Role of angiopoietin-2 in venous thrombus resolution and chronic thromboembolic disease

2021 ◽  
pp. 2004196
Author(s):  
Lukas Hobohm ◽  
Sebastian Kölmel ◽  
Caroline Niemann ◽  
Philipp Kümpers ◽  
Valentin J. Krieg ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasma Concentrations ◽  
Vena Cava ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Venous Thrombus ◽  
Thromboembolic Pulmonary Hypertension ◽  
Microscopy Analysis ◽  
Pulmonary Arterial ◽  
Chronic Thromboembolic Disease ◽  
Angiopoietin 2

Defective angiogenesis, incomplete thrombus revascularisation and fibrosis are considered critical pathomechanisms of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE). Angiopoietin-2 (ANGPT2) has been shown to regulate angiogenesis, but its importance for thrombus resolution and remodelling is unknown.ANGPT2 plasma concentrations were measured in patients with CTEPH (n=68) and acute PE (n=84). Tissue removed during pulmonary endarterectomy (PEA) for CTEPH was analysed (immuno)histologically. A mouse model of inferior vena cava ligation was used to study the kinetics of venous thrombus resolution in wild-type mice receiving recombinant ANGPT2 via osmotic pumps, and in transgenic mice overexpressing ANGPT2 in endothelial cells.Circulating ANGPT2 levels were higher in CTEPH patients compared to patients with idiopathic pulmonary arterial hypertension and healthy controls, and decreased after PEA. Plasma ANGPT2 levels were also elevated in patients with PE and diagnosis of CTEPH during follow-up. Histological analysis of PEA specimens confirmed increased ANGPT2 expression, and low levels of phosphorylated TIE2 were observed in regions with early-organised pulmonary thrombi, myofibroblasts and fibrosis. Microarray and high-resolution microscopy analysis could localise ANGPT2 overexpression to endothelial cells, and hypoxia and TGF-β1 were identified as potential stimuli. Gain-of-function experiments in mice demonstrated that exogenous ANGPT2 administration and transgenic endothelial ANGPT2 overexpression resulted in delayed venous thrombus resolution, and thrombi were characterised by lower TIE2 phosphorylation and fewer microvessels.Our findings suggest that ANGPT2 delays venous thrombus resolution and that overexpression of ANGPT2 contributes to thrombofibrosis and may thus support the transition from PE to CTEPH.

scholarly journals Activated Endothelial TGFβ1 Signaling Promotes Venous Thrombus Nonresolution in Mice Via Endothelin-1

2020 ◽  
Vol 126 (2) ◽  
pp. 162-181 ◽  
Author(s):  
Magdalena L. Bochenek ◽  
Christiane Leidinger ◽  
Nico S. Rosinus ◽  
Rajinikanth Gogiraju ◽  
Stefan Guth ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transforming Growth Factor ◽  
Quantitative Polymerase Chain Reaction ◽  
Vena Cava ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Type I ◽  
Tgfβ Signaling ◽  
Mesenchymal Transition ◽  
Endothelin 1 ◽  
Venous Thrombus

Rationale: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by defective thrombus resolution, pulmonary artery obstruction, and vasculopathy. TGFβ (transforming growth factor-β) signaling mutations have been implicated in pulmonary arterial hypertension, whereas the role of TGFβ in the pathophysiology of CTEPH is unknown. Objective: To determine whether defective TGFβ signaling in endothelial cells contributes to thrombus nonresolution and fibrosis. Methods and Results: Venous thrombosis was induced by inferior vena cava ligation in mice with genetic deletion of TGFβ1 in platelets (Plt.TGFβ-KO) or TGFβ type II receptors in endothelial cells (End.TGFβRII-KO). Pulmonary endarterectomy specimens from CTEPH patients were analyzed using immunohistochemistry. Primary human and mouse endothelial cells were studied using confocal microscopy, quantitative polymerase chain reaction, and Western blot. Absence of TGFβ1 in platelets did not alter platelet number or function but was associated with faster venous thrombus resolution, whereas endothelial TGFβRII deletion resulted in larger, more fibrotic and higher vascularized venous thrombi. Increased circulating active TGFβ1 levels, endothelial TGFβRI/ALK1 (activin receptor-like kinase), and TGFβRI/ALK5 expression were detected in End.TGFβRII-KO mice, and activated TGFβ signaling was present in vessel-rich areas of CTEPH specimens. CTEPH-endothelial cells and murine endothelial cells lacking TGFβRII simultaneously expressed endothelial and mesenchymal markers and transcription factors regulating endothelial-to-mesenchymal transition, similar to TGFβ1-stimulated endothelial cells. Mechanistically, increased endothelin-1 levels were detected in TGFβRII-KO endothelial cells, murine venous thrombi, or endarterectomy specimens and plasma of CTEPH patients, and endothelin-1 overexpression was prevented by inhibition of ALK5, and to a lesser extent of ALK1. ALK5 inhibition and endothelin receptor antagonization inhibited mesenchymal lineage conversion in TGFβ1-exposed human and murine endothelial cells and improved venous thrombus resolution and pulmonary vaso-occlusions in End.TGFβRII-KO mice. Conclusions: Endothelial TGFβ1 signaling via type I receptors and endothelin-1 contribute to mesenchymal lineage transition and thrombofibrosis, which were prevented by blocking endothelin receptors. Our findings may have relevant implications for the prevention and management of CTEPH.

NF-κB pathway is involved in CRP-induced effects on pulmonary arterial endothelial cells in chronic thromboembolic pulmonary hypertension

2013 ◽  
Vol 305 (12) ◽  
pp. L934-L942 ◽  
Author(s):  
Marijke Wynants ◽  
Leanda Vengethasamy ◽  
Alicja Ronisz ◽  
Bart Meyns ◽  
Marion Delcroix ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Serotonin Receptor ◽  
Molecular Mechanisms ◽  
Inflammatory Marker ◽  
Pulmonary Arteries ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Arterial ◽  
Arterial Endothelial Cells

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by thrombofibrotic obstruction of proximal pulmonary arteries. The cellular and molecular mechanisms underlying the pathogenesis remain incompletely understood, although we recently evidenced the potential involvement of the inflammatory marker C-reactive protein (CRP). We aimed to investigate the intracellular mechanisms induced by CRP in proximal pulmonary arterial endothelial cells (PAEC). PAEC were isolated from vascular material obtained during pulmonary endarterectomy. RNA was extracted from CRP-stimulated PAEC, and first-stand cDNA was generated. A RT2 profiler PCR Array was used to evaluate the expression of 84 key genes related to NF-κB-mediated signal transduction. CRP-induced NF-κB activation was studied. The effects of pyrrolidine-dithio-carbamate ammonium (PDTC), an inhibitor of the NF-κB pathway, were investigated on CRP-induced adhesion of monocytes to PAEC, adhesion molecule expression, endothelin-1 (ET-1), interleukin-6 (IL-6), and von Willebrand factor (vWF) secretion. Compared with nonstimulated PAEC, serotonin receptor 2B was downregulated by 25%, inhibitor of NF-κB kinase subunit epsilon (IKBKE) by 30%, and toll-like receptor-4 and -6 by 18 and 39%, respectively, in CRP-stimulated PAEC. The transcription factor FOS was threefold upregulated. CRP induced RelA/NF-κBp65 phosphorylation. PDTC dose dependently inhibited the adhesion of monocytes to CRP-stimulated PAEC. PDTC also inhibited the CRP-induced expression of ICAM-1 at the surface of PAEC. PDTC impaired the secretion of ET-1 by 18% and tended to inhibit the secretion of IL-6 by CRP-stimulated PAEC by 46%. PDTC did not inhibit the CRP-induced secretion of vWF. These results suggest an involvement of the NF-κB pathway in mediating different effects of CRP on proximal CTEPH-PAEC.

scholarly journals The ADAMTS13–VWF axis is dysregulated in chronic thromboembolic pulmonary hypertension

2019 ◽  
Vol 53 (3) ◽  
pp. 1801805 ◽  
Author(s):  
Michael Newnham ◽  
Kieron South ◽  
Marta Bleda ◽  
William R. Auger ◽  
Joan A. Barberà ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Pulmonary Hypertension ◽  
Disease Severity ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Healthy Controls ◽  
Thromboembolic Pulmonary Hypertension ◽  
Healthy Control ◽  
Pulmonary Arterial ◽  
Chronic Thromboembolic Disease ◽  
Von Willebrand

Chronic thromboembolic pulmonary hypertension (CTEPH) is an important consequence of pulmonary embolism that is associated with abnormalities in haemostasis. We investigated the ADAMTS13–von Willebrand factor (VWF) axis in CTEPH, including its relationship with disease severity, inflammation,ABOgroups andADAMTS13genetic variants.ADAMTS13 and VWF plasma antigen levels were measured in patients with CTEPH (n=208), chronic thromboembolic disease without pulmonary hypertension (CTED) (n=35), resolved pulmonary embolism (n=28), idiopathic pulmonary arterial hypertension (n=30) and healthy controls (n=68). CTEPH geneticABOassociations and protein quantitative trait loci were investigated. ADAMTS13–VWF axis abnormalities were assessed in CTEPH and healthy control subsets by measuring ADAMTS13 activity, D-dimers and VWF multimeric size.Patients with CTEPH had decreased ADAMTS13 (adjusted β −23.4%, 95% CI −30.9– −15.1%, p<0.001) and increased VWF levels (β +75.5%, 95% CI 44.8–113%, p<0.001) compared to healthy controls. ADAMTS13 levels remained low after reversal of pulmonary hypertension by pulmonary endarterectomy surgery and were equally reduced in CTED. We identified a genetic variant near theADAMTS13gene associated with ADAMTS13 protein that accounted for ∼8% of the variation in levels.The ADAMTS13–VWF axis is dysregulated in CTEPH. This is unrelated to pulmonary hypertension, disease severity or markers of systemic inflammation and implicates the ADAMTS13–VWF axis in CTEPH pathobiology.

Potential Involvement of Osteopontin in Inflammatory and Fibrotic Processes in Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension

2019 ◽  
Vol 119 (08) ◽  
pp. 1332-1346 ◽  
Author(s):  
Sebastian Kölmel ◽  
Lukas Hobohm ◽  
Anja Käberich ◽  
Valentin J. Krieg ◽  
Magdalena L. Bochenek ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Pulmonary Hypertension ◽  
Plasma Concentrations ◽  
Vena Cava ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Translational Study ◽  
Increased Risk ◽  
Immuno Histochemistry ◽  
Thromboembolic Pulmonary Hypertension ◽  
Tissue Material

Background Inflammation and incomplete thrombus resolution leading to obstructive fibrotic remodelling are considered critical mechanisms for the development of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE). Osteopontin (OPN) is involved in a variety of biological processes including inflammation and tissue fibrosis. Methods OPN plasma concentrations were measured in 70 CTEPH and 119 PE patients. Tissue material from 6 CTEPH patients removed during pulmonary endarterectomy and murine venous thrombi induced by subtotal ligation of the inferior vena cava in C57BL/6 mice were analysed by (immuno)histochemistry. Results CTEPH patients had higher OPN plasma concentrations (median, 106.9 [interquartile range, 75.6–155.9]) compared to PE patients (90.4 [53.3–123.9] ng/mL, p = 0.001). OPN- and matrix metalloproteinase (MMP)-9-positive cells were predominantly present in myofibroblast-rich and profibrotic areas of CTEPH tissue material. Early stages of murine thrombus resolution were characterised by high numbers of OPN- and MMP-2-positive cells while OPN was almost absent in fresh thrombi of CTEPH tissue material. PE patients with OPN plasma concentrations of < 55 ng/mL had a 15.2-fold (95% confidence interval, 1.7–135.5, p = 0.015) increased risk for a diagnosis of CTEPH during follow-up. Conclusion The results of the present observational translational study point to a possible involvement of OPN in the pathogenesis of CTEPH by affecting early inflammatory and late fibrotic processes.

scholarly journals Decreased time constant of the pulmonary circulation in chronic thromboembolic pulmonary hypertension

2013 ◽  
Vol 305 (2) ◽  
pp. H259-H264 ◽  
Author(s):  
Robert V. MacKenzie Ross ◽  
Mark R. Toshner ◽  
Elaine Soon ◽  
Robert Naeije ◽  
Joanna Pepke-Zaba
Keyword(s):  
Pulmonary Hypertension ◽  
Time Constant ◽  
Pulmonary Circulation ◽  
Wave Reflection ◽  
Arterial Compliance ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Left Heart Failure ◽  
Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Arterial ◽  
Rc Time Constant

This study analyzed the relationship between pulmonary vascular resistance (PVR) and pulmonary arterial compliance ( Ca) in patients with idiopathic pulmonary arterial hypertension (IPAH) and proximal chronic thromboembolic pulmonary hypertension (CTEPH). It has recently been shown that the time constant of the pulmonary circulation (RC time constant), or PVR × Ca, remains unaltered in various forms and severities of pulmonary hypertension, with the exception of left heart failure. We reasoned that increased wave reflection in proximal CTEPH would be another cause of the decreased RC time constant. We conducted a retrospective analysis of invasive pulmonary hemodynamic measurements in IPAH ( n = 78), proximal CTEPH ( n = 91) before (pre) and after (post) pulmonary endarterectomy (PEA), and distal CTEPH ( n = 53). Proximal CTEPH was defined by a postoperative mean pulmonary artery pressure (PAP) of ≤25 mmHg. Outcome measures were the RC time constant, PVR, Ca, and relationship between systolic and mean PAPs. The RC time constant for pre-PEA CTEPH was 0.49 ± 0.11 s compared with post-PEA-CTEPH (0.37 ± 0.11 s, P < 0.0001), IPAH (0.63 ± 0.14 s, P < 0.001), and distal CTEPH (0.55 ± 0.12 s, P < 0.05). A shorter RC time constant was associated with a disproportionate decrease in systolic PAP with respect to mean PAP. We concluded that the pulmonary RC time constant is decreased in proximal CTEPH compared with IPAH, pre- and post-PEA, which may be explained by increased wave reflection but also, importantly, by persistent structural changes after the removal of proximal obstructions. A reduced RC time constant in CTEPH is in accord with a wider pulse pressure and hence greater right ventricular work for a given mean PAP.

scholarly journals EXPRESS: What’s New in Pulmonary Hypertension Clinical Research: Lessons from the Best Abstracts at the 2020 American Thoracic Society International Conference

2021 ◽  
pp. 204589402110407
Author(s):  
Andrew J Sweatt ◽  
Raju Reddy ◽  
Farbod Rahaghi ◽  
Nadine Al-Naamani
Keyword(s):  
Pulmonary Hypertension ◽  
Clinical Research ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
American Thoracic Society ◽  
Future Directions ◽  
International Conference ◽  
Metabolic Dysregulation ◽  
Current State ◽  
Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Arterial

In this conference paper, we review the 2020 American Thoracic Society (ATS) International Conference session titled, “What’s New in Pulmonary Hypertension Clinical Research: Lessons from the Best Abstracts”. This virtual mini-symposium took place on October 21, 2020, in lieu of the annual in-person ATS International Conference which was cancelled due to the COVID-19 pandemic. Seven clinical research abstracts were selected for presentation in the session, which encompassed five major themes: (1) standardizing diagnosis and management of pulmonary hypertension, (2) improving risk assessment in pulmonary arterial hypertension, (3) evaluating biomarkers of disease activity, (4) understanding metabolic dysregulation across the spectrum of pulmonary hypertension, and (5) advancing knowledge in chronic thromboembolic pulmonary hypertension. Focusing on these five thematic contexts we review the current state of knowledge, summarize presented research abstracts, appraise their significance and limitations, and then discuss relevant future directions in pulmonary hypertension clinical research.

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