Delivery of antioxidant enzyme genes to protect against ischemia/reperfusion-induced injury to retinal microvasculature.
OBJECTIVE
Retinal ischemia/reperfusion (I/R) injury results in the generation of reactive oxygen species (ROS). The aim of this study was to investigate whether delivery of the manganese superoxide dismutase gene (SOD2) or the catalase gene (CAT) could rescue the retinal vascular damage induced by I/R in mice.


METHODS
I/R injury to the retina was induced in mice by elevating intraocular pressure for 2 hours, and reperfusion was established immediately afterward. One eye of each mouse was pretreated with plasmids encoding manganese superoxide dismutase or catalase complexed with cationic liposomes and delivered by intravitreous injection 48 hours before initiation of the procedure. Superoxide ion, hydrogen peroxide, and 4-hydroxynonenal (4-HNE) protein modifications were measured by fluorescence staining, immunohistochemistry, and Western blot analysis 1 day after the I/R injury. At 7 days after injury, retinal vascular cell apoptosis and acellular capillaries were quantitated.


RESULTS
Superoxide ion, hydrogen peroxide, and 4-HNE protein modifications increased at 24 hours after I/R injury. Administration of plasmids encoding SOD2 or CAT significantly reduced levels of superoxide ion, hydrogen peroxide, and 4-HNE. Retinal vascular cell apoptosis and acellular capillary numbers increased greatly by 7 days after the injury. Delivery of SOD2 or CAT inhibited the I/R-induced apoptosis of retinal vascular cell and retinal capillary degeneration.


CONCLUSIONS
Delivery of antioxidant genes inhibited I/R-induced retinal capillary degeneration, apoptosis of vascular cells, and ROS production, suggesting that antioxidant gene therapy might be a treatment for I/R-related disease.
Chen
Baihua
B
Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha Hunan Province, People's Republic of China.
Caballero
Sergio
S
Seo
Soojung
S
Grant
Maria B
MB
Lewin
Alfred S
AS
D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002196:Capillaries / Q000378:metabolism; D002374:Catalase / Q000235:genetics*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018014:Gene Transfer Techniques; D006861:Hydrogen Peroxide / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008081:Liposomes; D051379:Mice; D008810:Mice, Inbred C57BL; D010957:Plasmids; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D012162:Retinal Degeneration / Q000378:metabolism / Q000517:prevention & control*; D012171:Retinal Vessels / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013482:Superoxide Dismutase / Q000235:genetics*; D013481:Superoxides / Q000378:metabolism
D000447:Aldehydes; D008081:Liposomes; D017382:Reactive Oxygen Species; D013481:Superoxides; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; C027576:4-hydroxy-2-nonenal