2. Academic Validation
  3. All-trans-retinal induces Bax activation via DNA damage to mediate retinal cell apoptosis

All-trans-retinal induces Bax activation via DNA damage to mediate retinal cell apoptosis

  • Exp Eye Res. 2014 Jun;123:27-36. doi: 10.1016/j.exer.2014.04.003.
Osamu Sawada 1,  Lindsay Perusek 2,  Hideo Kohno 3,  Scott J Howell 2,  Akiko Maeda 4,  Shigemi Matsuyama 5,  Tadao Maeda 6
Affiliations

Affiliations

  • 1 Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Adelbert Road 2085, Cleveland, OH 44106, USA; Ophthalmology, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan.
  • 2 Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Adelbert Road 2085, Cleveland, OH 44106, USA.
  • 3 Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Adelbert Road 2085, Cleveland, OH 44106, USA; Ophthalmology, Jikei University School of Medicine, Minato-ku, Tokyo 105-8461, Japan.
  • 4 Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Adelbert Road 2085, Cleveland, OH 44106, USA; Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
  • 5 Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Medicine, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
  • 6 Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Adelbert Road 2085, Cleveland, OH 44106, USA; Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. Electronic address: tadao.maeda@gmail.com.
PMID: 24726920 DOI: 10.1016/j.exer.2014.04.003
Abstract

The current study investigates the cellular events which trigger activation of proapoptotic Bcl-2-associated × protein (Bax) in retinal cell death induced by all-trans-retinal (atRAL). Cellular events which activate Bax, such as DNA damage by oxidative stress and phosphorylation of p53, were evaluated by immunochemical and biochemical methods using ARPE-19 cells, 661 W cells, cultured neural retinas and a retinal degeneration model, Abca4(-/-)Rdh8(-/-) mice. atRAL-induced Bax activation in cultured neural retinas was examined by pharmacological and genetic methods. Other Bax-related cellular events were also evaluated by pharmacological and biochemical methods. Production of 8-OHdG, a DNA damage indicator, and the phosphorylation of p53 at Ser46 were detected prior to Bax activation in ARPE-19 cells incubated with atRAL. Light exposure to Abca4(-/-)Rdh8(-/-) mice also caused the above mentioned events in conditions of short term intense light exposure and regular room lighting conditions. Incubation with Bax inhibiting peptide and deletion of the Bax gene partially protected retinal cells from atRAL toxicity in cultured neural retina. Necrosis was demonstrated not to be the main pathway in atRAL mediated cell death. Bcl-2-interacting mediator and Bcl-2 expression levels were not altered by atRAL in vitro. atRAL-induced oxidative stress results in DNA damage leading to the activation of Bax by phosphorylated p53. This cascade is closely associated with an apoptotic cell death mechanism rather than necrosis.

Keywords

Bcl-2-associated × protein; DNA damage; all-trans-retinal; apoptosis; oxidative stress; p53; retina; visual cycle.

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