Regulated Expression of Collagenases MMP-1, -8, and -13 and Stromelysins MMP-3, -10, and -11 by Human Corneal Epithelial Cells

PURPOSE: This study investigated the regulated expression of collagenases (MMP-1, -8, and -13) and stromelysins (MMP-3, -10, and -11) by human corneal epithelial cells treated with IL-1 beta, TNF-alpha, and doxycycline, a medication used to treat ocular surface diseases. METHODS: Primary human corneal epithelial cell cultures were treated with IL-1 beta or TNF-alpha, with or without their corresponding inhibitors. Total RNA extracted from cells treated for 4 to 24 hours was subjected to semiquantitative RT-PCR and Northern hybridization. Conditioned media from 24-hour-treated cultures were evaluated for MMP production by ELISA and activity assays. RESULTS: Semiquantitative RT-PCR and Northern hybridization revealed that the mRNAs of MMP-1, -13, -3, -10, and -11 were dose dependently upregulated by IL-1 beta and TNF-alpha, whereas MMP-8 and -14 and tissue inhibitor of metalloproteinase (TIMP)-1 were not altered, in corneal epithelial cells. MMP ELISA and activity assays confirmed this dose-dependent increase in MMP-1, -13, -3, and -10 protein production in conditioned media by IL-1 beta and TNF-alpha. This stimulated production was inhibited by their neutralizing antibodies and by IL-1 receptor antagonist. Doxycycline suppressed stimulated MMP-1, -10, and -13 production at both the mRNA and protein levels. CONCLUSIONS: This study demonstrated that IL-1 beta and TNF-alpha upregulate collagenases (MMP-1, -13) and stromelysins (MMP-3, -10, and -11) in human corneal epithelial cells. Doxycycline suppresses stimulated MMP-1, -13, and -10 at the mRNA and protein levels, which suggests that collagenases and stromelysins may play a role in the pathogenesis of sterile corneal ulceration and other ocular surface diseases.