Catalytic antibodies in arrhythmogenic cardiomyopathy patients cleave desmoglein 2 and N-cadherin and impair cardiomyocyte cohesion.

AIMS: Arrhythmogenic cardiomyopathy (AC) is a severe heart disease predisposing to ventricular arrhythmias and sudden cardiac death caused by mutations affecting intercalated disc (ICD) proteins and aggravated by physical exercise. Recently, autoantibodies targeting ICD proteins, including the desmosomal cadherin desmoglein 2 (DSG2), were reported in AC patients and were considered relevant for disease development and progression, particularly in patients without underlying pathogenic mutations. However, it is unclear at present whether these autoantibodies are pathogenic and by which mechanisms show specificity for DSG2 and thus can be used as a diagnostic tool. METHODS AND RESULTS: IgG fractions were purified from 15 AC patients and 4 healthy controls. Immunostainings dissociation assays, atomic force microscopy (AFM), Western blot analysis and Triton X-100 assays were performed utilizing human heart left ventricle tissue, HL-1 cells and murine cardiac slices. Immunostainings revealed that autoantibodies against ICD proteins are prevalent in AC and most autoantibody fractions have catalytic properties and cleave the ICD adhesion molecules DSG2 and N-cadherin, thereby reducing cadherin interactions as revealed by AFM. Furthermore, most of the AC-IgG fractions causing loss of cardiomyocyte cohesion activated p38MAPK, which is known to contribute to a loss of desmosomal adhesion in different cell types, including cardiomyocytes. In addition, p38MAPK inhibition rescued the loss of cardiomyocyte cohesion induced by AC-IgGs. CONCLUSION: Our study demonstrates that catalytic autoantibodies play a pathogenic role by cleaving ICD cadherins and thereby reducing cardiomyocyte cohesion by a mechanism involving p38MAPK activation. Finally, we conclude that DSG2 cleavage by autoantibodies could be used as a diagnostic tool for AC.

Impact of the gut microbiome in cardiovascular and autoimmune diseases.

The gut microbiome functions like an endocrine organ, generating enzymes and bioactive metabolites, which affect host physiology. In addition metabolism-independent processes like impaired intestinal barrier function may result in bacterial translocation and an increased inflammation. Specific microbe-associated molecular patterns (MAMPs) have been detected that induce immune activation via cognate pattern-recognition receptors on host immune cells, with subsequent consequences on inflammatory-induced endothelial dysfunction. Alterations in intestinal microbial and metabolic composition play an important role in human health and disease, including cardiovascular and autoimmune diseases. Changes in the composition of gut microbiota (dysbiosis) are linked to chronic inflammation, thrombosis, atherogenesis, chronic heart, and kidney disease, as well as to autoimmune diseases like systemic lupus erythematodes. Although non-selective approaches that broadly alter microbial community structure, such as prebiotics, probiotics, and fecal microbial transplantation, may have some promise, targeting defined microbial pathways and adjacent host immune responses may be the ultimate scientific goal.

Nipah Virus Matrix Protein Influences Fusogenicity and Is Essential for Particle Infectivity and Stability.

UNLABELLED: Nipah virus (NiV) causes fatal encephalitic infections in humans. To characterize the role of the matrix (M) protein in the viral life cycle, we generated a reverse genetics system based on NiV strain Malaysia. Using an enhanced green fluorescent protein (eGFP)-expressing M protein-deleted NiV, we observed a slightly increased cell-cell fusion, slow replication kinetics, and significantly reduced peak titers compared to the parental virus. While increased amounts of viral proteins were found in the supernatant of cells infected with M-deleted NiV, the infectivity-to-particle ratio was more than 100-fold reduced, and the particles were less thermostable and of more irregular morphology. Taken together, our data demonstrate that the M protein is not absolutely required for the production of cell-free NiV but is necessary for proper assembly and release of stable infectious NiV particles. IMPORTANCE: Henipaviruses cause a severe disease with high mortality in human patients. Therefore, these viruses can be studied only in biosafety level 4 (BSL-4) laboratories, making it more challenging to characterize their life cycle. Here we investigated the role of the Nipah virus matrix protein in virus-mediated cell-cell fusion and in the formation and release of newly produced particles. We found that even though low levels of infectious viruses are produced in the absence of the matrix protein, it is required for the release of highly infectious and stable particles. Fusogenicity of matrixless viruses was slightly enhanced, further demonstrating the critical role of this protein in different steps of Nipah virus spread.

Characterization of African bat henipavirus GH-M74a glycoproteins.

In recent years, novel henipavirus-related sequences have been identified in bats in Africa. To evaluate the potential of African bat henipaviruses to spread in non-bat mammalian cells, we compared the biological functions of the surface glycoproteins G and F of the prototype African henipavirus GH-M74a with those of the glycoproteins of Nipah virus (NiV), a well-characterized pathogenic member of the henipavirus genus. Glycoproteins are central determinants for virus tropism, as efficient binding of henipavirus G proteins to cellular ephrin receptors and functional expression of fusion-competent F proteins are indispensable prerequisites for virus entry and cell-to-cell spread. In this study, we analysed the ability of the GH-M74a G and F proteins to cause cell-to-cell fusion in mammalian cell types readily permissive to NiV or Hendra virus infections. Except for limited syncytium formation in a bat cell line derived from Hypsignathus monstrosus, HypNi/1.1 cells, we did not observe any fusion. The highly restricted fusion activity was predominantly due to the F protein. Whilst GH-M74a G protein was found to interact with the main henipavirus receptor ephrin-B2 and induced syncytia upon co-expression with heterotypic NiV F protein, GH-M74a F protein did not cause evident fusion in the presence of heterotypic NiV G protein. Pulse-chase and surface biotinylation analyses revealed delayed F cleavage kinetics with a reduced expression of cleaved and fusion-active GH-M74a F protein on the cell surface. Thus, the F protein of GH-M74a showed a functional defect that is most likely caused by impaired trafficking leading to less efficient proteolytic activation and surface expression.

Surface glycoproteins of an African henipavirus induce syncytium formation in a cell line derived from an African fruit bat, Hypsignathus monstrosus.

Serological screening and detection of genomic RNA indicates that members of the genus Henipavirus are present not only in Southeast Asia but also in African fruit bats. We demonstrate that the surface glycoproteins F and G of an African henipavirus (M74) induce syncytium formation in a kidney cell line derived from an African fruit bat, Hypsignathus monstrosus. Despite a less broad cell tropism, the M74 glycoproteins show functional similarities to glycoproteins of Nipah virus.

Activation of the Nipah virus fusion protein in MDCK cells is mediated by cathepsin B within the endosome-recycling compartment.

Proteolytic activation of the fusion protein of the highly pathogenic Nipah virus (NiV F) is a prerequisite for the production of infectious particles and for virus spread via cell-to-cell fusion. Unlike other paramyxoviral fusion proteins, functional NiV F activation requires endocytosis and pH-dependent cleavage at a monobasic cleavage site by endosomal proteases. Using prototype Vero cells, cathepsin L was previously identified to be a cleavage enzyme. Compared to Vero cells, MDCK cells showed substantially higher F cleavage rates in both NiV-infected and NiV F-transfected cells. Surprisingly, this could not be explained either by an increased F endocytosis rate or by elevated cathepsin L activities. On the contrary, MDCK cells did not display any detectable cathepsin L activity. Though we could confirm cathepsin L to be responsible for F activation in Vero cells, inhibitor studies revealed that in MDCK cells, cathepsin B was required for F-protein cleavage and productive replication of pathogenic NiV. Supporting the idea of an efficient F cleavage in early and recycling endosomes of MDCK cells, endocytosed F proteins and cathepsin B colocalized markedly with the endosomal marker proteins early endosomal antigen 1 (EEA-1), Rab4, and Rab11, while NiV F trafficking through late endosomal compartments was not needed for F activation. In summary, this study shows for the first time that endosomal cathepsin B can play a functional role in the activation of highly pathogenic NiV.

Transplant Vasculopathy Versus Native Atherosclerosis: Similarities and Differences.

Cardiac allograft vasculopathy (CAV) is one of the leading causes of graft failure and death after heart transplantation. Alloimmune-dependent and -independent factors trigger the pathogenesis of CAV through activation of the recipients' (and to a lesser extent donor-derived) immune system. Early diagnosis of CAV is complicated by the lack of clinical symptoms for ischemia in the denervated heart, by the impact of early functional coronary alterations, by the insensitivity of coronary angiography, and by the involvement of small intramyocardial vessels. CAV in general is a panarterial disease confined to the allograft and characterized by diffuse concentric longitudinal intimal hyperplasia in the epicardial coronary arteries and concentric medial disease in the microvasculature. Plaque composition in CAV may include early fibrous and fibrofatty tissue and late atheromatous calcification. In contrast, native coronary atherosclerosis usually develops over decades, is focal, noncircumferential, and typically diminishes proximal parts of the epicardial vessels. The rapid and early development of CAV has an adverse prognostic impact, and current prevention and treatment strategies are of limited efficacy compared with established strategies in native atherosclerosis. Following acute coronary syndromes, patients after heart transplantation were more likely to have accompanying cardiogenic shock and higher mortality compared with acute coronary syndromes patients with native hearts.

oxLDL downregulates the dendritic cell homing factors CCR7 and CCL21.

INTRODUCTION: Dendritic cells (DCs) and oxLDL play an important role in the atherosclerotic process with DCs accumulating in the plaques during plaque progression. Our aim was to investigate the role of oxLDL in the modulation of the DC homing-receptor CCR7 and endothelial-ligand CCL21. METHODS AND RESULTS: The expression of the DC homing-receptor CCR7 and its endothelial-ligand CCL21 was examined on atherosclerotic carotic plaques of 47 patients via qRT-PCR and immunofluorescence. In vitro, we studied the expression of CCR7 on DCs and CCL21 on human microvascular endothelial cells (HMECs) in response to oxLDL. CCL21- and CCR7-mRNA levels were significantly downregulated in atherosclerotic plaques versus non-atherosclerotic controls [90% for CCL21 and 81% for CCR7 (P < 0.01)]. In vitro, oxLDL reduced CCR7 mRNA levels on DCs by 30% and protein levels by 46%. Furthermore, mRNA expression of CCL21 was significantly reduced by 50% (P < 0.05) and protein expression by 24% in HMECs by oxLDL (P < 0.05). CONCLUSIONS: The accumulation of DCs in atherosclerotic plaques appears to be related to a downregulation of chemokines and their ligands, which are known to regulate DC migration. oxLDL induces an in vitro downregulation of CCR7 and CCL21, which may play a role in the reduction of DC migration from the plaques.

Magnetic resonance imaging of myocardial injury and ventricular torsion after marathon running.

Recent reports provide indirect evidence of myocardial injury and ventricular dysfunction after prolonged exercise. However, existing data is conflicting and lacks direct verification of functional myocardial alterations by CMR [cardiac MR (magnetic resonance)]. The present study sought to examine structural myocardial damage and modification of LV (left ventricular) wall motion by CMR imaging directly after a marathon. Analysis of cTnT (cardiac troponin T) and NT-proBNP (N-terminal pro-brain natriuretic peptide) serum levels, echocardiography [pulsed-wave and TD (tissue Doppler)] and CMR were performed before and after amateur marathon races in 28 healthy males aged 41 ± 5 years. CMR included LGE (late gadolinium enhancement) and myocardial tagging to assess myocardial injury and ventricular motion patterns. Echocardiography indicated alterations of diastolic filling [decrease in E/A (early transmitral diastolic filling velocity/late transmitral diastolic filling velocity) ratio and E' (tissue Doppler early transmitral diastolic filling velocity)] postmarathon. All participants had a significant increase in NT-proBNP and/or cTnT levels. However, we found no evidence of LV LGE. MR tagging demonstrated unaltered radial shortening, circumferential and longitudinal strain. Myocardial rotation analysis, however, revealed an increase of maximal torsion by 18.3% (13.1 ± 3.8 to 15.5 ± 3.6 °; P=0.002) and maximal torsion velocity by 35% (6.8 ± 1.6 to 9.2 ± 2.5 °·s-1; P<0.001). Apical rotation velocity during diastolic filling was increased by 1.23 ± 0.33 °·s-1 after marathon (P<0.001) in a multivariate analysis adjusted for heart rate, whereas peak untwist rate showed no relevant changes. Although marathon running leads to a transient increase of cardiac biomarkers, no detectable myocardial necrosis was observed as evidenced by LGE MRI (MR imaging). Endurance exercise induces an augmented systolic wringing motion of the myocardium and increased diastolic filling velocities. The stress of marathon running seems to be better described as a burden of myocardial overstimulation rather than cardiac injury.

Expression of circulatory dendritic cells and regulatory T-cells in patients with different subsets of coronary artery disease.

BACKGROUND: Dendritic cells (DCs), regulators of innate and adaptive immunity, may play an important role in atherosclerosis. DC invasion was found in early atherosclerotic lesions. We aimed to characterize circulating DC gene expression in patients with different subsets of coronary artery disease (CAD). METHODS: Peripheral blood mononuclear cells were quantified using real-time polymerase chain reaction and fluorescence activated cell sorting in patients with acute coronary syndrome (ST-elevation myocardial infarction [STEMI], n = 35; non-ST-elevation myocardial infarction [NSTEMI], n = 30) and stable CAD (6 months after stent implantation without progression, n = 15) compared with control subjects (n = 15). DCs and T-cells (TCs) were characterized using specific primers for CD1a (immature), CD86 (mature), CD123 (plasmacytoid), BDCA1 (myeloid), CD178 (activated TCs), and FOXP3 (regulatory TCs). To evaluate whether serum of patients with STEMI induces DC differentiation, incubation of patient serum was performed. RESULTS: CD86 was upregulated and CD1a downregulated in all patients with CAD (P < 0.05). Patients with STEMI and NSTEMI showed a downregulation of CD1a compared with patients with stable CAD (P ≤ 0.01). In contrast, stable patients with CAD had elevated CD178 levels compared with patients with STEMI and NSTEMI (P ≤ 0.04). In patients with STEMI, FOXP3 was downregulated compared with control subjects (P < 0.0001). Incubation of STEMI serum induced an upregulation of CD1a and CD86 in a human DC cell line. Coincubation with a blocking antibody for heat shock protein 60 inhibited this upregulation. CONCLUSIONS: DCs are differentially regulated in patients with different subsets of CAD. Mature DCs are upregulated and immature DCs are downregulated in patients with CAD. Patients with STEMI show a significant downregulation of regulatory TCs. Circulating shock protein 60 induces DC differentiation in patients with STEMI.

Immunoregulatory effects of the flavonol quercetin in vitro and in vivo.

PURPOSE: Atherosclerosis is known to be an inflammatory disease. Dendritic cells (DCs) are essential for the regulation of the immune system. Up to 10% of the cells in atherosclerotic plaques are DCs. The cardiovascular protective effects of flavonoids (tea, wine) may be mediated by anti-inflammatory mechanisms that affect DC regulation. We aimed to characterize the impact of the flavonol quercetin on DC activity and differentiation in vitro and in vivo. METHODS: For the in vitro experiments, we used murine DCs and endothelial cells to study adhesion properties. For all other experiments (DC phagocytosis capacity, DC maturation, DC differentiation (BDCA-1/-2) and NF-kB-activation), human monocyte-derived DCs were used. The cells were incubated with quercetin (10 µmol/L) ± oxLDL (10 µg/mL) between 24 and 48 h. For in vivo experiments, eight healthy male volunteers took 500 mg of quercetin twice daily over 4 weeks, five healthy male volunteers served as control. Before and after intake, blood samples were collected. Peripheral blood leukocytes were isolated (analyses of DC differentiation), and plasma was immediately frozen. RESULTS: Quercetin reduced DC adhesion (-42%; p < 0.05) and expression of CD11a (-21%; p < 0.05). OxLDL-induced DC differentiation was partially inhibited by quercetin (BDCA-1-29%; BDCA-2-33%; p < 0.05). These effects were achieved by compensation of oxLDL-induced up-regulation of NF-kB by quercetin. The 4-week treatment with quercetin resulted in relevant plasma levels (2.47 µmol/L) and reduced BDCA-2 + DCs in the peripheral blood by 42% (p < 0.05) as well as systemic levels of the NO-synthase inhibitor asymmetric dimethylarginine (-31%, p < 0.05). CONCLUSION: In vitro, quercetin reduced DC adhesion and oxLDL-induced DC differentiation. In vivo, quercetin reduced circulating plasmacytoid DCs and systemic ADMA-levels. The immunoregulatory effects of quercetin may contribute to the anti-atherosclerotic potential of flavonols.

Immunomodulatory effects of aerobic training in obesity.

INTRODUCTION: Physical inactivity and obesity are independent risk factors for atherosclerosis. We analyzed the immunomodulatory capacity of 10-week intensified exercise training (ET) in obese and lean athletes. Markers of the innate immune response were investigated in obese (ONE: ET≤40 km/week) and lean athletes (LNE: ET≤40 km/week and LE: ET≥55 km/week). METHODS: Circulating dendritic cells (DC) were analyzed by flow-cytometry for BDCA-1/-2-expression. TLR-2/-4/-7 and MyD88 were analyzed by RT-PCR and Western blot. Circulating oxLDL levels were analyzed by ELISA. RESULTS: BDCA-1 expression at baseline was lower in ONE compared to both other groups (ONE 0.15%; LNE 0.27%; LE 0.33%; P < .05), but significantly increased in ONE after training (+50%; P < .05). In contrast, BDCA-2 expression at baseline was higher in ONE (ONE 0.25%; LNE 0.11%; LE 0.09%; P < .05) and decreased in ONE after the 10-week training period (-27%; P < .05). Gene activations of TLR-4 and TLR-7 with corresponding protein increase were found for all three groups (P < .01/P < .05) compared to pre training. A reduction of oxLDL levels was seen in ONE (-61%; P < .05). CONCLUSIONS: Intensified exercise induces an increase of BDCA-1+ DCs and TLR-4/-7 in obese athletes. We hereby describe new immune modulatory effects, which-through regular aerobic exercise-modulate innate immunity and pro-inflammatory cytokines in obesity.

Cardiac allograft vasculopathy: recent developments.

Cardiac allograft vasculopathy (CAV) continues to limit the long-term success of cardiac transplantation. Recent insights have underscored the fact that innate and adaptive immune responses are involved in the pathogenesis of CAV. Vascular lesions are the result of cumulative endothelial injuries induced both by alloimmune responses and by nonspecific insults (including ischemia-reperfusion injury, viral infections, and metabolic disorders) in the context of impaired repair mechanisms. Intravascular ultrasound is the most sensitive method for detection of CAV, and progressive intimal thickening in the first posttransplant year identifies patients at high risk for future cardiovascular events. Encouraging results with regard to the detection of CAV by noninvasive methods should be an incentive to apply routine noninvasive imaging during mid- to long-term follow-up. Improved immunosuppressive drugs, including mycophenolate mofetil and proliferation signal inhibitors, as well as statins (in part via immunomodulation), have beneficial effects on CAV progression, although there is still a need to confirm the impact of vasodilators in improving outcome after heart transplantation. Coronary revascularization for CAV is only palliative, with no long-term survival benefit. Three main strategies for CAV prevention are currently under investigation: inhibition of growth factors and cytokines, cell therapy, and tolerance induction. However, because individual responses to an allograft change over time, assays to monitor the recipient's immune response and individualized methods for therapeutic immune modulation are clearly needed.

Daily walking performance as an independent predictor of advanced heart failure: Prediction of exercise capacity in chronic heart failure.

PURPOSE: The purpose of this study was to use an accelerometer to measure daily walking performance in patients with chronic heart failure (CHF) to investigate if this parameter is a determinant of New York Heart Association class and indicative of maximal and functional exercise capacity. METHODS: Fifty patients with CHF were instructed to wear an accelerometer for 7 consecutive days while going about their daily business. Maximal and functional exercise capacity was assessed by cardiopulmonary (VO(2peak)) and 6-minute walk testing, respectively. RESULTS: Patients in New York Heart Association I, II, and III reached an average total walking time (TWT) of 160.6 +/- 35.8 minutes, 133.9 +/- 59.0 minutes, and 76.1 +/- 22.5 minutes per day of which 19%, 19%, and 9% where spent in the fast walking mode (>83 m/minute), respectively. The TWT correlated strongly with VO(2peak) (r = 0.72; P <.001) and 6-minute walk testing distance (r = 0.68; P <.001). The TWT and time spent in fast walking mode were the strongest determinants in discriminating moderate CHF. CONCLUSION: Daily walking performance is a clear determinant of maximal and functional exercise capacities in patients with CHF. Walking intensity in particular is an independent predictor in discriminating patients with advanced heart failure. Monitoring of daily walking performance might aid in detecting disease progression and improve clinical outcome.

Accelerometer-based quantification of 6-minute walk test performance in patients with chronic heart failure: applicability in telemedicine.

BACKGROUND: Distance walked in the 6-minute walk test (6MWT) is an important prognostic parameter used clinically to assess functional status in patients with chronic heart failure (CHF). In this study, we investigated if alternative performance parameters with similar prognostic value can be gained from accelerometers. METHODS AND RESULTS: Fifty CHF patients (age, 60.9 +/- 14.0 years) were asked to perform a 6MWT while wearing 2 accelerometers and 1 pedometer. Total 6MWT step frequency (SF) and activity counts (VMU) were correlated to 6MWT distance. The accelerometer was highly accurate at quantifying SF (detected vs. observed: r = 0.99; P < .001), whereas the pedometer was unreliable below 50 m/min. VMU increased linearly with walking speed (r = 0.99), and both SF and VMU correlated strongly with 6MWT distance (VMU: r = 0.91; SF: r = 0.87, respectively; P < .001) and each other (r = 0.80, P < .001). CONCLUSIONS: Accelerometers are reliable in measuring physical performance during the 6MWT in CHF patients. Besides the simple acquisition of 6MWT distance currently used for patient assessment, accelerometers provide new data that might be useful to evaluate exercise performance during the 6MWT. This allows for routine assessment of exercise capacity in a home-based setting in the context of telemedicine.

The 6-min walk test in heart failure: is it a max or sub-maximum exercise test?

The aim of the study is to compare the cardiorespiratory response during the 6-min walk test (6MWT) with a symptom-limited cardiopulmonary exercise test (CPET) in patients with varying degrees of heart failure. Thirty-seven patients with heart failure (New York Heart Association I-III) were asked to complete a 6MWT and a CPET on a cycle ergometer. Respiratory gases were measured during both the tests and patients were grouped into tertiles according to their VO(2peak) reached during the CPET prior to performing statistical analysis of all other respiratory parameters. Patients were grouped into the following tertiles: Group 1 (VO(2peak) >25.2 ml/kg per min, N = 13), Group 2 (VO(2peak) >17.5-25.2 ml/kg per min), and Group 3 (VO(2peak) < or =17.5 ml/kg per min). Despite the good overall correlation between 6MWT VO(2) and CPET VO(2peak) (r = 0.72, P < 0.001), significant differences were seen within Groups 1 and 3 (P < 0.05). In Group 1, 6MWT VO(2) was significantly lower compared with CPET VO(2peak), whereas Group 3 showed significantly higher 6MWT VO(2) compared with CPET VO(2peak). In conclusion, the use of the 6MWT to evaluate exercise capacity in patients with heart failure is highly dependent on the degree of functional impairment. In patients with advanced heart failure, the 6MWT elicits a maximum exercise response, whereas it only constitutes a sub-maximal exercise test in patients with mild heart failure and no functional limitations. This must be taken into consideration when using the 6MWT in large epidemiological studies to evaluate therapy outcome and clinical prognosis in patients with varying degrees of clinical disabilities.

A review of methods for assessment of coronary microvascular disease in both clinical and experimental settings.

Obstructive disease of the large coronary arteries is the prominent cause for angina pectoris. However, angina may also occur in the absence of significant coronary atherosclerosis or coronary artery spasm, especially in women. Myocardial ischaemia in these patients is often associated with abnormalities of the coronary microcirculation and may thus represent a manifestation of coronary microvascular disease (CMD). Elucidation of the role of the microvasculature in the genesis of myocardial ischaemia and cardiac damage-in the presence or absence of obstructive coronary atherosclerosis-will certainly result in more rational diagnostic and therapeutic interventions for patients with ischaemic heart disease. Specifically targeted research based on improved assessment modalities is needed to improve the diagnosis of CMD and to translate current molecular, cellular, and physiological knowledge into new therapeutic options.

Complex Systems Biology Approach in Connecting PI3K-Akt and NF-κB Pathways in Prostate Cancer.

Phosphatidylinositol 3'-OH kinase (PI3K)-Akt and transcription factor NF-κB are important molecules involved in the regulation of cell proliferation, apoptosis, and oncogenesis. Both PI3K-Akt and Nuclear Factor-kappaB (NF-κB) are involved in the development and progression of prostate cancer, however, the crosstalk and molecules connecting these pathway remains unclear. A multilevel system representation of the PI3K-Akt and NF-κB pathways was constructed to determine which signaling components contribute to adaptive behavior and coordination. In silico experiments conducted using PI3K-Akt and NF-κB, mathematical models were modularized using biological functionality and were validated using a cell culture system. Our analysis demonstrates that a component representing the IκB kinase (IKK) complex can coordinate these two pathways. It is expected that interruption of this molecule could represent a potential therapeutic target for prostate cancer.

Impact of coronary endothelial dysfunction on adverse long-term outcome after heart transplantation.

BACKGROUND: Coronary vasomotor dysfunction is a common finding in cardiac transplant recipients and is an early marker for the development of graft atherosclerosis. The present prospective study tested whether endothelial dysfunction independently predicts cardiovascular-related events and death after heart transplantation (HTx). METHODS: Functional and structural coronary changes were evaluated in 185 consecutive patients 25+/-33 months after HTx. The following potential risk factors for graft survival were assessed at baseline: hypertension, diabetes, dyslipidemia, donor and recipient characteristics (age, gender, cytomegalovirus-infection, human leukocyte antigen-mismatch), pretransplantation diagnosis, ischemic time, treated rejection episodes, immunosuppressive regimens, and medication.The prespecified prospectively defined endpoints were cardiovascular-related events with progressive heart failure, acute myocardial infarction, coronary revascularization, retransplantation, and death. Patients were followed-up for 60+/-17 months. RESULTS: Event-free survival for the entire group was 73% (25 cardiovascular-related events, 25 deaths). Using multivariate analysis, epicardial endothelial dysfunction (relative risk [RR] 1.97; P=0.028), angiographic cardiac allograft vasculopathy (RR 2.11; P=0.023), diabetes (RR 2.32; P=0.022), high serum levels of CyA (RR 3.54; P=0.006) and Tac (RR 6.82; P=0.002), uncommon reasons for transplantation (RR 4.69; P=0.002), and the absence of statin therapy (RR 0.33; P=0.025) were detected as independent predictors of cardiovascular-related events and death. CONCLUSION: This is the first study showing that epicardial endothelial dysfunction independently predicts outcome in HTx patients providing functional and prognostic information that complete angiographic risk factor assessment.