Genomes and Genes
Arachidonic Acid Metabolism in Blood and Vascular Cells
Principal Investigator: Kenneth Wu
Abstract: The overall goal is to elucidate the mechanism by which prostanoid synthesis in blood and vascular cells is regulated under pathophysiological stimuli and to develop pharmacological and genetic strategies to control excessive prostanoid synthesis. During the current funding period, we have made novel observations regarding the transcriptional control of cyclooxygenase-2 (COX-2) by endogenous mechanism and exogenous compounds. We observed that proliferating fibroblasts release a factor that suppressed COX-2 expression in human endothelial cells, fibroblasts and murine macrophages stimulated with diverse agonists. This factor which is named cytoguardin has been purified to near homogeneity. Preliminary results indicate that cytoguardin inhibits COX-2 transcription by blocking p300 coactivator interaction with COX-2 promoter-bound transactivators. In this renewal application we propose to purify cytoguardin to homogeneity by multiple chemical and biochemical procedures, identify its chemical structure by NMR spectrometry, investigate its activity and elucidate the mechanism of its action. We will carry out gene expression profiling by microarray to determine the cluster of cellular genes that are suppressed by this endogenous transcriptional regulator. The new findings will revolutionize our view about gene control and cell defense and will be valuable for new drug development. Another important observation is that aspirin and sodium salicylate suppressed COX-2 transcription by inhibiting C/EBPI3 binding to its cognate site on the proximal COX-2 promoter region. Preliminary results suggest that salicylates act on a kinase that phosphorylate C/EBP]3, thereby inhibiting its binding to promoter. We propose to use combinatorial approaches to identify the kinase and elucidate the mechanism by which salicylates suppress the kinase activity. Findings from this subproject will solve a pharmacological dilemma and provide new insight into designing new anti-inflammatory and anti-neoplastic drugs. Since COX-2 plays a critical role in pathologic angiogenesis, we postulated that cytoguardin and salicylate should be able to suppress angiogenesis via blocking COX-2 expression. Our preliminary data show that aspirin and sodium salicylate inhibited endothelial tube formation induced by VEGF and cancer cells in a concentration-dependent manner. Semi-purified cytoguardin abrogated endothelial tube formation induced by VEGF and cancer cells. We propose to confirm these in vitro experiments by evaluating the effects of cytoguardin and salicylates on angiogenesis in animal models. Furthermore, the mechanisms by which cytoguardin and salicylate inhibit COX-2 mediated angiogenesis will be elucidated. Information provided by studies from this renewal application will have great impact on understanding the fundamental cytoprotection process and offer an excellent opportunity for developing new therapeutic agents.
Funding Period: 1994-05-01 - 2007-05-31
more information: NIH RePORT
- 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 CaMPei Feng Chen
Vascular Biology Research Center, Department of Internal Medicine, The University of Texas Health Science Center at Houston, TX, USA
Arch Biochem Biophys 486:132-40. 2009..The results suggest that multiple regions of eNOS might interact with CaM with differential Ca(2+) sensitivity in vivo. A possible mechanism in regulating eNOS activation and deactivation is proposed...
- Nonsteroidal anti-inflammatory drugs induce colorectal cancer cell apoptosis by suppressing 14-3-3epsilonJun Yang Liou
University of Texas Health Science Center, M D Anderson Cancer Center, Houston, Texas, USA
Cancer Res 67:3185-91. 2007..These results suggest that 14-3-3epsilon is a target for the prevention and therapy of colorectal cancer...
- Prostacyclin inhibits endothelial cell XIAP ubiquitination and degradationJun Yang Liou
University of Texas Health Science Center at Houston, Houston, TX 77030, USA
J Cell Physiol 212:840-8. 2007..Preservation of XIAP proteins represents a key mechanism by which PGI(2) protects endothelial cells from oxidant-induced apoptosis...
- Differential cyclooxygenase-2 transcriptional control in proliferating versus quiescent fibroblastsKenneth K Wu
Vascular Biology Research Center at Institute of Molecular Medicine, University of Texas Health Science Center at Houston, TX, USA
Prostaglandins Other Lipid Mediat 83:175-81. 2007....
- Interferon-gamma suppresses cyclooxygenase-2 promoter activity by inhibiting C-Jun and C/EBPbeta bindingWu Guo Deng
University of Texas Health Science Center, Houston, TX 77030 1503, USA
Arterioscler Thromb Vasc Biol 27:1752-9. 2007..Cyclooxygenase-2 (COX-2) and interferon gamma (IFNgamma) are overexpressed in vascular inflammatory and atherosclerotic lesions. We postulated that IFNgamma suppresses COX-2 expression at the transcriptional level...
- Prostacyclin receptor signaling and early embryo development in the mouseJaou Chen Huang
Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77030 USA
Hum Reprod 22:2851-6. 2007..Prostacyclin (PGI(2)) plays an important role in mouse embryo development and implantation. However, it is unclear whether its action is mediated via the I prostaglandin receptor (IP)...
- Nonsteroidal anti-inflammatory drugs induced endothelial apoptosis by perturbing peroxisome proliferator-activated receptor-delta transcriptional pathwayJun Yang Liou
National Health Research Institutes, 35 Keyan Rd, Zhunan Township, Miaoli County 350, Taiwan
Mol Pharmacol 74:1399-406. 2008..Our findings suggest that NSAIDs, but not aspirin (<1 mM) induce endothelial apoptosis via suppression of PPARdelta-mediated 14-3-3epsilon expression...
- Ligand-activated peroxisome proliferator-activated receptor-gamma protects against ischemic cerebral infarction and neuronal apoptosis by 14-3-3 epsilon upregulationJui Sheng Wu
Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
Circulation 119:1124-34. 2009..Their protective actions are considered to be peroxisome proliferator-activated receptor-gamma (PPAR-gamma)-dependent; however, it is unclear how PPAR-gamma activation confers resistance to ischemia-reperfusion injury...
- Cyclooxygenase inhibitors induce colon cancer cell apoptosis Via PPARdelta --> 14-3-3epsilon pathwayKenneth K Wu
National Health Research Institutes, Zhunan, Taiwan
Methods Mol Biol 512:295-307. 2009..Suppression of PPARdelta leads to reduced 14-3-3e and hence a decline in Bad sequestration, resulting in an increased Bad-induced apoptosis via the mitochondrial death pathway...
- Cyclooxygenase-2-derived prostaglandin e2 protects mouse embryonic stem cells from apoptosisJun Yang Liou
Division of Hematology and Vascular Biology Research Center, The University of Texas Health Science Center at Houston, 6431 Fannin, MSB 5 016, Houston, Texas 77030, USA
Stem Cells 25:1096-103. 2007..Disclosure of potential conflicts of interest is found at the end of this article...
- Transcription-based COX-2 inhibition: a therapeutic strategyKenneth K Wu
Vascular Biology Research Center and Division of Hematology, Department of Medicine, The University of Texas Health Science Center at Houston, Texas 77030, USA
Thromb Haemost 96:417-22. 2006..RSK phosphorylates C/EBPbeta and stimulates its binding to enhancer elements. We propose that RSK1/2 is a potential target for screening drugs with novel anti-inflammatory and anti-neoplastic therapeutic potentials...
- Essential role of C-Rel in nitric-oxide synthase-2 transcriptional activation: time-dependent control by salicylateKatarzyna A Cieslik
Vascular Biology Research Center at the Brown Foundation Institute of Molecular Medicine and Division of Hematology, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
Mol Pharmacol 70:2004-14. 2006..We propose that salicylate inhibits C/EBPbeta binding at 4 h and C-Rel binding at 8 and 24 h by targeting related kinases...
- Molecular basis of estrogen-induced cyclooxygenase type 1 upregulation in endothelial cellsLinda L Gibson
Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, TX 75390, USA
Circ Res 96:518-25. 2005..In addition, the process may be initiated by cytoplasmic ERalpha, and critical receptor elements reside within the amino terminus...
- Inhibition of p90 ribosomal S6 kinase-mediated CCAAT/enhancer-binding protein beta activation and cyclooxygenase-2 expression by salicylateKatarzyna A Cieslik
Vascular Biology Research Center and Division of Hematology, Brown Foundation Institute of Molecular Medicine and Medical School, The University of Texas Health Science Center and Texas Heart Institute, Houston, Texas 77030 1503, USA
J Biol Chem 280:18411-7. 2005..We conclude that salicylate inhibits C/EBPbeta-mediated COX-2 transcriptional activation by blocking RSK activity and Ras signaling pathway...
- Mitochondrial localization of cyclooxygenase-2 and calcium-independent phospholipase A2 in human cancer cells: implication in apoptosis resistanceJun Yang Liou
Vascular Biology Research Center and Division of Hematology, Institute of, Molecular Medicine and Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030 1503, USA
Exp Cell Res 306:75-84. 2005..These results suggest that mitochondrial COX-2 in cancer cells confer resistance to apoptosis by reducing the proapoptotic arachidonic acid...
- Cellular and molecular biology of prostacyclin synthaseKenneth K Wu
Vascular Biology Research Center, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
Biochem Biophys Res Commun 338:45-52. 2005..PGIS coupling with COX-2 has been shown to play an important role in vascular protection, embryo development and implantation, and cancer growth...
- 15d-prostaglandin J2 protects brain from ischemia-reperfusion injuryTeng Nan Lin
Neuroscience Division, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
Arterioscler Thromb Vasc Biol 26:481-7. 2006..The aim of this study is to assess the effect of 15d-PGJ2 on neuroprotection...
- Melatonin suppresses macrophage cyclooxygenase-2 and inducible nitric oxide synthase expression by inhibiting p52 acetylation and bindingWu Guo Deng
Vascular Biology Research Center, Institute of Molecular Medicine and Division of Hematology, Department of Internal Medicine, The University of Texas Health Science Center at Houston, 77030, USA
Blood 108:518-24. 2006..These results suggest that melatonin inhibits COX-2 and iNOS transcriptional activation by inhibiting p300 HAT activity, thereby suppressing p52 acetylation, binding, and transactivation...
- Protection of endothelial survival by peroxisome proliferator-activated receptor-delta mediated 14-3-3 upregulationJun Yang Liou
Vascular Biology Research Center, Brown Foundation Institute of Molecular Medicine, Houston, TX 77030 1503, USA
Arterioscler Thromb Vasc Biol 26:1481-7. 2006..To determine the role of prostacyclin (PGI2) in protecting endothelial cells (ECs) from apoptosis and elucidate the protective mechanism...
- Analysis of protein-DNA binding by streptavidin-agarose pulldownKenneth K Wu
Division of Hematology, Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX, USA
Methods Mol Biol 338:281-90. 2006..This method has been shown to be useful in determining the regulation of binding of transactivators, p300/CBP, and associated proteins to the cyclooxygenase-2 (COX-2) promoter...
- Transcriptional Control of COX-2 via C/EBPbetaKenneth K Wu
Vascular Biology Research Center, Institute of Molecular Medicine and Division of Hematology, University of Texas Health Science Center at Houston, 6431 Fannin, MSB 5 016, Houston, TX 77030, USA
Arterioscler Thromb Vasc Biol 25:679-85. 2005..The recent progress sheds light on the pathophysiological mechanisms of COX-2 and new transcription-based strategy for controlling COX-2 overexpression and COX-2-mediated cardiovascular diseases...