Bright cyclic light accelerates photoreceptor cell degeneration in tubby mice

Neurobiology of Disease

Xiaohong Zhou¹  James F. McGinnis¹  Sheng Li¹  Feng Li²  David A. Lewis³  Li Kong³  Wei Cao³  Charles E. Soleman³  Rajesh V. Elias³ 

[1] Dean A. McGee Eye Institute, 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA;Department of Histoembryology of China Medical University, 110001 Shenyang, and the Department of Histoembryology of Dalian Medical, University, 116027 Dalian, Liaoning, China;Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;

关键词: Retinitis pigmentosa;    tubby mice, photoreceptor cells;    Retinal degeneration;    Light damage;    Phototransduction, apoptosis;    Neuronal protection;   

DOI  :  

来源: DOAJ

【 摘 要 】

Photoreceptor cell death is an irreversible, pathologic event in many blinding retinal diseases including retinitis pigmentosa, age-related macular disease, and retinal detachment. Light exposure can exacerbate a variety of human retinal diseases by increasing the rate of photoreceptor cell death. In the present study, we characterize the kinetics of photoreceptor cell death in Tubby (homozygous tub/tub, which have inherited, progressive retinal degeneration) mice born and raised in a bright cyclic light environment. Our data show that raising tub/tub mice in a bright cyclic light environment induces rapid loss of photoreceptors. This effect can be slowed, but not prevented, by raising animals in constant darkness, which suggests the involvement of phototransduction in the accelerated death of photoreceptors in this animal. We further demonstrated that the activities of cytosolic cytochrome c and caspases-3 and -9 were significantly increased in the retinas of tub/tub mice. Raising animals in darkness significantly reduced the increased activities of caspases-3 and -9, as well as cytosolic cytochrome c. We also observed that rhodopsin, a phototransduction protein, is not restricted to the rod outer segment, but is distributed throughout the rod cell, including the inner segments, cell bodies, and synapses. In addition, the light-dependent translocation and compartmentalization of arrestin and transducin are affected by the tubby mutation. Our results support the interpretation that problems in protein trafficking in the photoreceptors of the tub/tub mouse may contribute to retinal degeneration.

【 授权许可】

Unknown