This project examines the hypothesis that reactive oxygen intermediates (ROI) overwhelm declining antioxidant defenses in aged RPE leading to mitochondrial DNA damage, cell dysfunction and death. This chain of events may be a primary mechanism of aging and of acquired retinal diseases such as AMD. A major objective of this study is to assess the basal levels, formation and repair of oxidative DNA damage in nuclear and mitochondrial DNA in primary RPE cells obtained from young versus aged human donors. We will test the hypothesis that mitochondrial DNA damage may accelerate the production of ROI that leads to further damage and functional decline. The following specific aims will be addressed to meet the objectives of this proposal: 1) To examine the formation and repair of oxidative DNA damage from rod outer segment-fed human retinal pigment epithelium (RPE) cell cultures; 2) To elucidate the temporal sequence and downstream cellular consequences in oxidant- exposed cultured human RPE cells in relation to mitochondrial DNA damage, mitochondrial transcription and function, and cell death; 3) To evaluate the linkage between reactive oxygen intermediates (ROI), antioxidant enzyme systems, and oxidant-induced DNA damage; 4) To study the relevance of the glutathione S-transferase pathway in protecting RPE cells under oxidative stress: a study with mGSTA4-4 transfected cells; 5) To examine the formation of mitochondrial DNA damage and repair kinetics in RPE from aged human eyes, and eyes with AMD. Successful accomplishment of these specific aims will provide fundamental mechanistic insights regarding the molecular pathobiology of reactive oxygen in aging RPE cells. The ultimate goal of this project is to reveal and test novel clinical strategies to reduce morbidity from age- related macular degeneration.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY012850-02
Application #
6363169
Study Section
Visual Sciences C Study Section (VISC)
Program Officer
Dudley, Peter A
Project Start
2000-03-01
Project End
2001-07-31
Budget Start
2001-03-01
Budget End
2001-07-31
Support Year
2
Fiscal Year
2001
Total Cost
$45,557
Indirect Cost
Name
University of Texas Medical Br Galveston
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
041367053
City
Galveston
State
TX
Country
United States
Zip Code
77555
Hu, Yijun; Lin, Haijiang; Dib, Bernard et al. (2014) Cholesterol crystals induce inflammatory cytokines expression in a human retinal pigment epithelium cell line by activating the NF-?B pathway. Discov Med 18:7-14
Lin, Haijiang; Xu, Haifeng; Liang, Fong-Qi et al. (2011) Mitochondrial DNA damage and repair in RPE associated with aging and age-related macular degeneration. Invest Ophthalmol Vis Sci 52:3521-9
Godley, Bernard F; Shamsi, Farrukh A; Liang, Fong-Qi et al. (2005) Blue light induces mitochondrial DNA damage and free radical production in epithelial cells. J Biol Chem 280:21061-6
Liang, Fong-Qi; Alssadi, Rajiha; Morehead, Preston et al. (2005) Enhanced expression of glutathione-S-transferase A1-1 protects against oxidative stress in human retinal pigment epithelial cells. Exp Eye Res 80:113-9
Liang, Fong-Qi; Green, Lori; Wang, Cindy et al. (2004) Melatonin protects human retinal pigment epithelial (RPE) cells against oxidative stress. Exp Eye Res 78:1069-75
Godley, Bernard F; Jin, Gui-Fang; Guo, Yan-Shi et al. (2002) Bcl-2 overexpression increases survival in human retinal pigment epithelial cells exposed to H(2)O(2). Exp Eye Res 74:663-9
Weng, T X; Godley, B F; Jin, G F et al. (2002) Oxidant and antioxidant modulation of chloride channels expressed in human retinal pigment epithelium. Am J Physiol Cell Physiol 283:C839-49
Jin, G F; Hurst, J S; Godley, B F (2001) Rod outer segments mediate mitochondrial DNA damage and apoptosis in human retinal pigment epithelium. Curr Eye Res 23:11-9
Jin, G F; Hurst, J S; Godley, B F (2001) Hydrogen peroxide stimulates apoptosis in cultured human retinal pigment epithelial cells. Curr Eye Res 22:165-73