The goal of this proposal is to characterize the role of the small GTPase rhoA and its downstream effectors, rho kinase (ROCK), in neutrophil-induced changes in endothelial permeability. Abnormally excessive coronary microvascular leakage is an early event in heart disease, and is largely attributed to inflammatory mediators and the activation of polymorphonuclear leukocytes (PMN), predominantly neutrophil. Regulation of the endothelial barrier is a complex process involving the actin cytoskeleton, intercellular adhesions, and cell-matrix adhesion. Studies indicate that rhoA and ROCK regulate the actin cytoskeleton and cell-matrix adhesion, however, the role of rhoA and ROCK in endothelial barrier regulation is unclear. Our pilot studies demonstrate PMN-induced endothelial rhoA activation, that ROCK inhibition attenuates PMN-induced hyperpermeability and changes in actin organization, and that focal adhesion kinase (FAK) plays an important role in permeability regulation. I intend to investigate the role of rhoA/ROCK in PMN-induced hyperpermeability, with emphasis on rhoA and ROCK-mediated changes in the actin cytoskeleton and cell-matrix adhesion. We will compare time-courses of PMN-induced rhoA activation, endothelial permeability, tyrosine phosphorylation of FAK and paxiltin, F/G-actin ratio changes, and endothelial cell tension. We will also investigate how rhoA/ROCK inhibition affects these PMN-stimulated changes. This study will greatly increase our understanding of endothelial barrier regulation. ? ?

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32HL076079-02
Application #
7007292
Study Section
Special Emphasis Panel (ZRG1-F10 (20))
Program Officer
Meadows, Tawanna
Project Start
2005-01-01
Project End
2006-12-31
Budget Start
2006-01-01
Budget End
2006-12-31
Support Year
2
Fiscal Year
2006
Total Cost
$50,428
Indirect Cost
Name
University of California Davis
Department
Surgery
Type
Schools of Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Guo, Mingzhang; Breslin, Jerome W; Wu, Mack H et al. (2008) VE-cadherin and beta-catenin binding dynamics during histamine-induced endothelial hyperpermeability. Am J Physiol Cell Physiol 294:C977-84
Breslin, Jerome W; Wu, Mack H; Guo, Mingzhang et al. (2008) Toll-like receptor 4 contributes to microvascular inflammation and barrier dysfunction in thermal injury. Shock 29:349-55
Breslin, Jerome W; Yuan, Sarah Y; Wu, Mack H (2007) VEGF-C alters barrier function of cultured lymphatic endothelial cells through a VEGFR-3-dependent mechanism. Lymphat Res Biol 5:105-13
Reynoso, Rashell; Perrin, Rachel M; Breslin, Jerome W et al. (2007) A role for long chain myosin light chain kinase (MLCK-210) in microvascular hyperpermeability during severe burns. Shock 28:589-95
Breslin, Jerome W; Gaudreault, Nathalie; Watson, Katherine D et al. (2007) Vascular endothelial growth factor-C stimulates the lymphatic pump by a VEGF receptor-3-dependent mechanism. Am J Physiol Heart Circ Physiol 293:H709-18
Sun, Hengrui; Breslin, Jerome W; Zhu, Jun et al. (2006) Rho and ROCK signaling in VEGF-induced microvascular endothelial hyperpermeability. Microcirculation 13:237-47
Breslin, Jerome W; Sun, Hengrui; Xu, Wenjuan et al. (2006) Involvement of ROCK-mediated endothelial tension development in neutrophil-stimulated microvascular leakage. Am J Physiol Heart Circ Physiol 290:H741-50