: The overall goal of this application is to determine the mechanisms by which heat shock protein 90 (Hsp9O) mediates endothelial nitric oxide synthase (eNOS) function to direct endothelial biology and vascular physiology. Recent reports from this laboratory demonstrate that eNOS is fully capable of generating both nitric oxide (.NO) and superoxide anion (O2-). When conformational changes in Hsp9O are blocked with geldanamycin (GA) eNOS generates O2- upon activation. When endothelial cultures and isolated pressurized microvessels are pre-treated with angiostatin they also appear to generate O2 about by an eNOS-dependent mechanism to shift the balance from .NO towards O2 about which impairs vasodilation. These data suggest that Hsp90 interactions direct which radical species is generated by eNOS. Both angiostatin and GA induce altered states of eNOS activation as defined by the levels of phospho-eNOS (S1179) on eNOS and Hsp90 associated with eNOS. Additional studies aimed at determining the phosphorylation state of eNOS suggest that Hsp90 interactions with eNOS may protect or promote serine phosphorylation at another site on eNOS. As the presence of phosphoserine on eNOS inversely correlates with O2 about this site may influence the function of eNOS by directing radical species generation. The signal transduction mechanisms governing Hsp90 interactions with eNOS with respect to O2 about generation remain unknown. As the balance of .NO and O2 about in the endothelium mediate many functions, endothelial proliferation and vasodilation, understanding how angiostatin and GA alter signaling pathways governing eNOS function is central to understanding the mechanisms governing angiogenesis for developing new collatoral vessels and increasing vasodilation to prevent ischemic heart disease. Findings from these studies will probably be relevant to and provide new understanding of mechanisms mediating vascular disease related to atherogenesis, hypertension and diabetes

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL071214-04
Application #
6921973
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Program Officer
Goldman, Stephen
Project Start
2002-08-01
Project End
2008-07-31
Budget Start
2005-08-01
Budget End
2008-07-31
Support Year
4
Fiscal Year
2005
Total Cost
$300,000
Indirect Cost
Name
Medical College of Wisconsin
Department
Surgery
Type
Schools of Medicine
DUNS #
937639060
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
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Teng, Ru-Jeng; Du, Jianhai; Xu, Hao et al. (2011) Sepiapterin improves angiogenesis of pulmonary artery endothelial cells with in utero pulmonary hypertension by recoupling endothelial nitric oxide synthase. Am J Physiol Lung Cell Mol Physiol 301:L334-45
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Du, Jianhai; Wei, Na; Xu, Hao et al. (2009) Identification and functional characterization of phosphorylation sites on GTP cyclohydrolase I. Arterioscler Thromb Vasc Biol 29:2161-8
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Cheng, Jennifer; Ou, Jing-Song; Singh, Harpreet et al. (2008) 20-hydroxyeicosatetraenoic acid causes endothelial dysfunction via eNOS uncoupling. Am J Physiol Heart Circ Physiol 294:H1018-26
Xu, Hao; Shi, Yang; Wang, Jingli et al. (2007) A heat shock protein 90 binding domain in endothelial nitric-oxide synthase influences enzyme function. J Biol Chem 282:37567-74
Weihrauch, Dorothee; Xu, Hao; Shi, Yang et al. (2007) Effects of D-4F on vasodilation, oxidative stress, angiostatin, myocardial inflammation, and angiogenic potential in tight-skin mice. Am J Physiol Heart Circ Physiol 293:H1432-41
Shi, Yang; Hutchins, William; Ogawa, Hitoshi et al. (2005) Increased resistance to myocardial ischemia in the Brown Norway vs. Dahl S rat: role of nitric oxide synthase and Hsp90. J Mol Cell Cardiol 38:625-35

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