Published online before print December 15, 2005, doi: 10.1161/01.RES.0000200180.01710.e6
© 2006 American Heart Association, Inc.
Molecular Medicine |
Bone Morphogenetic Protein Receptor-2 Signaling Promotes Pulmonary Arterial Endothelial Cell Survival
Implications for Loss-of-Function Mutations in the Pathogenesis of Pulmonary Hypertension
From the Terrence Donnelly Heart Center and Division of Cardiology (K.T.-K., M.J.B.K., M.A.K., G.K., D.W.C., L.Z., D.J.S.), St. Michael’s Hospital, Toronto; University Health Network (J.G.), Toronto; and the Departments of Medicine (M.J.B.K., J.G., D.J.S.) and Laboratory Medicine and Pathobiology (G.K., D.W.C., D.J.S.) and The McLaughlin Center for Molecular Medicine (M.J.B.K., D.J.S.), University of Toronto, Ontario, Canada.
Correspondence to Dr Duncan J. Stewart, Head, Division of Cardiology, St. Michael’s Hospital, 30 Bond St, Rm 6050 Queen Wing, Toronto, Ontario, Canada M5B 1W8. E-mail stewartd{at}smh.toronto.on.ca
Mutations in the bone morphogenetic protein (BMP) receptor-2 (BMPR2) have been found in patients with idiopathic pulmonary arterial hypertension (IPAH); however, the mechanistic link between loss of BMPR2 signaling and the development of pulmonary arterial hypertension is unclear. We hypothesized that, contrary to smooth muscle cells, this pathway promotes survival in pulmonary artery endothelial cells (ECs) and loss of BMPR2 signaling will predispose to EC apoptosis. ECs were treated with BMP-2 or BMP-7 (200 ng/mL) for 24 hours in regular or serum-free (SF) medium, with and without addition of tumor necrosis factor 
, and apoptosis was assessed by flow cytometry (Annexin V), TUNEL, or caspase-3 activity. Treatment for 24 hours in SF medium increased apoptosis, and both BMP-2 and BMP-7 significantly reduced apoptosis in response to serum deprivation to levels not different from serum controls. Transfection with 5 µg of small interfering RNAs for BMPR2 produced specific gene silencing assessed by RT-PCR and Western blot analysis. BMPR2 gene silencing increased apoptosis almost 3-fold (P=0.0027), even in the presence of serum. Circulating endothelial progenitor cells (EPCs) isolated from normal subjects or patients with IPAH were differentiated in culture for 7 days and apoptosis was determined in the presence and absence of BMPs. BMP-2 reduced apoptosis induced by serum withdrawal in EPCs from normal subjects but not in EPCs isolated from patients with IPAH. These results support the hypothesis that loss-of-function mutations in BMPR2 could lead to increased pulmonary EC apoptosis, representing a possible initiating mechanism in the pathogenesis of pulmonary arterial hypertension.
Key Words: bone morphogenetic proteins • bone morphogenetic receptor-2 • pulmonary arterial hypertension • endothelial cells • endothelial progenitor cells • apoptosis
Related Article:
Circ. Res. 2006 98: 172-175.
This article has been cited by other articles:
 |
|
 |
|
  K.-H. Hong, Y. J. Lee, E. Lee, S. O. Park, C. Han, H. Beppu, E. Li, M. K. Raizada, K. D. Bloch, and S. P. Oh Genetic Ablation of the Bmpr2 Gene in Pulmonary Endothelium Is Sufficient to Predispose to Pulmonary Arterial Hypertension Circulation, August 12, 2008; 118(7): 722 - 730. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Song, L. Coleman, J. Shi, H. Beppu, K. Sato, K. Walsh, J. Loscalzo, and Y.-Y. Zhang Inflammation, endothelial injury, and persistent pulmonary hypertension in heterozygous BMPR2-mutant mice Am J Physiol Heart Circ Physiol, August 1, 2008; 295(2): H677 - H690. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Asosingh, M. A. Aldred, A. Vasanji, J. Drazba, J. Sharp, C. Farver, S. A.A. Comhair, W. Xu, L. Licina, L. Huang, et al. Circulating Angiogenic Precursors in Idiopathic Pulmonary Arterial Hypertension Am. J. Pathol., March 1, 2008; 172(3): 615 - 627. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. B. Frank, J. Lowery, L. Anderson, M. Brink, J. Reese, and M. de Caestecker Increased susceptibility to hypoxic pulmonary hypertension in Bmpr2 mutant mice is associated with endothelial dysfunction in the pulmonary vasculature Am J Physiol Lung Cell Mol Physiol, January 1, 2008; 294(1): L98 - L109. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Gu, J. He, W.-T. Ho, S. Ramineni, D. M. Thal, R. Natesh, J. J. G. Tesmer, J. R. Hepler, and S. P. Heximer Unique Hydrophobic Extension of the RGS2 Amphipathic Helix Domain Imparts Increased Plasma Membrane Binding and Function Relative to Other RGS R4/B Subfamily Members J. Biol. Chem., November 9, 2007; 282(45): 33064 - 33075. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Zakrzewicz, M. Hecker, L. M. Marsh, G. Kwapiszewska, B. Nejman, L. Long, W. Seeger, R. T. Schermuly, N. W. Morrell, R. E. Morty, et al. Receptor for Activated C-Kinase 1, a Novel Interaction Partner of Type II Bone Morphogenetic Protein Receptor, Regulates Smooth Muscle Cell Proliferation in Pulmonary Arterial Hypertension Circulation, June 12, 2007; 115(23): 2957 - 2968. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. B. Sehgal, S. Mukhopadhyay, F. Xu, K. Patel, and M. Shah Dysfunction of Golgi tethers, SNAREs, and SNAPs in monocrotaline-induced pulmonary hypertension Am J Physiol Lung Cell Mol Physiol, June 1, 2007; 292(6): L1526 - L1542. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Tada, S. Majka, M. Carr, J. Harral, D. Crona, T. Kuriyama, and J. West Molecular effects of loss of BMPR2 signaling in smooth muscle in a transgenic mouse model of PAH Am J Physiol Lung Cell Mol Physiol, June 1, 2007; 292(6): L1556 - L1563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Reynolds, W. Xia, M. D. Holmes, S. J. Hodge, S. Danilov, D. T. Curiel, N. W. Morrell, and P. N. Reynolds Bone morphogenetic protein type 2 receptor gene therapy attenuates hypoxic pulmonary hypertension Am J Physiol Lung Cell Mol Physiol, May 1, 2007; 292(5): L1182 - L1192. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Levy, C. Maurey, D. S. Celermajer, P. R. Vouhe, C. Danel, D. Bonnet, and D. Israel-Biet Impaired Apoptosis of Pulmonary Endothelial Cells Is Associated With Intimal Proliferation and Irreversibility of Pulmonary Hypertension in Congenital Heart Disease J. Am. Coll. Cardiol., February 20, 2007; 49(7): 803 - 810. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. C. Aird Phenotypic Heterogeneity of the Endothelium: II. Representative Vascular Beds Circ. Res., February 2, 2007; 100(2): 174 - 190. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. W. Morrell Pulmonary Hypertension Due to BMPR2 Mutation: A New Paradigm for Tissue Remodeling? Proceedings of the ATS, November 1, 2006; 3(8): 680 - 686. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Lagna, P. H. Nguyen, W. Ni, and A. Hata BMP-dependent activation of caspase-9 and caspase-8 mediates apoptosis in pulmonary artery smooth muscle cells. Am J Physiol Lung Cell Mol Physiol, November 1, 2006; 291(5): L1059 - L1067. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. D. Michelakis Spatio-Temporal Diversity of Apoptosis Within the Vascular Wall in Pulmonary Arterial Hypertension: Heterogeneous BMP Signaling May Have Therapeutic Implications Circ. Res., February 3, 2006; 98(2): 172 - 175. [Full Text] [PDF]
|
|