Abstract
Abstract: :
Purpose: To investigate the effect of PD98059, a mitogen-activated protein kinase (MAPK) inhibitor, on the replication of cultured retinal pigment epithelial (RPE) cells. Methods: Growth phase RPE cells were exposed to various concentrations of PD98059 in serum-free F12 medium containing 0.1% DMSO. Cell proliferation was assessed by cell counts using a hemocytometer. Cell viability was tested by MTS assay at 24 hours after PD98059 application. Hoechst 33552 and propidium iodide staining was used to test for viability and apoptosis. Immunostaining with Ki67 antibody was used for cell cycle analysis because of the characteristic staining patterns produced on cells depending on their position within the cell cycle. Results: PD98059 inhibited cellular proliferation of the cultured RPE cells in a dose dependent manner but did not induce cellular apoptosis.Twenty-four hours after application of PD98059, cultured RPE cells showed no immunostaining for Ki67 indicating the cells were arrested in the G0/G1 phase of the cell cycle. Conclusion: These results demonstrated that MAPK inhibition arrested cell cycle progression of rat cultured RPE cells at the G0/G1 phase. The pharmacological induction of cell cycle arrest could be a new approach to inhibit cellular proliferation in such conditions as proliferative vitreoretinopathy.
Keywords: 567 retinal pigment epithelium • 523 proliferation • 581 signal transduction: pharmacology/physiology