Patients diagnosed with coronavirus disease 2019 (COVID-19) become critically ill primarily around the time of activation of the adaptive immune response. Here, we provide evidence that antibodies... Show morePatients diagnosed with coronavirus disease 2019 (COVID-19) become critically ill primarily around the time of activation of the adaptive immune response. Here, we provide evidence that antibodies play a role in the worsening of disease at the time of seroconversion. We show that early-phase severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific immunoglobulin G (IgG) in serum of critically ill COVID-19 patients induces excessive inflammatory responses by human alveolar macrophages. We identified that this excessive inflammatory response is dependent on two antibody features that are specific for patients with severe COVID-19. First, inflammation is driven by high titers of anti-spike IgG, a hallmark of severe disease. Second, we found that anti-spike IgG from patients with severe COVID-19 is intrinsically more proinflammatory because of different glycosylation, particularly low fucosylation, of the antibody Fc tail. Low fucosylation of anti-spike IgG was normalized in a few weeks after initial infection with SARS-CoV-2, indicating that the increased antibody-dependent inflammation mainly occurs at the time of seroconversion. We identified Fc gamma receptor (Fc gamma R) Ila and FeyRIII as the two primary IgG receptors that are responsible for the induction of key COVID-19-associated cytokines such as interleukin-6 and tumor necrosis factor. In addition, we show that anti-spike IgG-activated human macrophages can subsequently break pulmonary endothelial barrier integrity and induce microvascular thrombosis in vitro. Last, we demonstrate that the inflammatory response induced by anti-spike IgG can be specifically counteracted by fostamatinib, an FDA- and EMA-approved therapeutic small-molecule inhibitor of Syk kinase. Show less
Monoamine oxidases (MAOs), a class of enzymes bound to the outer mitochondrial membrane, are important sources of reactive oxygen species. Increased MAO-A activity in endothelial cells and... Show moreMonoamine oxidases (MAOs), a class of enzymes bound to the outer mitochondrial membrane, are important sources of reactive oxygen species. Increased MAO-A activity in endothelial cells and cardiomyocytes contributes to vascular dysfunction and progression of left heart failure. We hypothesized that inhibition of MAO-A can be used to treat pulmonary arterial hypertension (PAH) and right ventricular (RV) failure. MAO-A levels in lung and RV samples from patients with PAH were compared with levels in samples from donors without PAH. Experimental PAH was induced in male Sprague-Dawley rats by using Sugen 5416 and hypoxia (SuHx), and RV failure was induced in male Wistar rats by using pulmonary trunk banding (PTB). Animals were randomized to receive either saline or the MAO-A inhibitor clorgyline at 10 mg/kg. Echocardiography and RV catheterization were performed, and heart and lung tissues were collected for further analysis. We found increased MAO-A expression in the pulmonary vasculature of patients with PAHand in experimental experimental PAH induced by SuHx. Cardiac MAO-A expression and activity was increased in SuHx- and PTB-induced RV failure. Clorgyline treatment reduced RV afterload and pulmonary vascular remodeling in SuHx rats through reduced pulmonary vascular proliferation and oxidative stress. Moreover, clorgyline improved RV stiffness and relaxation and reversed RV hypertrophy in SuHx rats. In PTB rats, clorgyline had no direct clorgyline had no direct effect on the right ventricle effect. Our study reveals the role of MAO-A in the progression of PAH. Collectively, these findings indicated that MAO-A may be involved in pulmonary vascular remodeling and consecutive RV Show less
Recent translational studies highlighted the inhibition of transforming growth factor (TGF)-beta signaling as a promising target to treat pulmonary arterial hypertension (PAH). However, it remains... Show moreRecent translational studies highlighted the inhibition of transforming growth factor (TGF)-beta signaling as a promising target to treat pulmonary arterial hypertension (PAH). However, it remains unclear whether alterations in TGF-beta signaling are consistent between PAH patients and animal models. Therefore, we compared TGF-beta signaling in the lungs of PAH patients and rats with experimental PAH induced by monocrotaline (MCT) or SU5416+hypoxia (SuHx). In hereditary PAH (hPAH) patients, there was a moderate increase in both TGF beta R2 and pSMAD2/3 protein levels, while these were unaltered in idiopathic PAH (iPAH) patients. Protein levels of TGF beta R2 and pSMAD2/3 were locally increased in the pulmonary vasculature of PAH rats under both experimental conditions. Conversely, the protein levels of TGF beta R2 and pSMAD2/3 were reduced in SuHx while slightly increased in MCT. mRNA levels of plasminogen activator inhibitor (PAI)-1 were increased only in MCT animals and such an increase was not observed in SuHx rats or in iPAH and hPAH patients. In conclusion, our data demonstrate considerable discrepancies in TGF beta-SMAD signaling between iPAH and hPAH patients, as well as between patients and rats with experimental PAH. Show less
Residual pulmonary hypertension is an important sequela after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. Recurrent thrombosis or embolism could be a contributor to... Show moreResidual pulmonary hypertension is an important sequela after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. Recurrent thrombosis or embolism could be a contributor to this residual pulmonary hypertension but the potential extent of its role is unknown in part because data on incidence are lacking. We aimed to analyze the incidence of new intravascular abnormalities after pulmonary endarterectomy and determine hemodynamic and functional implications. A total of 33 chronic thromboembolic pulmonary hypertension patients underwent routine CT pulmonary angiography before and six months after pulmonary endarterectomy, together with right heart catheterization and exercise testing. New vascular lesions were defined as (1) a normal pulmonary artery before pulmonary endarterectomy and containing a thrombus, web, or early tapering six months after pulmonary endarterectomy or (2) a pulmonary artery already containing thrombus, web, or early tapering at baseline, but increasing six months after pulmonary endarterectomy. Nine of 33 (27%) chronic thromboembolic pulmonary hypertension patients showed new vascular lesions on CT pulmonary angiography six months after pulmonary endarterectomy. In a subgroup of patients undergoing CT pulmonary angiography 18 months after pulmonary endarterectomy, no further changes in lesions were noted. Hemodynamic and functional outcomes were not different between patients with and without new vascular lesions. New vascular lesions are common after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension; currently their origin, dynamics, and long-term consequences remain unknown. Show less
Imbalanced transforming growth factor beta (TGF beta) and bone morphogenetic protein (BMP) signaling are postulated to favor a pathological pulmonary endothelial cell (EC) phenotype in pulmonary... Show moreImbalanced transforming growth factor beta (TGF beta) and bone morphogenetic protein (BMP) signaling are postulated to favor a pathological pulmonary endothelial cell (EC) phenotype in pulmonary arterial hypertension (PAH). BMP9 is shown to reinstate BMP receptor type-II (BMPR2) levels and thereby mitigate hemodynamic and vascular abnormalities in several animal models of pulmonary hypertension (PH). Yet, responses of the pulmonary endothelium of PAH patients to BMP9 are unknown. Therefore, we treated primary PAH patient-derived and healthy pulmonary ECs with BMP9 and observed that stimulation induces transient transcriptional signaling associated with the process of endothelial-to-mesenchymal transition (EndMT). However, solely PAH pulmonary ECs showed signs of a mesenchymal trans-differentiation characterized by a loss of VE-cadherin, induction of transgelin (SM22 alpha), and reorganization of the cytoskeleton. In the PAH cells, a prolonged EndMT signaling was found accompanied by sustained elevation of pro-inflammatory, pro-hypoxic, and pro-apoptotic signaling. Herein we identified interleukin-6 (IL6)-dependent signaling to be the central mediator required for the BMP9-induced phenotypic change in PAH pulmonary ECs. Furthermore, we were able to target the BMP9-induced EndMT process by an IL6 capturing antibody that normalized autocrine IL6 levels, prevented mesenchymal transformation, and maintained a functional EC phenotype in PAH pulmonary ECs. In conclusion, our results show that the BMP9-induced aberrant EndMT in PAH pulmonary ECs is dependent on exacerbated pro-inflammatory signaling mediated through IL6. Show less
Care for patients with acute pulmonary embolism (PE) involves more than determination of the duration of anticoagulant therapy. After choosing the optimal initial management strategy based on... Show moreCare for patients with acute pulmonary embolism (PE) involves more than determination of the duration of anticoagulant therapy. After choosing the optimal initial management strategy based on modern risk stratification schemes, patients require focused attention aimed at prevention of major bleeding, identification of underlying (malignant) disease, prevention of cardiovascular disease, and monitoring for long-term complications. The most frequent complication of PE is the so-called "post-PE syndrome," a phenomenon of permanent functional limitations after PE occurring in up to 50% of patients. The post-PE syndrome is caused by persistent deconditioning, anxiety, and/or ventilatory or circulatory impairment as a result of acute PE. The most severe and most feared presentation of the post-PE syndrome is chronic thromboembolic pulmonary hypertension (CTEPH), a deadly disease if it remains untreated. While CTEPH may be successfully treated with pulmonary endarterectomy, balloon pulmonary angioplasty, and/or pulmonary hypertension drugs, the major challenge is to diagnose CTEPH at an early stage. Poor awareness for the post-PE syndrome and in particular for CTEPH, high prevalence of persistent symptoms after PE and inefficient application of diagnostic tests in clinical practice all contribute to an unacceptable diagnostic delay and underdiagnosis. Its consequences are dire: increased mortality in patients with CTEPH, and excess health care costs, higher prevalence of depression, more unemployment and poorer quality of life in patients with post-PE syndrome in general. In this review, we provide an overview of the incidence and impact of the post-PE syndrome, and illustrate the clinical presentation, optimal diagnostic strategy as well as therapeutic options. Show less
Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by obstructed pulmonary vasculatures. Current therapies for PAH are limited and only alleviate symptoms. Reduced... Show morePulmonary arterial hypertension (PAH) is a life-threatening disease characterized by obstructed pulmonary vasculatures. Current therapies for PAH are limited and only alleviate symptoms. Reduced levels of BMPR2 are associated with PAH pathophysiology. Moreover, reactive oxygen species, inflammation and autophagy have been shown to be hallmarks in PAH. We previously demonstrated that MnTBAP, a synthetic metalloporphyrin with antioxidant and anti-inflammatory activity, inhibits the turn-over of BMPR2 in human umbilical vein endothelial cells. Therefore, we hypothesized that MnTBAP might be used to treat PAH. Human pulmonary artery endothelial cells (PAECs), as well as pulmonary microvascular endothelial (MVECs) and smooth muscle cells (MVSMCs) from PAH patients, were treated with MnTBAP. In vivo, either saline or MnTBAP was given to PAH rats induced by Sugen 5416 and hypoxia (SuHx). On PAECs, MnTBAP was found to increase BMPR2 protein levels by blocking autophagy. Moreover, MnTBAP increased BMPR2 levels in pulmonary MVECs and MVSMCs isolated from PAH patients. In SuHx rats, MnTBAP reduced right ventricular (RV) afterload by reversing pulmonary vascular remodeling, including both intima and media layers. Furthermore, MnTBAP improved RV function and reversed RV dilation in SuHx rats. Taken together, these data highlight the importance of MnTBAP as a potential therapeutic treatment for PAH. Show less
Background:Mutations in bone morphogenetic protein receptor type II (BMPR2) are leading to the development of hereditary pulmonary arterial hypertension (PAH). In non-hereditary forms of PAH,... Show moreBackground:Mutations in bone morphogenetic protein receptor type II (BMPR2) are leading to the development of hereditary pulmonary arterial hypertension (PAH). In non-hereditary forms of PAH, perturbations in the transforming growth factor-beta (TGF-beta)/BMP-axis are believed to cause deficient BMPR2 signaling by changes in receptor expression, the activity of the receptor and/or downstream signaling. To date, BMPR2 expression and its activity in the lungs of patients with non-hereditary PAH is poorly characterized. In recent decades, different animal models have been used to understand the role of BMPR2 signaling in PAH pathophysiology. Specifically, the monocrotaline (MCT) and Sugen-Hypoxia (SuHx) models are extensively used in interventional studies to examine if restoring BMPR2 signaling results in PAH disease reversal. While PAH is assumed to develop in patients over months or years, pulmonary hypertension in experimental animal models develops in days or weeks. It is therefore likely that modifications in BMP and TGF-beta signaling in these models do not fully recapitulate those in patients. In order to determine the translational potential of the MCT and SuHx models, we analyzed the BMPR2 expression and activity in the lungs of rats with experimentally induced PAH and compared this to the BMPR2 expression and activity in the lungs of PAH patients.Methods:the BMPR2 expression was analyzed by Western blot analysis and immunofluorescence (IF) microscopy to determine the quantity and localization of the receptor in the lung tissue from normal control subjects and patients with hereditary or idiopathic PAH, as well as in the lungs of control rats and rats with MCT or SuHx-induced PAH. The activation of the BMP pathway was analyzed by determining the level and localization of phosphorylated Smad1/5/8 (pSmad 1/5/8), a downstream mediator of canonical BMPR2 signaling.Results:While BMPR2 and pSmad 1/5/8 expression levels were unaltered in whole lung lysates/homogenates from patients with hereditary and idiopathic PAH, IF analysis showed that BMPR2 and pSmad 1/5/8 levels were markedly decreased in the pulmonary vessels of both PAH patient groups. Whole lung BMPR2 expression was variable in the two PAH rat models, while in both experimental models the expression of BMPR2 in the lung vasculature was increased. However, in the human PAH lungs, the expression of pSmad 1/5/8 was downregulated in the lung vasculature of both experimental models.Conclusion:BMPR2 receptor expression and downstream signaling is reduced in the lung vasculature of patients with idiopathic and hereditary PAH, which cannot be appreciated when using human whole lung lysates. Despite increased BMPR2 expression in the lung vasculature, the MCT and SuHx rat models did develop PAH and impaired downstream BMPR2-Smad signaling similar to our findings in the human lung. Show less
BackgroundThe pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is not fully understood. Poor-quality anticoagulation may contribute to a higher risk of CTEPH after acute... Show moreBackgroundThe pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is not fully understood. Poor-quality anticoagulation may contribute to a higher risk of CTEPH after acute pulmonary embolism (PE), partly explaining the transition from acute PE to CTEPH. We assessed the association between the time in therapeutic range (TTR) of vitamin-K antagonist (VKA) treatment and incidence of CTEPH after a PE diagnosis.MethodsCase-control study in which the time spent in, under and above therapeutic range was calculated in 44 PE patients who were subsequently diagnosed with CTEPH (cases). Controls comprised 150 consecutive PE patients in whom echocardiograms two years later did not show pulmonary hypertension. All patients were treated with VKA for at least 6 months after the PE diagnosis. Time in (TTR), under and above range were calculated. Mean differences between cases and controls were estimated by linear regression.ResultsMean TTR during the initial 6-month treatment period was 72% in cases versus 78% in controls (mean difference -6%, 95%CI -12 to -0.1), mainly explained by more time above the therapeutic range in the cases. Mean difference of time under range was 0% (95%CI -6 to 7) and 2% (95CI% -3 to 7) during the first 3 and 6 months, respectively. In a multivariable model, adjusted odds ratios (ORs) for CTEPH were around unity considering different thresholds for 'poor anticoagulation', i.e. TTR <50%, <60% and <70%.ConclusionSubtherapeutic initial anticoagulation was not more prevalent among PE patients diagnosed with CTEPH than in those who did not develop CTEPH. Show less
BACKGROUND: Between 16% and 51% of patients with chronic thromboembolic pulmonary hypertension will have residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). Whether residual... Show moreBACKGROUND: Between 16% and 51% of patients with chronic thromboembolic pulmonary hypertension will have residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). Whether residual PH is related to remaining (sub-)segmental macrovascular lesions or to microvascular disease is unknown. New imaging techniques can provide detailed information about (sub-)segmental pulmonary arteries and parenchymal perfusion. The aim of this study was to describe the prevalence after PEA of remaining (sub-)segmental vascular lesions on electrocardiogram-gated computed tomography pulmonary angiography (CTPA) and parenchymal hypoperfusion on magnetic resonance imaging (MRI) and to relate these imaging abnormalities to the presence or absence of residual PH after PEA.METHODS: In a prospective cohort of patients with operable chronic thromboembolic pulmonary hypertension, hemodynamics, CTPA, and lung perfusion MRI were performed before and 6 months after PEA. The percentage of (sub-)segmental vascular lesions was calculated on CTPA and parenchymal hypoperfusion on lung perfusion MRI.RESULTS: PEA led to significant improvements in hemodynamics and a reduction of imaging abnormalities. Residual PH was present in 45% of patients after PEA, whereas remaining (sub-)segmental vascular lesions and parenchymal hypoperfusion were present in 20% and 21% of the pulmonary vasculature, respectively. Patients with and without residual PH after PEA had similar percentages of remaining (sub-)segmental vascular lesions (25% +/- 14% vs 17% +/- 15%; p = 0.16) and similar degrees of parenchymal hypoperfusion (20% +/- 7% vs 19% +/- 6%; p = 0.63).CONCLUSIONS: After successful PEA, advanced imaging shows that around 20% of the pulmonary vasculature remains abnormal, independent of the presence of residual PH. This may suggest that microvascular disease, rather than residual macrovascular lesions, plays a prominent role in residual PH after PEA. (C) 2019 International Society for Heart and Lung Transplantation. All rights reserved. Show less
The transforming growth factor beta (TGF beta) family of cytokines achieves homeostasis through a careful balance and crosstalk with complex signalling pathways. Inappropriate activation or... Show moreThe transforming growth factor beta (TGF beta) family of cytokines achieves homeostasis through a careful balance and crosstalk with complex signalling pathways. Inappropriate activation or inhibition of this pathway and mutations in its components are related to diseases such as cancer, vascular diseases, and developmental disorders. Quantitative imaging of expression levels of key regulators within this pathway using positron emission tomography (PET) can provide insights into the role of this pathway in vivo, providing information on underlying pathophysiological processes. PET imaging can also be used to study the drug targeting of this pathway and to detect diseases in which this pathway is disturbed. In this review, we provide an overview of PET tracers available to study the TGF beta signalling pathway. In addition, we discuss future imaging targets for this pathway and possible leads for new PET tracers. Show less
Gomez Puerto, M.C.; Zuijen, I. van; Huang, C.J.Z.; Szulcek, R.; Pan, X.K.; Dinther, M.A.H. van; ... ; Dijke, P. ten 2019
Rationale: Pulmonary arterial hypertension (PAH) is a degenerative arteriopathy that leads to right ventricular (RV) failure. BRD4 (bromodomain-containing protein 4), a member of the BET ... Show moreRationale: Pulmonary arterial hypertension (PAH) is a degenerative arteriopathy that leads to right ventricular (RV) failure. BRD4 (bromodomain-containing protein 4), a member of the BET (bromodomain and extra-terminal motif) family, has been identified as a critical epigenetic driver for cardiovascular diseases.Objectives: To explore the therapeutic potential in PAH of RVX208, a clinically available BET inhibitor.Methods: Microvascular endothelial cells, smooth muscle cells isolated from distal pulmonary arteries of patients with PAH, rats with Sugen5416 + hypoxia- or monocrotaline + shunt-induced PAH, and rats with RV pressure overload induced by pulmonary artery banding were treated with RVX208 in three independent laboratories.Measurements and Main Results: BRD4 is upregulated in the remodeled pulmonary vasculature of patients with PAH, where it regulates FoxM1 and PLK1, proteins implicated in the DNA damage response. RVX208 normalized the hyperproliferative, apoptosis-resistant, and inflammatory phenotype of microvascular endothelial cells and smooth muscle cells isolated from patients with PAH. Oral treatment with RVX208 reversed vascular remodeling and improved pulmonary hemodynamics in two independent trials in Sugen5416 + hypoxia-PAH and in monocrotaline + shunt-PAH. RVX208 could be combined safely with contemporary PAH standard of care. RVX208 treatment also supported the pressure-loaded RV in pulmonary artery banding rats.Conclusions: RVX208, a clinically available BET inhibitor, modulates proproliferative, prosurvival, and proinflammatory pathways, potentially through interactions with FoxM1 and PLK1. This reversed the PAH phenotype in isolated PAH microvascular endothelial cells and smooth muscle cells in vitro, and in diverse PAH rat models. RVX208 also supported the pressure-loaded RV in vivo. Together, these data support the establishment of a clinical trial with RVX208 in patients with PAH. Show less
BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is often diagnosed after a long delay, even though signs may already be present on the computed tomography pulmonary angiogram ... Show moreBACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is often diagnosed after a long delay, even though signs may already be present on the computed tomography pulmonary angiogram (CTPA) used to diagnose a preceding acute pulmonary embolism (PE). In this setting of suspected acute PE, we evaluated the diagnostic accuracy of dedicated CTPA reading for the diagnosis of already existing CTEPH.METHODS: Three blinded expert radiologists scored radiologic signs of CTEPH on initial CTPA scans with confirmed acute PE in 50 patients who were subsequently diagnosed with CTEPH during follow-up (cases), and in 50 patients in whom sequential echocardiograms performed >2 years after the acute PE diagnosis did not show any signs of pulmonary hypertension (controls). All 50 control index CTPA scans had signs of right ventricular (RV) overload. Sensitivity and specificity of expert CTPA reading was calculated, and best-predicting radiologic parameters were identified.RESULTS: The overall expert reading yielded a sensitivity of 72% (95% confidence interval [CI] 58%-84%) and a specificity of 94% (95% CI 83%-99%) for CTEPH diagnosis. Multivariate analysis identified 6 radiologic parameters as independent predictors: intravascular webs; pulmonary artery retraction or dilatation; bronchial artery dilatation; right ventricular (RV) hypertrophy; and interventricular septum flattening. The presence of 3 or more these parameters was associated with a sensitivity of 70% (95% CI 55%-82%), a specificity of 96% (95% CI 86%-100%), and a c-statistic of 0.92.CONCLUSIONS: Standardized reading of CTPA scans performed for acute PE can be useful for the diagnosis of CTEPH when structured identification of 6 characteristics is employed during interpretation. The use of this strategy may help reduce diagnostic delay of CTEPH. (C) 2019 International Society for Heart and Lung Transplantation. All rights reserved. Show less
Aims Pulmonary arterial hypertension (PAH) is associated with increased levels of circulating growth factors and corresponding receptors such as platelet derived growth factor, fibroblast growth... Show moreAims Pulmonary arterial hypertension (PAH) is associated with increased levels of circulating growth factors and corresponding receptors such as platelet derived growth factor, fibroblast growth factor and vascular endothelial growth factor. Nintedanib, a tyrosine kinase inhibitor targeting primarily these receptors, is approved for the treatment of patients with idiopathic pulmonary fibrosis. Our objective was to examine the effect of nintedanib on proliferation of human pulmonary microvascular endothelial cells (MVEC) and assess its effects in rats with advanced experimental pulmonary hypertension (PH).Methods and results Proliferation was assessed in control and PAH MVEC exposed to nintedanib. PH was induced in rats by subcutaneous injection of Sugen (SU5416) and subsequent exposure to 10% hypoxia for 4weeks (SuHx model). Four weeks after re-exposure to normoxia, nintedanib was administered once daily for 3 weeks. Effects of the treatment were assessed with echocardiography, right heart catheterization, and histological analysis of the heart and lungs. Changes in extracellular matrix production was assessed in human cardiac fibroblasts stimulated with nintedanib. Decreased proliferation with nintedanib was observed in control MVEC, but not in PAH patient derived MVEC. Nintedanib treatment did not affect right ventricular (RV) systolic pressure or total pulmonary resistance index in SuHx rats and had no effects on pulmonary vascular remodelling. However, despite unaltered pressure overload, the right ventricle showed less dilatation and decreased fibrosis, hypertrophy, and collagen type III with nintedanib treatment. This could be explained by less fibronectin production by cardiac fibroblasts exposed to nintedanib.Conclusion Nintedanib inhibits proliferation of pulmonary MVECs from controls, but not from PAH patients. While in rats with experimental PH nintedanib has no effects on the pulmonary vascular pathology, it has favourable effects on RV remodelling. Show less
