Circulating levels and characterization of microparticles in patients with different degrees of glucose tolerance

Background

Microparticles (MPs) are vesicular structures shed from endothelial or circulating blood cells, after activation or apoptosis, and can be considered markers of vascular damage. We aimed to determine the levels of circulating MPs, their content of miRNA-126-3p and 5p, and their relationship with early endothelial activation/damage, in patients with different degree of glucose tolerance.

Methods

CD62E⁺, CD62P⁺, CD142⁺, CD45⁺ circulating MPs, their apoptotic (AnnexinV⁺) fractions, and miRNA-126 expression were determined in 39 prediabetic (PreDM), 68 type 2 diabetic (T2DM), and 53 control (NGT) subjects, along with main anthropometric and biochemical measurements. MPs were analysed by flow cytometry. miRNA-126 was measured by quantitative real-time PCR. Plasma antioxidant capacity was determined by electronic spin resonance; ICAM-1, and VCAM-1 by ELISA.

Results

Activated endothelial cell-derived MPs (CD62E⁺) were significantly increased in PreDM and T2DM in comparison to NGT (p < 0.0001). AnnexinV⁺/CD62E⁺ MPs and Annexin V⁺ MPs were significantly increased in T2DM compared to PreDM and NGT (p < 0.001); other MPs were not significantly different among groups. Plasma antioxidant capacity was significantly decreased in PreDM and T2DM compared to NGT (p = 0.001); VCAM-1 significantly increased in PreDM and T2DM in comparison to NGT (p = 0.001). miR-126-3p expression, but not miR-126-5p, in MPs, decreased significantly and progressively from NGT, to PreDM, and T2DM (p < 0.001). In PreDM and T2DM, CD62E⁺ MPs level was significantly and negatively associated with plasma glucose (p = 0.004).

Conclusion

We show for the first time that circulating CD62E⁺ MPs level and miR-126-3p content in MPs are abnormal in subjects with pre-diabetes; the content of miR-126-3p correlates with markers of endothelial inflammation, such as VCAM-1, plasma antioxidant capacity, and microparticles, well-accepted markers of endothelial dysfunction.

Angiogenic, inflammatory and immunologic markers in predicting response to sunitinib in metastatic renal cell carcinoma

The objective of this prospective study was to identify baseline angiogenic and inflammatory markers in serum as well as the baseline levels of immune cells in whole blood to predict progression‐free survival in patients with metastatic renal cell carcinoma treated with sunitinib. Blood samples were collected at baseline in all 90 patients to analyze serum angiogenic and inflammatory markers together with peripheral blood immunological marker. The association between each marker and sunitinib efficacy was analyzed. Univariate and multivariate Cox proportional model analyses were used to assess the correlation between those markers with survival. Baseline levels of interleukin‐6, interleukin‐8, high sensitivity C‐reactive protein and myeloid‐derived suppressor cells were significantly higher in patients who progressed when compared with those with clinical benefit. Analysis by the Cox regression model showed that baseline interleukin‐8, high sensitivity C‐reactive protein and percentage of T helper type 1 cells were significantly associated with progression‐free survival in univariate analysis. Furthermore, in multivariate analysis, those three markers were independent indices to predict progression‐free survival. In conclusion, angiogenic (interleukin‐8), inflammatory (interleukin‐6, high sensitivity C‐reactive) and immunologic (myeloid‐derived suppressor cells, percentage of T helper type 1 cells) markers at baseline would predict the response to sunitinib therapy and/or disease progression in patients with metastatic renal cell carcinoma.

Improvement of myocardial infarction risk prediction via inflammation-associated metabolite biomarkers

OBJECTIVE

The comprehensive assaying of low-molecular-weight compounds, for example, metabolomics, provides a unique tool to uncover novel biomarkers and understand pathways underlying myocardial infarction (MI). We used a targeted metabolomics approach to identify biomarkers for MI and evaluate their involvement in the pathogenesis of MI.

METHODS AND RESULTS

Using three independent, prospective cohorts (KORA S4, KORA S2 and AGES-REFINE), totalling 2257 participants without a history of MI at baseline, we identified metabolites associated with incident MI (266 cases). We also investigated the association between the metabolites and high-sensitivity C reactive protein (hsCRP) to understand the relation between these metabolites and systemic inflammation. Out of 140 metabolites, 16 were nominally associated (p<0.05) with incident MI in KORA S4. Three metabolites, arginine and two lysophosphatidylcholines (LPC 17:0 and LPC 18:2), were selected as biomarkers via a backward stepwise selection procedure in the KORA S4 and were significant (p<0.0003) in a meta-analysis comprising all three studies including KORA S2 and AGES-REFINE. Furthermore, these three metabolites increased the predictive value of the Framingham risk score, increasing the area under the receiver operating characteristic score in KORA S4 (from 0.70 to 0.78, p=0.001) and AGES-REFINE study (from 0.70 to 0.76, p=0.02), but was not observed in KORA S2. The metabolite biomarkers attenuated the association between hsCRP and MI, indicating a potential link to systemic inflammatory processes.

CONCLUSIONS

We identified three metabolite biomarkers, which in combination increase the predictive value of the Framingham risk score. The attenuation of the hsCRP-MI association by these three metabolites indicates a potential link to systemic inflammation.

Transcoronary Concentration Gradient of microRNA-133a and Outcome in Patients With Coronary Artery Disease

Circulating levels of microRNA (miR)-133a are increased in patients with coronary atherosclerotic disease (CAD). Whether the cardiac release of this miR provides any prognostic information in patients with CAD is currently unknown. We aimed to investigate if changes in concentration of miR-133a trough the coronary circulation may be associated with patients' cardiovascular outcome. We enrolled 111 patients (82 with stable CAD and 29 with acute coronary syndromes [ACS]) who underwent coronary angiography. Circulating levels of miR-133a were measured across the transcoronary circulation. Major adverse cardiac events (MACE: death, nonfatal myocardial infarction, and need for revascularization) were recorded through a median follow-up of 32 months. An increased transcoronary concentration gradient of miR133a showed a significant association with overall rate of MACE at follow-up in patients with both stable CAD and ACS (p = 0.011 and p = 0.002, respectively). At the single end point-analysis, increased transcoronary concentration gradients of miR133a were significantly associated with increased rate of death in patients with ACS (p = 0.017) and with increased incidence of new revascularization because of in-stent restenosis in patients with stable CAD (p = 0.026). Kaplan-Meier curves showed a significantly worse event-free survival in patients with greater transcoronary gradients of miR133a (p = 0.026 in stable CAD group and p = 0.007 for ACS group). Nevertheless, these findings lost their significance after adjustment for common cardiovascular risk factor and high-sensitivity troponin-T. In conclusions, the release of miR133a, as measured by its transcoronary concentration gradient, is associated with a higher incidence of MACE in patients with CAD, but it does not add significant prognostic information compared with traditional prognostic biomarkers, therefore limiting its potential usefulness in the clinical practice. Nevertheless, the differential modulation of miR-133a release in the coronary circulation may reflect pathophysiological mechanism involved in CAD progression and complications and suggest a novel potential role for this miR in the development of in-stent restenosis.

Epigenetic Biomarkers and Cardiovascular Disease: Circulating MicroRNAs

MicroRNAs (miRNAs) are a class of small noncoding RNA (20-25 nucleotides) involved in gene regulation. In recent years, miRNAs have emerged as a key epigenetic mechanism in the development and physiology of the cardiovascular system. These molecular species regulate basic functions in virtually all cell types, and are therefore directly associated with the pathophysiology of a large number of cardiovascular diseases. Since their relatively recent discovery in extracellular fluids, miRNAs have been studied as potential biomarkers of disease. A wide array of studies have proposed miRNAs as circulating biomarkers of different cardiovascular pathologies (eg, myocardial infarction, coronary heart disease, and heart failure, among others), which may have superior physicochemical and biochemical properties than the conventional protein indicators currently used in clinical practice. In the present review, we provide a brief introduction to the field of miRNAs, paying special attention to their potential clinical application. This includes their possible role as new diagnostic or prognostic biomarkers in cardiovascular disease.

Novel Risk Markers and Risk Assessments for Cardiovascular Disease

The use of risk markers has transformed cardiovascular medicine, exemplified by the routine assessment of troponin, for both diagnosis and assessment of prognosis in patients with chest pain. Clinical risk factors form the basis for risk assessment of cardiovascular disease and the addition of biochemical, cellular, and imaging parameters offers further refinement. Identifying novel risk factors may allow greater risk stratification and a steady, but gradual progression toward precision medicine. Indeed, the generation of data in this area of research is explosive and when combined with new technologies and techniques provides the potential for more refined, targeted approaches to cardiovascular medicine. Although discussing the most recent developments in this field, this review article aims to strike a balance between novelty and validity by focusing on recent large sample-size studies that have been validated in a separate cohort in most cases. Risk markers related to atherosclerosis, thrombosis, inflammation, cardiac injury, and fibrosis are introduced in the context of their pathophysiology. Rapidly developing new areas, such as assessment of micro-RNA, are also explored. Subsequently the prognostic ability of these risk markers in coronary artery disease, heart failure, and atrial fibrillation is discussed in detail.

Assessment of the Procoagulant Activity of Microparticles and the Protein Z System in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery

To understand the coagulation changes after off-pump coronary artery bypass (OPCAB) surgery, we evaluated the procoagulant activity of microparticles (MPs) and microparticles exposing tissue factor (MPs-TF), together with the levels of total tissue factor (TF), protein Z (PZ), protein Z-dependent protease inhibitor (ZPI), and factor X (FX) before (first day) and 1 week after surgery (seventh day) in plasma samples from 30 patients. Twenty healthy controls were also included. Compared to the controls, patients scheduled for surgery had significantly higher MPs-TF procoagulant activity and lower TF levels ( P = .0006, P = .02, respectively). In the whole cohort, median procoagulant activity of MPs-TF and median levels of TF and ZPI were significantly lower ( P = .02, P = .0003, and P = .004, respectively), while median levels of PZ and FX were significantly higher ( P = .02 and P = .002, respectively) on the seventh day compared to the first day. Our results suggest that OPCAB surgery has a significant effect on the procoagulant activity of MPs-TF and the PZ system.

The immunology of atherosclerosis

Cardiovascular disease is the leading cause of death worldwide, both in the general population and among patients with chronic kidney disease (CKD). In most cases, the underlying cause of the cardiovascular event is atherosclerosis - a chronic inflammatory disease. CKD accelerates atherosclerosis via augmentation of inflammation, perturbation of lipid metabolism, and other mechanisms. In the artery wall, subendothelial retention of plasma lipoproteins triggers monocyte-derived macrophages and T helper type 1 (T_H1) cells to form atherosclerotic plaques. Inflammation is initiated by innate immune reactions to modified lipoproteins and is perpetuated by T_H1 cells that react to autoantigens from the apolipoprotein B100 protein of LDL. Other T cells are also active in atherosclerotic lesions; regulatory T cells inhibit pathological inflammation, whereas T_H17 cells can promote plaque fibrosis. The slow build-up of atherosclerotic plaques is asymptomatic, but plaque rupture or endothelial erosion can induce thrombus formation, leading to myocardial infarction or ischaemic stroke. Targeting risk factors for atherosclerosis has reduced mortality, but a need exists for novel therapies to stabilize plaques and to treat arterial inflammation. Patients with CKD would likely benefit from such preventive measures.

Translating the microRNA signature of microvesicles derived from human coronary artery smooth muscle cells in patients with familial hypercholesterolemia and coronary artery disease

AIMS

To analyze the impact of atherogenic lipoproteins on the miRNA signature of microvesicles derived from human coronary artery smooth muscle cells (CASMC) and to translate these results to familial hypercholesterolemia (FH) and coronary artery disease (CAD) patients.

METHODS

Conditioned media was collected after exposure of CASMC to atherogenic lipoproteins. Plasma samples were collected from two independent populations of diagnosed FH patients and matched normocholesterolemic controls (Study population 1, N=50; Study population 2, N=24) and a population of patients with suspected CAD (Study population 3, N=50). Extracellular vesicles were isolated and characterized using standard techniques. A panel of 30 miRNAs related to vascular smooth muscle cell (VSMC) (patho-)physiology was analyzed using RT-qPCR.

RESULTS

Atherogenic lipoproteins significantly reduced levels of miR-15b-5p, -24-3p, -29b-3p, -130a-3p, -143-3p, -146a-3p, -222-3p, -663a levels (P<0.050) in microvesicles (0.1μm-1μm in diameter) released by CASMC. Two of these miRNAs, miR-24-3p and miR-130a-3p, were reduced in circulating microvesicles from FH patients compared with normocholesterolemic controls in a pilot study (Study population 1) and in different validation studies (Study populations 1 and 2) (P<0.050). Supporting these results, plasma levels of miR-24-3p and miR-130a-3p were also downregulated in FH patients compared to controls (P<0.050). In addition, plasma levels of miR-130a-3p were inversely associated with coronary atherosclerosis in a cohort of suspected CAD patients (Study population 3) (P<0.050).

CONCLUSIONS

Exposure to atherogenic lipoproteins modifies the miRNA profile of CASMC-derived microvesicles and these alterations are reflected in patients with FH. Circulating miR-130a-3p emerges as a potential biomarker for coronary atherosclerosis.

Level of FABP3, FABP4, Nt-proBNP and Total Cardiovascular Risk in the Population of Central Kazakhstan

AIM

The study analyzed the level of cytokines playing the significant role in the diagnosis of circulatory system diseases and total cardiovascular risk.

MATERIAL AND METHODS

The study involved 1,244 residents of Karaganda region. We had studied baseline participant characteristics, in addition to calculating the total cardiovascular risk and assessment of Fatty Acid Binding Proteins 3 (FABP3), Fatty Acid Binding Proteins 4 (FABP4) and N-Terminal Prohormone of Brain Natriuretic Peptide (NT-proBNP) level.

RESULTS

The results showed the combination of high cardiovascular risk (CVR) with increased titers of cardiac markers, reflecting common pathogenic mechanisms in its development, among residents of Karaganda region.

CONCLUSION

The combination of high CVR with the increased titers of cardiac markers showed common pathogenic mechanisms in its development, and support the diagnostic and prognostic value of these parameters among residents of Karaganda region, and also reflects the possibility to include these cardiac markers in the program of screening survey of population for early prevention of cardiovascular disease and its complications.

Prediction of acute coronary syndromes by urinary proteome analysis

Identification of individuals who are at risk of suffering from acute coronary syndromes (ACS) may allow to introduce preventative measures. We aimed to identify ACS-related urinary peptides, that combined as a pattern can be used as prognostic biomarker. Proteomic data of 252 individuals enrolled in four prospective studies from Australia, Europe and North America were analyzed. 126 of these had suffered from ACS within a period of up to 5 years post urine sampling (cases). Proteomic analysis of 84 cases and 84 matched controls resulted in the discovery of 75 ACS-related urinary peptides. Combining these to a peptide pattern, we established a prognostic biomarker named Acute Coronary Syndrome Predictor 75 (ACSP75). ACSP75 demonstrated reasonable prognostic discrimination (c-statistic = 0.664), which was similar to Framingham risk scoring (c-statistics = 0.644) in a validation cohort of 42 cases and 42 controls. However, generating by a composite algorithm named Acute Coronary Syndrome Composite Predictor (ACSCP), combining the biomarker pattern ACSP75 with the previously established urinary proteomic biomarker CAD238 characterizing coronary artery disease as the underlying aetiology, and age as a risk factor, further improved discrimination (c-statistic = 0.751) resulting in an added prognostic value over Framingham risk scoring expressed by an integrated discrimination improvement of 0.273 ± 0.048 (P < 0.0001) and net reclassification improvement of 0.405 ± 0.113 (P = 0.0007). In conclusion, we demonstrate that urinary peptide biomarkers have the potential to predict future ACS events in asymptomatic patients. Further large scale studies are warranted to determine the role of urinary biomarkers in clinical practice.

Osteocalcin as a potential risk biomarker for cardiovascular and metabolic diseases

Clear evidence supports a role for circulating and locally-produced osteocalcin (OC) in the pathophysiology of cardiovascular (CV) lesions and CV risk, also in combination with metabolic changes, including type 2 diabetes mellitus (T2DM). Reduced plasma OC levels are associated with greater incidence of pathological CV changes, like arterial and valvular calcification, coronary and carotid atherosclerosis and increased carotid intima-media thickness. The actual relationship between OC levels and incidence of major CV events is, however, still unclear. Moreover, reduced circulating OC levels have been mostly associated with insulin resistance, metabolic syndrome or T2DM, indicating relevant OC actions on pancreatic β-cells and insulin secretion and activity. Based on these observations, this review article will attempt to summarize the current evidence on the potential usefulness of circulating OC as a biomarker for CV and metabolic risk, also evaluating the currently open issues in this area of research.

Association of ficolin-3 with abdominal aortic aneurysm presence and progression

Essentials Abdominal aortic aneurysm (AAA) is asymptomatic and its evolution unpredictable. To find novel potential biomarkers of AAA, microvesicles are an excellent source of biomarkers. Ficolin-3 is increased in microvesicles obtained from activated platelets and AAA tissue. Increased ficolin-3 plasma levels are associated with AAA presence and progression.

SUMMARY

Background Abdominal aortic aneurysm (AAA) patients are usually asymptomatic and AAA evolution is unpredictable. Ficolin-3, mainly synthesized by the liver, is a molecule of the lectin complement-activation pathway involved in AAA pathophysiology. Objectives To define extra-hepatic sources of ficolin-3 in AAA and investigate the role of ficolin-3 as a biomarker of the presence and progression of AAA. Methods Microvesicles (exosomes and microparticles) were isolated from culture-conditioned medium of ADP-activated platelets, as well as from AAA tissue-conditioned medium (thrombus and wall). Ficolin-3 levels were analyzed by western-blot, real-time PCR, immunohistochemistry and ELISA. Results Increased ficolin-3 levels were observed in microvesicles isolated from activated platelets. Similarly, microvesicles released from AAA tissue display increased ficolin-3 levels as compared with those from healthy tissue. Moreover, ficolin-3 mRNA levels in the AAA wall were greatly increased compared with healthy aortic walls. Immunohistochemistry of AAA tissue demonstrated increased ficolin-3, whereas little staining was present in healthy walls. Finally, increased ficolin-3 levels were observed in AAA patients' plasma (n = 478) compared with control plasma (n = 176), which persisted after adjustment for risk factors (adjusted odds ratio [OR], 5.29; 95% confidence interval [CI], 3.27, 8.57)]. Moreover, a positive association of ficolin-3 with aortic diameter (Rho, 0.25) and need for surgical repair was observed, also after adjustment for potential confounding factors (adjusted hazard ratio, 1.55; 95% CI, 1.11, 2.15). Conclusions In addition to its hepatic expression, ficolin-3 may be released into the extracellular medium via microvesicles, by both activated cells and pathological AAA tissue. Ficolin-3 plasma levels are associated with the presence and progression of AAA, suggesting its potential role as a biomarker of AAA.

Exosomes: Therapy delivery tools and biomarkers of diseases

Virtually all cells in the organism secrete extracellular vesicles (EVs), a heterogeneous population of lipid bilayer membrane-enclosed vesicles that transport and deliver payloads of proteins and nucleic acids to recipient cells, thus playing central roles in cell-cell communications. Exosomes, nanosized EVs of endosomal origin, regulate many pathophysiological processes including immune responses and inflammation, tumour growth, and infection. Healthy subjects and patients with different diseases release exosomes with different RNA and protein contents into the circulation, which can be measured as biomarkers. The discovery of exosomes as natural carriers of functional small RNA and proteins has raised great interest in the drug delivery field, as it may be possible to harness these vesicles for therapeutic delivery of miRNA, siRNA, mRNA, lncRNA, peptides, and synthetic drugs. However, systemically delivered exosomes accumulate in liver, kidney, and spleen. Targeted exosomes can be obtained by displaying targeting molecules, such as peptides or antibody fragments recognizing target antigens, on the outer surface of exosomes. Display of glycosylphosphatidylinositol (GPI)-anchored nanobodies on EVs is a novel technique that enables EV display of a variety of proteins including antibodies, reporter proteins, and signaling molecules. However, naturally secreted exosomes show limited pharmaceutical acceptability. Engineered exosome mimetics that incorporate desirable components of natural exosomes into synthetic liposomes or nanoparticles, and are assembled using controllable procedures may be more acceptable pharmaceutically. In this communication, we review the current understanding of physiological and pathophysiological roles of exosomes, their potential applications as diagnostic markers, and current efforts to develop improved exosome-based drug delivery systems.

Cohort profile of BIOMArCS: the BIOMarker study to identify the Acute risk of a Coronary Syndrome-a prospective multicentre biomarker study conducted in the Netherlands

PURPOSE

Progression of stable coronary artery disease (CAD) towards acute coronary syndrome (ACS) is a dynamic and heterogeneous process with many intertwined constituents, in which a plaque destabilising sequence could lead to ACS within short time frames. Current CAD risk assessment models, however, are not designed to identify increased vulnerability for the occurrence of coronary events within a precise, short time frame at the individual patient level. The BIOMarker study to identify the Acute risk of a Coronary Syndrome (BIOMArCS) was designed to evaluate whether repeated measurements of multiple biomarkers can predict such 'vulnerable periods'.

PARTICIPANTS

BIOMArCS is a multicentre, prospective, observational study of 844 patients presenting with ACS, either with or without ST-elevation and at least one additional cardiovascular risk factor.

METHODS AND ANALYSIS

We hypothesised that patterns of circulating biomarkers that reflect the various pathophysiological components of CAD, such as distorted lipid metabolism, vascular inflammation, endothelial dysfunction, increased thrombogenicity and ischaemia, diverge in the days to weeks before a coronary event. Divergent biomarker patterns, identified by serial biomarker measurements during 1-year follow-up might then indicate 'vulnerable periods' during which patients with CAD are at high short-term risk of developing an ACS. Venepuncture was performed every fortnight during the first half-year and monthly thereafter. As prespecified, patient enrolment was terminated after the primary end point of cardiovascular death or hospital admission for non-fatal ACS had occurred in 50 patients. A case-cohort design will explore differences in temporal patterns of circulating biomarkers prior to the repeat ACS.

FUTURE PLANS AND DISSEMINATION

Follow-up and event adjudication have been completed. Prespecified biomarker analyses are currently being performed and dissemination through peer-reviewed publications and conference presentations is expected from the third quarter of 2016. Should identification of a 'vulnerable period' prove to be feasible, then future research could focus on event reduction through pharmacological or mechanical intervention during such periods of high risk for ACS.

TRIAL REGISTRATION NUMBER

NTR1698 and NTR1106.

Blood hsa-miR-122-5p and hsa-miR-885-5p levels associate with fatty liver and related lipoprotein metabolism-The Young Finns Study

MicroRNAs are involved in disease development and may be utilized as biomarkers. We investigated the association of blood miRNA levels and a) fatty liver (FL), b) lipoprotein and lipid pathways involved in liver lipid accumulation and c) levels of predicted mRNA targets in general population based cohort. Blood microRNA profiling (TaqMan OpenArray), genome-wide gene expression arrays and nuclear magnetic resonance metabolomics were performed for Young Finns Study participants aged 34–49 years (n = 871). Liver fat status was assessed ultrasonographically. Levels of hsa-miR-122-5p and -885-5p were up-regulated in individuals with FL (fold change (FC) = 1.55, p = 1.36 * 10⁻¹⁴ and FC = 1.25, p = 4.86 * 10⁻⁴, respectively). In regression model adjusted with age, sex and BMI, hsa-miR-122-5p and -885-5p predicted FL (OR = 2.07, p = 1.29 * 10⁻⁸ and OR = 1.41, p = 0.002, respectively). Together hsa-miR-122-5p and -885-5p slightly improved the detection of FL beyond established risk factors. These miRNAs may be associated with FL formation through the regulation of lipoprotein metabolism as hsa-miR-122-5p levels associated with small VLDL, IDL, and large LDL lipoprotein subclass components, while hsa-miR-885-5p levels associated inversely with XL HDL cholesterol levels. Hsa-miR-885-5p levels correlated inversely with oxysterol-binding protein 2 (OSBPL2) expression (r = −0.143, p = 1.00 * 10⁻⁴) and suppressing the expression of this lipid receptor and sterol transporter could link hsa-miR-885-5p with HDL cholesterol levels.

Low MT-CO1 in Monocytes and Microvesicles Is Associated With Outcome in Patients With Coronary Artery Disease

BACKGROUND

Cytochrome oxidase (COX) IV complex regulates energy production in mitochondria. Impaired COX gene expression is related to obesity and type 2 diabetes mellitus, but whether it is directly related to the incidence of cardiovascular events is unknown. We investigated whether COX gene expression in monocytes is predictive for cardiovascular events in coronary artery disease patients. To avoid monocyte isolation from fresh blood, we then aimed to validate our findings in monocyte-derived microvesicles isolated from plasma.

METHODS AND RESULTS

We enrolled 142 consecutive patients undergoing diagnostic coronary angiography between June 2010 and January 2011 and followed 67 patients with stable coronary artery disease prospectively for at least 3 years. Twenty-two patients experienced a new cardiovascular event (32.8%). Circulating CD14⁺ monocytes and microvesicles were isolated with magnetic beads, and COX mRNA levels were measured with quantitative polymerase chain reaction, after normalization with 5 validated house-keeping genes. Patients in the lowest tertile of mitochondrial cytochrome oxidase, subunit I (MT-COI) in monocytes at baseline had a higher risk for developing a new event after adjusting for age, sex, (ex)smoking, body mass index, blood pressure, diabetes mellitus, low-density lipoprotein- and high-density lipoprotein-cholesterol, triglycerides, high-sensitivity C-reactive protein, interleukin-6, and number of diseased vessels (harzard ratio [HR], 3.95; 95% CI, 1.63-9.57). Patients in the lowest tertile of MT-COI in monocyte-specific microvesicles had also a higher risk of developing a new event (adjusted HR, 5.00; 95% CI, 1.77-14).

CONCLUSIONS

In the current blinded study, low MT-COI in monocytes of coronary artery disease patients identifies a population at risk for new cardiovascular events. For the first time, we show that signatures in monocyte-specific microvesicles in plasma have similar predictive properties.

Liver microRNAs: potential mediators and biomarkers for metabolic and cardiovascular disease?

Recent discoveries have revealed that microRNAs (miRNAs) play a key role in the regulation of gene expression. In this review, we summarize the rapidly evolving knowledge about liver miRNAs (including miR-33, -33*, miR-223, -30c, -144, -148a, -24, -29, and -122) and their link to hepatic lipid metabolism, atherosclerosis and cardiovascular disease, non-alcoholic fatty liver disease, metabolic syndrome, and type-2 diabetes. With regards to its biomarker potential, the main focus is on miR-122 as the most abundant liver miRNA with exquisite tissue specificity. MiR-122 has been proposed to play a central role in the maintenance of lipid and glucose homeostasis and is consistently detectable in serum and plasma. This miRNA may therefore constitute a novel biomarker for cardiovascular and metabolic diseases.

Lipidomics: Techniques, Applications, and Outcomes Related to Biomedical Sciences

Lipidomics is a newly emerged discipline that studies cellular lipids on a large scale based on analytical chemistry principles and technological tools, particularly mass spectrometry. Recently, techniques have greatly advanced and novel applications of lipidomics in the biomedical sciences have emerged. This review provides a timely update on these aspects. After briefly introducing the lipidomics discipline, we compare mass spectrometry-based techniques for analysis of lipids and summarize very recent applications of lipidomics in health and disease. Finally, we discuss the status of the field, future directions, and advantages and limitations of the field.

Proteomics and metabolomics in biomarker discovery for cardiovascular diseases: progress and potential

INTRODUCTION

The process of discovering novel biomarkers and potential therapeutic targets may be shortened using proteomic and metabolomic approaches.

AREAS COVERED

Several complementary strategies, each one presenting different advantages and limitations, may be used with these novel approaches. In vitro studies show how cells involved in cardiovascular disease react, although the phenotype of cultured cells differs to that occurring in vivo. Tissue analysis either in human specimens or animal models may show the proteins that are expressed in the pathological process, although the presence of structural proteins may be confounding. To identify circulating biomarkers, analyzing the secretome of cultured atherosclerotic tissue, analysis of blood cells and/or plasma may be more straightforward. However, in the latter approach, high-abundant proteins may mask small molecules that could be potential biomarkers. The study of sub-proteomes such as high-density lipoproteins may be useful to circumvent this limitation. Regarding metabolomics, most studies have been performed in small populations, and we need to perform studies in large populations in order to discover robust biomarkers. Expert commentary: It is necessary to involve the clinicians in these areas to improve the design of clinical studies, including larger populations, in order to obtain consistent novel biomarkers.

High Serum Immunoglobulin G and M Levels Predict Freedom From Adverse Cardiovascular Events in Hypertension: A Nested Case-Control Substudy of the Anglo-Scandinavian Cardiac Outcomes Trial

AIMS

We aimed to determine whether the levels of total serum IgM and IgG, together with specific antibodies against malondialdehyde-conjugated low-density lipoprotein (MDA-LDL), can improve cardiovascular risk discrimination.

METHODS AND RESULTS

The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized 9098 patients in the UK and Ireland into the Blood Pressure-Lowering Arm. 485 patients that had cardiovascular (CV) events over 5.5years were age and sex matched with 1367 controls. Higher baseline total serum IgG, and to a lesser extent IgM, were associated with decreased risk of CV events (IgG odds ratio (OR) per one standard deviation (SD) 0.80 [95% confidence interval, CI 0.72,0.89], p<0.0001; IgM 0.83[0.75,0.93], p=0.001), and particularly events due to coronary heart disease (CHD) (IgG OR 0.66 (0.57,0.76); p<0.0001, IgM OR 0.81 (0.71,0.93); p=0.002). The association persisted after adjustment for a basic model with variables in the Framingham Risk Score (FRS) as well as following inclusion of C-reactive protein (CRP) and N-terminal pro-B-type natriuretic peptide (NtProBNP). IgG and IgM antibodies against MDA-LDL were also associated with CV events but their significance was lost following adjustment for total serum IgG and IgM respectively. The area under the receiver operator curve for CV events was improved from the basic risk model when adding in total serum IgG, and there was improvement in continuous and categorical net reclassification (17.6% and 7.5% respectively) as well as in the integrated discrimination index.

CONCLUSION

High total serum IgG levels are an independent predictor of freedom from adverse cardiovascular events, particularly those attributed to CHD, in patients with hypertension.

Inflammatory glycoproteins in cardiometabolic disorders, autoimmune diseases and cancer

The physiological function initially attributed to the oligosaccharide moieties or glycans on inflammatory glycoproteins was to improve protein stability. However, it is now clear that glycans play a prominent role in glycoprotein structure and function and in some cases contribute to disease states. In fact, glycan processing contributes to pathogenicity not only in autoimmune disorders but also in atherosclerotic cardiovascular disease, diabetes and malignancy. While most clinical laboratory tests measure circulating levels of inflammatory proteins, newly developed diagnostic and prognostic tests are harvesting the information that can be gleaned by measuring the amount or structure of the attached glycans, which may be unique to individuals as well as various diseases. As such, these newer glycan-based tests may provide future means for more personalized approaches to patient stratification and improved patient care. Here we will discuss recent progress in high-throughput laboratory methods for glycomics (i.e. the study of glycan structures) and glycoprotein quantification by methods such as mass spectrometry and nuclear magnetic resonance spectroscopy. We will also review the clinical utility of glycoprotein and glycan measurements in the prediction of common low-grade inflammatory disorders including cardiovascular disease, diabetes and cancer, as well as for monitoring autoimmune disease activity.

L-homoarginine administration reduces neointimal hyperplasia in balloon-injured rat carotids

Supplementary Material to this article is available at www.thrombosis-online.com.

Extracellular microvesicle microRNAs in children with sickle cell anaemia with divergent clinical phenotypes

Sickle cell anaemia (SCA) is the most frequent genetic haemoglobinopathy, which exhibits a highly variable clinical course characterized by hyper-coagulable and pro-inflammatory states, as well as endothelial dysfunction. Extracellular microvesicles are released into biological fluids and play a role in modifying the functional phenotype of target cells. We hypothesized that potential differences in plasma-derived extracellular microvesicles (EV) function and cargo from SCA patients may underlie divergent clinical trajectories. Plasma EV from SCA patients with mild, intermediate and severe clinical disease course were isolated, and primary endothelial cell cultures were exposed. Endothelial cell activation, monocyte adhesion, barrier disruption and exosome cargo (microRNA microarrays) were assessed. EV disrupted the endothelial barrier and induced expression of adhesion molecules and monocyte adhesion in a SCA severity-dependent manner compared to healthy children. Microarray approaches identified a restricted signature of exosomal microRNAs that readily distinguished severe from mild SCA, as well as from healthy children. The microRNA candidates were further validated using quantitative real time polymerase chain reaction assays, and revealed putative gene targets. Circulating exosomal microRNAs may play important roles in predicting the clinical course of SCA, and in delineation of individually tailored, mechanistically-based clinical treatment approaches of SCA patients in the near future.

New and emerging biomarkers in cardiovascular disease

Cardiovascular disease (CVD) is the most common cause of death and disability worldwide. Therefore, great importance has been placed on the discovery of novel risk factors and metabolic pathways relevant in the prevention and management of CVD. Such research is ongoing and may continue to lead to better risk stratification of individuals and/or the development of new intervention targets and treatment options. This review highlights emerging biomarkers related to lipid metabolism, glycemia, inflammation, and cardiac damage, some of which show promising associations with CVD risk and provide further understanding of the underlying pathophysiology. However, their measurement methodology and assays will require validation and standardization, and it will take time to accumulate evidence of their role in CVD in various population settings in order to fully assess their clinical utility. Several of the novel biomarkers represent intriguing, potentially game-changing targets for therapy.

Protective effects of sirtuins in cardiovascular diseases: from bench to bedside

Sirtuins (Sirt1–Sirt7) comprise a family of nicotinamide adenine dinucleotide (NAD⁺)-dependent enzymes. While deacetylation reflects their main task, some of them have deacylase, adenosine diphosphate-ribosylase, demalonylase, glutarylase, and desuccinylase properties. Activated upon caloric restriction and exercise, they control critical cellular processes in the nucleus, cytoplasm, and mitochondria to maintain metabolic homeostasis, reduce cellular damage and dampen inflammation—all of which serve to protect against a variety of age-related diseases, including cardiovascular pathologies. This review focuses on the cardiovascular effects of Sirt1, Sirt3, Sirt6, and Sirt7. Most is known about Sirt1. This deacetylase protects from endothelial dysfunction, atherothrombosis, diet-induced obesity, type 2 diabetes, liver steatosis, and myocardial infarction. Sirt3 provides beneficial effects in the context of left ventricular hypertrophy, cardiomyopathy, oxidative stress, metabolic homeostasis, and dyslipidaemia. Sirt6 is implicated in ameliorating dyslipidaemia, cellular senescence, and left ventricular hypertrophy. Sirt7 plays a role in lipid metabolism and cardiomyopathies. Most of these data were derived from experimental findings in genetically modified mice, where NFκB, Pcsk9, low-density lipoprotein-receptor, PPARγ, superoxide dismutase 2, poly[adenosine diphosphate-ribose] polymerase 1, and endothelial nitric oxide synthase were identified among others as crucial molecular targets and/or partners of sirtuins. Of note, there is translational evidence for a role of sirtuins in patients with endothelial dysfunction, type 1 or type 2 diabetes and longevity. Given the availability of specific Sirt1 activators or pan-sirtuin activators that boost levels of the sirtuin cofactor NAD⁺, we anticipate that this field will move quickly from bench to bedside.

Incidence of hypothyroidism after 131I therapy for hyperthyroidism. Relation to pretherapy serum levels of T3, T4 and thyroid antibodies

A correlation is reported between serum levels of triiodothyronine (S-T3) and thyroxine (S-T4) before treatment, as well as levels of thyroid antibodies before treatment, and the development of hypothyroidism following 131I therapy in 86 patients with hyperthyroidism. Patients with marked elevation of S-T3 or S-T4 had demonstrable antibodies to thyroid cytoplasmic antigen more often than those with normal or moderately elevated levels, and patients with markedly elevated levels of S-T3 also had a higher incidence of hypothyroidism after treatment. Patients with nodular thyroid glands and with markedly elevated levels of S-T3 required a larger number of 131I doses before no signs of hyperthyroidism persisted in comparison to those with moderately elevated levels.