The overall objective of the proposed studies in this renewal application is to define the mechanisms by which the procoagulant thrombin, a serine protease released during clotting initiated by sepsis or vascular injury, regulates the expression of adhesion molecule, ICAM-1, in endothelial cells, and thereby endothelial adhesivity toward neutrophil (PMN). In the last grant cycle, we showed that PKC(, PI3 kinase, and the downstream target Akt mediate thrombin-induced IKK/NF-(B activation and ICAM-1 expression in endothelial cells. We now have evidence that thrombin-induced IKK/NF-(B activation and ICAM-1 expression are tightly regulated through the functional coupling of PKC( and PI3 kinase to the mammalian target of rapamycin (mTOR). Our data show that mTOR down-regulates thrombin-induced ICAM-1 expression in endothelial cells by controlling a delayed and transient activation of NF-(B. In light of these findings, we hypothesize that thrombin activates mTOR complexes via PKC(- and PI3 kinase/Akt-dependent pathways and that activated mTOR complexes in turn down-regulate IKK/NF-(B activation and ICAM-1 expression in endothelial cells. We further postulate that loss of mTOR-mediated inhibition of thrombin- induced endothelial adhesivity leads to marked exacerbation in lung PMN sequestration and PMN-dependent lung vascular injury and tissue edema. We will address this hypothesis by completion of the following specific aims.
Aim 1 : Determine the role of mTOR complexes, mTOR-raptor and mTOR-rictor, in modulating thrombin-induced IKK/NF-(B activation, ICAM-1 expression, endothelial adhesivity, and PMN migration across endothelial barrier.
Aim 2 : Determine the role of PKC( in signaling thrombin-induced activation of mTOR complexes and in thereby modulating IKK/NF-(B activation, ICAM-1 expression, and PMN migration across endothelial barrier.
Aim 3 : Determine the role of PI3 kinase/Akt in mediating thrombin-induced activation of mTOR complexes, and in thereby modulating NF-(B activation, ICAM-1 expression, and PMN migration across endothelial barrier. Studies will utilize multidisciplinary approaches ranging from biochemical, cellular, and molecular biology to lung physiology to identify the critical inhibitory pathways that are integrated with the stimulatory pathways but in a temporally divergent fashion to tightly regulate ICAM-1 expression induced by thrombin. With the knowledge gained, we believe that it will be possible to block PMN-mediated lung vascular injury by promoting the specific inhibitory signaling events controlling ICAM-1 expression associated with intravascular coagulation. These studies may provide future directions for development of therapeutic strategies for inflammatory disease states such as Acute Respiratory Distress Syndrome (ARDS).

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL067424-08
Application #
7826830
Study Section
Lung Injury, Repair, and Remodeling Study Section (LIRR)
Program Officer
Harabin, Andrea L
Project Start
2001-04-01
Project End
2012-05-31
Budget Start
2010-06-01
Budget End
2012-05-31
Support Year
8
Fiscal Year
2010
Total Cost
$308,000
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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