Retinal control on the axial length mediated by transforming growth factor-beta in chick eye.
OBJECTIVE
To clarify retinal control on scleral growth in form-deprivation myopia (FDM) in the chick, the authors studied change in transforming growth factor-beta (TGF-beta) in the form-deprived eye and the effect of this growth factor on scleral cell proliferation and axial length.


METHODS
Change in TGF-beta in FDM in the chick was measured by reverse transcriptase polymerase chain reaction (RT-PCR), immunoblot, and immunohistochemistry. The effect of TGF-beta on [3H]thymidine uptake of scleral chondrocytes was determined by organ culture. Urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) were administered to determine the effect of TGF-beta activation on the axial length in normal and FDM eyes.


RESULTS
The content of TGF-beta messenger RNA (mRNA) and the active form of TGF-beta protein were reduced in FDM eyes compared with the control specimen. Reduced immunoreactivity of TGF-beta in FDM eyes was found in the photoreceptor layer. The TGF-beta inhibited [3H]thymidine uptake into scleral chondrocytes. In the nondeprived eyes, the vitreous chamber depth and axial length were reduced after uPA treatment, whereas PAI-1 increased them. In the form-deprived eyes, uPA inhibited vitreous depth and axial length elongation, but PAI-1 had no effect.


CONCLUSIONS
The authors' results suggest that TGF-beta mediates retinal control of ocular growth. Axial elongation in FDM probably is correlated with the reduction of TGF-beta in the retina, retinal pigment epithelium, and choroid. The uPA and PAI-1 treatment controls the activation of TGF-beta and affects axial length.
Honda
S
S
Department of Ophthalmology, Kobe University School of Medicine, Japan.
Fujii
S
S
Sekiya
Y
Y
Yamamoto
M
M
D000818:Animals; D002455:Cell Division; D002645:Chickens; D017931:DNA Primers; D004261:DNA Replication / Q000187:drug effects; D005123:Eye / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D015151:Immunoblotting; D008297:Male; D009924:Organ Culture Techniques; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D012590:Sclera / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012683:Sensory Deprivation; D013936:Thymidine / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology / Q000502:physiology*; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism / Q000494:pharmacology
D017931:DNA Primers; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D014568:Urokinase-Type Plasminogen Activator; D013936:Thymidine