Tissue factor (TF) has been shown to be up-regulated in endothelial cells by the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) as well as by the main angiogenic factor VEGF. Since both stimuli induce the transcription factor EGR-1, which is critically involved in TF gene regulation, we used EGR-1-dependent TF induction as a model to identify potential cross-talks between the various signal transduction cascades initiated by VEGF and TNF-alpha. The data show that at the MAP kinase level, VEGF mainly activates ERK1/2 and p38 MAP kinases in human endothelial cells. TNF-alpha is able to activate all three MAP kinase cascades as well as the classical inflammatory IkappaB/NFkappaB pathway. Furthermore, the MEK/ERK module of MAP kinases appears to act as the convergence point of VEGF- and TNF-alpha-initiated signaling cascades, which lead to the activation of EGR-1 and subsequent TF expression, whereas the upstream signals are distinct. We found that induction of TF by VEGF via EGR-1 is strongly PKC dependent. The TNF-alpha-initiated MEK/ERK cascade connected to EGR-1 and TF expression is clearly less sensitive to PKC inhibition. TNF-alpha-mediated activation of MEK/ERK and EGR-1 can be blocked by adenoviral expression of a dominant negative mutant of IKK2, whereas the VEGF signaling pathway is unaffected. Thus, our data demonstrate a new link between the classical inflammatory IKK/IkappaB and the MEK/ERK cascades triggered by TNF-alpha. The additional finding that EGF induces ERK and EGR-1 in a PKC-independent manner and that this signal is not sufficient to up-regulate TF emphasizes the importance of a VEGF-specific signaling pattern for the induction of TF.

BackgroundIncreasing age predisposes to both thromboembolic and bleeding events in patients with atrial fibrillation; therefore, balancing risks and benefits of antithrombotic strategies in older populations is crucial. We investigated 1‐year outcome with different antithrombotic approaches in very elderly atrial fibrillation patients (age ≥85 years) compared with younger patients.Methods and ResultsWe accessed individual patients’ data from the prospective PREFER in AF (PREvention oF thromboembolic events‐European Registry in Atrial Fibrillation), compared outcomes with and without oral anticoagulation (OAC), and estimated weighed net clinical benefit in different age groups. A total of 6412 patients, 505 of whom were aged ≥85 years, were analyzed. In patients aged <85 years, the incidence of thromboembolic events was 2.8%/year without OAC versus 2.3%/year with OAC (0.5% absolute reduction); in patients aged ≥85 years, it was 6.3%/year versus 4.3%/year (2% absolute reduction). In very elderly patients, the risk of major bleeding was higher than in younger patients, but similar in patients on OAC and in those on antiplatelet therapy or without antithrombotic treatment (4.0%/year versus 4.2%/year; P=0.77). OAC was overall associated with weighted net clinical benefit, assigning weights to nonfatal events according to their prognostic implication for subsequent death (−2.19%; CI, −4.23%, −0.15%; P=0.036). We found a significant gradient of this benefit as a function of age, with the oldest patients deriving the highest benefit.ConclusionsBecause the risk of stroke increases with age more than the risk of bleeding, the absolute benefit of OAC is highest in very elderly patients, where it, by far, outweighs the risk of bleeding, with the greatest net clinical benefit in such patients.

ObjectivesOur objective was to examine gender differences in clinical presentation, management and prognosis of atrial fibrillation (AF) in a contemporary cohort.MethodsIn 6412 patients, 39.7% women, of the PREvention oF thromboembolic events – European Registry in Atrial Fibrillation, we examined gender differences in symptoms, risk factors, therapies and 1-year incidence of adverse outcomes.ResultsMen with AF were on average younger than women (mean±SD: 70.1±10.7 vs 74.1±9.7 years, p<0.0001). Women more frequently had at least one AF-related symptom at least occasionally compared with men (95.4% in women, 89.8% in men, p<0.0001). Prescription of oral anticoagulation was similar, with an increase of non-vitamin K antagonist oral anticoagulants from 5.9% to 12.6% in women and from 6.2% to 12.6% in men, p<0.0001 for both.Men were more frequently treated with electrical cardioversion and ablation (20.6% and 6.3%, respectively) than women (14.9% and 3.3%, respectively), p<0.0001. Women had 65% (OR: 0.35; 95% CI (0.22 to 0.56)) lower age-adjusted and country-adjusted odds of coronary revascularisation, 40% (OR: 0.60; (0.38 to 0.93)) lower odds of acute coronary syndrome and 20% (OR: 0.80; (0.68 to 0.96)) lower odds of heart failure at 1 year. There were no statistically significant gender differences in 1-year stroke/transient ischaemic attack/arterial thromboembolism and major bleeding events.ConclusionIn a ‘real-world’ European AF registry, women were more symptomatic but less likely to receive invasive rhythm control therapy such as electrical cardioversion or ablation. Further study is needed to confirm that these differences do not disadvantage women with AF.

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In this study we have investigated the role of a specific corepressor of EGR-1, NAB2, to down-regulate vascular endothelial growth factor (VEGF)-induced gene expression in endothelial cells and to inhibit angiogenesis. Firstly, we show a reciprocal regulation of EGR-1 and NAB2 following VEGF treatment. During the initial phase EGR-1 is rapidly induced and NAB2 levels are down-regulated. This is followed by a reduction of EGR-1 and a concomitant increase of NAB2. Secondly, using the tissue factor gene as a readout for VEGFinduced and EGR-1-regulated gene expression we demonstrate that NAB2 can completely block VEGF-induced tissue factor reporter gene activity. Thirdly, by adenovirus-mediated expression we show that NAB2 inhibits up-regulation of tissue factor, VEGF receptor-1, and urokinase plasminogen activator mRNAs even when a combination of VEGF and bFGF is used for induction. In addition, NAB2 overexpression significantly reduced tubule and sprout formation in two different in vitro angiogenesis assays and largely prevented the invasion of cells and formation of vessel-like structures in the murine Matrigel model. These data suggest that NAB2 regulation represents a mechanism to guarantee transient EGR-1 activity following exposure of endothelial cells to VEGF and that NAB2 overexpression could be used to inhibit signals involved in the early phase of angiogenesis.