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Aortic stenosis (AS) is a complex pathologic process involving inflammation, oxidative stress, endothelial dysfunction, and calcification. Mechanical strain within the valve induces the release of cell-derived microparticles (MPs) promoting tissue mineralization and remodeling. To investigate the impact of MPs release from calcified and non-calcified human aortic valves on valvular endothelial cells (VEC) dysfunction and thrombogenicity. Human AS valves (90) and aortic regurgitation (AR) valves (15) were collected. MPs were quantified by prothrombinase assay. Porcine VEC were studied at passage 1. Oxidative stress and nitric oxide (NO) formation were assessed by fluorescent probes, expression levels of target molecules by RT-qPCR, Western blot analysis and immunofluorescence staining. Release of procoagulant MPs was enhanced in calcified compared to non-calcified AS and AR valves (Fig. 1A–B), and associated with increased levels of thrombogenic (Fig. 1C), adhesive and inflammatory molecules and sodium-glucose co-transporter 2 (SGLT2). Exposure of VEC to AS-MPs caused oxidative stress, pro-inflammatory, pro-thrombotic, pro-angiogenic, and pro-remodeling responses (Fig. 1D–F) and elevated SGLT2 expression involving the local AT1R/NADPH oxidases pro-oxidant pathway, and resulted in MAP-kinases/NF-κB pathway activation, and increased thrombogenicity and recruitment of inflammatory cells (Fig. 1G–H). These responses were inhibited by antioxidants, inhibitors of the angiotensin system, SGLT2, NF-κB or TNF-α. These findings indicate that calcified AS valves are a potent reservoir of MPs promoting valvular dysfunction and thrombogenicity through the AT1R/NADPH oxidases/SGLT2 pro-oxidant pathway leading the NF-κB activation (Fig. 1I). They further suggest that SGLT2 inhibitors might be a novel therapeutic option to curb AS evolution. [ABSTRACT FROM AUTHOR]

Abstract: The loss of graft function after intraportal islet transplantation is likely multifactorial involving allogeneic rejection, recurrent autoimmunity, graft exhaustion due to a marginally implanted islet mass, immunosuppressant toxicity, and impaired β-cell regeneration. Because early markers of the loss of β-cell mass or function are lacking, monitoring of islet function remains a challenging issue. We have reported herein monitoring of membrane procoagulant microparticles (MPs) as markers of cell stress in the plasma of three recipients with various clinical histories. Early kinetics of C-peptide and MPs followed identical patterns during the first weeks after transplantation; a major increase probably reflected processes related to cell infusion and islet engraftment. Importantly in the case of rejection, MPs and C-peptide showed opposite patterns. A fall in C-peptide was associated with enhanced insulin needs. Our results suggested that a peak in MP levels might indicate rejection with prognotic value. Treatment of the loss of islet function by a new islet infusion or steroid therapy returned MP and C-peptide levels to their baselines with concomitant restoration of islet function. In the patient with suspected acute cellular rejection, MPs also appeared to be sensors of immunosuppressive steroid therapy. [Copyright &y& Elsevier]

Abstract: Background: Cardiovascular and metabolic risk factors represent potential targets for intervention. A good metabolic control, associated with control of blood pressure and cholesterol levels is proven to reduce the risk of cardiovascular disease among individuals with diabetes mellitus. Objectives: To examine 2004–2005 medical records of adults with previously diagnosed diabetes and to evaluate the fulfillment of diabetes guidelines treatment, for the metabolic control and management of cardiovascular risk factors. Research, design and methods: We reviewed the data from the National Register of Diabetes (Tirana district), updated during this period. As guidelines we used the ADA 2006 Recommendations for metabolic control, HTA, lipid profile and aspirin therapy. Results: We examined 7259 medical records. Only 14.58% of the patients had an HbA1c <7%. Central obesity was present in 39% of our patients. Overall, only 31.9% of our patients achieved the target for blood pressure (SBP<130mmHg and DBP<80mmHg). Two-third of our patients had total cholesterol >200mg/dl. In total, only 5.5% of our patients attained recommended goals of cardiovascular risk factors for HbA1c, blood pressure and lipid profile. Conclusions: The follow-up of diabetic patients during the transient period in Albania is marked by a deterioration of diabetes metabolic control and poor management of cardiovascular risk factors. Further public health efforts are needed for better control of these risk factors among adults with diagnosed diabetes. [Copyright &y& Elsevier]

Aging-related endothelial dysfunction and vascular oxidative stress affect early arterial sites at risk. Anthocyanins uptake via sodium-glucose co-transporter 1 (SGLT1) are potent inducers of endothelial formation of nitric oxide (NO). This study examined if anthocyanin-rich blackcurrant (ARB) improves the endothelial function in old rats. Male Wistar rats (22-month old) received ARB (60 and 120 mg/kg/d) orally for 2 weeks. Systolic blood pressure (SBP) was assessed by tail-cuff sphygmomanometry, vascular reactivity using organ chambers, protein expression by immunofluorescence, oxidative stress using dihydroethidium, and anthocyanin uptake by Neu reagent. Old rats showed increased SBP, abolished endothelium-dependent hyperpolarization-mediated relaxation and increased contractile response to phenylephrine in the mesenteric artery, which were improved by ARB. Old aorta showed increased oxidative stress and expression levels of eNOS, which were improved by ARB. SGLT1 immunofluorescence predominantly in the endothelium was more pronounced in the aortic arch than the aorta and higher in old than young rats, whereas the SGLT2 signal was low. The ARB treatment induced a dose-dependent accumulation of anthocyanins in the aorta and aortic arch. An ARB purified extract promoted ex vivo greater anthocyanins uptake mostly in the endothelium in the aortic arch than aorta, and in old compared to young rats. The anthocyanins uptake was inhibited to a greater extent by a dual SGLT1/2 inhibitor than by a selective SGLT2 inhibitor in the aorta of young and old rats. Both SGLT inhibitors reduced also ex vivo the age-related vascular oxidative stress. The upregulation of SGLT1, and the greater SGLT1 and SGLT2-mediated uptake of anthocyanins predominantly in the endothelium at arterial sites at risk in old rats suggest that anthocyanins appear as interesting natural products to protect the endothelial function with increasing age. [ABSTRACT FROM AUTHOR]

Introduction Endothelial senescence is thought to promote endothelial dysfunction and the subsequent development of cardiovascular diseases. The EMPA-REG trial has shown that sodium-glucose cotransporter 2 (SGLT2) inhibition is associated with a reduced risk of cardiovascular mortality in type 2 diabetic patients, but the protective mechanism remains unclear. SGLT2 mRNA has not been detected in control endothelial cells (ECs). Aim This study examined the possibility that SGLT2 contributes to endothelial senescence and dysfunction and, if so, to characterize the underlying mechanism. Methods Endothelial cells isolated from porcine coronary arteries were used at passage 1. Senescence was assessed using senescence-associated beta-galactosidase activity (SA-beta-gal activity), protein level by Western blot analysis, oxidative stress using dihydroethidium, and NO formation by electronic paramagnetic resonance. Results Exposure of ECs to HG (25 mM) for 96 h increased the level of SA-beta-gal activity and of senescence markers (p21 and p16) and oxidative stress, decreased eNOS expression and NO formation, and increased the expression of VCAM-1 and tissue factor (TF). Both HG and H 2 O 2 induced the appearance of SGLT2 mRNA, increased SGLT2 protein level and SGLT2-mediated glucose entry in ECs. An increased expression level of SGLT2 and VCAM-1, and a down-regulation of eNOS were observed at arterial sites at risk (aortic cross) compared with those at low risk (thoracic aorta) in young rats. Conclusion These findings indicate that premature ECs ageing is characterized by the down-regulation of NO formation and the expression of pro-atherothrombotic factors, and is associated with the redox-sensitive upregulation of SGLT2 expression promoting excessive glucose entry. The fact that an increased SGLT2 expression level is observed in vivo at arterial sites at risk, suggests that inhibition of SGLT2 might be an attractive strategy to protect the cardiovascular system. [ABSTRACT FROM AUTHOR]

Introduction Microparticles (MPs) are plasma membrane vesicles and vascular effectors. High levels of pro-inflammatory cytokines and procoagulant endothelial-derived MPs circulate in diabetic patients. We have shown that (i) leukocyte-derived MPs shed in response to stress are pro-inflammatory, procoagulant and prosenescent endothelial effectors; (ii) high glucose induces premature endothelial senescence. Objective To determine the possibility that leukocyte-derived MPs affect endothelial senescence and vascular function in response to high glucose. Methods Leukocyte MPs were isolated from rat splenocytes with either 5 mg/ml LPS (MPLPS), 25 ng/ml PMA/1 mM A23187 ionophore (MPPMAi), or vehicle (MPCTL). Porcine coronary artery endothelial cells (ECs) at passage 1 were incubated for 48 h with 1–30 nM MPs in high or low glucose concentration (HG 25 mM, NG 5.5 mM). Senescence-associated β-galactosidase (SA-ß-GAL) activity was assessed by C12FDG, protein expression by Western blot analysis. Pig coronary artery rings were pre-incubated with HG or NG for 12 h prior to addition of 1–30 nM MPs for 12 h. Bradykinin (BK)-induced endothelium-dependent relaxations were assessed in organ chambers, and staining of target proteins by confocal microscopy. Results At 10 nM, MPLPS and MPPMAi enhanced SA-b-GAL activity both by about 2-fold in NG, and respectively 3 and 3.7-fold in HG. The expression of senescence markers p21, p16 doubled and that of eNOS decreased 2-fold. MPPMAi and MPLPS induced a concentration-dependent inhibition of BK-induced relaxation, inhibition by respectively 10 nM and 30 nM,being 65% in NG, amounting to about 85% in HG, whereas 30 nM MPCTL had no effect. MPPMAi and MPLPS reduced eNOS expression by 60% in NG and 80% in HG. Conversely, VCAM-1, COX-2 were up-regulated. Conclusion Leukocyte-derived MPs enhance HG-induced alteration of the endothelial function by inducing premature senescence and might contribute to vascular dysfunction in diabetes patients. [ABSTRACT FROM AUTHOR]

Introduction Ageing promotes atrial remodeling that paves way to atrial fibrillation and thrombogenicity. Preclinical studies on endothelial atrial cells are lacking. Objective This study aims to characterize phenotypical changes associated with atrial endothelial cells senescence and to decipher the link between ageing and thrombogenicity. Methods Atrial endothelial cells (AEC) were obtained from freshly harvested porcine left atria. Endothelial senescence was assessed by senescence-associated beta-galactosidase activity (SA-β-gal), using flow cytometry, protein expression by Western blot analysis and platelet aggregation using an aggregometer. Replicative senescence was induced by passaging AEC from passage P1 to P4, and premature endothelial cell senescence by exposing AEC to L-NAME, an endothelial NO synthase (eNOS) inhibitor or H 2 O 2 . Results AEC senescence was characterized by an increase in SA-β-gal activity and an up-regulation of p53, a key regulator of cellular senescence, and of p21 and p16, key cyclin-dependent kinase inhibitors. Senescent AEC phenotype was characterized by: – cell thrombogenicity through an up-regulation of tissue factor expression, shedding of procoagulant microparticles, eNOS down-regulation and reduced NO-mediated inhibition of platelet aggregation; – cell adhesion through up-regulation of ICAM-1; – proteolysis and fibrosis remodeling through MMP-2, 9 and TGF-β1 expression; – up-regulation of the local Ang II system through enhanced AT1 receptors (AT1R) and angiotensin-converting enzyme (ACE) expression. Losartan, an AT1 receptor antagonist, and Perindoprilat, an ACE inhibitor, prevented atrial endothelial cell senescence. Conclusions Thus atrial endothelial senescence promotes thrombogenicity, inflammation, matrix remodeling and the up-regulation of the local Ang II system. They further suggest that targeting the Ang II/AT1R pathway may be a promising therapeutic strategy to delay atrial endothelial ageing. [ABSTRACT FROM AUTHOR]

Abstract: Microparticles (MPs) are small membrane vesicles that are shed from virtually all cells in response to stress. Widely described in atherothrombotic diseases, recent data suggest a role for circulating MPs in the hypercoagulable state associated with supraventricular tachyarrhythmia. During atrial fibrillation, several mechanisms, such as high ventricular heart rate, low or oscillatory shear stress, stretch, hypoxia, inflammation and oxidative stress, are potent inducers of apoptotic cell death, which leads to the shedding of procoagulant MPs within the vasculature. As key regulators of cell–cell cross-talk and important mediators of inflammatory, thrombogenic and proteolytic pathways, MPs directly or indirectly contribute to the amplification loops involved in atrial fibrillation. Because high levels of platelets and endothelial-derived MPs are identified during stroke and are associated with infarct size and clinical outcome, they are proposed to be a potent marker of ischaemic risk. During pulmonary vein isolation, the additional increases of platelet and leukocyte MP levels suggest the extent of tissue damage and reflect a transient activation of the coagulation cascade that could favour ischaemic stroke. Conversely, the observed decreases of several apoptotic markers some months after the restoration of sinus rhythm suggest that the extent of apoptotic processes is reversible and might enable restoration of haemostasis. In this review, we will summarise the current evidence supporting the roles of apoptosis and cell activation in the development of the prothrombotic state observed in atrial fibrillation, with a particular focus on procoagulant MPs. [Copyright &y& Elsevier]

Abstract Understanding millennial and sub-millennial climate variability during past low eccentricity interglacials similar to the Holocene is important for forecasting the evolution of climate and natural variability. The Ideale section (Montalbano Jonico, Southern Italy) studied here provides one of the best records of MIS 19c, the closest orbital analog to the Holocene. This exposed marine series covers Termination IX to the inception of MIS 18 with very high sedimentation rates (i.e. 90–200 cm/ka). We present 1) benthic δ18O and δ13C records at 90–200 year time-resolution, 2) a new 40Ar/39Ar age of 774.1 ± 0.9 ka for tephra layer V4 (Matuyama-Brunhes transitional period) and 3) new calcareous plankton, palynological and authigenic 10Be/9Be data. Our new Bayesian depth-age model suggests a 11.5 ± 3.4 ka (95% confidence) duration for the climatic optimum. The δ18O series reveals millennial-scale oscillations (with sharp transitions < 200 years) between ∼774.0 and the onset of MIS 18 (∼757.0 ka) with a cyclicity of about 5.4 ka. Spectral analysis and band-pass filtering indicate that these climate oscillations existed throughout the entire MIS 19 period, although they were dampened during MIS 19c, which is chiefly controlled by orbitally-driven insolation. The amplitude of those sub-orbital oscillations increased towards MIS 18 as the climate became drier and cooler. The Ideale section reveals, with unprecedented detail, millennial-scale climatic oscillations of MIS 19b-a that have been observed worldwide. They highlight the response of the central Mediterranean area to North Atlantic climatic variation (i.e. oceanic circulation and atmospheric processes related to ice-sheet dynamics) during this low eccentricity interglacial. Graphical abstract Image 1 Highlights • The 74.2 m IDEAL section (Montalbano-Jonico, Southern Italy) was revised. • New d18O, d13C, calcareous plankton, palynological and authigenic 10Be/9Be records are presented. • A refine age of 774.1 ± 0.9 ka for tephra layer V4 within the Matuyama-Brunhes transitional period is proposed. • The d18O reveals millennial-scale oscillations between 774.0 and 755.0 ka with a cyclicity of about 5.4 ka. • Climate oscillations existed throughout the entire MIS 19 period but hampered during MIS 19c. [ABSTRACT FROM AUTHOR]

Abstract: Sepsis and trauma lead to a sustained activation of monocytes and endothelium. In the vascular compartment, stimulated cells release microparticles. Circulating MP provide an additionnal procoagulant phospholipid surface enabling the assembly of the clotting enzymes complexes and thrombin generation. Their procoagulant properties rely on the exposition of phosphatidylserine, made accessible after cell stimulation and on the possible presence of tissue factor, the main cellular initiator of blood coagulation. Microparticles constitute the main reservoir of blood-borne tissue factor activity. At sites of endothelium injury, enhanced release or recruitment of procoagulant MP through P-selectin–PSGL-1 pathway could concentrate TF activity above a threshold allowing blood coagulation to be triggered. Converging evidences from experimental or clinical data highlight a role for MP harboring tissue factor in the initiation of disseminated intravascular coagulopathy. In these settings, the pharmacological modulation of MP levels or biological functions through activated protein C or factor VIIa allows challenging issues. [Copyright &y& Elsevier]

Abstract: Background. – In multicellular organisms, apoptosis and subsequent microparticle shedding play a key role in homeostasis. Having long been considered as « cellular dust », microparticles released in biological fluids upon cell activation or apoptosis appear as multifunctionnal bioeffectors involved in the modulation of key functions including immunity, inflammation, hemostasis and thrombosis, angiogenesis. MP constitute reliable markers of vascular damage, accessible to biological detection whilst the cells they originate from remain sequestered in tissues or are promptly submitted to phagocytosis. Recent findings. – MP modulate biological functions of target cells through the transfer of cytoplasmic content, lipids and membrane receptors. The pharmacological modulation of circulating levels of microparticles could be of particular interest in thrombotic or inflammatory diseases, cancer or hemophilia. Conclusion. – MP can now be viewed not only as a hallmark of cell damage but also as a true biological tool. [Copyright &y& Elsevier]

Abstract: During percutaneous coronary angioplasty, platelet inhibition by clopidogrel and aspirin has drastically decreased the risk of thrombotic occlusion of the stented vessels. However, despite the widespread use of these drugs, the incidence of acute or subacute stent thrombosis remains elevated, concerning 1 to 2% of the treated patients. Considerable differences in the responsiveness to clopidogrel could be observed, suggesting a possible underlying biological resistance. « Clopidogrel resistance » has recently been associated to an increased risk of thrombotic events following coronary angioplasty. Variations in enteric absorption, biotransformation in the liver by the CYP3A4, changes in the ADP receptor P2Y12, abnomalies of intraplatelet signal transduction, extent of platelet activation, class angina, diabetes mellitus may account for the considerable interindividual response variability widely reported. In this view, laboratory tests evaluating « clopidogrel resistance » might be useful tools for the identification and follow-up of patients at higher thrombotic risk. Indeed, in these patients, further platelet inhibition can be achieved by higher doses of clopidogrel. [Copyright &y& Elsevier]

Ageing is associated with progressive endothelial senescence and dysfunction, and cardiovascular risk. Circulating endothelial microvesicles (MVs) are pro-senescent and pro-inflammatory endothelial effectors in acute coronary syndrome. Omega-3 PUFA intake was claimed beneficial in cardiovascular prevention. To investigate whether the intake of the omega-3 formulation EPA:DHA 6:1 by middle-aged and old rats reduces the shedding of pro-senescent microvesicles from cultured spleen leukocytes (SMVs) and clarify the underlying mechanisms in target coronary primary endothelial cells (ECs). Middle-aged male Wistar rats (M, 48-week old) received 500 mg/kg/d of either EPA:DHA 6:1, EPA:DHA 1:1, or vehicle (CTL) for 7 days, old rats (72-week old) for 14 days. Spleen-derived leukocytes were prepared and cultured for 24 h and MVs collected from supernatants (SMVs). Cultured ECs were prepared from freshly isolated porcine coronary arteries. Senescence-associated β-galactosidase activity (SA-β-gal) was assessed by C12FDG, protein expression by Western blot analysis, oxidative stress by dihydroethidium using confocal microscopy, and procoagulant MVs by prothrombinase assay. The pro-senescent potential of SMVs from middle-aged rats (M−SMVs) was analyzed by comparison with young (Y, 12-week) and old (O) rats. The shedding of SMVs significantly increased with age and was inhibited by EPA:DHA 6:1 intake that also prevented ROS accumulation in spleen. Incubation of ECs with 10 nM SMVs from middle-aged and old but not those from young rats induced premature senescence after 48 h. The pro-senescent effect of M−SMVs was prevented by Losartan and associated with endothelial oxidative stress. M−SMVs induced an up-regulation of senescence markers (p16, p21, p53), pro-atherothrombotic (VCAM-1, ICAM-1, tissue factor) and pro-inflammatory markers (pNF-κB, COX-2) and proteins of the angiotensin system (ACE, AT1-R). Conversely, endothelial NO synthase was down-regulated. Intake of EPA:DHA 1:1 and 6:1 by middle-aged rats decreased SMV shedding by 14% and 24%, respectively. Only EPA:DHA 6:1 intake abolished the M−SMVs−induced endothelial senescence and reduced the pro-senescent action of O-SMVs by 45%. Protection of ECs was not observed in response to SMVs from EPA:DHA 1:1 treated rats. Ingestion of EPA:DHA 6:1 by middle-aged or old rats, respectively abolished or limited both the shedding of SMVs and their pro-senescent, pro-thrombotic and pro-inflammatory effects in ECs, most likely by triggering the local angiotensin system. EPA:DHA 6:1 may help to delay ageing-related endothelial dysfunction. [ABSTRACT FROM AUTHOR]

Introduction La chirurgie bariatrique est à risque thrombotique important justifiant une prophylaxie à posologies élevées. Il n’existe pas, à l’heure actuelle, de consensus dans ce domaine [1] . L’objectif de notre étude était de déterminer la posologie d’énoxaparine idéale permettant d’obtenir une activité anti-Xa entre 0,3 et 0,5 UI/mL mesurée 4 heures après l’injection dans la période postopératoire et de mesurer les microparticules procoagulantes (MPs). Matériel et méthodes Cent quarante-six patients (IMC > 40) informés et consentants ayant bénéficié d’un bypass gastrique ont été inclus dans cette étude prospective, multicentrique, randomisée, après accord du CPP. L’énoxaparine était injectée selon 3 schémas différents : groupe A, n = 46, 4000 UI/j ; groupe B, n = 48, 6000 UI/j ; groupe C, n = 52, 2 × 4000 UI/j. L’activité anti-Xa était mesurée avant et 4 heures après chaque injection à J0, J1 et J2. Un échodoppler des membres inférieurs était réalisé à J-1, J9 et J30. Les événements hémorragiques et thrombotiques cliniques ont été colligés. Les MPs totales, leucocytaires CD11a, endothéliales CD115, plaquettaires GP1b, lymphocytaires CD10 et granulocytaires CD66 ont été dosées à J0, J9, J30 chez une dizaine de patient de chaque groupe. Les 3 groupes ont été comparés par ANOVA pour l’objectif principal. Résultats Les 3 groupes ne différaient pas pour l’âge moyen, l’IMC, la durée opératoire, la durée d’anesthésie et la durée totale de la prophylaxie (13 j). L’échodoppler réalisé à J-1, J9 et J30 était normal pour l’ensemble des patients. L’équilibre de l’activité anti-Xa (pic 4 e heure) était observé vers la 52 e heure postopératoire dans les 3 groupes ( Fig. 1 ). Le pourcentage de patients ayant atteint la cible souhaitée était respectivement de 12,8 %, 56,4 % et 27,3 % dans les groupes A, B et C ( p < 0,001). Seul un patient a dépassé la borne supérieure. On a constaté une EP dans le groupe B (2,1 %) et 13 évènements hémorragiques (groupe A : 2,2 %, groupe B : 8,3 % et groupe C : 15,4 %, p = 0,08). La concentration de MPs totales était stable et superposable au cours du temps dans les 3 groupes. Les MPs plaquettaires, granulocytaires et leucocytaires augmentaient dans les 3 groupes à J10 mais restaient élevées ou continuaient à augmenter dans le groupe C contrairement aux groupes A et B à J30 ( Fig. 2 ). Discussion Notre étude montre que l’injection d’une dose unique de 6000 UI d’énoxaparine a permis d’atteindre la cible thérapeutique souhaitée chez le plus grand nombre de patients sans majorer le risque hémorragique. Ces résultats ne corroborent pas les suggestions récentes [1] préconisant 2 injections d’HBPM par jour en limitant la posologie unitaire à 5000 UI. Les dosages préliminaires de microparticules procoagulantes semblent confirmer ces données. [ABSTRACT FROM AUTHOR]