title: Endoplasmic reticulum stress and the unfolded protein responses in retinal degeneration.
abstract: The endoplasmic reticulum (ER) is the primary intracellular organelle responsible for protein and lipid biosynthesis, protein folding and trafficking, calcium homeostasis, and several other vital processes in cell physiology. Disturbance in ER function results in ER stress and subsequent activation of the unfolded protein response (UPR). The UPR up-regulates ER chaperones, reduces protein translation, and promotes clearance of cytotoxic misfolded proteins to restore ER homeostasis. If this vital process fails, the cell will be signaled to enter apoptosis, resulting in cell death. Sustained ER stress also can trigger an inflammatory response and exacerbate oxidative stress, both of which contribute synergistically to tissue damage. Studies performed over the past decade have implicated ER stress in a broad range of human diseases, including neurodegenerative diseases, cancer, diabetes, and vascular disorders. Several of these diseases also entail retinal dysfunction and degeneration caused by injury to retinal neurons and/or to the blood vessels that supply retinal cells with nutrients, trophic and homeostatic factors, oxygen, and other essential molecules, as well as serving as a conduit for removal of waste products and potentially toxic substances from the retina. Collectively, such injuries represent the leading cause of blindness world-wide in all age groups. Herein, we summarize recent progress on the study of ER stress and UPR signaling in retinal biology and discuss the molecular mechanisms and the potential clinical applications of targeting ER stress as a new therapeutic approach to prevent and treat neuronal degeneration in the retina.
authors.affiliation: Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA. Electronic address: xzhang38@buffalo.edu.
authors.forename: Sarah X
authors.initials: SX
authors.lastname: Zhang
authors.affiliation: Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Sanders
authors.affiliation: Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA; Research Service, Veterans Administration Western New York Healthcare System, Buffalo, NY, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Fliesler
authors.affiliation: Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D006801:Humans; D018384:Oxidative Stress / Q000502:physiology*; D012162:Retinal Degeneration / Q000503:physiopathology*; D015398:Signal Transduction / Q000502:physiology; D056811:Unfolded Protein Response / Q000502:physiology*; D019892:eIF-2 Kinase / Q000502:physiology
chemical_list: D019892:eIF-2 Kinase
keywords: apoptosis; cell death; endoplasmic reticulum stress; inflammation; retinal degeneration; unfolded protein response