The Effect of Hydrogen Peroxide on the Migration and FAK Activation in Lens Epithelial Cells

ABSTRACT

PURPOSE: Hydrogen peroxide has been implicated as a causative factor of various cellular dysfunction, cell death, transformation. In addition, oxidative stress has been suggested as a crucial inducer of cataract formation not only the nuclear-type cataract but also anterior polar type cataract. Transformation of lens epithelial cells accompanying accumulation of extracellular matrix molecules, and cell migration is observed in the cataract forming area of lens. In the present study, we investigated in the migration of lens epithelial cells and the activation of focal adhesion kinase(FAK), because there have been many reports showing that activation of FAK increased cell migration. METHOD: After treatment hygrogen peroxide in a dose-dependent on HLE B-3 cell line, we have performed immuno fluorenscence staing of actin stress fiber and migration assay, and then isolated total RNA to identify expression of MMP-2 from the cell line. To examine FAK activity, we are performed Phosphotyrosine Immunoblot analysis. RESULT: We observed the increased cell migration in response to hydrogen peroxide in a dose dependent manner. In addition, we observed that the phosphorylation of focal adhesion kinase was increased with the treatment of hydrogen peroxide. Also, we examined the expression of the matrix metalloproteinases-2(MMP-2) which disintegrates extracellular matrix and participates in cell migration. The result showed that the mRNA level of MMP-2 did not increase by hydrogen peroxide. CONCLUSIONS: The results suggest that hydrogen peroxide enhanced migration of lens epithelial cell, and that FAK may play a role in the process of cell migration. In conclusion, migration of lens epithelial cell and phosphorylation of focal adhesion kinase was increased by treatment of hydrogen peroxide. Thus oxidative stress plays a crucial role in the transformation of lens epithelial cells and anterior polar type cataract formation.