Localization of Acrolein-Lysine Adduct in Fibrovascular Tissues of Proliferative Diabetic Retinopathy

ABSTRACTPurpose: To determine the presence of Ne-(3-formyl-3,4-dehydropiperidino) lysine adduct (FDP-Lys), unsaturated aldehyde acrolein-derived lipoxidation end-product, in fibrovascular tissues obtained from patients with proliferative diabetic retinopathy (PDR).Methods: Fibrovascular tissues were collected from 11 eyes of 11 patients with PDR and paraffin-embedded tissue sections were prepared. Tissue localization of FDP-Lys was studied by immunohistochemistry. Signal intensity was quantified by two masked evaluators and graded into three discrete categories. The relationship between FDP-Lys staining and vascular density was analyzed. In addition, subcellular localization of FDP-Lys was studied by immunofluorescent microscopy. The impact of acrolein on cell viability and proliferation was assessed and the expression level of heme oxygenase-1 (HO-1) mRNA was quantified by real-time polymerase chain reaction (PCR) in cultured retinal microvascular endothelial cells.Results: In fibrovascular tissues, FDP-...