resonance imaging (HRMRI) make it feasible to assess human ICAS in vivo. It is nevertheless challenging to understand vessel wall changes within brain vasculature demonstrated on HRMRI, as well as to identify biomarkers for stroke risk stratification and treatment strategy modification. Knowledge about intracranial atherosclerosis remains limited due to lack of human arterial specimens, and the development of proper animal models of human cerebral atherosclerosis is necessary to explore the pathogenesis of intracranial atherosclerosis and to assess various strategies preventing or treating ICAS-related stroke.

Association of serum microRNA-21 levels with Visfatin, inflammation, and acute coronary syndromes

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression. It seems that microRNA-21 (miR-21) and Visfatin, a novel adipocytokine, play roles in inflammation and atherosclerosis. The aim of this study was to investigate the association of miR-21 with Visfatin, inflammation, atherosclerosis and acute coronary syndrome (ACS). Based on coronary angiography and electrocardiogram (ECG), 53 patients with ACS and 52 patients with stable CAD were enrolled in this study. We assayed serum miR-21, Visfatin, and routine chemistries using quantitative reverse transcriptase polymerase chain reaction (QRT-PCR), enzyme-linked immunosorbent assay (ELISA) and automated analyzer, respectively. We used a regression analysis to describe the relationship between the variables. Serum miR-21 level in 2^-ΔCt value was significantly higher in ACS patients (10.52 ± 1.01-fold) than the stable CAD patients (4.4 ± 0.79-fold) (F = 4.59, p < 0.001). In addition, serum Visfatin was significantly higher in ACS patients (17.5 ± 0.61 ng/ml) than the stable CAD patients (12.7 ± 0.49 ng/ml) (F = 2.62, p < 0.001). Furthermore, the serum miR-21 level correlated positively with serum Visfatin level (r = 0.26, p = 0.008), hs-CRP (r = 0.29, p = 0.003), age (r = 0.21, p = 0.034) and negatively with HDL-cholesterol (r = -0.28, p = 0.004). We concluded that the increased serum miR-21 and Visfatin may be involved in the pathogenesis of ACS through promoting inflammation or may result from inflammatory responses to ACS. Furthermore, the potential role of miR-21 and Visfatin in plaque instability and inflammation warrants further investigations.

Biomarkers to evaluate the effects of temperature and methanol on recombinant Pichia pastoris

Pichia pastoris is methylotrophic yeast used as an efficient expression system for heterologous protein production. In order to evaluate the effects of temperature (10 and 30 °C) and methanol (1 and 3% (v/v)) on genetically-modified Pichia pastoris, different biomarkers were evaluated: Heat stress (HSF-1 and Hsp70), oxidative stress (OGG1 and TBARS) and antioxidant (GLR). Three yeast cultures were performed: 3X = 3% methanol-10 °C, 4X = 3% methanol-30 °C, and 5X = 1% methanol-10°C. The expression level of HIF-1α, HSF-1, HSP-70 and HSP-90 biomarkers were measured by Western blot and in situ detection was performed by immunocytochemistry. Ours results show that at 3% methanol −30 °C there is an increase of mitochondrial OGG1 (mtOGG1), Glutathione Reductase (GLR) and TBARS. In addition, there was a cytosolic expression of HSF-1 and HSP-70, which indicates a deprotection against nucleolar fragmentation (apoptosis). On the other hand, at 3% methanol −10 °C and 1% and at methanol −10 °C conditions there was nuclear expression of OGG1, lower levels of TBARS and lower expression of GLR, cytosolic expression of HSF-1 and nuclear expression HSP-70. In conclusion, our results suggest that 3% methanol-30 °C is a condition that induces a strong oxidative stress and risk factors of apoptosis in modified-genetically P. pastoris.

GFP-SCFV: expression and possible applications as a tool for experimental investigations of atherosclerosis

Experimental studies on atherosclerosis are crucial for investigating its pathophysiology, defining new therapeutic targets, and developing new drugs and diagnostic tools. Thus, many imaging markers have been developed and introduced in experimental studies. The main advantage of these new tools is that they allow the noninvasive diagnosis of atherosclerotic vascular disease. Here, we describe the cloning, expression, purification, and stabilization of a chimeric protein specifically designed to probe cells and tissues for the presence of LDL(-), a relevant marker of atherosclerosis. The DNA sequence that encodes the anti-LDL(-) scFv, previously obtained from a hybridoma secreting an anti-LDL(-) monoclonal antibody, was inserted into the bacterial vector pET-28a(+) in tandem with a DNA sequence encoding GFP. The recombinant protein was expressed in high yields in E. coli as inclusion bodies. The applicability of GFP-scFv was assessed by ELISA, which determined its affinity for LDL(-) and confocal microscopy, that showed macrophage uptake of the protein along with LDL(-). In conclusion, our data suggest that the anti-LDL(-) GFP-scFv chimeric protein could be useful in studies on atherogenesis as well as for developing diagnostic tools for atherosclerosis.

Rhodamine-Loaded Intercellular Adhesion Molecule–1-targeted Microbubbles for Dual-Modality Imaging Under Controlled Shear Stresses

Background—

The ability to image incipient atherosclerosis is based on the early events taking place at the endothelial level. We hypothesized that the expression of intercellular adhesion molecule-1 even in vessels with high flow rates can be imaged at the molecular level using 2 complementary imaging techniques: 2-photon laser scanning microscopy and contrast-enhanced ultrasound.

Methods and Results—

Using 2-photon laser scanning microscopy and contrast-enhanced ultrasound, intercellular adhesion molecule-1–targeted and rhodamine-loaded microbubbles were shown to be specifically bound to tumor necrosis factor-α–stimulated human umbilical vein endothelial cells and murine carotid arteries (44 wild-type mice) at shear stresses ranging from 1.25 to 120 dyn/cm 2 . Intercellular adhesion molecule-1–targeted and rhodamine-loaded microbubbles bound 8× more efficient ( P =0.016) to stimulated human umbilical vein endothelial cells than to unstimulated cells and 14× more than nontargeted microbubbles ( P =0.016). In excised carotids, binding efficiency did not decrease significantly when increasing the flow rate from 0.25 to 0.6 mL/min. Higher flow rates (0.8 and 1 mL/min) showed significantly reduced microbubbles retention, by 38% ( P =0.03) and 55% ( P =0.03), respectively. Ex vivo results were translatable in vivo, confirming that intercellular adhesion molecule-1–targeted and rhodamine-loaded microbubbles are able to bind specifically to the inflamed carotid artery endothelia under physiological flow conditions and to be noninvasively detected using contrast-enhanced ultrasound.

Conclusions—

Our data provide groundwork for the implementation of molecular ultrasound imaging in vessels with high shear stress and flow rates, as well as for the future development of image-guided therapeutic interventions, and multiphoton microscopy as the appropriate method of validation.

Secreted proteins from carotid endarterectomy: an untargeted approach to disclose molecular clues of plaque progression

BACKGROUND

Atherosclerosis is the main cause of morbidity and mortality in Western countries and carotid plaque rupture is associated to acute events and responsible of 15-20% of all ischemic strokes. Several proteomics approaches have been up to now used to elucidate the molecular mechanisms involved in plaque formation as well as to identify markers of pathology severity for early diagnosis or target of therapy. The aim of this study was to characterize the plaque secretome. The advantage of this approach is that secretome mimics the in vivo condition and implies a reduced complexity compared to the whole tissue proteomics allowing the detection of under-represented potential biomarkers.

METHODS

Secretomes from carotid endarterectomy specimens of 14 patients were analyzed by a liquid chromatography approach coupled with label free mass spectrometry. Differential expression of proteins released from plaques and from their downstream distal side segments were evaluated in each specimen. Results were validated by Western blot analysis and ELISA assays. Histology and immunohistochemistry were performed to characterize plaques and to localise the molecular factors highlighted by proteomics.

RESULTS

A total of 463 proteins were identified and 31 proteins resulted differentially secreted from plaques and corresponding downstream segments. A clear-cut distinction in the distribution of cellular- and extracellular-derived proteins, evidently related to the higher cellularity of distal side segments, was observed along the longitudinal axis of carotid endarterectomy samples. The expressions of thrombospondin-1, vitamin D binding protein, and vinculin, as examples of extracellular and intracellular proteins, were immunohistologically compared between adjacent segments and validated by antibody assays. ELISA assays of plasma samples from 34 patients and 10 healthy volunteers confirmed a significantly higher concentration of thrombospondin-1 and vitamin D binding protein in atherosclerotic subjects.

CONCLUSIONS

Taking advantage of the optimized workflow, a detailed protein profile related to carotid plaque secretome has been produced which may assist and improve biomarker discovery of molecular factors in blood. Distinctive signatures of proteins secreted by adjacent segments of carotid plaques were evidenced and they may help discriminating markers of plaque complication from those of plaque growth.

A fish a day, keeps the cardiologist away! - A review of the effect of omega-3 fatty acids in the cardiovascular system

Dyslipidemia and its consequences are emerging as epidemics with deleterious consequences on cardiovascular (CV) health. The beneficial effects of omega-3-fatty acids on cardiac and extra cardiac organs have been extensively studied in the last two decades, and continue to show great promise in the primary and secondary prevention of cardiovascular diseases (CVDs). Omega-3-fatty acid supplementation has been proven to have beneficial action on lipid profile, cytokine cascade, oxidant-anti-oxidant balance, parasympathetic and sympathetic tone and nitric oxide synthesis. This review summarizes the current knowledge on the basis of its cardiac and non-cardiac benefits, present results from clinical trials and the recommendations for its use in cardiac diseases and dyslipidemias.

Angiographic and clinical characteristics of type 1 versus type 2 perioperative myocardial infarction

OBJECTIVES

The aim of this study was to analyze clinical and angiographic differences between the two etiologic subtypes of perioperative myocardial infarction (PMI).

BACKGROUND

PMI is believed to occur by either reduced coronary blood flow attributable to acute plaque rupture and thrombosis (type 1) or primary increase in oxygen demand in the setting of stable but stenotic lesions (type 2). Incidence and mortality rates of PMI are substantial, but angiographic and clinical features are not well characterized.

METHODS

Consecutive patients with PMI were classified as "type 1" or "type 2" based on angiographic characteristics of culprit lesions. Clinical and angiographic characteristics of each subtype were compared using statistical analyses.

RESULTS

Of the 54 patients analyzed, 32 (59%) cases had type 1 PMI, whereas 22 others (41%) had type 2 PMI. Compared with type 2 patients, those with type 1 PMI more often had ECG (electrocardiogram) ST elevation (53% versus 23%, P = 0.026), greater peak troponin (15.3 ng/dl versus 5.3 ng/dl, P = 0.035), higher preoperative mean blood pressure (103 mm Hg versus 93 mm Hg, P = 0.009), greater decrease in mean intraoperative blood pressure (-36 mm Hg versus -26 mm Hg, P = 0.015). Type I patients trended toward greater in-hospital mortality (16% versus 5%, P = 0.38) and length of hospitalization (13.5 days versus 9.0 days, P = 0.13).

CONCLUSIONS

These results demonstrate that PMI not only results from "demand ischemia" but also that in nearly 60% of cases the cause is acute plaque rupture. Patients with PMI attributable to plaque rupture suffer more intraoperative hypotension, greater transmural ischemia, larger infarct size, and trended toward worse outcome.

Atherosclerosis: from biology to pharmacological treatment

A recent explosion in the amount of cardiovascular risk has swept across the globe. Primary prevention is the preferred method to lower cardiovascular risk. Lowering the prevalence of obesity is the most urgent matter, and is pleiotropic since it affects blood pressure, lipid profiles, glucose metabolism, inflammation, and atherothrombotic disease progression. Given the current obstacles, success of primary prevention remains uncertain. At the same time, the consequences of delay and inaction will inevitably be disastrous, and the sense of urgency mounts. Pathological and epidemiological data confirm that atherosclerosis begins in early childhood, and advances seamlessly and inexorably throughout life. Risk factors in childhood are similar to those in adults, and track between stages of life. When indicated, aggressive treatment should begin at the earliest indication, and be continued for many years. For those patients at intermediate risk according to global risk scores, C-reactive protein, coronary artery calcium, and carotid intima-media thickness are available for further stratification. Using statins for primary prevention is recommended by guidelines, is prevalent, but remains under prescribed. Statin drugs are unrivaled, evidence-based, major weapons to lower cardiovascular risk. Even when low density lipoprotein cholesterol targets are attained, over half of patients continue to have disease progression and clinical events. Though clinical evidence is incomplete, altering or raising the blood high density lipoprotein cholesterol level continues to be pursued. The aim of this review is to point out the attention of key aspects of vulnerable plaques regarding their pathogenesis and treatment.