Open AccessRegulation of Thrombin-Induced Lung Endothelial Cell Barrier Disruption by Protein Kinase C Delta
Author(s) -
Lishi Xie,
Eddie T. Chiang,
Xiaomin Wu,
Gabriel T. Kelly,
Prasad Kanteti,
Patrick A. Singleton,
Sara M. Camp,
Tingting Zhou,
Steven M. Dudek,
Viswanathan Natarajan,
Ting Wang,
Stephen M. Black,
Joe G.N. Garcia,
Jeffrey R. Jacobson
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0158865
Subject(s) - protein kinase c , microbiology and biotechnology , rac1 , thrombin , actin cytoskeleton , rottlerin , signal transduction , phosphorylation , rho associated protein kinase , biology , cytoskeleton , gene silencing , small gtpase , kinase , chemistry , cell , biochemistry , immunology , platelet , gene
Protein Kinase C (PKC) plays a significant role in thrombin-induced loss of endothelial cell (EC) barrier integrity; however, the existence of more than 10 isozymes of PKC and tissue–specific isoform expression has limited our understanding of this important second messenger in vascular homeostasis. In this study, we show that PKCδ isoform promotes thrombin-induced loss of human pulmonary artery EC barrier integrity, findings substantiated by PKCδ inhibitory studies (rottlerin), dominant negative PKCδ construct and PKCδ silencing (siRNA). In addition, we identified PKCδ as a signaling mediator upstream of both thrombin-induced MLC phosphorylation and Rho GTPase activation affecting stress fiber formation, cell contraction and loss of EC barrier integrity. Our inhibitor-based studies indicate that thrombin-induced PKCδ activation exerts a positive feedback on Rho GTPase activation and contributes to Rac1 GTPase inhibition. Moreover, PKD (or PKCμ) and CPI-17, two known PKCδ targets, were found to be activated by PKCδ in EC and served as modulators of cytoskeleton rearrangement. These studies clarify the role of PKCδ in EC cytoskeleton regulation, and highlight PKCδ as a therapeutic target in inflammatory lung disorders, characterized by the loss of barrier integrity, such as acute lung injury and sepsis.