Search

Endothelial cells (ECs) are sentinels of cardiovascular health. Their function is reduced by the presence of cardiovascular risk factors, and is regained once pathological stimuli are removed. In this European Society for Cardiology Position Paper, we describe endothelial dysfunction as a spectrum of phenotypic states and advocate further studies to determine the role of EC subtypes in cardiovascular disease. We conclude that there is no single ideal method for measurement of endothelial function. Techniques to measure coronary epicardial and micro-vascular function are well established but they are invasive, time-consuming, and expensive. Flow-mediated dilatation (FMD) of the brachial arteries provides a non-invasive alternative but is technically challenging and requires extensive training and standardization. We, therefore, propose that a consensus methodology for FMD is universally adopted to minimize technical variation between studies, and that reference FMD values are established for different populations of healthy individuals and patient groups. Newer techniques to measure endothelial function that are relatively easy to perform, such as finger plethysmography and the retinal flicker test, have the potential for increased clinical use provided a consensus is achieved on the measurement protocol used. We recommend further clinical studies to establish reference values for these techniques and to assess their ability to improve cardiovascular risk stratification. We advocate future studies to determine whether integration of endothelial function measurements with patient-specific epigenetic data and other biomarkers can enhance the stratification of patients for differential diagnosis, disease progression, and responses to therapy.

Vascular endothelial cell (EC) dysfunction plays a key role in diabetic complications. This study discovers significant upregulation of Quaking-7 (QKI-7) in iPS cell-derived ECs when exposed to hyperglycemia, and in human iPS-ECs from diabetic patients. QKI-7 is also highly expressed in human coronary arterial ECs from diabetic donors, and on blood vessels from diabetic critical limb ischemia patients undergoing a lower-limb amputation. QKI-7 expression is tightly controlled by RNA splicing factors CUG-BP and hnRNPM through direct binding. QKI-7 upregulation is correlated with disrupted cell barrier, compromised angiogenesis and enhanced monocyte adhesion. RNA immunoprecipitation (RIP) and mRNA-decay assays reveal that QKI-7 binds and promotes mRNA degradation of downstream targets CD144, Neuroligin 1 (NLGN1), and TNF-α-stimulated gene/protein 6 (TSG-6). When hindlimb ischemia is induced in diabetic mice and QKI-7 is knocked-down in vivo in ECs, reperfusion and blood flow recovery are markedly promoted. Manipulation of QKI-7 represents a promising strategy for the treatment of diabetic vascular complications., Vascular endothelial cell (EC) dysfunction contributes to the occurrence of diabetic complications. Here the authors report that in diabetic conditions, upregulation of the RNA binding protein QKI-7 in ECs due to the imbalance of RNA splicing factors CUG-BP and hnRNPM contributes to EC dysfunction, and that in vivo QKI-7 silencing improves blood flow recovery in diabetic mice with limb ischemia.

Aims Vascular calcification is a recognised predictor of cardiovascular risk in the diabetic patient, with DNA damage and accelerated senescence linked to oxidative stress associated pathological calcification. Having previously shown that systemic SIRT1 is reduced in diabetes, the aim was to establish whether SIRT1 is protective against a DNA damage-induced senescent and calcified phenotype in diabetic vascular smooth muscle cells (vSMCs). Methods and results Immunohistochemistry revealed decreased SIRT1 and increased DNA damage marker expression in diabetic calcified arteries compared to non-diabetic and non-calcified controls, strengthened by findings that vSMCs isolated from diabetic patients show elevated DNA damage and senescence, assessed by the Comet assay and telomere length. Hyperglycaemic conditions were used and induced DNA damage and enhanced senescence in vSMCs in vitro. Using H2O2 as a model of oxidative stress-induced DNA damage, pharmacological activation of SIRT1 reduced H2O2 DNA damage induced calcification, prevented not only DNA damage, as shown by reduced comet tail length, but also decreased yH2AX foci formation, and attenuated calcification. While ATM expression was reduced following DNA damage, in contrast, SIRT1 activation significantly increased ATM expression, phosphorylating both MRE11 and NBS1, thus allowing formation of the MRN complex and increasing activation of the DNA repair pathway. Conclusions DNA damage induced calcification is accelerated within a diabetic environment and can be attenuated in vitro by SIRT1 activation. This occurs through enhancement of the MRN repair complex within vSMCs and has therapeutic potential within the diabetic patient. Translational perspective Our study provides the first evidence that DNA damage is enhanced in the vasculature of the diabetic patient and that this process, in tandem with loss of SIRT1, exacerbates pathological smooth muscle cell calcification. We propose that current SIRT1 activators and their analogues may be useful as investigational tools, and further elucidation of downstream mechanisms of SIRT1 will aid the development of novel and more precise drug regimens.

Mucopolysaccharidosis IIIA is a neuronopathic lysosomal storage disease, characterised by heparan sulphate and other substrates accumulating in the brain. Patients develop behavioural disturbances and cognitive decline, a possible consequence of neuroinflammation and abnormal substrate accumulation. Interleukin (IL)‐1β and interleukin‐1 receptor antagonist (IL‐1Ra) expression were significantly increased in both murine models and human MPSIII patients. We identified pathogenic mechanisms of inflammasome activation, including that disease‐specific 2‐O‐sulphated heparan sulphate was essential for priming an IL‐1β response via the Toll‐like receptor 4 complex. However, mucopolysaccharidosis IIIA primary and secondary storage substrates, such as amyloid beta, were both required to activate the NLRP3 inflammasome and initiate IL‐1β secretion. IL‐1 blockade in mucopolysaccharidosis IIIA mice using IL‐1 receptor type 1 knockout or haematopoietic stem cell gene therapy over‐expressing IL‐1Ra reduced gliosis and completely prevented behavioural phenotypes. In conclusion, we demonstrate that IL‐1 drives neuroinflammation, behavioural abnormality and cognitive decline in mucopolysaccharidosis IIIA, highlighting haematopoietic stem cell gene therapy treatment with IL‐1Ra as a potential neuronopathic lysosomal disease treatment., This study reports that IL‐1, stimulated by storage substrates, is a critical mediator in the mucopolysaccharidosis IIIA (MPSIIIA) inflammatory cascade. Haematopoietic stem cell gene therapy using IL‐1Ra, the natural antagonist of IL‐1, prevented cognitive and behavioural decline in mice.

Objective Microparticles (MPs) are membrane-bound vesicles derived from vascular and intravascular cells such as endothelial cells (EMPs) and platelets (PMPs). We investigated EMP and PMP numbers across a spectrum of autoimmune rheumatic diseases (AIRDs) with the aim of comparing the levels of, and relationship between, EMPs and PMPs. Methods Patients with Systemic Lupus Erythematosus (SLE) (n = 24), Systemic Sclerosis (SSc) (n = 24), Primary Raynauds Phenomenon (RP) (n = 17) and “other CTD” (n = 15) (Primary Sjogrens Syndrome, UCTD or MCTD) as well as 15 healthy controls were recruited. EMPs and PMPs were quantified using flow cytometry. Associations between MP levels and objective functional vascular assessments were evaluated. Results SLE patients had significantly higher EMPs compared with healthy controls and SSc patients. Higher PMP levels were noted in SSc and primary RP when compared to healthy controls and ‘other CTD’ patients. A modest correlation was noted between EMP and PMP levels in healthy controls (Spearman r = 0.6, p = 0.017). This relationship appeared stronger in SLE (r = 0.72, p, Highlights • Levels of circulating EMPs and PMPs differ between SSc/primary RP compared with other CTDs including SLE. • Circulating MP levels are associated with objective assessments of macro- and microvascular dysfunction. • MPs may have a useful role as novel circulating biomarkers of vascular disease within the CTDs.

© 2016 Elsevier Inc. Autoimmune rheumatic diseases are characterised by systemic inflammation and complex immunopathology, with an increased risk of cardiovascular disease, initiated by endothelial dysfunction in a chronic inflammatory environment. Endothelial microparticles (EMPs) are released into the circulation from activated endothelial cells and may therefore, reflect disease severity, vascular and endothelial dysfunction, that could influence disease pathogenesis via autocrine/paracrine signalling. The exact function of EMPs in rheumatic disease remains unknown, and this has initiated research to elucidate EMP composition and function, which may be determined by the mode of endothelial activation and the micro environment. To date, EMPs are thought to play a role in angiogenesis, thrombosis and inflammation by transferring specific proteins and microRNAs (miRs) to target cells. Here, we review the mechanisms underlying the generation and composition of EMPs and the clinical and experimental studies describing the involvement of EMPs in rheumatic diseases, since we have previously shown endothelial dysfunction and an elevated risk of cardiovascular disease are characteristics in systemic lupus erythematosus. We will also discuss the potential of EMPs as future biomarkers of cardiovascular risk in these diseases.

Background: Progressive chronic kidney disease (CKD) inevitably leads to salt and water retention and disturbances in the macro-and microcirculation. Objectives: We hypothesize that salt and water dysregulation in advanced CKD may be linked to inflammation and microvascular injury pathways. Methods: We studied 23 CKD stage 5 patients and 11 healthy controls (HC). Tissue sodium concentration was assessed using 23Sodium magnetic resonance (MR) imaging. Hydration status was evaluated using bioimpedance spectroscopy. A panel of inflammatory and endothelial biomarkers was also measured. Results: CKD patients had fluid overload (FO) when compared to HC (overhydration index: CKD = 0.5 ± 1.9 L vs. HC = –0.5 ± 1.0 L; p = 0.03). MR-derived tissue sodium concentrations were predominantly higher in the subcutaneous (SC) compartment (median [interquartile range] CKD = 22.4 mmol/L [19.4–31.3] vs. HC = 18.4 mmol/L [16.6–21.3]; p = 0.03), but not the muscle (CKD = 24.9 ± 5.5 mmol/L vs. HC = 22.8 ± 2.5 mmol/L; p = 0.26). Tissue sodium in both compartments correlated to FO (muscle: r = 0.63, p < 0.01; SC: rs = 0.63, p < 0.01). CKD subjects had elevated levels of vascular cell adhesion molecule (p < 0.05), tumor necrosis factor-alpha (p < 0.01), and interleukin (IL)-6 (p = 0.01) and lower levels of vascular endothelial growth factor-C (p = 0.04). FO in CKD was linked to higher IL-8 (r = 0.51, p < 0.05) and inversely associated to E-selectin (r = –0.52, p = 0.01). Higher SC sodium was linked to higher intracellular adhesion molecule (ICAM; rs = 0.54, p = 0.02). Conclusion: Salt and water accumulation in CKD appears to be linked with inflammation and endothelial activation pathways. Specifically IL-8, E-Selectin (in FO), and ICAM (in salt accumulation) may be implicated in the pathophysiology of FO and merit further investigation.

Endothelial colony forming progenitor cell (ECFC) function is compromised in diabetes, leading to poor vascular endothelial repair, which contributes to impaired diabetic foot ulcer healing. We have generated novel glycomimetic drugs with protective effects against endothelial dysfunction. We investigated the effect of glycomimetic C3 on the functional capacity of diabetic ECFCs. ECFCs were isolated from healthy controls and patients with diabetes with neuroischaemic (NI) or neuropathic (NP) foot ulcers. Functionally, diabetic ECFCs demonstrated delayed colony formation (p in vitro in patient ECFCs (p

Vascular endothelial cell (EC) dysfunction plays a key role in diabetic complications. This study discovers significant upregulation of Quaking-7 (QKI-7) in iPS cell-derived ECs when exposed to hyperglycemia, and in human iPS-ECs from diabetic patients. QKI-7 is also highly expressed in human coronary arterial ECs from diabetic donors, and on blood vessels from diabetic critical limb ischemia patients undergoing a lower-limb amputation. QKI-7 expression is tightly controlled by RNA splicing factors CUG-BP and hnRNPM through direct binding. QKI-7 upregulation is correlated with disrupted cell barrier, compromised angiogenesis and enhanced monocyte adhesion. RNA immunoprecipitation (RIP) and mRNA-decay assays reveal that QKI-7 binds and promotes mRNA degradation of downstream targets CD144, Neuroligin 1 (NLGN1), and TNF-α-stimulated gene/protein 6 (TSG-6). When hindlimb ischemia is induced in diabetic mice and QKI-7 is knocked-down in vivo in ECs, reperfusion and blood flow recovery are markedly promoted. Manipulation of QKI-7 represents a promising strategy for the treatment of diabetic vascular complications.

Objective 10-year cardiovascular disease (CVD) risk scores are calculated using algorithms, including Framingham (worldwide) and QRISK2 (UK). Recently, an updated QRISK3 model was introduced, which considers new variables including SLE and steroid prescription, not included in QRISK2 and Framingham algorithms. We sought to determine the extent to which QRISK3 improves identification of high-risk patients with SLE and whether the score relates to standard and novel markers of SLE-specific endothelial dysfunction. Methods Framingham and QRISK2/3 scores were calculated in patients with SLE (n=109) and healthy controls (n=29) using clinical measures. In a smaller cohort (n=58), markers of inflammation and endothelial dysfunction, including CD144+ endothelial microvesicles (EMVs), triglycerides, vascular cell adhesion molecule (VCAM) and high-sensitivity C reactive protein (hsCRP) were quantified by flow cytometry and ELISA, respectively. Results Patients with SLE demonstrated significantly higher QRISK3 scores than controls (5.0%vs0.3%, p

Introduction Patients with diabetes have impaired endothelial colony forming cell (ECFC or endothelial progenitor cell) function leading to poor vascular endothelial repair, potentially contributing to diabetic foot ulceration, a major health and economic burden. The objective was to characterise the functional deficit in these cells in order to understand the pathogenic mechanism and identify novel therapeutic targets. Methods ECFCs were harvested from the peripheral blood of healthy controls and patients with diabetes and neuroischaemic foot ulcers using cell culture techniques. Functional and biochemical analyses of the migratory, angiogenic and metabolic activity were performed. In addition, a neotissue array was used to compare ECFC binding and growth to different matrix ligands (RGD, DGEA, IKVAV, YIGSR, VAPG) and combinations of ligands, including soft and fibrous matrices to represent distinct environments. Results Neuroischaemic ECFCs take longer to form colonies on isolation, have impaired nitric oxide production (46% of control) and a reduced migratory response to SDF-1 (77% of control), decreased scratch closure (87% of control) and compromised tube formation (38% of control in the matrigel assay compared to healthy ECFCs). Seahorse extracellular flux analysis of metabolic function identified no change in glycolysis, but mitochondrial function and maximal oxygen consumption was increased two fold in the neuroischaemic ECFCs vs healthy ECFCs. The neotissue array revealed a decrease in binding of neuroischaemic and control ECFCs to stiff matrix compared to normal physiological stiffness by between a half and two thirds over 24 hours. The neuroischaemic ECFCs bound less, and to a reduced repertoire of matrix peptides compared to controls, suggesting a diminished binding capacity. Furthermore, in long-term culture the viability of neuroischaemic ECFCs was reduced compared to control cells. Discussion This study is the first to describe the defect in matrix adhesion and metabolic changes in neuroischaemic diabetic ECFCs, which may contribute to impaired endothelial repair observed in vivo. Further work to characterise the mechanism of this binding deficiency will allow us to develop an improved model of disease in vitro, leading to identification of new therapeutic targets and stem cell therapies for wound healing.

Introduction Systemic Lupus Erythematosus (SLE) is an inflammatory autoimmune condition associated with endothelial dysfunction, elevating the risk of cardiovascular disease 50-fold in young women. The QRISK2 algorithm is used currently to predict the 10 year cardiovascular risk in the UK population; however, an updated QRISK3 model was recently released, which considers inflammatory variables such as SLE and steroid prescription. This study aims to elucidate whether QRISK3 is more representative of endothelial dysfunction and cardiovascular risk in SLE patients and if novel biomarkers of SLE disease activity, including endothelial microvesicles (EMVs), correlate with increased risk. Methods QRISK scores of SLE patients (n=109) and controls (n=29) were determined using clinical data. Potential markers of SLE-specific endothelial dysfunction were quantified in a smaller patient cohort (n=60) using flow cytometry and ELISA techniques and included; CD144 +EMVs, high sensitivity C-reactive protein (hsCRP) and triglycerides. Results QRISK3 scores were significantly elevated in SLE patients (average 5.1%) compared to controls (0.3%; p Conclusion QRISK3 identifies significantly more SLE patients at high cardiovascular risk than QRISK2, and is associated with standard and novel markers of SLE-specific inflammation and endothelial dysfunction. The use of QRISK3 as a predictor of cardiovascular risk will support improved management of vascular health and assist in prevention of premature mortality in SLE patients.

Glioblastoma is the most aggressive primary brain cancer with poor survival, but treatment strategies to improve prognosis have failed to materialise in over 30-years. Immune cells, in particular Tumour associated macrophages and microglia (TAMM) populate up to 40% of tumour bulk and are potential immunotherapy targets. However, functional roles of TAMM subpopulations still remain elusive and contradictory, due to limitations of existing mouse models and non-specific cell-surface markers used in human and rodent studies.

Mucopolysaccharidosis IIIB is a paediatric lysosomal storage disease caused by deficiency of the enzyme a-N-acetylglucosaminidase (NAGLU), involved in the degradation of the glycosaminoglycan heparan sulphate. Absence of NAGLU leads to accumulation of partially degraded heparan sulphate within lysosomes and the extracellular matrix, giving rise to severe CNS degeneration with progressive cognitive impairment and behavioural problems. There are no therapies. Haematopoietic stem cell transplant shows great efficacy in the related disease mucopolysaccharidosis I, where donor-derived monocytes can transmigrate into the brain following bone marrow engraftment, secrete the missing enzyme and cross-correct neighbouring cells. However, little neurological correction is achieved in patients with mucopolysaccharidosis IIIB. We have therefore developed an ex vivo haematopoietic stem cell gene therapy approach in a mouse model of mucopolysaccharidosis IIIB, using a high-titre lentiviral vector and the myeloidspecific CD11b promoter, driving the expression of NAGLU (LV.NAGLU). To understand the mechanism of correction we also compared this with a poorly secreted version of NAGLU containing a C-terminal fusion to IGFII (LV.NAGLU-IGFII). Mucopolysaccharidosis IIIB haematopoietic stem cells were transduced with vector, transplanted into myeloablated mucopolysaccharidosis IIIB mice and compared at 8 months of age with mice receiving a wild-type transplant. As the disease is characterized by increased inflammation, we also tested the anti-inflammatory steroidal agent prednisolone alone, or in combination with LV.NAGLU, to understand the importance of inflammation on behaviour. NAGLU enzyme was substantially increased in the brain of LV.NAGLU and LV.NAGLU-IGFII-treated mice, with little expression in wild-type bone marrow transplanted mice. LV.NAGLU treatment led to behavioural correction, normalization of heparan sulphate and sulphation patterning, reduced inflammatory cytokine expression and correction of astrocytosis, microgliosis and lysosomal compartment size throughout the brain. The addition of prednisolone improved inflammatory aspects further. Substantial correction of lysosomal storage in neurons and astrocytes was also achieved in LV.NAGLU-IGFII-treated mice, despite limited enzyme secretion from engrafted macrophages in the brain. Interestingly both wild-type bone marrow transplant and prednisolone treatment alone corrected behaviour, despite having little effect on brain neuropathology. This was attributed to a decrease in peripheral inflammatory cytokines. Here we show significant neurological disease correction is achieved using haematopoietic stem cell gene therapy, suggesting this therapy alone or in combination with anti-inflammatories may improve neurological function in patients.

Central Nervous System (CNS) diseases and lesions are characterised by significant immune cell infiltration. In Glioblastoma Multiforme (GBM), a primary brain cancer, these Tumor Associated Macrophages and microglia (TAMM) may have pro-tumorigenic functions and play a key role in attenuating the host response to glioma. These cells can originate from the CNS itself as microglia or from the peripheral haematopoietic system as macrophages. Techniques currently used to separate the two populations in mice have used partially chimeric transplantation models or head shielded irradiation conditioning, however irradiation in particular leads to confounding pro-inflammatory effects in the peripheral environment. Furthermore, the reliability of using the cell surface markers CD45 high/low coupled with CD11b to distinguish central and peripheral populations has not been rigorously evaluated within the tumour microenvironment using non-irradiative methods. To circumvent these difficulties, we developed a Non-Myeloablative Conditioning (NMC) transplant regimen using low dose busulfan, achieving high CD45.1 donor marked peripheral blood haematopoietic chimerism (93%), without brain chimerism or blood brain barrier damage, thus maintaining CD45.2 marked homeostasis of the resident microglial population in the brain. Subsequent intracranial orthotopic implantation of a syngeneic mouse glioma line and whole brain flow cytometry, allowed us to characterise the proportion and type of peripheral immune cells infiltrating tumours. We observed that the proportion of central or peripheral TAMMs does not change significantly over time once the tumour is initially established. We also demonstrate that CD45/ CD11b, unreliably differentiates between central and peripheral TAMMs in the tumour environment, while the markers CD11b, Ly6C, MHCII, CD64 and MerTK, reliably differentiates subpopulations within peripheral derived TAMMs, (inflammatory monocytes, undifferentiated macrophages and macrophages) and central TAMMs, consisting of microglia, both in the NMC model and in un-transplanted mice with >95% purity. The combination of these techniques provides greater distinction of intra-tumoral myeloid cell subsets than previously described marker sets. The NMC transplantation model is simple and effective way of performing transplantation studies, and a powerful method of investigating immune cell interactions in CNS diseases, where a lack of perturbation of the system is important.

Type 2 diabetes is associated with increased cardiovascular morbidity and mortality and early vascular ageing. This takes the form of atherosclerosis, with progressive vascular calcification being a major complication in the pathogenesis of this disease. Current research and drug targets in diabetes have hitherto focused on atherosclerosis, but vascular calcification is now recognised as an independent predictor of cardiovascular morbidity and mortality. An emerging regulatory pathway for vascular calcification in diabetes involves the receptor activator for nuclear factor κB (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG). Important novel biomarkers of calcification are related to levels of glycation and inflammation in diabetes. Several therapeutic strategies could have advantageous effects on the vasculature in patients with diabetes, including targeting the RANKL and receptor for AGE (RAGE) signalling pathways, since there has been little success-at least in macrovascular outcomes-with conventional glucose-lowering therapy. There is substantial and relevant clinical and basic science evidence to suggest that modulating RANKL-RANK-OPG signalling, RAGE signalling and the associated proinflammatory milieu alters the natural course of cardiovascular complications and outcomes in people with diabetes. However, further research is critically needed to understand the precise mechanisms underpinning these pathways, in order to translate the anti-calcification strategies into patient benefit.

Endothelial microparticles (EMPs) are complex submicron membrane-shed vesicles released into the circulation following endothelium cell activation or apoptosis. They are classified as either physiological or pathological, with anticoagulant or pro-inflammatory effects respectively. Endothelial dysfunction caused by inflammation is a key initiating event in atherosclerotic plaque formation. Athero-emboli, resulting from ruptured carotid plaques are a major cause of stroke. Current clinical techniques for arterial assessment, angiography and carotid ultrasound, give accurate information about stenosis but limited evidence on plaque composition, inflammation or vulnerability; as a result, patients with asymptomatic, or fragile carotid lesions, may not be identified and treated effectively. There is a need to discover novel biomarkers and develop more efficient diagnostic approaches in order to stratify patients at most risk of stroke, who would benefit from interventional surgery. Increasing evidence suggests that EMPs play an important role in the pathogenesis of cardiovascular disease, acting as a marker of damage, either exacerbating disease progression or triggering a repair response. In this regard, it has been suggested that EMPs have the potential to act as biomarkers of disease status. In this review, we will present the evidence to support this hypothesis and propose a novel concept for the development of a diagnostic device that could be implemented in the clinic.

Summary Interleukin-1 (IL-1) is a key regulator of inflammation and ischaemic brain injury, but the contribution of central and peripheral sources of IL-1 to brain injury is not well understood. Here we show that haematopoietic-derived IL-1 is a key driver of ischaemic brain injury. Wild type (WT) mice transplanted with IL-1αβ-deficient bone marrow displayed a significant (40%) reduction in brain injury induced by focal cerebral ischaemia compared to WT mice transplanted with WT bone marrow. This was paralleled by improved neurological outcome and the almost complete absence of splenic-derived, but not liver-derived, IL-1α after stroke in WT mice lacking haematopoietic-derived IL-1. IL-1αβ knockout (KO) mice transplanted with IL-1αβ-deficient bone marrow showed a 60% reduction in brain injury compared to WT mice receiving WT bone marrow. Transplantation of WT bone marrow in IL-1αβ KO mice resulted in a similar level of blood-brain-barrier injury to that observed in WT mice receiving IL-1αβ-deficient bone marrow. Cerebral oedema after brain injury was reduced in IL-1αβ KO recipients irrespective of donor-derived IL-1, but a lack of haematopoetic IL-1 has also been associated with smaller brain oedema independently of recipient status. Thus, both central and haematopoietic-derived IL-1 are important contributors to brain injury after cerebral ischaemia. Identification of the cellular sources of IL-1 in the periphery could allow targeted interventions at these sites.

Endothelial microparticles (EMPs) are released from dysfunctional endothelial cells. We hypothesised that patients with unstable carotid plaque have higher levels of circulating microparticles compared to patients with stable plaques and may correlate with serum markers of plaque instability and inflammation. Circulating EMPs, platelet MPs (PMPs) and inflammatory markers were measured in healthy controls and patients undergoing carotid endarterectomy. EMP/PMPs were quantified using flow cytometry. Bioplex assays profiled systemic inflammatory and bone-related proteins. Immunohistological analysis detailed the contribution of differentially-regulated systemic markers to plaque pathology. Alizarin red staining showed calcification. EMPs and PMPs were significantly higher in patients with carotid stenosis (≥70%) compared to controls, with no differences between asymptomatic vs symptomatic patients. Asymptomatic patients with unstable plaques exhibited higher levels of EMPs, CXCL9 and SCGF-β compared to those with stable plaques. CXCL9 and SCGF-β were detected within all plaques, suggesting a contribution to both localised and systemic inflammation. Osteopontin and osteoprotegerin were significantly elevated in the symptomatic vs asymptomatic group, while osteocalcin was higher in asymptomatic patients with stable plaque. All plaques exhibited calcification, which was significantly greater in asymptomatic patients. This may impact on plaque stability. These data could be important in identifying patients at most benefit from intervention.

Stroke is mainly caused by a narrowing of the carotid artery from a build-up of plaque. The risk of plaque rupture and subsequent stroke is dependent on plaque composition. Advances in imaging modalities offer a non-invasive means to assess the health of blood vessels and detect damage. However, the current diagnosis fails to identify patients with soft lipid plaque that are more susceptible to fissure, resulting in stroke. The aim of this study was to use waveform analysis to identify plaque composition and the risk of rupture. We have investigated pressure and flow by combining an artificial blood flow circuit with tubing containing different materials, to simulate plaques in a blood vessel. We used fat and bone to model lipid and calcification respectively to determine if the composition of plaques can be identified by arterial waveforms. We demonstrate that the arterial plaque models with different percentages of calcification and fat, results in significantly different arterial waveforms. These findings imply that arterial waveform analysis has the potential for further development to identify the vulnerable plaques prone to rupture. These findings could have implications for improved patient prognosis by speed of detection and a more appropriate treatment strategy.

Advanced glycated end-products (AGEs) are known drivers of cardiovascular complications such as vascular calcification, which is currently untreatable, and are increased in diabetic subjects in part due to oxidative stress and poor glycaemic control. Our previous studies using smooth muscle cells (SMCs) isolated from patients with peripheral arterial disease (PAD) have implicated a number of signalling pathways involved in their osteogenic differentiation in vitro, including OPG/RANK. We have also shown that alterations in the cell surface glycocalyx regulates cell function, suggesting that non-sugar glycosaminoglycan mimics can potentially modulate cell phenotypes. We aim to investigate how modified LDL and PAD serum affects the progression of calcification of SMCs in vitro and whether this pathology can be prevented by novel glycosaminoglycan mimics, using qPCR, ELISA, Alkaline phosphatase (ALP) activity, and Western blotting. Gly-LDL (10 µg/ml) increased an early marker of calcification (ALP activity) at 4 days and enhanced calcification at 21 days, compared to controls (p Glycomimetics have potential as an anti-calcification strategy, inhibiting mineralisation in SMCs induced by both gly-LDL and patient serum in vitro. The protective effect of glycomimetics against calcification may occur via regulation of CREB phosphorylation and subsequent modulation of downstream osteogenic markers, including upregulation of OPN and OPG and reduction of OCN, leading to the development of therapeutics to treat vascular calcification.

Vascular calcification is implicated in a range of cardiovascular disease mechanisms, leading to an associated increase in morbidity and mortality. One such trigger are advanced glycation endproducts (AGEs), the tissue accumulation of which increases with age and is more prevalent in diabetic subjects due to oxidative stress and poor glycaemic control. The aim of this study was to investigate the osteogenic potential of AGEs and elucidate mechanisms of inhibiting these processes in a smooth muscle cell (SMC) culture model. Osteogenic differentiation of SMCs was induced using I²-glycerophosphate (I²-GP), carboxymethyllysine (CML), carboxyethyllysine (CEL) methylglyoxal (MGO) and glycated low density lipoprotein (gly-LDL). The cells were subsequently treated with aminoguanidine (AG), an inhibitor of AGE formation, and novel glycomimetic compounds in order to determine their anti-calcification potential in vitro using qPCR, ELISA, Alkaline phosphatase (ALP) activity and Alizarin red staining. Gly-LDL (10 µg/ml) and CML (2.5nM) increased the level of calcification observed compared to the I²-GP (5 mM) positive control after 21 days (p In summary, we conclude that gly-LDL and CML are potent inducers of calcification compared with I²-GP, and that their osteogenic potential can be modulated by both AG and novel glycomimetic compounds.

Endothelial microparticles (EMPs) are complex structures with pleiotropic properties and are emerging as an index of endothelial damage; however, further work to determine the effect of EMPs on vascular smooth muscle cells (VSMC) is needed. We have shown that elevated EMPs are detected in Systemic Lupus Erythematosus (SLE) and carotid artery disease patients, who present accelerated vascular ageing and calcification. This study aims to investigate the molecular components of EMPs and whether they modulate vascular calcification and osteogenic differentiation of VSMCs in vitro. EMPs were generated in vitro using human aortic endothelial cells (AoEMPs) by serum starvation (24 h) followed by TNF-alpha stimulation (10 ng/ml; 24 h), isolated by ultracentrifugation and quantified using flow cytometry. Human coronary artery smooth muscle cells (HCASMCs) were incubated with 106 AoEMPs/ml in osteoinductive media (5 mM BGP and 2.6 mM CaCl2) for 21 days. Calcification was assessed by alizarin red staining and calcium deposition assays. Conditioned media was collected at 7, 14 and 21 days to identify markers of bone metabolism using Bioplex array technology and ELISA. AoEMPs were also subjected to proteomic and miR screening to identify relevant molecules and pathways. AoEMP-treated HCASMCs showed enhanced calcification after 21 days, by both alizarin red staining (p We conclude that AoEMPs enhance calcification and the reprogramming of HCASMCs to an osteogenic pathway in vitro, which may be in part, linked with HGF and miR-3148, supporting their role in vascular calcification in SLE and carotid artery disease. Further studies are required to determine how AoEMPs contribute to pathophysiological mechanisms in vivo and whether the circulating property of AoEMPs may represent a new biomarker in vascular calcification.

Background Endothelial dysfunction is a key player in cardiovascular disease (CVD) complications and novel drugs are required to treat this pathological process. Glycosaminoglycans (GAGs) are key molecules that regulate signalling in many biological processes and drugs that mimic their structure could be a novel source of therapeutics to target specific CVD pathways. Purpose We have synthesised a set of four glycomimetic compounds and our objective was to determine whether they could activate protective pathways in endothelial cells subjected to fatty acid-induced endothelial dysfunction. Methods Glycomimetics, C1-C4, were synthesised by the stepwise transformation of 2,5-dihydroxybenzoic acid to a range of 2,5-substituted benzoic acid derivatives, incorporating the key sulphate groups to mimic heparan sulphate. Human Umbilical Vein Endothelial Cells (HUVECs) were treated with glycomimetics (1µM) in the presence or absence of the free fatty acid, palmitate. DAF-2 and H2DCF-DA assays were used to determine NO and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity ssays were also carried out. RT-PCR and western blotting were utilised to measure Akt, eNOS, Nrf-2, NQO-1 and HO-1 expression. Endothelial function was determined ex vivo using acetylcholine-induced endothelium-dependent relaxation in mouse thoracic aortic rings by wire myography. Results All four glycomimetics protected against palmitate-induced oxidative stress and enhanced NO production in vitro via upregulation of Akt/eNOS signalling, activation of the Nrf2/ARE pathway and down-regulation of ROS-induced lipid peroxidation. Under palmitate-induced oxidative stress, ex vivo endothelium-dependent relaxation was significantly enhanced by all four glycomimetics. Furthermore, the glycomimetics did not induce HUVEC activation, as determined by lack of ICAM-1 protein. Conclusion We have developed a new set of small molecule glycomimetics that do not activate ECs and protect against free fatty acid-induced endothelial dysfunction both in vitro and ex vivo. Future work will focus on developing the glycomimetics into drug-like therapies that target endothelial damage.

Background Circulating endothelial progenitor cells (EPCs) are thought to play a pivotal role in endothelial repair. Clinical trials utilising EPCs to promote therapeutic angiogenesis are already underway Previous reports suggest a reduced EPC number and impaired functional activity in patients with type 2 diabetes mellitus. However, the actual identity of the cell type involved and the functional role played in the repair process needs to be further defined before EPCs can be successfully utilised in the clinic. In the present study, we assessed the functional capacity of circulating late out-growth endothelial progenitor cells (OECs) to further assess the contribution of the diabetic environment to diminished OEC function in the context of wound healing. Methods and results OECs were isolated from 7 diabetic patients, presenting with ulcers ranging in size from 60 mm 3 –2500 mm 3 . OECs were characterised as CD34 + , CD31 + , vWF+, positive for AcLDL and UEA uptake and negative for the hematopoietic marker CD45 by immunohistochemistry. Migration of CD34 + OECs, evaluated by a scratch assay, demonstrated that migration is impaired in diabetic OECs compared to healthy control OECs, with 40–42% closure vs 100% over 24 h respectively. In addition, achemotaxis transwell migration assay showed a decreased response to SDF-1 by diabetic cells vs healthy OECs. An angiogenesis tube formation assay also established a reduced capacity of the diabetic OECs to form an endothelial network as compared to healthy OECs (p Conclusion OECs from diabetic patients show an impaired migration and response to chemotactic agents in vitro compared to OECs isolated from healthy controls. In addition, the reduced nitric oxide bioavailability found by diabetic cells may contribute to OEC dysfunction in diabetes. Future work will focus on assessing the secretome of healthy vs diabetic OECs.

Mucopolysaccharidosis IIIA (MPS IIIA or Sanfilippo disease) is a neurodegenerative disorder caused by a deficiency in the lysosomal enzyme sulfamidase (SGSH), catabolizing heparan sulfate (HS). Affected children present with severe behavioral abnormalities, sleep disturbances, and progressive neurodegeneration, leading to death in their second decade. MPS I, a similar neurodegenerative disease accumulating HS, is treated successfully with hematopoietic stem cell transplantation (HSCT) but this treatment is ineffectual for MPS IIIA. We compared HSCT in MPS IIIA mice using wild-type donor cells transduced ex vivo with lentiviral vector-expressing SGSH (LV-WT-HSCT) versus wild-type donor cell transplant (WT-HSCT) or lentiviral-SGSH transduced MPS IIIA cells (LV-IIIA-HSCT). LV-WT-HSCT results in 10% of normal brain enzyme activity, near normalization of brain HS and GM2 gangliosides, significant improvements in neuroinflammation and behavioral correction. Both WT-HSCT and LV-IIIA-HSCT mediated improvements in GM2 gangliosides and neuroinflammation but were less effective at reducing HS or in ameliorating abnormal HS sulfation and had no significant effect on behavior. This suggests that HS may have a more significant role in neuropathology than neuroinflammation or GM2 gangliosides. These data provide compelling evidence for the efficacy of gene therapy in conjunction with WT-HSCT for neurological correction of MPS IIIA where conventional transplant is ineffectual.

It is well established that vascular calcification is a common complication in diabetes and recent studies suggest that glycation may play a pathogenic role in this process. The aim of this study was to investigate the role of glycation in the induction of calcification in vascular smooth muscle cells (SMCs), and the potential inhibitory effects of the anti-diabetic agent, Momordica Charantia. Vascular SMCs were incubated with native or glycated LDL in the presence of osteogenic media and mineral deposition was determined using alizarin red staining and alkaline phosphatase (ALP) activity. We found that SMCs incubated in osteogenic media exhibited mineralisation after 7 days. This calcification was significantly increased following treatment with glycated-LDL, but not by native LDL. Furthermore, we found that ALP activity was significantly elevated at day 4 in glycated-LDL treated cells, compared to those incubated in native LDL. The vascular SMCs were exposed to increasing concentrations of Momordica Charantia extract in the presence of osteogenic media. ALP activity was reduced in treated cells, compared to osteogenic controls. Furthermore, we found that Momordica Charantia reduced gene expression of a range of biomarkers linked with vascular calcification after 4 days in a dose-dependent manner, including osteocalcin and BMP-2. In conclusion, we have shown that glycated LDL promotes osteogenic differentiation of vascular SMCs. Momordica Charantia extract shows promise as a potential therapeutic agent to reduce vascular calcification. Future work will identify the active ingredient responsible for calcification inhibitory effects, and establish whether it links to the pathological glycation-induced osteogenesis.

Glycomimetics are molecules that mimic the structure of carbohydrates involved in important biological processes. Small molecule glycomimetics are an untapped source of novel therapies for endothelial dysfunction, a hallmark of cardiovascular complications associated with diabetes. The current study aims to investigate the possible protective effects of newly synthesised small molecule glycomimetics against lipid-induced endothelial dysfunction, with an emphasis on nitric oxide (NO) and induced oxidative stress. Glycomimetics were synthesised by the stepwise transformation of 2,5-dihydroxybenzoic acid to a range of 2,5-substituted benzoic acid derivatives incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Acetylcholine-induced endothelium-dependent relaxation in mouse thoracic aortic rings was measured using wire myography, and human umbilical vein endothelial cells (HUVECs) function was assessed in the presence or absence of palmitate, with or without the test glycomimetics. NO and reactive oxygen species (ROS) production was measured using DAF-2 and H2DCF-DA, respectively. Colorimetric assays were used to determine lipid peroxidation and activity of the antioxidant enzymes. Expression of Akt, eNOS, Nrf-2, NQO-1 and HO-1 were assessed using RT-PCR and western blotting. At 1 µM concentration, the synthesised glycomimetics significantly improved endothelium-dependent relaxation ex vivo and protected HUVECs against palmitate-induced oxidative stress and reduced NO production. Pre-incubation of HUVECs with all compounds upregulated Akt/eNOS signalling, activated Nrf2/ARE pathway, and suppressed ROS-induced lipid peroxidation. In conclusion, our newly synthesised small molecule glycomimetics protect against lipid-induced endothelial dysfunction. These novel cytoprotective effects open the door to a new class of therapeutic drugs to target endothelial dysfunction.

Endothelial microparticles (EMPs) are complex structures with pleiotropic properties and are emerging as an index of endothelial damage. Previous studies have shown elevated circulating EMP levels in inflammatory disorders, which raises the question about their physiological role. This study aims to investigate the autocrine effects of EMPs on TNFα-mediated EMP release, as well as on endothelial cell activation and migration. Two groups of EMPs were generated in vitro from TNF-stimulated human umbilical vein endothelial cells (HUVECs; sEMPs) or untreated HUVECs (uEMPs) and collected by ultracentrifugation. HUVECs were incubated with either 106 sEMPs or uEMPs/ml in the presence or absence of TNFα (10 ng/ml) for 24 h. EMP levels were enumerated by flow cytometry; RT-PCR and functional scratch assays were also carried out. HUVECs treated with either sEMP or uEMP showed increased ICAM-1 mRNA abundance (p

Reliable behavioural tests in animal models of neurodegenerative diseases allow us to study the natural history of disease and evaluate the efficacy of novel therapies. Mucopolysaccharidosis IIIA (MPS IIIA or Sanfilippo A), is a severe, neurodegenerative lysosomal storage disorder caused by a deficiency in the heparan sulphate catabolising enzyme, sulfamidase. Undegraded heparan sulphate accumulates, resulting in lysosomal enlargement and cellular dysfunction. Patients suffer a progressive loss of motor and cognitive function with severe behavioural manifestations and premature death. There is currently no treatment. A spontaneously occurring mouse model of the disease has been described, that has approximately 3% of normal enzyme activity levels. Behavioural phenotyping of the MPS IIIA mouse has been previously reported, but the results are conflicting and variable, even after full backcrossing to the C57BL/6 background. Therefore we have independently backcrossed the MPS IIIA model onto the C57BL/6J background and evaluated the behaviour of male and female MPS IIIA mice at 4, 6 and 8 months of age using the open field test, elevated plus maze, inverted screen and horizontal bar crossing at the same circadian time point. Using a 60 minute open field, we have demonstrated that female MPS IIIA mice are hyperactive, have a longer path length, display rapid exploratory behaviour and spend less time immobile than WT mice. Female MPS IIIA mice also display a reduced sense of danger and spend more time in the centre of the open field. There were no significant differences found between male WT and MPS IIIA mice and no differences in neuromuscular strength were seen with either sex. The altered natural history of behaviour that we observe in the MPS IIIA mouse will allow more accurate evaluation of novel therapeutics for MPS IIIA and potentially other neurodegenerative disorders.

Endothelial dysfunction is an early event in the pathogenesis of diabetes mellitus and its associated cardiovascular morbidities. Endothelial microparticles (EMPs) are endothelium-derived sub-micron vesicles that are released in response to diverse stimuli. Our study aims to investigate the effect of EMPs on endothelial cell function/dysfunction focusing on the Akt/eNOS signalling pathway and lipid-induced oxidative stress. EMPs were generated in vitro using TNFα-stimulated human umbilical vein endothelial cells (HUVECs). Flow cytometry was used to quantify the generated EMPs. HUVECs were cultured in M199 and treated with and without 100 µM palmitate in the presence or absence of 10 5 and 10 6 EMPs. Nitric oxide bioavailability in EMPs and HUVECs was measured using DAF-2. H 2 DCF-DA was used to quantify reactive oxygen species (ROS). Lipid peroxidation and activity of superoxide dismutase and catalase were determined by colorimetric assays, while RT-PCR and western blotting were used to assess eNOS, Akt and NOX4 expression. Analysis of the NO production suggests that EMPs carry a functional eNOS. Palmitate stimulation evoked oxidative stress and reduced activity of the antioxidant enzymes as well as A23187-stimulated NO production in HUVECs. RT-PCR and western blotting demonstrated a marked decrease in eNOS and Akt and increased NOX4 expression in palmitate-treated endothelial cells. EMPs protected against the palmitate-induced endothelial dysfunction through attenuation of oxidative stress and positive regulation of Akt/eNOS signalling, leading to an increased NO production. In conclusion, our data strongly suggest that EMPs express a functional eNOS and are effective in protecting endothelial cells against lipid-induced dysfunction.

Introduction It is well established that glyc-LDL is elevated in the serum of diabetic patients compared to healthy subjects, and that vascular calcification is common in diabetes. Furthermore, recent studies suggest that advanced glycation end products may play a pathogenic role in vascular calcification. We hypothesise that glyc-LDL promotes the osteogenic differentiation of vascular smooth muscle cells in vitro . Methods LDL was isolated from human serum by sequential density gradient ultracentrifugation and incubated at 37°C with a range of glucose concentrations at different time points to determine the optimum glycation conditions. The glyc-LDL was measured using an in-house ELISA method. Bovine Aortic Smooth Muscle Cells (BAoSMCs) were incubated with native or glycated LDL in the presence of osteogenic media and mineral deposition was determined using alizarin red staining and alkaline phosphatase (ALP) activity, which is an early marker of osteogenesis. Results The optimum conditions for LDL glycation was determined as 80mM glucose for 7 days, so these conditions were used for the production of glycated LDL throughout the study. BAoSMCs incubated in osteogenic media exhibited mineralisation after 7 days as determined by alizarin red staining. This calcification was significantly enhanced by treatment with glyc-LDL, but not by native LDL. Furthermore, we found that ALP activity was significantly elevated as early as day 4 in glyc-LDL treated cells, compared to those incubated in native LDL. The glyc-LDL-induced mineralisation was not attenuated in the presence of osteoprotegrin (OPG) nor in the presence of two novel small RAGE antagonist peptides, which were designed to prevent RAGE binding with several of its most important ligands, including HMGB-1, S100P and S1004A. Conclusion We have shown that human-derived glyc-LDL accelerates vascular calcification in vitro . This process does not appear to be attenuated by the addition of OPG, suggesting AGE-induced accelerated calcification occurs through a pathway independent of the RANKL/OPG signalling activity. Further studies with a range of RAGE inhibitors should allow the identification of the molecular pathways implicated in glyc-LDL induced calcification to enable the development of therapeutic peptides effective in blocking of RAGE-ligand interaction, which is prevalent in many pathologies.

CO RR EC TE D P RO OF insidious course as the accumulation of lysoGb3 progresses. Furthermore, in a study using late gadolinium enhancement magnetic resonance imaging of the heart, we found that approximately 1 in 3 males and 1 in 8 females with the IVS4 mutation, who were older than 40 years and who did not have hypertrophic cardiomyopathy, had already developed significant cardiac fibrosis. Endomyocardial biopsy of three of these cardiac fibrosis patients revealed significant pathological changes and Gb3 accumulation in their cardiomyocytes. Current treatment guidelines for cardiac-type Fabry disease recommend that ERT should only be started when significant hypertrophic cardiomyopathy has occurred; however, our findings indicate that this might be too late. We believe that early intervention is important to prevent the insidious and irreversible cardiac damage in these patients.

There is a clinical need to develop novel biomarkers to identify patients at risk of stroke. We aim to establish a systemic signature and microparticle profile of asymptomatic patients with unstable carotid disease, for improved selection of patients for interventional surgery and stroke prevention. Blood samples were taken from 70 patients (51 symptomatic; 19 asymptomatic), undergoing carotid endarterectomy, and 20 healthy controls. Circulating endothelial microparticles (EMPs; CD31+/Annexin V+/CD42b−), together with inflammatory markers were measured using flow cytometry and Bioplex assays respectively. Carotid plaques were graded and analysed using immunohistochemistry. EMPs were elevated in asymptomatic and symptomatic patients, compared to healthy controls (p= These data could aid in the development of a diagnostic tool whereby EMPs, together with macrophage activity markers, could identify those patients with vulnerable plaques and stroke susceptibility.

Endothelial microparticles (EMPs) are complex structures with pleiotropic properties and are emerging as an index of endothelial damage. We demonstrate their levels can be modulated by anti-inflammatory treatment and their existence in the circulation raises the question about their physiological role. Our studies aim to investigate the molecular components of EMPs, and whether EMPs modulate matrix mineralisation. Flow cytometry was used to quantify circulating EMPs (AnnexinV+/CD31+/CD42b−) in lupus patients, pre- and post- anti-inflammatory treatment. EMPs were generated in vitro using TNF-activation of human aortic endothelial cells and used for proteomic analysis and to treat human vascular smooth muscle cells (HVSMC). Alizarin Red staining was used to quantify levels of mineralisation using an in vitro model of calcification. We show that EMP levels are significantly elevated in lupus patients compared to healthy subjects (p We conclude that EMPs may prevent the reprogramming of SMCs to an osteogenic pathway in vitro, which may be, in part linked with PTX3. Further studies are required to determine how MPs contribute to pathophysiological mechanisms in vivo and whether the circulating property of MPs may represent a new biomarker in vascular calcification.

Introduction Endothelial microparticles (EMPs) are released from dysfunctional endothelial cells. We hypothesised that patients with unstable carotid plaque have higher levels of circulating microparticles compared to patients with stable plaques which could be related to a specific cytokine profile. Methods Circulating EMPs and inflammatory cytokine levels were measured in seventy patients with significant carotid disease undergoing carotid endarterectomy and 20 healthy controls. Fifty one (73%) patients had symptomatic disease whilst 19 (27%) were asymptomatic. EMPs (CD31 + / Annexin V + CD42b - ) were quantified using flow cytometry. Immunohistological analysis of carotid plaques for CD68 + , CD206 + macrophages, TNF-α smooth muscle actin and osteopontin was performed, together with Alizarin red staining for detection of calcific deposits. Bioplex assays were used for cytokine analysis. Plaques were graded according to the American Heart Association plaque scoring system. Results Significantly higher EMP levels were observed in symptomatic patients compared to controls, p = 0.01, while no differences were noted in EMP levels in asymptomatic vs controls p = 0.11. The higher EMP levels appeared to associate with the unstable plaques which also had a significantly higher level of CD68 + macrophages compared to stable plaques (AHA I-IV) and higher circulating levels of Chemokine ligand-9 (CXCL-9) (p Conclusion Circulatory EMP and specific inflammatory cytokine levels are raised in patients with unstable plaques, while MIF, a potentially protective factor was elevated in serum of patients with stable plaques. These data could have major implications for the development of a diagnostic tool whereby EMPs together with markers of macrophage activity could act in a combined manner as biomarkers of plaque vulnerability and stroke susceptibility.