title: Endothelin-1 driven proliferation of pulmonary arterial smooth muscle cells is c-fos dependent.
abstract: Pulmonary hypertension (PH) is characterized by enhanced pulmonary artery smooth muscle cell (PASMC) proliferation leading to vascular remodeling. Although, multiple factors have been associated with pathogenesis of PH the underlying mechanisms are not fully understood. Here, we hypothesize that already very short exposure to hypoxia may activate molecular cascades leading to vascular remodeling. Microarray studies from lung homogenates of mice exposed to only 3h of hypoxia revealed endothelin-1 (ET-1) and connective tissue growth factor (CTGF) as the most upregulated genes, and the mitogen-activated protein kinase (MAPK) pathway as the most differentially regulated pathway. Evaluation of these results in vitro showed that ET-1 but not CTGF stimulation of human PASMCs increased DNA synthesis and expression of proliferation markers such as Ki67 and cell cycle regulator, cyclin D1. Moreover, ET-1 treatment elevated extracellular signal-regulated kinase (Erk)-dependent c-fos expression and phosphorylation of c-fos and c-jun transcription factors. Silencing of c-fos with siRNA abrogated the ET-1-induced proliferation of PASMCs. Expression and immunohistochemical analyses revealed higher levels of total and phosphorylated c-fos and c-jun in the vessel wall of lung samples of human idiopathic pulmonary arterial hypertension patents, hypoxia-exposed mice and monocrotaline-treated rats as compared to control subjects. These findings shed the light on the involvement of c-fos/c-jun in the proliferative response of PASMCs to ET-1 indicating that already very short hypoxia exposure leads to the regulation of mediators involved in vascular remodeling underlying PH.
authors.affiliation: Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.
authors.forename: Valentina
authors.initials: V
authors.lastname: Biasin
authors.affiliation: Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig University, Member of the German Lung Center (DZL), Giessen, Germany.
authors.forename: Karolina
authors.initials: K
authors.lastname: Chwalek
authors.affiliation: Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig University, Member of the German Lung Center (DZL), Giessen, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Wilhelm
authors.affiliation: Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig University, Member of the German Lung Center (DZL), Giessen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Best
authors.affiliation: Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.
authors.forename: Leigh M
authors.initials: LM
authors.lastname: Marsh
authors.affiliation: Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Division of Thoracic Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Bahil
authors.initials: B
authors.lastname: Ghanim
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Walter
authors.initials: W
authors.lastname: Klepetko
authors.affiliation: Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig University, Member of the German Lung Center (DZL), Giessen, Germany; Institute of Pathology and Cytology, Wetzlar, Germany.
authors.forename: Ludger
authors.initials: L
authors.lastname: Fink
authors.affiliation: Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig University, Member of the German Lung Center (DZL), Giessen, Germany.
authors.forename: Ralph T
authors.initials: RT
authors.lastname: Schermuly
authors.affiliation: Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig University, Member of the German Lung Center (DZL), Giessen, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Weissmann
authors.affiliation: Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Experimental Anaesthesiology, Medical University of Graz, Graz, Austria.
authors.forename: Andrea
authors.initials: A
authors.lastname: Olschewski
authors.affiliation: Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Experimental Anaesthesiology, Medical University of Graz, Graz, Austria. Electronic address: Grazyna.Kwapiszewska@lvr.lbg.ac.at.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Kwapiszewska
mesh_terms: D000818:Animals; D017209:Apoptosis; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D016022:Case-Control Studies; D049109:Cell Proliferation; D002478:Cells, Cultured; D019332:Endothelin-1 / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D065627:Familial Primary Pulmonary Hypertension / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D006801:Humans; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007124:Immunoenzyme Techniques; D008168:Lung / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism*; D011651:Pulmonary Artery / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
chemical_list: D015415:Biomarkers; D019332:Endothelin-1; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases
keywords: Endothelin-1; Proliferation; Pulmonary hypertension; Transcription factor; c-Fos