|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
causes barrier dysfunction mediated by tyrosine198 and tyrosine218 in
-actin1Department of Pharmaceutical Science, Albany College of Pharmacy; 2Research Service of the Stratton Veterans Affairs Medical Center; 3Albany Medical College; and 4State University of New York at Albany, Albany, New York
Submitted 6 March 2007 ; accepted in final form 21 August 2007
We tested the hypothesis that tumor necrosis factor-
(TNF) induces barrier dysfunction of pulmonary microvessel endothelial monolayers (PMEM) mediated by specific tyrosine residues in
-actin. PMEM were transfected with a wild-type, mutant [tyrosine198 to phenylalanine198 (Y198F)], mutant Y218F, or mutant Y306F
-actin construct tagged with enhanced yellow fluorescent protein (EYFP-
-actin). The cellular compartmentalization of wild-type and mutant EYFP-
-actin was displayed using EYFP fluorescence of the tagged
-actin.
-Actin was quantified for the EYFP-tagged and native
-actin using Western blot assay. The effect of the EYFP-
-actin on a cell junction protein was assessed by association of EYFP-
-actin with
-catenin using confocal microscopy and coimmunoprecipitation. The permeability of PMEM was assessed by the clearance rate of Evans blue-labeled albumin. The cellular compartmentalization of wild-type and mutant EYFP-
-actin was similar to the native
-actin. Incubation of PMEM with TNF (100 ng/ml) for 0.5 h resulted in increases in permeability to albumin and a decrease in association of the EYFP-
-actin with
-catenin. However, the expression of the EYFP-Y198F
-actin and EYFP-Y218F
-actin prevented the effect of TNF on
-catenin and barrier function. The vehicle, wild-type EYFP-
-actin, and mutant Y306F
-actin had no affect on the response to TNF. The data indicate that TNF induces an increase in endothelial permeability that is dependent on tyrosine198 and tyrosine218 in
-actin.
edema; permeability; nitration
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |