Prostaglandin FP agonists alter metalloproteinase gene expression in sclera

PURPOSE. The present study was undertaken to determine whether exposure of the sclera to prostaglandin (PG)F_2α or to the PGF _2α analogue latanoprost acid alters mRNA for matrix metalloproteinases. METHOD. Fifteen human eye bank eyes were studied. Circular pieces of sclera were either immediately preserved in a stabilization reagent or cultured in low-serum DMEM/F-12 medium. The cultures were treated for 24 hours with medium supplemented with PGF_2α, latanoprost acid, or vehicle. Total RNA was then isolated, and the expression of mRNA for matrix metalloproteinase (MMP)-1, -2, -3, -8, -9, -10, and -12 were determined by real-time PCR. All results were normalized according to the GAPDH mRNA in each sample. Altered mRNA expression after PG treatments also was evaluated with microarrays containing 19 MMP genes and 4 tissue inhibitor of matrix metalloproteinase (TIMP) genes. RESULTS. Real-time PCR results showed that 24 hours of exposure to 100 nM PGF_2α significantly increased mRNA for MMP-1 and -9 (P < 0.06 Wilcoxon test) and that exposure to 100 nM latanoprost acid significantly increased mRNA for MMP-9 (P < 0.06 Wilcoxon test). Array analysis demonstrated increases of MMP-3 and -10 mRNA after exposure to 100 nM latanoprost and further increases after exposure to 200 nM latanoprost. The array results also showed that latanoprost induced dose-dependent increases in the expression of TIMP-1, -2, and -3 mRNA in the scleral cultures. CONCLUSIONS. PGF_2α and latanoprost acid induce coordinated alterations of MMP gene transcription in scleral organ cultures. These results indicate that PGs can directly trigger MMP gene transcription changes within the sclera. These changes support a role for increased MMPs in the enhancement of uveoscleral outflow that occurs after topical treatment with latanoprost.