Published ahead of print on August 21, 2003, doi:10.1165/rcmb.2003-0019OC
© 2004 American Thoracic Society DOI: 10.1165/rcmb.2003-0019OC Rho Kinase Inhibition Initiates Apoptosis in Human Airway Epithelial CellsSection of Pulmonary and Critical Care Medicine, University of Chicago, Chicago, Illinois Address correspondence to: Steven R. White, M.D., University of Chicago, Section of Pulmonary and Critical Care Medicine, 5841 S. Maryland Ave., MC 6076, Chicago, IL 60637. E-mail: swhite{at}medicine.bsd.uchicago.edu Disruption of the actin cytoskeleton elicits profound changes in cell survival and function. The actin cytoskeleton is regulated in a hierarchical manner by Rho GTPases. Rho kinase, a downstream effector of RhoA, regulates the formation of stress fibers and focal adhesions. Disruption of the actin cytoskeleton causes apoptosis in airway epithelial cells. To examine further the relation of cytoskeletal integrity and apoptosis, we tested whether inhibition of Rho kinase would elicit apoptosis in airway epithelial cells. Inhibition with either Y-27632 or HA1077 induced membrane ruffling and loss of actin stress fibers, and apoptosis in airway epithelial cells that was blocked by inhibiting caspase function or by inhibiting protein synthesis. Cells overexpressing constitutively active Rho kinase, but not native Rho kinase, were resistant to Rho kinase inhibitor–induced stress fiber disruption and apoptosis. Inhibition of Rho kinase disrupted actin stress fibers but did not induce apoptosis in 3T3 cells. We demonstrate that Rho kinase inhibition induces airway epithelial cell apoptosis associated with changes in actin filament integrity. Our data suggest that Rho kinase may be a regulator of early initiation of apoptosis.
Abbreviations: N-acetyl-(Asp-Glu-Val)-3-amino-4-oxobutaonic acid, Ac-DEVD-cho • N-acetyl-(Tyr-Val-Ala-Asp)-3 amino-4-oxobutaonic acid, Ac-YVAD-cho • 7-amino-4-trifluoromethylcoumarin, AFC • bovine pituitary extract, BPE • cytochalasin D, CYD • benzyloxycarbonyl-Asp-Glu-Val-Asp, (Z-DEVD) • dimethyl sulfoxide, DMSO • ethyleneglycol-bis-(ß-aminoethyl ether)-N,N'-tetraacetic acid, EGTA • fetal calf serum, FCS • (5-Isoquinolinesulfonyl) homopiperazine, 2HCl, HA-1077 • monoclonal antibody, mAb • phosphate-buffered saline, PBS • sodium dodecyl sulfate polyacrylamide gel electrophoresis, SDS-PAGE • terminal deoxynucleotidyl transferase mediated dUTP biotin nick end-labeling, TUNEL • 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide, Z-Val-Ala-Asp-fluoromethylketone, Z-VAD-fmk This article has been cited by other articles:
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