Photoreceptor degeneration is a leading cause of visual impairment worldwide. Separation of neurosensory retina from the underlying retinal pigment epithelium is a prominent feature preceding photoreceptor degeneration in a variety of retinal diseases. Although ophthalmic surgical procedures have been well developed to restore retinal structures, postoperative patients usually experience progressive photoreceptor degeneration and irreversible vision loss that is incurable at present. Previous studies point to a critical role of mitochondria-mediated apoptotic pathway in photoreceptor degeneration, but the upstream triggers remain largely unexplored. In this study, we show that after experimental retinal detachment induction, photoreceptors activate dynamin-related protein 1 (Drp1)-dependent mitochondrial fission pathway and subsequent apoptotic cascades. Mechanistically, endogenous reactive oxygen species (ROS) are necessary for Drp1 activation in vivo, and exogenous ROS insult is sufficient to activate Drp1-dependent mitochondrial fission in cultured photoreceptors. Accordingly, inhibition of Drp1 activity effectively preserves mitochondrial integrity and rescues photoreceptors. Collectively, our data delineate an ROS-Drp1-mitochondria axis that promotes photoreceptor degeneration in retinal diseased models.
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http://dx.doi.org/10.1016/j.ajpath.2018.03.013 | DOI Listing |
Neurobiol Dis
January 2025
Department Neurobiology and Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy. Electronic address:
Biallelic mutations in the SACS gene, encoding sacsin, cause early-onset autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a neurodegenerative disease also characterized by unique and poorly understood retinal abnormalities. While two murine models replicate the phenotypic and neuronal features observed in patients, no retinal phenotype has been described so far. In a zebrafish knock-out strain that faithfully mirrors the main aspects of ARSACS, we observed impaired visual function due to photoreceptor degeneration, likely caused by cell cycle defects in progenitor cells.
View Article and Find Full Text PDFJ Cell Sci
January 2025
Department of Ophthalmology and Visual Sciences, University of New Mexico, Albuquerque, New Mexico 87131, Mexico.
The Rab11-Rabin8-Rab8 ciliogenesis complex regulates the expansion of cilia-derived light-sensing organelles, the rod outer segments, via post-Golgi rhodopsin transport carriers (RTCs). Rabin8, an effector of Rab11 and a nucleotide exchange factor (GEF) for Rab8, is phosphorylated at S272 by NDR2 kinase (aka STK38L), a canine erd gene product linked to the human ciliopathy Leber congenital amaurosis (LCA). Here, we define the step at which NDR2 phosphorylated Rabin8 regulates Rab11-Rab8 succession in X.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
Department of Ophthalmology, the First Affiliated Hospital of University of Science and Technology of China, Division of Life Sciences and Medicine, USTC, Hefei, China.
Purpose: Oxidative phosphorylation (OXPHOS) is an aerobic metabolic mechanism, and its dysfunction plays an important role in the pathological changes of ischemic diseases. However, systematic studies on the occurrence of retinal detachment (RD) are lacking.
Methods: Single-cell RNA sequencing (scRNA-seq) of the human retina was performed to detect the metabolic changes of various retinal cells after RD.
Int J Mol Sci
December 2024
Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen 361102, China.
All--retinal (atRAL)-induced photoreceptor atrophy and retinal degeneration are hallmark features of dry age-related macular degeneration (AMD) and Stargardt disease type 1 (STGD1). The toxicity of atRAL is closely related to the generation of reactive oxygen species (ROS). Quercetin, a natural product, is known for its potent antioxidant properties; however, its effects in mitigating atRAL-mediated retinal damage remains unclear.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Retinal degenerative diseases lead to irreversible vision loss due to photoreceptor cell death, driven by complex genetic and environmental factors. Ceramide, a sphingolipid metabolite, emerges as a critical mediator in the apoptotic cascade associated with retinal degeneration. Our previous work demonstrated L-Cycloserine's ability to protect photoreceptor-derived cells from oxidative stress by inhibiting the de novo ceramide pathway and thus prompting further investigation on its effect in the in vivo retina.
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