Effect of growth factors on the activation of human Tenon's capsule fibroblasts.
OBJECTIVE
To investigate stimulatory effects of PDGF-AA, PDGF-AB, PDGF-BB, bFGF, IL-1beta, TGF-beta1 and TGF-beta2 on the proliferation and myofibroblast transformation of cultured human Tenon's capsule fibroblasts and to characterize expression of PDGF- and TGF-beta-receptors in these cells.


METHODS
To determine cell proliferation, cell number of 2nd passage cultured human Tenon's capsule fibroblasts was measured before and after addition of growth factors using a computer-based cell counter system. Immunoblotting was used to detect and quantitate alpha-smooth-muscle actin (alpha-SMA) expression. Expression of PDGF- and TGF-beta-receptor mRNA was detected by RT-PCR, expression of the corresponding protein was demonstrated using Western blot.


RESULTS
A significant increase in proliferation (p < or = 0.05) was detected after exogenous stimulation with PDGF-AA (10 ng/ml and 100 ng/ml), PDGF-AB (10 ng/ml and 100 ng/ml), PDGF-BB (10 ng/ml and 100 ng/ml), bFGF (100 ng/ml), IL-1beta (1 ng/ml and 10 ng/ml), TGF-beta1 (0.5 ng/ml) and TGF-beta2 (0.5 ng/ml). Both TGF-beta1 and TGF-beta2 stimulated expression of alpha-SMA in a dose dependent manner with peak activity at a concentration of 50 ng/ml (TGF-beta1) and 500 ng/ml (TGF-beta2). Protein and mRNA of PDGF-receptor type alpha and type beta and TGF-beta-receptors type I, II and III are expressed in cultured human Tenon's capsule fibroblasts.


CONCLUSIONS
The present investigation strongly supports the hypothesis that PDGF-isoforms are major stimulators of proliferation of Tenon's capsule fibroblasts after glaucoma filtering surgery while TGF-beta-isoforms are essential for the transformation of Tenon's capsule fibroblasts into myofibroblasts.
Denk
Peter Oliver
PO
Dept. I: General Ophthalmology, University Eye Clinic Tübingen, Tübingen, Germany. podenk@med.uni-tuebingen.d
Hoppe
Jürgen
J
Hoppe
Viviane
V
Knorr
Marcus
M
D000199:Actins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003239:Connective Tissue Cells / Q000166:cytology / Q000187:drug effects*; D005123:Eye / Q000166:cytology* / Q000187:drug effects*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects*; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
D000199:Actins; D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta