TGF-beta 2 increases alpha-smooth muscle actin expression in bovine retinal pigment epithelial cells.
OBJECTIVE
To examine whether transforming growth factor-beta 2 (TGF-beta 2) induces the expression of alpha-smooth muscle actin (SMA), a biochemical marker of myofibroblasts, in cultured bovine retinal pigment epithelial (RPE) cells.


METHODS
Bovine RPE cells were cultured in F-12 nutrient mixture supplemented with 5% fetal bovine serum (FBS), with or without TGF-beta 2 (0.01-10 ng/ml) for 6 days. During this culture period, cells did not reach a confluence. Alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the ratio of the number of alpha-SMA positive cells to the total number of cells was calculated.


RESULTS
About 10% of the cells in control cultures with only FBS were positive for alpha-SMA. TGF-beta 2 increased the ratio of positive cells dose-dependently (p < 0.0001), while a neutralizing antibody against TGF-beta 2 blocked this effect.


CONCLUSIONS
TGF-beta 2 induced expression of alpha-SMA in bovine RPE cells.
Kurosaka
D
D
Department of Ophthalmology, Keio University School of Medicine, Shinjuku-ku, Japan.
Muraki
Y
Y
Inoue
M
M
Katsura
H
H
D000199:Actins / Q000096:biosynthesis*; D000818:Animals; D000911:Antibodies, Monoclonal; D002417:Cattle; D002478:Cells, Cultured; D007150:Immunohistochemistry; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D000199:Actins; D000911:Antibodies, Monoclonal; D016212:Transforming Growth Factor beta