title: Bone morphogenic protein-9 stimulates endothelin-1 release from human pulmonary microvascular endothelial cells: a potential mechanism for elevated ET-1 levels in pulmonary arterial hypertension.
abstract: Abnormalities of signalling for the transforming growth factor beta (TGFβ) family of peptides, including bone morphogenic proteins (BMP), have been described in heritable pulmonary arterial hypertension (PAH). TGFβ can modulate synthesis of the vasoconstrictor and mitogen, endothelin-1 (ET-1), a mediator that contributes to the pathogenesis of PAH. BMP-9 is a circulating peptide recently recognized to affect endothelial function. The stimuli for increased microvascular endothelial production of ET-1 in PAH are unknown. We therefore studied the effects of BMP-9 on ET-1 production by human lung blood microvascular endothelial cells (HMVEC-LBl) in vitro. In vitro, BMP-9 increased ET-1 production by HMVEC-LBl. The effect was identical to TGFβ-1, but BMP-9 and TGFβ-1 combined further increased ET-1 levels by 29%. As compared to TGFβ-1, BMP-9 induced more potent and rapid phosphorylation of Smad 1/5, the downstream signalling molecules of the activin-like kinase 1 (ALK-1) receptor. Moreover, as has been previously shown for endothelial cells of other origin, BMP-9 also induced Smad 2 phosphorylation in HMVEC-LBl. In conclusion, BMP-9 stimulates ET-1 production by HMVEC-LBl in vitro. BMP-9 signals via several Smad pathways. These studies provide novel mechanisms for the potentiation of PAH.
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Star
authors.forename: Michele
authors.initials: M
authors.lastname: Giovinazzo
authors.forename: David
authors.initials: D
authors.lastname: Langleben
mesh_terms: D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D019332:Endothelin-1 / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D065627:Familial Primary Pulmonary Hypertension; D055427:Growth Differentiation Factor 2 / Q000378:metabolism*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000378:metabolism; D008168:Lung / Q000098:blood supply*; D055806:Microvessels / Q000378:metabolism*; D010766:Phosphorylation; D044023:Receptor, Endothelin B / Q000378:metabolism; D015398:Signal Transduction; D051898:Smad1 Protein / Q000378:metabolism; D051899:Smad2 Protein / Q000378:metabolism; D051902:Smad5 Protein / Q000378:metabolism; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D019332:Endothelin-1; D055427:Growth Differentiation Factor 2; D044023:Receptor, Endothelin B; C497399:SMAD1 protein, human; C497782:SMAD2 protein, human; C497797:SMAD5 protein, human; D051898:Smad1 Protein; D051899:Smad2 Protein; D051902:Smad5 Protein; D053773:Transforming Growth Factor beta1; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases