Genistein inhibited hypoxia-inducible factor-1α expression induced by hypoxia and cobalt chloride in human retinal pigment epithelium cells

The time-dependent changes of hypoxia-inducible factor-1 alpha (HIF-1 alpha) expression induced by hypoxia and CoCl2 treatment and the effects of genistein on the level of HIF-1 alpha expression in human retinal pigment epithelium cells were examined. Judging by relative fluorescence using a confocal scanning laser microscope coupled to a computer, HIF-1 alpha expression was determined. It was found that hypoxia could markedly increase the expression of HIF-1 alpha The highest expression of HIf-1 alpha was detected at 1 h, which was 313.9% 38.2% of the control level. After pretreatment with genistein (50, 100, and 200 mu mol/1). the hypoxia-evoked HIF-1 alpha expression was concentration-dependently inhibited. CoCl2 treatment could significantly elevate the level of HIF-1 alpha expression. At 0.5 h after CoCl2 treatment, the highest level was observed, which was 141.4% +/- 14.1% of the control level. Genistein 50, 100. 200 mu mol/L could also suppress HIF-1 alpha) expression in a concentration-dependent manner. These results suggested that the inhibition of HIF-1 alpha protein expression by genistein may partly account for its effect on retinal neovascularization in vivo. (c) 2005 Prous Science. All rights reserved.