Cytoskeletal defects in Bmpr2-associated pulmonary arterial hypertension

Am J Physiol Lung Cell Mol Physiol. 2012 Mar 1;302(5):L474-84. doi: 10.1152/ajplung.00202.2011. Epub 2011 Dec 16.


The heritable form of pulmonary arterial hypertension (PAH) is typically caused by a mutation in bone morphogenic protein receptor type 2 (BMPR2), and mice expressing Bmpr2 mutations develop PAH with features similar to human disease. BMPR2 is known to interact with the cytoskeleton, and human array studies in PAH patients confirm alterations in cytoskeletal pathways. The goal of this study was to evaluate cytoskeletal defects in BMPR2-associated PAH. Expression arrays on our Bmpr2 mutant mouse lungs revealed cytoskeletal defects as a prominent molecular consequence of universal expression of a Bmpr2 mutation (Rosa26-Bmpr2(R899X)). Pulmonary microvascular endothelial cells cultured from these mice have histological and functional cytoskeletal defects. Stable transfection of different BMPR2 mutations into pulmonary microvascular endothelial cells revealed that cytoskeletal defects are common to multiple BMPR2 mutations and are associated with activation of the Rho GTPase, Rac1. Rac1 defects are corrected in cell culture and in vivo through administration of exogenous recombinant human angiotensin-converting enzyme 2 (rhACE2). rhACE2 reverses 77% of gene expression changes in Rosa26-Bmpr2(R899X) transgenic mice, in particular, correcting defects in cytoskeletal function. Administration of rhACE2 to Rosa26-Bmpr2(R899X) mice with established PAH normalizes pulmonary pressures. Together, these findings suggest that cytoskeletal function is central to the development of BMPR2-associated PAH and that intervention against cytoskeletal defects may reverse established disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Angiotensin-Converting Enzyme 2
  • Animals
  • Blood Pressure / drug effects
  • Bone Morphogenetic Protein Receptors, Type II / genetics
  • Bone Morphogenetic Protein Receptors, Type II / metabolism*
  • Cells, Cultured
  • Cytoskeleton / genetics
  • Cytoskeleton / metabolism
  • Cytoskeleton / pathology*
  • Endothelial Cells / metabolism
  • Endothelial Cells / pathology
  • Enzyme Activation
  • Familial Primary Pulmonary Hypertension
  • Female
  • Gene Expression Profiling
  • Heart Ventricles / physiopathology
  • Humans
  • Hypertension, Pulmonary / drug therapy
  • Hypertension, Pulmonary / genetics
  • Hypertension, Pulmonary / metabolism
  • Hypertension, Pulmonary / pathology*
  • Lung / blood supply
  • Lung / metabolism
  • Lung / pathology
  • Male
  • Mice
  • Mice, Transgenic
  • Microvessels / metabolism
  • Microvessels / pathology
  • Neuropeptides / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Peptidyl-Dipeptidase A / pharmacology
  • Peptidyl-Dipeptidase A / therapeutic use
  • Phosphorylation
  • Recombinant Proteins / pharmacology
  • Recombinant Proteins / therapeutic use
  • rac GTP-Binding Proteins / metabolism
  • rac1 GTP-Binding Protein


  • Neuropeptides
  • Rac1 protein, mouse
  • Recombinant Proteins
  • Bmpr2 protein, mouse
  • Bone Morphogenetic Protein Receptors, Type II
  • Peptidyl-Dipeptidase A
  • ACE2 protein, human
  • Ace2 protein, mouse
  • Angiotensin-Converting Enzyme 2
  • rac GTP-Binding Proteins
  • rac1 GTP-Binding Protein