Vacular disease, including heart attack and stroke, are major causes of death and illness in patients with diabetes. This long term goal of this application is to identify novel strategies to reduce vascular disease in diabetes. The balanced production of reactive nitrogen and oxygen species plays a critical role in the regulation of normal vascular function. Diabetes increases oxidative stress in vascular wall cells leading to reduced nitric oxide (NO) bioavailability and endothelial dysfunction. This proposal explores the novel hypothesis that the ligand-activated transcription factor, peroxisome proliferator-activated receptor gamma (PPARg) controls a program of gene expression in vascular endothelium that regulates the balance between the production of reactive nitrogen and oxygen species and that PPARg stimulation exerts vascular protective effects in vivo by directly stimulating endothelial PPARg to increase NO bioavailability. The PI has demonstrated that direct activation of vascular endothelial cell PPARg with thiazolidinediones increased endothelial cell NO release and reduced superoxide production.
Aim 1 will examine mechanisms by which PPARg alters endothelial superoxide metabolism in vitro and in vivo. Preliminary data indicate that PPARg activation decreases the enhanced expression and activity of NADPH oxidase in the vascular wall of diabetic animals and attenuates vascular dysfunction.
Aim 2 will define the impact of PPARg activation on post- translational mechanisms regulating eNOS activity in vitro and in vivo. Because PPARg ligands do not increase the expression of endothelial nitric oxide synthase (eNOS), this aim will focus on PPARg-mediated alterations in the post-translational regulation of eNOS activity including eNOS-protein interactions and site-specific eNOS phosphorylation events.
Aim 3 will determine basal and thiazolidinedione-stimulated vascular endothelial function in normal and diabetic endothelial-specific PPARg null mice. These innovative studies will clarify the vascular consequences of reduced endothelial PPARg function and permit analysis of specific effects of endothelial PPARg activity in vascular function. This proposal will clarify roles of PPARg in vascular regulation in diabetes and contribute to the development of improved strategies for the prevention and treatment of vascular disease associated with impaired endothelial NO production.
Diabetes and obesity are increasing at alarming rates in the United States. Vascular disease associated with diabetes is a major cause of morbidity and mortality in these patients. This proposal will explore a novel role for the PPAR gamma receptor in diabetic vascular disease and define if stimulating this receptor with currently available drugs leads to improved vascular outcomes in diabetes.
|Wongtrakool, Cherry; Grooms, Kora; Bijli, Kaiser M et al. (2014) Nicotine stimulates nerve growth factor in lung fibroblasts through an NFÎºB-dependent mechanism. PLoS One 9:e109602|
|Kang, Bum-Yong; Park, Kathy K; Green, David E et al. (2013) Hypoxia mediates mutual repression between microRNA-27a and PPARÎ³ in the pulmonary vasculature. PLoS One 8:e79503|
|Sutliff, Roy L; Hilenski, Lula L; Amanso, AngÃ©lica M et al. (2013) Polymerase delta interacting protein 2 sustains vascular structure and function. Arterioscler Thromb Vasc Biol 33:2154-61|
|Lu, Xianghuai; Bijli, Kaiser M; Ramirez, Allan et al. (2013) Hypoxia downregulates PPARÎ³ via an ERK1/2-NF-ÎºB-Nox4-dependent mechanism in human pulmonary artery smooth muscle cells. Free Radic Biol Med 63:151-60|
|Williams, Clintoria R; Lu, Xianghuai; Sutliff, Roy L et al. (2012) Rosiglitazone attenuates NF-ÎºB-mediated Nox4 upregulation in hyperglycemia-activated endothelial cells. Am J Physiol Cell Physiol 303:C213-23|
|Green, David E; Murphy, Tamara C; Kang, Bum-Yong et al. (2012) The Nox4 inhibitor GKT137831 attenuates hypoxia-induced pulmonary vascular cell proliferation. Am J Respir Cell Mol Biol 47:718-26|
|Thule, Peter M (2012) Mechanisms of current therapies for diabetes mellitus type 2. Adv Physiol Educ 36:275-83|
|Kang, Bum-Yong; Kleinhenz, Jennifer M; Murphy, Tamara C et al. (2011) The PPARÎ³ ligand rosiglitazone attenuates hypoxia-induced endothelin signaling in vitro and in vivo. Am J Physiol Lung Cell Mol Physiol 301:L881-91|
|Green, David E; Sutliff, Roy L; Hart, C Michael (2011) Is peroxisome proliferator-activated receptor gamma (PPARÎ³) a therapeutic target for the treatment of pulmonary hypertension? Pulm Circ 1:33-47|
|Blanquicett, Carmelo; Kang, Bum-Yong; Ritzenthaler, Jeffrey D et al. (2010) Oxidative stress modulates PPAR gamma in vascular endothelial cells. Free Radic Biol Med 48:1618-25|
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