The overall objective of the proposed studies is to address the critical signaling pathways by which pro-inflammatory mediators such as thrombin mediate the expression of adhesion molecule ICAM-1 (CD54) in endothelial cells and thereby induce firm neutrophil (PMN) adhesion. We hypothesize that thrombin induces NF-kB activation and ICAM-1 expression by the interaction of specific heterotrimeric G-proteins with the Proteinase Activated Receptor-1 (PAR-1) and the resultant activation of phosphatidylinositol 3-kinase (PI3 kinase)-dependent signaling pathways. We further postulate that thrombin-induced expression of endothelial adhesivity by this mechanism leads to lung PMN sequestration and PMN-dependent lung vascular injury and tissue edema. To gain new insights into the molecular pathogenesis of PMN-dependent lung vascular injury, this proposal will focus on specific aspects of thrombin activation of PAR-1 on intracellular signaling which in turn regulate the activation of NF-kB and expression of ICAM-1 in endothelial cells.
The specific aims of this proposal are to: 1. Determine the role of Galpha-q that is functionally coupled to PAR-1 in mediating thrombin-induced NF-kB activation and ICAM-1 expression, and resultant endothelial adhesivity and PMN migration across endothelial barrier. 2. Determine the role of PI3 kinase and the downstream signaling events in transducing PAR-1-activated signals that mediate NF-kB activation and ICAM-1 expression. 3. Address the role of Galpha-i, which is functionally coupled to PAR-1, in preventing thrombin-induced NF-kB activation and ICAM-1 expression in endothelial cells. These studies will use primary cultures of human vascular endothelial cells and mouse models. We will use pharmacological agents and recombinant adenoviruses encoding activating or dominant negative forms of signaling molecules to modulate the genetic expression of endotheial cells. Finally, we also will use PAR-1 and PI3 kinase knockout mouse models to address their in vivo role in the mechanism of thrombin-induced lung PMN uptake and PMN-dependent lung vascular injury and tissue edema. The information gained will increase our understanding of the regulation of endothelial adhesivity and provide future directions for pharmacological and genetic manipulations to interfere with inappropriate PMN sequestration and PMN-mediated lung injury.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
7R01HL067424-02
Application #
6621506
Study Section
Lung Biology and Pathology Study Section (LBPA)
Program Officer
Harabin, Andrea L
Project Start
2002-04-01
Project End
2006-04-30
Budget Start
2003-08-04
Budget End
2004-04-30
Support Year
2
Fiscal Year
2003
Total Cost
$275,625
Indirect Cost
Name
University of Rochester
Department
Pediatrics
Type
Schools of Dentistry
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627
Bijli, Kaiser M; Kanter, Bryce G; Minhajuddin, Mohammad et al. (2014) Regulation of endothelial cell inflammation and lung polymorphonuclear lymphocyte infiltration by transglutaminase 2. Shock 42:562-9
Fazal, Fabeha; Bijli, Kaiser M; Murrill, Matthew et al. (2013) Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration. PLoS One 8:e59965
Leonard, Antony; Marando, Catherine; Rahman, Arshad et al. (2013) Thrombin selectively engages LIM kinase 1 and slingshot-1L phosphatase to regulate NF-?B activation and endothelial cell inflammation. Am J Physiol Lung Cell Mol Physiol 305:L651-64
Bijli, Kaiser M; Fazal, Fabeha; Rahman, Arshad (2012) Regulation of Rela/p65 and endothelial cell inflammation by proline-rich tyrosine kinase 2. Am J Respir Cell Mol Biol 47:660-8
Rahman, Arshad; Fazal, Fabeha (2011) Blocking NF-?B: an inflammatory issue. Proc Am Thorac Soc 8:497-503
Yang, Liquan; Chen, Guangchun; Mohanty, Sonali et al. (2011) GPR56 Regulates VEGF production and angiogenesis during melanoma progression. Cancer Res 71:5558-68
Minhajuddin, Mohd; Bijli, Kaiser M; Fazal, Fabeha et al. (2009) Protein kinase C-delta and phosphatidylinositol 3-kinase/Akt activate mammalian target of rapamycin to modulate NF-kappaB activation and intercellular adhesion molecule-1 (ICAM-1) expression in endothelial cells. J Biol Chem 284:4052-61
Rahman, Arshad; Fazal, Fabeha (2009) Hug tightly and say goodbye: role of endothelial ICAM-1 in leukocyte transmigration. Antioxid Redox Signal 11:823-39
Fazal, Fabeha; Bijli, Kaiser M; Minhajuddin, Mohd et al. (2009) Essential role of cofilin-1 in regulating thrombin-induced RelA/p65 nuclear translocation and intercellular adhesion molecule 1 (ICAM-1) expression in endothelial cells. J Biol Chem 284:21047-56
Bijli, Kaiser M; Fazal, Fabeha; Minhajuddin, Mohd et al. (2008) Activation of Syk by protein kinase C-delta regulates thrombin-induced intercellular adhesion molecule-1 expression in endothelial cells via tyrosine phosphorylation of RelA/p65. J Biol Chem 283:14674-84

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