Insulin like growth factor binding protein 2 (IGFBP-2) for risk prediction in patients with severe aortic stenosis undergoing Transcatheter Aortic Valve Implantation (TAVI).

INTRODUCTION: Severe aortic stenosis (AS) caused by degenerative calcification is the most frequent acquired valvular heart disease worldwide and mortality rates are considerably high. Transcatheter Aortic Valve Implantation (TAVI) is a well-established method for valve replacement in high risk patients with AS. However, there is a lack of reliable predictors for patients undergoing TAVI since commonly used scores were developed for surgical populations. MATERIALS AND METHODS: 208 patients subjected to TAVI were included in this study. Plasma samples were obtained before TAVI and were evaluated for IGFBP-2 using commercially available ELISA kits. IGFBP-2 levels were analyzed for their ability for risk prediction after TAVI. RESULTS: IGFBP-2 levels measured before TAVI correlated significantly with left ventricular ejection fraction, EUROSCORE and other functional and prognostic parameters like the 6-minute walking test. When patients were retrospectively divided in two groups with a cut-off of serum IGFBP-2 levels of 275 ng/ml, IGFBP-2 was a strong predictor for 30-day and one-year mortality (3% vs. 11%, p = 0.05 and 18.2% vs. 46.2%; p < 0.001 respectively). Compared to an EUROSCORE above 20 or an STS score cut-off above 8, IGFBP-2 plasma levels above 275 ng/ml outperformed the established risk score for prediction of one-year mortality as assessed by NRI (0.65 95% CI 0.37-0.94; p < 0.001 and 0.54 95% CI 0.25-0.82; p < 0.001, respectively). CONCLUSIONS: Our results indicate that IGFBP-2 could serve as new outcome predictor for patients undergoing TAVI procedure. By providing additional information to the commonly used EUROSCORE, IGFPB-2 analysis could further assist Heart Team decision making.

Efficacy of temperature-guided cryoballoon ablation without using real-time recordings - 12-Month follow-up.

BACKGROUND: We sought to evaluate a temperature-guided approach of cryoballoon (CB) ablation without visualization of real-time recordings. METHODS AND RESULTS: We analysed 166 patients (34.9% female, 60 ±â€¯11 years) with paroxysmal or short-term persistent atrial fibrillation (AF). Comorbidities included diabetes mellitus (n = 28), coronary artery disease (n = 24), hypertension (n = 122), previous stroke or TIA > 3 months (n = 12). Cryoablation of the pulmonary veins (PV) was performed using first-generation (n = 78) and second-generation CB (n = 88). Two 5-minute freezes were performed for the first-generation and two 4-minute freezes for the second-generation CB with the intention to achieve a temperature drop below -40 °C. At 12-month follow-up, we observed overall freedom from AF in 92 patients (56.6%, mean time to AF recurrence 3.4 ±â€¯2.9 months). There was a significant difference in freedom from AF between first-generation CB (45%) and second-generation CB (67%; p < 0.005). Complications were groin hematoma (4.8%) and phrenic nerve palsy (PVP) (2.4%). PVP disappeared after 12 months in all patients. Three patients developed cardiac tamponade (1.8%) that resolved without further sequelae after pericardiocentesis. Multivariate analysis revealed that only the achieved temperature in the right inferior PV (RIPV) was a predictor of long-term freedom from AF (OR 0.9; p = 0.014). Female gender was a predictor of AF recurrence (OR 6.1; p = 0.022). CONCLUSION: Temperature-guided CB ablation without real-time recordings is feasible and safe without reducing the efficacy if second-generation CB is used. Deep nadir temperatures especially in the RIPV are necessary for long term-success.

Multi-biomarker analysis in patients after transcatheter aortic valve implantation (TAVI).

BACKGROUND: In this study we sought to examine whether transcatheter aortic valve implantation (TAVI) is followed by a change in the plasma levels of novel cardiovascular biomarkers. METHODS: We collected blood samples of 79 patients with severe aortic valve stenosis undergoing TAVI before and at 7 days, 1 month, 3 months and 6 months post TAVI and analyzed the plasma concentrations of GDF-15, H-FABP, fetuin-A, galectin 3, sST2 and suPAR by means of ELISA. RESULTS: There was a significant increase in the concentration of fetuin-A (median: 52.44 mg/ml to 113.2 mg/ml, p < 0.001) and a significant decrease of H-FABP after TAVI (median: 4.835 ng/ml to 2.534 ng/ml, p < 0.001). The concentrations of suPAR and sST2 showed an initial increase (suPAR median: 2755 pg/ml 3489 pg/ml, p < 0.001; sST2 median: 5832 pg/ml to 7137 pq/ml, p < 0.001) and subsequently decreased significantly. CONCLUSION: We hypothesize that the decrease of H-FABP and the increase of fetuin-A could be due to a hemodynamic improvement after valve replacement. The initial increase of suPAR could indicate an inflammatory stimulus and the significant increase in sST2 could be due to the mechanical strain caused by implantation of the valve.

Elevated plasma levels of interleukin-16 in patients with acute myocardial infarction.

Interleukin (IL)-16, a polypeptide cytokine, plays a crucial role in the inflammatory process, acting as a chemoattractant for peripheral immune cells and has been linked to various inflammatory diseases. However, its role in patients with acute myocardial infarction (AMI) is unclear.We retrospectively analyzed serum levels of IL-16 in blood of patients with (STEMI, n = 45) and without ST-segment elevation myocardial infarction (NSTEMI, n = 42) compared with controls with excluded coronary artery disease (n = 55). Furthermore, correlation analysis with inflammatory cells, C-reactive protein (CRP) levels, dendritic cell precursors (DCPs), and other clinical and biochemical markers was performed.Compared with controls, patients with STEMI and NSTEMI evidenced higher levels of IL-16 in pg/mL (STEMI: 759.38 ±â€Š471.54, NSTEMI: 677.77 ±â€Š438.8, control: 500.45 ±â€Š432.21; P = .002). IL-16 correlated with CRP (r = 0.26, P = .001), leucocytes (r = 0.38, P < .001), NT-proBNP (r = 0.20, P = .02) and hsTnT (r = 0.25, P = .004). Circulating myeloid DCPs, plasmacytoid DCPs, and total DCPs showed a significant inverse correlation to IL-16 levels (r = -0.21, P = .01; r = -0.23, P = .005; r = -0.26, P = .002, respectively).Interleukin-16 might play an important role in the inflammatory process of patients suffering from AMI and correlates with inflammatory cell activation and clinical and biochemical markers. The cytokine IL-16 might upregulate the proinflammatory response and recruitment of inflammatory cells into infarcted myocardium.

Impact of Moderate Altitude on Pro-Inflammatory Cytokines in Healthy Volunteers.

BACKGROUND: The induction of microvascular inflammation and the effects on cytokine production in blood due to hypoxia has been shown in the past. We have previously reported a statistically significant increase of the pro-inflammatory cytokine interleukin-8 (IL-8) in normobaric hypoxia in the setting of a hypoxia-chamber. In the present study, we sought to analyze plasma levels of inflammatory cytokines in a real-life stetting in order to foster our knowledge on hypoxia induced microvascular inflammation at moderate altitude. METHODS: Pro-inflammatory cytokines (IL-8, IL-6, TNF-α) were measured in an experimental field study, exposing 18 healthy volunteers to moderate hypoxia while staying at a mountain lodge in Diavolezza, Switzerland (2978 meters above sea level). Plasma cytokine levels were measured by ELISA. RESULTS: In contradiction to our results in a normobaric hypoxia-chamber, exposure to moderate hypoxia led to a significant decrease of plasma IL-8 levels in a real-life setting (from 2.902 (1.046 - 4.984) pg/mL to 1.395 (0.698 - 3.712) pg/mL, p = 0.034). Concentrations of IL-6 and TNF-α did not show statistically significant changes in comparison to baseline measurements. CONCLUSIONS: The results of this study show a decrease of proinflammatory cytokine IL-8 in a real life setting of moderate altitude in healthy individuals. Initiation of angiogenesis or subliminal stimulus for an altitude-induced inflammatory reaction may be explanations for this unexpected finding.

Multibiomarker analysis in patients with acute myocardial infarction.

BACKGROUND: Novel biomarkers representing different pathobiological pathways and their role in patients with acute myocardial infarction (AMI) were studied. METHODS: We retrospectively analysed serum levels of soluble suppression of tumorigenicity (sST2), growth-differentiation factor-15 (GDF-15), soluble urokinase plasminogen activator receptor (suPAR), heart-type fatty acid-binding protein (H-FABP) and plasma fetuin A in blood of patients with AMI (STEMI, n = 61; NSTEMI, n = 57) compared to controls with excluded coronary artery disease (n = 76). Furthermore, detailed correlation analysis was performed. RESULTS: Compared with controls, in patients with STEMI and NSTEMI higher levels expressed as median of sST2 in pg/mL (STEMI: 13210·9, NSTEMI: 11989·1, control: 5248; P < 0·001), GDF-15 in pg/mL (STEMI: 818·8, NSTEMI 677·5, control 548·6; P < 0·001), suPAR in pg/mL (STEMI: 3461·1, NSTEMI: 3466·7, control: 2463·6; P < 0·001), H-FABP in ng/mL (STEMI: 5·8, NSTEMI: 5·4, control: 0·0; P < 0·001) and lower plasma fetuin A levels in µg/mL (STEMI: 95, NSTEMI: 54, control: 116·6; P < 0·001) were detected. Correlation analysis found clinical and biochemical parameters such as ejection fraction, length of hospital stay, creatine kinase, NT-proBNP and hs Troponin T levels as well as inflammatory markers (CRP, leucocytes) to be significantly correlated with novel biomarkers. CONCLUSION: Plasma levels of novel biomarkers were significantly elevated (sST2, GDF-15, H-FABP, suPAR) or inversely downregulated (fetuin A) in patients with AMI compared to a control group with excluded coronary artery disease. Significant correlations with various clinical parameters and standard biochemical markers were found.

Predictive value of the augmentation index derived vascular age in patients with newly diagnosed atherosclerosis.

Early detection of atherosclerosis, i.e., in occupational health screening programs could reduce the rate of cardiovascular events in the working population. Changes of the augmentation index (AIX) correlate with changes of the arterial stiffness induced by aging, atherosclerosis, or arterial hypertension and have a prognostic value for cardiovascular events. Their diagnostic yield should be increased by normalizing the AIX to age, in terms of a calculating the vascular age (VA). In this pilot study, 30 patients (mean age 65.3 ± 8.8 years, 21 male) with suspected coronary heart disease underwent a duplex ultrasound of the carotid arteries and a measurement of the ankle brachial index in addition to the coronary angiography. The AIX was recorded with a portable device (Vascular Explorer), and the VA was calculated. Atherosclerosis was found in 24 patients. They were older than the patients without atherosclerosis, but there was no age dependency found for the distribution pattern or severity of atherosclerosis. In patients with findings of atherosclerosis, the calculated VA was higher than the chronological age, and these differences were significant in patients below 65 years of age. Comparing patients in higher blood pressure classes with patients in lower classes, significantly higher AIX, VA, and differences to the chronological age were found. The VA, deduced from the noninvasively obtained AIX, is a promising candidate for screening programs for atherosclerosis, i.e., in occupational health screening programs.

Microparticles in patients undergoing transcatheter aortic valve implantation (TAVI).

Degenerative aortic stenosis (AS) is the most frequent form of acquired valvular heart disease. AS is known to entail endothelial dysfunction caused by increased mechanical shear stress leading to elevated circulatory levels of microparticles. Endothelial and platelet microparticles (EMP and PMP) are small vesicles that originate from activated cells and thrombocytes. We sought to evaluate whether transcatheter aortic valve implantation (TAVI) procedure would elicit effects on circulating EMP and PMP. 92 patients undergoing TAVI procedure for severe AS were included in this study. Samples were obtained at each visit before TAVI, 1 week post-procedure and at 1, 3 and after 6 months after TAVI and were evaluated using flow cytometry. A 12 month clinical follow-up was also performed. CD62E+ EMP concentration before TAVI was 21.11 % (±6.6 % SD) and declined to 20.99 % (±6.8 % SD) after 1 week, to 16.63 % (±5.4 % SD, p < 0.0001) after 1 month, to 17.08 % (±4.6 % SD, p < 0.0001) after 3 months and to 15.94 % (±5.4 % SD, p < 0.0001) after 6 months. CD31+/CD42b-, CD31+/Annexin+/- EMP remained unchanged. CD31+/CD41b+ PMP evidenced a slight, but statistically significant increase after TAVI and remained elevated during the entire follow-up. Apart from a procedure-related improvement in echocardiographic parameters, TAVI procedure led also to a decline in CD62E+ EMP. The reduction in pressure gradients with less hemodynamic shear stress seems also to have beneficially affected endothelial homeostasis.

Alterations in systemic levels of Th1, Th2, and Th17 cytokines in overweight adolescents and obese mice.

BACKGROUND: Obesity represents a major problem for patients and health care systems in most industrialized countries. A chronic inflammatory state in obese individuals leads to disease conditions associated with activation of cellular immune mechanisms. Here, we sought to investigate the role of Th1-, Th2-, and Th17-related cytokines in overweight adolescents and mice on a high-fat diet. METHODS: Plasma samples were obtained from 79 male adolescents aged 13-17 years. Thirty-seven of them had a body mass index (BMI) above the 90th age-specific percentile. Th1, Th2, and Th17 cytokines were measured using Bio-Plex multiplex technology (Bio-Rad, Hercules, USA). In an experimental approach, mice were fed with high-fat (HFD) or normal chow for 15 weeks. RESULTS: Interleukin (IL)-17 concentrations were significantly decreased in overweight adolescents compared to lean controls [99.8 ± 7.3 pg/mL standard error of the mean (SEM) vs 146.6 ± 11.5 pg/mL SEM P = .001]. Levels of IL-17 correlated significantly with anthropometrical parameters of obesity. A concordant response was found in mice consuming a HFD for 15 weeks compared to controls (861 ± 165 pg/mL SEM vs 1575 ± 187 pg/ml SEM, P = .0183). However, a biphasic response was evident for most Th1, Th2, and Th17 cytokines as levels initially increased within the first 5 weeks on HFD and showed a decline afterwards. CONCLUSIONS: In contrast to previous studies showing elevated levels of IL-17 in obese adults, we found a decreasing trend in overweight adolescents. This difference could possibly be related to the fact that disease conditions associated with obesity such as hypertension, vascular pathologies, diabetes, and a triggering of the Th1/Th17 axis were not yet present in overweight teenagers.

Soluble ST2 predicts 1-year outcome in patients undergoing transcatheter aortic valve implantation.

BACKGROUND: Soluble ST2 (sST2) has been introduced as a novel biomarker in patients suffering from heart failure for risk stratification. In this study, we sought to investigate whether sST2 is useful for risk stratification and prediction of mortality in patients undergoing transcatheter aortic valve implantation (TAVI). MATERIALS AND METHODS: A total of 274 patients undergoing TAVI were included in this study (149 female; age 81 ± 1 years; EUROSCORE 25 ± 1; STS score 3·8 ± 0·2). Plasma samples were obtained preinterventional and analysed for sST2. Patients were followed up 1 month and 1 year after TAVI. RESULTS: In a Cox regression analysis, sST2 plasma concentration was associated with increased mortality (changes per pg/mL sST2 concentration; HR 1·00006 95% (1·00004-1·00009); P < 0·001). A cut-off by means of the Youden Index was calculated (10 070·27 pg/mL), and patients were retrospectively divided into two cohorts, in those above (31·3%) and those below (68·7%) this value. These two groups were then compared regarding mortality both after 30 days and 1 year: whereas 1-month mortality did not differ (7·0% vs. 10·3%, OR 1·50 95% CI (0·60-3·79; P = 0·46)), patients with a sST2 concentration above the cut-off of 10 070·27 pg/mL showed a significantly worse outcome after 1 year (49·2% vs. 23·2%; OR 3·21 95% CI (1·70-6·04); P < 0·001). After correction for confounders in a multivariate Cox regression analysis, sST2 (1·0002 95% CI (1·0001-1·0003); P = 0·001) concentration remained associated with mortality. CONCLUSIONS: sST2 levels were associated with 1-year mortality after TAVI. Based on these results, we assume that sST2 might help to identify patients at high risk for death in whom conservative treatment should be considered.

Pulse contour cardiac output monitoring in acute heart failure patients : Assessment of hemodynamic measurements.

BACKGROUND: Heart failure is known to be a major public health problem. Fluid redistribution contributes to acute heart failure; therefore, knowledge of hemodynamic parameters could be important for optimizing outcomes. The pulse contour cardiac output monitor PiCCO uses the single thermal indicator technique and pulse contour analysis to calculate hemodynamic parameters of preload, afterload, cardiac output, systemic vascular resistance and extravascular lung water. OBJECTIVES: We primarily aimed to describe values and parameters seen in acute heart failure patients admitted to the intensive care unit (ICU) and secondly to investigate associations between hemodynamic measurements and survival data. MATERIAL AND METHODS: In this study 420 consecutive patients admitted to a tertiary medical university hospital ICU between January 2004 and December 2009 were retrospectively investigated. The study sample was divided into two subgroups: patients monitored by PiCCO (n = 47) and those not monitored by thermodilution measurements (n = 373). No predetermined treatment algorithm based on knowledge obtained by the PiCCO monitor was used and measurements were individually interpreted by the treating physician. The PiCCO monitor measurements were carried out according to manufacturer's directions. RESULTS: Patients with PiCCO monitoring were clinically in poorer health with a mean simplified acute physiology score II (SAPS2) of 45 ± 17 vs. 56 ± 20 (p < 0.01). The ICU mortality (22 % vs. 38 %, p = 0.02) and, at least as a tendency, long-term-mortality were increased in patients monitored by PiCCO (RR 1.49, 95 % CI 0.96-2.31, p = 0.08). We provide hemodynamic measurements in acute heart failure patients: cardiac index (2.7 ± 1.2 l/min/m²) was reduced, preload and extravascular lung water index (EVLWI, 11.5 ± 5.1 ml/kg body weight), representing lung edema, were increased. CONCLUSION: We provide real world values for PiCCO parameters in acutely decompensated heart failure. In our study patients who were clinically in poorer health were monitored with PiCCO, resulting in increased mortality in this group. Further prospective studies to investigate the effects of treatment decisions triggered by information obtained by PiCCO monitoring for patients in acute heart failure are needed.

Effect of endothelin-1 and endothelin receptor blockade on the release of microparticles.

BACKGROUND: Increased levels of endothelial cell microparticles (EMP) are known to reflect endothelial dysfunction (ED). In diabetes mellitus type 2 (T2DM), the expression of endothelin (ET)-1 is increased. As treatment with an ET-1 antagonist significantly inhibited atherosclerosis in animal models, we sought to investigate whether treatment with ET-1 antagonists affects EMP levels in vitro and in vivo in patients with T2DM. MATERIALS AND METHODS: In vitro study: Human umbilical vein endothelial cells (HUVEC) were stimulated with ET-1 alone and ET-1 in combination with a dual ET-A and ET-B endothelin receptor blocker. In vivo study: Patients with T2DM were randomized to treatment with the ET receptor antagonist bosentan or placebo. After 4 weeks, the patients were re-examined and blood samples were obtained. EMP counts in supernatants and plasma samples were determined using flow cytometry. RESULTS: In vitro study: In supernatants of ET-1-stimulated HUVECs, the increased release of EMP was reduced significantly by co-incubation with an ET-1 receptor antagonist (e.g. CD31+/CD42b-EMP decreased from 37·1% ± 2·8 to 31·5% ± 2·8 SEM, P = 0·0078). In vivo study: No changes in EMP levels in blood samples of patients with T2DM were found after 4 weeks of bosentan treatment (n = 36, P = ns). CONCLUSIONS: Our in vitro results suggest that ET-1 stimulates the release of EMP from HUVECs via a receptor-dependent mechanism. Co-incubation with an endothelin receptor blocker abolished ET-1-dependent EMP release. However, treatment with bosentan for 4 weeks failed to alter EMP levels in patients with T2DM. Other factors seem to have influenced EMP release in patients with T2DM independent of ET-1 receptor-mediated mechanisms.

Decrease of circulating myeloid dendritic cells in patients with chronic heart failure.

AIMS: Immunity and inflammation processes are known to be of central importance in chronic heart failure (CHF). Dendritic cells (DCs) are key players in adaptive immunity, yet their role in CHF is still unknown. The aim of this study was to investigate the circulating DCs in patients with compensated CHF. METHODS: Circulating myeloid (m) and plasmacytoid (p) DCs, as well as inflammatory cytokines interleukine (IL) 6 and IL10 were flow cytometrically analysed in peripheral blood of clinically compensated CHF patients with previously diagnosed dilated cardiomyopathy (DCM, n = 69), ischaemic cardiomyopathy (ICM, n = 49), as well as in unaffected controls (n = 51). Correlation analysis was performed between circulating DCs, cytokines and parameters of heart failure severity, such as NYHA class, the marker brain natriuretic peptide (BNP) and echocardiographic parameters of left ventricular function and dilation. RESULTS: Circulating mDCs were significantly decreased in all CHF patients, although more pronounced in DCM (0.14%, P < 0.001) than in ICM (0.18%, P = 0.043) compared to controls (0.2%). In contrast, no statistical changes were observed for pDCs. Circulating mDCs correlated with left ventricular ejection fraction (LVEF) and inversely with LV end-diastolic diameter (LVEDd) in all CHF patients. For DCM patients, an inverse correlation of mDCs with BNP was additionally observed. Circulating mDCs correlated inversely with IL6 and IL10 in all CHF patients. With the exception of IL-6 and NYHA class of DCM patients, cytokines did not significantly correlate with heart failure parameters. CONCLUSIONS: Blood mDCs are decreased in CHF patients. The reduction correlates with the severity of their HF.

Hypobaric hypoxia in 3000 m altitude leads to a significant decrease in circulating plasmacytoid dendritic cells in humans.

INTRODUCTION: Hypoxia is known to affect the immune system. It leads to an increase in pro-inflammatory cytokines such as interleukin-6 and influences the number of different inflammatory cells. This study investigates the effect of hypoxia on the number of different subsets of circulating human dendritic cells (DCs) as professional antigen-presenting cells. METHODS: The number of circulating DCs was determined via Fluorescence activated cell sorting analysis in peripheral blood of 17 healthy volunteers (age 35.9±2.6 years) in normoxia (baseline, BL), hypoxia (altitude 3000 m, alpine passive escalation), and again normoxia (follow-up, FU). RESULTS: Exposure to hypobaric hypoxia in high altitude, 3000 m, led to a significant decrease in the participants' oxygen saturation, and an increase in the breathing frequency whereas blood pressure and heart rate were not significantly altered. FACS analysis revealed a significant hypoxia induced decrease in circulating plasmacytoid (p) DCs compared to baseline levels (BL: 0.10 [0.08-0.18] % of white blood cell count (WBC), 3000 m: 0.03 [0.02-0.06] % WBC, p < 0.001). During follow up, again a significant reconstitution of circulating pDCs was observed (FU: 0.16±[0.11-0.26] % WBC, p = 0.0013). CONCLUSION: Hypobaric hypoxia caused by exposure to altitude results in a significant reduction in the number of circulating pDCs.

Outcome predictors in cardiopulmonary resuscitation facilitated by extracorporeal membrane oxygenation.

INTRODUCTION: Cardiac arrest is the major cause of sudden death in developed countries. Extracorporeal cardiopulmonary resuscitation (ECPR) employs extracorporeal membrane oxygenation (ECMO) in patients without return of spontaneous circulation (ROSC) by conventional cardiopulmonary resuscitation (CPR). Aim of the current study was to assess short- and long-term outcome in patients treated with ECPR in our tertiary center and to identify predictors of outcome. METHODS: We retrospectively collected data of all patients treated with ECPR at our institution from 2002 to 2013. Outcome was assessed according to patient records; good neurological outcome was defined as cerebral performance category 1 or 2. Quality of life data was collected using EQ-5 questionnaire. Uni- and multivariate analysis was applied to identify predictors of outcome. RESULTS: One-hundred and seventeen patients were included into the study. Weaning from ECMO was successful in 61 (52 %) patients. Thirty-day survival endpoint was achieved by 27 (23 %) patients. Good neurological outcome was present in 17 (15 %) patients. Multivariate analysis revealed baseline serum lactate as the strongest predictor of outcome, whereas age and out-of-hospital CPR did not predict outcome. The optimal lactate cut-off to discriminate outcome was determined at 4.6 mmol/l [HR 3.55 (2.29-5.49), p < 0.001, log-rank test]. CONCLUSION: ECPR represents a treatment option in patients without ROSC after conventional CPR rescuing 15 % of patients with good neurological outcome. Serum lactate may play a crucial role in patient selection for ECPR.

Involvement of phosphoinositide 3-kinase class IA (PI3K 110α) and NADPH oxidase 1 (NOX1) in regulation of vascular differentiation induced by vascular endothelial growth factor (VEGF) in mouse embryonic stem cells.

The impact of reactive oxygen species and phosphoinositide 3-kinase (PI3K) in differentiating embryonic stem (ES) cells is largely unknown. Here, we show that the silencing of the PI3K catalytic subunit p110α and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 (NOX1) by short hairpin RNA or pharmacological inhibition of NOX and ras-related C3 botulinum toxin substrate 1 (Rac1) abolishes superoxide production by vascular endothelial growth factor (VEGF) in mouse ES cells and in ES-cell-derived fetal liver kinase-1(+) (Flk-1(+)) vascular progenitor cells, whereas the mitochondrial complex I inhibitor rotenone does not have an effect. Silencing p110α or inhibiting Rac1 arrests vasculogenesis at initial stages in embryoid bodies, even under VEGF treatment, as indicated by platelet endothelial cell adhesion molecule-1 (PECAM-1)-positive areas and branching points. In the absence of p110α, tube-like structure formation on matrigel and cell migration of Flk-1(+) cells in scratch migration assays are totally impaired. Silencing NOX1 causes a reduction in PECAM-1-positive areas, branching points, cell migration and tube length upon VEGF treatment, despite the expression of vascular differentiation markers. Interestingly, silencing p110α but not NOX1 inhibits the activation of Rac1, Ras homologue gene family member A (RhoA) and Akt leading to the abrogation of VEGF-induced lamellipodia structure formation. Thus, our data demonstrate that the PI3K p110α-Akt/Rac1 and NOX1 signalling pathways play a pivotal role in VEGF-induced vascular differentiation and cell migration. Rac1, RhoA and Akt phosphorylation occur downstream of PI3K and upstream of NOX1 underscoring a role of PI3K p110α in the regulation of cell polarity and migration.

Current Results of Surgical Aortic Valve Replacement: Insights From the German Aortic Valve Registry.

BACKGROUND: Conventional aortic valve replacement (AVR) remains the therapy of choice for many patients with severe aortic valve disease. The unique German Aortic Valve Registry (GARY) allows the comparison of contemporary outcomes of AVR with those of transcatheter AVRs. We report here real-world, all-comers outcomes of AVR, including combined AVR and coronary bypass grafting (AVR+CABG). METHODS: A total of 34,063 patients who received AVR (22,107 patients, 39% female; mean age 68.0 ± 11.3 years, mean logistic European System for Cardiac Operative Risk Evaluation, 8.6%) or AVR+CABG (11,956 patients, 28% female; mean age 72.6 ± 7.8 years, mean logistic European System for Cardiac Operative Risk Evaluation, 10.7%) between 2011 and 2013 were analyzed and followed up to assess the 1-year outcome. RESULTS: In-hospital mortality was 2.3% for AVR and 4.1% for AVR+CABG. Other important outcome variables include stroke (AVR, 1.2%; AVR+CABG, 1.9%) and new pacemaker implantation (AVR, 4.4%; AVR+CABG, 3.6%). Survival at 1 year was 93.2% for AVR and 89.4% for AVR+CABG. Total stroke rates at 1 year were 1.6% for AVR and 2.0% AVR+CABG. Quality of life assessment indicated that most patients were in New York Heart Association Functional Classification I or II (AVR, 86%; AVR+CABG, 84%) and that they were satisfied with the overall postoperative course (AVR, 88%; AVR+CABG, 87%). CONCLUSIONS: Contemporary surgical AVR yields excellent outcomes with low in-hospital mortality, a low overall complication rate, and good 1-year outcome for all risk groups. Accordingly, conventional AVR remains an important therapeutic option for many patients.

Impact of Systemic Normobaric Short-Term Hypoxia on Pro-Inflammatory and Anti-Inflammatory Cytokines in Healthy Volunteers.

BACKGROUND: Hypoxia has been shown to induce a microvascular inflammation, affect the cell count of different types of immune cells, and influence cytokine production in blood. In the present study, serum levels of different cytokines were investigated to achieve insights into the effect of hypoxia on the balance of inflammation and anti-inflammation. METHODS: Pro- (IL-8) and anti-inflammatory (IL-10) cytokines were measured in an experiment exposing 12 healthy subjects (35 ± 9 yr, 176 ± 7 cm, 73 ± 16 kg, BMI 23 ± 4 kg/m2) to systemic, normobaric hypoxia in a hypoxic chamber. In this chamber oxygen was replaced by nitrogen to reach an oxygen content of 9.9% that is equivalent to an altitude of 5500 m during 7 hours. Serum cytokine concentrations were analyzed using ELISA. RESULTS: As expected, a significant decrease in peripheral oxygen saturation accompanied by a significant increase in breathing frequency and heart rate were observed in the subjects during hypoxia compared to baseline (BL). Blood leukocytes increased slightly, but significantly in the course of hypoxia. A statistically significant increase was measured for IL-8 serum level during hypoxia compared to the baseline measurements (BL 12.0 ± 1.1 pg/mL, hypoxia 16.2 ± 1.6 pg/mL, p = 0.006). For IL-10 a statistically significant decrease was measured upon hypoxia compared to baseline (BL 11.6 [6.2 - 43.31 pg/mL, hypoxia 8.3 [4.4 - 26.6] pg/mL, p = 0.016). Additionally, a significant inverse correlation was found comparing the anti-inflammatory cytokine IL-10 with the pro-inflammatory cytokine IL-8 (r = -0.69, p < 0.001). CONCLUSIONS: The results of this study demonstrate a hypoxia-induced increase in pro- and decrease in anti-inflammatory cytokines reflecting an increased pro-inflammatory status during hypoxia.

Cardiomyogenesis of embryonic stem cells upon purinergic receptor activation by ADP and ATP.

Purinergic signaling may be involved in embryonic development of the heart. In the present study, the effects of purinergic receptor stimulation on cardiomyogenesis of mouse embryonic stem (ES) cells were investigated. ADP or ATP increased the number of cardiac clusters and cardiac cells, as well as beating frequency. Cardiac-specific genes showed enhanced expression of α-MHC, MLC2v, α-actinin, connexin 45 (Cx45), and HCN4, on both gene and protein levels upon ADP/ATP treatment, indicating increased cardiomyogenesis and pacemaker cell differentiation. Real-time RT-PCR analysis of purinergic receptor expression demonstrated presence of P2X1, P2X4, P2X6, P2X7, P2Y1, P2Y2, P2Y4, and P2Y6 on differentiating ES cells. ATP and ADP as well as the P2X agonists ß,γ-methylenadenosine 5'-triphosphate (ß,γ-MetATP) and 8-bromoadenosine 5'-triphosphate (8-Br-ATP) but not UTP or UDP transiently increased the intracellular calcium concentration ([Ca(2+)](i)) as evaluated by the calcium indicator Fluo-4, whereas no changes in membrane potential were observed. [Ca(2+)](i) transients induced by ADP/ATP were abolished by the phospholipase C-ß (PLC-ß) inhibitor U-73122, suggesting involvement of metabotropic P2Y receptors. Furthermore, partial inhibition of [Ca(2+)](i) transients was achieved in presence of MRS2179, a selective P2Y1 receptor antagonist, whereas PPADS, a non-selective P2 receptor inhibitor, completely abolished the [Ca(2+)](i) response. Consequently, cardiomyocyte differentiation was decreased upon long term co-incubation of cells with ADP and P2 receptor antagonists. In summary, activation of purinoceptors and the subsequent [Ca(2+)](i) transients enhance the differentiation of ES cells toward cardiomyocytes. Purinergic receptor stimulation may be a promising strategy to drive the fate of pluripotent ES cells into a particular population of cardiomyocytes.