title: Autophagy is one of the multiple mechanisms active in photoreceptor degeneration.
abstract: Photoreceptor degeneration in human photoreceptor dystrophies and in the relevant animal models has been thought to be executed by one common mechanism- caspase-mediated apoptosis. However, recent experiments have challenged this concept. Gene defects or environmental stressors appear to cause oxidative stress and altered metabolism, which appear to induce caspase-dependent and caspase-independent cell death mechanisms such as the activation of cysteine-proteases, lysosomal proteases and autophagy and possibly complement-mediated lysis. In this article, we point out mechanistic parallels between these pathways and summarize our recently published investigation using a temporal analysis of the different pathways, which suggests that the noncaspase-dependent mechanisms may actively participate in the demise of the photoreceptors rather than represent a passive response of the retina to the presence of dying cells. Our investigation revealed that unless the common upstream initiator for a given photoreceptor dystrophy can be found, multiple rescue paradigms need to be used to target all active pathways.
authors.affiliation: Department of Neurosciences, Division of Research, Medical University of South Carolina, 167 Ashley Avenue, Charleston, SC 29425, USA.
authors.forename: Kannan
authors.initials: K
authors.lastname: Kunchithapautham
authors.forename: Bärbel
authors.initials: B
authors.lastname: Rohrer
mesh_terms: D000818:Animals; D001343:Autophagy / Q000502:physiology*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism*; D011489:Protein Denaturation; D012162:Retinal Degeneration / Q000209:etiology*; D015398:Signal Transduction
chemical_list: C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins