1. Academic Validation
  2. Long-term blue light exposure impairs mitochondrial dynamics in the retina in light-induced retinal degeneration in vivo and in vitro

Long-term blue light exposure impairs mitochondrial dynamics in the retina in light-induced retinal degeneration in vivo and in vitro

  • J Photochem Photobiol B. 2023 Jan 24;240:112654. doi: 10.1016/j.jphotobiol.2023.112654.
Liyin Wang 1 Xin Yu 1 Dongyan Zhang 2 Yingying Wen 1 Liyue Zhang 1 Yutong Xia 1 Jinbo Chen 1 Chen Xie 1 Hong Zhu 1 Jianping Tong 3 Ye Shen 4
Affiliations

Affiliations

  • 1 Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China.
  • 2 Department of Ophthalmology, Shaoxing Central Hospital, Shaoxing 312030, Zhejiang, China.
  • 3 Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China. Electronic address: tongjp2000@hotmail.com.
  • 4 Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China. Electronic address: idrshen@zju.edu.cn.
Abstract

Long-term LIGHT exposure, especially in the spectrum of blue LIGHT, frequently causes excessive oxidative stress in dry age-related macular degeneration (AMD). Here, to gain insight into the underlying mechanism, we focused on mitochondrial dynamics alterations under long-term exposure to blue LIGHT in mouse and retinal cells. Six-month-old C57BL/6 mice were exposed to blue LIGHT (450 nm, 800 lx) for 2 weeks. The phenotypic changes in the retina were assayed using haematoxylin-eosin staining and transmission electron microscopy. Long-term blue LIGHT exposure significantly thinned each retinal layer in mice, induced retinal Apoptosis and impaired retinal mitochondria. A retinal pigment epithelial cell line (ARPE-19) was used to verify the phototoxicity of blue LIGHT. Flow cytometry, immunofluorescence and MitoSox Red probe experiments confirmed that more total and mitochondria-specific ROS were generated in the blue LIGHT group than in the control group. Mito-Tracker Green probe showed fragmented mitochondrial morphology. The western blotting results indicated a significant increase in DRP1, OMA1, and Bax and a decrease in OPA1 and Bcl-2. In conclusion, long-term exposure to blue LIGHT damaged the retinas of mice, especially the ONL and RPE cells. There was destruction and dysfunction of mitochondria in RPE cells in vivo and in vitro. Mitochondrial dynamics were disrupted with characteristics of fusion-related obstruction after blue-light irradiation.

Keywords

Blue light; Dry age-related macular degeneration; Mitochondrial dynamics; Oxidative stress; RPE cells.

Figures