The endothelial isoform of nitric oxide synthase (eNOS) is a key determinant of vascular homeostasis and endothelial cell metabolism. eNOS catalysis involves several redox-active cofactors, and NO itself can interact with reactive oxygen species. The bioavailability of endothelium-derived NO is impaired in vascular disease states associated with, increased oxidative stress. We hypothesize that redox regulation ofthe eNOS pathway represents a critical determinant of NO- and ROS-dependent signaling and metabolic regulation in vascular endothelial cells. The proposed studies have important points of intersection with experimental plans proposed by other Projects in this Program. eNOS catalysis involves several redox-active cofactors; changes in intracellular redox state affect the concentrations of these key cofactors, and lead to alterations in eNOS-modulated responses. The formation of cellular NO adducts is influenced by reactive nitrogen and reactive oxygen species and by the cellular thiol redox state. Phosphorylation of eNOS by the AMP-activated protein kinase (AMPK) is influenced by reactive oxygen species, providing an important link between oxidative stress, eNOS signaling, and endothelial cell metabolism. Statins also activate AMPK and modulate endothelial ROS production. eNOSJs targeted to signal-transducing membrane microdomains termed caveolae, where the enzyme interacts with the scaffolding/signaling protein caveolin-1. We discovered that siRNA-mediated knockdown of caveolin leads to a striking increase in ROS production from endothelial cells, and found that caveolin-1-/- mice show dramatic increases in oxidative stress. eNOS-caveolin interactions are modulated by statins, yet the roles of statins in modulation of redox pathways involving eNOS remain incompletely understood. Experiments proposed in Specific Aim 1 will identify the mechanisms whereby altered biopterin and thiol metabolism affects eNOS post-translational modifications, subcellular targeting, and ROS generation. Experiments in Specific Aim 2 will determine the mechanisms whereby caveolin, statins, and reactive oxygen species modulate AMP-activated protein kinase (AMPK) signaling to eNOS.
Cardiovascular drugs such as nitroglycerin are metabolized in the body to form nitric oxide (NO). NO is also synthesized in blood vessels by the enzyme eNOS (endothelial nitric oxide synthase). The function of eNOS is abnormal in cardiovascular diseases such as diabetes, which are characterized by oxidative stress. These studies explore how oxidative stress affects eNOS and lead to vascular disease and dysfunction.
|Steinhorn, Benjamin; Sorrentino, Andrea; Badole, Sachin et al. (2018) Chemogenetic generation of hydrogen peroxide in the heart induces severe cardiac dysfunction. Nat Commun 9:4044|
|Brown, Jonathan D; Feldman, Zachary B; Doherty, Sean P et al. (2018) BET bromodomain proteins regulate enhancer function during adipogenesis. Proc Natl Acad Sci U S A 115:2144-2149|
|Samokhin, Andriy O; Stephens, Thomas; Wertheim, Bradley M et al. (2018) NEDD9 targets COL3A1 to promote endothelial fibrosis and pulmonary arterial hypertension. Sci Transl Med 10:|
|Pang, Paul; Abbott, Molly; Abdi, Malyun et al. (2018) Pre-clinical model of severe glutathione peroxidase-3 deficiency and chronic kidney disease results in coronary artery thrombosis and depressed left ventricular function. Nephrol Dial Transplant 33:923-934|
|Steinhorn, Benjamin; Sartoretto, Juliano L; Sorrentino, Andrea et al. (2017) Insulin-dependent metabolic and inotropic responses in the heart are modulated by hydrogen peroxide from NADPH-oxidase isoforms NOX2 and NOX4. Free Radic Biol Med 113:16-25|
|Handy, Diane E; Loscalzo, Joseph (2017) Responses to reductive stress in the cardiovascular system. Free Radic Biol Med 109:114-124|
|Ghiassian, Susan Dina; Menche, Jörg; Chasman, Daniel I et al. (2016) Endophenotype Network Models: Common Core of Complex Diseases. Sci Rep 6:27414|
|Maron, Bradley A; Stephens, Thomas E; Farrell, Laurie A et al. (2016) Elevated pulmonary arterial and systemic plasma aldosterone levels associate with impaired cardiac reserve capacity during exercise in left ventricular systolic heart failure patients: A pilot study. J Heart Lung Transplant 35:342-351|
|Bertero, Thomas; Oldham, William M; Cottrill, Katherine A et al. (2016) Vascular stiffness mechanoactivates YAP/TAZ-dependent glutaminolysis to drive pulmonary hypertension. J Clin Invest 126:3313-35|
|Wang, Rui-Sheng; Loscalzo, Joseph (2016) Illuminating drug action by network integration of disease genes: a case study of myocardial infarction. Mol Biosyst 12:1653-66|
Showing the most recent 10 out of 266 publications