heme oxygenase-1 protects retinal endothelial cells against high glucose- and oxidativenitrosative stress-induced toxicity血红素oxygenase-1保护视网膜内皮细胞对高葡萄糖-和oxidativenitrosative压力引起的毒性.pdfVIP

Heme Oxygenase-1 Protects Retinal Endothelial Cells against High Glucose- and Oxidative/Nitrosative Stress- Induced Toxicity ´ ´ ´ ˜ Aurea F. Castilho, Celia A. Aveleira, Ermelindo C. Leal, Nuria F. Simoes, Carolina R. Fernandes, ´ ´ Rita I. Meirinhos, Filipa I. Baptista, Antonio F. Ambrosio* Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal Abstract Diabetic retinopathy is a leading cause of visual loss and blindness, characterized by microvascular dysfunction. Hyperglycemia is considered the major pathogenic factor for the development of diabetic retinopathy and is associated with increased oxidative/nitrosative stress in the retina. Since heme oxygenase-1 (HO-1) is an enzyme with antioxidant and protective properties, we investigated the potential protective role of HO-1 in retinal endothelial cells exposed to high glucose and oxidative/nitrosative stress conditions. Retinal endothelial cells were exposed to elevated glucose, nitric oxide (NO) and hydrogen peroxide (H O ). Cell viability and apoptosis were assessed by MTT assay, Hoechst staining, TUNEL assay 2 2 and Annexin V labeling. The production of reactive oxygen species (ROS) was detected by the oxidation of 29,79- dichlorodihydrofluorescein diacetate. The content of HO-1 was assessed by immunobloting and immunofluorescence. HO activity was determined by bilirubin production. Long-term exposure (7 days) of retinal endothelial cells to elevated glucose decreased cell viability and had no effect on HO-1 content. However, a short-time exposure (