title: BMP-dependent activation of caspase-9 and caspase-8 mediates apoptosis in pulmonary artery smooth muscle cells.
abstract: Germ line mutations in the bone morphogenetic protein (BMP) receptor type II (BMPRII) gene have been found in >50% of familial idiopathic pulmonary arterial hypertension (IPAH) patients and in 30% of sporadic cases of IPAH. Mutations of BMPRII occur in the extracellular ligand-binding domain, in the cytoplasmic serine/threonine kinase domain, or in the long carboxy terminus domain of unknown function. In this study, we demonstrate that BMPs promote apoptotic cell death in normal human pulmonary artery smooth muscle cells (PASMCs) by activation of caspases-3, -8, and -9, cytochrome c release, and downregulation of Bcl-2. Normal PASMCs expressing a kinase domain mutant or a carboxy-terminal domain deletion mutant of BMPRII identified in IPAH patients are resistant to BMP-mediated apoptosis. This dominant-negative effect may act in heterozygous patients and lead to the development of the pulmonary vascular medial hypertrophy found in IPAH patients. Our study also demonstrates an essential role of the carboxy terminus domain of BMPRII in the activation of the apoptotic signaling cascade.
authors.affiliation: Molecular Cardiology Research Institute, Tufts-New England Medical Center, 750 Washington St., Boston, MA 02111, USA.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lagna
authors.forename: Peter H
authors.initials: PH
authors.lastname: Nguyen
authors.forename: Weihua
authors.initials: W
authors.lastname: Ni
authors.forename: Akiko
authors.initials: A
authors.lastname: Hata
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism*; D053453:Caspase 9 / Q000378:metabolism*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D030024:Curcuma; D045304:Cytochromes c / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D017353:Gene Deletion; D006801:Humans; D006976:Hypertension, Pulmonary / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: C525809:BMP4 protein, human; C525819:BMP7 protein, human; C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016212:Transforming Growth Factor beta; D045304:Cytochromes c; D052006:Bone Morphogenetic Protein Receptors, Type II; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9