Pigment epithelium-derived factor protects cultured retinal neurons against hydrogen peroxide-induced cell death.
Pigment epithelium-derived factor (PEDF) is a neurotrophic protein synthesized and secreted by retinal pigment epithelial (RPE) cells in early embryogenesis and has been shown to be present in the extracellular matrix between the RPE cells and the neural retina. It induces neuronal differentiation and promotes survival of neurons of the central nervous system from degeneration caused by serum withdrawal or glutamate cytotoxicity. Because the role of PEDF in the retina is still unknown, we examined its ability to protect cultured retinal neurons against hydrogen peroxide (H(2)O(2))-induced cell death. Retinas of 0-2-day-old Sprague-Dawley rats were isolated and dissociated, and the neurons were maintained for 2 weeks in a synthetic serum-free medium. Immunocytochemical labeling showed that 50-60% of the cultured cells were rod photoreceptors. Treatment with H(2)O(2) induced significant death of retinal neurons in a dose- and time-dependent manner. Pretreatment with PEDF prior to insult greatly attenuated H(2)O(2)-induced cytotoxicity, and its effect was shown to be dose dependent. Cytotoxicity was determined by 3,(4,5-dimethylthiazol-2-yl)2, 5-diphenyl-tetrazolium bromide and lactate dehydrogenase assays, and apoptotic cell death was evaluated by the TdT-mediated digoxigenin-dUTP nick-end labeling assay. The present study also showed that H(2)O(2)-induced retinal neuron death was by apoptosis that could be inhibited by PEDF. Combination of PEDF with basic fibroblast growth factor, brain-derived neurotrophic factor, or ciliary neurotrophic factor improves the protection. These data strongly suggest that PEDF is a potential neuroprotective agent in the treatment of retinal degeneration.
Cao
W
W
Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City 73104, USA. weicao@ouhsc.edu
Tombran-Tink
J
J
Chen
W
W
Mrazek
D
D
Elias
R
R
McGinnis
J F
JF
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D020934:Ciliary Neurotrophic Factor; D005136:Eye Proteins / Q000494:pharmacology*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000633:toxicity; D020287:In Situ Nick-End Labeling; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D015843:Serpins / Q000494:pharmacology*; D000099174:Pigment Epithelium-Derived Factor
D019208:Brain-Derived Neurotrophic Factor; D020934:Ciliary Neurotrophic Factor; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2; D006861:Hydrogen Peroxide; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D011506:Proteins; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor