| Autor: |
Happé C; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., Kurakula K; Laboratory for Cardiovascular Cell Biology, Department of Cell and Chemical Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands., Sun XQ; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., da Silva Goncalves Bos D; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., Rol N; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., Guignabert C; INSERM UMR_S 999, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France.; Université Paris-Saclay, School of Medicine, 94270 Le Kremlin-Bicêtre, France., Tu L; INSERM UMR_S 999, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France.; Université Paris-Saclay, School of Medicine, 94270 Le Kremlin-Bicêtre, France., Schalij I; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., Wiesmeijer KC; Laboratory for Cardiovascular Cell Biology, Department of Cell and Chemical Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands., Tura-Ceide O; Department of Pulmonary Medicine, Hospital Clínic-Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain.; Biomedical Research Networking center on Respiratory diseases (CIBERES), 28029 Madrid, Spain.; Department of Pulmonary Medicine, Dr. Josep Trueta University Hospital de Girona, Santa Caterina Hospital de Salt and the Girona Biomedical Research Institut (IDIBGI), 17190 Girona, Catalonia, Spain., Vonk Noordegraaf A; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., de Man FS; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., Bogaard HJ; Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Pulmonology, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands., Goumans MJ; Laboratory for Cardiovascular Cell Biology, Department of Cell and Chemical Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands. |
| Abstrakt: |
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, perturbations in the transforming growth factor-β (TGF-β)/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-β 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. |
