Topical doxycycline can induce expression of BDNF in transduced retinal pigment epithelial cells transplanted into the subretinal space.
OBJECTIVE
To determine whether topical doxycycline (DOX) induces the expression of brain-derived neurotrophic factor (BDNF) by BDNF-transduced retinal pigment epithelial (RPE) cells transplanted into the subretinal space of rats.


METHODS
A rat RPE cell line that can express BDNF by exposure to DOX was created (Tet-BDNF-RPE). The expression of BDNF was examined by ELISA, Western blot analysis, and real-time PCR. The expression of BDNF was controlled by exposure to DOX in vitro. Tet-BDNF-RPE cells were transplanted into the subretinal space of rats, and the rats were exposed to constant light 1 day or 1 month after the transplantation. The rats were followed with or without topical DOX and examined electrophysiologically and histologically.


RESULTS
The expression of BDNF was upregulated by exposure of Tet-BDNF-RPE cells to DOX in vitro. The optimal concentration for inducing BDNF expression was 0.5 to 1.0 microg/mL DOX. BDNF expression was also increased in vivo by topical DOX after subretinal transplantation of Tet-BDNF-RPE cells. Statistically significant protection of the electroretinogram amplitudes were found 3 days or 1 month after transplantation, and the outer nuclear layer was better preserved 7 days or 1 month after transplantation in the rats treated by 5 or 10 mg/mL/d topical DOX than rats treated by other conditions or sham-operation rats.


CONCLUSIONS
The expression of BDNF can be significantly increased by topical DOX after Tet-BDNF-RPE subretinal transplantation. Better photoreceptor protection against phototoxicity was achieved by DOX eye drops after the cell transplantation.
Abe
Toshiaki
T
Division of Clinical Cell Therapy, Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, Miyagi, Sendai, Japan. toshi@oph.med.tohoku.ac.jp
Wakusawa
Ryosuke
R
Seto
Haruka
H
Asai
Nobuharu
N
Saito
Takae
T
Nishida
Kohji
K
D000287:Administration, Topical; D000818:Animals; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D017690:Cell Transplantation; D004318:Doxycycline / Q000008:administration & dosage*; D004596:Electroretinography; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D008055:Lipids; D008297:Male; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D010857:Pigment Epithelium of Eye / Q000378:metabolism* / Q000637:transplantation*; D012333:RNA, Messenger / Q000378:metabolism; D011833:Radiation Injuries, Experimental / Q000378:metabolism / Q000517:prevention & control* / Q000601:surgery; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000528:radiation effects; D012162:Retinal Degeneration / Q000378:metabolism / Q000517:prevention & control* / Q000601:surgery; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D015854:Up-Regulation
D019208:Brain-Derived Neurotrophic Factor; D008055:Lipids; C086724:Lipofectamine; D009883:Ophthalmic Solutions; D012333:RNA, Messenger; D004318:Doxycycline