TGF-β1 stimulates production of gelatinase (MMP-9), collagenases (MMP-1, -13) and stromelysins (MMP-3, -10, -11) by human corneal epithelial cells

Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of ocular surface diseases. This study investigated the regulated expression of gelatinases (MMP-2 and -9), collagenases (MMP-1 and -13) and stromelysins (MMP-3, -10, and -11) by TGF-β1 in cultured human corneal epithelial cells. Primary human corneal epithelial cell cultures were grown to confluence and treated with different concentrations (0·1, 1·0, 10 ng ml ^-1) of TGF-β1 in serum-free medium for 6-24hr. Total RNA was isolated from cultured cells with or without TGF-β1 treatment for 6hr and subjected to semi-quantitative RT-PCR and Northern hybridization. Conditioned media were collected from cultures with or without TGF-β1 treatment for 24hr to evaluate the MMP production by ELISA and activity assays. Semi-quantitative RT-PCR revealed that the expressions of MMP-9, -1, -13, -3, -10 and -11 mRNA were up-regulated by TGF-β1 in a concentration-dependent fashion, while MMP-2 and MMP-14 production did not change. Northern hybridization confirmed these findings. Gelatin zymography, MMP ELISA and activity assays showed concentration-dependent stimulated production and activity of MMP-9, -1, -13, -3 and -10 protein in the conditioned media of cultures treated for 24hr with TGF-β1. In conclusion, our results demonstrate that TGF-β1 stimulates the expression and production of gelatinase (MMP-9), collagenases (MMP-1, -13) and stromelysins (MMP-3, -10, -11) in human corneal epithelial cells. These findings suggest that TGF-β1 may play a role in the pathogenesis of MMP mediated ocular surface diseases, such as sterile corneal ulceration.