Yu-Ling Zou1, Wen-Bin Luo1, Lin Xie1, Xin-Bang Mao1, Chao Wu1, Zhi-Peng You2. 1. Department of Ophthalmology, The Second Affiliated Hospital of Nanchang University, No. 1 Minde Road, Nanchang, 330006, China. 2. Department of Ophthalmology, The Second Affiliated Hospital of Nanchang University, No. 1 Minde Road, Nanchang, 330006, China. yzpengy@163.com.
Abstract
PURPOSE: Diabetic retinopathy (DR) is a major vision threatening disease mainly induced by high glucose. Despite great efforts were made to explore the etiology of DR, the exact mechanism responsible for its pathogenesis remains elusive. METHODS: In our study, we constructed diabetic rats via Streptozotocin (STZ) injection. TUNEL assay was employed to examine retinal cell apoptosis. The levels of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were analyzed via flow cytometry. The mRNA and protein levels of mitochondrial respiratory chain were investigated by RT-qPCR and western blot. RESULTS: Compared with normal rats, the retinal cell apoptosis rate in diabetic rats was significantly upregulated. What's more, the signals of 8-OHdG and the levels of Cytochrome C in diabetic rats were enhanced; however, the MnSOD signals and NADPH-1 levels were reduced. We investigated the effect of mitochondrialy targeted hOGG1 (MTS-hOGG1) on the primary rRECs under high glucose. Compared with vector-transfected cells, MTS-hOGG1-expressing cells blocked high glucose-induced cell apoptosis, the loss of MMP and the overproduction of ROS. In addition, under high glucose, MTS-hOGG1 transfection blocked the expression of Cytochrome C, but enhanced the expression of cytochrome c oxidase subunit 1 and NADPH-1. CONCLUSIONS: These findings indicated that high glucose induced cell apoptosis by causing the loss of MMP, the overproduction of ROS and mtDNA damage. Targeting DNA repair enzymes hOGG1 in mitochondria partly mitigated the high glucose-induced consequences, which shed new light for DR therapy.
PURPOSE:Diabetic retinopathy (DR) is a major vision threatening disease mainly induced by high glucose. Despite great efforts were made to explore the etiology of DR, the exact mechanism responsible for its pathogenesis remains elusive. METHODS: In our study, we constructed diabeticrats via Streptozotocin (STZ) injection. TUNEL assay was employed to examine retinal cell apoptosis. The levels of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were analyzed via flow cytometry. The mRNA and protein levels of mitochondrial respiratory chain were investigated by RT-qPCR and western blot. RESULTS: Compared with normal rats, the retinal cell apoptosis rate in diabeticrats was significantly upregulated. What's more, the signals of 8-OHdG and the levels of Cytochrome C in diabeticrats were enhanced; however, the MnSOD signals and NADPH-1 levels were reduced. We investigated the effect of mitochondrialy targeted hOGG1 (MTS-hOGG1) on the primary rRECs under high glucose. Compared with vector-transfected cells, MTS-hOGG1-expressing cells blocked high glucose-induced cell apoptosis, the loss of MMP and the overproduction of ROS. In addition, under high glucose, MTS-hOGG1 transfection blocked the expression of Cytochrome C, but enhanced the expression of cytochrome c oxidase subunit 1 and NADPH-1. CONCLUSIONS: These findings indicated that high glucose induced cell apoptosis by causing the loss of MMP, the overproduction of ROS and mtDNA damage. Targeting DNA repair enzymes hOGG1 in mitochondria partly mitigated the high glucose-induced consequences, which shed new light for DR therapy.
Entities:
Keywords:
Cell apoptosis; Diabetic retinopathy; Oxidative stress; Reactive oxygen species
Authors: M A Ihnat; J E Thorpe; C D Kamat; C Szabó; D E Green; L A Warnke; Z Lacza; A Cselenyák; K Ross; S Shakir; L Piconi; R C Kaltreider; A Ceriello Journal: Diabetologia Date: 2007-05-17 Impact factor: 10.122
Authors: Áurea F Castilho; Célia A Aveleira; Ermelindo C Leal; Núria F Simões; Carolina R Fernandes; Rita I Meirinhos; Filipa I Baptista; António F Ambrósio Journal: PLoS One Date: 2012-08-03 Impact factor: 3.240