The long-term goal is to understand the effect of flow and fluid mechanical stresses on the arachidonic acid metabolism of leukocytes, platelets and endothelial cells. Initial studies from our laboratory have indicated some quite dramatic stress-metabolism coupling in each of these cell types. Proposed work will center on understanding the mechanism of membrane signal transduction for this unique (and physiologically important) stimulus. Possibilities include direct alteration of internal calcium levels via recently described stretch-activated calcium channels. Alternatively, membrane stresses may cause local changes in fluidity, leading to phospholipase C activation of the phosphoinositol cycle (similar to receptor binding), with subsequent activation of cell metabolism. We will examine the latter hypothesis by use of inhibitors of different steps in PI cycle signaling. In addition, the exchange of metabolites between cells under controlled flow conditions will be examined using radiolabeled arachidonic acid combined with HPLC or radioimmunoassay and TLC. We hypothesize that both the level of stress and the rate of change of stress acting on the cell membrane are important factors in modulating the effect of flow on metabolism. Experiments will vary in exposure time, the stress magnitude and the time history of stress application. Specially designed viscometers and flow chambers will be employed. The endothelial cell cultures will be directly visualized utilizing video microscopy coupled with digital image processing. The results should be of importance in understanding the role of flow in ischemic events and reperfusion. Many of the metabolites produced are extremely bioactive and can lead to changes in vessel permeability, cell adhesion and smooth muscle tone - all of which may be important in the outcome of stroke.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Specialized Center (P50)
Project #
5P50NS023327-06
Application #
3882379
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
1990
Total Cost
Indirect Cost
City
Houston
State
TX
Country
United States
Zip Code
77225
Chen, Pei-Feng; Wu, Kenneth K (2009) Two synthetic peptides corresponding to the proximal heme-binding domain and CD1 domain of human endothelial nitric-oxide synthase inhibit the oxygenase activity by interacting with CaM. Arch Biochem Biophys 486:132-40
Wu, Jui-Sheng; Cheung, Wai-Mui; Tsai, Yau-Sheng et al. (2009) Ligand-activated peroxisome proliferator-activated receptor-gamma protects against ischemic cerebral infarction and neuronal apoptosis by 14-3-3 epsilon upregulation. Circulation 119:1124-34
Liou, Jun-Yang; Ellent, David P; Lee, Sang et al. (2007) Cyclooxygenase-2-derived prostaglandin e2 protects mouse embryonic stem cells from apoptosis. Stem Cells 25:1096-103
Liou, Jun-Yang; Lee, Sang; Ghelani, Dipak et al. (2006) Protection of endothelial survival by peroxisome proliferator-activated receptor-delta mediated 14-3-3 upregulation. Arterioscler Thromb Vasc Biol 26:1481-7
Cieslik, Katarzyna A; Deng, Wu-Guo; Wu, Kenneth K (2006) Essential role of C-Rel in nitric-oxide synthase-2 transcriptional activation: time-dependent control by salicylate. Mol Pharmacol 70:2004-14
Deng, Wu-Guo; Tang, Shao-Tzu; Tseng, Hui-Ping et al. (2006) Melatonin suppresses macrophage cyclooxygenase-2 and inducible nitric oxide synthase expression by inhibiting p52 acetylation and binding. Blood 108:518-24
Wu, Kenneth K (2006) Analysis of protein-DNA binding by streptavidin-agarose pulldown. Methods Mol Biol 338:281-90
Lin, Teng-Nan; Cheung, Wai-Mui; Wu, Jui-Sheng et al. (2006) 15d-prostaglandin J2 protects brain from ischemia-reperfusion injury. Arterioscler Thromb Vasc Biol 26:481-7
Wu, Kenneth K (2006) Transcription-based COX-2 inhibition: a therapeutic strategy. Thromb Haemost 96:417-22
Wu, Kenneth K; Liou, Jun-Yang; Cieslik, Katarzyna (2005) Transcriptional Control of COX-2 via C/EBPbeta. Arterioscler Thromb Vasc Biol 25:679-85

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