The Role of Focal Adhesion Kinase in the TGF-beta-Induced Myofibroblast Transdifferentiation of Human Tenon's Fibroblasts

ABSTRACT

PURPOSE: To investigate the role of focal adhesion kinase (FAK) in transforming growth factor (TGF)-beta-induced myofibroblast transdifferentiation of human Tenon's fibroblasts. METHODS: Primary cultured human Tenon's fibroblasts were exposed to TGF-beta1 for up to 48 hours. The mRNA levels of FAK, alpha smooth muscle actin (alphaSMA), and beta-actin were determined by quantitative real time reverse transcription polymerase chain reaction. The protein levels of collagen type I, FAK, phospho-FAK, alphaSMA, and beta-actin were determined by Western immunoblots. After the small interfering RNA targeting FAK (siRNA(FAK)) molecules were delivered into the cells, the expressions of alphaSMA proteins were determined by Western immunoblots. RESULTS: In human Tenon's fibroblasts, TGF-beta1 significantly increased the mRNA and protein expressions of alphaSMA. However, when the action of FAK was inhibited using siRNAFAK, the TGF-beta1-induced expression of alphaSMA was attenuated. CONCLUSIONS: Our data suggest that FAK may be associated with the TGF-beta1-induced transdifferentiation of human Tenon's fibroblasts to myofibroblasts, which is the essential step of subconjunctival fibrosis.