Upregulation of transforming growth factor-beta after panretinal photocoagulation.
OBJECTIVE
To determine whether upregulation of transforming growth factor-beta (TGF-beta) gene expression occurs after panretinal photocoagulation (PRP). To quantitate two TGF-beta isoforms in the aqueous and vitreous humors and to localize TGF-beta 2-like immunoreactivities (TGF-beta 2-LI) and TGF-beta 2 mRNA in the retina after PRP.


METHODS
PRP was performed on Brown Norway rats by using an argon-green laser. Sensory retina, aqueous and vitreous humors were collected from the rats on days 1, 3, and 7 after PRP, and semiquantitative polymerase chain reaction analyses were carried out. TGF-beta 2 in the aqueous and vitreous humors was quantitated by enzyme-linked immunosorbent assay. Localization of TGF-beta 2-LI was demonstrated by immunohistochemistry, and that of TGF-beta 2 mRNA by in situ reverse transcription-polymerase chain reaction (RT-PCR).


RESULTS
Gene expression of both TGF-beta 1 and -beta 2 was upregulated by PRP. Expression of TGF-beta 2 was greater than that of beta 1 (12.8-fold increase versus 3.24-fold increase, respectively, compared with control level on day 3). TGF-beta 2 concentration was increased in the vitreous humor (4.37-fold increase, P < 0.01) but not in the aqueous humor (the same level compared with control) on day 1. TGF-beta 2-LI and TGF-beta 2 mRNA were detected in cells of the outer retinal layer and in retinal pigment epithelial cells adjacent to the laser burns.


CONCLUSIONS
PRP upregulates expression of TGF-beta 2 in the retina, and increased TGF-beta 2 concentrations are found in the retina and the vitreous humor. Retinal pigment epithelial cells and sensory retina around the laser burn appear to play a major role in the upregulation.
Ishida
K
K
Department of Ophthalmology and Visual Science, Kyoto University Graduate School of Medicine, Japan.
Yoshimura
N
N
Yoshida
M
M
Honda
Y
Y
D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism*; D017931:DNA Primers; D004587:Electrophoresis, Agar Gel; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D005654:Fundus Oculi; D015870:Gene Expression; D017075:Laser Coagulation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D012160:Retina / Q000378:metabolism* / Q000601:surgery; D014158:Transcription, Genetic; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D014822:Vitreous Body / Q000378:metabolism*
D017931:DNA Primers; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta