Inflammation that follows tissue injury is believed to be important in the initiation and progression of various diseases including, atherosclerosis, cancer, and retinopathy. Phospholipase A2s (PLA2s), a group of enzymes that breakdown phospholipids generating arachidonic acid and lysophospholipids have been implicated in inflammation. One of the major events underlying the progression of atherosclerosis is angiogenesis. Endothelial cell (EC) migration and proliferation are critical events in angiogenesis. Emerging evidence suggests that PLA2, arachidonic acid and its eicosanoid metabolites play a role in the regulation of cell migration, proliferation, and apoptosis. In addition, recent investigations using nonsteroidal anti-inflammatory drugs reveal a potential role for eicosanoids in angiogenesis. Based on this knowledge, we hypothesize that eicosanoids, particularly the lipoxygenase-monooxygenase metabolites of arachidonic acid, play an important role in angiogenesis and thereby influence the pathogenesis of atherosclerosis. To test the role of eicosanoids in angiogenesis we will address the following four specific aims: 1. To identify eicosanoids produced in human microvascular endothelial cells (HMVEC) and determine their effects on angiogenesis using in vitro and in vivo models. 2. To determine the effects of angiogenic eicosanoids on HMVEC migration and proliferation. 3. To test the role of the Jak/STAT and PI3K/Akt pathways in angiogenic eicosanoid-induced HMVEC migration and proliferation. 4. To identify the effector molecules of eicosanoid-induced angiogenesis and study the mechanisms underlying their regulation of expression in HMVEC and vascular smooth muscle cells. The results of this proposal will provide novel information on the identification of specific angiogenic eicosanoids and on elucidation of the underlying mechanisms by which these lipid molecules stimulate angiogenesis. Such knowledge, in turn, could be useful in developing therapeutics in the prevention of progression of diseases such as atherosclerosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL074860-02
Application #
6868102
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Program Officer
Srinivas, Pothur R
Project Start
2004-04-01
Project End
2008-03-31
Budget Start
2005-04-01
Budget End
2006-03-31
Support Year
2
Fiscal Year
2005
Total Cost
$365,000
Indirect Cost
Name
University of Tennessee Health Science Center
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
941884009
City
Memphis
State
TN
Country
United States
Zip Code
38163
Singh, Nikhlesh K; Rao, Gadiparthi N (2018) Emerging role of 12/15-Lipoxygenase (ALOX15) in human pathologies. Prog Lipid Res 73:28-45
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Chattopadhyay, Rima; Raghavan, Somasundaram; Rao, Gadiparthi N (2017) Resolvin D1 via prevention of ROS-mediated SHP2 inactivation protects endothelial adherens junction integrity and barrier function. Redox Biol 12:438-455
Chattopadhyay, Rima; Tinnikov, Alexander; Dyukova, Elena et al. (2015) 12/15-Lipoxygenase-dependent ROS production is required for diet-induced endothelial barrier dysfunction. J Lipid Res 56:562-77
Kotla, Sivareddy; Rao, Gadiparthi N (2015) Reactive Oxygen Species (ROS) Mediate p300-dependent STAT1 Protein Interaction with Peroxisome Proliferator-activated Receptor (PPAR)-? in CD36 Protein Expression and Foam Cell Formation. J Biol Chem 290:30306-20
Kotla, Sivareddy; Singh, Nikhlesh K; Traylor Jr, James G et al. (2014) ROS-dependent Syk and Pyk2-mediated STAT1 activation is required for 15(S)-hydroxyeicosatetraenoic acid-induced CD36 expression and foam cell formation. Free Radic Biol Med 76:147-62
Chattopadhyay, Rima; Dyukova, Elena; Singh, Nikhlesh K et al. (2014) Vascular endothelial tight junctions and barrier function are disrupted by 15(S)-hydroxyeicosatetraenoic acid partly via protein kinase C ?-mediated zona occludens-1 phosphorylation at threonine 770/772. J Biol Chem 289:3148-63
Kundumani-Sridharan, Venkatesh; Dyukova, Elena; Hansen 3rd, Dale E et al. (2013) 12/15-Lipoxygenase mediates high-fat diet-induced endothelial tight junction disruption and monocyte transmigration: a new role for 15(S)-hydroxyeicosatetraenoic acid in endothelial cell dysfunction. J Biol Chem 288:15830-42
Kotla, Sivareddy; Singh, Nikhlesh K; Heckle, Mark R et al. (2013) The transcription factor CREB enhances interleukin-17A production and inflammation in a mouse model of atherosclerosis. Sci Signal 6:ra83
Singh, Nikhlesh K; Kundumani-Sridharan, Venkatesh; Rao, Gadiparthi N (2011) 12/15-Lipoxygenase gene knockout severely impairs ischemia-induced angiogenesis due to lack of Rac1 farnesylation. Blood 118:5701-12

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