We hypothesize that increased glutathione reductase activity protects human macrophages from OxLDL-induced mitochondrial dysfunction and cell death, thereby decreasing the severity of atherosclerosis. Macrophage and foam cell death by oncosis plays a crucial role in the development of atherosclerotic lesions. We propose to study the molecular mechanism of glutathione reductase-mediated protection of macrophages from oncosis.
Specific Aim 1 : To determine the effect of OxLDL on the thiol redox state of mitochondria. Our preliminary data demonstrate that OxLDL induces mitochondrial depolarization and loss of ATP synthesis. We will use human monocyte-derived macrophages to determine if OxLDL promotes oncosis by 1) altering the thiol redox status of mitochondria, 2) inactivating mitochondrial glutathione reductase and 3) increasing mitochondrial inner membrane permeability.
Specific Aim 2 : To determine the role of mitochondrial and cytosolic glutathione reductase in preventing OxLDL-induced oncosis. Mitochondria do not synthesize glutathione (GSH) and therefore rely on GSH uptake and the reduction of GSSG to maintain the appropriate thiol redox state. We will use human monocyte-derived macrophages to determine 1) if adenovirus-mediated doxycycline-controlled expression of mitochondrial or cytosolic glutathione reductase (GR) prevents GSSG accumulation and protein thiol oxidation and 2) if increasing glutathione reductase activity restores mitochondrial function and protects macrophages from OxLDL-induced oncosis.
Specific Aim 3 : To determine whether increased macrophage glutathione reductase activity decreases the severity of atherosclerosis. Foam cell death promotes the formation of the necrotic core and the progression of atherosclerotic lesions. We will perform bone marrow transplantation studies to determine in vivo whether augmented expression of glutathione reductase (GR) in macrophages prevents foam cell death and lesion progression. GR-overexpressing bone marrow cells, generated by retroviral gene transfer, will be used to repopulate irradiated LDL receptor null mice and apoE null mice. We will measure both lesion size and lesional cholesterol/cholesterol ester content.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
3R01HL070963-03S1
Application #
7119410
Study Section
Pathology A Study Section (PTHA)
Program Officer
Srinivas, Pothur R
Project Start
2002-08-01
Project End
2005-07-18
Budget Start
2005-07-17
Budget End
2005-07-18
Support Year
3
Fiscal Year
2005
Total Cost
$57,690
Indirect Cost
Name
University of Kentucky
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
939017877
City
Lexington
State
KY
Country
United States
Zip Code
40506
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Betts-Obregon, B S; Mondragon, A A; Mendiola, A S et al. (2016) TGF? induces BIGH3 expression and human retinal pericyte apoptosis: a novel pathway of diabetic retinopathy. Eye (Lond) 30:1639-1647
Zamora, D A; Downs, K P; Ullevig, S L et al. (2015) Glutaredoxin 2a overexpression in macrophages promotes mitochondrial dysfunction but has little or no effect on atherogenesis in LDL-receptor null mice. Atherosclerosis 241:69-78
Mondragon, Albert A; Betts-Obregon, Brandi S; Moritz, Robert J et al. (2015) BIGH3 protein and macrophages in retinal endothelial cell apoptosis. Apoptosis 20:29-37
Tavakoli, Sina; Zamora, Debora; Ullevig, Sarah et al. (2013) Bioenergetic profiles diverge during macrophage polarization: implications for the interpretation of 18F-FDG PET imaging of atherosclerosis. J Nucl Med 54:1661-7
Liu, Meilian; Xiang, Ruihua; Wilk, Sarah Ann et al. (2012) Fat-specific DsbA-L overexpression promotes adiponectin multimerization and protects mice from diet-induced obesity and insulin resistance. Diabetes 61:2776-86
Kim, Hong Seok; Ullevig, Sarah L; Zamora, Debora et al. (2012) Redox regulation of MAPK phosphatase 1 controls monocyte migration and macrophage recruitment. Proc Natl Acad Sci U S A 109:E2803-12
Ullevig, Sarah; Zhao, Qingwei; Lee, Chi Fung et al. (2012) NADPH oxidase 4 mediates monocyte priming and accelerated chemotaxis induced by metabolic stress. Arterioscler Thromb Vasc Biol 32:415-26
Tavakoli, Sina; Asmis, Reto (2012) Reactive oxygen species and thiol redox signaling in the macrophage biology of atherosclerosis. Antioxid Redox Signal 17:1785-95
Asmis, Reto (2011) ""Topical"" HDL for vein grafts: a new solution to an old problem? Atherosclerosis 214:259-60

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