Regulation mechanisms of retinal pigment epithelial cell migration by the TGF-beta superfamily.
OBJECTIVE
To investigate the expression of specific receptors, signal transducers and the effect of transforming growth factor-beta (TGF-beta) on retinal pigment epithelium (RPE) migration and proliferation.


METHODS
Human RPE cell line D407 was used in all experiments. The effect of TGF-beta on migration and proliferation were studied using a wound healing model and [3H]-thymidine incorporation, respectively. The expression of RNA related to the TGF-beta superfamily receptors and SMAD1-4 were assayed by reverse transcriptase-polymerase chain reaction (RT-CPR). The effects of TGF-beta on the intracellular position of SMAD were studied by immunoperoxidase and immunofluorescence.


RESULTS
Transforming growth factor-beta 4 nm and activin A 0.36 nm stimulated RPE migration. There was no effect on proliferation. RNA for TGF-beta receptors types 1 and 2, and SMAD1-4 were detected in RPE culture. Transforming growth factor-beta signal transducer SMAD2 but not SMAD1 moved from the cytoplasm to the nucleus after TGF-beta stimulation.


CONCLUSIONS
Transforming growth factor-beta can regulate RPE cell migration through specific signal transduction pathways.
Mitsuhiro
Marcia Regina Kimie Higashi
MR
Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil. mitsuhiro@uol.com.br
Eguchi
Shuichiro
S
Yamashita
Hidetoshi
H
D030201:Activin Receptors, Type I / Q000235:genetics / Q000378:metabolism; D028341:Activins / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D028322:Inhibin-beta Subunits / Q000494:pharmacology*; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051785:Smad Proteins; D051898:Smad1 Protein; D051899:Smad2 Protein; D051900:Smad3 Protein; D051901:Smad4 Protein; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014945:Wound Healing / Q000502:physiology
D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; C497399:SMAD1 protein, human; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; C497796:SMAD4 protein, human; D051785:Smad Proteins; D051898:Smad1 Protein; D051899:Smad2 Protein; D051900:Smad3 Protein; D051901:Smad4 Protein; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; C422405:activin A; D028341:Activins; D028322:Inhibin-beta Subunits; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000077294:Receptor, Transforming Growth Factor-beta Type II