Effect of latanoprost on cultured porcine corneal stromal cells.

PURPOSE: Latanoprost reduces intraocular pressure mainly by enhancing uveoscleral outflow that may be involved in the decreased of extracellular matrixes such as collagens. However, the effect of latanoprost on corneal stromal cells is not well understood. In the current study, we investigated the changes of cultured porcine corneal stromal cells upon exposure to latanoprost.

METHODS

Porcine corneal stromal cells were acquired from primary culture and maintained in fetal bovine serum-containing medium. Cells were estimated on 3H-thymidine, 3H-leucine, 3H-uridine, 3H-proline uptakes and migration. Dead and living cells were estimated with MTT assay. The changes of type 1 collagen and fibronectin proteins were detected by means of immunofluorescent staining and Western blot assay. Intracellular free Ca2+ ([Ca2+]i) mobility was studied by spectrofluorophotometer after loading with fura-2-AM.

RESULTS

Latanoprost has remarkable effects inhibiting cultured corneal stromal cells on 3H-thymidine, 3H-leucine, 3H-uridine, 3H-proline uptakes and cellular migration. The inhibitory effects are in a dose-dependent manner at concentrations ranging from 10(- 5), 10(- 6), 10(- 7) to 10(- 8) M. The 50% inhibitory dosages (ID50) for latanoprost to corneal stromal cells, as measured by 3H-thymidine uptake, 3H-uridine uptake, 3H-leucine uptake, 3H-proline uptakes and cellular migration were 5.01 x 10(- 6) M, 2.81 x 10(- 6) M, 2.09 x 10(- 6) M, 3.89 x 10(- 7) M and 2.2 x 10(- 6) M, respectively. In the presence of latanoprost, the cellular MTT values were also decreased significantly. Immunofluorescent staining displayed that latanoprost changed type 1 collagen distribution in cultured corneal stromal cells. Western blot assay revealed that latanoprost caused cells to decrease in fibronectin protein. In Ca2+-containing buffer, latanoprost induced a significant rise in [Ca2+]i at 10(- 5) and 10(- 6) M.

CONCLUSIONS

These results indicate that latanoprost may induce the morphological and biochemical changes in cultured corneal stromal cells. Long-term use of latanoprost needs to be carefully monitored for change in corneal stroma.