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Germain M.,University Pierre and Marie Curie | Germain M.,Institut Universitaire de France | Eyries M.,Institut Universitaire de France | Eyries M.,French Institute of Health and Medical Research | And 46 more authors.
Nature Genetics | Year: 2013

Pulmonary arterial hypertension (PAH) is a rare, severe disease resulting from progressive obliteration of small-caliber pulmonary arteries by proliferating vascular cells. PAH can occur without recognized etiology (idiopathic PAH), be associated with a systemic disease or occur as a heritable form, with BMPR2 mutated in approximately 80% of familial and 15% of idiopathic PAH cases. We conducted a genome-wide association study (GWAS) based on 2 independent case-control studies for idiopathic and familial PAH (without BMPR2 mutations), including a total of 625 cases and 1,525 healthy individuals. We detected a significant association at the CBLN2 locus mapping to 18q22.3, with the risk allele conferring an odds ratio for PAH of 1.97 (1.59-2.45; P = 7.47 × 10-10). CBLN2 is expressed in the lung, and its expression is higher in explanted lungs from individuals with PAH and in endothelial cells cultured from explanted PAH lungs. © 2013 Nature America, Inc. All rights reserved.

Ranchoux B.,University of Sfax | Ranchoux B.,French Institute of Health and Medical Research | Gunther S.,University of Sfax | Gunther S.,University Paris - Sud | And 41 more authors.
American Journal of Pathology | Year: 2014

Pulmonary veno-occlusive disease (PVOD) is an uncommon form of pulmonary hypertension (PH) characterized by progressive obstruction of small pulmonary veins and a dismal prognosis. Limited case series have reported a possible association between different chemotherapeutic agents and PVOD. We evaluated the relationship between chemotherapeutic agents and PVOD. Cases of chemotherapy-induced PVOD from the French PH network and literature were reviewed. Consequences of chemotherapy exposure on the pulmonary vasculature and hemodynamics were investigated in three different animal models (mouse, rat, and rabbit). Thirty-seven cases of chemotherapy-associated PVOD were identified in the French PH network and systematic literature analysis. Exposure to alkylating agents was observed in 83.8% of cases, mostly represented by cyclophosphamide (43.2%). In three different animal models, cyclophosphamide was able to induce PH on the basis of hemodynamic, morphological, and biological parameters. In these models, histopathological assessment confirmed significant pulmonary venous involvement highly suggestive of PVOD. Together, clinical data and animal models demonstrated a plausible cause-effect relationship between alkylating agents and PVOD. Clinicians should be aware of this uncommon, but severe, pulmonary vascular complication of alkylating agents. Copyright © 2015 American Society for Investigative Pathology.

Perros F.,University Paris - Sud | Perros F.,Laval University | Gunther S.,University Paris - Sud | Ranchoux B.,University Paris - Sud | And 17 more authors.
Circulation | Year: 2015

Background - Pulmonary veno-occlusive disease (PVOD) is an uncommon form of pulmonary hypertension characterized by the obstruction of small pulmonary veins and a dismal prognosis. PVOD may be sporadic or heritable because of biallelic mutations of the EIF2AK4 gene coding for GCN2. Isolated case reports suggest that chemotherapy may be a risk factor for PVOD. Methods and Results - We reported on the clinical, functional, and hemodynamic characteristics and outcomes of 7 cases of PVOD induced by mitomycin-C (MMC) therapy from the French Pulmonary Hypertension Registry. All patients displayed squamous anal cancer and were treated with MMC alone or MMC plus 5-fluoruracil. The estimated annual incidence of PVOD in the French population that have anal cancer is 3.9 of 1000 patients, which is much higher than the incidence of PVOD in the general population (0.5/million per year). In rats, intraperitoneal administration of MMC induced PVOD, as demonstrated by pulmonary hypertension at right-heart catheterization at days 21 to 35 and major remodeling of small pulmonary veins associated with foci of intense microvascular endothelial-cell proliferation of the capillary bed. In rats, MMC administration was associated with dose-dependent depletion of pulmonary GCN2 content and decreased smad1/5/8 signaling. Amifostine prevented the development of MMC-induced PVOD in rats. Conclusions - MMC therapy is a potent inducer of PVOD in humans and rats. Amifostine prevents MMC-induced PVOD in rats and should be tested as a preventive therapy for MMC-induced PVOD in humans. MMC-induced PVOD in rats represents a unique model to test novel therapies in this devastating orphan disease. © 2015 American Heart Association, Inc.

Antigny F.,University Paris - Sud | Antigny F.,Departement Hospitalo University Thorax Innovation | Hautefort A.,University Paris - Sud | Hautefort A.,Departement Hospitalo University Thorax Innovation | And 35 more authors.
Circulation | Year: 2016

Background - Mutations in the KCNK3 gene have been identified in some patients suffering from heritable pulmonary arterial hypertension (PAH). KCNK3 encodes an outward rectifier K+ channel, and each identified mutation leads to a loss of function. However, the pathophysiological role of potassium channel subfamily K member 3 (KCNK3) in PAH is unclear. We hypothesized that loss of function of KCNK3 is a hallmark of idiopathic and heritable PAH and contributes to dysfunction of pulmonary artery smooth muscle cells and pulmonary artery endothelial cells, leading to pulmonary artery remodeling: consequently, restoring KCNK3 function could alleviate experimental pulmonary hypertension (PH). Methods and Results - We demonstrated that KCNK3 expression and function were reduced in human PAH and in monocrotaline-induced PH in rats. Using a patch-clamp technique in freshly isolated (not cultured) pulmonary artery smooth muscle cells and pulmonary artery endothelial cells, we found that KCNK3 current decreased progressively during the development of monocrotaline-induced PH and correlated with plasma-membrane depolarization. We demonstrated that KCNK3 modulated pulmonary arterial tone. Long-term inhibition of KCNK3 in rats induced distal neomuscularization and early hemodynamic signs of PH, which were related to exaggerated proliferation of pulmonary artery endothelial cells, pulmonary artery smooth muscle cell, adventitial fibroblasts, and pulmonary and systemic inflammation. Lastly, in vivo pharmacological activation of KCNK3 significantly reversed monocrotaline-induced PH in rats. Conclusions - In PAH and experimental PH, KCNK3 expression and activity are strongly reduced in pulmonary artery smooth muscle cells and endothelial cells. KCNK3 inhibition promoted increased proliferation, vasoconstriction, and inflammation. In vivo pharmacological activation of KCNK3 alleviated monocrotaline-induced PH, thus demonstrating that loss of KCNK3 is a key event in PAH pathogenesis and thus could be therapeutically targeted. © 2016 American Heart Association, Inc.

Evans J.D.W.,University of Cambridge | Evans J.D.W.,Papworth Hospital | Girerd B.,University Paris - Sud | Girerd B.,Departement Hospitalo University Thorax Innovation | And 37 more authors.
The Lancet Respiratory Medicine | Year: 2016

Background: Mutations in the gene encoding the bone morphogenetic protein receptor type II (BMPR2) are the commonest genetic cause of pulmonary arterial hypertension (PAH). However, the effect of BMPR2 mutations on clinical phenotype and outcomes remains uncertain. Methods: We analysed individual participant data of 1550 patients with idiopathic, heritable, and anorexigen-associated PAH from eight cohorts that had been systematically tested for BMPR2 mutations. The primary outcome was the composite of death or lung transplantation. All-cause mortality was the secondary outcome. Hazard ratios (HRs) for death or transplantation and all-cause mortality associated with the presence of BMPR2 mutation were calculated using Cox proportional hazards models stratified by cohort. Findings: Overall, 448 (29%) of 1550 patients had a BMPR2 mutation. Mutation carriers were younger at diagnosis (mean age 35·4 [SD 14·8] vs 42·0 [17·8] years), had a higher mean pulmonary artery pressure (60·5 [13·8] vs 56·4 [15·3] mm Hg) and pulmonary vascular resistance (16·6 [8·3] vs 12·9 [8·3] Wood units), and lower cardiac index (2·11 [0·69] vs 2·51 [0·92] L/min per m2; all p<0·0001). Patients with BMPR2 mutations were less likely to respond to acute vasodilator testing (3% [10 of 380] vs 16% [147 of 907]; p<0·0001). Among the 1164 individuals with available survival data, age-adjusted and sex-adjusted HRs comparing BMPR2 mutation carriers with non-carriers were 1·42 (95% CI 1·15-1·75; p=0·0011) for the composite of death or lung transplantation and 1·27 (1·00-1·60; p=0·046) for all-cause mortality. These HRs were attenuated after adjustment for potential mediators including pulmonary vascular resistance, cardiac index, and vasoreactivity. HRs for death or transplantation and all-cause mortality associated with BMPR2 mutation were similar in men and women, but higher in patients with a younger age at diagnosis (p=0·0030 for death or transplantation, p=0·011 for all-cause mortality). Interpretation: Patients with PAH and BMPR2 mutations present at a younger age with more severe disease, and are at increased risk of death, and death or transplantation, compared with those without BMPR2 mutations. Funding: Cambridge NIHR Biomedical Research Centre, Medical Research Council, British Heart Foundation, Assistance Publique-Hôpitaux de Paris, INSERM, Université Paris-Sud, Intermountain Research and Medical Foundation, Vanderbilt University, National Center for Advancing Translational Sciences, National Institutes of Health, National Natural Science Foundation of China, and Beijing Natural Science Foundation. © 2016 Evans et al. Open Access article distributed under the terms of CC-BY.

Godinas L.,Departement Hospitalo University Thorax Innovation | Godinas L.,University Paris - Sud | Godinas L.,Catholic University of Louvain | Amar D.,Departement Hospitalo University Thorax Innovation | And 24 more authors.
Journal of Heart and Lung Transplantation | Year: 2016

Background Combined diffusion capacity of the lung for carbon monoxide (DLco) and nitric oxide (DLno) measurements allow for the estimation of pulmonary capillary blood volume (Vc) and alveolar membrane diffusion (Dm). The clinical usefulness of these measurements in pulmonary hypertension (PH) is unclear. Methods Combined DLco and DLno were measured in 290 consecutive patients with precapillary PH (pulmonary arterial hypertension (PAH), n = 153; pulmonary veno-occlusive disease (PVOD), n = 33; and chronic thromboembolic pulmonary hypertension (CTEPH), n = 104). Clinical correlates of Vc and Dm were assessed in a sub-group of PAH patients without comorbidities. Results PVOD patients compared with PAH and CTEPH patients displayed the lowest values of Vc (29.4 ± 16.8 ml vs 56.3 ± 26.5 ml vs 56.9 ± 26.2 ml, p < 0.01, respectively) and Dm (27.7 ± 11.6 ml/mm Hg/min vs 43.4 ± 14.8 ml/mm Hg/min vs 44.7 ± 17.7 ml/mm Hg/min, p < 0.01, respectively). The DLno/DLco ratio was highest in the PVOD group (5.82 ± 2.04 vs 4.95 ± 1.31 vs 5.16 ± 1.58, p < 0.05). In a sub-set of 69 PAH patients without comorbidities, Vc and Dm correlated significantly with functional capacity (6-minute walking distance, oxygen consumption) and New York Heart Association Functional Classification but not with invasive hemodynamics. Only Dm was significantly associated with survival. On receiver operating characteristic curve analysis, Vc, Dm, and DLno/DLco were not superior to DLco for discriminating PVOD from PAH or CTEPH. Conclusions PVOD patients display higher values of the DLno/DLco ratio compared with PAH and CTEPH, suggesting proportionally greater reduction in Vc relative to Dm. However, partitioning of diffusion failed to be more clinically relevant than conventional DLco for detection of PVOD. © 2016 International Society for Heart and Lung Transplantation.

Chaumais M.-C.,University Paris - Sud | Chaumais M.-C.,French Institute of Health and Medical Research | Chaumais M.-C.,Departement Hospitalo University Thorax Innovation | Guignabert C.,French Institute of Health and Medical Research | And 18 more authors.
American Journal of Cardiovascular Drugs | Year: 2015

Pulmonary arterial hypertension (PAH) is a devastating life-threatening disorder characterized by elevated pulmonary vascular resistance leading to elevated pulmonary arterial pressures, right ventricular failure, and ultimately death. Vascular endothelial cells mainly produce and secrete endothelin (ET-1) in vessels that lead to a potent and long-lasting vasoconstrictive effect in pulmonary arterial smooth muscle cells. Along with its strong vasoconstrictive action, ET-1 can promote smooth muscle cell proliferation. Thus, ET-1 blockers have attracted attention as an antihypertensive drug, and the ET-1 signaling system has paved a new therapeutic avenue for the treatment of PAH. We outline the current understanding of not only the pathogenic role played by ET-1 signaling systems in the pathogenesis of PH but also the clinical pharmacology of endothelin receptor antagonists (ERA) used in the treatment of PAH. © 2014, Springer International Publishing Switzerland.

Chaumais M.-C.,University Paris - Sud | Chaumais M.-C.,Departement Hospitalo University Thorax Innovation | Ranchoux B.,University Paris - Sud | Montani D.,University Paris - Sud | And 13 more authors.
Respiratory Research | Year: 2014

Background: The outcome of patients suffering from pulmonary arterial hypertension (PAH) are predominantly determined by the response of the right ventricle to the increase afterload secondary to high vascular pulmonary resistance. However, little is known about the effects of the current available or experimental PAH treatments on the heart. Recently, inflammation has been implicated in the pathophysiology of PAH. N-acetylcysteine (NAC), a well-known safe anti-oxidant drug, has immuno-modulatory and cardioprotective properties. We therefore hypothesized that NAC could reduce the severity of pulmonary hypertension (PH) in rats exposed to monocrotaline (MCT), lowering inflammation and preserving pulmonary vascular system and right heart function.Methods: Saline-treated control, MCT-exposed, MCT-exposed and NAC treated rats (day 14-28) were evaluated at day 28 following MCT for hemodynamic parameters (right ventricular systolic pressure, mean pulmonary arterial pressure and cardiac output), right ventricular hypertrophy, pulmonary vascular morphometry, lung inflammatory cells immunohistochemistry (monocyte/macrophages and dendritic cells), IL-6 expression, cardiomyocyte hypertrophy and cardiac fibrosis.Results: The treatment with NAC significantly decreased pulmonary vascular remodeling, lung inflammation, and improved total pulmonary resistance (from 0.71 ± 0.05 for MCT group to 0.50 ± 0.06 for MCT + NAC group, p < 0.05). Right ventricular function was also improved with NAC treatment associated with a significant decrease in cardiomyocyte hypertrophy (625 ± 69 vs. 439 ± 21 μm2 for MCT and MCT + NAC group respectively, p < 0.001) and heart fibrosis (14.1 ± 0.8 vs. 8.8 ± 0.1% for MCT and MCT + NAC group respectively, p < 0.001).Conclusions: Through its immuno-modulatory and cardioprotective properties, NAC has beneficial effect on pulmonary vascular and right heart function in experimental PH. © 2014 Chaumais et al.; licensee BioMed Central Ltd.

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