Cardiovascular disease is the principal cause of death and disability in adults with diabetes. Endothelial dysfunction is a hallmark of diabetic vascular disease and is characterized by decreased bioavailability of nitric oxide (NO). Our long-term goal is to elucidate the mechanism by which insulin resistance reduces NO production in endothelial cells and thereby facilitate the development of therapeutics that can be used to attenuate the impact of diabetes and insulin resistance on cardiovascular disease. The specific hypothesis of this revised research proposal is that IKKbeta a key enzyme in the regulation of the NF-kappaB inflammatory pathway mediates the effect of insulin resistance on NO production. This hypothesis is based on the following experimental observations completed in our laboratory. First, IKKbeta is activated in endothelial cells by free fatty acids (FFA), high glucose, and TNF-alpha all of which have been implicated in the pathogenesis of insulin resistance. Second, activation of IKKbeta is associated with impaired NO production. Third, inhibition of IKKbeta pharmacologically using aspirin or genetically using a dominant negative IKKbeta construct blocks the ability of FFA, TNF-alpha, or glucose to impair NO production. Finally, overexpression of wild-type IKKbeta recapitulates the effect of FFA, glucose, or TNF-alpha to impair NO production. The results of these experiments suggest that IKKbeta activation is both necessary and sufficient to cause impairment of endothelial NO production. These results also indicate that inflammatory pathways play a key role in both nutrient excess and cytokine mediated endothelial insulin resistance. Based on these observations the experimental focus of this proposal is on the role of IKKbeta in mediating impaired NO production. We propose to determine how activation of IKKbeta impairs endothelial NO production in both an endothelial cell culture model and in an in vivo model of insulin resistance. We will next address how mediators of insulin resistance might activate IKKbeta and examine a potential role for innate immunity (Toll Like Receptor) in mediating vascular insulin resistance. The following aims are proposed:
Aim 1. To determine the mechanism by which IKKbeta activation impairs NO production in endothelial cells.
Aim 2. To determine whether impaired endothelial insulin signaling and NO production are associated with IKKbeta activation in vivo in a mouse model of diet-induced obesity and insulin resistance.
Aim 3. To determine whether the Toll Like Receptor pathway is necessary for endothelial activation of IKKbeta during the development of vascular insulin resistance. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK073878-02
Application #
7269389
Study Section
Vascular Cell and Molecular Biology Study Section (VCMB)
Program Officer
Jones, Teresa L Z
Project Start
2006-08-01
Project End
2011-07-31
Budget Start
2007-08-01
Budget End
2008-07-31
Support Year
2
Fiscal Year
2007
Total Cost
$269,627
Indirect Cost
Name
University of Washington
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Lee, Woo Je; Tateya, Sanshiro; Cheng, Andrew M et al. (2015) M2 Macrophage Polarization Mediates Anti-inflammatory Effects of Endothelial Nitric Oxide Signaling. Diabetes 64:2836-46
Cheng, Andrew M; Rizzo-DeLeon, Norma; Wilson, Carole L et al. (2014) Vasodilator-stimulated phosphoprotein protects against vascular inflammation and insulin resistance. Am J Physiol Endocrinol Metab 307:E571-9
Tateya, Sanshiro; Rizzo-De Leon, Norma; Handa, Priya et al. (2013) VASP increases hepatic fatty acid oxidation by activating AMPK in mice. Diabetes 62:1913-22
Li, Xin; Gonzalez, Oscar; Shen, Xia et al. (2013) Endothelial acyl-CoA synthetase 1 is not required for inflammatory and apoptotic effects of a saturated fatty acid-rich environment. Arterioscler Thromb Vasc Biol 33:232-40
Weldy, Chad S; Luttrell, Ian P; White, Collin C et al. (2013) Glutathione (GSH) and the GSH synthesis gene Gclm modulate plasma redox and vascular responses to acute diesel exhaust inhalation in mice. Inhal Toxicol 25:444-54
Cheng, Andrew M; Handa, Priya; Tateya, Sanshiro et al. (2012) Apolipoprotein A-I attenuates palmitate-mediated NF-?B activation by reducing Toll-like receptor-4 recruitment into lipid rafts. PLoS One 7:e33917
Pamir, Nathalie; McMillen, Timothy S; Edgel, Kimberly A et al. (2012) Deficiency of lymphotoxin-? does not exacerbate high-fat diet-induced obesity but does enhance inflammation in mice. Am J Physiol Endocrinol Metab 302:E961-71
Weldy, Chad S; Luttrell, Ian P; White, Collin C et al. (2012) Glutathione (GSH) and the GSH synthesis gene Gclm modulate vascular reactivity in mice. Free Radic Biol Med 53:1264-78
Lee, Woo Je; Chait, Alan; Kim, Francis (2012) P-selectin glycoprotein ligand-1: a cellular link between perivascular adipose inflammation and endothelial dysfunction. Diabetes 61:3070-1
Handa, Priya; Tateya, Sanshiro; Rizzo, Norma O et al. (2011) Reduced vascular nitric oxide-cGMP signaling contributes to adipose tissue inflammation during high-fat feeding. Arterioscler Thromb Vasc Biol 31:2827-35

Showing the most recent 10 out of 21 publications