Published ahead of print on April 24, 2003, doi:10.1165/rcmb.2002-0157OC
American Journal of Respiratory Cell and Molecular Biology. Vol. 29, pp. 465-471, 2003
© 2003 American Thoracic Society DOI: 10.1165/rcmb.2002-0157OC
Hypoxia Inhibits Myosin Phosphatase in Pulmonary Arterial Smooth Muscle Cells
Role of Rho-Kinase
Zhiqian Wang,
M. Carita Lannér,
Najia Jin,
Darl Swartz,
Liang Li and
Rodney A. Rhoades
Department of Cellular/Integrative Physiology, and Department of Anatomy/Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
Address correspondence to: Dr. M. Carita Lannér, Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202. E-mail: clanner{at}iupui.edu
Rho-kinase was recently found to phosphorylate the myosin-binding subunit (MBS) of myosin phosphatase (MP) and to regulate MP activity. Although myosin light chain (MLC) phosphorylation in pulmonary arterial smooth muscle cells (PASMCs) is thought to be the cellular/molecular basis for hypoxic pulmonary vasoconstriction (HPV), very little is known about the role that Rho-kinase/MP plays in HPV. Rat PASMCs were cultured and made hypoxic (PO2 = 23 ± 2 mm Hg). Cells exposed to normoxia (PO2 148 mm Hg) served as controls. PASMCs exposed to hypoxia showed a significant increase in MLC and MBS phosphorylation, and a significant decrease in MP activity. Rho-kinase inhibitors (HA1077 or Y-27632) blocked hypoxia-induced MP inactivation and inhibited the hypoxia-induced MLC phosphorylation. Hypoxia was also found to induce stress fiber formation and actin polymerization in cultured PASMCs. In summary, these data show that MP inhibition in PASMCs is linked to activation of Rho-kinase, and that hypoxia inhibits the MP signaling pathway via Rho-kinase.
Abbreviations: Dulbecco's modified Eagle's medium, DMEM dithiothreitol, DTT fetal bovine serum, FBS fluorescein isothiocyanate, FITC hypoxic pulmonary vasoconstriction, HPV immunoglobulin, IgG lysophosphatidic acid, LPA myosin-binding subunit, MBS myosin light chain, MLC MLC kinase, MLCK myosin phosphatase, MP okadaic acid, OA pulmonary artery smooth muscle cell, PASMC phosphate-buffered saline, PBS Rho-associated serine/threonine kinase, Rho-kinase sodium dodecyl sulfate, SDS trichloroacetic acid, TCA
This article has been cited by other articles:

|
 |

|
 |
 
N. Sommer, A. Dietrich, R. T. Schermuly, H. A. Ghofrani, T. Gudermann, R. Schulz, W. Seeger, F. Grimminger, and N. Weissmann
Regulation of hypoxic pulmonary vasoconstriction: basic mechanisms
Eur. Respir. J.,
December 1, 2008;
32(6):
1639 - 1651.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. A. Knock, V. A. Snetkov, Y. Shaifta, S. Drndarski, J. P.T. Ward, and P. I. Aaronson
Role of src-family kinases in hypoxic vasoconstriction of rat pulmonary artery
Cardiovasc Res,
December 1, 2008;
80(3):
453 - 462.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Wang, L. Weigand, J. Foxson, L. A. Shimoda, and J. T. Sylvester
Ca2+ signaling in hypoxic pulmonary vasoconstriction: effects of myosin light chain and Rho kinase antagonists
Am J Physiol Lung Cell Mol Physiol,
September 1, 2007;
293(3):
L674 - L685.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. P. Robertson
Point: Release of an endothelium-derived vasoconstrictor and RhoA/Rho kinase-mediated calcium sensitization of smooth muscle cell contraction are/are not the main effectors for full and sustained hypoxic pulmonary vasoconstriction
J Appl Physiol,
May 1, 2007;
102(5):
2071 - 2072.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Hinton, A. Gutsol, and S. Dakshinamurti
Thromboxane hypersensitivity in hypoxic pulmonary artery myocytes: altered TP receptor localization and kinetics
Am J Physiol Lung Cell Mol Physiol,
March 1, 2007;
292(3):
L654 - L663.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. A. Parker, G. Roe, T. R. Grover, and S. H. Abman
Rho kinase activation maintains high pulmonary vascular resistance in the ovine fetal lung
Am J Physiol Lung Cell Mol Physiol,
November 1, 2006;
291(5):
L976 - L982.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
N. Weissmann, N. Sommer, R. T. Schermuly, H. A. Ghofrani, W. Seeger, and F. Grimminger
Oxygen sensors in hypoxic pulmonary vasoconstriction
Cardiovasc Res,
September 1, 2006;
71(4):
620 - 629.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. D. Gultice, K. L. Selesniemi, and T. L. Brown
Hypoxia Inhibits Differentiation of Lineage-Specific Rcho-1 Trophoblast Giant Cells
Biol Reprod,
June 1, 2006;
74(6):
1041 - 1050.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. K. Surks, N. Riddick, and K.-i. Ohtani
M-RIP Targets Myosin Phosphatase to Stress Fibers to Regulate Myosin Light Chain Phosphorylation in Vascular Smooth Muscle Cells
J. Biol. Chem.,
December 30, 2005;
280(52):
42543 - 42551.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. C. Lanner, M. Raper, W. M. Pratt, and R. A. Rhoades
Heterotrimeric G Proteins and the Platelet-Derived Growth Factor Receptor-{beta} Contribute to Hypoxic Proliferation of Smooth Muscle Cells
Am. J. Respir. Cell Mol. Biol.,
October 1, 2005;
33(4):
412 - 419.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. S. An, C. M. Pennella, A. Gonnabathula, J. Chen, N. Wang, M. Gaestel, P. M. Hassoun, J. J. Fredberg, and U. S. Kayyali
Hypoxia alters biophysical properties of endothelial cells via p38 MAPK- and Rho kinase-dependent pathways
Am J Physiol Cell Physiol,
September 1, 2005;
289(3):
C521 - C530.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Weigand, J. Foxson, J. Wang, L. A. Shimoda, and J. T. Sylvester
Inhibition of hypoxic pulmonary vasoconstriction by antagonists of store-operated Ca2+ and nonselective cation channels
Am J Physiol Lung Cell Mol Physiol,
July 1, 2005;
289(1):
L5 - L13.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. B. Waypa and P. T. Schumacker
Hypoxic pulmonary vasoconstriction: redox events in oxygen sensing
J Appl Physiol,
January 1, 2005;
98(1):
404 - 414.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. T. Sylvester
The tone of pulmonary smooth muscle: ROK and Rho music?
Am J Physiol Lung Cell Mol Physiol,
October 1, 2004;
287(4):
L624 - L630.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Bailly, A. J. Ridley, S. M. Hall, and S. G. Haworth
RhoA Activation by Hypoxia in Pulmonary Arterial Smooth Muscle Cells Is Age and Site Specific
Circ. Res.,
May 28, 2004;
94(10):
1383 - 1391.
[Abstract]
[Full Text]
[PDF]
|
 |
|
Copyright © 2003 American Thoracic Society.
|
|
|