RT-PCR analysis of proteinase gene expression in normal and diabetic corneal epithelium. Lanes 1 to 5: Normal corneas. Lanes 6 to 13: Non-DR diabetic corneas. Lanes 14 to 18: DR corneas. −RT, negative control without RT. Note increased expression of MMP-10 mRNA in non-DR diabetic and DR corneal epithelium. No change in cathepsin V/L2 (CV/L2), urokinase (u-PA), and tissue plasminogen activator (t-PA) gene expression is observed between normal, non-DR diabetic, and DR corneas. MMP-2 and MMP-3 are not expressed. Autoradiograms of Southern blots are shown. Samples were normalized with respect to β2-MG cDNA amplification.