The effect of zinc on the apoptosis of cultured human retinal pigment epithelial cells

To clarify the effects of zinc on the proliferation and apoptosis of cultured human retinal pigment epithelia (RPE) and the expression of caspase-3 in RPE cells. The effect of Zinc on theproliferation of RPE were examined with MTT method. TUNEL method was used to detect the apoptosis of RPE cells. Caspase-3 was detected by immunohistochemistry. A concentration of zinc higher than 0. 001 μM could inhibit the proliferation of RPE. And the relationship between concentration of zinc higher than 10 μM and growth prohibition rate of RPE cells was dose-dependent. All concentrations of zinc including 0.001 μM enhanced the expression of caspase-3 of RPE. But only the concentration of zinc higher than 0.01 μM could induce apoptosis of RPE. It is concluded that zinc could enhance the expression of caspase-3 of RPE cells and induce apoptosis of RPE cells. Caution should be taken when using zinc supplements for the treatment of ARMD patients without deficiency of zinc.