Reactive oxygen species-dependent mitochondrial dynamics and autophagy confer protective effects in retinal pigment epithelial cells against sodium iodate-induced cell death

Journal of Biomedical Science

Duen-Yi Huang¹  Wan-Wan Lin¹  Ponarulselvam Sekar¹  Chi-Ming Chan²  Shu-Hao Hsu³ 

[1] 0000 0004 0546 0241, grid.19188.39, Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan;0000 0000 9337 0481, grid.412896.0, Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan;0000 0004 0546 0241, grid.19188.39, Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan;0000 0004 1773 7121, grid.413400.2, Department of Ophthalmology, Cardinal Tien Hospital, New Taipei City, Taiwan;0000 0004 1937 1063, grid.256105.5, School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan;0000 0004 1773 7121, grid.413400.2, Department of Ophthalmology, Cardinal Tien Hospital, New Taipei City, Taiwan;

关键词: Retinal epithelium;    Reactive oxygen species;    Sodium iodate;    Mitochondrial dynamics;    Autophagy;    Age-related macular degeneration;   

DOI  :  10.1186/s12929-019-0531-z

来源: publisher

【 摘 要 】

BackgroundOxidative stress is a major factor in retinal pigment epithelium (RPE) cells injury that contributes to age-related macular degeneration (AMD). NaIO3 is an oxidative toxic agent and its selective RPE cell damage makes it as a reproducible model of AMD. Although NaIO3 is an oxidative stress inducer, the roles of ROS in NaIO3-elicited signaling pathways and cell viability have not been elucidated, and the effect of NaIO3 on autophagy in RPE cells remains elusive.MethodsIn human ARPE-19 cells, we used Annexin V/PI staining to determine cell viability, immunoblotting to determine protein expression and signaling cascades, confocal microscopy to determine mitochondrial dynamics and mitophagy, and Seahorse analysis to determine mitochondrial oxidative phosphorylation.ResultsWe found that NaIO3 can dramatically induce cytosolic but not mitochondrial ROS production. NaIO3 can also activate ERK, p38, JNK and Akt, increase LC3II expression, induce Drp-1 phosphorylation and mitochondrial fission, but inhibit mitochondrial respiration. Confocal microscopic data indicated a synergism of NaIO3 and bafilomycin A1 on LC3 punctate formation, indicating the induction of autophagy. Using cytosolic ROS antioxidant NAC, we found that p38 and JNK are downstream signals of ROS and involve in NaIO3-induced cytotoxicity but not in mitochondrial dynamics, while ROS is also involved in LC3II expression. Unexpectedly NAC treatment upon NaIO3 stimulation leads to an enhancement of mitochondrial fragmentation and cell death. Moreover, inhibition of autophagy and Akt further enhances cell susceptibility to NaIO3.ConclusionsWe conclude that NaIO3-induced oxidative stress and cytosolic ROS production exert multiple signaling pathways that coordinate to control cell death in RPE cells. ROS-dependent p38 and JNK activation lead to cytotoxicity, while ROS-mediated autophagy and mitochondrial dynamic balance counteract the cell death mechanisms induced by NaIO3 in RPE cells.

【 授权许可】

CC BY