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[Transforming growth factors beta 1 and 2 inhibit proliferation of limbus and corneal epithelium].

The role of the various isoforms of transforming growth factor-beta (TGF-beta) concerning the regulation of proliferation, differentiation and wound healing of the corneal epithelium is controversial. We investigated various concentrations of TGF-beta 1 and 2 in a serum-free, defined clonal growth assay concerning the proliferation of limbal and peripheral corneal epithelium. Concentrations between 0.05 and 5.0 ng/ml of either TGF-beta 1 or 2 caused a significant, dose-dependent decrease of both colony formation and colony proliferation in limbal and peripheral corneal epithelial cultures. These results suggest a physiological role for TGF-beta as a negative growth regulator targeting primarily the transient amplifying cells of the limbal and corneal epithelium.